REVIEW | doi:10.20944/preprints201810.0323.v1
Subject: Chemistry, Organic Chemistry Keywords: Controlled Polymerization; Reversible Polymerization; Sustainable Polymers
Online: 15 October 2018 (16:19:19 CEST)
The field of controlled polymerization is growing and evolving at unprecedented rates, facilitating polymer scientists to engineer the structure and property of polymer materials for a variety of applications. However, the lack of degradability, particularly in vinyl polymers, is a general concern for not only environmental sustainability but also biomedical applications. In recent years, there has been a significant effort to develop reversible polymerization approaches in those well-established controlled polymerization systems. Reversible polymerization typically involves two steps including (i) forward polymerization which converts small monomers into macromolecules, and (ii) depolymerization capable of regenerating original monomers. Furthermore, recycled monomers can be repolymerized into new polymers. In this perspective, we highlight recent developments of reversible polymerization in those controlled polymerization systems and offer insight into the promise and utility of reversible polymerization systems. More importantly, the current challenges and future directions to solve those problems are discussed. We hope this perspective can serve as an “initiator” to promote continuing innovations in this fairly new area.
REVIEW | doi:10.20944/preprints202010.0321.v1
Subject: Medicine & Pharmacology, Allergology Keywords: fat; obesity; randomized controlled trials; meta-analysis
Online: 15 October 2020 (11:53:54 CEST)
Background: Overweight and obese adults seek effective exercise interventions to reduce accumulated fat, but the effectiveness of these interventions vary across studies. The purpose of this meta-analysis was to investigate the effectiveness of exercise interventions in overweight and obese adults based on measurement of accumulated fat distributions. (2) Methods: Databases were used to select eligible studies for this meta-analysis. Randomized controlled trials with a control and experimental group were included. Degrees of effectiveness of exercise interventions were computed to assess the benefits on reducing weight and subcutaneous, visceral, and ectopic fat accumulation. (3) Results: A total of twenty-one studies were included in this meta-analysis. Participation in exercise interventions showed beneficial effects in reducing weight and subcutaneous and visceral fat. The effectiveness of exercise interventions on ectopic fat accumulation could not be assessed due to the limited number of studies measuring ectopic fat. Additionally, effectiveness of exercise interventions that depended on measurements of accumulated fat varied. The average exercise intervention for overweight and obese individuals was moderate to vigorous intensity, 4 times per week, 50 minutes per session, and 22 weeks duration. (4) Conclusions: Participating in exercise interventions has favorable effects on reducing weight and accumulation of subcutaneous and visceral fat.
ARTICLE | doi:10.20944/preprints202111.0188.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: cookstoves; LPG; randomized controlled trial; adherence; fidelity; intervention
Online: 9 November 2021 (15:17:51 CET)
Background: Clean cookstove interventions can theoretically reduce exposure to household air pollution and benefit health, but this requires near-exclusive use of the stoves, with simultaneous disuse of traditional stoves. Previous cookstove trials have reported low adoption of new stoves and/or extensive continued traditional stove use. Methods: The Household Air Pollution Intervention Network (HAPIN) trial randomized 3195 pregnant women in Guatemala, India, Peru, and Rwanda either to a liquefied petroleum gas (LPG) stove and fuel intervention (n = 1590) or to control (n = 1605). The intervention consisted of an LPG stove and two initial cylinders of LPG, free fuel refills delivered to the home, and regular behavioral messaging. We assessed intervention fidelity (delivery of the intervention as intended) and adherence (intervention use) through the end of gestation, as relevant to the first primary health outcome of the trial: infant birth weight. Fidelity and adherence were evaluated using stove and fuel delivery records, questionnaires, visual observations, and temperature-logging stove use monitors (SUMs). Results: 1585 women received the intervention, at a median (interquartile range) of 8.0 (5.0–15.0) days post-randomization and gestational age of 17.9 (15.4–20.6) weeks. Over 96% reported cooking exclusively with LPG at two follow-up visits during pregnancy. Less than 4% reported ever running out of LPG. Complete abandonment of traditional stove cooking was observed in over 67% of intervention households. 31.4% removed their traditional stoves upon receipt of the intervention, and among those who retained traditional stoves, the majority did not use them: traditional stove use was detected via SUMs on a median (interquartile range) of 0.0% (0.0%, 1.6%) of follow-up days (median follow-up = 134 days). Conclusions: Fidelity of the HAPIN intervention, as measured by stove installation, timely ongoing fuel deliveries, and behavioral reinforcement as needed, was high. Exclusive use of the intervention during pregnancy was also high.
REVIEW | doi:10.20944/preprints202008.0417.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: hepatic fibrosis; hepatocullar carcinoma; vibration controlled transient elastography
Online: 19 August 2020 (13:00:28 CEST)
The prevalence of obesity or metabolic syndrome is increasing worldwide (“Globally metabodemic”). Approximately 25% of adult general population is suffering from nonalcoholic fatty liver disease (NAFLD) which has become serious health problem. Hepatic fibrosis is the most significant determinant of all cause and liver -related mortality in NAFLD. Noninvasive test (NIT) should be urgently required to evaluate hepatic fibrosis in NAFLD. Fibrosis-4 (FIB-4) index is the 1st triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness especially for general physicians or endocrinologists, although FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the 2nd step after triaging by FIB-4 index. The leading cause of mortality in NAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. NAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation (SLKT). FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocullar carcinoma (HCC) but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, FIB- 4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of FIB-4 index as 1st step NIT in management of NAFLD.
ARTICLE | doi:10.20944/preprints201705.0197.v1
Subject: Mathematics & Computer Science, Other Keywords: mathematics; videogame; education; self-competency; randomized controlled trial
Online: 29 May 2017 (10:32:30 CEST)
Development of early math skills is linked to future success in mathematics and other academics. Educational videogames have been shown to promote academic achievement; however, few rigorous studies have evaluated the use of educational videogames in supporting math development, especially in early primary education. In the current study, an open-label randomized controlled trial was conducted involving 134 first grade students to determine, using standardized assessments, the impact of the educational mathematics tablet-based videogame, Knowledge Battle, on math scores and self-competency. Overall, Knowledge Battle did improve math skills in participants who played the game. Among those with lower pre-game math skills, the Knowledge Battle group’s mean math score increased more than the control group’s mean math score (9.7 vs. 6.0; p=0.02). There was no association between perceived sense of self-competency and total math score (p=0.8141). However, players who had a higher sense of self-competency were more likely to enjoy playing the game. In conclusion, our findings suggest that Knowledge Battle was an acceptable and enjoyable educational mathematical videogame for first grade students, and may be most impactful for those with low math skills.
ARTICLE | doi:10.20944/preprints202102.0023.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Depression; Major depressive disorder; Diet; Nutrition; Randomized controlled trial, Randomized controlled pilot trial; Healthy Nordic diet; Mental health; Palatability; Food liking
Online: 1 February 2021 (12:31:47 CET)
Healthy diet interventions have been shown to improve depressive symptoms, but there is a need for randomized controlled trials (RCTs) that are double-blind and investigate biological mechanisms. The primary objectives of this randomized controlled pilot trial were to test the palatability of the meals and acceptability of the intervention in preparation for a future 8-week RCT which will investigate whether a healthy Nordic diet improves depressive symptoms in individuals with major depressive disorder, and associated biological mechanisms. Depressed (n=10) and non-depressed (n=6) women and men were randomized to receive either a healthy Nordic diet (ND) or a control diet (CD) for 8 days. Participants were blinded to diet allocation and study hypotheses. Health questionnaires were completed before and after the intervention, and, throughout the study, questionnaires assessed ratings of liking and sensory properties of the meals, adherence, and open-ended feedback. In the ND group, 75% of participants consumed no non-study foods, compared to 50% of CD participants. The meals of both diets, on average, received good ratings for liking and sensory properties, though the ND ratings were somewhat higher. Overall, results were positive and informative, indicating that the planned RCT will be feasible and well-accepted, with some proposed modifications.
ARTICLE | doi:10.20944/preprints202108.0035.v1
Subject: Engineering, Automotive Engineering Keywords: presplitting, smooth blasting, line drilling, mechanical cutting, controlled blasting.
Online: 2 August 2021 (12:56:17 CEST)
The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by the objective, and therefore by the type of technique applied to achieve it. To attain the best results in terms of rock breakage and respect of the final profile, it’s important to evaluate the excavation specific energy and its optimization. This research focuses on evaluating the effects of different techniques on the quality of final walls in open-pit and underground operations. Different geometries and configurations can be applied to both quarrying and tunnelling blasts. The research is aimed to push contour blasts to their limits, and the main aspects are discussed in order to improve the blast parameters in the daily practice.
COMMUNICATION | doi:10.20944/preprints202105.0397.v1
Subject: Chemistry, Analytical Chemistry Keywords: phosphazenes; cyclization; controlled cycle size; living cationic polymerization; hexamethyldisilazane
Online: 17 May 2021 (17:02:38 CEST)
Despite a significant number of investigations in the field of phosphazene chemistry, the mechanism of this class cyclic compounds formation is still poorly studied. At the same time, a thorough understanding of this process is necessary both for the direct production of phosphazene rings with a given size, and for the controlled cyclization reaction when it is secondary and undesirable. Here we have synthesized a series of short linear phosphazene oligomers with the general formula Cl[PCl2=N]n–PCl3+PCl6– and studied their tendency to form cyclic structures under the influence of elevated temperature or in the presence of nitrogen-containing agents, such as hexamethyldisilazane (HMDS) or ammonium chloride. It was established that linear oligophosphazenes are inert when heated in the absence of the mentioned cyclization agents, and the formation of cyclic products occurs only when these agents are involved in the process. It is for the first time shown the ability to obtain the desired size phosphazene cycle from corresponding linear chain. Known obstacles like side interaction with the PCl6– counterion and a tendency of longer chains to undergo crosslinking elongation instead of cyclization are still relevant and ways to overcome them are being discussed.
ARTICLE | doi:10.20944/preprints202011.0440.v1
Subject: Chemistry, Analytical Chemistry Keywords: Au nanoparticles; nanocarriers; methotrexate; anticancer drug; chemotherapeutics; controlled release
Online: 16 November 2020 (17:38:03 CET)
In the present study the synthesis of gold nanoparticles (AuNPs) loaded with methotrexate (MTX) has been carried out in order to obtain controlled size and monodispersed nanocarriers, around 20nm. Characterization study shows metallic AuNPs with MTX polydispersed on the surface. MTX is linked by a replacement of citrate by the MTX carboxyl group. The drug release profiles showed faster MTX release when it is conjugated, which leads to the best control of plasma concentration. Also, the enhanced release observed at pH 5 could take advantage of the pH gradients that exist in tumor microenvironments to achieve high local drug concentrations. AuNPs-MTX conjugates were tested by flow cytometry against lung (A-549) and colon (HTC-116) cancer cell lines. Results for A-549 showed a lighter dose-response effect than for colon cancer ones. This could be related to the presence of folate receptors in line HTC-116 on the contrary than line A-549, supporting the specific uptake of folate-conjugated AuNPs-MTX by folate receptor positive tumor cells. Conjugates exhibited considerably higher cytotoxic effects compared with the effects of equal doses of free MTX. Anexin V-PI test sustain as cell death mechanism apoptosis, which is normally disabled in cancer cells.
Online: 22 July 2020 (06:32:26 CEST)
A new covered yarn system is proposed in this manuscript by controlling the tension of the spandex elastic yarn drawing.. By analyzing the relationship between the draw ratio and yarn tension, it has been verified that the new tension controlled drawing system is feasible and results in yarns with superior quality and process stability.
ARTICLE | doi:10.20944/preprints202006.0265.v1
Subject: Social Sciences, Other Keywords: life habits; mindfulness; flow meditation; university students; controlled trial
Online: 21 June 2020 (11:33:25 CEST)
The present study explored the effects of a Second-generation mindfulness-based intervention known as Flow Meditation (Meditación-Fluir) in the improvement of life habits. A sample of university students (n = 51) in Spain were randomly assigned to a seven-week mindfulness treatment or a waiting list control group. Results showed that compared to the control group, individuals in the mindfulness group demonstrated significant improvements across all outcome measures, including healthy eating habits (balanced diet, intake rate, snacking between meals, decrease in consumption by emotional states negative, increased consumption by negative emotional states, amount of consumption, meal times, consumption of low-fat products), tobacco, alcohol and cannabis consumption, and resting habits. There were differences between males and females in some of these variables and a better effect of the treatment was evident in the females of the experimental group as compared to males. The Flow Meditation program shows promise for fostering healthy life habits, thus decreasing behaviors related to maladaptive eating, tobacco, alcohol and drug consumption, as well as negative resting habits, in university students. This mindfulness program can significantly contribute in the treatment of eating disorders and addictions, wherein negative emotional states and impulsivity are central features of the condition.
ARTICLE | doi:10.20944/preprints201910.0276.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: epidemiology; causality; cancer; methodology; mendelian randomisation; randomised controlled trials
Online: 24 October 2019 (10:53:36 CEST)
Background: Feasibility trials are preliminary trials that assess the viability and acceptability of intervention studies and the effects of the intervention on intermediate endpoints. Due to their short duration, they are unable to establish the effects of the intervention on long-term clinical outcomes. We propose a novel method that could transform the interpretation of feasibility trials using modified two-stage randomisation analyses. Methods In this two-stage process, we explored the effects of a 6-month feasibility factorial randomised controlled trial (RCT) of lycopene and green tea dietary interventions (ProDiet) on 159 serum metabolic traits in 133 men with raised PSA levels but prostate cancer (PCA) free. In the first stage, we conducted an intention-to-treat analysis, using linear regression to examine the effects of the interventions on metabolic traits, compared to the placebo group and instrumental variable analysis to assess the causal effect of the intervention on the outcomes. In the second stage, we used a two-sample Mendelian Randomization (MR) approach to assess the causal effect of metabolic traits altered by the interventions, on PCA risk, using summary statistics data from an international PCA consortium of 44,825 cancer cases and 27,904 controls. ResultsThe systemic effects of lycopene and green tea supplementation on serum metabolic profile were comparable to the effects of the respective dietary advice interventions (R2= 0.65 and 0.76 for lycopene and green tea respectively). Metabolites which were altered in response to lycopene supplementation were acetate (standard deviation difference versus placebo (β)): 0.69; 95% CI= 0.24, 1.15; p=0.003), valine (β: -0.62; -1.03, -0.02; p=0.004), pyruvate (β: -0.56; -0.95, -0.16; p=0.006), and docosahexaenoic acid (β: -0.50; -085, -0.14; p=0.006). The instrumental variable analysis showed there was no evidence that green tea altered the metabolome, but lycopene was associated with an increase in acetate (β=2.13; p=0.006) and decreases in pyruvate (β=-1.90; p=0.009), valine (β=-1.79; p=0.023), diacylglycerol (β=-1.81; p=0.026), alanine (β=-1.55; p=0.015) and DHA (p=0.097), where the regression coefficient represents the standard deviation (SD) difference in metabolite measures per unit change in lycopene (µmol/L) or EGCG (nM).Using MR, a genetically instrumented SD increase in pyruvate increased the odds of PCA by 1.29 (1.03, 1.62; p=0.027). Conclusion Using a two-stage randomization analysis in a feasibility RCT, we found that lycopene lowered levels of pyruvate, which our Mendelian randomization analysis suggests may be causally related to reduced PCA risk.
ARTICLE | doi:10.20944/preprints201808.0282.v1
Subject: Mathematics & Computer Science, Computational Mathematics Keywords: Ternary; subdivision scheme; Non-stationary, Tension controlled, shape preservation
Online: 16 August 2018 (12:14:35 CEST)
The aim of this work is to analyze and investigate the shape preserving properties of ternary 4-point non-stationary interpolating subdivision schemes constructed by Beccari et al.  with a tension parameter !k+1 which can reproducing exponential. Moreover, the conditions on the initial control points are developed that allow user to generate shape preserving limit curves after a nite number of subdivision steps and generalize these results in limiting case. Signicance of derived conditions are illustrated through graphs and the whole discussion is followed by examples.
ARTICLE | doi:10.20944/preprints201710.0049.v3
Subject: Materials Science, Biomaterials Keywords: halloysite nanotubes; surface modification; structural characteristics; controlled release; biocompatibility
Online: 15 November 2017 (07:55:33 CET)
Halloysite nanotubes (HNTs) are natural occurring mineral clay nanotubes that have excellent application potential in different fields. However, HNTs are heterogeneous in size, surface charge and formation of surfacial hydrogen bond, which lead to weak affinity and aggregation at a certain extent. It is very important to modify the HNTs’ surface to expand its applications. In this review, the structural characteristics, performance and the related applications of surface-modified HNTs are reviewed. We focus on the surface-modified variation of HNTs, the effects of surface modification on the materials and related applications in various regions. In addition, future prospects and the meaning of surface modification were also discussed in HNTs studies. This review provides a reference for the application of HNTs modifications in the field of new nanomaterials.
REVIEW | doi:10.20944/preprints201710.0178.v1
Subject: Materials Science, Nanotechnology Keywords: hydrogels; peptides; proteins; crosslinked networks; controlled release; biodegradable polymers
Online: 30 October 2017 (03:39:55 CET)
Hydrogels evolved as an outstanding carrier material for local and controlled drug delivery that tend to the shortcomings of old conventional dosage forms for small drugs (NSAIDS) and large peptides and proteins. Aqueous swellable and crosslinked polymeric network structure of hydrogels is composed of various natural, synthetic and semisynthetic biodegradable polymers. Hydrogels have remarkable properties of functionality, reversibility, sterilizability, and biocompatibility. All these dynamic properties of hydrogels have increased the interest in their use as a carrier for peptides and proteins to be released slowly in a sustained manner. The therapeutical peptide and proteins are remarkable therapeutic agents in today’s world that allows the treatment of severe, chronic and life‐threatening diseases, such as diabetes, rheumatoid arthritis, hepatitis in an easy manner. Despite few limitations, hydrogels provide fine tuning of proteins and peptides delivery with enormous impact in clinical medicine. The primary objective of this article is to review current issues concerned with the therapeutics peptides and proteins and impact of remarkable properties of hydrogels on these therapeutic agents. Different routes for pharmaceutical peptides and proteins and superiority over other drugs candidates are presented. The article will also review literature concerning classification of hydrogels on different basis, polymers used, release mechanisms their physical and chemical characteristics and diverse applications.
ARTICLE | doi:10.20944/preprints201705.0002.v1
Subject: Chemistry, Applied Chemistry Keywords: controlled/”living” radical polymerization (CRP); polymer brush; poly(acrylonitrile)
Online: 1 May 2017 (07:32:56 CEST)
A new approach for the preparation of polymer brush was developed via the union of controlled/“living” radical polymerization and click chemistry. The application of the approach realized the more quickly and accurate design and synthesis of the polymer brushes. A novel functional polymer brush of poly(acrylonitrile-g-glycidyl methacrylate) with tremendous application potential in the field of biology has been successfully synthesized via the new approach. The reaction conditions of click chemistry were optimized with the reaction time and the reactant ratio and judged from UV-vis spectra. Under the optimum of click chemistry, the novel functional polymer brushes were prepared. The GPC, FTIR analyses, 1H NMR spectrum and TGA were employed to ensure the successful synthesis of poly(acrylonitrile-g-glycidyl methacrylate) polymer brushes.
ARTICLE | doi:10.20944/preprints201703.0104.v1
Subject: Earth Sciences, Environmental Sciences Keywords: controlled releasefertilizer (CRF); organic fertilizer; nitrous oxide; row; canopy
Online: 15 March 2017 (09:01:01 CET)
A field experiment was conducted for 2 years in Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center, Iruma, Saitama, Japan from March 2014 to December 2015. Controlled release fertilizers (CRF) or organic fertilizers (ORG) which is the mixture of chicken manure and oil cakewere applied with the amount of 450 kg N ha-1 yr-1 in 2014 and 397 kg N ha-1 yr-1 in 2015. Nitrous oxide (N2O) emissionsfrom soil in green tea fields were measured by closed chamber method. The results showed that CRF has significantly lower N2O compared to ORG. The cumulative N2O emissions from CRF accounted for 51% of N2O emissions from ORG fields and 138% of control with no fertilizer treatment. The N2O flux from the row was higher than that of under the canopy, since fertilizer were applied on the row. However the total emission from the area between the rows was lower than that under the canopy because of the area ratio of row and canopy was 1:5.
ARTICLE | doi:10.20944/preprints202208.0388.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: time-restricted feeding; controlled feeding study; study design; nutrition interventions
Online: 22 August 2022 (19:16:58 CEST)
The efficacy of time-restricted feeding for weight loss has not been established as prior studies were limited by lack of controlled isocaloric designs. This study describes the design and implementation of a controlled feeding study evaluating time-restricted feeding. We designed a randomized, controlled, parallel-arm, feeding study comparing time restricted feeding (TRF) to a usual feeding pattern (UFP) for the primary outcome of weight change. Participants were aged 18-69 years with prediabetes and obesity. TRF consumed 80% of calories by 1300, and UFP consumed ≥50% of calories after 1700. Both arms consumed identical macro- and micro-nutrients, based on a healthy palatable diet. We calculated individual calorie requirements which were maintained throughout the intervention. We randomized 41 participants who all completed the study. The desired distribution of calories across feeding windows in both arms was achieved, as were weekly averages for macronutrients and micronutrients. All randomized participants completed the study. We actively monitored participants and adapted diets to facilitate adherence. We provide the first report, to our knowledge, on the design and implementation of a feeding study that isolated the effect of meal timing on weight, while maintaining constant caloric intake and identical diets during the study period.
ARTICLE | doi:10.20944/preprints202105.0392.v1
Subject: Keywords: Age; adherence; anti-hypertensive; Controlled hypertension; clinic; hypertension; Prevalence; Systemic
Online: 17 May 2021 (15:57:01 CEST)
Objectives: To determine the prevalence of controlled systemic hypertension and its associated risk factors among the hypertensive patients who attended the clinic at Mbeya Zonal Referral Hospital in Tanzania. Methods: A descriptive cross-sectional quantitative study was used determine the prevalence of co to 252 hypertensive patients were recruited during clinic visit from September to November 2020 and participant was randomly selected interviews using structured self-administered questionnaires. Data was analyzed using chi square test to find the risk factors associated with controlled hypertension. Results: Among 252 participants, 94(39.7%) individuals with controlled hypertension giving the prevalence of controlled hypertension. The proportion of females with controlled hypertension was slightly higher than male (49 females to 45 males). The prevalence of uncontrolled hypertension was 152(60.3%) participants. The prevalence of controlled hypertension was higher among patients who have regular clinic visit (p< .05) and have daily adherence to their anti-hypertensive medication. A similar trend was observed among participants without financial challenges to attend clinic, short duration of illness, higher level of education and there was no association between age, sex, marital status, smoking, alcohol consumption, having health insurance and having chronic illness. Conclusion: Prevalence of controlled hypertension is higher among patients who have regular clinic visit and have daily adherence to their anti-hypertensive medication. Also, it is higher among participants without financial challenges to attend clinic so they can have regular clinic visit and checkup. Reinforcement on regular drug intake and clinic visit, good nutrition and reduced salt intake and modifying lifestyles of patient with hypertension is important.
REVIEW | doi:10.20944/preprints202103.0095.v1
Subject: Medicine & Pharmacology, Allergology Keywords: doxorubicin; drug delivery; polymers; targeted therapy; anticancer treatment; controlled release
Online: 2 March 2021 (14:14:38 CET)
Doxorubicin, a member of the anthracycline family, is a common anticancer agent often used as a first line treatment for the wide spectrum of cancers. Doxorubicin-based chemotherapy, although effective, is associated with serious side effects, such as irreversible cardiotoxicity or nephrotoxicity. Those often life-threatening adverse risks, responsible for the elongation of the patients' recuperation period and increasing medical expenses, have prompted the need for creating novel and safer drug delivery systems. Among many proposed concepts, polymeric nanocarriers are shown to be a promising approach, allowing for controlled and selective drug delivery simultaneously enhancing its activity towards cancerous cells and reducing toxic effects on healthy tissues. This article is a chronological examination of the history of the work progress on polymeric nanostructures, designed as efficient doxorubicin nanocarriers, with the emphasis on the main achievements of 2010-2020. Numerous publications have been reviewed to provide an essential summation of the nanopolymer types and their essential properties, mechanisms towards efficient drug delivery, as well as active targeting stimuli-responsive strategies that are currently utilized in the doxorubicin transportation field.
ARTICLE | doi:10.20944/preprints202009.0745.v1
Subject: Materials Science, Biomaterials Keywords: Biodegradable polymers; Nanoparticles; Cancer chemotherapy; Controlled release; Drug delivery systems
Online: 30 September 2020 (12:47:17 CEST)
Polyhydroxyalkanoate (PHA) co-polymers show relatively higher in vivo degradation rate compared to other PHAs thus they received a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water soluble anticancer drug docetaxel (DCX) were produced using poly 3-hydroxybutyrate-co-4-hydroxybutyrate, P(3HB-co-4HB), co-polymers biosynthesised from Cupriavidus sp. USMAA1020 isolated from Malaysian environment. Three co-polymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Pre-formulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in term of average particles sizes around 150 nm and narrow particle size distribution (PDI below 0.100). The encapsulation efficiencies result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticles system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug to polymer ratio while for the 30% and 40% drug to polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.
ARTICLE | doi:10.20944/preprints201904.0075.v1
Subject: Chemistry, Applied Chemistry Keywords: amphiphilc copolymer; hydrolyzable polyurea; micelle; controlled drug delivery; cancer chemotherapy
Online: 8 April 2019 (08:35:46 CEST)
In recent years, polyureas with dynamic hindered urea bonds (HUBs), as a class of promising biomedical polymers, have attracted attention as a benefit of their controlled hydrolytic property. The effect of the chemical structures on the properties of polyureas and their assemblies was rarely reported. In this study, four kinds of polyureas with different chemical groups have been synthesized, and the polyurea from cyclohexyl diisocyanate and tert-butyl diamine showed the fastest hydrolytic rate. The amphiphilic polyurea composed of hydrophobic cyclohexyl-tert-butyl polyurea and hydrophilic poly(ethylene glycol) was synthesized for controlled delivery of antitumor drug paclitaxel (PTX). The PTX-loaded PEGylated polyurea micelle more effectively entered into the murine breast cancer 4T1 cells and inhibited the corresponding tumor growth in vitro and in vivo. Therefore, the PEGylated polyurea with adjustable degradation might be a promising polymer matrix for drug delivery.
ARTICLE | doi:10.20944/preprints201902.0157.v1
Subject: Materials Science, Biomaterials Keywords: chitosan hydrogels, silver nanowires, controlled release, antimicrobial activity, bone regeneration
Online: 18 February 2019 (10:38:46 CET)
One-dimensional nanostructures such as silver nanowires (AgNWs) have attracted considerable attention owing to their outstanding electrical, thermal and antimicrobial properties; however, their application in the prevention of infections linked to bone tissue regeneration interventions has not yet been explored. Here we report on the development of an innovative scaffold prepared from chitosan, composite hydroxyapatite and AgNWs (CS-HACS-AgNWs) having both bioactive and antibacterial properties. In vitro results highlighted the antibacterial potential of AgNWs against both gram-positive and gram-negative bacteria. The CS-HACS-AgNWs composite scaffold demonstrated suitable Ca/P deposition, improved gel strength, reduced gelation time, and sustained Ag+ release within therapeutic concentrations. Antibacterial studies showed that the composite formulation was capable of inhibiting bacterial growth in suspension and of completely preventing biofilm formation on the scaffold in the presence of resistant strains. The hydrogels were also shown to be biocompatible, allowing cell proliferation. In summary, the developed CS-HACS-AgNWs composite hydrogels demonstrated significant potential as a scaffold material to be employed in bone regenerative medicine, as it presents enhanced mechanical strength combined with the ability to allow calcium salts deposition, while efficiently decreasing the risk of infections. The results presented justify further investigations into potential clinical applications of these materials.
CONCEPT PAPER | doi:10.20944/preprints201803.0238.v1
Subject: Social Sciences, Education Studies Keywords: applied behaviour analysis; autism; policy; randomised controlled trials; fake news
Online: 28 March 2018 (12:40:58 CEST)
Since autism was first recognised, prevalence has increased rapidly. The growing economic as well as social cost to society can only be mitigated by effective interventions and supports. It is therefore not surprising that most governments have developed public policy documents to address the management of autism. Over the past 40-50 years, meaningful evidence has accrued showing that interventions based on the scientific discipline of Applied Behaviour Analysis (ABA) can help people with autism reach their potential. In view of this, nearly all of North America has laws to mandate that ABA-based interventions are available through the health care systems. In contrast, across Europe there are no such laws. In fact, the National Institute for Health and Care Excellence (NICE), the body guiding health and social policy in the UK, concluded that it could not find any evidence to support ABA, and therefore could not recommend it. This paper addresses the reasons for these diametrically opposed perspectives. In particular, it examines what happens when health and social care policy is misinformed about effective autism intervention.
ARTICLE | doi:10.20944/preprints202110.0153.v1
Subject: Keywords: Life Cycle Assessment; Urban agriculture; Wheat; Controlled environment agriculture, Vertical garden
Online: 11 October 2021 (10:14:56 CEST)
Main purposes and research question: Wheat is the second largest grain crop by tonnage in the world and the largest in Denmark. Given the observed, adverse impacts on wheat yields of climate change and the importance of wheat in the human diet, the purpose of this study was to use life cycle assessment to compare conventional wheat farming with indoor vertical farming using hydroponics. Methods: Life Cycle Assessment was used to assess the base case systems up to the “farm gate” for 1 tonne of wheat grain. The processes contributing most of the impacts were identified, and scenarios were assessed to determine how much the impacts could be reduced. Results: The conventional system outperformed the base case vertical system in every impact category, due to the electricity consumption in the lighting system. The scenarios included increasing the efficiency of the LED lighting and using 100% wind energy, but the conventional system still outperformed the vertical system by significant margins in all impact categories. This was due to the low photosynthetic conversion efficiency and the high energy density of wheat. Conclusions: Until significant improvements are made to lighting efficiency, the photosynthesis conversion efficiency of wheat, new wheat variants designed for vertical gardens and the sustainability of electricity supply, conventional wheat production will be environmentally preferable and vertical gardens would be advised to focus on food products with low energy densities.
ARTICLE | doi:10.20944/preprints202107.0316.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Randomized Controlled Trial; Equal Group Size; Nursing; Allocation Bias; Effect Size
Online: 14 July 2021 (10:49:38 CEST)
The manipulation of participant allocation in randomized controlled trials to achieve equal groups sizes may introduce allocation bias potentially leading to larger treatment effect estimates. This study aimed to estimate the proportion of nursing trials that have precisely equal group sizes and examine if there was an association with trial outcome. Data were extracted from a sample of 148 randomized controlled trials published in nursing science journals in 2017. One hundred trials (68%) had precisely equal group sizes. Respectively, a positive outcome was reported in 70% and 58% of trials with equal/unequal groups. Trials from Asia were more likely to have equal group sizes than those from the rest of the world. Most trials reported a sample size calculation (n=105, 71%). In a third of trials (n=36, 34%), the number of participants recruited precisely matched the requirement of the sample size calculation; this was significantly more common in studies with equal group sizes. The high number of nursing trials with equal groups may suggest nurses con-ducting clinical trials are manipulating participant allocation to ensure equal group size increasing the risk of bias.
Subject: Earth Sciences, Atmospheric Science Keywords: vertical farming; controlled environment agriculture; plant factories; biostimulant; microbiome; hydroponics; aeroponics
Online: 28 May 2021 (11:07:33 CEST)
Vertical farming (VF) is a potential solution for the production of high-quality, accessible, and climate-friendly nutrition for growing urban populations. However, to realize VF’s potential as a sustainable food source, innovative technologies are required to ensure that VF can be industrialized on a massive scale and extended beyond leafy greens and fruits into the production of food staples or row crops. A major obstacle to the economic and environmental sustainability of VF is the lighting energy consumed. While technological advances have improved the energy efficiency of VF lighting systems, there has been insufficient research into biostimulation as an approach to reduce energy needs. We conducted a controlled trial to investigate the application of a phycocyanin-rich Spirulina extract (PRSE) as a biostimulant in hydroponically grown, vertically farmed lettuce (Lactuca sativa and Salanova®). PRSE application reduced the time from seeding to harvest by 6 days, increased yield by 12.5%, and improved quality including color, taste, texture, antioxidant flavonoid levels and shelf life. Metagenomic analysis of the microbial community of the nutrient solution indicated that PRSE increased the overall bacterial diversity including raising the abundance of Actinobacteria and Firmicutes and reducing the abundance of potentially pathogenic bacteria. This preliminary study demonstrates that microalgae-derived biostimulants may play an important role in improving the economic and environmental sustainability of VF.
ARTICLE | doi:10.20944/preprints202103.0546.v1
Subject: Materials Science, Biomaterials Keywords: Metal waste valorization; aluminum breakage scrap; green hydrogen; hydrogen-controlled generation.
Online: 22 March 2021 (15:45:21 CET)
In this article, it is proposed to use aluminum breakage scraps to obtain Green Hydrogen through the aluminum-water reaction with caustic soda as a catalyst. From this exothermic reaction, both hydrogen and the heat generated can be used. Due to the low price of aluminum chips, this allows us to produce Green hydrogen below the current price that is obtained using renewable energy sources and electrolyzers. On the other hand, we have developed a process that is sustainable since it is obtained as alumina and caustic soda waste that can be reused. This alumina obtained, once filtered, has high purity which allows us to produce high-quality primary aluminum without the need to use bauxite and reducing the production of red sludge. A comparative study-analysis has been carried out of two of the types of forms in which the most common aluminum is presented in the industry to analyze which one performs better by studying key factors such as the hydrogen produced, and the waste generated during the process. Finally, the mathematical model has been defined to be able to control the flow based on different key parameters such as temperature, molarity, and geometry. Undoubtedly, the study that we present represents a milestone for the recovery of metallic aluminum waste and may be of great interest to industries that use aluminum in their processes, such as recuperators, but also the vehicle or aerospace industry.
ARTICLE | doi:10.20944/preprints202007.0122.v1
Subject: Medicine & Pharmacology, Other Keywords: Transcriptionally controlled tumor protein (TCTP); Tryptophan; Florescence; Flavonoid; Native gel electrophoresis
Online: 7 July 2020 (09:49:17 CEST)
Transcriptionally controlled tumor protein (TCTP) is a highly conserved protein performing a large number of cellular functions by binding with various partner proteins. The importance of its roles in many diseases requires an assay method to find regulatory compounds. However, the molecular characteristics of TCTP made it difficult to search for chemicals interacting with it. In this study, a tryptophan-based assay method was designed and Y151W mutant TCTP was constructed to search binding chemicals. Since there is no tryptophan in the native sequence of TCTP, the incorporation of tryptophan in the Y151W mutant was very effective to establish the method. A flavonoid library was employed to the assay with the method. With the native and Y151W mutant TCTPs, three flavonoids such as morin, myricetin and isobavachalcone have been found to interact with TCTP. Combined with native gel electrophoresis, the binding region of isobavachalcone was suggested to be the flexible loop of TCTP. This approach can be easily applicable to find binding compounds of proteins with similar molecular characteristics of TCTP.
ARTICLE | doi:10.20944/preprints202012.0513.v1
Subject: Life Sciences, Biochemistry Keywords: apoferritin nanocarriers; controlled drug delivery; idarubicin; ferritin receptor targeting; folate receptor targeting
Online: 21 December 2020 (11:28:08 CET)
The interactions of chemotherapeutic drugs with nanocage protein apoferritin (APO) are the key features in the effective encapsulation and release of highly toxic drugs in APO-based controlled drug delivery systems. The encapsulation enables mitigating the drugs side effects, collateral damage to healthy cells, and adverse immune reactions. Herein, the interactions of anthracycline drugs with APO were studied to assess the effect of drug lipophilicity on their encapsulation excess n and in vitro activity. Anthracycline drugs, including doxorubicin (DOX), epirubicin (EPI), daunorubicin (DAU), and idarubicin (IDA), with lipophilicity P from 0.8 to 15, were investigated. We have found that in addition to hydrogen-bonded supramolecular ensemble formation with n = 24, there are two other competing contributions that enable increasing n under strong polar interactions (APO(DOX)) or under strong hydrophobic interactions (APO(IDA) of the highest efficacy). The encapsulation/release processes were investigated using UV-Vis, fluorescence, circular dichroism, and FTIR spectroscopies. In vitro cytotoxicity/growth inhibition tests and flow cytometry corroborate high apoptotic activity of APO(drugs) against targeted MDA-MB-231 adenocarcinoma and HeLa cancer cells, and low activity against non-tumorigenic MCF10A cells, demonstrating targeting ability of nanodrugs. A model for molecular interactions between anthracyclines and APO nanocarriers was developed, and the relationships derived compared with experimental results.
ARTICLE | doi:10.20944/preprints202010.0563.v1
Subject: Life Sciences, Biochemistry Keywords: diabetes; omega-3 polyunsaturated fatty acid; lipoprotein subfraction; dyslipidemia; randomized controlled trial
Online: 27 October 2020 (20:37:15 CET)
Objectives To determine the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFA) from animal and plant sources on glucolipid metabolism and lipoprotein subfractions in type 2 diabetic patients with dyslipidemia. Methods Participants were recruited from the diabetes clinic at the Guanlin Hospital, Yixing City in Jiangsu province, China, from March 2017 through June 2017. Ninety participants were randomly assigned to take 3g/day fish oil (FO, containing EPA and DHA), 3g/day perilla oil (PO, containing ALA), or 3g/day blend oil containing fish oil and linseed oil (BO, containing EPA, DHA and ALA) for 3 months. The levels of serum glucose, glycated hemoglobin (HbA1c), C-peptide, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), non-HDL, apolipoprotein A1 (Apo A1), apolipoprotein B (Apo B), lipoprotein a (Lp(a)), and free fatty acids were determined at baseline and after the 3 months. In addition, four fatty acids in serum and red blood cells membranes (RBCm) were analyzed using gas chromatography-mass spectrometry. The Lipoprint System was used to determine the lipoprotein subfractions. Results All 90 participants completed the final 3-month follow-up at the end of the study. After three months of intervention, blood glucose and HbA1c levels in the PO group were significantly lower than those at the baseline (p < 0.05). On the other hand, in the BO group, the HbA1c, non-HDL, Apo A1 and Lp(a) levels were significantly lower, while the C-peptide levels were significantly higher after intervention compared to the baseline (p < 0.05). In the FO group, the HbA1c and TG levels were significantly lower after the intervention compared to the baseline (p < 0.05). In addition, at the end of the study, there was significant increase in the levels of DPA and DHA in serum and RBCm of the FO group (p < 0.05), while in the BO group, there was significant increase in the levels of EPA, DPA and DHA in RBCm (p < 0.05). Finally, the FO group had the highest levels of large HDL subfractions compared to the BO and PO groups, but had the lowest levels of small HDL subfractions among the three groups. Conclusion For patients with diabetes, plant-derived ω-3 PUFAs are more effective at controlling blood glucose than animal-derived ω-3 PUFAs. However, animal-derived ω-3 PUFAs play a critical role in controlling blood lipids. Particularly, fish oil can effectively increase the beneficial large HDL subfractions and reduce the nonbeneficial small HDL subfractions. Both the animal- and plant-derived ω - 3 PUFAs have practical value in improving glucose and lipids metabolism in T2DM patients with dyslipidemia.
ARTICLE | doi:10.20944/preprints201808.0427.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: overweight; obesity; body fat; maximal oxygen uptake; double-blind; randomized controlled trial
Online: 24 August 2018 (07:40:00 CEST)
: Background: Overweight and obesity are major risk factors for many chronic diseases, and weight-loss interventions often include systematic exercising and nutritional supplements. The purpose of this study was to determine the independent/synergistic effects of Spirulina maxima supplementation (6-week, 4.5 g/day) and a systematic physical exercise program (6 weeks/ 2 times) on body composition and cardiorespiratory fitness of overweight and obese subjects. Methods: 27 overweight and 25 obese sedentary male subjects were assigned to four interventions through a randomized double-blind, crossover controlled trial: Physical exercise program with (SE) or without (Ex) Spirulina maxima or no-exercise program with (Sm) and without (C) Spirulina maxima. Body composition and cardiorespiratory fitness parameters were taken during a maximal intensity test. Results: As compared to C group, SE, Sm and Ex groups reduced (p < 0.05) their body fat percentage while improving their maximal oxygen uptake (VO2max; r = −0.40), being obese subjects more benefited. Weight loss, time to reach fatigue and onset of blood lactate accumulation were improved in both Spirulina maxima supplemented groups, regardless the subjects’ body composition. Conclusions: Spirulina maxima supplementation synergistically improves the effects of systematic exercise in body composition and cardiorespiratory fitness parameters in overweight but mostly in obese adults.
ARTICLE | doi:10.20944/preprints202206.0021.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: vertical farming; controlled environment; lettuce cultivars; anthocyanin; light quality; LEDs; light recipe; stomata
Online: 1 June 2022 (13:17:55 CEST)
Indoor crop cultivation systems such as vertical farms or plant factories necessitate artificial lighting. Light spectral quality can affect plant growth and metabolism and, consequently, the amount of biomass produced and the value of the produce. Conflicting results on the effects of light spectrum in different plant species and cultivars make it critical to implement a singular lighting solution. In this study we explored the response of green and red leaf lettuce cultivars (’Aquino’, CVg, or ‘Barlach’, CVr, respectively) to long-term blue-enriched light application (WB). Plants were grown for 30 days in a growth chamber with optimal environmental condi-tions (temperature: 20°C, relative humidity: 60%, ambient CO2, Photon Flux Density (PFD) of 260 µmol m-2 s-1 over an 18-h photoperiod). At 15 days after sowing (DAS) white spectrum LEDs (WW) were compared to WB (λPeak = 423 nm) maintaining the same PFD of 260 µmol m-2 s-1. At 30 DAS, both lettuce cultivars resulted adapted to the blue light variant, though the adaptive re-sponse was specific to the variety. Rosette weight, light use efficiency and maximum operating efficiency of PSII photochemistry in the light, Fv/Fm’, were comparable between the two light treatments. Significant light quality effect was detected on stomatal density and conductance (20% and 17% increase under WB, respectively, in CVg) and, on the modified anthocyanin re-flectance index (mARI) (40% increase under WB, in CVr). Net photosynthesis response was gen-erally stronger in CVg compared to CVr; e.g. net photosynthetic rate, Pn, at 1000 µmol m-2 s-1 PPFD increased from WW to WB by 23% in CVg, compared to 18% in CVr. Results obtained suggest the occurrence of distinct physiological adaptive strategies in green and red pigmented lettuce cultivars to adapt to the higher proportion of blue light environment.
ARTICLE | doi:10.20944/preprints202108.0197.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: bibliometric analysis, IEEE Xplore, INSPEC Controlled Terms, keywords co-occurrence, research trends, Scopus
Online: 9 August 2021 (12:53:01 CEST)
The article is aimed at a brief comparison and analysis of the results of queries to IEEE Xplore and the leading abstract databases Scopus and Web of Science to identify research trends. Some errors in the Author Keywords in Web of Science have been revealed. Therefore, a more detailed analysis was conducted by comparing different types of key terms for IEEE Xplore and Scopus platforms only. I used IEEE Access journal metadata as indexed on both platforms. The sample match for IEEE Xplore and Scopus was achieved by comparing DOI. The IEEE Xplore metadata contains more types of key terms, which provides an advantage in analyzing research trends. Using NSPEC Controlled Terms from expert-compiled vocabulary provides a more stable data, which gives an advantage when considering the change of terms over time. Apriori, an algorithm for finding association rules, has been used to compare co-occurrence of terms for a more detailed description of sample subjects on both platforms. VOSviewer was used to analyze trends in scientific research based on IEEE Xplore data. The 2011-2021 ten-year period was divided into two sub-intervals for comparing the occurrence of Author Keywords, IEEE Terms, and NSPEC Controlled Terms. Using the IEEE conference proceedings bibliometric data, I illustrated the importance of context in estimating the rate of growth of publishing activity on a topic of interest.
ARTICLE | doi:10.20944/preprints202102.0584.v1
Subject: Biology, Anatomy & Morphology Keywords: controlled atmosphere (CA) storage; crop load; internal browning disorders; receiver operating characteristic (ROC)
Online: 25 February 2021 (13:45:54 CET)
Physiological storage disorders continue to cause sizable economic losses in a range of commercially important pomefruit cultivars. Given similar storage regimes, the incidence and severity of browning disorders in the apple cultivar ‘Braeburn’ can vary in different years in a way that can be explained by the interaction of preharvest seasonal and orchard factors. Over a three-year period (2016 to 2019) at the Kompetenzzentrum Obstbau-Bodensee (KOB) in Southwest Germany a range of orchard and storage treatments were conducted for: air temperature during cell division for three weeks post petalfall or during four weeks preharvest, calcium orchard sprays, crop load and harvest timings. Following controlled atmosphere (CA) storage, the disorder incidence for internal browning and cavity formation varied markedly over the three different growing seasons. Crop load treatments strongly influenced the expression of browning disorders in all years. Differences in air temperatures (△ +/- 2 °C compared to ambient) during the cell division period showed little effect on browning incidence. Warm night temperatures (>10 °C) prior to harvest can reduce internal browning in ‘Braeburn’ apples during CA storage and shelf-life.
ARTICLE | doi:10.20944/preprints202012.0305.v1
Subject: Medicine & Pharmacology, Allergology Keywords: background infusion; intravenous infusions; laparoscopic cholecystectomy; opioid analgesics; patient-controlled analgesia; postoperative pain
Online: 14 December 2020 (08:18:43 CET)
Background and objectives: Traditional intravenous, patient-controlled analgesia (PCA) uses a fixed-rate continuous background infusion mode. However, some patients suffer from inadequate analgesia or opioid-related adverse effects due to the biphasic pattern of postoperative pain. Therefore, we investigated the postoperative analgesic efficacy of PCA using an optimizing background infusion mode (OBIM), where the background injection rate varies depending on the patient's bolus demand. Materials and Methods: We prospectively enrolled 204 patients who underwent laparoscopic cholecystectomy in a randomized, controlled, double-blind study. Patients were allocated into either the optimizing (group OBIM) or the traditional background infusion group (group TBIM). The numeric rating scale (NRS) score for pain was evaluated at admission to and discharge from the recovery room, as well as at the 6th, 24th, and 48th postoperative hours. Data of bolus demand count, total infused volume, and background infusion rate was downloaded from the PCA device at 30-min intervals until the 48th postoperative hour. Results: The NRS score was not significantly different between groups throughout the postoperative period (P = 0.621), decreasing with time in both groups (P < 0.001). The bolus demand count was not significantly different between groups throughout (P = 0.756). The mean cumulative infused PCA volume was lower in group OBIM [84.0 (95% confidence interval: 78.9−89.1) mL) than in group TBIM [102 (97.8−106.0) mL] (P < 0.001). The background infusion rate was significantly different between groups throughout (P < 0.001); it was higher in group OBIM than in group TBIM before the 12th postoperative hour, and lower from the 18th to the 48th postoperative hours. Conclusions: The OBIM combined with bolus dosing is useful in that it reduces the cumulative PCA volume compared to the TBIM combined with bolus dosing, while yielding comparable postoperative analgesia and bolus demand in patients undergoing laparoscopic cholecystectomy.
REVIEW | doi:10.20944/preprints201803.0005.v1
Subject: Materials Science, Polymers & Plastics Keywords: chitin; chitosan; derivatization; controlled functionalization, click chemistry; graft copolymer; cyclodextrin; dendrimer; ionic liquids
Online: 1 March 2018 (07:13:47 CET)
The functionalization of polymeric substances is of great interest for the development of innovative materials for advanced applications. For many decades, the functionalization of chitosan has been a convenient way to improve its properties with the aim to prepare new materials with specialized characteristics. In the present article, we summarize the latest methods for the modification and derivatization of chitin and chitosan, trying to introduce specific functional groups under experimental conditions, which allow a control over the macromolecular architecture. This is motivated because an understanding of the interdependence between chemical structure and properties is an important condition for proposing innovative materials. New advances in methods and strategies of functionalization such as click chemistry approach, grafting onto copolymerization, coupling with cyclodextrins and reactions in ionic liquids are discussed.
ARTICLE | doi:10.20944/preprints202107.0115.v1
Subject: Biology, Anatomy & Morphology Keywords: Controlled drainage; Water content; Salinity (EC); Mineral nitrogen; Nitrogen loss; Yield of oilseed sunflower
Online: 5 July 2021 (16:06:58 CEST)
Controlled drainage (CD) is an important agricultural measure for maintaining soil moisture and nutrients, controlling groundwater level, and increasing crop yield. In arid regions, CD can be used to improve the water supply in agriculture and reduce environmental pollution. In this study, we investigated the effect of CD, including a drainage depth of 40 cm (CWT1) and 70 cm (CWT2) during the plant growth period, free drainage (FD), and open ditch drainage (OD) on the migration of water, nutrients, and salts in the soil; the dynamics of groundwater level; the loss of soil nitrogen; and the growth of oilseed sunflower plants. Compared with FD, CD increased the water and nutrient content in the soil, reduced nitrogen loss, and enhanced the ability of the soil to continuously supply nitrogen to the oilseed sunflower plants, which benefited plant growth at later growth stages and reduced environmental pollution. During the period between irrigation at the budding stage and harvest stage, the average soil water content in the 0–20 cm soil layer in CWT1 increased by 3.67%, 4.78%, and 0.55%, respectively, compared with that in CWT2, FD, and OD. The soil mineral content in CWT1 was 25.17%, 35.05%, and 17.78% higher than that in CWT2, FD, and OD, respectively, indicating that higher soil salinity occurred at the later stage of plant growth in CWT1, which actually had little effect on the plants due to their enhanced salt tolerance and increased need for water and nutrients at that stage. In addition, CD delayed the decline in groundwater level, which allowed the plants to use groundwater at later growth stages, and as a result the yield and water use efficiency were improved. CWT1 significantly increased oilseed sunflower yield by 4.52–11.14% and increased water use efficiency by 1.16–10.8%. Moreover, CWT1 also increased the survival rate of the oilseed sunflower plants by 2.62–2.92%, and the plants demonstrated good growth. Therefore, under CD conditions, plants used soil water and nitrogen more efficiently and, as a result, their productivity was increased, and the water quality was improved.
ARTICLE | doi:10.20944/preprints202105.0495.v1
Subject: Medicine & Pharmacology, Allergology Keywords: nephrectomy; Neuropathic Pain Symptom Inventory; patient-controlled analgesia; quadratus lumborum block; persistent postoperative pain
Online: 20 May 2021 (17:17:47 CEST)
Background: New regional techniques can improve pain management after nephrectomy. Methods: This study was a randomized controlled trial conducted at two teaching hospitals. Patients undergoing elective open and laparoscopic nephrectomy were eligible to participate in the trial. A total of 100 patients were divided into a quadratus lumborum block (QLB) group and a control (CON) group. At the end of surgery, but while still under general anesthesia, unilateral QLB with ropivacaine was performed on the side of nephrectomy for patients in the QLB group. The main measured outcome of this study was oxycodone consumption via a patient-controlled anesthesia (PCA) pump during the first 24 hours following surgery; other measured outcomes included postoperative pain intensity assessment, patient satisfaction with pain management, and persistent pain evaluation. Results: Patients undergoing QLB needed less oxycodone than those in the CON group (34.5 mg [interquartile range 23–40 mg] vs. 47.5 mg [35–50 mg]; p<0.001). No difference between the groups was seen in postoperative pain intensity measured on the visual analog scale, except for the evaluation at hour 2, which was in favor of the QLB group (p=0.03). Patients who received QLB were more satisfied with postoperative pain management than the CON group. Persistent postoperative pain was assessed with the Neuropathic Pain Symptom Inventory (NPSI) at months 1, 3, and 6 and was found to be significantly lower in the QLB group at each evaluation (p<0.001). We also analyzed the impact of the surgery type on persistent pain severity, which was significantly lower after laparoscopic procedures than open procedures at months 1, 3, and 6. Conclusions: QLB reduces oxycodone consumption in patients undergoing open and laparoscopic nephrectomy and decreases persistent pain severity months after hospital discharge.
ARTICLE | doi:10.20944/preprints202011.0406.v1
Subject: Engineering, Automotive Engineering Keywords: energy use; demand-controlled ventilation; hybrid ventilation; humidity; multi-unit residential building; simulation; CONTAM
Online: 16 November 2020 (09:16:41 CET)
A humidity-sensitive demand-controlled ventilation system is known for many years. It has been developed and commonly applied in regions with an oceanic climate. Some attempts were made to introduce this solution in Poland in a much severe continental climate. The article evaluates this system's performance and energy consumption applied in an 8-floor multi-unit residential building, virtual reference building described by the National Energy Conservation Agency NAPE, Poland. The simulations using the computer program CONTAM were performed for the whole hating season for Warsaw's climate. Besides passive stack ventilation that worked as a reference, two versions of humidity-sensitive demand-controlled ventilation were checked. The difference between them lies in applying the additional roof fans that convert the system to hybrid. The study confirmed that the application of demand-controlled ventilation in multi-unit residential buildings in a continental climate with warm summer (Dfb) leads to significant energy savings. However, the efforts to ensure acceptable indoor air quality require hybrid ventilation, which reduces the energy benefits. It is especially visible when primary energy use is analyzed.
ARTICLE | doi:10.20944/preprints202206.0249.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: rolled flat products; accelerated cooling; temperature; mathematical model; oxide scale; Ther-mo-Mechanical Controlled Process
Online: 17 June 2022 (05:14:37 CEST)
To verify the authors’ mathematical model for water jet cooling of steel sheet, the previously performed experimental studies of temperature of the test plate in the roller quenching machine (RQM) were used. The calculated data of steel temperature evolution along the RQM length were compared with the readings of thermocouples inserted in the center of the test plate and at its surfaces. The core of the model is the dependence of the temperatures of film, transition and nucleate boiling regimes on the thickness of the oxide scale layer on the cooled surface. It was found that the model correctly takes into account the oxide scale on the sheet surface, flow rates and combinations of the RQM banks used, water temperature and other factors. For all experiments the calculated metal temperature corresponds well to the measured one. In the experiments with interrupted cooling, the calculated temperature plots repeat the characteristic changes in the experimental curves. The main uncertainty in the modeling of cooling in a wide temperature range can be contributed by the random nature of changes in the oxide scale thickness during water cooling. In this regard, the estimated thickness of the oxide scale layer should be considered as the main parameter for adapting the sheet temperature control process. The obtained data confirm the possibility of effective application of the model in the ACS of industrial TMCP (Thermo-Mechanical Controlled Process) systems.
ARTICLE | doi:10.20944/preprints202109.0406.v1
Subject: Earth Sciences, Geophysics Keywords: Array electromagnetics, magnetotellurics, controlled source electromagnetics, microseismics, reservoir monitoring, enhanced oil recovery, recovery factor improvement
Online: 23 September 2021 (12:27:38 CEST)
Focusing geophysics to improve recovery factor of hydrocarbon reservoirs adds value and contributes toward ZERO carbon footprint by increasing the recovery factor by of 30-40 % and thus reducing the cost/carbon emission per produced barrel. Thus, the Enhanced Oil Recovery (EOR) market is expected to grow more than 3.5% annually. This will be even more fueled by the Green-House-Gas (GHG) reduction and subsequent CO2 injection into the reservoirs as they are being produced. Presently, geophysics only ac-counts for a small percentage of this market, thus its growth is inevitable since more deterministic observation lead higher operating efficiency. Imaging the fluids (hydro-carbon, water, and CO2) is a key component to optimized production and injection. We designed a novel electromagnetic (EM) acquisition system that combines mul-ti-physics fluid imaging and acquires surface and borehole data with high fidelity. Borehole calibration is needed to upscale reservoir data and parameters to measurement scale. Multiple electromagnetic methods are used as well as microseismics in one layout for Exploration and Production (E & P) problems. Multi-components in electromagnetics allows resolving oil and water-bearing zones equally well while achieving the best ac-curacy suitable for repeat measurements. Because sedimentary basins are intrinsically anisotropic, considering 3-dimensional anisotropy is essential from measurement and 3D modeling viewpoint. Thus, the results have the better subsurface images. Here, we combine hardware design, methodology, 3D modeling, processing, and interpretations into an integrated technology and demonstrate the success with verifiable case histories.
ARTICLE | doi:10.20944/preprints202105.0472.v1
Subject: Life Sciences, Biochemistry Keywords: rootstock; 1-MCP; cost-effectiveness of technology, controlled atmosphere, cold storage, ORAC, TSS, acidity, firmness
Online: 20 May 2021 (10:12:37 CEST)
Late pear cultivars, such as ‘Conference’, can be stored for a long period, with their storability depending on storage conditions. A three-year study (2011-2013) compared the impact of half-year storage using four technologies – normal atmosphere, normal atmosphere + 1-methylcyclopropene (1-MCP), controlled atmosphere, controlled atmosphere + 1-MCP – on the quality parameters of ‘Conference’ pears, such as mass loss, firmness, total soluble solids, acidity, antioxidant capacity, and the incidence of diseases and disorders. Additionally, the study analysed different storage conditions in terms of profitability, based on the market prices for pears in the seasons during which the pears were stored. The storage conditions had a very strong influence on the fruit quality parameters, and was found to affect most visibly the mass loss and the incidence of postharvest diseases and disorders. The storage of ‘Conference’ pears for 180 days in normal atmosphere is not economically viable, even if the fruit is subjected to 1-MCP treatment.
Subject: Engineering, Control & Systems Engineering Keywords: hybrid energy storage system; L2-gain disturbance attenuation; passivity-based control; port-controlled Hamiltonian model
Online: 16 April 2020 (06:36:09 CEST)
Battery/Supercapacitor(SC) current tracking control is a key issue for hybrid energy storage system (HESS) in electric vehicles. An innovative passivity-based L2-gain adaptive control (PBL2AC) based on port-controlled Hamiltonian model with dissipativity (PCHD) for reference current tracking and bus voltage stability in HESS is presented. The developed PCHD model has considered both parameter variations and external disturbances. By using L2-gain disturbance attenuation, the PBL2AC ensures robust reference current tracking and stable bus voltage. Moreover, adaptive mechanism is adopted to estimate the electrical parameters. To validate the proposed control scheme for HESS, simulations and experiments were done and compared with traditional PID and sliding mode control under several typical driving cycles, and results show that the effectiveness of the proposed controller can be confirmed.
ARTICLE | doi:10.20944/preprints201804.0156.v1
Subject: Behavioral Sciences, Social Psychology Keywords: forest beauty; outdoor recreation; graphic elicitation technique; controlled burning; red-cockaded woodpecker, Ocala National Forest
Online: 12 April 2018 (04:46:34 CEST)
Prescribed burning and other active forest management treatments have been proven to be essential for maintaining suitable habitat conditions for many wildlife species, including the federally endangered red-cockaded woodpecker (RCW). This study examines the perception of forest management treatments of recreation users participating in various activities (hunting, hiking/backpacking, camping, off-highway vehicle riding, and canoeing/kayaking) in terms of scenic beauty and recreation satisfaction. We used photographic images to capture various forest management treatments of different intensity levels and times after treatments, and assessed users’ perception of scenic beauty and recreation satisfaction. Results indicated variation among users participating in different recreation activities, but that good quality RCW habitat offered both higher scenic beauty and higher recreation satisfaction than poor quality habitat for most user groups. Finally, recreation satisfaction was statistically equal to perceived scenic beauty from both good and poor-quality RCW habitats for most of the user groups, thus suggesting the importance of scenic beauty on forest sites in determining recreation users’ attainment of visit satisfaction. Findings conclude that forest sites developed as good quality RCW habitat in the present state also offer quality experience to recreation users, thus supporting multi-objective forestry practices in public forests.
REVIEW | doi:10.20944/preprints202007.0459.v1
Subject: Chemistry, Electrochemistry Keywords: current-potential curve; multi-enzymatic cascades; multi-analyte detection; mass-transfer-controlled amperometric response; potentiometric coulometry
Online: 20 July 2020 (08:16:47 CEST)
Bioelectrocatalysis provides the intrinsic catalytic-functions of redox enzymes to non-specific electrode reactions and is the most important and basic concept for biosensors. This review starts by describing fundamental characteristics of bioelectrocatalytic reactions in mediated and direct electron transfer types from a theoretical viewpoint and summarizes amperometric biosensors based on multi-enzymatic cascades and for multi-analyte detection. The review also introduces prospective aspects of two new concepts of biosensors: mass-transfer-controlled (pseudo)steady-state amperometry at microelectrodes with enhanced enzymatic activity without calibration curves and potentiometric coulometry at enzyme/mediator-immobilized biosensors for absolute determination.
REVIEW | doi:10.20944/preprints202207.0141.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: review; real -world evidence; real -world data; randomized controlled trials; registry; digital health technology; early drug approval
Online: 8 July 2022 (11:09:58 CEST)
Real-world evidence (RWE) is increasingly involved in the early benefit assessment of medicinal drugs. It is expected that RWE will help to speed up approval processes comparable to RWE developments in vaccine research during the COVID-19 pandemic. Definitions of RWE are diverse marking the highly fluid status in this field. So far, RWE comprises information produced from data routinely collected on patient’s health status and/or delivery of health care from various sources other than traditional clinical trials. These sources can include electronic health records, claims, patient-generated data including in home-use settings, data from mobile devices as well as patient, product and disease registries. The aim of the present update was to review the current RWE developments and guidelines mainly in the U.S., the UK, Europe and Germany field during the last decade. RWE has already been included in various approval procedures of regulatory authorities reflecting its actual acceptance and growing importance in evaluating and accelerating new therapies. However, since the RWE research is still in a transition process and since a number of gaps in this field have been explored, more guidance and a consented definition are necessary to increase the implementation of real-world data.
REVIEW | doi:10.20944/preprints202112.0278.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: systematic review; meta-analysis; dietary pattern; prospective cohort; randomized controlled trial; cancer prognosis; cancer survival; dietary intervention
Online: 16 December 2021 (15:06:33 CET)
Cancer survival continues to improve in high-income countries, partly explained by advances in screening and treatment. Previous studies have mainly examined the relationship between individual dietary components and cancer prognosis in tumours with good therapeutic response (breast, colon and prostate cancers). The aim of this review was to assess qualitatively (and quantitatively where appropriate) the associations of dietary patterns and cancer prognosis from published prospective cohort studies, as well as the effect of diet interventions by means of randomized controlled trials (RCT). A systematic search was conducted in PubMed, and a total of 35 prospective cohort studies and 14 RCT published between 2011 and 2021 were selected. Better overall diet quality was associated with improved survival among breast and colorectal cancer survivors; adherence to the Mediterranean diet was associated to lower risk of mortality in colorectal and prostate cancer survivors. A meta-analysis using a random-effects model showed that higher versus lower diet quality was associated with a 23% reduction in overall mortality in breast cancer survivors. There was evidence that dietary interventions, generally combined with physical activity, improved overall quality of life, though most studies were in breast cancer survivors. Further cohort and intervention studies in other cancers are needed to make more specific recommendations.
ARTICLE | doi:10.20944/preprints202104.0470.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: wireless body area networks; controlled sensing; energy efficiency; partially observable Markov decision processes (POMDPs); remote health monitoring
Online: 19 April 2021 (12:08:56 CEST)
Abstract: Wireless body area networks (WBANs) have strong potential in the field of health monitoring. However, the energy consumption required for accurate monitoring limits the time between battery charges of the wearable sensors, which is a key performance factor (and can be critical in the case of implantable devices). In this paper, we study the inherent trade-off between the power consumption of the sensors and the probability of misclassifying a patient’s health state. We formulate this trade-off as a dynamic problem, in which at each step we can choose to activate a subset of sensors that provide noisy measurements of the patient’s health state. We assume that the (unknown) health state follows a Markov chain, so our problem is formulated as a partially observable Markov decision problem (POMDP). We show that all the past measurements can be summarized as a belief state on the true health state of the patient, which allows tackling the POMDP problem as an MDP on the belief state. We then empirically study the performance of a greedy one-step look-ahead policy compared to the optimal policy obtained by solving the dynamic program. For that purpose, we use an open-source Continuous Glucose Monitoring (CGM) data set of 232 patients over six months and extract the transition matrix and sensor accuracies from the data. We find that the greedy policy saves ~50% of the energy costs while reducing the misclassification costs by less than 2% compared to the most accurate policy possible that always activates all sensors. Our sensitivity analysis reveals that the greedy policy remains nearly optimal across different cost parameters and a varying number of sensors. The results also have practical importance, because while the optimal policy is too complicated, a greedy one-step look-ahead policy can be easily implemented in WBAN systems.
ARTICLE | doi:10.20944/preprints202009.0047.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: silk fibroin; nanoparticles; drug loading content; quantification; infrared spectroscopy; FTIR spectroscopy.; nanotechnology; nanomedicine; drug delivery; controlled release
Online: 3 September 2020 (03:56:19 CEST)
Nanotechnology has enabled the development of novel therapeutic strategies such as targeted nanodrug delivery systems, control and stimulus-responsive release mechanisms, and the production of theranostic agents. As a prerequisite for the use of nanoparticles as drug delivery systems, the amount of loaded drug must be precisely quantified, a task for which two approaches are currently used. However, both approaches suffer from the inefficiencies of drug extraction and of the solid-liquid separation process, as well as from dilution errors. This work describes a new, reliable, and simple method for direct drug quantification in polymeric nanoparticles using attenuated total reflection Fourier transform infrared spectroscopy, which can be adapted for a wide variety of drug delivery systems. Silk fibroin nanoparticles and naringenin were used as model polymeric nanoparticle carrier and drug, respectively. The specificity, linearity, detection limit, precision and accuracy of the spectroscopic approach were determined in order to validate the method. A good linear relation was observed within 0.00 to 7.89 % of naringenin relative mass with an R2 of 0.973. The accuracy was determined by the spike and recovery method. Results showed an average 104% recovery. The limit of detection and limit of quantification of the drug loading content were determined to be 0.3 and 1.0 %, respectively. The method's robustness is demonstrated by the notable similarities between the calibrations carried out in two different equipment and institutions.
REVIEW | doi:10.20944/preprints201710.0046.v1
Subject: Engineering, Civil Engineering Keywords: comparative study; full-scale measurement; wind tunnel model test; multiple-fan actively controlled wind tunnel; research scheme
Online: 9 October 2017 (06:38:40 CEST)
Full-scale/model test comparison studies to validate the traditional ABL wind tunnel simulation technique are reviewed. According to the literature review, notable discrepancies between full-scale measurement results and model test results were observed by most performed comparison studies, but the causes of the observed discrepancies were not revealed in a scientific way by those studies. In this regard, a new research scheme for future full-scale/model test comparison studies is proposed in this article, which utilizes the multiple-fan actively controlled wind tunnel simulation technique. With the new research scheme, future full-scale/model test comparison studies are expected to reasonably disclose the main problems with the traditional ABL wind tunnel simulation technique, and the technique can be improved correspondingly.
ARTICLE | doi:10.20944/preprints202109.0016.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Chance constraint programming; Source-load systems; Demand response control; Thermostatically controlled loads (TCLs); Plug-in electric vehicles (PEVs).
Online: 1 September 2021 (12:25:48 CEST)
Demand response flexible loads can provide fast regulation and ancillary services as reserve capacity in power systems. This paper proposes a joint optimization dispatch control strategy for source-load system with stochastic renewable power injection and flexible thermostatically controlled loads (TCLs) and plug-in electric vehicles (PEVs). Specifically, the optimization model is characterized by a chance constraint look-ahead programming to maximal the social welfare of both units and load agents. By solving the chance constraint optimization with sample average approximation (SAA) method, the optimal power scheduling for units and TCL/PEV agents can be obtained. Secondly, two demand response control algorithms for TCLs and PEVs are proposed respectively based on the aggregate control models of the load agents. The TCLs are controlled by its temperature setpoints and PEVs are controlled by its charging power such that the DR control objective can be fulfilled. The effectiveness of the proposed dispatch and control algorithm has been demonstrated by the simulation studies on a modified IEEE 39 bus system with a wind farm, a photovoltaic power station, two TCL agents and two PEV agents.
ARTICLE | doi:10.20944/preprints201707.0092.v1
Subject: Engineering, Mechanical Engineering Keywords: wear debris detection; resonance method; sensitivity; phase controlled variable-frequency exciting system (PCVFES); modified lock-in amplifier (MLIA)
Online: 31 July 2017 (12:20:27 CEST)
That how to improve the sensitivity and the detection ability of the Large-caliber sensor is critical to satisfy the requirement of heavy vehicle wear condition monitoring. In this paper, we introduced the LC resonance principle to the design of sensor with large flow channel (7mm). The resonant exciting coil increases the impedance change of the exciting circuit caused by wear particles which magnify the current difference between the two exciting coils and improve the sensitivity of the sensor. The resonant induction coil greatly suppresses the interference signals and magnifies the weak induced electromotive force which is beneficial to enhance the detection ability. In order to boost the detectability for different materials particles, a phase controlled variable-frequency exciting system (PCVFES) was adopted to automatically switch the exciting frequency between 284kHz for ferromagnetic particles and 420KHz for non-ferromagnetic particles. For the weak signal detection, based on the essential characteristic of the signal, we apply a simpler method that modified lock-in amplifier (MLIA) rather than the conventional algorithms (Wavelet transform, EMD). Results show that using these methods the sensitivity and the detection ability of the sensor are significantly improved and the 75μm iron particles and 220μm copper particles were successfully detected which realizes the initial abnormal wear monitoring for the large flow project.
HYPOTHESIS | doi:10.20944/preprints202108.0531.v1
Subject: Social Sciences, Accounting Keywords: nature of stock rights; state-controlled firm; income smoothing; institutional investor; pressure-resistant institutional investor; pressure-sensitive institutional investor
Online: 28 August 2021 (15:07:13 CEST)
The purpose of this study is to examine the relationship between the institutional investors which can affect financial performance for corporate sustainability on the income smoothing. Therefore, this study focus on the connection between the nature of stock rights and income smoothing in China. For this study, hypotheses were established on the relationship each state-controlled companies, income smoothing, and information equilibrium of individual investors, and empirical analysis was conducted through related variables. The analysis results are summarized in three categories as follows. First, this research finds that state-controlled firms (CONTs) prefer income smoothing activities compared to non-state-controlled firms for the long-term sustainable development of firms using data from 2011 to 2019. Second, this study found out that Institutional investors support the behavior of CONTs to smooth their earnings because this behavior is seen as an attempt by CONTs to convey valuable private information to other investors. Third, we was able to discover that institutional investors' monitoring effect is predominantly driven by pressure-resistant institutional investors. This research complements the lack of empirical research on income smoothing and enable to give a guideline that the type of stock rights is a critical key determinant of participation in income smoothing activities for stable growth and sustainability in the future.
REVIEW | doi:10.20944/preprints202102.0193.v1
Subject: Biology, Anatomy & Morphology Keywords: mild cognitive impairment (MCI); mild dementia; Alzheimer’s disease; Ginkgo biloba (EGb761®); Tebonin; anti-dementia drugs; randomized controlled trials
Online: 8 February 2021 (11:37:05 CET)
Mild cognitive impairment (MCI) and mild dementia are a clinically relevant health problem in the elderly and Alzheimer's disease being the most common neurodegenerative disorder. Furthermore, MCI and mild dementia are characterized by a deterioration of cognitive function and their diagnosis is mainly based on cognitive examination and, the prognosis of the disease seems to be an essential reason for the diagnosis, because there is a high risk of cognitive decline in the two syndromes. This review describes the effectiveness of Ginkgo biloba (EGb761®) leaf extract for the treatment of dementia syndrome and EGb761® combination therapy with other medications for symptomatic dementia. Tebonin® is a drug of plant origin based on the active ingredient “Ginkgo biloba”. This drug has shown encouraging results, improving cognitive function, neuropsychiatric disorders and consequent reduction of caregiver stress and maintenance of autonomy in patients with age-related cognitive decline, MCI and mild dementia. Nowadays, there is little evidence to support the efficacy of EGb761® combination therapy with anti-dementia drugs and, therefore, more evidence is needed to evaluate the role of EGb761® in mixed therapy.
ARTICLE | doi:10.20944/preprints202009.0572.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: randomized controlled clinical trials; mathematical model; binary system; statistical analysis; epidemiological model; junk science; reductionist treatments; failure of medicine
Online: 24 September 2020 (08:13:15 CEST)
Modern medicine adopted four presumptions when it evolved from ancient experienced-based mind-body medicine. To understand its failure in finding cures for chronic diseases, we examined four presumptions, and found that statistical population of health properties does not exist for most research purposes, mathematical models are misused to model intensive properties, synthetic drugs are inherently more dangerous than nature-made medicines under their respective application conditions, and reductionist treatments are inferior and inherently dangerous. We found that clinical trials are valid only for research where treatment effect is much stronger than the total effects of all interfering or co-causal factors or errors introduced by misused mathematical models can be tolerated. In all other situations, clinical trials introduce excessive errors and fail to detect treatment effects, or produce biased, incorrect or wrong results. We further found that chronic diseases are manifestation of small departures in multiple process attributes in distinctive personal biological pathways networks, that modern medicine lacks required accuracy for accurately characterizing chronic diseases, and that reductionist treatments are good at controlling symptoms and safe for short term uses. For all stated reasons, as long as modern medicine continues relying on the flawed presumptions, it can never find predictable cures for chronic diseases. By implication, predictable cures to chronic diseases are adjustments to lifestyle, dietary, emotional, and environmental factors to slowly correct departures in process attributes responsible for chronic diseases.
REVIEW | doi:10.20944/preprints202002.0427.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: adipose derived regenerative cells; ADRCs, efficacy; point of care treatment; randomized controlled trials; safety; stem cells; stromal vascular fraction
Online: 28 February 2020 (12:12:23 CET)
It has become practically impossible to survey the literature on cells derived from adipose tissue with the aim to apply them in regenerative medicine. The aim of this review is to provide a jump start to understanding the potential of UA-ADRCs (uncultured, unmodified, fresh, autologous adipose derived regenerative cells isolated at the point of care) in regenerative medicine. We show that serious and adequate clinical research demonstrates that tissue regeneration with UA-ADRCs is safe and effective. ADRCs are neither 'fat stem cells' nor could they exclusively be isolated from adipose tissue, as ADRCs contain the same adult (depending on the definition) pluripotent or multipotent stem cells that are ubiquitously present in the walls of small blood vessels. Of note, the specific isolation procedure used has significant impact on the number and viability of the cells and hence on safety and efficacy of UA-ADRCs. Furthermore, there is no need to further separate adipose-derived stem cells (ASCs) from ADRCs if the latter were adequately isolated from adipose tissue. Most importantly, UA-ADRCs have the physiological capacity to adequately regenerate tissue without need for manipulating, stimulating and/or (genetically) reprogramming the cells for this purpose. Tissue regeneration with UA-ADRCs fulfills the criteria of homologous use.
ARTICLE | doi:10.20944/preprints202111.0299.v1
Subject: Social Sciences, Education Studies Keywords: Education for Sustainable Development; Systems Thinking; System Dynamics; simulation; transfer of skills; effectiveness; randomised controlled trial; RCT; factorial study; ANOVA
Online: 17 November 2021 (10:47:24 CET)
Education for Sustainable Development (ESD) is considered vital to the success of the United Nations’ Sustainable Development Goals. Systems Thinking has been identified as a core competency necessary to incorporate into ESD. Systems Thinking orientated ESD learning tools, established methods of assessment of sustainability skills, and studies to demonstrate effectiveness of such learning tools, are all lacking. There is a wealth of experience in the System Dynamics field regarding the application of Systems Thinking and simulation to environmental problems, sustainability and systems education. Many System Dynamicists regard simulation as essential for teaching Systems Thinking. The substantial body of research into the design of effective simulation-based learning environments (SBLEs) can also inform ESD initiatives. This research describes a randomised controlled trial (n=106) to investigate whether an online sustainability learning tool that incorporates Systems Thinking and System Dynamics simulation increases understanding of a specific problem and supports transfer of knowledge to a second problem with a similar systemic structure. The effects of Systems Thinking and simulation were tested separately and in combination. The learning tool was designed for a single online learning session. Simulation was found to increase ESD learning outcomes significantly, and also to support transfer of skills, although less significantly.
ARTICLE | doi:10.20944/preprints202010.0156.v1
Subject: Keywords: Artificial intelligence; Deep reinforcement learning; Demand Response; Dynamic pricing; Energy management system; Microgrid; Neural networks; Price-responsive loads; Smart grid; Thermostatically controlled loads
Online: 7 October 2020 (11:21:03 CEST)
In this paper, we study the performance of various deep reinforcement learning algorithms to enhance the energy management system of a microgrid. We propose a novel microgrid model that consists of a wind turbine generator, an energy storage system, a set of thermostatically controlled loads, a set of price-responsive loads, and a connection to the main grid. The proposed energy management system is designed to coordinate among the different flexible sources by defining the priority resources, direct demand control signals, and electricity prices. Seven deep reinforcement learning algorithms were implemented and are empirically compared in this paper. The numerical results show that the deep reinforcement learning algorithms differ widely in their ability to converge to optimal policies. By adding an experience replay and a semi-deterministic training phase to the well-known asynchronous advantage actor-critic algorithm, we achieved the highest model performance as well as convergence to near-optimal policies.
ARTICLE | doi:10.20944/preprints202003.0257.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: divergent current density; new superconductivity; Meissner effect; new type of condensation; energy generation; electrostatic potential; independent current source; voltage-controlled current source; renewable energy
Online: 16 March 2020 (04:18:23 CET)
Societies around the world face serious energy problems related to the consumption of fossil fuels and the emission of dangerous radiation. To solve these problems, a new superconductor exhibiting a critical temperature higher than room temperature has been pursued but not achieved. This paper proposes a new energy generation system based on a circuit approach. Secondary to this process, a new type of superconductivity without refrigeration is demonstrated. In our previous paper , this system was proposed, but it did not describe the underlying theory in detail and did not mention an actual method to generate energy from the system. The present paper describes the theory of the existence of divergent current density and new superconductivity with no refrigeration. Moreover, the present paper proposes a method for extracting energy from the system by employing a voltage-controlled current source (i.e., a voltage–current converting method).The principle of the system is based on a circuit of two loops and independent current sources. First, the two electric loops are prepared, each with 4 diodes, where the diodes are oriented in the same direction within each loop, but their direction is opposite from loop to loop; four independent current sources connect the loops. In this circuit system, current is added iteratively as it flows along the loop according to Kirchhoff’s circuit law. As a result, a large current and electric potential are present along the loop. To confirm that this system works properly, it is necessary to demonstrate the presence of divergent currents in the transient state, and to do this, the present paper employs the Dirac equation and Lorentz conservation. Electric circuit software is employed to demonstrate that the presented method generates energy actually from our system.Our results confirm the presence of divergent current at a connected point of an independent current source in the transient state. Moreover, in the steady state, the theory demonstrates the Meissner effect (i.e., a London equation) and a new type of macroscopic wave function and condensation. For an initial small input current of 0.1 μA, the simulation reveals a large generating current of 7 kA and electric power of 1011 W, which is much larger than unit of power from an average thermal power station; moreover, the system presents with superconducting electrical transport conditions.The present study is significant because it demonstrates theoretically the existence of divergent current density and a new type of superconductivity requiring no refrigeration. Secondly, the simulations show the generation of a large energy density that can be obtained in a small laboratory room with minimal cost.
ARTICLE | doi:10.20944/preprints202207.0361.v1
Subject: Medicine & Pharmacology, Anesthesiology Keywords: PSPS; FBSS; SCS; surgical lead; SCS implantation; MAST (for Minimal Access Spine Technologies); TCIVA (for Target Controlled Intra-Veinous Anesthesia); composite score; pain mapping; neuropathic pain; chronic pain; quality of life; anesthesia; hypnosis
Online: 25 July 2022 (08:34:26 CEST)
Spinal Cord Stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in Persistent Spinal Pain Syndrome-Type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that Awake Anesthesia (AA), consisting in Target Controlled Intra-Veinous Anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with Minimal Invasive Surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or General Anesthesia (MISGA group), or by Laminectomy under General Anesthesia (LGA group). All in all, MISAA appears to show significantly better performance in terms of patient pain coverage, as well as improved secondary outcomes. One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.
CONCEPT PAPER | doi:10.20944/preprints202103.0350.v1
Subject: Materials Science, Biomaterials Keywords: carbyne-enriched nanostructured metamaterials; sp1-hybridized bonds; carbon atomic wires; ion-assisted pulsed-plasma deposition; nanocavities; cluster-assembling; vibration-assisted growing; acoustic activation; vibrational patterns; electromagnetic activation; self-organizing of the nanostructures; nano-cymatics; controlled patterning; synergistic effect
Online: 12 March 2021 (20:07:52 CET)
Structural self-organizing and pattern formation are universal and key phenomena observed during growth and cluster-assembling of the carbyne-enriched nanostructured metamaterials at the ion-assisted pulse-plasma deposition. Fine tuning these universal phenomena opens access to designing the properties of the growing carbyne-enriched nano-matrix. The structure of bonds in the grown carbyne-enriched nano-matrices can be programmed by the processes of self-organization and auto-synchronization of nanostructures. We propose the innovative concept, connected with application of the universal Cymatics phenomena during the predictive growth of the carbyne-enriched nanostructured metamaterials. We also propose the self-organization approach for increase stability of the long linear carbon chains. The main idea of suggested concept is manipulating by the self-organized wave patterns excitation phenomenon and their distribution by the spatial structure and properties of the nanostructured metamaterial grows region through the new synergistic effect. Mentioned effect will be provided through the vibration-assisted self-organized wave patterns excitation along with simultaneous manipulating by their properties through the electric field. We propose to use acoustic activation of the plasma zone of nano-matrix growing. Interaction between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions will serve as the additional energizing factor controlling the local pattern formation and self-organizing of the nano-structures. Suggested concept makes it possible to provide precise predictive designing the spatial structure and properties of the advanced carbyne-enriched nanostructured metamaterials.