REVIEW | doi:10.20944/preprints202308.1785.v1
Online: 25 August 2023 (11:50:54 CEST)
Fractures are the most common large organ trauma in humans. The initial inflammatory re-sponse promotes bone healing during the initial post-fracture phase, but chronic and persistent inflammation due to infection or other factors does not contribute to the healing process. The precise mechanisms by which immune cells and their cytokines are regulated in bone healing remain unclear. The use of mesenchymal stem cells (MSCs) for cellular therapy of bones injury is a novel clinical treatment approach. Bone progenitor MSCs not only differentiate into bone, but also interact with the immune system to promote the healing process. We review in vitro and in vivo studies on the role of the immune system and bone marrow MSCs in bone healing and their interactions. A deeper understanding of this paradigm may provide clues to potential therapeu-tic targets in the healing process, thereby improving the reliability and safety of clinical applica-tions of MSCs to promote bone healing.
ARTICLE | doi:10.20944/preprints202306.0570.v1
Subject: Engineering, Other Keywords: optical fiber data communication system; EML; PAM4; Volterra; DFE
Online: 8 June 2023 (03:00:45 CEST)
A novel simplifying Volterra structure algorithm is proposed for intensity modulation direct detection (IM-DD) optical fiber short distance communication system by using the decision feedback equalization algorithm (DFE). Based on this algorithm, the signal damage for four-level pulse amplitude modulation signal (PAM-4) is compensated, which is caused by device bandwidth limitation and dispersion during transmission. Experiments have been carried out using a 25GHz Electro-absorption Modulated Laser (EML), showing that PAM-4 signals can transmit over 10km in standard single-mode fiber (SSMF). The 112Gbps and 128Gbps signals can reach the error rate threshold of KP4-FEC (BER=2*10-4) and HD-FEC (BER=3.8*10-3), respectively. The simplified principle and process of proposed Volterra-based equalization algorithm are presented. Experimental results show that the algorithm complexity is greatly reduced by 75%, which provides an effective theoretical support for the commercial application of this algorithm.
ARTICLE | doi:10.20944/preprints201808.0070.v1
Subject: Chemistry And Materials Science, Ceramics And Composites Keywords: CFRP/steel; bond behavior; elevated temperatures; bond stress
Online: 3 August 2018 (14:31:16 CEST)
Carbon fiber reinforced polymer (CFRP) has been used widely in strengthening of steel structures. Steel/CFRP systems subjected to elevated temperatures is realistic in a summer climate event in many countries where the temperature in steel may approach 50 °C or even higher, which will lead to the degradation of the bond performance between CFRP and steel. Therefore, predicting the bond behavior of the CFRP/steel system under elevated temperature is critical. This paper investigated the mechanical performance of CFRP/steel adhesively-bonded double strap joints at elevated temperatures. Thirty CFRP-steel double strap joints were tested to failure under temperatures between 10 °C and 90 °C. It was found that the joint failure mode changed from adherend failure to debonding failure as the temperature approached Tg. In addition, the ultimate load and joint stiffness decreased significantly at temperatures near to and greater than Tg. Based on the experimental results, a model is proposed to predict the bond stress of the CFRP/steel at different temperatures.
ARTICLE | doi:10.20944/preprints201902.0248.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: 10-methoxycanthin-6-one; quaternization; antibacterial; SARs
Online: 27 February 2019 (05:08:02 CET)
Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure–activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.
ARTICLE | doi:10.20944/preprints201905.0288.v1
Subject: Social Sciences, Behavior Sciences Keywords: adolescent; current smoking; smoking behavior; tobacco message exposure
Online: 24 May 2019 (08:34:44 CEST)
This study investigated the influence and interaction of tobacco promotional and control information with adolescents’ current smoking and smoking susceptibility. 12,278 students were recruited from junior, senior and vocational high schools located in Shanghai, China. The exposure to tobacco promotional and control message of participants over the past 30 days were examined, as well as current smoking and never smokers’ initiation susceptibility. Complex sample analysis was applied. Descriptive and multivariate logistic regressions were conducted. 89.3% and 91.5% of adolescents investigated were exposed to tobacco promotional and control message respectively, which separately increased and decreased the risk of current smoking and never-smokers’ smoking susceptibility, especially among males and junior high school students. The risk changed in consistency with the exposure level（Ptrend < 0.001）. Tobacco control message seemed to mitigate the influence of tobacco promotions in the risk of both current smoking (OR = 0.64, 95%CI: 0.41–0.99) and smoking susceptibility (OR = 0.65, 95%CI: 0.46–0.93). Tobacco-related message exposure was highly prevalent and associated with youth smoking risk and smoking susceptibility. It is important to enhance the comprehensiveness and enforcement of promotion bans. Given the improvement of tobacco control message on smoking risk brought by tobacco promotions, the publicity and dissemination of tobacco control information need to be consistently strengthened.
ARTICLE | doi:10.20944/preprints202305.2072.v1
Subject: Computer Science And Mathematics, Computer Vision And Graphics Keywords: stereo SLAM; semantic segmentation; moving object detection; dynamic scenarios
Online: 30 May 2023 (07:54:13 CEST)
As we all know, many more dynamic objects appear almost continuously in real world, which are immensely able to impair the performance of the majority of vision-based SLAM systems that are based on the static-world assumption. In order to improve the robustness and accuracy of visual SLAM in the high dynamic environment, a real-time and robust stereo SLAM system for dynamic scenes was proposed. To weaken influences of dynamic content, the moving object detection method was put forward in our visual odometry, then the semantic segmentation network was combined into our stereo SLAM to extract pixel-level contours of dynamic objects. Then influences of dynamic objects were extremely weaken and the performance of our system was increased markedly in dynamic, complex and crowed city spaces. Experiment with both on KITTI Odometry dataset and in a real-life scene, the results show that our method can dramatically decrease the tracking error or drift, improve the robustness and stability of our stereo SLAM in high dynamic outdoor scenarios.
REVIEW | doi:10.20944/preprints202310.2022.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: SREBPs; NAFLD; NASH; fibrosis; hepatocellular carcinoma (HCC); lipogenesis, endoplasmic reticulum (ER) stress; therapeutic target
Online: 31 October 2023 (09:02:44 CET)
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate genes involved in the biogenesis of cholesterol, fatty acids, and triglycerides. SREBPs are involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma (HCC). We review the mechanisms by which SREBPs regulate lipogenesis, the alterations in these processes associated with liver diseases, and therapeutic strategies to target these pathways.
ARTICLE | doi:10.20944/preprints202311.0868.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: silver nanoparticles; Fructus mori; green synthesis; antibacterial properties; antioxidant activity
Online: 14 November 2023 (10:45:24 CET)
Novel antibacterial silver nanomaterials have become promising substitutes for traditional antibiotics, because pathogens do not develop resistance to them. However, it is necessary to produce silver nanoparticles with appropriate size and better performance through a green and simple synthesis process. In the present study, Fructus mori-composite silver nanoparticles (M-AgNPs) were greenly synthesized using medicinal plant mulberry fruits (Fructus mori), with silver nitrate (AgNO3) as a precursor. UV-Vis spectroscopy and X-ray diffraction (XRD) indicated the formation of silver nanoparticles with face centered cubic structure. Fourier transform infrared (FTIR) spectroscopy confirmed the reducing and capping effects of mulberry fruits' active components (polyphenols, flavonoids, etc.) on M-AgNPs. The reaction parameters including temperature, time, pH, and concentration of AgNO3 were gradually optimized. The particle size and morphology of M-AgNPs were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. The minimum particle size of M-AgNPs was about 30 nm, and they were approximately spherical and equably distributed. The excellent stability of M-AgNPs ensured that no agglomeration occurred for up to 60 days. The antioxidant activity of M-AgNPs was evaluated by 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) assay, and the DPPH radical clearance rate of M-AgNPs was up to about 79%. Greenly synthesized M-AgNPs exhibited better antibacterial activity than chemically synthesized commercial silver nanoparticles (C-AgNPs), due to the active molecules attached to their surfaces. The inhibition zone diameters of M-AgNPs against P.aeruginosa, E.coli and S.aureus were 13.9±0.4、12.2±0.3、12.8±0.7 mm, respectively. Such greenly synthesized AgNPs from medicinal plants have good prospects in the field of biomedicine.
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: GWAS; drought; rapeseed; water loss ratio
Online: 26 September 2020 (14:20:53 CEST)
Rapeseed (Brassica napus) is one of the most important oil crops in the world; however, drought significantly curtails its growth and productivity. Identifying drought-tolerant germplasm is an efficient and low-cost strategy for addressing water shortages. Using water loss ratio (WLR) as an index of drought tolerance, we screened a panel of 265 B. napus lines. We identified eight low-WLR and six high-WLR accessions, which were regarded as drought-tolerant and drought-sensitive, respectively. Further validated these selected accessions at the seedling stage under drought-stress conditions. The drought-tolerant accessions had significantly greater fresh and dry weights under drought stress than the drought sensitive accessions. Using RT-qPCR, we showed that a set of previously reported drought-adaptive marker genes were expressed at higher levels in the drought-tolerant lines than in the drought-sensitive lines. These results indicated that the drought-tolerant genotypes could be identified from natural populations using WLR. Then, we performed a genome-wide association study to identify loci harboring single nucleotide polymorphisms (SNPs). A total of 139 SNPs were significantly associated with the WLR, of which chromosome A10 harbored the largest number. Furthermore, four putative candidate genes were selected by combining the SNP–WLR association results and transcriptional expression data with the changes in drought tolerance. Thus, we have identified two drought-tolerant B. napus cultivars and uncovered genome-wide variation differentiating B. napus lines related to WLR, in addition to providing insights for further research into WLR-related drought mechanisms.
ARTICLE | doi:10.20944/preprints202311.0835.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: organic selenium; nano-selenium; drought stress; physiological response; transcriptome
Online: 13 November 2023 (15:26:42 CET)
Keywords: Organic selenium; Nano-selenium; Drought stress; Physiological response; Transcriptome
ARTICLE | doi:10.20944/preprints202110.0284.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Watershed; biogeographic patterns; microbial biogeography; biodiversity; spatial distribution; research unit
Online: 20 October 2021 (09:34:27 CEST)
Biogeography research is flawed by the poor understanding of microbial distributions due to the lack of a systematic research framework, especially regarding appropriate study units. By combining pure culture and molecular methods, we studied the biogeographic patterns of nematode-trapping fungi by collecting and analysing 2,250 specimens from 228 sites in Yunnan Province, China. We found typical watershed patterns at the species and genetic levels of nematode-trapping fungi. The results showed that microbial biogeography could be better understood by 1) using watersheds as research units, 2) removing the coverup of widespread species, and 3) applying good sampling efforts and strategies. We suggest that watersheds could help unify the understanding of the biogeographic patterns of animals, plants, and microbes and may also help account for the historical and contemporary factors driving species distributions.
ARTICLE | doi:10.20944/preprints201701.0095.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: polymeric composite; surface initiated atom transfer radical polymerization; photo-induced; living radical polymerization; metal-free atom transfer radical polymerization
Online: 22 January 2017 (04:56:44 CET)
Surface initiated atom transfer radical polymerization (SI-ATRP) is one of the most versatile technique to modify the surface properties of material. Recent developed metal free SI-ATRP makes such technique more widely applicable. Herein photo-induced metal-free SI-ATRP of methacrylates, such as methyl methacrylate, N-isopropanyl acrylamide, and N,N- dimethylaminoethyl methacrylate, on the surface of SBA-15 was reported to fabricate organic-inorganic hybrid materials. SBA-15 based polymeric composite with adjustable graft ratio was obtained. The structure evolution during the SI-ATRP modification of SBA-15 was monitored and verified by FT-IR, XPS, TGA, BET, and TEM. The obtained polymeric composite showed enhanced adsorption ability for the model compound toluene in aqueous. This procedure provides a low cost, ready availability, and facile modification way to synthesize the polymeric composites without the contamination of metal.
ARTICLE | doi:10.20944/preprints201701.0043.v1
Subject: Engineering, Control And Systems Engineering Keywords: plain river network; urban flood; flood analysis; Shanghai; Puxi Flood Protected Area
Online: 9 January 2017 (07:17:24 CET)
Considering characteristics of high river density, special underlying surface in plain river network region, and municipal drainage system function, river network drainage unit model is proposed, which is defined as a region surrounded by main river or embankment. Flood storage variety and control projects regulation of small rivers in each unit is simulated. With drainage catchment as an object, according to its drainage capacity, simplified municipal drainage model was developed. Coupling river network drainage unit model, simplified municipal drainage model and 2D flood routing model, urban flood analysis model for plain tidal river network region was developed, which could be applied to analyzing flood from upstream river, storm surge and local rainfall. Demonstration research was carried out in Puxi flood protected area in Shanghai.
ARTICLE | doi:10.20944/preprints201701.0083.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: periodontitis; PMX-53; miniature swines
Online: 19 January 2017 (01:52:00 CET)
Periodontitis is a chronic inflammatory disease which results in the destruction of the tooth’ s supporting tissues and the alveolar bone resorption. The complement becomes a major link between infection and inflammatory pathology including periodontitis. Gingipians as important virulence factors of P. gingivalis have the activity of C5 convertase, could cleave C5 into fully functional C5a to activate C5aR. The above process could be blocked by the C5aR antagonist (PMX-53) to suppress local periodontal inflammation, and then achieves the purpose of treatment of periodontitis. Nanoparticles incorporated within gelatin are promising carrier system for drug delivery in recent years. This study aimed to investigate whether gelatin nanoparticles loaded with PMX-53 prevents alveolar bone resorption in miniature swines model of periodontitis. Four miniature swines were placed ligatures around the maxillary and mandibular fourth premolar and first molar on both sides for seven weeks to induce periodontitis. Then, animals were assigned randomly to four groups: minocycline-treated group, gelatin with PMX53-treated group, gelatin-treated group and a sham control group. They were treated with 1ml related drugs respectively, into gingival sulcusl for 4 times at one-week intervals. We showed that local treatments with gelatin nanoparticles loaded with PMX-53 could inhibit alveolar bone loss of periodontitis. Our study revealed that gelatin nanoparticles loaded with PMX-53 prevented alveolar bone resorption miniature swines model of periodontitis. In addition, provided proof-of-concept for local targeting of gelatin nanoparticles loaded with PMX-53 as a powerful candidate for the treatment of periodontitis.