ARTICLE | doi:10.20944/preprints201608.0189.v1
Subject: Chemistry, Physical Chemistry Keywords: amine-modified MCM-41; CO2 adsorption; inorganic alkali; alkali amounts
Online: 22 August 2016 (05:47:02 CEST)
Three kinds of inorganic alkali are introduced into tetraethylenepentamine (TPEA) and polyethyleneimine (PEI) modified MCM-41 as the CO2 adsorbents. FT-IR and TGA are used to characterize the surface groups and the thermal stability of adsorbents. Chemical titration method is used to measure the alkali amounts of adsorbents. Thermo-gravimetric analysis with 10%CO2/N2 as the simulated flue gas is used to test the CO2 adsorption performance of adsorbents. The results show that all three kinds of inorganic alkali containing adsorbents exhibit promoted CO2 adsorption capability than traditional TPEA and PEI modified samples. Ca(OH)2 and PEI modified samples exhibit the highest adsorption capacity and stable regeneration property. The introduction of inorganic alkali changes the chemical adsorption mechanism between CO2 and increases the effective alkali amounts due to its hydroxyl groups. The CO2 adsorption capacities have a linear dependence relation with the alkali amounts of adsorbents, indicating that alkali amount is a critical factor for novel adsorbents exploring.
ARTICLE | doi:10.20944/preprints202202.0082.v1
Online: 7 February 2022 (11:57:16 CET)
Trace amine-associated receptor 5 (TAAR5) is a G protein-coupled receptor that belongs to the TAARs family (TAAR1-TAAR9). TAAR5 is expressed in the olfactory epithelium and is responsible for sensing 3-methylamine (TMA). However, recent studies showed that TAAR5 is also expressed in the limbic brain regions and is involved in the regulation of emotional behaviour and adult neurogenesis, suggesting that TAAR5 antagonism may represent a novel therapeutic strategy for anxiety and depression. We used the AtomNet® model, the first deep learning neural network for structure-based drug discovery, to identify putative TAAR5 ligands and tested them in an in vitro BRET assay. We found two mTAAR5 antagonists with low to submicromolar activity that are able to inhibit the cAMP production induced by TMA. Moreover, these two compounds also inhibited the mTAAR5 downstream signalling, such as the phosphorylation of CREB and ERK. These two hits exhibit drug-like properties and could be used to develop further more potent TAAR5 ligands with putative anxiolytic and antidepressant activity.
Subject: Chemistry, Analytical Chemistry Keywords: innovative grape varieties; organic wine; biogenic amine; polyphenol
Online: 13 November 2020 (13:58:14 CET)
Society considers wine as a special product among food and beverages because of its high gastronomical value and its positively distinctive quality. In recent years, philosophies of the agricultural techniques and development of the oenological technology have been focused on the reduction of wasteful, "polluting" elements, and trends are moving towards an environmental friendly approach. Due to the stricter regulations and rules (with the limited amount and selection of the permitted chemicals) resistant, also known as interspecific or innovative grape varieties can be the ideal basic materials of alternative cultivation technologies. In terms of variety selection, innovative varieties can be equivalent to international varieties, although organically their quality could not compete with them. These grapes are more resistant to various fungal diseases and infections than international varieties. Well-founded analytical and organoleptic results have to provide the scientific background of resistant varieties, as these cultivars with the environmental friendly cultivation techniques, could be the raw material of the future.
ARTICLE | doi:10.20944/preprints202007.0043.v1
Subject: Engineering, Control & Systems Engineering Keywords: aerosol; amine emission; CO2 capture; absorber; particle number concentration
Online: 5 July 2020 (04:41:13 CEST)
In this study, a monoethanolamine aerosol growth model was developed to investigate the aerosol growth factor. Interactions among the internal conditions in an absorber were considered in this aerosol model. Additionally, an experiment was conducted to measure aerosol particle size, for collecting in-house validation data. Sucrose was used as the aerosol nuclei instead of sulfuric acid to prevent the corrosion of equipment used in the experiment. Experimental results showed that the outlet aerosol sizes increased to the same size regardless of the sucrose concentrations. The aerosol growth model was validated using the in-house experimental data. The aerosol growth model efficiently predicted the aerosol size. For investigating aerosol growth effects, particle number concentration was determined to be the primary factor affecting aerosol growth and amine emissions. When the particle number concentration increased, the aerosol size decreased, whereas the MEA emission increased.
ARTICLE | doi:10.20944/preprints202201.0385.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: Trace amine-associated receptor 5; cognition; decision-making; switch task
Online: 25 January 2022 (14:49:51 CET)
Trace amine-associated receptors (TAARs) are a family of G protein-coupled receptors present in mammals in the brain and in several peripheral organs. Apart from its olfactory role, TAAR5 is expressed in the major limbic brain areas and regulates brain serotonin functions and emotional behaviors. However, most of its functions remain undiscovered. Given the role of serotonin and limbic regions in some aspects of cognition, we used a temporal decision-making task to unveil a possible role of TAAR5 in cognitive processes. We found that TAAR5 knock-out (KO) mice showed a generally better performance due to a reduced number of errors and displayed a greater rate of improvement at the task than WT littermates. However, task-related parameters, such as time accuracy and uncertainty have not changed significantly. Overall, we show that TAAR5 modulates specific domains of cognition, highlighting a new role in brain physiology.
Subject: Chemistry, Analytical Chemistry Keywords: CO2 capture; adsorption; amine-based adsorbents; mesoporous carbon; triethylenetetramine; ethylenediamine
Online: 3 March 2021 (14:16:48 CET)
Carbon sequestration via carbon capture and storage (CCS) method is one of the most useful methods to lower the CO2 emission in the atmosphere. Ethylenediamine (EDA) and triethylenetetramine (TETA) modified mesoporous carbon (MC) has been successfully prepared as CO2 storage materials. The effect of various concentrations of EDA or TETA added to MC as well as activated carbon (AC) on their CO2 adsorption capacity were investigated using high purity CO2 as feed and titration method to quantitatively measure the amount of adsorbed CO2. The results showed that within 60 min adsorption time, MCEDA49 gave the highest CO2 capacity adsorption (19.68 mmol/g), followed by MC-TETA30 (11.241 mol/g). The improvement of CO2 adsorption capacity at low TETA loadings proved that the four amine functional groups in TETA gave advantages to CO2 adsorption. TETA functionalized MC has a potential to be used as CO2 storage materials as it is used at low concentration. Therefore, it is more benign and friendly to the environment.
ARTICLE | doi:10.20944/preprints202301.0154.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Amine functionalized MWCNTs; Reactive yellow 2; Adsorption; Rapid removal; Ionic strength; Reusability
Online: 9 January 2023 (09:02:49 CET)
This research intended to report amine-functionalized multiwall carbon nanotubes (MWCNTs) prepared by a simple method for efficient and rapid removal of Reactive Yellow 2 (RY2) from water. EDS analysis showed that the N content increased from 0 to 2.42% and from 2.42 to 8.66% after modification by APTES and PEI, respectively. BET analysis displayed that the specific surface area, average pore size, and total pore volume were reduced from 405.22 to 176.16 m2/g, 39.67 to 6.30 nm, and 4.02 to 0.28 cm3/g, respectively. These results proved that the PEI/APTES-MWCNTs were successfully prepared. pH edge experiment indicated that pH 2 was optimal for RY2 removal. At pH 2 and 25 °C, the time required for adsorption equilibrium was 10, 15, and 180 min at initial concentrations of 50, 100, and 200 mg/L, respectively; and the maximum RY2 uptake calculated by the Langmuir model was 714.29 mg/g. Thermodynamic studies revealed that the adsorption process was spontaneous and endothermic. 0-0.1 mol/L of NaCl showed negligible effect on RY2 removal by PEI/APTES-MWCNTs. Five adsorption/desorption cycles confirmed the good reusability of PEI/APTES-MWCNTs in RY2 removal. Overall, the PEI/APTES-MWCNTs are a potential and efficient adsorbent for reactive dye wastewater treatment.
ARTICLE | doi:10.20944/preprints201702.0087.v1
Subject: Biology, Other Keywords: α-C(sp3)–H functionalization; oxidative cyclization; tertiary amine; 6-exo-trig; metal free
Online: 23 February 2017 (10:40:53 CET)
The mechanistic pathway of TEMPO/I2-mediated oxidative cyclization of N,N-diaryl amino alcohols 1 is investigated in this study. Based on our direct empirical experiments, three key intermediates (the aminium radical cation 3, the α-aminoalkyl radical 4, and the iminium 5), four kind reactive species (radical TEMPO, cationic TEMPO, TEMPO-I and iodo radical) and three kind pathways (1. SET/PCET mechanism, 2. HAT/1,6-H transfer mechanism, 3. Ionic mechanism) were assumed. Under the assumption, nine free energy diagrams are acquired through DFT calculation. From the comparison of the solution phase free energy, some possibility can be excluded and then the chosen plausible mechanisms are concretized with the more stable intermediate 7.
ARTICLE | doi:10.20944/preprints202106.0502.v1
Subject: Chemistry, Analytical Chemistry Keywords: polymerization kinetics; conversion efficacy; free radical and cationic radical; benzophenone–triphenylamine amine; photoredox catalyst; 3D bioprinting
Online: 21 June 2021 (10:37:40 CEST)
This article presents, for the first time, the kinetics and the general conversion features of a 3-component system, BT(BC)/iodonium/Amine, based on proposed mechanism of Liu et al, for both free radical polymerization (FRP) of acrylates and the free radical promoted cationic polymerization (CP) of epoxides using the new multi-functional initiator of benzophenone–triphenylamine (BT). The additives, iodonium and EDB, have the dual function of (i) regeneration BT and (ii) produce of extra radicals for improved FRP and CP. Analytic formulas are developed to explore the new features including: (i) the conversion efficacy (CE) of FRP is an increasing function of the light intensity, the effective absorption coefficient, and the concentration sum of each of the components, BT, Iod, amine, for transient state. However, CE at steady-state is independent to the light intensity; (ii) the trifunctional hybrid structures of BT3 leads to larger light absorption than other types of BT; it also provides more active sites for the H-abstraction in the presence of EDB, leading to high CE; (iii) the efficacy of FRP is an increasing function of the amine (EDB) concentration, in contrast to that of CP having an opposite dependence; (iv) the consumption rate of BT3 in the BT3/ Iod/EDB system is slower than that of the BT3/Iod system due to photoredox catalytic cycle, and the larger initiator regeneration (RGE) in the three-component system. A comprehensive model is also proposed that the CE (for both FRP and CP) is governed by (NjKjbI), whereas more complex formulas are developed; where Kj is an effective rate constant proportional to the electron transfer quantum yield, and the combined effects of other coupling rate constants; b is an effective absorption coefficient given by the light absorption and excited state quantum yield.
ARTICLE | doi:10.20944/preprints201710.0126.v1
Subject: Chemistry, Organic Chemistry Keywords: (2-fluoro-phenyl)ethanone; phenyl trimethyl ammonium tribromide; 3-bromopyridine-2-amine; zinc dust; ammonium chloride
Online: 18 October 2017 (04:34:12 CEST)
We report here the synthesis and characterization of new N-(3-(8-bromoimidazo[1, 2-a]pyridin-2-yl)-4-fluorophenyl)benzamide derivatives. This collection was obtained from 3-(8-bromoimidazo [1,2-a]pyridin-2-yl)-4-fluoroaniline(5). The family of new compounds was characterized by 1H-NMR, 13C-NMR, FT-IR and LC-MS analysis.
SHORT NOTE | doi:10.20944/preprints202103.0604.v1
Subject: Chemistry, Analytical Chemistry Keywords: H-bonds (-bonding): hydrogen bonds (-bonding); q: quinoline; 3-/2D: three-/two dimensional & VdW: Van der Waal & bqma: bis(2-quinolinylmethyl)amine
Online: 24 March 2021 (16:40:02 CET)
The compound, C27H23N3 (1), crystallizes in the triclinic system of the P-1 space group. The unit cell comprises a dimer of 1, in which the monomers are linked by two complementary hydrogen bonds between N1 and H1-C1 of another molecule. The dimers form chains along the a-axis through intermolecular interactions between the N2 acceptor atoms and C17 donors from molecules in the nearest neighbouring dimer. These interactions form extended sheets of the dimers of 1, along the ab plane. The quinolinylmeth-2-yl groups of 1 lie in almost orthogonal planes and their N1/2(q) donor atoms being away from the apical amino N3 atom.