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1دورية أكاديمية
المؤلفون: Yuxin ZHU, Wenbin WANG, Jiajing WANG, Yunlan ZHU, Yifei ZHANG, Xue XU, Yongqi DAI
المصدر: Shipin gongye ke-ji, Vol 45, Iss 8, Pp 21-28 (2024)
مصطلحات موضوعية: auricularia auricula, different solvent, extract, organic germanium, antioxidant activity, polysaccharide, polyphenol, flavone, Food processing and manufacture, TP368-456
الوصف: In order to explore the antioxidant ability of different solvent extracts of Ge-riched Auricularia auricular mycelium in vitro, the Ge-riched A. auricular mycelium was extracted by water, 70% ethanol and ethyl acetate. The scavenging ability of different extracts on superoxide anion free radical, hydroxyl free radical and DPPH free radical were compared. The comprehensive antioxidant capacity of different solvent extracts was evaluated by subordinate function value, and the correlation between substance content and antioxidant capacity were analyzed. The results showed that the content of organic Ge in Ge-riched A. auricular mycelium was 542.83 μg/g. The extraction rate and substance content of different solvent extracts were different, the extraction rate of water extract and ethanol extract was higher, the polysaccharide content of water extract was the highest, and the polyphenol and flavonoid content of ethyl acetate extract was the highest. Different solvent extracts had certain scavenging ability on free radicals，and the extract concentration increased with the increase. Water extract had the strongest scavenging rate of superoxide anion free radical，when the extract concentration was 9 mg/mL, the highest clearance rate was 43.32%. 70% ethanol extract had the best scavenging effect on hydroxyl free radical and DPPH free radical. When the extract concentration was 9 mg/mL, the scavenging rate was 70.10% and 76.99%, respectively. Polysaccharides, polyphenols and flavonoids all played different roles in scavenging free radicals, and ethanol extract had the strongest comprehensive antioxidant capacity. The contents of polysaccharides, polyphenols and flavonoids were significant (P
وصف الملف: electronic resource
العلاقة: https://doaj.org/toc/1002-0306Test
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2دورية أكاديمية
المؤلفون: Anand Kumar Sahu, U. Chandrasekhar Reddy, Muraleedharan Kannoth Manheri, Ashok Kumar Mishra
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Biotechnology, Evolutionary Biology, Ecology, Environmental Sciences not elsewhere classified, Mathematical Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, two hydroxy groups, hydroxy groups present, hydrogen bonding interactions, different solvent environments, lipid head groups, study two variants, present study focuses, effective synthetic alternative, archaeal lipid membranes, 74 ± 1, 68 ± 1, size ), fluidity, phase transition temperature, based lipids differing, lipid membranes based, based lipid membranes, 3oh lipid membranes, resolved fluorescence properties, dph fluorescent probes
الوصف: The present study focuses on exploring the physical properties of lipid membranes based on the polyhydroxy oxanorbornane (PH-ONB) headgroup, designed as synthetic analogues of naturally occurring archaeal lipid membranes. Specifically, we study two variants of PH-ONB headgroup-based lipids differing in the number of hydroxy groups present in the headgroup, with one having two hydroxy groups (ONB-2OH) and the other having three (ONB-3OH). These lipids form stable bilayer membranes. The study begins with a comprehensive analysis of the fluorescence characteristics of nitrobenzoxadiazole (NBD)-tagged ONB-based lipids in different solvent environments and within a model lipid membrane 1,2-dimyristoyl- sn -glycero-3-phosphocholine (DMPC). Subsequently, the physical properties of the ONB-based membranes were examined by using an NBD-tagged ONB-based probe and a commonly used extrinsic 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescent probe. The steady-state and time-resolved fluorescence properties of the NBD-tagged ONB-based probe and DPH were used to compare the physical properties of the ONB-based membranes, including polarity, fluidity, phase transition, order, hydration, location, heterogeneity, and rotational diffusion. The solid gel to liquid crystalline phase transition temperatures of ONB-2OH and ONB-3OH lipid membranes are found to be (68 ± 1) °C and (74 ± 1) °C, respectively. The variation in organization (size), fluidity, and phase transition temperature of ONB-based lipid membranes is explained by the extent of hydrogen bonding interactions between lipid head groups. ONB-based membranes exhibit characteristics similar to those of phospholipid membranes and possess a notably high phase transition temperature. These properties make them a promising and cost-effective synthetic alternative to archaeal lipid membranes with a wide range of potential applications.
الإتاحة: https://doi.org/10.1021/acs.langmuir.3c02941.s001Test
https://figshare.com/articles/journal_contribution/Exploring_the_Physical_Properties_of_Lipid_Membranes_with_Polyhydroxy_Oxanorbornane_Head_Group_Using_NBD-Conjugated_and_DPH_Fluorescent_Probes/25328680Test -
3دورية أكاديمية
المؤلفون: Haomin Wu, YingYing Jiang, Chen Shen, Yuanhui Ji
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Pharmacology, Biotechnology, Hematology, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, polymer aqueous solution, polyethylene glycol 6000, average relative deviations, mixed solutions measuring, binary mixtures within, drug formulation development, different solvent systems, mixed solvents, hplc within, drug development, different compositions, binary solvents, various stages, uv spectrophotometry, ternary system, prediction accuracy, polyvinylpyrrolidone k30, phase behavior, organic solvents, molecular weight, gravimetrical method, experimental values
الوصف: Measuring and modeling the solubility of drugs in different solvent systems is helpful to guide the selection of appropriate solvents at various stages of drug formulation development. In this work, the gravimetrical method was used to determine the solubility data of oxaprozin (OXA) in different compositions of water/organic solvents (methanol and ethanol) binary mixtures within the range of 293.15 to 333.15 K. Subsequently, the differential scanning calorimetry method was used to measure the solubility of the drug in polymers (Polyethylene Glycol 6000 and Polyvinylpyrrolidone K30) at above 400 K. Then, the solubility of OXA in ultrapure water and polymer aqueous solution was acquired by UV spectrophotometry or HPLC within a temperature range of 303.15 to 323.15 K. Finally, the experimental values were compared with the calculated values from the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) to investigate the prediction accuracy of this model in different complex mixed solvent systems. The average relative deviations (ARD) were used to evaluate the model performance of PC-SAFT. Furthermore, PC-SAFT combined with solid–liquid equilibrium theory not only modeled the phase behavior between pure or mixed solvents and drugs independent of the molecular weight of the solvent but also did not require any experimental data or model parameters from the ternary system to predict the phase behavior of OXA in binary solvents. The results of this work illustrate that PC-SAFT is a beneficial model in drug development.
الإتاحة: https://doi.org/10.1021/acs.jced.3c00564.s007Test
https://figshare.com/articles/journal_contribution/Measurement_and_Thermodynamic_Modeling_of_Oxaprozin_Solubility_in_Polymers_and_Mixed_Solutions/25342506Test -
4دورية أكاديمية
المؤلفون: Vipin Kumar, Sarah Ahmad Siraj, Dillip K. Satapathy
مصطلحات موضوعية: Biophysics, Physiology, Biotechnology, Ecology, Immunology, Cancer, Science Policy, Plant Biology, Space Science, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, weight upon exposure, smart lifting systems, showcased various proof, lift 10 times, fascinating behavior opens, established upon subjecting, bidirectional electric switches, different solvent vapors, responsive controlled actuation, 1400 actuation cycles, applications significantly broaden, based actuator sustains, based actuator, toxic vapors, based actuators, actuation performance, vast potential, soft robotics
الوصف: Multivapor-responsive biocompatible soft actuators have immense potential for applications in soft robotics and medical technology. We report fast, fully reversible, and multivapor-responsive controlled actuation of a pure cassava-starch-based film. Notably, this starch-based actuator sustains its actuated state for over 60 min with a continuous supply of water vapor. The durability of the film and repeatability of the actuation performance have been established upon subjecting the film to more than 1400 actuation cycles in the presence of water vapor. The starch-based actuators exhibit intriguing antagonistic actuation characteristics when exposed to different solvent vapors. In particular, they bend upward in response to water vapor and downward when exposed to ethanol vapor. This fascinating behavior opens up new possibilities for controlling the magnitude and direction of actuation by manipulating the ratio of water to ethanol in the binary solution. Additionally, the control of the bending axis of the starch-based actuator, when exposed to water vapor, is achieved by imprinting-orientated patterns on the surface of the starch film. The effect of microstructure, postsynthesis annealing, and pH of the starch solution on the actuation performance of the starch film is studied in detail. Our starch-based actuator can lift 10 times its own weight upon exposure to ethanol vapor. It can generate force ∼4.2 mN upon exposure to water vapor. To illustrate the vast potential of our cassava-starch-based actuators, we have showcased various proof-of-concept applications, ranging from biomimicry to crawling robots, locomotion near perspiring human skin, bidirectional electric switches, ventilation in the presence of toxic vapors, and smart lifting systems. These applications significantly broaden the practical uses of these starch-based actuators in the field of soft robotics.
الإتاحة: https://doi.org/10.1021/acsami.3c15065.s001Test
https://figshare.com/articles/journal_contribution/Multivapor-Responsive_Controlled_Actuation_of_Starch-Based_Soft_Actuators/25000026Test -
5دورية أكاديمية
المؤلفون: Leon A. Smook, Sissi de Beer
مصطلحات موضوعية: Biophysics, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, uncharged monomers display, distributed inhomogeneously along, different solvent qualities, electrical chain rearrangement, inhomogeneous charge along, critical field required, random copolymer brushes, induced structure changes, gradient polyelectrolyte brushes, copolymer brushes, random copolymers, polyelectrolyte brushes, charge gradient, bimodal chain, pure polyelectrolyte, brushes show, total charge, systematically study, switching behavior, surface charge, stretched conditions, pure polyelectrolytes, polymer backbone, phase transition, local composition, latter could, key role
الوصف: Under the influence of electric fields, the chains in polyelectrolyte brushes can stretch and collapse, which changes the structure of the brush. Copolymer brushes with charged and uncharged monomers display a similar behavior. For pure polyelectrolyte and random copolymer brushes, the field-induced structure changes only the density of the brush and not its local composition, while the latter could be affected if charges are distributed inhomogeneously along the polymer backbone. Therefore, we systematically study the switching behavior of gradient polyelectrolyte brushes in electric fields for different solvent qualities, grafting densities, and charges per chain via coarse-grained molecular dynamics simulations. Similar to random copolymers and pure polyelectrolytes, these brushes show a mixed-phase transition: intermediate states between fully stretched and collapsed are characterized by a bimodal chain-end distribution. Additionally, we find that the total charge of the brush plays a key role in the critical field required for a complete transition. Finally, we find that gradient polyelectrolyte brushes are charge-enriched at the brush–solvent interface under stretched conditions and charge-depleted under collapsed conditions, allowing for control over the local composition and thus the surface charge of the brush due to the inhomogeneous charge along the grafted chains.
الإتاحة: https://doi.org/10.1021/acs.langmuir.3c03127.s001Test
https://figshare.com/articles/journal_contribution/Electrical_Chain_Rearrangement_What_Happens_When_Polymers_in_Brushes_Have_a_Charge_Gradient_/25222856Test -
6دورية أكاديمية
المؤلفون: Jim H. C. Lee, Sendhil K. Poornachary, Xin Yi Tee, Liangfeng Guo, Connie K. Liu, Liling Zhang, Tiedong Sun, Qiubo Chen, Jianwei Zheng, Pui Shan Chow
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Biotechnology, Ecology, Sociology, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, ray scattering measurements, different solvent systems, polymer solutions measured, simulation results show, base oil polarity, vm counteracted temperature, sq solution increased, polymer coil expansion, combining solution viscosity, dispersing oil, polymer solution, temperature due, polar solvent, nonpolar solvent, increasing temperature, solution viscosity, polymer conformation, polymer association, wide range, vm decreased
الوصف: Viscosity improvement property of a lubricant additive is commonly attributed to polymer coil expansion with increasing temperature, although only some polymer chemistries show conformance to this conceptual mechanism. Herein, we show that the polarity of base oil governs whether this mechanism underlies the action of a viscosity modifier (VM) by combining experimental and computational studies. Poly(butyl methacrylate) (PBMA) dissolved in diethylene glycol diethyl ether (DGDE) or a mixture of DGDE (polar solvent) and squalane (SQ, nonpolar solvent) was used as a model lubricant oil system. Specific viscosity of the polymer solutions measured over a wide range of additive concentrations and temperatures revealed that thickening efficiency of the VM decreased with decreasing base oil polarity. While the VM counteracted temperature-induced thinning of the low polarity base oil, in the polar solvent, the polymer did not enhance the solution viscosity at higher temperatures. Aiming to unravel the molecular mechanism underlying viscosity improvement at elevated temperatures in the different solvent systems, the polymer conformation and size in the dispersing oil were determined by combining solution viscosity, small-angle X-ray scattering measurements, and coarse-grained molecular dynamics simulations. Collectively, the experimental and simulation results show that the coil-swelling model underpins viscosity improvement of the polymer solution in DGDE, and the viscosity of PBMA in DGDE/SQ solution increased with temperature due to polymer association in solution. However, the thermoresponsive behavior of the polymer is more pronounced in the mixed solvent system due to their higher propensity to aggregate at elevated temperatures.
الإتاحة: https://doi.org/10.1021/acs.iecr.3c02712.s001Test
https://figshare.com/articles/journal_contribution/Effect_of_Base_Oil_Polarity_on_the_Functional_Mechanism_of_a_Viscosity_Modifier_Unraveling_the_Conundrum_of_Coil_Expansion_Model/24647082Test -
7دورية أكاديمية
المؤلفون: Angelica Petrongari, Vanessa Piacentini, Adriano Pierini, Paola Fattibene, Cinzia De Angelis, Enrico Bodo, Sergio Brutti
مصطلحات موضوعية: Biochemistry, Molecular Biology, Evolutionary Biology, Infectious Diseases, Space Science, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, lithium iodide rm, highly promising next, low polarity solvent, different solvent environments, oxygen evolution reaction, requires large overpotentials, based electrolytes leads, aprotic li –, 2 , 1 , lii redox mediation, based electrolytes, redox mediation, polar solvent, singlet oxygen, redox mediators, strong interplay, results show, practical implementation, parasitic reactions, dimethyl sulfoxide, cycle life, challenges lies
الوصف: Lithium–oxygen aprotic batteries (aLOBs) are highly promising next-generation secondary batteries due to their high theoretical energy density. However, the practical implementation of these batteries is hindered by parasitic reactions that negatively impact their reversibility and cycle life. One of the challenges lies in the oxidation of Li 2 O 2 , which requires large overpotentials if not catalyzed. To address this issue, redox mediators (RMs) have been proposed to reduce the oxygen evolution reaction (OER) overpotentials. In this study, we focus on a lithium iodide RM and investigate its role on the degradation chemistry and the release of singlet oxygen in aLOBs, in different solvent environments. Specifically, we compare the impact of a polar solvent, dimethyl sulfoxide (DMSO), and a low polarity solvent, tetraglyme (G4). We demonstrate a strong interplay between solvation, degradation, and redox mediation in OER by LiI in aLOBs. The results show that LiI in DMSO-based electrolytes leads to extensive degradation and to 1 O 2 release, affecting the cell performance, while in G4-based electrolytes, the release of 1 O 2 appears to be suppressed, resulting in better cyclability.
الإتاحة: https://doi.org/10.1021/acsami.3c12330.s001Test
https://figshare.com/articles/journal_contribution/Insights_into_the_LiI_Redox_Mediation_in_Aprotic_Li_O_sub_2_sub_Batteries_Solvation_Effects_and_Singlet_Oxygen_Evolution/24800490Test -
8دورية أكاديمية
المؤلفون: Hao Lu (354247), Jiayi Chen (3358625), Wenjun Zhou (310993), Lifen Peng (1581322), Shuang-Feng Yin (1478986), Nobuaki Kambe (1621282), Renhua Qiu (1478992)
مصطلحات موضوعية: Biochemistry, Microbiology, Genetics, Molecular Biology, Pharmacology, Cancer, Plant Biology, Chemical Sciences not elsewhere classified, simple solvent modification, different solvent ratios, acyl allylic methylsulfones, promoted cascade cyclization, aryl methyl ketones, methyl ketones, promoted reactions, selectively introduced, method enables, excellent chemoselectivity, dimethyl sulfoxide, coupling reactions, convenient synthesis, c –, bonds via
الوصف: In this paper, a convenient synthesis of 2,5-diacylthiophenes and β-acyl allylic methylsulfones from aryl methyl ketones with dimethyl sulfoxide (DMSO) through Selectfluor-promoted cascade cyclization and cross-coupling reactions by simple solvent modification is described. This method enables the formation of new C–C and C–S bonds via the selection of different solvent ratios, in which DMSO molecules as synthons can be selectively introduced into methyl ketones. The features of this transformation include readily available starting materials, excellent chemoselectivity, and good functional group tolerance.
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9دورية أكاديمية
المؤلفون: Chao Zhang, Jing Yu, Qiang Tu, Fu Yan, Zhao Hu, Youming Zhang, Chun Song
المصدر: Antioxidants; Volume 11; Issue 8; Pages: 1542
مصطلحات موضوعية: Celery ( Apium graveolens L.) seed, different solvent fractions, main flavone glycosides, antioxidant capacities, α-amylase inhibitory activities, α-glucosidase inhibitory activities, molecular docking
جغرافية الموضوع: agris
الوصف: To extend the application of celery (Apium graveolens L.) seeds, the antioxidant and enzymatic inhibitory activities of different fractions and their main flavones were investigated. The n-butanol fractions possessed the highest total phenolic content (TPC) and total flavonoid content (TFC) values. The n-butanol fractions from Northeast China samples exhibited the strongest free radical scavenging (DPPH IC50 = 20.27 μg/mL, ABTS IC50 = 15.11 μg/mL) and ferric reducing antioxidant power (FRAP 547.93 mg trolox (TE)/g) capacity, while those collected from Hubei China showed the optimal cupric reducing antioxidant capacity (CUPRAC) values (465.78 mg TE/g). In addition, the dichloromethane fractions from Jiangsu samples displayed a maximum Fe2+ chelating capacity (20.81 mg ethylene diamine tetraacetic acid (EDTA)/g). Enzyme level experiments indicated polyphenolic compounds might be the main hypoglycemic active components. Subsequently, the enzyme inhibitory activity of nine main flavones was evaluated. Chrysoeriol-7-O-glucoside showed better α-glucosidase inhibitory activity than others. However, apigenin showed the best inhibitory effect on α-amylases, while the presence of glycosides would reduce its inhibitory effect. This study is the first scientific report on the enzymatic inhibitory activity, molecular docking, and antioxidant capacity of celery seed constituents, providing a basis for treating or preventing oxidative stress-related diseases and hyperglycemia.
وصف الملف: application/pdf
العلاقة: Natural and Synthetic Antioxidants; https://dx.doi.org/10.3390/antiox11081542Test
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10دورية أكاديمية
المؤلفون: Nicholas A. Jose (11553519), Jithin John Varghese (6095030), Samir H. Mushrif (1559155), Hua Chun Zeng (1441510), Alexei A. Lapkin (484904)
مصطلحات موضوعية: Biophysics, Biochemistry, Medicine, Microbiology, Ecology, Space Science, Environmental Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, tunable chemical composition, different mof surfaces, functionally diverse surfaces, different solvent environments, diverse range, via <, unique opportunity, synthesized using, situ <, oriented attachment, membrane separation, likely responsible, high anisotropy, great potential, generation materials, electrochemical catalysis, controllable synthesis, building blocks, binding energy, applications , aggregation dynamics, 2d mofs
الوصف: Due to their high anisotropy and tunable chemical composition, two-dimensional metal organic frameworks (2D MOFs) have great potential as building blocks for next-generation materials in a diverse range of applicationsfrom electrochemical catalysis to membrane separation. However, the controllable synthesis is complicated by the environment–surface interactions that arise from the high anisotropy, thinness, and functionally diverse surfaces of 2D MOFs. Liquid cell transmission electron microscopy (LCTEM) offers a unique opportunity to study these interactions in situ . In this work, we analyzed the effects of different solvent environments on the structure and aggregation dynamics of copper benzene dicarboxylic acid (CuBDC) nanosheets, which were synthesized using a high shear annular microreactor. LCTEM revealed that 2D MOF nanosheets undergo oriented attachment and that the rate and direction of oriented attachment is controlled by solvent–surface interactions. We investigated the nature of these solvent interactions using density functional theory calculations, which suggest that the binding energy of solvents to different MOF surfaces is likely responsible for this behavior. The CuBDC nanosheets were then applied as adsorbents in organic solvents, in which we showed how solvent-mediated oriented attachment could significantly affect adsorption properties.
