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61.
Eugenia Dzib José Luis Cabellos Filiberto Ortíz-Chi Sudip Pan Annia Galano Gabriel Merino 《International journal of quantum chemistry》2019,119(2):e25686
Eyringpy is a modular program for calculating thermochemical properties and rate constants for reactions in the gas phase and in solution. The code is written in Python and it has a user-friendly interface and a simple input format. Unimolecular and bimolecular reactions with one and two products are supported. Thermochemical properties are estimated through canonical ensemble and rate constants are computed according to the transition state theory. One-dimensional Wigner and Eckart tunneling corrections are also available. Rate constants of bimolecular reactions involving the formation of pre-reactive complexes are also estimated. To compute rate constants in solution, Eyringpy uses the Collins–Kimball theory to include the diffusion-limit, the Marcus theory for electron transfer processes, and the molar fractions to account for the solvent pH effect. 相似文献
62.
Elizabeth Galati Huachen Tao Moritz Tebbe Rija Ansari Michael Rubinstein Ekaterina B. Zhulina Eugenia Kumacheva 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(10):3155-3159
Chiral packing of ligands on the surface of nanoparticles (NPs) is of fundamental and practical importance, as it determines how NPs interact with each other and with the molecular world. Herein, for gold nanorods (NRs) capped with end‐grafted nonchiral polymer ligands, we show a new mechanism of chiral surface patterning. Under poor solvency conditions, a smooth polymer layer segregates into helicoidally organized surface‐pinned micelles (patches). The helicoidal morphology is dictated by the polymer grafting density and the ratio of the polymer ligand length to nanorod radius. Outside this specific parameter space, a range of polymer surface structures was observed, including random, shish‐kebab, and hybrid patches, as well as a smooth polymer layer. We characterize polymer surface morphology by theoretical and experimental state diagrams. The helicoidally organized polymer patches on the NR surface can be used as a template for the helicoidal organization of other NPs, masked synthesis on the NR surface, as well as the exploration of new NP self‐assembly modes. 相似文献
63.
de León ME Pérez-García B Márquez-Guzmán J Mendoza-Ruiz A 《Micron (Oxford, England : 1993)》2008,39(8):1351-1362
The morphogenesis of the sexual phase of seven species of Thelypteris subg. Cyclosorus (Thelypteridaceae) is described and compared. Spores of all species are monolete, ellipsoid and have positive photoblastism. They have Vittaria-type germination, germinal filaments are short and uniseriate, and Aspidium-type development. Adult gametophytes are spatulate-cordiform, and have wide wings with numerous glandular, marginal and superficial hairs. Antheridia have a narrow or widened basal cell, an undivided annular cell, and an opercular cell; antherozoids are liberated through three mechanisms. Archegonia have short necks and four triangular cells on the neck's mouth. The sporophyte's first leaf is lobed, with open dichotomous veins, glandular hairs similar to those of the gametophyte, and anomocytic stomata. Differences observed between the studied species are: spore size; ornamentation of the perispore; germination and emergence periods; size of hairs; developmental period of gametangia; and antherozoid liberation mechanisms through total detachment of the operculum, partial detachment of the operculum, and development of an apical pore through tearing of the operculum. These taxonomically valuable characters, combined with the sporophyte characteristics, can be useful tools in the identification of the species studied to the subg. Cyclosorus. 相似文献
64.
This paper focuses on MOOCs (massive open online courses), a fairly recent paradigm in e-learning educational projects. Despite the high dropout rate, and 相似文献
65.
Alessio Alesci Andrea Salvo Eugenia Rita Lauriano Teresa Gervasi Deborah Palombieri Maurizio Bruno 《Natural product research》2015,29(12):1122-1126
The effect of astaxanthin (3,3′-dihydroxy-s-carotene-4,4′-dione) on alcohol-induced morphological changes in Carassius auratus, as an experimental model, was determined. The yeast Phaffia rhodozyma was used as a source of astaxanthin. The animals were divided into three groups for 30 days: one group was treated with ethanol at a dose of 1.5% mixed in water, the second one with EtOH 1.5% and food enriched with astaxanthin from P. rhodozyma, and the third was a control group. After a sufficient experimental period, the samples were processed using light microscopy and evaluated by histomorphological and histochemical staining, and the data were supported by immunohistochemical analysis, using a wide range of antibodies, such as calbindin, vimentin and alpha-smooth muscle actin. The results show that the alcoholic damage in the kidney led to hypoxia. In contrast, the group fed with astaxanthin from P. rhodozyma showed a normal morphological picture, with better glomeruli organisation and the presence of the area of filtration. Furthermore, the immunohistochemistry has confirmed these results. 相似文献
66.
Xing Liang Veronika Kozlovskaya Christopher P. Cox Yun Wang Mohammad Saeed Eugenia Kharlampieva 《Journal of polymer science. Part A, Polymer chemistry》2014,52(19):2725-2737
We report on novel diblock copolymers of poly(N‐vinylcaprolactam) (PVCL) and poly(N‐vinyl‐2‐pyrrolidone) (PVPON) (PVCL‐b‐PVPON) with well‐defined block lengths synthesized by the MADIX/reversible addition‐fragmentation chain transfer (RAFT) process. We show that the lower critical solution temperatures (LCST) of the block copolymers are controllable over the length of PVCL and PVPON segments. All of the diblock copolymers dissolve molecularly in aqueous solutions when the temperature is below the LCST and form spherical micellar or vesicular morphologies when temperature is raised above the LCST. The size of the self‐assembled structures is controlled by the molar ratio of PVCL and PVPON segments. The synthesized homopolymers and diblock copolymers are demonstrated to be nontoxic at 0.1–1 mg mL?1 concentrations when incubated with HeLa and HEK293 cancer cells for various incubation times and have potential as nanovehicles for drug delivery. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2725–2737 相似文献
67.
68.
Janey JM Orella CJ Njolito E Baxter JM Rosen JD Palucki M Sidler RR Li W Kowal JJ Davies IW 《The Journal of organic chemistry》2008,73(8):3212-3217
An expedient, five step synthesis of caprolactam 1 is reported starting from natural L-homoserine. The key step is a chemoselective reductive cyclization of alpha,beta-unsaturated nitrile 10 mediated by Raney-Co type metals. This hydrogenation is extensively investigated in order to account for the observed product distribution and yields. 相似文献
69.
Olga L. Mezentseva Galina B. Slepchenko Elena V. Dorozhko Eugenia S. Moiseeva Vladimir P. Kryukovskiy Nikolay K. Zaycev 《Electroanalysis》2023,35(4):e202200252
A highly sensitive electrochemical sensor based on arenediazonium tosylates was designed to detect meldonium in urine. The effect of the concentration of ArN2+OTs− arenediazonium tosylate modifier and various substituents was studied. Basic operating parameters for voltammetric meldonium detection were established and the procedure for urine sample preparation was developed. The following values were obtained: limit of detection (LOD) 0.005 mg ⋅ L−1 (P=0.95) and limit of quantification (LOQ) 0.01 mg ⋅ L−1. The relationship between the analytical signal and meldonium concentration in the solution ranging from 0.01 to 400 mg ⋅ L−1 was described by a linear function. The meldonium concentration error did not exceed 18 %. The analysis time for a single urine sample was reduced to 15 minutes. 相似文献
70.
Patricia H. Risso Domingo Mariano Borraccetti César Araujo María Eugenia Hidalgo Carlos A. Gatti 《Colloid and polymer science》2008,286(12):1369-1378
κ-Casein (κ-CN) aggregation by heating has been studied at pH 7.2 and 5.2 using UV-visible spectrophotometry, sodium dodecyl
sulfate polyacrylamide gel electrophoresis, spectrofluorometric study of the 1–8 aniline naphtalene sulfonate (ANS)–κ-CN binding
and circular dichroism (CD) spectroscopy. The aggregation process to form aggregates like micelles or submicelles and the
structural characteristics of these aggregates were pH dependent. Far-UV CD showed that the aggregates obtained by heating
presented changes in the κ-CN secondary structure. Near-UV CD spectra showed a certain degree of tertiary organization in
the Tyr environment for the protein heated or unheated, only at pH 5.2. ANS binding at both pH was quite different and depends
on the self-association process. Heating produced exposition of hydrophobic binding sites only at pH 7.2, including those
in the neighborhood of the κ-CN Trp residue. 相似文献