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排序方式: 共有1352条查询结果,搜索用时 15 毫秒
1.
Kumar Mahesh Reddy G. Janardhana Bég O. Anwar 《Journal of Thermal Analysis and Calorimetry》2019,138(1):531-543
Journal of Thermal Analysis and Calorimetry - This article studies the pattern of heat lines in free convection non-Newtonian flow from a semi-infinite vertical cylinder via Bejan’s heat... 相似文献
2.
Zaki Nadia G. Mahmoud Walaa H. El Kerdawy Ahmed M. Abdallah Abanoub Mosaad Mohamed Gehad G. 《Research on Chemical Intermediates》2020,46(6):3193-3216
Research on Chemical Intermediates - Reaction of cocaine (Cn) with Ln(III) chloride salts [where Ln?=?La(III), Er(III), and Yb(III)] afforded complexes of the [Ln(Cn)Cl(OH2)3].2Cl type... 相似文献
3.
Nadia Sharif Faiza Saleem Farheen Aslam Shagufta Naz 《Natural product research》2015,29(20):1938-1941
Microalgae have been proposed as a promising source for biodiesel production. Focusing on algal strains for biodiesel production, efforts should be made to search new strains. Experiments were carried out to investigate the effects of growth parameters (nutrients, pH, light, aeration and temperature) and the oil percentage of eight algal strains (Chlorella sp., Cladophora sp., Hydrodictylium sp., Oedogonium sp., Oscillatoria sp., Spirogyra sp., Stigeocolonium sp., Ulothrix sp.). Results show that 6.5–7.5 is the optimum pH for the growth of all algal species. Temperature showed a greater variation (25°40°C). Ulothrix sp. gave more biomass productivity and is the most suitable strain for biodiesel production due to higher oil percentage (62%). Least biomass production was observed for Stigeocolonium sp. and least oil content was obtained from Hydrodictylium sp. It was observed that among these eight algal strains for biodiesel production, Ulothrix and Chlorella are the most promising algae species. 相似文献
4.
Nafissa Dehimeche Bruno Buatois Nadia Bertin Michael Staudt 《Molecules (Basel, Switzerland)》2021,26(1)
The in-vivo monitoring of volatile organic compound (VOC) emissions is a potential non-invasive tool in plant protection, especially in greenhouse cultivation. We studied VOC production from above and belowground organs of the eight parents of the Multi-Parent Advanced Generation Intercross population (MAGIC) tomato population, which exhibits a high genetic variability, in order to obtain more insight into the variability of constitutive VOC emissions from tomato plants under stress-free conditions. Foliage emissions were composed of terpenes, the majority of which were also stored in the leaves. Foliage emissions were very low, partly light-dependent, and differed significantly among genotypes, both in quantity and quality. Soil with roots emitted VOCs at similar, though more variable, rates than foliage. Soil emissions were characterized by terpenes, oxygenated alkanes, and alkenes and phenolic compounds, only a few of which were found in root extracts at low concentrations. Correlation analyses revealed that several VOCs emitted from foliage or soil are jointly regulated and that above and belowground sources are partially interconnected. With respect to VOC monitoring in tomato crops, our results underline that genetic variability, light-dependent de-novo synthesis, and belowground sources are factors to be considered for successful use in crop monitoring. 相似文献
5.
Dr. Jan Nekvinda Michael Kugler Dr. Josef Holub Dr. Suzan El Anwar Dr. Jiří Brynda Klára Pospíšilová Dr. Zdeňka Růžičková Dr. Pavlína Řezáčová Dr. Bohumír Grüner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16541-16553
Carbonic anhydrase IX (CA IX), a tumor-associated metalloenzyme, represents a validated target for cancer therapy and diagnostics. Herein, we report the inhibition properties of isomeric families of sulfonamidopropyl-dicarba-closo-dodecaboranes group(s) prepared using a new direct five-step synthesis from the corresponding parent cages. The protocol offers a reliable solution for synthesis of singly and doubly substituted dicarba-closo-dodecaboranes with a different geometric position of carbon atoms. The closo-compounds from the ortho- and meta-series were then degraded to corresponding 11-vertex dicarba-nido-undecaborate(1−) anions. All compounds show in vitro enzymatic activity against CA IX in the low nanomolar or subnanomolar range. This is accompanied by clear isomer dependence of the inhibition constant (Ki) and selectivity towards CA IX. Decreasing trends in Ki and selectivity index (SI) values are observed with increasing separation of the cage carbon atoms. Interactions of compounds with the active sites of CA IX were explored with X-ray crystallography, and eight high-resolution crystal structures uncovered the structural basis of inhibition potency and selectivity. 相似文献
6.
A novel Schiff base namely (E)-3-((2,6-dihydroxypyrimidin-4-ylimino)methyl)-4H-chromen-4-one and its Co (II), N (II)i, Cu (II) and Cd (II) complexes have been synthesized and proved by elemental analysis, molar conductance, thermal analysis (TGA), Inductive Coupled plasma (ICP), magnetic moment measurements, X-ray powder diffraction, IR, EI-mass,1H NMR, 13C NMR,UV–Vis. and ESR spectral studies. On the basis of these data, it is evident that the Schiff base acts as bidentate via oxygen atom of carbonyl group and azomethine nitrogen atom for Co (II) complex; monobasic bidentate ligand for Ni (II), Cu (II) and Cd (II) complexes via oxygen atom of hydroxyl group and nitrogen atom of pyrimidine ring. The results showed all complexes have octahedral geometry. The average particle size of the ligand and its complexes were found to be 1.010–0.343 nm. The pharmacological action (antioxidant, antimicrobial and anticancer) of the prepared compounds is studied. The antitumor activity of the ligand and its metal complexes is evaluated against human liver carcinoma (HEPG2) cell. The data displayed the Co (II) complexes strong cytotoxicity where IC50 values of Co (II) complex and 5-fluorouracil (stander drug) are 9.33 and 7.86 μg/ml respectively. The Co (II) and Cd (II) complexes have antibacterial activity more than ampicillin (stander drug). The interaction of the synthesized compounds with calf-thymus DNA (CT-DNA) has been performed via absorption spectra and viscosity technique. The DNA- binding constants have been determined. 相似文献
7.
Anwar Jacintomoreno Dr. Hemant K. Sharma Dr. Alejandro Metta-Magaña Prof. Dr. Keith H. Pannell 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11302-11307
The reactions of the Mannich reagent Et3SiOCH2NMe2 ( 1 ) with a variety of anilines (mono-substituted RC6H4NH2, R=H, 4-CN, 4-NO2, 4-Ph, 4-Me, 4-MeO, 4-Me2N; di-substituted R2C6H3NH2, R2=3,5-(CH3)2, 3,5-(CF3)2; tri-substituted R3C6H2NH2, R3=3,5-Me2-4-Br and a “super bulky” aniline (Ar*NH2) [Ar*=2,6-bis(diphenylmethyl)-4-tert-butylphenyl]) led to the formation of a range of products dependent upon the substituent. With electron-withdrawing substituents, previously unknown diamines, RC6H4NH(CH2NMe2) [R=CN ( 2 a ), NO2 ( 2 b )] and R2C6H3NH(CH2NMe2) [R2=3,5-(CF3)2 ( 2 c) ] were formed. Further reaction of 2 a , b , c with 1 yielded the corresponding triamines RC6H4N(CH2NMe2)2 (R=CN ( 3 a ), NO2 ( 3 b ) and R2C6H3N(CH2NMe2)2, R2=3,5-(CF3)2 ( 3 c ). The new polyamines were characterized by NMR spectroscopy, and for 2 a , 2 c , and 3 c , by single crystal XRD. In the case of electron-donating groups, R=4-OMe, 4-NMe2, 4-Me, 3,5-Me2, 3,5-Me2-4-Br, and for R=4-Ph, the reactions with 1 immediately led to the formation of the related 1,3,5-triazines, R=4-MeO ( 5 a ), 4-Me2N ( 5 b ), 4-Me ( 5 c ), 3,5-Me2 ( 5 d ), 3,5-Me2-4-Br ( 5 e ), 4-Ph ( 5 f ), 4-Cl ( 5 g ). The “super bulky” aniline rapidly produced a single product, namely the corresponding imine Ar*N=CH2 ( 4 ) which was also characterized by single crystal XRD. Imine 4 is both thermally and oxidatively stable. All reactions are very fast, thus based upon the presence of Si we are tempted to denote the reactions of 1 as examples of “Silick” chemistry. 相似文献
8.
Nehal F. Farid Ibrahim A. Naguib Nessreen S. Abdelhamid Basma H. Anwar Maimana A. Magdy 《Journal of separation science》2020,43(12):2330-2337
A novel ecofriendly, cost and time saving high‐performance thin‐layer chromatographic method was developed and validated for simultaneous determination of metoclopramide, ergotamine, caffeine, and paracetamol in bulk and pharmaceutical formulation. The separation was carried out on silica gel plates, using ethyl acetate:ethanol:ammonia (9:1:0.1, v/v/v) as a developing system. Ultraviolet detection was carried out at 272 nm. The resulting retention times were 0.15, 0.36, 0.49, and 0.74 min for metoclopramide, ergotamine, caffeine, and paracetamol, respectively. The greenness profile assessment was achieved to the proposed method to evaluate its greenness characters to the environment with acceptable results. Validation parameters were checked according to International Conference of Harmonization guidelines to achieve the international requirements for quality control analysis of the proposed drugs. 相似文献
9.
Ibrahim Musa Guy Raffin Marie Hangouet Marie Martin Albert Alcacer Nadia Zine Francesca Bellagambi Nicole Jaffrezic-Renault Abdelhamid Errachid 《Electroanalysis》2022,34(8):1338-1347
Thin-film composite of chitosan/nickel phthalocyanine (NiPc) was electrochemically deposited on the fingers of interdigitated gold electrodes, applying chronoamperometric polymerization technique. The presence of crystallized NiPc in the chitosan was confirmed by EDX and FTIR analysis. Acetone, ethanol, and methanol gas-sensing properties of the films prepared at optimum conditions were studied at atmospheric temperature, through differential measurements at an optimized frequency of 10 kHz, using a lock-in amplifier. The conductometric sensor presents the highest sensitivity of 60.2 μS.cm−1(v/v) for methanol and 700 ppm as the limit of detection. For validation, the methanol content of a commercial rubbing alcohol was determined. 相似文献
10.
van Vuuren Nadia Janse van Rensburg Helena D. Janse Terre’Blanche Gisella Legoabe Lesetja J. 《Molecular diversity》2022,26(4):2211-2220
Molecular Diversity - In a pilot study, eleven pyrrolopyridine and pyrrolopyrimidine derivatives (specifically, 7-azaindole and 7-deazapurine derivatives) were synthesised by Suzuki cross-coupling... 相似文献