全文获取类型
收费全文 | 126篇 |
免费 | 2篇 |
专业分类
化学 | 94篇 |
力学 | 1篇 |
数学 | 15篇 |
物理学 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 15篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 6篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 9篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 10篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有128条查询结果,搜索用时 62 毫秒
71.
Hahn H Huck CW Rainer M Najam-ul-Haq M Bakry R Abberger T Jennings P Pfaller W Bonn GK 《Analytical and bioanalytical chemistry》2007,388(8):1763-1769
A simple and highly effective reversed-phase (RP) high-performance liquid chromatography (HPLC) method is described for analysing
glutathione (GSH) and glutathione disulfide (GSSG) in out-flowing supernatants and lysates of perfusion cell cultures of human
kidney cells (HK-2 cells) continuously exposed to cadmium chloride (CdCl2), which is a well-known nephrotoxin. The developed linear liquid chromatographic gradient employs monolithic poly(styrene-co-divinylbenzene) (PS/DVB) as a stationary phase and is adaptable for coupling to mass spectrometry via an electrospray ionisation
interface (LC-ESI/MS), which is carried out in case of co-eluting peaks. This study presents a quantitative assay of glutathione
over the time of experiment and cell lysates at the end of the experiment. The assay of out-flowing supernatants has the potential
to be applied as an online assay in high time resolution. Glutathione (reduced and oxidised, GSH and GSSG) is chosen as an
indicator for toxic effects in the cultured cells. In principle it is possible to show the concentration of glutathione as
a function of time in an investigation of exposure of the HK-2 cell line to CdCl2. In addition to glutathione analysis, well-established assays of cell death such as enzyme release and cell viability are
performed to obtain information about the number of living cells. Toxicity of 5 μM CdCl2 is manifested in all of the assays applied. Fast (<7 min) and highly reproducible (max. aberration 4.7%) determination of
glutathione could be achieved. 相似文献
72.
A CE method employing capacitively coupled contactless conductivity (C(4)D) compared to indirect UV-detection was developed for the analysis of phytochemically relevant flavonoids, such as 6-hydroxyflavone, biochanin A, hesperetin and naringenin. To ensure fast separation at highest selectivity, sensitivity and peak symmetry, the pH value and the concentration of the running BGE had to be optimized regarding both co- and counter-EOF mode. Optimum conditions were found to be 1.0 and 5.0 mM chromate BGE (pH 9.50) in the counter- and co-EOF mode, respectively. Validation of the established CE-C(4)D method pointed out to be approximately seven times more sensitive compared to indirect UV-detection applying the same conditions. The lower LOD defined at an S/N of 3:1 was found between 0.12 and 0.21 microg/mL for the analytes of interest using C(4)D and between 0.77 and 1.20 microg/mL using indirect UV-detection. Compared to an earlier published CE method employing direct UV-detection, C(4)D was found to be approximately two times more sensitive. Due to the lower baseline noise, C(4)D showed an excellent regression coefficient >0.99 compared to 0.93 when using indirect UV detection calibrating within a concentration range between 1 and 10 microg/mL. The influence of the sugar moiety on the conductivity of a flavonoid was studied upon the analysis of the aglycon hesperetin and the rutinosid hesperidin. The sugar moiety in hesperedin shows a higher conductivity compared to hesperetin. Finally, the optimized established CE-C(4)D method was applied to the determination and quantification of naringenin in Sinupret. 相似文献
73.
Mohamed F. Abdelhameed Gihan F. Asaad Tamer I. M. Ragab Rania F. Ahmed Abd El-Nasser G. El Gendy Sahar S. Abd El-Rahman Abdelbaset M. Elgamal Abdelsamed I. Elshamy 《Molecules (Basel, Switzerland)》2021,26(19)
Different parts of Araucaria bidiwillii (bunya pin) trees, such as nuts, seeds, bark, and shoots, are widely used in cooking, tea, and traditional medicines around the world. The shoots essential oil (EO) has not yet been studied. Herein, the chemical profile of A. bidiwillii shoots EO (ABSEO) was created by GC–MS analysis. Additionally, the in vivo oral and topical anti-inflammatory effect against carrageenan-induced models, as well as antipyretic potentiality of ABSEO and its nanoemulsion were evaluated. Forty-three terpenoid components were identified and categorized as mono- (42.94%), sesqui- (31.66%), and diterpenes (23.74%). The main compounds of the ABSEO were beyerene (20.81%), α-pinene (16.21%), D-limonene (14.22%), germacrene D (6.69%), β-humulene (4.14%), and sabinene (4.12%). The ABSEO and its nanoemulsion exhibited significant inflammation suppression in carrageenan-induced rat paw edema model, in both oral (50 and 100 mg/kg) and topical (5% in soyabean oil) routes, compared to the control and reference drugs groups. All the results demonstrated the significant inflammation reduction via the inflammatory cytokines (IL-1β and IL8), nitrosative (NO), and prostaglandin E2 (PGE2) supported by the histopathological studies and immunohistochemical assessment of MMP-9 and NF-κβ levels in paw tissues. Moreover, the oral administration of ABSEO and its nanoemulsion (50 and 100 mg/kg) exhibited antipyretic activity in rats, demonstrated by the inhibition of hyperthermia induced by intramuscular injection of brewer’s yeast. These findings advised that the use of ABSEO and its nanoemulsion against numerous inflammatory and hyperthermia ailments that could be attributed to its active constituents. 相似文献
74.
Journal of Fluorescence - The MB and MR removal process by two mechanisms of adsorption using rice straw (absence of UV light) and photodegradation on TiO2 surfaces was investigated. MB and MR... 相似文献
75.
Rania Ben Hmida Nourzed Frikha Soumaya Bouguerra Neji Geoffrey Kit Francisco Medina Mohamed Bouaziz 《国际化学动力学杂志》2020,52(2):124-133
An effective procedure was developed to produce high-value added phenolic compounds through the conversion of 2-phenylethanol (2-PhEt) by using acid-activated clays KSF for the hydrogen peroxide. Owing to KSF's ability to catalyze a variety of complex oxidations, it was likely to convert 2-PhEt to hydroxytyrosol (HTY) and tyrosol (TY) derivatives. The analyses of catalytic solution revealed that the optimum conditions, giving a higher concentration of oxidation products such as HTY, were as follows: 2-PhEt concentration 10−2 mol/L, the hydrogen peroxide concentration 5.05 × 10−2 and 0.6 g L–1 of KSF clays . The yield during the conversion reaction into HTY was around 25%. All compounds in the reaction mixture were identified by mass spectrophotometry using a LC-MS apparatus. HTY, TY, meta-tyrosol and ortho-tyrosol were the major compounds. The antioxidant activity was realized by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. In fact, it is revealed that the strongest inhibition percentage (PI = 96) was detected with the increase in the concentration of HTY. The approach proposed in the present work presents an environment friendly method. 相似文献
76.
Gamil A.A. Al-Hazmi Khlood S. Abou-Melha Nashwa M. El-Metwaly Ismail Althagafi Fathy Shaaban Rania Zaky 《应用有机金属化学》2020,34(3):e5403
Green synthesis of Fe (III), Cu (II), Zn (II) and Ni (II)-Schiff's-base complexes from 2-oxo-N-(pyridine-2-yl)-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)acetamide(H2L)ligand. All new complexes were characterized via several spectroscopic and analytical techniques, to establish their molecular and structural formulae. All complexes appeared have 1:1 molar ratio (M:L). The ligand contributed as a neutral poly-dentate towards the metal ions. Moreover, material-studio program was used to predict the most fitted atomic-skeletons for investigated compounds by applying DFT method. MOE docking module (vs. 2015) was used to examine the degree of inhibition for new compounds versus three infected-cell proteins (1bqb, 2gt1 and 4esw). Also, antimicrobial and colorimetric assess for compounds that bind DNA were performed 相似文献
77.
Journal of Fluorescence - The present study is set out to determine the photocatalytic degradation potential of ZnO nanoparticles for effective degradation of Eosin dye. The heterogeneous... 相似文献
78.
Shattat G Al-Qirim R Al-Hiari Y Sheikha GA Al-Qirim T El-Huneidi W Shahwan M 《Molecules (Basel, Switzerland)》2010,15(9):5840-5849
The lipid-lowering activity of a series of novel N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives has been studied in Triton WR-1339-induced hyperlipidemia in rats. The test animals were divided into four groups: control, hyperlipidemic, compound + 4% DMSO [C1: N-(2-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (1), C2: N-(3-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (2), C3: N-(4-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (3)]-treated and bezafibrate (BF)-treated. At a dose of 15 mg/Kg body weight, compounds 2, 3 and BF significantly reduced elevated plasma triglycerodes levels after 12 h. Moreover, high density lipoprotein-cholesterol levels were significantly increased in all treated groups after 12 h compared to the hyperlipidemic control group, except for C1 which was inactive. In sum, it may be stated that the results of the present study demonstrated new properties of some N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives as potent lipid lowering agents and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role. 相似文献
79.
Mostafa Y. El‐Bakry 《国际流体数值方法杂志》2011,67(10):1283-1290
The radial basis function neural network (RBFNN) simulation has been designed to simulate and predict the mean velocity of capillary flow in transition from laminar to turbulent flow and the root‐mean‐square vorticity as a function of wall‐normal position at different values of Reynolds number. The system was trained on the available data of the two cases. Therefore, we designed the system to work in automatic way for finding the best network that has the ability to have the best test and prediction. The proposed system shows an excellent agreement with that of an experimental data in these cases. The technique has been also designed to simulate the other distributions not presented in the training set and predicted them with effective matching. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
80.
We establish, by simple semigroup arguments, a Lévy-Gromov isoperimetric inequality for the invariant measure of an infinite dimensional diffusion generator of positive curvature with isoperimetric model the Gaussian measure. This produces in particular a new proof of the Gaussian, isoperimetric inequality. This isoperimetric inequality strengthens the classical logarithmic Sobolev inequality in this context. A local version for the heat kernel measures is also proved, which may then be extended into an isoperimetric inequality for the Wiener measure on the paths of a Riemannian manifold with bounded Ricci curvature.Oblatum 19-VI-1995 相似文献