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1.
Two adolescent native Canadians who presented with peripheral neuropathy secondary to the abuse of volatile hydrocarbons are described. They were initially thought to have been sniffing leaded gasoline fumes, but public health investigation revealed that they had been sniffing naphtha fumes. Naphtha contains a significant amount of n-hexane, a known inducer of neuropathy. Nerve conduction studies and nerve biopsy confirmed the diagnosis of naphtha abuse. These cases emphasize the need to specifically identify the formulation of hydrocarbons being abused. 相似文献
2.
Summary A simple new technique has been developed to greatly increase the yield of protoplasts from plant organs without injury to the plant. Mechanical perturbation (MP) by non-stressful rubbing of oat leaf segments and bean internodes yielded ten to twenty times more viable protoplasts than did controls. The increase in protoplast yield due to MP is best manifested, if the organs are excised and transferred to the cellulytic enzymes immediately after MP is given to the intact organ. The enzymes begin digesting from the lower end of the bean internodes and proceed acropetally. Vacuum infiltration of control oat leaf segments for 15 min with enzyme solution resulted in increased yield but less than due to MP. Increased levels of calcium (10 mM) in the medium decreased the yield of protoplasts from both control and MP-treated plant organs. EGTA significantly increased the yield of protoplasts from control oat leaf segments and marginally over that found in the control bean internodes. Cycloheximide increased the yield of protoplasts from oat leaf segments but not from bean internodes. It is suggested that MP may increase the susceptibility of cell wall polymers to cellulytic enzymes by reducing calcium cross linking. MP is thus a tool for increasing the yield of protoplasts from plant organs without causing injury.Abbreviations CHI
cycloheximide
- EGTA
ethyleneglycol-bis-(ß-aminoethyl ether)-N,N-tetraacetic acid
- FDA
fluorescein diacetate
- MP
mechanical perturbation 相似文献
3.
Rajani R. Joshi 《Bulletin of mathematical biology》1985,47(4):551-564
This paper introduces a double-layer enzyme-membrane model representing the Na+−K+ pump in living cells. We present a mathematical solution to the problem of controlling the sodium flux in malignant cells,
where an inhibitor exists in the outer layer of the membrane. We give an algorithm for the numerical resolution of this problem
of optimal control with illustrations. Finally, we point out the biological importance of this study. 相似文献
4.
The effect of micromixing and macromixing on enzyme reaction of Michaelis-Menten type in a real continuously stirred tank reactor (CSTR) is considered. The effect of bypassing of a fraction of feed stream, dead space, initial enzyme concentration and Michaelis-Menten constant on substrate conversion is evaluated. Bypass reduces the substrate conversion significantly compared with other parameters in the case of micro and macromixing. Micromixing predicts higher substrate conversions compared with macromixing. The effect of micro and macromixing on substrate conversion is negligible at low and high conversions.List of Symbols C kmol/m3
concentration of reactant
- ¯C kmol/m3
average concentration of reactant
- CA kmol/m3
exit concentration of reactant A
- CAa kmol/m3
exit concentration of reactant A from active zone
- CAO kmol/m3
initial concentration of reactant A
- CEO kmol/m3
initial enzyme concentration
- CO kmol/m3
initial concentration of reactant
- E(t) 1/s
exit age distribution function
- k 1/s
reaction rate constant
- M kmol/m3
Michaelis-Menten constant
- r kmol/(m3s)
rate of reaction
- –rA kmol/(m3s)
rate of reaction with respect to A
- t s
time
- v m3/s
volumetric feed rate
- va m3/s
volumetric feed rate entering the active zone
- vb m3/s
volumetric feed rate entering the bypass stream
- V m3
total volume of the vessel
- Va m3
active volume of the vessel
- Vd m3
volume of dead space
- XA
conversion of A
Greek Letters
fraction of feed stream bypassing the vessel (vb/v)
-
fraction of the total volume as dead space (Vd/V)
-
(t) 1/s
Dirac delta function, an ideal pulse occurring at time t = 0
-
s
life expectancy of a molecule
- 1/s
intensity function or escape probability function
-
s
space time or mean residence time 相似文献
5.
6.
R. K. Saini K. R. Saad G. A. Ravishankar P. Giridhar N. P. Shetty 《Plant Systematics and Evolution》2013,299(7):1205-1213
Moringa oleifera is a less used, drought-tolerant tropical plant, rich in nutritionally and nutraceutically important bioactive compounds. It is native to India and now under cultivation in many countries, but no data is available on genetic variability. Three DNA marker techniques, i.e., random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR) and cytochrome P450 gene-based markers were used for the detection of genetic variability in eight Indian cultivars of M. oleifera, collected from various states of India. A total of 17 RAPD, 6 ISSR and 7 pairs of cytochrome P450-based markers generated 48.68, 48.57 and 40.00 % polymorphisms, respectively. The marker index (MI) for each of these marker systems (3.25 for RAPD, 4.73 ISSR and 2.95 for Cyt P450-based markers) suggest that ISSR markers are the most effective for assessment of genetic diversity. Based on the three types of marker data, the eight cultivars of M. oleifera were grouped into four sub-clusters in a dendrogram, but without any distinct geographical pattern. This suggests spread of planting material and high rates of gene flow through cross pollination. High bootstrap values (94.4 and 82.3) were obtained at major nodes of the dendrogram using the winboot software. The dendrogram and PCA plots generated from the binary data matrices of the three marker systems were found highly concordant to each other. This study reveals a huge genetic diversity among the cultivars and this can be utilised for conservation and cultivar development in breeding programmes to produce high yielding, nutritionally superior cultivars. 相似文献
7.
Background and aim
PSCA is a tissue specific tumor suppressor or oncogene which has been found to be associated with several human tumors including gallbladder cancer. It is considered to be involved in the cell-proliferation inhibition and/or cell-death induction activity. Therefore, we aimed to investigate the role of PSCA gene polymorphisms in gallbladder cancer risk in North Indian population.Methodology
A total of 405 gallbladder cancer patients and 247 healthy controls were included in the case–control study for risk prediction. We examined the association of two functional SNPs, rs2294008 and rs2978974 in PSCA gene by genotyping using Taqman allelic discrimination assays. Statistical analysis was done using SPSS software, version 17. Linkage disequilibrium and haplotype analysis was done with the help of SNPstats software. FDR test was used to correct for multiple comparisons.Results
No significant associations of rs2294008 and rs2978974 genetic variants of the PSCA gene were found with GBC risk at allele, genotype or haplotype levels. Stratifying the subjects on the basis of gallstone also did not show any significant result. However, on gender stratification, we found a significant association of Trs2294008-Grs2978974 haplotype with higher risk of GBC in females (FDR Pcorr = 0.021, OR = 1.6). In contrary, Trs2294008-A rs2978974 haplotype conferred significant lower risk in males (FDR Pcorr = 0.013; OR = 0.25).Conclusions
These findings suggest that PSCA genetic variants may have a significant effect on GBC susceptibility in a gender specific manner. 相似文献8.
9.
10.
Riyaj S. Tamboli Rajani Giridhar Hardik P. Gandhi Ashish M. Kanhed Hemant M. Mande 《Journal of enzyme inhibition and medicinal chemistry》2016,31(5):704-713
The aim of this research work was to investigate a series of novel 5,6-diaryl-1,2,4-triazines (3a–3q) containing 3-morpholinoethylamine side chain, and to address their antiplatelet activity by in vitro, ex vivo and in vivo methods. All compounds were synthesized by environment benign route and their structures were unambiguously confirmed by spectral data. Compounds (3l) and (3m) were confirmed by their single crystal X-ray structures. Out of all the synthesized compounds, 10 were found to be more potent in vitro than aspirin; six of them were found to be prominent in ex vivo assays and one compound (3d) was found to have the most promising antithrombotic profile in vivo. Moreover, compound (3d) demonstrated less ulcerogenicity in rats as compared to aspirin. The selectivity of the most promising compound (3d) for COX-1 and COX-2 enzymes was determined with the help of molecular docking studies and the results were correlated with the biological activity. 相似文献