全文获取类型
收费全文 | 3382篇 |
免费 | 250篇 |
出版年
2023年 | 23篇 |
2022年 | 38篇 |
2021年 | 54篇 |
2020年 | 35篇 |
2019年 | 70篇 |
2018年 | 127篇 |
2017年 | 96篇 |
2016年 | 170篇 |
2015年 | 245篇 |
2014年 | 192篇 |
2013年 | 340篇 |
2012年 | 250篇 |
2011年 | 212篇 |
2010年 | 185篇 |
2009年 | 183篇 |
2008年 | 122篇 |
2007年 | 101篇 |
2006年 | 97篇 |
2005年 | 100篇 |
2004年 | 74篇 |
2003年 | 64篇 |
2002年 | 65篇 |
2001年 | 65篇 |
2000年 | 67篇 |
1999年 | 59篇 |
1998年 | 25篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 25篇 |
1993年 | 11篇 |
1992年 | 49篇 |
1991年 | 37篇 |
1990年 | 32篇 |
1989年 | 30篇 |
1988年 | 25篇 |
1987年 | 31篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 15篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1975年 | 11篇 |
1974年 | 13篇 |
1973年 | 16篇 |
1972年 | 20篇 |
1970年 | 16篇 |
1968年 | 11篇 |
1965年 | 20篇 |
排序方式: 共有3632条查询结果,搜索用时 15 毫秒
1.
Iteng Ng-Choi ngel Oliveras Lidia Feliu Marta Planas 《International journal of peptide research and therapeutics》2020,26(2):695-707
The feasibility of the solid-phase intramolecular 4(5)-arylation of a histidine residue to obtain biaryl cyclic peptides bearing a His-Phe linkage was esta 相似文献
2.
3.
4.
5.
Mercedes González-Wangüemert Francisca Giménez-Casalduero Ángel Pérez-Ruzafa 《Biochemical Systematics and Ecology》2006
Genetic variation at 10 enzyme loci was analysed in Elysia timida sacoglossan mollusc samples, originating from both coastal lagoon and marine sites. The observed heterozygosity ranged from 0.390 (Los Urrutias) to 0.277 (Tabarca). Marine and coastal lagoon populations were characterised by exclusive alleles. 相似文献
6.
I Monta?és A Badía M A Réngel J M López-Novoa 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1992,199(3):321-326
Renal metabolism has been studied in eight dogs before and 48 hr after a 60-min period of renal ischemia induced by clamping the left renal artery with the simultaneous removal of the right kidney, and in 12 sham-operated animals. The study involved the measurement of renal uptake and production of lactate, glutamine, glutamate, alanine, ammonium, and oxygen, and the measurement of the tissue concentrations of ATP, glutamine, lactate, alpha-ketoglutarate, aspartate, and alanine in the renal cortex. Two days after a temporary renal ischemia, the remaining kidney showed a 22% decrease in glomerular filtration rate (GFR) and a 25% decrease in renal plasma flow. Fractional sodium and potassium excretions were similar to those of control dogs. Renal production or extraction of glutamine, glutamate, alanine, ammonium, and oxygen (all expressed by 100 ml of GFR) was not significantly different in basal conditions or 2 days after ischemia, but lactate extraction was reduced in postischemic kidneys (-101 +/- 29 vs -204 +/- 38 mumol/100 ml GFR in control dogs). The cortical concentrations of glutamine and glutamate were lower in postischemic than in control kidneys. No differences were found in cortical concentration of alpha-ketoglutarate, aspartate, lactate, pyruvate, or ATP, but total nucleotides and inorganic phosphate were decreased in postischemic kidneys. It is concluded that in the recovery phase of the ischemia, a decreased lactate uptake is the main metabolic change, and total ATP production is adapted to the decrease of GFR and sodium reabsorption. 相似文献
7.
Background
With increasing computer power, simulating the dynamics of complex systems in chemistry and biology is becoming increasingly routine. The modelling of individual reactions in (bio)chemical systems involves a large number of random events that can be simulated by the stochastic simulation algorithm (SSA). The key quantity is the step size, or waiting time, τ, whose value inversely depends on the size of the propensities of the different channel reactions and which needs to be re-evaluated after every firing event. Such a discrete event simulation may be extremely expensive, in particular for stiff systems where τ can be very short due to the fast kinetics of some of the channel reactions. Several alternative methods have been put forward to increase the integration step size. The so-called τ-leap approach takes a larger step size by allowing all the reactions to fire, from a Poisson or Binomial distribution, within that step. Although the expected value for the different species in the reactive system is maintained with respect to more precise methods, the variance at steady state can suffer from large errors as τ grows. 相似文献8.
The cell cycle modulated glycoprotein GP115 is one of the major yeast proteins containing glycosylphosphatidylinositol 总被引:11,自引:0,他引:11
The cell cycle modulated protein gp115 (115 kDa, isoelectric point about 4.8-5) of Saccharomyces cerevisiae undergoes various post-translational modifications. It is N-glycosylated during its maturation along the secretory pathway where an intermediary precursor of 100 kDa (p100), dynamically related to the mature gp115 protein, is detected at the level of endoplasmic reticulum. Moreover, we have shown by the use of metabolic labeling with [35S]methionine, [3H]palmitic acid and myo-[3H]inositol combined with high resolution two-dimensional gel electrophoresis and immunoprecipitation with a specific antiserum, that gp115 is one of the major palmitate- and inositol-containing proteins in yeast. These results, and the susceptibility of gp115 to phosphatidylinositol-specific phospholipase C treatment strongly indicate that gp115 contains the glycosylphosphatidylinositol (GPI) structure as membrane anchor domain. The two-dimensional analysis of the palmitate- and inositol-labeled proteins has also allowed the characterization of other polypeptides which possibly contain a GPI structure. 相似文献
9.
10.