全文获取类型
收费全文 | 11023篇 |
免费 | 601篇 |
国内免费 | 8篇 |
专业分类
11632篇 |
出版年
2023年 | 54篇 |
2022年 | 72篇 |
2021年 | 149篇 |
2020年 | 129篇 |
2019年 | 162篇 |
2018年 | 368篇 |
2017年 | 316篇 |
2016年 | 429篇 |
2015年 | 429篇 |
2014年 | 549篇 |
2013年 | 772篇 |
2012年 | 685篇 |
2011年 | 848篇 |
2010年 | 483篇 |
2009年 | 373篇 |
2008年 | 587篇 |
2007年 | 606篇 |
2006年 | 664篇 |
2005年 | 558篇 |
2004年 | 487篇 |
2003年 | 528篇 |
2002年 | 432篇 |
2001年 | 272篇 |
2000年 | 251篇 |
1999年 | 178篇 |
1998年 | 92篇 |
1997年 | 52篇 |
1996年 | 40篇 |
1995年 | 41篇 |
1994年 | 44篇 |
1993年 | 38篇 |
1992年 | 53篇 |
1991年 | 50篇 |
1990年 | 42篇 |
1989年 | 36篇 |
1988年 | 28篇 |
1987年 | 40篇 |
1986年 | 28篇 |
1985年 | 42篇 |
1984年 | 41篇 |
1983年 | 35篇 |
1982年 | 25篇 |
1979年 | 34篇 |
1978年 | 26篇 |
1977年 | 28篇 |
1975年 | 24篇 |
1974年 | 28篇 |
1973年 | 23篇 |
1972年 | 28篇 |
1952年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
R.P. Herd L. Ko S.E. Weisbrode D.D. Heath 《International journal for parasitology》1984,14(2):141-149
Herd R. P., Ko L., Weisbrode S. E. and Heath D. D. 1984. Sequential morphologic changes in adult Echinococcus granulosus during complement-mediated lysis in vitro. International Journal for Parasltology14:141–149. Sequential changes (5,10, 20, 30,40, 50 min, 1, 2, 3, 4, 5, 6, 7, 8, h) were observed by light, scanning and transmission electron microscopy after 38-day-old adult Echinococcus granulosus were exposed to 50% guinea pig serum in vitro. Early changes within 3 h included contraction of worms, fusion of microtriehes, vacuolization and vesiculization of the distal cytoplasm, followed by rupture of vesicles leading to erosion and loss of the distal cytoplasm. This was most marked in the terminal proglottid but ultimately there was complete erosion of the distal cytoplasm of all proglottids and the scolex. After 3 h there was loss of definition of organelles, apparent edema of the perinuclear cytoplasm and, in some instances, rupture of the circular muscle layer with extrusion of parenchyma. Adult tape-worms exposed to heat-inactivated complement showed none of these changes. Lysis and death of the parasite was attributed to osmotic changes subsequent to the formation of trans-membrane channels induced by complement-mediated attack of the tegument after activation of the alternate pathway by factors present in the cestode tegument. 相似文献
72.
This review focuses on utilization of plant lectins as medical diagnostic reagents and tools. The lectin-related diagnostic
is aimed at detection of several diseases connected to alteration of the glycosylation profiles of cells and at identification
of microbial and viral agents in clinical microbiology. Certain lectins, proposed for or used as diagnostic tools could even
recognize those cellular determinants, which are not detected by available antibodies. Broad information is presented on the
lectinomics field, illustrating that lectin diagnostics might become practical alternative to antibody-based diagnostic products.
In addition, the rising trend of lectin utilization in biomedical diagnostics might initiate a development of innovative methods
based on better analytical technologies. Lectin microarray, a rapid and simple methodology, can be viewed as an example for
such initiative. This technology could provide simple and efficient screening tools for analysis of glycosylation patterns
in biological samples (cellular extracts, tissues and the whole cells), allowing thus personalized detection of changes associated
with carbohydrate-related diseases. 相似文献
73.
D V Lychakov Ia A Vinnikov K A Ko?chev A Boiadzhieva-Mikha?lova I Khristov 《Zhurnal evoliutsionno? biokhimii i fiziologii》1983,19(4):369-373
Rhesus monkeys have been kept in horizontal position under klinostatic or antiorthostatic hypokinetic conditions for 7 and 19 days. Using scanning electron microscope, studies were made of the otolithic membrane of the utricle, the receptor surface of the utricle, crista ampullaris of the lateral semicircular canals, the organ of Corti, the stria vascularis and spiral ligament. No significant differences were found between control and experimental animals. 相似文献
74.
75.
76.
77.
Hanna Grajek Regina Drabent Grażyna Żurkowska Czesław Bojarski 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,801(3):456-460
The electronic absorption spectra of the flavomononucleotide (FMN) in aqueous solution and in glycerine-water solution with change of the dye concentration have been measured. The FMN dimer absorption spectrum, monomer absorption spectrum, dimerization constant K and molar fraction of the monomer were calculated. It was found that FMN dimerization constants in aqueous solution were Ka = 118.0 l/mol and in glycerine Kg = 20.5 l/mol. In the region of the monomer absorption band two dimer absorption bands appear, in accordance with the Kasha molecular exciton theory. 相似文献
78.
79.
80.
J P Heggers F Ko M C Robson R Heggers K E Craft 《Plastic and reconstructive surgery》1980,65(6):798-804
Although edema is evident immediately after a burn, the diffusion of nutrient chemical constituents of the body is not impaired. Blister fluid, not unlike plasma or serum, contained all substances found in the body, including parenterally administered penicillin. The elevation of potassium and the cation to anion imbalance is primarily due to the Na/K cellular pump malfunction, and the destruction of the permeability of the cell membrane is most likely a direct result of complement and other cellular enzymes, which include the prostaglandins and thromboxanes. The elevated SGOT, CPK, and LDH indicated severe trauma to the cells in the immediate area of burn and possibly to the skeletal muscle. The presence of immunoglobulins indicated that high-molecular-weight proteins diffuse equally well during this edematous phase (IgM, 900,000; IgG, 190,000). Evidence of this nature strongly suggests that the integrity of the burn blister by maintained. 相似文献