首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   898篇
  免费   37篇
  2021年   5篇
  2020年   6篇
  2018年   12篇
  2017年   5篇
  2016年   22篇
  2015年   24篇
  2014年   34篇
  2013年   60篇
  2012年   46篇
  2011年   72篇
  2010年   43篇
  2009年   26篇
  2008年   30篇
  2007年   58篇
  2006年   46篇
  2005年   39篇
  2004年   34篇
  2003年   35篇
  2002年   37篇
  2001年   11篇
  1999年   9篇
  1998年   12篇
  1997年   11篇
  1995年   8篇
  1994年   6篇
  1992年   11篇
  1991年   13篇
  1989年   17篇
  1988年   8篇
  1987年   7篇
  1986年   6篇
  1985年   12篇
  1984年   9篇
  1983年   10篇
  1982年   4篇
  1981年   6篇
  1980年   5篇
  1979年   11篇
  1978年   10篇
  1977年   5篇
  1976年   5篇
  1975年   8篇
  1974年   7篇
  1973年   8篇
  1972年   18篇
  1971年   9篇
  1970年   8篇
  1968年   8篇
  1966年   5篇
  1965年   7篇
排序方式: 共有935条查询结果,搜索用时 15 毫秒
1.
Various chemicals commonly found in food (twelve monosaccharides, nine sugar alcohols, twenty triglycerides, eleven unsaturated fatty acids and nine saturated fatty acids) were tested in different concentrations for their ability to attract and sustain feeding by the dried-fruit mite,Carpoglyphus lactis (L.). Oleic acid, -d-glucose and some triglycerides act as phagoincitants and phagostimulants, whiled-fucose and trilaurin are phagodeterrents.  相似文献   
2.
3.
A case of a 32-year female patient with the systemic lupus erythematosus is presented. The patient was treated with prednisone in a daily dose of 40-60 mg. Due to the exacerbations of the symptoms and advanced renal disorders, the patient was given TFX together with corticotherapy. Thymus factor X is an extract of real thymus of immunorecorrective properties. It specifically acts on the lymphatic system, especially disordered mechanisms of both cellular and humoral immunity. Thymus factor X was given in the dose of 10 mg (one ampoule) i.m. for the three first months followed by one ampoule every three days for the next three months. The patient is given one ampoule of TFX once a week since the 6th months of therapy. Diminishment of the symptoms was observed. The patient is in remission since a one-year follow-up period. It was also possible to reduce the dose of prednisone to 15 mg a day. The patient is controlled every 3 months. Partial normalization of renal functioning and immunological mechanisms are seen. A decrease in antinuclear antibodies and immunoglobulins, normalization in complement components, an increase in T-cells percentage and conversion of the delayed skin reaction are noted. The authors conclude that TFX may be helpful in the treatment of the autoimmunological diseases, including the systemic lupus erythematosus.  相似文献   
4.
125I-Wheat germ agglutinin (WGA) binding parameters of human urothelial cell lines of different grades of transformation (TGrll and TGrlll) were compared. The values of association constant (Ka) and the number of binding sites/cell for HCV29 (TGrll) cell line were about 3×106M–1 and over 4×107, respectively. Two TGrlll cell lines, HCV29T and Hu549 revealed lower values for Ka, and considerably higher numbers of binding sites/cell (about 3×108 and 2×108, respectively). Binding of125I-WGA to total cellular proteins resolved by SDS-PAGE and transferred to nitrocellulose showed multiple diffused bands in the range of 58–180 kDa. Some of these bands were characteristic for TGrll cells (124 kDa) or TGrlll cells (135 and 148 kDa).Abbreviations TGr transformation grade - WGA wheat germ agglutinin - sWGA succinylated wheat germ agglutinin - GlcNAc N-acetyl-d-glucosamine - BSA bovine serum albumin - SDS-PAGE sodium dodecyl sulphate polyacrylamide gel electrophoresis  相似文献   
5.
6.
7.
8.
Four bi-antennary glycan fractions of theN-acetyllactosamine-type, derived from a Lewis lung carcinoma (LL2) cell subline resistant to theAleuria aurantia agglutinin were studied by 400 MHz1H-NMR spectroscopy. By this method, their antennae were found to be terminated either by (2-3 or 6)-linkedN-acetylneuraminic acid or (1-3)-linked galactose residues. The primary structure of glycans of these four glycopeptide or derived oligosaccharide-alditols has been determined in full detail.Abbreviations NAc N-acetyl group - NGc N-glycolyl group - GlcNAc N-acetylglucosamine - NeuAc N-acetylneuraminic acid - NeuGc N-glycolylneuraminic acid - Man mannose - Gal galactose - Fuc fucose - Con A concanavalin A - LCA Lens culinaris agglutinin - AAA Aleuria aurantia agglutinin - WGA Wheat germ agglutinin - RCA II Ricinus communis agglutinin II - PBS phosphate buffered saline, 0.01m Na2HPO4/0.14m NaCl, pH 7.2 - HPLC high performance liquid chromatography - EMEM Eagle's Minimal Essential Medium - LecR lectin resistant - MG -methylglycoside  相似文献   
9.
Nongrowing Escherichia coli deprived of an essential amino acid continued to produce peptidoglycan at a rate approximately 30% of that of growing cells. The composition of this peptidoglycan was very different from that of growing cells and resembled that of peptidoglycan left undegraded during partial autolysis of the bacteria. Synthesis of this peptidoglycan of anomalous composition began at once upon the removal of the amino acid from the medium. Fifteen minutes of amino acid deprivation was sufficient to virtually completely prevent penicillin-induced autolytic wall degradation in vivo. During this time, although the specific activities of soluble and membrane-bound hydrolytic transglycosylases and endopeptidases remained high, the peptidoglycan produced showed decreased sensitivity to degradation in vitro. After more extensive (2-h) starvation, triggering of autolysis by chaotropic agents was also blocked. Autolysis in growing cells may be selective for peptidoglycan representing the cylindrical portion of the sacculus. It is suggested that at least part of the mechanism of the well-known lysis resistance of nongrowing E. coli is related to the deposition of structurally anomalous and relatively autolysin-resistant peptidoglycan at some strategically located sites on the bacterial surface.  相似文献   
10.
Estradiol stimulation and progesterone inhibition of human uterine PGF2 alpha production were studied using in vitro preparations of endometrial tissue and cells. Measurement of PGF2 alpha levels in media from primary cultures of glandular epithelia and stoma revealed that basal outputs were similar in both cell types but could be increased by estradiol only in epithelial cells. Tamoxifen (Tam) and trans-4-hydroxy tamoxifen (OHTam) did not affect basal PGF2 alpha outputs by secretory endometrium in organ culture and by monolayer cultures of epithelial cells, but counteracted the stimulatory effects of estradiol in both systems. The almost pure antiestrogenic activity exhibited by OHTam was at least 10 times greater than that of Tam, suggesting that the estrogen-stimulated increases in uterine PGF2 alpha output are mediated by specific estrogen receptors. Fragments of endometrium also released lipocortin, a phospholipase A2-inhibiting protein believed to mediate inhibitory effects of glucocorticoids on prostaglandin production in several types of cells. Although dexamethasone increased lipocortin and decreased PGF2 alpha output in secretory endometria in vitro, progesterone inhibited both lipocortin and PGF2 alpha output. The mechanisms by which P inhibits PGF2 alpha production remain to be elucidated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号