全文获取类型
收费全文 | 2153篇 |
免费 | 218篇 |
国内免费 | 1篇 |
出版年
2022年 | 15篇 |
2021年 | 54篇 |
2020年 | 26篇 |
2019年 | 41篇 |
2018年 | 55篇 |
2017年 | 38篇 |
2016年 | 58篇 |
2015年 | 105篇 |
2014年 | 105篇 |
2013年 | 128篇 |
2012年 | 184篇 |
2011年 | 148篇 |
2010年 | 102篇 |
2009年 | 92篇 |
2008年 | 124篇 |
2007年 | 97篇 |
2006年 | 111篇 |
2005年 | 101篇 |
2004年 | 95篇 |
2003年 | 78篇 |
2002年 | 77篇 |
2001年 | 35篇 |
2000年 | 39篇 |
1999年 | 37篇 |
1998年 | 26篇 |
1997年 | 35篇 |
1996年 | 18篇 |
1995年 | 23篇 |
1994年 | 16篇 |
1993年 | 17篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 15篇 |
1986年 | 22篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 22篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1971年 | 6篇 |
排序方式: 共有2372条查询结果,搜索用时 15 毫秒
961.
Leigh C. Murphy Helmut Dotzlaw Etienne Leygue Deborah Douglas Amanda Coutts Peter H. Watson 《The Journal of steroid biochemistry and molecular biology》1997,62(5-6):363-372
There is a large and increasing body of experimental and clinical data supporting the existence of variant estrogen receptor (ER) proteins in both normal and neoplastic estrogen target tissues, including human breast. Therefore, future examination of ER signal transduction and/or measurement of ER protein must take into account variant ER expression. The functions of variant ER proteins, either physiological or pathological, remain unclear, although a role(s) for some ER variants in breast tumorigenesis and breast cancer progression would be consistent with the accumulated data. Possible tissue specific expression leads to the speculation that ER variants may have a role in tissue specific estrogen action. The following review focuses on the current knowledge available in the scientific literature with respect to the type and characteristics of estrogen receptor variants and mutations that have been identified to occur naturally in tissues and cell lines. 相似文献
962.
963.
964.
Characterization of the tea fungus metabolites 总被引:9,自引:0,他引:9
Philippe J. Blanc 《Biotechnology letters》1996,18(2):139-142
Summary The tea fungus (commonly designed as kombucha) is a symbiotic culture of at least three microorganisms: the acetic acid bacteria Acetobacter xylinum and two yeasts Zygosaccharomyces rouxii and Candida sp. in sugared tea (Hesseltine, 1965; Anonymous, 1983). These microorganisms were cultured in their traditional medium and several metabolites were identified and quantified : ethanol, lactic, acetic, gluconic and glucuronic acids. The antibacterial product known as usnic acid was also searched. 相似文献
965.
The GPI-Phospholipase C of Trypanosoma brucei Is Nonessential But Influences Parasitemia in Mice 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Helena Webb Nicola Carnall Luc Vanhamme Sylvie Rolin Jakke Van Den Abbeele Sue Welburn Etienne Pays Mark Carrington 《The Journal of cell biology》1997,139(1):103-114
In the mammalian host, the cell surface of Trypanosoma brucei is protected by a variant surface glycoprotein that is anchored in the plasma membrane through covalent attachment of the COOH terminus to a glycosylphosphatidylinositol. The trypanosome also contains a phospholipase C (GPI-PLC) that cleaves this anchor and could thus potentially enable the trypanosome to shed the surface coat of VSG. Indeed, release of the surface VSG can be observed within a few minutes on lysis of trypanosomes in vitro. To investigate whether the ability to cleave the membrane anchor of the VSG is an essential function of the enzyme in vivo, a GPI-PLC null mutant trypanosome has been generated by targeted gene deletion. The mutant trypanosomes are fully viable; they can go through an entire life cycle and maintain a persistent infection in mice. Thus the GPI-PLC is not an essential activity and is not necessary for antigenic variation. However, mice infected with the mutant trypanosomes have a reduced parasitemia and survive longer than those infected with control trypanosomes. This phenotype is partially alleviated when the null mutant is modified to express low levels of GPI-PLC. 相似文献
966.
Identification of volatile flavour compounds obtained in culture of Kluyveromyces marxianus 总被引:1,自引:0,他引:1
When Kluyveromyces marxianus was cultivated on a defined medium, flavour volatile compounds accumulated in the broth. Besides superior alcohols and aldehydes, acids and fruit esters could be analyzed by gas chromatography and coupled gas chromatography-mass spectrometry. The predominant components are isoamyl alcohol, 2-phenylethyl alcohol and isobutyric acid with 180 mg/L, 400 mg/L and 290 mg/L broth, respectively. 相似文献
967.
L. Somody S. Fagette S. Blanc J. Frutoso C. Gharib G. Gauquelin-Koch 《European journal of applied physiology and occupational physiology》1998,78(4):296-302
Exposure to microgravity in humans causes cardiovascular deconditioning affecting blood pressure, heart rate and vascular
responsiveness. This study investigated cardiac output, arterial blood pressure and regional blood flows [radioactive microspheres:
57Co, 15.5 (SEM 0.1) μm in diameter] in conscious and freely moving rats subjected to 14 days of simulated microgravity (head-down
suspension, HDS) in male Wistar rats: control (horizontally attached, n = 7), suspended for 14 days (n = 8) and suspended/allowed to recover for 10 min (R10min, n = 5) or 24 h (n = 9). Compared to the control group, 14 days of HDS resulted in reduced total peripheral resistance (37%); an increased cardiac
index (65%) was associated with no significant change in the mean arterial pressure . There were elevated brain (63%), visceral (>20%), hindlimb (>80%) and forelimb (>215%) muscle blood flows. In the R10min
group, the decreased (18%) and the regional blood flows returned to control values. Within 24 h the as well as cardiac index and total peripheral resistance were restored. In conclusion, 14 days of HDS engendered local circulatory
changes resulting in transient blood pressure instability during recovery.
Accepted: 26 March 1998 相似文献
968.
969.
His-154 is involved in the linkage of the Saccharomyces cerevisiae L-A double-stranded RNA virus Gag protein to the cap structure of mRNAs and is essential for M1 satellite virus expression. 总被引:8,自引:3,他引:5
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The coat protein (Gag) of the double-stranded RNA virus L-A was previously shown to form a covalent bond with the cap structure of eukaryotic mRNAs. Here, we identify the linkage as a phosphoroimidazole bond between the alpha phosphate of the cap structure and a nitrogen in the Gag protein His-154 imidazole side chain. Mutations of His-154 abrogate the ability of Gag to bind to the cap structure, without affecting cap recognition, in vivo virus particle formation from an L-A cDNA clone, or in vitro specific binding and replication of plus-stranded single-stranded RNA. However, genetic analyses demonstrate that His-154 is essential for M1 satellite virus expression. 相似文献
970.
Etienne Hollande Marjorie Fanjul Serge Claret Marie-Elizabeth Forgue-Lafitte Jacques Bara 《In vitro cellular & developmental biology. Animal》1995,31(3):227-233
Summary The effects of Vasoactive intestinal peptide (VIP) on mucin secretion in the pancreatic cancer Capan-1 cell line were studied
by Enzyme-linked-immunosorbent-assay (ELISA), and by light and electron microscopy using immunocytological methods. During
the exponential growth phase, mucins were accumulated in the cytoplasm of cells and slowly exocytosed. In contrast, there
was enhanced exocytosis of mucins during the stationary phase when the cells were well-polarized. Moreover, during this phase,
VIP induced a dose-dependent rise in mucin content in the extracellular medium. The reaction with anti-MI monoclonal antibodies,
which recognize specifically the peptide core of gastric mucins, showed an accumulation of secretion granules near the apex
of well-polarized cells together with fusion of the granule and plasma membranes after VIP stimulation. Moreover, mucin exocytosis
was stimulated by Pituitary adenylate cyclase activating polypeptide (PACAP) and secretin. It was also increased after forskolin
treatment suggesting that this mechanism was cAMP-dependent. Our results suggested that exocytosis of mucins could be under
the control of VIP in pancreatic duct cells of the Capan-1 cell line. 相似文献