全文获取类型
收费全文 | 573篇 |
免费 | 19篇 |
国内免费 | 19篇 |
专业分类
儿科学 | 10篇 |
妇产科学 | 5篇 |
基础医学 | 128篇 |
口腔科学 | 11篇 |
临床医学 | 39篇 |
内科学 | 102篇 |
皮肤病学 | 5篇 |
神经病学 | 66篇 |
特种医学 | 10篇 |
外科学 | 41篇 |
综合类 | 38篇 |
预防医学 | 5篇 |
眼科学 | 2篇 |
药学 | 70篇 |
中国医学 | 24篇 |
肿瘤学 | 55篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 20篇 |
2018年 | 30篇 |
2017年 | 14篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 27篇 |
2013年 | 25篇 |
2012年 | 23篇 |
2011年 | 24篇 |
2010年 | 24篇 |
2009年 | 36篇 |
2008年 | 41篇 |
2007年 | 34篇 |
2006年 | 33篇 |
2005年 | 21篇 |
2004年 | 27篇 |
2003年 | 23篇 |
2002年 | 26篇 |
2001年 | 23篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有611条查询结果,搜索用时 13 毫秒
1.
The epithelial cells of the colonic mucosa of the animal have proved impossible to culture using standard tissue culture techniques. Immortalization of adult colonic epithelial cells has been unsuccessful due to the lack of DNA synthesis in these cells once they are isolated from the tissue. Recently an unique transgenic mouse bearing a temperature sensitive mutant of the known immortalizing gene, SV40 large T has become available. The advantage of this mouse is that the SV40 large T gene is expressed in every cell. Active immortalizing protein is produced in each cell at the permissive temperature. We have used colonic mucosa from these mice to initiate cultures of epithelial cells from the colon of adult mice. The cells grow readily at the permissive temperature but die within 7 days at the non-permissive temperature. The methods used to develop these cultures are described. 相似文献
2.
Kathryn Leary Harry H. Yim Lu Bing Zhou Rose E. Sekulovich Rozanne M. Sandri-Goldin 《Virus genes》1989,3(1):57-68
To determine the role of the HSV-1 genome structure and environment on the regulation of gene expression, we constructed recombinant viruses containing a heterologous gene inserted into either the immediate early ICP0 or late glycoprotein C (gC) genes of HSV-1. The heterologous gene consisted of the SV40 early promoter (without enhancer sequences) linked to the coding sequences for the bacterial chloramphenicol acetyl transferase (CAT). The expression of CAT was examined in Vero cells infected with either virus (named ICP0-CAT and Sph 6). For both recombinants, expression of CAT was not dependent upon prior viral protein synthesis. The kinetics of expression of CAT-specific mRNA resembled that of the HSV-1 genes into which CAT was inserted. Primer extension analysis revealed that the SV40 promoter is recognized and used when placed in cis in two different HSV-1 genome locations, and Northern hybridization experiments confirmed that the heterologous gene was expressed in the absence of prior viral protein synthesis. Therefore, this gene was not regulated as strictly as an HSV-1 gene, but was influenced by the environment into which it was placed, presumably by factors that are present when the normal viral gene is on. 相似文献
3.
Mounir Fouad F Mamer O Khayyal M Sauriol F Lesimple A Ruhenstroth-Bauer G 《Medical hypotheses》2004,63(6):1024-1034
We are elaborating on the kinetics and mechanisms of septic rabbit liver to de novo biosynthesize acute-phase response (APR) proteins under in vitro conditions of deepening ischemia in reference to their in vivo prevalence in serum and cerebrospinal fluids (CSF) collected at predetermined times. The significance of the data is interpreted as relevant to grafting cadaveric liver into end-stage liver diseased patients and APR-induced ischemic heart diseases (IHD). Hepatic APR was induced by CCl(4)-intubation, and the administration of cholera toxin (CT) or scorpion venom (SV), or both, to rabbits. Hepatic functional efficiency, in terms of biosynthesis of APR proteins in closed circuit perfusion of the isolated intoxicated liver with oxygenated saline or L-15 media paralleled the two-dimensional immunoelectrophoresis (2D-IEP) spectrum of APR serum proteins at time of liver isolation. We are suggesting: (a) in vitro biosynthesis of plasma proteins by isolated perfused liver is the result of in vivo decoded and retained APR inflammatory signals; and (b) decoded inflammatory signals are expressed not withstanding the perfusate's organic composition. Furthermore, 90 min of ischemic perfusion in saline or L-15 medium precipitated mitochondrial aberrations which resulted in further deterioration of de novo biosynthesis of APR plasma proteins. Regardless of the nature of the inflammatory stimuli, mitochondrial aberrations rendered the perfused organ a biologically inert tissue mass that was incapable of resuming biological function upon perfusion with oxygenated L-15 medium. This is most likely due to ischemia-induced irreversible hepatic necrosis. Thus, in vitro aberrations of mitochondrial function(s) critically limit the capability of the isolated liver to resume its organic function to sustain biosynthesis of de novo plasma proteins. Extrapolation of these results to the surgical management of end-stage liver diseases points to the importance of the status and the handling protocol(s) of the cadaver donor liver prior to successful grafting. We conclude that although histology of a cadaver liver may reveal well-preserved hepatic cellular organelles with at least minimal intra- and intercellular communication required for viable hepatic function, we deem it essential to further define acceptable minimal capabilities to de novo biosynthesize plasma proteins by a cadaver liver as a measure of its functional viability and suitability for transplantation. Ultimately, this measure may improve the success of liver transplants with minimal surgical and drug interventions. 相似文献
4.
Candusso ME Luinetti O Villani L Alberizzi P Klersy C Fiocca R Ranzani GN Solcia E 《The Journal of pathology》2002,196(1):44-50
Identification of neuroendocrine differentiation in tumours has important implications for prognosis and therapy. The aim of the present study was to evaluate monoclonal antibodies against synaptic vesicle protein 2 (SV2) as histopathological markers for neuroendocrine differentiation in tumours of the gastrointestinal tract and pancreas. Paraffin blocks from 211 gastrointestinal tumours were examined by immunocytochemistry, using a monoclonal antibody against SV2. Virtually all endocrine tumours of the gastrointestinal tract (11/11 gastric, 53/53 ileal, 16/21 appendiceal, and 22/22 rectal) and pancreas (24/24) were positively labelled. SV2 labelling was also demonstrated in gastrointestinal pacemaker cell tumours (8/8), while adenocarcinomas of the gastrointestinal tract and pancreas were negative, with the exception of occasional adenocarcinomas demonstrating weak SV2 labelling (stomach 1/22, rectum 1/29, and pancreas 0/21). Western blotting of tumour biopsies confirmed expression of SV2 in endocrine tumours of the gastrointestinal tract and pancreas. No relationship was observed between SV2 expression in tumours and hormone production or malignant potential. In conclusion, SV2 is expressed in neuroendocrine tumours of the gastrointestinal tract and pancreas, but not in non-endocrine tumours. The SV2 monoclonal antibody can therefore be used as a general marker for neuroendocrine differentiation in gastrointestinal and pancreatic tumours. 相似文献
5.
Critical role for SV40 small-t antigen in human cell transformation 总被引:14,自引:0,他引:14
Defining the ability of simian virus 40 (SV40) to transform human cells has become of even greater importance with the increased understanding that this virus may play a role in some human malignancies. This report documents the requirement for viral small-t (ST) antigen in large-T (LT)-driven transformation of primary fibroblasts, a requirement that cannot be met by a well-known oncogene, c-Ha-ras (EJ-ras), which can cooperate with LT in rodent systems. The cellular gene telomerase is not essential for transformation, although transformed clones are not immortal without it. Similarly, an immortal mesothelial cell line has been developed using LT and telomerase. Immortalized mesothelial cells are morphologically normal, but can be transformed by introduction of ST, or ST + ras, but not by ras alone. It is likely that ST will be required along with LT for transformation of most human cell types. 相似文献
6.
7.
8.
Hyperbaric oxygenation induced tolerance against focal cerebral ischemia in mice is strain dependent 总被引:18,自引:0,他引:18
Prass K Wiegand F Schumann P Ahrens M Kapinya K Harms C Liao W Trendelenburg G Gertz K Moskowitz MA Knapp F Victorov IV Megow D Dirnagl U 《Brain research》2000,871(1):146-150
SV129 or C57BL/6 mice were exposed to hyperbaric oxygenation (HBO, 5 days, 1 h every day, 100% O(2) at 3 atm absolute). One day after the 5th HBO session focal cerebral ischemia was induced. In SV129 mice, HBO induced tolerance against permanent focal cerebral ischemia (n=42, mean infarct volume reduction 27%, P=0.001), but not against transient (30 or 60 min) focal cerebral ischemia. In the C57BL/6 strain of mice, HBO did not induce tolerance against focal cerebral ischemia, even when the duration of ischemia or the HBO protocol were modified. For the first time we demonstrate that HBO can induce tolerance to focal cerebral ischemia, but this effect is strain dependent. 相似文献
9.