全文获取类型
收费全文 | 2221篇 |
免费 | 193篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 107篇 |
妇产科学 | 52篇 |
基础医学 | 244篇 |
口腔科学 | 71篇 |
临床医学 | 412篇 |
内科学 | 346篇 |
皮肤病学 | 60篇 |
神经病学 | 115篇 |
特种医学 | 287篇 |
外科学 | 213篇 |
综合类 | 48篇 |
一般理论 | 4篇 |
预防医学 | 214篇 |
眼科学 | 20篇 |
药学 | 116篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 123篇 |
出版年
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 41篇 |
2017年 | 19篇 |
2016年 | 25篇 |
2015年 | 50篇 |
2014年 | 52篇 |
2013年 | 76篇 |
2012年 | 62篇 |
2011年 | 66篇 |
2010年 | 85篇 |
2009年 | 75篇 |
2008年 | 69篇 |
2007年 | 100篇 |
2006年 | 70篇 |
2005年 | 73篇 |
2004年 | 63篇 |
2003年 | 75篇 |
2002年 | 63篇 |
2001年 | 70篇 |
2000年 | 57篇 |
1999年 | 62篇 |
1998年 | 102篇 |
1997年 | 91篇 |
1996年 | 83篇 |
1995年 | 74篇 |
1994年 | 48篇 |
1993年 | 54篇 |
1992年 | 51篇 |
1991年 | 57篇 |
1990年 | 43篇 |
1989年 | 71篇 |
1988年 | 56篇 |
1987年 | 47篇 |
1986年 | 35篇 |
1985年 | 37篇 |
1984年 | 33篇 |
1983年 | 27篇 |
1982年 | 24篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1975年 | 16篇 |
1973年 | 10篇 |
1969年 | 6篇 |
排序方式: 共有2436条查询结果,搜索用时 0 毫秒
91.
The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques 总被引:9,自引:5,他引:9
Philpott NJ; Turner AJ; Scopes J; Westby M; Marsh JC; Gordon-Smith EC; Dalgleish AG; Gibson FM 《Blood》1996,87(6):2244-2251
The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states. 相似文献
92.
Treatment of cervical intraepithelial neoplasia (CIN) greatly reduces the risk of cervical cancer. Treatment involves ablation or excision of the transformation zone of the cervix, most commonly using an electrosurgical excision technique known as LLETZ. However, the peak incidence of CIN occurs in young women, so if excision of a portion of the cervix has an adverse effect on pregnancy outcome, this might have a significant impact. This review discusses the methodology and findings of the published literature on the association between cervical treatment and preterm birth, and the clinical implications of these findings. 相似文献
93.
94.
Fifty years ago this summer, the Uniform Anatomical Gift Act was adopted by the National Conference of Commissioners on Uniform State Laws and approved by the American Bar Association. The UAGA has provided a sound and stable legal platform on which to base an effective nationwide organ donation system. The cardinal principles of altruism, autonomy, and public trust are still important. At a time when confidence and trust in our government and many private institutions has declined, maintaining trust and confidence in our health care system and its commitment to “first, do no harm” has never been more important. Any policies that override these core ethical principles could cause irreparable damage to the public's faith in our transplant system. While progress has been made to increase organ registration and the number of organs transplanted, much more must be done to realize the potential of life‐saving therapy without jeopardizing ethical principles. 相似文献
95.
96.
97.
98.
Progesterone inhibition of Xenopus oocyte adenylate cyclase is not mediated via the Bordetella pertussis toxin substrate 总被引:5,自引:0,他引:5
Preincubation of intact Xenopus laevis oocytes with islet-activating protein (IAP) stimulates plasma membrane adenylate cyclase activity measured in the presence of either GTP or 5'-guanylyl imidodiphosphate. The toxin appears to act by catalyzing the ADP-ribosylation of a 41,000-D protein in the oocyte plasma membrane that is distinct from the 45,000- and 52,000-D proteins labeled by cholera toxin. Preincubation of intact oocytes with IAP for 2.5 hr inhibits 80% of the ADP-ribosylation of oocyte membranes subsequently prepared and treated in vitro with IAP in the presence of [alpha-32P]NAD. The abilities of progesterone and the P site agonist, 2',5'-dideoxyadenosine, to inhibit plasma membrane adenylate cyclase are not inhibited by IAP treatment, but IAP pretreatment abolishes inhibition by acetylcholine. In addition, IAP pretreatment of oocytes slows the time course of germinal vesicle breakdown induced by suboptimal concentrations of progesterone. This effect of toxin upon oocyte maturation is apparently due to its effect upon basal cyclase activity, since IAP has no effect upon the time course of maturation induced by 10 microM progesterone. These results indicate that, even though the oocyte adenylate cyclase does contain a functional Ni subunit, inhibition of Xenopus oocyte adenylate cyclase by progesterone or 2',5'-dideoxyadenosine is not mediated via the Bordetella pertussis toxin substrate. 相似文献
99.
Inflammatory carcinoma of the breast 总被引:2,自引:0,他引:2