全文获取类型
收费全文 | 3490篇 |
免费 | 266篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 105篇 |
妇产科学 | 57篇 |
基础医学 | 342篇 |
口腔科学 | 143篇 |
临床医学 | 483篇 |
内科学 | 579篇 |
皮肤病学 | 50篇 |
神经病学 | 227篇 |
特种医学 | 293篇 |
外科学 | 424篇 |
综合类 | 120篇 |
一般理论 | 3篇 |
预防医学 | 282篇 |
眼科学 | 108篇 |
药学 | 209篇 |
中国医学 | 16篇 |
肿瘤学 | 304篇 |
出版年
2022年 | 22篇 |
2021年 | 40篇 |
2020年 | 21篇 |
2019年 | 29篇 |
2018年 | 41篇 |
2017年 | 28篇 |
2016年 | 26篇 |
2015年 | 60篇 |
2014年 | 94篇 |
2013年 | 153篇 |
2012年 | 134篇 |
2011年 | 156篇 |
2010年 | 101篇 |
2009年 | 137篇 |
2008年 | 132篇 |
2007年 | 153篇 |
2006年 | 130篇 |
2005年 | 131篇 |
2004年 | 138篇 |
2003年 | 127篇 |
2002年 | 121篇 |
2001年 | 94篇 |
2000年 | 99篇 |
1999年 | 105篇 |
1998年 | 106篇 |
1997年 | 69篇 |
1996年 | 86篇 |
1995年 | 68篇 |
1994年 | 63篇 |
1993年 | 66篇 |
1992年 | 63篇 |
1991年 | 52篇 |
1990年 | 64篇 |
1989年 | 73篇 |
1988年 | 78篇 |
1987年 | 49篇 |
1986年 | 70篇 |
1985年 | 43篇 |
1984年 | 51篇 |
1983年 | 47篇 |
1982年 | 37篇 |
1981年 | 38篇 |
1980年 | 34篇 |
1979年 | 29篇 |
1978年 | 39篇 |
1977年 | 30篇 |
1976年 | 27篇 |
1975年 | 29篇 |
1973年 | 20篇 |
1970年 | 20篇 |
排序方式: 共有3769条查询结果,搜索用时 15 毫秒
51.
Morphological studies have shown that macrophages and microglia undergo
apoptosis in the central nervous system (CNS) in acute experimental
autoimmune encephalomyelitis (EAE) in the Lewis rat. To assess the relative
levels of macrophage and microglial apoptosis, and the molecular mechanisms
involved in this process, we used three-colour flow cytometry to identify
CD45lowCD11b/c+ microglial cells and CD45highCD11b/c+ macrophages in the
inflammatory cells isolated from the spinal cords of Lewis rats 13 days
after immunization with myelin basic protein (MBP) and complete Freund's
adjuvant. Simultaneously, we analyzed the DNA content of these cell
populations to assess the proportions of cells undergoing apoptosis and in
different stages of the cell cycle or examined their expression of three
apoptosis- regulating proteins, i.e. Fas (CD95), Fas ligand (FasL) and
Bcl-2. Microglia were highly vulnerable to apoptosis and were
over-represented in the apoptotic population. Macrophages were less
susceptible to apoptosis than microglia and underwent mitosis more
frequently than microglia. The different susceptibilities of microglia and
macrophages to apoptosis did not appear to be due to variations in Fas,
FasL or Bcl- 2 expression, as the proportions of microglia and macrophages
expressing these proteins were similar, and were relatively high.
Furthermore, in contrast to T cell apoptosis, apoptosis of
microglia/macrophages did not occur more frequently in cells expressing Fas
or FasL, or less frequently in cells expressing Bcl-2. These results
indicate that the apoptosis of microglia and CNS macrophages in EAE is not
mediated through the Fas pathway, and that Bcl-2 expression does not
protect them from apoptosis. Expression of FasL by macrophages and
microglia may contribute to the pathogenesis and immunoregulation of EAE
through interactions with Fas+ oligodendrocytes and Fas+ T cells. The high
level of microglial apoptosis in EAE indicates that microglial apoptosis
may be an important homeostatic mechanism for controlling the number of
microglia in the CNS following microglial activation and proliferation.
相似文献
52.
A Sclafani H Hertwig M Vigorito H Sloan B Kerzner 《Neuroscience and biobehavioral reviews》1987,11(2):197-200
The appetite of female rats for saccharides of different chain lengths was assessed in brief (5-min) one-bottle acceptance and two-bottle preference tests. The saccharides (and their lengths in glucose units) included glucose (1), maltose (2), maltotriose (3), maltooligosaccharide (4-8), maltopolysaccharide (average length 43), and Polycose (1 to 30+); 0.0125 and 0.025 molar solutions of these saccharides were tested. The results revealed that the rats' order of preference for these saccharides was as follows: maltooligosaccharide greater than maltotriose = maltose greater than glucose; and maltooligosaccharide greater than Polycose = maltopolysaccharide greater than maltose. Thus, as saccharide chain length increased from 1 to 4-8 glucose units palatability increased, but with further increases in chain length palatability declined somewhat. Previous findings have suggested that rats have a "polysaccharide" taste receptor and the present results indicate that the receptor is maximally (or near-maximally) stimulated by saccharides of 4-8 glucose units in length. 相似文献
53.
Two Mannich-base prodrugs of 5-iodo-2-deoxycytidine (5-IDC) have been synthesized. The prodrugs exhibit increased lipid solubility compared to 5-IDC and rapidly revert to 5-IDC in buffer. One of the prodrugs delivered about twice as much 5-IDC from isopropyl myristate (IPM) through hairless mouse skin in diffusion-cell experiments as did 5-IDC from IPM. Subsequent applications of theophylline/ propylene glycol onto the diffusion cells to determine the effect of prodrug/IPM, 5-IDC/IPM, or IPM on the resistance of the skins to subsequent applications showed that the prodrug/IPM had no more effect than IPM itself. 相似文献
54.
Feinberg Mark E. Fang Shichen Fosco Gregory M. Sloan Carlie J. Mogle Jacqueline Spoth Richard L. 《Prevention science》2022,23(7):1264-1275
Prevention Science - We examined whether participation in adolescent substance use prevention programming can enhance long-term resilience into adulthood such that individuals were better able to... 相似文献
55.
56.
57.
Sloan NE Peroutka JA Morgan DE Ross MB Mutnick AH 《Topics in hospital pharmacy management / Aspen Systems Corporation》1994,14(3):1-12
Influencing prescribing practices and the implementation of pharmaceutical care utilizing the drug use evaluation (DUE) process at a 891-bed teaching hospital are described. The DUE program has been structured to provide for significant pharmacy involvement while maintaining medical staff responsibility as outlined by the Joint Commission on Accreditation of Healthcare Organizations. A multidisciplinary approach is used to identify problems and develop prescribing criteria and educational initiatives. Pharmacists provide drug therapy monitoring and engage in clinical interventions and documentation of outcomes on a daily basis. DUE program pharmacists help target possible interventions, assure monitoring and outcome documentation, and compile results of all initiatives for reporting purposes to the medical staff and quality assessment program. Specific performance compliance and problems are identified and incorporated into the credentialing process. Corrective measures are determined by the Pharmacy and Therapeutics (P&T) Subcommittee with subsequent actions carried out by peer physicians. The net result is a positive influence on prescribing practices that improves the appropriate and effective use of drugs and improves patient outcomes. 相似文献
58.
Valproate, an antiepileptic drug, is useful in the management of various nonepileptic disorders. It is an effective and generally well-tolerated medication for the treatment of bipolar disorder and has been approved by the Food and Drug Administration for use in manic states. Studies also suggest that it is effective in other bipolar spectrum illnesses. This report describes 2 clinical cases of DSM-IV bipolar disorder where valproate provided robust, sustained relief of mood symptoms. In the first case, valproate was chosen for initial therapy in a bipolar patient suffering from a mixture of hypomanic and depressive symptoms. In the second case, valproate replaced lithium in the management of a patient with an incomplete response to lithium plus an antidepressant. This report addresses relevant clinical issues and includes a brief review of the clinical pharmacology of valproate. 相似文献
59.
60.
A E James S J Gibbs M Sloan J Erickson J Diggs 《AJR. American journal of roentgenology》1983,140(2):215-220
Radiographic techniques may be helpful in evaluation of the condition of paintings for their restoration, preservation, and occasionally to determine their authenticity. On the basis of experience with several of these procedures, the utility of each method is described in reference to specific "diagnoses" regarding paintings. Radiographic techniques have several advantages over other methods; they are nondestructive, they may be used to survey the entire painting, and they are subject to quantitative and serial analysis. 相似文献