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   56569篇
  免费   2904篇
  国内免费   458篇
耳鼻咽喉   583篇
儿科学   1065篇
妇产科学   1721篇
基础医学   6874篇
口腔科学   2094篇
临床医学   4510篇
内科学   15105篇
皮肤病学   1122篇
神经病学   4879篇
特种医学   1579篇
外国民族医学   3篇
外科学   8677篇
综合类   414篇
一般理论   13篇
预防医学   3065篇
眼科学   831篇
药学   3037篇
  1篇
中国医学   160篇
肿瘤学   4198篇
  2023年   396篇
  2022年   898篇
  2021年   1803篇
  2020年   968篇
  2019年   1369篇
  2018年   1864篇
  2017年   1232篇
  2016年   1365篇
  2015年   1593篇
  2014年   2166篇
  2013年   2834篇
  2012年   4415篇
  2011年   4350篇
  2010年   2447篇
  2009年   2119篇
  2008年   3678篇
  2007年   3853篇
  2006年   3521篇
  2005年   3508篇
  2004年   3212篇
  2003年   2857篇
  2002年   2586篇
  2001年   619篇
  2000年   534篇
  1999年   629篇
  1998年   480篇
  1997年   435篇
  1996年   367篇
  1995年   346篇
  1994年   297篇
  1993年   230篇
  1992年   311篇
  1991年   257篇
  1990年   233篇
  1989年   232篇
  1988年   145篇
  1987年   176篇
  1986年   157篇
  1985年   127篇
  1984年   140篇
  1983年   110篇
  1982年   122篇
  1981年   96篇
  1980年   96篇
  1979年   90篇
  1978年   70篇
  1977年   57篇
  1976年   65篇
  1975年   54篇
  1974年   61篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Summary 4-amino-1-hydroxybutylidene-1,1-bis-phosphonate (AHButBP) was given intravenously (2.5–25 mg/day for 4 days) to 14 patients with Paget's disease of bone, five of whom had been treated with dichloromethylidene bisphosphonate (Cl2MBP) 32 months earlier. In the nine patients who had not been treated previously with bisphosphonates, the short course of AHButBP induced a suppression of serum alkaline phosphatase and urinary hydroxyproline values down to 30% of initial values. The biochemical suppression of the disease was sustained for 2–18 months and the time to relapse did correlate to the logarithm of the dose (P<0.001). In the five patients previously treated for Paget's disease, an apparent resistence to treatment with AHButBP was observed. However, in these patients both serum alkaline phosphatase and urinary hydroxyproline fell to or even below the nadir values which had previously been achieved with Cl2MBP, irrespective of the degree of relapse. Thus the degree of suppression of Paget's disease of bone, achievable after treatment with bisphosphonates, seems to be constant for each patient, such that normal levels of serum alkaline phosphatase and urinary hydroxyproline cannot usually be attained in patients with extremely active disease.  相似文献   
22.
23.
24.
25.
Hyperexcitability of the motor system has been reported in Parkinson's disease (PD). We evaluate how cutaneous afferents modulate motor excitability in PD patients and whether abnormal modulation is correlated to parkinsonian symptoms. Digital stimulation causes abnormal enhancement of motor responses in patients. This effect may be one of the features of motor hyperexcitability in PD. Cutaneomotor hyperexcitability correlates with clinical scores, suggesting that abnormal processing of cutaneous inputs might contribute to the pathogenesis of parkinsonian symptoms.  相似文献   
26.
Fluphenazine decanoate is commonly used as part of maintenance treatment of schizophrenia, but its pharmacokinetics are poorly understood. We administered a single intramuscular dose of fluphenazine decanoate to nine patients and found that plasma fluphenazine level did not decline to 50% of the peak level by day 26 in any of the patients. This means that it has a long half-life measurable in months rather than weeks.  相似文献   
27.
The isoleucyl-tRNA synthetase (ileS) gene was sequenced in toto from 9 and in part from 31 Staphylococcus aureus strains with various degrees of susceptibility to mupirocin. All strains for which the mupirocin MIC was greater than 8 microg/ml contained point mutations affecting the Rossman fold via Val-to-Phe changes at either residue 588 (V588F) or residue 631 (V631F). The importance of the V588F mutation was confirmed by an allele-specific PCR survey of 32 additional strains. Additional mutations of uncertain significance were found in residues clustered on the surface of the IleS protein.  相似文献   
28.
29.
We report a case of cervical dystonia occurring in a 33-year-old without personal history of movement disorder but with family history of essential tremor, primigravid, primiparous woman at 1 weeks' amenorrhea, resolved completely after delivery in the course of 3 months. Dystonia never recurred in the following 5 years. Several neurological disorders are known to occur or worsen during pregnancy. As far as we know, this is the second reported case of dystonia occurring during pregnancy, thus confirming that dystonia gravidarum represents a new entity and should be considered in women of reproductive age affected by dystonia, especially when presenting with rapid-onset cervical dystonia.  相似文献   
30.
Tumor necrosis factor-alpha (TNFalpha) and Fas are induced after traumatic brain injury (TBI); however, their functional roles are incompletely understood. Using controlled cortical impact (CCI) and mice deficient in TNFalpha, Fas, or both (TNFalpha/Fas-/-), we hypothesized that TNFalpha and Fas receptor mediate secondary TBI in a redundant manner. Compared with wild type (WT), TNFalpha/Fas-/- mice had improved motor performance from 1 to 4 days (P<0.05), improved spatial memory acquisition at 8 to 14 days (P<0.05), and decreased brain lesion size at 2 and 6 weeks after CCI (P<0.05). Protection in TNFalpha/Fas-/- mice from histopathological and motor deficits was reversed by reconstitution with recombinant TNFalpha before CCI, and TNFalpha-/- mice administered anti-Fas ligand antibodies had improved spatial memory acquisition versus similarly treated WT mice (P<0.05). Tumor necrosis factor-alpha/Fas-/- mice had decreased the numbers of cortical cells with plasmalemma damage at 6 h (P<0.05 versus WT), and reduced matrix metalloproteinase-9 activity in injured brain at 48 and 72 h after CCI. In immature mice subjected to CCI, genetic inhibition of TNFalpha and Fas conferred beneficial effects on histopathology and spatial memory acquisition in adulthood (both P<0.05 versus WT), suggesting that the beneficial effects of TNFalpha/Fas inhibition may be permanent. The data suggest that redundant signaling pathways initiated by TNFalpha and Fas play pivotal roles in the pathogenesis of TBI, and that biochemical mechanisms downstream of TNFalpha/Fas may be novel therapeutic targets to limit neurological sequelae in children and adults with severe TBI.  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