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   109261篇
  免费   12007篇
  国内免费   4865篇
耳鼻咽喉   1177篇
儿科学   2345篇
妇产科学   1278篇
基础医学   8047篇
口腔科学   2542篇
临床医学   14261篇
内科学   12634篇
皮肤病学   1505篇
神经病学   4520篇
特种医学   4408篇
外国民族医学   1篇
外科学   11333篇
综合类   21993篇
现状与发展   13篇
一般理论   13篇
预防医学   13918篇
眼科学   1605篇
药学   10254篇
  119篇
中国医学   8449篇
肿瘤学   5718篇
  2024年   493篇
  2023年   1510篇
  2022年   2916篇
  2021年   3873篇
  2020年   3452篇
  2019年   2070篇
  2018年   2648篇
  2017年   3083篇
  2016年   2553篇
  2015年   4174篇
  2014年   5318篇
  2013年   6961篇
  2012年   8708篇
  2011年   9098篇
  2010年   8022篇
  2009年   7280篇
  2008年   7398篇
  2007年   7228篇
  2006年   6484篇
  2005年   5378篇
  2004年   4035篇
  2003年   3418篇
  2002年   2866篇
  2001年   2338篇
  2000年   1756篇
  1999年   1106篇
  1998年   697篇
  1997年   630篇
  1996年   627篇
  1995年   524篇
  1994年   468篇
  1993年   438篇
  1992年   629篇
  1991年   525篇
  1990年   490篇
  1989年   502篇
  1988年   480篇
  1987年   421篇
  1986年   441篇
  1985年   424篇
  1984年   331篇
  1983年   342篇
  1982年   258篇
  1981年   276篇
  1980年   228篇
  1979年   302篇
  1978年   238篇
  1977年   208篇
  1974年   204篇
  1973年   214篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的 探讨^99mTC-MIBI动态显像对非小细胞肺癌化疗疗效的预测价值。方法 对确诊为不能手术的非小细胞肺癌患者化疗前,静脉注射740mbq ^99mTC-MIBI后分别于30min,2h行SPECT动态扫描,计算早期/晚期肿瘤组织与对侧正常肺组织的放射活性比(T/Ne,T/Nd),全身采用卡铂/顺铂+VP16化疗3周期,随后复查胸部CT,评判化疗疗效及其与^99mTC-MIBI动态显像的关系。结果 78例NSCLC符合入选标准,并完成化疗方案,66例呈阳性显像,12例阴性显像,66例阳性显像中化疗有效率为90.7%,阴性显像12例中化疗全部进展,两者比较差异有显著性(P〈0.01)。结论 ^99mTC-MIBI动态显像的放射活性越高,化疗效果越好,对非小细胞肺癌化疗疗效有预测价值,可为合理制定治疗方案提供重要依据。  相似文献   
62.
AIM: The aim of this study was to investigate the nature and organization of maternal needs and priorities in a neonatal unit. BACKGROUND: The relationship between maternal needs and priorities appears to be an under studied area in neonatal nursing. METHODS: A quantitative survey was carried out based on 209 mothers with premature infants. Two self-assessment schedules were used: critical care maternal needs inventory (J. Leske, Heart and Lung 15, 27-42) and a ranking scale. The data were analysed with multivariate analysis. FINDINGS: Data analysis revealed clear priorities in maternal needs. In particular the need for accurate infant related information was a priority for 93% of the mothers. Good communication practices with professionals were also valued. The mothers displayed altruistic behaviour, and self-related needs took second place. It is proposed that maternal needs demonstrate a hierarchical organization. CONCLUSION: It is important for nurses to consider the individual needs of the mothers, simply because the satisfaction of these needs is essential for maternal well-being.  相似文献   
63.
64.
SUMMARY Disease-modifying antirheumatic drugs are used in virtually all patients with established rheumatoid arthritis. An increasingly large number of new drugs is now available. Furthermore, old therapies are being used in novel ways. Treatment is now begun earlier and patients are rarely left untreated. This report summarises recent developments regarding the drugs currently in use and those that may be available in the near future.  相似文献   
65.
I Ahmad  T M Allen 《Cancer research》1992,52(17):4817-4820
Liposome entrapment of doxorubicin has been shown to reduce its cardiotoxicity in vivo and increase its therapeutic index. A further improvement in therapeutic index could be achieved through targeting of liposome-entrapped drug selectively to cancer cells. Monoclonal antibodies against the squamous lung cancer cell line KLN-205 have been ligated to the surface of long-circulating (Stealth) and conventional liposomes. The antibody-bearing liposomes showed specific, competitive uptake by KLN-205 cells as compared to liposomes bearing nonspecific isotype-matched antibodies or antibody-free liposomes. Doxorubicin-containing antibody-liposomes resulted in as much as a 15-fold decrease in the 50% inhibitory concentration for doxorubicin against KLN-205 cells as compared to free doxorubicin or doxorubicin entrapped in antibody-free liposomes.  相似文献   
66.
Genetic analysis of a set of six Mycobacterium tuberculosis strains differing in virulence for the guinea pig revealed an altered restriction enzyme fragmentation pattern associated with the superoxide dismutase (SOD) gene in a low-virulence, isoniazid-resistant strain. In addition, it was found that the SOD enzyme produced by the isoniazid-resistant strain differed in its electrophoretic mobility from the SOD of other M. tuberculosis strains. Detailed analysis of these strain-specific differences showed that the restriction fragment length polymorphism resulted from the presence of a copy of a repetitive element 552 bp upstream of the SOD gene and that the anomalous electrophoretic mobility arose from a single nucleotide change, resulting in replacement of an aspartic acid residue by histidine in the SOD enzyme of the isoniazid-resistant strain. Possible relationships between genetic changes and strain-dependent differences in virulence are discussed.  相似文献   
67.
A fatal case of strychnine intoxication is reported. The patient expired despite early aggressive management and prevention of metabolic complications. Serial blood levels are reported. In contrast to a previous report describing first order elimination kinetics, our data suggest that strychnine follows Michaelis-Menton elimination kinetics. The case illustrates the rapid, dramatic course of severe strychnine ingestions. A review of the toxicokinetics, mechanism of action and treatment of strychnine intoxication follows.  相似文献   
68.
69.
A new look at grief   总被引:1,自引:0,他引:1  
  相似文献   
70.
Medical complications of prematurity   总被引:4,自引:0,他引:4  
The improved survival of extremely premature infants has generated intense interest in the quality of life of the survivors. This review focuses on the major long-term complications of prematurity (developmental disability, retinopathy of prematurity, chronic lung disease) and concludes with an overview of the broader spectrum of morbidity. Severe impairment (cerebral palsy, mental retardation, retrolental fibroplasia, severe chronic lung disease) fortunately occurs in a small proportion of survivors. However, the prevalence of the lesser morbidities (minimal cerebral dysfunction/learning disability, poor growth, postneonatal illnesses, rehospitalization) is less clearly defined. These problems all have an impact on families, and on medical and educational services.  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