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   53915篇
  免费   3351篇
  国内免费   249篇
耳鼻咽喉   528篇
儿科学   1043篇
妇产科学   726篇
基础医学   7028篇
口腔科学   1114篇
临床医学   5762篇
内科学   11668篇
皮肤病学   1064篇
神经病学   6442篇
特种医学   2684篇
外科学   9014篇
综合类   352篇
一般理论   14篇
预防医学   2510篇
眼科学   735篇
药学   3261篇
中国医学   73篇
肿瘤学   3497篇
  2023年   449篇
  2022年   718篇
  2021年   1459篇
  2020年   873篇
  2019年   1316篇
  2018年   1499篇
  2017年   1176篇
  2016年   1417篇
  2015年   1638篇
  2014年   2055篇
  2013年   2528篇
  2012年   4081篇
  2011年   4099篇
  2010年   2447篇
  2009年   2231篇
  2008年   3557篇
  2007年   3661篇
  2006年   3376篇
  2005年   3348篇
  2004年   2944篇
  2003年   2857篇
  2002年   2581篇
  2001年   647篇
  2000年   517篇
  1999年   549篇
  1998年   520篇
  1997年   401篇
  1996年   336篇
  1995年   275篇
  1994年   258篇
  1993年   210篇
  1992年   239篇
  1991年   233篇
  1990年   204篇
  1989年   192篇
  1988年   183篇
  1987年   147篇
  1986年   156篇
  1985年   185篇
  1984年   180篇
  1983年   147篇
  1982年   118篇
  1981年   97篇
  1980年   89篇
  1979年   122篇
  1978年   92篇
  1977年   101篇
  1976年   89篇
  1974年   104篇
  1973年   87篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Dealing with psychiatry's stigma   总被引:1,自引:0,他引:1  
The stigma associated with psychiatry is the most critical problem facing the profession, the author contends. He identifies the major sources of stigma as psychiatrists' internal conflicts over treatment ideologies and methods and the hostility between psychiatrists and other physicians that has led to disparagement of psychiatry as a medical specialty. To combat the stigma he recommends that highest priority be given to efforts to unify the profession and to increase psychiatry's participation in organized medicine. He also urges psychiatrists to limit self-revelation and self-exploration in the media, to emphasize the broad range of knowledge and skills that makes them uniquely suited to perform evaluative and triage functions, and to halt the current practices of shunting whole classes of patients off to other disciplines for care and of educating other disciplines in psychiatric techniques.  相似文献   
52.
53.
Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up&go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function.  相似文献   
54.
55.
56.
57.
The lipid-lowering agents, statins, are the most commonly prescribed class of drugs in the western world. Because of their widespread use, many patients undergo surgical procedures while on statins. Statins, in addition to cholesterol-lowering effects, also have anticoagulant, immunosuppressive, and antiproliferative properties that may affect the risk of local wound complications. This study investigated the relationship between statins and postoperative wound complications in a large cohort of patients undergoing inguinal or ventral hernia repair. Data mining was performed in the Veterans Integrated Service Network (VISN)16 Data Warehouse. This database contains clinical and demographic information about all veterans cared for at the ten VA Medical Centers that comprise the South Central VA Healthcare Network in the mid-south region of the US. Aggregate data (age, body mass index, smoking history, gender, race, history of diabetes, statin use, and postoperative wound complications) were obtained for all patients who underwent inguinal or ventral hernia repair during the period October 1, 1996–November 30, 2004. During the period of the query, 10,782 patients (10,676 male, 106 female), 1,242 (11.5%) of whom received statins, underwent herniorrhaphy. Statin use did not affect the risk of wound infection or delayed wound healing. Statin use was, however, associated with an increased rate of local postoperative bleeding complications (P=0.01). When the type of hernia, age, smoking, diabetes, and body mass index were included in a multivariate analysis, statins remained borderline significant as an independent predictor of wound hematoma/postoperative bleeding (P=0.04), odds ratio 1.6 (95% CI 1.03–2.44). Patients who undergo inguinal herniorrhaphy while on statins have an increased risk of postoperative wound hematoma/hemorrhage. Focus on additional factors that may affect the propensity to postoperative bleeding and on meticulous intraoperative hemostasis are particularly important in such patients.  相似文献   
58.
Chromosome 17 is a frequent target during breast-cancer formation and progression. It has been shown to be affected by allele losses at multiple sites, as well as by DNA amplification. Our aim was to delineate a map of the genetic alterations on chromosome 17 in a given set of breast tumors. To this end we analyzed 151 pairs of tumor and cognate lymphocyte DNAs by Southern blotting with 5 RFLP or VNTR probes and by PCR at 8 CA repeat polymorphic loci for LOHs. Moreover, we studied DNA amplification of the evi2, erbB2, thra1, gcsf and rara genes. Data presented here point strongly to the existence of 5 distinct regions of allele losses on chromosome 17:2 on 17p, 3 on 17q. Of the 2 regions on 17p, one involves tp53 while the second is located more distally toward the telomere. LOH was found in 45.9% and 58.8% respectively. The 3 regions on 17q are located: (i) on the proximal portion of the long arm band q21, corresponding to the brcal region; (ii) in a central region defined by the marker D17S74; (iii) on the distal part of 17q (band q25) characterized by losses of the marker D17S24. Each of these regions presented respectively allele losses in 47.5%, 33.3% and 40.8% of the informative tumors. Whereas some tumors presented patterns of LOH consistent with the loss of a complete chromosomal arm or of large portions of the chromosome, a high proportion of the analyzed tumors showed interstitial losses. Amplifications were found in 15% of the tumors and were centered around erbB2. An altered chromosome 17 (bearing an LOH or a DNA amplification) was found in more than 80% of the breast tumor set analyzed here and multiple anomalies affecting this chromosome were often detected in the same sample.  相似文献   
59.
60.
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