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   22431篇
  免费   2794篇
  国内免费   459篇
耳鼻咽喉   131篇
儿科学   791篇
妇产科学   385篇
基础医学   1709篇
口腔科学   209篇
临床医学   2510篇
内科学   5634篇
皮肤病学   348篇
神经病学   1547篇
特种医学   369篇
外科学   2256篇
综合类   1747篇
现状与发展   1篇
一般理论   5篇
预防医学   5069篇
眼科学   777篇
药学   937篇
  3篇
中国医学   226篇
肿瘤学   1030篇
  2024年   56篇
  2023年   443篇
  2022年   264篇
  2021年   472篇
  2020年   444篇
  2019年   215篇
  2018年   779篇
  2017年   774篇
  2016年   833篇
  2015年   804篇
  2014年   743篇
  2013年   998篇
  2012年   1263篇
  2011年   2041篇
  2010年   1238篇
  2009年   1021篇
  2008年   1151篇
  2007年   1155篇
  2006年   965篇
  2005年   1089篇
  2004年   1884篇
  2003年   1677篇
  2002年   1208篇
  2001年   945篇
  2000年   504篇
  1999年   476篇
  1998年   412篇
  1997年   343篇
  1996年   162篇
  1995年   119篇
  1994年   112篇
  1993年   143篇
  1992年   125篇
  1991年   87篇
  1990年   87篇
  1989年   73篇
  1988年   63篇
  1987年   53篇
  1986年   46篇
  1985年   32篇
  1984年   24篇
  1983年   19篇
  1982年   20篇
  1981年   22篇
  1980年   14篇
  1977年   13篇
  1975年   13篇
  1974年   18篇
  1968年   17篇
  1928年   13篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
BACKGROUND:  The worst outcome of gastrointestinal complications is death. Data regarding those associated with nonsteroidal antiinflammatory drug (NSAID) or aspirin use are scarce.
AIM:  To determine mortality associated with hospital admission due to major gastrointestinal (GI) events and NSAID/aspirin use.
METHODS:  The study was based on actual count of deaths from two different data sets from 2001. Study 1 was carried out in 26 general hospitals serving 7,901,198 people. Study 2 used a database from 197 general hospitals, representative of the 269 hospitals in the Spanish National Health System. Information regarding gastrointestinal complications and deaths was obtained throughout the Minimum Basic Data Set (CIE-9-MC) provided by participating hospitals. Deaths attributed to NSAID/aspirin use were estimated on the basis of prospectively collected data from hospitals of study 1.
RESULTS:  The incidence of hospital admission due to major GI events of the entire (upper and lower) gastrointestinal tract was 121.9 events/100,000 persons/year, but those related to the upper GI tract were six times more frequent. Mortality rate was 5.57% (95% CI = 4.9–6.7), and 5.62% (95% CI = 4.8–6.8) in study 1 and study 2, respectively. Death rate attributed to NSAID/aspirin use was between 21.0 and 24.8 cases/million people, respectively, or 15.3 deaths/100,000 NSAID/aspirin users. Up to one-third of all NSAID/aspirin deaths can be attributed to low-dose aspirin use.
CONCLUSION:  Mortality rates associated with either major upper or lower GI events are similar but upper GI events were more frequent. Deaths attributed to NSAID/ASA use were high but previous reports may have provided an overestimate and one-third of them can be due to low-dose aspirin use.  相似文献   
992.
During 1993-2003, incidence of tuberculosis (TB) in the United States decreased 44% and is now occurring at a historic low level (14,874 cases in 2003). The Advisory Council for the Elimination of Tuberculosis has called for a renewed commitment to eliminating TB in the United States, and the Institute of Medicine has published a detailed plan for achieving that goal. In this statement, the American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), and the Infectious Diseases Society of America (IDSA) propose recommendations to improve the control and prevention of TB in the United States and to progress toward its elimination. This statement is one in a series issued periodically by the sponsoring organizations to guide the diagnosis, treatment, control, and prevention of TB. This statement supersedes the previous statement by ATS and CDC, which was also supported by IDSA and the American Academy of Pediatrics (AAP). This statement was drafted, after an evidence-based review of the subject, by a panel of representatives of the three sponsoring organizations. AAP, the National Tuberculosis Controllers Association, and the Canadian Thoracic Society were also represented on the panel. This statement integrates recent scientific advances with current epidemiologic data, other recent guidelines from this series, and other sources into a coherent and practical approach to the control of TB in the United States. Although drafted to apply to TB-control activities in the United States, this statement might be of use in other countries in which persons with TB generally have access to medical and public health services and resources necessary to make a precise diagnosis of the disease; achieve curative medical treatment; and otherwise provide substantial science-based protection of the population against TB. This statement is aimed at all persons who advocate, plan, and work at controlling and preventing TB in the United States, including persons who formulate public health policy and make decisions about allocation of resources for disease control and health maintenance and directors and staff members of state, county, and local public health agencies throughout the United States charged with control of TB. The audience also includes the full range of medical practitioners, organizations, and institutions involved in the health care of persons in the United States who are at risk for TB.  相似文献   
993.
导管灌注化疗栓塞治疗肝癌55例临床分析   总被引:1,自引:0,他引:1  
目的:为了解介入治疗对进行期肝癌的临床疗效。方法:本文分析了我院55例肝癌经导管灌注化疗及栓塞治疗的临床资料,随访48例。结果:48例中存活时间半年以上者36例,占75%,1年以上者16例,占33.3%,1年半以上者3例,占6.3%。其中单纯灌注化疗6例,存活超过半年者仅5例。灌注化疗 碘油栓塞(二联)15例,存活超过半年者13例,超过1年者6例。灌注化疗 碘油 明胶海绵栓塞(三联)23例,存活超过半年者18例,超过1年者10例,超过1年半者3例。结论:本法治疗肝癌有较好疗效,二联和三联疗法存活时间显著高于单灌疗法。  相似文献   
994.
995.
单细胞电泳法检测肿瘤患者化疗后淋巴细胞DNA损伤   总被引:1,自引:0,他引:1  
应用单细胞电泳 (SCGE)检测肿瘤患者环磷酰胺化疗后外周血T淋巴细胞DNA损伤。在标准SCGE条件下应用彗星图象分析系统定量分析人T淋巴细胞DNA的损伤程度。彗星图象分析研究结果显示 ,肿瘤患者外周血T淋巴细胞DNA损伤明显强于正常对照组 ,肿瘤患者外周血T淋巴细胞拖尾动量为 10 42± 1 98,正常人群为 1 2 6± 0 77;两者差异极显著 (P <0 .0 1)。肿瘤患者化疗后T淋巴细胞的拖尾长度为 3 3 69± 7 56μm ,DNA损伤的百分比为 3 1 5± 5 46% ;正常人群T淋巴细胞的拖尾长度和DNA损伤的百分比分别为 16 2± 1 5μm和7 46± 1 15% ;两组数据相比差异极显著 (P <0 .0 1)。结论 :单细胞电泳可快速灵敏地检测细胞DNA损伤 ,能用于肿瘤化疗患者的流行病学观察。对于指导临床用药和预后也有指导意义  相似文献   
996.
分米波防治屈肌腱粘连机制的实验研究   总被引:9,自引:2,他引:9  
目的 研究分米波对肌腱粘连和愈合的影响。方法 选用 2 8只白色Leghorn鸡 ,随机平均分为A组 (术后分米波治疗组 )和B组 (手术对照组 ) ,将趾深屈肌腱切断、修复 ,术后 1d~ 3周A组足爪局部用分米波治疗 ,B组不行分米波治疗。每组动物分别于术后 3、6周随机处死 7只 ,进行大体和光镜、电镜观察及生物力学检测。结果 大体和组织学观察见A组粘连明显减少 ,电镜检查A组成纤维细胞蛋白合成代谢较B组更旺盛。生物力学检测显示A组肌腱滑动距离、康复顺应性 抗张力强度均大于B组 (P <0 .0 1)。结论 分米波可有效地促进肌腱愈合 ,减少肌腱粘连 ,为肌腱损伤修复术后的早期康复训练提供了必要的条件 ,是防治肌腱粘连理想的辅助措施  相似文献   
997.
By employing a common protocol and data from electronic health registries in Denmark, Navarre (Spain), Norway and Portugal, we estimated vaccine effectiveness (VE) against hospitalisation due to COVID-19 in individuals aged ≥ 65 years old, without previous documented infection, between October 2021 and March 2022. VE was higher in 65–79-year-olds compared with ≥ 80-year-olds and in those who received a booster compared with those who were primary vaccinated. VE remained high (ca 80%) between ≥ 12 and < 24 weeks after the first booster administration, and after Omicron became dominant.  相似文献   
998.
OBJECTIVE: Because career satisfaction among general internists is relatively low, we sought to understand the impact on satisfaction of general internists managing patients both in and outside of the hospital. Using data from a national survey, we asked, “Among outpatient-oriented general internists (i.e., internists who spend less than 50% of their clinical time caring for inpatients), what effect does time spent in the hospital have on physician satisfaction, stress, and burnout?” DESIGN/PARTICIPANTS: The Physician Worklife Study, in which 5,704 physicians in primary and specialty nonsurgical care selected from the American Medical Association’s Masterfile were surveyed (adjusted response rate=52%), was used. Our analyses focused on clinically active outpatient-oriented general internists (N=339). MEASUREMENTS AND MAIN RESULTS: We constructed multivariate linear models to test for statistically significant associations between the amount of time spent seeing inpatients and physician satisfaction as measured by several satisfaction scales. Even after controlling for total hours worked and other possible confounding variables, we found that increased time working in the hospital was significantly associated with decreases in satisfaction with administration, specialty, autonomy, and personal time, and significantly associated with an increase in life stress. There was also a significant association between increased time spent in the hospital and burnout. CONCLUSIONS: Our findings imply that there may be a tension between the practice of inpatient and outpatient medicine by general internists, and suggest that fewer hospital duties may increase career satisfaction for outpatient-oriented internists. Although additional studies are warranted in order to better understand why these relationships exist, our data suggest that the hospitalist model of inpatient care might be one approach to alleviate stress and improve satisfaction for many general internists.  相似文献   
999.
1000.
BackgroundCentralization of a pancreatoduodenectomy (PD) leads to a lower post-operative mortality, but is unclear whether it also leads to improved radical (R0) or overall resection rates.MethodsBetween 2004 and 2009, pathology reports of 1736 PDs for pancreatic and peri-ampullary neoplasms from a nationwide pathology database were analysed. Pre-malignant lesions were excluded. High-volume hospitals were defined as performing ≥ 20 PDs annually. The relationship between R0 resections, PD-volume trends, quality of pathology reports and hospital volume was analysed.ResultsDuring the study period, the number of hospitals performing PDs decreased from 39 to 23. High-volume hospitals reported more R0 resections in the pancreatic head and distal bile duct tumours than low-volume hospitals (60% versus 54%, P=0.035) although they operated on more advanced (T3/T4) tumours (72% versus 58%, P < 0.001). The number of PDs increased from 258 in 2004 to 394 in 2009 which was partly explained by increased overall resection rates of pancreatic head and distal bile duct tumours (11.2% in 2004 versus 17.5% in 2009, P < 0.001). The overall reported R0 resection rate of pancreatic head and distal bile duct tumours increased (6% in 2004 versus 11% in 2009, P < 0.001). Pathology reports of low-volume hospitals lacked more data including tumour stage (25% versus 15%, P < 0.001).ConclusionsCentralization of PD was associated with both higher resection rates and more reported R0 resections. The impact of this finding on overall survival should be further assessed.  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