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   21931篇
  免费   1457篇
  国内免费   479篇
耳鼻咽喉   149篇
儿科学   1073篇
妇产科学   304篇
基础医学   1911篇
口腔科学   46篇
临床医学   2775篇
内科学   2635篇
皮肤病学   102篇
神经病学   1290篇
特种医学   800篇
外国民族医学   2篇
外科学   3951篇
综合类   3056篇
现状与发展   2篇
预防医学   2007篇
眼科学   41篇
药学   2237篇
  14篇
中国医学   586篇
肿瘤学   886篇
  2024年   61篇
  2023年   308篇
  2022年   573篇
  2021年   815篇
  2020年   772篇
  2019年   721篇
  2018年   747篇
  2017年   706篇
  2016年   742篇
  2015年   765篇
  2014年   1492篇
  2013年   1513篇
  2012年   1317篇
  2011年   1367篇
  2010年   1124篇
  2009年   1074篇
  2008年   1084篇
  2007年   1078篇
  2006年   966篇
  2005年   843篇
  2004年   722篇
  2003年   594篇
  2002年   512篇
  2001年   456篇
  2000年   362篇
  1999年   353篇
  1998年   307篇
  1997年   257篇
  1996年   214篇
  1995年   191篇
  1994年   162篇
  1993年   157篇
  1992年   169篇
  1991年   125篇
  1990年   122篇
  1989年   109篇
  1988年   100篇
  1987年   86篇
  1986年   105篇
  1985年   123篇
  1984年   94篇
  1983年   73篇
  1982年   99篇
  1981年   72篇
  1980年   52篇
  1979年   35篇
  1978年   36篇
  1977年   27篇
  1976年   23篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The pattern of gastro-intestinal (GIT) and Respiratory tract (RTI) diseases in rural areas of the Varanasi district, U.P. (India) was studied from the outpatient (OPD) attendance between July 1985 to June 1986. Out of a total of new patients, 19.71% had respiratory diseases in contrast to 27.9% with GIT disease. A decreasing trend was observed in attendance rates as age advanced. The difference in age distribution of males and females was statistically significant. The attendance rates for GIT diseases were higher in female (29.16%) than in males (25.16%) whereas in RTI, the rates were higher in males (19.39%) than in females (18.77%). The attendance rate was found to be higher in rainy season (23.59%) followed by summer (14.50%). Diarrhoea (15.44%) and upper (URTI) respiratory tract infection (19.93%) occupied the major recorded episodes.  相似文献   
72.
Until recently, most reported cases of bacteraemia caused by multidrug-resistant strains of Enterobacteriacae producing an extended-spectrum beta-lactamase (ESBL) in Europe have been nosocomial in origin. However, increasing numbers of reports of community-acquired bacteraemia and urinary tract infection caused by ESBL-producing microorganisms suggest that the geographical origin of patients should be taken into account as a risk-factor for possible ESBL production. Early identification of patients at high-risk of infection with ESBL-producing microorganisms, based on their geographical origin and travel history, should help to optimise initial antibiotic treatment strategies for severe urinary tract infections in Europe.  相似文献   
73.
The effect of 4 mg oral naloxone on preoperative gastric volume and pH of gastric aspirate was studied in a double-blind, randomized study. Twenty patients received 10 ml of naloxone (4 mg) mixed with 10 ml of orange juice, and 20 patients received 10 ml of isotonic saline mixed with 10 ml of orange juice, 2 h before surgery. Gastric content was obtained immediately after intubation of the trachea. No significant difference in gastric volume and pH of gastric aspirate was found between the two groups. It is concluded that naloxone does not affect gastric emptying and gastric acid secretion to a degree great enough to protect against aspiration of gastric contents into the lungs.  相似文献   
74.
本文对121例急性梗阻性化脓性胆管炎(AOSC)进行了临床分析讨论了诊断及治疗。结果表明,早期诊断,尽快手术治疗,积极防治并发症,是提高疗效降低死亡的关键。肝肾功能衰竭和中毒性休克是本病的主要死因,占死亡总人数的83%,60岁以上的老人不是手术的禁忌症。  相似文献   
75.
76.
血清TPS浓度在消化道肿瘤中价值的研究   总被引:4,自引:0,他引:4  
共选择30例消化道肿瘤病人,其中食管癌,胃癌,大肠癌各10例,设健康献血者30例,对两组血清特异型组织多肽抗原浓度进行了检测,结果肿瘤组血清TPS浓度明显高于健康人。消化道肿瘤阳性检出经达70%,其中食管癌80%,胃癌60%,大肠癌70%。消化道肿瘤合并淋巴转移阳性检出率达76.9%,其中食管癌100%,胃癌66.7%,大肠癌70.0%。随着病程发展,血清TPS浓度呈现升高趋势。  相似文献   
77.
78.
Previous studies from this laboratory indicated a role for epidermal growth factor (EGF) in androgen-dependent male reproductive tract differentiation of the fetal mouse. Expression of an EGF-like protein during Wolffian duct differentiation was indicated from the determinations by radioimmunoassay (RIA) and radioreceptor assay. To further characterize the protein and to assess its role in male sexual differentiation, expression of the protein has been analyzed by Western blot assay and its tissue-specific cellular expression has been determined by immunocytochemical assay in the present study. Western blot analysis of the 18-day fetal male reproductive tract detected an immunoreactive band of the predicted 6-kDa size. Immunocytochemical analysis also detected EGF-specific immunostaining in the Wolffian duct derivatives. At day 18 of gestation, the staining was localized predominantly in the epithelial nuclei of the Wolffian duct derivatives whereas at days 14 and 16 of gestation, the staining was equally distributed in the mesenchymal and epithelial sites of the Wolffian duct derivative. The intensity of the staining increased with progression of differentiation during the 14th–18th days of gestation. Prenatal exposure to the antiandrogen flutamide significantly reduced the immunostaining of the duct. Thus, a role for EGF in Wolffian duct differentiation is indicated.  相似文献   
79.
不明原因下消化道出血的血管造影及导管治疗   总被引:2,自引:1,他引:1       下载免费PDF全文
目的:明确下消化道出血原因及止血治疗。材料与方法:对21例不明原因下消化造出血病人行选择性血管造影,并经导管灌注垂体后叶素、明胶海绵条栓塞。结果:血管造影诊断阳性率为76%,16例病人治疗后均止血。结论:血管造影是诊断不明原因下消化道出血的首选方法,垂体后叶素灌注短期(1周)止血效果显著,但易复发,栓塞治疗更重要的在于确定病变部位以利手术。  相似文献   
80.
The effect of epidural infusions containing fentanyl on maternal gastric emptying in labour was examined using the rate of paracetamol absorption. Women were randomly allocated to receive one of two epidural infusions, bupivacaine 0.125% alone or bupivacaine 0.0625% with fentanyl 2.5 μgml−1 at a rate of 10–12 mlh−1. Paracetamol 1.5 g was given orally to women after either 30 ml of the infusion solution had been given (mean time 2.5 h, study A) or 40–50 ml (mean time 4.5 h, study B). Six venous blood samples were taken over the next 90 min for measurement of plasma paracetamol concentration. There were no significant differences in maximum plasma paracetamol concentration, time to maximum paracetamol concentration and area under the concentration–time curve between the two groups for study A. In study B the time to maximum plasma paracetamol concentration was significantly delayed in women receiving > 100 μg fentanyl compared with controls (p < 0.05). We conclude that the dose of fentanyl that may delay gastric emptying when given by epidural infusion is greater than 100 μg.  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