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   3750篇
  免费   334篇
  国内免费   5篇
耳鼻咽喉   11篇
儿科学   146篇
妇产科学   72篇
基础医学   545篇
口腔科学   91篇
临床医学   387篇
内科学   617篇
皮肤病学   56篇
神经病学   267篇
特种医学   241篇
外国民族医学   1篇
外科学   550篇
综合类   106篇
一般理论   3篇
预防医学   539篇
眼科学   23篇
药学   196篇
中国医学   2篇
肿瘤学   236篇
  2021年   69篇
  2020年   43篇
  2019年   60篇
  2018年   75篇
  2017年   54篇
  2016年   63篇
  2015年   49篇
  2014年   92篇
  2013年   134篇
  2012年   152篇
  2011年   180篇
  2010年   83篇
  2009年   83篇
  2008年   151篇
  2007年   153篇
  2006年   158篇
  2005年   147篇
  2004年   145篇
  2003年   135篇
  2002年   125篇
  2001年   142篇
  2000年   121篇
  1999年   101篇
  1998年   63篇
  1997年   42篇
  1996年   37篇
  1995年   27篇
  1994年   48篇
  1993年   39篇
  1992年   94篇
  1991年   79篇
  1990年   61篇
  1989年   77篇
  1988年   86篇
  1987年   74篇
  1986年   70篇
  1985年   66篇
  1984年   47篇
  1983年   49篇
  1982年   42篇
  1981年   32篇
  1980年   33篇
  1979年   50篇
  1978年   44篇
  1977年   36篇
  1976年   25篇
  1974年   35篇
  1973年   27篇
  1972年   30篇
  1968年   24篇
排序方式: 共有4089条查询结果,搜索用时 15 毫秒
1.
2.
The precision and accuracy of manual reticulocyte counts using the Miller disc reticle, other ruled reticle and no reticle are compared with the reticulocyte results from the automated Hematrak 590 instrument. Two slides of each of 50 patient blood specimens were sent to the hematology laboratories of each of six participating hospitals. In addition to between-method comparison (precision), the manual method results using the three different counting techniques were each compared with the Hematrak results to determine if there were significant differences in reported results (accuracy). Statistical analysis revealed that the Miller disc method was the most precise and accurate manual method as compared with the Hematrak. Methods without a Miller disc reported significantly higher reticulocyte counts. Imprecision was also higher among non-Miller manual methods. By using the Miller disc, the accuracy and precision of manual methods may be increased to that of the automated Hematrak method.  相似文献   
3.
4.
Study Objective . To evaluate the effects of flurbiprofen therapy on the pharmacokinetics of lithium. Design . Placebo-controlled, single-blind, crossover study. Setting . University-affiliated hospital. Patients . Eleven healthy women with bipolar disorder. Interventions . The subjects received therapeutic doses of lithium administered as an immediate-release capsule every 12 hours. In addition, they received one placebo tablet every 12 hours during phase I and flurbiprofen 100 mg every 12 hours during phase II of the study. Measurements and Main Results . Steady-state pharmacokinetic parameters were measured for each phase. Lithium trough plasma concentration (Cmin) and area under the curve were statistically significantly increased (p<0.05) when patients received flurbiprofen. Flurbiprofen also caused decreases in lithium clearance and 24-hour lithium urine excretion, although the changes did not reach statistical significance. Clinically significant increases in Cmin appeared to be associated with a greater than 1000-μg/24 hour decrease in urinary excretion of prostaglandin E2. Conclusion . Patients with clinically normal renal function may experience an increase in lithium levels with the initiation of flurbiprofen therapy.  相似文献   
5.
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.  相似文献   
6.
Suppurative corneal ulceration in Bangladesh   总被引:8,自引:0,他引:8  
Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.  相似文献   
7.
We studied 637 transfusion recipients seronegative for cytomegalovirus (CMV) in the following categories: neonates; pregnant women; and patients experiencing trauma, burns, cardiovascular surgery (adult or pediatric), major surgery, or gastrointestinal hemorrhages. Cultures and serological tests were used to follow up subjects for evidence of CMV infection for a period of three months after their last transfusion. Six (0.9%) developed CMV infection. No significant differences in risk among patient categories were observed. Infected patients received a significantly larger mean number of units of cellular blood products (CBP; 50.0 +/- 38.9 vs. 6.2 +/- 8.5; P less than .001) and plasma (23.7 +/- 15.3 vs. 2.6 +/- 4.6, P less than .001) than did uninfected patients. This result represents a risk per unit of CBP transfused of 0.14%, or approximately 0.38% per unit of seropositive CBP transfused. We observed, however, that patients exposed to CBP from greater than 30 donors had a higher risk of acquiring CMV infection than would be predicted if infectious units were randomly distributed among all donors (P less than .01).  相似文献   
8.
Intermittent nipple stimulation has been proposed as a substitute for exogenous oxytocin infusion in the performance of contraction stress tests. To compare the uterine activity produced by these two methods, we studied a group of 45 term pregnant women undergoing indicated inductions of labor. Twenty-five patients had nipple stimulation and 20 patients received oxytocin infusions according to a study protocol. The two groups were similar in all obstetric parameters. Pre- and posttest uterine activity was measured by internal tocodynamometry and quantified in Montevideo units. A significant increase in uterine activity occurred in both groups (P less than .01). Regular uterine activity (three contractions in ten minutes) was achieved more rapidly (P less than .005), but at a lower level (P less than .001) in the nipple stimulation group. Pre- and posttest tonus did not change significantly in either group. In the nipple stimulation group, five patients (20%) did not achieve adequate contraction patterns after 15 stimulation-rest cycles (a total of 110 minutes) and three subjects (12%) experienced uterine hyperstimulation. These observations suggest that exogenous oxytocin and intermittent nipple stimulation may not have equivalent effects on uterine contractility. Therefore, it may not be justified to substitute one technique for the other or to use the same criteria for interpretation of contraction stress tests produced by both techniques.  相似文献   
9.
Aim: The purpose of this project was to operationalize and apply a previously identified set of performance measures designed to evaluate services for those experiencing a first episode of a schizophrenia spectrum disorder. Methods: Operational definitions were developed for previously identified measures through an iterative process of discussions between clinical experts and health‐care evaluators. Data were collected from existing sources including corporate databases, clinical databases and chart review. Results: Definitions were developed for 44 measures covering seven of eight domains recommended for service level evaluation by the Canadian Institute for Health Information domains. Forty measures could be calculated. Conclusions: The measures represent a comprehensive set of performance measures suitable for the evaluation of services for people with a first‐episode psychosis. The measures could be used by other services in order to establish standards and norms for routine clinical practice.  相似文献   
10.
Antibody Conjugates for the Treatment of Cancer   总被引:3,自引:0,他引:3  
  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