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   4109篇
  免费   227篇
  国内免费   16篇
耳鼻咽喉   25篇
儿科学   53篇
妇产科学   140篇
基础医学   511篇
口腔科学   174篇
临床医学   319篇
内科学   743篇
皮肤病学   100篇
神经病学   368篇
特种医学   157篇
外科学   652篇
综合类   45篇
一般理论   1篇
预防医学   408篇
眼科学   49篇
药学   282篇
中国医学   9篇
肿瘤学   316篇
  2023年   15篇
  2022年   37篇
  2021年   74篇
  2020年   52篇
  2019年   62篇
  2018年   86篇
  2017年   55篇
  2016年   58篇
  2015年   85篇
  2014年   121篇
  2013年   133篇
  2012年   223篇
  2011年   263篇
  2010年   134篇
  2009年   148篇
  2008年   219篇
  2007年   275篇
  2006年   259篇
  2005年   266篇
  2004年   239篇
  2003年   261篇
  2002年   228篇
  2001年   73篇
  2000年   79篇
  1999年   68篇
  1998年   38篇
  1997年   30篇
  1996年   35篇
  1995年   16篇
  1994年   17篇
  1993年   20篇
  1992年   35篇
  1991年   22篇
  1990年   32篇
  1989年   32篇
  1988年   16篇
  1987年   29篇
  1986年   30篇
  1985年   17篇
  1984年   29篇
  1983年   17篇
  1982年   14篇
  1981年   24篇
  1980年   22篇
  1979年   25篇
  1978年   24篇
  1975年   17篇
  1974年   17篇
  1971年   14篇
  1970年   14篇
排序方式: 共有4352条查询结果,搜索用时 31 毫秒
1.
2.

Background

We have recently shown that human epididymis protein 4 (HE4) levels correlate with the severity of cystic fibrosis (CF) lung disease. However, there are no data on how HE4 levels alter in patients receiving CFTR modulating therapy.

Methods

In this retrospective clinical study, 3 independent CF patient cohorts (US-American: 29, Australian: 12 and Irish: 19 cases) were enrolled carrying at least one Class III CFTR CF-causing mutation (p.Gly551Asp) and being treated with CFTR potentiator ivacaftor. Plasma HE4 was measured by immunoassay before treatment (baseline) and 1–6?months after commencement of ivacaftor, and were correlated with FEV1 (% predicted), sweat chloride, C-reactive protein (CRP) and body mass index (BMI).

Results

After 1?month of therapy, HE4 levels were significantly lower than at baseline and remained decreased up to 6?months. A significant inverse correlation between absolute and delta values of HE4 and FEV1 (r?=??0.5376; P?<?.001 and r?=??0.3285; P?<?.001), was retrospectively observed in pooled groups, including an independent association of HE4 with FEV1 by multiple regression analysis (β?=??0.57, P?=?.019). Substantial area under the receiver operating characteristic curve (ROC-AUC) value was determined for HE4 when 7% mean change of FEV1 (0.722 [95% CI 0.581–0.863]; P?=?.029) were used as classifier, especially in the first 2?months of treatment (0.806 [95% CI 0.665–0.947]; P?<?.001).

Conclusions

This study shows that plasma HE4 levels inversely correlate with lung function improvement in CF patients receiving ivacaftor. Overall, this potential biomarker may be of value for routine clinical and laboratory follow-up of CFTR modulating therapy.  相似文献   
3.
The objective of this study is to test the luminous efficiency functions V(lambda), V'(lambda), V(10)(lambda) and their linear combinations on the basis of a data set gained from a simulated mesopic night-time driving experiment. Another aim is to provide 'real-world' data for the 'X framework' or 'linear combination model', and to find out its limits in a practical situation. Human performance was measured by the reaction time method. Results show that the single parameter of the linear combination of photopic and scotopic luminous efficiency functions can be determined analytically with little variation for a given mesopic background luminance level and a given visual target colour, but the computation leads to considerable deviations comparing all three target colours (red, green and blue) used in the experiment. The conclusion for the given experimental conditions is that the single parameter of the linear combination model has an increasing deviation for lower background luminance levels.  相似文献   
4.
1. The importance of early relief of scar disabilities of the hand is emphasized–that is, before joint changes are established. 2. The part of early wound healing, early function and correct use of physiotherapy in preventing and minimizing scar disabilities of the hand is stated. 3. The “hand grenade” type of injury is described and used as a basis to describe the principles of an effective scar excision and replacement by a full-thickness skin graft. 4. A “through” type of hand wound is described in so far as scar effects are concerned. The principles of effective treatment by (a) scar excision and rearrangement for small scars and (b) scar excision and direct flap replacement for large scars are set out. 5. Other types of scar disability and their treatment are indicated– namely, web scars, adherent scars of fingers and burn scars. 6. A plea is made for the full application of plastic surgery to obtain better results from all hand wounds.  相似文献   
5.
INTRODUCTION: To plan for future acceptance and implementation of computer-related technology, it is necessary to understand orthodontists' current perceptions and attitudes toward emerging technologies. METHODS: An anonymous, self-administered, mail-out survey of Canadian orthodontists was conducted. The response rate was 45.6% (304/667). RESULTS: Most orthodontists indicated that computer technology could improve current practice efficiency and quality of patient care. Only 15% reported that digital models are quite or very useful; 73.6%, 69.1%, 55%, and 37.4% agreed or strongly agreed with using digital and electronic technology to consult with other dental specialists, other orthodontists, general dentists, and the public, respectively. Cost of the technology was reported as a significant or insurmountable obstacle by 54% of the respondents. Interprovincial legislation, unclear consultation remuneration guidelines, and lack of comfort with the technology were not perceived as significant obstacles. Only 36% reported security or privacy issues as a significant or insurmountable obstacle. CONCLUSIONS: Canadian orthodontists seem to view digital and electronic technology as useful and capable of improving their offices' efficiency and production. Although they are sensitive to some potential obstacles, they are willing to overcome these and incorporate the technology into their practices.  相似文献   
6.
7.
8.
PURPOSE: To study efficacy and toxicity of radiochemotherapy in esophageal cancer including initial endoluminal high-dose-rate brachytherapy (HDR-BT). PATIENTS AND METHODS: Between 01/1995 and 06/2005, 61 patients with esophageal cancer were treated preoperatively with definitive and palliative intent. Treatment started with intraluminal HDR-BT for recanalization of the esophagus (single fraction size of 8 Gy in 0.5 cm depth, three times, q7d) followed by external-beam radiation therapy (50 Gy total dose, 5 x 2 Gy/week, 25 fractions in 5 weeks). Chemotherapy was started simultaneously with external irradiation (three courses of cisplatin and 5-fluorouracil, q21d). RESULTS: Swallowing function improved in 55/61 patients (dysphagia classification according to the RTOG), and worsened in 6/61 patients, respectively. Median duration of symptomatic improvement was 11 months, median follow-up 12 months (range 3-68 months). Following simultaneous radiochemotherapy, tumor resectability was achieved in 7/25 patients of the neoadjuvant group, and the histological specimen showed complete remission in 6/7 patients. CONCLUSION: These results indicate a favorable effect of simultaneous radiochemotherapy starting with endoluminal HDR-afterloading-( AL-)BT in esophageal cancer.  相似文献   
9.
Summary Rats were treated with desipramine 5mg/kg, nomifensine 10mg/kg, zimelidine 25 mg/kg or with 0.9% sodium chloride once a day during the second and third weeks after birth, and brain stem, caudate/putamen and cortical monoamines, and caudate/putamen dopamine D1 (3[H]SCH 23390) and D2 (3[H]spiroperidol) receptor binding were measured when rats were at two months of age. In the brain stem, the concentration of 3-methoxy-4-hydroxy-phenyl glycol was increased in nomifensine rats and the ratio of 5-hydroxyindoleacetic acid to 5-hydroxytryptamine was increased in zimelidine rats. In the caudate/putamen, the concentrations of 3,4-dihydroxyphenylacetic acid and homovanillic acid and the ratio of homovanillic acid to dopamine were increased in desipramine rats; neither3[H]SCH 23390 nor3[H]spiroperidol binding were affected by any of the three monoamine uptake inhibiting antidepressants studied. In the cortex, the ratio of 5-hydroxyindoleacetic acid to 5-hydroxytryptamine was increased in desipramine and zimelidine rats. The findings suggest that desipramine but not nomifensine increases the metabolism of dopamine in the caudate/ putamen and nomifensine but not desipramine increases the metabolism of norepinephrine in the brain stem, and furthermore that the metabolism of serotonin is affected by desipramine as well as by zimelidine. It is possible that also treatment of women with these drugs during late pregnancy causes long-lasting changes in the brain of human fetus.  相似文献   
10.
OBJECTIVES: Persisting air leakage after pulmonary resection remains a significant problem. The aim of the study was to evaluate the incidence of air leakage after standard lobectomy and test the efficacy and safety of TachoComb (TC). METHODS: A total of 189 patients undergoing lobectomy were enrolled in a multi-centre, open, randomised, and prospective study to test the efficacy and safety of TachoComb (TC) for air leakage treatment. Air leakage was assessed by water submersion test, and scored as grades 0 if no, 1 if countable, 2 if a stream of and 3 if coalescent bubbles have been observed. Any sites with grade 3 air leakage received further stapling or limited suturing until grade 0, 1 or 2 was obtained. Treatment of air leakage was done with TC or suturing according to randomisation. Air leakage was assessed by further submersion tests. Postoperative air leakage was assessed using the Pleur-Evac system. RESULTS: Overall incidence of air leakage 48+/-6 h after surgery was 34% for TC and 37% for standard treatment (P=0.76). The reduction of intra-operative air leak intensity in the subgroup with grades 1-2 was significantly higher for the TC group (P=0.015). Postoperative air leakage intensity in the subgroup with air leakage grades 1-2 was lower for TC than standard treatment (P=0.047). The mean duration of postoperative air leakage in the subgroup with grades 1-2 was shorter for the TC group than for standard treatment, i.e. 1.9+/-1.4 vs. 2.7+/-2.2 days (P=0.015). CONCLUSIONS: TC could be proven as well-tolerated and safe. In the subgroup of patients with established air leakage, TC showed superior potential in reduction of intra-operative air leakage as well as in reduction of intensity and duration of postoperative air leakage.  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