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   1003677篇
  免费   75502篇
  国内免费   5966篇
耳鼻咽喉   13592篇
儿科学   25526篇
妇产科学   23757篇
基础医学   139348篇
口腔科学   29399篇
临床医学   90060篇
内科学   192121篇
皮肤病学   20009篇
神经病学   75041篇
特种医学   39451篇
外国民族医学   108篇
外科学   158698篇
综合类   34299篇
现状与发展   19篇
一般理论   245篇
预防医学   69041篇
眼科学   23053篇
药学   80747篇
  115篇
中国医学   8007篇
肿瘤学   62509篇
  2021年   9093篇
  2019年   8140篇
  2018年   11141篇
  2017年   9530篇
  2016年   10008篇
  2015年   12238篇
  2014年   16372篇
  2013年   22173篇
  2012年   30508篇
  2011年   31963篇
  2010年   20316篇
  2009年   18814篇
  2008年   29450篇
  2007年   30435篇
  2006年   30827篇
  2005年   29098篇
  2004年   27206篇
  2003年   26077篇
  2002年   25238篇
  2001年   56285篇
  2000年   57616篇
  1999年   47624篇
  1998年   11074篇
  1997年   9835篇
  1996年   9848篇
  1995年   9125篇
  1994年   8435篇
  1993年   7711篇
  1992年   35572篇
  1991年   33980篇
  1990年   32808篇
  1989年   31946篇
  1988年   29028篇
  1987年   28294篇
  1986年   26320篇
  1985年   25175篇
  1984年   17848篇
  1983年   15161篇
  1982年   7806篇
  1979年   15795篇
  1978年   10606篇
  1977年   9061篇
  1976年   7874篇
  1975年   8631篇
  1974年   10468篇
  1973年   9861篇
  1972年   9359篇
  1971年   8856篇
  1970年   8427篇
  1969年   7923篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
13.
Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.  相似文献   

14.
目的:观察非霍奇金淋巴瘤(non-Hodgkin's lymphoma,NHL)患者自体造血干细胞移植(autologous hematopoietic stem cell transplantation,ASCT)术后应用重组人α-2b干扰素(α-2b IFN)进行早期干预治疗的临床疗效。方法:选取18例行ASCT的NHL患者为研究对象,移植前疾病评估均未达到完全缓解(complete remission,CR),试验组血象恢复后给予IFN 3 000 000 U次/隔日干预治疗,3个月后停用;对照组未行干扰素干预治疗,分析总体疗效及两组对比的生存情况。结果:随访中位时间为34(10~50)个月,患者中位生存时间为37(31~45)个月,3年总体无进展生存(progressive free survival,PFS)、总生存(overall survivial,OS)分别为54.7%、66.8%。ASCT后试验组1年内无疾病复发,2年内复发率为12.5%;对照组1年内复发率为20%,2年内复发率为30%。结论:NHL患者在ASCT后给予重组人α-2b IFN早期干预治疗,患者耐受性好,可能降低移植后早期复发率。  相似文献   
15.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
16.
17.
18.
19.
20.
Acne vulgaris (acne) is a chronic inflammatory disease of the sebaceous gland, characterized by follicular hyperkeratinization, excessive colonization by Propionibacterium acnes (Pacnes) as well as immune reactions and inflammation. Despite an armamentarium of topical treatments available including benzoyl peroxide, retinoids and azelaic acid, topical antibiotics in monotherapies, especially erythromycin and clindamycin, are still used in Europe to treat acne. This intensive use led to antimicrobial‐resistant P. acnes and staphylococci strains becoming one of the main health issues worldwide. This is an update on the current topical acne treatments available in Europe, their mechanism of action, their potential to induce antimicrobial resistance and their clinical efficacy and safety.  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