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   516739篇
  免费   31162篇
  国内免费   587篇
耳鼻咽喉   6905篇
儿科学   16841篇
妇产科学   13521篇
基础医学   85062篇
口腔科学   14486篇
临床医学   44413篇
内科学   93766篇
皮肤病学   12167篇
神经病学   36257篇
特种医学   18461篇
外国民族医学   63篇
外科学   77078篇
综合类   8475篇
一般理论   118篇
预防医学   38977篇
眼科学   12150篇
药学   40563篇
  4篇
中国医学   1007篇
肿瘤学   28174篇
  2018年   4941篇
  2015年   4509篇
  2014年   6067篇
  2013年   9545篇
  2012年   12866篇
  2011年   14268篇
  2010年   8299篇
  2009年   7770篇
  2008年   13692篇
  2007年   14697篇
  2006年   14937篇
  2005年   14353篇
  2004年   14046篇
  2003年   13387篇
  2002年   13266篇
  2001年   24066篇
  2000年   25079篇
  1999年   20555篇
  1998年   5426篇
  1997年   4705篇
  1996年   5041篇
  1995年   4625篇
  1994年   4318篇
  1993年   4135篇
  1992年   15725篇
  1991年   16309篇
  1990年   16422篇
  1989年   15796篇
  1988年   14575篇
  1987年   14419篇
  1986年   13597篇
  1985年   12975篇
  1984年   9627篇
  1983年   8247篇
  1982年   4559篇
  1981年   4229篇
  1979年   9418篇
  1978年   6855篇
  1977年   5772篇
  1976年   5602篇
  1975年   6396篇
  1974年   7634篇
  1973年   7130篇
  1972年   6960篇
  1971年   6685篇
  1970年   6172篇
  1969年   5888篇
  1968年   5559篇
  1967年   5012篇
  1966年   4451篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Neuroscience and Behavioral Physiology - Objective. To assess the association of the DRD2 gene and its interaction with the HTR2C gene with the characteristics of the hedonistic and activatory...  相似文献   
52.
Neuroscience and Behavioral Physiology - The characteristics of long-term potentiation (LTP) in field CA1 of living hippocampal slices from rats aged 17–33 days were studied after neonatal...  相似文献   
53.
Neuroscience and Behavioral Physiology - Confocal microscopy was used to analyze double immunolabeling and provided evidence of the locations of a large number of tyrosine...  相似文献   
54.
Neuroscience and Behavioral Physiology - Objective: To study the characteristics of the expression of inducible NO synthase (iNOS) in hippocampal fields CA1 and CA3 in adult male humans and adult...  相似文献   
55.
Vanillylmandelic acid, a catecholamine end-metabolite, has been shown to have several biological properties in previous studies, despite considered biologically inactive. We examined the potential effects of vanillylmandelic acid on the ischemic heart following myocardial infarction and reperfusion on a rat model. Thirty-four female Wistar rats were randomized into two groups, control and experimental. They were anesthetized and subjected to myocardial infarction through left anterior descending artery ligation. A previously studied dose of vanillylmandelic acid (10 mg/kg) was administered and the following parameters were studied during ischemia and reperfusion: a) mortality b) severity of ventricular tachyarrhythmias c) premature ventricular contractions and d) heart rate. Administration of vanillymandelic acid significantly reduced the severity of ventricular tachyarrhythmias and mortality rate during reperfusion, while it did not affect any other of the parameters studied. In conclusion, reperfusion injury was blunted through vanillylmandelic acid administration, which seems to be mediated by parasympathetic activation.  相似文献   
56.
Tuberculosis (TB) is described as lethal disease in the world. Resistant to TB drugs is the main reason to have unfavourable outcomes in the treatment of TB. Therefore, new agents to replace existing drugs are urgently needed. Previous reports suggested that InhA inhibitors, an enoyl-ACP-reductase, might provide auspicious candidates which can be developed into novel antitubercular agents. In this review, we explain the role of InhA in the resistance of isoniazid. Furthermore, five classes of InhA inhibitors, which display novel binding modes and deliver evidence of their prosperous target engagement, have been debated.  相似文献   
57.
Background Appropriate antibiotic treatment of cat scratch disease (CSD) in pediatrics is not well established. Objective The purpose of this study was to evaluate the response rates of antibiotic therapy in pediatrics with CSD. Methods The electronic medical records of a cohort of pediatric patients with confirmed diagnosis of CSD (2006–2016) were reviewed, retrospectively. Data collection included patient demographics, clinical and laboratory results, antibiotic treatment and follow-up evaluations. Results One hundred and seventy-five patients (aged 7.4?±?4.4 years) had confirmed CSD. Azithromycin and trimethoprim/sulfamethoxazole (TMP/SMX) were the largest groups with documented effectiveness at follow-up visits. Resolution and improvement of CSD was observed in 51.4% and 61.5% of patients with azithromycin and TMP/SMX, respectively among those with follow-up assessment. The effectiveness of azithromycin and TMP/SMX was comparable (p?=?0.56). Conclusion Azithromycin and TMP/SMX were most frequently prescribed antibiotics. Azithromycin appeared to be an appropriate option for the treatment of CSD. TMP/SMX may be considered as an alternative antibiotic when azithromycin cannot be used.  相似文献   
58.
Policy makers increasingly rely on hospital competition to incentivize patients to choose high-value care. Amongst all possible drivers, the travel distance without any doubt is one of the most important. In this paper we propose the use of a spatial Bayesian hierarchical model to assess the impact of distance on the number of patient admissions in hospitals, and thereby, compare hospital attractiveness. To this aim a MCMC sampler has been designed. We apply our methodology to patient admissions for asthma in four hospitals located in the Hérault department of France. Results indicate that the most attractive hospital is the CHU Montpellier.  相似文献   
59.
60.
The relationship between volatile fatty acids (VFAs) in pus and infecting bacterial species was examined in order to establish a rapid identification system for anaerobic microorganisms in purulent inflammation in the oro-maxillary region. VFAs were detected by the direct injection of pus into gas-liquid chromatography (GLC). Bacterial examination was carried out by anaerobic culture using blood agar plates. The bacterial identification was carried out mainly according to the VPI manual. Analysis of the direct VFA patterns of each sample resulted in 5 groups. The following bacterial species were the main isolates in each group: Streptococcus intermedius in Group A, Peptostreptococcus micros in Group B, Fusobacterium nucleatum in Group C, Bacteroides gingivalis in Group D, and Peptostreptococcus anaerobius in Group E. The profile of VFAs produced in the PYG culture medium of the above isolated bacteria was compared with the direct VFA patterns. Agreement ratios between direct and PYG VFA patterns were as follows: Group A, 47.1%; Groups B and C, 45.0%; Group D, 87.5%; and Group E, 62.9%. The acetic acid concentration was more than 14 x 10(-4) meq/ml in Group B, the butyric acid concentration was more than 7 x 10(-4) meq/ml in Group C, and the iso-caproic acid concentration was more than 14 x 10(-4) meq/ml in Group E. In these cases, it was found that the agreement ratios between the direct and PYG FVA pattern were high. In Group D, irrespective of the concentration of iso-valeric acid detected, the agreement ratio was very high. The antibiotic susceptibility of the isolates was studied. Efficiency rates of ABPC, PIPC, CCL, CEZ, CMZ, SBT/CPZ, JM, CLDM, MINO and GM were relatively low and resistant rates were high for the gram-negative rods.  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