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   1501096篇
  免费   125846篇
  国内免费   3244篇
耳鼻咽喉   19724篇
儿科学   50289篇
妇产科学   41539篇
基础医学   213697篇
口腔科学   42120篇
临床医学   137083篇
内科学   304306篇
皮肤病学   39314篇
神经病学   128609篇
特种医学   55642篇
外国民族医学   464篇
外科学   222059篇
综合类   32757篇
现状与发展   3篇
一般理论   506篇
预防医学   113782篇
眼科学   32786篇
药学   103279篇
  42篇
中国医学   4315篇
肿瘤学   87870篇
  2021年   12323篇
  2020年   12893篇
  2019年   22984篇
  2018年   24804篇
  2017年   22209篇
  2016年   24353篇
  2015年   25853篇
  2014年   32277篇
  2013年   43551篇
  2012年   48608篇
  2011年   50990篇
  2010年   35527篇
  2009年   31493篇
  2008年   45898篇
  2007年   47419篇
  2006年   48010篇
  2005年   46295篇
  2004年   44224篇
  2003年   42172篇
  2002年   40744篇
  2001年   73641篇
  2000年   75120篇
  1999年   61785篇
  1998年   17018篇
  1997年   15457篇
  1996年   15607篇
  1995年   14810篇
  1994年   13410篇
  1993年   12587篇
  1992年   45846篇
  1991年   43487篇
  1990年   41492篇
  1989年   39554篇
  1988年   36179篇
  1987年   35353篇
  1986年   32860篇
  1985年   31276篇
  1984年   23824篇
  1983年   20023篇
  1982年   12210篇
  1979年   20700篇
  1978年   14577篇
  1977年   12084篇
  1976年   11364篇
  1975年   11619篇
  1974年   13988篇
  1973年   13533篇
  1972年   12633篇
  1971年   11469篇
  1970年   10910篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
The measures for leishmaniasis control include the precise diagnosis of disease. However, although several recombinant antigens have been tested with this biotechnological purpose, no effective product exists, which could detects patients with the active disease, as well as differentiates them from cured and treated patients. In this study, a conserved Leishmania hypothetical protein, which was identified in Leishmania infantum parasites, but evaluated to presents high homology in the amino acid sequences between distinct parasite species, was evaluated for the diagnosis of tegumentary and visceral leishmaniasis. In addition, PBMCs collected from treated and untreated mucosal leishmaniasis (ML) and visceral leishmaniasis (VL) patients, as well as in healthy subjects living in endemic region of disease, were in vitro stimulated, when IFN-γ, IL-4 and IL-10 levels were evaluated in the cell supernatant. Regarding the serological analyses, ELISA experiments using the recombinant protein (rLiHyL) and a human serological panel revealed high sensitivity and specificity values to detect both diseases, while control antigens showed worst results. Regarding the cellular response, results showed that rLiHyL-stimulated cells produced higher IFN-γ and lower IL-4 and IL-10 levels in the supernatants. Also, the anti-protein antibody production was evaluated in these patients, and data showed higher IgG2 and lower IgG1 levels found in the treated patients and healthy controls, demonstrating the stimulation of a Th1-type response induced by the rLiHyL protein. In conclusion, this hypothetical protein can be considered as antigenic in TL and VL, as well as a vaccine candidate to be tested in future studies to protect against disease.  相似文献   
94.
95.
96.

A total of 482 bats representing 32 species and two families were captured in the Amazon forests of the Amapá state in northern Brazil. Nineteen Artibeus planirostris bats (3.9 %) were infested with 160 ticks, all identified as Ornithodoros hasei. Three pools of larvae were screened for rickettsial DNA via polymerase chain reaction (PCR) targeting three rickettsial genes: gltA, ompA and htrA. Only one of them yielded an amplicons of the expected size for all three molecular assays. Comparisons of the obtained sequences including a phylogenetic analysis confirmed the occurrence of “Candidatus Rickettsia wissemanii” in Brazil.

  相似文献   
97.
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   
98.
Inflammation Research - Although some glycolytic intermediates have been shown to modulate several cell type formation and activation, the functional role of fructose 1,6-bisphosphate (FBP) on...  相似文献   
99.
Frequently, patients receiving parenteral nutrition (PN) report hunger during the parenteral infusion, yet experience early satiety once PN is tapered off. Post-PN satiety can interfere with the ability to consume enough nutrients to maintain body weight and nutritional status. Factors such as caloric quantity of infusate, gastric motility changes, and disease pathology have been related to appetite changes. To investigate the effects of PN on food intake and gastric motility without the complicated interactions associated with disease pathology, four normal, healthy rhesus monkeys (Macaca mulatta) were studied. The monkeys were administered PN in amounts ranging from 25% to 100% of their normal daily caloric intake. Food and water were continuously available. PN consistently suppressed voluntary food intake in direct relationship to the amount of nutrient infused. The frequency of large-amplitude hunger-type gastric contractions decreased from control conditions. Upon cessation of PN, appetite remained suppressed for one to two weeks, indicating a self-limiting physiological basis to post-PN satiety. Thus, reduced appetite following PN termination might occur in the clinical setting and the patients' feelings of satiety may not be completely attributed to lack of cooperation or disease pathology.  相似文献   
100.
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   
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