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   395篇
  免费   10篇
  国内免费   27篇
儿科学   23篇
妇产科学   1篇
基础医学   39篇
口腔科学   7篇
临床医学   48篇
内科学   100篇
皮肤病学   6篇
神经病学   13篇
特种医学   52篇
外科学   52篇
综合类   7篇
预防医学   9篇
眼科学   2篇
药学   46篇
中国医学   2篇
肿瘤学   25篇
  2023年   1篇
  2022年   2篇
  2021年   7篇
  2020年   1篇
  2019年   6篇
  2018年   9篇
  2017年   6篇
  2016年   8篇
  2015年   3篇
  2014年   8篇
  2013年   14篇
  2012年   18篇
  2011年   18篇
  2010年   10篇
  2009年   13篇
  2008年   14篇
  2007年   34篇
  2006年   13篇
  2005年   7篇
  2004年   17篇
  2003年   6篇
  2002年   4篇
  2001年   10篇
  2000年   6篇
  1999年   7篇
  1998年   18篇
  1997年   18篇
  1996年   11篇
  1995年   10篇
  1994年   13篇
  1993年   15篇
  1992年   5篇
  1991年   10篇
  1990年   2篇
  1989年   8篇
  1988年   15篇
  1987年   5篇
  1986年   7篇
  1985年   9篇
  1984年   4篇
  1983年   2篇
  1982年   6篇
  1981年   2篇
  1980年   5篇
  1979年   1篇
  1978年   9篇
  1977年   5篇
  1976年   7篇
  1975年   3篇
排序方式: 共有432条查询结果,搜索用时 46 毫秒
1.
Background Processing multiple tissue sections in large Mohs cases is time consuming and labor intensive.
Objective To present innovative laboratory techniques to facilitate processing of large Mohs cases.
Methods A method for processing a large dermatofibrosarcoma protuberans Mohs case is outlined.
Results Modifications in tissue processing and equipment employed in a large Mohs case are presented.
Conclusion Innovative modifications to the standard Mohs laboratory technique can facilitate processing of large Mohs cases, resulting in high-quality, rapid frozen sections while optimizing efficiency.  相似文献   
2.
Renz  JF; Kalf  GF 《Blood》1991,78(4):938-944
Chronic exposure of humans to benzene (BZ), a myelotoxin, causes aplastic anemia and acute leukemia. The stromal macrophage that produces interleukin-1 (IL-1), a cytokine essential for hematopoiesis, is a target of BZ's toxicity. Monocyte dysfunction and decreased IL-1 production have been shown to be involved in aplastic anemia in humans. Hydroquinone (HQ), a toxic bone marrow (BM) metabolite of BZ, causes time- and concentration-dependent inhibition of processing of the 34-Kd pre-interleukin-1 alpha (IL-1 alpha) to the 17-Kd mature cytokine in murine P388D1 macrophages and BM stromal macrophages, as measured by Western immunoblots of cell lysate proteins using a polyclonal rabbit antimurine IL-1 alpha antibody. HQ over a 10-fold concentration range had no effect on the lipopolysaccharide (LPS)-induced production of pre- IL-1 alpha precursor or on cell viability or DNA and protein synthesis. Stromal macrophages obtained from the femoral BM of C57Bl/6 mice exposed to BZ (600 or 800 mg/kg body weight) for 2 days were incapable of processing the 34-Kd pre-IL-1 alpha to the mature 17-Kd cytokine when stimulated in culture with LPS. Stromal macrophages from mice coadministered BZ and indomethacin, a prostaglandin H synthase (PHS) inhibitor that has been shown to prevent BZ-induced myelotoxic and genotoxic effects in mice when coadministered with benzene were able to convert the pre-IL-1 alpha to mature cytokine. Administration of recombinant murine IL-1 alpha (rMuIL-1 alpha) to mice before a dose of BZ that causes severe depression of BM cellularity completely prevents BM depression, most probably by bypassing the inability of the stromal macrophage in BZ-treated animals to process pre-IL-1 alpha to the mature cytokine.  相似文献   
3.
4.
5.

Background  

Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population.  相似文献   
6.
Several lines of evidence indicate that mammalian fertilization is initiated via a binding process that is dependent upon the recognition of oligosaccharide sequences associated with zona pellucida (ZP) glycoproteins. Here, specific chemical and enzymatic methods were employed to modify human ZP and to test their effects on sperm binding in the hemizona assay system (HZA). Periodate oxidation of human ZP under very mild conditions (10 min, 0 degrees C, 1 mM sodium m- periodate) that attacks only terminal sialic acid resulted in a 30% loss of human sperm binding in the HZA [hemizona index (HZI) = 70.2 +/- 10.9, n = 22; P < 0.05]. Periodate oxidation under mild conditions (1 h, 23 degrees C, 10 mM sodium m-periodate) caused a 40% decrease in binding (HZI = 60.8 +/- 10.3; n = 24; P< 0.01). Treatment of human ZP with neuraminidase caused a substantial increase in sperm binding to human ZP (HZI = 297 +/- 45, n = 22; P < 0.01). These findings indicate that there are sialic acid dependent binding sites coexisting with binding sites that are obscured by sialic acid. To determine the periodate sensitivity of these obscured sites, hemizona were first digested with neuraminidase and subsequently subjected to mild periodate oxidation. The combined enzymatic and chemical treatments caused a 79% decrease in sperm binding compared to control hemizona (HZI = 20.7 +/- 4.4, n = 16; P < 0.001). Human sperm-ZP interaction was also increased by digestion of human ZP with endo-beta-galactosidase (HZI = 710 +/- 232, n = 14; P < 0.01), indicating that potential binding sites for spermatozoa are also obscured by lactosaminoglycan sequences. These studies support a definitive role for the involvement of ZP-associated glycans in the binding of human spermatozoa to oocytes.   相似文献   
7.
Diet has been associated with the risk of depression, whereas different subtypes of depression have been linked with different cardiovascular risk factors (CVRFs). In this study, our aims were to (1) identify dietary patterns with exploratory factor analysis, (2) assess cross-sectional associations between dietary patterns and depression subtypes, and (3) examine the potentially mediating effect of dietary patterns in the associations between CVRFs and depression subtypes. In the first follow-up of the population-based CoLaus|PsyCoLaus study (2009–2013, 3554 participants, 45.6% men, mean age 57.5 years), a food frequency questionnaire assessed dietary intake and a semi-structured interview allowed to characterize major depressive disorder into current or remitted atypical, melancholic, and unspecified subtypes. Three dietary patterns were identified: Western, Mediterranean, and Sweet-Dairy. Western diet was positively associated with current atypical depression, but negatively associated with current and remitted melancholic depression. Sweet-Dairy was positively associated with current melancholic depression. However, these dietary patterns did not mediate the associations between CVRFs and depression subtypes. Hence, although we could show that people with different subtypes of depression make different choices regarding their diet, it is unlikely that these differential dietary choices account for the well-established associations between depression subtypes and CVRFs.  相似文献   
8.
The in vitro and in vivo activity of a new water soluble polyene antibiotic, anmed SPA-S-222, has been studied on numerous Candida and Cryptococcus species. The in vitro tests were carried out in comparison with nystatin and amphotericin B whose antimycotic properties are already well known. The inhibition of "germination" of various strains of Candida albicans was also investigated. The results show that SPA-S-222 has greater antimycotic activity than nystatin or amphotericin B. Tests on the protection afforded by SPA-S-222 in Swiss albino mice infected with C, albicans were satisfactory as regards both the total protective dose and the partial protective dose (P.D. 50%).  相似文献   
9.
BackgroundCardiac rehabilitation is a medically supervised program after coronary events that involves exercise and dietary modification. We evaluated the comparative benefits and harms of cardiac rehabilitation strategies via a network meta-analysis.MethodsWe followed a pre-specified protocol (PROSPERO: CRD42018094998). We searched Embase, MEDLINE, and Cochrane Central Register of Randomized Trials databases for randomized controlled trials that evaluated cardiac rehabilitation vs a second form of rehabilitation or standard/usual care in adults after myocardial infarction, coronary artery bypass grafting, percutaneous coronary intervention, or angiography. Risk of bias and evidence quality was evaluated using the Cochrane tool and Grading of Recommendations Assessment, Development and Evaluation (GRADE), respectively. Pairwise and Bayesian network meta-analyses were performed for 11 clinical outcomes.ResultsWe included 134 randomized controlled trials involving 62,322 participants. Compared with standard care, exercise-only cardiac rehabilitation reduced the odds of cardiovascular mortality (odds ratio [OR], 0.70; 95% credibility interval [CrI], 0.51-0.96; moderate-quality evidence), major adverse cardiovascular events (OR, 0.57; 95% CrI, 0.40-0.78; low-quality evidence), nonfatal myocardial infarction (OR, 0.71; 95% CrI, 0.54-0.93; moderate-quality evidence), all-cause hospitalization (OR, 0.74; 95% CrI, 0.54-0.98; moderate-quality evidence), and cardiovascular hospitalization (OR, 0.69; 95% CrI, 0.51-0.88; moderate-quality evidence). Exercise-only cardiac rehabilitation was associated with lower cardiovascular hospitalization risk relative to cardiac rehabilitation without exercise (OR, 0.68; 95% CrI, 0.48-0.97; moderate-quality evidence).ConclusionsCardiac rehabilitation programs containing exercise might provide broader cardiovascular benefits compared with those without exercise.  相似文献   
10.
Manometry of the alimentary tract is a valuable and widely used means to evaluate and diagnose the function of the alimentary tract. However, the measurement can be inconvenient due to the invasive method used, and the many factors affecting results. Research on colonic pressure data is even more insufficient. This paper deals with colonic pressure data via an improved method ensuring that pressure data of the whole colon is available. The data is analysed based on the learning vector quantization (LVQ) method. Testing results show that this method distinguishes the normal data and the abnormal data, consistently with the original diagnoses. This method can serve as an assistant diagnosis of colonic motility and contributes to further research on colonic motility based on pressure data.  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