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   464篇
  免费   36篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   7篇
妇产科学   4篇
基础医学   69篇
口腔科学   7篇
临床医学   28篇
内科学   118篇
皮肤病学   9篇
神经病学   43篇
特种医学   26篇
外科学   14篇
综合类   8篇
预防医学   92篇
眼科学   6篇
药学   39篇
中国医学   3篇
肿瘤学   23篇
  2023年   4篇
  2022年   7篇
  2021年   21篇
  2020年   14篇
  2019年   12篇
  2018年   21篇
  2017年   15篇
  2016年   12篇
  2015年   11篇
  2014年   9篇
  2013年   15篇
  2012年   28篇
  2011年   35篇
  2010年   21篇
  2009年   20篇
  2008年   29篇
  2007年   18篇
  2006年   27篇
  2005年   24篇
  2004年   32篇
  2003年   30篇
  2002年   11篇
  2001年   17篇
  2000年   16篇
  1999年   16篇
  1998年   1篇
  1997年   3篇
  1993年   4篇
  1992年   5篇
  1991年   3篇
  1990年   1篇
  1988年   2篇
  1987年   3篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1981年   2篇
  1977年   1篇
  1974年   1篇
  1973年   2篇
  1970年   1篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
  1964年   1篇
排序方式: 共有502条查询结果,搜索用时 62 毫秒
21.
22.
23.
Distant metastasis affecting the parotid gland are a rare entity, with origin in most cases from cutaneous tumors of the head and neck, mainly melanoma and epidermoid carcinoma. Other histological types of metastasis and tumors originated from distant organs or sites are very rare and may be a diagnostic and therapeutic challenge, for this reason, we consider it interesting for discussion. In this paper, we present the case of a patient with a metastatic tumor of the parotid gland secondary to a liposarcoma of the leg, extremely rare case, about which we have no found previous references in the literature.  相似文献   
24.
25.
26.
One of the major difficulties in mental health research is finding suitable research instruments. In the last few decades questionnaires that are supposed to work in different languages and cultures have been developed by WHO to solve this problem. One of such instruments is SCAN, an instrument which uses computer algorithm to make a diagnosis. It is meant to be used for semi-structured interview by qualified psychiatrists or clinical psychologists. This and a few other research instruments have been translated and used in clinical and community settings for psychiatric research in Ethiopia over the last few years. In this study computer assisted SCAN Diagnoses and clinical diagnoses made by trainee psychiatrists in Butajira, a rural setting in Ethiopia, were compared Seven hundred twenty nine persons were diagnosed to have schizophrenia and bipolar disorder using both methods. The agreement between the clinical and SCAN derived diagnosis was shown to be 100% for schizophrenia (Kappa = 1.0). However, the agreement between the two methods of diagnosis was shown to be lower when it comes to subtypes of schizophrenia. The agreement for the diagnoses of bipolar disorder was 95.3%, kappa = 0.9, P < 0.0001 and for depression it was 93.0%, kappa = 0.8, p < 0.0001. Taking into account the limited number of psychiatrists and clinical psychologists in the third world countries like Ethiopia we have shown that using trainees in psychiatry for SCAN interview is a feasible and reliable method to identify major categories of mental disorders in community studies.  相似文献   
27.
Entomological studies were conducted over a 24-month period in 8 villages to establish the behavior patterns, seasonal densities, and variation in entomological inoculation rates (EIRs) of Anopheles arabiensis, the main vector of malaria in Eritrea. A total of 5,683 anopheline mosquitoes were collected through indoor sampling (1,613), human-landing catches (2,711), and outdoor pit shelters (1,359). Overall, An. arabiensis was the predominant species at all of the study sites, with its population density increasing during the rainy season. Peak indoor-resting densities was observed during September and October. Human landing indices for An. arabiensis averaged 1.9 and 3.8 per person per night in October and September, respectively. Peak biting and landing rates occurred between 2000-2200 h and 0100-0300 h. Of the total number of bites, 44.7% occurred between 1800 and 2300 h, and at least 56.5% of the total bites occurred outdoors, indicating that the species was partially exophagic. The fed to gravid ratio for An. arabiensis in indoor-resting collections was 2:1, indicating some degree of exophily. The sporozoite rates (SRs) for An. arabiensis ranged from 0.54% in the Anseba zone to 1.3% in the Gash-Barka zone. One mosquito each of An. d'thali (SR = 0.45%) and An. cinereus (SR = 2.13%) was found to be positive. Of the total positive An. arabiensis (n = 64), 18.2% came from human-landing collections outdoors. Blood-meal analysis by enzyme-linked immunosorbent assay for An. arabiensis indicated that this species was partially zoophilic with a human to bovine ratio of 2:1 being recorded. The EIR profiles indicated that malaria transmission is highly seasonal, increasing during the wet season and declining drastically during the dry season. On average, the greatest risk of infection occurs in Hiletsidi, in the Gash-Barka zone (6.5 infective bites per month). The exophilic behavior and early evening biting of An. arabiensis present obstacles for control with treated bed-nets and indoor residual spraying within the context of integrated malaria control, and call for greater focus on strategies such as larval control.  相似文献   
28.
29.
The ErbB-2 interacting protein receptor-associated late transducer (RALT) was previously identified as a feedback inhibitor of ErbB-2 mitogenic signals. We now report that RALT binds to ligand-activated epidermal growth factor receptor (EGFR), ErbB-4 and ErbB-2.ErbB-3 dimers. When ectopically expressed in 32D cells reconstituted with the above ErbB receptor tyrosine kinases (RTKs) RALT behaved as a pan-ErbB inhibitor. Importantly, when tested in either cell proliferation assays or biochemical experiments measuring activation of ERK and AKT, RALT affected the signalling activity of distinct ErbB dimers with different relative potencies. RALT deltaEBR, a mutant unable to bind to ErbB RTKs, did not inhibit ErbB-dependent activation of ERK and AKT, consistent with RALT exerting its suppressive activity towards these pathways at a receptor-proximal level. Remarkably, RALT deltaEBR retained the ability to suppress largely the proliferative activity of ErbB-2.ErbB-3 dimers over a wide range of ligand concentrations, indicating that RALT can intercept ErbB-2.ErbB-3 mitogenic signals also at a receptor-distal level. A suppressive function of RALT deltaEBR towards the mitogenic activity of EGFR and ErbB-4 was detected at low levels of receptor occupancy, but was completely overcome by saturating concentrations of ligand. We propose that quantitative and qualitative aspects of RALT signalling concur in defining identity, strength and duration of signals generated by the ErbB network.  相似文献   
30.
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