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   10908篇
  免费   351篇
  国内免费   34篇
耳鼻咽喉   158篇
儿科学   170篇
妇产科学   294篇
基础医学   2145篇
口腔科学   219篇
临床医学   560篇
内科学   1033篇
皮肤病学   409篇
神经病学   858篇
特种医学   1562篇
外科学   1471篇
综合类   58篇
预防医学   767篇
眼科学   84篇
药学   1105篇
中国医学   102篇
肿瘤学   298篇
  2023年   37篇
  2022年   30篇
  2021年   58篇
  2020年   50篇
  2019年   70篇
  2018年   194篇
  2017年   136篇
  2016年   180篇
  2015年   130篇
  2014年   226篇
  2013年   384篇
  2012年   723篇
  2011年   1054篇
  2010年   474篇
  2009年   176篇
  2008年   777篇
  2007年   941篇
  2006年   910篇
  2005年   727篇
  2004年   661篇
  2003年   655篇
  2002年   573篇
  2001年   368篇
  2000年   487篇
  1999年   264篇
  1998年   80篇
  1997年   53篇
  1996年   42篇
  1995年   48篇
  1994年   25篇
  1993年   21篇
  1992年   23篇
  1991年   26篇
  1990年   31篇
  1989年   24篇
  1988年   26篇
  1987年   20篇
  1985年   30篇
  1984年   20篇
  1983年   21篇
  1982年   32篇
  1981年   31篇
  1980年   29篇
  1979年   29篇
  1978年   28篇
  1976年   21篇
  1975年   26篇
  1974年   20篇
  1973年   20篇
  1963年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Information production and its communication being a key public health activity, developing modern information systems is a precondition for its fulfilling these assignments. A national public health information system (NPHIS) is a set of human resources combined with computing and communication technologies. It enables data linkage and data coverage as well as undertaking information production and dissemination in an effective, standardized and safe way. The Croatian Institute of Public Health LAN/WAN modules are under development. Health Safety System, Health Workers Registry, and Digital Library are among the Institute's developmental priorities. Communication between NPHIS participants would unfold over the Internet by using every relevant data protection method. Web technology-based applications would be run on special servers. Between individual applications, use would be made of the transaction module of communication through an exchange of the HL7 standard-based xml messages. In the conditions of transition, the health system must make an optimal use of the resources, which is not feasible without applying modern information and communication technologies.  相似文献   
32.
Opportunistic fungal infections are becoming more frequent complications during cancer therapy, after organ transplantation and in AIDS infections, especially after better control of bacterial infections in immunocompromised patients. Periods of prolonged neutropenia with neutrophil count less than 0.5 x 10(9)/L longer than 7 days, are the most important risk factors for the development of systemic fungal infections. Especially susceptible are the patients during treatment of acute leukemia, or after bone marrow transplantation. The most frequent causing agents of systemic fungal infections are Candida and Aspergillus species, than Cryptococcus neoformans and Mucor. Some other unusual species such Fusarium, Trichosporon, non-albicans Candida species of Candida are becoming more frequent, and is frequently resistant to conventional therapy. The difficulties in early and precise diagnosis of fungal infections, and the lack of adequate and efficient drugs are responsible for the high mortality of immunocompromised patients, even in potentially curable diseases. The recognition of risk factors, introduction of prophylactic measures, application of empirical antifungal therapy, are the procedures for the reduction of morbidity and mortality of invasive fungal infections. Fluconazole administration in prevention of systemic fungal infections, has become the standard approach, especially after bone marrow transplantation, while the oral itraconazole solution, has even more extended activity. Fluconazole appears successful also in the treatment of systemic Candidiasis. Conventional amphotericin-B is still the "gold standard" in the treatment of fungal infections. The new lipid formulations of amphotericin-B, intravenous itraconazole, has an identical efficacy, but are less toxic than conventional amphotericin-B. Several new promising agents are in the stage of clinical investigation like voriconazole, caspofungin, mycafungin and some other.  相似文献   
33.
34.
Rat thymic epithelial cells (TEC) in long-term culture were characterized by anticytokeratin monoclonal antibodies (mAbs) and electron microscopy. Phenotypic analysis performed by a large panel of mAbs showed that the highest percentage of these cells was of the subcapsular/medullary type. Recombinant rat interferon (IFN)-gamma up-regulated class-I and class-II MHC expression by TEC in culture as confirmed by immunohistochemistry and flow cytometry, but did not significantly alter other cell markers. TEC supernatants of IFN-gamma- treated cultures showed higher interleukin-6 (IL-6) activity, compared to the control, as determined by proliferation of the IL-6-sensitive B9-cell line. Increased IL-6 activity was probably not a consequence of increased TEC number in IFN-gammatreated cultures because IFN did not significantly stimulate TEC proliferation in vitro. In contrast, IL-6 significantly stimulated TEC proliferation, indicating that this cytokine is not only a regulatory molecule for T-cell proliferation, but could also be an autocrine growth factor for thymic epithelium.  相似文献   
35.
36.
37.
Left Bochdalek hernia is a serious and complex condition with high mortality. In most cases, it presents in the neonatal period and is seldom found later in life when symptomatology, usually after an asymptomatic period, is quite different and the prognosis excellent. The embryological development of left Bochdalek hernia suggests the presence of abdominal content in the left pleural cavity before birth. The type of clinical presentation and the prognosis depend on the time of visceral herniation. This study presents two cases of left Bochdalek hernia with delayed presentation. In both cases, after surgical reposition of the hernia, a small congenital diaphragmatic defect was found hidden between the rims of diaphragm. This indicates the possibility for the abdominal content to enter the left pleural cavity at the time of presentation.  相似文献   
38.
Variation of the photoactivation rate across radiation fields of three different bremsstrahlung beams of two medical accelerators has been measured, making use of the photonuclear reactions in natural indium probes: 115In(y,y')115mIn and 115In(y,n)114mIn. The third nuclear reaction, 115In(n,y)116mIn, was used to detect the presence of neutrons in the photon beam and to estimate the spatial distribution of thermal and fast neutrons in the patient plane as a function of collimator opening.  相似文献   
39.
40.
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