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   3222篇
  免费   153篇
  国内免费   14篇
耳鼻咽喉   58篇
儿科学   158篇
妇产科学   85篇
基础医学   424篇
口腔科学   61篇
临床医学   246篇
内科学   756篇
皮肤病学   64篇
神经病学   173篇
特种医学   73篇
外科学   348篇
综合类   111篇
一般理论   8篇
预防医学   208篇
眼科学   70篇
药学   306篇
  1篇
中国医学   28篇
肿瘤学   211篇
  2023年   10篇
  2022年   54篇
  2021年   96篇
  2020年   51篇
  2019年   74篇
  2018年   106篇
  2017年   55篇
  2016年   77篇
  2015年   74篇
  2014年   97篇
  2013年   131篇
  2012年   218篇
  2011年   208篇
  2010年   122篇
  2009年   96篇
  2008年   199篇
  2007年   187篇
  2006年   168篇
  2005年   176篇
  2004年   131篇
  2003年   117篇
  2002年   109篇
  2001年   65篇
  2000年   89篇
  1999年   54篇
  1998年   31篇
  1997年   23篇
  1996年   11篇
  1995年   11篇
  1993年   14篇
  1992年   39篇
  1991年   33篇
  1990年   35篇
  1989年   32篇
  1988年   21篇
  1987年   33篇
  1986年   35篇
  1985年   25篇
  1984年   29篇
  1983年   19篇
  1979年   18篇
  1977年   18篇
  1976年   15篇
  1975年   12篇
  1974年   13篇
  1973年   21篇
  1972年   16篇
  1971年   18篇
  1970年   16篇
  1969年   15篇
排序方式: 共有3389条查询结果,搜索用时 31 毫秒
61.
Development of a primary cancer after treatment of the first with radiotherapy or chemotherapy is well documented, but it is common with hematological malignancies. Variety of reasons are suggested by various researchers, but a conclusive evidence is not yet available. Excepting a few correlations like the tamoxifen therapy and endometrial cancer, angiosarcoma of the breast following radiotherapy, occurrence of other metachronous malignancies seem to be dependent on genetic and environmental factors. A patient with three primary malignancies is presented here.  相似文献   
62.
We investigated the safety, tolerability and effectiveness of locally produced generic highly active antiretroviral therapy (HAART) regimens with a chart review conducted at YRG CARE, a tertiary HIV referral centre in India. A total of 333 patients had been on Indian-manufactured generic HAART for at least 3 months. In this cohort, generic HAART was safe, well tolerated and effective at increasing CD4 T-lymphocyte counts in patients with advanced HIV, comparable to the experience with proprietary HAART.  相似文献   
63.
Background Platelets play a pivotal role in the pathogenesis of the thrombotic complications in cardiovascular disease (CVD). Abnormal platelet activation indices are evolving as potentially useful markers in CVD risk stratification. Whilst there has been some investigation into the effects of storage time on several of these indices, the effects of underlying disease severity on these temporal changes have not been previously studied. Methods Using the ADVIATM120 haematology analyser, we assessed the effects of time-dependent storage of whole blood in EDTA, on a number of platelet activation indices: mean platelet volume (MPV), mean platelet component (MPC, measure of platelet density) and platelet component distribution width (PCDW, a marker of platelet shape change. We studied three age- and sex-matched patient groups: (i) healthy controls (n = 10), (ii) stable patients with coronary artery disease (CAD, n = 9); and (iii) patients with acute myocardial infarction (n = 8). Whole blood samples were processed at exactly 5 min following venesection and at 15, 30, 60 and 120 min later in storage in EDTA tubes at room temperature. Results There was a significant and stepwise increase in MPV (P = 0.01) and decrease in PCDW (P = 0.03), with a non-significant trend to increasing MPM and decreasing MPC with increasing underlying disease (that is healthy, ‘stable’ and ‘acute’ artery disease). There was a significant time-dependent increase in MPV and decrease in MPC and PCDW (all P < 0.05), which were all significant on ‘post-hoc’ analyses by 30 min. There were no significant changes in platelet count or MPM with time. There was no interaction of underlying disease with whole-blood storage time for any of the platelet indices reported (P = NS). Conclusion There is a temporal increase in MPV and decrease in MPC and PCDW in venous blood stored over 2 h in EDTA. These changes are not influenced by the underlying CVD disease severity.  相似文献   
64.
65.
BACKGROUND: Duodenal duplication cysts are rare congenital anomalies. Symptomatic cases have classically been treated by surgical resection, which can be complex because of the close proximity of the cysts to the papilla. OBJECTIVE: To describe a series of 8 patients with symptomatic duodenal duplication cysts who were treated endoscopically, with a special focus on the long-term outcome. DESIGN: Retrospective case series. SETTING: Three tertiary-care European academic hospitals. PATIENTS: Eight patients, age 8 to 72 years, were treated endoscopically for symptomatic intraluminal duodenal duplication cysts between 1981 and 2006. Seven patients presented with acute pancreatitis, and one patient presented with jaundice. INTERVENTION: Endoscopic incision and marsupialization of the cysts was performed by using a variety of endoscopic tools (needle-knife and regular sphincterotomes, cystotomes, and polypectomy snares). MAIN OUTCOME MEASUREMENTS: Technical success of endoscopic intervention and long-term clinical recurrence of symptoms. RESULTS: No major complications occurred. All patients remained asymptomatic at a median follow-up of 7.3 years. LIMITATIONS: Retrospective study; the small number of patients. CONCLUSIONS: The endoscopic treatment of symptomatic intraluminal duodenal duplication cysts is a safe and effective technique, with excellent long-term results. It represents a minimally invasive alternative to surgical resection and might be considered the preferred therapeutic modality for these cases.  相似文献   
66.
Emergence of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB over the past decade presents an unprecedented public health challenge to which countries of concern are responding far too slowly. Global Tuberculosis Report 2014 marks the 20th anniversary of the Global Project on Anti-Tuberculosis Drug Resistance Surveillance, indicating the highest global level of drug-resistance ever recorded detection of 97?000 patients with MDR-TB resulting in 170?000 deaths in 2013. Treatment of MDR-TB is expensive, complex, prolonged (18–24 months) and associated with a higher incidence of adverse events. In this context, nanocarrier delivery systems (NDSs) efficiently encapsulating considerable amounts of second-line anti tubercular drugs (sATDs), eliciting controlled, sustained and more profound effect to trounce the need to administer sATDs at high and frequent doses, would assist in improving patient compliance and avoid hepatotoxicity and/or nephrotoxicity/ocular toxicity/ototoxicity associated with the prevalent sATDs. Besides, NDSs are also known to inhibit the P-glycoprotein efflux, reduce metabolism by gut cytochrome P-450 enzymes and circumnavigate the hepatic first-pass effect, facilitating absorption of drugs via intestinal lymphatic pathways. This review first provides a holistic account on MDR-TB and discusses the molecular basis of Mycobacterium tuberculosis resistance to anti-tubercular drugs. It also provides an updated bird’s eye view on current treatment strategies and laboratory diagnostic test for MDR-TB. Furthermore, a relatively pithy view on patent studies on second-line chemotherapy using NDSs will be discussed.  相似文献   
67.
BackgroundTreatment outcomes for Multidrug-Resistant Tuberculosis (MDR TB) is generally poor. The study aims to know about the treatment outcomes of MDR-TB under programmatic conditions in Hyderabad District and to analyze the factors influencing the treatment outcomes.MethodsThis is a retrospective study in which 377 patients of Hyderabad district, Telangana state who were diagnosed with MDR TB and registered at Drug Resistance TB Treatment site of Government General & Chest Hospital, Hyderabad from 4th quarter 2008 to 4th quarter 2013 were included in the study. Impact of Demographic factors (age, sex; Nutritional status (BMI); Co-morbid condition (Diabetes, HIV, Hypothyroidism); Programmatic factors (time delay in the initiation of treatment); Initial Resistance pattern on the outcomes were studied and analyzed.ResultsThe treatment outcomes of Multidrug-Resistant Tuberculosis under Programmatic Conditions were: 57% cured, 21.8% died, 19.6% defaulted, 1.1% failed and 0.5% switched to XDR. Age, Sex, BMI had a statistically significant impact on treatment outcomes. Hypothyroidism and Delay in the initiation of treatment >1 a month had an impact on the outcomes though not statistically significant. NO impact on treatment outcomes was found when Rifampicin resistance & INH sensitive patients were compared with those resistant to both INH and Rifampicin.ConclusionTo reduce MDR-TB transmission in the community, improvement of treatment outcomes, via ensuring adherence, paying special attention to elderly patients is required. The Programmatic Management of Drug Resistance Tuberculosis (PMDT) should seriously think of providing Nutritional support to patients with low BMI to improve outcomes. In the programmatic conditions if we could address the problems like delay in initiation of treatment and proper management of comorbidities like HIV, Diabetes, Hypothyroidism would definitely improve the treatment outcomes.  相似文献   
68.
69.
The present study was proposed to investigate the effect of rifaximin (RFX) on methyl nitrosourea (MNU) induced mammary gland carcinoma in albino wistar rats. Animals were randomized and divided among four groups of six animals each. Group I (control 0.9% normal saline, 3 ml kg−1, p.o.); Group II (toxic control, MNU 47 mg kg−1, i.v.); Group III (RFX, 25 mg kg−1, p.o.); Group IV (RFX, 50 mg kg−1, p.o.). Toxicity was induced by single i.v. injection of MNU. MNU treatment was evident with increased alveolar bud count, differentiation score, up-regulated inflammatory enzyme markers (COX, LOX, NO and H2S) and oxidative stress markers (TBAR''s, protein carbonyl, SOD, catalase and Ach). The mammary gland surface architecture was studied using SEM, carmine staining and H&E staining. The treatment with RFX elicited noticeable restoration of the overall histological architecture in the experimental animals similar to the control. In the MNU treated toxic group, the levels of oxidative stress markers significantly increased in comparison to the control, which was subsequently restored after RFX treatment. Furthermore, RFX up regulated the levels of caspase 3 and caspase 8, when compared to the MNU treated animals. MNU associated toxicity was also ascertained, when determined for UCHL-1, COX, NF-κBp65, BAD, and BCL-xl expression, while RFX demonstrated modulation of the same.

The present study was proposed to investigate the effect of rifaximin (RFX) on methyl nitrosourea (MNU) induced mammary gland carcinoma in albino wistar rats.  相似文献   
70.

Background:

Maps show well the spatial configuration of information. Considerable effort is devoted to the development of geographical information systems (GIS) that increase understanding of public health problems and in particular to collaborate efforts among clinicians, epidemiologists, ecologists, and geographers to map and forecast disease risk.

Objectives:

Small populations tend to give rise to the most extreme disease rates, even if the actual rates are similar across the areas. Such situations will follow the decision-maker''s attention on these areas when they scrutinize the map for decision making or resource allocation. As an alternative, maps can be prepared using P-values (probabilistic values).

Materials and Methods:

The statistical significance of rates rather than the rates themselves are used to map the results. The incidence rates calculated for each village from 2000 to 2009 is used to estimate λ, the expected number of cases in the study area. The obtained results are mapped using Arc GIS 10.0.

Results:

The likelihood of infections from low to high is depicted in the map and it is observed that five villages namely, Odanthurai, Coimbatore Corporation, Ikkaraiboluvampatti, Puliakulam, and Pollachi Corporation are more likely to have significantly high incidences.

Conclusion:

In the probability map, some of the areas with exceptionally high or low rates disappear. These are typically small unpopulated areas, whose rates are unstable due to the small numbers problem. The probability map shows more specific regions of relative risks and expected outcomes.  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