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   1636篇
  免费   127篇
  国内免费   6篇
耳鼻咽喉   10篇
儿科学   51篇
妇产科学   56篇
基础医学   270篇
口腔科学   40篇
临床医学   177篇
内科学   318篇
皮肤病学   18篇
神经病学   107篇
特种医学   52篇
外科学   185篇
综合类   46篇
预防医学   146篇
眼科学   31篇
药学   124篇
中国医学   24篇
肿瘤学   114篇
  2023年   29篇
  2022年   71篇
  2021年   106篇
  2020年   85篇
  2019年   88篇
  2018年   101篇
  2017年   75篇
  2016年   78篇
  2015年   91篇
  2014年   95篇
  2013年   121篇
  2012年   143篇
  2011年   134篇
  2010年   71篇
  2009年   53篇
  2008年   73篇
  2007年   64篇
  2006年   53篇
  2005年   39篇
  2004年   22篇
  2003年   16篇
  2002年   18篇
  2001年   9篇
  2000年   9篇
  1999年   9篇
  1998年   3篇
  1997年   4篇
  1996年   8篇
  1993年   2篇
  1992年   4篇
  1991年   13篇
  1990年   11篇
  1989年   7篇
  1988年   6篇
  1987年   3篇
  1986年   5篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   2篇
  1980年   4篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1973年   2篇
  1972年   2篇
  1971年   4篇
  1970年   2篇
  1969年   3篇
  1967年   7篇
排序方式: 共有1769条查询结果,搜索用时 15 毫秒
11.
ObjectiveThe present study was designed to delineate the hepatotoxicological roles of histamine dose-dependently in immunized rabbits.MethodsThe cohort comprised of three groups (II, III and IV), containing 18 rabbits each, and received subcutaneous histamine 50 μg/kg, 100 μg/kg and 200 μg/kg, respectively for 10 days (b.i.d., starting from 3 days prior to immunization until 7 days after immunization). Group I (control, n = 18) received subcutaneous sterile distilled water for 10 days. They were subsequently immunized at day 3 with intravenous injection of SRBC (1 × 109 cells/ml). Blood samples were collected on pre-immunization (pre-I) day 0, as well as on days 7-, 14-, 21-, 28- and 58-post-immunization (post-I). Biochemical parameters aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and bilirubin [total bilirubin (TB), direct bilirubin (DB) and indirect bilirubin (IB)] were determined.ResultsGroups II and IV revealed a significant decrease (on day 0-pre-I) and a significant increase (on days 7-, 14-, 21-, 28- and 58-post-I) in ALT and AST levels, when compared with the corresponding values of groups I and III while group II showed a significant increase in ALT and AST levels as compared to group IV. ALP levels in groups II, III and IV showed a significant enhancement when compared with group I. Moreover, results of TB, DB and IB demonstrated increased levels in group III when compared with groups I, II and IV. The results were found statistically significant (p < 0.05).ConclusionShort-term treatment of histamine produces dose-dependent differential patterns of hepatic dysfunctions suggestive mild liver degeneration warranting further long-term studies.  相似文献   
12.
Breast cancer is the most common malignancy among women and the second leading cause of mortality due to cancer worldwide. The complexity of breast cancer resembles an intricate ecosystem comprising various cleverly designed interaction levels of internal and external factors to generate a pliable context in the clonal evolution of breast cancer cells. Principally, the complex entity can become evident toward delineating a number of significant variations in the specific fields of breast cancer analyses, including the molecular, physiological, and morphological characteristics, clinical presentations, risk factors, the histopathological conditions, and response to systemic therapy regarding the maintenance of tumor as a whole. In hindsight, various classification systems developing based on specific inclusion criteria have indisputably changed both our appreciation of the biological demeanor of breast cancer and the main strategies for designing tailored therapy regimens through the proper evaluation of diagnosis and prognostication of given specimens. Here, we endeavor to provide a general overview of different types of breast cancer classification as well as the clinical acceptance of their applications along with the latest findings in this area. Taken together, the major significance of breast cancer management that can be ascertained by operational convergent points of its stratification areas is owing to the fact that the achievement of individualized and targeted therapy may denounce new horizons of surveillance and treatment strategies in which they may function as a rheostat of specific therapy regimens toward reducing the detected distances between experimental data and operating options in clinical practice.  相似文献   
13.
BackgroundAccording to the American College of Cardiology/the American Heart Association (ACC/AHA) recommendations, health-related risk behaviors for secondary prevention of myocardial infarction (MI) are critical to determine.ObjectiveThis study aimed to compare health-related risk behaviors between MI survivors and propensity-score-matched non-MI controls using nationally representative data.MethodsThis cross-sectional, matched case-control study used publicly available Behavioral Risk Factor Surveillance System (BRFSS) 2017 data. Older adults with MI were propensity-score-matched to their non-MI controls. The 10 dependent variables included body mass index (BMI), smoking status, heavy alcohol consumption, influenza vaccine, length of time since last routine and cholesterol checkup, alcohol consumption, fruit and vegetable consumption, and physical activity. Chi-square tests and binomial logistic regression were used to examine the health-related risk behaviors differences between MI survivors and propensity-score-matched non-MI controls.ResultsThe final study sample consisted of 18,021 MI survivors and 54,063 non-MI controls after propensity score matching. Multivariable logistic regression analysis showed significant differences between MI survivors and matched non-MI controls in terms of cholesterol checkup, smoking status, and alcohol consumption. For example, multivariate analysis of health-related risk behaviors showed MI survivors were more likely to be smokers (AOR = 1.46, 95% CI: 1.28–1.68).ConclusionBased on this national survey of adults, MI survivors were more likely to be smokers but less likely to consume alcohol compared to their propensity-score-matched controls. Moreover, MI survivors were more likely to have their cholesterol checkup within the past 2 years compared to matched non-MI controls. Although lower alcohol consumption and greater chances of cholesterol checkups are reassuring health-related behaviors, interventions are needed to minimize the chances of smoking in this population.  相似文献   
14.
Introduction: Poor maternal mental health during the perinatal period has been shown to have potentially long-lasting effects for mother and child. In recognition of this, maternal mental health is receiving increased attention from political and healthcare organizations, with a growing focus on preventing the onset of common mental health disorders.

Objective: The objective for this review is to provide an update of randomized controlled trials examining the use of interventions targeted to prevent the onset of postnatal depression and anxiety in nondiagnostic populations with universal or selected samples.

Methods: A total of four databases, EBSCO Host, Science Direct, Scopus, and Web of Science, incorporating PsychINFO were searched and papers selected according to clearly specified inclusion criteria. A large Health Technology review was published in 2016, for which the final search was conducted in December 2012. Therefore inclusion criteria were studies published from January 2013 onwards, available in English language, had a focus on prevention of postnatal maternal depression and anxiety, and used psychological interventions. Drug intervention trials were excluded.

Findings: 12 studies were identified as examining antenatal or postnatal intervention trials with an aim of preventing maternal postnatal depression and/or anxiety. There continues to be limited evidence to recommend specific prevention strategies for universal samples without further testing. There is evidence to suggest the use of rational-emotive behavioral therapy in an antenatal sample may have some utility, and the use of psychotherapy-based interventions in a postnatal setting is also supported although both require further investigation. Additionally, there is a need to gather information on acceptability, as many trials were hindered by poor adherence to interventions and high attrition that were otherwise unexplained.  相似文献   
15.
In the present study, the microscopy and polymerase chain reaction methods were used for detection and identification of soil contamination by Toxocara eggs in squares, streets, public parks, and rubbish dumps in Ahvaz, southwestern Iran.  相似文献   
16.
17.
18.
Acoustic manipulation of porous spherical shells, widely used as drug delivery carriers and magnetic resonance imaging contrast agents, is investigated analytically. The technique used for this purpose is based on the application of high-order Bessel beams as a single-beam acoustic manipulation device, by which particles lying on the axis of the beam can be pulled toward the beam source. The exerted acoustic radiation force is calculated using the standard partial-wave series method, and the wave propagation within the porous media is modeled using Biot's theory of poro-elasticity. Numerical simulations are performed for porous aluminum and silica shells of different thickness and porosity. Results indicate that manipulation of low-porosity shells is possible using Bessel beams with large conical angles, over a number of broadband frequency ranges, whereas manipulation of highly porous shells can occur over both narrowband and broadband frequency domains.  相似文献   
19.
20.
Metabolic Brain Disease - mTOR has been shown to be involved in the regulation of immune responses and differentiation of immune cells. This protein is a candidate molecule for unraveling the...  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