首页 | 官方网站   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   3440篇
  免费   264篇
  国内免费   15篇
医药卫生   3719篇
  2023年   30篇
  2022年   31篇
  2021年   134篇
  2020年   87篇
  2019年   97篇
  2018年   141篇
  2017年   88篇
  2016年   114篇
  2015年   106篇
  2014年   163篇
  2013年   150篇
  2012年   230篇
  2011年   256篇
  2010年   142篇
  2009年   150篇
  2008年   221篇
  2007年   221篇
  2006年   192篇
  2005年   201篇
  2004年   186篇
  2003年   131篇
  2002年   123篇
  2001年   76篇
  2000年   64篇
  1999年   60篇
  1998年   17篇
  1997年   14篇
  1996年   14篇
  1995年   15篇
  1994年   12篇
  1993年   15篇
  1992年   24篇
  1991年   26篇
  1990年   17篇
  1989年   17篇
  1988年   15篇
  1987年   18篇
  1986年   17篇
  1985年   9篇
  1984年   6篇
  1983年   8篇
  1982年   12篇
  1981年   13篇
  1979年   13篇
  1978年   4篇
  1977年   5篇
  1976年   8篇
  1975年   4篇
  1972年   4篇
  1970年   3篇
排序方式: 共有3719条查询结果,搜索用时 31 毫秒
1.
Demographic projections for hip fragility fractures indicate a rising annual incidence by virtue of a multimorbid, ageing population with more noncommunicable diseases (NCDs). NCDs are characterised by slow progression and long duration ranging from ischaemic cardiovascular disease, cerebrovascular disease, diabetes, chronic obstructive pulmonary disease to various cancers. Management of this disease burden often involves commencing patients on oral anticoagulants to reduce the risk of thromboembolic events. The use of direct oral anticoagulants (DOACs) in clinical practice has increased due to their rapid onset of action, short half-life and predictable anticoagulant effects, without the need for routine monitoring. Safe and timely surgical intervention relies on reversal of anticoagulants. However, the lack of specific evidence-based guidelines for the perioperative management of patients on DOACs with hip fractures has proved challenging; in particular, the accessibility of DOAC-specific assays, justification of the cost-benefit ratio of targeted reversal agents and indications for neuraxial anaesthesia. This has led to potentially avoidable delays in surgical intervention. Following a literature review of the pharmacokinetic and pharmacodynamics of commonly used DOACs in our region including the role of surrogate markers, we propose a systematic, evidence-based guideline to the perioperative management of hip fractures DOACs. We believe this standardised protocol can be easily replicated between hospitals. We recommend that if patients are deemed suitable for a general anaesthesia, with satisfactory renal function, optimal surgical time should be 24 h following the last ingested dose of DOAC.  相似文献   
2.
3.
The objective of the study was to evaluate the reliability of sonoelastography in ductal carcinoma in patients in primary and secondary health care settings. Google Scholar, PubMed, Medline, Medscape, Wikipedia and NCBI were searched in January 2018 for all original research and review articles to identify relevant studies. Two reviewers selected the articles independently for based on the title and abstract. The selection criteria were sonoelastography accuracy for diagnosing ductal carcinoma as index text, B-mode sonography, and micropure imaging; surgery and histologic findings were used as reference text; and benign and malignant breast abnormalities and ductal carcinoma were used as target conditions. Two reviewers extracted the data on selected study characteristics, and the results were used to construct the tables and figures. Fifteen studies on ductal carcinoma were found. The overall sensitivity of sonoelastography in diagnosing ductal carcinoma was 85.7%, and the specificity, 79.8%. On the basis of the literature review, it was concluded that sonoelastography has high sensitivity and specificity in diagnosing ductal carcinoma.  相似文献   
4.
Hepatitis C is a global public health problem, and Pakistan is the second largest country in the globe with highest prevalence rate of hepatitis C virus (HCV). Until 2014, pegylated interferon (PEG-IFN) plus ribavirin (RBV) has been the standard therapy for HCV, however, owing to its adverse side effects and very low sustained virologic response (SVR) rates therapeutics trend is shifted toward direct-acting antivirals. Tripartite motif containing 22 (TRIM22) is a dynamic antiviral protein that can inhibit multiple viruses in vivo. Expression of TRIM22 mRNA has been linked to outcome of PEG-IFN and ribavirin therapy, where its higher expression leads to rapid virus clearance. However, in terms of therapy with direct-acting antiviral (DAA) or double DAA, impact of TRIM22 expression is largely unknown. These new drugs show more than 90% of SVR rates and lesser side effects and have proven to be better than IFN therapy. Endogenous IFN system suppresses various pathogens through the induction of antiviral effectors termed as interferon-stimulating genes (ISGs). We have studied the expression levels of one of these antiviral effectors, TRIM22 in response to sofosbuvir (SOF) and daclatasvir (DAC) in combination with RBV, using quantitative PCR in the peripheral blood mononuclear cells (PBMCs) of HCV-infected patients. We have observed sustained virus clearance in more than 90% of patients treated with DAA and double DAA and have seen the expression of TRIM22 to be higher in patients who attained SVR as compared to the untreated patients. We have also observed downregulation of TRIM22 in patients who failed to attain rapid virus clearance, and upregulation in those who achieved rapid clearance of virus. Genetic factors that determine the lower TRIM22 expression in these patients are needed to be explored that may also play a role in lower response to anti-HCV therapy. Endogenous IFN system and effects of antiviral proteins in response to DAA therapy is needed to be studied in order to better understand the host response toward these drugs to make them more effective.  相似文献   
5.
Anaphylaxis     
A 60 year old man attends to discuss his recent allergic reaction to an insect sting. He presents you with the casualty letter which reads : " Treated for anaphylaxis after bee sting-see GP for follow-up. "  相似文献   
6.
7.
Exposure to electromagnetic fields and the risk of leukemia   总被引:4,自引:0,他引:4  
Evidence from animal experiments and human studies suggests that electromagnetic fields may be human leukemogens. Epidemiological studies of leukemia in occupational groups and in the general populations are reviewed. The results are inconsistent. In the few studies showing an association between exposure to electromagnetic fields and the risk of leukemia, the temporal relationship between exposure and effect was not established, the observed associations were weak, the dose-response relationships were based on qualitative levels of exposure without regard to the duration of exposure or secondary sources of exposure, and the risk ratios were probably biased due to the population selection procedures used and misclassification of exposure. The proportionate mortality or cancer incidence ratios are unreliable estimates of relative risk. Further epidemiological research is needed to establish an association between exposure to electromagnetic fields and the risk of leukemia.  相似文献   
8.
There is a broad differential for patients presenting with fever, eosinophilia, and pneumonia. We present a case of a 48-year-old man who presented with recurrent fever, pleuritic chest pain, and cough. His medical history was significant for a recent trip to Arizona. A chest X ray showed a right lower lobe infiltrate and CT examination of the chest showed extensive mediastinal lymphadenopathy. Tissue culture from a biopsy specimen of the mediastinal lymph nodes revealed growth of Coccidioides immitis and a diagnosis of coccidioidomycosis was made. He was treated with a total of a 9-month course of itraconazole and has remained disease free for >2 years. This case shows how a careful history and evaluation will direct the clinician to the correct diagnosis.  相似文献   
9.
10.
The purpose of this study was to investigate the ovarian response and the receptivity of the endometrium in women pre-treated with micronized progesterone. Eighty-two normogonodotropic women undergoing in vitro fertilization were studied. Thirty received micronized progesterone 1500 mg/day from day 21 of the cycle for a minimum of 2 weeks, and 52 did not receive micronized progesterone (control group). A gonadotropin releasing hormone agonist (GnRH-a) was administered to all the patients in the follicular phase (flare-up). Twenty-five cycles were cancelled for fertilization failure due to male factor, 12 (40%) in the progesterone group and 13 (25%) in the control group (p = 0.271). There was no difference in the number of oocytes retrieved (7.3 +/- 5 vs. 8.2 +/- 4), fertilization rate (50.8% vs. 65%), clinical pregnancy rate (16.6% vs. 25%) or implantation rate (8% vs. 14%). In the progesterone group cases without fertilization, we performed two biopsies to evaluate the receptivity of the endometrium. Pinopode expression was noted 7 days after oocyte retrieval. It seems that the administration of micronized progesterone in the previous cycle does not affect the ovarian response to the combination of follicular phase GnRH-a and gonadotropins, nor the receptivity of the endometrium.  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-23

京公网安备 11010802026262号