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   7364篇
  免费   2572篇
  国内免费   44篇
耳鼻咽喉   213篇
儿科学   231篇
妇产科学   241篇
基础医学   166篇
口腔科学   67篇
临床医学   1241篇
内科学   2141篇
皮肤病学   443篇
神经病学   701篇
特种医学   224篇
外国民族医学   1篇
外科学   2351篇
综合类   31篇
一般理论   1篇
预防医学   553篇
眼科学   549篇
药学   154篇
中国医学   5篇
肿瘤学   667篇
  2024年   55篇
  2023年   690篇
  2022年   101篇
  2021年   331篇
  2020年   420篇
  2019年   204篇
  2018年   698篇
  2017年   735篇
  2016年   641篇
  2015年   597篇
  2014年   820篇
  2013年   754篇
  2012年   385篇
  2011年   390篇
  2010年   539篇
  2009年   676篇
  2008年   329篇
  2007年   181篇
  2006年   221篇
  2005年   142篇
  2004年   107篇
  2003年   75篇
  2002年   72篇
  2001年   102篇
  2000年   44篇
  1999年   70篇
  1998年   86篇
  1997年   91篇
  1996年   63篇
  1995年   64篇
  1994年   40篇
  1993年   33篇
  1992年   38篇
  1991年   35篇
  1990年   19篇
  1989年   19篇
  1988年   21篇
  1987年   11篇
  1986年   8篇
  1985年   6篇
  1984年   5篇
  1983年   7篇
  1982年   13篇
  1981年   9篇
  1980年   7篇
  1979年   3篇
  1978年   4篇
  1977年   3篇
  1972年   2篇
  1971年   3篇
排序方式: 共有9980条查询结果,搜索用时 31 毫秒
51.
Young people from migrant and ethnic minority backgrounds are recognised as emerging priority populations for reducing alcohol and other drug (AOD)-related harms in Australia. Limited research has investigated how service providers address AOD challenges in migrant communities. In this qualitative study, we interviewed 15 service providers from AOD, migrant support, community and other health services in a diverse region of Melbourne. Interviews explored the challenges that service providers faced and the strategies they implemented to engage with young migrants in relation to AOD use. Thematic analysis was used to generate four themes: stigma as a barrier to service delivery, intergenerational differences between young people and parents, the need for outreach and establishing trust and understanding over time. Service providers believed that stigma prevented many young people from migrant backgrounds having open conversations about their AOD use with family members and professionals. Participants perceived that some parents had less AOD-related knowledge and lower English language proficiency than their children creating challenges for effective communication. Service providers recognised the importance of engaging with young people in settings where they felt comfortable rather than expecting them to approach their service. Participants also acknowledged the need to invest time in establishing trust and understanding with young migrants so they could facilitate conversations about AOD use as relationships evolved. Although service providers had a strong understanding of young people's needs, they found it challenging to build relationships in the context of funding and time constraints. Our results indicate the need for long-term funding and timelines that enable service providers to build strong relationships with young migrants, their families and their broader cultural communities to facilitate access to AOD support.  相似文献   
52.
Host cell proteases such as TMPRSS2 are critical determinants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tropism and pathogenesis. Here, we show that antithrombin (AT), an endogenous serine protease inhibitor regulating coagulation, is a broad-spectrum inhibitor of coronavirus infection. Molecular docking and enzyme activity assays demonstrate that AT binds and inhibits TMPRSS2, a serine protease that primes the Spike proteins of coronaviruses for subsequent fusion. Consequently, AT blocks entry driven by the Spikes of SARS-CoV, MERS-CoV, hCoV-229E, SARS-CoV-2 and its variants of concern including Omicron, and suppresses lung cell infection with genuine SARS-CoV-2. Thus, AT is an endogenous inhibitor of SARS-CoV-2 that may be involved in COVID-19 pathogenesis. We further demonstrate that activation of AT by anticoagulants, such as heparin or fondaparinux, increases the anti-TMPRSS2 and anti-SARS-CoV-2 activity of AT, suggesting that repurposing of native and activated AT for COVID-19 treatment should be explored.  相似文献   
53.
Objective. The objective of our study was to determine if clinical observation of pressure-flow relationships (PFR) can differentiate between partial external obstruction (obstruction) and infiltration as a cause of poor performance of gravity-fed infusions.Methods. A total of 24 patients with functional intravenous cannulae in situ had obstruction simulated by the application of a tourniquet proximal to the cannula. The change in flow (F) for a discrete change in pressure (P) was determined in each case by counting drop rates at two different elevations of the fluid reservoir level, 10 cm apart. The same process was repeated in 15 patients in whom the cannula was in an extra vascular location (infiltration). Three sizes of cannula—16-gauge, 18-gauge, and 20-gauge—were examined, with equal distribution of sizes in each group. The effect on flow rates of inflating a blood pressure (BP) cuff proximally on the cannulated limb was assessed. The ratio P/F is the total resistance of the infusion system, and by subtracting known values for resistance of infusion tubing and cannula, the venous or tissue resistance was calculated.Results. There was a statistically significant difference between the change in flow for obstructed compared with infiltrated cannulae for the same change in pressure for each cannula size. The mean venous resistance was 23 mm Hg/L/hr, while that of tissue was 280 mm Hg/L/hr, with no overlap between groups. There was no effect on flow rate with blood pressure cuff inflation in the infiltrated group whereas flow progressively fell in the obstructed group.Conclusions. Clinical observation of PFRs in poorly functioning gravity-fed IV infusions can assist in detecting infiltration as a cause. Inflation of a blood pressure cuff will further impair flow where the cannula is intravascular, but will have no effect in an extravascular location.  相似文献   
54.
Varieties of gastric surgery have increasingly been used in the management of morbid obesity. Generally, however, research and commentary in this area have related to surgical technique, with weight loss or morbidity being regarded as the most important dependent measures. In the context of the publication of several papers relating to the effects of surgery in the long-term, we believe that it is timely for surgeons to examine their criteria for success. In this paper, we argue that weight loss is inadequate as a primary criterion for success in this context, and that the value of the intervention should be measured against a multidimensional concept of success.  相似文献   
55.
There has been a prolific growth of voluntary organizations in India since independence in 1947. One of the major areas of this growth has been in the field of community health. The purpose of this article is to historically trace the voluntary movement in community health in India, analyze the current status, and predict future trends of voluntary efforts. A review of the literature in the form of a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis was the method of this study. Some of the key trends which emerged as the priority areas for progress and for strengthening voluntary organizations in the future were enhancing linkages between health and development; building upon collective force; greater utilization of participatory training; establishing egalitarian and effectual linkages for decision making at the international level; developing self-reliant community-based models; and the need for attaining holistic empowerment at individual, organizational, and community levels through duty consciousness as opposed to merely asking for rights.The authors would like to express gratitude to Voluntary Health Association of India for sharing the necessary documents and to Dr. Rick Petosa for valuable editorial comments.  相似文献   
56.
Objectives. To examine relationships between body mass index (BMI) and cardiovascular risk factors in 279 Europeans and 231 Polynesian Pacific Islanders in New Zealand.

Methods. Participants were recruited from Seventh‐Day Adventist church meetings or camps, and were surveyed by self‐administered questionnaire. Blood pressure, weight and height were measured. Fasting blood samples were analysed for lipids, glucose and fructosamine.

Results. Age‐adjusted BMI was higher in Pacific Islanders than in Europeans: 32.8(0.3) versus 25.6(0.3); means(SE); p = 0.0001). In Europeans, BMI was positively associated with systolic and diastolic blood pressures, triglycerides, total cholesterol, LDL cholesterol and fasting blood glucose, and negatively associated with HDL cholesterol. In Pacific Islanders, BMI was associated only with systolic and diastolic blood pressures, and with HDL cholesterol. These associations were stronger in Europeans than in Pacific Islanders.

Conclusions. In this group of Pacific Islanders, the association between BMI and cardiovascular risk factors was weaker than in Europeans. This suggests that either BMI is a poor measure of adiposity in Pacific Islanders, or that adiposity may be less strongly linked to cardiovascular disease in Pacific Islanders.  相似文献   

57.
The large thyroid mass with substernal extension often requires a combination of cervical and thoracic approach for its access and removal. We have developed a technique that uses a cervical incision and combines clear access to the mass with low morbidity. The principle features include complete sternocleidomastoid mobilization, early identification of the neurovascular pedicle through a lateral approach, and finger dissection to deliver the substernal component of the mass. This article also describes the elements of our technique in detail, from preoperative considerations through wound closure and discusses the debate concerning the ideal treatment of these challenging tumors.  相似文献   
58.
In a group of 35 patients with relapsed and/or chemo-resistant non-Hodgkin's lymphoma (NHL), low-dose total body irradiation (LTBI) (+involved-field radiotherapy to bulky sites) achieved a complete remission rate of 29%, 2-years progression-free survival of 32% and a median progression-free survival of 12 months. The 2-year survival was 42% and the median survival was 17 months. Immuno-staining and flow cytometry of peripheral blood in 14 patients showed that LTBI leads to a significant increase in the percentage of CD4+ cells with a consequent significant increase in the CD4+/CD8+ ratio. High lymphocytic percent and a high percentage of CD4+ cells before LTBI were significantly correlated with longer response duration and overall survival. These data may suggest that the palliative potential of LTBI should be investigated as an alternative to chemotherapy in NHL patients. The pre-treatment percentage of lymphocytes and CD4+ cells may be used as predictors for response to LTBI.  相似文献   
59.
All primary carbon dioxide (CO2) laser stapedectomies supervised by the senior author since 1986 were retrospectively reviewed and reported according to 1995 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing guidelines. Sixty-three cases had more than 6 weeks of follow-up with an average residual gap of 6.49 dB (SD = 5.55 dB) and an 89% success rate. Thirty cases had more than 1 year of follow-up with the average hearing result of 6.58 dB (SD = 5.93 dB) and an 87% success rate. In 11 cases, 14 operative problems or complications occurred. Suctioning the vestibule occurred in five cases. Because suction is required to evacuate laser smoke, these cases are attributed to the laser. One of these patients had delayed sensorineural hearing loss. One patient had profound delayed sensorineural hearing loss as a result of granuloma formation. These were the only major complications. The laser is a tool that gives reproducible technique and good success rates.  相似文献   
60.
EDITORIAL COMMENT: This study of amnioinfusion during labour complicated by the known passage of meconium shows that the technique seems clinically worthwhile, even in a centre without facilities for electronic fetal heart monitoring or scalp blood pH and blood gas analysis. The series is small and more data from larger studies is required to test the conclusions reported by the authors.
Summary: A prospective study to see the safety and efficacy of transcervical amnioinfusion in labour complicated by meconium-stained amniotic fluid (MSAF) was carried out in a teaching hospital with limited resources. Fifty patients in labour with meconium-stained amniotic fluid and fulfilling the inclusion criteria (vertex presentation, gestational age of 36 weeks or more, no medical or obstetrical complications and normal fetal heart rate at time of inclusion) were taken for the study; 25 patients received amnioinfusion. The control group received only supportive therapy. Labour outcome was compared in the 2 groups. The incidence of Caesarean section was seen to be decreased but neonatal parameters showed no significant difference in the amnioinfusion group.  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