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   3474篇
  免费   339篇
  国内免费   13篇
耳鼻咽喉   24篇
儿科学   104篇
妇产科学   72篇
基础医学   365篇
口腔科学   78篇
临床医学   346篇
内科学   543篇
皮肤病学   64篇
神经病学   390篇
特种医学   186篇
外国民族医学   1篇
外科学   612篇
综合类   104篇
预防医学   292篇
眼科学   34篇
药学   299篇
中国医学   1篇
肿瘤学   311篇
  2022年   40篇
  2021年   49篇
  2020年   35篇
  2019年   47篇
  2018年   53篇
  2017年   47篇
  2016年   56篇
  2015年   48篇
  2014年   81篇
  2013年   109篇
  2012年   120篇
  2011年   150篇
  2010年   82篇
  2009年   90篇
  2008年   120篇
  2007年   121篇
  2006年   128篇
  2005年   127篇
  2004年   125篇
  2003年   112篇
  2002年   133篇
  2001年   119篇
  2000年   138篇
  1999年   85篇
  1998年   61篇
  1997年   38篇
  1996年   48篇
  1995年   54篇
  1994年   50篇
  1993年   48篇
  1992年   93篇
  1991年   86篇
  1990年   82篇
  1989年   91篇
  1988年   73篇
  1987年   71篇
  1986年   61篇
  1985年   61篇
  1984年   44篇
  1983年   46篇
  1982年   39篇
  1981年   38篇
  1980年   32篇
  1979年   36篇
  1978年   30篇
  1977年   36篇
  1976年   26篇
  1975年   24篇
  1974年   26篇
  1972年   24篇
排序方式: 共有3826条查询结果,搜索用时 0 毫秒
41.
The obesity epidemic has serious implications for women of reproductive age; its rising incidence is associated not just with health implications for the mother but also has transgenerational ramifications for the offspring. Increased incidence of diabetes, cardiovascular disease, obesity, and kidney disease are seen in both the mothers and the offspring. Animal models, such as rodent studies, are fundamental to studying maternal obesity and its impact on maternal and offspring health, as human studies lack rigorous controlled experimental design. Furthermore, the short and prolific reproductive potential of rodents enables examination across multiple generations and facilitates the exploration of interventional strategies to mitigate the impact of maternal obesity, both before and during pregnancy. Given that obesity is a major public health concern, it is important to obtain a greater understanding of its pathophysiology and interaction with reproductive health, placental physiology, and foetal development. This narrative review focuses on the known effects of maternal obesity on the mother and the offspring, and the benefits of interventional strategies, including dietary intervention, before or during pregnancy on maternal and foetal outcomes. It further examines the contribution of rodent models of maternal obesity to elucidating pathophysiological pathways of disease development, as well as methods to reduce the impact of obesity on the mothers and the developing foetus. The translation of these findings into the human experience will also be discussed.  相似文献   
42.
Objective: This paper reports on the logistics of conducting a validation study of a routinely collected dataset against medical records at hospitals to inform planning of similar studies. Method: A stratified random sample of 15 hospitals and two homebirth practitioners was included. Site visits were arranged following consent. In addition to the validation of perinatal data, information was collected regarding logistics. Results: Records at 14 metropolitan and rural hospitals up to 500 km from the research centre, and two homebirth practitioners, were audited. Obtaining consent to participate took between 5 days and 10 months. Auditors visited sites on 101 days, auditing 737 medical record pairs at 16 sites. Median audit time per record was 51.3 minutes; electronic records each took 36 minutes longer than paper. Travel time accounted for nearly one‐quarter of audit time. Conclusions: Delays obtaining consents, long travel times and electronic records prolonged audit duration and expense. Employment of experts maximised use of available audit time. Conducting a validation study is a time‐consuming and expensive exercise; however, confidence in the accuracy of public health data is vital. Implications: Validation studies are unquestionably important. Three alternative strategies have been proposed to make future studies viable.  相似文献   
43.
Liposarcomas account for approximately 20% of all adult sarcomas and have limited therapeutic options outside of surgery. Inhibition of ataxia-telangiectasia and Rad3 related protein kinase (ATR) has emerged as a promising chemotherapeutic strategy in various cancers. However, its activation, expression, and function in liposarcoma remain unkown. In this study, we investigated the expression, function, and potential of ATR as a therapeutic target in liposarcoma. Activation and expression of ATR in liposarcoma was analyzed by immunohistochemistry, which was further explored for correlation with patient clinical characteristics. ATR-specific siRNA and the ATR inhibitor VE-822 were applied to determine the effect of ATR inhibition on liposarcoma cell proliferation and anti-apoptotic activity. Migration activity and clonogenicity were examined using wound healing and clonogenic assays. ATR (p-ATR) was overexpressed in 88.1% of the liposarcoma specimens and correlated with shorter overall survival in patients. Knockdown of ATR via specific siRNA or inhibition with VE-822 suppressed liposarcoma cell growth, proliferation, migration, colony-forming ability, and spheroid growth. Importantly, ATR inhibition significantly and synergistically enhanced liposarcoma cell line chemosensitivity to doxorubicin. Our findings support ATR as critical to liposarcoma proliferation and doxorubicin resistance. Therefore, the addition of ATR inhibition to a standard doxorubicin regimen is a potential treatment strategy for liposarcoma.  相似文献   
44.
Acute otomastoiditis and its complications: role of CT   总被引:2,自引:0,他引:2  
Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess.  相似文献   
45.
46.
47.
Digestive Diseases and Sciences - Clostridioides difficile infection (CDI) is caused by Toxins A and B, secreted from pathogenic strains of C. difficle. This infection can vary greatly in symptom...  相似文献   
48.
Little is known about how cell shape is controlled. We are using the morphogenesis of trichomes (plant hairs) on the plant Arabidopsis thaliana as a model to study how cell shape is controlled. Wild-type Arabidopsis trichomes are large, single epidermal cells with a stalk and three or four branches, whereas in zwichel (zwi) mutants the trichomes have a shortened stalk and only two branches. To further understand the role of the ZWI gene in trichome morphogenesis we have cloned the wild-type ZWICHEL (ZWI) gene by T-DNA tagging, and report here that it encodes a member of the kinesin superfamily of microtubule motor proteins. Kinesin proteins transport diverse cellular materials in a directional manner along microtubules. Kinesin-like proteins are characterized by a highly conserved “head” region that comprises the motor domain, and a nonconserved “tail” region that is thought to participate in recognition and binding of the appropriate cargo.  相似文献   
49.

Background

The intensive care nursing workforce plays an essential role in the achievement of positive healthcare outcomes. A growing body of evidence indicates that inadequate nurse staffing and poor skill mix are associated with negative outcomes for patients, and potentially compromises nurses’ ability to maintain the safety of those in their care. In Australia, the Australian College of Critical Care Nurses (ACCCN) has previously published a position statement on intensive care staffing. There was a need for a stronger more evidence based document to support the intensive nursing workforce.

Objectives

To undertake a systematic and evidence review of the evidence related to intensive care nurse staffing and quality of care, and determine evidence-based professional standards for the intensive care nursing workforce in Australia.

Methods

The National Health and Medical Research Council standard for clinical practice guidelines methodology was employed. The English language literature, for the years 2000-2015 was searched. Draft standards were developed and then peer- and consumer-reviewed.

Results

A total of 553 articles was retrieved from the initial searches. Following evaluation, 231 articles met the inclusion criteria and were assessed for quality using established criteria. This evidence was used as the basis for the development of ten workforce standards, and to establish the overall level of evidence in support of each standard. All draft standards and their subsections were supported multi-professionally (median score >6) and by consumers (85–100% agreement). Following minor revisions, independent appraisal using the AGREE II tool indicated that the standards were developed with a high degree of rigour.

Conclusion

The ACCCN intensive care nursing nurse workforce standards are the first to be developed using a robust, evidence-based process. The standards represent the optimal nurse workforce to achieve the best patient outcomes and to maintain a sustainable intensive care nursing workforce for Australia.  相似文献   
50.

Objective

To determine adverse event rates for adult cranial neuro-oncologic surgeries performed at a high-volume quaternary academic center and assess the impact of resident participation on perioperative complication rates.

Patients and Methods

All adult patients undergoing neurosurgical intervention for an intracranial neoplastic lesion between January 1, 2009, and December 31, 2013, were included. Cases were categorized as biopsy, extra-axial/skull base, intra-axial, or transsphenoidal. Complications were categorized as neurologic, medical, wound, mortality, or none and compared for patients managed by a chief resident vs a consultant neurosurgeon.

Results

A total of 6277 neurosurgical procedures for intracranial neoplasms were performed. After excluding radiosurgical procedures and pediatric patients, 4151 adult patients who underwent 4423 procedures were available for analysis. Complications were infrequent, with overall rates of 9.8% (435 of 4423 procedures), 1.7% (73 of 4423), and 1.4% (63 of 4423) for neurologic, medical, and wound complications, respectively. The rate of perioperative mortality was 0.3% (14 of 4423 procedures). Case performance and management by a chief resident did not negatively impact outcome.

Conclusion

In our large-volume brain tumor practice, rates of complications were low, and management of cases by chief residents in a semiautonomous manner did not negatively impact surgical 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