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   1311篇
  免费   63篇
  国内免费   66篇
耳鼻咽喉   2篇
儿科学   92篇
妇产科学   17篇
基础医学   103篇
口腔科学   39篇
临床医学   171篇
内科学   271篇
皮肤病学   30篇
神经病学   25篇
特种医学   292篇
外科学   165篇
综合类   34篇
预防医学   56篇
眼科学   14篇
药学   67篇
中国医学   6篇
肿瘤学   56篇
  2021年   8篇
  2019年   7篇
  2018年   9篇
  2017年   13篇
  2016年   8篇
  2015年   21篇
  2014年   16篇
  2013年   36篇
  2012年   26篇
  2011年   27篇
  2010年   40篇
  2009年   53篇
  2008年   41篇
  2007年   81篇
  2006年   40篇
  2005年   39篇
  2004年   22篇
  2003年   18篇
  2002年   33篇
  2001年   30篇
  2000年   31篇
  1999年   27篇
  1998年   69篇
  1997年   73篇
  1996年   74篇
  1995年   62篇
  1994年   43篇
  1993年   51篇
  1992年   14篇
  1991年   23篇
  1990年   19篇
  1989年   43篇
  1988年   24篇
  1987年   39篇
  1986年   15篇
  1985年   26篇
  1984年   17篇
  1983年   23篇
  1982年   20篇
  1981年   17篇
  1980年   20篇
  1978年   5篇
  1977年   10篇
  1976年   4篇
  1975年   6篇
  1948年   4篇
  1935年   4篇
  1933年   4篇
  1929年   4篇
  1928年   7篇
排序方式: 共有1440条查询结果,搜索用时 31 毫秒
51.
52.
PurposeWe identify the expression of PRL-3 in primary endometrioid endometrial cancer and metastases in relation to the clinicopathological characteristics.Material/MethodsThe study involved 30 patients with type I endometrial cancer. Twelve of them were diagnosed with metastases in various localization of abdomen. The PRL-3 expression was evaluated on the basis of immunohistochemistry results by the use of monoclonal antibody anti-PRL3 clone 3B6.ResultsThe intensity of PRL-3 expression in correlation with tumor stage was statistically significant (p = 0.024). The strongest reaction was noted in cases classified as a 1a and 1b stage defined by FIGO. The strength of PRL-3 expression is significantly associated with the degree of histological tumor grade (p = 0.035).ConclusionsThe strong expression of PRL-3 in the primary tumor that was significantly correlated with the grade and clinical stage suggest that PTP4A3 participates in the process of endometrial carcinogenesis.  相似文献   
53.
54.

Introduction

African American mothers and other mothers of historically underserved populations consistently have higher rates of adverse birth outcomes than White mothers. Increasing prenatal care use among these mothers may reduce these disparities. Most prenatal care research focuses on prenatal care adequacy rather than concepts of quality. Even less research examines the dual perspectives of African American mothers and prenatal care providers. In this qualitative study, we compared perceptions of prenatal care quality between African American and mixed race mothers and prenatal care providers.

Methods

Prenatal care providers (n = 20) and mothers who recently gave birth (n = 19) completed semistructured interviews. Using a thematic analysis approach and Donabedian's conceptual model of health care quality, interviews were analyzed to identify key themes and summarize differences in perspectives between providers and mothers.

Findings

Mothers and providers valued the tailoring of care based on individual needs and functional patient–provider relationships as key elements of prenatal care quality. Providers acknowledged the need for knowing the social context of patients, but mothers and providers differed in perspectives of “culturally sensitive” prenatal care. Although most mothers had positive prenatal care experiences, mothers also recalled multiple complications with providers' negative assumptions and disregard for mothers’ options in care.

Conclusions

Exploring strategies to strengthen patient–provider interactions and communication during prenatal care visits remains critical to address for facilitating continuity of care for mothers of color. These findings warrant further investigation of dual patient and provider perspectives of culturally sensitive prenatal care to address the service needs of African American and mixed race mothers.  相似文献   
55.
56.

Introduction

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

Methods

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

Results

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

Conclusions

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.  相似文献   
57.
巨噬细胞迁移抑制因子最初是由于能抑制体外巨噬细胞随机迁移而被发现,现在它作为一种重要的调节因子参与一系列炎症性疾病过程.我们最近发现,巨噬细胞迁移抑制因子的缺失使一些由炎症介质诱发的白细胞-内皮细胞相互作用减弱,提示巨噬细胞迁移抑制因子在炎症反应中起作用的机制之一是促进白细胞聚集.……  相似文献   
58.
PURPOSE: Patients with pneumonia often remain hospitalized after becoming clinically stable, without demonstrated benefits on outcome. The purposes of this study were to assess the relation between length of hospital stay and daily medical care costs and to estimate the potential cost savings associated with a reduced length of stay for patients with pneumonia. SUBJECTS AND METHODS: As part of a prospective study of adults hospitalized with community-acquired pneumonia at a community hospital and two university teaching hospitals, daily medical care costs were estimated by multiplying individual charges by department-specific cost-to-charge ratios obtained from each hospital's Medicare cost reports. RESULTS: The median total cost of hospitalization for all 982 inpatients was $5, 942, with a median daily cost of $836, including $491 (59%) for room and $345 (41%) for non-room costs. Average daily non-room costs were 282% greater on the first hospital day, 59% greater on the second day, and 19% greater on the third day than the average daily cost throughout the hospitalization (all P <0.05), and were 14% to 72% lower on the last 3 days of hospitalization. Average daily room costs remained relatively constant throughout the hospital stay, with the exception of the day of discharge. A projected mean savings of $680 was associated with a 1-day reduction in length of stay. CONCLUSIONS: Despite institutional differences in total costs, patterns of daily resource use throughout hospitalization were similar at all institutions. A 1-day reduction in length of stay might yield substantial cost-savings.  相似文献   
59.
60.
Background and hypothesis: The aim of this study was to define the prevalence of previously undetected coronary heart disease among asmptomatic males, aged 30-65 years, by means of resting and exercise electrocardiography in conjunction with an analysis of conventional and exertional coronary risk factors. Methods: Between January 1985 and December 1989 we examined 5,000 clinically asymptomatic subjects. A detailed case history was obtained for each individual, followed by a complete physical examination, comprehensive blood (including lipid) profile, lung function tests, chest x-ray, a resting 12-lead electrocardiogram (ECG), and a maximal treadmill exercise ECG. Whenever possible, on-line computerized respiratory analysis (Beckman Metabolic Measurement Cart) was carried out during the exercise tests. Conventional and exertional coronary heart disease risk factors were also recorded. Results: A total of 162 persons (3.2%) showed abnormal S-T segment responses during the exercise or recovery period. Of these, 92 subjects underwent further investigations: coronary angiography (79), 201thallium scanning (13), 201thallium scanning followed by coronary angiography(7). Of the 86 patients who proceeded to cornoary angiography, 19 (22%) had either normal coronary artery anatomy or only insignificant disease. Among the 67 (78%) of patients with significant angiographically demonstrable disease, 26 received coronary artery bypass grafting, 7 underwent coronary angioplasty, and the remainder continued on medical management. Conclusions: These results are discussed in relation to a variety of conventional and exertional coronary risk factors.  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