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   657篇
  免费   23篇
  国内免费   21篇
耳鼻咽喉   1篇
儿科学   26篇
妇产科学   5篇
基础医学   84篇
口腔科学   33篇
临床医学   38篇
内科学   111篇
皮肤病学   13篇
神经病学   11篇
特种医学   97篇
外科学   85篇
综合类   51篇
预防医学   27篇
眼科学   42篇
药学   51篇
肿瘤学   26篇
  2021年   1篇
  2020年   10篇
  2019年   4篇
  2018年   14篇
  2017年   7篇
  2016年   8篇
  2015年   18篇
  2014年   17篇
  2013年   28篇
  2012年   12篇
  2011年   29篇
  2010年   33篇
  2009年   33篇
  2008年   20篇
  2007年   39篇
  2006年   40篇
  2005年   20篇
  2004年   26篇
  2003年   7篇
  2002年   11篇
  2001年   11篇
  2000年   11篇
  1999年   8篇
  1998年   26篇
  1997年   31篇
  1996年   40篇
  1995年   21篇
  1994年   13篇
  1993年   20篇
  1992年   9篇
  1991年   5篇
  1990年   4篇
  1989年   22篇
  1988年   10篇
  1987年   13篇
  1986年   10篇
  1985年   10篇
  1984年   9篇
  1983年   6篇
  1982年   5篇
  1981年   5篇
  1980年   10篇
  1979年   3篇
  1978年   3篇
  1977年   5篇
  1976年   5篇
  1975年   5篇
  1969年   1篇
  1962年   1篇
  1935年   1篇
排序方式: 共有701条查询结果,搜索用时 31 毫秒
1.
BackgroundCampylobacter spp. are one of the commonest causes of diarrhea in children under five and in resource poor settings also lead to malabsorption and stunting. The purpose of this systematic review was to understand the burden of Campylobacter spp. associated diarrhea among children in the South Asian countries.MethodsThis systematic review followed the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) guidelines. Databases were searched with defined keywords for publications from the years 1998–2018. Data on proportion of positive samples was extracted to compare the rates of Campylobacter infection among children (under the age of 19) from different study populations.ResultsOf the 359 publications screened, 27 eligible articles were included in this systematic review and categorized based on study design. In 8 case-control studies, Campylobacter spp. was detected more frequently among diarrheal cases (range, 3.2–17.4%) than non-diarrheal cases (0–13%). Although there were variations in the study population, overall, children under the age of two years experienced Campylobacter diarrhea more often than older children. Most studies reported stool culture as the method used to detect Campylobacter spp. however retesting using PCR-based methods significantly increased detection rates. Limited data were available on Campylobacter species. In 4 studies that provided species data, C. jejuni (3.2–11.2%) was shown to be the most common species, followed by C. coli.ConclusionIn South Asia, Campylobacter spp. are one of the most common bacterial diarrheal pathogens affecting children but there is a paucity of data on species, risk factors and attributable sources. Although a few studies were available, the epidemiology of campylobacteriosis remains uncertain. To understand the true burden and sources of infection, more detailed studies are needed collecting data from human, animal and environmental sources and using both culture and genomic tools.  相似文献   
2.
Previously, our lab discovered the protein Nischarin and uncovered its role in regulating cell migration and invasion via its interactions with several proteins. We subsequently described a role for Nischarin in breast cancer, in which it is frequently underexpressed. To characterize Nischarin's role in breast tumorigenesis and mammary gland development more completely, we deleted a critical region of the Nisch gene (exons 7–10) from the mouse genome and observed the effects. Mammary glands in mutant animals showed delayed terminal end bud formation but did not develop breast tumors spontaneously. Therefore, we interbred the animals with transgenic mice expressing the mouse mammary tumor virus-polyoma middle T-antigen (MMTV-PyMT) oncogene. The MMTV-PyMT mammary glands lacking Nischarin showed increased hyperplasia compared to wild-type animal tissues. Furthermore, we observed significantly increased tumor growth and metastasis in Nischarin mutant animals. Surprisingly, Nischarin deletion decreased activity of AMPK and subsequently its downstream effectors. Given this finding, we treated these animals with metformin, which enhances AMPK activity. Here, we show for the first time, metformin activates AMPK signaling and inhibits tumor growth of Nischarin lacking PyMT tumors suggesting a potential use for metformin as a cancer therapeutic, particularly in the case of Nischarin-deficient breast cancers.  相似文献   
3.
Hepatitis C virus infection and lichen planus: a short review   总被引:2,自引:0,他引:2  
OBJECTIVE: To review the current literature regarding the association of lichen planus (LP) and liver disease, with particular attention to the association of the oral variant of the disease with hepatitis C virus (HCV) infection.
MATERIALS AND METHODS: Available literature of the possible association of LP with systemic disorders, in particular chronic hepatic disease, has been reviewed. RESULTS: LP is sometimes associated with infectious or autoimmune disease and/or neoplasia, however an aetio-logical association between LP and these disorders seems unlikely. A more consistent association exists between LP and chronic hepatic disease. The precise cause of this association is not known. However, in the last 6 years a notable association between HCV infection and LP has been observed, particularly in patients in Spain, Italy and Japan. The pathogenesis of this possible HCV-associated LP is not known, but it may involve a cell mediated response to an altered epithelial antigen.
CONCLUSION: There is now evidence to suggest a significant association between HCV infection and LP in some groups of patients.  相似文献   
4.
5.
OBJECTIVE: Patients may have various forms of angioedema and require dental treatment which can cause or contribute to the onset of an episode of angioedema. This paper seeks to highlight the causes and the management of this serious condition.
DESIGN: An outline of the different types of angioedema is given here, along with three case reports which illustrate treatment and management.
SUBJECTS AND METHODS: Three patients who presented to an Oral Medicine clinic with angioedema are presented to illustrate various types of angioedema and the different contributing factors that precipitated episodes of the condition.
MAIN OUTCOME MEASURES: The three patients were all investigated for biochemical and allergic factors which may have caused their disease.
RESULTS: Both drugs and dental materials were shown to be involved in the pathogenesis of angioedema in this short series of patients.
CONCLUSIONS: Dental treatment or the use of some materials may promote or contribute to the disorder. Referral to hospital for specialist care is indicated for certain groups of patients who require invasive dental treatment. The multi-disciplinary team approach in the investigation and management of patients with angioedema is emphasised.  相似文献   
6.
7.
8.
9.
Distal radius fractures are often treated using percutaneous Kirschner wires (K-wires). The sensory nerves in this area, extensor tendons, radial artery and cephalic vein are at risk of injury in this procedure. We undertook a cadaveric investigation to identify probability of damage to these ‘at risk’ structures by measuring their distances in relation to standard K-wire sites. Nine upper limbs from six formalin-preserved cadavers were studied. Four K-wires were placed percutaneously simulating fixation of a distal radius fracture. Careful dissection was done preserving the original position of neurovascular and tendinous structures. Distances to relevant soft-tissue structures from each K-wire were measured using an electronic digital caliper. Distance of superficial nerves from radial styloid and Lister’s tubercle was measured to determine their ‘safe distance’ from these fixed landmarks. None of the superficial nerves were injured by a K-wire. Cephalic vein had been pierced on 4 occasions (4/18) and extensor tendons on 3 occasions (3/18). Wilcoxon signed-rank test was used to compare distance of the superficial nerves from radial styloid and Lister tubercle, and the latter was found to be the safer option. This study highlights the inherent danger in percutaneous K-wire fixation of wrist fractures. Limited size of the area, where K-wires can be positioned, and anatomic variations of neurovascular structures pose obstacles in developing guidelines for reducing risk of injury. We advocate use of mini-open approach and guiding devices to avert complications of inadvertent impalement and damage to these structures.  相似文献   
10.

Objective:

The study is aimed to evaluate anti-inflammatory activity of Caesalpinia bonducella Fleming (Caesalpiniaceae) flower extract (CBFE) and to study its effect on radiographic outcome in adjuvant induced arthritis and authentication by high performance thin layer chromatography (HPTLC) chemical fingerprinting.

Materials and Methods:

CBFE was administered orally (30, 100, and 300 mg/kg b.wt.) and tested for its anti-inflammatory activity in carrageenan-induced inflammation, cotton pellet induced chronic granulomatous inflammation and autacoids-induced inflammation. Effect on radiographic outcome was tested in adjuvant-induced arthritis. CBFE was HPTLC fingerprinted in suitable solvent system.

Result:

In carrageenan-induced inflammation, CBFE produced significant inhibition in edema volume at all the doses (30, 100 and 300 mg/kg b.wt.) and percentage of inhibition was 28.68, 31.00, and 22.48, respectively as compared to control at 5 h of its administration. In cotton pellet granuloma assay, CBFE significantly decreased the granuloma weight at 300 mg/kg dose level by 22.53%. CBFE (300 mg/kg) caused significant inhibition by 37.5, 44.44, and 35.29% edema volume, at ½, 1 and 3 h after 5-hydroxytryptamine injection, respectively. Radiographic score of animals treated with 300 mg/kg CBFE was significantly decreased when compared to arthritic control animals.

Conclusion:

The extract was found to possess significant anti-inflammatory activity. CBFE treatment improved the bony architecture in adjuvant-induced arthritis in rats. The developed HPTLC fingerprint would be helpful in the authentication of C. bonducella flower extract.KEY WORDS: 5-hydroxy tryptamine, Caesalpinia bonducella, carrageenan-induced inflammation, cotton pellet granuloma, high performance thin layer chromatography, radiography  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