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   1940篇
  免费   122篇
  国内免费   7篇
耳鼻咽喉   8篇
儿科学   53篇
妇产科学   52篇
基础医学   221篇
口腔科学   79篇
临床医学   197篇
内科学   335篇
皮肤病学   16篇
神经病学   222篇
特种医学   134篇
外国民族医学   1篇
外科学   272篇
综合类   28篇
预防医学   207篇
眼科学   46篇
药学   123篇
中国医学   6篇
肿瘤学   69篇
  2023年   13篇
  2022年   15篇
  2021年   34篇
  2020年   29篇
  2019年   39篇
  2018年   40篇
  2017年   27篇
  2016年   34篇
  2015年   43篇
  2014年   57篇
  2013年   95篇
  2012年   83篇
  2011年   99篇
  2010年   49篇
  2009年   42篇
  2008年   92篇
  2007年   98篇
  2006年   94篇
  2005年   80篇
  2004年   93篇
  2003年   66篇
  2002年   87篇
  2001年   85篇
  2000年   57篇
  1999年   53篇
  1998年   27篇
  1997年   25篇
  1996年   24篇
  1995年   19篇
  1994年   19篇
  1993年   24篇
  1992年   42篇
  1991年   32篇
  1990年   38篇
  1989年   42篇
  1988年   36篇
  1987年   23篇
  1986年   29篇
  1985年   30篇
  1984年   16篇
  1983年   14篇
  1982年   11篇
  1980年   14篇
  1978年   15篇
  1977年   10篇
  1976年   7篇
  1975年   10篇
  1974年   7篇
  1972年   8篇
  1970年   8篇
排序方式: 共有2069条查询结果,搜索用时 937 毫秒
1.
2.
Critical care nurses within acute care settings are responsible for providing healthcare to a wide variety of patients and, consequently, knowledge regarding how to care for a patient with acute necrotizing fasciitis is imperative. A case study is presented to evidence the need for a multidisciplinary approach. Necrotizing fasciitis is defined and treatment options are presented. Caring for this patient is very challenging and demands a multidisciplinary team to coordinate all aspects of care to promote better patient outcomes.  相似文献   
3.
This study evaluates associations between soil lead concentrations (SPb), age of housing, and blood lead levels (BPb) of children in metropolitan New Orleans and Lafourche Parish, Louisiana. The database includes over 2,600 SPb and 6,000 BPb samples paired by their median values and pre-1940 housing percentages for 172 census tracts. Associations were evaluated with Fisher's exact test and Spearman's rho test and modeled with the least sum of absolute deviations regression. Census tracts with low SPb are associated with new housing, but census tracts with high SPb are evenly split between old and new housing [Fisher's exact test, p = 8.60 X 10(-13) for the percentage of housing built before 1940 (percent pre-1940 housing) versus SPb]. The p-value for SPb versus BPb is 12 orders of magnitude stronger than the p-value for percent pre-1940 housing versus BPb. Census tracts with low BPb are associated with new housing, but census tracts with high BPb are split evenly between old and new housing (Fisher's exact test, p = 1. 67 X 10(-12) for percent pre-1940 housing versus BPb). Census tracts with high SPb are associated with high BPb and census tracts with low SPb are associated with low BPb (Fisher's exact test, p = 3.18 X 10(-24) for BPb versus SPb). The Spearman's rho test of the association of SPb and BPb in Orleans and Lafourche Parishes yielded a p-value of 6.12 X 10(-24). The least sum of absolute deviations regression model of the data is BPb = 1. 845 + 0.7215 (SPb)0.4. A comparison of the modeled BPb versus observed BPb has an r(2) of 0.552 and a p-value of 2.83 X 10(-23) that this relation was due to chance. If blood lead in children is more closely associated to soil lead than to the age of housing, then primary lead prevention should also include soil lead.  相似文献   
4.
5.
6.
The present study was designed to examine the effects of a >30kDa fraction of medium conditioned for 2 days by adult rat seminiferoustubules on inhibin secretion by cultured tubules, and on spermatogenesisand fertility of male rats. Inhibin secretion was assayed byadding the >30 kDa fraction to 5 cm segments of adult ratseminiferous tubules and measuring inhibin by radioimmunoassayat 2 day intervals. Fertility was assayed by injecting malerats daily for up to 45 days with the >30 kDa fraction andthen mating them with a proestrus female, or by injecting for15 days and mating them with two female rats. The assay usedto evaluate the in-vivo effect of the >30 kDa fraction onthe testis involved an assessment of frequencies of seminiferoustubule stages scored by transillumination on intact tubules.The addition of the >30 kDa fraction to the adult rat seminiferoustubules cultured for 2 days resulted in an inhibition of inhibinsecretion into the medium. This effect was reversed when thefraction was removed and changed with fresh medium and culturedfor a further 4 days. The >30 kDa fraction administered i.p.to adult male rats resulted in a low fertilization rate comparedto control rats (67%) (P < 0.05). The assessment of frequenciesof seminiferous tubule stages scored by transillumination showedan increased frequency of stage VI and decreased frequency ofstages VII and VIII after treatment. The results of the presentstudy provide additional evidence that local regulation of Sertolicell function is mediated by a >30 kDa component or componentssecreted by adult seminiferous tubules which could arrest spermatogenesis.  相似文献   
7.
8.
The functions of the meniscus and subsequently the importance of meniscus preservation are well known. Thirty-one of 105 patients who underwent (closed) arthroscopic meniscus repair between 1982 and 1986 using an inside-out technique previously described were studied. Evaluations were based on The Hospital for Special Surgery knee rating system. Eighty-eight percent of the study population had a good-to-excellent outcome at an average 4.1 years follow-up. Most of these patients had no Fairbank changes on follow-up radiographs. Factors affecting outcome were analyzed. From this series, the at-risk factor for failure of meniscus repair is chronicity of injury (lasting longer than 2 weeks). Factors not noted to significantly influence results in this series include (a) age of the patient; (b) sex of the patient; (c) rim width up to 6 mm from the synovial meniscal junction; and (d) anterior cruciate ligament insufficiency. History of a reinjury and noncompliance with the postoperative rehabilitation protocol may also adversely influence results, but this is difficult to prove.  相似文献   
9.
10.
Fine-needle aspiration biopsy, used extensively for evaluating head and neck masses in adults, also provides an excellent minimally invasive means of evaluating infants with neck masses and torticollis. Three cases of torticollis involving infants are presented. In each case, fine-needle aspiration revealed a benign fibrous lesion, ruling out malignancy. The remaining cytologic differential diagnosis between infantile fibromatosis, fibromatosis colli, and calcifying aponeurotic fibrosis is discussed, with mention of the possible causes of and treatment for congenital torticollis. We conclude that fine-needle aspiration provides a fast and accurate diagnosis of neck masses in infants who have congenital torticollis, thereby avoiding surgical procedures in this very young age 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