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   2413篇
  免费   208篇
  国内免费   1篇
耳鼻咽喉   32篇
儿科学   69篇
妇产科学   40篇
基础医学   321篇
口腔科学   30篇
临床医学   313篇
内科学   477篇
皮肤病学   51篇
神经病学   196篇
特种医学   50篇
外科学   253篇
综合类   77篇
一般理论   1篇
预防医学   333篇
眼科学   49篇
药学   195篇
中国医学   6篇
肿瘤学   129篇
  2022年   29篇
  2021年   41篇
  2020年   26篇
  2019年   40篇
  2018年   36篇
  2017年   31篇
  2016年   31篇
  2015年   52篇
  2014年   71篇
  2013年   72篇
  2012年   111篇
  2011年   111篇
  2010年   81篇
  2009年   56篇
  2008年   120篇
  2007年   118篇
  2006年   119篇
  2005年   124篇
  2004年   113篇
  2003年   112篇
  2002年   92篇
  2001年   80篇
  2000年   67篇
  1999年   71篇
  1998年   38篇
  1997年   23篇
  1996年   17篇
  1995年   17篇
  1994年   20篇
  1992年   45篇
  1991年   48篇
  1990年   40篇
  1989年   52篇
  1988年   38篇
  1987年   38篇
  1986年   39篇
  1985年   45篇
  1984年   24篇
  1983年   30篇
  1982年   25篇
  1981年   13篇
  1980年   13篇
  1979年   20篇
  1978年   16篇
  1974年   18篇
  1973年   15篇
  1972年   20篇
  1970年   16篇
  1969年   20篇
  1968年   12篇
排序方式: 共有2622条查询结果,搜索用时 15 毫秒
1.

Background

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin. MM primarily affects bone marrow, but extramedullary sites can also be involved. Myelomatous pleural effusion (MPE) is an atypical and rare complication of MM. We aimed to systematically study the incidence and clinicopathologic profile of patients with MPE in a real-world setting.

Patients and Methods

In this retrospective study, 415 consecutive patients with MM managed at a tertiary care center in North India during a study period of January 1, 2010 to December 31, 2015 were evaluated for MPE. The patients with MPE were analyzed for their clinical profile, diagnosis, treatment, and outcomes.

Results

Of these 415 patients, 11 (2.65%) patients had MPE. The median age of the study population was 50 years with male preponderance. The majority of these patients had immunoglobin (Ig)G Kappa disease. All patients had higher than International Staging System stage I disease. MPE was a presenting feature at MM diagnosis in 45.45% (n = 5) of the patients, whereas the rest developed MPE during follow-up. MPE presented predominantly (81.8%) as a unilateral effusion. Concurrent extramedullary involvement at other site was seen in 45.45% (n = 5), with 3 (27%) patients having concurrent myelomatous ascites. Six of these were managed aggressively, whereas 5 patients opted for palliation. The outcomes were dismal (90.9% mortality), with a median survival of 2.47 months.

Conclusion

MPE is a rare entity, and positive outcomes of therapy remain low with dismal prognosis.  相似文献   
2.
3.
Numerous surveys at the national and regional level have demonstrated that large inequalities in infant health status exist in Southern Africa. Few studies have assessed infant mortality at the intra-urban scale of geographic analysis. Comparisons between infant mortality rates from different areas are made even more meaningful if the data are divided into two primary categories based on period-of-death; these being the neonatal and post-neonatal components. This study presents the results of a survey undertaken in Metropolitan Cape Town (population 1.6 million) during 1982. The aim was to determine the spatial variation of neonatal and post-neonatal mortality at the suburb (or community) level within the city. Overall, a total of 36,789 live births and 928 infant deaths were recorded; 53.4% in the neonatal period and 46.6% in the post-neonatal period. The mean infant mortality rate was 25.2 per 1000 live births; the neonatal mortality rate and post-neonatal mortality rate being 13.5/1000 and 11.7/1000, respectively. A marked range in death rates was evident for both components. For the neonatal category it was 0.0-49.9/1000 and 0.0-40.0/1000 for the post-neonatal period. The generally low post-neonatal mortality rate among the 69 suburbs studied has made the neonatal component the dominant contributor to the infant mortality rate. However, in the lowest socio-economic areas the post-neonatal mortality rate was responsible for over 60% of infant deaths.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
4.
Osteoporosis is a common disease with a strong genetic component characterized by reduced bone mass and an increased risk of fragility fractures. Bone mineral density (BMD) is the most important determinant of osteoporotic fracture risk, but the genes responsible for BMD regulation and fracture are incompletely defined. To enable multi-center studies to examine the genetic influences on BMD there is a requirement to standardize measurements across different manufacturers of bone densitometers, different versions of machines and different normative ranges. This paper describes a method developed to allow near-identical subjects with low age-adjusted BMD (based on Z-scores) to be recruited in 17 centers using 27 different densitometers. Cross-calibration was based on measurements using a European spine phantom circulated to all centers and measured ten times on each individual machine. From theses values an individual exponential curve, based on nominal versus observed BMD, was derived for each machine. As expected, there were large and significant variations in nominal BMD values, not only between scanners from different manufacturers but also between different versions of scanners from the same manufacturer. Hologic scanners tended to underestimate the nominal BMD, while Lunar scanners overestimated the value. Norland scanners gave mixed values over estimating BMD at the lower nominal value (0.5 g/cm2) while underestimating the value at the higher value (1.5 g/cm2). The validity of the exponential equations was tested using hip and spine measurements on 991 non-proband women from a familial osteoporosis study (FAMOS). After cross-calibration there was a considerable reduction in variation between machines. This observation, coupled with the absence of a similar reduction in variation attributable to a linear regression on age, demonstrated the validity of the cross-calibration approach. Use of the cross-calibration curves along with a standard normative range (in the case of this study, the Hologic normative range) allowed age-specific Z-scores to be used as an inclusion criterion in this genetic study, a method that will be useful for other trials where age-specific BMD inclusion criteria are required.  相似文献   
5.
6.
7.
Deb Miller  RN  BS  CNOR 《AORN journal》2002,76(5):898
  相似文献   
8.
Say yes to life: a pilot study.   总被引:1,自引:1,他引:0       下载免费PDF全文
In an attempt to assess whether there are any characteristics which a majority of ordinary people regard as life-affirming or life-denying, a questionnaire was given to a pilot group of 167 respondents, representing three different age and social categories. Five life-affirming and five life-denying characteristics were mentioned by more than 10% of respondents. Of the former, Drive, Sociability, Happiness and Optimism were endorsed by 15-20%. Of the latter, Unsociability and Poor Coping were mentioned by 22%, making them distinctly more frequent than the following categories of Pessimism, Lack of Drive and Unhappiness (11-14%). It is suggested that a number of these subjectively determined characteristics, which the general public perceive as being life-affirming or denying, do indeed influence physical or mental health, illness or illness behaviour. It may therefore be of value to utilize this set of public perceptions in future programmes of health education.  相似文献   
9.
The antiviral nucleoside derivative zidovudine (3'-azido-3'-deoxythymidine) previously has been shown to be an effective antibacterial agent in animals infected with Escherichia coli or Salmonella typhimurium. Since HIV infection can alter the course of human syphilis with serious consequences, it was of interest to determine if the noncultivable spirochaetal agent of syphilis, Treponema pallidum, is susceptible to this compound. The progression of experimental rabbit syphilis over a three week period was unchanged in animals receiving either 50 or 150 mg/kg oral zidovudine daily. In addition, a number of cultivable pathogenic and nonpathogenic spirochaetes were tested for susceptibility to zidovudine in vitro. At a concentration of 100 mg/L, zidovudine had no detectable effect on spirochaete growth, morphology, or motility. Thus it appears that spirochaetes are generally not susceptible to this compound, and that long-term zidovudine therapy will not be of benefit in preventing or controlling syphilis or other spirochaetoses in HIV-infected humans receiving this drug.  相似文献   
10.
The effect of valproic acid on the distribution of gavaged 65Zn in maternal and embryonic tissue of Sprague-Dawley rats was examined 24 h after gavaging of the drug on d 13 of pregnancy. Valproic acid treatment resulted in a significantly higher retention of 65Zn in maternal liver and lower amounts in uterus, placenta and embryos than in controls. Compared to controls, gel chromatography of maternal liver from valproic acid-treated dams showed higher 65Zn counts associated with a protein peak of molecular weight of 6,500, the approximate molecular weight of the Zn-binding protein metallothionein. These results support the idea that the teratogenicity of valproic acid is in part due to an induction of embryonic Zn deficiency secondary to a drug-induced sequestering of Zn into maternal liver that results in a decrease in maternal plasma Zn and subsequent reduction in embryonic Zn uptake.  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