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   80篇
  免费   5篇
  国内免费   7篇
儿科学   1篇
妇产科学   3篇
基础医学   11篇
口腔科学   4篇
临床医学   16篇
内科学   17篇
特种医学   6篇
外科学   4篇
综合类   3篇
预防医学   15篇
眼科学   4篇
药学   7篇
肿瘤学   1篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   1篇
  2013年   10篇
  2011年   3篇
  2010年   4篇
  2009年   8篇
  2008年   2篇
  2007年   7篇
  2006年   1篇
  2005年   5篇
  2004年   4篇
  2003年   1篇
  2001年   1篇
  1999年   1篇
  1998年   6篇
  1997年   3篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1989年   2篇
  1988年   4篇
  1986年   2篇
  1983年   1篇
  1980年   1篇
  1965年   1篇
  1959年   1篇
  1951年   1篇
排序方式: 共有92条查询结果,搜索用时 631 毫秒
41.
42.
Since the transition from a centrally planned to a market economy, Tajikistan has witnessed a high rate of child and maternal mortality, a decline in the birth rate and a significant drop in public expenditures on health care. Against this backdrop, this paper analyses the determinants of prenatal health care utilization using Andersen's behavioural model, which has been modified to the context of Tajikistan. We applied a two-stage sequential model to data drawn from a nationally representative survey. Binary logit regression is used to predict and explain the probability of using prenatal health care services, while negative binomial regression is used to predict and explain the frequency of using these services. Findings suggest that higher educational attainment increases the utilization of prenatal care. Conversely, poverty, limited knowledge about matters related to sex, low quality of health care service, lack of public infrastructure, as well as absence of or long distance of travel to the nearest health facility, all reduce the utilization of prenatal health care. Health policy and research implications are presented and discussed.  相似文献   
43.
细胞色素P450 2C19单碱基突变位点CYP2C19m1的分析   总被引:1,自引:0,他引:1  
目的:CYP2C19ml是引起CYP2C19酶活性缺陷的主要等位基因,有83%左右的慢代谢者含有CYP2C19ml等位基因,本文试图建立一步PCR测定CYP2C19ml等位基因的方法。方法:根据等位基因特异扩增(ASA)原理设计两对分别特异扩增野生型等位基因和突变型等位基因的引物,建立了一步PCR测定CYP2C19ml等位基因的方法。结果:对39位随机受试者进行了基因分型研究,发现3位CYP2C19ml纯合子、18位CYP2C19ml杂合子,其余18位为野生型纯合子。结论:说明效法能够用于测定CYP2C19ml等住基因,并且证明该法具有简便、快速和污染少的优点。  相似文献   
44.
Genez  BM; Wilson  MR; Houk  RW; Weiland  FL; Unger  HR  Jr; Shields  NN; Rugh  KS 《Radiology》1988,168(2):521-524
To determine whether magnetic resonance (MR) imaging can demonstrate the early stages of osteonecrosis that are not detectable radiographically, the authors compared radiologic findings with histologic results in seven patients at high risk for osteonecrosis of the femoral head. Radiography and MR imaging were performed, and proximal femoral intramedullary pressures were measured in all patients, even if results from imaging studies were normal. If the pressures were elevated, core decompression with biopsy was performed. Seven patients had elevated pressures in 11 hips. Of 11 hips from which biopsy specimens were taken, all had histologic evidence of osteonecrosis. However, in only five were the MR imaging findings consistent with osteonecrosis. In the remaining six hips with osteonecrosis, MR imaging findings were normal. Sensitivity of MR imaging in detection of osteonecrosis was 46%. The authors conclude that normal MR imaging results in high-risk patients do not rule out the presence of osteonecrosis.  相似文献   
45.
The DAZ (Deleted in AZoospermia) and DAZLA (DAZ-like autosomal) genes may be determinants of male infertility. The DAZ gene on the long arm of the human Y chromosome is a strong candidate for the 'azoospermia factor' (AZF). Its role in spermatogenesis is supported by its exclusive expression in testis, its deletion in a high percentage of males with azoospermia or severe oligospermia, and its homology with a Drosophila male infertility gene boule. No DAZ homologous sequences have been found on the mouse Y chromosome. Instead, a Dazla gene was isolated from mouse chromosome 17 and has been considered to be a murine homologue of DAZ. However, the homology between human DAZ and mouse Dazla is not strong, and Dazla contains only one of the seven DAZ repeats found in DAZ. We report the isolation of the human DAZLA gene by screening a human testis cDNA library with a DAZ cDNA clone. DAZLA encodes only one DAZ repeat and shares high homology with the mouse Dazla, indicating that these two genes are homologues. Using a panel of rodent-human somatic cell lines and fluorescence in situ hybridization, the DAZLA gene was mapped to 3p24, a region not known to share homology with mouse chromosome 17. The DAZLA gene may be involved in some familial cases of autosomal recessive male infertility.   相似文献   
46.
Fragile X premutation screening in women with premature ovarian failure   总被引:9,自引:6,他引:9  
We have screened 132 women with premature ovarian failure for fragile X (FRAXA) premutations. Three out of 23 (13%) pedigrees with the familial premature ovarian failure and 3/106 (3%) of women with the sporadic form of premature ovarian failure have FRAXA premutations compared with an expected prevalence of 1:590 (P=0.02). The mechanism of the association between FRAXA premutations and premature ovarian failure is unknown but as a genetic marker, FRAXA screening will be particularly valuable in predicting premature ovarian failure in some pedigrees and in the identification of families at risk of transmitting fragile X syndrome.   相似文献   
47.
通信兵智力水平与专业水平的关系   总被引:4,自引:0,他引:4  
朱霞  刘志宏  陈国民  江楠楠 《医学争鸣》2001,22(12):F002-F002
0 引言 智力在很大程度上决定着个体的作业绩效水平 [1 - 3] ,同时也是预测个体职业成就的一个重要指标 .因此 ,我们试图通过对通信兵智力的测量与分析 ,揭示通信兵智力与专业技术水平的关系以及通信兵重要岗位人员智力与专业技术水平的关系 ,为最终科学地建立通信兵职业适宜性测评体系奠定必要的工作基础 .1 对象和方法1.1 对象 某集团军通信团在岗专业技术人员 ,其中技术难度高的报、话务专业人员 6 3名 ,载波、接力等仅对仪器进行操作的专业人员 5 1名 ,外线、架设等一般专业人员 43名 ,共 15 7名 .工作 1a以上 ,年龄在 18~ 32岁之…  相似文献   
48.
49.
Objectives?The aim of this study is to review the development of NuvaRing® over the past decade to illustrate its use-effectiveness and acceptance as an alternative contraceptive option for women.

Methods?The data were extracted from the literature using computerised MEDLINE system. NuvaRing® is a new combined hormonal contraceptive vaginal ring made of ethylene-vinyl-acetate copolymer, releasing 120?μg etonorgestrel and 15?μg ethinyloestradiol per day. This ring is inserted on any day from day 1 to day 5 of a menstrual cycle for 21 days, thereafter removed for 7 days ring-free period and discarded.

Results?Complete inhibition of ovulation is observed during treatment with this device. Clinical exposure to NuvaRing® for 1786 women-years has resulted in 21 pregnancies, giving a Pearl Index of 1.18. Withdrawal bleeding (4.7–5.3 days) is regular (97–99% of cycles) with rare incidence of irregular bleeding (2.6–6.4%). The cycle control is good with the use of this combined contraceptive vaginal ring. NuvaRing® is well tolerated and accepted by women as compared to oral pill.

Conclusions?NuvaRing® is an effective vaginal contraceptive option for women. However, further study is needed for monitoring its long-term effectiveness and impact on patient's quality of life since the NuvaRingR is marketed in many countries.  相似文献   
50.

Objectives:

To assess the position of the temporomandibular joint (TMJ) disc in patients with TMJ pain and compare it with equivalent published data of asymptomatic volunteers.

Methods:

The oblique coronal closed- and open-jaw MR images from 66 patients with TMJ pain were evaluated. Clinical examination followed the research diagnostic criteria for temporomandibular disorders. In all coronal images, the transverse condylar axis and the medial and lateral edges of the disc were determined using special software. Inter-rater agreement was calculated [two raters; inter-rater correlation coefficient (ICC)]. The presence of osteoarthrosis (OA) was determined by two independent raters. The influence of OA was estimated in patients (generalized estimation equation model). The results were compared with those of healthy volunteers (t-test). Differences between closed and open jaw in patients were analysed with the Wilcoxon matched-pair test.

Results:

The ICC was good for the transverse condylar axis (0.987) and the medial edge of the disc (0.799) and fair for the lateral edge (0.355). On average, the disc projected 5.5% to the medial side; laterally, the condyle was partially uncovered by the disc (−16.6%). In the open-jaw position, both the medial and the lateral edges shifted medially (to 17.6% vs −23.6%, Wilcoxon matched-pair test, p < 0.001). OA had no significant influence (generalized estimation equation model, p = 0.952). The disc position differed significantly from asymptomatic individuals (t-test, p < 0.001) who showed a medial disc position and full coverage of the condyle.

Conclusions:

In patients with TMJ pain, the disc seems to be smaller and located less medially than in healthy volunteers. The extent of the medial shift on opening was similar.  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