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   16814篇
  免费   1333篇
  国内免费   32篇
耳鼻咽喉   191篇
儿科学   637篇
妇产科学   405篇
基础医学   2594篇
口腔科学   448篇
临床医学   1740篇
内科学   3501篇
皮肤病学   279篇
神经病学   1308篇
特种医学   498篇
外国民族医学   1篇
外科学   2192篇
综合类   103篇
一般理论   8篇
预防医学   1417篇
眼科学   372篇
药学   1344篇
中国医学   17篇
肿瘤学   1124篇
  2022年   101篇
  2021年   251篇
  2020年   220篇
  2019年   289篇
  2018年   319篇
  2017年   297篇
  2016年   361篇
  2015年   340篇
  2014年   478篇
  2013年   659篇
  2012年   864篇
  2011年   820篇
  2010年   494篇
  2009年   462篇
  2008年   728篇
  2007年   799篇
  2006年   727篇
  2005年   697篇
  2004年   741篇
  2003年   644篇
  2002年   604篇
  2001年   443篇
  2000年   486篇
  1999年   438篇
  1998年   211篇
  1997年   169篇
  1996年   191篇
  1995年   168篇
  1994年   163篇
  1993年   159篇
  1992年   321篇
  1991年   356篇
  1990年   343篇
  1989年   357篇
  1988年   275篇
  1987年   288篇
  1986年   248篇
  1985年   296篇
  1984年   200篇
  1983年   174篇
  1982年   136篇
  1981年   117篇
  1980年   99篇
  1979年   176篇
  1978年   131篇
  1977年   112篇
  1975年   104篇
  1974年   123篇
  1973年   109篇
  1972年   92篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
31.
32.
33.
34.
ABSTRACT:Background: In 1996 a new model of maternity care characterized by continuity of midwifery care from early pregnancy through the postpartum period was implemented for women attending Monash Medical Centre, a tertiary level obstetric service, in Melbourne, Australia. This study's purpose was to assess the impact of this model on women's views and experiences of care during the antenatal, intrapartum, and postpartum periods compared with views of women receiving standard maternity care. Methods: One thousand low‐ and high‐risk women who booked at the antenatal clinic and met the eligibility criteria were randomly allocated to continuity of midwifery care from a group of seven midwives in collaboration with medical staff, or to standard care from a variety of midwives and medical staff. Women's views of care were measured by means of a postal questionnaire at four months after the birth. Results: Team midwifery care was associated with increased satisfaction with antenatal, intrapartum, and some aspects of postpartum care. The differences were most obvious for antenatal care. Conclusions: Continuity of midwifery care is realistically achievable in a tertiary obstetric referral service and is associated with increased satisfaction. (BIRTH 30:1 March 2003)  相似文献   
35.
36.
37.
Ulla Waldenstrm 《分娩》2003,30(4):248-254
Abstract: Background: Studies of women's memory of labor and birth have generally concluded that women's recall is fairly accurate, but the findings are not unanimous. The aim of this study was to compare women's experiences of labor pain and overall experience of the birth at 2 months and 1 year after the delivery. Methods: A longitudinal cohort study of 2,428 women recruited in early pregnancy from all antenatal clinics in Sweden during 3 weeks evenly spread during 1999–2000 was conducted. In addition to a questionnaire in early pregnancy including background data, the women completed a questionnaire at 2 months and 1 year after the birth including the same 7‐point rating scale of pain intensity and the same question about overall experience of labor and birth. Results: Forty‐seven percent of the women made the same assessment of pain intensity, and 60 percent of childbirth overall, at 1 year as they did at 2 months after the birth. One year after the birth, 35 percent recalled pain as less severe, and 18 percent as more severe, and 24 percent said labor and birth overall was more negative, whereas 16 percent said it was more positive. Conclusion: This study showed great variation in women's memories of labor and birth, and conclusions by some other studies, often based on analyses of group data rather than on the responses of the individual participants were, to some extent, challenged. (BIRTH 30:4 December 2003)  相似文献   
38.
A separation of the individual latex layers is a known complication of endotracheal armoured tubes manufactured by immersion technique. This can result in herniation into the lumen with obstruction of the tube. Diffusion of nitrous oxide into the inner hernia considerably intensifies the obstruction. This can lead to life-threatening situations. We observed a similar herniation caused by layer separation with subsequent tube obstruction of silicolatex anaesthesia tubes used in paediatric circuit systems. This is caused by manufacturing defects and above all by damage incurred in reprocessing. Therefore it is important to process the tubes carefully. A too-high drying temperature can cause premature layer separation. The tubes should never be processed more than 80 times. Routine examination of the tubes is imperative, especially at the predilection sites for layer separation.  相似文献   
39.
Autopsy results on patients and corresponding studies in nonhuman primates have revealed that autografts of adrenal medulla into the striatum, used as a treatment for Parkinson's disease, do not survive well. Because adrenal chromaffin cell viability may be limited by the low levels of available nerve growth factor (NGF) in the striatum, the present study was conducted to determine if transected peripheral nerve segments could provide sufficient levels of NGF to enhance chromaffin cell survival in vitro and in vivo. Aged female rhesus monkeys, rendered hemiparkinsonian by the drug MPTP (n-methyl-4-phenyl-1,2,3,6 tetrahydropyridine), received autografts into the striatum using a stereotactic approach, of either sural nerve or adrenal medulla, or cografts of adrenal medulla and sural nerve (three animals in each group). Cell cultures were established from tissue not used in the grafts. Adrenal chromaffin cells either cocultured with sural nerve segments or exposed to exogenous NGF differentiated into a neuronal phenotype. Chromaffin cell survival, when cografted with sural nerve into the striatum, was enhanced four- to eightfold from between 8000 and 18,000 surviving cells in grafts of adrenal tissue only up to 67,000 surviving chromaffin cells in cografts. In grafts of adrenal tissue only, the implant site consisted of an inflammatory focus. Surviving chromaffin cells, which could be identified by both chromogranin A and tyrosine hydroxylase staining, retained their endocrine phenotype. Cografted chromaffin cells exhibited multipolar neuritic processes and numerous chromaffin granules, and were also immunoreactive for tyrosine hydroxylase and chromogranin A. Blood vessels within the graft were fenestrated, indicating that the blood-brain barrier was not intact. Additionally, cografted chromaffin cells were observed in a postsynaptic relationship with axon terminals from an undetermined but presumably a host origin.  相似文献   
40.
Scotopic b-wave stimulus/response (S/R) functions are abnormal in several human retinal degenerative disorders. However, the mechanisms by which diseases affect the S/R parameters are not yet fully known. Three experiments were done to simulate functional pathologies known to occur in retinal degenerations: 1) attenuated sensitivity of retinal units, 2) loss of rhodopsin, 3) loss of sensitivity with little or no loss of rhodopsin. None of the experimental perturbations of normal function replicated the pattern of S/R abnormalities caused by retinal degenerations. Thus, in the retinal degenerative disorders intrinsic abnormalities of cellular processing must affect the organization of distal retinal function indexed by the b-wave.  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