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   436篇
  免费   30篇
耳鼻咽喉   2篇
儿科学   9篇
妇产科学   34篇
基础医学   30篇
口腔科学   2篇
临床医学   70篇
内科学   30篇
皮肤病学   1篇
神经病学   92篇
特种医学   18篇
外科学   41篇
综合类   8篇
预防医学   41篇
药学   8篇
肿瘤学   80篇
  2024年   1篇
  2023年   1篇
  2022年   1篇
  2021年   11篇
  2020年   6篇
  2019年   13篇
  2018年   10篇
  2017年   8篇
  2016年   9篇
  2015年   8篇
  2014年   11篇
  2013年   7篇
  2012年   34篇
  2011年   29篇
  2010年   17篇
  2009年   25篇
  2008年   38篇
  2007年   27篇
  2006年   25篇
  2005年   24篇
  2004年   11篇
  2003年   19篇
  2002年   12篇
  2001年   23篇
  2000年   12篇
  1999年   11篇
  1998年   3篇
  1997年   2篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1992年   9篇
  1991年   8篇
  1990年   8篇
  1989年   4篇
  1988年   5篇
  1987年   4篇
  1986年   4篇
  1985年   2篇
  1984年   2篇
  1983年   6篇
  1982年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   2篇
  1974年   2篇
  1970年   2篇
排序方式: 共有466条查询结果,搜索用时 0 毫秒
21.
Objective: To evaluate the nonselective application of extended embryo culture on the outcome of IVF.

Design: Retrospective analysis.

Setting: Private practice assisted reproductive technology center.

Patient(s): Seven hundred ninety nonselected patients undergoing IVF with controlled ovarian stimulation.

Intervention(s): For day 3 ET, multicell embryos were cultured in human tubal fluid medium and 12% synthetic serum substitute. For day 5 ET, embryos were cultured for 48 hours in S1 medium and then for 48 hours in S2 medium.

Main Outcome Measure(s): Implantation rate (determined by total no. of visualized gestational sacs), ongoing pregnancy rate, and number of embryos available for ET.

Result(s): Respective day 3 and day 5 implantation rates for patients aged <35 years (29.5% and 38.9%), patients aged 35–39 years (20.7% and 28.2%), and all patients combined (23.3% and 32.4%) were statistically significantly different. Significantly more embryos were transferred on day 3 than on day 5 for patients aged <35 years (2.9 vs 2.4), patients aged 35–39 years (3.1 vs 2.6), and all patients combined (3.0 vs 2.5). The difference in ongoing pregnancy rates per retrieval was statistically significant for day 3 compared with day 5 transfers for all patients combined (35.9% vs 43.8%). Cancellation rates for transfer after retrieval increased significantly for day 3 compared with day 5 transfer (2.9% vs 6.7%).

Conclusion(s): These results demonstrate the feasibility of using extended embryo culture in a nonselective manner for couples undergoing IVF. Overall, extended embryo culture was associated with a significant increase in pregnancy rates and implantation rates and a significant decrease in the number of embryos transferred. The rate of multiple implantation among patients aged <35 years warrants consideration of single blastocyst transfers for this group.  相似文献   

22.
23.
Impaired deficit awareness is important to detect because of its clinical implications; for example, patients with impaired awareness are more likely to engage in potentially dangerous activities, such as operating the stove. This study evaluated the reliability and validity of the Dementia Deficits Scale (DDS), a new multidimensional instrument for the assessment of self-awareness of cognitive, emotional, and functional deficits associated with dementia. Three parallel forms of the DDS were independently completed by the patient, clinician, and informant. The DDS yields two measures of deficit awareness: the discrepancy between clinician and patient assessments of the patient's deficits, and the discrepancy between informant and patient assessments. The DDS demonstrated adequate reliability and good divergent and convergent validity. Clinician and informant reports each added unique information, highlighting the importance of including both perspectives in the awareness assessment process. The DDS is recommended as a reliable and valid tool for the clinical and empirical assessment of deficit awareness in patients with dementia.  相似文献   
24.
Hormone replacement therapy regimens and breast cancer risk(1)   总被引:3,自引:0,他引:3  
Hormone replacement therapy (HRT) has increased in the United States over the past 2 decades in response to reports of long-term health benefits. A relationship between HRT and breast cancer risk has been observed in a number of epidemiological studies. In 2002, the Women's Health Initiative Randomized Controlled Trial reported an association between continuous combined HRT and breast cancer risk. The objective of this study was to examine the association between breast cancer risk and HRT according to regimen and duration and recency of use.A multicenter, population-based, case-control study was conducted in five United States metropolitan areas from 1994 to 1998. Analyzed were data from 3823 postmenopausal white and black women (1870 cases and 1953 controls) aged 35-64 years. Odds ratios (ORs) were calculated as estimates of breast cancer risk using standard, unconditional, multivariable logistic regression analysis. Potential confounders were included in the final model if they altered ORs by 10% or more. Two-sided P values for trend were computed from the likelihood ratio statistic.Continuous combined HRT was associated with increased breast cancer risk among current users of 5 or more years (1.54; 95% confidence interval 1.10, 2.17). Additionally, a statistically significant trend indicating increasing breast cancer risk with longer duration of continuous combined HRT was observed among current users (P =.01). There were no positive associations between breast cancer risk and other HRT regimens.Our data suggest a positive association between continuous combined HRT and breast cancer risk among current, longer term users. Progestin administered in an uninterrupted regimen may be a contributing factor. Risk dissipates once use is discontinued.  相似文献   
25.
BackgroundWomen with visual impairment may have reduced ability to access standard care resources, however, information on their pregnancy and neonatal outcomes is limited.ObjectiveTo assess risk of adverse pregnancy and neonatal outcomes among visually impaired women in Washington State from 1987 to 2014.MethodsWe conducted a retrospective cohort study using linked Washington State birth/fetal death hospital discharge records to compare outcomes among women with and without visual impairment noted at their delivery hospitalization. Pregnancy conditions and outcomes evaluated included gestational diabetes, pre-eclampsia, labor induction and cesarean delivery. Neonatal outcomes included preterm delivery and birth weight <2500 g. We assessed length of maternal and infant delivery hospitalization. We performed Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CIs) for each outcome, adjusting for year of delivery, maternal age, and parity.ResultsMost adverse pregnancy and neonatal outcomes were similar for visually impaired (N = 232) and comparison women (N = 2362). However, visually impaired women had increased risks of severe pre-eclampsia (RR 3.77, 95% CI 1.69–8.43), labor induction (RR 1.33, 95% CI 1.10–1.61) and preterm delivery (RR 1.60, 95% CI 1.06–2.42). They were also more likely to have delivery hospitalizations of 3 or more days following a vaginal (RR 1.86, 95% CI 1.41–2.47). Among cesarean deliveries, infants of visually impaired women had increased risk (RR 1.24, 95% CI 1.02–1.51) of hospitalization for 3 or more days postpartum.ConclusionOur findings may be useful for obstetric providers in counseling their visually impaired patients.  相似文献   
26.
Bilaterality is uncommon in Wilms' tumor, being present in 4% to 8% of the cases. We report the combined experience of two children's hospitals in one city over a 20-year period. We encountered nine cases of synchronous bilateral nephroblastoma (National Wilms' Tumor Study 3, stage V). Age at diagnosis ranged from 9 to 41 months (mean 23 months). There were five girls and four boys. Associated findings include nephroblastomatosis in three cases (33%), one of which also had a familial history; undescended testis in two cases; and minor anomalies in two other cases. Surgical treatment consisted of unilateral nephrectomy with contralateral partial nephrectomy or tumorectomy in six cases, nephrectomy with contralateral biopsy only in two cases, and the other patient had bilateral biopsies initially, followed at a later date by partial nephrectomy on one side. All patients received chemotherapy; actinomycin D (AMD) only was used in the oldest case, vincristine and AMD in five cases, to which was added cyclophosphamide in one case and adriamycin in two. Seven patients received radiation therapy. Seven out of the nine patients survived more than 2 years (77%); five are well, off chemotherapy, with no evidence of disease from 4 to 11 years after diagnosis. Two patients suffered from chronic renal failure and one died from complications after renal transplantation more than 19 years after diagnosis. The two patients who died from their disease presented with more advanced tumor. Therefore, the agressiveness of multimodal therapy can be tailored according to stage and histology, and effective chemotherapy allows maximal preservation of renal parenchyma in patients with stage I and II tumors.  相似文献   
27.
28.
Scapulo-humeral goniometer   总被引:1,自引:0,他引:1  
  相似文献   
29.
30.

Background  

We present the case of a 14-year-old with a 3-month history of back pain, who on presentation, was demonstrated to have neurological signs.  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