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   355篇
  免费   25篇
  国内免费   1篇
耳鼻咽喉   49篇
儿科学   8篇
妇产科学   19篇
基础医学   20篇
口腔科学   2篇
临床医学   49篇
内科学   80篇
皮肤病学   10篇
神经病学   39篇
特种医学   34篇
外科学   55篇
预防医学   2篇
眼科学   1篇
药学   7篇
肿瘤学   6篇
  2022年   2篇
  2021年   8篇
  2020年   7篇
  2019年   11篇
  2018年   11篇
  2017年   16篇
  2016年   14篇
  2015年   8篇
  2014年   11篇
  2013年   17篇
  2012年   22篇
  2011年   25篇
  2010年   19篇
  2009年   9篇
  2008年   28篇
  2007年   27篇
  2006年   24篇
  2005年   18篇
  2004年   23篇
  2003年   12篇
  2002年   13篇
  2001年   13篇
  2000年   7篇
  1999年   7篇
  1998年   2篇
  1997年   3篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   5篇
  1991年   2篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1971年   1篇
  1967年   1篇
排序方式: 共有381条查询结果,搜索用时 15 毫秒
1.
2.
Natural cycles were abandoned in in-vitro fertilization (IVF) embryo transfer, due to premature luteinizing hormone (LH) surges--and subsequent high cancellation rates. In this study, we investigated the administration of a new gonadotrophin-releasing hormone antagonist (Cetrorelix) in the late follicular phase of natural cycles in patients undergoing IVF and intracytoplasmic sperm injection (ICSI). A total of 44 cycles from 33 healthy women [mean age 34.1 +/- 1.4 (range 26-36) years] were monitored, starting on day 8 by daily ultrasound and measurement of serum concentrations of oestradiol, LH, follicle stimulating hormone (FSH) and progesterone. When plasma oestradiol concentrations reached 100-150 pg/ml, with a lead follicle between 12-14 mm diameter, a single injection (s.c.) of 0.5 mg (19 cycles) or 1 mg (25 cycles) Cetrorelix was administered. Human menopausal gonadotrophin (HMG; 150 IU) was administered daily at the time of the first injection of Cetrorelix, and repeated thereafter until human chorionic gonadotrophin (HCG) administration. Four out of 44 cycles were cancelled (9.0%). No decline in follicular growth or oestradiol secretion was observed after Cetrorelix administration. A total of 40 oocyte retrievals leading to 22 transfers (55%) was performed. In 10 cycles (25%), no oocyte was obtained. Fertilization failure despite ICSI occurred in six cycles (15%). In two patients the embryo was arrested at the 2 pronuclear (PN) stage. The stimulation was minimal (4.7 +/- 1.4 HMG ampoules). A total of seven clinical pregnancies was obtained (32.0% per transfer, 17.5% per retrieval), of which five are ongoing. Thus, a spontaneous cycle and the GnRH antagonist Cetrorelix in single dose administration could represent a first-choice IVF treatment with none of the complications and risks of current controlled ovarian hyperstimulation protocols, and an acceptable success rate.  相似文献   
3.
Since the first birth after IVF, many scientific papers have been published on the technical aspects of the IVF procedure, but few studies have addressed the issue of the perinatal outcome of IVF pregnancies and of the children's development and well-being. A high rate of adverse outcome has been demonstrated in a large group of IVF pregnancies. Prematurity, low birth weight and perinatal mortality are higher than in the general population. The majority of these complications are related to multiple births, but they are also found in singleton pregnancies. An analysis of the multiple risk factors involved in these complications is needed. The infertile status of IVF patients clearly plays a role in the risk of adverse outcome. Age and parity may be important factors. The role of IVF itself has not been demonstrated convincingly. The effect of ovarian stimulation deserves further study. Most of the studies published on the follow-up of IVF children are reassuring, but it is clear that these studies are not sufficient to eliminate without doubt any adverse effects on the well-being of IVF children. All IVF pregnancies should be followed with great care, not because they are more precious than spontaneous pregnancies, but because they are exposed to an increased risk of complications. The main problem of IVF remains the high rate of multiple pregnancies, including twins.  相似文献   
4.
Uterine contractility decreases at the time of blastocyst transfers   总被引:3,自引:0,他引:3  
High-frequency uterine contractions at the time of non-cavitating embryo transfer influence adversely IVF-embryo transfer outcome. This prompted us to quantify prospectively the possible decline in uterine contraction frequency occurring during later stages of the luteal phase of ovarian stimulation, up to the time of blastocyst transfers, in 43 IVF-embryo transfer candidates. Contractility was assessed on the day of human chorionic gonadotrophin (HCG) administration, 4 days after HCG (non-cavitating embryo transfer; HCG + 4), and 7 days after HCG (blastocyst transfers; HCG + 7). For this, 2 min sagittal uterine scans were obtained by ultrasound and digitized with a computerized system for the assessment of uterine contraction frequency. Our results indicated that a slight, yet significant, decrease in uterine contraction frequency, observed from the day of HCG (4.4 +/- 0.2 contractions/min) to HCG + 4 (3.5 + 0.2 contractions/min), was followed by a more pronounced, additional decrease between HCG + 4 and HCG + 7 (1.5 +/- 0.2 contractions/min; P < 0.001). In conclusion, during the luteal phase of ovarian stimulation, uterine contractility decreases progressively, and reaches a nearly quiescent status 7 days after HCG administration, at the time of blastocyst transfers. It is possible that such a uterine relaxation assists blastocyst implantation.  相似文献   
5.
6.
7.
8.
We report a case of a celiac trunk stenting using a steerable guiding catheter, to fix a residual endoleak following fenestrated endovascular repair (FEVAR) of a thoraco‐abdominal aortic aneurysm (TAAA). A systematic search of the literature about the use of steerable catheters was also performed on Pubmed according to the PRISMA Guidelines, including all papers in which the device was used for in vivo endovascular procedures. In our case report, the patient had undergone a failed attempt of cannulation due to the presence of a severely angulated and stenosed ostium of the vessel. A steerable catheter was then used to fix the residual endoleak. The search of the Literature retrieved 544 papers. Of them, 13 met the inclusion criteria and were therefore assessed. The use of steerable sheaths and catheters was reported as effective and safe for the cannulation of 157 target vessels in 131 endovascular procedures, with a success rate of 95.5% and no complications. The use of a steerable guiding catheter in our experience was safe and effective for the selective cannulation of a severely stenosed and angulated celiac trunk, to correct a residual endoleak after FEVAR for TAAA. Steerable catheters could be useful tools for the selective cannulation of target vessels with a challenging ostium.  相似文献   
9.

Background

Assessment of pre-test probability of pulmonary embolism (PE) and prognostic stratification are two widely recommended steps in the management of patients with suspected PE. Some items of the Geneva prediction rule may have a prognostic value.We analyzed whether the initial probability assessed by the Geneva rule was associated with the outcome of patients with PE.

Methods

In a post-hoc analysis of a multicenter trial including 1,693 patients with suspected PE, the all-cause death or readmission rates during the 3-month follow-up of patients with confirmed PE were analyzed. PE probability group was prospectively assessed by the revised Geneva score (RGS). Similar analyses were made with the a posteriori-calculated simplified Geneva score (SGS).

Results

PE was confirmed in 357 patients and 21 (5.9%) died during the 3-month follow-up. The mortality rate differed significantly with the initial RGS group, as with the SGS group. For the RGS, the mortality increased from 0% (95% Confidence Interval: [0–5.4%]) in the low-probability group to 14.3% (95% CI: [6.3-28.2%]) in the high-probability group, and for the SGS, from 0% (95% CI: [0–5.4%] to 17.9% (95% CI: [7.4-36%]). Readmission occurred in 58 out of the 352 patients with complete information on readmission (16.5%). No significant change of readmission rate was found among the RGS or SGS groups.

Conclusions

Returning to the initial PE probability evaluation may help clinicians predict 3-month mortality in patients with confirmed PE.(ClinicalTrials.gov: NCT00117169)  相似文献   
10.

Background

Patients with acute deep vein thrombus (DVT) can safely be treated as outpatients. However the role of outpatient treatment in patients diagnosed with a pulmonary embolism (PE) is controversial. We sought to determine the safety of outpatient management of patients with acute symptomatic PE.

Materials and Methods

A systematic literature search strategy was conducted using MEDLINE, EMBASE, the Cochrane Register of Controlled Trials and all EBM Reviews. Pooled proportions for the different outcomes were calculated.

Results

A total of 1258 patients were included in the systematic review. The rate of recurrent venous thromboembolism (VTE) in patients with PE managed as outpatients was 1.47% (95% CI: 0.47 to 3.0%; I2: 65.4%) during the 3 month follow-up period. The rate of fatal PE was 0.47% (95% CI: 0.16 to 1.0%; I2: 0%). The rates of major bleeding and fatal intracranial hemorrhage were 0.81% (95% CI: 0.37 to 1.42%; I2: 0%) and 0.29% (95% CI: 0.06 to 0.68%; I2: 0%), respectively. The overall 3 month mortality rate was 1.58% (95% CI: 0.71 to 2.80%; I2: 45%). The event rates were similar if employing risk stratification models versus using clinical gestalt to select appropriate patients for outpatient management.

Conclusions

Independent of the risk stratification methods used, the rate of adverse events associated with outpatient PE treatment seems low. Based on our systematic review and pooled meta-analysis, low-risk patients with acute PE can safely be treated as outpatients if home circumstances are adequate.  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