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   310篇
  免费   10篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   27篇
基础医学   29篇
口腔科学   5篇
临床医学   18篇
内科学   47篇
皮肤病学   1篇
神经病学   27篇
特种医学   24篇
外科学   45篇
综合类   1篇
预防医学   32篇
药学   16篇
肿瘤学   39篇
  2024年   1篇
  2023年   3篇
  2022年   9篇
  2021年   5篇
  2020年   3篇
  2019年   7篇
  2018年   10篇
  2017年   13篇
  2016年   17篇
  2015年   12篇
  2014年   12篇
  2013年   11篇
  2012年   22篇
  2011年   15篇
  2010年   11篇
  2009年   5篇
  2008年   11篇
  2007年   11篇
  2006年   17篇
  2005年   13篇
  2004年   12篇
  2003年   12篇
  2002年   6篇
  2001年   14篇
  2000年   12篇
  1999年   4篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1992年   2篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1987年   5篇
  1986年   6篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
  1972年   4篇
  1971年   3篇
  1969年   4篇
  1968年   1篇
  1935年   1篇
排序方式: 共有321条查询结果,搜索用时 0 毫秒
1.
2.
A recent large increase in Caesarean section (CS) in Italy was the initial stimulus for a study to identify risk factors for CS and, if possible, to suggest strategies to counteract the rise. The study was conducted in three hospitals where a wide range of individual variables was collected from the clinical records and from personal interviews. Crude CS rates and odds ratios were evaluated for each single variable while logistic regression has been used to investigate possible confounding factors. The study involved 1316 consecutive deliveries. Crude CS rates were 29.4%, 15.7% and 16.1%. Variables identified as high risk factors were pre-eclampsia, previous CS, breech and other non-vertex presentations. Antenatal care under an obstetrician working in the same hospital, a low number of antenatal consultations, previous miscarriages, offer (by obstetrician) and request (by women) for CS showed significantly high odds ratios (ORs). Previous live births was strongly negatively associated with CS. No relationship between type of delivery and social status was observed while a physician factor was detected in all three hospitals where rates for different physicians ranged from 0% to 52.8%. Apart from the main medical indications for Caesarean section (previous CS, breech presentation), the results seem to indicate that individual practice style may be an important determinant of the wide variation in the rates of Caesarean delivery. While this may have been suspected before this study, these results are the first hard data to indicate that, in Italy, CS is widely performed for non-medical reasons.  相似文献   
3.
Our aim was to assess the association between a priori defined dietary patterns and incident depressive symptoms. We used data from The Maastricht Study, a population-based cohort study (n = 2646, mean (SD) age 59.9 (8.0) years, 49.5% women; 15,188 person-years of follow-up). Level of adherence to the Dutch Healthy Diet (DHD), Mediterranean Diet, and Dietary Approaches To Stop Hypertension (DASH) were derived from a validated Food Frequency Questionnaire. Depressive symptoms were assessed at baseline and annually over seven-year-follow-up (using the 9-item Patient Health Questionnaire). We used Cox proportional hazards regression analyses to assess the association between dietary patterns and depressive symptoms. One standard deviation (SD) higher adherence in the DHD and DASH was associated with a lower hazard ratio (HR) of depressive symptoms with HRs (95%CI) of 0.78 (0.69–0.89) and 0.87 (0.77–0.98), respectively, after adjustment for sociodemographic and cardiovascular risk factors. After further adjustment for lifestyle factors, the HR per one SD higher DHD was 0.83 (0.73–0.96), whereas adherence to Mediterranean and DASH diets was not associated with incident depressive symptoms. Higher adherence to the DHD lowered risk of incident depressive symptoms. Adherence to healthy diet could be an effective non-pharmacological preventive measure to reduce the incidence of depression.  相似文献   
4.
Tentorial Meningiomas. Report on Twenty-Seven Cases   总被引:14,自引:0,他引:14  
Summary ? Objective. Report our experience with 27 tentorial meningiomas (TM) surgically treated between 1985 and 1998.  Methods. The records of 27 patients with TMs were retrospectively reviewed for clinical presentation, neuroradiological evaluation, surgical treatment and long-term outcome. The extent of tumor resection was scored according to the Simpson's grading for tumor removal. Long-term results were evaluated according to the Glasgow Outcome Score (GOS).  Results. The average age was 53 years. Female predominance was 74%. The most common complaints at presentation were headaches (51%), gait ataxia (33%), memory disturbances (30%) and hypo-acousia (30%). A classification of TMs into 5 subgroups according to tumor site is proposed on the basis of imaging studies. A cerebrospinal fluid shunt was established prior to direct approach in 7 patients and as the sole procedure in one inoperable patient. Twenty-seven direct approaches were undertaken in 26 patients, including 17 infratentorial and 10 supratentorial approaches. Total tumor removal was achieved in 20 patients (77%) and subtotal removal in 6 (23%). Fifteen patients (55%) experienced 22 postoperative complications. One patient died three months after a subtotal resection (mortality=3,7%). With a mean follow-up of 54 months, all 26 survivors are currently alive with 23 having resumed their normal activities and 3 needing assistance. Five of 6 patients with subtotal resection survived and were followed for a period ranging from 72 to 132 months: none showed residual tumor progression and no re-operation was considered. An additional patient experienced a ?true? recurrence 6 years after total removal, with no tumor progression 2 years after his recurrence was recognized.  Discussion. The best surgical approach to TMs is still a controversial matter. The advantages and drawbacks of conventional versus transbasal approaches are reviewed. Our experience suggests that subtotal removal can be associated with long recurrence-free intervals and preserved quality of life. TMs located at the tentorial edge carried a definitely worse prognosis than peripheral forms.  相似文献   
5.
6.
7.

Background

Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury.

Methods

Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal–external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus–valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx).

Results

Concerning the AP30, LTPs (P = 0.047) and MTPsublx (P = 0.039) were shown to be independent predictors while for the AP90 only LTPs (P = 0.049) was an independent predictor. The LTPs (P = 0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P = 0.007).

Conclusions

A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope < 5.5°.  相似文献   
8.
Purpose

To compare the accuracy of Contrast-Enhanced Spectral Mammography (CESM), MG, US, and breast MRI in estimating the size of breast lesions requiring surgery. The postoperative histology size of the lesion was used as the gold standard.

Material and methods

Two hundred thirty-three non-benign lesions in 189 patients were included in the analyses. All the selected patients underwent CESM and at least one other conventional diagnostic exam (US, MG, or MRI). Subsequently, all the patients underwent surgery preceded by cytological/histological examination. The largest diameter of the lesion at imaging was measured by a radiologist with more than 10 years’ experience and then compared with the size of the lesion in the histological sample at the surgery (gold standard).

Results

Among the 233 breast lesions, 196 were evaluated with US, 206 with MG and 160 with MRI. We found no statistically significant differences between size measurements using CESM and MRI compared with the measurements at the surgery (p value 0.63 and 0.51), whereas a significant difference was found for MG and US (p?<?0.001).

Conclusion

CESM is a reliable method for estimating the size of breast lesions: its performance seems superior to US and MG and comparable to MRI.

  相似文献   
9.
10.
BACKGROUND AND PURPOSE:Endovascular coiling of wide-neck intracranial aneurysms is associated with low rates of initial angiographic occlusion and high rates of recurrence. The WEB intrasaccular device has been developed specifically for this indication. To date, there has been no report of the long-term follow-up of a series of patients with aneurysms treated with this type of device, to our knowledge. Our aim was to evaluate a 1-year follow-up of angiographic results in a prospective single-center series of patients treated with the WEB-Single-Layer (SL) device.MATERIALS AND METHODS:All patients treated with the WEB-SL device in our center between August 2013 and May 2014 were prospectively included. One-year angiographic outcomes were assessed. Results at follow-up were graded as complete occlusion, neck remnant, or residual aneurysm.RESULTS:Eight patients with 8 unruptured wide-neck aneurysms were enrolled in this study. Average dome width was 7.5 mm (range, 5.4–10.7 mm), and average neck size was 4.9 mm (range, 2.6–6.5 mm). One-year angiographic follow-up obtained in all aneurysms included 1 complete aneurysm occlusion (12.5%), 6 neck remnants (75%), and 1 aneurysm remnant (12.5%). Of 8 aneurysms, worsening of aneurysm occlusion was observed in 2 (25%) by compression of the WEB device. There was no angiographic recurrence of initially totally occluded aneurysms. No bleeding was observed during the follow-up period.CONCLUSIONS:Endovascular therapy of intracranial aneurysms with the WEB-SL device allows treatment of wide-neck aneurysms with a high rate of neck remnant at 1 year, at least partially explained by WEB compression. Initial size selection and technologic improvements could be an option for optimization of aneurysm occlusion in WEB-SL treatment.

The WEB aneurysm embolization system (Sequent Medical, Aliso Viejo, California) is an intrasaccular braided device specifically developed for endovascular treatment of wide-neck intracranial aneurysms with the goal of disrupting flow at the aneurysm neck and promoting aneurysmal thrombosis without the need for reconstruction of the entire parent artery segment with a stent. Several types of WEB devices are currently available1: the WEB-Dual-Layer (DL), which is made of 2 layers held together and creating 2 compartments, and the WEB-Single-Layer (SL), which is a single-layer device creating only 1 compartment. Only a few studies on the treatment of intracranial aneurysms by using the WEB-DL have been published,25 and to date, only a single published article on aneurysms treated with WEB-SL reported a series including any anatomic follow-up.6 We recently published the 6-month clinical and anatomic outcomes of WEB-SL endovascular treatment.7The purpose of this study was to evaluate the 1-year angiographic results of patients managed with the WEB-SL device in a prospective single-center series.  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