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   458篇
  免费   22篇
  国内免费   14篇
耳鼻咽喉   2篇
儿科学   21篇
妇产科学   20篇
基础医学   39篇
口腔科学   4篇
临床医学   31篇
内科学   57篇
皮肤病学   6篇
神经病学   16篇
特种医学   163篇
外科学   42篇
综合类   7篇
预防医学   10篇
眼科学   39篇
药学   20篇
肿瘤学   17篇
  2023年   2篇
  2022年   4篇
  2021年   3篇
  2019年   1篇
  2018年   9篇
  2017年   3篇
  2016年   13篇
  2015年   13篇
  2014年   9篇
  2013年   20篇
  2012年   10篇
  2011年   6篇
  2010年   12篇
  2009年   17篇
  2008年   27篇
  2007年   26篇
  2006年   15篇
  2005年   16篇
  2004年   16篇
  2003年   8篇
  2002年   9篇
  2001年   12篇
  2000年   4篇
  1999年   5篇
  1998年   17篇
  1997年   18篇
  1996年   17篇
  1995年   17篇
  1994年   17篇
  1993年   15篇
  1991年   1篇
  1990年   3篇
  1989年   10篇
  1988年   13篇
  1987年   14篇
  1986年   17篇
  1985年   23篇
  1984年   8篇
  1983年   13篇
  1982年   10篇
  1981年   2篇
  1980年   3篇
  1978年   2篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1966年   2篇
  1963年   1篇
排序方式: 共有494条查询结果,搜索用时 15 毫秒
101.
The aim of this study was to find the minimal effective daily s.c. dose of the gonadotrophin-releasing hormone (GnRH) agonist, triptorelin acetate, that suppresses the GnRH-induced release of luteinizing hormone (LH) at time of human chorionic gonadotrophin (HCG) injection and thereby prevents spontaneous LH surges during in-vitro fertilization (IVF) stimulation cycles. Therefore, a double-blind, prospective and randomized titration study was performed. A total of 48 IVF patients were divided into four groups of 12 patients. Each group received a different dose of triptorelin acetate, namely 5, 15, 50 or 100 microg s.c. daily. Standard ovarian stimulation was carried out using urinary follicle stimulating hormone (FSH) preparations. A 500 microg GnRH test was performed 90 min before the HCG injection in order to measure the degree of pituitary desensitization. Spontaneous LH surges were not detected in any of the groups, although three patients in the 5 microg group had ovulated at the time of ovum retrieval. The pituitary LH response to the GnRH test at time of HCG, expressed as area under the curve (AUC), appeared to be dose-dependent. Thus, a daily s.c. dose of 100 microg triptorelin acetate appears to be too high, since adequate desensitization of the pituitary (i.e. no spontaneous LH surge) can be achieved with doses as low as 15 and 50 microg.   相似文献   
102.
Blood flow imaging with MR: spin-phase phenomena   总被引:2,自引:0,他引:2  
von Schulthess  GK; Higgins  CB 《Radiology》1985,157(3):687-695
Blood flow phenomena occurring when flow is within the magnetic resonance (MR) imaging plane were analyzed. In this situation, the signal intensity of vascular lumina is predominantly determined by spin-phase change phenomena, and section transition effects of moving spins can be neglected. In this paper, we develop the concepts of in-plane flow, with emphasis on the notion that the spatial variations in velocity and acceleration of blood, which mainly occur along vessel walls, are important determinants of intravascular signal loss in MR images. Flow patterns in the large mediastinal arteries were qualitatively and quantitatively analyzed in six healthy subjects and 14 patients with hemodynamic abnormalities using multiple electrocardiograph-gated image acquisition; ungated studies of 30 patients were analyzed for venous flow effects. Intraluminal signal was strongly dependent on the phase of the cardiac cycle and the echo number. Signal loss was found to occur along vessel walls, in vascular bends, and at bifurcations.  相似文献   
103.
OBJECTIVE: To evaluate the pain level, analgesic consumption, operation time, bleeding and early complications after open and closed hemorrhoidectomy using a harmonic scalpel (HS) and classical methods. METHODS: Between January 2005 and January 2006, 87 patients with grade III-IV hemorrhoids, admitted in General Surgery Clinic, Gulhane Military Medical Academy, Ankara, Turkey were enrolled in the study. They were randomized into open HS (n=22), closed HS (n=22), Miligan Morgan (n=22), and Ferguson (n=21) hemorrhoidectomy. Patients were evaluated for postoperative pain, painkiller consumption, bleeding and operation time. RESULTS: Bleeding volume was significantly lower in Groups I-II (p<0.001). Operation time was significantly shorter in Group I (p<0.001). Postoperative pain and pain at the time of first defecation, was significantly lower in Groups I-III (p<0.001) compared with the other 2 groups and lower during days 2-6 in Group I compared to the Group III (p<0.004). Visual Analogue Scale results were similar in Groups II and IV. Analgesic consumption in Groups I-III was significantly lower than Groups II-IV (p<0.001). Oral analgesic consumption during 2-5 postoperative days was lower in Group I than in Group III (p<0.007) and similar in closed hemorrhoidectomy group. CONCLUSION: The use of HS in hemorrhoidectomy reduces postoperative pain, analgesic consumption, operation time, and bleeding. Harmonic scalpel hemorrhoidectomy is an effective, comfortable, and safe procedure. Use of suture in hemorrhoidectomy is a major cause of postoperative pain.  相似文献   
104.
A 57-year old man was referred to our hospital with spontaneous cerebrospinal fluid (CSF) rhinorrhoea of 6 years duration. He had an episode of meningitis 2 months previously. CT cisternography and cranial MRI revealed a defect in the lateral wall of the sphenoid sinus, with an anteromedial temporosphenoidal encephalocele. Surgery was performed transcranially through a pterional approach. The temporal encephalocele was amputated, the sphenoid sinus obliterated and the dural defect repaired. Lumbar drainage was used for 5 days after surgery. Spontaneous CSF rhinorrhoea is only infrequently due to temporal encephalocele. Anteromedial temporosphenoidal encephaloceles are the least common type of temporal encephalocele, with only 12 reported in the literature.  相似文献   
105.
106.
107.
108.
An electrocardiographic (ECG) sensing and gating device compatible with a 0.35-tesla (T) magnetic resonance (MR) imager has been developed and used to produce 802 MR images of the heart in 30 patients. The instrument consists of an isolated acquisition module, an electrically floating preamplifier, and a monitor gating module. Two spin-echo images were acquired for each of five, 0.7-cm thick, transaxial sections from the base to the apex of the heart during each ECG-synchronized imaging run. Image quality was assessed in a blind study by two investigators, on a scale from 0 to 3, as diagnostic [2-3] or nondiagnostic [0-1]. There was agreement in 91.4% of their assessments of diagnostic images (68.1% of the images studied). Resolution of heart anatomy on the MR images was adversely affected by prolonged spin-echo time delay, imaging in late diastole, image acquisition at the cardiac apex, irregular triggering, and artifacts. The synchronization of gradient pulses to the ECG at 0.35 T appears safe for patients, permits diagnostic resolution of images, allows image acquisition at distinct points during the cardiac cycle, and enables monitoring of patients during imaging.  相似文献   
109.
Obstructive sleep apnea in pregnancy and fetal outcome.   总被引:1,自引:0,他引:1  
OBJECTIVE: To simultaneously investigate the polysomnography (PSG) and nonstress test (NST) records of pregnant women with obstructive sleep apnea (OSA) to observe NST changes during maternal desaturation and determine maternal and fetal outcomes. METHODS: A prospective observational study of pregnant women assessed by questionnaire for symptoms of OSA. Women with self-reported frequent snoring or apnea were offered PSG and NST. RESULT: OSA was diagnosed in 4 (11.4%) of the 35 pregnant women who underwent PSG. Three (75%) had fetal heart decelerations accompanying maternal desaturation. The neonates of women diagnosed with OSA had lower mean Apgar scores and birth weights compared with neonates of women without OSA. Three neonates from the women diagnosed with OSA were admitted to the newborn healthcare unit. CONCLUSION: OSA in pregnancy has important maternal and fetal outcomes. Pregnant women should be assessed for symptoms of OSA and suspected cases should be offered PSG.  相似文献   
110.

Purpose

Hesperidin (HES), a citrus fruit extract, has beneficial effects on various ischemia/reperfusion (I/R) models. We aimed to evaluate the possible positive effects of hesperetin (HPT), an active metabolite of HES, on a rat ovarian I/R model.

Methods

We divided 24 Wistar Albino rats into four groups. Group I (n = 6) was sham operated, Group II (n = 6) was the I/R group, Group III (n = 6) was the I/R + solvent group and Group IV (n = 6) was the I/R + HPT group. Three hours of ischemia and 3 h of reperfusion were performed on each rat in Groups II, III, and IV. Dimethyl sulfoxide (DMSO) was given intraperitoneally to the rats in the III. Group, and 50 mg/kg of HPT dissolved in DMSO was given intraperitoneally to the rats in the IV. Group 30 min before reperfusion. After 3 h of reperfusion, the ipsilateral ovaries of the rats were examined immunohistochemically to detect apoptosis.

Results

Hematoxylin and eosin (H and E) staining demonstrated less edema and hemorrhage in the group where HPT was applied. Caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining showed significantly lower apoptosis in the group where HPT was used when compared to either the I/R or solvent group.

Conclusions

To the best of our knowledge, this is the first study that shows the beneficial effects of HPT in an ovarian I/R injury. HPT improved tissue damage and apoptosis caused by I/R injury. To identify the possible positive effects of HPT in ovarian torsion of humans and use in clinical practice, more studies must be performed.  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