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   688篇
  免费   32篇
  国内免费   5篇
耳鼻咽喉   29篇
儿科学   20篇
妇产科学   11篇
基础医学   54篇
口腔科学   47篇
临床医学   57篇
内科学   208篇
皮肤病学   4篇
神经病学   51篇
特种医学   34篇
外科学   138篇
综合类   9篇
一般理论   1篇
预防医学   17篇
眼科学   7篇
药学   14篇
中国医学   2篇
肿瘤学   22篇
  2023年   4篇
  2022年   7篇
  2021年   20篇
  2020年   14篇
  2019年   24篇
  2018年   15篇
  2017年   11篇
  2016年   28篇
  2015年   27篇
  2014年   29篇
  2013年   34篇
  2012年   32篇
  2011年   44篇
  2010年   27篇
  2009年   24篇
  2008年   40篇
  2007年   28篇
  2006年   42篇
  2005年   37篇
  2004年   39篇
  2003年   27篇
  2002年   25篇
  2001年   17篇
  2000年   4篇
  1999年   6篇
  1998年   12篇
  1997年   9篇
  1996年   11篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   3篇
  1991年   6篇
  1990年   5篇
  1989年   12篇
  1988年   11篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1982年   2篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1975年   3篇
  1972年   2篇
  1971年   1篇
  1968年   1篇
  1966年   2篇
  1963年   1篇
排序方式: 共有725条查询结果,搜索用时 31 毫秒
1.
2.
3.
The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients with operations other than fusion.No patient had previously undergone fusion.Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.  相似文献   
4.
Background: Recent development of extracorporeal magnetic stimulation (ECMS) which uses current‐changing magnetic fields allows the induction of electrical stimulation in the desired deep tissue. Recent study showed the sacral nerve stimulation reduces corticoanal excitability that may play a functional role in anal continence mechanisms. Preliminary study shows that ECMS of sacral nerve can modify pelvic floor function and expel rectal balloon in patients with pelvic floor dyssynergia (PFD). Aims: To evaluate the effect of ECMS compared with biofeedback therapy (BF) in patients with PFD. Methods and Materials: Thirty‐eight patients who fulfilled Rome II criteria for PFD by colon transit time and anorectal function tests, were randomly treated with 8 sessions of ECMS (2/weeks; n = 19) at prone position or BF (2/weeks; n = 19) at sitting position. Stimulation parameters were set at 50–80% of maximum intensity, 10 and 50 Hz frequency, 3 s burst length with 3 and 6 s off using arm‐typed stimulator (BioCom‐1000, Mcube Co., Korea). Symptom scores for constipation with/without anorectal function test were repeatedly measured after each treatment. Response was defined as 50% or more decreased symptom score after treatment (partial response: 30–50%, poor: <30%). Results: Fifteen patients (age 49.1 ± 13.4 years, mean ± SD; 4 men) completed 8 session of BF and 14 patients (54.5 ± 17.6 years, 3 men) completed 8 session of ECMS. Four patients of BF group discontinued treatment due to unsatisfactory therapeutic effect (n = 1) and withdrew consent (n = 3) and 5 patients of ECMS group discontinued treatment because of same reasons (n = 1, 4). Total symptom scores were significantly decreased after treatment of 8 session in both treatment groups (13.4 ± 6.6 vs. 4.3 ± 4.0 for BF, p = 0.009; 14.9 ± 5.6 vs. 3.4 ± 4.0 for ECMS, p < 0.001). Bowel movements per week were also significantly increased after treatment in both groups (median 2 vs. 7 for BF, p = 0.035; median 2 vs. 7 for ECMS, p = 0.008). Thirteen out of 15 patients showed response in BF group and 12 out of 14 showed good response in ECMS group. No adverse effects in both groups. Conclusions: ECMS is as effective as BF for the treatment of PFD. Long‐term effect of ECMS for the patients with pelvic floor dyssynergia need to be evaluated in the near future.  相似文献   
5.
6.
7.
Supraventricular tachyarrhythmias frequently complicate myocardial revascularization. Intravenous administration of verapamil has been effective in terminating these arrhythmias. To determine the effects of verapamil on left ventricular systolic function, we implanted ultrasonic dimension transducers in dogs and, after they had recovered from the operation, studied them while they were awake and unsedated. Intravenous administration of verapamil (0.2 mg/kg) resulted in an elevation of cardiac output above baseline because of reflex-induced tachycardia. Contractility, as measured by the load-independent end-systolic pressure-volume relationship, remained unchanged. When the animals were pretreated with atropine and propranolol, verapamil resulted in a fall in cardiac output and contractility. The intact animal responded to the vasodilatory effect of verapamil by releasing catecholamines to maintain cardiac output and hemodynamic stability. Only when this compensatory mechanism was blocked by a beta-adrenergic blocker do the inherently negative inotropic and chronotropic effects of verapamil become apparent. The clinical ramifications of this finding are of greater importance to the surgeon as more patients receive beta-adrenergic blocking agents up to the time of the immediate preoperative period. We conclude that verapamil should be administered with caution to patients with supraventricular tachyarrhythmias who have been receiving beta-adrenergic blocking agents.  相似文献   
8.
OBJECTIVE: We aimed to determine whether general practitioner GP hospitals, compared with alternative modes of health care, are cost- saving. METHODS: Based on a study of admissions (n = 415) to fifteen GP hospitals in the Finnmark county of Norway during 8 weeks in 1992, a full 1-year patient throughput in GP hospitals was estimated. The alternative modes of care (general hospital, nursing home or home care) were based on assessments by the GPs handling the individual patients. The funds transferred to finance GP hospitals were taken as the cost of GP hospitals, while the cost of alternative care was based on municipality and hospital accounts, and standard charges for patient transport. RESULTS: The estimated total annual operating cost of GP hospitals was 32.2 million NOK (10 NOK = 1 Pound) while the cost of alternative care was in total 35.9 million NOK. Sensitivity analyses, under a range of assumptions, indicate that GP care in hospitals incurs the lowest costs to society. CONCLUSION: GP hospitals are likely to provide health care at lower costs than alternative modes of care.   相似文献   
9.
The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy.  相似文献   
10.

Background  

The objective of this study is to investigate the perceptions of first and third year medical students on self-study and reporting processes of Problem-based Learning (PBL) sessions and their usage of learning resources.  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