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   669篇
  免费   32篇
耳鼻咽喉   21篇
儿科学   33篇
妇产科学   39篇
基础医学   58篇
口腔科学   30篇
临床医学   46篇
内科学   122篇
皮肤病学   6篇
神经病学   76篇
特种医学   20篇
外科学   153篇
综合类   6篇
预防医学   19篇
眼科学   15篇
药学   37篇
肿瘤学   20篇
  2023年   7篇
  2022年   13篇
  2021年   29篇
  2020年   24篇
  2019年   23篇
  2018年   25篇
  2017年   15篇
  2016年   23篇
  2015年   25篇
  2014年   24篇
  2013年   29篇
  2012年   45篇
  2011年   42篇
  2010年   9篇
  2009年   18篇
  2008年   33篇
  2007年   34篇
  2006年   38篇
  2005年   56篇
  2004年   37篇
  2003年   24篇
  2002年   17篇
  2001年   11篇
  2000年   6篇
  1999年   6篇
  1998年   1篇
  1997年   3篇
  1996年   3篇
  1995年   5篇
  1994年   2篇
  1993年   1篇
  1992年   10篇
  1991年   8篇
  1990年   7篇
  1989年   6篇
  1988年   3篇
  1987年   2篇
  1986年   3篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   8篇
  1978年   6篇
  1977年   3篇
  1976年   3篇
  1975年   2篇
  1974年   5篇
  1972年   1篇
排序方式: 共有701条查询结果,搜索用时 0 毫秒
1.
PURPOSE: Bone healing is impaired in diabetes mellitus, particularly due to increased collagen breakdown. Recently, tetracyclines have been used to treat experimental bone defects because they have anticollagenolytic properties, and positive effects on the healing process have been obtained. The objective of this study was to develop a computer-assisted histomorphometric technique to quantitatively determine the amount of regenerating bone within experimental bone defects in a diabetic rodent model. MATERIALS AND METHODS: This study examined the effects of systemic doxycycline administration on the healing of tibial bone defects in healthy albino rats and in experimentally induced diabetic rats. Twenty-four female albino rats were assigned to 4 groups: diabetic, diabetic plus doxycycline, control, or control plus doxycycline. The standardized bone defects were histomorphometrically examined 10 and 30 days postoperatively. Histomorphometric analysis of the amount of new bone formation was performed using the Zeiss Vision image analysis program KS 400 (Kontron Elektron GmbH, Eching, Germany). RESULTS: At 10 days of healing, the diabetic groups exhibited inferior healing compared with the control groups in terms of the amount of new bone formation within the defects. However, the effect of doxycycline administration to the diabetic and control groups was not statistically different. At 30 days of healing, there were no statistically significant differences between the amount of newly formed bone in any of the groups. CONCLUSIONS: This study found that doxycycline administration did not significantly alter the amount of new bone formation during the healing of bone defects in control and diabetic rats.  相似文献   
2.
This article provides a brief overview of the changing nature of the concept of minor depression. It then discusses treatment studies conducted from 1980 to 1991 of patients diagnosed as neurotic depression, depressive neurosis or dysthymia, characterologic depression, "double depression" and minor depression or dysthymia, if there has been a full remission of a major depressive episode lasting at least six months prior to the development of dysthymia. Long-term treatment of chronic depression is also reviewed. Cognitive-behavioral intervention and marital therapy have been reported beneficial for patients diagnosed as having neurotic depression, characterological depression, or dysthymia. All studies of antidepressant drug treatment showed drugs to be efficacious and superior to placebo, with few differences found between drugs. In addition, they all showed the importance of analyzing the interactions between treatment and severity or diagnosis. Patients diagnosed as "double depression" also appear responsive to both psychosocial intervention and drug treatment; in general, however, these patients tend to have a poor long-term outcome and continued treatment is indicated. The most obvious finding to emerge from this review is that the diagnosis of minor depression is ambiguous, in large part because of the lack of defining criteria related to severity and course. The review also revealed that in addition to poorly defined subgroups, many studies lacked controls, had small sample sizes, inadequate and/or inconsistent measures of outcome, and limited follow-up. For these reasons, their findings cannot be considered conclusive. Finally, the literature revealed a dearth of controlled studies of psychosocial treatment for well defined subgroups of neurotic depression.  相似文献   
3.
The Harmonized Alert Sensing Technology (HASTE) device was developed to overcome the primary shortcomings of interval based noninvasive blood pressure (BP) monitoring. This study was conducted to assess the reliability of the HASTE system compared with standard cuff BP values in patients on hemodialysis. A total of 1,370 HASTE measurements were compared with oscillometric standard cuff systolic BP values in 42 sessions of 15 patients on hemodialysis. The average discrepancy between the HASTE and cuff systolic BP was 1.41 +/- 16.90 mm Hg. Compared with cuff measurements, 31% of systolic BP fell within a range of 5 mm Hg difference, 57% of systolic BP fell within 10 mm Hg, and 73% of systolic BP fell within a 15 mm Hg band. According to British Hypertension Society standards or Association for the Advancement of Medical Instrumentation criteria, the current HASTE method did not perform well. Technology to provide noninvasive hemodynamic monitoring is, however, in its developmental stage. The effort at continuous systolic pressure monitoring using existing, readily available, and frequently used techniques is exciting. Although the HASTE system as currently configured and calibrated did not adequately perform, variations in site analysis and conversion factors may increase pressure sensitivity and tracking over the course of a standard dialysis treatment.  相似文献   
4.
This study investigated outpatients' satisfaction with therapists, as determined by their perceptions of therapists' behaviors and characteristics, and related patient satisfaction to measures of psychotherapy outcome derived from patients themselves, therapists, and an independent rater. After discharge, 138 demographically and diagnostically heterogeneous patients who had been in psychodynamically oriented psychotherapy returned mailed questionnaires. Therapist characteristics and behaviors such as being likeable, accepting, encouraging, and respectful, helping patients to understand themselves better, and not being "too quiet," as well as overall ratings of satisfaction with therapists, were significantly correlated with patients' ratings of improvement and of help received and with therapists' ratings of outcome.  相似文献   
5.
The constant release of nitric oxide (NO) is essential to maintain basal cerebrovascular tone. Oxyhaemoglobin, liberated by lysis of red blood cells after subarachnoid haemorrhage binds NO and prevents its entry into vascular smooth muscle cells. While endothelium-dependent vasoconstriction is preserved, decreased levels of NO inhibit endothelium-dependent relaxation and may cause vasospasm. S-nitrosothiols are potent vasodilators and precursors of NO. The authors' aim was to determine whether S-nitroso-N-acetylpenicillamine (SNAP), a stable S-nitrosothiol compound, could reverse vasospasm in an experimental vasospasm model in rabbit. Experimental subarachnoid haemorrhage (SAH) was induced in 37 New Zealand white rabbits. The animals were divided into four groups. Control (no SAH), SAH only, SAH plus saline and SAH plus SNAP. SNAP (15 micrograms/kg/min) or 0.09% saline (equal volume) was infused 46 hours after induction of SAH. All animals were killed by perfusion fixation 48 hours after SAH occurred. Basilar arteries were removed, sectioned and their cross sectional areas were evaluated in a blind manner, by light microscopy and by using computer assisted morphometry. Experimental SAH elicited vasospasm in all animals of SAH only and SAH plus saline group. In animals treated with SNAP, arterial narrowing was markedly attenuated without producing systemic hypotension. This widening achieved statistical significance when compared to the arteries of the SAH only and SAH plus saline group (p < 0.01). This study indicates that the NO donor SNAP is a potentially useful drug to reverse cerebral vasospasm due to SAH.  相似文献   
6.
Two studies are reported. The first examined the factor structure of the Psychological Mindedness (PM) Scale, and the second reassessed the scale's predictive validity. A principal components analysis (varimax rotation) of the data of 256 psychiatric outpatients produced five factors that accounted for 38% of the variance. A tentative definition of PM based on these factors is proposed. For a subsample of 116 patients who attended at least four psychotherapy sessions, PM was unrelated to levels of functioning and psychosocial symptoms at admission and was positively associated with number of sessions attended, consistent with findings of a preliminary investigation. Not replicated were significant correlations between PM and outcome measures derived from therapists' and an independent rater's evaluations. Initially high PM was significantly related to patients' self-ratings of symptoms and problems after discharge.  相似文献   
7.
The emergence of different models of psychological healing from Freud to the present, and specific features which characterize "new" psychotherapies in contrast to psychoanalysis are examined. The author maintains that these represent a chronological evolution of therapeutic forms which are complementary and which portend the unification of the psychotherapies.  相似文献   
8.
Objective:This study aimed to evaluate clinical results, femoral head survival, and the need for total hip arthroplasty (THA) in patients with precollapse osteonecrosis of the femoral head (OFH) (Steinberg stage II and III) treated by free vascularized fibula graft (FVFG) application.Methods:We retrospectively reviewed 54 hips of 47 patients (39 males, eight females; mean age 36 ± 14 years) who underwent FVFG due to OFH, with at least two years of follow-up. The patient data, including Harris Hip Score (HHS), Visual Analogue Scale (VAS), and conversion to THA, were documented.Results:The right hip of 26 patients and the left hip of 28 patients were involved. Bilateral FVFG surgery was performed on seven patients due to bilateral OFH. The mean follow-up time was 5.5 (range 2-14) years. Survival of the femoral head was observed in 39 hips (72.2%), while the femoral head collapse was observed in 15 femoral heads (27.8%). The mean preoperative HHS increased from 46.5 (range = 12-85) to 86.5 (range = 33-100) postoperatively (P < 0.001). The mean preoperative VAS score improved from 8.2 (range = 2-10) to 1.3 (range = 0-10) postoperatively (P < 0.001). THA was performed on seven hips at a mean follow-up time of 1.8 years (range = 0.7–3.3). There was no significant difference in the collapse rate between unilateral or bilateral OFH (P = 0.175). A higher survival rate was observed in the Steinberg stage II femoral head patients compared to the stage III femoral head (P = 0.021).Conclusion:This study has shown that FVFG surgery can be a good option for managing patients with Steinberg stage II and III precollapse OFH to prevent femoral head collapse and joint function.  相似文献   
9.
10.
The fact thatH. pylori gastritis results in an increased secretion of basal and meal-stimulated gastrin, which is also a physiologic amplifier of insulin release directed us to investigate whetherH. pylori gastritis may lead to an enhancement of nutrient-stimulated insulin secretion. For this purpose, we have investigated the insulin responses to both oral glucose and a mixed meal in 15 patients withH. pylori gastritis before and one month after the eradication therapy and also in 15H. pylori-negative control subjects. The areas under the curve (AUC) for serum insulin following both oral glucose and a mixed meal in the patients withH. pylori gastritis before the eradication were significantly (P<0.05) higher than those in theH. pylori-negative controls. After the eradication ofH. pylori, the AUC for serum insulin following oral glucose and mixed meal decreased by 9.4% and 13.1%, respectively (P<0.001 in both), and serum basal and meal-stimulated gastrin levels decreased significantly (P<0.001). These results suggest thatH. pylori gastritis enhances glucose and meal-stimulated insulin release probably by increasing gastrin secretion.Presented in part as an abstract at the 8th Balkan Congress of Endocrinology, Bursa, Turkey, May 3–5, 1995.  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