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   2049篇
  免费   82篇
  国内免费   11篇
耳鼻咽喉   96篇
儿科学   120篇
妇产科学   57篇
基础医学   189篇
口腔科学   59篇
临床医学   176篇
内科学   361篇
皮肤病学   30篇
神经病学   144篇
特种医学   59篇
外科学   566篇
综合类   28篇
预防医学   51篇
眼科学   64篇
药学   112篇
中国医学   3篇
肿瘤学   27篇
  2023年   9篇
  2022年   20篇
  2021年   29篇
  2020年   20篇
  2019年   29篇
  2018年   50篇
  2017年   33篇
  2016年   54篇
  2015年   57篇
  2014年   59篇
  2013年   107篇
  2012年   123篇
  2011年   139篇
  2010年   94篇
  2009年   78篇
  2008年   152篇
  2007年   160篇
  2006年   152篇
  2005年   154篇
  2004年   162篇
  2003年   123篇
  2002年   119篇
  2001年   46篇
  2000年   31篇
  1999年   28篇
  1998年   15篇
  1997年   10篇
  1996年   14篇
  1995年   11篇
  1994年   8篇
  1993年   2篇
  1992年   7篇
  1991年   5篇
  1990年   6篇
  1989年   6篇
  1988年   4篇
  1987年   4篇
  1986年   3篇
  1985年   4篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1976年   3篇
  1972年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有2142条查询结果,搜索用时 15 毫秒
61.
In this article, a 9-year-old boy with arterial priapism is presented. The patient was managed with the conservative measures including imipramine hydrochloride and a favorable outcome was achieved after 2 months of follow-up. The pathophysiology, diagnostic tools and treatment alternatives are discussed.  相似文献   
62.
Magnetic resonance imaging (MRI) is important in the diagnosis of and follow-up for the treatment of multiple sclerosis (MS); evoked potentials may be important if MRI is normal or cannot be performed. We assessed serial visual evoked potentials (VEPs) and cranial MRI in a group of clinically relapsing-remitting multiple sclerosis (N = 15) treated with interferon beta-lb (INFB-1b) and in normal subjects (N = 15). The investigations were done 1 week before INFB-lb therapy, 1 year later (N = 15), and 2 years later (N = 10). VEPs were abnormal in most of the patients; MRIs were abnormal in all patients. We used P100 latency as an electrophysiological index for the progress of illness. There were significant differences in VEPs between the beginning and ending of the interferon treatment. We concluded that VEPs would be a reliable index for following up the progress of MS under interferon therapy.  相似文献   
63.
64.
OBJECTIVE: To investigate the effect of diltiazem, a calcium channel blocker, on healing of the traumatic urethral inflammation when applied systemically or locally. MATERIALS AND METHODS: 21 adult male Wistar rats (230-250 g) were assigned to group 1 (n = 7) = control, group 2 (n = 7) = local application or group 3 (n = 7) = systemic application. In group 1, only a urethral injury was achieved at the 12-o'clock position by gently introducing and drawing a tiny hook in the urethra until urethral bleeding occurred. In group 2, after the same procedure, 10 mg/kg diltiazem was applied retrogradely via a 22-gauge Angiocath intraurethrally for 5 consecutive days, while the same account of the drug was administered intraperitoneally in group 3. After 21 days, the rats were sacrificed for urethrectomy. Pathologically, the thickness of connective tissue, the regularity of the epithelial lining, the presence of the inflammation and the density of collagen were evaluated with Masson's trichrome staining. The Mann-Whitney U test was used for statistical analyses. RESULTS: The mean connective tissue thickness was 0.77 +/- 0.39, 1.01 +/- 0.77 and 0.93 +/- 0.53 microm in groups 1, 2 and 3, respectively. The differences between the groups were insignificant (p > 0.05). The hyperplastic epithelial lining in the study groups, with both systemic and local applications, was markedly infrequent and the inflammation was less prominent. However, these differences did not reach statistical significance. CONCLUSIONS: Diltiazem appears not to have any preventive effect on connective tissue formation when applied locally or systemically in our urethral injury model.  相似文献   
65.
OBJECTIVE: Familial benign prostatic hyperplasia (BPH) is a recently popularized entity with yet uncertain clinical and pathological features. In the present study we investigated whether there was any difference between clinical characteristics of familial and sporadic BPH in a series of 148 surgically treated BPH patients. MATERIALS AND METHODS: A retrospective analysis was performed in 148 patients subjected to transvesical or transurethral prostatectomy to determine the clinical features of familial BPH. Patients were categorised as having familial BPH when 3 or more (including the patient) first-degree family members gave a history of BPH. Accordingly 23 cases who fit this criterion were accepted as having familial BPH and the rest of the cases were taken as the control group. The two groups were compared with respect to age, International Prostate Symptom Score (IPSS), quality of life score, prostate specific antigen (PSA), maximum urinary flow rate and the weight of the surgical prostate specimen. RESULTS: The mean age, IPSS, quality of life score, total PSA, maximum urinary flow rate and the weight of the surgical prostate specimen were found as 65.13 +/- 5.51 years, 23.13 +/- 4.82, 4.78 +/- 0.95, 6.0 +/- 4.1 ng/ml, 6.9 +/- 2.7 ml/s and 62.96 +/- 38.76 g, respectively, in the familial BPH group whereas the same parameters were measured as 68.13 +/- 7.68 years, 24.74 +/- 3.73, 4.52 +/- 0.85, 5.93 +/- 4.75 ng/ml, 4.6 +/- 1.71 ml/s and 70.87 +/- 53.21 g, respectively. No significant difference was present between familial and sporadic BPH cases in any of the studied parameters. CONCLUSION: The clinical features of familial BPH did not differ significantly from those of sporadic BPH.  相似文献   
66.
67.
68.
Nesher R  Cerasi E 《Diabetes》2002,51(Z1):S53-S59
The cellular and molecular mechanisms of insulin secretion are being intensively investigated, yet most researchers are seemingly unaware of the complexity of the dynamic regulation of the secretion. In this article, we summarize studies of the physiology of insulin secretion performed over several decades. The insulin response of perifused islets of rats, perfused rat pancreas, or that of a human, to a square-wave glucose stimulus is biphasic, a transient first-phase response of 4- to 10-min duration followed by a gradual rise in secretion rates (second-phase response). Several hypotheses have been proposed to account for the phasic nature of insulin secretion; they are briefly discussed in this review. We have favored the hypothesis that nutrient stimulators such as glucose, in addition to a primary and almost immediate secretory signal, with time induce both stimulatory and inhibitory messages in the beta-cell, and those messages modulate the primary insulinogenic signal. Indeed, studies in the rat pancreas and in humans have demonstrated that short stimulations with glucose generate a state of refractoriness of the insulin secretion, which we have termed time-dependent inhibition (TDI). Nonnutrient secretagogues such as arginine induce strong TDI independent of the duration of stimulation. Once the agent is removed, TDI persists for a considerable period. In contrast, prolonged stimulations with glucose (and other nutrients) lead to the amplification of the insulin response to subsequent stimuli; this can be demonstrated in the perfused rat pancreas, in perifused islets from several rodents, and in humans. We have termed this stimulatory signal time-dependent potentiation (TDP). The generation of TDP requires higher glucose concentrations and prolonged stimulation; the effect is retained for some time after cessation of the stimulus. Of major interest is the observation that, while the acute insulin response to glucose is severely reduced in glucose-intolerant animals and humans, TDP seems to be intact. The cellular mechanisms of TDI and TDP are poorly understood, but data reviewed here suggest that they are distinct from those that lead to the acute insulin response to stimuli. A model is proposed whereby the magnitude and kinetics of the insulin response to a given stimulus reflect the balance between TDP and TDI. Researchers studying the cellular and molecular mechanisms of insulin release are urged to take into consideration these complex and opposing factors which regulate insulin secretion.  相似文献   
69.
70.
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