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   866篇
  免费   64篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   71篇
妇产科学   9篇
基础医学   116篇
口腔科学   22篇
临床医学   99篇
内科学   221篇
皮肤病学   26篇
神经病学   42篇
特种医学   105篇
外国民族医学   1篇
外科学   90篇
综合类   12篇
预防医学   37篇
眼科学   2篇
药学   35篇
中国医学   1篇
肿瘤学   40篇
  2023年   4篇
  2022年   5篇
  2021年   7篇
  2019年   5篇
  2018年   14篇
  2017年   12篇
  2016年   11篇
  2015年   23篇
  2014年   22篇
  2013年   32篇
  2012年   27篇
  2011年   27篇
  2010年   41篇
  2009年   36篇
  2008年   27篇
  2007年   27篇
  2006年   31篇
  2005年   26篇
  2004年   14篇
  2003年   24篇
  2002年   30篇
  2001年   24篇
  2000年   30篇
  1999年   24篇
  1998年   27篇
  1997年   35篇
  1996年   34篇
  1995年   36篇
  1994年   24篇
  1993年   39篇
  1992年   9篇
  1991年   10篇
  1990年   18篇
  1989年   22篇
  1988年   19篇
  1987年   12篇
  1986年   15篇
  1985年   16篇
  1984年   4篇
  1983年   7篇
  1982年   6篇
  1981年   14篇
  1980年   7篇
  1979年   3篇
  1978年   8篇
  1977年   7篇
  1976年   15篇
  1975年   4篇
  1969年   4篇
  1968年   4篇
排序方式: 共有932条查询结果,搜索用时 15 毫秒
1.
Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment.  相似文献   
2.
3.
Zanin M  Ruggera L  Beltrami P  Zattoni F 《Urologia》2007,74(3):148-151
Flexible ureterorenoscopy should be routinely used at the Urological Centers that deal with urinary stones. Flexible instruments should be used for both diagnostic and therapeutic purposes, allowing a safe exploration of the whole upper urinary tract. Thanks to their flexibility and to the active and passive deflection of their distal part, these instruments allowed to successfully treat several difficult situations, such as renal caliceal calculi in the lower calices or even in some middle/upper calices or in horseshoe kidneys. The therapeutic potential of this approach is enhanced by the large availability of ancillary instrumentation, such as baskets, grasps, holmium laser fibers, etc, which is continuously growing. On the other side, a steep learning curve of the technique is usually required for the surgeon. Furthermore, the intrinsic fragility of the instrument components and a potentially lower quality, when compared to that of the rigid and semi-rigid ureteroscopes, should be considered.  相似文献   
4.
5.
The receptor tyrosine kinase (RTK) Ret is activated by the formation of a complex consisting of ligands such as glial cell line-derived neurotrophic factor (GDNF) and glycerophosphatidylinositol-anchored coreceptors termed GFRalphas. During activation, Ret translocates into lipid rafts, which is critical for functional responses to GDNF. We found that Ret was rapidly ubiquitinated and degraded in sympathetic neurons when activated with GDNF, but, unlike other RTKs that are trafficked to lysosomes for degradation, Ret was degraded predominantly by the proteasome. After GDNF stimulation, the majority of ubiquitinated Ret was located outside of lipid rafts and Ret was lost predominantly from nonraft membrane domains. Consistent with the predominance of Ret degradation outside of rafts, disruption of lipid rafts in neurons did not alter either the GDNF-dependent ubiquitination or degradation of Ret. GDNF-mediated survival of sympathetic neurons was inhibited by lipid raft depletion, and this inhibitory effect of raft disruption on GDNF-mediated survival was reversed if Ret degradation was blocked via proteasome inhibition. Therefore, lipid rafts sequester Ret away from the degradation machinery located in nonraft membrane domains, such as Cbl family E3 ligases, thereby sustaining Ret signaling.  相似文献   
6.
We studied saccadic and smooth pursuit eye movements in 24 patients suffering from multiple sclerosis during disease worsening, before and after high-dose 6-methylprednisolone infusions. Quantitative evaluation of saccades was based on amplitude/duration and amplitude/peak velocity relationships, precision (i.e. the ratio of actual to desired saccade amplitude) and the latency, whereas smooth pursuit eye movements were studied using target velocity/performance index relationship. At basal recordings, 22/24 (91.7%) of the patients showed at lest one abnormality. Eleven of the 24 patients (45.8%) showed modification of one or several parameters: improvement in 6 patients, worsening in 2, coexistence of both trends in 3. Latency improvement was the only significant modification when patients were considered as a group. Neurophysiological modifications did not correspond to clinical changes.  相似文献   
7.
Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X‐ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X‐ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X‐ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field.  相似文献   
8.
From 1987 to 1988 we used cold biopsy forceps to remove completely 92 urothelial neoplasms ranging from 0.3 to 3 mm. Rigid biopsy forceps were used. The urologist usually treats these bladder neoplasms by diathermy coagulation, which obviously makes histological study impossible. On the other hand, due to the small size of these lesions even removal with the cutting loop inevitably causes deep regressive modifications that prevent accurate morphological evaluation. Histological examination of the neoplasms removed revealed the presence of low to medium grade (stage Ta, grades 1 to 2) noninfiltrating papillary carcinoma in 75 cases, high grade (stage Ta, grade 3) noninfiltrating papillary carcinoma in 9 and medium to high grade (stage T1, grades 2 to 3) infiltrating papillary carcinoma in 8, 1 of which had areas of squamous cell carcinoma. This method enabled us to study the morphology of the urothelial lesions in the initial phase. In our study population the number of high grade lesions and/or lesions with early signs of infiltration (17 of 92) appears to be noteworthy despite the small size of the tumors.  相似文献   
9.
SUMMARY Serum potassium was measured within 24 hours in 156 patients (48 male, 108 female) with an average age of 81.9 years admitted to the unit with acute illness. Of the 156 patients, 88 (56.4%) were taking diuretics (none was on ACE inhibitors); 20 patients (12.8%) were also on digoxin therapy. In all, 24 patients (16%) had hypokalaemia and 3 (2%) hyperkalaemia. Hypokalaemia was seen in patients associated with acute illness. There was no significant difference between the diuretic and non-diuretic groups. Monitoring of serum potassium is not routinely indicated to detect hypokalaemia in patients on diuretic therapy except in those with severe hepatic or renal impairment or those on digoxin.  相似文献   
10.
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