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   172538篇
  免费   33446篇
  国内免费   2513篇
耳鼻咽喉   5368篇
儿科学   5831篇
妇产科学   2788篇
基础医学   6366篇
口腔科学   1930篇
临床医学   27917篇
内科学   52944篇
皮肤病学   7741篇
神经病学   16673篇
特种医学   7307篇
外科学   44620篇
综合类   327篇
现状与发展   72篇
一般理论   5篇
预防医学   7687篇
眼科学   3758篇
药学   2439篇
中国医学   48篇
肿瘤学   14676篇
  2024年   516篇
  2023年   4854篇
  2022年   1373篇
  2021年   3478篇
  2020年   6230篇
  2019年   2452篇
  2018年   7721篇
  2017年   7619篇
  2016年   8746篇
  2015年   8780篇
  2014年   15965篇
  2013年   16218篇
  2012年   6489篇
  2011年   6527篇
  2010年   10920篇
  2009年   14754篇
  2008年   6758篇
  2007年   5117篇
  2006年   7525篇
  2005年   4802篇
  2004年   4028篇
  2003年   3010篇
  2002年   3173篇
  2001年   4476篇
  2000年   3765篇
  1999年   3908篇
  1998年   3974篇
  1997年   3725篇
  1996年   3600篇
  1995年   3437篇
  1994年   2170篇
  1993年   1779篇
  1992年   2025篇
  1991年   1978篇
  1990年   1615篇
  1989年   1742篇
  1988年   1524篇
  1987年   1342篇
  1986年   1327篇
  1985年   1162篇
  1984年   803篇
  1983年   740篇
  1982年   611篇
  1981年   494篇
  1980年   448篇
  1979年   540篇
  1978年   461篇
  1977年   504篇
  1975年   379篇
  1972年   391篇
排序方式: 共有10000条查询结果,搜索用时 562 毫秒
111.
112.
Background Hydatid disease is the most severe helminthic zoonosis, with an important public health problem especially in rural areas in Turkey. The aim of this study was to review the problems and advantages encountered in surgical treatment of 43 patients who were ventilated with one-lung ventilation during last four years. Methods Patients, operated with one-lung ventilation, constitute the study group. Data related to symptoms, radiographic findings, performed surgical procedures, perioperative and postoperative morbidity, hospitalization time, and cyst recurrence were collected from each individual's records. Results Cystotomy and capitonnage were performed in all cases. Perioperative complications were seen in 5 patients. Four of these 5 patients had double-lumen endotracheal tube malpositioning. In one patient hypoxemia developed. The most common postoperative complication was atelectasis. One patient had recurrent cysts. There was no perioperative or postoperative death. Conclusions We prefer cystotomy and capitonnage because it is a fast and effective technique with limited postoperative complications. One-lung ventilation prevents the exposure of lower lung areas from massive aspiration, which may cause acute obstruction of airways, and contamination by cyst contents from the operative part of the lung that causes recurrent disease. One-lung ventilation in pulmonary hydatid cyst surgery may be preferred owing to lower mortality and morbidity rates.  相似文献   
113.
SONI NANDA  MD    VINEET RELHAN  MD    CHANDER GROVER  MD  DNB  MNAMS    B.S.N. REDDY  MD  MNAMS 《Dermatologic surgery》2006,32(3):387-392
BACKGROUND: Suction blister epidermal grafting is an established technique for the treatment of resistant and stable vitiligo especially over small and cosmetically important areas like the face. However, certain areas, such as lips and eyelids, require special considerations because of their anatomic peculiarities. PATIENTS AND METHODS: The current study was carried out on six patients of stable eyelid vitiligo, not responding to medical treatment. Suction blister was obtained from the thigh using the suction apparatus and the roof was grafted on to the dermabraded eyelid. Certain precautions were taken during the procedure, which will be highlighted in the current study. RESULTS: Response was excellent in all the patients in 3 to 6 months, with no complications. CONCLUSIONS: If carried out properly, suction blister technique is the procedure of choice for cosmetically important sites like eyelids.  相似文献   
114.
Genetically modified keratinocytes and fibroblasts are suitable for delivery of therapeutic genes capable of modifying the wound healing process. However, efficient gene delivery is a prerequisite for successful gene therapy of wounds. Whereas adenoviral vectors (Ads) exhibit superior levels of in vivo gene transfer, their transductional efficiency to cells resident within wounds may nonetheless be suboptimal, due to deficiency of the primary adenovirus receptor, coxsackie-adenovirus receptor (CAR). We explored CAR-independent transduction to fibroblasts and keratinocytes using a panel of CAR-independent fiber-modified Ads to determine enhancement of infectivity. These fiber-modified adenoviral vectors included Ad 3 knob (Ad5/3), canine Ad serotype 2 knob (Ad5CAV-2), RGD (Ad5.RGD), polylysine (Ad5.pK7), or both RGD and polylysine (Ad5.RGD.pK7). To evaluate whether transduction efficiencies of the fiber-modified adenoviral vectors correlated with the expression of their putative receptors on keratinocytes and fibroblasts, we analyzed the mRNA levels of CAR, alpha upsilon integrin, syndecan-1, and glypican-1 using quantitative polymerase chain reaction. Analysis of luciferase and green fluorescent protein transgene expression showed superior transduction efficiency of Ad5.pK7 in keratinocytes and Ad5.RGD.pK7 in fibroblasts. mRNA expression of alpha upsilon integrin, syndecan-1 and glypican-1 was significantly higher in primary fibroblasts than CAR. In keratinocytes, syndecan-1 expression was significantly higher than all the other receptors tested. Significant infectivity enhancement was achieved in keratinocytes and fibroblasts using fiber-modified adenoviral vectors. These strategies to enhance infectivity may help to achieve higher clinical efficacy of wound gene therapy.  相似文献   
115.
116.
117.
118.
Hydration and Cognitive Function in Children   总被引:3,自引:0,他引:3  
Adequate fluid intake is critical for survival. While adults are at liberty to drink fluids as wanted, children and infants are dependent upon caregivers for food and fluid. Children are at greater risk for dehydration than adults due to their higher surface-to-mass ratio. Additionally, children have different thirst sensitivities and body cooling mechanisms than adults. Children differ from adults in total body water content, and boys and girls differ in body water content with maturation. Research in young adults shows that mild dehydration corresponding to only 1% to 2% of body weight loss can lead to significant impairment in cognitive function. Dehydration in infants is associated with confusion, irritability, and lethargy; in children, it may produce decrements in cognitive performance.  相似文献   
119.
120.
BACKGROUND AND PURPOSE: Dot-like low intensity spots (dot-like hemosiderin spots: dotHSs) on gradient echo T2*-weighted MRI have been histologically diagnosed to represent old cerebral microbleeds associated with microangiopathies. They have also been correlated to the fragility of small vessels and the tendency to bleed. Therefore, a substantial number of dotHSs might be associated with a large-sized, deep intracerebral hematoma (ICH). On the other hand, dotHSs may reflect old microbleeds that did not enlarge to symptomatic size. METHODS: To investigate how dotHSs are related to the size (maximal diameter) of primary deep ICH, we analyzed the diameter and the number of dotHSs in 151 patients with deep ICH not associated with subarachnoid hemorrhage or intraventricular hemorrhage (75 males and 76 females, age ranged from 37 to 90 [65.7 +/- 11.3 years old] who were consecutively admitted to Hakodate Municipal Hospital. The hazard ratio (HR) for a maximal diameter of deep ICH < or =2 cm was estimated, using the number of dotHSs and risk factors for stroke. RESULTS: The number of dotHSs associated with the diameter < or =2 cm was 9.2 +/- 11.5, significantly larger than that with the diameter > or =2 cm (4.7 +/- 7.0, P= .012). Multivariate analysis revealed that a maximal diameter of deep ICH of < or =2 cm was found in patients with dotHS (HR, 3.7; 95% confidence interval [CI], 1.4-10.1; P= .009). CONCLUSION: Though small sample size limited the power of our analyses, these findings suggest that the number of dotHSs may be associated with a small diameter of deep ICH.  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