首页 | 官方网站   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   2799篇
  免费   126篇
  国内免费   12篇
医药卫生   2937篇
  2024年   5篇
  2023年   27篇
  2022年   16篇
  2021年   83篇
  2020年   46篇
  2019年   67篇
  2018年   104篇
  2017年   68篇
  2016年   101篇
  2015年   85篇
  2014年   122篇
  2013年   144篇
  2012年   199篇
  2011年   177篇
  2010年   117篇
  2009年   90篇
  2008年   163篇
  2007年   174篇
  2006年   188篇
  2005年   171篇
  2004年   163篇
  2003年   152篇
  2002年   113篇
  2001年   51篇
  2000年   50篇
  1999年   34篇
  1998年   16篇
  1997年   10篇
  1996年   11篇
  1995年   18篇
  1994年   6篇
  1993年   9篇
  1992年   22篇
  1991年   8篇
  1990年   15篇
  1989年   14篇
  1988年   6篇
  1987年   6篇
  1986年   5篇
  1985年   9篇
  1984年   8篇
  1983年   8篇
  1980年   4篇
  1979年   4篇
  1978年   5篇
  1973年   5篇
  1972年   4篇
  1971年   9篇
  1970年   5篇
  1967年   3篇
排序方式: 共有2937条查询结果,搜索用时 31 毫秒
1.
2.
3.
Conclusions: This study revealed a significant correlation between red-green-blue (RGB) values of tympanic membrane (TM) images and the presence of effusion in the middle ear. These results confirm that endoscopic RGB evaluation is a rapid and non-invasive procedure yielding objective results. Objective: To investigate, in cases of otitis media with effusion (OME), the correlation of the TM color changes with the presence and viscosity of the effusion in the middle ear. Methods: Endoscopic images of the TMs of 52 patients (group 1) and 52 healthy controls (group 2) were taken during their otologic examinations. RGB values of particular points were measured on the TM images of both groups. Additionally, in group 1 the viscosity of each effusion taken by paracentesis during surgery was also measured intraoperatively with a viscometer. Patients with viscosity values lower and higher than 450 cP (centipoise) were subdivided into groups 1a and 1b, respectively. Results: Study and control groups were comparable regarding the number of patients and their mean ages (p > 0.05). Statistically significant differences were found in RGB values of the TM between groups 1 and 2, but not between groups 1a and 1b.  相似文献   
4.
5.
The authors describe the evidence and results obtained in 21 out of 100 patients who underwent salvage retroperitoneal lymphadenectomy for advanced testicular cancer (UICC stage II/B bulky and stage III) in the period 1982–1993, and in whom inductive chemotherapy was not followed by marker conversion. It is stated that if AFP positivity is low (titres below 100 ng/ml) salvage retroperitoneal lymphadenectomy (RLA) is of high therapeutic value, whereas in all cases with HCG positivity or AFP titres higher than 500 ng/ml tumorous death ensued without exception. In our cases viable tumour residues occurred in 81%. Salvage resection was feasible in 76%, but every incomplete resection (19%) was followed by death due to tumour. In all but one of the cases marker positivity, an indicator of therapy-resistant viable tumour residues, persisted after having used more than four PVB combinations or changes in the chemotherapeutic regimen.  相似文献   
6.
The case of a child injured by a knitting needle penetrating transorbitally and intracranially, resulting in carotid cavernous fistula and pontine injury, is reported. After receiving medical and endovascular treatment, the only remaining abnormal neurological manifestation was right peripheral facial nerve palsy. The clinical sequences of events and the demonstration of a pontine lesion leading to peripheral facial palsy are presented. Facial nuclear injury with a penetrating trauma is an extremely rare condition. It is important to identify the anatomical regions injured in penetrating traumas. The lesions must be identified by computerized tomography, magnetic resonance imaging, clinical and laboratory investigation.  相似文献   
7.
Some new macroinitiators ( 5 ) containing azo and peroxy groups were synthesized by transformation of esters of poly(ethylene glycol) ( 1 ) (PEG) of different molecular weight with hydroxyl end groups and an azo group in the middle into the corresponding polymers with tert-butylperoxycarbonyl end groups by reaction with terephthaloyl chloride and subsequently with tert-butyl hydroporoxide. Decomposition in the presence of styrene at 60°C or with 3,6,9-triazaun-decane-1,11-diamine in presence of methyl methacrylate gave the corresponding ABA block copolymer 6 and the ABBA block copolymer 7 , respectively. Both block copolymers were used as polymeric initiators. The ABCBA block copolymer 8 was synthesized from 6 and methyl methacrylate or from 7 and styrene by thermally induced polymerization at 80°C. The resulting block copolymers were separated from the homopolymers by selective solvent extraction and characterized by spectroscopic and fractional precipitation methods.  相似文献   
8.
The presence of certain defects in both cellular and humoral immunity after thermal injury has been established. Likewise, the translocation of enteric bacteria to the mesenteric lymph nodes and to distant organs has also been observed following serious thermal injury. The effects of granulocyte colony-stimulating factor (G-CSF) on bacterial translocation, the small bowel mucosa, and cecal bacterial content were investigated in a rat model of burn wound sepsis in which albino Wistar rats were scalded over 30% of their bodies, after which the lesions were infected by 1×108 colony-forming units (cfu)Pseudomonas aeruginosa. The control group was treated with 5% dextrose solution subcutaneously starting 2 days preburn, while the treatment group received 100μg/kg human G-CSF subcutaneously. On the 4th day post burn all animals were killed to examine the bowel and culture of the mesenteric lymph nodes (MLN), livers, and spleens. No significant differences were observed between the groups regarding the cecal bacterial content and small bowel; however, a difference was seen in the ratio of translocation in the MLN liver and spleen and quantitative MLN cultures. Based on these findings, G-CSF was thus found to be significantly effective in reducing bacterial translocation due to burn wound sepsis.  相似文献   
9.
Autistic disorder and 22q11.2 duplication.   总被引:2,自引:0,他引:2  
Although several reports have described the co-occurrence of autism in subjects with chromosome 22 abnormalities including trisomy 22, translocation 20/22, 22q11.2 deletion, ring chromosome 22, and 22q13.3 deletion, there is no report with 22q11.2 duplication. We report a 9-year-old girl, referred to our department for her behavioural problems and language delay. She was diagnosed with autistic disorder according to DSM-IV criteria. Because of her dysmorphic characteristics comprising narrow face, narrow forehead, mandibular prognathism, synophrys, and operated cleft palate and cardiac problems, she had gone under cytogenetic analysis. Although she was ascertained as suspected velocardiofacial syndrome (VCFS), the duplication of 22q11.2 was detected by interphase fluorescence in situ hybridization. Previous reports on the psychiatric aspects of 22q11.2 duplication have shown the existence of hyperactivity, learning disability, speech problems, and aggressive behaviours but not autism. Moreover, the lack of reports of co-occurrence of autism and 22q11.2 duplication may be related to paucity as a result of technical problems.  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-23

京公网安备 11010802026262号