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   1384篇
  免费   162篇
  国内免费   19篇
儿科学   78篇
妇产科学   4篇
基础医学   157篇
口腔科学   64篇
临床医学   156篇
内科学   231篇
皮肤病学   48篇
神经病学   57篇
特种医学   245篇
外科学   130篇
综合类   53篇
预防医学   128篇
眼科学   16篇
药学   129篇
  1篇
肿瘤学   68篇
  2021年   6篇
  2020年   10篇
  2019年   13篇
  2018年   15篇
  2017年   7篇
  2016年   13篇
  2015年   33篇
  2014年   40篇
  2013年   49篇
  2012年   30篇
  2011年   28篇
  2010年   60篇
  2009年   59篇
  2008年   36篇
  2007年   44篇
  2006年   34篇
  2005年   47篇
  2004年   28篇
  2003年   39篇
  2002年   24篇
  2001年   32篇
  2000年   21篇
  1999年   26篇
  1998年   86篇
  1997年   82篇
  1996年   61篇
  1995年   57篇
  1994年   43篇
  1993年   51篇
  1992年   32篇
  1991年   36篇
  1990年   20篇
  1989年   53篇
  1988年   54篇
  1987年   36篇
  1986年   26篇
  1985年   24篇
  1984年   22篇
  1983年   23篇
  1982年   22篇
  1981年   20篇
  1980年   18篇
  1979年   13篇
  1978年   19篇
  1977年   13篇
  1976年   13篇
  1975年   14篇
  1974年   5篇
  1973年   5篇
  1972年   4篇
排序方式: 共有1565条查询结果,搜索用时 406 毫秒
101.
102.
Development of a new access device for transgastric surgery   总被引:10,自引:0,他引:10  
Flexible endoscope-based endoluminal and transgastric surgery for cholecystectomy, appendectomy, bariatric, and antireflux procedures show promise as a less invasive form of surgery. Current endoscopes and instruments are inadequate to perform such complex surgeries for a variety of reasons: they are too flexible and are insufficient to provide robust grasping and anatomic retraction. The lack of support for a retroflexed endoscope in the peritoneal cavity makes it hard to reach remote structures and makes vigorous retraction of tissues and organs difficult. There is also a need for multiple channels in scopes to allow use of several instruments and to provide traction/countertraction. Finally, secure means of tissue approximation are critical. The aim was to develop and test a new articulating flexible endoscopic system for endoluminal and transgastric endosurgery. A multidisciplinary group of gastrointestinal physicians and surgeons worked with medical device engineers to develop new devices and instruments. Needs assessments and design parameters were developed by consensus. Prototype devices were tested using inanimate models until usable devices were arrived at. The devices were tested in nonsurvival pigs and dogs. The devices were accessed through an incision in the wall of the stomach and manipulated in the peritoneal cavity to accomplish four different tasks: right upper quadrant wedge liver biopsy, right lower quadrant cecal retraction, left lower quadrant running small bowel, and left lower quadrant exposure of esophageal hiatus. In another three pigs, transgastric cholecystectomy was attempted. The positions of the device, camera, and endosurgical instruments, with and without ShapeLock technology, were recorded using laparoscopy and endoscopy and procedure times and success rates were measured. Instrument design parameters and their engineering solutions are described. Flexible multilumen guides which could be locked in position, including a prototype which allowed triangulation, were constructed. Features of the 18-mm devices include multidirectional mid body and/or tip angulation, two 5.5-mm accessory channels allowing the use of large (5-mm) flexible endosurgical instruments, as well as a 4-mm channel for an ultraslim prototype video endoscope (Pentax 4 mm). Using the resulting devices, the four designated transgastric procedures were performed in anesthetized animals. One hundred percent of the transgastric endosurgical procedures were accomplished with the exception of a 50% success for hiatal exposure, a 90% success rate for wedge liver biopsy, and a 33.3% success rate for cholecystectomy. A new endosurgical multilumen device and advanced instrumentation allowed effective transgastric exploration and procedures in the abdominal cavity including retraction of the liver and stomach to allow exposure of the gallbladder, retraction of the cecum, manipulation of the small bowel, and exposure of the esophageal hiatus. This technology may serve as the needed platform for transgastric cholecystectomy, gastric reduction, fundoplication, hiatus hernia repair, or other advanced endosurgical procedures. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Partially funded and supported by USGI Medical, San Clemente, California.  相似文献   
103.
PURPOSE: To evaluate a statewide campaign that was designed to reduce television viewing by clients and staff of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Television reduction is frequently recommended as a strategy for preventing pediatric overweight. METHODS: Data were collected from a convenience sample of 10,445 clients and staff who attended clinics during a 3-week period before the intervention and 9188 clients and staff who attended clinics after the intervention. Chi-square tests were used to compare the proportion of WIC clients watching television 2 or 3 hours per day before and after the intervention. Within the context of WIC, which is a large and complex public health program, it was not possible to measure individual exposures or response rates. RESULTS: At baseline, 64.2% of WIC clients reported watching 2 or less hours of television per day. After the intervention, 70.5% limited television viewing to this recommended level. CONCLUSIONS: It is feasible to deliver television-reduction messages in large public health programs.  相似文献   
104.
105.
106.
107.
Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.  相似文献   
108.
Delirium Tremens     
The varied clinical manifestations and management of 14 male patients with delirium tremens (DT) have been studied. Eight patients were initially hospitalised for diseases unrelated to ethanol abuse i.e. 2 each for gun shot wound, myocardial infarction and stroke, and one each for pneumonia and gastroenteritis. One patient was going through withdrawal because of prodrome of viral hepatitis before he was hospitalised for uncontrolled agitation and delirium. Two known cases of mild essential hypertension on dietary therapy reported for agitation, abnormal behaviour, a single episode of tonic clonic seizure and hypertensive encephalopathy as they could not/did not get alcohol for 3 days. Three patients presented denovo with DT without concomitant illness. The other features besides delirium and hallucinations were tremulousness in 10, tachycardia in 12, fever in 3, diaphoresis in 2 and tonic clonic seizures in 4 patients. The symptoms fluctuated markedly at short intervals and 2 patients did not have any features of sympathetic overactivity. Altered hepatic biochemical parameters and ketonuria with normal blood sugar were noted in 4 and one patients respectively. Other biochemical parameters including serum electrolytes were normal. CT scan brain done for 5 patients revealed subdural haematoma in one. Cerebro spinal fluid (CSF) and EEG findings were noncontributory. All made good recovery with heavy doses of intravenous vitamin B complex, glucose and oral benzodiazepine. Short course of haloperidol was used in 2 patients. Two patients developed pancreatitis during follow up. All patients made complete recovery, and 8 patients have been followed for 8 to 12 months without relapse. The reason for hospitalisation in such cases is often unrelated to alcohol abuse; hence a detailed history of alcoholism is mandatory to identify those at risk as well as for prompt treatment and decreasing the mortality.Key Words: Alcohol withdrawal, Concomitant illnesses, Delirium, Precipitating events  相似文献   
109.
Supplemental Nutrition Program for Women, Infants, and Children (WIC) families were asked to identify motivators and barriers to health behavior change and preferred approaches to nutrition education in WIC. Six focus groups involved a total of 41 English-speaking WIC participants and addressed parenting, family meals, food preparation, and physical activity. The discussions were audiotaped, transcribed, and analyzed using NUD*IST software (Non-Numerical Unstructured Data Indexing, Searching, and Theorizing, version 4.0. Thousand Oaks, CA: Sage Publications Software, 1997). Key barriers to behavior change included inadequate parenting skills, lack of knowledge, unhealthy social environments, lack of time, and lack of social or financial support. Key motivators included feelings of responsibility, concern for child health and development, and positive social support. Participants identified facilitated discussions, support groups, cooking classes, and a WIC Web site as preferred methods of nutrition education. Results provided the foundation for the Healthy Habits nutrition education modules implemented in the Washington State WIC program and can be used to improve future nutrition education in WIC.  相似文献   
110.
The aim of GH replacement therapy in GH-deficient adults is to optimize response with minimum incidence of adverse reactions, but optimal therapy regimens are still to be established. This two-arm parallel study examined effects of two GH dose algorithms in adults with GH deficiency of adult or childhood onset. Patients on low dose (LD; n = 302) received GH at 3 microg/kg per day for 3 months increasing to 6 microg/kg per day for 3 months, and those on conventional dose (CD; n = 293) started on 6 microg/kg per day for 3 months increasing to 12 microg/kg per day for 3 months. The proportion of patients completing therapy was greater for the LD group than the CD group for the first 3 months (93.0% vs. 88.1%; P = 0.037) and overall for the 6 months (90.7% vs. 84.0%; P = 0.013). Both dose groups showed significant increases in lean body mass and decreases in fat mass for all time points. Percent increase in lean body mass was less with LD than CD over the first 3 months (2.43 +/- 4.33 vs. 3.58 +/- 4.69%; P = 0.006) but not overall for the 6-month period (4.38% +/- 5.34% vs. 5.21% +/- 5.99%; P = 0.141). Percent decrease in fat mass was less with LD than CD for the first 3 months (-2.81% +/- 7.81% vs. -5.53% +/- 8.64%; P < 0.001) and overall for the 6-month period (-6.35% +/- 9.42% vs. -9.45% +/- 12.07%; P = 0.006). IGF-I SD score increased less with LD than CD for 0 to 3 and 0 to 6 months, although for IGF-binding protein-3 SD score, there was no significant difference between doses at any time. Arthralgia was the only adverse event that occurred significantly less frequently with LD than with CD. Calculated changes based on gender and onset indicated greater changes in males than females for body composition, but there was little difference in GH-related adverse events between males and females. The lower starting dose with dose titration appeared more favorable, but differences in response between genders and onset of GH deficiency need to be taken into account when setting an individual dose regimen.  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