全文获取类型
收费全文 | 1264039篇 |
免费 | 94818篇 |
国内免费 | 1578篇 |
专业分类
耳鼻咽喉 | 16314篇 |
儿科学 | 41003篇 |
妇产科学 | 34950篇 |
基础医学 | 189408篇 |
口腔科学 | 34748篇 |
临床医学 | 117791篇 |
内科学 | 247837篇 |
皮肤病学 | 27283篇 |
神经病学 | 101852篇 |
特种医学 | 46764篇 |
外国民族医学 | 265篇 |
外科学 | 178601篇 |
综合类 | 25759篇 |
现状与发展 | 3篇 |
一般理论 | 568篇 |
预防医学 | 104670篇 |
眼科学 | 28044篇 |
药学 | 92587篇 |
7篇 | |
中国医学 | 2022篇 |
肿瘤学 | 69959篇 |
出版年
2018年 | 13530篇 |
2017年 | 10390篇 |
2016年 | 11326篇 |
2015年 | 13079篇 |
2014年 | 17999篇 |
2013年 | 27482篇 |
2012年 | 37573篇 |
2011年 | 39969篇 |
2010年 | 23058篇 |
2009年 | 22258篇 |
2008年 | 37753篇 |
2007年 | 40382篇 |
2006年 | 39964篇 |
2005年 | 39095篇 |
2004年 | 37543篇 |
2003年 | 35953篇 |
2002年 | 34864篇 |
2001年 | 56030篇 |
2000年 | 57043篇 |
1999年 | 48099篇 |
1998年 | 13402篇 |
1997年 | 12235篇 |
1996年 | 12657篇 |
1995年 | 11924篇 |
1994年 | 11116篇 |
1993年 | 10406篇 |
1992年 | 38209篇 |
1991年 | 37676篇 |
1990年 | 36449篇 |
1989年 | 35267篇 |
1988年 | 32696篇 |
1987年 | 32032篇 |
1986年 | 30529篇 |
1985年 | 28788篇 |
1984年 | 21943篇 |
1983年 | 19196篇 |
1982年 | 11368篇 |
1981年 | 10327篇 |
1979年 | 20946篇 |
1978年 | 15396篇 |
1977年 | 12793篇 |
1976年 | 11848篇 |
1975年 | 12811篇 |
1974年 | 15589篇 |
1973年 | 15363篇 |
1972年 | 14512篇 |
1971年 | 13553篇 |
1970年 | 12787篇 |
1969年 | 12065篇 |
1968年 | 11229篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
T F Kruger J P Van der Merwe H J Odendaal F S Stander G M Grobler V A Hulme E L Erasmus K Coetzee M L Windt Y Swart 《Suid-Afrikaanse tydskrif vir geneeskunde》1990,77(12):634-636
The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate. 相似文献
102.
Technetium-99-labelled methylene diphosphonate uptake scans in patients with dialysis arthropathy 总被引:1,自引:0,他引:1
Patients on long-term haemodialysis suffer from dialysis arthropathy due to the deposition of dialysis amyloid. We investigated the use of 99Tc-labelled methylene diphosphonate bone scans in 17 patients as a possible in vivo diagnostic technique. In most clinically affected joints, with the exception of shoulders and hands, there was increased radioisotope uptake consistent with uptake by periarticular bone. In addition, we describe intense soft-tissue uptake around some clinically affected large joints. In contrast, control groups of patients on haemodialysis without arthropathy and patients without renal failure did not have increased uptake. A semi-quantitative scale of uptake was devised, and the following correlations were significant: pain perception and isotope uptake score in the ankles and feet, and the number of radiological lesions and isotope uptake scores in the wrists and knees. The following sites where the radioisotope might bind in the affected joints are proposed: amyloid deposits, areas of soft-tissue calcification, or areas of increased bone turnover. It is concluded that whereas the scanning technique cannot make a definite diagnosis of amyloid and, therefore, cannot be expected to supersede histological diagnosis, it is a useful adjuvant investigation, of particular importance in those patients unable or unwilling to undergo biopsy. 相似文献
103.
104.
105.
106.
Extravesical versus Leadbetter-Politano ureteroneocystostomy: a comparison of urological complications in 320 renal transplants 总被引:3,自引:0,他引:3
The urological complications of 320 consecutive renal transplants performed at our institution between October 17, 1985 and November 10, 1989 are reviewed. The Leadbetter-Politano technique of ureteroneocystostomy was used in the first 160 patients (group 1) and an anterior extravesical technique modified from the methods of Witzel, Sampson and Lich was performed in the second 160 patients (group 2). Urological complications occurred in 15 patients (9.4%) in group 1 and 6 (3.7%) in group 2 (p = 0.04). Ureterovesical junction obstruction occurred in 6 patients (3.7%) in group 1 and 1 (0.6%) in group 2 (p = 0.05). Complications of leakage, ureteral necrosis and ureteral stricture were comparable in the 2 groups. Therefore, we advocate the use of the anterior extravesical technique over Leadbetter-Politano ureteral reimplantation based on the lower incidence of urological complications and various technical advantages, including less operative time, avoidance of a separate cystotomy, less hematuria and ability to use short donor ureters. 相似文献
107.
D A Evans B N Hamid E M Hoare 《Journal of the Royal College of Surgeons of Edinburgh》1990,35(1):33-35
Thirteen cases of primary appendicular adenocarcinoma are reported. This rare tumour usually presents as acute appendicitis. The correct diagnosis is rarely entertained before or during surgery. The main treatment choice lies between appendicectomy alone and appendicectomy followed by right hemicolectomy. There are anatomical reasons for advising the latter and survival figures from the literature tend to support this preference. The cases reported here indicate that in the period 1972-1984, in the North West Region, there was a slight preference for appendicectomy alone. The additional procedure of right hemicolectomy did not confer any clear-cut survival advantage. 相似文献
108.
From 1979 to 1987 1428 patients with blunt abdominal trauma were treated in the Department of Surgery of the University of Freiburg; 119 patients had intestinal injuries. They were mainly young adults who had sustained a car accident. 71.3% of the small bowel injuries were overseen, 14.2% needed resection, and in 14.5% an operative procedure was not necessary. The surgical procedure for colonic injuries has to be chosen with regard to the age and general condition of the patient, to the severity of the trauma, to associated injuries and to the stage of peritonitis. Accordingly, 18% of the patients were treated with and 58% without a protective colostomy, 24% could be treated conservatively. Mortality and morbidity correlated with the severity of associated injuries. Morbidity was also dependent on the time interval between accident and operative therapy. 相似文献
109.
The results of a controlled randomized and prospective clinical study including 113 patients from March 1987 until August 1988 showed that prophylactic drainage in elective resection for cancer of the colon was not necessary. 60 patients received a drain, 53 patients were not drained. The drain turned out to be ineffective even concerning its expected function of draining intraabdominal fluid: its diagnostic and therapeutic value failed in clinical practice. The rate of surgical complications--i.e. anastomotic leakage, impaired wound healing and relaparotomy--was significantly higher in the drained group. In elective colon resection the use of a drain as a routine procedure cannot be recommended. 相似文献
110.
It has become common practice to rely on fitted estimates ofapparent in vivo metabolic constants (e.g., Vmax and KM) inparameterization of PBPK models. Yet, quantitative estimatesof precision in these fitted parameters are not routinely reported.Such information is needed to assess the reliability of modelpredictions. The purpose of this study was to assess the precisionin estimates of Vmax and KM for chloroform, accounting for boththe statistical uncertainties in parameter estimates from individualdata sets and any additional uncertainty due to differencesin the parameter estimates derived from various experiments.Joint confidence regions for Vmax and KM from each experiment,generated using maximum likelihood techniques, were used toevaluate these questions. Three previously published data setswere considered. Estimates of Vmax and KM obtained from thesedata sets differed more than could be explained as a consequenceof a limited number of observations, measurement error, or stochasticerror. Issues associated with the use of maximum likelihoodtechniques to estimate joint confidence regions, the estimationof metabolic constants from individual experiments within agas uptake study versus the full data set, the degree of overlapin the joint confidence regions for metabolic constants obtainedfrom separate data sets, and the implications for risk assessmentare discussed. 相似文献