全文获取类型
收费全文 | 1264027篇 |
免费 | 94827篇 |
国内免费 | 1578篇 |
专业分类
耳鼻咽喉 | 16313篇 |
儿科学 | 41001篇 |
妇产科学 | 34952篇 |
基础医学 | 189403篇 |
口腔科学 | 34734篇 |
临床医学 | 117758篇 |
内科学 | 247808篇 |
皮肤病学 | 27278篇 |
神经病学 | 101867篇 |
特种医学 | 46760篇 |
外国民族医学 | 265篇 |
外科学 | 178587篇 |
综合类 | 25749篇 |
现状与发展 | 3篇 |
一般理论 | 568篇 |
预防医学 | 104700篇 |
眼科学 | 28085篇 |
药学 | 92586篇 |
7篇 | |
中国医学 | 2022篇 |
肿瘤学 | 69986篇 |
出版年
2018年 | 13531篇 |
2017年 | 10391篇 |
2016年 | 11326篇 |
2015年 | 13081篇 |
2014年 | 18001篇 |
2013年 | 27484篇 |
2012年 | 37583篇 |
2011年 | 39978篇 |
2010年 | 23061篇 |
2009年 | 22255篇 |
2008年 | 37768篇 |
2007年 | 40395篇 |
2006年 | 39978篇 |
2005年 | 39106篇 |
2004年 | 37556篇 |
2003年 | 35969篇 |
2002年 | 34881篇 |
2001年 | 56039篇 |
2000年 | 57050篇 |
1999年 | 48102篇 |
1998年 | 13397篇 |
1997年 | 12222篇 |
1996年 | 12646篇 |
1995年 | 11916篇 |
1994年 | 11108篇 |
1993年 | 10404篇 |
1992年 | 38204篇 |
1991年 | 37671篇 |
1990年 | 36447篇 |
1989年 | 35260篇 |
1988年 | 32691篇 |
1987年 | 32031篇 |
1986年 | 30526篇 |
1985年 | 28786篇 |
1984年 | 21947篇 |
1983年 | 19194篇 |
1982年 | 11366篇 |
1981年 | 10321篇 |
1979年 | 20948篇 |
1978年 | 15393篇 |
1977年 | 12791篇 |
1976年 | 11845篇 |
1975年 | 12810篇 |
1974年 | 15590篇 |
1973年 | 15362篇 |
1972年 | 14512篇 |
1971年 | 13552篇 |
1970年 | 12786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 0 毫秒
131.
132.
133.
134.
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
135.
Monolayer cultures of normal human bone cells contain multiple subpopulations of alkaline phosphatase positive cells 总被引:5,自引:0,他引:5
Toshikatsu Matsuyama K. -H. William Lau Jon E. Wergedal 《Calcified tissue international》1990,47(5):276-283
Summary Cytochemical staining of normal human bone cells in monolayer cultures for alkaline phosphatase (ALP) indicated that the cultures
contained mixed-cell populations. Time course evaluations of the cytochemical staining revealed, in addition to the ALP-negative
cell population, at least two subpopulations of ALP-positive human bone cells with different levels of ALP. A cytochemical
method has been developed which separates the ALP-positive cells into high and intermediate ALP subpopulations. In this method,
human bone cells were stained for ALP using an azo-dye method and incubating at 4°C for 10 and 30 minutes, respectively. We
defined the cell population that stained positively for ALP at 10 minutes as strong ALP-positive cells, and both strong and
intermediate cells were stained at 30 minutes. The intermediate cells were determined from the difference between the values
at the two time points. The intra- and interassay variations of the assay, with the same investigator in blinded investigations,
were both less than 10% and the interobserver variation was approximately 25%. Analysis of the distribution of ALP levels
in cells with a laser densitometer confirmed the presence of at least three cell subpopulations. 1,25(OH)2D3 treatment increased the proportions of both ALP-positive cell populations, whereas TGF-beta treatment increased only the
intermediate ALP-positive cell population. On the contrary, fluoride increased the proportion of the strong ALP cells, and
IGF-1 had no effect on the proportions of either ALP-positive subpopulation. When the ALP-specific activity was compared with
the percentage of each ALP-positive subpopulations for the cells treated with effectors, the ALP-specific activity correlated
with the total ALP-positive and with the strong ALP-positive populations but not with the intermediate ALP-positive subpopulation.
In summary, this study represents the first evidence that normal human bone cells in monolayer cultures contained at least
two subpopulations of ALP-positive cells, and that bone cell effectors could have differential effects on each cell population. 相似文献
136.
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
137.
Effects of hypothermia on testicular ischemia 总被引:14,自引:0,他引:14
The ischemic effects of prolonged testicular torsion have been well documented; however, prevention or arrest of the damaging effects of prolonged ischemia has been incompletely studied. Two groups of Sprague-Dawley rats were subjected to varying lengths of bilateral testicular ischemia. Group I underwent normothermic ischemia for two, four, and six hours. Likewise, Group II underwent similar time periods of ischemia, however, after thirty minutes of normothermic ischemia the scrotum of each animal was placed into an ice bath maintained at 4C. Two weeks postoperatively, bilateral orchiectomy was performed. Histology of the testes of the two groups was compared. Neither group revealed significant destruction of the germinal epithelium after two hours of ischemia. Group I revealed only 25% preservation of the germinal epithelium at four hours and only 8% preservation at six hours of ischemia. In contrast, Group II which received ice showed 90% preservation of germinal epithelium at four hours and 85% preservation at six hours of ischemia. We conclude that external ice application significantly preserves seminiferous tubules at four and six hours of ischemic injury in the rat testicle. 相似文献
138.
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
139.
Uptake of Adriamycin in tumour and surrounding brain tissue in patients with malignant gliomas 总被引:1,自引:0,他引:1
H. von Holst E. Knochenhauer H. Blomgren V. P. Collins L. Ehn M. Lindquist G. Norén C. Peterson 《Acta neurochirurgica》1990,104(1-2):13-16
Summary Eight patients with malignant gliomas verified on CT scan, received an intravenous injection of 50 mg of Adriamycin R, 24 hours prior to surgical removal of the tumour. Peroperatively, both tumour and surrounding tissue specimens were obtained for determination of the tissue concentrations of Adriamycin and its reduced metabolite Adriamycinol. It was found that Adriamycin could be detected in tumour tissue from all patients. The concentration varied between 0,9 and 4,6 nmol/g tissue. In contrast, Adriamycin could only be detected in surrounding brain tissue from one patient.In anin vitro study a human malignant glioma cell line (U-251 MG) was exposed to various concentrations of Adriamycin for 24 hours. It was found that an intracellular drug concentration above 30 nmol/g cells caused a concentration dependent inhibition of cell growth. Thus, it is likely that the poor effect of Adriamycin on patients with malignant gliomas is due to an ineffective drug accumulation in the tumour tissue. 相似文献