全文获取类型
收费全文 | 3580911篇 |
免费 | 263670篇 |
国内免费 | 8725篇 |
专业分类
耳鼻咽喉 | 48909篇 |
儿科学 | 118601篇 |
妇产科学 | 99819篇 |
基础医学 | 503506篇 |
口腔科学 | 102170篇 |
临床医学 | 325158篇 |
内科学 | 697086篇 |
皮肤病学 | 82631篇 |
神经病学 | 293739篇 |
特种医学 | 139399篇 |
外国民族医学 | 1129篇 |
外科学 | 535979篇 |
综合类 | 79299篇 |
现状与发展 | 6篇 |
一般理论 | 1400篇 |
预防医学 | 278661篇 |
眼科学 | 81773篇 |
药学 | 265094篇 |
10篇 | |
中国医学 | 6969篇 |
肿瘤学 | 191968篇 |
出版年
2018年 | 37606篇 |
2017年 | 29139篇 |
2016年 | 33507篇 |
2015年 | 38109篇 |
2014年 | 52423篇 |
2013年 | 79475篇 |
2012年 | 105696篇 |
2011年 | 111678篇 |
2010年 | 67171篇 |
2009年 | 64376篇 |
2008年 | 105105篇 |
2007年 | 111417篇 |
2006年 | 113275篇 |
2005年 | 109091篇 |
2004年 | 105930篇 |
2003年 | 101996篇 |
2002年 | 98871篇 |
2001年 | 167389篇 |
2000年 | 172025篇 |
1999年 | 145570篇 |
1998年 | 42009篇 |
1997年 | 37549篇 |
1996年 | 37575篇 |
1995年 | 36488篇 |
1994年 | 33779篇 |
1993年 | 31730篇 |
1992年 | 116018篇 |
1991年 | 112589篇 |
1990年 | 109328篇 |
1989年 | 105900篇 |
1988年 | 97661篇 |
1987年 | 95942篇 |
1986年 | 90737篇 |
1985年 | 86984篇 |
1984年 | 65118篇 |
1983年 | 55663篇 |
1982年 | 32971篇 |
1981年 | 29629篇 |
1979年 | 59674篇 |
1978年 | 41848篇 |
1977年 | 35548篇 |
1976年 | 33153篇 |
1975年 | 35344篇 |
1974年 | 42329篇 |
1973年 | 40370篇 |
1972年 | 37727篇 |
1971年 | 35249篇 |
1970年 | 32468篇 |
1969年 | 31057篇 |
1968年 | 28385篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A metropolitan experience with infrainguinal revascularization. Operative risk and late results in northeastern Ohio 总被引:1,自引:0,他引:1
T D Rafferty J C Avellone C J Farrell N R Hertzer F R Plecha R S Rhodes W V Sharp J M Rogers 《Journal of vascular surgery》1987,6(4):365-371
Despite being of fundamental importance, the late results of major arterial reconstruction rarely have been documented throughout a large metropolitan area. In this study of 932 patients entered into the computer registry of the Cleveland Vascular Society, 19 surgeons representing 13 community hospitals and referral centers in Cleveland and Akron report the intermediate-term outcome during a mean interval of 35 months after infrainguinal lower extremity revascularization performed in northeastern Ohio from 1978 through 1982. Operative risk (5%), the early amputation rate (7%), and actuarial 5-year survival (48% to 55%) for patients with rest pain or tissue necrosis were significantly worse (p less than 0.05) than comparable figures (0.6%, 0%, and 77%, respectively) for others who underwent procedures for disabling claudication. Although both materials had similar success above the knee, the cumulative 3-year patency rate of autogenous vein bypass to the distal popliteal (69% to 88%; p less than 0.05) and tibioperoneal arteries (43%; 0.05 less than p less than 0.1) was superior to the results of polytetrafluoroethylene grafts (32% to 50% and 19%, respectively). Moreover, polytetrafluoroethylene grafts required reoperations at three times the rate of vein grafts to maintain limb salvage. 相似文献
992.
J M Hurpe C Zerr P Lebreton G Fauchon M Nivaud P Renouf A Khayat J Quesnel 《Annales fran?aises d'anesthèsie et de rèanimation》1987,6(1):11-16
The use of autologous blood transfusion in cardiac surgery is still controversial. This study was prospectively designed to evaluate the haemodynamic and haematological benefits of this method, with special attention to its impact on reducing bank blood requirements. Between November 1983 and October 1984, 160 patients underwent cardiac surgery with extracorporeal circulation and were randomly assigned to two groups: group I (81 patients) was the control group and group II (79 patients) received autologous transfusion following extracorporeal circulation. Blood was withdrawn immediately after the induction of anaesthesia via a jugular catheter and stored in CPD solution at room temperature. The volume of blood removed was replaced with gelatin solutions; after bypass, blood was returned to the patient. There was no difference in systolic, diastolic or mean blood pressures between the two groups. Right atrial pressure and heart rate were not statistically different in both groups. Myocardial perfusion and myocardial oxygen consumption remained unchanged in group II compared with group I. Complete haematological evaluation was carried out before and during bypass, and thereafter daily for the first twelve days of the postoperative period. There was no significative difference between the two groups in platelet counts, fibrinogen levels, prothrombin and partial thromboplastin times. During extracorporeal circulation, mean haematocrit was 22.9 +/- 0.4% in group II and 25.3 +/- 0.5% in group I (p less than 10(-3)). The mean haematocrit time course was similar in both groups during the postoperative period and returned to preoperative value at discharge.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
993.
994.
J. K. M. Quartey 《World journal of urology》1987,5(1):37-40
Summary Short traumatic strictures of the membranous urethra can be repaired by excision and end-to-end urethroprostatic anastomosis. Long membranous or bulbomembranous strictures with or without associated periurethral fibrosis, abscess or urinary fistulae require substitution urethroplasty. Tubed full-thickness skin grafts have a poor chance of survival in such circumstances. Scrotal flaps are hairy, but the penile/preputial island flap, which is relatively hairless, is ideal for such reconstructions in one stage. Difficult perineal exposure led to the development of the transpubic and the abdominoperineal routes. Modification of the incision for perineal prostatectomy by dividing the posterior part of the urogenital diaphragm in the midline up to the urethra improves the exposure so that almost all such reconstructions can be done by the perineal route. A total of 21 cases are reviewed. Flap survival is 100%, but stenosis or restricture at the anastomotic sites can occur as a result of faulty technique. These can be treated by internal urethrotomy or excision and reanastomosis. 相似文献
995.
996.
997.
998.
There is evidence suggesting that the diabetic state adversely affects replication of certain cell populations. We document that exposure to high ambient glucose (20 mM) induces delay in various phases of the cell cycle of human endothelial cells in primary culture. Cells in S phase were labeled with bromodeoxyuridine (an analogue of thymidine), and the cell-cycle position of the labeled cohort was analyzed by flow cytometry at successive time points. The movement of cells exposed to high glucose for 7-8 days was retarded both in S and G2 phases so that the increase in bromodeoxyuridine-positive cells over 24 h was 1.6-fold, versus 2.0-fold in control cultures. In experiments in which mitotic arrest with vinblastine was used to investigate the movement of cells out of G1 phase without interference from reentering cells, depletion of the G1 compartment was significantly inhibited in cultures grown in high glucose. The effects of chronic high glucose on cell cycle occurred while total protein synthesis was not diminished. Acute exposure to high glucose had no effect on cell-cycle traversal or cell generation time. Cell-cycle abnormalities observed in this study may relate to the DNA damage we have previously observed in endothelial cells exposed to high glucose and, if occurring in vivo, could be of pathogenetic importance for the vascular lesions and teratogenicity of diabetes. 相似文献
999.
Failure of genetically selected miniature swine to model NIDDM 总被引:2,自引:0,他引:2
Ten young adult miniature swine from a line reported to be genetically selected for glucose intolerance and eight normal controls were obtained from Colorado State University. They were consecutively exposed to 4 mo of a high-fiber, low-fat standard swine diet; 4 mo of a high-sucrose, high-fat, low-fiber diabetogenic diet; and 4 mo of excess diabetogenic diet for obesification. Results of oral glucose tolerance and intravenous insulin tolerance tests conducted at the end of each regimen were compared. Hyperglycemia was not observed in any animals after any manipulation. Insulin sensitivity was also not influenced by diet. We conclude that F7 low-K miniature swine from this colony fail to model human non-insulin-dependent diabetes. 相似文献
1000.