全文获取类型
收费全文 | 9810篇 |
免费 | 693篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 58篇 |
儿科学 | 201篇 |
妇产科学 | 183篇 |
基础医学 | 1465篇 |
口腔科学 | 379篇 |
临床医学 | 945篇 |
内科学 | 2220篇 |
皮肤病学 | 405篇 |
神经病学 | 1074篇 |
特种医学 | 511篇 |
外科学 | 1293篇 |
综合类 | 47篇 |
预防医学 | 468篇 |
眼科学 | 138篇 |
药学 | 567篇 |
中国医学 | 3篇 |
肿瘤学 | 594篇 |
出版年
2023年 | 41篇 |
2022年 | 85篇 |
2021年 | 204篇 |
2020年 | 169篇 |
2019年 | 179篇 |
2018年 | 181篇 |
2017年 | 162篇 |
2016年 | 229篇 |
2015年 | 258篇 |
2014年 | 326篇 |
2013年 | 426篇 |
2012年 | 710篇 |
2011年 | 696篇 |
2010年 | 435篇 |
2009年 | 398篇 |
2008年 | 706篇 |
2007年 | 710篇 |
2006年 | 647篇 |
2005年 | 638篇 |
2004年 | 548篇 |
2003年 | 497篇 |
2002年 | 521篇 |
2001年 | 166篇 |
2000年 | 130篇 |
1999年 | 144篇 |
1998年 | 120篇 |
1997年 | 94篇 |
1996年 | 58篇 |
1995年 | 58篇 |
1994年 | 40篇 |
1993年 | 40篇 |
1992年 | 63篇 |
1991年 | 58篇 |
1990年 | 61篇 |
1989年 | 44篇 |
1988年 | 55篇 |
1987年 | 50篇 |
1986年 | 37篇 |
1985年 | 48篇 |
1984年 | 33篇 |
1979年 | 33篇 |
1978年 | 24篇 |
1975年 | 31篇 |
1974年 | 31篇 |
1973年 | 38篇 |
1972年 | 30篇 |
1971年 | 25篇 |
1970年 | 24篇 |
1969年 | 23篇 |
1967年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
I. Kaare Tesdal Werner Jaschke Mathias Bühler Ralf Adamus Thomas Filser Eggert Holm Max Georgi 《Cardiovascular and interventional radiology》1997,20(1):29-37
Purpose To evaluate prospectively our experience with transjugular intrahepatic portosystemic shunt (TIPS) using four different metallic
stents.
Methods Between November 1991 and April 1995, 57 patients (41 men and 16 women; age 35–72 years, mean 54 years) underwent the TIPS
procedure. Techniques for portal vein localization before and during TIPS were fluoroscopy, computed tomography (CT) studies,
wedged hepatic venography, arterial portography, and ultrasound. After predilation we deployed balloon-expandable (n=48) and self-expanding (n=45) metallic stents. Fifteen patients underwent variceal embolization. Initial follow-up angiograms (mean 6.9 months, range
3–24 months) were obtained in 39 of these patients.
Results Fifty-three patients (93%) had successful TIPS placement. The mean decrease in portal pressure was 42.7%. Besides fluoroscopy,
the most helpful techniques for portal vein localization were venography and CT. Residual stenosis (n=1) and late shortening (n=4) of Wallstents resulted in shunt dysfunction. The technical problems encountered with the Palmaz stent resulted from its
lack of flexibility. We combined balloon-expandable and self-expanding stents in 12 patients. The 30-day and late follow-up
(mean 11.9 months) percutaneous reintervention rates were 11.3% and 64.2%, respectively. There were no clinically significant
complications related to the TIPS insertions.
Conclusion An ideal stent does not exist for TIPS, and the authors recommend combining a Palmaz stent with a flexible self-expanding
stent. 相似文献
13.
14.
15.
D Machover E Goldschmidt P Chollet G Metzger J Zittoun M Benavides J Marquet J M Vandenbulcke J L Misset L Schwarzenberg 《NCI monographs : a publication of the National Cancer Institute》1987,(5):193-198
We report the results of an expanded trial of 5-fluorouracil (FUra) combined with high-dose folinic acid for treatment of patients with advanced colorectal or gastric adenocarcinoma. In each treatment course, the patients received both FUra (340-400 mg/m2/day by iv infusion over 15 minutes) and folinic acid (200 mg/m2/day by iv bolus) for 5 consecutive days, with a 21-day interval between courses. Eighty-six patients with colorectal carcinoma were evaluated. The combined complete response (CR) and partial response (PR) rates were 39% for 54 patients who did not receive prior chemotherapy and 22% for 32 patients who had previously received chemotherapy. Four patients who were previously resistant to FUra attained objective responses. The median time to disease progression for the 28 responders was 10 months. The median survival time of responders was 19.5 months, and the probability of their being alive at 2 years was 40%. Of 27 patients with gastric adenocarcinoma, 13 (48%) responded to therapy. Their median time to disease progression was 5.5 months. The median survival time of responders was 11 months, and their probability of being alive at 15 months was 30%. Toxicity was within acceptable limits. Toxic effects included stomatitis, diarrhea, conjunctivitis, skin rash, and mild myeloid hypoplasia. In a separate study, plasma concentrations of L-folates above 10(-5) M were achieved after a rapid single iv injection of 200 mg/m2 of folinic acid.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
16.
We have investigated the activation of mouse peritoneal macrophages by injection of aclacinomycin (ACM). Macrophages from ACM-treated mice have an increased phagocytic activity as measured by Candida ingestion. The microbicidal activity indirectly evaluated by chemiluminescence and superoxide determination in response to stimulation with zymosan and 4 beta-phorbol-12-myristate-13 alpha-acetate is also greater in the cells from treated mice. Direct measurement of the cytostatic function, and of in vitro and in vivo cytotoxicity shows comparable significant increases against L1210 or P815 target cells. The enhanced antitumoral activity could not be attributed to the residual presence of ACM in the peritoneal cells since no drug was detected by high-performance liquid chromatography and since their freeze-thaw lysates incubated with P815 cells did not modify the growth of tumor cells as measured by [3H]-thymidine incorporation. We also checked that the presence of ACM did not influence the intensity of the chemiluminescence. In all tests performed, only i.p. ACM administration could stimulate the peritoneal cells. Since the doses of ACM inducing an increase in macrophage activity are effective on the survival of tumor-bearing mice, the participation of this mechanism in tumor control might be suggested. 相似文献
17.
18.
Stefan Beckers Michael Fries Johannes Bickenbach Matthias Derwall Ralf Kuhlen Rolf Rossaint 《Critical care (London, England)》2004,9(2):R110
Introduction
There is evidence that use of automated external defibrillators (AEDs) by laypersons improves rates of survival from cardiac arrest, but there is no consensus on the optimal content and duration of training for this purpose. In this study we examined the use of semiautomatic or automatic AEDs by laypersons who had received no training (intuitive use) and the effects of minimal general theoretical instructions on their performance. 相似文献19.
Ralf F Schuler Frank A Roberts 《Practical procedures & aesthetic dentistry》2005,17(10):697-704; quiz 706
While less emphasis has traditionally been placed on aesthetics in order to focus on successful osseointegration, increased success rates provided by contemporary endosseous root-form dental implants have improved postoperative peri-implant hard and soft tissue structures. The criteria for the evaluation of implant success should, therefore, include lack of pain, mobility, radiolucency, bone loss, infection, or paresthesia, as well as acceptability and stable aesthetics. This article discusses surgical means to preserve or restore hard and soft tissues around dental implants to achieve ideal and predictable outcomes. 相似文献
20.
Bernhard Croissant Fred Rist Ralf Demmel Robert Olbrich 《International journal of psychophysiology》2006,61(2):253-261
Individuals with a family history of alcoholism (FH+) are at risk to develop alcohol problems. In several studies, psychophysiological stress responses were more attenuated by alcohol in FH+ than in FH- subjects. However, it is not clear from these studies, if this stronger stress-response dampening effect of alcohol (SRD) in FH+ subjects is confined to aversive stimuli, or would hold for nonaversive stress conditions as well. Also, male and female FH+ subjects seem to respond differently to the alcohol challenge, but have rarely been directly compared in a SRD paradigm. Participants were 54 female and 63 male healthy adults; 31 women were daughters (DOAs) and 40 men were sons (SOAs) of alcohol-dependent fathers. The remaining 23 women (DONAs) and 23 men (SONAs) had no FH of any alcohol use disorder. The participants took part in two laboratory sessions, one with and one without alcohol. In each session, three stressor procedures were presented. Heart rate is the main dependent variable in this report. SOAs, but not SONAs showed a tendency towards SRD. Among female participants, a strong SRD occurred, but contrary to our expectation only in controls. Stress responses and SRD effects were somewhat stronger in the aversive than in the rewarding task. The extent of alcohol induced SRD was strongly influenced by BAL and the amplitude of the stress response in the no-alcohol condition (multiple regression analysis). Thus, aversive tasks might have the advantage of eliciting stronger stress responses than rewarding tasks, thereby providing better conditions for observing differences in alcohol induced SRD between FH+ and FH- subjects. 相似文献