全文获取类型
收费全文 | 12436篇 |
免费 | 1180篇 |
国内免费 | 175篇 |
专业分类
耳鼻咽喉 | 144篇 |
儿科学 | 434篇 |
妇产科学 | 331篇 |
基础医学 | 1008篇 |
口腔科学 | 194篇 |
临床医学 | 2032篇 |
内科学 | 2689篇 |
皮肤病学 | 161篇 |
神经病学 | 1042篇 |
特种医学 | 347篇 |
外科学 | 2397篇 |
综合类 | 164篇 |
一般理论 | 11篇 |
预防医学 | 1237篇 |
眼科学 | 457篇 |
药学 | 569篇 |
中国医学 | 3篇 |
肿瘤学 | 571篇 |
出版年
2023年 | 174篇 |
2022年 | 150篇 |
2021年 | 286篇 |
2020年 | 249篇 |
2019年 | 262篇 |
2018年 | 368篇 |
2017年 | 357篇 |
2016年 | 377篇 |
2015年 | 339篇 |
2014年 | 516篇 |
2013年 | 724篇 |
2012年 | 628篇 |
2011年 | 655篇 |
2010年 | 476篇 |
2009年 | 561篇 |
2008年 | 480篇 |
2007年 | 417篇 |
2006年 | 435篇 |
2005年 | 391篇 |
2004年 | 261篇 |
2003年 | 311篇 |
2002年 | 265篇 |
2001年 | 211篇 |
2000年 | 156篇 |
1999年 | 233篇 |
1998年 | 248篇 |
1997年 | 243篇 |
1996年 | 353篇 |
1995年 | 311篇 |
1994年 | 248篇 |
1993年 | 150篇 |
1992年 | 186篇 |
1991年 | 202篇 |
1990年 | 115篇 |
1989年 | 195篇 |
1988年 | 154篇 |
1987年 | 130篇 |
1986年 | 146篇 |
1985年 | 119篇 |
1984年 | 125篇 |
1983年 | 105篇 |
1982年 | 96篇 |
1981年 | 90篇 |
1980年 | 104篇 |
1979年 | 72篇 |
1978年 | 91篇 |
1977年 | 67篇 |
1976年 | 74篇 |
1975年 | 66篇 |
1972年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
J. Byrne MB BCh FRCSI J. W. Hallett Jr. MD C. F. Kollmorgen MD M. M. Gayari BS W. Davies MD FRCSC 《Annals of vascular surgery》1996,10(2):156-165
Our aim was to examine the feasibility of a totally laparoscopic insertion of a bifurcated aortofemoral bypass graft in a canine model and to compare the surgical results with those in control animals undergoing standard grafting and laparoscopic-assisted bypass procedures. Using a six-port approach, we exposed and cross clamped the aorta, tunneled a bifurcated Dacron graft, and performed an end-to-end aortic anastomosis while maintaining pneumoperitoneum by means of CO2. Proximal anastomoses were performed with 4/0 double-ended continuous Prolene sutures and distal anastomoses were performed through standard groin incisions. Total operating and aortic cross-clamp times were measured as was the total blood loss for each procedure. Clinical outcome was also documented. Eight female laboratory-bred hounds underwent successful totally laparoscopic aortobifemoral bypass grafting, eight underwent open grafting, and eight underwent laparoscopic-assisted bypass. Mean operating time was 193 minutes in the animals undergoing totally laparoscopic insertion vs. 156 minutes in the open group and 180 minutes in the laparoscopic-assisted group. Aortic cross-clamping time was also significantly longer at 87 minutes vs. 43 minutes (p < 0.001)=" in=" the=" totally=" laparoscopic=" group,=" but=" blood=" loss=" was=" less.=" all=" eight=" laparotomy=" and=" laparoscopic-assisted=" dogs=" were=" still=" alive=" with=" no=" complications=" at=" 28=" days,=" whereas=" three=" of=" the=" eight=" in=" the=" totally=" laparoscopic=" group=" showed=" evidence=" of=" temporary=" paraplegia.=" this=" experimental=" study=" demonstrates=" that=" a=" totally=" laparoscopic=" approach=" can=" be=" used=" to=" insert=" a=" bifurcated=" aortofemoral=" bypass=" with=" a=" proximal=" end-to-end=" anastomosis=" but=" currently=" does=" not=" save=" time=" and=" may=" increase=" the=" risk=" of=" neurologic=">Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995. 相似文献
94.
Jorge E. Zamora Ola P. Rosaeg M. Patrice Lindsay Mary Lou Crossan 《Journal canadien d'anesthésie》1996,43(4):347-352
Purpose
The efficacy of infusion of 0.5 L and 1.0 L Ringer’s lactate (LR) to prevent hypotension during induction of obstetric analgesia was studied. The effect of the different fluid boluses on fetal heart rate (FHR) and frequency of uterine contractions were also determined.Methods
Ninety-two ASA 1–2 parturients were randomized to receive 0.5 L (Group 1) and 1.0 L (Group 2) LR immediately before incremental epidural injections with lidocaine to achieve T10 sensory block. Systolic blood pressure (SBP) was measured with an automated BP cuff every two minutes for 30 min after infusion of fluid bolus. Fetal heart rate monitoring and tocometry were used continuously. The number of uterine contractions were recorded 30 min before and 60 min after iv bolus.Results
The SBP decreased in both groups, but there was no difference between groups in mean SBP or maternal heart rate. The incidence of hypotension (SBP < 90 mmHg or decrease of 20%) was 4% in both groups. The FHR record of a patient in Group 1 showed a single late deceleration, and a decrease in beat-to-beat variability occured in one patient in Group 2. A decrease in the frequency of uterine contractions of two or more contractions per 30 min was noted more frequently in Group 2 (P < 0.05). The duration of iv bolus was longer in Group 2 than Group 1 (18.8 ± 4.3 min vs 12.3 ± 4.5 min, P < 0.01).Conclusion
Administration of 1.0 L LR iv does not provide added protection against maternal hypotension, and is associated with delay in providing pain relief and a risk of decreasing uterine contraction frequency. 相似文献95.
96.
Two cases with acute myocardial infarction are presented. Both had thrombotic occlusion of the infarct-related artery. Following successful thrombolysis with streptokinase, coronary angiography was normal. These cases prove that "myocardial infarction with normal coronaries" can be associated with coronary thrombosis in the acute stage. 相似文献
97.
Jeri W. Nieves Felicia Cosman Chris Mars Robert Lindsay 《Calcified tissue international》1992,51(5):352-355
Summary Forearm bone mineral density (BMD) was measured at proximal and distal sites by 125I single photon absorptiometry (SPA) and by dual energy X-ray absorptiometry (DXA) in 67 consecutive subjects, aged 18–75 years. Correlations and regression equations between these two techniques were determined. All forearm measurements were significantly correlated with each other (r=0.599–0.926; P0.0001). Although SPA and DXA correct for fat in different ways, we found similar correlation and regression equations in women with body mass index measurements above and below the mean. In addition, forearm measurements by both techniques were moderately correlated with vertebral spine and hip BMD. We conclude that overall, SPA forearm measurements in a population can be calibrated to DXA measurements if necessary, and that DXA forearm measurements are as predictive of the remainder of the skeleton as SPA measurements. 相似文献
98.
The success of vertical gastroplasty may be jeopardized by gastric leakage or ulceration due to failure of the technique.
Reports of band erosion and staple-line leakage have led us to seek technical improvements to reduce technical failures. We
describe a modification to the technique of band placement and a manoeuvre to aid the placement of staples when the TA90 staple
gun is used. 相似文献
99.
Frydenberg HB 《Obesity surgery》1991,1(3):315-317
Many forms of gastric banding have been described and high reoperation rates reported. These can be mainly attributed to excess
vomiting associated both with and without stenosis. Reflux oesophagitis and the ‘sump’ effect may be other causes. This paper
examines the problems associated with banding leading to revisional surgery and introduces a new technique, ‘fundal supporting
suture’, to correct these problems. Preliminary results on 126 bandings without the modification and 22 with the modification
are presented. 相似文献
100.
J S Lindsay 《The New Zealand medical journal》1977,86(591):12-16
Analyses of hospital functioning are frequently reported with patient outcomes as the independent variable. However, the main focus in this paper is the length of stay in hospital not just in terms of "short stay" or "long stay", but ranked in tenths so that ten-point distributions of patient use of hospital resources are available for study. From the analysis of these distributions three patterns emerge: (a) a "standard procedure" model with best fitting "curves" given by a linear function, eg routine surgery; (b) a "finite disease" model (exponential series) eg internal medicine and, (c) a "person in hospital care" model (power series) eg psychiatry. 相似文献