全文获取类型
收费全文 | 30276篇 |
免费 | 2333篇 |
国内免费 | 730篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 664篇 |
妇产科学 | 782篇 |
基础医学 | 1918篇 |
口腔科学 | 34篇 |
临床医学 | 5317篇 |
内科学 | 9851篇 |
皮肤病学 | 59篇 |
神经病学 | 486篇 |
特种医学 | 1615篇 |
外国民族医学 | 4篇 |
外科学 | 4349篇 |
综合类 | 3973篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 787篇 |
眼科学 | 181篇 |
药学 | 2152篇 |
24篇 | |
中国医学 | 665篇 |
肿瘤学 | 444篇 |
出版年
2024年 | 44篇 |
2023年 | 583篇 |
2022年 | 838篇 |
2021年 | 1355篇 |
2020年 | 1440篇 |
2019年 | 1354篇 |
2018年 | 1298篇 |
2017年 | 1035篇 |
2016年 | 958篇 |
2015年 | 1098篇 |
2014年 | 1969篇 |
2013年 | 2283篇 |
2012年 | 1481篇 |
2011年 | 1622篇 |
2010年 | 1283篇 |
2009年 | 1340篇 |
2008年 | 1293篇 |
2007年 | 1281篇 |
2006年 | 1191篇 |
2005年 | 1108篇 |
2004年 | 891篇 |
2003年 | 776篇 |
2002年 | 640篇 |
2001年 | 641篇 |
2000年 | 444篇 |
1999年 | 526篇 |
1998年 | 446篇 |
1997年 | 448篇 |
1996年 | 358篇 |
1995年 | 356篇 |
1994年 | 346篇 |
1993年 | 279篇 |
1992年 | 282篇 |
1991年 | 261篇 |
1990年 | 211篇 |
1989年 | 157篇 |
1988年 | 159篇 |
1987年 | 167篇 |
1986年 | 138篇 |
1985年 | 174篇 |
1984年 | 159篇 |
1983年 | 119篇 |
1982年 | 83篇 |
1981年 | 103篇 |
1980年 | 77篇 |
1979年 | 53篇 |
1978年 | 47篇 |
1977年 | 47篇 |
1976年 | 38篇 |
1975年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
71.
72.
Autotransfusion after open heart surgery: the oxygen delivery capacity of shed mediastinal blood is maintained 总被引:1,自引:0,他引:1
H. Schmidt U. Kongsgaard J. Kofstad O. Geiran H. E. Refsum 《Acta anaesthesiologica Scandinavica》1995,39(6):754-758
Autotransfusion of mediastinal shed blood after open heart surgery has become a common and accepted procedure in reducing the need for homologous transfusion during the last 15 years. The objectives of the present study were to investigate the oxygen delivery capacity of autotransfused shed mediastinal blood, compared to patient-blood, during cardiopulmonary bypass and in the postoperative period.
Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3-diphosphoglycerate (2,3-DPG) concentration.
Autotransfusion volume ranged from 450–1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3-DPG concentration in the patient-blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3-DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient-blood.
The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient-blood is not influenced by autotransfusion. 相似文献
Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3-diphosphoglycerate (2,3-DPG) concentration.
Autotransfusion volume ranged from 450–1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3-DPG concentration in the patient-blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3-DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient-blood.
The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient-blood is not influenced by autotransfusion. 相似文献
73.
Stephan E. Maier Harvey E. Cline Ferenc A. Jolesz 《Magnetic resonance in medicine》1995,34(5):706-712
Three dimensional (3D) phase contrast angiograms contain velocity data, which is discarded after the reconstruction of the projections. In extension to earlier work on velocity quantification with ungated 2D phase data, this paper shows that a useful estimate of the average velocity and flow rate can be extracted from ungated 3D phase contrast angiograms. Simulations and experiments in a phantom and in vivo were performed. For pulsatile flow and strong spin saturation, an over-estimation of the flow rate at the net in-flow end of the imaging volume and underestimation at the net out-flow end was observed. Imaging at lower RF tip angles yielded flow rates close to the correct value within the entire imaging volume. In contrast to ungated 2D experiments, the flow rates determined by repeated 3D experiments showed no variation. 相似文献
74.
N. Ya. Kovalenko D. D. Matsievskii Yu. V. Arkhipenko 《Bulletin of experimental biology and medicine》1998,126(4):983-987
Study of the dynamics of cardiac output in rats with different tolerance to acute massive blood loss showed that the pumping
ability of the heart remains intact during the entire posthemorrhagic period in all high-resistant and in 65% low-resistant
rats. In 35% rats that were low-resistant to blood loss, the cardiac output deficiency syndrome developed after cessation
of bleeding against the background fall in arterial pressure and a decrease in the hepatic blood flow, which are the signs
of rapid variant of the dysfunction produced by acute blood loss.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 384–388, October, 1998 相似文献
75.
76.
A fit 38-year-old female patient developed absent foot pulses following a routine arthroscopic partial medial meniscectomy. Irrigation fluid, which was delivered using an arthroscopic flushing set, had extravasated through a ruptured Baker's cyst into the popliteal fossa causing vascular compression and spasm. The pulses gradually returned to normal following the procedure. Knee arthroscopy is a common procedure and a Baker's cyst is a common sequel to degenerative disease. With the increasing popularity of pressurised fluid irrigation systems, this previously unreported complication is both relevant and important. 相似文献
77.
78.
应用99mTc-甲氧基异丁基异腈(MIBI)对29例受检者进行首次通过法心室显像,测定左室射血分数(LVEF),并与同期平衡法心室显像测得的LVEF进行相关分析。结果:首次通过法和平衡法心室显像测得的LVEF分别为(46.5±16.7)%、(49.1±16.1)%(P>0.05)。相关分析结果显示,二者有明显的相关(r=0.787,P<0.01)。结果表明:99mTc-MIBI为心肌显像剂,采用首次通过法心室显像,在观察心肌血流改变的同时,可准确可靠地评价左室收缩功能状态。 相似文献
79.
80.
A. Zuckermann M.D. M. Grimm Regine Ahner Paul Simon Peter Buxbaum G. Laufer E. Wolner 《European Surgery》1996,28(3):176-177
Summary
Background Pregnancy is prossible in female patients who underwent cardiac transplantation but is associated with unpredictable risks.
Methods A 23-year old female patient underwent cardiac transplantation because of dilatative cardiomyopathy.
Results Against our advice, she became pregnant 4 months after transplantation. Following an uneventful pregnancy, spontaneous vaginal
delivery occurred 13 months after transplantation. The patient gave birth to a healthy new-born in good physical condition.
Thereafter, the patient refused to attend any further routine follow-up control. 9 months after delivery, the patient was
admitted to hospital in severe cardiac shock. Biopsy showed a serious, acute rejection which was treated with a course of
methylprednisolone. Clinically, the patient recovered within 1 week, but died from acute myocardial infarction 1 day after
discharge from hospital.
Conclusions Only women without a history of rejection episodes, with good kidney function, good graft function, and high compliance should
be counselled to become pregnant.
相似文献