全文获取类型
收费全文 | 1311篇 |
免费 | 89篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 21篇 |
妇产科学 | 11篇 |
基础医学 | 86篇 |
口腔科学 | 7篇 |
临床医学 | 156篇 |
内科学 | 355篇 |
皮肤病学 | 9篇 |
神经病学 | 28篇 |
特种医学 | 76篇 |
外科学 | 112篇 |
综合类 | 199篇 |
预防医学 | 94篇 |
眼科学 | 6篇 |
药学 | 142篇 |
中国医学 | 95篇 |
肿瘤学 | 47篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 24篇 |
2021年 | 33篇 |
2020年 | 29篇 |
2019年 | 8篇 |
2018年 | 17篇 |
2017年 | 21篇 |
2016年 | 34篇 |
2015年 | 36篇 |
2014年 | 53篇 |
2013年 | 53篇 |
2012年 | 99篇 |
2011年 | 129篇 |
2010年 | 107篇 |
2009年 | 119篇 |
2008年 | 88篇 |
2007年 | 83篇 |
2006年 | 56篇 |
2005年 | 96篇 |
2004年 | 60篇 |
2003年 | 56篇 |
2002年 | 33篇 |
2001年 | 49篇 |
2000年 | 34篇 |
1999年 | 15篇 |
1998年 | 10篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 11篇 |
1991年 | 5篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1958年 | 1篇 |
1949年 | 1篇 |
1944年 | 1篇 |
1942年 | 2篇 |
排序方式: 共有1446条查询结果,搜索用时 15 毫秒
1.
油茶皂甙对实验动物造血机能的影响 总被引:4,自引:0,他引:4
目的:研究油茶皂甙对豚鼠和罗非鱼造血功能的影响。方法:比较油茶皂甙(1mg/kg)处理前和处理后豚鼠红细胞和血红蛋白量计数变化。罗非鱼分对照组和油茶皂甙处理组,分别在清水和含1ppm油茶皂甙水饲养6天后,再同时置入清水中净养,观察其存活20%的最高温度。结果:豚鼠用药前后红细胞计数和血红蛋白含量改变轻微,无明显统计学差异(P>0.05),对照组和油茶皂甙处理组罗非鱼在清水中饲养的耐受最高温度为41.5℃,但在含油茶皂甙水中能耐受的最主温度为36℃。结论:油茶皂甙可短暂,轻微地降低红细胞和血红蛋白,但并不影响造血功能。 相似文献
2.
Coupling intervals of premature ventricular beats and complex arrhythmias were studied by 24-h ambulatory electrocardiographic recordings in 76 patients (35 sudden death patients and 41 survivors) with coronary artery disease. A first Holter (HM 1) was recorded at the time of left ventricular angiography and a second Holter (HM 2) after a mean interval of 34.4 +/- 11.2 months (range 2-61 months). All patients were only treated medically. The mean heart rate was significantly faster in patients who died suddenly than in survivors in both HM 1 and HM 2 (p less than 0.01). In HM 1, there were no significant differences in mean coupling intervals between patients who died suddenly and survivors, whereas in HM 2, coupling intervals of premature ventricular beats and couplets were significantly shorter in patients who died suddenly than in survivors (p less than 0.05). Patients with coupling intervals for couplets less than 500 ms died significantly earlier than those patients with coupling intervals greater than 500 ms (p less than 0.05). Our data show that there is a relationship between heart rate, coupling intervals and sudden death. Patients with fast heart rates and coupling intervals for couplets less than 500 ms represent a group at high risk of sudden death. 相似文献
3.
[目的]本研究旨在探讨乳腺浸润性小叶癌(Invasive lobular carcinoma,ILC)患者腋窝淋巴结转移(axillary lymph node metastasis, ALNM)的超声特征及其他参数影响因素。[方法]收集病理已证实为ILC且术前行超声检查的病例91例,根据有无腋窝淋巴结转移分为ALNM组和无ALNM组,采用回顾性研究,收集患者的超声图像特征、术前CA153以及免疫指标等。[结果] 91例ILC患者中,45例发生ALNM,46例未发生ALNM。单因素x2分析显示,病灶>23.5mm、纵横比≧1、周边高回声晕等超声特征,以及术前CA153>6.5U/ml与ALNM有关(P<0.05)。多因素logistic回归分析显示,周边高回声晕和术前CA153>6.5U/ml是影响ILC患者ALNM的独立危险因素(P<0.05)。[结论]周边高回声晕和术前CA153>6.5U/ml是影响ILC患者发生ALNM的独立危险因素,可作为临床实践参考指标。 相似文献
4.
细胞因子诱导的杀伤细胞(cytokin induced killer cells,CIK细胞)因具有体外增殖倍数高、抗瘤谱广、杀瘤活性强、副作用极小等特点而受到关注。研究表明,CIK细胞对肿瘤细胞的杀伤作用是LAK细胞的100倍[1]。CIK细胞过继性免疫治疗是肿瘤治疗中的一项新技术,目前已逐步在临床上应用,因此,制订科学、严格的技术规范对该技术的正确使用及推广意义重大。但迄今国内还没有关于CIK细胞培养和临床应用的统一技术规范。无锡旺庄医院生物治疗中心参考国家食品药品监督管理局1999年制订的《新生物制品审批办法》和美国FDA 1998年制订的《人体细胞治疗和基因治疗指导原则》,结合数年的CIK细胞临床应用经验,制订出我们的CIK细胞临床应用技术规范,现介绍如下,供同行切磋和讨论,以期促成全国性统一技术规范的早日制定。 相似文献
5.
研制出一台采用永磁轴承的左心室辅助装置(LVAD)。该装置包括一个定子和一个转子,采用径向驱动方式;转子包括驱动磁钢和叶轮,电机定子线圈和泵壳组成定子。装置设计采用了一种特殊结构的永磁轴承。转子的位置测量表明,转子稳定悬浮的前提条件是必须有较高的转速(大于3250r/min)且流量大于1L/min。用猪血为介质所做的液动力测试表明,当转速达到3500r/min~4000r/min时,血泵输出流量达到4L/min~6L/min,输出压力达到100mmHg。该装置重200g,最大处直径为40mm。 相似文献
6.
7.
Trappe HJ Fieguth HG Pfitzner P Heintze J Wenzlaff P Kielblock B Lichtlen PR 《Journal of interventional cardiology》1995,8(3):219-228
OBJECTIVE: The intraoperative and follow-up results were compared in 67 patients with ventricular tachyarrhythmias who underwent implantation of the Ventritex Cadence defibrillator with either epicardial patch (EPI, 25 patients) or nonthoracotomy CPI Endotak (ENDO, 42 patients) defibrillation lead systems. RESULTS: There was no significant difference between groups in age, sex, structural heart disease, ejection fraction, arrhythmia history, or drug therapy. Successful implantation was accomplished in all patients using either lead system. In the ENDO group, 35 patients (83%) had a defibrillation threshold < or = 550 V and did not require a subcutaneous patch. Intraoperatively, the defibrillation threshold was 453 +/- 139 V (13 +/- 9 J) for EPI and 490 +/- 113 V (15 +/- 8 J) for ENDO (P = NS). There were no perioperative deaths in either group. At predischarge testing, the defibrillation threshold was 445 +/- 183 V (14 +/- 12 J) for EPI and 439 +/- 133 V (13 +/- 7 J) for ENDO (P = NS). During a mean follow-up of 16 +/- 8 months, there were no sudden deaths, and four patients died from congestive heart failure (3 EPI, 1 ENDO). During follow-up, 916 spontaneous arrhythmia episodes occurred in 16 of 25 EPI patients (64%) and 967 episodes occurred in 31 of 42 ENDO patients (74%) (P = NS). The number of episodes detected as ventricular fibrillation were 192 for EPI (21%) and 232 for ENDO (24%), with first shock success in 76% and 75%, respectively; all episodes were successfully terminated by the device. In the remaining episodes detected as ventricular tachycardia, antitachycardia pacing was attempted and was successful in 672 of 724 episodes (93%) with EPI and 666 of 735 episodes (91%) with ENDO lead systems (P = NS). Acceleration of ventricular tachycardia with antitachycardia pacing occurred in 21 episodes (3%) with EPI and in 37 episodes (5%) with ENDO leads (P = NS). CONCLUSIONS: A nonthoracotomy approach using the third generation cardioverter defibrillator Cadence V-100 is safe and effective and has clinical results that are not significantly different from epicardial defibrillation lead systems. 相似文献
8.
Bolster DR Trappe SW Short KR Scheffield-Moore M Parcell AC Schulze KM Costill DL 《Medicine and science in sports and exercise》1999,31(2):251-257
PURPOSE: The purpose of this study was to examine the effect of a decreased body core temperature before a simulated portion of a triathlon (swim,15 min; bike, 45 min) and examine whether precooling could attenuate thermal strain and increase subjective exercise tolerance in a warm environment (26.6 degrees C/60% relative humidity (rh)). METHODS: Six endurance trained triathletes (28+/-2 yr, 8.2+/-1.7% body fat) completed two randomly assigned trials 1 wk apart. The precooling trial (PC) involved lowering body core temperature (-0.5 degrees C rectal temperature, Tre) in water before swimming. The control trial (CON) was identical except no precooling was performed. Water temperature and environmental conditions were maintained at 25.6 degrees C and 26.6 degrees C/60% rh, respectively, throughout all testing. RESULTS: Mean time to precool was 31+/-8 min and average time to reach baseline Tre during cycling was 9+/-7 min. Oxygen uptake (VO2), HR, skin temperature (Tsk), Tre, RPE, and thermal sensation (TS) were recorded following the swim segment and throughout cycling. No significant differences in mean body (Tb) or Tsk were noted between PC and CON, but a significant difference (P < 0.05) in Tre between treatments was noted through the early phases of cycling. No significant differences were reported in HR, VO2, RPE, TS, or sweat rate (SR) between treatments. Body heat storage (S) was negative following swimming in both PC (-92+/-6 W x m2) and CON (-66+/-9 W x m2). A greater S occurred in PC (109+/-6 W x m2) vs CON (79+/-4 W x m2) during cycling (P < 0.05). CONCLUSIONS: Precooling attenuated the rise in Tre, but this effect was transient. Therefore, precooling is not recommended before a triathlon under similar environmental conditions. 相似文献
9.
Kestlmeier R Becker I Trappe AE 《Zeitschrift für Orthop?die und ihre Grenzgebiete》1999,137(4):345-347
Most frequently the ependymomas of the central nervous system affect the Conus medullaris and Filum terminale. Ependymomas of the thoracic spine with association of a tumor-caused syringomyelia are extremely rare. The reported 50 years old patient with a thoracic ependymoma realized first symptoms as a shoulder-arm pain caused by the tumor-syrinx. The case report indicates that MRI is the superior imaging modality for primary tumors of the central nervous system. All relevant diagnostic and therapeutic informations derived from the MRI. The article describes the clinical manifestations, the diagnostic way and therapeutic procedure in the problem region thoracic spine. 相似文献
10.
目的 评价应用血浆置换治疗重型肝炎的临床疗效。方法 对48例重型肝炎患在综合保肝治疗基础上给予血浆置换治疗。结果 早期好转率85.71%,中期好转率33.33%,差异具有显性。结论 血浆置换是重肝较为安全有效的治疗手段,早期应用效果尤佳。 相似文献