全文获取类型
收费全文 | 26408篇 |
免费 | 2601篇 |
国内免费 | 1377篇 |
专业分类
耳鼻咽喉 | 423篇 |
儿科学 | 587篇 |
妇产科学 | 280篇 |
基础医学 | 2017篇 |
口腔科学 | 461篇 |
临床医学 | 3250篇 |
内科学 | 2849篇 |
皮肤病学 | 267篇 |
神经病学 | 1064篇 |
特种医学 | 1172篇 |
外科学 | 2470篇 |
综合类 | 5901篇 |
现状与发展 | 8篇 |
一般理论 | 5篇 |
预防医学 | 3029篇 |
眼科学 | 313篇 |
药学 | 3038篇 |
35篇 | |
中国医学 | 1994篇 |
肿瘤学 | 1223篇 |
出版年
2024年 | 134篇 |
2023年 | 309篇 |
2022年 | 701篇 |
2021年 | 928篇 |
2020年 | 791篇 |
2019年 | 468篇 |
2018年 | 473篇 |
2017年 | 571篇 |
2016年 | 518篇 |
2015年 | 819篇 |
2014年 | 1041篇 |
2013年 | 1439篇 |
2012年 | 2193篇 |
2011年 | 2265篇 |
2010年 | 2040篇 |
2009年 | 1714篇 |
2008年 | 1921篇 |
2007年 | 1834篇 |
2006年 | 1723篇 |
2005年 | 1370篇 |
2004年 | 1029篇 |
2003年 | 896篇 |
2002年 | 701篇 |
2001年 | 745篇 |
2000年 | 635篇 |
1999年 | 322篇 |
1998年 | 129篇 |
1997年 | 114篇 |
1996年 | 97篇 |
1995年 | 78篇 |
1994年 | 73篇 |
1993年 | 80篇 |
1992年 | 186篇 |
1991年 | 159篇 |
1990年 | 166篇 |
1989年 | 153篇 |
1988年 | 134篇 |
1987年 | 129篇 |
1986年 | 114篇 |
1985年 | 128篇 |
1984年 | 83篇 |
1983年 | 78篇 |
1981年 | 54篇 |
1979年 | 72篇 |
1978年 | 66篇 |
1977年 | 50篇 |
1975年 | 44篇 |
1974年 | 52篇 |
1973年 | 81篇 |
1972年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
目的:探讨休克后促炎细胞因子的表达、释放时相及伴随的肠、肝、肺组织病理变化。方法:80只SD大鼠随机均分为失血性休克组和对照组。采用RT-PCR、ELISA方法检测失血性休克后30、60、90min及复苏后30、90min肠、肝、肺组织内TNF-α、IL-6 mRNA表达及血清中TNF-α、IL-6含量;HE和IHC染色检测伴随的组织病理变化。结果:①休克30min时,肠、肝、肺内的促炎细胞因子表达未见升高;60min时肠道先出现TNF-αmRNA表达升高(P〈0.05):而肝脏在90min开始表达升高(P〈0.05),肺脏则在复苏后30min开始表达升高(P〈0.05)。复苏后90min肠、肝、肺的细胞因子表达都继续显著升高(P〈0.01)。②TNF-α 在肠、肝、肺的表达升高最早,其后为IL-6 mRNA。③30min时门静脉和外周血中TNF-α、IM的含量与对照组相比无显著差异,而60min时门静脉血中含量显著升高(P〈0.01)。④休克后肠黏膜坏死脱落;肝组织结构紊乱、肝窦增宽、肝细胞变性坏死;肺脏间质水肿、炎症细胞浸润。结论:失血性休克时细胞因子的释放顺序是肠道、肝脏和肺脏,推测存在“肠-肝-肺”细胞因子释放轴的可能,有待进一步确定。 相似文献
72.
化疗药物性静脉炎及渗漏损伤的动物实验模型是研究体内化疗药物性静脉炎及渗漏损伤的发病机制和评价各种治疗方法的重要条件。化疗药物性静脉炎及渗漏损伤的实验研究进展缓慢,其主要原因是缺乏理想的动物模型。依文献报道,化疗药物性静脉炎模型主要以大白兔耳缘静脉注射长春瑞滨等化疗药物为多见,化疗药物渗漏损伤模型主要以大鼠及大白兔背部皮下注射盐酸阿霉素等化疗药物为多见。文章就近年来常用的一些化疗药物性静脉炎及渗漏损伤的动物模型综述如下。 相似文献
73.
目的:探讨成人先天性肺内支气管囊肿在CT、MRI表现上的特征。方法:37例经手术及病理证实的肺内支气管囊肿;男25例,女12例,年龄18~63岁,平均35岁。均行X胸片,24例行CT平扫及增强扫描,13例行MRI检查。结果:分布在右肺16例,左肺21例。形态以圆形为主,可以呈葫芦状、长条状或不规则形。22例囊肿含有液体,8例含气体,6例含有气液面,4例含有曲菌球,囊壁钙化7例,呈点状和弧线状。囊壁见有轻-中度强化,其中以含液囊肿较明显,囊肿周围气肿15例。结论:大部分成人先天性肺内支气管囊肿的CT、MRI表现有一定的特征,有助于术前诊断。 相似文献
74.
Jugular venous desaturation following cardiac surgery 总被引:2,自引:2,他引:0
Twenty-two patients undergoing coronary artery bypass surgery underwent
postoperative measurement and recording of jugular venous oxyhaemoglobin
saturation (SjO2) with desaturation defined as a value of less than 50% for
5 min or longer. Fifteen of the 22 patients monitored experienced
desaturations. An average of four episodes were experienced by those 15
patients (range 1-14). The mean duration of a single episode was 46 (range
5-212) min whilst mean total duration of desaturation was 175 (range 5-570)
min. The mean duration of desaturation in the 15 patients, expressed as a
percentage of monitored time, was 21.1% (range 0.58%-61.96%). SjO2
desaturation, possibly indicating cerebral hypoperfusion, occurs in the
early post-operative period following cardiac surgery.
相似文献
75.
This article is based on 4 years of data for a cohort of Medicaid enrollees in California and Georgia to determine patterns of enrollment and expenditures. The analyses were developed from the statistical system known as Tape-to-Tape, which is based on Medicaid enrollment and claims files from these and other States. The composition of the cohort changed over times as a result of the differential rates of turnover for subgroups of the Medicaid population. Longitudinal expenditure patterns also varied by health service and eligibility group. These Medicaid expenditure patterns differed from those observed previously in Medicare studies, undoubtedly reflecting differences in service coverage under Medicare and Medicaid. 相似文献
76.
Piper I. R.; Garrioch M. A.; Souter M. J.; Andrews PJD.; Thomson D. 《British journal of anaesthesia》1998,80(5):639-643
Diaspirin cross-linked haemoglobin (DCLHb) is a new oxygen carrying blood
substitute with vasoactive properties. Vasoactive properties may be
mediated via high affinity binding of nitric oxide by the haem moiety.
Using a rodent model of head injury combined with ischaemia, we studied the
effects of DCLHb on cerebral blood flow (CBF) and intracranial pressure
(ICP). Twenty anaesthetized rats were allocated randomly to receive
treatment with DCLHb 400 mg kg-1 i.v. or placebo (oncotically matched
plasma protein substitute 4.5% i.v.). To produce diffusely increased ICP,
after a severe weight drop injury, all animals underwent a 30-min period of
bilateral carotid ligation combined with a period of induced hypotension.
After reperfusion, DCLHb or placebo was infused and the animals
instrumented for measurement of intraventricular ICP and CBF in the region
of the sensorimotor cortex using the hydrogen clearance technique. Mean
arterial pressure (MAP), ICP, cerebral perfusion pressure (CPP) (CPP = MAP
- ICP) and CBF were measured 4 h after injury in all animals. DCLHb
significantly reduced ICP from mean 13 (SEM 2) to 3 (1) mm Hg (P <
0.001), increased CPP from 52 (8) to 95 (6) mm Hg (P < 0.001) and
increased CBF from 21 (2) to 29 (2) ml 100 g-1 min-1 (P = 0.032). We
conclude that DCLHb improved CPP without a reduction in CBF in a rodent
model of post-traumatic brain swelling.
相似文献
77.
JI Elizalde ; J Clemente ; JL Marin ; J Panes ; B Aragon ; A Mas ; JM Pique ; J Teres 《Transfusion》1997,37(6):573-576
BACKGROUND: Equilibration of hemoglobin concentration after transfusion has been estimated to take about 24 hours, but some studies have shown that earlier measurements reflect steady-state values in persons who have not bled recently. This study was aimed at assessing the changes over time in hemoglobin concentration after transfusion in acutely anemic patients because of recent bleeding. STUDY DESIGN AND METHODS: Thirty-two normovolemic patients recovering from an acute bleeding episode who were no longer thought to be bleeding and who received a 2- unit red cell transfusion were studied. At baseline and 15, 30, 60, and 120 minutes and 24 hours after transfusion, hemoglobin concentration and hematocrit values were measured. RESULTS: The administration of 2 units of packed red cells elicited a 24-hour increase of 22.4 +/− 6.8 g per L in hemoglobin concentration. Hemoglobin values were not different at any of the defined posttransfusion times. Hematocrit levels experienced similar changes over time. Agreement between 15-minute and 24-hour values was excellent, as only 6 percent of patients exhibited a clinically significant difference (> 6 g/L) between the hemoglobin measurements. CONCLUSION: Hemoglobin and hematocrit values rapidly equilibrate after transfusion in normovolemic patients who are recovering from an acute bleeding episode. This fact would allow a rapid assessment of the effects of transfusion and of the recurrence of bleeding in patients remaining at risk. 相似文献
78.
去痛片中四组分的HPLC测定 总被引:4,自引:0,他引:4
季申 《中国医药工业杂志》1997,28(10):455-457
以十八烷基硅烷键合硅胶为固定相,采用HPLC法测定去痛片中氨基比林、非那西丁、咖啡因、苯巴比妥的含量。各组分的回收率分别为99.8±0.50%、99.7±0.76%、99.3±0.54%、99.6±0.58%。 相似文献
79.
80.
诺氟沙星合成工艺概述 总被引:3,自引:0,他引:3
纪耿豪 《中国医药工业杂志》1992,23(3):138-140
对诺氟沙星的生产工艺作了简要述评,着重对生产上存在的技术问题及可能解决的途径提出了看法。 相似文献