全文获取类型
收费全文 | 1938篇 |
免费 | 227篇 |
国内免费 | 64篇 |
专业分类
儿科学 | 38篇 |
妇产科学 | 28篇 |
基础医学 | 246篇 |
口腔科学 | 2篇 |
临床医学 | 151篇 |
内科学 | 512篇 |
皮肤病学 | 13篇 |
神经病学 | 429篇 |
特种医学 | 48篇 |
外科学 | 129篇 |
综合类 | 235篇 |
预防医学 | 147篇 |
眼科学 | 2篇 |
药学 | 103篇 |
1篇 | |
中国医学 | 104篇 |
肿瘤学 | 41篇 |
出版年
2024年 | 13篇 |
2023年 | 48篇 |
2022年 | 62篇 |
2021年 | 80篇 |
2020年 | 83篇 |
2019年 | 99篇 |
2018年 | 67篇 |
2017年 | 89篇 |
2016年 | 79篇 |
2015年 | 78篇 |
2014年 | 119篇 |
2013年 | 152篇 |
2012年 | 114篇 |
2011年 | 108篇 |
2010年 | 89篇 |
2009年 | 96篇 |
2008年 | 100篇 |
2007年 | 90篇 |
2006年 | 90篇 |
2005年 | 68篇 |
2004年 | 44篇 |
2003年 | 61篇 |
2002年 | 44篇 |
2001年 | 42篇 |
2000年 | 40篇 |
1999年 | 19篇 |
1998年 | 28篇 |
1997年 | 17篇 |
1996年 | 12篇 |
1995年 | 18篇 |
1994年 | 22篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 19篇 |
1984年 | 11篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有2229条查询结果,搜索用时 31 毫秒
1.
Judith Brock Andreas Schmid Thomas Karrasch Petra Pfefferle Jutta Schlegel Inga Busse Annette Hauenschild Barbara Schmidt Maria Koukou Efthymia Arapogianni Andreas Schultz Miriam Thomalla Secil Akinci Johannes Kruse Winfried Padberg Andreas Schffler Jens Albrecht 《Clinical endocrinology》2019,91(3):400-410
2.
同型半胱氨酸(Hcy)是体内一碳单位代谢的一个正常中间产物,Hcy的重要代谢途径就是转甲基反应,体内Hcy浓度的调节受到多种因素的影响,高Hcy浓度会导致多种疾病的发生,近年来Hcy与临床多种疾病相关性的研究更加受到重视,因此,对于Hcy体内代谢及调节因素的研究显得非常关键,本文就此进行综述。 相似文献
3.
目的 探讨5km重复低压缺氧对小鼠肝脏及脾脏中微量元素的影响。方法 将小白鼠分为5km重复低压缺氧实验组及地面对照组。实验组每天进行5km重复低压缺氧30min,连续7d后,处死小鼠,取肝脏、脾脏烘干至恒重,采用火焰原子吸收法测定锌、铜、铁。结果 5km重复低压缺氧小鼠肝脏中Cu、Fe含量与对照组比较有显差异(P<0.05);脾脏中微量元素Fe的含量与对照组比较有显性差异(P<0.05)。结论 5km重复低压缺氧,使肝脏中Fe、Cu含量降低,脾脏中Fe含量升高。 相似文献
4.
大鼠脊髓缺血再灌流时脊髓神经元对躯体和内脏传入刺激的反应 总被引:1,自引:0,他引:1
50只大鼠用乌拉坦麻醉,箭毒制动。通过阻断腹主动脉血流以模拟腰段脊髓的局部缺血和再灌流损伤,玻璃微电极记录L2节段脊髓单位放电(SCUDs),观察缺血再灌流时脊髓神经元对腓神经刺激(PNV),内脏大神经刺激(VLNV)及两者同时刺激(SV)的反应。结果在缺血前所记录的133个自发放电单位中,对3种刺激均产生兴奋(E)、抑制(I)及无反应(NR)3种形式的反应,表明大鼠L2节段脊髓存在躯体、内脏和躯体内脏反应性神经元,并有会聚和阻塞现象。在脊髓缺血再灌流时,神经元对PNV、VLNV、SV也产生E、I、NR3种形式的反应,提示脊髓缺血再灌流时神经元对躯体和内脏传入刺激的反应形式不受影响;但缺血时SCUDs对PNV、VLNV产生反应的单位数减少,这表明脊髓缺血损伤时神经元对躯体和内脏传入刺激的反应性减弱,随着缺血损伤加重,脊髓神经元对躯体内脏信号的整合功能下降 相似文献
5.
6.
l. a. houghton f. cremonini † m. camilleri † i. busciglio † c. fell v. cox d. h. alpers ‡ o. e. dewit § g. e. dukes § e. gray § r. lea a. r. zinsmeister ¶ & p. j. whorwell 《Neurogastroenterology and motility》2007,19(9):732-743
Visceral hypersensitivity is important in the pathophysiology of irritable bowel syndrome and thus a target for modulation in drug development. Neurokinin (NK) receptors, including NK(3) receptors, are expressed in the motor and sensory systems of the digestive tract. The aim of this study was to compare the effects of two different doses (25 and 100 mg) of the NK(3) receptor antagonist, talnetant (SB223412) with placebo on rectal sensory function and compliance in healthy volunteers studied at two centres. Rectal barostat tests were performed on 102 healthy volunteers, randomized to receive either oral talnetant 25 or 100 mg or placebo over 14-17 days. Studies were performed on three occasions: day 1 immediately prior to 1st dose, day 1 4 h postdose, and after 14- to17-day therapy. Compliance, and pressure thresholds for first sensation, urgency, discomfort and pain were measured using ascending method of limits, and sensory intensity ratings for gas, urgency, discomfort and pain determined during four random phasic distensions (12, 24, 36 and 48 mmHg). Talnetant had no effect on rectal compliance, sensory thresholds or intensity ratings compared with placebo. In general, the results obtained at the two centres differed minimally, with intensity scores at one centre consistently somewhat lower. At the doses tested, talnetant has no effect on rectal compliance or distension-induced rectal sensation in healthy participants. 相似文献
7.
用印地安墨汁注入活体鸡胚心脏,在体现显微镜下观察112例第10~20期鸡胚第一对弓动脉的发生。第一对弓动脉于第10期出现,至第20期退化消失。第一对弓动脉出现时尚无相应的第一咽弓,随着第一咽弓的出现,第一对弓动脉的起始端形成一个突入第一咽弓内的动脉瘤样隆起,此隆起随着第一咽弓的增大逐渐发育成一对贯穿第一咽弓的弓状血管。第一对弓动脉可以分为位于第一咽弓内的近侧段和位于此咽弓之外,与背主动脉相连的远侧段。 相似文献
8.
Segmental distribution and peptide content of primary afferent neurons innervating the urogenital organs and colon of male rats. 总被引:8,自引:0,他引:8
Many visceral afferent neurons contain peptides, which have been proposed as histochemical markers for nerve pathways of particular targets or as transmitter candidates. The former possibility was investigated in the present study. Primary afferent neurons which project to the urinary bladder, distal colon or penis of rats, and the colon of cats were labelled with retrogradely transported fluorescent dyes (Fast Blue, True Blue, or Fluoro Gold). One to six weeks after dye injection into the organs, lumbosacral dorsal root ganglia were removed, treated with colchicine, and processed for immunohistochemical identification of five peptides. Dye-labelled neurons were distributed in an organ-specific manner in the lower lumbosacral ganglia, where colon afferent neurons were almost exclusively found in S1 ganglia, penis neurons primarily in L6, and bladder neurons at both levels. Substance P- (SP), calcitonin gene-related peptide-(CGRP), vasoactive intestinal peptide- (VIP), enkephalin- (ENK), and somatostatin- (SOM) immunoreactivity (IR) were detected in neurons in all lumbosacral ganglia but only some of these peptides were present in a large percentage of labelled neurons. The numbers of peptide-containing neurons innervating each organ were CGRP greater than SP greater than VIP greater than ENK greater than SOM; however some differences were observed in the relative proportions of these neuronal populations between upper lumbar and lower lumbosacral ganglia and between different organs. The major difference seen at the upper lumbar level was amongst the SP-IR neurons, which were common (25-30%) amongst bladder and colon afferent neurons but absent in penis neurons.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Rectal sensorimotor characteristics in female patients with idiopathic constipation with or without paradoxical sphincter contraction 总被引:2,自引:0,他引:2
Patients with chronic constipation fulfilling the Thompson criteria can show paradoxical sphincter contraction. Aim of this study was to evaluate rectal sensorimotor characteristics in patients with constipation with or without paradoxical sphincter contraction. Thirty female patients with chronic constipation and 22 female controls were investigated with anal manometry and rectal barostat. Paradoxical sphincter contraction was shown with manometry as a paradoxical increase of anal pressure during straining. Visceral sensitivity and compliance were tested by intermittent and continuous pressure-controlled distension. Patients were classified according to their sensations and compliance into normal, hypersensitive, reduced compliant, insensitive or excessive compliant rectum. Postprandial rectal response (PRR) and phasic volume events (PVEs) were registered for 1 h after a 600-kCal meal. Paradoxical sphincter contraction was found in 13 (43%) patients. In these patients, rectal sensitivity scores were higher (P = 0.045) than in patients without paradoxical contractions, but rectal compliance was not different. In 90% of patients an abnormal rectal sensitivity or compliance was found: excessively compliant in 35%, reduced compliant in 10%, hypersensitive in 27% and hyposensitive in 17%. Both patients with constipation (11%; P = 0.042) and controls (25%; P = 0.002) exhibited the presence of a postprandial rectal response. This response was not significantly different between idiopathic constipation, paradoxical sphincter contraction and controls. Patients with rectal hypersensitivity had lower response than other patients (P = 0.04). Patients with constipation had fewer basal PVEs compared controls (P = 0.03). Postprandial PVEs increased in both patients (P = 0.014) and controls (P < 0.001). Postprandial rectal response and PVE were not different in patients with or without paradoxical sphincter contraction. A total of 90% of female patients with idiopathic constipation show an abnormality in rectal sensation or compliance. The postprandial rectal response was comparable between patients with constipation and controls, however, PVEs were diminished. Patients with paradoxical sphincter contraction had higher rectal sensitivity but an unaltered compliance and postprandial rectal response. Future trials should investigate whether the classification of rectal abnormalities in patients with constipation has clinical importance. 相似文献
10.
腹部多脏器损伤的救治 总被引:1,自引:0,他引:1
报告了腹部多脏器损伤158例的救治情况。致伤因素中交通事故和高空坠落伤占67.0%,抢救存活132例,存活率83.5%;死亡26例,病死率16.5%。作者分析了病死率与致伤暴力强、现场急救延误、就诊时间及受伤的脏器数的密切关系。作者认为院前救护、院内正确诊断、及时治疗、果断手术是抢救成功的重要环节;术中应仔细探查、止血,术后应注意防治多脏器衰竭的发生。 相似文献