全文获取类型
收费全文 | 2515篇 |
免费 | 169篇 |
国内免费 | 301篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 74篇 |
妇产科学 | 26篇 |
基础医学 | 268篇 |
口腔科学 | 39篇 |
临床医学 | 303篇 |
内科学 | 468篇 |
皮肤病学 | 49篇 |
神经病学 | 158篇 |
特种医学 | 341篇 |
外国民族医学 | 3篇 |
外科学 | 115篇 |
综合类 | 295篇 |
预防医学 | 160篇 |
眼科学 | 55篇 |
药学 | 307篇 |
2篇 | |
中国医学 | 105篇 |
肿瘤学 | 211篇 |
出版年
2023年 | 15篇 |
2022年 | 26篇 |
2021年 | 56篇 |
2020年 | 49篇 |
2019年 | 61篇 |
2018年 | 52篇 |
2017年 | 38篇 |
2016年 | 40篇 |
2015年 | 67篇 |
2014年 | 106篇 |
2013年 | 101篇 |
2012年 | 122篇 |
2011年 | 143篇 |
2010年 | 107篇 |
2009年 | 115篇 |
2008年 | 114篇 |
2007年 | 205篇 |
2006年 | 105篇 |
2005年 | 121篇 |
2004年 | 83篇 |
2003年 | 66篇 |
2002年 | 61篇 |
2001年 | 50篇 |
2000年 | 56篇 |
1999年 | 54篇 |
1998年 | 105篇 |
1997年 | 103篇 |
1996年 | 90篇 |
1995年 | 79篇 |
1994年 | 74篇 |
1993年 | 66篇 |
1992年 | 30篇 |
1991年 | 29篇 |
1990年 | 33篇 |
1989年 | 61篇 |
1988年 | 46篇 |
1987年 | 36篇 |
1986年 | 38篇 |
1985年 | 29篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 27篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 16篇 |
1976年 | 28篇 |
1975年 | 13篇 |
排序方式: 共有2985条查询结果,搜索用时 15 毫秒
21.
Is technology the best medicine? Three practice theoretical perspectives on medication administration technologies in nursing 下载免费PDF全文
Even though it is often presumed that the use of technology like medication administration technology is both safer and more effective, the importance of nurses' know‐how is not to be underestimated. In this article, we accordingly try to argue that nurses' labor, including their different forms of knowledge, must play a crucial role in the development, implementation and use of medication administration technology. Using three different theoretical perspectives (‘heuristic lenses') and integrating this with our own ethnographic research, we will explore how nursing practices change through the use of medication technology. Ultimately, we will argue that ignoring (institutional) complexity and the various types of important knowledge that nurses have, will seriously complicate the implementation of medication administration technology. 相似文献
22.
目的:比较C17.2神经干细胞和NURR1基因修饰的C17.2神经干细胞移植治疗对脑梗死模型鼠神经功能缺损的改善效果,观察细胞移植后与宿主脑组织的整合、存活、移行及分化情况。方法:实验于2005-06/12在中山大学附属第二医院林百欣实验中心完成。①实验材料:选取清洁级健康SD雄性大鼠78只,随机数字表法分为模型对照组、神经干细胞组、转基因神经干细胞组,26只/组。条件永生化神经干细胞系C17.2由哈佛大学儿童医院Even Synder教授惠赠。pAdeasy-NURR1重组复制缺陷性腺病毒由本实验室成功构建。Dil18荧光染料(Chemicon公司产品)。②实验方法:收集C17.2神经干细胞和pAdeasy-NURR1 C17.2神经干细胞,各分为两管,一管加入Dil18荧光示踪剂。各组大鼠均采用线栓法建立局灶性脑缺血/再灌注损伤模型,3d后进行细胞移植,以江湾Ⅱ型脑立体定向仪进行立体定位,选择缺血半暗区3个位点为移植区:前囟头侧1mm,旁开2mm,深度1.2mm;前囟尾侧3mm,旁开1.5mm,深度1.2mm;前囟尾侧6mm,旁开2mm,深度1.2mm。模型对照组每位点注射单纯培养液2μL;神经干细胞组取6只每位点移植Dil18标记的C17.2神经干细胞悬液2μL,剩余20只每位点移植C17.2神经干细胞悬液2μL;转基因神经干细胞组取6只每位点移植Dil18标记的pAdeasy-NURR1 C17.2神经干细胞悬液2μL,余20只每位点移植pAdeasy-NURR1 C17.2神经干细胞悬液2μL。③实验评估:各组大鼠分别在移植前1d及移植后1周、2周、1个月进行神经功能缺损评分。移植后1周、2周、1个月进行荧光示踪检查及神经元特异烯醇化酶免疫组化检测。移植后6个月行组织学检查。结果:移植后1周,模型对照组死亡1只,神经干细胞组死亡2组,转基因神经干细胞组死亡2只,均淘汰并予以补充。①神经功能缺损评分:移植前1d各组大鼠神经功能缺损评分基本相似(P>0.05)。移植后1周、2周、1个月神经干细胞组、转基因神经干细胞组神经功能缺损评分均明显低于模型对照组(P<0.05);转基因神经干细胞组下降趋势较神经干细胞组更为显著(P<0.05)。②Dil18荧光细胞示踪结果:移植后1周荧光示踪细胞主要在针道内,少数细胞开始移行至周围神经组织。移植后2周,细胞移行至更远距离,并明显向梗死灶方向移行,细胞有突触样结构与周围细胞形成联系。移植后1个月细胞向周围扩散,甚至在远隔部位也可见荧光细胞。③神经元特异烯醇化酶免疫组化检测结果:移植后2周、1个月,转基因神经干细胞组神经元特异烯醇化酶阳性细胞数均明显高于神经干细胞组(P均<0.05)。④细胞组织学检查:移植后6个月,各组大鼠注射针道周围脑组织仍呈正常的层次和结构,未见有明显异型细胞增生。结论:①NURR1基因修饰的C17.2神经干细胞移植治疗局灶性脑梗死能显著改善神经功能缺损,效果优于C17.2神经干细胞。②移植后供体细胞存活并向注射针道周围神经组织移行,促进神经干细胞向神经元方向的分化。 相似文献
23.
人发角蛋白植入大鼠损伤脊髓部位的电镜观察 总被引:4,自引:0,他引:4
目的:脊髓外伤后的继发性病理改变,是影响脊髓神经组织再生修复的重要因素。采用人发角蛋白(humanhairkeratin,HHK)植入脊髓损伤(spinalcordinjury,SCI)部位,以期达到减轻继发性损害,诱导和促进损伤脊髓组织的再生。方法:采用改制Ⅱ型纽约大学(NewYorkUniversity,NYU)装置,在建立大鼠脊髓损伤模型基础上,将经过特殊处理后能在体内降解的HHK植入大鼠损伤脊髓部位,对植入后1,4,12,26周的损伤脊髓组织进行电镜观察。结果:第1周为急性炎症时期,HHK周围结构紊乱,集聚大量的炎症细胞,灰质出现坏死;第4周时,炎症细胞减少,巨噬细胞吞噬髓鞘,胶质细胞增生;第12周时,多核巨噬细胞出现在HHK周围,HHK开始崩解,崩解物被多核巨细胞所吞噬;第26周时,神经轴突沿HHK间隙排列生长,灰质中神经元数量增加,HHK周边细胞有序生长。结论:植入的人发角蛋白具有诱导神经胶质细胞增生,阻止脊髓空洞的形成,从而减轻了脊髓损伤组织的继发性伤害的程度,改善了神经元再生的外环境,并可以桥接诱导神经轴突定向再生的作用。 相似文献
24.
Nozawa Y Sato A Piao H Morioka T Narita I Oite T 《Clinical and experimental nephrology》2012,16(2):221-230
Background and methods
There is increasing evidence that a change in glomerular hemodynamics may promote the development of glomerulosclerosis. In this study, we focused on the pharmacological effects of 2 contrasting agents, etodolac, a preferential cyclooxygenase-2 inhibitor, and beraprost sodium (BPS), a prostaglandin I2 analog, delivered renally, on the disease course of progressive anti-Thy-1 (ATS) glomerulonephritis.Results
Intravital microscopic analysis showed that the diameters of glomerular capillaries and glomerular blood flow in unilaterally nephrectomized (Nx) rats treated locally with BPS were significantly increased, as compared to those of Nx rats treated locally with normal saline (NS) or etodolac. We then examined the effects of BPS and etodolac on the course of progressive glomerulosclerosis. Mesangial cell proliferation, adhesion of glomerular capillary tufts and crescent formation in the BPS-treated group appeared to be more severe compared to the ATS?+?NS and the ATS?+?etodolac groups. Scoring of mesangial proliferation and glomerulosclerosis revealed that local BPS treatment significantly worsened glomerular pathology. At day 28, there were significant differences in blood flow between the ATS?+?etodolac group and both the ATS?+?NS and ATS?+?BPS groups, indicating that local treatment with etodolac enhanced the recovery of glomerular circulation.Conclusion
This study provides hemodynamic-based evidence showing that disturbance of intraglomerular microcirculation is a critical marker for progressive glomerulonephritis. 相似文献25.
Monocyte‐derived dendritic cells can induce autoreactive CD4+ T cells showing myeloid lineage directed reactivity in healthy individuals 下载免费PDF全文
Tin Sing Lam Marian van de Meent JH Frederik Falkenburg Inge Jedema 《European journal of immunology》2015,45(4):1030-1042
T cells against self‐antigens can be detected in peripheral blood of healthy individuals, although intrathymic negative selection removes most high‐avidity T cells specific for self‐antigens from the peripheral repertoire. Moreover, spontaneous T‐cell proliferation following stimulation with autologous monocyte‐derived dendritic cells (autoDCs) has been observed in vitro. In this study, we characterized the nature and immunological basis of the autoDC reactivity in the T‐cell repertoire of healthy donors. We show that a minority of naive and memory CD4+ T cells within the healthy human T‐cell repertoire mediates HLA‐restricted reactivity against autoDCs, which behave like a normal antigen‐specific immune response. This reactivity appeared to be primarily directed against myeloid lineage cells. Although cytokine production by the reactive T cells was observed, this did not coincide with overt cytotoxic activity against autoDCs. AutoDC reactivity was also observed in the CD8+ T‐cell compartment, but this appeared to be mainly cytokine‐induced rather than antigen‐driven. In conclusion, we show that the presence of autoreactive T cells harboring the potential to react against autologous and HLA‐matched allogeneic myeloid cells is a common phenomenon in healthy individuals. These autoDC‐reactive T cells may help the induction of primary T‐cell responses at the DC priming site. 相似文献
26.
Sturge–Weber Syndrome Is Associated with Cortical Dysplasia ILAE Type IIIc and Excessive Hypertrophic Pyramidal Neurons in Brain Resections for Intractable Epilepsy 下载免费PDF全文
Dan‐Dan Wang Ingmar Blümcke Roland Coras Wen‐Jing Zhou De‐Hong Lu Qiu‐Ping Gui Jing‐Xia Hu Huan‐Cong Zuo Shi‐Yun Chen Yue‐Shan Piao 《Brain pathology (Zurich, Switzerland)》2015,25(3):248-255
Sturge–Weber syndrome (SWS) is a rare syndrome characterized by capillary‐venous malformations involving skin and brain. Many patients with SWS also suffer from drug‐resistant epilepsy. We retrospectively studied a series of six SWS patients with epilepsy and extensive neurosurgical resections. At time of surgery, the patients' age ranged from 11 to 35 years (with a mean of 20.2 years). All surgical specimens were well preserved, which allowed a systematic microscopical inspection utilizing the 2011 ILAE classification for focal cortical dysplasia (FCD). Neuropathology revealed dysmorphic‐like neurons with hypertrophic cell bodies reminiscent to those described for FCD type IIa in all cases. However, gross architectural abnormalities of neocortical layering typical for FCD type IIa were missing, and we propose to classify this pattern as FCD ILAE type IIIc. In addition, our patients with earliest seizure onset also showed polymicrogyria (PMG; n = 4). The ictal onset zones were identified in all patients by subdural electrodes, and these areas always showed histopathological evidence for FCD type IIIc. Four out of five patients had favorable seizure control after surgery with a mean follow‐up period of 1.7 years. We concluded from our study that FCD type IIIc and PMG are frequently associated findings in SWS. FCD type IIIc may play a major epileptogenic role in SWS and complete resection of the associated FCD should be considered a prognostic key factor to achieve seizure control. 相似文献
27.
28.
棘阿米巴是致病性的自由生活阿米巴,因其特殊的形态特征在属级分类不难,但仅根据形态学特征鉴定到种较为困难。本文就国内外对棘阿米巴分类与虫种鉴定方法的研究进展进行综述。 相似文献
29.
Z E Piao D K Murdock M H Hwang R M Raymond P J Scanlon 《Catheterization and cardiovascular diagnosis》1989,16(3):149-154
The hemodynamic effects induced by coronary angiography in dogs with low osmolar ionic dimer Hexabrix (HB) and nonionic Omnipaque-350 (OM) were compared to the standard ionic contrast medium, Hypaque-76 (H76), both in the normal heart and in one with simulated severe cardiac disease. Left coronary angiography was performed in 12 "normal" closed-chest dogs with 10-cc injections of H76, HB, and OM in a randomized, blinded fashion. The maximal change in the left ventricular (LV) systolic pressure (SP), mean aortic pressure (MAP), left ventricular end diastolic pressure (LVEDP), and LV dp/dt were recorded. The LVSP and MAP fell 30 +/- 3 mm Hg and 26 +/- 4 mm Hg with H76, 22 +/- 2 mm Hg and 19 +/- 2 mm Hg with HB, and 7 +/- 1.5 mm Hg and 5 +/- 1 mm Hg with OM (P less than .001). The LVEDP increased 4.8 +/- 0.5 mm Hg with H76, 3 +/- 0.5 mm Hg with HB, but only 0.2 mm Hg with OM (P less than .001). The LV dp/dt decreased 392 +/- 63 mm Hg/sec with H76 and 235 +/- 21 mm Hg/sec with HB, but increased 411 +/- 50 mm Hg with OM (P less than .001). In eight additional open-chest dogs, left coronary angiography was performed 1 hr after occlusion of the proximal LAD coronary artery and in the presence of a critical circumflex coronary artery (CX) stenosis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
30.