全文获取类型
收费全文 | 26224篇 |
免费 | 1011篇 |
国内免费 | 234篇 |
专业分类
耳鼻咽喉 | 130篇 |
儿科学 | 697篇 |
妇产科学 | 145篇 |
基础医学 | 2507篇 |
口腔科学 | 42篇 |
临床医学 | 2827篇 |
内科学 | 2327篇 |
皮肤病学 | 22篇 |
神经病学 | 6625篇 |
特种医学 | 2642篇 |
外科学 | 1785篇 |
综合类 | 2798篇 |
预防医学 | 799篇 |
眼科学 | 41篇 |
药学 | 2244篇 |
3篇 | |
中国医学 | 513篇 |
肿瘤学 | 1322篇 |
出版年
2023年 | 163篇 |
2022年 | 378篇 |
2021年 | 601篇 |
2020年 | 480篇 |
2019年 | 415篇 |
2018年 | 481篇 |
2017年 | 643篇 |
2016年 | 730篇 |
2015年 | 617篇 |
2014年 | 1275篇 |
2013年 | 1419篇 |
2012年 | 1366篇 |
2011年 | 1535篇 |
2010年 | 1400篇 |
2009年 | 1411篇 |
2008年 | 1425篇 |
2007年 | 1361篇 |
2006年 | 1333篇 |
2005年 | 1190篇 |
2004年 | 915篇 |
2003年 | 818篇 |
2002年 | 605篇 |
2001年 | 644篇 |
2000年 | 567篇 |
1999年 | 499篇 |
1998年 | 451篇 |
1997年 | 449篇 |
1996年 | 380篇 |
1995年 | 382篇 |
1994年 | 336篇 |
1993年 | 254篇 |
1992年 | 272篇 |
1991年 | 227篇 |
1990年 | 218篇 |
1989年 | 155篇 |
1988年 | 158篇 |
1987年 | 180篇 |
1986年 | 143篇 |
1985年 | 172篇 |
1984年 | 165篇 |
1983年 | 105篇 |
1982年 | 131篇 |
1981年 | 114篇 |
1980年 | 114篇 |
1979年 | 116篇 |
1978年 | 93篇 |
1977年 | 104篇 |
1976年 | 94篇 |
1975年 | 79篇 |
1973年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Ian F. Dunn Pankaj K. Agarwalla Alexander M. Papanastassiou William E. Butler Edward R. Smith 《Child's nervous system》2007,23(10):1191-1194
Objective Approximately 10% of patients with neurofibromatosis I (NFI) patients will have central nervous system (CNS) tumors. The most
common of these are hypothalamic–optic gliomas, followed by brainstem and cerebellar pilocytic astrocytomas. While isolated
pilocytic astrocytomas in NFI are well described, the appearance of multiple pilocytic astrocytomas in an individual patient
is less common. The most frequent combination in NFI patients with more than one pilocytic astrocytoma is optic tract/hypothalamic
and brainstem. Other combinations are exceedingly rare; multiple pilocytic astrocytomas have only been reported once in the
cerebral hemispheres in a patient with NFI. This report presents the first documented case, to our knowledge, of multiple
pilocytic astrocytomas in the cerebellum of a patient with NF1.
Methods Case report.
Conclusion The finding of multiple cerebellar pilocytic astrocytomas in a patient with NF1 is important because it expands the spectrum
of presentations for patients with NF1 and also highlights specific diagnostic and therapeutic challenges faced by the treating
physicians. The genetic and molecular basis of NF1 is reviewed. Strategies of diagnosis and treatment outlined here are relevant
to both patients with NF1 and all patients with multiple posterior fossa tumors. 相似文献
54.
Understanding the mechanisms of food intake and obesity 总被引:2,自引:1,他引:1
E. T. Rolls 《Obesity reviews》2007,8(S1):67-72
55.
56.
目的研究骨髓基质细胞(BMSCs)移植对大鼠局灶性脑损伤血管生成的影响,探讨BMSCs移植修复大鼠脑损伤的机制。方法制备大鼠局灶性脑损伤动物模型,进行BMSCs移植,通过免疫组织化学、电镜等观察移植局部内皮细胞及微循环的变化。结果BMSCs移植后,局部凝血因子FⅧ染色阳性细胞数增加,染色加深,出现血管样结构;局部微血管内膜较光滑,内皮细胞间可见紧密连接,细胞核形态较规则,基底膜较完整,微血管管腔受压缓解。结论BMSCs移植促进损伤区周围内皮细胞增殖和新生血管形成。损伤区局部微循环得以改善进而修复脑损伤。 相似文献
57.
F. Giangaspero C. Doglioni M. T. Rivano S. Pileri J. Gerdes H. Stein 《Acta neuropathologica》1987,74(2):179-182
Summary The monoclonal antibody Ki-67, which reacts with cells in the active part of the cell cycle, was used to evaluate immunocytochemically the growth fraction in 22 primary brain neoplasms. The percentage of labelled cells reflected the histological grade of malignancy of each neoplasms. High percentage of Ki-67-positive cells were observed in one choroid plexus carcinoma (60%), one primary melanoma of meninges (40%), three medulloblastomas (40%–50%), one anaplastic astrocytoma and six glioblastomas (10%–40%). One ependymoma had 7% positive cells. Rare positive cells (1%) were present in one pilocytic astrocytoma and one ganglioglioma. Except one negative case, the meningiomas (five cases) had values of positivity ranging from 1% to 6%. Two acoustic schwannomas were negative. These results suggest that immunocytochemical staining with the Ki-67 may be a useful method for measuring the growth fraction in brain neoplasms.Supported in part by Associazione Italiana Ricerca sul Cancro and Ministero Italiano della Pubblica Istruzione 相似文献
58.
人脑外伤后皮层核因子-κB的表达 总被引:5,自引:0,他引:5
目的 探讨核因子-κB(nuclear factor—κB,NF—κB)在人创伤性脑损伤(traumatic brain injury,TBI)后挫伤皮层中的表达情况,包括表达位置、表达强度和表达时相。方法 挫伤区皮层的标本来自24例TBI患者,取样时间为伤后5h-5d,利用凝胶电泳迁移分析法(electrophoretic mobility shift assay,EMSA)和免疫组化技术测定NF—κB的活性和表达强度。结果 在人TBI后的挫伤区皮层中,NF—κB表达明显上调,表达高峰为伤后48—72h,NF—κBP65主要在血管内皮细胞和神经胶质细胞中表达,NF—κBP50主要在神经胶质细胞和少量神经元中表达,NF—κBP65的表达强度高于NF—κBP50。结论 NF—κB在人TBI后的挫伤区皮层中表达上调,提示其可能在TBI后的病理生理过程中起着重要作用。 相似文献
59.
Using the whole-cell configuration of the patch clamp technique, calcium-activated potassium currents (IK,Ca) were investigated in ramified murine brain macrophages. In order to induce IK,Ca the intracellular concentration of nominal free Ca2+ was adjusted to 1μM. The Ca2+-activated K+ current of brain macrophages did not show any voltage dependence at test potentials between –120 and +30mV. A tenfold change
in extracellular K+ concentration shifted the reversal potential of IK,Ca by 51mV. The bee venom toxin apamin applied at concentrations of up to 1μM did not affect IK,Ca. Ca2+-activated K+ currents of ramified brain macrophages were highly sensitive to extracellularly applied charybdotoxin (CTX). The half-maximal
effective concentration of CTX was calculated to be 4.3nM. In contrast to CTX, the scorpion toxin kaliotoxin did not inhibit
IK,Ca at concentrations between 1 and 50nM. Tetraethylammonium (TEA) blocked 8.0% of IK,Ca at a concentration of 1mM, whereas 31.4% of current was blocked by 10mM TEA. Several inorganic polyvalent cations were tested
at a concentration of 2mM for their ability to block IK,Ca. La3+ reduced IK,Ca by 72.8%, whereas Cd2+ decreased IK,Ca by 17.4%; in contrast, Ni2+ did not have any effect on IK,Ca. Ba2+ applied at a concentration of 1mM reduced IK,Ca voltage-dependently at hyperpolarizing potentials.
Received: 17 January / Accepted: 5 May 1997 相似文献
60.