全文获取类型
收费全文 | 5750篇 |
免费 | 411篇 |
国内免费 | 210篇 |
专业分类
耳鼻咽喉 | 224篇 |
儿科学 | 14篇 |
妇产科学 | 3篇 |
基础医学 | 1088篇 |
口腔科学 | 72篇 |
临床医学 | 356篇 |
内科学 | 159篇 |
皮肤病学 | 26篇 |
神经病学 | 1962篇 |
特种医学 | 71篇 |
外科学 | 317篇 |
综合类 | 616篇 |
现状与发展 | 1篇 |
预防医学 | 34篇 |
眼科学 | 972篇 |
药学 | 322篇 |
1篇 | |
中国医学 | 99篇 |
肿瘤学 | 34篇 |
出版年
2024年 | 18篇 |
2023年 | 68篇 |
2022年 | 122篇 |
2021年 | 163篇 |
2020年 | 155篇 |
2019年 | 146篇 |
2018年 | 139篇 |
2017年 | 159篇 |
2016年 | 167篇 |
2015年 | 123篇 |
2014年 | 227篇 |
2013年 | 232篇 |
2012年 | 250篇 |
2011年 | 267篇 |
2010年 | 300篇 |
2009年 | 243篇 |
2008年 | 261篇 |
2007年 | 261篇 |
2006年 | 309篇 |
2005年 | 212篇 |
2004年 | 198篇 |
2003年 | 201篇 |
2002年 | 162篇 |
2001年 | 130篇 |
2000年 | 108篇 |
1999年 | 100篇 |
1998年 | 113篇 |
1997年 | 111篇 |
1996年 | 87篇 |
1995年 | 103篇 |
1994年 | 97篇 |
1993年 | 75篇 |
1992年 | 82篇 |
1991年 | 83篇 |
1990年 | 63篇 |
1989年 | 68篇 |
1988年 | 75篇 |
1987年 | 67篇 |
1986年 | 82篇 |
1985年 | 125篇 |
1984年 | 82篇 |
1983年 | 70篇 |
1982年 | 67篇 |
1981年 | 72篇 |
1980年 | 54篇 |
1979年 | 19篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1974年 | 6篇 |
排序方式: 共有6371条查询结果,搜索用时 15 毫秒
1.
《Neuromodulation》2021,24(8):1422-1428
ObjectivesA recent approach to treatment of cluster headaches (CH) employs a microstimulator device for on-demand neuromodulation of the sphenopalatine ganglion (SPG) during an acute CH attack. A precise anatomical localization of the SPG within the pterygopalatine fossa (PPF) is optimal in order to position the SPG electrode array. This study aims to investigate a novel approach for SPG localization using computed tomography angiographic studies (CTA).Materials and MethodsTwo independent observers identified the location of the SPG on 54 computed tomography angiographic studies (CTA) and measured its position relative to the vidian canal (VC). The qualitative confidence of identification, morphology, position within the PPF and its relation to vascular structures were also recorded.ResultsThe SPG was detectable in 88% of cases with a variable position. The most frequent positions were superior (56%) and lateral (99%) relative to the VC with a mean (±SD) craniocaudal distance of 0.34 mm (±1.38) and a mean mediolateral distance of 3.04 mm (±1.2). However, in a considerable proportion of cases, the SPG was identified inferiorly to the VC (33%). Interobserver and intraobserver agreement for SPG location were moderate and strong respectively.ConclusionsSince localization of SPG on CTAs is feasible and reproducible, it has future clinical potential to aid placement, optimal positioning and individualized programming of the electrode array. 相似文献
2.
3.
Yuanqing Yao Jun Qian Shunkang Rong Yuwen Huang Bo Xiong Gang Yang Dengqing Zhang Shimin Deng Jie Tan Que Zhu Changming Deng Dichuan Liu Haitao Ran Zhigang Wang Jing Huang 《Ultrasound in medicine & biology》2019,45(2):490-499
Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases. 相似文献
4.
5.
6.
Bi-Hua BIE Yong CHEN Zhi-Qi ZHAO Institute of Neurobiology Fu-Dan University Shanghai China Institute of Shanghai Physiology Chinese Academy of Sciences Shanghai China 《中国神经科学杂志》2006,(2)
Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinoci-ceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency ( PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron in the rat. 相似文献
7.
目的:通过逆行神经追踪法研究大鼠骶髂关节的传入神经通路。方法:30只雄性Sprague-Dawley大鼠随机分成非交感神经切除组(A组)和交感神经切除组(B组),每组15只,交感神经切除组切除左侧L1以下椎旁交感干。两组左侧骶髂关节注入30%的辣根过氧化物酶(HRP)20μl,72h后取出双侧的L1-S1背根神经节(DRG),TMB法染色后在光学显微镜下观察HRP阳性神经元细胞并计数。结果:两组左侧L1、L2背根神经节内HRP阳性神经元差异有显著性意义(P<0·05),B组HRP阳性神经元明显减少;左侧L3-S1背根神经节内HRP阳性神经元差异无显著性意义(P>0·05)。结论:L1-S1神经节含有支配同侧骶髂关节的传入神经元,同侧椎旁交感干可能是骶髂关节到L1-L2神经节重要的传入神经旁路,而不是到L3-L5神经节的传入旁路或重要的传入旁路。 相似文献
8.
Oren N Gottfried Steven Chin H Christian Davidson William T Couldwell 《Skull base》2007,17(5):317-324
The authors present a case of amyloid infiltration involving the trigeminal nerve that mimicked a malignant cavernous sinus tumor with perineural tumor infiltration. A 64-year-old man presented with trigeminal nerve numbness. Imaging revealed a plaque-like enhancing lesion along the right lateral cavernous sinus extending anteriorly into Meckel's cave and involving the proximal V2 and V3 branches of the trigeminal nerve. The patient underwent an extradural frontotemporal craniotomy with middle fossa exposure of the cavernous sinus to diagnose and treat the presumed malignant cavernous sinus tumor. A reddish mass involving the lateral dural wall of the cavernous sinus was resected. The gasserian ganglion, V2, and V3, the latter of which was biopsied, were enlarged. Permanent histopathological studies showed microscopic eosinophilic, amorphous material, which stained positive for Congo red, and an absence of neoplastic cells. The final diagnosis was amyloidoma. Thus, amyloidomas can involve the trigeminal nerve or ganglia and should be considered in the differential diagnosis of a cavernous sinus lesion mimicking a tumor. Patients may have symptomatic improvement of trigeminal neuropathy with resection of the amyloidoma outside the nerve capsule that is compressing the nerve, while resection of the lesion from within the capsule may result in permanent trigeminal nerve dysfunction. 相似文献
9.
人胎视网膜发生的光镜和电镜观察 总被引:3,自引:0,他引:3
本文在光镜下观察40例人胎视网膜的发生,在电镜下观察15例人胎视网膜视细胞、双极细胞、节细胞的发育。结果表明:胚胎第9周时神经上皮可分内、外成神经细胞层。第10周时内、外成神经细胞层之间的Chievitz带消失;第11周时节细胞从内成神经细胞层内迁;第13周节细胞与内成神经细胞之间出现内网层;第16周始双极细胞从外成神经细胞层中内迁形成外网层和内核层。第20周后视网膜各层形成。而视细胞、双极细胞、节细胞的超微结构于胎儿8个月后才发育完善。其结构与成人基本相同。 相似文献
10.
目的:探讨背根神经节(DRG)内P物质(SP)、降钙素基因相关肽(CGRP)免疫阳性神经元与阴茎包皮系带感觉信息传递之间的关系。方法:通过荧光金(FG)逆行标记对大鼠阴茎包皮系带内神经末梢的来源作追踪定位,并结合SP、CGRP免疫荧光标记法,研究大鼠DRG内FG标记阳性神经元中SP、CGRP免疫阳性神经元的形态和分布。结果:FG逆行标记结果发现,大鼠阴茎包皮系带内的神经末梢起源于第6腰髓对应的背根神经节(L6-DRG)和第1骶髓对应的背根神经节(S1-DRG)的神经元。对这些神经元分别作SP、CGRP免疫荧光标记后发现,标记细胞大小不等,分别呈深红色和深绿色,沿神经束成行排列或散在分布。FG/SP、FG/CGRP双标记阳性细胞均为中小型,其数量分别占FG逆行标记阳性细胞总数的1/3和1/2,FG/SP/CGRP三标记阳性细胞占FG逆行标记阳性细胞总数的1/5。结论:大鼠L6-DRG和S1-DRG内的SP、CGRP免疫阳性神经元可能参与阴茎包皮系带感觉信息的传递。 相似文献