全文获取类型
收费全文 | 18256篇 |
免费 | 832篇 |
国内免费 | 781篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 210篇 |
妇产科学 | 60篇 |
基础医学 | 1825篇 |
口腔科学 | 62篇 |
临床医学 | 2241篇 |
内科学 | 292篇 |
皮肤病学 | 38篇 |
神经病学 | 2854篇 |
特种医学 | 1234篇 |
外科学 | 7301篇 |
综合类 | 1788篇 |
预防医学 | 403篇 |
眼科学 | 15篇 |
药学 | 778篇 |
8篇 | |
中国医学 | 363篇 |
肿瘤学 | 363篇 |
出版年
2024年 | 56篇 |
2023年 | 206篇 |
2022年 | 464篇 |
2021年 | 690篇 |
2020年 | 581篇 |
2019年 | 485篇 |
2018年 | 527篇 |
2017年 | 509篇 |
2016年 | 501篇 |
2015年 | 582篇 |
2014年 | 1119篇 |
2013年 | 1434篇 |
2012年 | 929篇 |
2011年 | 1262篇 |
2010年 | 1005篇 |
2009年 | 944篇 |
2008年 | 966篇 |
2007年 | 844篇 |
2006年 | 796篇 |
2005年 | 715篇 |
2004年 | 609篇 |
2003年 | 536篇 |
2002年 | 450篇 |
2001年 | 402篇 |
2000年 | 390篇 |
1999年 | 291篇 |
1998年 | 243篇 |
1997年 | 253篇 |
1996年 | 201篇 |
1995年 | 166篇 |
1994年 | 149篇 |
1993年 | 161篇 |
1992年 | 169篇 |
1991年 | 109篇 |
1990年 | 119篇 |
1989年 | 103篇 |
1988年 | 108篇 |
1987年 | 112篇 |
1986年 | 73篇 |
1985年 | 78篇 |
1984年 | 77篇 |
1983年 | 55篇 |
1982年 | 61篇 |
1981年 | 39篇 |
1980年 | 47篇 |
1979年 | 30篇 |
1978年 | 31篇 |
1977年 | 46篇 |
1973年 | 23篇 |
1971年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
71.
72.
Minerva Giménez y Ribotta Christelle Roudet Françoise Sandillon Alain Privat 《Brain research》1996,707(2):245
The synaptic connections established by grafted noradrenergic (NA) neurons into the lesioned adult rat spinal cord were analysed using immunocytochemistry at the electron microscopic level. An embryonic cell suspension of the locus coeruleus region from E-13 rat embryos was transplanted into the spinal cord following either: (1) spinal cord transection or (2), partial selective denervation by 6-hydroxy dopamine (6-OH DA). One month after grafting, the NA-neurons established, in the two models, an innervation pattern similar to that found in the intact spinal cord. In both models, the transplanted NA-immunoreactive neurons formed extensive synaptic contacts with dendrites, spines and perikarya. The proportion of axodendritic and axospinous contacts was inverse in the two models. The first model thus reproduced more closely the normal synaptic pattern prefering dendritic targets, which could correspond to a better integration of the graft. In the second model, a partially NA-denervated spinal cord, there existed a competition between residual intrinsic and grafted neuron-derived fibres, which presumably affects synaptogenesis. In conclusion, the present study illustrate the complexity of cell interations conducting to the formation of a specific circuitry. Recognition phenomenon are likely modulated by space constraints, which ultimately shape-up the geometry of synaptic contacts. 相似文献
73.
胚胎脊髓细胞悬液植入急性成年大鼠损伤脊髓 总被引:6,自引:2,他引:4
目的:建立胚胎脊髓细胞悬液移植于脊髓损伤模型,以评价其治疗脊髓损伤的可能性。方法:42只Wistar大鼠以改良Alen法(50gcm)打击脊髓,3天后将孕14天(E14)FSCS20μl植入损伤空腔,移植后2、4、6、8、10、12周,以光、电镜、免疫组织化学观察移植物存活、分化及其与宿主之间关系。结果:移植细胞逐渐长大。充满不规则空腔,宿主NF、5-HT、CGRP纤维分别出现于移植物,GFAP纤维于宿主移植物交界处适量存在。移植成神经细胞、成少突胶质细胞、成星形细胞的细胞器日渐完善,细胞功能活跃。复杂及多样突触与细胞连接,将上述细胞与神经纤维、胶质纤维、毛细血管网在三维空间内连接成一体,并与宿主紧密嵌合。结论:(1)成年大鼠脊髓损伤3天后植入FSCS可以存活。(2)移植物进入宿主后,出现再分布,继而器官样分化。(3)长、短传导束进入移植物,显示了移植物的桥作用。(4)成少突胶质细胞的神经营救作用。(5)移植区内出现多种突触,提示移植物中继作用的可能性。 相似文献
74.
We present a case of spinal cord sarcoidosis which resembled a disseminated intramedullary tumour. The case is unusual because the spinal cord is only rarely affected by sarcoidosis and the patient developed a neurological deficit as the first manifestation of the disease. This condition thus has to be considered in the differential diagnosis of primary intramedullary tumours, or metastatic disease with involvement of the spinal cord. 相似文献
75.
氟骨症性椎管狭窄症的手术治疗 总被引:2,自引:1,他引:1
1987~1990年手术治疗氟骨症性椎管狭窄症100例。包括颈椎9例,胸椎8例,腰、骶椎83例。术后随访1~4年,复查结果:临床治愈93例(93%):显效3例(3%)、有效3例(3%)、无效1例(1%)。手术原则是彻底减压,因氟骨症具有椎骨及其骨周组织严重退变、异化和骨化的临床病理特点,故在胸、腰椎减压术后,一般不影响其稳定性,在颈椎施行双开式或单开式椎管扩大加植骨融合术,则可收减压、稳定及防止或减少椎板间隙瘢痕狭窄的效果。 相似文献
76.
椎板后移回植的椎管扩大术治疗椎管狭窄症 总被引:43,自引:0,他引:43
作者报告棘突劈开、椎板后移回植的椎管扩大术治疗椎管狭窄症182例,使椎管容积扩大34.8%,横径扩大3.8mm,矢径扩大6.1mm。随访2年9个月,优良率86.6%,椎板愈合率96.9%。本文探讨少数椎板迟延愈合的原因和预防措施,如斜切椎板、缝合固定和腰背筋膜与棘上韧带悬吊缝合等。术后卧床10~12周,用石膏型保护。作者认为本法能有效的预防术后脊柱不稳,顽固性腰痛等并发症。 相似文献
77.
Mitsuhiko Yanagisawa Rumiko Hosoki Masanori Otsuka 《European journal of pharmacology》1992,220(2-3):111-117
We have developed an isolated spinal cord-skin preparation of the newborn rat. The spinal cord together with a piece of skin connected to the cord by the saphenous nerve was isolated from 1- to 4-day-old rats and separately superfused with artificial cerebrospinal fluid in two neighbouring chambers. Potentials were recorded extracellularly from the third lumbar ventral root. Application of capsaicin (0.5-2 μM) or KCl (60–350 mM) with brief pressure pulses to the perfusion bath of the skin evoked a depolarizing response of 20- to 40-s duration in the ventral root. The response was depressed by [Met5]enkcphalin (0.03–3 μM). morphine (0.1–2 μM) and a tachykinin antagonist, [D-Arg1,D-Trp7,9,Leu11] substance P (spantide), 1–10 μM), applied to the spinal cord by superfusion, whereas the response was augmented by centrally administered calcitonin gene-related peptide (0.1–0.2 μM) or bicuculline (0.5–1 μM). 相似文献
78.
经椎弓根减压固定和植重组异体骨治疗脊柱脊髓损伤 总被引:6,自引:1,他引:5
目的 :探讨严重脊柱脊髓损伤经一侧椎弓根和椎体后缘复位减压 ,经椎弓根植重组异体骨和椎弓根钉固定的可行性及效果。方法 :经一侧椎弓根和椎体后缘复位或截骨减压 ,用特制环锯套管经椎弓根植重组异体骨 ,以X线片和CT片分类分型 ,评估手术前后骨折复位减压和植重组异体骨融合效果 ;按Frank分类标准评估脊髓损伤和恢复程度。结果 :除A级病人外 ,其他病人脊髓神经功能均进步 1~ 2级 ,无感染和断钉病人 ,脊柱后凸角度矫正后再丢失平均 3° ;部分病人术后早期对重组异体骨有反应 ,但几周后可消失。结论 :经一侧椎弓根椎体后缘复位或截骨减压 ,同样可达到较理想脊髓减压效果 ,经椎弓根植重组异体骨和椎弓根钉固定简单、安全、有效。 相似文献
79.
Objective To explore the clinical outcome of atlantoaxial pedicle screw instrument in treatment of extension-type odontoid fracture combined with aflantoaxial subluxation. Methods From December 2002 to December 2006, seven patients with extension-type odontoid fracture combined with at-lantoaxial subluxation were reduced and fixed with atlantoaxial pedicle screw instrument of Vertex system under general anesthesia. There were five males and two females, at mean age of 39.2 years (range 21-59 years). All odontoid fractures were fresh type Aderson Ⅱ. JOA scores of spinal core function was 8.6-14.9 (average 10.7) preoperatively. The X-ray examination, CT scanning and skull traction were performed in all patients preoperatively. Results There found no severe complications such as injuries of vertebral artery, nerve root and spinal cord postoperatively. All patients obtained complete reduction and healing of the fracture and dislocation. The mean off-bed time was four days (3-6 days) after opera-tion. A follow-up for 12-36 months (average 22 months) in all patients showed that the clinical symptom was improved significantly six months postoperatively and that all screws were in proper position verified by X-ray and CT scanning. All patients obtained solid bony union on radiographs, with no loosing or breakage of instrument. The postoperative JOA scores was 13.5-16.9 (average 15.8). Conclusions Allantoaxial pedicle screw fixation has advantages of intraoperative reduction, reliable fixation and high fusion rate and can be used as an effective method for extension-type odontoid fracture combined with at-lantoaxial subluxation. 相似文献
80.
腰椎管狭窄症的手术减压与内固定选择(259例临床分析) 总被引:20,自引:2,他引:18
目的:探讨腰椎管狭窄症的手术减压指征、减压范围及内固定选择。方法:回顾性分析腰椎管狭窄症患者259例,平均年龄52.2岁,平均病程4年1个月。根据病情分别采用椎板间节段开窗潜行减压术139例,腰椎管内径扩大成形术63例,全椎板切除减压、椎间植骨融合内固定术57例。结果:221例获得平均4年2个月随访。三种手术方法优良率分别为91.53%、87.50%和85.45%;手术并发症发生率为13.69%、15.87%和20.11%。结论:对严重的腰椎管狭窄症若手术适应证和减压范围掌握恰当,不论采取何种手术方式的神经减压术,均可取得满意疗效。正确选择病例和熟练的外科技术是应用内固定器械的重要条件。 相似文献