全文获取类型
收费全文 | 44293篇 |
免费 | 3877篇 |
国内免费 | 2070篇 |
专业分类
耳鼻咽喉 | 801篇 |
儿科学 | 1150篇 |
妇产科学 | 198篇 |
基础医学 | 5878篇 |
口腔科学 | 7664篇 |
临床医学 | 3898篇 |
内科学 | 4166篇 |
皮肤病学 | 163篇 |
神经病学 | 937篇 |
特种医学 | 2157篇 |
外国民族医学 | 20篇 |
外科学 | 9151篇 |
综合类 | 6575篇 |
现状与发展 | 6篇 |
预防医学 | 1449篇 |
眼科学 | 157篇 |
药学 | 2151篇 |
26篇 | |
中国医学 | 1334篇 |
肿瘤学 | 2359篇 |
出版年
2024年 | 104篇 |
2023年 | 694篇 |
2022年 | 1242篇 |
2021年 | 1738篇 |
2020年 | 1765篇 |
2019年 | 1570篇 |
2018年 | 1430篇 |
2017年 | 1539篇 |
2016年 | 1519篇 |
2015年 | 1701篇 |
2014年 | 2740篇 |
2013年 | 3833篇 |
2012年 | 2285篇 |
2011年 | 2633篇 |
2010年 | 2323篇 |
2009年 | 2164篇 |
2008年 | 2076篇 |
2007年 | 2102篇 |
2006年 | 1915篇 |
2005年 | 1828篇 |
2004年 | 1642篇 |
2003年 | 1460篇 |
2002年 | 1244篇 |
2001年 | 1093篇 |
2000年 | 910篇 |
1999年 | 805篇 |
1998年 | 667篇 |
1997年 | 676篇 |
1996年 | 622篇 |
1995年 | 436篇 |
1994年 | 456篇 |
1993年 | 336篇 |
1992年 | 333篇 |
1991年 | 287篇 |
1990年 | 235篇 |
1989年 | 226篇 |
1988年 | 188篇 |
1987年 | 149篇 |
1986年 | 142篇 |
1985年 | 170篇 |
1984年 | 128篇 |
1983年 | 110篇 |
1982年 | 129篇 |
1981年 | 95篇 |
1980年 | 91篇 |
1979年 | 91篇 |
1978年 | 95篇 |
1977年 | 69篇 |
1976年 | 61篇 |
1975年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
带血管蒂跗骨瓣移位术修复踝及足部骨病损 总被引:6,自引:2,他引:4
目的 为治疗踝及足部骨质病损提供系列手术方式。方法 在解剖学研究基础上,设计了带血管蒂的骰骨瓣、内侧楔骨瓣、舟骨瓣和跟骨前外侧骨瓣移位术,以修复踝及足骨质病损。临床应用55例。结果 术后经l—10年随访48例,平均为4年6个月,疗效满意。结论 上述4种跗骨瓣均具有血管蒂位置表浅、解剖容易和手术安全可靠等优点。 相似文献
72.
J Goldhahn M Reinhold M Stauber C Knop R Frei E Schneider B Linke 《Journal of orthopaedic research》2006,24(5):917-925
The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant. 相似文献
73.
生物衍生骨复合骨髓基质干细胞修复山羊胫骨缺损的血管化研究 总被引:10,自引:5,他引:5
目的研究生物衍生骨与骨髓基质干细胞(marrow stromal stem cells, MSCs)复合修复山羊胫骨缺损的血管化过程,了解其修复长段管状负重骨缺损的血管化情况. 方法制备生物衍生骨作为支架材料,培养、诱导MSCs作为种子细胞,二者在体外复合构建组织工程骨.20只山羊双侧胫骨中段制备成20 mm长的骨-骨膜缺损模型,采取自身左右侧对照,实验侧(右侧)缺损处植入组织工程骨,对照侧(左侧)植入单纯支架材料,采用钢板内固定.术后2、4、6及8周用墨汁灌注透明标本及血管面积图像分析方法观察血管化过程,组织学观察血管形成及成骨情况. 结果术后2、4周,实验侧血管形成较对照侧少(P<0.05);术后8周,两侧均完全血管化,差异无统计学意义(P>0.05).实验侧于术后6、8周新骨形成逐渐增加,材料降解吸收较对照组快;对照侧术后8周材料孔隙内仍无明显新骨形成. 结论生物衍生骨作为骨组织工程的支架材料,能够较快发生血管化;组织工程骨成骨能力较单纯支架材料强. 相似文献
74.
可吸收螺钉治疗股骨头骨折12例报告 总被引:1,自引:0,他引:1
肖东民 《中国现代手术学杂志》2003,7(5):386-387
目的 探讨应用可吸收螺钉治疗股骨头骨折的效果。方法 对12例股骨头骨折患使用可吸收螺钉行内固定治疗。结果 术后平均随访1.5年,患髋关节功能恢复良好,无骨折部位感染和股骨头坏死等并发症。结论 可吸收螺钉不需再次手术取出内固定,是股骨头骨折理想的内固定材料。 相似文献
75.
Osteoclastogenesis in the nonadherent cell population of human bone marrow is inhibited by rhBMP-2 alone or together with rhVEGF. 总被引:1,自引:0,他引:1
During bone development and repair, angiogenesis, osteogenesis, and bone remodeling are closely associated processes that share some common mediators. In the present study nonadherent human bone marrow mononuclear cells under the induction of sRANKL and M-CSF, differentiated into osteoclasts with TRAP-positive staining, VNR expression, and Ca-P resorptive activity. The effects of various combinations of rhBMP-2 (0, 3, 30, and 300 ng/mL) and rhVEGF (0 and 25 ng/mL) on osteoclastogenesis potentials were examined in this experimental system. The percentages of TRAP-positive multiple nucleated cells represent osteoclast differentiation potential, and the percentages of resorptive areas in the Ca-P coated plates resemble osteoclast resorption capability. The presence of rhBMP-2 at 30 and 300 ng/mL showed inhibitory effects on osteoclast differentiation and their resorptive capability in the human osteoclast culture system. rhVEGF (25 ng/mL) enhanced the resorptive function of osteoclast whenever it was used alone or combined with 3 ng/mL rhBMP-2. However, rhVEGF-induced resorptive function was inhibited by 30 ng/mL and 300 ng/mL rhBMP-2 in a dose-dependent manner. Statistical analysis demonstrated that an interactive effect exists between rhBMP-2 and rhVEGF on human osteoclastogenesis. These findings suggested that an interactive regulation may exist between BMPs and VEGF signaling pathways during osteoclastogenesis; exact mechanisms are yet to be elucidated. 相似文献
76.
本文观察了52侧(男46,女6)成人尸体臀上动、静脉深上支进入髂嵴情况.臀上动、静脉深上支分为前、中、后支;本文测量了臀上动、静脉深上支的外径及各分支进入髂嵴的距离.臀上动、静脉深上支的分支在髂嵴前部及中部分布较多,前支的分支为3~8支,其中以4~6支者为多见,占78.8±5.5%;中支的分支1~4支,其中以2~3者为多见,占73.1±6.1%.因此,臀上动脉深上支作为游离髂骨移植术取髂嵴的前部和中部较宜. 相似文献
77.
78.
流式细胞术检测非小细胞肺癌患者骨髓微转移 总被引:5,自引:1,他引:4
目的 应用流式细胞术检测非小细胞肺癌患者骨髓中的微转移。方法 骨髓经Ficoll梯度离心分离单核细胞后,用细胞角蛋白 19(Cytokeratin, CK19)单克隆抗体染色,应用流式细胞仪检测。结果 检测了 96例肺癌患者骨髓,发现 25例患者骨髓中有微转移。20例肺良性病变患者、10例正常人骨髓均无微转移。肺癌患者阳性率与患者病理分期、分化程度和细胞组织学类型密切相关 (P<0. 05)。结论 应用流式细胞术检测非小细胞肺癌患者骨髓中的微转移,有助于肺癌的综合治疗。 相似文献
79.
High energy laser has emerged to be an important surgical tool in medical technology. However, the application of laser energy
to drill or cut a bone is still in an experimental state. In order to estimate the adequacy of laser heating of bone surface
and at the same time minimize the damage to the bone tissue, we developed a mathematical model of the temperature distribution
in bone due to laser irradiation. The thermal analysis shows that the temperature distribution depends on several parameters,
including the density, the specific heat, and the thermal conductivity of the osseous tissue. 相似文献
80.
YY Ho 《Journal of Medical Imaging and Radiation Oncology》2005,49(6):445-459
Bone and soft tissue tumours are rare neoplasms. There are five major roles of imaging in the management of primary musculoskeletal tumours, that is, to differentiate between benignity and malignancy, to evaluate for local tumour extension, to screen for metastases, to judge the effect of chemotherapy, and to monitor for recurrence. To accomplish this, multiple modalities are required because no single examination is able to complete all these tasks. These modalities include plain radiography, CT, MRI, conventional nuclear medicine as well as positron emission tomography (PET) imaging. Elsewhere, PET imaging has been discussed at length, because it is likely to be superior in the assessment of bone and soft tissue tumours over conventional nuclear medicine procedures. However, conventional nuclear medicine may be of value when PET is unavailable. In this review, an overview of anatomical imaging will be given and the role of non‐PET functional imaging will be discussed in detail. A variety of illustrative cases will be presented. 相似文献