全文获取类型
收费全文 | 47772篇 |
免费 | 4061篇 |
国内免费 | 2195篇 |
专业分类
耳鼻咽喉 | 805篇 |
儿科学 | 1213篇 |
妇产科学 | 212篇 |
基础医学 | 6397篇 |
口腔科学 | 7299篇 |
临床医学 | 4304篇 |
内科学 | 4656篇 |
皮肤病学 | 187篇 |
神经病学 | 1184篇 |
特种医学 | 2469篇 |
外国民族医学 | 20篇 |
外科学 | 10085篇 |
综合类 | 7085篇 |
现状与发展 | 6篇 |
预防医学 | 1456篇 |
眼科学 | 175篇 |
药学 | 2237篇 |
28篇 | |
中国医学 | 1485篇 |
肿瘤学 | 2725篇 |
出版年
2024年 | 103篇 |
2023年 | 686篇 |
2022年 | 1236篇 |
2021年 | 1738篇 |
2020年 | 1721篇 |
2019年 | 1585篇 |
2018年 | 1478篇 |
2017年 | 1584篇 |
2016年 | 1572篇 |
2015年 | 1762篇 |
2014年 | 2920篇 |
2013年 | 3982篇 |
2012年 | 2430篇 |
2011年 | 2898篇 |
2010年 | 2551篇 |
2009年 | 2402篇 |
2008年 | 2329篇 |
2007年 | 2403篇 |
2006年 | 2234篇 |
2005年 | 2149篇 |
2004年 | 1885篇 |
2003年 | 1647篇 |
2002年 | 1341篇 |
2001年 | 1178篇 |
2000年 | 982篇 |
1999年 | 870篇 |
1998年 | 702篇 |
1997年 | 712篇 |
1996年 | 665篇 |
1995年 | 486篇 |
1994年 | 506篇 |
1993年 | 351篇 |
1992年 | 362篇 |
1991年 | 310篇 |
1990年 | 243篇 |
1989年 | 224篇 |
1988年 | 202篇 |
1987年 | 166篇 |
1986年 | 152篇 |
1985年 | 194篇 |
1984年 | 151篇 |
1983年 | 125篇 |
1982年 | 139篇 |
1981年 | 108篇 |
1980年 | 106篇 |
1979年 | 108篇 |
1978年 | 107篇 |
1977年 | 79篇 |
1976年 | 71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.
瘤体骨切除灭活再植治疗四肢长骨巨细胞瘤 总被引:21,自引:0,他引:21
体内刮除及灭活植骨治疗骨巨细胞瘤(GCT)的复发率高。我科从1986年6月~1996年2月治疗四肢长骨GCT24例。随访11个月~8年4个月。其中7例采用局部切刮体内灭活植骨和(或)骨水泥充填治疗。结果1例感染,6例复发,1例恶变后死于肺转移。作者自1991年1月采用瘤体骨切除,离体灭活再植,与骨残端体内灭活相结合,骨缺损采用自家腓、髂骨移植,L-梯形加压钢板(L-TCP)或梯形加压钢板(TCP)固定治疗17例,其中12例保留关节,5例做膝关节融合。本组无菌创口感染1例,1例复发。在保留关节的12例中9例关节功能恢复优良,1例尚可,2例差。充分说明瘤段骨切除体外灭活再植术疗效确实,复发率低。保留关节术式适于关节破坏较轻(<=1/2)者,结合关节残端体内灭活和有效的骨结构重建,有利于恢复关节功能。如关节面累及>1/2,宜做骨关节端切除,灭活再植,下肢宜做关节融合或人工关节置换术。 相似文献
72.
自体骨髓多次注射治疗家兔骨缺损的实验研究 总被引:1,自引:0,他引:1
目的:观察骨髓多次注射的成骨性能。方法:利用家兔实验性骨缺损模型,通过大体、组织学观察,生物力学测定,评价骨髓不同移植次数促进骨缺损愈合的情况。结果:骨髓单次移植能够促进骨缺损的愈合,然而,骨髓二次移植组骨折愈合程度明显优于骨髓单次移植组,但骨髓三次移植组与骨髓二次移植组骨折愈合无明显差异。结论:在骨折愈合早期增加骨髓移植次数,能明显增强骨髓的成骨能力,加快骨折愈合 相似文献
73.
M. Kneissel P. Roschger W. Steiner D. Schamall G. Kalchhauser A. Boyde M. Teschler-Nicola 《Calcified tissue international》1997,61(2):95-100
There is abundant data on cancellous bone in the aging human spine, but little relating to the growing vertebral cancellous
bone in childhood and adolescence. The purpose of this study was to map vertebral cancellous bone in a growth and age series
of historic skeletal samples and to make comparisons with data published on recent material. Lumbar vertebral bodies were
collected from 65 skeletons (0–60 years) from a medieval Nubian population. Ethnohistoric information was collected to interpret
conditions that might have influenced bone structure and metabolism. The cancellous bone was studied three dimensionally,
using stereophotography and scanning electron microscopy and morphometrically by performing a semiautomatic structural analysis
on digitized backscattered electron images of polymethacrylate-embedded material. The cancellous bone structure in the children
consisted mainly of a densely packed, uniform network of small rodlike trabeculae. The greatest bone volume fraction with
small, more platelike trabeculae was observed during adolescence. In young adults, larger platelike trabeculae were present
in the central zone and smaller trabeculae in the superior and inferior zones, as described for modern skeletal material.
Structural changes associated with aging were observed much sooner than in modern man. By the estimated age of approximately
50–60 years, the predominant architectural elements were slender rarified rods in both sexes. The ethnohistorical data suggest
that this was essentially a black African population of physically active peasants, not likely to suffer Vitamin D insufficiency
or deficient calcium intake. Thus an earlier onset of the biological age changes in cancellous bone found in modern populations
was probably prevalent.
Received: 1 March 1996 / Accepted: 31 December 1996 相似文献
74.
Anterior lumbar fusion using a hybrid interbody graft 总被引:3,自引:0,他引:3
Summary This is a radiographic report of 40 patients (20 men, 20 women) who underwent anterior lumbar interbody fusions (73 levels)
utilizing a “hybrid” interbody graft composed of femoral cortical allograft (FCA) bone and iliac crest cancellous autograft
bone. The average age at surgery was 38 years (range 17–64 years), and follow-up averaged 1.4 years (range 1.0–2.4 years).
Nineteen of the patients had undergone previous lumbar surgery. Thirty-two patients (63 levels) underwent anterior fusion
combined with some type of posterior fixation, and eight patients (10 levels) had no posterior fixation. Types of posterior
fixation included: for 20 patients (36 levels) Steffee variable screw placement fixation, for 10 patients (23 levels) translaminar
facet screws (TFS), for 1 patient (3 levels) Knodt rods and for 1 patient (1 level) facet screws. Based on the persistence
of lucent lines at the graft-host interface, three patients (one level each) were felt to have non-unions at their latest
follow-ups at 1.4, 1.5 and 2.0 years, respectively. Two of these patients had no posterior fixation, and the other had TFS
fixation. The overall fusion rate was 96% (70 of 73 levels). The fusion rate for all levels treated with posterior fixation
was 98% compared with 75% for those without fixation. Intervertebral disc heights (IVDH) were measured on all films and corrected
for magnification with computer assistance. On average, the IVDH was increased postoperatively but returned to preoperative
values at follow-up. IVDH loss was independent of the type of instrumentation used. No complications arose from the use of
the hybrid graft. Incorporation of the allograft portion of the graft is slow and was felt to be complete in only 7 of the
73 levels at follow-up. We conclude that the hybrid interbody graft technique is a safe and reliable method for performing
anterior lumbar interbody fusions and should be combined with some type of posterior fixation. Long-term follow-up will be
required to assess the behaviour of the allograft until incorporation is complete. 相似文献
75.
N. J. Friedman S. E. Shiff F. E. Ward R. I. Schiff R. H. Buckley 《Pediatric allergy and immunology》1991,2(3):111-116
We describe a patient with severe combined immunodeficiency and transplacental transfer of maternal T cells who received an unfractionated HLA-identical sibling bone marrow transplant without prior conditioning. He presented prior to transplantation with a dermatitis later diagnosed as mild graft versus host disease. He had a normal absolute lymphocyte count, but proliferative responses to mitogens were very low. Antigens of the noninherited maternal HLA haplotype were detected on his blood lymphocytes. After transplantation, he developed a severe reaction including fever, cutaneous erythema and hepatosplenomegaly. Lymphocytes carrying the noninherited maternal HLA haplotype disappeared from his circulation, and his unprimed mononuclear cells became spontaneously cytotoxic to maternal lymphoblasts. He subsequently developed a lymphocytosis of 69,000/mm3 , diarrhea, elevated transaminases and a worsening rash, necessitating treatment with immunosuppressive agents. Full T-cell engraftment and evidence of B-cell function later ensued and spontaneously cytotoxic lymphocytes against maternal cells disappeared by 47 days post-transplantation. We postulate that the patient's constellation of signs and symptoms after transplantation represented a combination of severe graft versus graft and mild graft versus host reactions. 相似文献
76.
77.
6例肺癌患者接受了大剂量卡铂并自体骨髓移植治疗 ,卡铂剂量从 5 60~ 1375 mg/ m2 ,5例加用 VP~ 1630 0 mg,1例并用 MMC6mg和 VCR2 mg;主要毒性反应为白细胞、中性粒细胞、血小板减少和脱发 ( WHO毒性反应 ~ 级 )其次是贫血、皮肤粘膜出血、呕吐和可逆性肝功能损害 ,口腔粘膜溃疡及轻度发烧各 2例 ,一过性蛋白尿、室上性心动过速和便秘各 1例 ,尿素氮和肌酐未见升高 ;全部患者骨髓均获解救 ,从自体骨髓回输到骨髓造血功能重建成功平均 2 6.67( 17~ 32 )天 相似文献
78.
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
79.
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
80.
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