全文获取类型
收费全文 | 41599篇 |
免费 | 3659篇 |
国内免费 | 2003篇 |
专业分类
耳鼻咽喉 | 821篇 |
儿科学 | 1039篇 |
妇产科学 | 191篇 |
基础医学 | 5424篇 |
口腔科学 | 7137篇 |
临床医学 | 3686篇 |
内科学 | 3662篇 |
皮肤病学 | 158篇 |
神经病学 | 895篇 |
特种医学 | 2063篇 |
外国民族医学 | 20篇 |
外科学 | 8963篇 |
综合类 | 6163篇 |
现状与发展 | 6篇 |
预防医学 | 1314篇 |
眼科学 | 154篇 |
药学 | 1930篇 |
25篇 | |
中国医学 | 1324篇 |
肿瘤学 | 2286篇 |
出版年
2024年 | 98篇 |
2023年 | 648篇 |
2022年 | 1155篇 |
2021年 | 1653篇 |
2020年 | 1640篇 |
2019年 | 1503篇 |
2018年 | 1345篇 |
2017年 | 1467篇 |
2016年 | 1428篇 |
2015年 | 1617篇 |
2014年 | 2591篇 |
2013年 | 3660篇 |
2012年 | 2130篇 |
2011年 | 2483篇 |
2010年 | 2206篇 |
2009年 | 2039篇 |
2008年 | 1951篇 |
2007年 | 1992篇 |
2006年 | 1794篇 |
2005年 | 1735篇 |
2004年 | 1553篇 |
2003年 | 1376篇 |
2002年 | 1165篇 |
2001年 | 1030篇 |
2000年 | 848篇 |
1999年 | 754篇 |
1998年 | 622篇 |
1997年 | 616篇 |
1996年 | 578篇 |
1995年 | 408篇 |
1994年 | 424篇 |
1993年 | 294篇 |
1992年 | 310篇 |
1991年 | 254篇 |
1990年 | 206篇 |
1989年 | 205篇 |
1988年 | 164篇 |
1987年 | 130篇 |
1986年 | 126篇 |
1985年 | 154篇 |
1984年 | 111篇 |
1983年 | 108篇 |
1982年 | 123篇 |
1981年 | 91篇 |
1980年 | 86篇 |
1979年 | 87篇 |
1978年 | 93篇 |
1977年 | 62篇 |
1976年 | 60篇 |
1975年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
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
22.
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
23.
Cranioplasty with autogenous autoclaved calvarial bone flap in the cases of tumoural invasion 总被引:2,自引:0,他引:2
V. Vanaclocha N. Sáiz-Sapena C. Garcia-Casasola E. De Alava 《Acta neurochirurgica》1997,139(10):970-976
Summary When a bone flap is raised in the course of a craniotomy, the ideal is to replace it at the end of the procedure. When it is invaded by tumoural cells, it cannot be replaced due to the risk of tumoural recurrence. In these cases we have autoclaved the bone flap to be able to replace it with no fear of tumoural recurrence.Between October 1989 and October 1995 sixty-two patients required autoclaving of the bone flap in the course of a craniotomy due to tumoural invasion (thirty-five meningiomas, sixteen bone tumours, five metastases, and eight scalp tumours).The infiltrated bone flaps were removed, cleaned, autoclaved for 20 minutes at 134 °C and 1 kg/cm2 and re-implanted.Patients were followed-up for 10 to 58 months (average 41 months). At every follow-up visit skull x-ray studies, clinical examination, and photographs were done. When needed a CT scan was performed to assess the thickness of the bone flap.On follow-up roentgenograms partial resorption was observed in twelve cases (19.3%). CT scan studies showed loss of thickness in another thirty-five cases (56.4%). Meanwhile the external aspect remained unchanged.In six cases (3.2%) biopsies of the bone flaps were taken at a second surgical procedure. They showed newly formed bone partly re-populated by osteocytes but retaining areas of sequestered bone.We conclude that autoclaved bone, if replaced with direct contact with living bone, it is gradually repopulated with osteocytes. Cranial vault autoclaved autologous bone flap is a good alternative when the original bone flap is invaded but not destroyed by tumoural cells. 相似文献
24.
An atypical variant of reflex sympathetic dystrophy (RSD) is presented in a 45 year old female with a vascular malformation
of the right arm and chest wall. The mechanism was thought to be compression of the brachial plexus by the malformation. The
unique scintigraphic features of this presentation of RSD in the ulnar arterial distribution are illustrated. 相似文献
25.
肢体不同延长速度对局部血流量的影响 总被引:1,自引:1,他引:0
本文报告20只兔胫骨以不同速度延长时用末梢微循环测定系统动态连续监测局部血流量变化的结果,发现一次延长>1 mm时,局部肌肉血流量开始急骤下降,恢复延长前血流量所需的时间>8 h。作者认为肢体的血管、肌肉等组织对1 mm/次/d延长速度有相当大的生物适应性。延长速度>1 mm/次/d易造成局部血流量大幅度减少。延长肢肌肉萎缩、肌力减弱可能与血流量减少有关。 相似文献
26.
Dmitriy A. Yablonskiy William R. Reinus Helmut Stark E. Mark Haacke 《Magnetic resonance in medicine》1997,37(2):214-221
In this paper, the authors quantitate the anisotropy of susceptibility effects in an uniaxial trabecular bone model and show its relevance to clinical MR bone mineral density measurements. A physical model is described that quantitates the anisotropic MR behavior of uniaxial trabecular bone. To test the model, a phantom of parallel polyethylene filaments was scanned every 15° between 0° and 90° with respect to the system's main magnetic field (B0). The distal radial metaphysis of a healthy female volunteer was scanned in orthogonal projections. The signal from each phantom image and each radial image was separated in a pixel-wise fashion into R2 and R2′ maps. As predicted, R2′ relaxation showed anisotropic behavior and changed according to sin2 (?), confirming that columnar structures parallel with B0 will cause no MR susceptibility effects. Scans of the distal radius showed that R2′ relaxation was twice as great with the forearm perpendicular to B0 as when it was parallel to it, demonstrating different contributions from struts and columns. For both phantom and radial bone scans, R2 relaxation was isotropic and did not change with object orientation. 相似文献
27.
28.
Kyung‐Sub Moon Shin Jung Jae‐Hyuk Lee Tae‐Young Jung In‐Young Kim Soo‐Han Kim Sam‐Suk Kang 《Neuropathology》2006,26(2):141-146
We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation. 相似文献
29.
取32只2~3个月的BALB/C小白鼠,随机分为4组,每组8只,第1组为对照组,其余3个组为实验组,实验组小白鼠左腿皮下注射苯0.3ml(15ml/kg体重).注射后分别于24h,48h,72h脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明,苯中毒时骨髓变化先于末梢血象的变化,骨髓的病变为造血细胞变性、坏死,大量毛细血管扩张、充血,骨髓细胞构成降低,而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。 相似文献
30.
P. KISS K. KOZLOWSKI E. ZAVODI 《Journal of Medical Imaging and Radiation Oncology》1991,35(3):266-267
A newborn with rhizomelic bone dysplasia with club-like femora is reported. This is the fourth case Of this easily recognizable, recently reported, congenital bone disease. Maroteaux et al recently reported two patients with rhizomelic bone dysplasia and club-like femora as a distinctive new bone dysplasia. Their observation was confirmed by Gugliantini et al (2) who reported another case. This paper reports a fourth patient with this easily recognisable disorder. 相似文献