全文获取类型
收费全文 | 6642篇 |
免费 | 421篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 235篇 |
妇产科学 | 72篇 |
基础医学 | 1220篇 |
口腔科学 | 286篇 |
临床医学 | 542篇 |
内科学 | 995篇 |
皮肤病学 | 251篇 |
神经病学 | 702篇 |
特种医学 | 286篇 |
外科学 | 830篇 |
综合类 | 38篇 |
一般理论 | 2篇 |
预防医学 | 262篇 |
眼科学 | 290篇 |
药学 | 471篇 |
中国医学 | 9篇 |
肿瘤学 | 532篇 |
出版年
2023年 | 17篇 |
2022年 | 52篇 |
2021年 | 94篇 |
2020年 | 86篇 |
2019年 | 67篇 |
2018年 | 107篇 |
2017年 | 97篇 |
2016年 | 139篇 |
2015年 | 181篇 |
2014年 | 189篇 |
2013年 | 247篇 |
2012年 | 388篇 |
2011年 | 379篇 |
2010年 | 263篇 |
2009年 | 257篇 |
2008年 | 480篇 |
2007年 | 411篇 |
2006年 | 427篇 |
2005年 | 423篇 |
2004年 | 467篇 |
2003年 | 418篇 |
2002年 | 386篇 |
2001年 | 114篇 |
2000年 | 96篇 |
1999年 | 105篇 |
1998年 | 104篇 |
1997年 | 102篇 |
1996年 | 76篇 |
1995年 | 59篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 37篇 |
1991年 | 33篇 |
1990年 | 33篇 |
1989年 | 53篇 |
1988年 | 41篇 |
1987年 | 33篇 |
1986年 | 32篇 |
1985年 | 32篇 |
1984年 | 20篇 |
1983年 | 17篇 |
1982年 | 28篇 |
1981年 | 26篇 |
1980年 | 20篇 |
1979年 | 23篇 |
1978年 | 18篇 |
1977年 | 23篇 |
1974年 | 14篇 |
1973年 | 20篇 |
1972年 | 18篇 |
排序方式: 共有7084条查询结果,搜索用时 15 毫秒
1.
2.
Detailed pathological changes of human lumbar facet joints L1–L5 in elderly individuals 总被引:4,自引:1,他引:3
Facet joints play an important role in intervertebral load transmission and are crucial for rotational kinematics. Clinically, the role of facet joints as a possible source of low back pain is seen as controversial and at present is not sufficiently investigated. In this study, human lumbar facet (zygapopyhysial) joints from donors with advanced age were analyzed macroscopically, for degenerative changes. The aim was to determine the extent and morphology of degenerative changes in these joints. Lumbar facet joints (L1–L5) of 32 donors were studied (mean age 80.1±11.2 years). Joint capsules were carefully removed and joint surfaces (5 zones) examined using magnifying glasses and probes. In the result, the majority of facet joints showed cartilage defects of varying extent. Defects were located mostly at the margins of the articular surface, the central zone being relatively well preserved. Defect localization was different between superior (most cartilage defects in superior zone) and inferior (most defects inferiorly) facets. Further, defects were more severe caudal (level of L5) and in older persons. Osteophytes were present in up to 30%, located mostly at the latero-dorsal enthesis of the joint capsule on the superior facet. In conclusion, most margins of the articular facets are subject to degenerative changes in the lumbar spine of elderly persons, the topographical pattern being different in superior and inferior facets. This observation can be explained by the segmental motion patterns during extension/flexion movements of the facets. Sometimes, due to the marginal extension, it is obvious that not all changes can be assessed by CT or MRI. 相似文献
3.
S Balzer D T Schneider M B Bernbeck M J?ger O Mils J Schaper R Willers R Krauspe U G?bel R Wessalowski 《International journal of hyperthermia》2006,22(6):451-461
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads. 相似文献
4.
Lei Li Jürgen Bruns Reinhard E. Friedrich Rainer Schmelzle 《European journal of plastic surgery》2006,29(2):93-96
Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile. 相似文献
5.
6.
Depression in Alzheimer's disease: is there a temporal relationship between the onset of depression and the onset of dementia? 总被引:4,自引:0,他引:4
Alzheimer's disease (AD) patients often present with concurrent major depression (MD). To investigate the reasons for this comorbidity, e.g. MD being a risk factor for AD, or both diagnoses having a common neurobiology, the temporal relationship between the first onset of AD and of MD during lifetime was investigated-57 out of 146 AD patients had a lifetime diagnosis of MD. The correlation between the ages at onset of MD and dementia was calculated. The incidence of MD in AD patients in several 5-year-intervals before and after the onset of AD was compared with the average incidence of MD in the present AD sample and with the expected incidence of MD in the general population. No significant correlation between the onset of AD and of MD could be found after controlling for age, gender and the Mini-Mental-State. However, the incidence of MD 5 years before and after the onset of AD significantly exceeded the expected incidences-MD is only partially related to AD. However, the increased incidence of MD within 5 years before and after the onset of dementia may indicate that a common neurobiological process causes cognitive decline and depression in a subsample of AD patients. 相似文献
7.
8.
Structural vertebral changes in the horizontal plane in idiopathic scoliosis and the long-term corrective effect of spine instrumentation 总被引:1,自引:0,他引:1
Summary The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8°, r 13°–30°) and from 33 with severe scoliosis (mean Cobb angle 46.2°, r 35°–71°). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation. 相似文献
9.
10.
In 1906 Bergonié and Tribondeau postulated a correlation between proliferation rate and radiosensitivity. Allowing for modern radiotherapeutic and radiobiological experience this postulate is no longer tenable. 相似文献