全文获取类型
收费全文 | 423篇 |
免费 | 36篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 25篇 |
妇产科学 | 7篇 |
基础医学 | 61篇 |
口腔科学 | 12篇 |
临床医学 | 38篇 |
内科学 | 93篇 |
皮肤病学 | 14篇 |
神经病学 | 25篇 |
特种医学 | 42篇 |
外科学 | 36篇 |
综合类 | 47篇 |
预防医学 | 18篇 |
眼科学 | 1篇 |
药学 | 37篇 |
肿瘤学 | 22篇 |
出版年
2024年 | 3篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 12篇 |
2011年 | 13篇 |
2010年 | 19篇 |
2009年 | 19篇 |
2008年 | 24篇 |
2007年 | 24篇 |
2006年 | 25篇 |
2005年 | 14篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 25篇 |
1997年 | 32篇 |
1996年 | 26篇 |
1995年 | 17篇 |
1994年 | 8篇 |
1993年 | 15篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 4篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 18篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有480条查询结果,搜索用时 15 毫秒
71.
72.
Moore AD; Godwin JD; Muller NL; Naidich DP; Hammar SP; Buschman DL; Takasugi JE; de Carvalho CR 《Radiology》1989,172(1):249-254
The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities. 相似文献
73.
We describe three cases of fetal intracranial teratoma diagnosed by ultrasound and review the literature. Sonographic features include cranial enlargement, gross distortion of normal cerebral architecture by a hyperechoic, multicystic mass, and polyhydramnios. Despite early diagnosis, the cesarean section rate is high and the overall prognosis is dismal. 相似文献
74.
75.
Timothy Shiraev Sundeep Singh Pasricha Peter Choong Stephen Schlicht Catharina SP van Rijswijk Simon Dimmick Stephen Stuckey Suzanne E Anderson 《Journal of Medical Imaging and Radiation Oncology》2013,57(6):687-700
Retroperitoneal sarcomas are a rare disease. The overall 5‐year survival rate for these lesions remains low, and surgical management offers the only option for effective treatment and potential for cure. Radiotherapy is increasingly being employed in addition to standard surgical treatment. Improvements in cross‐sectional imaging have also facilitated better characterisation of lesions, preoperative planning and long‐term follow‐up. This article reviews the current literature and documents the various types of retroperitoneal sarcomas with a particular approach to their imaging features. We also highlight the pathology, diagnostic methods and most current management of these tumours. 相似文献
76.
Grimaldi LM Prosperini L Vitello G Borriello G Fubelli F Pozzilli C 《Multiple sclerosis (Houndmills, Basingstoke, England)》2012,18(9):1337-1339
The recommended natalizumab dosage is 300 mg every 4 weeks. We evaluated radiological activity at various times from the last natalizumab infusion by examining 386 magnetic resonance imaging (MRI) scans from 166 natalizumab-treated patients with relapsing-remitting MS. Of 113 scans performed >4 weeks after last natalizumab infusion, 26 were active (i.e. had ≥1 contrast-enhancing lesions). Risk of radiological activity increased by 1.34 fold for each week of delay with respect to the recommended 4-week dosing interval, compared with schedule-adherent patients (p<0.0001). Our data suggest that an increased MRI activity ≥7 weeks from the last infusion of natalizumab should be considered in cases of therapy discontinuation. 相似文献
77.
Gilda Varricchi Maria R. Galdiero Giancarlo Marone Francescopaolo Granata Francesco Borriello Gianni Marone 《Experimental dermatology》2017,26(1):11-17
Cancer development is a multistep process characterized by genetic and epigenetic alterations during tumor initiation and progression. The stromal microenvironment can promote tumor development. Mast cells, widely distributed throughout all tissues, are a stromal component of many solid and haematologic tumors. Mast cells can be found in human and mouse models of skin cancers such as melanoma, basal and squamous cell carcinomas, primary cutaneous lymphomas, haemangiomas and Merkel cell carcinoma. However, human and animal studies addressing potential functions of mast cells and their mediators in skin cancers have provided conflicting results. In several studies, mast cells play a pro‐tumorigenic role, whereas in others, they play an anti‐tumorigenic role. Other studies have failed to demonstrate a clear role for tumor‐associated mast cells. Many unanswered questions need to be addressed before we understand whether tumor‐associated mast cells are adversaries, allies or simply innocent bystanders in different types and subtypes of skin cancers. 相似文献
78.
Maurizio Guida Elena Greco Attilio Di Spiezio Sardo Maddalena Borriello Ilaria Morra Carmine Nappi 《Journal of minimally invasive gynecology》2009,16(1):95-97
A 33-year-old woman with a 2-year history of swelling and pain in her buttock and left thigh fluctuating with her menstrual cycle who was becoming progressively disabled was referred to the department of orthopedics. Magnetic resonance imaging (MRI) detected a left buttock lesion of 3 × 2 cm that was initially diagnosed as muscular-fiber laceration with associated hematoma. The worsening of her symptomatology required an ultrasound-guided biopsy of the lesion that revealed endometriosis. Laparoscopy showed the pelvis to be free of gross disease. Hormonal suppression by means of gonadotropin-releasing hormone analog therapy proved adequate in temporarily alleviating symptoms. A year later the patient underwent surgical excision of the buttock lesion, which was effective in alleviating her symptoms for a short period of 10 months. A 1-year follow-up MRI revealed several small endometriotic foci, located among piriformis and obturator internus muscle fibers, which were considered not suitable for surgical removal. The patient is currently on a drug regime for pain management. However, she has experienced permanent muscular damage on her left buttock including significant omolateral gluteus strength reduction, functional impairment (inability to rotate laterally or bend her left leg), and the assumption of an antalgic gait while walking. Because of impairment in her deambulation capability, total physical invalidity was agreed for her by the National Health Care Services. 相似文献
79.
80.
Joining the dots: a plea for precise estimates of the maternal mortality ratio in sub-Saharan Africa
Monitoring of maternal mortality levels in sub-Saharan Africa (SSA) to assess the achievements of safe motherhood programmes and for MDG-5 has been made difficult because of the lack of precise estimates of the maternal mortality ratio (MMR). Projections based on the slow rate of decline of the MMR indicate that MDG-5 may not be reached before the end of this century in this region. Measurements done using demographical and health surveys, statistical modelling and censuses are imprecise and do not allow trends in individual countries to be established. SSA countries should be encouraged to measure mortality levels from their own resources, using methods that produce precise estimates such as population-based surveys. Establishment of the trends will lead to country-specific program targets. The less frequent but more precise measurements can be afforded by SSA countries, as a case study from Zimbabwe shows. 相似文献