全文获取类型
收费全文 | 474篇 |
免费 | 25篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 21篇 |
妇产科学 | 6篇 |
基础医学 | 63篇 |
口腔科学 | 10篇 |
临床医学 | 53篇 |
内科学 | 88篇 |
皮肤病学 | 3篇 |
神经病学 | 33篇 |
特种医学 | 131篇 |
外科学 | 23篇 |
综合类 | 8篇 |
预防医学 | 14篇 |
眼科学 | 7篇 |
药学 | 29篇 |
肿瘤学 | 27篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 8篇 |
2013年 | 11篇 |
2012年 | 8篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 8篇 |
2007年 | 17篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 35篇 |
1997年 | 19篇 |
1996年 | 25篇 |
1995年 | 18篇 |
1994年 | 22篇 |
1993年 | 13篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 11篇 |
1989年 | 20篇 |
1988年 | 35篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有517条查询结果,搜索用时 15 毫秒
21.
22.
Santos RS Silva PL Oliveira GP Cruz FF Ornellas DS Morales MM Fernandes J Lanzetti M Valença SS Pelosi P Gattass CR Rocco PR 《Respiratory physiology & neurobiology》2011,179(2-3):129-136
We analysed the effects of oleanolic acid (OA) on lung mechanics and histology and its possible mechanisms of action in experimental acute lung injury (ALI). BALB/c mice were randomly divided into Control (saline, ip) and ALI (paraquat, 25 mg/kg, ip) groups. At 1 h, both groups were treated with saline (SAL, 50 μl ip), OA (10 mg/kg ip), or dexamethasone (DEXA, 1 mg/kg ip). At 24 h, lung static elastance, viscoelastic pressure, and alveolar collapse reduced more after OA compared to DEXA administration. Tumour necrosis factor-α, macrophage migration inhibitory factor, interleukin-6, interferon-γ, and transforming growth factor-β mRNA expressions in lung tissue diminished similarly after OA or DEXA. Conversely, only OA avoided reactive oxygen species generation and yielded a significant decrease in nitrite concentration. OA and DEXA restored the reduced glutathione/oxidized glutathione ratio and catalase activity while increasing glutathione peroxidase induced by paraquat. In conclusion, OA improved lung morphofunction by modulating the release of inflammatory mediators and oxidative stress. 相似文献
23.
Congenital radioulnar synostosis(CRS) is a rare anomaly and approximately 400 cases were reported worldwide so far. CRS is the failure of the longitudinal segmentation and the persistence of the cartilaginous anlage between the radius and ulna during the seventh week of development that results in a persistent bridge of tissue. Here we are discussing on a case of 25yrs old, male patient with bilateral congenital synostosis. On the left hand the pronation and supination movements are restricted completely where as on right side 10 degree of supination and 20 degree of pronation is possible. Radiologically in our patient synostosis is classified as type II variety by Wilkie(1914)1 classification and type IV by the Cleary and Omer classification(1985). The position of forearm was not found to be related to subjective functional limitation, or employment status. Main line of treatment is surgical mainly rotational osteotomy but is rarely indicated. Our patient is not able to rotate his forearm especially on the left side still he has no functional limitation so he has refused for the operative treatment. No study has objectively compared the preoperative functional limitation of the patients with their postoperative functional improvement in order to justify surgical intervention In the authors opinion the only major factor that is to be taken into consideration of operative treatment is functional limitation to the patient. 相似文献
24.
25.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm). 相似文献
26.
Twenty-one patients with insulin-dependent diabetes mellitus received simultaneous renal and segmental pancreatic transplants. A retrospective analysis of 112 real-time ultrasound (US) images, 108 technetium-99m glucoheptonate scinti-scans, 55 computed tomography (CT) scans, and 11 cystograms was performed. Complications that were observed included pancreatic transplant rejection, pancreatitis, arteriovenous occlusions, hemorrhage, abscesses, and extravasation at the pancreaticocystostomy site. Scintigraphy is a sensitive indicator of normal transplant function but is non-specific when findings are abnormal. Real-time US aids in the differentiation of acute rejection from pancreatitis and arteriovenous occlusion. CT is helpful for evaluation of postoperative complications. Imaging may play an important role in the noninvasive management of pancreatic transplants. 相似文献
27.
Strangulation in child abuse: CT diagnosis 总被引:2,自引:0,他引:2
The central nervous system is commonly affected in child abuse. Between April 1985 and July 1986 three infants were identified in whom the primary mode of injury had been strangulation. In each case computed tomography (CT) demonstrated a large cerebral infarction confined to vascular territories associated with small subdural hematomas. There was no history or visible evidence of significant head trauma. Autopsy of one infant confirmed the presence of a hemispheric infarct, thin subdural hematoma, and an area of subintimal hemorrhage in the carotid artery ipsilateral to the infarct. The remaining two patients survived with residual hemiparesis. CT findings of a large cerebral infarction with an associated subdural hematoma in an infant without a history of a significant trauma should suggest the possibility of child abuse and may be the primary manifestation of abuse in some patients. 相似文献
28.
Duplex Doppler ultrasound (US) was used in 68 consecutive patients with focal liver lesions, including 12 hepatocellular carcinomas, one cholangiocarcinoma, 37 metastases, 15 hemangiomas, one hemangioendothelioma, and two focal nodular hyperplasias. Of the hepatocellular carcinomas, six were diffusely hyperechoic, two were hypoechoic, two were single hyperechoic lesions, and two were multifocal and hyperechoic. All ten tumors with Doppler shifts of 5 kHz or above proved to be hepatocellular carcinomas. The other two hepatocellular carcinomas showed Doppler shifts of 3 kHz. In contrast, no hemangioma showed shifts above 0.7 kHz, and ten of the 15 gave no detectable signal. Of the metastases, 20 gave no signal and 17 had signals of up to 4 kHz. Three-kilohertz signals were also obtained from a cholangiocarcinoma, a hemangioendothelioma, and focal nodular hyperplasia. Correlation with angiographic findings suggested that the high-velocity Doppler signals were associated with large pressure gradients due to arteriovenous shunting. Duplex Doppler US can therefore aid in the differential diagnosis of diffuse and focal liver lesions. 相似文献
29.
30.
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