全文获取类型
收费全文 | 5657篇 |
免费 | 272篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 91篇 |
妇产科学 | 47篇 |
基础医学 | 609篇 |
口腔科学 | 303篇 |
临床医学 | 348篇 |
内科学 | 1393篇 |
皮肤病学 | 141篇 |
神经病学 | 416篇 |
特种医学 | 195篇 |
外科学 | 1037篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 143篇 |
眼科学 | 181篇 |
药学 | 384篇 |
中国医学 | 4篇 |
肿瘤学 | 617篇 |
出版年
2023年 | 31篇 |
2022年 | 88篇 |
2021年 | 130篇 |
2020年 | 61篇 |
2019年 | 90篇 |
2018年 | 110篇 |
2017年 | 87篇 |
2016年 | 99篇 |
2015年 | 110篇 |
2014年 | 133篇 |
2013年 | 156篇 |
2012年 | 244篇 |
2011年 | 262篇 |
2010年 | 148篇 |
2009年 | 136篇 |
2008年 | 242篇 |
2007年 | 256篇 |
2006年 | 271篇 |
2005年 | 283篇 |
2004年 | 258篇 |
2003年 | 279篇 |
2002年 | 283篇 |
2001年 | 219篇 |
2000年 | 220篇 |
1999年 | 171篇 |
1998年 | 71篇 |
1997年 | 49篇 |
1996年 | 38篇 |
1995年 | 42篇 |
1994年 | 34篇 |
1992年 | 101篇 |
1991年 | 104篇 |
1990年 | 99篇 |
1989年 | 117篇 |
1988年 | 90篇 |
1987年 | 91篇 |
1986年 | 78篇 |
1985年 | 84篇 |
1984年 | 68篇 |
1983年 | 50篇 |
1982年 | 24篇 |
1980年 | 28篇 |
1979年 | 44篇 |
1978年 | 28篇 |
1972年 | 26篇 |
1970年 | 24篇 |
1969年 | 24篇 |
1968年 | 39篇 |
1967年 | 27篇 |
1966年 | 26篇 |
排序方式: 共有5956条查询结果,搜索用时 15 毫秒
1.
2.
To clarify when and how rapidly individual muscles are damaged in the course of Duchenne muscular dystrophy (DMD), we followed X-ray CT of whole body skeletal muscles from 29 cases of DMD patients (age ranging 3 to 23 years) for a period of 2 to 6 years. Each patient had 2 to 5 scans with an average of 3.3. We evaluated chronological changes of 23 muscles from the entire body using the muscle damage stage defined as follows. The stages were classified into the following 5 stages: stage 0; normal, 1; area of fatty replacement less than 10% of whole muscle area, 2; area of fatty replacement between 10 to 50%, 3; area of fatty replacement 50 to 90%, 4; almost complete fatty replacement. Each muscle had its own period of rapid degeneration starting at 5 to 10 years of age and, continuing 5 to 10 years. In some muscles such as gluteus maximus or quadriceps femoris, fatty replacement started at 5 years or earlier and progressed for five years, while other muscles such as splenius capitis, damage started much later, e.g. around 10 years of age and the progression was much slower. There was a variation of at least 5 years among individual patients in any muscle damage stage, reflecting the variability of clinical severity in each patient. On the basis of the above results we defined the whole body muscle damage index as a summation of the muscle damage stages of the following five muscles: gluteus maximus, quadriceps femoris, gracilis, medial head of gastrocnemius and splenius capitis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
Pharynx and oesophagus evaluation during the swallow using helical computerized tomography. 总被引:2,自引:0,他引:2
PURPOSE: Videofluorography (VF) and endoscopy are commonly used for dynamic imaging (DI) of pharyngeal swallowing but do not offer transverse plane (TP) information. The aim of the present study was to evaluate helical computerized tomography (HCT) to measure the DI capability pharyngeal swallowing in the TP. METHODS: The HCT scan technique used was a single-slice cine mode with scan times of 100 ms. All 15 subjects were studied supine during dry swallow, swallowing of barium sulphate jelly and 3, 10, 15 or 20 ml of a 40% barium sulphate solution. Nine subjects repeated the test twice at more than 1 week's interval to determine the test-retest reliability. RESULTS: Swallowing leads to closure of the vocal folds, pharyngeal constriction and narrowing of the piriform sinuses allowing jelly passage between the sinuses. Laryngeal elevation then occurs with the opening of the pharyngoesophageal segment (PES). Swallowing a bolus of 20 ml produced the maximum anteroposterior and transverse diameters as well as the maximum opening area of the PES. The test-retest intraclass correlation coefficients with liquid deglutition ranged from 0.86 to 0.98. CONCLUSIONS: This study shows that HCT enables visualization of TP of PES complementing VF or endoscopic swallowing studies. 相似文献
4.
M Kurimoto N Hayashi H Kamiyama S Nagai T Shibata T Asahi N Matsumura Y Hirashima S Endo 《Minimally invasive neurosurgery》2004,47(5):278-283
Neuronavigation has become an effective therapeutic modality and is used routinely for intra-axial tumor removal. This retrospective study was conducted to evaluate the clinical impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas. Between 1990 and 2002, 76 adult patients with pathologically confirmed malignant astrocytomas underwent craniotomy and removal of the tumors at the Toyama Medical and Pharmaceutical University Hospital. Of these 76 patients, 42 were treated using neuronavigation with conventional microneurosurgery and the other 34 were treated with conventional microneurosurgery alone. Postoperative early MRI with contrast enhancement was done, and gross total resection was defined as the complete absence of residual tumor. Survival time was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. In univariate analysis, age (< 65), grade 3, preoperative KPS (>/= 80), use of neuronavigation, and gross total resection were significantly associated with longer survival. However, when the data were submitted to multivariate analysis, grade 3, preoperative KPS (>/= 80), and gross total resection were independent prognostic factors. The median survival periods of patients receiving gross total resection (vs. partial resection) and neuronavigation (vs. no neuronavigation) were 16 (vs. 9) months and 16 (vs. 10) months, respectively. The percentage of a gross total resection was significantly higher in the neuronavigation group compared to that in the no-navigation group (64.3 % vs. 38.2 %, p < 0.05). Neurological deterioration occurred in 4 of 42 (9.5 %) and in 6 of 34 (17.6 %) patients after surgery with neuronavigation and surgery without neuronavigation, respectively, although this difference was not statistically significant. Our results showed that neuronavigation increases the radicality in the resection of malignant astrocytomas and is objectively useful for improving survival time. 相似文献
5.
6.
7.
8.
Magnetic resonance imaging of 31 meningiomas in 29 patients was retrospectively reviewed and compared with pathologic specimens in 25 tumors to investigate how magnetic resonance imaging could delineate a tumor-brain interface. The thick, collagenous connective tissue, which was seen around four tumors, was shown as a low signal intensity rim on both a T1-weighted image and a T2-weighted image. A rim of low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted image most likely represented cerebrospinal fluid space: this finding was seen around eight tumors. No distinct rim could be identified in five tumors. Of these five, two tumors grew invasively into the brain. Although mixed features predominated in meningiomas, magnetic resonance imaging could well delineate a tumor-brain relationship in most of the cases. 相似文献
9.
Yukata Okita M.D. Shigehito Miki M.D. Yuichi Ueda M.D. Takafumi Tahata M.D. Tetsuro Sakai M.D. Katsuhiko Matsuyama M.D. Masahiko Matsumura M.D. 《Journal of cardiac surgery》1994,9(4):433-439
A 6-year-old boy was successfully operated on for double outlet ventricle, common atrioventricular canal with severe valvular regurgitation, right atrial Isomerism, L-loop ventricles, total anomalous pulmonary venous connection, and pulmonary stenosis with hypoplastic left pulmonary artery. The Interventricular rerouting from the left ventricle to the ascending aorta was performed with a spiral patch, the lnteratrlal switching was performed by a Mustard patch, the common atrioventricular orifice was partitioned and valve repair was performed, and an 18-mm valved conduit was inserted between the right ventricle and the pulmonary artery. Although the patient had a small residual ventricular septal defect and pulmonary stenosls, the patient Is alive and well. 相似文献
10.