全文获取类型
收费全文 | 2294篇 |
免费 | 148篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 47篇 |
妇产科学 | 45篇 |
基础医学 | 373篇 |
口腔科学 | 61篇 |
临床医学 | 234篇 |
内科学 | 417篇 |
皮肤病学 | 18篇 |
神经病学 | 228篇 |
特种医学 | 76篇 |
外科学 | 416篇 |
综合类 | 49篇 |
一般理论 | 2篇 |
预防医学 | 170篇 |
眼科学 | 21篇 |
药学 | 110篇 |
中国医学 | 7篇 |
肿瘤学 | 165篇 |
出版年
2023年 | 18篇 |
2022年 | 42篇 |
2021年 | 95篇 |
2020年 | 55篇 |
2019年 | 52篇 |
2018年 | 70篇 |
2017年 | 60篇 |
2016年 | 68篇 |
2015年 | 80篇 |
2014年 | 107篇 |
2013年 | 126篇 |
2012年 | 181篇 |
2011年 | 190篇 |
2010年 | 82篇 |
2009年 | 110篇 |
2008年 | 148篇 |
2007年 | 124篇 |
2006年 | 102篇 |
2005年 | 132篇 |
2004年 | 120篇 |
2003年 | 97篇 |
2002年 | 100篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 16篇 |
1998年 | 26篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1987年 | 7篇 |
1985年 | 4篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1963年 | 5篇 |
1962年 | 5篇 |
1961年 | 4篇 |
1942年 | 4篇 |
1933年 | 5篇 |
1929年 | 5篇 |
排序方式: 共有2454条查询结果,搜索用时 15 毫秒
71.
Hegyi L, Thway K, Fisher C & Sheppard M N (2012) Histopathology 61, 966–973 Primary cardiac sarcomas may develop from resident or bone marrow‐derived mesenchymal stem cells: use of immunohistochemistry including CD44 and octamer binding protein 3/4 Aims: To provide evidence that cardiac sarcomas ‘not otherwise specified’ express markers that might indicate their cellular origin or identify any lines of differentiation. Methods and results: We reviewed all 11 cases of primary undifferentiated cardiac sarcomas found in the archives of the Royal Marsden and Royal Brompton Hospitals, London, UK during the period 2000–2009. Five cases with appropriate consent and archived material were investigated using immunohistochemistry. We found that the spindle, pleomorphic or occasionally epithelioid cell sarcomas showed no lineage‐specific differentiation other than partial myofibroblastic or ‘myoid’ differentiation (all cases). All tumours showed some degree of cytoplasmic positivity for the mesenchymal stem cell marker CD44. In contrast, no nuclear octamer binding protein 3/4 (Oct3/4) expression was seen in any of the tumours, although very patchy cytoplasmic positivity was seen in some tumours. Conclusions: The cytoplasmic positivity for CD44 and the absence of nuclear Oct3/4 suggest that the cells of these sarcomas may represent ‘daughter’ stem cells that no longer have the capacity for tumour initiation, but have subsequently developed new lines of partial differentiation. Primary cardiac sarcomas may arise from mesenchymal stem cells with the ability to generate tumours with multilineage differentiation. 相似文献
72.
Al Ageeli E Mignot C Afenjar A Whalen S Dorison N Mayer M Esteva B Dubern B Momtchilova M Le Gargasson JF Bursztyn J Héron D 《European journal of medical genetics》2012,55(10):541-547
Myhre syndrome is a very rare condition described thirty years ago and related to mutations in the SMAD4 gene. It has been reported in 19 patients, including 13 males and 6 females before the recent finding of heterozygous mutations in the SMAD4 gene in 19 patients. It is characterized by mental retardation, short stature, muscle hypertrophy, limitation of joints movements, deafness, skeletal anomalies, and facial dysmorphism. Ophthalmological involvement includes hypermetropia and congenital cataract. We report here the new finding of retinal involvement including retinitis pigmentosa and maculopathy in two unrelated patients with Myhre syndrome. The patient with retinitis pigmentosa carried the p.I500T mutation in SMAD4, but no mutation was found in the patient with the maculopathy. 相似文献
73.
Cyrille Capel Johann Peltier Pascal Foulon Cyril Page Eric Havet Daniel Le Gars 《Surgical and radiologic anatomy : SRA》2012,34(10):969-972
Neurosurgeons use ventricular veins during an endoscopic third ventriculocisternostomy as landmark to progress in ventricles. In the current literature, there is lack of detailed intraventricular venous anatomy. Majority of those papers treats Monro’s foramen venous variations. There are no data of third ventricle venous anatomy and variations in the literature. We reported two cases of unusual interthalamic vein that we need to spare during endoscopy. 相似文献
74.
Biological integration of an implant to surrounding bone is an important event for its clinical success and is driven by numerous factors, including the attraction of bone forming cells. The implant's surface properties influence the initial cell response at the cell/material interface, ultimately affecting the rate and quality of new tissue formation and the stability of the implant. As a consequence, various surface treatments have been developed to increase the clinical performance of titanium-based implants. Among them, the Anodic Plasma-Chemical (APC) technique allows for the combined chemical and morphological modification of titanium surfaces in a single process step. In the present study, we compared the potential of APC surface treatment of high-strength titanium alloys with vacuum plasma spray treatment and yellow gold anodization in supporting osteogenic differentiation of two different osteoprogenitor cell types. Both human fetal osteoblast cell line (hFOB1.19) and human mesenchymal stromal cells showed extensive cell spreading, faster cell growth and differentiation on APC surfaces compared to vacuum plasma spray treated and yellow gold anodized surfaces. Our findings showed that APC titanium-based surfaces provided an effective substrate for osteoprogenitor cells adhesion, proliferation and differentiation. 相似文献
75.
76.
Josef Veselka Petr Hajek Cyril tchovský Martin Horvth Radka Adlov Robert Roland Ingrid Homolov Eva Hansvenclov Petra Zimolov 《Archives of Medical Science》2021,17(4):849
IntroductionThere is lack of long-term data outside of controlled clinical trials in carotid artery stenting (CAS). In this study, we compared the short-term outcome, long-term survival, and rate of re-interventions for restenosis in patients after CAS, related to the extent of carotid atherosclerosis classified as single-vessel (unilateral) or double-vessel (bilateral) carotid artery disease.Material and methodsWe retrospectively evaluated 599 patients with significant carotid artery stenosis, who underwent 763 CAS procedures, and used the propensity score to match 226 pairs (452 patients) in the single- or double-vessel carotid disease.ResultsThere was no significant difference in the occurrence of in-hospital major adverse events (3.5% vs. 3.1% of patients in the double-vessel carotid group vs. the single-vessel carotid group; p = 1) The mean follow-up was 6.1 ±4.0 years, and a total of 181 (40%) deaths occurred during 2759 patient-years, which translates into 7.8 and 5.3 deaths per 100 patient-years in the double-vessel carotid group and the single-vessel carotid group, respectively (p < 0.01). The survival in the double-vessel carotid group vs. the single-vessel carotid group at 10 years was 46% (95% CI: 38–54%) vs. 55% (95% CI: 47–63%) (p < 0.01). Twenty-four (11%) patients and 6 (3%) patients underwent re-interventions for restenosis in the double-vessel and the single-vessel carotid disease group, respectively (p < 0.01).ConclusionsPatients with CAS and significant double-vessel carotid artery disease had similar peri-procedural risk, but had a worse long-term survival, and a higher rate of re-interventions for restenosis compared to the single-vessel carotid artery disease patients. 相似文献
77.
Epithelioid hemangioma is a rare and benign vascular tumor, most often occurring in the skin. Numerous other localizations, including bones, have been reported. The overall favorable clinical outcome of cutaneous epithelioid hemangioma is now well documented, but it still remains debated in osseous localization, as local recurrences and metastases have been described. We report a case of epithelioid hemangioma of the spine occurring in a 25-year-old male, and discuss main differential diagnoses. Recent studies tend to demonstrate that osseous epithelioid hemangioma, as cutaneous epithelioid hemangioma, should be considered as a benign tumor. Histologically, epithelioid hemangioma consists of a vascular proliferation with diffuse or lobular pattern and features vascular spaces lined by epitheliod endothelial cells with numerous lymphocytes and eosinophils. The main differential diagnosis is represented by epithelioid hemangioendothelioma, the surgical treatment of which must be more aggressive. Precise histological diagnosis is essential for accurate clinical management and to avoid overtreatment. 相似文献
78.
Maud Bassement Cyril Garnier Mark Goss-Sampson Eric Watelain François-Xavier Lepoutre 《Journal of Science and Medicine in Sport》2010,12(5):554-558
This study attempts to characterise the electromyographic activity and kinematics exhibited during the performance of take-off for a pole vaulting short run-up educational exercise, for different expertise levels. Two groups (experts and novices) participated in this study. Both groups were asked to execute their take-off technique for that specific exercise. Among the kinematics variables studied, the knee, hip and ankle angles and the hip and knee angular velocities were significantly different. There were also significant differences in the EMG variables, especially in terms of (i) biceps femoris and gastrocnemius lateralis activity at touchdown and (ii) vastus lateralis and gastrocnemius lateralis activity during take-off. During touchdown, the experts tended to increase the stiffness of the take-off leg to decrease braking. Novices exhibited less stiffness in the take-off leg due to their tendency to maintain a tighter knee angle. Novices also transferred less energy forward during take-off due to lack of contraction in the vastus lateralis, which is known to contribute to forward energy transfers. This study highlights the differences in both groups in terms of muscular and angular control according to the studied variables. Such studies of pole vaulting could be useful to help novices to learn expert's technique. 相似文献
79.
80.
Shiloah Elizabeth Darmanayagam Khanna Nehemiah Harichandran Sunil Retmin Raj Cyril Kannan Arputharaj 《Journal of digital imaging》2013,26(3):496-509
Segmentation of lung parenchyma from the chest computed tomography is an important task in analysis of chest computed tomography for diagnosis of lung disorders. It is a challenging task especially in the presence of peripherally placed pathology bearing regions. In this work, we propose a segmentation approach to segment lung parenchyma from chest. The first step is to segment the lungs using iterative thresholding followed by morphological operations. If the two lungs are not separated, the lung junction and its neighborhood are identified and local thresholding is applied. The second step is to extract shape features of the two lungs. The third step is to use a multilayer feed forward neural network to determine if the segmented lung parenchyma is complete, based on the extracted features. The final step is to reconstruct the two lungs in case of incomplete segmentation, by exploiting the fact that in majority of the cases, at least one of the two lungs would have been segmented correctly by the first step. Hence, the complete lung is determined based on the shape and region properties and the incomplete lung is reconstructed by applying graphical methods, namely, reflection and translation. The proposed approach has been tested in a computer-aided diagnosis system for diagnosis of lung disorders, namely, bronchiectasis, tuberculosis, and pneumonia. An accuracy of 97.37 % has been achieved by the proposed approach whereas the conventional thresholding approach was unable to detect peripheral pathology-bearing regions. The results obtained prove to be better than that achieved using conventional thresholding and morphological operations. 相似文献