全文获取类型
收费全文 | 8113篇 |
免费 | 842篇 |
国内免费 | 495篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 38篇 |
妇产科学 | 73篇 |
基础医学 | 1127篇 |
口腔科学 | 80篇 |
临床医学 | 1120篇 |
内科学 | 1534篇 |
皮肤病学 | 62篇 |
神经病学 | 439篇 |
特种医学 | 279篇 |
外国民族医学 | 15篇 |
外科学 | 866篇 |
综合类 | 966篇 |
现状与发展 | 5篇 |
预防医学 | 473篇 |
眼科学 | 69篇 |
药学 | 837篇 |
35篇 | |
中国医学 | 599篇 |
肿瘤学 | 792篇 |
出版年
2024年 | 28篇 |
2023年 | 177篇 |
2022年 | 489篇 |
2021年 | 653篇 |
2020年 | 494篇 |
2019年 | 426篇 |
2018年 | 424篇 |
2017年 | 370篇 |
2016年 | 398篇 |
2015年 | 581篇 |
2014年 | 663篇 |
2013年 | 628篇 |
2012年 | 773篇 |
2011年 | 794篇 |
2010年 | 509篇 |
2009年 | 411篇 |
2008年 | 387篇 |
2007年 | 354篇 |
2006年 | 311篇 |
2005年 | 331篇 |
2004年 | 68篇 |
2003年 | 64篇 |
2002年 | 28篇 |
2001年 | 15篇 |
2000年 | 12篇 |
1999年 | 15篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1964年 | 1篇 |
排序方式: 共有9450条查询结果,搜索用时 14 毫秒
151.
Haifeng Wu Tao Sun Jingjing Wang Xia Li Wei Wang Da Huo Pingxin Lv Wen He Keyang Wang Xiuhua Guo 《Journal of digital imaging》2013,26(4):797-802
The objective of this study was to investigate the method of the combination of radiological and textural features for the differentiation of malignant from benign solitary pulmonary nodules by computed tomography. Features including 13 gray level co-occurrence matrix textural features and 12 radiological features were extracted from 2,117 CT slices, which came from 202 (116 malignant and 86 benign) patients. Lasso-type regularization to a nonlinear regression model was applied to select predictive features and a BP artificial neural network was used to build the diagnostic model. Eight radiological and two textural features were obtained after the Lasso-type regularization procedure. Twelve radiological features alone could reach an area under the ROC curve (AUC) of 0.84 in differentiating between malignant and benign lesions. The 10 selected characters improved the AUC to 0.91. The evaluation results showed that the method of selecting radiological and textural features appears to yield more effective in the distinction of malignant from benign solitary pulmonary nodules by computed tomography. 相似文献
152.
C. Li S.M. Liu L. Zheng M.W. Huang Y. Shi X.M. Lv J.G. Zhang X. Peng J. Zhang 《Brachytherapy》2021,20(1):171-177
We wished to investigate the outcome of surgery combined with external-beam radiotherapy (EBRT) or brachytherapy (125I seeds) for the treatment of primary adenoid cystic carcinoma (ACC) of the oral and maxillofacial region. Data of patients with primary ACC were reviewed retrospectively. Patients were divided into EBRT and brachytherapy groups. Wide tumor excision was done to achieve negative margins. Standard radiotherapy in the EBRT group was 60 Gy. A treatment-planning system was used to create implantation plans with a prescribed dose of 60–120 Gy and 125I seeds were implanted postoperatively. Kaplan–Meier method and log-rank tests were used to analyze local control and survival. The median duration of followup was 66.1 and 46.8 months for the EBRT group and brachytherapy group, respectively. There was no significant difference in local control, control of metastasis to regional lymph nodes, or control of distant metastasis between the two groups. There was no significant difference in overall survival, disease-specific survival, or disease-free survival in the two groups at 3 years and 5 years. The prevalence of complications in the brachytherapy group was lower than that in the EBRT group. Both methods elicited good treatment effects, but the prevalence of adverse events was lower in the brachytherapy group. 相似文献
153.
Adolescent idiopathic scoliosis (AIS) is a complex three dimensional spinal deformity which occurs mostly in prepubertal and pubertal girls. Although bracing and surgery have been the mainstays of treatment for AIS, because of the complications and poor compliance, many patients with this disorder continue to experience significant residual symptoms. The etiology and pathogenesis of AIS is unclear, but recent studies show the association between osteopenia and AIS and imply that osteopenia play a causative role in the development of AIS. Anti-osteoporosis treatment can improve bone strength, prevent osteoporosis and rebalance the OPG–RANK–RANKL system, which may help to prevent curve progression in AIS. This report proposes that anti-osteoporosis treatment may be an effective treatment for AIS. 相似文献
154.
Neurological Sciences - To summarize the clinical characteristics of patients with sporadic Creutzfeldt-Jakob disease (sCJD), analyze its sleep disorder characteristics using polysomnography (PSG),... 相似文献
155.
N.-N. Zheng X.-C. Guo W. Lv X.-X. Chen G.-F. Feng 《European journal of clinical microbiology & infectious diseases》2013,32(8):1031-1040
Pregnancy and diabetes are regarded as individual risk factors for vaginal candidiasis. The high prevalence of vaginal candidiasis in pregnant diabetic women can be explained by disruption of the balance of the vaginal normal flora. However, little is known about the overall structure and composition of the vaginal fungal flora in pregnant diabetic women. In the present study, the diversity and richness of the vaginal fungal flora in healthy non-pregnant women (group HN), healthy pregnant women (group HP), women with gestational diabetes mellitus (group GDM), and pregnant women with diabetes mellitus type I (group T1DM) were investigated using an 18S rRNA gene clone library method. Our data demonstrated that the composition of the vaginal fungal flora in the four groups could be divided into two phyla (Ascomycetes, 20/26, and Basidiomycetes, 6/26). The most predominant vaginal fungal species belonged to the Candida and Saccharomyces genera, uncultured fungi, and a large number of low-abundance taxa that were unrecorded or underrepresented in previous studies using cultivation-dependent methods. Variation in operational taxonomic units (OTUs) between the study cohorts was generally high in the clone libraries, as 9, 13, 17, and 20 phylotypes were identified in groups HN, HP, GDM, and T1DM, respectively. The Shannon indices of groups GDM and T1DM (with poorer glycemic control) were significantly higher compared to groups HN and HP (p?<?0.05). The data presented here revealed an increased diversity and varied composition of the vaginal fungal flora in pregnant diabetic women and demonstrated that poor glycemic control might be associated with disturbances in the vaginal fungal flora. 相似文献
156.
目的 探讨1、2伸肌间室支持带上动脉(the first and second intercompartmental supraretinacular artery,1,2 ICSRA)桡骨瓣治疗舟骨骨不连的可行性及疗效。 方法 收集47例正常人腕关节CT数据,分别测量桡骨茎突尖端到舟骨长轴近极及远极距离,并与1,2 ICRSA血管蒂的长度进行对比,分析1,2 ICSRA桡骨瓣治疗舟骨骨不连的可行性。对23例舟骨骨不连患者实施1,2 ICSRA桡骨瓣结合Herbert钉内固定手术治疗,随访患者骨折愈合情况;采用Cooney腕关节评分评估患者局部症状和功能。 结果 桡骨茎突尖端到舟骨长轴近极和远极距离分别为(15.66±1.89)mm和(17.07±1.60)mm,均小于1,2 ICSRA血管蒂长度。23例患者术后舟骨均获得愈合;随访时间(51.08±11.30)月,末次随访时21例患者腕关节疼痛感消失,2例患者重体力劳动时有轻微疼痛,但症状较术前得到明显改善;Cooney腕关节评分优20例,良3例,从术前(62.39±7.21)分提高至术后(92.39±4.23)分,差异有统计学意义(t=17.213,P=0)。 结论 1,2 ICSRA桡骨瓣长度足以覆盖舟骨任何部位,该方法治疗舟骨骨不连具备可行性且疗效肯定。 相似文献
157.
Inflammation - Acute ethanol intoxication increases the risk of sepsis and aggravates the symptoms of sepsis and lung injury. Therefore, this study aimed to explore whether sphingosine kinase 1... 相似文献
158.
Bin Zhang Ma-yi-di-li Ni-jia-Ti Ruike Yan Nan An Lv Chen Shuyi Liu Luyan Chen Qiuying Chen Minmin Li Zhuozhi Chen Jingjing You Yuhao Dong Zhiyuan Xiong Shuixing Zhang 《The British journal of radiology》2021,94(1122)
Objectives:To develop and validate a radiomic model to predict the rapid progression (defined as volume growth of pneumonia lesions > 50% within seven days) in patients with coronavirus disease 2019 (COVID-19).Methods:Patients with laboratory-confirmed COVID-19 who underwent longitudinal chest CT between January 01 and February 18, 2020 were included. A total of 1316 radiomic features were extracted from the lung parenchyma window for each CT. The least absolute shrinkage and selection operator (LASSO), Relief, Las Vegas Wrapper (LVW), L1-norm-Support Vector Machine (L1-norm-SVM), and recursive feature elimination (RFE) were applied to select the features that associated with rapid progression. Four machine learning classifiers were used for modeling, including Support Vector Machine (SVM), Random Forest (RF), Logistic Regression (LR), and Decision Tree (DT). Accordingly, 20 radiomic models were developed on the basis of 296 CT scans and validated in 74 CT scans. Model performance was determined by the receiver operating characteristic curve.Results:A total of 107 patients (median age, 49.0 years, interquartile range, 35–54) were evaluated. The patients underwent a total of 370 chest CT scans with a median interval of 4 days (interquartile range, 3–5 days). The combination methods of L1-norm SVM and SVM with 17 radiomic features yielded the highest performance in predicting the likelihood of rapid progression of pneumonia lesions on next CT scan, with an AUC of 0.857 (95% CI: 0.766–0.947), sensitivity of 87.5%, and specificity of 70.7%.Conclusions:Our radiomic model based on longitudinal chest CT data could predict the rapid progression of pneumonia lesions, which may facilitate the CT follow-up intervals and reduce the radiation.Advances in knowledge:Radiomic features extracted from the current chest CT have potential in predicting the likelihood of rapid progression of pneumonia lesions on the next chest CT, which would improve clinical decision-making regarding timely treatment. 相似文献
159.
目的 探讨维、汉族广泛性焦虑临床特征及人格特征的差异.方法 采用汉密尔顿焦虑量表(HAMA)和明尼苏达多项人格调查表(MMPI)对维族56例、汉族83例广泛性焦虑患者进行测试.结果 维族组HAMA睡眠障碍因子分、认知障碍因子分明显高于汉族组(t=1.873,P<0.05;t=3.245,P<0.01).MMH测试两组有8个量表T分同时高于70分,6个量表T分同时低于70分,且维族组校正分量表分值(K)低于汉族组(t=2.126,P<0.05),轻躁狂量表分值高于汉族组(t=2.366,P<0.05).结论 民族文化对广泛性焦虑发病规律、临床特征有影响,对人格特征影响很小,不同民族广泛性焦虑具有共同的人格特征. 相似文献
160.
目的探讨维、汉两族广泛性焦虑患者临床特征及人格特征的差异。方法采用汉密尔顿抑郁量表(HAMA)和明尼苏达多项人格调查表(MMPI)对维族56例、汉族83例广泛性焦虑患者进行测试。结果维族组HAMA中睡眠障碍因子分、认知障碍因子分明显高于汉族组(t=1.873,P<0.05;t=3.245,P<0.01)。MMPI测试两组有8个量表T分同时高于70分,6个量表T分同时低于70分,且维族组校正分量表分值(K)低于汉族组(t=2.126,P<0.05),轻躁狂量表分值高于汉族组(t=2.366,P<0.05)。结论民族文化对广泛性焦虑发病规律、临床特征有影响,对人格特征影响很小,不同民族广泛性焦虑具有共同的人格特征。 相似文献