全文获取类型
收费全文 | 421篇 |
免费 | 28篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 2篇 |
妇产科学 | 2篇 |
基础医学 | 54篇 |
口腔科学 | 19篇 |
临床医学 | 74篇 |
内科学 | 15篇 |
皮肤病学 | 1篇 |
神经病学 | 7篇 |
特种医学 | 29篇 |
外科学 | 24篇 |
综合类 | 30篇 |
预防医学 | 59篇 |
药学 | 81篇 |
中国医学 | 26篇 |
肿瘤学 | 29篇 |
出版年
2024年 | 3篇 |
2023年 | 13篇 |
2022年 | 19篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 14篇 |
2017年 | 15篇 |
2016年 | 19篇 |
2015年 | 10篇 |
2014年 | 34篇 |
2013年 | 29篇 |
2012年 | 40篇 |
2011年 | 40篇 |
2010年 | 20篇 |
2009年 | 24篇 |
2008年 | 15篇 |
2007年 | 26篇 |
2006年 | 15篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有453条查询结果,搜索用时 0 毫秒
71.
Li HS Kong LL Zhang J Li BS Chen JH Zhu J Liu TH Yin Y 《Asian Pacific journal of cancer prevention》2012,13(5):2393-2398
Objectives: The purpose of this study was to evaluate the geometric accuracy of thoracic anatomic landmarksas target surrogates of intrapulmonary tumors for manual rigid registration during image-guided radiotherapy(IGRT). Methods: Kilovolt cone-beam computed tomography (CBCT) images acquired during IGRT for 29 lungcancer patients with 33 tumors, including 16 central and 17 peripheral lesions, were analyzed. We selected the“vertebrae,” “carina,” and “large bronchi” as the candidate surrogates for central targets, and the “vertebrae,”“carina,” and “ribs” as the candidate surrogates for peripheral lesions. Three to six pairs of small identifiablemarkers were noted in the tumors for the planning CT and Day 1 CBCT. The accuracy of the candidate surrogateswas evaluated by comparing the distances of the corresponding markers after manual rigid matching basedon the “tumor” and a particular surrogate. Differences between the surrogates were assessed using 1-wayanalysis of variance and post hoc least-significant-difference tests. Results: For central targets, the residualerrors increased in the following ascending order: “tumor,” “bronchi,” “carina,” and “vertebrae;” there was asignificant difference between “tumor” and “vertebrae” (p = 0.010). For peripheral diseases, the residual errorsincreased in the following ascending order: “tumor,” “rib,” “vertebrae,” and “carina;” There was a significantdifference between “tumor” and “carina” (p = 0.005). Conclusions: The “bronchi” and “carina” are the optimalsurrogates for central lung targets, while “rib” and “vertebrae” are the optimal surrogates for peripheral lungtargets for manual matching of online and planned tumors. 相似文献
72.
摘要:目的 分析广西4个县传染病报告信息管理系统(大疫情)与结核病信息管理系统(专报)分别报告和登记的肺结核患者数据的不一致率以及原因。方法 选择两系统分别导出的报告与登记数差异较大的A、B、C、D 4个县进行现场核查和统计分析。内容包括:数据预分析、定性访谈、现场核查和抽样调查。结果 两系统的平均报告登记一致率为32.45%,最低17.09%。疑似肺结核患者被排除后没有从专报向大疫情推送占65.41%;专报 82例转诊到位未收治和未排除的疑似肺结核病例,其中15例(18.29%)为流动治疗患者,实则并未到位及登记;5例(6.10%)无诊疗资料;62例有资料者中,9例(14.52%)涂阳肺结核患者没有得到收治,10例(16.13%)既往有抗结核治疗史的涂阴肺结核病患者由于无法定性,未得到及时处理,其余43例到位后均未进行收治或排除;抽查40例排除活动性肺结核病例的排除符合率为67.50%。结论 专报系统排除活动性肺结核患者数据没有向大疫情推送,是导致两个系统报告和登记数据不一致的主要原因;结防机构过度排除患者成为疫情丢失的隐患;到位未收治或未排除体现了部分基层结防机构工作责任心和积极性不足;流动治疗患者及既往有抗结核治疗史涂阴肺结核患者的管理、收治是目前专报系统登记和管理的空白区。应加强基层人员能力建设,建立和优化两系统报告与登记数据质量定期核查机制。 相似文献
73.
目的通过分析无锡市惠山区2008--2012年度结核病疫情,了解该地区肺结核病流行特征,为制定下一步防控措施、降低肺结核病发病率提供科学依据。方法对2008--2012年无锡市惠山区肺结核病例统计监测资料进行整理并利用SPSS13.0、MicrosoftExcel软件进行流行病学、统计学分析。结果惠山区年均活动性肺结核登记率为39.07/10万,新涂阳登记率为16.19/10万。患者中男性病例975例,患病率为27.21/10万;女性425例,患病率为11.86/10万;男性肺结核患病率明显大于女性,差异有统计学意义(x2=6.401,P〈0.05)。除0—4岁组其余均有发病,其中15~24岁、25~34岁、35~44岁组病例数较多,占发病总数的57.21%。患者以农民、民工为主,共计988例,占活动性肺结核总数的70.57%。洛社、堰桥、钱桥等外来务工人员较多的地区,患者发现例数相对较多。全年各月均有发病,无明显季节性差异,11、12、1月份病例数较少。结论该区活动性结核患者以从事体力劳动的男性青壮年为主,根据结核病发病特点有针对性地采取防治措施才能更为有效的控制结核病传播流行。 相似文献
74.
本文检索近十年中成药上市后进行的临床研究,尤其是在SCI杂志上发表的高质量临床研究,回顾目前注册中成药中进行上市后再评价现状及与国际接轨的情况。列出目前中成药进入国际市场存在的问题,并以FDA、加拿大及欧盟对于植物药及草药的注册要求来详细陈述,指出中成药上市后再评价的必要性及未来的发展趋势。 相似文献
75.
Objective::In 2015, the Chinese Pancreatic Association of the Chinese Society of Surgery of the Chinese Medical Association launched a national multicenter onli... 相似文献
76.
《Brachytherapy》2014,13(2):128-136
PurposeTo present a high-dose-rate (HDR) brachytherapy procedure for prostate cancer using transrectal ultrasound (TRUS) to contour the regions of interest and registered in-room cone-beam CT (CBCT) images for needle reconstruction. To characterize the registration uncertainties between the two imaging modalities and explore the possibility of performing the procedure solely on TRUS.Methods and MaterialsPatients were treated with a TRUS/CBCT-based HDR brachytherapy procedure. For 100 patients, dosimetric results were analyzed. For 40 patients, registration uncertainties were examined by determining differences in fiducial marker positions on TRUS and registered CBCT. The accuracy of needle reconstruction on TRUS was investigated by determining the position differences of needle tips on TRUS and CBCT. The dosimetric impact of reregistration and needle reconstruction on TRUS only was studied for 8 patients.ResultsThe average prostate V100 was 97.8%, urethra D10 was 116.3%, and rectum D1 cc was 66.4% of the prescribed dose. For 85% of the patients, registration inaccuracies were within 3 mm. Large differences were found between needle tips on TRUS and CBCT, especially in cranial–caudal direction, with a maximum of 10.4 mm. Reregistration resulted in a maximum V100 reduction of 0.9%, whereas needle reconstruction on TRUS only gave a maximum reduction of 9.4%.ConclusionsHDR prostate brachytherapy based on TRUS combined with CBCT is an accurate method. Registration uncertainties, and consequently dosimetric inaccuracies, are small compared with the uncertainties of performing the procedure solely based on static TRUS images. CBCT imaging is a requisite in our current procedure. 相似文献
77.
78.
《European journal of cancer (Oxford, England : 1990)》2014,50(2):251-259
The European Clinical Trials Directive of 2004 has increased the amount of paper work and reduced the number of initiated clinical trials. Particularly multinational trials have been delayed. To meet this challenge we developed a novel, simplified, fast and easy strategy for on-line toxicity registration for patients treated according to the Nordic/Baltic acute lymphoblastic leukaemia protocol, NOPHO ALL 2008, for children and young adults, including three randomisations. We used a risk-assessment based approach, avoiding reporting of expected adverse events and instead concentrating on 20 well-known serious, but rarer events with focus on changes in therapy introduced in the treatment protocol. This toxicity registration strategy was approved by the relevant regulatory authorities in all seven countries involved, as compliant within the EU directive of 2004. The centre compliance to registration was excellent with 98.9% of all patients being registered within 5 weeks from the requested quarterly registration. Currently, four toxicities (thrombosis, fungal infections, pancreatitis and allergic reactions) have been chosen for further detailed exploration due to the cumulative fraction of patients with positive registrations exceeding 5%.This toxicity registration offers real-time toxicity profiles of the total study cohort and provides early warnings of specific toxicities that require further investigation. 相似文献
79.
Region of Interest (ROI) longitudinal studies have detected progressive gray matter (GM) volume reductions in patients with first-episode schizophrenia (FESZ). However, there are only a few longitudinal voxel-based morphometry (VBM) studies, and these have been limited in ability to detect relationships between volume loss and symptoms, perhaps because of methodologic issues. Nor have previous studies compared and validated VBM results with manual Region of Interest (ROI) analysis.In the present VBM study, high-dimensional warping and individualized baseline-rescan templates were used to evaluate longitudinal volume changes within subjects and compared with longitudinal manual ROI analysis on the same subjects. VBM evaluated thirty-three FESZ and thirty-six matched healthy control subjects (HC) at baseline (cross-sectionally) and longitudinally evaluated 21 FESZ and 23 HC after an average of 1.5 years from baseline scans. Correlation analyses detected the relationship between changes in regional GM volumes in FESZ and clinical symptoms derived from the Brief Psychiatric Rating Scale, as well as cognitive function as assessed by the Mini-Mental State Examination.At baseline, patients with FESZ had significantly smaller GM volume compared to HC in some regions including the left superior temporal gyrus (STG). On rescan after 1.5 years, patients showed significant GM volume reductions compared with HC in the left STG including Heschl's gyrus, and in widespread brain neocortical regions of frontal, parietal, and limbic regions including the cingulate gyrus. FESZ showed an association of positive symptoms and volume loss in temporal (especially STG) and frontal regions, and negative symptoms and volume loss in STG and frontal regions. Worse cognitive function was linked to widespread volume reduction, in frontal, temporal and parietal regions. The validation VBM analyses showed results similar to our previous ROI findings for STG and cingulate gyrus. We conclude FESZ show widespread, progressive GM volume reductions in many brain regions. Importantly, these reductions are directly associated with a worse clinical course. Congruence with ROI analyses suggests the promise of this longitudinal VBM methodology. 相似文献
80.
Anticevic A Repovs G Dierker DL Harwell JW Coalson TS Barch DM Van Essen DC 《NeuroImage》2012,59(3):2539-2547
Volume-based registration (VBR) is the predominant method used in human neuroimaging to compensate for individual variability. However, surface-based registration (SBR) techniques have an inherent advantage over VBR because they respect the topology of the convoluted cortical sheet. There is evidence that existing SBR methods indeed confer a registration advantage over affine VBR. Landmark-SBR constrains registration using explicit landmarks to represent corresponding geographical locations on individual and atlas surfaces. The need for manual landmark identification has been an impediment to the widespread adoption of Landmark-SBR. To circumvent this obstacle, we have implemented and evaluated an automated landmark identification (ALI) algorithm for registration to the human PALS-B12 atlas. We compared ALI performance with that from two trained human raters and one expert anatomical rater (ENR). We employed both quantitative and qualitative quality assurance metrics, including a biologically meaningful analysis of hemispheric asymmetry. ALI performed well across all quality assurance tests, indicating that it yields robust and largely accurate results that require only modest manual correction (< 10 min per subject). ALI largely circumvents human error and bias and enables high throughput analysis of large neuroimaging datasets for inter-subject registration to an atlas. 相似文献