全文获取类型
收费全文 | 58228篇 |
免费 | 4642篇 |
国内免费 | 1318篇 |
专业分类
耳鼻咽喉 | 947篇 |
儿科学 | 507篇 |
妇产科学 | 182篇 |
基础医学 | 2217篇 |
口腔科学 | 2299篇 |
临床医学 | 8949篇 |
内科学 | 6423篇 |
皮肤病学 | 195篇 |
神经病学 | 3065篇 |
特种医学 | 18285篇 |
外国民族医学 | 27篇 |
外科学 | 5018篇 |
综合类 | 6973篇 |
现状与发展 | 4篇 |
预防医学 | 1063篇 |
眼科学 | 3174篇 |
药学 | 1615篇 |
18篇 | |
中国医学 | 190篇 |
肿瘤学 | 3037篇 |
出版年
2024年 | 151篇 |
2023年 | 1057篇 |
2022年 | 1912篇 |
2021年 | 2665篇 |
2020年 | 2135篇 |
2019年 | 1882篇 |
2018年 | 1918篇 |
2017年 | 1840篇 |
2016年 | 1975篇 |
2015年 | 1994篇 |
2014年 | 3963篇 |
2013年 | 3179篇 |
2012年 | 3526篇 |
2011年 | 3777篇 |
2010年 | 3294篇 |
2009年 | 3400篇 |
2008年 | 3284篇 |
2007年 | 3310篇 |
2006年 | 2969篇 |
2005年 | 2512篇 |
2004年 | 2038篇 |
2003年 | 1694篇 |
2002年 | 1393篇 |
2001年 | 1234篇 |
2000年 | 965篇 |
1999年 | 823篇 |
1998年 | 655篇 |
1997年 | 669篇 |
1996年 | 515篇 |
1995年 | 480篇 |
1994年 | 423篇 |
1993年 | 308篇 |
1992年 | 252篇 |
1991年 | 211篇 |
1990年 | 198篇 |
1989年 | 193篇 |
1988年 | 165篇 |
1987年 | 181篇 |
1986年 | 125篇 |
1985年 | 161篇 |
1984年 | 165篇 |
1983年 | 98篇 |
1982年 | 143篇 |
1981年 | 117篇 |
1980年 | 79篇 |
1979年 | 61篇 |
1978年 | 34篇 |
1977年 | 40篇 |
1976年 | 23篇 |
1974年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
51.
《中国现代医生》2019,57(35):100-102+105
目的探讨多层螺旋CT(MSCT)定量评估慢性阻塞性肺疾病病情的价值。方法选取2017年8月~2018年7月在湖州市第一人民医院就诊的73例慢性阻塞性肺疾病(COPD)患者作为研究对象,按照病情轻重分为Ⅰ组(轻度患者17例)、Ⅱ组(中度患者32例)、Ⅲ组(重度患者24例),并选取同期于该院体检的健康者20例为对照组。所有研究对象均行MSCT低剂量扫描,观察比较各组管腔面积(Ai)、支气管壁面积百分比(WA%)、管壁厚度与体表面积比值(T/BSA)、壁厚度与直径比值(TDR),同时予以肺功能检查,采用定量CT气道分析软件分别测量气道相关参数,并用Siemens Pulmo软件Pearson定量分析其相关性。结果对照组、Ⅰ组、Ⅱ组、Ⅲ组的FEV1均呈逐渐下降趋势,FEV1/FVC呈逐渐上升趋势,差异均有统计学意义(P0.05)。对照组、Ⅰ组、Ⅱ组、Ⅲ组的WA%、T/BSA、TDR比较,均呈逐渐上升趋势,Ai呈下降趋势,差异均有统计学意义(P0.05)。FEV1与WA%、TDR之间呈负相关(r=-0.291,P=0.000;r=-0.473,P=0.000),FEV1/FVC与WA%、TDR之间呈正相关(r=0.285,P=0.000;r=0.472,P=0.000)。结论 MSCT扫描及定量分析可为COPD患者气道病变情况提供可靠的评估信息。 相似文献
52.
《Journal of Medical Imaging and Radiation Sciences》2020,51(1):173-181
IntroductionThis study aims to construct learning curves related to the realization of standardized postprocessing by radiographer students and to discuss their exploitation and interest.Materials and MethodsThis study was carried out in 21 French students in their 3rd year of training. Two postprocessing protocols in CT (#1 traumatic shoulder; #2 petrous bone) were repeated 15 times by each student. Each achievement was timed to obtain overall learning curves. The realization accuracy was also assessed for each student at each repetition.ResultsThe learning rates for the two protocols are 63% and 56%, respectively. The number of repetitions to reach the reference time for each protocol is 11 and 12, respectively. In both protocols, the standard deviations are significantly reduced and stabilized during repetitions. The mean accuracy progresses more quickly in protocol #1.DiscussionThe measured learning rates reflect a rapid learning process for each protocol. The analysis of the standard deviations shows that students have reached a homogeneous level. The average times and accuracies measured during the last repetitions show that the group has reached a high level of performance. Building learning curves helps students measure their progress and motivates them.ConclusionObtaining learning curves allows trainers/supervisors to qualify the learning difficulty of a task while motivating students/radiographers. The use of learning curves is inline with the competency-based training paradigm. 相似文献
53.
Matthew D. Li Katrina F. Chu Allegra DePietro Vincent Wu Eric Wehrenberg-Klee Omar Zurkiya Raymond W. Liu Suvranu Ganguli 《Journal of vascular and interventional radiology : JVIR》2019,30(3):314-319
Purpose
To evaluate the feasibility of a same-day yttrium-90 (90Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.Materials and Methods
All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.Results
All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned 90Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy–limiting toxicities. The mean total procedure time was 4.2 hours.Conclusions
A same-day 90Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy. 相似文献54.
55.
Xiaoxuan Liu Ameenat L. Solebo Livia Faes Sophie Beese Tasanee Braithwaite Matthew E. Round 《Ocular immunology and inflammation》2020,28(6):898-907
ABSTRACT
Purpose
New instrument-based techniques for anterior chamber (AC) cell counting can offer automation and objectivity above clinician assessment. This review aims to identify such instruments and its correlation with clinician estimates. 相似文献56.
57.
58.
段前深 《实用医学影像杂志》2020,(2):127-129
目的探讨CT扫描在胸膜外孤立性纤维瘤(E-SFT)中的诊断价值。方法回顾性分析2015年4月至2018年4月于我院接受手术治疗的90例E-SFT患者术前CT检查影像资料和术后病理、免疫组织化学资料,评估CT检查在E-SFT诊断中的应用价值。结果 90例E-SFT患者均为单发肿瘤,免疫组织化学及病理学检查示良性80例,恶性10例;CT检查结果为良性72例,平扫表现为圆形或类圆形软组织密度影,密度不均匀,大部分边缘清晰,增强扫描表现为均匀强化;恶性18例,平扫示肿瘤体积较大,边界不清,密度不均,可见大片不规则低密度区,增强扫描瘤体强化不均匀,低密度区无明显强化;CT诊断的敏感度、准确度、特异性阳性率、阴性率分别为60%(6/10)、82%(74/90)、85%(68/80)、33%(6/18)、94%(68/72)。结论 E-SFT的CT检查影像图像具有一定的特征性,尤其是增强扫描有助于评估纤维瘤的良恶性,可将其作为术前诊断及术后复查评估的有效依据用于临床诊疗工作中。 相似文献
59.
60.
Background:Colon cancer is a common malignant tumor of the gastrointestinal tract. Therefore, a clear diagnosis is particularly important for the treatment of colon cancer. Ultrasound and spiral computed tomography (CT) can both be used in the diagnosis, but each has its own advantages and disadvantages, which could cause confusion in clinical choice. The purpose of this study was to systematically evaluate the practicability of spiral CT and ultrasound in the diagnosis of colon cancer.Methods:A systematic search was performed by retrieving on English databases (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese databases (CNKI, Wanfang, Weipu [VIP], CBM). Besides, manually search for Google and Baidu academic of diagnostic experimental study of ultrasound and spiral CT in the diagnosis of Colon Cancer. The retrieval time limit was from the establishment of the database to October 2020. Two researchers independently extracted and evaluated the quality of the data in the included study. A meta-analysis was performed using Meta Disc1.4 and RevMan5.3 software.Results:Sensitivity, specificity, positive Likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were used to determine the diagnostic efficacy of ultrasonography and helical CT in colorectal cancer.Conclusions:This study will compare the practicability of CT and ultrasound in the diagnosis of colon cancer and provide reliable evidence-based basis for clinicians to choose the appropriate or best evidence-based basis.Ethics and dissemination:The private information from individuals will not be published. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.OSF Registration number:DOI 10.17605/OSF.IO/WAJHQ 相似文献