全文获取类型
收费全文 | 38140篇 |
免费 | 1919篇 |
国内免费 | 535篇 |
专业分类
耳鼻咽喉 | 400篇 |
儿科学 | 614篇 |
妇产科学 | 161篇 |
基础医学 | 1750篇 |
口腔科学 | 1130篇 |
临床医学 | 4198篇 |
内科学 | 3304篇 |
皮肤病学 | 111篇 |
神经病学 | 1703篇 |
特种医学 | 9125篇 |
外国民族医学 | 12篇 |
外科学 | 3494篇 |
综合类 | 7896篇 |
预防医学 | 1887篇 |
眼科学 | 205篇 |
药学 | 1913篇 |
40篇 | |
中国医学 | 528篇 |
肿瘤学 | 2123篇 |
出版年
2024年 | 24篇 |
2023年 | 300篇 |
2022年 | 751篇 |
2021年 | 1214篇 |
2020年 | 1164篇 |
2019年 | 1008篇 |
2018年 | 1167篇 |
2017年 | 1276篇 |
2016年 | 1330篇 |
2015年 | 1127篇 |
2014年 | 2506篇 |
2013年 | 2094篇 |
2012年 | 2103篇 |
2011年 | 2560篇 |
2010年 | 2306篇 |
2009年 | 2401篇 |
2008年 | 2202篇 |
2007年 | 2165篇 |
2006年 | 1849篇 |
2005年 | 1509篇 |
2004年 | 1200篇 |
2003年 | 1153篇 |
2002年 | 1085篇 |
2001年 | 881篇 |
2000年 | 755篇 |
1999年 | 575篇 |
1998年 | 485篇 |
1997年 | 447篇 |
1996年 | 337篇 |
1995年 | 348篇 |
1994年 | 333篇 |
1993年 | 202篇 |
1992年 | 197篇 |
1991年 | 157篇 |
1990年 | 126篇 |
1989年 | 112篇 |
1988年 | 96篇 |
1987年 | 108篇 |
1986年 | 95篇 |
1985年 | 157篇 |
1984年 | 142篇 |
1983年 | 65篇 |
1982年 | 120篇 |
1981年 | 114篇 |
1980年 | 88篇 |
1979年 | 64篇 |
1978年 | 40篇 |
1977年 | 29篇 |
1976年 | 14篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
1.
目的 运用CT区分脾脏血管性病变与淋巴瘤。方法 回顾性分析20例经手术、穿刺病理学检查证实的脾脏病变的发病年龄、性别、脾脏指数、病变大小、数目、有无液化、钙化、强化幅度、强化方式等特征,并进行统计学分析。结果 20例脾脏病变中,11例血管性病变(6例海绵状血管瘤,3例窦岸细胞血管瘤,2例硬化性血管瘤样结节性转化),9例淋巴瘤;两组间发病年龄、病变大小、数目、有无液化、钙化等差异无统计学意义;两组间脾脏指数、动脉期强化幅度差异具有统计学意义(P<0.05)。5例海绵状血管瘤呈不均匀性强化,1例呈渐进性填充式强化,2例窦岸细胞血管瘤呈“雀斑征”,1例硬化性血管瘤样结节性转化呈“辐轮征”;9例淋巴瘤实质部分均呈均匀、轻中度强化。结论 脾脏血管性病变与淋巴瘤CT表现不同,CT有助于明确诊断。 相似文献
2.
阿尔茨海默病是一种进行性且不可逆转的神经系统疾病,由于视网膜和中枢神经系统有相似的胚胎起源和生理特征,眼科检查可提供简单无创的诊断方法。光学相干断层扫描技术(OCT)能够精确地测量视网膜各个组织层面的厚度,以评估视网膜的退行性改变,光学相干断层扫描血管成像(OCTA)可以提供高分辨率三维成像,从而更直观地检测视网膜血管的变化,间接地反映脑神经元和血管的病理特征。就OCT测量视网膜厚度及OCTA测量视网膜血流变化在阿尔茨海默病诊断中的研究进展进行综述。 相似文献
3.
4.
5.
《Transfusion Clinique et Biologique》2022,29(2):138-140
PurposePlatelet transfusions for patients suffering from severe thrombocytopenia are regulated by clinical bleedings and platelet counts. The aim of this study was to assess the prevalence of retinal hemorrhage in patients with hematologic and oncologic malignancies and severe thrombocytopenia, and to determine the benefit of systematic funduscopic examination in this setting.Materials and methodsHospitalized patients with hematologic and oncologic malignancies having a platelet count less than 25,000 per μL underwent indirect ophthalmoscopy. The prevalence of retinal hemorrhage and its correlation with different patients’ characteristics were determined. The decision to transfuse platelets or not following bedside indirect ophthalmoscopy was left at the discretion of the treating physician.ResultsA total of 34 severe thrombocytopenic patients were included in the study. The prevalence of retinal hemorrhage was detected in 10 patients (29.4%). No significant correlation was found between the occurrence of retinal hemorrhage and age, platelet count or thrombocytopenia etiology (P > 0.05). No significant difference was found concerning the rate of transfusion between those with and without retinal hemorrhage.ConclusionAccording to our statistical results, retinal hemorrhage is a frequent finding in severely thrombocytopenic patients. Early detection may lead to an increase in the platelet transfusion threshold from to 30,000 per μL offering additional protection against spontaneous bleedings. Funduscopy is a safe and easy exam to perform systematically in patients with severe thrombocytopenia. 相似文献
6.
《Medical Journal Armed Forces India》2022,78(1):17-23
Pulmonary thromboembolism (PTE) is an important cause of mortality/morbidity even today despite advancement in clinical understanding as well as diagnostic facilities. Clinical diagnosis of PTE is often challenging because of nonspecific sign/symptoms. Adherence to clinical decision-making protocols and appropriate use of diagnostic modalities like computed tomography pulmonary angiography can resolve the diagnostic dilemma in most cases and help in the overall management of PTE. This article deals with various concerns as well as controversies surrounding accurate diagnosis of PTE as on date. 相似文献
7.
BackgroundLymph node recurrences (LNR) from colorectal cancer (CRC) still represent a therapeutic challenge, as standardized recommendations have yet to be established. The aim of this study was to analyze short- and long-term oncological outcomes following resection of LNR from CRC.MethodsAll patients with previously resected CRC who underwent histopathologically confirmed LNR resection in 3 tertiary referral centers between 2010 and 2017 were reviewed. Short- and long-term outcomes were analyzed, mainly recurrence-free and overall survival. Further recurrences following LNR resection were also analyzed.ResultsOverall, 18 patients were included. Primary CRC was left-sided in 16 (89%) patients, staged T3-4 in 15 (83%), N+ in 14 (78%) and presented with synchronous metastases in 8 (43%). Median time interval between primary CRC and LNR resections was 31 months. Performed lymphadenectomies were aortocaval (n = 10), pelvic (n = 7), in hepatic pedicle (n = 3) and mesenteric (n = 1). Four patients had associated liver metastases resection. Three (17%) presented with postoperative complications, of which one Clavien-Dindo 3. Fourteen (78%) patients presented with further recurrences after a mean delay of 9 months, with 36% of patients presenting with early (<6 months) recurrence. Five (36%) patients could undergo secondary recurrence resection and 3 (21%) patients radiotherapy. Median overall survival following LNR resection reached 44 months.ConclusionsCurrent results suggest that LNR resection is feasible and associated with improved survival, in selected patients. Longer time interval between primary CRC resection and LNR occurrence appeared to be a favorable prognostic factor whereas multisite recurrence appeared to be associated with impaired long-term survival. 相似文献
8.
9.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3
Objective
Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.Methods
Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.Results
In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.Conclusions
Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection. 相似文献10.
目的探讨CT与MRI在脑梗死后出血性转变(HT)中的诊断价值。方法对2011-01—2014-04我院收治的45例HT患者的临床资料进行回顾性分析,对CT与MRI的检查结果进行对比。结果45例患者中,脑内血肿34例(75.6%),脑梗死病灶内片状、斑点状或条状出血11例(24.4%)。其中大面积脑梗死继发出血24例(53.3%),中等面积继发出血15例(33.3%),小面积脑梗死继发出血6例(13.3%);CT检出HT 10例(22.2%),MRI检出45例(100%),差异有统计学意义(P0.05);在对不同部位的HT检查中,CT检出幕上出血9例(20.0%),幕下出血1例(2.2%);MRI检出幕上出血39例(86.7%),幕下出血6例(13.3%)。MRI对幕上及幕下出血的检出率均优于CT(P0.05)。结论在HT的诊断中,MRI比CT更加准确和敏感,在判断出血时间、指导临床治疗以及预后判断中具有重要意义。 相似文献