全文获取类型
收费全文 | 34142篇 |
免费 | 1711篇 |
国内免费 | 417篇 |
专业分类
耳鼻咽喉 | 464篇 |
儿科学 | 560篇 |
妇产科学 | 121篇 |
基础医学 | 1664篇 |
口腔科学 | 1138篇 |
临床医学 | 3609篇 |
内科学 | 2634篇 |
皮肤病学 | 102篇 |
神经病学 | 1444篇 |
特种医学 | 8081篇 |
外国民族医学 | 12篇 |
外科学 | 2799篇 |
综合类 | 7458篇 |
预防医学 | 1737篇 |
眼科学 | 149篇 |
药学 | 1682篇 |
40篇 | |
中国医学 | 442篇 |
肿瘤学 | 2134篇 |
出版年
2024年 | 26篇 |
2023年 | 290篇 |
2022年 | 672篇 |
2021年 | 1115篇 |
2020年 | 1146篇 |
2019年 | 980篇 |
2018年 | 1088篇 |
2017年 | 1178篇 |
2016年 | 1152篇 |
2015年 | 1004篇 |
2014年 | 2300篇 |
2013年 | 1899篇 |
2012年 | 1931篇 |
2011年 | 2406篇 |
2010年 | 2088篇 |
2009年 | 2215篇 |
2008年 | 1959篇 |
2007年 | 1904篇 |
2006年 | 1626篇 |
2005年 | 1306篇 |
2004年 | 1000篇 |
2003年 | 992篇 |
2002年 | 949篇 |
2001年 | 734篇 |
2000年 | 631篇 |
1999年 | 499篇 |
1998年 | 420篇 |
1997年 | 368篇 |
1996年 | 282篇 |
1995年 | 308篇 |
1994年 | 272篇 |
1993年 | 157篇 |
1992年 | 164篇 |
1991年 | 128篇 |
1990年 | 99篇 |
1989年 | 94篇 |
1988年 | 75篇 |
1987年 | 88篇 |
1986年 | 67篇 |
1985年 | 136篇 |
1984年 | 120篇 |
1983年 | 52篇 |
1982年 | 94篇 |
1981年 | 95篇 |
1980年 | 65篇 |
1979年 | 45篇 |
1978年 | 26篇 |
1977年 | 22篇 |
1976年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 278 毫秒
21.
22.
李玉霞 《中国医学文摘.耳鼻咽喉科学》2021,(2):142-143,146
目的探讨磁共振结合高分辨率CT在中耳乳突炎患者术前评估中的临床应用。方法选取我院2018年11月~2020年12月接收患有中耳乳突炎的患者40例为研究对象,所有患者均采用磁共振以及高分辨率CT进行诊断检查,比较两组患者诊断后手术特征显示度。结果诊断后,磁共振联合高分辨率CT检查图像显示度高于单独使用磁共振或高分辨率CT诊断(P<0.05)。结论使用磁共振结合高分辨率CT对中耳乳突炎患者进行术前评估,显示度较高,提高诊断准确度,值得推广。 相似文献
23.
目的 探讨十二指肠肿瘤血流量存在的异质性及容积灌注CT成像对降低肿瘤异质性的影响。方法 纳入我院2013年1月至2014年11月十二指肠结节病例的132例,其中腺癌48例,间质瘤52例,淋巴瘤32例。所有的病例均行单层面灌注CT和容积灌注CT成像扫描,比较两者对十二指肠恶性肿瘤的诊断效能,采用变异系数评价两者在影像学异质性的差异,评价肿瘤影像学异质性对十二指肠恶性肿瘤的影响。结果 容积灌注CT成像与单层面灌注CT诊断恶性结节的效能其敏感性、特异性、准确性、阴性预测值、阳性预测值比较均无明显差别(P0.05);中高分化组及低分化组两个亚组的容积灌注CT成像的变异系数也均小于单层面灌注CT的变异系数,组间相比具有统计学差异(P0.05);血流量差异性的大小相比具有统计学差异(P0.05)。结论 容积灌注CT成像与单层面灌注CT检查在诊断效能上无明显差异,稳定性好,肿瘤影像学异质性对评价十二指肠肿瘤血流量有着一定影响,容积灌注CT成像能够降低肿瘤异质性的影响。 相似文献
24.
J. Alarcón-Rodríguez M. Fernández-Velilla A. Ureña-Vacas J.J. Martín-Pinacho J.A. Rigual-Bobillo A. Jaureguízar-Oriol L. Gorospe-Sarasúa 《Radiologia》2021,63(3):258-269
Most of the patients who overcome the SARS-CoV-2 infection do not present complications and do not require a specific follow-up, but a significant proportion (especially those with moderate / severe clinical forms of the disease) require clinicalradiological follow-up. Although there are hardly any references or clinical guidelines regarding the long-term follow-up of post-COVID-19 patients, radiological exams are being performed and monographic surveillance consultations are being set up in most of the hospitals to meet their needs. The purpose of this work is to share our experience in the management of the post-COVID-19 patient in two institutions thathave had a high incidence of COVID-19 and to propose general follow-uprecommendations from a clinical and radiological perspective. 相似文献
25.
《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
26.
《Radiography》2020,26(3):e134-e139
IntroductionIn the Netherlands, Diagnostic Reference Levels (DRLs) have not been based on a national survey as proposed by ICRP. Instead, local exposure data, expert judgment and the international scientific literature were used as sources. This study investigated whether the current DRLs are reasonable for Dutch radiological practice.MethodsA national project was set up, in which radiography students carried out dose measurements in hospitals supervised by medical physicists. The project ran from 2014 to 2017 and dose values were analysed for a trend over time. In the absence of such a trend, the joint yearly data sets were considered a single data set and were analysed together. In this way the national project mimicked a national survey.ResultsFor six out of eleven radiological procedures enough data was collected for further analysis. In the first step of the analysis no trend was found over time for any of these procedures. In the second step the joint analysis lead to suggestions for five new DRL values that are far below the current ones. The new DRLs are based on the 75 percentile values of the distributions of all dose data per procedure.ConclusionThe results show that the current DRLs are too high for five of the six procedures that have been analysed. For the other five procedures more data needs to be collected. Moreover, the mean weights of the patients are higher than expected. This introduces bias when these are not recorded and the mean weight is assumed to be 77 kg.Implications for practiceThe current checking of doses for compliance with the DRLs needs to be changed. Both the procedure (regarding weights) and the values of the DRLs should be updated. 相似文献
27.
于洋 《中国CT和MRI杂志》2016,(6):85-87
目的研究~(18)F-FDG PETCT显像对膀胱癌的诊断价值。方法选取我院核医学科2013年3月-2015年2月收治的34例可疑膀胱癌患者,术前分别采用增强CT和~(18)F-FDG PETCT显像进行诊断,通过参考手术病理结果回顾性分析~(18)F-FDG PETCT显像诊断的效果。结果该34例经手术病理观察均确诊为移行细胞癌,增强CT、~(18)F-FDG PETCT显像诊断准确度分别为91.18%、94.12%,差异无统计学意义(P0.05);术中共有11例膀胱肿瘤出现盆腔淋巴结或邻近组织转移、浸润,~(18)F-FDG PETCT显像诊断准确度为72.73%,明显高于增强CT(27.27%),具有统计学意义(P0.05)。结论 ~(18)F-FDG PETCT显像和增强CT均是临床诊断膀胱癌的有效方法,但~(18)F-FDG PETCT显像在观察膀胱肿瘤病灶的转移和对邻近组织的浸润效果较好,对指导临床诊断和了解肿瘤病变具有重要参考价值。 相似文献
28.
《Digestive and liver disease》2020,52(4):420-426
BackgroundManagement of inflammatory bowel diseases (IBD) in the emergency department is often suboptimal.AimsTo develop a national consensus checklist of indicators to facilitate decision-making in emergency departments concerning hospitalisation and referral for abdominopelvic computed tomography (CT).MethodsA Delphi survey was used to obtain consensus on a checklist of clinical and biological variables. 119 healthcare professionals experienced in treating IBD were invited to participate. Panellists were provided with a literature survey and invited to agree or disagree with items on a prototype checklist. Two successive rounds of voting were organised.ResultsThe prototype checklist included fifteen clinical or laboratory indicators for hospitalisation or CT. Four indicators were not retained in the Delphi process and four additional indicators added. The final indicators retained were: abdominal signs/symptoms of disease exacerbation, intravenous morphine titration, fever, vomiting, dehydration, recent intestinal surgery, ano-perineal abscess, bowel obstruction, haemodynamic instability, anaemia, acute kidney failure and elevated C-reactive protein. Consensus for the retained indicators was >88%.ConclusionsUse of this consensus checklist for the management of IBD in the emergency department may help improve standards of care and thus reduce the burden of these diseases. 相似文献
29.
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
30.
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