首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   183055篇
  免费   17702篇
  国内免费   8575篇
耳鼻咽喉   2385篇
儿科学   3982篇
妇产科学   2223篇
基础医学   32255篇
口腔科学   5653篇
临床医学   14385篇
内科学   25194篇
皮肤病学   4643篇
神经病学   10051篇
特种医学   4085篇
外国民族医学   125篇
外科学   15891篇
综合类   29525篇
现状与发展   51篇
预防医学   4851篇
眼科学   5120篇
药学   14702篇
  29篇
中国医学   5964篇
肿瘤学   28218篇
  2024年   153篇
  2023年   2504篇
  2022年   3249篇
  2021年   6136篇
  2020年   5826篇
  2019年   5655篇
  2018年   5930篇
  2017年   6316篇
  2016年   6648篇
  2015年   7500篇
  2014年   11100篇
  2013年   12320篇
  2012年   10782篇
  2011年   12151篇
  2010年   10192篇
  2009年   9813篇
  2008年   10244篇
  2007年   10543篇
  2006年   9479篇
  2005年   8648篇
  2004年   7625篇
  2003年   6520篇
  2002年   5316篇
  2001年   4548篇
  2000年   3706篇
  1999年   3158篇
  1998年   2574篇
  1997年   2469篇
  1996年   2141篇
  1995年   2154篇
  1994年   1887篇
  1993年   1570篇
  1992年   1272篇
  1991年   1202篇
  1990年   929篇
  1989年   861篇
  1988年   806篇
  1987年   651篇
  1986年   603篇
  1985年   800篇
  1984年   710篇
  1983年   491篇
  1982年   518篇
  1981年   415篇
  1980年   356篇
  1979年   260篇
  1978年   184篇
  1977年   139篇
  1976年   103篇
  1975年   41篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
《Diagnostic Histopathology》2021,27(12):506-518
Recent discovery of new disease-defining molecular alterations and development of novel targeted therapies has dramatically changed the classification and management of uterine mesenchymal neoplasms. This review discusses diagnostic updates in endometrial stromal sarcoma, PEComa, uterine tumor resembling ovarian sex cord tumor (UTROSCT), inflammatory myofibroblastic tumor, NTRK fusion uterine sarcoma, COL1A1-PDGFB fusion sarcoma, and SMARC-deficient uterine sarcoma. Key clinical, morphologic, immunophenotypic, and molecular features are reviewed, with emphasis on common differential diagnoses and pitfalls, and their impact on prognosis or management. Where applicable, the role of novel targeted therapies is discussed. A stepwise approach to uterine mesenchymal neoplasms can achieve a proper diagnosis and guide appropriate clinical management in most cases. Nonetheless, given the rarity of these tumors, their overlapping pathologic features, and rapid evolution in their classification and management, we advocate a low threshold for diagnostic consultation.  相似文献   
52.
53.
ObjectiveTo study the clinical features and identify unique renal neoplasia subtypes and their prognostic implications in individuals with tuberous sclerosis complex (TSC).Patients and MethodsThe Mayo Clinic nephrectomy registry included 37 patients with TSC diagnosed between 1970 and 2018. Four additional patients were identified from the pathology consultation and autopsy files. All available renal tumors were further characterized using immunohistochemistry and fluorescence in situ hybridization. Clinicopathologic features and follow-up were obtained from the medical record. The American Association for Cancer Research Project GENIE registry was accessed using cBioPortal for molecular profiling of angiomyolipoma (AML).ResultsA total of 276 renal tumors from 41 patients were analyzed. Renal tumors were classified into 9 distinct morphological subtypes, with AML predominating (238 [86%]). Interestingly, all these tumors acted in a benign fashion except one renal cell carcinoma with clear cells and fibromyomatous stroma and one epithelioid AML that metastasized. Molecular profiling studies revealed that epithelioid AMLs were enriched for alterations of TP53, RB1, and ATRX. Eight patients died of direct complications of TSC, including 3 of end-stage renal disease. To date, none have died of a renal epithelial neoplasm.ConclusionThe identification of unique renal neoplasia subtypes may provide important clues to establish a diagnosis of TSC, and in the somatic setting, this finding has important implications for accurate prognostication. These tumors tend to be indolent, and only 2 of 276 tumors in our study exhibited metastatic behavior. Our results support multidisciplinary management with a focus on preservation of renal function.  相似文献   
54.
To investigate factors that affect and also decrease the duration for recurrences and secondary tumors in cSCC.A retrospective study was conducted for all patients who were treated for a cSCC of the head and neck between 2009 and 2016. Anamnestic as well as epidemiological and histological data were noted and correlated with the occurrence of recurrences and secondary cancers. The duration between surgery and these events was used to determine if histological factors accelerate their occurrence.The highest risk for recurrences was seen in patients with previous skin cancers (RR 3.23). Histological ulceration (p = 0.003) and grading (p = 0.031) of the tumor were found as significant factors accelerating the time to relapse. Surrounding chronic precancerotic lesions (p < 0.001) and poor tumor grading (p = 0.035) were found as significant factors accelerating the time until a secondary cSCC was observed.Known risk factors increase not only the risk for a cSCC but also for recurrences. Specific histologic findings can help to adjust follow-up intervals to identify recurrences and secondary tumors at an early stage as these were shown to decrease the duration for a further event.  相似文献   
55.
Pulmonary immune-related adverse events represent rare but potentially severe side effects of immunotherapies. Diagnosis is often challenging, as symptoms and imaging features are not specific and may mimic other lung diseases, thus potentially delaying appropriate patient management. In this setting, an accurate imaging evaluation is essential for a prompt detection and correct management of these drug-induced lung diseases. The purpose of this article is to review the different types of pulmonary immune-related adverse events, describe their imaging characteristics on both high-resolution computed tomography and positron emission tomography/computed tomography and stress their underlying diagnostic challenge by presenting the mimickers.  相似文献   
56.
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   
57.
BackgroundAdjuvant chemotherapy, postoperative radiation (PORT), and prophylactic cranial irradiation (PCI) have been individually examined in limited-stage small cell lung cancer (SCLC). There is a paucity of data on the effectiveness of each adjuvant treatment modality when used in combination after surgical resection of SCLC.MethodsData were collected from 5 cancer centers on all patients with limited-stage SCLC who underwent surgical resection between 1986 and 2019. Univariate and multivariable models were conducted to identify predictors of long-term outcomes, focusing on freedom from recurrence and survival benefit of adjuvant chemotherapy, PORT, and PCI.ResultsA total of 164 patients were analyzed. Multivariable Cox regression analysis did not identify any adjuvant therapies to significantly influence recurrence in this cohort. Specifically, PORT was not associated with a significant influence on locoregional recurrence and PCI was not significantly associated with intracranial outcomes. Adjuvant chemotherapy improved survival in all stage I through III disease (hazard ratio, 0.49; 95% confidence interval, 0.29-0.81; P = .005) and even in pathologically node negative patients (hazard ratio, 0.49; 95% confidence interval, 0.27-0.91; P = .024). Although PCI was found to improve survival in univariate analysis, it was not significant in a multivariable model. PORT was not found to affect survival on either univariate or multivariable analysis.ConclusionsThis is among the largest multi-institutional studies on surgically resected limited-stage SCLC. Our results highlight survival benefit of adjuvant chemotherapy, but did not identify a statistically significant influence from mediastinal PORT or PCI in our cohort. Larger prospective studies are needed to determine the benefit of PORT or PCI in a surgically resected limited-stage SCLC population.  相似文献   
58.
Mechanical intravascular hemolysis is frequently observed following procedures on heart valves and uncommonly observed in native valvular disease. In most cases, its severity is mild. Nevertheless, it can be clinically significant and even life threatening, requiring multiple blood transfusions and renal replacement therapy. This paper reviews the current knowledge on mechanical intravascular hemolysis in valvular disease, before and after correction, focusing on pathophysiology, approach to diagnosis, and impact of other hematological conditions on the resultant anemia. The importance of a multidisciplinary management is underscored. Laboratory data are provided about subclinical hemolysis that is commonly observed following the implantation of surgical and transcatheter valve prostheses and devices. Finally, clinical scenarios are reviewed and current medical and surgical treatments are discussed, including alternative options for inoperable patients.  相似文献   
59.
60.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号