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   105279篇
  免费   10381篇
  国内免费   6418篇
耳鼻咽喉   2124篇
儿科学   509篇
妇产科学   1740篇
基础医学   11199篇
口腔科学   3395篇
临床医学   7710篇
内科学   15383篇
皮肤病学   1987篇
神经病学   306篇
特种医学   4522篇
外国民族医学   122篇
外科学   16497篇
综合类   18648篇
现状与发展   23篇
预防医学   2508篇
眼科学   390篇
药学   5754篇
  23篇
中国医学   1739篇
肿瘤学   27499篇
  2024年   54篇
  2023年   1460篇
  2022年   2399篇
  2021年   3948篇
  2020年   3691篇
  2019年   3402篇
  2018年   3232篇
  2017年   3578篇
  2016年   4128篇
  2015年   4777篇
  2014年   7398篇
  2013年   6484篇
  2012年   6562篇
  2011年   6956篇
  2010年   5633篇
  2009年   5633篇
  2008年   5905篇
  2007年   6142篇
  2006年   5733篇
  2005年   5072篇
  2004年   3936篇
  2003年   3450篇
  2002年   2955篇
  2001年   2833篇
  2000年   2445篇
  1999年   1911篇
  1998年   1602篇
  1997年   1436篇
  1996年   1311篇
  1995年   1204篇
  1994年   1093篇
  1993年   764篇
  1992年   671篇
  1991年   606篇
  1990年   509篇
  1989年   451篇
  1988年   402篇
  1987年   329篇
  1986年   267篇
  1985年   296篇
  1984年   233篇
  1983年   172篇
  1982年   207篇
  1981年   171篇
  1980年   174篇
  1979年   154篇
  1978年   99篇
  1977年   74篇
  1976年   65篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
41.
Adenoid cystic carcinoma (AdCC) is a salivary gland-type of cancer that may also occur in the breast. Breast AdCC shows the same morphological spectrum as is observed in salivary glands, with recognition of individual subtypes that may differ in their clinical behaviour. AdCC classic variant (C-AdCC) is a slowly growing tumour, with a low rate of axillary node and distant metastases. Local recurrences may develop as a consequence of incomplete surgical excision. C-AdCC should be differentiated from the solid-basaloid variant of AdCC (SB-AdCC) that is characterized by nuclear atypia, frequent mitotic figures and necrosis, in addition to the solid architecture. SB-AdCC is a more aggressive tumour, with higher rates of axillary node and distant metastases. AdCC may also co-exist with more aggressive types of carcinoma including metaplastic and neuroendocrine carcinoma, referred to as AdCC with high grade transformation (HG-AdCC). This paper reviews the key diagnostic criteria of the different subtypes of breast AdCC with emphasis on differential diagnosis and prognostic parameters.  相似文献   
42.
Patients undergoing sentinel node biopsy (SLNB) for early oral squamous cell carcinoma (OSCC) who harbour occult metastases (pN+ve) may be at greater risk of mortality due to prolonged overall treatment times than those identified as pN+ve on elective neck dissection (ELND). A retrospective comparative survival analysis was therefore undertaken to test this hypothesis. Patients were identified from the South Glasgow multidisciplinary team (MDT) database. Group 1 comprised 38 patients identified as pN+ve, or who were false negative, on sentinel lymph node biopsy (SLNB). Group 2 comprised 146 patients staged pN+ve on ELND. The groups were compared with the Kaplan Meier method and Cox proportional hazards model. In addition, a matched-pair analysis was performed. A unique and specifically designed algorithm was deployed to optimise the pairings. No difference in disease-specific or overall survival was found between the groups. Patients undergoing SLNB as the initial neck staging modality in early OSCC and are identified as pN+ve do not appear to be at a survival disadvantage compared with those staged with ELND.  相似文献   
43.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
44.
45.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
46.
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   
47.
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   
48.
Tumor tissue is composed of tumor cells and tumor stroma. Tumor stroma contains various immune cells and non-immune stromal cells, forming a complex tumor microenvironment which plays pivotal roles in regulating tumor growth. Recent successes in immunotherapies against tumors, including immune checkpoint inhibitors, have further raised interests in the immune microenvironment of liver carcinoma. The immune microenvironment of tumors is formed because of interactions among tumor cells, immune cells and non-immune stromal cells, including fibroblasts and endothelial cells. Different patterns of immune microenvironment are observed among different tumor subtypes, and their clinicopathological significance and intertumor/intratumor heterogeneity are being intensively studied. Here, we review the immune microenvironment of hepatocellular carcinoma, intrahepatic cholangiocarcinoma and liver metastasis of colorectal adenocarcinoma, focusing on its histopathological appearance, clinicopathological significance, and relationship with histological and molecular classifications. Understanding the comprehensive histopathological picture of a tumor immune microenvironment, in addition to molecular and genetic approaches, will further potentiate the effort for precision medicine in the era of tumor-targeting immunotherapy.  相似文献   
49.
BackgroundDetails of perioperative outcomes and survival after gastric cancer surgery in prior transplant recipients have received minimal research attention.MethodsWe performed an observational cohort study using the database of 20,147 gastric cancer patients who underwent gastrectomy at a single gastric cancer center in Korea. Forty-one solid organ recipients [kidney (n = 35), liver (n = 5), or heart (n = 1)] were matched with 205 controls using propensity score matching.ResultsOperation time, blood loss, and postoperative pain were similar between groups. Short-term complication rates were similar between transplantation and control groups (22.0% vs. 20.1%, P = 0.777). Transplantation group patients with stage 1 gastric cancer experienced no recurrence, while those with stage 2/3 cancer had significantly higher recurrence risk compared to the controls (P = 0.049). For patients with stage 1 cancer, the transplantation group had a significantly higher rate of non-gastric cancer-related deaths compared to the controls (19.2% vs. 1.4%, P = 0.001). For those with stage 2/3 cancer, significantly lower proportion of the transplantation group received adjuvant chemotherapy compared to the control group (26.7% vs. 80.3%, P < 0.001). The transplantation group had a higher (albeit not statistically significant) rate of gastric cancer-related deaths compared to the controls (40.0% vs. 18.0%, P = 0.087).ConclusionTransplant recipients and non-transplant recipients exhibited similar perioperative and short-term outcomes after gastric cancer surgery. From long-term outcome analyses, we suggest active surveillance for non-gastric cancer-related deaths in patients with early gastric cancer, as well as strict oncologic care in patients with advanced cancer, as effective strategies for transplant recipients.  相似文献   
50.
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