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   99060篇
  免费   9735篇
  国内免费   5056篇
耳鼻咽喉   2205篇
儿科学   451篇
妇产科学   1714篇
基础医学   10796篇
口腔科学   3387篇
临床医学   7248篇
内科学   13943篇
皮肤病学   1979篇
神经病学   473篇
特种医学   4310篇
外国民族医学   135篇
外科学   14488篇
综合类   17694篇
现状与发展   25篇
预防医学   2101篇
眼科学   390篇
药学   4807篇
  17篇
中国医学   1257篇
肿瘤学   26431篇
  2024年   117篇
  2023年   1392篇
  2022年   2096篇
  2021年   3904篇
  2020年   3417篇
  2019年   3192篇
  2018年   3040篇
  2017年   3478篇
  2016年   4020篇
  2015年   4496篇
  2014年   6604篇
  2013年   5860篇
  2012年   5998篇
  2011年   6477篇
  2010年   5151篇
  2009年   5124篇
  2008年   5290篇
  2007年   5620篇
  2006年   5279篇
  2005年   4723篇
  2004年   3782篇
  2003年   3295篇
  2002年   2783篇
  2001年   2652篇
  2000年   2273篇
  1999年   1809篇
  1998年   1666篇
  1997年   1509篇
  1996年   1311篇
  1995年   1146篇
  1994年   1045篇
  1993年   717篇
  1992年   650篇
  1991年   591篇
  1990年   478篇
  1989年   422篇
  1988年   381篇
  1987年   315篇
  1986年   254篇
  1985年   284篇
  1984年   224篇
  1983年   162篇
  1982年   187篇
  1981年   157篇
  1980年   152篇
  1979年   114篇
  1978年   77篇
  1977年   58篇
  1976年   49篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 921 毫秒
81.
Recent meta-analyses on checkpoint inhibitors in cancer report conflicting data regarding the association of patient gender with inhibitor efficacy. In advanced kidney cancer, checkpoint inhibitors have shown improved outcomes in first- and second-line settings compared with standard of care, but the role of patient gender on treatment outcome is unclear. We aimed to assess the efficacy of immunotherapy according to patient gender in advanced kidney cancer.We performed a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search was performed using PubMed, Scopus, Web of Science, and The Cochrane Library to identify eligible studies published through February 16, 2019. Studies were included if they reported on the differential outcomes of male and female patients with metastatic kidney cancer receiving immunotherapy. Our outcomes of interest were overall survival (OS) or progression-free survival (PFS).Four randomized controlled trials comprising a total of 3664 patients (2715 males and 949 females) met our inclusion criteria. Both men and women with metastatic kidney cancer had an OS and PFS advantage with immunotherapy compared with standard-of-care, but no statistically significant difference between the genders was observed (OS hazard ratio [HR] for men, 0.69; 95% confidence interval [CI], 0.59-0.8; P = .40; HR for women, 0.62; 95% CI, 0.48-0.81; P = .13; PFS HR for men, 0.7; 95% CI, 0.59-0.82; P = .24; HR for women, 0.68; 95% CI, 0.52-0.90; P = .105).In patients with advanced kidney cancer receiving checkpoint inhibitors, there seems to be no association of patient gender with treatment outcome.  相似文献   
82.
《Neuro-Chirurgie》2022,68(2):196-201
BackgroundTumor-to-tumor metastases are extremely rarely reported lesions, which usually involve an indolent lesion hosting a more aggressive neoplasm. We present an unusual initial manifestation of a previously unknown clear cell renal cell carcinoma as a tumor-to-tumor metastasis in a typical meningothelial meningioma.Case reportA 73-year old patient with transient left slight monoparesis was addressed to our Neurosurgical Department after being evaluated by his general practitioner and passing a cerebral MRI which revealed a right frontotemporal mass attached to the meninge. At presentation, no deficits were identified; therefore an elective surgery was proposed. Histological analysis revealed a typical meningothelial meningioma containing a metastatic clear cell renal cell carcinoma. Additional thoraco-abdominal computer tomography identified a 6 cm diameter lesion within the right kidney with radiological features highly suggestive of a primary clear cell renal cell carcinoma.ConclusionOur case highlights the need for a specialized neuropathological approach to clinical and imagistic indolent meningiomas, as they may require important differential diagnosis that can highly impact the treatment and follow-up of brain tumor patients.  相似文献   
83.
Urothelial cell carcinoma (UCC) of the bladder is one of the most common malignancies, causing considerable morbidity and mortality worldwide. It is unique among the epithelial carcinomas as two distinct pathways to tumourigenesis appear to exist: low grade, recurring papillary tumours usually contain oncogenic mutations in FGFR3 or HRAS whereas high grade, muscle invasive tumours with metastatic potential generally have defects in the pathways controlled by the tumour suppressors p53 and retinoblastoma. Over the last two decades, a number of transgenic mouse models of UCC, containing deletions or mutations of key tumour suppressor genes or oncogenes, have helped us understand the mechanisms behind tumour development. In this summary, I present my work investigating the role of the WNT signalling cascade in UCC.  相似文献   
84.
Birt‐Hogg‐Dubé (BHD) syndrome is associated with the development of hereditary renal cell carcinoma (RCC) and is caused by a germline mutation in the folliculin gene. Most cases of BHD syndrome‐associated RCC (BHD‐RCC) are less aggressive than sporadic clear cell RCC and multifocal. Therefore, it is critical to distinguish BHD‐RCC from its sporadic counterparts to identify and monitor affected families and to preserve renal function for as long as possible. The World Health Organization/International Society of Urological Pathology consensus classification defined distinct entities for certain hereditary RCC; however, BHD‐RCC was not included in this classification. Although the clinical features and molecular mechanisms of BHD‐RCC have been investigated intensively over the last two decades, pathologists and urologists occasionally face difficulties in the diagnosis of BHD‐RCC that require genetic testing. Affected patients usually have miscellaneous benign disorders that often precede renal carcinogenesis. In the present review, we summarize the current understanding of the histopathological features of BHD‐RCC based on our epidemiological studies of Japanese families and a literature review. Pathological diagnostic clues and differential diagnosis of BHD‐RCC from other hereditary RCC are also briefly discussed.  相似文献   
85.
BackgroundClear-cell renal cell carcinoma (ccRCC) is one of the most common malignancies in humans and is usually associated with poor outcomes. Cancers are considered to be genetic diseases. Therefore, a better understanding of genetic alterations that are related to disease progression or poor prognosis can help to more precisely identify high-risk patients and treat them more effectively. The aim of this study was to examine the frequency of whole chromosome 9 loss (monosomy of chromosome 9) and its prognostic value in patients with ccRCC.Materials and MethodsSingle nucleotide polymorphism-based chromosome microarray (CMA) analysis was performed on 103 resected specimens from patients with ccRCC who had undergone partial or radical nephrectomy between January 2002 and March 2017 at Fox Chase Cancer Center. Monosomy 9 was correlated with clinicopathologic parameters and recurrence-free survival.ResultsChromosome 9 loss was detected in 31 (30%) of 103 tumors. Tumors with chromosome 9 loss had higher histologic grade (3 and 4; P < .001) and pathologic stage (P < .001). In 59 patients with non-metastatic ccRCC, chromosome 9 loss was also associated with higher recurrence rate and shorter recurrence-free survival (RFS) (12-month RFS, 77.8%; 95% confidence interval, 36.5%-93.9% for chromosome 9 loss vs. 95.7%; 95% confidence interval, 84.0%-98.9% for no loss; P = .002).ConclusionsChromosome 9 loss was found in 30% of patients with ccRCC and correlated with higher grade, advanced stage, and shorter RFS in patients with Stage I to III ccRCC.  相似文献   
86.
Harinakshi Sanikini  David C. Muller  Marisa Sophiea  Sabina Rinaldi  Antonio Agudo  Eric J. Duell  Elisabete Weiderpass  Kim Overvad  Anne Tjønneland  Jytte Halkjær  Marie-Christine Boutron-Ruault  Franck Carbonnel  Iris Cervenka  Heiner Boeing  Rudolf Kaaks  Tilman Kühn  Antonia Trichopoulou  Georgia Martimianaki  Anna Karakatsani  Valeria Pala  Domenico Palli  Amalia Mattiello  Rosario Tumino  Carlotta Sacerdote  Guri Skeie  Charlotta Rylander  María-Dolores Chirlaque López  Maria-Jose Sánchez  Eva Ardanaz  Sara Regnér  Tanja Stocks  Bas Bueno-de-Mesquita  Roel C.H. Vermeulen  Dagfinn Aune  Tammy Y.N. Tong  Nathalie Kliemann  Neil Murphy  Marc Chadeau-Hyam  Marc J. Gunter  Amanda J. Cross 《International journal of cancer. Journal international du cancer》2020,146(4):929-942
Obesity has been associated with upper gastrointestinal cancers; however, there are limited prospective data on associations by subtype/subsite. Obesity can impact hormonal factors, which have been hypothesized to play a role in these cancers. We investigated anthropometric and reproductive factors in relation to esophageal and gastric cancer by subtype and subsite for 476,160 participants from the European Prospective Investigation into Cancer and Nutrition cohort. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox models. During a mean follow-up of 14 years, 220 esophageal adenocarcinomas (EA), 195 esophageal squamous cell carcinomas, 243 gastric cardia (GC) and 373 gastric noncardia (GNC) cancers were diagnosed. Body mass index (BMI) was associated with EA in men (BMI ≥30 vs. 18.5–25 kg/m2: HR = 1.94, 95% CI: 1.25–3.03) and women (HR = 2.66, 95% CI: 1.15–6.19); however, adjustment for waist-to-hip ratio (WHR) attenuated these associations. After mutual adjustment for BMI and HC, respectively, WHR and waist circumference (WC) were associated with EA in men (HR = 3.47, 95% CI: 1.99–6.06 for WHR >0.96 vs. <0.91; HR = 2.67, 95% CI: 1.52–4.72 for WC >98 vs. <90 cm) and women (HR = 4.40, 95% CI: 1.35–14.33 for WHR >0.82 vs. <0.76; HR = 5.67, 95% CI: 1.76–18.26 for WC >84 vs. <74 cm). WHR was also positively associated with GC in women, and WC was positively associated with GC in men. Inverse associations were observed between parity and EA (HR = 0.38, 95% CI: 0.14–0.99; >2 vs. 0) and age at first pregnancy and GNC (HR = 0.54, 95% CI: 0.32–0.91; >26 vs. <22 years); whereas bilateral ovariectomy was positively associated with GNC (HR = 1.87, 95% CI: 1.04–3.36). These findings support a role for hormonal pathways in upper gastrointestinal cancers.  相似文献   
87.
《Cancer cell》2021,39(11):1497-1518.e11
  1. Download : Download high-res image (282KB)
  2. Download : Download full-size image
  相似文献   
88.
89.
90.
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