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   21101篇
  免费   1111篇
  国内免费   130篇
耳鼻咽喉   258篇
儿科学   359篇
妇产科学   272篇
基础医学   2678篇
口腔科学   470篇
临床医学   1383篇
内科学   5301篇
皮肤病学   302篇
神经病学   1402篇
特种医学   1281篇
外科学   3686篇
综合类   109篇
预防医学   525篇
眼科学   257篇
药学   1562篇
中国医学   47篇
肿瘤学   2450篇
  2023年   130篇
  2022年   91篇
  2021年   421篇
  2020年   270篇
  2019年   380篇
  2018年   509篇
  2017年   324篇
  2016年   487篇
  2015年   493篇
  2014年   595篇
  2013年   711篇
  2012年   1191篇
  2011年   1316篇
  2010年   717篇
  2009年   622篇
  2008年   1100篇
  2007年   1175篇
  2006年   1122篇
  2005年   1171篇
  2004年   1107篇
  2003年   991篇
  2002年   1018篇
  2001年   537篇
  2000年   536篇
  1999年   498篇
  1998年   225篇
  1997年   202篇
  1996年   185篇
  1995年   159篇
  1994年   156篇
  1993年   121篇
  1992年   369篇
  1991年   322篇
  1990年   327篇
  1989年   352篇
  1988年   319篇
  1987年   313篇
  1986年   260篇
  1985年   264篇
  1984年   180篇
  1983年   126篇
  1982年   63篇
  1981年   69篇
  1980年   53篇
  1979年   83篇
  1978年   76篇
  1977年   75篇
  1974年   63篇
  1972年   55篇
  1970年   49篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - This multi-institutional clinical trial evaluated the feasibility of intensity-modulated radiotherapy (IMRT) for patients with locally advanced...  相似文献   
2.
BackgroundIn shoulder arthroplasty, bone resorption around the stem can lead to stem loosening and makes surgery difficult at the time of revision. Proximal bone resorption after reverse shoulder arthroplasty can cause instability because of a decrease of deltoid wrapping effect. As factors of the stem itself, such as stem coating, shape, length, and use of bone cement, may also affect bone resorption, a single-stem model should be used to compare bone resorptions between different pathologies and surgical procedures. However, to date, a few reports have compared these differences in detail using a single-stem model. Therefore, we investigated the prevalence and location of humeral bone resorption in a single-stem model.MethodsThe study included 100 shoulders that underwent anatomical total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with a single uncemented humeral stem from 2008 to 2018. The patients were 31 men and 69 women. The mean age at surgery was 72.9 years (range, 41-86 years). The patients were divided into three groups: especially, 25, 61, and 14 shoulders received TSA for primary osteoarthritis without rotator cuff tears (TSA group), HHR using an anatomical head with rotator cuff repair for cuff tear arthropathy (CTA) (HHR group), and HHR using a CTA head without rotator cuff repair (CTA group), respectively. Patients were monitored for a mean of 56 months (range, 12-98 months). The location of bone resorption was divided into seven zones as follows: zone 1, greater tuberosity; zone 2, lateral diaphysis; zone 3, lateral diaphysis beyond the deltoid tuberosity; zone 4, tip of the stem; zone 5, medial diaphysis beyond the deltoid tuberosity; zone 6, medial diaphysis; and zone 7, calcar region. The degree of bone resorption was classified from grade 0 to 4.ResultsBone resorption of grade 3 or higher was significantly more frequent at the greater tuberosity in the HHR and CTA groups (P < .001 and P < .001, respectively) than that in the TSA group. Grade 4 bone resorption was significantly more frequent in the CTA than that in the TSA and HHR groups in zone 1 (P = .016 and P = .041, respectively).ConclusionThe state of attachment of the rotator cuff to the greater tuberosity might affect bone resorption at the greater tuberosity, such as the greater tuberosity after shoulder arthroplasty. In cases of shoulder arthroplasty for arthropathy with rotator cuff tear, performing rotator cuff repair might prevent bone resorption.Level of evidenceLevel IV; Prognosis Study  相似文献   
3.
4.
Small‐bowel capsule endoscopy (SBCE) is used widely because of its non‐invasive and patient‐friendly nature. SBCE can visualize entire small‐intestinal mucosa and facilitate detection of small‐intestinal abnormalities. In this review article, we focus on the current status of SBCE. Several platforms for SBCE are available worldwide. Third‐generation SBCE (PillCam® SB3) has a high‐resolution camera equipped with an adaptive frame rate system. Several software modes have been developed to reduce the reading time for capsule endoscopy and to minimize the possibility of missing lesions. The main complication of SBCE is capsule retention. Thus, the main contraindication for SBCE is known or suspected gastrointestinal obstruction unless intestinal patency is proven. Possible indications for SBCE are obscure gastrointestinal bleeding, Crohn's disease, small‐intestinal polyps and tumors, and celiac disease. Colon capsule endoscopy (CCE) can observe inflamed colonic mucosa non‐invasively, and allows for the continuous and non‐invasive observation of the entire intestinal tract (pan‐endoscopy). Recently, application of CCE as pan‐enteric endoscopy for inflammatory bowel diseases (including Crohn's disease) has been reported. In the near future, reading for CE will be assisted by artificial intelligence, and reading CE videos for long periods will not be required.  相似文献   
5.
6.
This study aimed to establish the Japanese Cancer Genome Atlas (JCGA) using data from fresh frozen tumor tissues obtained from 5143 Japanese cancer patients, including those with colorectal cancer (31.6%), lung cancer (16.5%), gastric cancer (10.8%) and other cancers (41.1%). The results are part of a single‐center study called “High‐tech Omics‐based Patient Evaluation” or “Project HOPE” conducted at the Shizuoka Cancer Center, Japan. All DNA samples and most RNA samples were analyzed using whole‐exome sequencing, cancer gene panel sequencing, fusion gene panel sequencing and microarray gene expression profiling, and the results were annotated using an analysis pipeline termed “Shizuoka Multi‐omics Analysis Protocol” developed in‐house. Somatic driver alterations were identified in 72.2% of samples in 362 genes (average, 2.3 driver events per sample). Actionable information on drugs that is applicable in the current clinical setting was associated with 11.3% of samples. When including those drugs that are used for investigative purposes, actionable information was assigned to 55.0% of samples. Germline analysis revealed pathogenic mutations in hereditary cancer genes in 9.2% of samples, among which 12.2% were confirmed as pathogenic mutations by confirmatory test. Pathogenic mutations associated with non–cancerous hereditary diseases were detected in 0.4% of samples. Tumor mutation burden (TMB) analysis revealed 5.4% of samples as having the hypermutator phenotype (TMB ≥ 20). Clonal hematopoiesis was observed in 8.4% of samples. Thus, the JCGA dataset and the analytical procedures constitute a fundamental resource for genomic medicine for Japanese cancer patients.  相似文献   
7.
8.
DHS is characterized by chin-on-chest deformity and devastatingly impedes activities of daily living in affected individuals. There is a paucity of literature about the pathophysiology of DHS including knowledge about spinal sagittal alignment. We conducted this study to clarify the relationship between cervical sagittal alignment and global sagittal balance in DHS. This is a retrospective radiographic study of a case series of DHS. Forty-one patients with diagnosed DHS were enrolled. Measurements were made using lateral standing radiograph. C2–C7 sagittal vertical axis (SVA) was estimated as 52.0 ± 2.4 mm. Among sagittal parameters, C7–S1 SVA positively correlated with C2–C7 angle (C2–C7 A) (r = 0.33). For the correlations between C7 and S1 SVA and C2–C7 A, both logistic and linear regression models were used to determine the threshold for C2–C7 A value responsible for global sagittal balance. C2–C7 A of − 15.0 and 6.0 were predicted by logistic and linear regression models and were considered responsible for the occurrence of global positive imbalance. Therefore, we divided into two groups, namely, cervical kyphosis group (C type) and diffuse kyphosis group (D type) by median value of C2–C7 A. Enlarged thoracic kyphosis and global positive imbalance were observed in D type compared to C type. C2–C7 A exhibited correlations with cervical balance and also with global balance. There should be various type of thoraco-lumbar alignment in DHS. These slides can be retrieved under Electronic Supplementary Material.  相似文献   
9.
10.
While the incidence of oropharyngeal squamous cell carcinoma (OPSCC) has been increasing in these two decades, primarily due to human papillomavirus (HPV), stratification of OPSCC into molecular subgroups showing different clinicopathological features has not been fully investigated. We performed DNA methylome analysis using Infinium 450k for 170 OPSCC cases, including 89 cases in our cohort and 81 cases reported by The Cancer Genome Atlas, together with targeted exon sequencing analysis. We stratified OPSCC by hierarchical clustering analysis using methylome data. Methylation levels of classifier markers were validated quantitatively using pyrosequencing, and area under the curve (AUC) values of receiver operating characteristics (ROC) curves were calculated. OPSCC was stratified into four epigenotypes: HPV(+) high-methylation (OP1), HPV(+) intermediate-methylation (OP2), HPV(−) intermediate-methylation (OP3) and HPV(−) low-methylation (OP4). Ten methylation marker genes were generated: five to classify HPV(+) cases into OP1 and OP2, and five to classify HPV(−) cases into OP3 and OP4. AUC values of ROC curves were 0.969 and 0.952 for the two marker panels, respectively. While significantly higher TP53 mutation and CCND1 copy number gains were observed in HPV(−) than in HPV(+) groups (p < 0.01), no significant difference of genomic aberrations was observed between OP1 and OP2, or OP3 and OP4. The four epigenotypes showed significantly different prognosis (p = 0.0006), distinguishing the most favorable OPSCC subgroup (OP1) among generally favorable HPV(+) cases, and the most unfavorable OPSCC subgroup (OP3) among generally unfavorable HPV(−) cases. HPV(+) and HPV(−) OPSCC are further divided into distinct DNA methylation epigenotypes, showing significantly different prognosis.  相似文献   
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