全文获取类型
收费全文 | 102815篇 |
免费 | 7296篇 |
国内免费 | 656篇 |
专业分类
耳鼻咽喉 | 1163篇 |
儿科学 | 2599篇 |
妇产科学 | 1839篇 |
基础医学 | 14271篇 |
口腔科学 | 1983篇 |
临床医学 | 10082篇 |
内科学 | 22329篇 |
皮肤病学 | 1937篇 |
神经病学 | 8993篇 |
特种医学 | 3837篇 |
外国民族医学 | 1篇 |
外科学 | 14234篇 |
综合类 | 1403篇 |
一般理论 | 87篇 |
预防医学 | 7681篇 |
眼科学 | 2645篇 |
药学 | 7643篇 |
1篇 | |
中国医学 | 418篇 |
肿瘤学 | 7621篇 |
出版年
2023年 | 586篇 |
2022年 | 1090篇 |
2021年 | 2373篇 |
2020年 | 1329篇 |
2019年 | 2167篇 |
2018年 | 2594篇 |
2017年 | 1910篇 |
2016年 | 2250篇 |
2015年 | 2807篇 |
2014年 | 3817篇 |
2013年 | 4862篇 |
2012年 | 7663篇 |
2011年 | 7864篇 |
2010年 | 4504篇 |
2009年 | 3958篇 |
2008年 | 6698篇 |
2007年 | 7055篇 |
2006年 | 6808篇 |
2005年 | 6468篇 |
2004年 | 6010篇 |
2003年 | 5534篇 |
2002年 | 5314篇 |
2001年 | 1328篇 |
2000年 | 1081篇 |
1999年 | 1265篇 |
1998年 | 1142篇 |
1997年 | 975篇 |
1996年 | 833篇 |
1995年 | 773篇 |
1994年 | 639篇 |
1993年 | 561篇 |
1992年 | 651篇 |
1991年 | 534篇 |
1990年 | 520篇 |
1989年 | 502篇 |
1988年 | 503篇 |
1987年 | 410篇 |
1986年 | 407篇 |
1985年 | 401篇 |
1984年 | 447篇 |
1983年 | 434篇 |
1982年 | 463篇 |
1981年 | 440篇 |
1980年 | 411篇 |
1979年 | 321篇 |
1978年 | 321篇 |
1977年 | 257篇 |
1976年 | 177篇 |
1975年 | 160篇 |
1974年 | 158篇 |
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
1.
2.
3.
4.
Kevin Kyung Ho Choi Santosh Sanagapalli 《World journal of gastrointestinal oncology》2022,14(3):568-586
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations. 相似文献
5.
Byrne Emma Abel Stephen Yu Alexander Shepard Matthew Karlovits Stephen M. Wegner Rodney E. 《Journal of neuro-oncology》2022,157(1):197-205
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54 Gy. We used the... 相似文献
6.
Brittney H. Cotta Margaret F. Meagher Aaron Bradshaw Stephen T. Ryan Gerant Rivera-Sanfeliz 《Expert review of anticancer therapy》2019,19(4):301-308
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.
Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.
Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings. 相似文献
7.
8.
9.
Ingmar Fleps Pierre Guy Stephen J Ferguson Peter A Cripton Benedikt Helgason 《Journal of bone and mineral research》2019,34(10):1837-1850
The majority of hip fractures in the elderly are the result of a fall from standing or from a lower height. Current injury models focus mostly on femur strength while neglecting subject-specific loading. This article presents an injury modeling strategy for hip fractures related to sideways falls that takes subject-specific impact loading into account. Finite element models (FEMs) of the human body were used to predict the experienced load and the femoral strength in a single model. We validated these models for their predicted peak force, effective pelvic stiffness, and fracture status against matching ex vivo sideways fall impacts (n = 11) with a trochanter velocity of 3.1 m/s. Furthermore, they were compared to sideways impacts of volunteers with lower impact velocities that were previously conducted by other groups. Good agreement was found between the ex vivo experiments and the FEMs with respect to peak force (root mean square error [RMSE] = 10.7%, R2 = 0.85) and effective pelvic stiffness (R2 = 0.92, RMSE = 12.9%). The FEMs were predictive of the fracture status for 10 out of 11 specimens. Compared to the volunteer experiments from low height, the FEMs overestimated the peak force by 25% for low BMI subjects and 8% for high BMI subjects. The effective pelvic stiffness values that were derived from the FEMs were comparable to those derived from impacts with volunteers. The force attenuation from the impact surface to the femur ranged between 27% and 54% and was highly dependent on soft tissue thickness (R2 = 0.86). The energy balance in the FEMS showed that at the time of peak force 79% to 93% of the total energy is either kinetic or was transformed to soft tissue deformation. The presented FEMs allow for direct discrimination between fracture and nonfracture outcome for sideways falls and bridge the gap between impact testing with volunteers and impact conditions representative of real life falls. © 2019 American Society for Bone and Mineral Research. 相似文献
10.
Hyun Jong Choi Jong Ho Moon Yun Nah Lee Hyun Su Kim Ji Su Ha Tae Hoon Lee Sang‐Woo Cha Young Deok Cho Sang‐Heum Park 《Digestive endoscopy》2015,27(7):772-775
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS. 相似文献