全文获取类型
收费全文 | 42741篇 |
免费 | 3146篇 |
国内免费 | 483篇 |
专业分类
耳鼻咽喉 | 686篇 |
儿科学 | 914篇 |
妇产科学 | 936篇 |
基础医学 | 6172篇 |
口腔科学 | 611篇 |
临床医学 | 4174篇 |
内科学 | 9221篇 |
皮肤病学 | 1132篇 |
神经病学 | 3583篇 |
特种医学 | 1839篇 |
外科学 | 5228篇 |
综合类 | 617篇 |
一般理论 | 33篇 |
预防医学 | 2617篇 |
眼科学 | 1132篇 |
药学 | 3498篇 |
中国医学 | 359篇 |
肿瘤学 | 3618篇 |
出版年
2023年 | 283篇 |
2022年 | 239篇 |
2021年 | 1376篇 |
2020年 | 699篇 |
2019年 | 1160篇 |
2018年 | 1303篇 |
2017年 | 928篇 |
2016年 | 1161篇 |
2015年 | 1549篇 |
2014年 | 1879篇 |
2013年 | 2331篇 |
2012年 | 3429篇 |
2011年 | 3475篇 |
2010年 | 1992篇 |
2009年 | 1756篇 |
2008年 | 2617篇 |
2007年 | 2561篇 |
2006年 | 2319篇 |
2005年 | 2216篇 |
2004年 | 1949篇 |
2003年 | 1863篇 |
2002年 | 1715篇 |
2001年 | 830篇 |
2000年 | 727篇 |
1999年 | 721篇 |
1998年 | 380篇 |
1997年 | 343篇 |
1996年 | 291篇 |
1995年 | 241篇 |
1994年 | 216篇 |
1993年 | 166篇 |
1992年 | 343篇 |
1991年 | 274篇 |
1990年 | 290篇 |
1989年 | 291篇 |
1988年 | 279篇 |
1987年 | 221篇 |
1986年 | 218篇 |
1985年 | 184篇 |
1984年 | 179篇 |
1983年 | 152篇 |
1982年 | 130篇 |
1981年 | 115篇 |
1980年 | 104篇 |
1979年 | 140篇 |
1978年 | 90篇 |
1977年 | 78篇 |
1975年 | 71篇 |
1974年 | 70篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
2.
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
3.
4.
Olga A. Klein Avril Drummond Jacqueline R. Mhizha-Murira Laura Mansford Roshan dasNair 《Neuropsychological rehabilitation》2019,29(4):491-512
While previous randomised controlled trials and meta-analyses offer only limited evidence for the effectiveness of cognitive rehabilitation, qualitative studies examining patient perspectives report more positive outcomes. This meta-synthesis of qualitative studies examined patient perspectives of cognitive rehabilitation for memory, attention, and executive function problems in people with multiple sclerosis. Using set eligibility criteria, we screened electronic databases, reference lists, and academic networks for relevant papers. Seven papers (195 participants) were selected. Two independent researchers conducted quality appraisals of papers. Data analysis, guided by the thematic synthesis approach, yielded six main themes. These suggested that patients benefitted from the group environment in rehabilitation. Cognitive rehabilitation facilitated the participants’ reflection and awareness of their cognitive deficits, and was associated with increased knowledge and understanding of their illness. Increased strategy use was reported and associated with improvements in cognitive functioning and greater confidence and perseverance. Participants reported emotional and social improvements, and felt more optimistic. Overall, these changes had a positive impact on participants’ quality of life. This synthesis of qualitative studies indicates that people with multiple sclerosis who experience cognitive deficits benefit from cognitive rehabilitation programmes. This finding must, however, be viewed in light of the limitations of this meta-synthesis. The meta-synthesis was registered in the PROSPERO database under CRD42017040148. 相似文献
5.
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
6.
Jae Yun Ahn Jung Bae Park Sungbae Moon Jae Wan Cho Dong Ho Park 《Ophthalmic epidemiology》2020,27(2):105-114
ABSTRACT
Purpose
Work-related eye injuries have been reported with a variety of epidemiologic and clinical characteristics. We aimed to identify epidemiologic characteristics of work-related eye injuries and risk factors associated with severe injury in a large metropolitan city. 相似文献7.
8.
The Pedagogical Challenges of Teaching High School Bioethics: Insights from the Exploring Bioethics Curriculum 下载免费PDF全文
Mildred Z. Solomon David Vannier Jeanne Ting Chowning Jacqueline S. Miller Katherine F. Paget 《The Hastings Center report》2016,46(1):11-18
A belief that high school students have the cognitive ability to analyze and assess moral choices and should be encouraged to do so but have rarely been helped to do so was the motivation for developing Exploring Bioethics, a six‐module curriculum and teacher guide for grades nine through twelve on ethical issues in the life sciences. A multidisciplinary team of bioethicists, science educators, curriculum designers, scientists, and high school biology teachers worked together on the curriculum under a contract between the National Institutes of Health and Education Development Center, a nonprofit research and development organization with a long history of innovation in science education. At the NIH, the Department of Bioethics within the Clinical Center and the Office of Science Education within the Office of the Director guided the project.Our overarching goal for Exploring Bioethics was to introduce students to bioethics as a field of inquiry and to enable them to develop ethical reasoning skills so they could move beyond “gut reactions” to more nuanced positions. 相似文献
9.
Michelle E. Wilson Charles Kim Jacqueline Carrasco 《Orbit (Amsterdam, Netherlands)》2016,35(5):288-291
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression. 相似文献
10.
A mixed‐method study of effects of a therapeutic play intervention for children on parental anxiety and parents' perceptions of the intervention 下载免费PDF全文