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   920475篇
  免费   64928篇
  国内免费   2476篇
耳鼻咽喉   12754篇
儿科学   29351篇
妇产科学   26810篇
基础医学   128793篇
口腔科学   25353篇
临床医学   76625篇
内科学   187934篇
皮肤病学   19459篇
神经病学   72389篇
特种医学   37163篇
外国民族医学   345篇
外科学   146103篇
综合类   19666篇
现状与发展   1篇
一般理论   268篇
预防医学   66099篇
眼科学   20756篇
药学   65613篇
中国医学   1930篇
肿瘤学   50467篇
  2019年   7250篇
  2018年   10210篇
  2017年   7852篇
  2016年   8395篇
  2015年   9504篇
  2014年   13358篇
  2013年   20413篇
  2012年   27319篇
  2011年   28982篇
  2010年   17460篇
  2009年   16512篇
  2008年   27178篇
  2007年   28890篇
  2006年   28924篇
  2005年   28320篇
  2004年   27107篇
  2003年   26163篇
  2002年   25666篇
  2001年   41617篇
  2000年   42792篇
  1999年   36505篇
  1998年   10107篇
  1997年   9254篇
  1996年   9173篇
  1995年   8531篇
  1994年   8145篇
  1993年   7634篇
  1992年   28307篇
  1991年   27081篇
  1990年   26497篇
  1989年   25430篇
  1988年   23640篇
  1987年   23251篇
  1986年   22338篇
  1985年   21226篇
  1984年   15865篇
  1983年   13560篇
  1982年   8119篇
  1979年   14660篇
  1978年   10246篇
  1977年   8676篇
  1976年   8180篇
  1975年   9001篇
  1974年   10732篇
  1973年   10207篇
  1972年   9680篇
  1971年   8937篇
  1970年   8596篇
  1969年   8040篇
  1968年   7694篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
73.
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.  相似文献   
74.
75.
76.
77.
Coronavirus disease 2019 (COVID-19) has resulted in many challenges in patient care, especially among high-risk populations such as heart transplant recipients. Patients with heart transplant experience a significantly higher mortality rate with COVID-19 infection, and management is based on extrapolation from clinical trials done on nontransplant patients and from clinical experience. Here we report 4 cases of patients with heart transplant who presented with COVID-19 infection in late 2020. Patients presented with symptoms similar to those seen in the general population. All 4 patients were admitted to the hospital, and they were all treated with dexamethasone. In addition, 2 patients received remdesivir. Immunosuppressive medications were adjusted to maintain adequate levels of immunosuppression but at the same time allow for an adequate immune response against the infection. All patients were discharged alive from the hospital. We then performed a literature review on studies that included heart transplant patients who developed the infection and developed suggestions for a standardized management approach, which we share in this article.  相似文献   
78.
79.
Psoriasis is a chronic, inflammatory, immune‐mediated disease. Approximately 30% of patients have disease onset before age 18 years. Psoriasis in children and adolescents may be difficult to control, with subsequent poor quality of life and psychosocial consequences. We describe the case of a 12‐year‐old boy with severe, refractory, chronic plaque psoriasis for 6 years. Various therapeutic regimens including different topical corticosteroids, topical vitamin D analogs, phototherapy, photochemotherapy, systemic therapy with methotrexate, cyclosporin, and combination therapies showed only partial or transient responses with frequent relapses. Because anti‐interleukin‐12/23 agents have been successfully used in adults with psoriasis, ustekinumab was initiated and our patient showed a rapid, excellent, sustained response. No recurrence or flares have been observed after 33 months of follow‐up. This case illustrates that ustekinumab may be an effective and safe therapeutic option in adolescents with psoriasis.  相似文献   
80.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  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