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   9570篇
  免费   782篇
  国内免费   138篇
耳鼻咽喉   102篇
儿科学   201篇
妇产科学   393篇
基础医学   1230篇
口腔科学   201篇
临床医学   1002篇
内科学   1944篇
皮肤病学   156篇
神经病学   633篇
特种医学   330篇
外科学   1375篇
综合类   330篇
现状与发展   1篇
一般理论   2篇
预防医学   449篇
眼科学   197篇
药学   949篇
  4篇
中国医学   195篇
肿瘤学   796篇
  2023年   92篇
  2022年   148篇
  2021年   282篇
  2020年   185篇
  2019年   284篇
  2018年   321篇
  2017年   216篇
  2016年   206篇
  2015年   317篇
  2014年   388篇
  2013年   510篇
  2012年   681篇
  2011年   785篇
  2010年   485篇
  2009年   397篇
  2008年   557篇
  2007年   529篇
  2006年   514篇
  2005年   483篇
  2004年   438篇
  2003年   356篇
  2002年   322篇
  2001年   258篇
  2000年   208篇
  1999年   180篇
  1998年   79篇
  1997年   70篇
  1996年   61篇
  1995年   72篇
  1994年   70篇
  1993年   52篇
  1992年   122篇
  1991年   99篇
  1990年   92篇
  1989年   62篇
  1988年   60篇
  1987年   68篇
  1986年   38篇
  1985年   41篇
  1984年   48篇
  1983年   26篇
  1982年   27篇
  1981年   19篇
  1980年   19篇
  1979年   26篇
  1978年   20篇
  1977年   26篇
  1976年   19篇
  1975年   19篇
  1972年   17篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
BACKGROUND: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. OBJECTIVE: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. METHODS: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia. RESULTS: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. CONCLUSIONS: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.  相似文献   
2.
3.
4.
5.
6.
7.
T lymphocytes play a fundamental role in the initiation and regulation of chronic inflammatory responses in patients with asthma. CD69 is an early marker of T‐cell activation. The levels of intercellular adhesion molecule‐1 (ICAM‐1, CD54) and L ‐selectin have been reported to increase in patients with allergic diseases and asthma. The present study was therefore undertaken to investigate the expression of CD69, CD54, and L ‐selectin by T lymphocytes of children with asthma, before and after immunotherapy. Eighteen children newly diagnosed with asthma, 11 good and nine poor responders to immunotherapy, and 16 normal subjects, were enrolled in this study. The percentages of CD69+, CD54+, and CD62L+ cells in T lymphocytes were measured by using flow cytometry. The levels of CD69, CD54, and CD62L in serum and culture supernatants were determined by using enzyme‐linked immunosorbent assay (ELISA). The expression of CD69 and CD54 on CD3+ T lymphocytes was significantly higher in children with asthma than in control patients. All the patient groups expressed (spontaneously and following stimulation with phorbol myristate acetate and ionomycin together with mite‐extract proteins) greater amounts of CD69 and CD54 than did control subjects. With long‐term immunotherapy, the percentages of CD69+ and CD54+ T lymphocytes were significantly lower in patients with a good response to immunotherapy. Our results also showed significantly lower serum L ‐selectin levels following immunotherapy. In conclusion, successful immunotherapy resulted in decreased expression and production of CD69 and CD54. These results may explain, in part, the clinical efficacy of immunotherapy.  相似文献   
8.
9.
BACKGROUND: A venous lake is a venous ectasia that appears mostly on the lower lip and other sun-exposed areas of an older person. Treatment of lip venous lake includes surgical excision, laser therapy, infrared coagulation, and cryotherapy. Although the use of sclerotherapy on varicose veins, leg telangiectasia, hemorrhoids, and hemangiomas is well established, the use of sclerotherapy for lip venous lake has not been reported. OBJECTIVE: We present two cases of lip venous lake treated with intralesional injection of 1% polidocanol. METHOD: Two cases are reported, and literature is reviewed. RESULT: The lesions virtually disappeared, leaving an inconspicuous scar, with two sessions of sclerotherapy. Side effects were not observed. CONCLUSION: Sclerotherapy with polidocanol is effective in the treatment of lip venous lake and offers an alternative to conventional methods.  相似文献   
10.
Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM.  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