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   2820篇
  免费   131篇
  国内免费   19篇
耳鼻咽喉   60篇
儿科学   98篇
妇产科学   194篇
基础医学   277篇
口腔科学   86篇
临床医学   223篇
内科学   570篇
皮肤病学   24篇
神经病学   131篇
特种医学   102篇
外国民族医学   1篇
外科学   478篇
综合类   44篇
一般理论   1篇
预防医学   128篇
眼科学   50篇
药学   333篇
中国医学   8篇
肿瘤学   162篇
  2024年   2篇
  2023年   45篇
  2022年   92篇
  2021年   153篇
  2020年   88篇
  2019年   92篇
  2018年   141篇
  2017年   88篇
  2016年   93篇
  2015年   92篇
  2014年   132篇
  2013年   153篇
  2012年   225篇
  2011年   252篇
  2010年   143篇
  2009年   107篇
  2008年   144篇
  2007年   166篇
  2006年   121篇
  2005年   141篇
  2004年   113篇
  2003年   81篇
  2002年   88篇
  2001年   19篇
  2000年   16篇
  1999年   23篇
  1998年   18篇
  1997年   11篇
  1996年   19篇
  1995年   5篇
  1994年   11篇
  1993年   8篇
  1992年   4篇
  1991年   6篇
  1990年   3篇
  1989年   8篇
  1988年   6篇
  1987年   6篇
  1986年   3篇
  1985年   2篇
  1984年   3篇
  1983年   7篇
  1982年   5篇
  1981年   5篇
  1980年   8篇
  1979年   8篇
  1977年   3篇
  1976年   4篇
  1975年   2篇
  1933年   1篇
排序方式: 共有2970条查询结果,搜索用时 15 毫秒
41.
42.
Ocular lesions are frequently associated with different parasitic infections. The classes of infection include protozoa, nematodes, cestodes, and ectoparasites. Ocular parasitic infections can manifest in any part of the eye; the disease manifestations are frequently characterized as either posterior or anterior eye disease. Parasite-induced lesions may be due to damage directly caused by the parasite, indirect pathology caused by toxic products or the immune response initiated by infectious parasitism. This review characterized the parasite-induced lesions in the posterior segment of the eye. Prompt diagnosis and early treatment of these lesions can reduce ocular morbidity. The method of the literature search was conducted on PubMed, Elsevier Scopus database, and Google Scholar with no limitation on the year of publication databases. It was limited to English articles published for ocular lesions in clinical studies and was focused on parasitic infections of the eye.  相似文献   
43.
Pituitary - In Cushing disease, early post-operative serum cortisol fluctuations have not been adequately characterized, and their association with initial remission and recurrence is unclear. A...  相似文献   
44.
Emergency Radiology - Computed tomography angiographies are frequently performed in the emergency department (ED) for the assessment of cervical artery dissection (CeAD) due to the high risk of...  相似文献   
45.
International Journal of Clinical Pharmacy - In recent years, increased longevity of the Danish population has resulted in a growing segment with age-related and chronic health conditions. This,...  相似文献   
46.
47.
Transmembrane channel-like protein isoform 1 (TMC1) is a major component of the mechano-electrical transducer (MET) channel in cochlear hair cells and is subject to numerous mutations causing deafness. We report a new dominant human deafness mutation, TMC1 p.T422K, and have characterized the homologous mouse mutant, Tmc1 p.T416K, which caused deafness and outer hair cell (OHC) loss by the fourth postnatal week. MET channels showed decreased Ca2+ permeability and resting open probability, but no change in single-channel conductance or expression. Three adjacent deafness mutations are TMC1 p.L416R, p.G417R, and p.M418K, the last homologous to the mouse Beethoven that exhibits similar channel effects. All substitute a positive for a neutral residue, which could produce charge screening in the channel pore or influence binding of an accessory subunit. Channel properties were compared in mice of both sexes between dominant (Tmc1 p.T416K, Tmc1 p.D569N) and recessive (Tmc1 p.W554L, Tmc1 p.D528N) mutations of residues near the putative pore of the channel. Tmc1 p.W554L and p.D569N exhibit reduced maximum current with no effect on single-channel conductance, implying a smaller number of channels transported to the stereociliary tips; this may stem from impaired TMC1 binding to LHFPL5. Tmc1 p.D528N, located in the pore''s narrowest region, uniquely caused large reductions in MET channel conductance and block by dihydrostreptomycin (DHS). For Tmc1 p.T416K and Tmc1 p.D528N, transduction loss occurred between P15 and P20. We propose two mechanisms linking channel mutations and deafness: decreased Ca2+ permeability, common to all mutants, and decreased resting open probability in low Ca2+, confined to dominant mutations.SIGNIFICANCE STATEMENT Transmembrane channel-like protein isoform 1 (TMC1) is thought to be a major component of the mechanotransducer channel in auditory hair cells, but the protein organization and channel structure are still uncertain. We made four mouse lines harboring Tmc1 point mutations that alter channel properties, causing hair cell degeneration and deafness. These include a mouse homolog of a new human deafness mutation pT416K that decreased channel Ca2+ permeability by introducing a positively-charged amino acid in the putative pore. All mutations are consistent with the channel structure predicted from modeling, but only one, p.D528N near the external face of the pore, substantially reduced channel conductance and Ca2+ permeability and virtually abolished block by dihydrostreptomycin (DHS), strongly endorsing its siting within the pore.  相似文献   
48.
In the present study, efficacy of the toltrazuril treatment for prevention of coccidiosis and necrotic enteritis was tested. Ninety-six 14-day-old commercial broiler chickens were caged and divided into eight groups (n=12), designated groups 1 to 8. Chickens of groups 1 to 6 were inoculated orally at 18 days of age with 25,000 oocysts of Eimeria tenella and 75,000 oocysts of Eimeria brunetti. At 22 days of age, chickens of groups 1 to 6 were infected with 109 colony-forming unit Clostridium perfringens. Chickens of group 1 were treated with 75 parts/106 toltrazuril in drinking water for 8 h on two consecutive days up to 12 h before Eimeria infection, while chickens of groups 2 to 5 were treated with the same dose of toltrazuril at 12 h, 36 h, 60 h and 84 h after Eimeria infection, respectively. The non-treated group 6 served as a positive control. Chickens in group 7 were treated with toltrazuril at 17 and 18 days of age, and those of group 8 remained uninfected and non-treated as a negative control. The feed conversion ratio was higher in the positive control compared with other groups. The mortality rates were 16.8% and 41.7% in the late toltrazuril-treated (at 84 h) and infected non-treated chickens, respectively. Lesions scores of necrotic enteritis or coccidiosis in infected, non-treated chickens were significantly more severe compared with negative controls (P<0.01) and late toltrazuril-treated (at 84 h) chickens (P<0.05). In conclusion, application of toltrazuril before Eimeria challenge protected chickens from coccidiosis and indirectly from successive necrotic enteritis caused by C. perfringens infection.  相似文献   
49.
50.
Oral and Maxillofacial Surgery - There is still no definitive consensus about the ideal technique in the treatment of anterior mandibular fractures. Therefore, this study aimed to determine...  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