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   3032篇
  免费   169篇
  国内免费   7篇
耳鼻咽喉   35篇
儿科学   57篇
妇产科学   106篇
基础医学   401篇
口腔科学   350篇
临床医学   230篇
内科学   620篇
皮肤病学   71篇
神经病学   240篇
特种医学   69篇
外科学   286篇
综合类   12篇
一般理论   3篇
预防医学   273篇
眼科学   40篇
药学   260篇
中国医学   17篇
肿瘤学   138篇
  2023年   28篇
  2022年   55篇
  2021年   102篇
  2020年   66篇
  2019年   94篇
  2018年   111篇
  2017年   87篇
  2016年   78篇
  2015年   106篇
  2014年   124篇
  2013年   168篇
  2012年   207篇
  2011年   249篇
  2010年   155篇
  2009年   108篇
  2008年   178篇
  2007年   182篇
  2006年   150篇
  2005年   140篇
  2004年   124篇
  2003年   100篇
  2002年   74篇
  2001年   65篇
  2000年   45篇
  1999年   56篇
  1998年   36篇
  1997年   23篇
  1996年   10篇
  1995年   12篇
  1994年   15篇
  1993年   12篇
  1992年   19篇
  1991年   22篇
  1990年   28篇
  1989年   23篇
  1988年   16篇
  1987年   9篇
  1986年   20篇
  1985年   7篇
  1984年   16篇
  1983年   13篇
  1982年   7篇
  1981年   10篇
  1979年   5篇
  1978年   6篇
  1976年   5篇
  1974年   6篇
  1973年   8篇
  1969年   4篇
  1967年   4篇
排序方式: 共有3208条查询结果,搜索用时 0 毫秒
1.
2.
Kim  SH; Chang  KH; Song  IC; Han  MH; Kim  HC; Kang  HS; Han  MC 《Radiology》1997,204(1):239
  相似文献   
3.
Background : Severe odontogenic infections are serious potentially lethal conditions. Following the death of a patient in the authors' institution this study was initiated to determine the risk factors, management and outcome of a consecutive series of patients.
Methods : All patients admitted to the Royal Adelaide Hospital under the care of the Oral and Maxillofacial Surgery Unit with odontogenic infections in calendar year 2003 were investigated. Detailed information relative to their pre-presentation history, surgical and anaesthetic management and outcome was obtained and analysed.
Results : Forty-eight patients, 32M, 16F, average age 34.5, range 19 to 88 years were treated. All presented with pain and swelling, with 21 (44 per cent) having trismus. Forty-four (92 per cent) were as a result of dental neglect and four (8 per cent) were regular dental patients having endodontic treatment which failed. Of those known to have been treated prior to presentation, most had been on antibiotics. Most patients had aggressive surgical treatment with extraction, surgical drainage, high dose intravenous antibiotics and rehydration. The hospital stay was 3.3 (range 1–16) days. Patients requiring prolonged intubation and high dependency or intensive care (40 per cent) had longer hospitalization. No patient died and all fully recovered.
Conclusion : Severe odontogenic infections are a serious risk to the patient's health and life. Management is primarily surgical with skilled anaesthetic airway management. Antibiotics are required in high intravenous doses as an adjunct and not as a primary treatment.  相似文献   
4.
An extensive field survey allowed us to expand the geographical distribution of the scorpion Tityus perijanensis in the Perijá range, western Zulia State, Venezuela, including areas where adult cases of severe scorpionism have been reported. 16S ribosomal RNA (rRNA) gene sequencing, DL(50) determination, and native PAGE suggest low genetic and venom proteomic divergence across the distribution range. The results also indicate phylogenetic divergence between T. perijanensis and T. discrepans, the species prevalent in northcentral Venezuela. T. perijanensis venom lethality (0.91-0.94 mg/kg) is comparable to that of the Brazilian T. serrulatus and ranks highest among toxic Venezuelan Tityus studied so far. The data indicate that the Perijá range should be included amongst the endemic areas of scorpionism of Venezuela and Colombia.  相似文献   
5.
OBJECTIVE: Kidney transplantation restores renal filtration, although it does not achieve the function of 2 native kidneys, and with time it may involute back to chronic renal failure. We hypothesized that bioelectrical impedance analysis (BIA) might highlight differences for body compartments among kidney transplants (Tx) with different filtration rates. METHODS: Thirty transplantation patients (19 male, 11 female) were studied at 62.4+/-26.6 months postsurgery and were divided into 3 groups: good creatinine clearance (crCl, mL/min/1.73 m2; >65.0), borderline (35.0相似文献   
6.
7.
8.
AMPA/kainate receptor activation in cultured oligodendrocyte precursor cells from embryonic mouse cortex leads to a blockade of delayed rectifying K+ currents. In the present study, we provide evidence using the patch-clamp technique in the whole-cell configuration that the mechanism linking kainate receptor activation and K+ conductance blockade is due to the receptor-mediated Na+ entry: (1) The blockade was not observed in Na+ -free bathing solution nor when intracellular [Na+] was elevated by dialzying the cell with a pipette solution containing high [Na+]. (2) Elevation of intracellular [Na+] alone led to a blockade of outward currents in contrast to cells dialyzed by sucrose. High [Li+]i also reduced the outward currents, and in Li+-containing bathing solution the kainate-induced blockade of K+ channels was more pronounced. Probably, Li+ accumulates intracellularly after permeation through the receptor pore due to slower extrusion mechanisms. Experiments with GTPγS or GDPβS and pertussis toxin indicated that GTP-binding protein-mediated mechanisms were not of importance for the kainate-induced K+ conductance blockade. Our data suggest that in glial precursor cells AMPA/kainate receptor activation leads to an intracellular [Na+] increase which blocks delayed rectifying K+ channels. © 1995 Wiley-Liss, Inc.  相似文献   
9.
10.
We present a case of invasive pneumococcal infection in a healthy 10-month-old infant from whom Streptococcus pneumoniae serotype 23F was isolated from the blood and serotype 23B was isolated from the cerebrospinal fluid. Both serotypes were penicillin nonsusceptible. Pulsed-field gel electrophoresis analysis demonstrated that the two serotypes had distinct DNA patterns, indicating that infection did not occur as a result of capsular transformation but as a result of a mixed infection with two distinct pneumococcal serotypes.  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