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   538篇
  免费   30篇
耳鼻咽喉   7篇
儿科学   9篇
妇产科学   21篇
基础医学   35篇
口腔科学   5篇
临床医学   25篇
内科学   94篇
皮肤病学   7篇
神经病学   134篇
特种医学   10篇
外科学   29篇
综合类   1篇
预防医学   138篇
眼科学   5篇
药学   35篇
中国医学   2篇
肿瘤学   11篇
  2023年   3篇
  2022年   17篇
  2021年   22篇
  2020年   12篇
  2019年   14篇
  2018年   9篇
  2017年   19篇
  2016年   17篇
  2015年   13篇
  2014年   18篇
  2013年   28篇
  2012年   29篇
  2011年   30篇
  2010年   10篇
  2009年   9篇
  2008年   26篇
  2007年   28篇
  2006年   55篇
  2005年   37篇
  2004年   40篇
  2003年   30篇
  2002年   43篇
  2001年   8篇
  2000年   3篇
  1999年   3篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   3篇
  1992年   5篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1987年   3篇
  1985年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   3篇
  1974年   1篇
  1973年   2篇
  1970年   1篇
  1969年   1篇
  1966年   1篇
排序方式: 共有568条查询结果,搜索用时 15 毫秒
1.
The aim of the project was to determine whether the rate of contaminant blood cultures could be reduced by using a team of dedicated phlebotomists. Comparisons were made between adult patients requiring blood cultures for suspected bacteremia on medical and surgical units before and after the introduction and withdrawal of a dedicated blood culture team. The results showed that a significant reduction in the contaminant blood culture rate was achieved by the blood culture team (P < 0.001; chi(2) test). Therefore, in our experience, the rate of contaminant blood cultures can be reduced in a teaching hospital by using a team of dedicated phlebotomists. Calculations made with our data and those published by others suggest that cost savings from reducing false-positive blood cultures are greater than the cost of the blood culture team.  相似文献   
2.
Four clinically normal stallions were infused intravenously with endotoxin (LPS) from Escherichia coli 055:B5 at a dose of 0.3 μg/kg b.w. and four stallions were treated with flunixin meglumine (FM) as a single intravenous injection at a dose of 1.1 mg/kg b.w., 5 min after the infusion of LPS. In response to endotoxin infusion, stallions’ reaction was fever (increased rectal and scrotal skin temperature), increased heart rate (HR) and leucopenia. Administration of endotoxin also influenced the level of testosterone (decrease at 3–24 h and increase at 48–72 h after LPS administration) in the blood serum. FM treatment prevented an endotoxin‐induced increase in rectal and scrotal skin temperature, HR, with no influence on the decrease of leucocytes. Administration of FM only had a significant effect on the latter changes (at 24–72 h) of serum testosterone concentration after addition of endotoxin.  相似文献   
3.
4.
The X‐linked McLeod neuroacanthocytosis syndrome strongly resembles Huntington's disease and has been reported in various countries world‐wide. Herein, we report two Chilean brothers with predominant psychiatric features at disease onset including schizophrenia‐like psychosis and obsessive compulsive disorder. Molecular genetic analysis revealed a small deletion in the XK gene (938‐942delCTCTA), which has been already described in a North American patient of Anglo‐Saxon descent and a Japanese family, presenting with seizures, muscle atrophy or chorea yet absence of psychiatric features. These findings argue against a founder effect and indicate a profound phenotypic variability associated with the 938‐942delCTCTA deletion. Our report supports the inclusion of McLeod syndrome in the differential diagnosis of Huntington's disease as well as acute psychosis in male subjects. © 2007 Movement Disorder Society  相似文献   
5.
Recombinant FimH adhesins of type 1 fimbriae from Salmonella enterica serovar Gallinarum biovars Gallinarum and Pullorum, in contrast to those of Salmonella enterica serovar Typhimurium, did not bind to high-mannose oligosaccharides or to human colon carcinoma HT-29 cells. However, mutated FimH proteins from biovar Gallinarum and biovar Pullorum, in which the isoleucine at position 78 was replaced by the threonine found in S. enterica serovar Typhimurium, bound well to glycoproteins carrying high-mannose oligosaccharides and colon carcinoma cells. The loss of sugar-binding properties by biovar Gallinarum and biovar Pullorum FimH adhesins, which are a part of the type 1 fimbriae, is most probably the result of a single T78I mutation, as was proven by site-directed mutagenesis of FimH proteins.  相似文献   
6.
The effect of adrenergic blockade on gastric secretion altered by catecholamines was studied for 4 hr after injection in rats with chronic gastric fistulas. The alpha-adrenergic blockers phenoxybenzamine and phentolamine significantly inhibited the basal secretion of HCl and pepsin. Blockade of the beta-adrenergic receptors with propranolol did not change this secretion. Practolol in small doses slightly increased and in larger doses inhibited HCl out-put. Of the catecholamines, adrenaline and dopamine most markedly reduced HCl and pepsin secretion, while noradrenaline and isoprenaline had a weaker effect. Neither alpha- nor beta-adrenergic blockers prevented the inhibitory action of the catecholamines employed, but intensified the depression of the gastric secretion provoked by them. Adrenergic blockers inhibited secretion after catecholamines as well as basal secretion. This indicates that these two antagonistic groups of compounds act independently on the mechanism controlling gastric secretion. It is unlikely that this takes place indirectly through changes in the blood supply of the gastric mucosa.  相似文献   
7.
The previously observed occurrence of antineutrophil cytoplasmic autoantibodies (ANCA) in patients who have cystic fibrosis (CF), together with the reported decrease in IgG2, a Th1-controlled isotype, suggests a potential for Th1/Th2 imbalance in CF patients with a possible Th2 predominance. 48 CF patients and 16 controls had levels of IFNgamma, IL-4, and IL-10 measured in supernatants of whole blood cell cultures stimulated by lipopolysaccharide (LPS) and phytohemaglutinine (PHA). The patients were divided into 2 groups: "low responders", having negligible secretion of cytokines (IFNgamma: 10.0-200.0 pg/ml, IL-4: 0.0-0.3 pg/ml) and "high responders", producing high levels of both IFNgamma (500.0-2000.0 pg/ml) and IL-4 (1.0-200.0 pg/ml). There was a statistically significant (P < 0.01) deterioration of lung function measured by an FEV(1) decline by 11.2% over 3 years in the "low responder" group. 10 of 16 "low responders" had chronic lung infections with P. aeruginosa while such infection was less prevalent in the "high responder" group where only 13 of 32 CF patients had positive cultures. A shift towards Th2 response was observed in the "high responder" group as children chronically infected with P. aeruginosa had greater IL-4 production than non-infected CF patients within the same cohort. ANCA autoantibodies were found only in the "high responder" group. Th2 immune response predominance in a subset of CF patients is associated with chronic P. aeruginosa infection.  相似文献   
8.
Targoński R  Salczyńska D  Sadowski J  Cichowski L 《Kardiologia polska》2008,66(7):729-36; discussion 737-9
BACKGROUND: Occurence of atrial fibrillation (AF) adversely affects left atrial size and cardiac function. This arrhythmia is also associated with an increase of plasma CRP and fibrinogen concentration. It is not clear whether elevated levels of inflammatory markers in patients with congestive heart failure (CHF) are associated with AF, clinical symptoms or adverse cardiac remodelling. AIM: To investigate the association between levels of inflammatory markers and selected clinical and echocardiographic parameters as well as used treatment in the population of CHF patients with various forms of AF. METHODS: The cross-sectional study included 99 patients with CHF divided into 3 groups. Group I included patients with sinus rhythm. Group II consisted of patients admitted to hospital with AF and discharged with sinus rhythm (the category of paroxysmal and persistent AF). Group III comprised patients with permanent AF. In all patients plasma CRP and fibrinogen concentrations were measured and echocardiographic examination was carried out. Left atrial dimension (LA), ejection fraction (LVEF) and right ventricular systolic pressure (RVSP) were assessed. RESULTS: Mean CRP concentration in group III (5.83+/-5.36 mg/l) was significantly higher than in group I (p=0.001) and group II (p=0.033). In the group with permanent AF mean fibrinogen concentration was elevated to a higher level (391.0+/-77.3 mg/dl) than in group II (p=0.007) and group I (p=0.099). Mean LA and RV dimensions and RVSP in group III were significantly higher than in group I and group II. Multivariable analysis revealed that plasma CRP concentration was significantly associated with the presence of arterial hypertension (p <0.001) and LA enlargement (p=0.007). A significant association between fibrinogen level and CRP level (p=0.038), presence of permanent AF (p=0.045) and metabolic syndrome (p <0.05) was found. Values of ln CRP were significantly correlated with LA diameter (r=0.24; p=0.015). CONCLUSIONS: Increased plasma CRP level in patients with CHF were significantly associated with arterial hypertension and LA enlargement. Permanent form of AF and CRP level have been shown to be significantly associated with increased plasma fibrinogen concentration in the course of CHF.  相似文献   
9.
Effect of bronchial thermoplasty on airway distensibility.   总被引:1,自引:0,他引:1  
Recent studies have reported that the application of thermal energy delivered through a bronchoscope (bronchial thermoplasty) impairs the ability of airways to narrow in response to methacholine. How such altered smooth muscle affects the response of airways to lung inflation may have important clinical implications, particularly as it relates to the abnormal response of asthmatic subjects to lung inflation and deep inspiration. The aim of this study was to examine whether bronchial thermoplasty affected airway distension with lung inflation in relaxed and contracted airways. A total of 230 airways were studied, ranging 2.5-15 mm, in six dogs. These airways were divided into two groups: an untreated (control) population and a bronchial thermoplasty-treated population. Prior to treatment, the airway pressure-area curves in the two groups of airways were identical. In contrast, the relaxed and contracted airway pressure-area curves in treated airways were shifted upward at all points, showing increased airway area at both 3 and 5 weeks post-treatment. In conclusion, these results show that reducing that amount of functional smooth muscle with bronchial thermoplasty leads to increased airway size in both relaxed and contracted states over a normal range of inflation pressures.  相似文献   
10.
Multiple sclerosis (MS) is a chronic demyelinating disease of primary autoimmune origin with essential component of subsequent axonal degeneration. It has been found that inflammatory cells crucial for MS pathogenesis are able to release neurotrophic factors (NFs). Thus the concept of neuroprotective effect of inflammation has arisen. Over recent years, increasing number of studies has revealed that NFs play an important role in MS and its animal model — experimental autoimmune encephalomyelitis (EAE). In the current review the evidence for the role of NFs in MS pathogenesis the same as their remarkable potential in MS therapy is presented.  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