OBJECTIVEThis study aimed to observe and evaluate six 3.0 T sequences of metallic artifacts produced by metal dental crowns.

METHODSDental crowns fabricated with four different materials (Co-Gr, Ni-Gr, Ti alloy and pure Ti) were evaluated. A mature crossbreed dog was used as the experimental animal, and crowns were fabricated for its upper right second premolar. Each crown was examined through head MRI (3.0 T) with six sequences, namely, T₁ weighted-imaging of spin echo (T₁W/SE), T₂ weighted-imaging of inversion recovery (T₂W/IR), T₂ star gradient echo (T₂*/GRE), T2 weighted-imaging of fast spin echo (T₂W/FSE), T₁ weighted-imaging of fluid attenuate inversion recovery (T₂W/FLAIR), and T₂ weighted-imaging of propeller (T₂W/PROP). The largest area and layers of artifacts were assessed and compared.

RESULTSThe artifact in the T₂*/GRE sequence was significantly wider than those in the other sequences (P < 0.01), whose artifact extent was not significantly different (P > 0.05).

CONCLUSIONT₂*/GRE exhibit the strongest influence on the artifact, whereas the five other sequences contribute equally to artifact generation.

Objective To describe the characteristics of organizational culture,to identify the level of quality of work life,and to explore the relationship between each dimension of organizational culture and quality of work life among nurses in tertiary hospitals in Yunnan Province,China.Methods The subjects were 416 nurses from six tertiary hospitals in Yunnan Province.Research instruments were the Organizational Culture Profile (OCP) and the Quality of Work Life Scale (QWLS).Results The results of this study showed that four dimensions of organizational culture including competitiveness (3.56 ± 0.49);performance orientation (4.08 ± 0.22);stability (3.68 ± 0.43) and social responsibility (3.95 ± 0.37) were prominent.The other 3 dimensions,namely supportiveness (3.19 ± 0.79);innovation (3.21 ±.0.62) and emphasis on rewards were perceived (2.42 ± 0.79) as less prominent.The overall mean score of quality of work life was at a moderate level (57.46 ± 15.17).Conclusion There are positive significant correlation between each dimension of organizational culture and quality of work life (P＜ 0.01).Improvement of organizational culture can enhance quality of work life among nurses,and then guarantee the nursing quality.

Objective To explore the value of temporary cardiac pacemaker therapy on children with Adam-Stoke syndrome(ASS).Methods Nine children with ASS was implanted the emporary cardiac pacemaker under X-ray or blinding inserted beside bed.Results Seven children was successfully implanted the temporary cardiac pacemaker within 1-2 d of ASS attack,and two children was successfully implanted at 10 d and 20 d after ASS attack, respectively. Five patients was cured, two children was died, and two children was implanted the permanent cardiac pacemaker. During pacing, two patients had the electrode shifted,and one patient had the cardiac murmur,and one patient had the local skin infected.Conclusion Temporary cardiac pacemaker can successfully treat children with ASS attack;the earlier the implantation,the better the prognosis.

The effect of acute ischemia on the electrophysiological characteristics of the three layers myocardium of canine in vivo was investigated. Twelve canines were divided into two groups randomly: acute ischemia (AI) group and sham operation (SO) group. By using the monophasic action potential (MAP) technique, MAP and effective refractory period (ERP) of the three layers myocardium were measured by specially designed plunge needle electrodes and the transmural dispersion of repolarization (TDR) and transmural dispersion of ERP (TDE) were analyzed. The results showed that in the AI group, MAP duration (MAPD) was shortened from 201.67 +/- 21.42 ms to 169.50 +/- 13.81 ms (P < 0.05), but ERP prolonged to varying degrees and TDE increased during ischemia. In the SO group, MAPD and ERP did not change almost. Among of the three layers myocardium of canine, MAPD was coincident in two groups. It was concluded that during acute ischemia, MAPD was shortened sharply, but there was no significant difference among of the three layers myocardium. The prolonged ERP was concomitant with increased TDE during acute ischemia, which may play an important role in the occurrence of arrhythmias induced by acute ischemia. These findings may have important implications in arrhythmogenesis.
Action Potentials/*physiology ; Electrodes ; Heart/physiopathology ; Myocardial Ischemia/*physiopathology ; Myocardium/*metabolism ; Random Allocation ; Refractory Period, Electrophysiological/*physiology

功能性电刺激（FES）这一技术打开了瘫痪运动功能重建的一个广阔领域。在临床应用的推广中，对FES的基本原理和存在的问题有充分的认识，是应用成功的关键因素之一。本文分三部分阐述FES的基本概念、设计和应用。第一部分将讨论电刺激的阈值、募集顺序等概念。第二部分将介绍肌肉电刺激的安全参数范围、组织损伤，并讨论刺激器的设计。第三部分以C5/C6患者手功能重建为例，阐明功能性电刺激系统的工作原理。

Objective To explore the prognosis and etiological treatment of cardiogenic syncope in children.Methods The cause,clinical manifestation,treatment and prognosis of 45 children with syncope were made in affiliated hospital of Qingdao medical university were su mmarized and analyzed.They were divided into arhythmia group and other groups,the former included myocarditis,dilated cardiomyopathy,and post-operation of congenital heart disease and the latter included tetralogy of fallot,pulmonary stenosis,hypertrophic cardiomyopathy,pericarclial effusion,and right atrial myxoma.Results There were 29 cases(64.44%) with arrhythmia in this group,of which there were 18 cases with complete atrioventricular block(CAVB),2 cases with second degree type Ⅱ atrioventricular block,3 cases with ventricular tachycardia,2 cases with bradycardia,2 cases with atrial flutter,1 case with supraventricular tachycardia,and 1 case with nonconducting atrial premature.There were 16 cases(35.56%) with other etiologies,of which there 8 cases with tetralogy of Fallot,2 cases with pulmonary stenosis,hypertrop-hic cardiomyopathy,pericardial effusion,and right atrial myxoma,respectively.Children with CAVB,bradycardia,or ventricular tachycardia resulted from viral myocarditis were given anti-virus medicine,protecting myocardium,neoepinephrine,and intravenous vitamin C 100-200 mg/(kg?d).Dexamethasone 1-2 mg/(kg?d) was given in earlier period for short course,and some children were given human ?-globulin.Eight cases were placed temporary pacemaker because of unsatisfactory therapeutic efficacy,and 1 case was placed permanent pacemaker.In all,38 cases(84.44%)were cured,1 case(2.22%)was improved,and 4 cases(8.88%) died.Conclusions Cardiogenic syncope is pediatric emergency and shall be treated immediately.Temporary pacemaker shall be placed at the right moment.

Objective To understand clinical distribution and antimicrobial resistance characteristics of Pseudomonas aeruginosa(P.aeruginosa)isolated from hospitalized patients, so as to provide reference for the empiric use of antimicrobial agents and control of healthcare-associated infection(HAI).Methods Clinical distribution and antimicrobial susceptibility testing results of P.aeruginosaisolated from patients in a hospital between 2012 and 2016 were analyzed retrospectively, statistical analysis were conducted based on different wards, specimen types and age groups.Results A total of 2 432 strains of P.aeruginosa were isolated from2012 to 2016, most of which were isolated from intensive care unit(ICU)(n=727, 29.89％), the main specimen was sputum(n=2 064, 84.87％). Resistance rates of P.aeruginosa to other antimicrobial agents except piperacillin/tazobactam in each year from 2012 to 2016 were significantly different(all P＜0.05).Resistance to piperacillin, ceftazidime, cefepime, imipenem, meropenem, levofloxacin, and ciprofloxacin decreased after peaked in2014;resistance rates to amikacin, gentamicin, and tobramycin were all low, showing decreased trend year by year(all P＜0.05).Except resistance rates to cefepime and tobramycin, resistance rates of P.aeruginosafrom sputum specimen were all higher than other specimens(all P＜0.05).Resistance rates of P.aeruginosaisolated from patients aged≥65 years to most antimicrobial agents were significantly higher than those isolated from patients aged＜65 years(all P＜0.05).Except resistance rates to gentamicin and tobramycin, resistance rates of P.aeruginosaisolated from ICU were higher than those isolated from other departments, which were 7.71％-66.02％.Resistance rate of P.aeruginosaisolated from department of surgery were relatively low, which were 1.69％-11.86％.Conclusion Clinical distribution of antimicrobial resistance of P.aeruginosais obviously heterogeneity, empiric antimicrobial use and formulation of HAI monitoring measures should be based on the data of antimicrobial resistance in different wards, different infection sites, and different age.

Objective To investigate the clinical characteristics of patients with polymyositis(PM) and dermatomyositis (DM), and compare the differences of PM/DM to help the understanding of clinical diagnosis and treatment. Methods One hundred and forty-five hospitalized PM/DM patients from Department of Rheumatology of the First Affiliated Hospital of Xiˊan Jiaotong University were collected from May 2008 to December 2014, and the clinical manifestations, muscle enzymes, electromyogram, muscle biopsy, treatment outcome were retrospectively analyzed. Mann-Whitney U test and χ2 test were used for statistical analysis. Results The most common initial symptom of PM was muscle weakness, accounted for 51.2%, while rash was the initial presentation in most DM patients(43.1%). The incidence of interstitial lung disease (ILD) (62.7% vs 39.5%, χ2=11.009, P=0.001), and the elevation of CRP (48.9% vs 26.8%, χ2=10.272, P=0.001) were all higher in DM than PM, while the elevation of level of CK (85.4% vs 61.8%, U=-2.668, P=0.008) and CKMB (82.9%vs 41.2%, U=-3.303, P=0.001) were more common in PM compared with DM. The pathological study showed degeneration of muscle fiber, connective tissue hyperplasia in most PM patients, and perimysium atrophy, vacuoles degeneration, muscle bundles, perivascular inflammatory cell infiltration were observed in most DM patients. During the follow-up, the clinical remission rate was 57.5%, the relapse rate and the mortality rate was 7.5%and 31.1%respectively. The mortality rate was higher in DM than PM (34.6% vs 21.4%, χ2=4.861, P=0.027). Infection and tumors were the major causes of death, and the lung was the most common site of infection. Conclusion Differences in the clinical features, muscle enzymes, CRP level, pathology and the mortality rate between PM and DM are evident, while ILD, infection and the higher mortality rate are more common in DM than in PM.

ABSTRACT:Objective To investigate the clinical features of seronegative rheumatoid arthritis (RA)in western China and its outcomes after one-year treatment with disease modifying anti-rheumatoid drugs (DMARDs) so as to provide evidence for effective therapy.Methods We made a retrospective analysis of 240 RA patients treated in our department from May 2013 to June 2014.We compared the 47 seropositive and 25 seronegative RA patients in clinical features,laboratory parameters and outcomes after one-year DMARDs medication.Results The percentage of seronegative RA was 10.4% (25/240).The number of swollen small joints was significantly smaller in seronegative RA group (P<0 .0 1 ).Compared with those in seropositive RA,the level of hemoglobin was lower,the level of platelets was higher,and the level of alkaline phosphatase was lower in seronegative RA (P<0 .0 5 ).The remission rate was higher in seronegative RA group than in seropositive RA group after one-year DMARDs administration (P<0.05).Conclusion Seronegative RA is not rare in clinic.Even though seronegative RA patients often present fewer swollen small joints, it is difficult to distinguish between seronegative and seropositve RA just based on the clinical features.Besides,hematological damage is more severe in some patients with seronegative RA.Only after one-year treatment with DMARDs,the remission rate is higher in seronegative RA patients than in seropositve RA ones.

Objective: To study the predictive value of 12-lead electrocardiogram (ECG) abnormality on prognosis of chronic heart failure in patients with dilated cardiomyopathy (DCM-CHF).
Methods: A prospective, multicenter follow-up study in 787 DCM-CHF patients was conducted, and the endpoints were obtained by clinical visit, mail contact and telephone conversation. The independent predictors for all cause death were determined by Cox regression analysis, QRS duration > 120 ms was studied and the survival rates were investigated by Kaplan-Meier analysis.
Results: There were 203 patients died during the follow-up period. Cox regression analysis found that the following indexes were related to all cause death: atrial fibrillation (AF) (HR=2.064, 95% CI 1.102-3.864,P<0.05), non-sustained ventricular tachycardia (NSVT) (HR=3.887, 95% CI 1.554-9.724,P<0.05) and QRS duration (HR=1.010, 95% CI 1.002-1.018, P<0.05). Kaplan-Meier analysis revealed that the survival rates were different by each stratiifcation of QRS duration,P<0.05.
Conclusion: ECG indexes of AF, NSVT and QRS duration had the important impact on the survival rate in DCM-CHF patients; there were signiifcant differences between QRS durations and survival rates.