Objective:To evaluate the effect of different shoulder width on the compressive strength of full-contour zirconia crowns.Methods:A computer aided design and computer aided manufacturing(CAD/CAM) system was used to prepare 24 full-contour zirconia crowns of the mandible first molar.1 mm occlusal thickness crowns with 4 shoulder width of knife-edge(group A),0.3 mm(group B),0.5 mm(group C) and 1.0 mm(group D) (n =6).The Co-Cr alloy PFM crowns made by the die of group C were used as the controls (n =6).All the full-contour zirconia crowns were bonded to the corresponding die using 3 M glass ionomer cement (GIC) and the compressive strength were measured by an universal testing machine.Based on the statistical analysis,crowns with the shoulder width of 0.5 mm were treated by the thermocycling test under cycling of 10000 times(group C1),20 000 times(group C2) and 30000 times (group C3) respectively(n =6).One-way ANOVA method was used for the statistical analysis.Results:The mean compressive strength(N) of group A,B,C,D and E was 3855.00 ± 305.47,2731.70 ± 261.80,3698.30 ± 276.87,3841.70 ± 544.88 and 2992.17 ± 168.41 respectively.The strength of group B and E were lower than that of group A,C and D(P ＜ 0.05),B vs E P ＞0.05.The compressive strength(N) of group C1,C2 and C3 was 3220.00 ± 504.38 (group C1),3148.33 ± 425.60(C2) and 2992.17 ±168.41 (C3) respectively (P＞0.05).Conclusion:For the full-contour zirconia crowns,both the knife-edge shoulder and the shoulder wider than 0.3 mm can meet the thermoclinical needs.The cycling times used in this study have no influences on the compressive strength.

Bordetella pertussis ; immunology ; Consensus ; Humans ; Pertussis Vaccine ; therapeutic use ; Whooping Cough ; immunology ; prevention & control

Abstract: Objective　To analyze the serotype distribution, drug resistance rate and drug resistance gene carrying of Streptococcus pneumoniae isolates in hospitalized patients, and evaluate the coverage of the vaccine to the serotype of Streptococcus pneumoniae in this area, so as to provide reference for the rational use of antibiotics in clinic. Methods　A total of 150 strains of non-repetitive Streptococcus pneumoniae isolated from inpatients from January 2015 to December 2019 were collected for serotyping and antimicrobial sensitivity test. The carrying rates of pbp2b, ermB and tetM were detected by PCR. Results　The PCR classification rate of 150 strains of Streptococcus pneumoniae was 93.1%, and the classification rate of capsular swelling test was 100%, and a total of 19 serotypes were divided, mainly 19F and 6B. Children's serotypes were predominantly 19F, 6B, and 15A; adult serotypes were predominantly 19F, 14, and 23F. The coverage rates of the PCV7, PCV10, PCV13 and PPV23 vaccines were 36.8%, 42.1%, 57.9% and 68.4%, respectively. Strains with serotypes of 19F, 6B, 3, and 23F had higher rates of resistance to antimicrobials. The sensitivity of Streptococcus pneumoniae to penicillin was greater than 96.0%. Antimicrobials with significant differences in resistance rates between invasive and non-invasive strains were penicillin, moxifloxacin, and levofloxacin. The percentage of strains carrying both ermB and tetM resistance genes was 96.0%, and the concordance rate between pbp2b, ermB and tetM resistance genes and the resistance phenotype was >98.0%. A total of 10 multi-resistance combinations were detected, with a multi-resistance rate of 62.6%, and the multi-drug resistance pattern of Streptococcus pneumoniae was mainly concentrated in the 19F and 6B serotypes. Conclusion　There are significant age differences in the serotypes of Streptococcus pneumoniae in this area. The vaccine currently used has low coverage in this region and therefore offer limited protection to the population. The drug resistance rates of Streptococcus pneumoniae varied significantly among serotypes. Erythromycin and tetracycline are not recommended for clinical treatment of Streptococcus pneumoniae. Penicillin can still be used as the first choice for clinical treatment of Streptococcus pneumoniae infection.

Background The usual transbronchial coagulation techniques include microwave,argon plasma coagulation (APC),electrocautery and cryotherapy.However,there are serious clinical problems in the safety of each.By analyzing the experimental data and clinical observations,we observed the variable effects of different coagulation techniques via bronchofibroscopy,to look for an optimal interventional management of luminal bronchus diseases,and evaluate the safety and the equivalent point.Methods Four kinds of coagulation techniques under bronchoscopy were performed on the fresh bronchus of healthy sheep,and the pathologic changes in all groups were observed under the microscope.The different treatment parameters were as follows:microwave 60 W×1 second,3 seconds,5 seconds and 40 W×1 second,3 seconds,5 seconds; APC 40 W×1 second,3 seconds,5 seconds; electrocautery 40 W×1 second,3 seconds,5 seconds;cryotherapy 100 Ω×60 seconds,120 seconds.Results After treatment,ovine bronchial mucosa in all groups showed pathologic changes such as local necrosis and amotio of the mucosa lining epithelium,local submucosa coagulative necrosis or tissue defects,while inflammation in the surrounding tissue was not obvious.Under the same output power and action time,different methods had different outcomes.The damage by APC was the most superficial,microwave was the second,and electrocautery caused the worst damage.The study also found that effects of electrocautery at 40 W×3 seconds,microwave at 40 W×5 seconds or 60 W×3 seconds,APC at 40 W×5 seconds and cryotherapy at 100 Ω×120 seconds were the equivalent point conditions.The appearance included mucosa absence,partial submucosa absence,and collagen fiber coagulation in treatment areas.Conclusions Each coagulation technique has its own characteristic.It is very important to choose the appropriate power and action time of the suitable method according to the therapy requirement.

Background:The preferred treatment for uncomplicated type B dissection (thoracic endovascular aortic repair [TEVAR] or medical) is still under debate.Since 2001,our center has performed TEVAR for uncomplicated type B dissection.Based on our data,5-and 10-year survival rates among patients with uncomplicated type B dissection after TEVAR were 96.5％ and 83.0％,respectively.We,therefore,believe that TEVAR is preferable for uncomplicated type B dissections.This study analyzed the impact of a pre-operative smoking history on long-term survival after TEVAR in patients with uncomplicated type B dissections.Methods:From May 2001 to December 2013,data from 751 patients with type B dissections were collected and analyzed.Patients were divided into two groups (337 smoking patients and 414 non-smoking patients).The Kaplan-Meier method and log-rank test were used to compare survival curves of the two groups.Multivariable analyses using the Cox proportional hazards model were used to estimate the effects of smoking on survival rates.Results:The 5-and 10-year survival rates of non-smokers were 97.6％ (95％ confidence interval [CI],96.0％-99.2％) and 87.0％ (95％ CI,81.6％-92.7％),respectively,and 94.9％ (95％ CI,92.2％-97.7％) and 73.8％ (95％ CI,62.3％-87.5％) for smokers,respectively (Log-rank test,P =0.006).Multivariable analyses showed that smoking increased the risk of death during follow-up,2.1-fold when compared to non-smokers (P =0.039).Conclusion:A pre-operative smoking history increases long-term mortality rates after TEVAR in patients with uncomplicated type B dissections.

OBJECTIVETo study the characteristics of the normal subjects with postural sway test and discuss the value of postural sway test in the diagnosis of dizzy patients.

METHODSTotally 112 normal subjects, 72 patients with peripheral vertigo, and 30 patients with central vertigo were examined using a stabilometer (EAB-100, Anima Co., Japan). Items include patterns, length of locus, envelope area, deflection average center displacement, and romberg rate were recorded and compared.

RESULTSThe postural sway was classified into the following five patterns: centripetal, forward and backward, right and left, diffuse, and multicentric. Centripetal pattern was the most prominent figure pattern in the normal subjects, while diffuse pattern was the most prominent figure pattern in the patients with central vertigo. When the normal subjects closed their eyes, age was linearly correlated with the length of locus, envelope area, rectangel area, and unit area path length (P < 0.05). Sex was not correlated to all of these parameters. The length of locus and envelope area in the patient groups were significantly increased when compared with the normal subjects (P < 0.0167). Romberg rate was not significantly different between the patients and the normal subjects.

CONCLUSIONSThe pattern of postural sway is useful for the diagnosis of vertigo. Age is an important factor that affects the balance function. Sex seems has no influence. Visual input plays an important role in maintaining postural balance. Stabilometer is a useful tool for evaluating balance function, and postural sway test may be a valuable assistant examination.

Adult ; Age Factors ; Case-Control Studies ; Dizziness ; diagnosis ; physiopathology ; Humans ; Male ; Middle Aged ; Postural Balance

OBJECTIVETo develop a novel scaffolding method for the copolymers poly lactide-co-glycolide acid (PLGA) to construct a three-dimensional (3-D) scaffold and explore its biocompatibility through culturing Schwann cells (SCs) on it.

METHODSThe 3-D scaffolds were made by means of melt spinning, extension and weaving. The queueing discipline of the micro-channels were observed under a scanning electronic microscope (SEM).The sizes of the micropores and the factors of porosity were also measured. Sciatic nerves were harvested from 3-day-old Sprague Dawley (SD) rats for culture of SCs. SCs were separated, purified, and then implanted on PLGA scaffolds, gelatin sponge and poly-L-lysine (PLL)-coated tissue culture polystyrene (TCPS) were used as biomaterial and cell-supportive controls, respectively. The effect of PLGA on the adherence, proliferation and apoptosis of SCs were examined in vitro in comparison with gelatin sponge and TCPS.

RESULTSThe micro-channels arrayed in parallel manners, and the pore sizes of the channels were uniform. No significant difference was found in the activity of Schwann cells cultured on PLGA and those on TCPS (P larger than 0.05), and the DNA of PLGA scaffolds was not damaged.

CONCLUSIONThe 3-D scaffolds developed in this study have excellent structure and biocompatibility, which may be taken as a novel scaffold candidate for nerve-tissue engineering.

Animals ; Biocompatible Materials ; Cell Adhesion ; Cell Proliferation ; Cell Separation ; Cells, Cultured ; Lactic Acid ; Microscopy, Electron, Scanning ; Polyglycolic Acid ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; Tissue Engineering ; methods ; Tissue Scaffolds

Aorta ; surgery ; Aorta, Thoracic ; surgery ; Aortic Aneurysm, Thoracic ; diagnosis ; Humans ; Male ; Middle Aged

OBJECTIVE: To study the clinical effect and complications of continuous blood purification (CBP) in the treatment of multiple organ dysfunction syndrome (MODS) in neonates. METHODS: A retrospective analysis was performed for the clinical data of 21 neonates with MODS who were admitted to the neonatal intensive care unit from November 2015 to April 2019 and were treated with CBP. Clinical indices were observed before treatment, at 6, 12, 24, and 36 hours of CBP treatment, and at the end of treatment to evaluate the clinical effect and safety of CBP treatment. RESULTS: Among the 21 neonates with MODS undergoing CBP, 17 (81%) had response to treatment. The neonates with response to CBP treatment had a significant improvement in oxygenation index at 6 hours of treatment, a significant increase in urine volume at 24 hours of treatment, a stable blood pressure within the normal range at 24 hours of treatment, and significant reductions in the doses of the vasoactive agents epinephrine and dopamine at 6 hours of treatment (P<0.05), as well as a significant reduction in serum K+ level at 6 hours of treatment, a significant improvement in blood pH at 12 hours of treatment, and significant reductions in blood lactic acid, blood creatinine, and blood urea nitrogen at 12 hours of treatment (P<0.05). Among the 21 neonates during CBP treatment, 6 experienced thrombocytopenia, 1 had membrane occlusion, and 1 experienced bleeding, and no hypothermia, hypotension, or infection was observed. CONCLUSIONS CBP is a safe, feasible, and effective method for the treatment of MODS in neonates, with few complications.
Blood Gas Analysis ; Blood Urea Nitrogen ; Hemofiltration ; Humans ; Infant, Newborn ; Multiple Organ Failure ; Retrospective Studies

Objective The aim of this study is to observe the effect of combined amiodarone and antiarrhythmic peptide (AAP10) use on the incidence of induced ventricular arrhythmias in healed myocardial infarction (MI) rabbits. Methods Twenty Japanese rabbits underwent thoracotomy without coronary artery ligation( Sham, group A) ,the middle left circumflex branch were ligated to induce MI in 180 Japanese rabbits. Eight weeks after operation, 124 rabbits survived MI operation and were divided into four groups: control group (group B, n =31 ), amiodarone group (group C, n =31 ), AAP10 group (group D,n =31 ) and amiodarone plus AAP10 group ( group E, n =31 ). The A and B and D groups were treated with saline 2 ml/d, the C and E groups were treated with 2 ml saline containing amiodarone 100 mg· kg-1·d-1. All rabbits were examined by echocardiogram at 12 weeks after operation, then anesthetized by sodium barbital, the left wedge ventricular preparations were cannulated and artery perfused by Tyrode's solution in vitro in the absence (Group A, B and C) and presence of AAP10 (500 nmol/L, Group D and E). The volume electrocardiogram, QT Interval, QRS interval, effective refractory period (ERP), the T-peak to Tend interval ( Tp-e ), and ventricular tachycardia episodes induced by programmed stimulation were recorded.The Tp-e/QT ratio was calculated. After perfusion, gap junctions protein connexin 43 (Cx43) expression was detected by Western blot and immunofluorescence. Results The incidence of induced ventricular tachycardia episodes of group A, B, C, D, E was 0, 62. 5%, 26. 9%, 40.0%, 22. 2% respectively. The incidence of induced ventricular tachycardia episodes of group E was less than group B. The Tp-e/QT ratio in group B, C, D were greater than in group A. The Tp-e/QT ratio of group E was less than group B. The myocardial Cx43 in the group B was down-regulated and disorganized compared to group A, up-regulated in group C and E compared to group B, up-regulated in group E compared to group D. The Cx43 in the heart of group D and E were well organized than in group B and C. Conclusions The artery perfused rabbits wedge preparations with healed myocardial infarction with high incidence of induced ventricular tachycardia episodes are good platform for ventricular arrhythmias research. Combined amiodarone and AAP10 use could decrease the Tp-e/QT ratio and the incidence of induced ventricular tachycardia episodes. Amiodarone and AAP10have synergistic effects on upregulating Cx43 and preventing ventricular arrhythmias in this rabbit model of healed myocardial infarction.