Objective To compare the effect between problem-based learning and lecture-based learning for clinical teaching in the department of cardiovascular medicine. Methods Totally 110 five-year-program cardiovascular interns from June 2011 and June 2012 were selected. They were randomly divided into the PBL group(n=55) and LBL group(n=55). PBL and LBL teach-ing methods were applied in the two groups respectively. Teaching effects were evaluated by exam and questionnaire investigation. SPSS 15.0 was used to do data processing; t test was used to compare the average score of two groups;chi-square test was used to process the results of the questionnaire. P<0.05 signifies sta-tistically significant differences. Results There were statistical differences in examinational average score between PBL group and LBL group ((87.89 ±5.39) vs. (82.63 ±5.26), P<0.05). PBL group had significantly higher satisfaction rate in motivating study interests , deepening understanding of theoretical knowledge, cultivating self-learning ability, training verbal expression and developing clin-ical thinking, etc(P<0.05). Conclusions PBL teaching method demonstrates advantages in teaching of cardiovascular medicine and enhances the teaching effect. But the PBL teaching method should be improved in basic knowledge teaching, cultivation of teachers' ability and case selection.

BACKGROUND:Studies have confirmed that the surface treatment methods such as silane coupling agent and sand blasting could improve bonding strength of zirconia ceramics and resin binder. In addition, the increase of micro cracks on the surface of zirconia ceramics can also improve the bonding strength of zirconia ceramics and resin binder. But there is a lack of related studies addressing whether repeatedly sintering would have an impact on shear bond strength of zirconia ceramics.
OBJECTIVE:To determine the effect of decorative porcelain temperature firing on the shear bond strength between dental zirconia ceramics and resin binder.
METHODS:Twenty pieces of zirconia ceramics specimens were selected from 40 tablets, and then randomly divided into five groups according to the number of sintered times:control group (without sintering), sintering groups for 2, 4, 6, 8 times. Heat starting temperature was 500 ℃, and final temperature was 1 000 ℃ with a heating rate of 55 ℃/min. The vacuum time was 7 minutes. During the sintering, the final temperature was constant. Unsintered ceramic pieces were bonded using resin binder. Universal testing machine was used to test the shear strength of the interface between the two pieces of zirconia ceramics. The interface after shearing was characterized by scanning electron microscope.
RESULTS AND CONCLUSION:The shear strength of sintering groups for 4, 6, 8 times was significantly higher than that of the control group (P<0.05). Shear strength of specimens sintered twice was slightly higher than that of specimens without sintering, but the difference was not significant (P>0.05). Shear strength of specimens sintered 8 times was slightly higher than that sintered 4 and 6 times (P<0.05). Under the scanning electron microscope, there was no crack on the surface of non-sintered zirconia ceramics. After 2 times sintering, the surface appeared to have fine cracks. After sintering 4 times, visible cracks were increased. After six rounds of sintering, the surface began to have significant changes;cracks rose along with slight gaps and a smal amount of adhesive residues were found. After sintering for 8 times, cracks and voids were obviously increased on the sintered surface and adhesive residues were found. It indicated that after sintering for 4, 6 and 8 times, zirconia ceramics could have a good shear strength binding to resin adhesives;with the increasing of sintering times, the shear bond strength could be increased.

BACKGROUND:At present, there are stil differences in the studies of total-etch, self-etch and self-bonding resin cement effect on the coronal microleakage and bonding strength of fiber posts.
OBJECTIVE:To evaluate the coronal microleakage and the bonding strength of fiber posts treated with three kinds of resin cements.
METHODS:Total y 32 upper incisors were randomly divided into five groups, including three experimental groups and two control groups. After the root canal preparation, three kinds of resin cements (EMBRACE WetBond, LuxaCore, Medental Multi-cure) were used to fiber posts with the bond diameter of 1.4 mm. Stereomicroscope was used to observe the microleakage. Then, the specimens were cut into 2 mm wafer along the axis of tooth, and universal testing machine for push-out test was used to observe the failure mode. In the positive control group, no root canal preparation was done, the root was coated with nail polish, and the crown was directly exposed to the dye. In the negative control group, no root canal preparation was done, the root canal orifice was covered with the resin, the tooth was overal coated with nail polish and then embedded 1 mm below the section.
RESULTS AND CONCLUSION:The microleakage was observed in al the three resin cements, Medental Multi-cure showed the least microleakage and LuxaCore showed the largest microleakage, and there was significantly different among the three kinds of resin cements (P<0.05). The bonding strength of three cements had significant differences (P<0.05), and ranked from high to low:Mdental Multi-cure, LuxaCore, and EMBRACE WetBond. The main fracture modes were binder/fiber post fracture and mixed failure. The results suggest that the total-etch resin cement binds tightly with the dentin, and owns a superiority in the microleakage and bonding property as compared with the self-etch resin cements and self-bonding resin cements.

BACKGROUND:Due to limitations of the physicochemical properties of soft denture liner material itself, whisker has been added in the soft lining material in recent years, so as to enhance its mechanical properties. OBJECTIVE:To investigate the effect of different additive amount of anhydrous calcium sulfate whisker on the mechanical function of self-curing soft denture liner. METHODS: There were six groups in this experiment. Anhydrous calcium sulfate whisker at the mass fraction of 0 (control), 1%, 2%, 3%, 4%, 5% was respectively added into self-curing soft liner materials, 10 test specimens in each group, a total of 60 test specimens. The shear bond strength, Shore hardness and tensile strength were detected. RESULTS AND CONCLUSION: With the increasing amount of the anhydrous calcium sulfate whisker, the Shore hardness of the soft lining material was increased continuously, and the tensile strength was increased firstly and then reduced. When 3% anhydrous calcium sulfate whisker was added, the bond strength and tensile strength of soft lining material reached the peak. Taken together, the mechanical properties of the soft lining materials became perfect when 3% anhydrous calcium sulfate whisker was added. These results demonstrate that anhydrous calcium sulfate whisker may affect the mechanical properties of self-curing soft liner.

Objective: To evaluate the safety and anticoagulant efficacy of domestic bivalirudin injection during emergent percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).
Methods: A total of 75 STEMI patients were randomly divided into 2 groups according to anticoagulant used in emergent PCI procedure. Bivalirudin group, the patients received intravenous domestic bivalirudin, n=40 and Heparin group, n=35. The activated clotting time (ACT) was tested at pre-PCI, 5 minutes after medication, immediately after PCI, 30 minutes, 1 hour and 2 hours after medication respectively. The activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and ifbrinogen (FIB) level were measured at before medication and 6, 24, 72 hours after medication.
Results: All patients in Bivalirudin group had ACT>225s at 5min after medication as PCI requirement, while 1 patient in Heparin group could not reach the requirement and the extra dose was added. Both groups maintained ACT>225s during PCI procedure. Bivalirudin group had the lower ACT levels than those in Heparin group at 30 min, 1-and 2-hour after the medication, P<0.05. The post-PCI levels of APTT, PT, TT and FIB were similar between 2 groups, all P>0.05. The no-cardiac event surviving rate at 30 days after PCI in Bivalirudin group and in Heparin group were similar P>0.05 and the mild bleeding at 24 hours after PCI in Bivalirudin group was lower (0 vs 11.43)%, P<0.05.
Conclusion: Compared with heparin, domestic bivalirudin may take faster effect, with shorter half-life period for anticoagulation during emergent PCI procedure in STEMI patients.

BACKGROUND:Microleakage between restoration, tooth structure and bonding agent can cause the entry of bacteria and liquid in the mouth into the gap, thereby damaging the bonding interface between the restoration and tooth tissues, and leading to bond failure. Microleakage detection can directly show whether the closure of the root canal of post and core system is good or bad. The severity of microleakage directly affects the restorative effects of post and core. OBJECTIVE: To evaluate the effects of different root canal cleaning methods on the microleakage between the fiber post and root canal dentin. METHODS: Thirty fresh non-caries premolar posts with free root canalin vitro were randomly divided into five groups, and the root canal wal was respectively washed with saline, 5.25% sodium hypochlorite solution+17% ethylenediamine tetra-acetic acid (EDTA)+saline, 3% hydrogen peroxide solution+5.25% sodium hypochlorite+ saline, 3% hydrogen peroxide solution+2% chlorhexidine solution+saline, and 2% chlorhexidine solution+17% EDTA+saline in different groups. Super-bond C&B adhesive agent was used for bonding fiber post, and the microleakage of each sample was observed under stereomicroscope. RESULTS AND CONCLUSION: The severity of microleakage in the al groups was ranged as folows: saline group > 3% hydrogen peroxide solution+5.25% sodium hypochlorite+saline group > 5.25% sodium hypochlorite solution+17% EDTA+saline and 3% hydrogen peroxide solution+2% chlorhexidine solution+saline groups > 2% chlorhexidine solution+17% EDTA+saline group.

Objective Analysis of the application effect after using 6S management of delicate instruments in Central Supply Sterilization Department.Methods 6S management's preliminary stage from December 2022 to December 2023,then created a departmental 6S management team and organized a mobilization meeting.Formulated specific implementation steps for 6S management,accepted on-site inspection of 6S management quality by the nursing department and self inspection of Central Supply Sterilization Department quarterly,compared the qualification rate of all instruments packaging and sterille goods supply quarterly,and the timely supply rate of emergency reprocessing instruments,the difference before and after 6S management was statistically significant(P＜0.05).Results The on-site inspection of 6S management quality by the nursing department found that the"seiton"in the first quarter,the"safety"of manual cleaning of employees in the second quarter,the"seiso"in the third quarter,the"safety"of on-site interview in the fourth quarter,and the quality of 6S management in the auxiliary area were quali-fied were unqualified.The qualification rate of all instruments packaging were higher than before using 6S management in the first,second,third,fourth quarters(P＜0.05),and the qualification rate of sterille goods supply were higher than before using 6S management in the first,second,fourth quarters(P＜0.05),and the timely supply rate of emergency reprocessing instru-ments were higher than before using 6S management in the second,third,fourth quarters(P＜0.05).Conclusion 6S manage-ment can improved the key link quality and identified various problems of delicate instrument management in Central Supply Steri-lization Department,among which seiri,seiton,seiso,seiketsu is the focus of daily management.

OBJECTIVETo retrospectively analyze the risk factors and clinical manifestations of myocardial damage of patients with severe burn in order to provide evidence for its prevention and treatment.

METHODSTwo hundred and fifty-two patients with severe burn admitted to 5 burn centers from January 2010 to June 2015, conforming to the study criteria, were treated in accordance with the fluid resuscitation formula of the Third Military Medical University. According to the creatine kinase isoenzyme-MB (CK-MB) level before treatment on admission, patients were divided into non-myocardial damage group (n=118, CK-MB level less than 75 U/mL) and myocardial damage group (n=134, CK-MB level higher than or equal to 75 U/mL). Data of patients in two groups were collected and evaluated such as gender, age, body mass, number of patients with chemical burn, admission time after injury, total burn area, full-thickness burn area, number of patients with inhalation injury, levels of haemoglobin, hematocrit, and blood lactate on admission and at post injury hour (PIH) 24 and 48, volumes of urine output and fluid input at PIH 24 and 48, levels of creatinine, urea nitrogen, total bile acid, diamine oxidase on admission and at PIH 24 and 48, and mortality. Furthermore, patients were divided into three groups, i. e. less than 50% total body surface area (TBSA) group (n=110), larger than or equal to 50% TBSA and less than 80% TBSA group (n=83), and larger than or equal to 80% TBSA group (n=59) according to the total burn area, and the incidence rates of myocardial damage in patients of three groups were recorded. Data were processed with chi-square test, t test, Wilcoxon test, analysis of variance for repeated measurement, and the values of P were adjusted by Bonferroni. Basic data of 252 patients were processed with binary logistic regression analysis. Receiver operating characteristic curve of total burn area of 252 patients was drawn to predict myocardial damage.

RESULTS(1) There were no statistically significant differences in age, body mass, number of patients with chemical burn, number of patients with inhalation injury, and full-thickness burn area between two groups (with t values respectively 0.20 and 0.31, χ(2) values respectively 0.49 and 4.10, Z=1.42, P values above 0.05). There were statistically significant differences in gender, admission time after injury, and total burn area of patients between two groups (χ(2)=5.00, with t values respectively 2.44 and 3.13, P<0.05 or P<0.01). (2) Gender, admission time after injury, and total burn area were independent risk factors related to myocardial damage in the patients (with odds ratios respectively 2.608, 3.620, and 1.030; 95% confidence intervals respectively 1.315-5.175, 1.916-6.839, and 1.011-1.049; P values below 0.01). (3) The incidence rates of myocardial damage of patients in less than 50% TBSA group, larger than or equal to 50% TBSA and less than 80% TBSA group, and larger than or equal to 80% TBSA group were 38.2% (42/110), 54.2% (45/83), and 61.0% (36/59) respectively, and there was statistically significant difference among them (χ(2)=9.46, P<0.05). (4) The total area under receiver operating characteristic curve of total burn area to predict myocardial damage of 252 patients was 0.706 (with 95% confidence interval 0.641-0.772, P<0.01), and 51.5% TBSA was chosen as the optimal threshold value, with sensitivity of 62.6% and specificity of 65.3%. (5) Compared with those in non-myocardial damage group, except the levels of haemoglobin and hematocrit at PIH 48 (with t values respectively -0.76 and -0.61, P values above 0.05), the levels of haemoglobin, hematocrit, and blood lactate of patients in myocardial damage group were significantly increased at each time point (with t values from -2.80 to -2.06, P<0.05 or P<0.01). Compared with those in non-myocardial damage group, the volume of urine output of patients was significantly declined (with t values respectively 2.05 and 3.68, P<0.05 or P<0.01), while the volume of fluid input of patients was not obviously changed in myocardial damage group at PIH 24 and 48 (with t values respectively 1.01 and 1.08, P values above 0.05). (6) Compared with those in non-myocardial damage group, the level of creatinine of patients was significantly increased on admission and at PIH 24 and 48 (with Z values from -2.91 to -1.99, P<0.05 or P<0.01), the level of urea nitrogen of patients was only significantly increased at PIH 24 and 48 (with t values respectively -4.75 and -5.24, P values below 0.01), the level of total bile acid of patients was not obviously changed on admission and at PIH 24 and 48 (with t values from -0.81 to -0.20, P values above 0.05), and the level of diamine oxidase of patients was only significantly increased on admission and PIH 24 in myocardial damage group (with t values respectively -3.97 and -2.02, P<0.05 or P<0.01). (7) Compared with that in myocardial damage group, the mortality of patients in non-myocardial damage group was significantly declined (χ(2)=5.81, P<0.05).

CONCLUSIONSPatients with severe burn have high incidence of myocardial damage, which may be predicted by total burn area. Severely burned patients with myocardial damage are more likely to suffer from decline of effective circulating volume, tissue oxygenation disorders, and damage in other organs in shock stage.

Body Surface Area ; Burn Units ; Burns ; pathology ; Fluid Therapy ; Hematocrit ; Hemoglobins ; analysis ; Humans ; Lactic Acid ; blood ; Myocardium ; pathology ; Retrospective Studies ; Shock

It was reported that pancreatic arteries constricted during the early phase of bile salt-induced acute pancreatitis (AP), leading to pancreatic microcirculatory disturbance. We conducted this experiment to verify whether the above-mentioned finding was true. AP was induced with intraductal injection of taurodeoxyholate. Small pancreatic artery pressure in dogs was recorded. Functional capillaries were counted and calibrated by multiplying wet weight of pancreas. Pancreatic perfusion was measured with Laser Doppler flowmeter. Pancreatic arterioles of rats dilated during the initial 20 min of AP, and pancreatic arterial pressure declined during the early phase of AP in dogs (from 104.5 +/- 4.8 mmHg to 54.6 +/- 5.6 mmHg). The hematocrit of blood from inferior vena cava was significantly lower than that of portal vein at 5 min after pancreatitis induction. The "true" pancreatic functional capillary density increased. The early pancreatic microcirculatory disturbance coincided with a marked increase of portal vein pressure (PVP) as high as 9.18 +/- 0.78 mmHg. Reduction of PVP to baseline level was followed by a marked increase of pancreatic perfusion (by 1.4-fold). Arterial dilatation, but not constriction, occurred during the early phase of bile salt-induced AP. The pancreatic microcirculatory disturbance was due to a marked rise in PVP that greatly reduced the pressure difference in the pancreatic blood vessels and increased plasma extravasation which led. to local hemoconcentration.
Animals ; Bile Acids and Salts ; adverse effects ; Hypertension, Portal ; complications ; Male ; Microcirculation ; drug effects ; physiology ; Pancreas ; blood supply ; Pancreatitis ; etiology ; physiopathology ; Portal Pressure ; Portal Vein ; physiopathology ; Rats ; Rats, Sprague-Dawley