Objective　To evaluate the influence of various cavity designs, lining and restorative materials on fracture resistance of teeth in vitro. Methods　Factorial design with three factors and various levels was used.36 extracted human maxillary premalors were prepared for occlusal cavity, MO cavity and MOD cavity. Various base material and restorations were used. All teeth were thermocycled and mounted for testing and then were loaded until fracture. The results were analyzed by a three-way ANOVA. Fracture patterns were observed at the same time. Results　There was significant difference in fracture resistance among various cavity designs and restorations. The fracture patterns were different. Conclusions　The different classes of cavities and various restorations have significantly influence upon fracture resistance of teeth. There are interactions between cavities and restorations.

Intravenous glucose tolerance test(IVGTT)and oral glucose-insulin releasing test(OGIRT) in 12 subjects with normal glucose tolerance were performed.The results showed that the peak of insulin secretion Was at 40 minutes during()GIRT.The ratio of the change of insulin-to-glucose at 40 minutes(△I40/△G40)is an index in reflecting insulin sensitivity and β-cell function.

OBJECTIVETo compare the influence of different investment materials, methods and crown height on the cast shrinkage of full crowns made of dental base metal alloy.

METHODSAll of the 288 wax patterns were made and divided into three groups according to their crown height. In every group, wax patterns were invested in metal rings and paper rings with three types investment material and cast with base metal alloys. Then the inside diameters of castings were measured and analyzed by statistical package SPSS.

RESULTSDifferences between groups invested with the three types of material were significant(P < 0.01). There were significant difference between the groups investing with metal rings and paper rings(P < 0.01).

CONCLUSIONThe component of investment material and invested ring can affect the cast shrinkage of dental base metal alloy apparently.

Crowns ; standards ; Dental Alloys ; standards ; Dental Casting Investment ; Dental Casting Technique ; instrumentation ; Humans ; Inlay Casting Wax ; chemistry ; classification ; Materials Testing ; instrumentation ; methods ; Metal Ceramic Alloys ; standards ; Prosthesis Fitting

OBJECTIVEThe purpose of this study was to compare the compressive strength of phosphate-bonded investments.

METHODSThe three sorts of investments were mixed according to manufacturer's recommendation before poured in the molds. After heated up to 900 degrees C, every sample was mounted on a universal experimental machine to test its compressive strength in ambient.

RESULTSSignificant differences were found between the four groups(P < 0.01).

CONCLUSIONFrom the data above it is concluded that the compressive strength of X-20 Chrome Investment mixed with the special liquid was the highest.

Compressive Strength ; Dental Bonding ; Dental Casting Investment ; chemistry ; Dental Casting Technique ; instrumentation ; Materials Testing ; Phosphates ; chemistry

OBJECTIVETo explore the expression of glucose transporter (GLUT)-1 and insulin receptor (IR) alpha1 in osteoblast obtained from diabetic rats' mandibles.

METHODSThe expression of GLUT-1 and IR alpha1 of diabetic and control groups were measured by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry stain.

RESULTSThe mRNA expressions of GLUT-1 and IR alpha1 of diabetic group were significantly higher than control group (P<0.05). The protein expressions of GLUT-1 and IR alpha1 were similar to the mRNA expressions.

CONCLUSIONOsteoblasts obtained from diabetic rats' mandibles keep the adaptation changes to hyperglycemia and hypoinsulinemia, which may contribute to their dysfunction.

Animals ; Diabetes Mellitus, Experimental ; Glucose Transport Proteins, Facilitative ; Mandible ; Osteoblasts ; Rats ; Receptor, Insulin

Objective To explore the diagnostic value of a wearable flexible patch ECG instrument in arrhythmia,the alarm situation during clinical application,patient satisfaction and safety.Methods A total of 1 443 subjects wore flexible patch ECG and conventional dynamic ECG(control)for 24 h to test the validity and consistency of arrhythmia diagnosis,and counted the alarm of remote ECG and the occurrence of related adverse events during the wearing of the instrument.Results There were 987 cases of arrhythmia detected by flexible patch ECG and 992 cases by conventional dynamic ECG.The total coincidence rate of arrhythmia diagnosis was 98.7%.The mean heart rate was measured by flexible patch ECG(75.4±11.4)times/min,conventional dynamic heart rate(71.5±12.1)times/min,the intra-group correlation coefficient(ICC)of 2 instruments was 0.892(95%CI:0.537-0.956),with good repeatability.The correct alarm rate of flexible patch ECG was 100%.The incidences of skin pruritus(0.28%vs.1.32%),skin allergy,redness and swelling(0.14%vs.0.69%)and electrode strip shedding(0 vs.0.28%)during wearing the flexible patch electrocardiogram were lower than those of the conventional holter electrocardiogram(P＜0.05).Conclusion The flexible patch ECG has few adverse reactions,high comfort,good safety and clinical applicability.

Aim To reveal the mechanism of cross-species ischemic heart failure from the perspective of spatial and gene co-expression networks.Methods GSE210374 and GSE57338 high-throughput sequencing datas were re-trieved from the national center for biotechnology information gene expression database(NCBI-GEO),and R language soft-ware packages was used to analyze and screen differentially expressed genes(DEG)in different myocardial regions of myo-cardial infarction rats,as well as DEG of myocardial samples from patients with ischemic heart failure and healthy controls,and the regional expression of common genes was analyzed.Weighted gene co-expression network analysis(WGCNA)was used to screen the genes related to myocardial infarction and to carry out enrichment analysis,protein-protein interac-tion network(PPI)was constructed to screen core genes(HG).Results A total of 4 835 differentially expressed genes were screened out in myocardial infarction rats and normal controls,and 51 differentially expressed genes were screened out in ischemic heart failure patients and normal control samples,which revealed representative gene sets in the left ventricular myocardial infarction area(I area),border area(BZ area),and remote area(R area)after myocardial in-farction.Spatial expression analysis revealed that there were 20 co-expressed genes in each myocardial region,16 of which were expressed in all three regions,the number of genes specifically expressed in I,BZ and R regions were 2,0 and 2,respectively.Enrichment analysis showed that the functions of co-expressed genes were different in different region.The I and BZ regions were related to collagen fiber assembly,stress-induced cardiomyocyte hypertrophy,down-regulation of c-Jun amino terminal kinase(JNK signal)and cell proliferation,and complement signaling pathways;The I and R regions were enriched in the binding of Wnt and collagen;As a non-ischemic distal R region,the co-expressed genes were signifi-cantly enriched in the extracellular matrix for functions such as compressive resistance,cytolysis and inhibition of T cell proliferation.Furthermore,it was worth noting that the products of co-expressed genes in the three regions were mostly lo-cated in the extracellular space and extracellular matrix,suggesting that there may be active cellular secretion and interac-tion regulation.Further PPI analysis suggested that asporin(ASPN),osteoglycin(OGN)and collagentype ⅩⅥ alpha chain(COL14A1)gene might be the core genes of the mechanism mentioned above.Conclusions The common mechanism of ischemic heart failure in rats and human involves multiple signaling pathways such as complement and coagu-lation cascade signaling and Wnt;which may be closely related to cell apoptosis mediated by extracellular matrix and exo-somes;ASPN,OGN,and COL14A1 may be the core genes.This work is expected to provide spatial and pathway refer-ence for the selection of intervention targets and pathway in the transformation research related to ischemic heart failure.