ABSTRACT
OBJECTIVE@#To investigate the influence of cuspal-coverage thickness on the stress distribution of all-ceramic onlay-restored premolars by using 3D finite element (FE) analysis and to provide references for the design of all-ceramic onlays for clinical application.@*METHODS@#3D FE models of all-ceramic onlays with three cuspal-coverage thicknesses (2, 3, and 4 mm) of endodontically treated maxillary premolar were constructed based on micro-CT images. Stress distributions in the onlay, adhesive resin cement layer, and dentin of models were analyzed under vertical load (600 N) and oblique load (200 N).@*RESULTS@#When the cuspal-coverage thickness increased, the peak maximum principal stress value decreased inside the onlay but increased in the margin of the adhesive resin cement layer. In addition, stress concentration areas increased in the coronal residual dentin on the palatal side under oblique load.@*CONCLUSIONS@#An increase in the cuspal-coverage thickness of all-ceramic onlays may reduce the risk of rupture of the restoration but may deteriorate the restoration and cause palatal dentin fracture.
Subject(s)
Bicuspid , Ceramics , Composite Resins , Dental Porcelain , Dental Stress Analysis , Finite Element Analysis , InlaysABSTRACT
X-chromosome short tandem repeats (X-STR) analysis has been confirmed to be effective for kinship testing such as in deficiency paternity cases. The aim of this study was to develop a new multiplex polymerase chain reaction (PCR) system that can simultaneously amplify 9 X-STR loci (GATA172D05, DXS10159, DXS6797, HPRTB, DXS10079, DXS6789, DXS9895, DXS10146 and GATA31E08) in the same PCR reaction, and to obtain the database of the 9 X-STR loci in three ethnic populations in China. The genetic data of 815 (404 females and 411 males) unrelated Han Chinese from Hubei province, and Yi and Zhuang Chinese from Yunnan province were analyzed by using this multiplex system. The results showed that a total of 93 alleles for all these loci were found, and 7 to 20 alleles for each locus were observed. All of the analyzed loci were in agreement with Hardy-Weinberg equilibrium after Bonferroni correction in the three studied populations. The polymorphism information content (PIC) and power of discrimination (PD) in females were 0.6566-0.8531 and 0.8639-0.9684, respectively. Pairwise comparisons of allele frequency distribution showed significant differences in the most of these loci between different populations. The results indicate that this multiplex system is very useful for forensic analysis of different ethnic populations in China.
ABSTRACT
X-chromosome short tandem repeats (X-STR) analysis has been confirmed to be effective for kinship testing such as in deficiency paternity cases. The aim of this study was to develop a new multiplex polymerase chain reaction (PCR) system that can simultaneously amplify 9 X-STR loci (GATA172D05, DXS10159, DXS6797, HPRTB, DXS10079, DXS6789, DXS9895, DXS10146 and GATA31E08) in the same PCR reaction, and to obtain the database of the 9 X-STR loci in three ethnic populations in China. The genetic data of 815 (404 females and 411 males) unrelated Han Chinese from Hubei province, and Yi and Zhuang Chinese from Yunnan province were analyzed by using this multiplex system. The results showed that a total of 93 alleles for all these loci were found, and 7 to 20 alleles for each locus were observed. All of the analyzed loci were in agreement with Hardy-Weinberg equilibrium after Bonferroni correction in the three studied populations. The polymorphism information content (PIC) and power of discrimination (PD) in females were 0.6566-0.8531 and 0.8639-0.9684, respectively. Pairwise comparisons of allele frequency distribution showed significant differences in the most of these loci between different populations. The results indicate that this multiplex system is very useful for forensic analysis of different ethnic populations in China.
Subject(s)
Humans , Base Sequence , China , Chromosomes, Human, X , DNA Primers , Ethnicity , Genetics , Microsatellite Repeats , Genetics , Multiplex Polymerase Chain Reaction , MethodsABSTRACT
Single nucleotide polymorphism (SNP) refers to the single base sequence variation in specific location of the human genome. Phenotype informative SNP has gradually become one of the research hot spots in forensic science. In this paper, the forensic research situation and application prospect of phenotype informative SNP in the characteristics of hair, eye and skin color, height, and facial feature are reviewed.
Subject(s)
Humans , Eye Color/genetics , Forensic Genetics/trends , Forensic Sciences , Genome, Human , Hair , Phenotype , Polymorphism, Single Nucleotide/geneticsABSTRACT
<p><b>OBJECTIVE</b>To study the evidence of severe acute respiratory syndrome (SARS) infection among close contacts to SARS patients and the level of sera IgG antibody in SARS cases.</p><p><b>METHODS</b>Specific IgG antibody against SARS-CoV in serum samples from contacts to patients, five months before an SARS outbreak in Beijing. Neutralized test, ELISA and immunity adherence test were studied. Samples were collected after clinical onset of patients or close contacts to patients, for 22 - 24 weeks. 19 close contacts and 13 cases were included in the study.</p><p><b>RESULTS</b>In close contacts, all tests were negative on three methods. All SARS cases were positive except one by immunity adherence test. The neutralized antibody levels were from 1:16 to 1:203, with medium level of 1:43.</p><p><b>CONCLUSION</b>According to our survey, there was no latent infection among close contacts. IgG antibody in sera continued to be at higher levels among SARS cases 22 - 24 weeks after onset.</p>