Hyperbolic Phonon-Plasmon Modes in Grounded Graphene-hBN Heterostructures for Mid-Infrared Applications

In recent years, the hybridization of hyperbolic van der Waals heterostructures with plasmonic two-dimensional nano-materials is one of the interesting research areas at THz frequencies due to the coupled features of the hybrid structure. This article investigates the propagation of tunable surface phonon-plasmon polaritons in grounded hybrid graphene-hexagonal Boron Nitride (hBN) heterostructures. An analytical model is presented for the proposed structure, by applying the boundary conditions for the electromagnetic components in the various regions, to derive an exact dispersion relation. The structure is simulated and the results are reported in the upper Reststrahlen band. A good agreement is seen between simulation and analytical results, which shows the high accuracy of our mathematical relations. The tunability of the heterostructures is shown by studying the effect of chemical potential on the performance of the structure. A high value of the figure of merit, i.e. FOM=190, is reported at the frequency of 48.3 THz. The presented study can open the way for the design of novel THz devices for future nano-plasmonic applications.Comment: 13 pages, 8 figure

Effective factors on the number of decayed and filled teeth using the Conway-Maxwell-Poisson count model

BACKGROUND AND AIM: Recognizing the factors affecting the number of decayed and filled teeth has a major role in oral health. Dental data usually suffer from over-dispersion and excess zero frequencies. The purpose of this study was to use the Conway-Maxwell-Poisson (COM-Poisson) model to determine some of the factors affecting the number of decayed and filled teeth. METHODS: In this cross-sectional study, a sample of 1000 people from a cohort study in Shahrekord City, Iran, aged 35-70 years, was selected through systematic sampling. The data were analyzed using the Bayesian approach through Markov chain Monte Carlo (MCMC) simulation by OpenBUGS. Zero-inflated Poisson (ZIP), COM-Poisson model, and zero-inflated Com-Poisson (ZICMP) model were fitted on the data and compared using the deviance information criterion (DIC). RESULTS: The mean numbers of decayed and filled teeth were 0.77 ± 1.63 and 4.37 ± 4.62, respectively. The Com-Poisson and ZICMP showed to be better fit for the number of decayed and filled teeth, respectively. Those people who were younger, male, smokers, diabetics, did not floss, and did not use mouthwash had significantly more number of decayed teeth (P < 0.05). Those people who were younger, female, non-diabetics, non-smokers, employed, literate, had less body mass index (BMI), flossed, and got higher score of quality of life had significantly more number of filled teeth (P < 0.05). CONCLUSION: By controlling such factors as education, BMI, flossing, using mouthwash, smoking, diabetes, and quality of life, we could improve the oral health. KEYWORDS: Bayes’ Theorem; Conway-Maxwell-Poisson Distribution; Decayed, Missing, and Filled Teeth; Zero-inflate

Structural and Dynamic Insight into Hirudin Epitopes-HLADRB1 0101 Complexes and their Modified Peptide Ligands: A Molecular Dynamic Simulation Study

Purpose: To develop a hirudin therapeutic protein that eliminates unwanted immune response.Methods: Molecular dynamic simulation was performed on immunodominant hirudin epitopes 1-15 and 13-27 and its analog, modified peptide ligands (MPLs), namely, [Lys4] Hir1-15 and [Gly9] Hir1-15, [Gly21] Hir13-27 and [Lys21] Hir13-27. The selected epitopes were modeled and 20 ns of molecular dynamics simulation was performed on peptide-HLA1 0101 and MPLs-HLA1 0101 complexes to gain a better understanding of molecular recognition mechanisms of MHC peptide binding. Characterization of the process was done by evaluation of root mean square deviation (RMSD) and total energy of binding.Result: All complexes of MPLs-HLA-DRB1 0101 showed thermodynamically unstable structure in comparison with native epitopes-HLA-DRB1 0101. The findings indicate that these analogs have different orientation in HLA grooves and are not available for suitable interaction with HLA-DRB1 0101.Conclusion: Altogether, the results show the potentials of predictive methods and molecular modeling in molecular mimicry of peptide-MHC interaction and provide insights into the binding characteristics of antigen presentation mechanism.Keywords: Modified peptide ligand, Epitopes, MHC peptide binding, Hirudin, Modified peptide ligands, Molecular dynamic simulation, Binding free energ

Investigation of genetic association between PRODH gene and schizophrenia in Iranian population

Schizophrenia is a complicated, debilitative mental disorder. Evidence is emerging for the association of polymorphisms in PRODH gene and increased risk of schizophrenia. In the present research, we investigated relationship between of this gene and schizophrenia disease by means of a gene polymorphism using PCR-RFLP technique.150 persons suffering from acute Schizophrenia and 160 healthy persons volunteering for this project were bled. . Based on intended SNP, pair of primers was designed by Oligo7 program and polymerase chain reaction (PCR) was performed by thermo cycler. Then the resulted reactive mixture was exposed to a special enzyme, which we had intended for our study. Finally, the fragments of enzyme cut were transferred on the gel (4%) and migration pattern of resulted components were compared in healthy and patient subjects , whereby obtaining genotypes of different persons in polymorphic position. We utilized SPSS 16.0 program for statistical investigation of the work and studied SNP 1945T&gt;C and its relation with the disease in statistical population. Our findings showed a meaningful relation between the occurrence of this nucleotide mutation and its frequency in patients (given P value=0.00). Results of this work indicate that PRODH gene can be considered to be a significant candidate in our population as a factor influencing the occurrence of Schizophrenia

Thyroid Peroxidase Gene Mutation in Patients with Congenital Hypothyroidism in Isfahan, Iran

Background. Thyroid peroxidase gene (TPO) mutations are one of the most common causes of thyroid dyshormonogenesis in patients with congenital hypothyroidism (CH). In this study, the prevalence of TPO gene mutations in patients with thyroid dyshormonogenesis in Isfahan was investigated. Methods. In this cross-sectional study, genomic DNA of 41 patients with permanent CH due to thyroid dyshormonogenesis was extracted using the salting out method. The 17 exonic regions of the TPO gene were amplified. SSCP technique was performed for scanning of the exonic regions of the TPO gene, except exon 8. DNA sequencing was performed for those with different migration patterns in SSCP by chain termination method. Exon 8 was sequenced directly in all patients. In 4 patients, all fragments were also sequenced. Results. One missense mutation c.2669G>A (NM_000547.5) at exon 15 (14th coding exon) in one patient in homozygous form and seven different single nucleotide polymorphisms (SNPs) in exons 1, 7, 8, 11, and 15 of TPO gene. Conclusion. The TPO gene mutations among CH patients with dyshormonogenesis in Isfahan were less frequent in comparison with other similar studies. It may be due to the presence of other unknown gene mutations which could not be detected by SSCP and sequencing methods

Theoretical analysis of hybrid surface plasmon polaritons in plasma-based elliptical structures with graphene layers for THz applications

In this article, tunable surface plasmon polaritons (SPPs) in graphene-based elliptical waveguides containing gyro-electric layers are investigated. The general structure has an elliptical cross section, where each gyro-electric layer is surrounded by two graphene layers. The DC magnetic bias is applied on the z-axis. By writing Maxwell’s equations inside the gyro-electric medium and applying boundary conditions, closed-form general relations are obtained for electromagnetic components of SPP waves. As a special case, a new plasma-based elliptical structure with double-layer graphene is studied in this paper. The figure of merit (FOM) for this waveguide can be varied by changing the magnetostatic bias and the chemical doping. At the frequency of 40 THz, the FOM of 139 for this waveguide is reported for the B = 1 T and μc = 0.9 eV. Ability to adjust and tune the propagating properties of SPPs in hybrid graphene-plasma elliptical structures can be exploited for the design of new plasmonic components in the THz spectral region

Heterozygosity and allele frequencies of the two VNTRs (ApoB and D1S80) in Iranian population

Genetic markers are used for identity testing and paternity analysis depends on knowing the allele frequencies in the population. Minisatellites show allelic variability in the number of repeat units. We have studied the allele frequencies and heterozygosity of two VNTRs (ApoB and D1S80) in Iranian populations. A total of 96 and 82 chromosomes were analyzed by PCR and gel electrophoresis for ApoB and D1S80 respectively. In the ApoB system, allele 37 was the most common followed by allele 35 whereas allele 23 was the most common followed by allele18 at the D1S80 locus. Observed heterozygosity was relatively low in ApoB than D1S80 locus, however, no significant differences were found between observed and expected heterozygosity