Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Control theory & CMOS. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Evolution of Synonymous Codon Usage Bias in West African and Central African Strains of Monkeypox Virus

Abstract: The evolution of bias in synonymous codon usage in chosen monkeypox viral genomes and the factors influencing its diversification have not been reported so far. In this study, various trends associated with synonymous codon usage in chosen monkeypox viral genomes were investigated, and the results are reported. Identification of factors that influence codon usage in chosen monkeypox viral genomes was done using various codon usage indices, such as the relative synonymous codon usage, the effective number of codons, and the codon adaptation index. The Spearman rank correlation analysis and a correspondence analysis were used for correlating various factors with codon usage. The results revealed that mutational pressure due to compositional constraints, gene expression level, and selection at the codon level for utilization of putative optimal codons are major factors influencing synonymous codon usage bias in monkeypox viral genomes. A cluster analysis of relative synonymous codon usage values revealed a g...

Exploring the Crosstalk between Inflammation and Epithelial-Mesenchymal Transition in Cancer

Abstract: Tumor cells undergo invasion and metastasis through epithelial-to-mesenchymal cell transition (EMT) by activation of alterations in extracellular matrix (ECM) protein-encoding genes, enzymes responsible for the breakdown of ECM, and activation of genes that drive the transformation of the epithelial cell to the mesenchymal type. Inflammatory cytokines such as TGFβ, TNFα, IL-1, IL-6, and IL-8 activate transcription factors such as Smads, NF-κB, STAT3, Snail, Twist, and Zeb that drive EMT. EMT drives primary tumors to metastasize in different parts of the body. T and B cells, dendritic cells (DCs), and tumor-associated macrophages (TAMs) which are present in the tumor microenvironment induce EMT. The current review elucidates the interaction between EMT tumor cells and immune cells under the microenvironment. Such complex interactions provide a better understanding of tumor angiogenesis and metastasis and in defining the aggressiveness of the primary tumors. Anti-inflammatory molecules in this context may open new therapeutic options for the better treatment of tumor progression. Targeting EMT and the related mechanisms by utilizing natural compounds may be an important and safe therapeutic alternative in the treatment of tumor growth.

Hydroamination of carbodiimides, isocyanates, and isothiocyanates by a bis(phosphinoselenoic amide) supported titanium(iv) complex.

Abstract: The hydroamination of heterocumulenes such as carbodiimides, isocyanates, and isothiocyanates by a bis(phosphinoselenoic amide) supported titanium(IV) complex as a precatalyst is reported here. The titanium(IV) complex [{Ph2P(Se)NCH2CH2NPPh2(Se)}Ti(NMe2)2] (1) was synthesised by the reaction of tetrakis-(dimethylamido)titanium(IV) [Ti(NMe2)4] with [{Ph2P(Se)NHCH2CH2NHPPh2(Se)}] in toluene at ambient temperature. Titanium complex 1 proved to be a competent pre-catalyst for the addition of an amine N–H bond to carbodiimides, isocyanates, and isothiocyanates. The reaction scope was expanded to reactions of aliphatic and aromatic amines with phenylisocyanates and phenylisothiocyanates in toluene solvents proceeding rapidly at room temperature with 5 mol% catalyst loadings to yield the corresponding urea and thio-urea derivatives up to 99%. However, ambient temperature was needed for hydroamination of 1,3-dicyclohexylcarbodiimide. The amine addition reactions with isocyanates showed first order kinetics with respect to catalyst 1 as well as substrates. The most plausible mechanism for the hydroamination reaction was established by isolating 1,1-dimethylphenyl urea as a side product.

A low cure thermo active polymerization of chalcone based benzoxazine and cross linkable olefin blends

Abstract: In the present work, an attempt has been made to develop a chalcone based benzoxazine (1,3-bis(3,4-dihydro-3-phenyl-2H-benzo[1,3]oxazin-6-yl)prop-2-en-1-one) using 1,3-bis(4-hydroxyphenyl)prop-2-en-1-one, aniline and formaldehyde at appropriate conditions. The molecular structure of the developed benzoxazine was confirmed by FT-IR and NMR analysis. The thermal properties were studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From the data resulted, it was observed that the curing temperature of chalcone based benzoxazine appears at 205 °C. Similarly, the maximum degradation temperature was obtained at 474 °C with a char yield of 43% and the glass transition temperature was noticed at 234 °C. The blending of Chal-Bz with conventional bismaleimides such as 4, 4′-diaminodiphenylsulfone based bismaleimide (BMI-M) and 4, 4′-diaminodiphenylmethane based bismaleimide (BMI-S) results in the improved thermal stability to an appreciable extent. Further, the effect of incorporation of bio based benzoxazines synthesized from cardanol-aniline (CrAb) and eugenol-aniline (EuAb) to the Chal-Bz thermal behavior was also studied. In addition, the effect of catalysts (4-hydroxy phenylmaleimide HPM, 4-Amino Phenol AP, 4-hydroxy acetophenone HAP) on thermal curing properties of benzoxazines was also studied to bring down the polymerization temperature by creating supplementary potential sites for polymerization. From that catalytic study, it was found that the incorporation of 10 wt% of HAP reduces the value of Tp (158 °C) more efficiently than that of other catalysts. Data resulted from different studies, it can be suggested that the polymer blends of chalcone based benzoxazine and conventional bismaleimide can be used in the form of encapsulants, sealants, adhesives, and matrices in the fields of microelectronics and automobile industries for enhanced performance.