On a class of rational p-adic dynamical systems

In this paper we investigate the behavior of trajectories of one class of rational p-adic dynamical systems in complex p-adic field Cp. We studied Siegel disks and attractors of such dynamical systems. We found the basin of the attractor of the system. It is proved that such dynamical systems are not ergodic on a unit sphere with respect to the Haar measure.     

A Three‐Component Organometallic Tyrosine Bioconjugation

Metal‐based bioconjugation linkages represent a little‐studied approach to protein functionalization that provides novel reactivity, stability, and function. Described is an organometallic bioconjugation, employing rhodium(III) salts, to link boronic acids with tyrosine residues by an arene complex. Both peptides and proteins are amenable to the mild bioconjugation in aqueous media, allowing incorporation of useful functionalities, such as affinity handles or fluorophores. Because of the metastability of the inorganic linkage, the conjugates are susceptible to cleavage by nucleophilic redox mediators but are stable toward typical biological conditions.     

Recent Advances in Transition Metal-Based Catalysts for Ethylene Copolymerization with Polar Comonomer

The synthesis of polar functionalized polyolefin (PFP) offers improvement in mixing properties, polymer surface, and rheological properties with the potential of upgraded polyolefins for modern and ingenious applications. The synthesis of PFP from metal-based catalyzed olefin (non-polar in nature) copolymerization with polar comonomers embodies energy-efficient, atom-efficient, and apparently an upfront methodology. Despite their outstanding success during conventional polymerization of olefin, 3^rd and 4^th group (early transition metal)-based catalysts, owing to their electrophilic nature, face challenges mainly due to Lewis basic sites of the polar monomers. On the contrary, late transition metal-based catalysts have also made progress, in recent years, for PFP synthesis. The recent past has also witnessed several advancements in the development of dominating palladium-based catalysts while their lower resistance towards ligand functional groups has limited the practical application of abundant and cheaper nickel-based catalysts. However, the relentless efforts of the scientific community, during the past half-decade, have indicated rigorous progress in the development of nickel-based catalysts for PFP synthesis. In this review, we have abridged the recent research trends in both early as well as late transition metal-based catalyst development. Furthermore, we have highlighted the role of transition metal-based catalysts in influencing the polymer properties.     

In vitro Inhibition Effect of Transition Metal Ions on Succinate‐Fumarate System in ATP Cycle

Oxidation of sodium succinate in aqueous solution by potassium ferricyanide was investigated. The effects of different reaction parameters such as initial concentration of succinate, concentration of ferricyanide, and influence of metal ions (Zn⁺², Ni⁺², Cu⁺², Cd⁺²) on the oxidation of succinate were investigated at 25 ± 0.05 °C. Large rate enhancements were observed in the redox reaction between succinate and ferricyanide with increasing concentrations of both oxidant and reductant. The kinetics results indicated that the succinate oxidation was significantly inhibited in the presence of metal ions. Pseudo first order rate constants values were found decreased with increase in concentrations of metal ions which reflected that inhibition rate was directly influenced with the metal ions concentration.     

Differential Activation of Signaling Pathways by UVA and UVB Radiation in Normal Human Epidermal Keratinocytes(†)

Ultraviolet (UV) radiation from the solar spectrum is a major etiological factor for many cutaneous pathologies including cancer. By understanding changes in cell signaling pathways induced by UVA and UVB, novel strategies for prevention and treatment of UV‐related pathologies could be developed. However, much of the information in the literature from various laboratories cannot cross talk because of difficulties associated with the use of ill‐defined light sources and physiologically irrelevant light dosimetry. Herein, we have assessed the effect of exposure of normal human epidermal keratinocytes (NHEK) to UVA (2 and 4 J cm^?2) or UVB (20 and 40 mJ cm^?2) radiation. Employing western blot analysis, we found that exposure of NHEK to UVB, but not UVA, phosphorylates JNK1/2 at Th¹⁸³/Tyr¹⁸⁵, STAT3 at Ser⁷²⁷, AKT at Ser⁴⁷³ and increases c‐Fos expression, whereas exposure to UVA, but not UVB, phosphorylates AKT at Thr³⁰⁸. UVB as well as UVA exposure leads to increased phosphorylation of (1) ERK1/2 at Th²⁰²/Tyr²⁰⁴; (2) p38 at Th¹⁸⁰/Tyr²⁰⁴; (3) STAT3 at Tyr⁷⁰⁵; (4) mTOR at Thr²⁴⁴⁸; and (v) p70S6k at Thr⁴²¹/Ser⁴²⁴; enhanced expression of PI3K (p85) and c‐jun; and nuclear translocation of NFκB proteins. These findings could be considered as a beginning for understanding the differential effects of UVA and UVB in the human skin and may have implications both with respect to risk assessment from exposure to solar UV radiation, and to target interventions against signaling events mediated by UVA and UVB.     

Catalytic protein modification with dirhodium metallopeptides: specificity in designed and natural systems

In this study, we present advances in the use of rhodium(II) metallopeptides for protein modification. Site-specific, proximity-driven modification is enabled by the unique combination of peptide-based molecular recognition and a rhodium catalyst capable of modifying a wide range of amino-acid side chains. We explore catalysis based on coiled-coil recognition in detail, providing an understanding of the determinants of specificity and culminating in the demonstration of orthogonal modification of separate proteins in cell lysate. In addition, the concepts of proximity-driven catalysis are extended to include modification of the natural Fyn SH3 domain with metallopeptides based on a known proline-rich peptide ligand. The development of orthogonal catalyst-substrate pairs for modification in lysate, and the extension of these methods to new natural protein domains, highlight the capabilities for new reaction design possible in chemical approaches to site-specific protein modification.     

On <Emphasis Type="Italic">p</Emphasis>-adic quasi Gibbs measures for <Emphasis Type="Italic">q</Emphasis> + 1-state Potts model on the Cayley tree

In the present paper we introduce a new kind of p-adic measures, associated with q + 1-state Potts model, called p-adic quasi Gibbs measure, which is totally different from the p-adic Gibbs measure. We establish the existence of p-adic quasi Gibbs measures for the model on a Cayley tree. If q is divisible by p, then we prove the occurrence of a strong phase transition. If q and p are relatively prime, then there is a quasi phase transition. These results are totally different from the results of [F. M. Mukhamedov and U. A. Rozikov, Indag. Math. N. S. 15, 85–100 (2005)], since when q is divisible by p, which means that q + 1 is not divided by p, so according to a main result of the mentioned paper, there is a unique and bounded p-adic Gibbs measure (different from p-adic quasi Gibbs measure)     

Effect of ultrasonically-assisted drilling on carbon-fibre-reinforced plastics

This research focuses on the effect of ultrasonically-assisted drilling (UAD) on carbon fibre-reinforced plastics. High-frequency vibration was used to excite a drill bit during its standard operation. An extensive experimental study of drilling forces, temperature, chip formation, surface finish, circularity, delamination and tool wear was conducted using ∅3 mm drill and presented here. UAD showed a significant improvement in drill quality when compared to conventional drilling processes. A finite-element study was also conducted to understand the nature of drilling-force reduction in UAD.     

On Julia Set and Chaos in <Emphasis Type="Italic">p</Emphasis>-adic Ising Model on the Cayley Tree

In this paper, we study the chaotic behavior of the p-adic Ising-Potts mapping associated with the p-adic Ising model on the Cayley tree. As an application of this result, we are able to show the existence of periodic (with any period) p-adic quasi Gibbs measures for the model.     

Measurable bundles of C^*-dynamical systems and its applications

In the present paper we investigate \(L_0\) -valued states and Markov operators on \( C^*\) -algebras over \(L_0\) . Here, \(L_0=L_0(\Omega )\) is the algebra of equivalence classes of complex measurable functions on \((\Omega ,\Sigma ,\mu )\) . In particular, we give representations for \(L_0\) -valued states and Markov operators on \(C^*\) -algebras over \(L_0\) , respectively, as measurable bundles of states and Markov operators. Moreover, we apply the obtained representations to study certain ergodic properties of \( C^*\) -dynamical systems over \(L_0\) .