Human prochymase activation. A novel role for heparin in zymogen processing

Human prochymase is packaged with heparin in mast cell granules and appears to be activated by dipeptidylpeptidase I. We show that a high affinity interaction between heparin and prochymase allows the 2-residue propeptide to be cleaved by dipeptidylpeptidase I. A conserved Glu in the propeptide is necessary for this heparin effect. Following propeptide cleavage, capture of the newly generated NH2 terminus by an "activation groove" on the enzyme activates the enzyme and concurrently prevents a progressive degradation of the NH2 terminus by dipeptidylpeptidase I. Surrogate peptide studies show that the activation groove is unoccupied in prochymase and is specific for the chymase NH2 terminus. These observations indicate that heparin is an important cofactor in the prochymase activation process and explain how dipeptidylpeptidase I, a nonspecific processing enzyme, can effect a specific cleavage of the zymogen propeptide.     

Quantum Junction Solar Cells: Development and Prospects

Nanocrystals, called semiconductor quantum dots (QDs), contain excitons that are three-dimensionally bound. QDs exhibit a discontinuous electronic energy level structure that is similar to that of atoms and exhibit a distinct quantum confinement effect. As a result, QDs have unique electrical, optical, and physical characteristics that can be used in a variety of optoelectronic device applications, including solar cells. In this review article, the stable and controllable synthesis of QD materials is outlined for upscaling solar cells, including material development and device performance enhancement. It includes a systematic variety of device structures for the fabrication of solar cells, such as QD, hybrid QD/organic, hybrid QD/inorganic, perovskite QD, and hybrid 2D MXene QD/perovskite. The mechanisms for the improvement of stability by QD treatment are examined. For example, the 2D MXene QD and/or Cu_1.8S nanocrystal doping significantly increases the long-term light and ambient stability of perovskite solar cells, resulting from improved perovskite crystallization, reduced hole transport layer (HTL) aggregation and crystallization of films, and reduced UV-induced photocatalytic activity of the electron transport layer (ETL). For the advancement of QD solar cells and their interaction with various materials, the conclusions from this review are crucial. Finally, future prospects for the development of QD solar cells as well as current challenges are discussed.     

Implementation of quantum optical tristate oscillators based on tristate Pauli-X, Y and Z gates by using joint encoding of phase and intensity

Oscillator circuit has the significant role to always repeat the same signal at the output after certain time interval. In quantum computing, intensity and phase of light signal can be made oscillatory at the output of a quantum optical oscillator circuit. In this paper, we have implemented quantum optical tristate oscillator circuits based on tristate Pauli-X, Y and Z gates using phase and intensity encoding technique of light signal. Here, three different oscillator circuits are developed. The phase of light signal is chosen as the oscillating parameter in all proposed circuits. The truth tables and oscillating phase diagrams are also shown for each oscillator circuit in this paper. The operation of one of the oscillator circuits is simulated with MATLAB to prove its feasibility.     

Transparent and Flexible Mn1−x−y(CexLay)O2−δ Ultrathin-Film Device for Highly-Stable Pseudocapacitance Application

Control over the fabrication of state-of-the-art portable pseudocapacitors with the desired transparency, mechanical flexibility, capacitance, and durability is challenging, but if resolved will have fundamental implications. Here, defect-rich Mn_1−x−y(Ce_xLa_y)O_2−δ ultrathin films with controllable thicknesses (5–627 nm) and transmittance (≈29–100%) are fabricated via an electrochemical chronoamperometric deposition using a aqueous precursor derived from end-of-life nickel-metal hydride batteries. Due to percolation impacts on the optoelectronic properties of ultrathin films, a representative Mn_1−x−y(Ce_xLa_y)O_2−δ film with 86% transmittance exhibits an outstanding areal capacitance of 3.4 mF cm⁻², mainly attributed to the intercalation/de-intercalation of anionic O²⁻ through the atomic tunnels of the stratified Mn_1−x−y(Ce_xLa_y)O_2−δ crystallites. Furthermore, the Mn_1−x−y(Ce_xLa_y)O_2−δ thin-film device exhibits excellent capacitance retention of ≈90% after 16 000 cycles. Such stability is associated with intervalence charge transfer occurring among interstitial Ce/La cations and Mn oxidation states within the Mn_1−x−y(Ce_xLa_y)O_2−δ structure. The energy and power densities of the transparent flexible Mn_1−x−y(Ce_xLa_y)O_2−δ full-cell pseudocapacitor device, is measured to be 0.088 μWh cm⁻² and 843 µW cm⁻², respectively. These values show insignificant changes under vigorous twisting and bending to 45–180° confirming these value-added materials are intriguing alternatives for size-sensitive energy storage devices.     

Parent–Daughter Confusion Component: A New Approach for the Construction of Nonlinear Confusion Component

The nonlinear confusion component is one of an integral part of any modern block cipher. This nonlinear confusion component is used to hides the relationship between the ciphertext and the key. The primary objective of this article is to formulate a new mechanism for the construction this confusion component. Usually substitution box (S-box) is used to achieve this kind of characteristics in block ciphers. We have utilized deoxyribonucleic acid (DNA) sequences for the construction of new S-boxes with optimized cryptographic characteristics. The projected technique fundamentally optimized the DNA sequences along with traditional confusion component to generate a completely new S-box. The obtained S-boxes have the same cryptographic strength as a parent S-box have.

     

A cooperative mobile throwbox-based routing protocol for social-aware delay tolerant networks

Wireless Networks - In delay tolerant networks (DTNs), nodes have intermittent connectivity patterns due to various factors such as mobility, sparse network topology, and unpredictable movement...     

Performance evaluation of underwater wireless optical CDMA system for different water types

In this paper, an analytical approach is presented to investigate the bit error rate (BER) performance of underwater wireless optical code division multiple access system for different water types. Optical orthogonal codes (OOC) are used as the user-specific address sequence to encode and decode the user’s data. LED with an operating wavelength of 532 nm is used as the optical source, and silicon avalanche photodiode is used as the optical detector. The system BER performance is analyzed on account of transmission distance, transmitted power, number of simultaneous users, and other system parameters where different water types (i.e., pure sea water, clear ocean water, and coastal ocean water) are considered as the communication channel qualities. It is found that the BER performance of this system significantly depends on the water types. However, the best overall system performance is achieved in pure sea water where clear ocean water provided better results than coastal ocean water.

     

Altered signaling associated with chronic arsenic exposure in human skin keratinocytes

Modulation of signaling pathways upon chronic arsenic exposure remains poorly studied. Here, we carried out SILAC‐based quantitative phosphoproteomics analysis to dissect the signaling induced upon chronic arsenic exposure in human skin keratinocyte cell line, HaCaT. We identified 4171 unique phosphosites derived from 2000 proteins. We observed differential phosphorylation of 406 phosphosites (twofold) corresponding to 305 proteins. Several pathways involved in cytoskeleton maintenance and organization were found to be significantly enriched (p<0.05). Our data revealed altered phosphorylation of proteins associated with adherens junction remodeling and actin polymerization. Kinases such as protein kinase C iota type (PRKCI), mitogen‐activated protein kinase kinase kinase 1 (MAP3K1), tyrosine‐protein kinase BAZ1B (BAZ1B) and STE20 like kinase (SLK) were found to be hyperphosphorylated. Our study provides novel insights into signaling perturbations associated with chronic arsenic exposure in human skin keratinocytes. All MS/MS data have been deposited to the ProteomeXchange with identifier PXD004868.     

A new chaos based color image encryption algorithm using permutation substitution and Boolean operation

Multimedia Tools and Applications - A new color image encryption algorithm is proposed by using chaotic maps. Cipher image is constructed in three phases. In the first phase permutation of digital...