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It has recently been suggested that differences in the charge radii of mirror nuclei (ΔRchmirr) are strongly correlated with the neutron-skin thickness (Rskin) of neutron-rich nuclei and with the slope of the symmetry energy (L). To test this assumption, we present ab initio calculations of Rskin in 48Ca and 208Pb, ΔRchmirr in 36Ca−36S, 38Ca−38Ar, 41Sc−41Ca, 48Ni−48Ca, 52Ni−52Cr, and 54Ni−54Fe mirror pairs, and L. Employing the recently developed 34 chiral interaction samples, identified by the history matching approach, we conduct rigorous statistical analysis of correlations among ΔRchmirr, Rskin and L, accounting for quantified uncertainties from low-energy constants of chiral interaction, chiral effective field theory truncation and many-body method approximation. The ab initio results reveal an appreciable ΔRchmirr−L correlation in fp-shell mirror pairs. However, contrary to previous studies, the present calculation finds that the studied sd-shell mirror pairs do not exhibit any ΔRchmirr−L correlation.

Free-space optical (FSO) communication has received widespread attention as a high-bandwidth, low-latency communication technique. However, the scintillation effect caused by atmospheric turbulence leads to intensity fluctuations of the transmission signal, which, in turn, affects the performance of the FSO communication system. This paper proposes a channel correlation-based adaptive power transmission for FSO communications. Based on the correlation between uplink and downlink turbulence channels, the power of the reverse transmission signal is adjusted by the fluctuation strength of the received uplink or downlink transmission signal and the channel correlation coefficient to improve the system’s performance. The proposed technique is investigated through a simulation using established uplink and downlink channels with different link distances and turbulence intensities. The simulation results show that the bit error rate (BER) performance of the proposed technique is significantly improved compared to the fixed threshold decision (FTD) technique, and it is close to the adaptive threshold decision (ATD) technique. The proposed technique provides an effective optimization scheme for FSO communications.

Free-space optical (FSO) communication has received widespread attention as a high-bandwidth, low-latency communication technique. However, the scintillation effect caused by atmospheric turbulence leads to intensity fluctuations of the transmission signal, which, in turn, affects the performance of the FSO communication system. This paper proposes a channel correlation-based adaptive power transmission for FSO communications. Based on the correlation between uplink and downlink turbulence channels, the power of the reverse transmission signal is adjusted by the fluctuation strength of the received uplink or downlink transmission signal and the channel correlation coefficient to improve the system's performance. The proposed technique is investigated through a simulation using established uplink and downlink channels with different link distances and turbulence intensities. The simulation results show that the bit error rate (BER) performance of the proposed technique is significantly improved compared to the fixed threshold decision (FTD) technique, and it is close to the adaptive threshold decision (ATD) technique. The proposed technique provides an effective optimization scheme for FSO communications. [ABSTRACT FROM AUTHOR]

Here, we present TP-DB; a pattern-based search engine based on 1.67 million helices from the Protein Database (PDB). We demonstrate the utility of TP-DB in identifying microbe-specific antigens, as well as the design of antimicrobial peptides and Protein-protein interaction blockers.

Polylactic acid (PLA) is a high-modulus, high-strength biodegradable thermoplastic polyester used in the packaging, textile and medical industries. Conventional plasticizers are usually non-biodegradable, the study used low molecular polyhexanediol succinate (PHS) blended with poly (L-lactic acid) (PLLA) to obtain a fully degradable system. The compatibility, crystallization and mechanical properties of the blended system were investigated by differential scanning calorimetry, polarizing microscope and universal testing machine. The results show that the crystallinity of PLLA/PHS ratios of 100/0, 95/5, 90/10, 85/15, and 80/20 were 7.5%, 8.7%, 11.5%, 14.1%, and 14.2%, respectively. The crystallinity of the blends increased with increasing PHS content, indicating that PHS successfully promoted PLLA crystallization. In addition, the crystallization rate of 80/20 was increased 10-fold and the semi-crystallization time was halved compared to pure PLLA. The elongation at break of the blends increased from less than 10% for pure PLLA to about 60% (PHS content 20%), with a slight decrease in strength and modulus. The elastic modulus of the blends decreased continuously with the increase of the PHS content, from 2.25 GPa for pure PLLA to 1.86 GPa at 20% PHS content. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) plays an important role as a signalling molecule in the biological system. Organoselenium-coated or grafted biomaterials have the potential to achieve controlled NO release as they can catalyse decomposition of endogenous S-nitrosothiols to NO. However, such biomaterials are often challenged by the loss of the catalytic sites, which can affect the stability in tissue repair applications. In this work, we prepare a diselenide-containing poly(ester urethane)urea (SePEUU) polymer with Se–Se in the backbone, which is further electrospun into fibrous membranes by blending with poly(ester urethane)urea (PEUU) without diselenide bonds. The presence of catalytic sites in the main chain demonstrates stable and long-lasting NO catalytic activity, while the porous structure of the fibrous membranes ensures uniform distribution of the catalytic sites and better contact with the donor-containing solution. PEUU/SePEUU50 in 50/50 mass ratio has a physiologically adapted rate of NO release, with a sustained generation of NO after exposure to PBS at 37 °C for 30 d. PEUU/SePEUU50 has a low hemolysis and protein adsorption, with mechanical properties in the wet state matching those of natural vascular tissues. It can promote the adhesion and proliferation of human umbilical vein endothelial cells in vitro and control the proliferation of vascular smooth muscle cells in the presence of NO generation. This study exhibits the electrospun fibrous membranes have potential for utilizing as hemocompatible biomaterials for regeneration of blood-contacting tissues. Electrospun membranes of diselenide-containing poly(ester urethane)urea exhibit stable catalytic activity of NO generation, which promotes human umbilical vein endothelial cell proliferation and control the proliferation of vascular smooth muscle cells for potential applications as blood-contacting biomaterials. [ABSTRACT FROM AUTHOR]

Dietary bioactive lipids, one of the three primary nutrients, is not only essential for growth and provides nutrients and energy for life's activities but can also help to guard against disease, such as Alzheimer's and cardiovascular diseases, which further strengthen the immune system and maintain many body functions. Many microorganisms, such as yeast, algae, and marine fungi, have been widely developed for dietary bioactive lipids production. These biosynthetic processes were not limited by the climate and ground, which are also responsible for superiority of shorter periods and high conversion rate. However, the production process was also exposed to the challenges of low stability, concentration, and productivity, which was derived from the limited knowledge about the critical enzyme in the metabolic pathway. Fortunately, the development of enzymatic research methods provides powerful tools to understand the catalytic process, including site-specific mutagenesis, protein dynamic simulation, and metabolic engineering technology. Thus, we review the characteristics of critical desaturase and elongase involved in the fatty acids' synthesis metabolic pathway, which aims to not only provide extensive data for enzyme rational design and modification but also provides a more profound and comprehensive understanding of the dietary bioactive lipids' synthetic process.

κ-carrageenases are members of the glycoside hydrolase family 16 (GH16) that hydrolyze sulfated galactans in red algae, known as κ-carrageenans. In this study, a novel κ-carrageenase gene from the marine bacterium Rhodopirellula sallentina SM41 (RsCgk) was discovered via the genome mining approach. There are currently no reports on κ-carrageenase from the Rhodopirellula genus, and RsCgk shares a low identity (less than 65%) with κ- carrageenase from other genera. The RsCgk was heterologously overexpressed in Escherichia coli BL21 and characterized for its enzymatic properties. RsCgk exhibited maximum activity at pH 7.0 and 40 °C, and 50% of its initial activity was retained after incubating at 30 °C for 2 h. More than 70% of its activity was maintained after incubation at pH 6.0–8.0 and 4 °C for 24 h. As a marine derived enzyme, RsCgk showed excellent salt tolerance, retaining full activity in 1.2 M NaCl, and the addition of NaCl greatly enhanced its thermal stability. Mass spectrometry analysis of the RsCgk hydrolysis products revealed that the enzyme had high degradation specificity and mainly produced κ-carrageenan disaccharide. Comparative molecular dynamics simulations revealed that the conformational changes of tunnel-forming loops under salt environments may cause the deactivation or stabilization of RsCgk. Our results demonstrated that RsCgk could be utilized as a potential tool enzyme for efficient production of κ-carrageenan oligosaccharides under high salt conditions.