Genetic diversity and haplotype structure of 21 Y‐STRs,including nine noncore loci,in South Tunisian Population: Forensic relevance

Y chromosome STRs (Y‐STRs) are being used frequently in forensic laboratories. Previous studies of Y‐STR polymorphisms in different groups of the Tunisian population identified low levels of diversity and discrimination capacity (DC) using various commercial marker sets. This definitely limits the use of such systems for Y‐STRs genotyping in Tunisia. In our investigation on South Tunisia, 200 unrelated males were typed for the 12 conventional Y‐STRs included in the PowerPlex® Y System. Additional set of nine noncore Y‐STRs including DYS446, DYS456, DYS458, DYS388, DYS444, DYS445, DYS449, DYS710, and DYS464 markers were genotyped and evaluated for their potential in improving DC. Allele frequency, gene diversity, haplotype diversity (HD), and DC calculation revealed that DYS464 was the most diverse marker followed by DYS710 and DYS449 markers. The standard panel of 12 Y‐STRs (DC = 80.5%) and the nine markers were combined to obtain DC of 99%. Among the 198 different haplotypes observed, 196 haplotypes were unique (HD = 99.999). Out of the nine noncore set, six Y‐STRs (DYS458, DYS456, DYS449, DYS710, DYS444, and DYS464) had the greatest impact on enhancing DC. Our data provided putative Y‐STRs combination to be used for genetic and forensic applications.     

Enzymatic hydrolysis of steam-exploded and ethanol organosolv-pretreated douglas-fir by novel and commercial fungal cellulases

Softwood residues are the most abundant feedstock available for bioconversion in many northern countries. However, the high costs for delignification and enzymatic hydrolysis currently deter commercialization of softwood bioconversion processes. This study evaluates the abilities of two novel fungal preparations (MSUBC1 and MSUBC2) and two commercial cellulase preparations (TR1 and TR2) to hydrolyze cellulose in Douglas-fir pretreated by steam explosion or ethanol organosolv process. MSUBC1 showed significantly better performance than the other preparations on both lignocellulosic substrates. In particular, MSUBC1 achieved >76% cellulose conversion for hydrolysis of steam-exploded Douglas-fir (～44% lignin) after 72 h at low enzyme loading (10 filter paper units/g of cellulose) and without β-glucosidase supplementation.     

New trend for optical signal-to-noise ratio of disturbed Raman fiber amplifier

In a distributed Raman fiber amplifier (DRFA), Raman amplification allows a lower signal launch powers to transverse the span above the noise floor while still increasing the optical signal-to-noise ratio (OSNR). It improves the noise figure and reduces the nonlinear penalty of fiber systems. In this paper, we demonstrate a new trend of OSNR at different pump configurations: forward, backward and bidirectional pumping for DRFAs as a function of fiber length. We also present the variation of OSNR with both input pump power and input signal power. It is found that forward pumping provides the highest OSNR, reaching its maximum value of 37 dB. However, backward pumping provides the smallest OSNR that has its maximum of 22 dB and the bidirectional pumping provides the moderate OSNR between the others having its peak of 26 dB.     

Pressurized hot ethanol extraction of carotenoids from carrot by-products

Carotenoids are known for their antioxidant activity and health promoting effects. One of the richest sources of carotenoids are carrots. However, about 25% of the annual production is regarded as by-products due to strict market policies. The aim of this study was to extract carotenoids from those by-products. Conventional carotenoid extraction methods require the use of organic solvents, which are costly, environmentally hazardous, and require expensive disposal procedures. Pressurized liquid extraction (PLE) utilizes conventional solvents at elevated temperatures and pressure, and it requires less solvent and shorter extraction times. The extraction solvent of choice in this study was ethanol, which is a solvent generally recognized as safe (GRAS). The extraction procedure was optimized by varying the extraction time (2-10 min) and the temperature (60-180 °C). β-Carotene was used as an indicator for carotenoids content in the carrots. The results showed that time and temperatures of extraction have significant effect on the yield of carotenoids. Increasing the flush volume during extraction did not improve the extractability of carotenoids, indicating that the extrication method was mainly desorption/diffusion controlled. Use of a dispersing agent that absorbs the moisture content was important for the efficiency of extraction. Analysing the content of β-carotene at the different length of extraction cycles showed that about 80% was recovered after around 20 min of extraction.     

A Comprehensive Investigation of Interactions between Antipsychotic Drug Quetiapine and Human Serum Albumin Using Multi-Spectroscopic,Biochemical, and Molecular Modeling Approaches

Quetiapine (QTP) is a short-acting atypical antipsychotic drug that treats schizophrenia or manic episodes of bipolar disorder. Human serum albumin (HSA) is an essential transport protein that transports hormones and various other ligands to their intended site of action. The interactions of QTP with HSA and their binding mechanism in the HSA-QTP system was studied using spectroscopic and molecular docking techniques. The UV-Vis absorption study shows hyperchromicity in the spectra of HSA on the addition of QTP, suggesting the complex formation and interactions between QTP and HSA. The results of intrinsic fluorescence indicate that QTP quenched the fluorescence of HSA and confirmed the complex formation between HSA and QTP, and this quenching mechanism was a static one. Thermodynamic analysis of the HSA-QTP system confirms the involvement of hydrophobic forces, and this complex formation is spontaneous. The competitive displacement and molecular docking experiments demonstrated that QTP is preferentially bound to HSA subdomain IB. Furthermore, the CD experiment results showed conformational changes in the HSA-QTP system. Besides this, the addition of QTP does not affect the esterase-like activity of HSA. This study will help further understand the credible mechanism of transport and delivery of QTP via HSA and design new QTP-based derivatives with greater efficacy.     

Electrocatalytic Sensor for Hydrogen Peroxide Based on Immobilized Benzoquinone

An amperometric chemosensor for the detection of hydrogen peroxide is reported. The sensor is based on 1,4-benzoquinone immobilized on the gold electrode using self-assembled monolayer of short chain symmetrical dithiol as an anchor layer. Sensor analysis was performed by cyclic voltammetry at the potential range from −0.6 V till +0.9 V as well as in the anodic or cathodic potential ranges only. The results indicate oxidative electrochemical decomposition of hydrogen peroxide at the potential of ∼+0.4 V leading to the formation of oxygen while at cathodic potentials a reduction of the formed oxygen as well as of the hydrogen peroxide occur. A decrease in the oxidation potential of hydrogen peroxide on the gold electrode coated by self-assembled monolayer with 1,4-benzoquinone in comparison with that measured on the electrodes coated by the same self-assembled monolayer without 1,4-benzoquinone, indicates electrocatalytic effect of this moiety on oxidative decomposition of hydrogen peroxide. Analytical evaluation of the sensor performance was done in the voltammetric as well as in the chronoamperometric mode. The sensor exhibited linear response over the concentration range till 2.5 mM with a limit of detection ∼4 μM.     

Impact of Charge Transfer Complex on the Dielectric Relaxation Processes in Poly(methyl methacrylate) Polymer

The impact of the charge transfer complex on the dielectric relaxation processes in free poly(methyl methacrylate) (PMMA) polymer sheets was investigated. The frequency dependence of dielectric properties was obtained over the frequency range 0.1 Hz–1 MHz at temperatures ranging between 303 K and 373 K for perylene dye and acceptors (picric acid (PA) and chloranilic acid (CLA)) in an in situ PMMA polymer. The TG/dTG technique was used to investigate the thermal degradation of the synthesized polymeric sheets. Additionally, the kinetic parameters have been assessed using the Coats–Redfern relation. The dielectric relaxation spectroscopy of the synthesized polymeric sheets was analyzed in terms of complex dielectric constant, dielectric loss, electrical modulus, electrical conductivity, and Cole–Cole impedance spectroscopy. α- and β-relaxation processes were detected and discussed. The σ(ω) dispersion curves of the synthesized polymeric sheets show two distinct regions with increasing frequency. The impedance data of the synthesized polymeric sheets can be represented by the equivalent circuit (parallel RC).     

Weak lignin-binding enzymes

Economic barriers preventing commercialization of lignocellulose-to-ethanol bioconversion processes include the high cost of hydrolytic enzymes. One strategy for cost reduction is to improve the specific activities of cellulases by genetic engineering. However, screening for improved activity typically uses “ideal” cellulosic substrates, and results are not necessarily applicable to more realistic substrates such as pretreated hardwoods and softwoods. For lignocellulosic substrates, nonproductive binding and inactivation of enzymes by the lignin component appear to be important factors limiting catalytic efficiency. A better understanding of these factors could allow engineering of cellulases with improved activity based on reduced enzyme-lignin interaction (“weak lignin-binding cellulases”). To prove this concept, we have shown that naturally occurring cellulases with similar catalytic activity on a model cellulosic substrate can differ significantly in their affinities for lignin. Moreover, although cellulose-binding domains (CBDs) are hydrophobic and probably participate in lignin binding, we show that cellulases lacking CBDs also have a high affinity for lignin, indicating the presence of lignin-binding sites on the catalytic domain.