Offline glucose biomonitoring in yeast culture by polyamidoamine/cysteamine-modified gold electrodes

This article deals with the use of pyranose oxidase (PyOx) and glucose oxidase (GOx) enzymes in amperometric biosensor design and their application in monitoring fermentation processes with the combination of flow injection analysis (FIA). The amperometric studies were carried out at -0.7 V by following the oxygen consumption due to the enzymatic reactions for both batch and FIA modes. Optimization studies (enzyme amounts and pH) and analytical parameters such as linearity, repeatability, effect of interference, storage, and operational stabilities have been studied. Under optimized conditions, for the PyOx-based biosensor, linear graph was obtained from 0.025 to 0.5 mM glucose in phosphate buffer (50 mM) at pH 7.0 with the equation of y = 3.358x + 0.028 and R(2) = 0.998. Linearity was found to be 0.01-1.0 mM in citrate buffer (50 mM and pH 4.0) with the equation of y = 1.539x + 0.181 and R(2) = 0.992 for the GOx biosensor. Finally, these biosensor configurations were further evaluated in a conventional flow injection system. Results from batch experiments provide a guide to design sensitive, stable, and interference-free biosensors for FIA mode. Biosensor stability, dynamic range, and repeatability were also studied in FIA conditions, and the applicability for the determination of glucose in fermentation medium could be successfully demonstrated. The FIA-combined glucose biosensor was used for the offline monitoring of yeast fermentation. The obtained results correlated well with HPLC measurements.     

Analysis of the structure and luminescence properties of Zn2GeO4:Eu3+ according to Judd–Ofelt theory

The preparation and characteristic of nanorod-like Zn₂GeO₄ doped with Eu³⁺ or zinc germanate (ZGO):xEu³⁺ (x = 0 ÷ 0.05), which was synthesized using the hydrothermal method, are described. The influence of Eu³⁺-doping ions on the structure and the optical properties of ZGO was also investigated. According to the photoluminescence spectra, ZGO:xEu³⁺ nanophosphors gave a red emission due to the ⁵D₀→⁷F₂ emission of Eu³⁺ ions. In accordance with Judd–Ofelt theory, the intensity parameters for f–f transitions from the emission and absorption spectrum were determined. At the ⁵D₀ excited state of Eu³⁺, total spontaneous emission probabilities (A_R), lifetimes (τ_R), branching ratios (β_R), and quantum efficiency (η) were calculated. The ZGO:xEu³⁺ (x = 0.02, 0.03, 0.04) phosphor showed the branch ratio β (⁵D₀→⁷F₂) > 60%, indicating that the phosphors prepared here have a promising potential as laser light. The sample with a concentration of 0.04Eu³⁺ achieved the highest quantum efficiency of 84%, suggesting that it has potential light-emitting diode applications.     

SHOX2 methylation in Vietnamese patients with lung cancer

Molecular Biology Reports - DNA methylation on cytosine in the CpG dinucleotides is one of the most common epigenetic perturbations taking place during cancer initiation, progression, occurrence...     

A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.     

An AIL family protein promotes type three secretion system‐1‐independent invasion and pathogenesis of Salmonella enterica serovar Typhi

Adhesion and invasion of Intestinal Epithelial Cells (IECs) are critical for the pathogenesis of Salmonella Typhi, the aetiological agent of human typhoid fever. While type three secretion system‐1 (T3SS‐1) is a major invasion apparatus of Salmonella, independent invasion mechanisms were described for non‐typhoidal Salmonellae. Here, we show that T2942, an AIL‐like protein of S. Typhi Ty2 strain, is required for adhesion and invasion of cultured IECs. That invasion was T3SS‐1 independent was proved by ectopic expression of T2942 in the non‐invasive E. coli BL21 and double‐mutant Ty2 (Ty2Δt2942ΔinvG) strains. Laminin and fibronectin were identified as the host‐binding partners of T2942 with higher affinity for laminin. Standalone function of T2942 was confirmed by cell adhesion of the recombinant protein, while the protein or anti‐T2942 antiserum blocked adhesion/invasion of S. Typhi, indicating specificity. A 20‐amino acid extracellular loop was required for invasion, while several loop regions of T2942 contributed to adhesion. Further, T2942 cooperates with laminin‐binding T2544 for adhesion and T3SS‐1 for invasion. Finally, T2942 was required and synergistically worked with T3SS‐1 for pathogenesis of S. Typhi in mice. Considering wide distribution of T2942 among clinical strains, the protein or the 20‐mer peptide may be suitable for vaccine development.     

Hsa-miR-584-5p as a novel candidate biomarker in Turkish men with severe coronary artery disease

Molecular Biology Reports - Coronary artery disease (CAD) is still the preliminary cause of mortality and morbidity in the developed world. Identification of novel predictive and therapeutic...     

Bio-catalytic asymmetric synthesis of β-adrenergic receptor blocker precursor: (R)-2-bromo-1-(naphthalen-2-yl)ethanol

Abstract

Aromatic α-halohydrins, particularly 2-haloethanols as significant precursor of drugs, can easily be converted to chiral β-adrenergic receptor blockers. Eight strains of Lactobacillus curvatus were tested as biocatalysts for asymmetric reduction of 2-bromo-1-(naphthalen-2-yl)ethanone 1 to 2-bromo-1- (naphthalen-2-yl) ethanol 2. The parameters of the bioreduction were optimized using L. curvatus N4, the best biocatalyst found. As a result, (R)-2-bromo-1-(naphthalen-2-yl)ethanol 2, which can be β-adrenergic receptor blocker precursor, was produced for the first time in high yield and enantiomerically pure form using biocatalysts. Moreover, the gram scale synthesis was performed and 7.54?g of (R)-2 was synthesized as enantiopure form (enantiomeric excess >99%) in 48?h. The important advantages of this process are that it produces of (R)-2 for the first time in enantiopure form, in excellent yield and under environmentally friendly and moderate reaction conditions. This system is of the potential to be applied at a commercial scale.     

Thermoluminescence properties of unique Rosso Levanto marble

This marble extracted from deposits in Elaz?? in Turkey resembles red meat in appearance and is only found in Elaz??. This type of marble has been widely used in the most famous architectural structures and buildings. In this study, the thermoluminescence (TL) properties of a unique marble that originated from Turkey, named Rosso Levanto, were investigated. Two distinct TL peaks were observed at 160°C and around 375°C. Particle size experiments showed that best TL intensity was seen at 200 μm particle size and therefore dose–response, heating rate, cycle of measurement and fading experiments were carried out on powdered samples with a particle size of 200 μm. The findings revealed good linearity in dose–response, observed up to 0.5 kGy. The reproducibility experiment gave good results, but peak intensity decreased by about 40% in first 6 h of storage in a dark room.