Glycogen as a Building Block for Advanced Biological Materials

Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. The biocatalytic synthesis of glycogen has evolved over time to form a nanometer-sized dendrimer-like structure (20–150 nm) with a highly branched surface and a dense core. This makes glycogen markedly different from other natural linear or branched polysaccharides and particularly attractive as a platform for biomedical applications. Glycogen is inherently biodegradable, nontoxic, and can be functionalized with diverse surface and internal motifs for enhanced biofunctional properties. Recently, there has been growing interest in glycogen as a natural alternative to synthetic polymers and nanoparticles in a range of applications. Herein, the recent literature on glycogen in the material-based sciences, including its use as a constituent in biodegradable hydrogels and fibers, drug delivery vectors, tumor targeting and penetrating nanoparticles, immunomodulators, vaccine adjuvants, and contrast agents, is reviewed. The various methods of chemical functionalization and physical assembly of glycogen nanoparticles into multicomponent nanodevices, which advance glycogen toward a functional therapeutic nanoparticle from nature and back again, are discussed in detail.     

A polymeric micro-optical system for the spatial monitoring in two-phase microfluidics

This article presents a polymeric micro-optical system that consists of two coupled miniaturized devices for spatially distributed characterization of microfluidic two-phase phenomena exploiting multiwavelength optical signals. The input device implements four optical windows (slits) which are superimposed on the centerline of a microfluidic serpentine channel and illuminate specific locations of the microchannel. The flow-related information is then collected by an ad hoc polymeric micro-optical output device that guides and merges the spatially distributed information into a single output signal, which maintains memory of the spatial coordinates by using the wavelengths as fingerprints of the slits’ position in the microfluidic channel. Both micro-optical devices were designed, simulated, and characterized in static and dynamic conditions. Experiments on two-phase (air and ethanol) flow were carried out by applying constant and periodic flow rate functions. In both cases, the system was proved to be efficient in capturing the spatial–temporal dynamics of flow profiles.     

Wage returns to interregional mobility among Ph.D graduates: Do occupations matter?

This paper addresses the wage returns to interregional mobility among Italian Ph.D workers. We control for selection bias in both migration and occupation choice by estimating a double sample selection model. While OLS estimates indicate a positive wage premium of mobility across all types of occupations examined, wage equations estimated by correcting for double sample selection evidence a wage penalty for movers within academia, no effects for movers carrying out R&D activities but positive returns if they work within the industry sector. The selection process appears to be stronger when mobility choice is considered in comparison to the choice of occupation.     

Influence of curing temperature on the evolution of magnesium oxychloride cement

Hardening behaviour and strength of oxychloride cement strongly depend on the formation of Phase 3 and Phase 5 from MgO and magnesium chloride water solution, and the initial composition can be chosen accordingly within the corresponding phase diagram. A certain number of reactions occur before the final formation of P5 or P3 crystals, and several parameters influence the transformations kinetic, such as MgO reactivity and temperature. Several articles deal with the first aspect, while no indications can be found with regard to the curing temperature’s effect on the formation of noble phases. In this article the evolution of magnesium oxychloride cement pastes is analysed at various curing temperatures between 5 and 40 °C. The study is carried out to simulate typical industrial processing conditions and indicate optimal conditions for the production of high chemical and mechanical resistance oxychloride cement. It is shown that at low temperature, Phase 3 is produced in place of Phase 5, and a certain amount of MgO remains non-reacted. The corresponding cement is characterised by lower mechanical strength and higher water solubility.     

The Impact of Sourdough Fermentation on Non‐Nutritive Compounds and Antioxidant Activities of Flours from Different Phaseolus Vulgaris L. Genotypes

This study dealt with the effect of sourdough fermentation on antinutrients, phytochemicals, and antioxidant activities of flours from three Phaseoulus vulgaris L. genotypes with differing composition of lectins. Specifically, cultivar Lady Joy (LJ) devoid of phytohemagglutinin (PHA) and enriched in alfa‐amylase inhibitor (αAI), breeding line P500 low in PHA and devoid of αAI, and Taylor's horticultivar, containing normal levels of both proteins. Sourdough fermentation positively affects the nutritional values of all bean flours by reducing some antinutrients, for example, phytic acid while preserving αAI activity. It significantly increased total polyphenols, flavonols, and ascorbic acid content, while reducing flavonoids. No significant differences in antioxidant activity, measured by in vitro and ex vivo assays on human erythrocytes, were found. The kinetic profiles of conjugated dienes analysis showed a strong inhibitory effect on low‐density lipoproteins oxidation of all tested powders, with unfermented flours displaying the best antioxidant activity. Among bean powders, unfermented and fermented LJ showed the highest polyphenols level (4.21 ± 0.18 and 4.96 ± 0.15 mg GAE/g dw, respectively), oxygen radical absorbance capacity (ORAC) values (24.17 ± 0.14 and 24.02 ± 0.93 µmol TE/100g dw, respectively) and cellular antioxidant activity (71.6 ± 7.05 and 62.7 ± 3.3 units, respectively). Finally, since fermentation drastically reduces phytic acid content while preserving αAI activity, fermented LJ represents an important natural slimming supplement.     

Three-dimensional fuzzy graphene ultra-microelectrodes for subcellular electrical recordings

Microelectrode arrays (MEAs) have enabled investigation of cellular networks at sub-millisecond temporal resolution. However, current MEAs are limited by the large electrode footprint since reducing the electrode's geometric area to sub-cellular dimensions leads to a significant increase in impedance thus affecting its recording capabilities. We report a breakthrough ultra-microelectrodes platform by leveraging the outstanding surface-to-volume ratio of nanowire-templated out-of-plane synthesized three-dimensional fuzzy graphene (NT-3DFG). The enormous surface area of NT-3DFG leads to 140-fold reduction in electrode impedance compared to bare Au microelectrodes, thus enabling scaling down the geometric size by 625-fold to ca. 2 μm × 2 μm. The out-of-plane morphology of NT-3DFG leads to a tight seal with the cell membrane thus enabling recording of electrical signals with high signal-to-noise ratio (SNR) of > 6. This work highlights the possibility to push the limits of the conventional MEA technology to enable electrophysiological investigation at sub-cellular level without the need of any surface coatings. This presented approach would greatly impact our basic understanding of signal transduction within a single cell as well as complex cellular assemblies.

     

The Saccharomyces cerevisiae poly (A) binding protein (Pab1): Master regulator of mRNA metabolism and cell physiology

Pab1, the major poly (A) binding protein of the yeast Saccharomyces cerevisiae, is involved in many intracellular functions associated with mRNA metabolism, such as mRNA nuclear export, deadenylation, translation initiation and termination. Pab1 consists of four RNA recognition motifs (RRM), a proline-rich domain (P) and a carboxy-terminal (C) domain. Due to its modular structure, Pab1 can simultaneously interact with poly (A) tails and different proteins that regulate mRNA turnover and translation. Furthermore, Pab1 also influences cell physiology under stressful conditions by affecting the formation of quinary assemblies and stress granules, as well as by stabilizing specific mRNAs to allow translation re-initiation after stress. The main goal of this review is to correlate the structural complexity of this protein with the multiplicity of its functions.     

Examining the bentonite produced in a biodiesel refinery process as soil amendment in a well-draining soil

Clean Technologies and Environmental Policy - The expansion of biofuels produced from cooking oils and vegetal oils is expected to increase, together with the production of exhausted clay used in...