Expanded Polystyrene Foam Formed from Polystyrene Beads Coated with a Nanocrystalline SiO2 Film and the Analysis of Its Moisture Adsorption and Resistance to Mechanical Stress

Conventional expanded polystyrene can absorb moisture, which significantly degrades its properties. In the present study, it was demonstrated that SiO₂ can be deposited on polystyrene beads before pre-expansion and molding steps. Under the applied test conditions, expanded polystyrene with nanocrystalline SiO₂ additives had approximately 10% lower moisture adsorption and an 8.4% better resistance to deformation. Expanded polystyrene analysis suggested that the observed improvements were caused by the hydrophobic nature of nanocrystalline SiO₂ and, even more importantly, because SiO₂ acted as an amalgamation catalyst and significantly increased adhesion between the expanded polystyrene beads during the expanded polystyrene molding process.     

Effects of Various Energy Suppliers in Green Processes for Obtaining Silver Nanoparticles

The productions of stable suspensions of silver nanoparticles using a microwave reactor, an ultraviolet (UV) reactor, a low‐frequency low‐temperature plasma reactor, a high‐pressure reactor, and an open reactor are compared. All reactors served as sources of energy for stimulating the nanoparticle growth process. The silver nanoparticles were obtained based on the chemical reduction method. The processes were conducted using gallic acid as the reducing‐stabilizing substance. The influence of the variable parameters time (for all types of reactors), temperature (for the open and high‐pressure reactors), power (for the microwave reactor), energy density (for the UV reactor), and voltage (for the low‐frequency low‐temperature plasma reactor) was investigated. Temperature was found to be the most important factor influencing all processes.     

Polymorphisms of Encoding Genes IL1RN and P2RX7 in Apical Root Resorption in Patients after Orthodontic Treatment

External apical root resorption (EARR) is one of the most serious complications associated with orthodontic treatment. The aim of the study was to analyze the relationships between selected single nucleotide polymorphisms (SNPs) in Interleukin 1 receptor antagonist (IL1RN), purinoreceptor P2X7 (P2RX7) and EARR in patients after orthodontic treatment. The study comprised 101 patients who underwent a complex orthodontic treatment with a combination of fixed appliances. Roots were measured based on orthopantomograms and lateral cephalometric radiographs taken before and at the end of the treatment using diagnostic software. Proportional measurements of selected teeth were made using the modified Linge and Linge methods. Based on the presence or absence of EARR, patients were divided into two groups: control group, 61 patients without EARR (with 0.90 ≤ rRCR ≤ 1.00), and EARR group, 40 patients with EARR (rRCR < 0.90). Root resorption in selected groups was also evaluated with the scores of Malmgren and Levander. SNP analysis was performed using the real-time polymerase chain reaction (PCR) method. The analysis indicated that a specific haplotype of P2RX7 (rs208294) and IL1RN (rs419598) modified the risk of EARR development (p < 0.05), with a Bonferroni correction. The analysis of the P2RX7 and IL1RN gene polymorphisms showed that the presence of SNPs of these genes may predispose individuals to EARR. These findings indicate that EARR is a complex condition influenced not only by environmental factors and needs further study on the genetic risk factors.     

Evaluation of Gene Expression Knock-Down by Chemically and Structurally Modified Gapmer Antisense Oligonucleotides

We analyzed the effect of modified nucleotides within gapmer antisense oligonucleotides on RNase H mediated gene silencing. Additionally, short hairpins were introduced into antisense oligonucleotides as structural motifs, and their influence on biological and physicochemical properties of pre-structured gapmers was investigated for the first time. The results indicate that two LNA residues in specified positions of the gap flanking regions are sufficient and favorable for efficient knock-down of the β-actin gene. Furthermore, the introduction of other modified nucleotides, i. e. glycyl-amino-LNA−T, 2′-O-propagyluridine, polyamine functionalized uridine, and UNA, in specified positions, also increases the inhibition of β-actin expression. Importantly, the presence of hairpins within the gapmers improves their silencing properties.     

Two-stage method of obtaining high bulk density sodium tripolyphosphate: Design and mechanism of process

The paper presents a two-step method for obtaining sodium tripolyphosphate (STPP) with a bulk density of about 0.90 kg/dm³ after the first step, using sodium phosphates after spray drying and water as the raw materials. STPP with a bulk density of 0.95–1.00 kg/dm³ was generated in the second stage, using STPP from the first step and water as the raw materials. The paper presents statistical analyses to define the process parameters which significantly affect sodium tripolyphosphate bulk density. The determination of the profile approximation and utility function enabled the optimization of process parameters for obtaining a product with a bulk density of 0.95–1.00 kg/dm³. Mechanisms of increasing bulk density was indicated by studies on the microstructure of the product and phase transformation during the process. The data were empirically verified and satisfactory results were found.     

Migraine: Calcium Channels and Glia

Migraine is a common neurological disease that affects about 11% of the adult population. The disease is divided into two main clinical subtypes: migraine with aura and migraine without aura. According to the neurovascular theory of migraine, the activation of the trigeminovascular system (TGVS) and the release of numerous neuropeptides, including calcitonin gene-related peptide (CGRP) are involved in headache pathogenesis. TGVS can be activated by cortical spreading depression (CSD), a phenomenon responsible for the aura. The mechanism of CSD, stemming in part from aberrant interactions between neurons and glia have been studied in models of familial hemiplegic migraine (FHM), a rare monogenic form of migraine with aura. The present review focuses on those interactions, especially as seen in FHM type 1, a variant of the disease caused by a mutation in CACNA1A, which encodes the α1A subunit of the P/Q-type voltage-gated calcium channel.     

Al-Tolerant Barley Mutant hvatr.g Shows the ATR-Regulated DNA Damage Response to Maleic Acid Hydrazide

ATR, a DNA damage signaling kinase, is required for cell cycle checkpoint regulation and detecting DNA damage caused by genotoxic factors including Al³⁺ ions. We analyzed the function of the HvATR gene in response to chemical clastogen-maleic acid hydrazide (MH). For this purpose, the Al-tolerant barley TILLING mutant hvatr.g was used. We described the effects of MH on the nuclear genome of hvatr.g mutant and its WT parent cv. “Sebastian”, showing that the genotoxic effect measured by TUNEL test and frequency of cells with micronuclei was much stronger in hvatr.g than in WT. MH caused a significant decrease in the mitotic activity of root cells in both genotypes, however this effect was significantly stronger in “Sebastian”. The impact of MH on the roots cell cycle, analyzed using flow cytometry, showed no differences between the mutant and WT.     

Effects of the spray drying conditions of chokeberry (Aronia melanocarpa L.) juice concentrate on the physicochemical properties of powders

A semi‐industrial spray drying process of chokeberry juice concentrate using maltodextrin was analysed. The influence of the content and dextrose equivalent (DE) of maltodextrin, inlet air temperature and rotary disc atomiser speed was studied on the physicochemical properties of the obtained powders. The size and structure of the powder particles, bulk density, moisture content, flowability, yield and total polyphenol content were analysed. An increase in carrier content from 50% to 70% caused a 4.9% increase in total polyphenol retention, better flowability (Hausner ratio decrease of 0.17) and greater yield of the powder (60%). An increase in the drying temperature (150–170 °C) caused larger particle size and improved powder flowability but also resulted in greater loss of total polyphenols. A decrease in rotary atomiser speed (11 000–15 000 rpm) had a moderate influence on particle size and improvement in flowability but had no effect on polyphenol retention. Changes in the DE (8–22) of maltodextrin as a carrier indicated a moderate growing dependence on particle size and worse flowability.