Comparison of ZnO:Al,ITO and carbon nanotube transparent conductive layers in flexible solar cells applications

In the paper the mechanical, optical and electrical parameters of transparent conductive layers (TCLs) made of carbon nanotubes and metal conductive oxides are explored and compared. All investigated materials are deposited on transparent, flexible polymer foils used for solar cell applications. Obtained results are compared with available parameters of rigid transparent conductive oxides (TCOs) as well as literature reports about Indium–Tin Oxide (ITO) on flexible substrates. Presented paper is a report from the preliminary stage of a new flexible solar cell construction.     

Interactions Via α2β1 Cell Integrin May Protect against the Progression of Airway Structural Changes in Asthma

Increased airway wall thickness and remodeling of bronchial mucosa are characteristic of asthma and may arise from altered integrin signaling on airway cells. Here, we analyzed the expression of β₁-subfamily integrins on blood and airway cells (flow cytometry), inflammatory biomarkers in serum and bronchoalveolar lavage, reticular basement membrane (RBM) thickness and collagen deposits in the mucosa (histology), and airway geometry (CT-imaging) in 92 asthma patients (persistent airflow limitation subtype: n = 47) and 36 controls. Persistent airflow limitation was associated with type-2 inflammation, elevated soluble α₂ integrin chain, and changes in the bronchial wall geometry. Both subtypes of asthma showed thicker RBM than control, but collagen deposition and epithelial α₁ and α₂ integrins staining were similar. Type-I collagen accumulation and RBM thickness were inversely related to the epithelial expression of the α₂ integrin chain. Expression of α₂β₁ integrin on T-cells and eosinophils was not altered in asthma. Collagen I deposits were, however, more abundant in patients with lower α₂β₁ integrin on blood and airway CD8⁺ T-cells. Thicker airway walls in CT were associated with lower α₂ integrin chain on blood CD4⁺ T-cells and airway eosinophils. Our data suggest that α₂β₁ integrin on inflammatory and epithelial cells may protect against airway remodeling advancement in asthma.     

The Structure–Properties–Cytotoxicity Interplay: A Crucial Pathway to Determining Graphene Oxide Biocompatibility

Interest in graphene oxide nature and potential applications (especially nanocarriers) has resulted in numerous studies, but the results do not lead to clear conclusions. In this paper, graphene oxide is obtained by multiple synthesis methods and generally characterized. The mechanism of GO interaction with the organism is hard to summarize due to its high chemical activity and variability during the synthesis process and in biological buffers’ environments. When assessing the biocompatibility of GO, it is necessary to take into account many factors derived from nanoparticles (structure, morphology, chemical composition) and the organism (species, defense mechanisms, adaptation). This research aims to determine and compare the in vivo toxicity potential of GO samples from various manufacturers. Each GO sample is analyzed in two concentrations and applied with food. The physiological reactions of an easy model Acheta domesticus (cell viability, apoptosis, oxidative defense, DNA damage) during ten-day lasting exposure were observed. This study emphasizes the variability of the GO nature and complements the biocompatibility aspect, especially in the context of various GO-based experimental models. Changes in the cell biomarkers are discussed in light of detailed physicochemical analysis.     

Identification of Three Type II Toxin-Antitoxin Systems in Model Bacterial Plant Pathogen Dickeya dadantii 3937

Type II toxin-antitoxin (TA) systems are genetic elements usually encoding two proteins: a stable toxin and an antitoxin, which binds the toxin and neutralizes its toxic effect. The disturbance in the intracellular toxin and antitoxin ratio typically leads to inhibition of bacterial growth or bacterial cell death. Despite the fact that TA modules are widespread in bacteria and archaea, the biological role of these systems is ambiguous. Nevertheless, a number of studies suggests that the TA modules are engaged in such important processes as biofilm formation, stress response or virulence and maintenance of mobile genetic elements. The Dickeya dadantii 3937 strain serves as a model for pathogens causing the soft-rot disease in a wide range of angiosperm plants. Until now, several chromosome-encoded type II TA systems were identified in silico in the genome of this economically important bacterium, however so far only one of them was experimentally validated. In this study, we investigated three putative type II TA systems in D. dadantii 3937: ccdAB_2Dda, phd-doc_Dda and dhiTA, which represents a novel toxin/antitoxin superfamily. We provide an experimental proof for their functionality in vivo both in D. dadantii and Escherichia coli. Finally, we examined the prevalence of those systems across the Pectobacteriaceae family by a phylogenetic analysis.     

Self-stratifying coatings based on Schiff base epoxy resins

Schiff base epoxy resin was used as a component of self-stratifying compositions, in which different acrylic resins were used. The degree of stratification was determined using the ATR FTIR spectroscopy and microscopy technique. Results were compared with those for commercial epoxy resins with a comparable epoxy number. A determination was made of the mechanical properties of the coatings obtained. Based on the previous studies, it was concluded that Schiff base epoxy resin in a film-forming composition behaves in a similar manner to BPA-based epoxy resins. The best mechanical properties and a high degree of stratification were achieved using a Schiff base epoxy resin/poly(isobutyl methacrylate) composition. Use of a self-stratifying composition not only reduces the time and cost of preparing a multilayer coating system, thanks to the formation of two layers in one application, but also causes the Schiff based epoxy coatings to become more flexible.     

Effect of nanosilver on the photodegradation of poly(lactic acid)

The poly(lactic acid), PLA, mixed with nanosilver in solution easily forms nanocomposite in solid state (after solvent evaporation), which was proved by UV–Vis spectroscopy. This work focuses on photodegradation occurring in PLA films doped with nanosilver. The changes in chemical structure of photodegraded PLA has been determined using FTIR spectroscopy. Differential scanning calorimetry of UV‐irradiated PLA samples provided information on polymer glass transition and crystallization/melting processes. It was found that PLA alone is more sensitive to photodegradation than PLA/silver nanocomposites. The mechanism of nanocomposite photodegradation and effect of nanosilver was discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40144.     

The Removal of Atrazine from Water using Specific Polymeric Adsorbent

In order to obtain a specific polymer adsorbent for atrazine removal, the poly(divinylbenzene) beads were synthesized in radical polymerization using suspension polymerization, and modified with maleic anhydride in Diels-Alder reaction with subsequent base hydrolysis. The porous structure of the adsorbent was obtained by using various mixtures of solvents during the polymerization step; both porous and gel materials were prepared. The objective of the study was to investigate the sorption of atrazine by polymeric adsorbent and thereby evaluate the possibility of the pesticide residues’ removal from the aqueous solution. Implementation of carboxylic groups into the polymer structure resulted in obtaining specific interactions between modified poly(divinylbenzene) and atrazine, and therefore, intensification of adsorption was observed. To characterize the hydrogen bond between the herbicide and the adsorbent, quantum mechanics calculations were performed.     

A Novel Method for Degradation of DDT in Contaminated Soil

A novel method for remediation of DDT contaminated soil based on advanced oxidation processes including reactions with hydroxyl radicals and ozone has been developed. On the basis of the conducted experiments the authors concluded that ozone did not degrade DDT in soil. Analysis of degradation products that were formed during exposure to a stream of gaseous ozone indicated that hydroxyl radicals might play a key role in degradation of this compound. In the modified fluidized bed reactor where hydroxyl radicals could be generated from ozone and water vapor, reduction of over 90% of DDT residue level has been achieved. Authors proposed a pathway of DDT degradation, under the influence of hydroxyl radicals and ozone. As a result of this research, an effective method for remediation of DDT-contaminated soil has been proposed.     

The Alterations of Mitochondrial Function during NAFLD Progression—An Independent Effect of Mitochondrial ROS Production

The progression of non-alcoholic fatty liver (NAFL) into non-alcoholic steatohepatitis implicates multiple mechanisms, chief of which is mitochondrial dysfunction. However, the sequence of events underlying mitochondrial failure are still poorly clarified. In this work, male C57BL/6J mice were fed with a high-fat plus high-sucrose diet for 16, 20, 22, and 24 weeks to induce NAFL. Up to the 20th week, an early mitochondrial remodeling with increased OXPHOS subunits levels and higher mitochondrial respiration occurred. Interestingly, a progressive loss of mitochondrial respiration along “Western diet” feeding was identified, accompanied by higher susceptibility to mitochondrial permeability transition pore opening. Importantly, our findings prove that mitochondrial alterations and subsequent impairment are independent of an excessive mitochondrial reactive oxygen species (ROS) generation, which was found to be progressively diminished along with disease progression. Instead, increased peroxisomal abundance and peroxisomal fatty acid oxidation-related pathway suggest that peroxisomes may contribute to hepatic ROS generation and oxidative damage, which may accelerate hepatic injury and disease progression. We show here for the first time the sequential events of mitochondrial alterations involved in non-alcoholic fatty liver disease (NAFLD) progression and demonstrate that mitochondrial ROS are not one of the first hits that cause NAFLD progression.     

Vaporization of zinc during thermal treatment of ZnO with tetrabromobisphenol A (TBBPA)

In the present work we investigate the vaporization of zinc or its compounds during thermal treatment of ZnO with tetrabromobisphenol A. Samples of 2g of ZnO:TBBPA (3.34:1) were isothermally heated in a laboratory-scale furnace at temperatures from 490 °C to 950 °C, and the solid, condensed and gaseous products formed were analyzed by X-ray diffraction analysis, electron probe microanalysis, inductively coupled plasma analysis, ion chromatography, and gas chromatography coupled with mass spectrometry. The results obtained indicate that the vaporization of ZnBr(2) formed strongly depends on heating time and temperature, yet is restrained by char, if formed with sufficient yield (above 15 wt%). Starting from 850 °C, this char commences carbothermic reduction of any remaining ZnO, which from then begins to evaporate as zinc metal vapor. Volatilization of zinc is completed at 950 °C. The presence of 5 vol.% of oxygen has no significant effect on the vaporization of formed ZnBr(2), the carbothermic reduction or the volatilization of metallic zinc. Strongly oxidizing conditions (20 vol.% of oxygen), however, boost the oxidation of char and thus the vaporization of ZnBr(2), but prevent carbothermic reduction of any un-reacted ZnO by depleting this char.