Deformation Characteristics of Leather for Shoe Upper,Filled with Natural Minerals

A promising direction in the tanning industry is the use of natural minerals as environmentally friendly technologically efficient materials that are able to adjust and regulate the efficiency of formation of the dermis structure and the properties of finished leather. The use of finely-dispersed minerals promotes alignment of topographic areas in thickness, increases the yield of leather on the area by avoiding bonding structural elements of the dermis. Changes in the microstructure of the dermis, as a result of mineral filling, contribute to improvement of performance and hygienic properties of finished leather. And the study of the properties of the specified skins should be consistent with the features of operations on their cutting, shoe molding and shoe upper fixing preparations. The most important properties of leather materials, which largely determine the quality of basic technological operations of shoe manufacturing are the deformation properties. Lack of information about relaxation and deformation properties of the leather produced by the new technologies do not allow to predict their ability to form shapes and save it--indicates the relevance of this study. This paper analyzes relaxation and deformation characteristics of natural leather for shoe uppers, filled with natural minerals montmorillonite and zeolite, and the ability to predict their formation and preservation of shape in service. Features of deformation of the skin with mineral content were assessed by determining single-cycle characteristics when attaching to a complete test cycle ＂loading-unloading-rest＂ sample. Correlations of elastic and plastic （permanent） deformation have been established, kinetics of changes in linear characteristics of the samples after removal of the load has been investigated. Introduction of dispersions of mineral to the structure of the dermis contributes to the strength of semi-finished leather, increase of the uniformity of mechanical properties in the longitudinal and transverse directions and rise of shape stability index. It is shown that the direction of this study allows us to offer new competitive ecologically friendly materials to produce shoes.     

Green synthesis of Ag nanoparticles: Effect of algae life cycle on Ag nanoparticle production and long-term stability

Spherical Ag nanoparticles (AgNPs) were biologically synthesized using four different extracts prepared from Parachlorella kessleri algae cultivated for 1, 2, 3 and 4 weeks. The influence of algae life cycle on AgNPs formation and effect of different storage conditions on AgNPs long-term stability were investigated. The age of algae influenced the rate of AgNPs synthesis and amount of AgNPs in solution. The age of algae did not influence the AgNPs long-term stability. UV–vis and TEM observation revealed that long-term stability of AgNPs can be influenced by storage temperatures, and low temperature positively influences the AgNPs stability. AgNPs stored at dark and at temperature of ～5 °C showed the best long-term stability regardless of the culture age. Such AgNPs remained spherical, fine (5–20 nm) and stable (no agglomeration) even after 6 months.     

Trabecular Bone Parameters,TIMP-2, MMP-8, MMP-13, VEGF Expression and Immunolocalization in Bone and Cartilage in Newborn Offspring Prenatally Exposed to Fumonisins

Fumonisins are protein serine/threonine phosphatase inhibitors and potent inhibitors of sphingosine N-acyltransferase (ceramide synthase) disrupting de novo sphingolipid biosynthesis. The experiment was conducted to evaluate the effects of fumonisins (FB) exposure from the 7th day of pregnancy to parturition on offspring bone development. The rats were randomly allocated to either a control group (n = 6), not treated with FBs, or to one of the two groups intoxicated with FBs (either at 60 mg FB/kg b.w. or at 90 mg FB/kg b.w. Numerous negative, offspring sex-dependent effects of maternal FB exposure were observed with regards to the histomorphometry of trabecular bone. These effects were due to FB-inducted alterations in bone metabolism, as indicated by changes in the expression of selected proteins involved in bone development: tissue inhibitor of metalloproteinases 2 (TIMP-2), matrix metalloproteinase 8 (MMP-8), matrix metalloproteinase 13 (MMP-13), and vascular endothelial growth factor (VEGF). The immunolocalization of MMPs and TIMP-2 was performed in trabecular and compact bone, as well as articular and growth plate cartilages. Based on the results, it can be concluded that the exposure of pregnant dams to FB negatively affected the expression of certain proteins responsible for bone matrix degradation in newborns prenatally exposed to FB in a dose- and sex-dependent manner.     

Fibrosis Protein-Protein Interactions from Google Matrix Analysis of MetaCore Network

Protein–protein interactions is a longstanding challenge in cardiac remodeling processes and heart failure. Here, we use the MetaCore network and the Google matrix algorithms for prediction of protein–protein interactions dictating cardiac fibrosis, a primary cause of end-stage heart failure. The developed algorithms allow identification of interactions between key proteins and predict new actors orchestrating fibroblast activation linked to fibrosis in mouse and human tissues. These data hold great promise for uncovering new therapeutic targets to limit myocardial fibrosis.     

Therapeutic Effects of Hypoxic and Pro-Inflammatory Priming of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Inflammatory Arthritis

Mesenchymal stem cells (MSCs) immunomodulate inflammatory responses through paracrine signalling, including via secretion of extracellular vesicles (EVs) in the cell secretome. We evaluated the therapeutic potential of MSCs-derived small EVs in an antigen-induced model of arthritis (AIA). EVs isolated from MSCs cultured normoxically (21% O₂, 5% CO₂), hypoxically (2% O₂, 5% CO₂) or with a pro-inflammatory cytokine cocktail were applied into the AIA model. Disease pathology was assessed post-arthritis induction through swelling and histopathological analysis of synovial joint structure. Activated CD4+ T cells from healthy mice were cultured with EVs or MSCs to assess deactivation capabilities prior to application of standard EVs in vivo to assess T cell polarisation within the immune response to AIA. All EVs treatments reduced knee-joint swelling whilst only normoxic and pro-inflammatory primed EVs improved histopathological outcomes. In vitro culture with EVs did not achieve T cell deactivation. Polarisation towards CD4+ helper cells expressing IL17a (Th17) was reduced when normoxic and hypoxic EV treatments were applied in vitro. Normoxic EVs applied into the AIA model reduced Th17 polarisation and improved Regulatory T cell (Treg):Th17 homeostatic balance. Normoxic EVs present the optimal strategy for broad therapeutic benefit. EVs present an effective novel technology with the potential for cell-free therapeutic translation.     

Nanoscale Control of the Surface Functionality of Polymeric 2D Materials

Typically, 2D nanosheets have a homogeneous surface, making them a major challenge to structure. This study proposes a novel concept of 2D organic nanosheets with a heterogeneously functionalized surface. This work achieves this by consecutively crystallizing two precisely synthesized polymers with different functional groups in the polymer backbone in a two-step process. First, the core platelet is formed and then the second polymer is crystallized around it. As a result, the central area of the platelets has a different surface functionality than the periphery. This concept offers two advantages: the resulting polymeric 2D platelets are stable in dispersion, which simplifies further processing and makes both crystal surfaces accessible for subsequent functionalization. Additionally, a wide variety of polymers can be used, making the process and the choice of surface functionalization very flexible.