Melting behavior,crystallization kinetics and morphology of random copolyesters of poly(2‐hydroxyethoxybenzoate) with ε‐caprolactone

The melting behavior after isothermal crystallization and the crystallization kinetics of random poly(2‐hydroxyethoxybenzoate/ε‐caprolactone) copolymers rich in 2hydroxyethoxybenzoate units were investigated by means of differential scanning calorimetry and hot‐stage optical microscopy. The observed multiple endotherms, which are commonly displayed by polyesters, were found to be influenced both by crystallization temperature and composition. By applying the Hoffman‐Weeks method to the melting temperatures of isothermally crystallized samples, the equilibrium melting temperatures of the copolymers were obtained. Furthermore, isothemal crystallization kinetics was analyzed according to the Avrami treatment. Values of the exponent n close to 3 were obtained, independently of crystallization temperature and composition, in agreement with a crystallization process originating from predeterminated nuclei and characterized by three‐dimensional spherulitic growth. Space‐filling banded spherulites were observed by hot‐stage optical polarizing microscopy at all the crystallization temperatures explored, the band spacing being affected by both crystallization temperature and composition. As expected, the introduction of ε‐caprolactone comonomeric units in the polymer chain of PHEBA was found to decrease its crystallization rate.     

Détermination des caractéristiques diffusionnelles de transfert d'un solute gazeux adsorbable au sein d'un milieu poreux. Application au cas de la vapeur d'eau au sein du bois de hêtre

An experimental method is proposed to characterize the diffusional transfer of adsorbable gaseous solute medium in a porous medium. Three types of experimental measurements are used to successively access to the solute apparent diffusivity in the gas phase, in the adsorbed phase and to check whether the hypothesis of the thermodynamic equilibrium between the gas phase solute and the adsorbed solute is verified during the transient transfer process. This methodology is applied to a longitudinal section of a beech wood sample for the water transfer in the wood hygroscopic domain.     

Bio-based sustainable films from the Algerian Opuntia ficus-indica cladodes powder: Effect of plasticizer content

The present study investigated the fabrication and characterization of bio-based sustainable films composed of a terrestrial plant raw material, namely Opuntia ficus-indica (OFI) cladodes powder (CP) and a marine seaweed derivative, namely agar (A). The effect of glycerol concentration on the properties of the casted films was evaluated at four different contents, namely 30, 40, 50 and 60 wt%. The films present UV-blocking properties, as well as moderate mechanical performance, thermal stability, and water vapor transmission rate (WVTR). The results point to an increase in thickness, elongation at break, moisture content, water solubility, and WVTR with increasing glycerol content. On the contrary, Young's modulus, tensile strength, and water contact angle decreased as glycerol concentration increased. The best combination is obtained for the film with 30% glycerol, based on an intermediate compromise between physical, mechanical, thermal, and barrier properties. All these outcomes express the potentiality of the powder obtained from grinding the OFI cladodes as raw material to produce low-cost films for the development of sustainable packaging materials.     

Tumor-Derived Small Extracellular Vesicles Induce Pro-Inflammatory Cytokine Expression and PD-L1 Regulation in M0 Macrophages via IL-6/STAT3 and TLR4 Signaling Pathways

Tumor-associated macrophages play a key role in promoting tumor progression by exerting an immunosuppressive phenotype associated with the expression of programmed cell death ligand 1 (PD-L1). It is well known that tumor-derived small extracellular vesicles (SEVs) affect the tumor microenvironment, influencing TAM behavior. The present study aimed to examine the effect of SEVs derived from colon cancer and multiple myeloma cells on macrophage functions. Non-polarized macrophages (M0) differentiated from THP-1 cells were co-cultured with SEVs derived from a colorectal cancer (CRC) cell line, SW480, and a multiple myeloma (MM) cell line, MM1.S. The expression of PD-L1, interleukin-6 (IL-6), and other inflammatory cytokines as well as of the underlying molecular mechanisms were evaluated. Our results indicate that SEVs can significantly upregulate the expressions of PD-L1 and IL-6 at both the mRNA and protein levels and can activate the STAT3 signaling pathway. Furthermore, we identified the TLR4/NF-kB pathway as a convergent mechanism for SEV-mediated PD-L1 expression. Overall, these preliminary data suggest that SEVs contribute to the formation of an immunosuppressive microenvironment.     

Molecular Epidemiology of Mitochondrial Cardiomyopathy: A Search Among Mitochondrial and Nuclear Genes

Mitochondrial Cardiomyopathy (MCM) is a common manifestation of multi-organ Mitochondrial Diseases (MDs), occasionally present in non-syndromic cases. Diagnosis of MCM is complex because of wide clinical and genetic heterogeneity and requires medical, laboratory, and neuroimaging investigations. Currently, the molecular screening for MCM is fundamental part of MDs management and allows achieving the definitive diagnosis. In this article, we review the current genetic knowledge associated with MDs, focusing on diagnosis of MCM and MDs showing cardiac involvement. We searched for publications on mitochondrial and nuclear genes involved in MCM, mainly focusing on genetic screening based on targeted gene panels for the molecular diagnosis of the MCM, by using Next Generation Sequencing. Here we report twelve case reports, four case-control studies, eleven retrospective studies, and two prospective studies, for a total of twenty-nine papers concerning the evaluation of cardiac manifestations in mitochondrial diseases. From the analysis of published causal mutations, we identified 130 genes to be associated with mitochondrial heart diseases. A large proportion of these genes (34.3%) encode for key proteins involved in the oxidative phosphorylation system (OXPHOS), either as directly OXPHOS subunits (22.8%), and as OXPHOS assembly factors (11.5%). Mutations in several mitochondrial tRNA genes have been also reported in multi-organ or isolated MCM (15.3%). This review highlights the main disease-genes, identified by extensive genetic analysis, which could be included as target genes in next generation panels for the molecular diagnosis of patients with clinical suspect of mitochondrial cardiomyopathies.     

Investigation of zeolitic imidazolate frameworks–derived carbon nanotubes thin film in solar vapor generation

Journal of Porous Materials - Solar vapor generation is considered a green and practical approach to take advantage of solar energy as a renewable source and provide pure water. However, developing...     

Effect of blend composition in BisEH-PFDTBT:PC70BM solar cells

The photovoltaic properties of bulk-heterojunction solar cells with an active layer made of an alternating fluorene copolymer, poly{[2,7-(9,9-bis-(2-ethylhexyl)-fluorene)]-alt-[5,5-(4,7-di-2′-thienyl-2,1,3-benzothiadiazole)]}, and [6,6]-phenyl-C₇₁-butyric acid methylester are investigated by varying the blend composition and the incident light power intensity. An efficient donor-acceptor intermixing is reached with donor to acceptor weight ratios of at least 1:3, while at lower acceptor content charge trapping effects are evidenced by the light intensity dependent study. Reverse bias analysis demonstrates that a major limiting factor for the performance of the investigated solar cells is represented by the poor ability of the generation of free charge carriers, attributed to the low hole mobility in the polymer phase.