Synthesis and properties of ZnS nanoparticles by solvothermal and pyrolysis routes using the Zn dithiocarbamate complex as novel single source precursor

In this work, the synthesis and characterization of ZnS nanoparticles prepared via two approaches, involving the thermal decomposition of the precursor complex in a furnace (pyrolysis) and by solvothermal process in the presence of hexadecylamine (HDA-ZnS), are reported. The precursor complex, Zinc (II) bis (N,N-diallyl dithiocarbamate), was synthesized and characterized by spectroscopic and single-crystal X-ray techniques. The spectroscopic analyses of the complex indicated a symmetrical bidentate coordination of the dithio ligand through the S-atoms. The single-crystal X-ray structure revealed a distorted square pyramidal coordinate geometry with S atoms around the Zn ion. The optical properties and the morphology of the as-prepared nanoparticles were studied by UV-Vis and photoluminescense spectroscopy, and transmission electron microscopy (TEM), respectively. HDA-ZnS are spherical and monodispersed with an average size of 4.5?nm, as estimated from the optical absorption spectrum and the TEM image. The ZnS nanoparticles obtained via pyrolysis in a furnace yielded the hexagonal wurtzite phase, whereas the HDA-ZnS nanoparticles showed a mixture of wurtzite and cubic phase with the cubic phase being dominant.     

New Poly(N-isopropylacrylamide-butylacrylate) Copolymer Biointerfaces and Their Characteristic Influence on Cell Behavior In Vitro

Designing and obtaining new synthetic smart biointerfaces with specific and controlled characteristics relevant for applications in biomedical and bioengineering domains represents one of the main challenges in these fields. In this work, Matrix-Assisted Pulsed Laser Evaporation (MAPLE) is used to obtain synthetic biointerfaces of poly(N-isopropyl acrylamide-butyl acrylate) p(NIPAM-BA) copolymer with different characteristics (i.e., roughness, porosity, wettability), and their effect on normal HEK 293 T and murine melanoma B16-F1 cells is studied. For this, the influence of various solvents (chloroform, dimethylsulfoxide, water) and fluence variation (250–450 mJ/cm²) on the morphological, roughness, wettability, and physico–chemical characteristics of the coatings are evaluated by atomic force microscopy, scanning electron microscopy, contact angle measurements, Fourier-transform-IR spectroscopy, and X-ray photoelectron spectroscopy. Coatings obtained by the spin coating method are used for reference. No significant alteration in the chemistry of the surfaces is observed for the coatings obtained by both methods. All p(NIPAM-BA) coatings show hydrophilic character, with the exception of those obtained with chloroform at 250 mJ/cm². The surface morphology is shown to depend on both solvent type and laser fluence and it ranges from smooth surfaces to rough and porous ones. Physico–chemical and biological analysis reveal that the MAPLE deposition method with fluences of 350–450 mJ/cm² when using DMSO solvent is more appropriate for bioengineering applications due to the surface characteristics (i.e., pore presence) and to the good compatibility with normal cells and cytotoxicity against melanoma cells.     

Impact strength elastomer composites based on polystyrene components separated from waste electrical and electronic equipment

The reuse of plastic components of waste electrical and electronic equipment (WEEE) is an important concern both for environmental issues and to preserve the material resources, with minimum energy consumption. Considering that polystyrene fraction was reported as approximate 80% of the total amount of WEEE plastic, this article aims to evaluate the recycling of this fraction, without separation by components, by melt compounding with styrene-butadiene block-copolymer (SBS) and hydrogenated and maleinized SBS, the blend of the two elastomers acting both as an impact modifier and compatibilizer. The composites are characterized by mechanical analysis, impact tests, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. The recycling conditions of the polystyrene fraction as composites without eliminating the WEEE additives for improved UV and flame resistance, with physical mechanical properties comparable to those of high-impact polystyrene resulted from the study. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48329.     

Comparitive study on facilitated pertraction of succinic acid using TRI‐n‐octylamine without and with 1‐octanol

Succinic acid has been pertracted with TOA using free liquid membranes without or with 1‐octanol. The addition of the alcohol led to the increase of up to 2.8–3 times of the acid's initial and final mass flows. At the same time, the influence of 1‐octanol on the transport capacity of the pertraction system was negative, its addition inducing the accumulation of succinic acid into the liquid membrane. A mathematical model describing the acid accumulation inside the liquid membrane has been developed for pertraction systems without and with 1‐octanol and offers good concordance with the experimental data. © 2012 Canadian Society for Chemical Engineering     

Total and individual carotenoids and phenolic acids content in fresh,refrigerated and processed spinach (Spinacia oleracea L.)

The carotenoid and phenolic acid contents in fresh, stored and processed (blanched, frozen and boiled) spinach were comparatively determined by spectrophotometric and HPLC analyses. The major carotenoids identified after HPLC analysis in saponified samples were lutein (37–53 μg/kg), β-carotene (18–31 μg/kg), violaxanthin (9–23 μg/kg) and neoxanthin (10–22 μg/kg). These carotenoids were all affected by storage and/or heating. The content of carotenoids was best preserved after storage for one day at 4 °C.     

Glucose and lactate biosensors for scanning electrochemical microscopy imaging of single live cells

We have developed glucose and lactate ultramicroelectrode (UME) biosensors based on glucose oxidase and lactate oxidase (with enzymes immobilized onto Pt UMEs by either electropolymerization or casting) for scanning electrochemical microscopy (SECM) and have determined their sensitivity to glucose and lactate, respectively. The results of our evaluations reveal different advantages for sensors constructed by each method: improved sensitivity and shorter manufacturing time for hand-casting, and increased reproducibility for electropolymerization. We have acquired amperometric approach curves (ACs) for each type of manufactured biosensor UME, and these ACs can be used as a means of positioning the UME above a substrate at a known distance. We have used the glucose biosensor UMEs to record profiles of glucose uptake above individual fibroblasts. Likewise, we have employed the lactate biosensor UMEs for recording the lactate production above single cancer cells with the SECM. We also show that oxygen respiration profiles for single cancer cells do not mimic cell topography, but are rather more convoluted, with a higher respiration activity observed at the points where the cell touches the Petri dish. These UME biosensors, along with the application of others already described in the literature, could prove to be powerful tools for mapping metabolic analytes, such as glucose, lactate, and oxygen, in single cancer cells.     

Multidimensional urban segregation: toward a neural network measure

We introduce a multidimensional, neural network approach to reveal and measure urban segregation phenomena, based on the self-organizing map algorithm (SOM). The multidimensionality of SOM allows one to apprehend a large number of variables simultaneously, defined on census blocks or other types of statistical blocks, and to perform clustering along them. Levels of segregation are then measured through correlations between distances on the neural network and distances on the actual geographical map. Further, the stochasticity of SOM enables one to quantify levels of heterogeneity across census blocks. We illustrate this new method on data available for the city of Paris.

     

Conceptual approaches to wellbeing in buildings: a scoping review

ABSTRACT

Several industry-led initiatives in various countries demonstrate a new interest in wellbeing and buildings. This paper adopts a scoping review method aiming to establish the most prevalent and insightful definitions and dimensions of wellbeing in buildings applied in the recent published literature. The paper adopts a two-step method for identifying and categorizing the conceptual approaches to wellbeing encountered in the current literature. First, an overview is presented of the term ‘wellbeing’ and its development over time. Second, the broad wellbeing categories identified are further refined and complemented via a deductive approach, drawing the final set of conceptual themes informed by the papers reviewed in this study. Nine themes were identified, two of which deductively emerged from the papers included in this study: environmental satisfaction/comfort and cognitive performance/productivity. The findings emphasize the heterogeneity of conceptual approaches to research concerning ‘wellbeing in buildings’, an ambiguity between wellbeing outcomes or determinants, and the need for greater clarity on the relative contributions of different wellbeing dimensions to overall individual or population wellbeing. Based on these findings, future work could be carried out to provide guidance on how to evaluate claims of evidence-based building design which foster individual or population wellbeing.     

Formalizing Cognitive Acceptance of Arguments: Durum Wheat Selection Interdisciplinary Study

In this paper we present an interdisciplinary approach that concerns the problem of argument acceptance in an agronomy setting. We propose a computational cognitive model for argument acceptance based on the dual model system in cognitive psychology. We apply it in an agronomy setting within a French national project on durum wheat.     

Sericin Enhances the Bioperformance of Collagen-Based Matrices Preseeded with Human-Adipose Derived Stem Cells (hADSCs)

Current clinical strategies for adipose tissue engineering (ATE), including autologous fat implants or the use of synthetic surrogates, not only are failing in the long term, but also can’t face the latest requirements regarding the aesthetic restoration of the resulted imperfections. In this context, modern strategies in current ATE applications are based on the implantation of 3D cell-scaffold bioconstructs, designed for prospective achievement of in situ functional de novo tissue. Thus, in this paper, we reported for the first time the evaluation of a spongious 60% collagen and 40% sericin scaffold preseeded with human adipose-derived stem cells (hADSCs) in terms of biocompatibility and adipogenic potential in vitro. We showed that the addition of the sticky protein sericin in the composition of a classical collagen sponge enhanced the adhesion and also the proliferation rate of the seeded cells, thus improving the biocompatibility of the novel scaffold. In addition, sericin stimulated PPARγ2 overexpression, triggering a subsequent upregulated expression profile of FAS, aP2 and perilipin adipogenic markers. These features, together with the already known sericin stimulatory potential on cellular collagen production, promote collagen-sericin biomatrix as a good candidate for soft tissue reconstruction and wound healing applications.