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The conversion of CO2 into chemicals of commercial interest is a rapidly expanding area of research. Here, we present a highly active and stable CO2 methanation catalyst that is derived from a Ru-impregnated zirconium-based metal–organic framework (MOF) material. The Ru-doped MOF is transformed, under reaction conditions, into an active catalyst which yields CO2 conversions of 96% and a CH4 selectivity of 99%. We demonstrate that the final catalyst was composed of a mixture of Ru-nanoparticles supported on monoclinic and tetragonal ZrO2 nanoparticles. Notably, such catalytic activity has only been achieved using the MOF templating strategy. Catalysts of the same composition were synthesized via different methods but were less active for CO2 methanation. [ABSTRACT FROM AUTHOR]

Biomass tar, an inevitable byproduct of biomass pyrolysis and gasification, poses a significant challenge due to its tendency to condense in pipelines, causing clogging and operational issues. Catalytic steam reforming can convert tar into syngas, addressing the tar issue while simultaneously producing hydrogen. However, the reforming catalyst is highly susceptible to deactivation by coking, especially when dealing with highly concentrated polymeric hydrocarbons such as tar. This study focused on enhancing the durability of tar-reforming catalysts. Nickel-based catalysts were prepared using carbon supports known for their high coking resistance, such as carbon black (CB), activated carbon (AC), and low-rank coal (LRC). Their performance was then tested for the steam reforming of high-concentration toluene, a representative tar. All three carbon supports (CB, AC, LRC) showed high catalytic performance with NiMg catalysts at 500 °C. Among them, the mesoporous CB support exhibited the highest stability when exposed to steam, with NiMg on CB (NiMg/CB) remaining stable for long-term continuous operation without any deactivation due to coking or thermal degradation. [ABSTRACT FROM AUTHOR]

As the global quest for sustainable energy keeps rising, exploring novel efficient and practical photocatalysts remains a research and industrial urge. Particularly, metal organic frameworks were proven to contribute to various stages of the carbon cycle, from CO2 capture to its conversion. Herein, we report the photo-methanation activity of three isostructural, nickel-based metal organic frameworks incorporating additional niobium, iron, and aluminum sites, having demonstrated exceptional CO2 capture abilities from thin air in previous reports. The niobium version exhibits the highest performance, with a CO2 to CH4 conversion rate in the order of 750–7500 µmol*gcatalyst−1*h−1 between 180 °C and 240 °C, achieving 97% selectivity under light irradiation and atmospheric pressure. The in-depth characterization of this framework before and after catalysis reveals the occurrence of an in-situ restructuring process, whereas active surface species are formed under photocatalytic conditions, thus providing comprehensive structure-performance correlations for the development of efficient CO2 conversion photocatalysts.This study correlates the structure and the CO2 photohydrogenation performance of a series of isostructural Ni-based MOFs. Comparative characterization reveals the occurrence of an in situ restructuring, yielding different surface active sites. [ABSTRACT FROM AUTHOR]

Several Cu and Ni-based catalysts were synthetized over Ce-based supports, either pure or mixed with different amounts of alumina (1:2 and 1:3 mol/mol). Different metal loadings (10–40 wt%) and preparation methods (wet impregnation, co-precipitation, and flame-spray pyrolysis—FSP) were compared for the oxidative steam reforming of methanol. Characterization of the catalysts has been performed, e.g., through XRD, BET, XPS, TPR, SEM, and EDX analyses. All the catalysts have been tested in a bench-scale continuous setup. The hydrogen yield and methanol conversion obtained have been correlated with the operating conditions, metal content, crystallinity of the catalyst particles, total surface area, and with the interaction of the metal with the support. A Cu loading of 20% wt/wt was optimal, while the presence of alumina was not beneficial, decreasing catalyst activity at low temperatures compared with catalysts supported on pure CeO2. Ni-based catalysts were a possible alternative, but the activity towards the methanation reaction at relatively high temperatures decreased inevitably the hydrogen yield. Durability and deactivation tests showed that the best-performing catalyst, 20% wt. Cu/CeO2 prepared through coprecipitation was stable for a long period of time. Full methanol conversion was achieved at 280 °C, and the highest yield of H2 was ca. 80% at 340 °C, higher than the literature data. [ABSTRACT FROM AUTHOR]

Objective: To compare metabolic, nutritional and epidemiological data in two groups of patients, one receiving total enteral nutrition, via nasoenteric tube, and one receiving both enteral and parenteral nutrition., Design: A prospective, randomized study., Setting: A general ICU, with both medical and surgical patients, in a big regional University and National Health Service hospital., Patients: 24 patients requiring Intensive Care after major surgery or because suffering from severe head injury or major neurological impairment., Interventions: All patients initially received total parenteral nutrition: after 4 days 12 patients were "weaned" to total enteral nutrition and 12 stayed on mixed parenteral and enteral nutrition. LABORATORY INVESTIGATIONS AND OBSERVATIONAL DATA: Blood levels of albumin, prealbumin, transferrin, ALT, AST, bilirubin, blood urea, blood glucose, total linfocite count, and nutritional and epidemiological data such as nitrogen balance, calorie intake, diarrhea incidence, blood and sputum cultures and radiologic evidence of pneumonia are analysed., Results: At T1, NET patients were able to reduce their nitrogen losses (0.27.1 g/kg +/-0.12 vs 0.35 +/- 0.13 at TO; p < 0.05) and improve nitrogen balance (-9 +/- 7 vs -2 +/- 6 at T0; p < 0.05); they also had a better total linfocite count (2034 +/- 304 vs. 1413 +/- 360 of the MISTA group; p < 0.05), and a lower incidence of pneumonia as documented by sputum cultures and radiograms., Conclusions: Patients fed with both parenteral and enteral nutrition did no better than those on total enteral nutrition as far as nutritional and metabolic indices were concerned; they also seemed more prone to infections than those on total enteral nutrition, indicating that mixed nutrition may result in more stable feeding, but this does not seem to have any beneficial nutritional, immunological and metabolic effect.

In this study we synthesized and characterized Ni/AC (Activated Carbon) systems. AC was obtained through pyrolysis of golden rod's dried biomass. Ni nanoparticles were deposited on AC's surface using a wet impregnation method from a nickel nitrate solution. SEM, MP-AES and DSC-TGA techniques were used for surficial and structural characterization, while ash content was made to check mineral ingredients input. The DSC-TGA study revealed that all carbons show good thermal stability up to 900 °C, which is far above operating temperatures in the methanation process. For all three carbons the BET isotherms were made as well. They show that in most cases the carbon's surface is well developed and can adsorb decent amounts of metal. MP-AES helped to evaluate the efficiency of the impregnation process, which reached 76 mg of Ni per 1 g of carbon. The SEM-EDS study showed good distribution of Ni nanoparticles across AC's surface. We also made a comparison of our systems to similar materials from other works. [ABSTRACT FROM AUTHOR]

A series of MOF-derived ZrO2-supported Pd-Ni bimetallic catalysts (PdNi/UiO-67-CTAB(n)-A500) were prepared by co-impregnation and pyrolysis at 500 °C under air atmosphere using UiO-67-CTAB(n) (CTAB: cetyltrimethylammonium bromide; n: the concentration of CTAB; n = 0, 3, 8, 13, 18) as a sacrificial template. The catalytic activity of PdNi/UiO-66-CTAB(n)-A500 in 1,3-butadiene hydrogenation was found to be dependent on the crystal morphology of the UiO-67 template. The highest activity was observed over the PdNi/UiO-67-CTAB(3)-A500 catalyst which was synthesized using UiO-67-CTAB(3) with uniform octahedral morphology as the template for the 1,3-butadiene selective hydrogenation. The 1,3-butadiene conversion and total butene selectivity were 98.4% and 44.8% at 40 °C within 1 h for the PdNi/UiO-67-CTAB(3)-A500 catalyst, respectively. The catalyst of PdNi/UiO-67-CTAB(3)-A500 can be regenerated in flowing N2 at 200 °C. Carbon deposited on the surface of the catalyst was the main reason for its deactivation. This work is valuable for the high-efficiency bimetallic catalyst's development on the selective hydrogenation of 1,3-butadiene. [ABSTRACT FROM AUTHOR]

Acknowledging the neurological symptoms of COVID‐19 and the long‐lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS‐CoV‐2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro‐inflammatory, pro‐coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID‐19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID‐19 due to their innate homing properties, low immunogenicity, and ability to cross the blood‐brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID‐19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID‐19 neuropathology as carriers of SARS‐CoV‐2 or other pathogenic contents, as predictors of COVID‐19 neuropathology by transporting brain‐derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID‐19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease. [ABSTRACT FROM AUTHOR]

Two hundred years ago, the first of the nine volumes of Paolo Mascagni’s Anatomia universa was published posthumously. This work was the fruit of a project that had occupied Mascagni for most of his life: an Atlas of anatomy that was the perfect replica on paper of dissection, a fundamental part of the teaching of this discipline. Through a short journey that traces some of the most important passages in the life of the great anatomist, the authors commemorate the Anatomia universa, an extraordinary work in the history and teaching of medicine. To do so, they draw on information and recover evocative Anatomical plates that are still conserved intact today in the prestigious Museum of Siena. The plates are organized to reveal the body from the superficial muscle layer down to the skeleton, as in the process of dissection. For the first time in the history of anatomy, the plates were life-size. Furthermore, in an original manner, and again for the first time, these plates showed the network of lymphatic vessels that Mascagni had brought to light a few years earlier. The beauty and perfection of these drawings are the result of Mascagni’s knowledge and his ability to recruit the most expert artists and engravers of the time. Mascagni’s treatises testify to the modernity of his approach to medical education, and his deep conviction that the main objective was to educate young people and to enable them to acquire the most perfect knowledge of the structure of the human body. [ABSTRACT FROM AUTHOR]

Copyright of Ecologia Austral is the property of Asociacion Argentina de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

CO2 methanation offers a promising route for converting CO2 into valuable chemicals and energy fuels at the same time as hydrogen is stored in methane, so the development of suitable catalysts is crucial. In this review, the performance of catalysts for CO2 methanation is presented and discussed, including noble metal-based catalysts and non-noble metal-based catalysts. Among the noble metal-based catalysts (Ru, Rh, and Pd), Ru-based catalysts show the best catalytic performance. In the non-noble metal catalysts, Ni-based catalysts are the best among Ni-, Co-, and Fe-based catalysts. The factors predominantly affecting catalytic performance are the dispersion of the active metal; the synergy of the active metal with support; and the addition of dopants. Further comprehensive investigations into (i) catalytic performance under industrial conditions, (ii) stability over a much longer period and (iii) activity enhancement at low reaction temperatures are anticipated to meet the industrial applications of CO2 methanation. [ABSTRACT FROM AUTHOR]

Photon Bose–Einstein condensation and photon thermalisation have been largely studied with molecular gain media in optical cavities. However, their observation with semiconductors has remained elusive despite a large body of experimental results and very well established theoretical models. In this work, these models are used to build a new theoretical framework that enables revisiting lasing to compare with photon Bose–Einstein condensation in the driven‐dissipative regime. The thermalisation figures of merit and the different experimental procedures to asses thermalization are discussed. Finally, the fluctuations of the system and their relation to the different regimes are explored. [ABSTRACT FROM AUTHOR]

Global population growth and rising consumption levels have significantly increased resource use and energy demand, leading to higher greenhouse gas concentrations and increased waste output. As a result, alternative waste treatment methods for sustainable municipal solid waste (MSW) management are crucial. This research evaluates the efficiency of integrating hydrothermal carbonization (HTC) and gasification for an optimized MSW biomass blend. HTC was conducted for one hour at 220°C in a 5 L reactor, followed by gasification in a hybrid porous medium gasifier. The study investigated the effects of different filtration speeds on combustion temperature and hydrogen concentrations. The results showed that a filtration speed of 35 cm/s resulted in a maximum combustion temperature of 1035.7°C. The temperature remained consistent across filter speeds, while higher velocities yielded higher hydrogen concentrations. Additionally, increasing the filtration velocity raised temperatures in the hybrid bed while increasing the volumetric fraction of biomass decreased maximum temperatures. This research contributes to the understanding of merging HTC and gasification for MSW biomass blend treatment, aiming to reduce environmental impacts and costs while promoting renewable resources for long-term energy production. [ABSTRACT FROM AUTHOR]

Copyright of Diálogo com a Economia Criativa is the property of Dialogo com a Economia Criativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanoscopic materials have demonstrated a versatile role in almost every emerging field of research. Nanomaterials have come to be one of the most important fields of advanced research today due to its controllable particle size in the nanoscale range, capacity to adopt diverse forms and morphologies, high surface area, and involvement of transition and non-transition metals. With the introduction of porosity, nanomaterials have become a more promising candidate than their bulk counterparts in catalysis, biomedicine, drug delivery, and other areas. This review intends to compile a self-contained set of papers related to new synthesis methods and versatile applications of porous nanomaterials that can give a realistic picture of current state-of-the-art research, especially for catalysis and sensor area. Especially, we cover various surface functionalization strategies by improving accessibility and mass transfer limitation of catalytic applications for wide variety of materials, including organic and inorganic materials (metals/metal oxides) with covalent porous organic (COFs) and inorganic (silica/carbon) frameworks, constituting solid backgrounds on porous materials. [ABSTRACT FROM AUTHOR]

Large number of solid wastes is produced from ethanol and wine plants sourcing from grain and inedible plant wastes, for example, WDGS (wet distiller's grain with soluble) and DDGS (dry distiller's grain with soluble) produced from ethanol plants using corn. This study investigates alternative methods for using these co-products through combustion and anaerobic digestion. Process simulation and economic analysis were conducted using current market prices to evaluate the viability of the processes. Products in the form of energy are produced. Optimization of the corn ethanol plant was also explored for re-using the heat and electricity produced in those processes. These processes will supply more viable options to utilisation of those wastes. The anaerobic digestion of WDGS to produce electricity scenario was found to have the biggest profit among the four scenarios which can bring the annual income of 14.1 million Australian dollar to the ethanol plant. An environmental analysis of the CO2 emissions was also conducted. Using the Australian state emission factor, the amount of CO2 offset through both combustion and anaerobic digestion can be seen. The anaerobic digestion of WDGS to supply heat to the plant was proved having the largest CO2 abatement with the value of 0.58 kg-CO2e/L-EtOH. Highlights: Different processing scenarios of wet solid residues in ethanol or wine plants were compared. Process simulation and economic analysis were performed. Anaerobic digestion to produce electricity has the best economic benefit. Anaerobic digestion to produce heat is the most environmentally friendly. [ABSTRACT FROM AUTHOR]

Copyright of Arqueología Iberoamericana is the property of Arqueologia Iberoamericana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of metal–organic frameworks (MOFs) as templates or precursors in the manufacture of heterogeneous catalysts is highly attractive due to the transfer of MOFs' inherent porosity and homogeneous metallic distribution to the derived structure. Herein, we report on the preparation of MOF-derived Ru@ZrO2 catalysts by controlled thermal treatment of zirconium-based MOF UiO-66 with ruthenium moieties. Ru3+ (3 or 10 mol%) precursor was added to UiO-66 synthesis and, subsequently, the as-synthesized hybrid structure was calcined in flowing air at different temperatures (400–600 °C) to obtain ZrO2-derived oxides doped with highly dispersed Ru metallic clusters. The materials were tested for the catalytic photo-thermal conversion of CO2 to CH4. Methanation experiments were conducted in a continuous flow (feed flow rate of 5 sccm and 1:4 CO2 to H2 molar ratio) reactor at temperatures from 80 to 300 °C. Ru0.10@ZrO2 catalyst calcined at 600 °C was able to hydrogenate CO2 to CH4 with production rates up to 65 mmolCH4·gcat.–1·h–1, CH4 yield of 80% and nearly 100% selectivity at 300 °C. The effect of the illumination was investigated with this catalyst using a high-power visible LED. A CO2 conversion enhancement from 18% to 38% was measured when 24 sun of visible LED radiation was applied, mainly due to the increase in the temperature as a result of the efficient absorption of the radiation received. MOF-derived Ru@ZrO2 catalysts have resulted to be noticeably active materials for the photo-thermal hydrogenation of CO2 for the purpose of the production of carbon-neutral methane. A remarkable effect of the ZrO2 crystalline phase on the CH4 selectivity has been found, with monoclinic zirconia being much more selective to CH4 than its cubic allotrope. [ABSTRACT FROM AUTHOR]

Sustainable production of acetic acid is a high priority due to its high global manufacturing capacity and numerous applications. Currently, it is predominantly synthesized via carbonylation of methanol, in which both the reactants are fossil-derived. Carbon dioxide transformation into acetic acid is highly desirable to achieve net zero carbon emissions, but significant challenges remain to achieve this efficiently. Herein, we report a heterogeneous catalyst, thermally transformed MIL-88B with Fe0 and Fe3O4 dual active sites, for highly selective acetic acid formation via methanol hydrocarboxylation. ReaxFF molecular simulation, and X-ray characterisation results show a thermally transformed MIL-88B catalyst consisting of highly dispersed Fe0/Fe(II)-oxide nanoparticles in a carbonaceous matrix. This efficient catalyst showed a high acetic acid yield (590.1 mmol/gcat.L) with 81.7% selectivity at 150 °C in the aqueous phase using LiI as a co-catalyst. Here we present a plausible reaction pathway for acetic acid formation reaction via a formic acid intermediate. No significant difference in acetic acid yield and selectivity were noticed during the catalyst recycling study up to five cycles. This work is scalable and industrially relevant for carbon dioxide utilisation to reduce carbon emissions, especially when green methanol and green hydrogen are readily available in future. Carbon dioxide conversion into chemicals is essential for carbon capture and utilization. Here, the authors present a novel iron-based catalyst, synthesized from the thermal treatment of a parent metal-organic framework (MIL-88B), to produce a dual-active site for carbon dioxide reduction into acetic acid. [ABSTRACT FROM AUTHOR]

As outstanding electrocatalytic materials, both metal oxide and conducting polymers have been synergically explored to fabricate electrochemical sensors. A novel electrochemical sensing interface was obtained by electrodeposition of the composite film based on polyaniline (PANI), carbon nanotubes (CNTs) and nickel oxide modified on lab-made screen-printed carbon electrode (SPE) for methanol electrooxidation in alkaline medium. The prepared composite electrode was characterized using various methods, including the Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction pattern (XRD), Energy-dispersive X-ray spectroscopy (EDX) and Scanning electron microscope (SEM). The methanol electrochemical oxidation of NiO–NiOOH/PANI-CNTs/SPE in an alkaline medium was studied by using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The obtained excellent sensing parameters including a sensor sensitivity of 8.056 × 10–5 mA/(mM cm2) with a limit detection LOD of 5 mM (S/N = 3) in wide range of methanol from 30 to 880 mM (R2 = 0.997) demonstrated that NiO–NiOOH/PANI-CNTs/SPE truly displayed highly electrochemical and catalytic activities for methanol electrooxidation. Furthermore, our proposed SPE sensors exhibited the good stability, repeatability and reproducibility that are crucial for on-site real sample detection and validation. [ABSTRACT FROM AUTHOR]

There is no consistent conclusion on the impact of improving the physical accessibility of medical facilities/resources on the utilisation of medical facilities and health outcomes, which may be due to neglecting the role of spatial cognition of physical facilities, which will be directly related to health behaviour and outcomes. This article uses China Migrants Dynamic Survey to examine the relationship between perceived accessibility of medical facilities and health and health behaviour. The results show that perceived accessibility is positively associated with health and related behaviour. The higher the perceived accessibility to the medical facilities, the better the subjective and objective health status of migrant residents. Similarly, the more positive the preventive and healthcare‐seeking behaviour is. This study suggests that public policymakers need to intervene in residents' spatial cognition of medical resources around their neighbourhoods to enhance the collective benefits of medical facilities. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

Copyright of Thiasos Monografie is the property of Edizioni Quasar di Severino Tognon s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polypyrrole (PPy) and metallic silver (Ag) particles were used as a new combination for food packaging applications. Due to numerous interesting properties offered by such materials, their use as a direct contact product in the food industry is of great interest. PPy was coated on cellulosic paper, previously extracted from carton packages of food and beverages, by an in situ chemical oxidative polymerization in the presence of two different oxidizing agents, namely iron chloride and silver nitrate. The first one, well known as a typical oxidant, led to PPy coating-doped chloride ions (PPy–Cl), while the second gives, after an electronic transfer between the monomer and silver cation, a composite containing polymer and metallic silver particles (PPy–Ag). The modification of the cellulosic paper was confirmed by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopies and scanning electron microscopy (SEM). On the other hand, the prepared materials were tested as antibacterial agents as well as sensors for toxic volatile organic compounds generally produced during food spoilage. The presence of metallic silver particles increases the antibacterial activity of our formulation compared to the system without silver. Furthermore, the significant change in the internal resistance of PPy–Ag composite when exposed to ammonia, acetone, methanol and ethanol vapors proved its high sensing properties. [ABSTRACT FROM AUTHOR]

On a global level, COVID-19 has shaken the foundations of every sector. In the South African education context, the traditional methods of teaching, learning, and managing schools changed drastically overnight and management roles and responsibilities were pushed to unprecedented levels. Moreover, the roles of middle leaders and managers took place within a more distributive framework, encouraging school leaders to adopt varying styles of leadership to cope with the demands of COVID-19. For this study, middle leaders constitute departmental heads, grade heads and subject heads. This study utilised a qualitative research design, adopting a case study approach within the interpretivist paradigm. Three departmental heads and seven post level one educators who occupy grade heads/leaders' roles in a primary school constituted the sample. Semi-structured individual interviews were conducted with participants to gain their understanding of how distributive leadership was practiced during the pandemic. Four themes emerged, namely leadership styles and factors informing the leadership behaviour and leadership growth of middle leaders and managers in schools; middle leaders' and managers' perceptions of distributive leadership and the responsibilities of the different stakeholders; the impact of COVID-19 on distributive leadership as perceived by middle leaders and managers; and the advantages and disadvantages of distributive leadership practices. The study recommends that School Management Teams (SMTs) involve middle leaders and managers to a greater degree to secure an effective 'buy-in' to the concept of distributive leadership and that middle managers offer opportunities for others to lead, by developing leadership-specific courses for them. SMTs must also ensure that individuals have a stable working environment where their psychological, sociological, and emotional needs are respected, fulfilled, and validated during any pandemic. [ABSTRACT FROM AUTHOR]

Polymers are extensively used in food and beverage packaging to shield against contaminants and external damage due to their barrier properties, protecting the goods inside and reducing waste. However, current trends in polymers for food, water, and beverage applications are moving forward into the design and preparation of advanced polymers, which can act as active packaging, bearing active ingredients in their formulation, or controlling the head-space composition to extend the shelf-life of the goods inside. In addition, polymers can serve as sensory polymers to detect and indicate the presence of target species, including contaminants of food quality indicators, or even to remove or separate target species for later quantification. Polymers are nowadays essential materials for both food safety and the extension of food shelf-life, which are key goals of the food industry, and the irruption of smart materials is opening new opportunities for going even further in these goals. This review describes the state of the art following the last 10 years of research within the field of food and beverage polymer's applications, covering present applications, perspectives, and concerns related to waste generation and the circular economy. [ABSTRACT FROM AUTHOR]

Exosomes derived from human umbilical cord mesenchymal stem cells (UMSC‐Exos) have shown encouraging effects in regulating inflammation and attenuating myocardial injury. Macrophages are regulated dynamically in response to environmental cues. However, the underlying mechanisms by which UMSC‐Exos regulate macrophage polarization are still not well understood. Herein, it is aimed to explore the effects of UMSC‐Exos on macrophage polarization and their roles in cardiac repair after myocardial infarction (MI). These results show that UMSC‐Exos improve cardiac function by increasing M2 macrophage polarization and reducing excessive inflammation. RNA‐sequencing results identify Plcb3 as a key gene involved in UMSC‐Exo‐facilitated M2 macrophage polarization. Further bioinformatic analysis identifies exosomal miR‐24‐3p as a potential effector mediating Plcb3 downregulation in macrophages. Increasing miR‐24‐3p expression in macrophages effectively enhances M2 macrophage polarization by suppressing Plcb3 expression and NF‐κB pathway activation in the inflammatory environment. Furthermore, reducing miR‐24‐3p expression in UMSC‐Exos attenuates the effects of UMSC‐Exos on M2 macrophage polarization. This study demonstrates that the cardiac therapeutic effects of UMSC‐Exos are at least partially through promoting M2 macrophage polarization in an inflammatory microenvironment. Mechanistically, exosomal miR‐24‐3p is found to inhibit Plcb3 expression and NF‐κB pathway activation to promote M2 macrophage polarization. [ABSTRACT FROM AUTHOR]

The conversion and utilization of carbon dioxide (CO2) have dual significance for reducing carbon emissions and solving energy demand. Catalytic reduction of CO2 is a promising way to convert and utilize CO2. However, high-performance catalysts with excellent catalytic activity, selectivity and stability are currently lacking. High-throughput methods offer an effective way to screen high-performance CO2 reduction catalysts. Here, recent advances in high-throughput screening of electrocatalysts for CO2 reduction are reviewed. First, the mechanism of CO2 reduction reaction by electrocatalysis and potential catalyst candidates are introduced. Second, high-throughput computational methods developed to accelerate catalyst screening are presented, such as density functional theory and machine learning. Then, high-throughput experimental methods are outlined, including experimental design, high-throughput synthesis, in situ characterization and high-throughput testing. Finally, future directions of high-throughput screening of CO2 reduction electrocatalysts are outlooked. This review will be a valuable reference for future research on high-throughput screening of CO2 electrocatalysts. [ABSTRACT FROM AUTHOR]

A series of L‐lyxo and L‐xylo‐ pentofuranose‐mimetic iminosugars and derivatives were efficiently synthesized in a stereoselective manner, through a concise strategy which involves an organocatalyzed Mannich reaction of an imine and a protected dioxanone as key step, using D‐proline as catalyst. A preliminary evaluation of their activity as potential anti‐trypanosomal agents was studied. One of the synthesized compounds showed an interesting activity against bloodstream Trypanosoma brucei brucei (EC50=3.8±1.0 μM). [ABSTRACT FROM AUTHOR]

Gas used to distend the abdomen during laparoscopic surgery is released to the external environment when trocar internal valves are opened during instrumentation. Particulate matter, including smoke pollutants and both biological and microbial materials, may be transported within the leakage gas. Here, we quantify the percentage of particulate matter that escape to the airspace and put surgical staff at risk of inhalation using a high-fidelity computational fluid dynamics model, validated with direct Schlieren observation of surgery on a porcine cadaver, to model the gas leak occurring due to the opening of 12 mm trocar valves around insertion/extraction of a 5 mm laparoscopic instrument. Fluid flow was modeled through the internal double-valved geometry of the trocar to a large external region representing the operating room (OR) space. Aerosol particles in the range 0.3–10 μm were injected into the simulation. A range of intra-abdominal pressures (IAPs) and leakage durations were studied. For gas leak durations of 0.5–1 s, at least 65% of particles reach the surgical team's breathing zone across all IAPs. A typical leak had an estimated volume of 0.476 l of CO2 meaning for a typical laparoscopic operation (averaging 51 instrument exchanges), and 24.3 l escapes via this mechanism alone. Trocar gas-leak emissions propel considerable gas and particle volumes into the OR. Reducing the IAP does not mitigate their long-range travel. This work indicates the potential for powerful computational tools like large eddy simulation to play an impactful role in the design of medical devices such as surgical trocars where complex gas dynamics occur. [ABSTRACT FROM AUTHOR]

Nanocomposite materials have acquired great importance, as have similar composite materials on a macroscopic scale, because the reinforcement complements the defects in the properties of the matrix, thus obtaining materials with better mechanical, thermal, and electrical properties, among others. At the same time, the importance and research of polymeric nanocomposites reinforced with nanoparticles of various types have grown. Among those that have stood out the most in the electronics industry are polymeric matrices reinforced with nanoparticles that present dual behavior, that is, both magnetic and semiconductor. This property has been very well used in developing electronic devices such as televisions, computers, and smartphones, which are part of everyday life. In this sense, this review presents a compilation of the synthetic methods to produce polymer nanocomposites with dual magnetic and semiconductor behavior and their potential applications within electronic fields and new relevant trends. [ABSTRACT FROM AUTHOR]

Tree diversity inventories were undertaken. The goal of this study was to understand changes in tree community dynamics that may result from common anthropogenic disturbances at the Reserva Los Cedros, a tropical montane cloud forest reserve in northern Andean Ecuador. The reserve shows extremely high alpha and beta tree diversity. We found that all primary forest sites, regardless of age of natural gaps, are quite ecologically resilient, appearing to return to a primary-forest-type community of trees following gap formation. In contrast, forests regenerating from anthropogenic disturbance appear to have multiple possible ecological states. Where anthropogenic disturbance was intense, novel tree communities appear to be assembling, with no indication of return to a primary forest state. Even in ancient primary forests, new forest types may be forming, as we found that seedling community composition did not resemble adult tree communities. We also suggest small watersheds as a useful basic spatial unit for understanding biodiversity patterns in the tropical Andes that confound more traditional Euclidean distance as a basic proxy of dissimilarity. Finally, we highlight the conservation value of Reserva Los Cedros, which has managed to reverse deforestation within its boundaries despite a general trend of extensive deforestation in the surrounding region, to protect a large, contiguous area of highly endangered Andean primary cloud forest. [ABSTRACT FROM AUTHOR]

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Summary: In this work, metal‐organic frameworks (MOFs), known as porous carbon, organic ligands, and crystalline materials have been reviewed as it consists of excellent properties, including high surface area, porosity, functional consistency, and uniform structure. The structural of MOFs, including secondary building units, open metal sites, pore sizes, functional materials, and development of MOF have been extensively studied as it helps to conduct electricity and promising good efficiency. To improve the performance in fuel cell applications, especially in catalytic activity such as oxygen reduction reaction and proton exchange membrane, the combination of MOF and other materials such as MOF/carbon material composites, MOF/metal nanoparticles (NPs), and MOF/biocomposites has been discussed in details, which can increase the potential and efficiency of catalysts. MOF‐derivatives, including MOF‐derived porous carbon, MOF‐derived NPs, MOF‐derived metal oxides, and MOF‐derived metal phosphide, has been provided in this review as it has its advantages; (a) increase the mass density of active sites, (b) increase intrinsic activity of active sites, (c) increase electrocatalyst conductivity (d), and accelerate electron transfer. Hence, it can produce materials with high thermal and chemical stability, embracing metal sites, and efficiency in active sites. These advantages have made the MOF a promising material to increase efficiency in fuel cell application and attract interest to further expand in other fields in the future. [ABSTRACT FROM AUTHOR]

Developing and/or modifying fundamental chemical reactions using chemical industry-favorite heterogeneous recoverable catalytic systems in the water solvent is very important. In this paper, we developed convenient, green, and efficient approaches for the chemoselective reduction of nitroarenes, N-acetylation of arylamines, and one-pot reductive acetylation of nitroarenes in the presence of the recoverable heterogeneous carbon-supported palladium (Pd/C) catalytic system in water. The utilize of the simple, effective, and recoverable catalyst and also using of water as an entirely green solvent along with relatively short reaction times and good-to-excellent yields of the desired products are some of the noticeable features of the presented synthetic protocols. [ABSTRACT FROM AUTHOR]

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The generation of methane fuel using surplus renewable energy with CO 2 as the carbon source enables both the decarbonization and substitution of fossil fuel feedstocks. However, high temperatures are usually required for the efficient activation of CO 2 . Here we present a solid catalyst synthesized using a mild, green hydrothermal synthesis that involves interstitial carbon doped into ruthenium oxide, which enables the stabilization of Ru cations in a low oxidation state and a ruthenium oxycarbonate phase to form. The catalyst shows an activity and selectivity for the conversion of CO 2 into methane at lower temperatures than those of conventional catalysts, with an excellent long-term stability. Furthermore, this catalyst is able to operate under intermittent power supply conditions, which couples very well with electricity production systems based on renewable energies. The structure of the catalyst and the nature of the ruthenium species were acutely characterized by combining advanced imaging and spectroscopic tools at the macro and atomic scales, which highlighted the low-oxidation-state Ru sites (Ru n+ , 0 < n < 4) as responsible for the high catalytic activity. This catalyst suggests alternative perspectives for materials design using interstitial dopants., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)