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The work presented herein describes the synthesis and characterization of metal–organic frameworks (MOFs) and their application for gas separations and hydrogen storage. Metal–organic frameworks are crystalline, porous materials that offer a high degree of synthetic tunability and can be thought of as designer zeolites. With an upfront investment in material design, followed by discovery of the appropriate synthetic conditions, new materials with specific properties optimized for a target application can be realized. Herein a new framework, V2Cl2.8(btdd), is synthesized and its unprecedented properties for gas separations and hydrogen storage is described. Other frameworks are also discussed, and overall designing orbital interactions to engender specific adsorption behavior is discussed as a relatively underexplored frontier to develop adsorbents for various important use cases.Chapter 1 introduces metal–organic frameworks, highlights how bulk properties can be controlled at the molecular level, and notable examples are provided. Key concepts of adsorption, gas separations, and hydrogen storage are discussed. Emphasis is placed on the various mechanisms of gas binding and the implications for gas separations and storage applications. The limitations of adsorbents today are discussed, and some of the outstanding challenges in gas separations are outlined. The idea of expanding the functionality of adsorbents based on orbital interactions is established.Chapter 2 describes the first example of a porous material with coordinatively unsaturated vanadium(II) sites, V2Cl2.8(btdd). The material is characterized by powder X-ray diffraction (PXRD), K-edge X-ray absorption spectroscopy, infrared spectroscopy, solid-state NMR, and gas adsorption experiments. The exposed vanadium sites are capable of backbonding with industrially- relevant π-acids, such as N2. This orbital-mediated binding and high-density of binding sites gives rise to record N2 uptake capacities and importantly enables selective capture of N2 in the presence of CH4. This work expands the functionality available to adsorbents to now include the ability to discriminate gas mixtures based on π-acidities. This has immensely important implications for industrial use, as many industrial processes utilize π-acidic gases.Chapter 3 explores the hydrogen adsorption properties of V2Cl2.8(btdd). While hydrogen is a promising zero-emission transportation fuel, its implementation is limited in part by the difficulty in its storage. Current approaches require high pressures or cryogenic temperatures to reach sufficiently high storage densities. An adsorbent with an optimal binding enthalpy for ambient-temperature hydrogen storage could transform the transportation sector. In this chapter, we show that V2Cl2.8(btdd) is the first porous material that exhibits an optimal binding enthalpy, −21kJ/mol. The orbital-mediated binding, or Kubas-type complexation, is characterized by neutron diffraction, infrared spectroscopy, and electronic structure calculations. Ultimately, the pursuit of MOFs containing high densities of weakly π-basic metal sites may enable storage capacities under ambient conditions that far surpass those accessible with compressed gas storageChapter 4 details a spectrochemical walk of relevant industrial adsorbates (H2, C3H8, C2H6, CH4, CO2, N2, C3H6, and C2H4) with V2Cl2.8(btdd). Thermodynamic binding values are obtain and electronic structure calculations are used to understand orbital interactions and their contributions to binding. Notably, V2Cl2.8(btdd) exhibits a higher enthalpy for methane than ethane and propane, in contrast to traditional adsorbents with open metal sites. This surprising result is explained by the unique orbital-mediated binding as well as steric effects. Importantly, this binding mechanism establishes a new design principle to realize selective capture of methane over other paraffins. Methane binding is characterized further by high pressure gas adsorption experiments.Chapter 5 presents a perspective on oxygen-selective adsorbents for air separations. The need for small-scale, low-capital air separation units is described. Limitations of current adsorbents are discussed and molecular principles for O2 capture are highlighted. The bulk of the chapter details with key considerations for designing oxygen-selective adsorbents that can greatly outperform incumbent technologies. A thermodynamic analysis is described which is used to benchmark materials based on the ∆G of O2 binding. The importance of entropy of O2 binding and its effect on working capacities is emphasized. Promising research direction are described, and calculation results are included which substantiate some of the proposed directions.

Perovskite solar cells (PSCs) have revolutionized photovoltaic research. As a result, a certified power conversion efficiency (PCE) of 25.53% was recorded in late 2020. Although this efficiency is comparable with silicon solar cells; some issues remain partially unsolved, such as lead toxicity, instability of perovskite materials under continuous illumination, moisture and oxygen, and degradation of the metallic counter electrodes. As an alternative to tackle this last concern, carbon materials have been recently used, due to their good electrical and thermal conductivity, and chemical stability, which makes them one of the most promising materials to replace metallic counter electrodes in the fabrication of PSCs. This review highlights the recent advances of carbon-based PSCs, where the carbon electrode (CE) is the main actor. CEs have become very promising candidates for PSCs; they are mainly fabricated using a simple combination of graphite and carbon black powders embedded in a binder matrix, giving a paste that is then solution-processable, resulting in devices with improved quality stability, when compared to metallic electrodes. In this review, CE’s composition is emphasized, since it can give both, high and low-temperature processed electrodes, compatible with different device configurations. Finally, the tendencies and opportunities to use CE in PSCs devices are presented.

Regenerative medicine is used for tissue healing, replace missing organs and tissues which are affected by aging, disease, or trauma both structurally and functionally. Materials are the key component of regenerative medicine approaches because the material can imitate the native extracellular matrix of those tissues and improve both the physical behavior and the properties of new tissue. However, most of the available materials used for that purpose fail to provide adequate mechanical properties to replicate the behavior of the original tissue. Thus, most of these applications are still far from being enduring. This project aims to determine the multi-scale mechanical properties of some biopolymers with potential use in regenerative medicine. In this very first part, Dynamic Mechanical Analysis (DMA) was performed using shear mode on different type VII agarose-based biopolymers at room temperature during 10 min cycles at 1 Hz frequency. On one hand, samples of fibrine-agarose were tested, and on the other, different compositions of chitosan-agarose, while pure type VII agarose was used as control. Computed values for the storage and loss modulus and the small values for Tan delta ratio (tan δ) show that all materials become elastic, and they have a good capacity to dissipate energy per cycle of deformation. This fact means that all materials are suitable for being used as a scaffold for cell culture, a possible material for bioprinting applications and they could have potential use in regenerative medicine.

Objectives The purpose of this study was (i) to investigate whether nanocomposite poly(methyl-methacrylate)-zinc oxide nanowires (PMMA-ZnO-NWs) have C. albicans antibiofilm activity; (ii) to evaluate the interaction between components of the nanocomposites based on PMMA-ZnO-NWs by Raman spectroscopy; and (iii) to assess ultrastructural alterations. Design Sixty-eight rectangles (17 PMMA (control) and 51 PMMA–ZnO-NWs (250, 500, 1000 ppm ZnO nanowires) were fabricated. C. albicans ATCC 10231 and a C. albicans clinical strain were tested. Adherence, biofilm formation and ultrastructural alterations were assessed by transmission electron microscopy. Raman mapping images and spectra were analyzed using main component analysis. Results Nanocomposite PMMA-ZnO-NWs inhibited the formation of C. albicans biofilms 94% at 1000 ppm and 80% at 500 ppm against both C. albicans strains. PMMA-ZnO-NWs induced ultrastructural alterations, including cell wall damage and disorganization of the cytoplasmic membrane, resulting in cell lysis. Raman spectroscopy showed new vibrational modes (300–365–485–600 cm−1) for PMMA and ZnO-NW interactions. Conclusions PMMA-ZnO-NWs inhibited C. albicans dose-dependent biofilm formation and led to changes in the structures and cell membrane. Raman spectroscopy showed chemical interactions between ZnO-NWs and PMMA, as suggested by the appearance of new bands at 301 and 485 cm−1.

Lutein (L) and zeaxanthin (Z), as macular pigments, are water-insoluble, chemically unstable, and have low bioaccessibilities; they are often emulsified to overcome these limitations. This study investigated the impact of various emulsifiers (ethyl lauroyl arginate (LAE); Tween 80; and sodium dodecyl sulfate (SDS)) on the physicochemical properties and in vitro digestibilities of L/Z-fortified oil-in-water emulsions. Droplet aggregation and creaming extents were dependent on the emulsifier type. The ζ-potentials of emulsions stabilized by LAE, Tween 80, and SDS were + 87, - 26, and - 95 mV, respectively. SDS-stabilized emulsion had the smallest particles, while the particle sizes for the LAE- and Tween 80-stabilized emulsions were larger and not significantly different. The rates of L/Z degradation were sensitive to the emulsifier type and to heat, not to light. The L/Z bioaccessibility was the highest for the Tween 80 emulsion. Surfactants should therefore be carefully selected to optimize L/Z physicochemical stability and bioaccessibility in emulsions.

Chitin and its derived products have great potential in various industries, such as biomedical, pharmaceutical, food, among others, due to its biodegradability, biocompatibility, null toxicity, and...

Dinuclear complex [Co2(H2O)4(dmb)2(muc)][muc] (1) (muc = muconate; dmb = 5,5′-dimethyl-2,2′-bipyridine), was obtained by self-assembly solution reaction, under ambient conditions, and it was structurally characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction. The complex 1 crystallizes in the monoclinic system in the C2/c space group. Noticeably, the six-coordinated Co(II) centers display a distorted-trigonal prismatic configuration. This uncommon coordination geometry is attained due to the hydrogen bonding interactions of the crystalline structure of 1, yielding thus a 2D supramolecular array. Magnetic properties measurements reveal that metaprism 1 exhibits weak antiferromagnetic ordering with θ(C-W) = -14.4 K and an E2 = 0.032 cm−1 accordingly to Curie–Weiss model and Rueff phenomenological approach, respectively. Influence of the 2D supramolecular array in the distorted trigonal prismatic geometry of a dinuclear Co(II)-muconate complex exhibiting weak antiferromagnetic exchange.

The annual worldwide production of coffee exceeds 10 million tons, and more than 90% of this production is waste, including the husk. On the other hand, plastic consumption increases every year, and sustainable alternatives are necessary to decrease it. This work arises to solve these two problems, and seeks to produce products at an industrial level from polyethylene/coffee husk eco-composites. Both Low Density Polyethylene and High Density Polyethylene were used, and the amounts of coffee husk added as filler were 20 and 40 wt%. The composites were characterized by different morphological, thermal and mechanical techniques. Scanning Electron Microscopy images showed husk particles embedded in the polymer matrix, but with some gaps between the polymer and the filler, because no compatibilizer agent was used. The addition of large amounts of natural filler negatively affected the tensile strength and elongation at break, but increases eco-composites crystallinity, and hence, their Young modulus and hardness. The industrial applicability of the eco-composites was verified through the production of five different consumer products by extrusion and injection processes, using mixtures with 40 wt% coffee husks. All products were obtained without significant defects. If only 3.25 wt% of the polyethylene products produced each year in Colombia did so with the eco-composites developed in this work, all the coffee husk produced in the country would be used, and the emission of about 5.390 million m3 of greenhouse gases would be avoided.

We report on the sintering of powders of the chalcogenide perovskite BaZrS3 at low and intermediate temperatures. BaZrS3 is the most widely studied chalcogenide perovskite semiconductor. Most experimental results to-date have been made using loose powder and cold-pressed pellets (i.e. green bodies). Straightforward sintering methods to achieve dense ceramics are challenging because BaZrS3 decomposes and oxidizes in air above 550 °C. Here, we take inspiration from the cold-sintering process to develop a low-to-intermediate densification process for chalcogenide perovskites. Typical additives for cold sintering of oxides do not accelerate BaZrS3 sintering. At higher temperature, iodine is remarkably successful as an additive to accelerate densification. We achieve density up to 92% for sintering at 450 °C and 425 MPa. Our sintering process does not cause significant oxidation. Thermogravimetric measurements reveal the formation of an intergranular phase. Impedance spectroscopy measurements reveal that the bulk dielectric properties are unaffected by ball milling and subsequent sintering. Graphical abstract

In order to provide adequate fire resistance to construction materials, such as steel and wood, the use of high and low molecular weight tannins (TMw-H and TMw-L), extracted from the bark of Pinus radiata, as carbonaceous agents, was studied. The extracts were fully characterized by GPC, HPLC, and UV to determine the total amount of phenols, percentage of the monomers, and total yield. The molecular weights of both extracts varied between 2986 and 5573 Da, and they were mainly composed of catechin and taxifolin. Eco-friendly water-based formulations were obtained, without producing volatile organic compounds (VOCs), by varying the extract content between 15.5 and 37.8% w/w. The coatings, varying in thickness and substrates, were evaluated for their film-forming properties, covering power, mechanical properties, such as adhesion, embossing, abrasion, and flexibility, as well as their resistance to fire. The results indicated that good mechanical properties were obtained when using coatings containing TMw-L compared with those obtained when using TMw-H. The carbonization index (28%) and the mass loss percentage (9.35%) of the coatings containing TMw-L compared well to commercial coatings, indicating that they have excellent fire-retardant properties. However, the behavior of the TMw-H containing coatings was rather intumescent.

In this study, the relationship between the physicochemical properties of kaolin slurries and their particles produced by spray drying to obtain FCC matrices was discussed. Eight aqueous slurries were prepared with 40 wt.% solids using two types of kaolin (K1 and K2) and sodium silicate solution as the dispersant. Additionally, nitric acid at 5.0 wt.% was used to adjust the pH in the range between 6 and 8. Both kaolin sources were characterized by X-ray diffraction and scanning electron microscopy. The K2 kaolin had a higher crystallinity of kaolinite and smaller particle size in comparison with K1. Likewise, while K2 showed 4 well defined bands of hydroxyl groups in the infrared spectrum at 3688, 3666, 3653 and 3620 cm−1, the K1 IR spectrum consisted of two sharp signals at 3692 cm−1 and 3620 cm−1 and two poorly developed bands at 3666 cm−1 and 3653 cm−1. These features intimately related to their structure were shown to have an effect on the morphology of the particles obtained during the drying process; in the case of the K1 slurries, these led to the formation of microspheres, and on the contrary, from K2 slurries mushroom head shape particles were formed. Furthermore, the average diameter (D50) of the particles increased with the increase of the amount of the binder in the slurry. Thus, the results show that a less crystalline kaolin favors the formation of microspherical particles during the spray drying process that allows a better control of the FCC matrix produced to be used in in-situ zeolite Y crystallization on kaolin particles.

Actualmente el uso de la nanotecnología está revolucionando la producción agrícola. Se ha demostrado que las nanopartículas de cobre tienen un efecto en el crecimiento y desarrollo de las diferentes especies vegetales, además de operar como inductores de resistencia al estrés. El objetivo del presente trabajo fue evaluar la respuesta en el crecimiento y rendimiento, así como la activación del sistema de defensa de plantas de tomate. Los tratamientos evaluados fueron un complejo de alcohol polivinílico-quitosán-nanopartículas de cobre (PVA-Cts-nCu), otro complejo de PVA-Cts y un testigo absoluto (T0). Los tratamientos se aplicaron vía foliar en plantas de tomate bajo condiciones de invernadero. Durante el ciclo del cultivo, se determinaron variables agronómicas, y la actividad de enzimas relacionadas a la tolerancia a estrés como β-1,3 glucanasa, quitinasa y fenilalanina amonio liasa (PAL), así como la expresión del gen PR1. El complejo PVA-Cts-nCu incrementó el rendimiento, número de frutos, peso promedio de fruto, peso fresco aéreo y peso fresco de la raíz, además, promovió el sistema de defensa mediante el aumento en la actividad enzimática PAL, así como la sobreexpresión del gen PR1.

Bridging polymer design with catalyst surface science is a promising direction for tuning and optimizing electrochemical reactors that could impact long-term goals in energy and sustainability. Particularly, the interaction between inorganic catalyst surfaces and organic-based ionomers provides an avenue to both steer reaction selectivity and promote activity. Here, we studied the role of imidazolium-based ionomers for electrocatalytic CO2 reduction to CO (CO2R) on Ag surfaces and found that they produce no effect on CO2R activity yet strongly promote the competing hydrogen evolution reaction (HER). By examining the dependence of HER and CO2R rates on concentrations of CO2 and HCO3-, we developed a kinetic model that attributes HER promotion to intrinsic promotion of HCO3- reduction by imidazolium ionomers. We also show that varying the ionomer structure by changing substituents on the imidazolium ring modulates the HER promotion. This ionomer-structure dependence was analyzed via Taft steric parameters and density functional theory calculations, which suggest that steric bulk from functionalities on the imidazolium ring reduces access of the ionomer to both HCO3- and the Ag surface, thus limiting the promotional effect. Our results help develop design rules for ionomer-catalyst interactions in CO2R and motivate further work into precisely uncovering the interplay between primary and secondary coordination in determining electrocatalytic behavior.

Thermal conductivity is an essential property to understand the rate of charging/discharging of thermal energy storage systems, but there is still a lack of experimental studies in this field. The temperature dependence of thermal conductivity of eutectic mixtures capric/myristic acid (CA/MA), lauric/myristic acid (LA/MA), and palmitic/stearic acid (PA/SA), as well as their respective shape-stabilized forms (SSPCMs), were measured by the hot wire technique. Thermal conductivity presented a linear correlation with temperature for all the materials. Besides, the thermal conductivity of the samples was compared with a commercial SS-PCM finding out that the SS-PCMs produced by the authors exhibit higher thermal conductivity than the commercial sample, with an increase between 10.57% and 33.33%. In addition, the minerals that comprise the clay were acquired and their effect on the thermal conductivity on the support studied. Between the crystalline phases, kaolin governed the thermal conductivity of the support. Afterward, kaolin additions were made, resulting in an increase of thermal conductivity between 6.49% and 17.68% of the SS-PCM. Thus, the novelty of this study relies, first, on the experimental data obtained of thermal conductivity, and second, on the study of the effect of some minerals in the overall thermal conductivity of the samples. The authors are pleased to acknowledge the financial assistance of the “Ministerio de Ciencia, Tecnología e Innovación- MINCIENCIAS” through the PhD grant 758-2016-Contract 036–2016, Universidad de Antioquia and Sumicol S.A.S. This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31 - MCIU/AEI/FEDER, UE) and by the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). The authors at the University of Lleida would like to thank the Catalan Government for the quality accreditation given to her research group GREiA (2017 SGR 1537). GREiA is a certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia programme.

Improving soil strength by physical and chemical methods is a common practice in geotechnical engineering. This study investigated the chemical stabilisation of soil with calcium oxide to modify the physical and chemical properties of clay materials — which can rapidly transform a material with poor mechanical properties into one with favourable properties for different surface working conditions and good short-, medium- and long-term geotechnical behaviours — the effects of this chemical stabilisation on the environment, and effects on the site and other regions beyond the airport construction polygon. The main advantages measured were the mitigation of the exploitation of borrow pits (27·6%), the use of natural materials from the site (81·1%) and the mitigation of the transport demand (11·1%). The analysed materials were lacustrine clay soils (cohesive soils) with low strength, high compressibility and moisture contents of 55, 100 and 170% from ex-Lake Texcoco in the basin of the Valley of Mexico. In this study, the authors performed Atterberg limits tests, compaction tests, unconfined compressive strength (UCS) tests, California bearing ratio (CBR) and expansion tests, Eades and Grim tests and quantitative chemical analyses by X-ray fluorescence and X-ray diffraction. The optimum lime contents for the analysed samples were 5 and 15%.

Silk sericin (SS) is a natural polymer widely studied in the design of biodegradable materials for cosmetic, biomedical, food, and chemical applications. This work was designed to explore the molecular and structural characteristics of SS extracted from different silk sources with different processing degrees: high-quality cocoons (NCs), defective cocoons (DCs), and raw silk yarn (Y). The last two sources have been less studied. SS solutions were obtained from each source using the high-temperature and high-pressure degumming method (HTHP). The molecular weight distribution and amino acid composition of SS extracts were determined using gel permeation chromatography (GPC) and reversed-phase chromatography (RP HPLC), respectively. SS films were formed from each solution and then characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), nuclear magnetic resonance spectroscopy (NMR), and differential scanning calorimetry (DSC). Water uptake and degradation of SS films were also evaluated. The molecular characteristics of SS extracts were related to the processing degree of the silk source. Moreover, the properties of SS films seemed to be dominated by the primary structure and the presence of natural impurities in each extract. The results suggest that silk sources could be selected ad hoc to design SS materials with distinctive properties for specific applications. Three different silk sources were explore for sericin (SS) extraction and film formation. Features of each raw material, especially the degree of processing, have remarkable effects on the primary structure and the presence of nonprotein compounds in the sericin extract. As a result, sericin films exhibited distinctive properties that seemed to be correlated with the amount of natural impurities and the molecular properties of the SS extract obtained from each raw material.

The histological structure, histochemical features, and enzymatic activity of the digestive tract of juvenile Pacific seahorse (Hippocampus ingens) are described to provide information during the cultivation of this species. Serial histological sections were stained with either hematoxylin-eosin, alcian blue-PAS, toluidine blue, Sudan black, Masson's trichome, and ninhydrin-Schiff to describe the general features and the presence of glycogen, mucopolysaccharides, lipids, muscle layers, and proteins, respectively. The enterocytes height and the mucosal villi height in the esophagus and intestines were measured. Additionally, the digestive enzymes trypsin, chymotrypsin, lipase, amylase, aminopeptidase, acid phosphatase, and alkaline phosphatase activities were recorded. The esophagus showed two distinctive regions, the anterior with numerous mucous cells secreting acid mucins and the posterior with longitudinal folds and no mucous cells. The intestine was differentiated into three regions. The anterior showed goblet cells secreting acid and neutral mucins, while the middle and posterior regions presented goblet cells secreting only acid mucins. The activity of aminopeptidase, chymotrypsin, and amylase showed low levels, while the trypsin and acid phosphatase activity levels were intermediate. Lipase and alkaline phosphatase showed the highest activities. The results point that juvenile H. ingens presents a digestive structure similar to other teleost species. The high levels of lipase suggest that juvenile H. ingens have high requirements for lipids during this stage.

Tuning bimetallic effects is a promising strategy to guide catalytic properties. However, the nature of these effects can be difficult to assess and compare due to the convolution with other factors such as the catalyst surface structure and morphology and differences in testing environments. Here, we investigate the impact of atomic-scale bimetallic effects on the electrochemical CO2 reduction performance of Cu-based catalysts by leveraging a systematic approach that unifies protocols for materials synthesis and testing and enables accurate comparisons of intrinsic catalytic activity and selectivity. We used the same physical vapor deposition method to epitaxially grow Cu(100) films decorated with a small amount of noble or base metal atoms and a combination of experimental characterization and first-principles calculations to evaluate their physicochemical and catalytic properties. The results indicate that the metal atoms segregate to under-coordinated Cu sites during physical vapor deposition, suppressing CO reduction to oxygenates and hydrocarbons and promoting competing pathways to CO, formate, and hydrogen. Leveraging these insights, we rationalize bimetallic design principles to improve catalytic selectivity for CO2 reduction to CO, formate, oxygenates, or hydrocarbons. Our study provides one of the most extensive studies on Cu bimetallics for CO2 reduction, establishing a systematic approach that is broadly applicable to research in catalyst discovery.

In situ missions of exploration require analytical methods that are capable of detecting a wide range of molecular targets in complex matrices without a priori assumptions of sample composition. Furthermore, these methods should also minimize the number of reagents needed and any sample preparation steps. We have developed a method for the detection of metabolically relevant inorganic and organic anions that is suitable for implementation on in situ spaceflight missions. Using 55 mM acetic acid, 50 mM triethylamine, and 5% glycerol, more than 21 relevant anions are separated in less than 20 minutes. The method is robust to sample ionic strength, tolerating high concentrations of background salts (up to 900 mM NaCl and 300 mM MgSO₄). This is an important feature for future missions to ocean worlds. The method was validated using a culture of Escherichia coli and with high salinity natural samples collected from Mono Lake, California.

Selective and stable production of C2 oxygenates from syngas is enabled by a phosphate-passivated mordenite catalyst used in tandem with a commercial Cu/ZnO/AlMgOx catalyst. Unmodified mordenite used in this arrangement is accompanied by substantial hydrocarbon formation and carbon deposition. Therefore, phosphate groups are used to remove or significantly reduce Bronsted acidity in mordenite by capping aluminum sites. Such groups are stable to calcination and catalyst regeneration. Trimethylphosphite is used as a phosphate precursor because it is able to enter the 12 membered-ring pores of mordenite where hydrocarbon formation occurs, but not enter the 8 membered-ring side-pockets, where methanol carbonylation occurs selectively. The catalyst was characterized using X-ray fluorescence, X-ray diffraction, and thermal gravimetric analysis. Optionally, a third bed of Cu/ZnO/AlMgO x catalyst is able to hydrodeoxygenate acetic acid to ethanol. The C2 oxygenate selectivity is over 96% and among the best reported in a single reactor with a syngas feed.

Lactic acid has a privileged position in the family of carboxylic substances due to its several applications, including the production of biodegradable polymers such as polylactic acid in recent years. Thus, it has been considered one of the top 10 biorefinery chemicals by the United States Department of Energy. Lactic acid can be obtained by chemical synthesis and fermentation. However, only the fermentative process allows the formation of a pure enantiomer, which is crucial in biopolymer production. In this context and considering a possible second-generation production of lactic acid, the aim of the study was to evaluate the enantiomer produced by 4 lactic acid bacteria and their capacity of production in MRS medium containing xylose. There was no observed xylose consumption or catabolite repression. Lactobacillus helveticus produced a racemic mixture of D(–) and L(+) lactic acid and Lactobacillus delbrueckii lactis produced mostly D(–) lactic acid. In comparison, Lactobacillus coryniformis strains presented the most expressive results, with an exclusive production of D(–) lactic acid (optical purity >99%) and high resistance to pH variation, achieving production from 18.5 to 21.0 g/L with yield of 0.95 g/g of glucose. These strains could be indicated for the second-generation D(–) lactic acid production.

Understanding the differences between reactions driven by elevated temperature or electric potential remains challenging, largely due to materials incompatibilities between thermal catalytic and electrocatalytic environments. We show that Ni, N-doped carbon (NiPACN), an electrocatalyst for the reduction of CO2 to CO (CO2 R), can also selectively catalyze thermal CO2 to CO via the reverse water gas shift (RWGS) representing a direct analogy between catalytic phenomena across the two reaction environments. Advanced characterization techniques reveal that NiPACN likely facilitates RWGS on dispersed Ni sites in agreement with CO2 R active site studies. Finally, we construct a generalized reaction driving-force that includes temperature and potential and suggest that NiPACN could facilitate faster kinetics in CO2 R relative to RWGS due to lower intrinsic barriers. This report motivates further studies that quantitatively link catalytic phenomena across disparate reaction environments.

Resumen Antecedentes: la asociación del alto consumo de carnes rojas procesadas con el cáncer colorrectal hace que los consumidores empiecen a demandar productos cárnicos con un perfil nutricional mejorado. Objetivo: diseñar una carne de hamburguesa comercializable, a base de pechuga de pollo, fuente de fibra y baja en grasa con buena aceptación por los consumidores. Materiales y métodos: con base en una formulación estándar de hamburguesa, se hicieron tres formulaciones con adición de fibra como reemplazante de grasa: F1 contenía fibra de cidra (Sechium edule); F2, de zanahoria (Daucus carota); y F3, de inulina. Se calculó la composición nutricional teórica y se realizó una prueba de aceptación por consumidores con una escala de nueve puntos. Resultados: la formulación más aceptada y con mayor contenido de fibra fue la que contenía inulina, con un puntaje de 7,7±1,4 y diferencias significativas, según la prueba T3 de Dunett, con las formulaciones F2 (p=0,001) y F1 (p=0,000), cuyos promedios de aceptación fueron similares: 6,0±2,5 puntos para F2 y 5,9±2,2 para F1 (p=0,931). Las formulaciones con fibra contenían menos grasa y calorías que la formulación control. Conclusión: es posible lograr derivados cárnicos con reducción del contenido de grasa y aporte de fibra sensorialmente aceptados. Abstract Background: The association between increased consumption of processed red meat and colorectal cancer has driven the demand for meat products with improved nutritional profiles. Objective: To design commercialized hamburger meat that contains chicken breast as the base, fiber, reduced fat, and is accepted by consumers. Materials and Methods: Three formulations were created with a standard hamburger base and additional fiber as a fat replacement: F1 contained fiber from citron (Sechium edule); F2, from carrots (Daucus carota); and F3 from inulin. The theoretical nutritional composition was calculated and a consumer acceptance test was performed on a scale of nine points. Results: The most accepted formulation by consumers with the highest fiber content was the hamburger containing inulin, rated at 7.7±1.4 points. According to the Dunett T3 test, significant differences were reached by F1 (p=0.000) and F2 (p=0.001). They also had similar acceptance averages: F1 (5.9±2.2 points; p=0,000) and F2 (6.0±2.5 points; p=0.001) (p=0.931). The formulations containing added fiber were lowest in fat and calories when compared to the control formulation. Conclusion: It is possible to achieve meat derivatives with reduced fat and added fiber that are sensorily accepted by consumers.

Upscaling perovskite solar cell fabrication is one of the key challenges in the pathway for commercialization. The slow evaporation of frequently used solvents (DMF or DMSO) limits the fast perovskite layer crystallization, hindering their implementation in large scale deposition methods. Alternatively, methylamine-based precursors have demonstrated rapid crystallization, leading to uniform and specular films. Nonetheless, their application has been limited to MAPbI3 perovskites with limited efficiency and stability. In this work, we report the requirements for stabilizing α-phase of mixed cation perovskites with high amount of formamidinium by using a methylamine-based precursor. We found that even though, there are many methods for incorporating the methylamine (MA) in precursors or films; the MA content determines stabilization of the α-phase and therefore the viscous-solution route is the only method to incorporate high amounts of MA. At low amounts of MA, perovskite tend to crystallize in 1D dimensional FA3(MA)PbI5 phases due to the incomplete solvation of the PbI6− clusters. In contrast, high MA ratio induces a full solvation of the clusters, leading to a rapid crystallization and a full stabilization of the active 3D α-phase. These results open a window in the development and understanding of new precursors for the fabrication of high efficient, stable and scalable perovskite devices.

Protein splicing is a post-translational process by which an intein catalyzes its own excision from flanking polypeptides, or exteins, concomitant with extein ligation. Many inteins have nested homing endonuclease domains that facilitate their propagation into intein-less alleles, whereas other inteins lack the homing endonuclease (HEN) and are called mini-inteins. The mini-intein that interrupts the DNA PolII of Pyrococcus horikoshii has a linker region in place of the HEN domain that is shorter than the linker in a closely related intein from Pyrococcus abyssi. The P. horikoshii PolII intein requires a higher temperature for catalytic activity and is more stable to digestion by the thermostable protease thermolysin, suggesting that it is more rigid than the P. abyssi intein. We solved a crystal structure of the intein precursor that revealed a domain-swapped dimer. Inteins found as domain swapped dimers have been shown to promote intein-mediated protein alternative splicing, but the solved P. horikoshii PolII intein structure has an active site unlikely to be catalytically competent.

The gene for galectin-13 (Gal-13, placental protein 13) is only present in primates, and its low expression level in maternal serum may promote preeclampsia. In the present study, we used pull-down experiments and biolayer interferometry to assess the interaction between Gal-13 and actin. These studies uncovered that human Gal-13 (hGal-13) and Saimiri boliviensis boliviensis (sGal-13) strongly bind to α- and β-/γ-actin, with Ca2+ and adenosine triphosphate, significantly enhancing the interactions. This in turn suggests that h/sGal-13 may inhibit myosin-induced contraction when vascular smooth muscle cells undergo polarization. Here, we solved the crystal structure of sGal-13 bound to lactose and found that it exists as a monomer in contrast to hGal-13 which is a dimer. The distribution of sGal-13 in HeLa cells is similar to that of hGal-13, indicating that monomeric Gal-13 is the primary form in cells. Even though sGal-13 binds to actin, hGal-13 ligand-binding site mutants do not influence hGal-13/actin binding, whereas the monomeric mutant C136S/C138S binds to actin more strongly than the wild-type hGal-13. Overall, our study demonstrates that monomeric Gal-13 binds to actin, an interaction that is independent of the galectin canonical ligand-binding site.

Objective: an innovative non−thermal plasma (NTP) system constituted by a radiofrequency (RF) power generator directly coupled to a treatment probe is described and characterized. This system is intended to be applied as a medical device for therapeutic treatments. Methods: electrical characterization of the radiofrequency power generator supplying the treatment probe was performed. Meanwhile, generated NTP was optically analyzed. Obtained data were studied to establish the safety profile of plasma application on heat sensitive matter. Results: the NTP system was validated through bacterial deactivation trials, as well as, of being capable of deactivating carcinogenic cells. Besides promoting and accelerating wound closure in vivo performed in mice, demonstrating faster healing than that done with conventional treatments. Conclusion: the NTP system's characterization is an essential stage to determine the adequate application of the generated plasma over organic media. The therapeutic benefits of the NTP system were proved by the development of in vivo experiences involving laboratory mice. Significance: the generated NTP interacts with surrounding air particles producing reactive oxygen and nitrogen species, which, exhibit bactericidal and antiseptic effects due to their strong biochemical reactivity; functioning like critical mediators in animal physiology and promoting wound healing processes. These properties make the NTP system a feasible technology intended for therapeutic treatments.

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The widespread implementation of H2 as a fuel is currently hindered by the high pressures or cryogenic temperatures required to achieve reasonable storage densities. In contrast, the realization of materials that strongly and reversibly adsorb hydrogen at ambient temperatures and moderate pressures could transform the transportation sector and expand adoption of fuel cells in other applications. To date, however, no adsorbent has been identified that exhibits a binding enthalpy within the optimal range of -15 to -25 kJ/mol for ambient-temperature hydrogen storage. Here, we report the hydrogen adsorption properties of the metal-organic framework (MOF) V2Cl2.8(btdd) (H2btdd, bis(1H-1,2,3-triazolo[4,5-b],[4',5'-i])dibenzo[1,4]dioxin), which features exposed vanadium(II) sites capable of backbonding with weak π acids. Significantly, gas adsorption data reveal that this material binds H2 with an enthalpy of -21 kJ/mol. This binding energy enables usable hydrogen capacities that exceed that of compressed storage under the same operating conditions. The Kubas-type vanadium(II)-dihydrogen complexation is characterized by a combination of techniques. From powder neutron diffraction data, a V-D2(centroid) distance of 1.966(8) A is obtained, the shortest yet reported for a MOF. Using in situ infrared spectroscopy, the H-H stretch was identified, and it displays a red shift of 242 cm-1. Electronic structure calculations show that a main contribution to bonding stems from the interaction between the vanadium dπ and H2 σ* orbital. Ultimately, the pursuit of MOFs containing high densities of weakly π-basic metal sites may enable storage capacities under ambient conditions that far surpass those accessible with compressed gas storage.

Introduction The habit of consuming energy drinks is a life-threatening risk, because it can produce a syndrome characterised by a muscle necrosis. This promotes the release of enzymes and myoglobin from inside the myocyte into the circulation, creating lipid peroxidation and leading to acute kidney injury, and hyperkalaemia, together producing rhabdomyolysis. Rhabdomyolysis can be expected to be found within 24–48 h after strenuous activities, even more so with a modified BORG index greater than or equal to 5 points. However, energy drinks, due to their high content of caffeine and other components, can generate this little known adverse event. Clinical case A 37-year-old patient admitted to the emergency department due to clinical symptoms of myalgia, and dark urine that appeared 24 h after four days of low-intensity muscular exercises, and was associated with daily consumption of an energizing drink for 2 years. The diagnosis of rhabdomyolysis was confirmed by increased creatine kinase and transaminases. It was not possible to measure myoglobin levels. The patient was treated with aggressive fluid therapy. He never presented with any renal or electrolyte complications. Conclusion This case highlights the appearance of acute rhabdomyolysis in patients taking low intensity exercises, and not ruling out long-term consumption of energy drinks as the main cause. There are few cases currently reported in the literature. Owing to the timely treatment, progression to acute kidney injury was avoided.

Cocos nucifera L. is a palm tree (Arecaceae) with a high economic value. The coconut husk fibers are nonedible, thick, and abrasion-resistant and correspond up to 85% of biomass discarded as solid waste residue. Therefore, the husk fibers are an underexploited byproduct with a high content of extractives of unreported nature. Two varieties of C. nucifera L. husk extracts were investigated to uncover bioactive metabolites and their possible application as a green corrosion inhibitor for carbon steel AISI 1020 under neutral pH conditions. The chemical analysis indicated 3% (w/w) of proanthocyanidins in the husk fibers with a high B-type procyanidin content. The husk fibers' crude extract showed promising results as an eco-friendly corrosion inhibitor for carbon steel AISI 1020 under neutral pH conditions. Although it formed a film on the metal surface in all tested concentrations (0.4, 0.8, 1.2, and 1.6 g L-1), the highest protective efficiency was shown at a concentration of 1.2 g L-1, determined by electrochemical techniques and mass loss. This was the first comprehensive report on coconut husk fibers' chemical composition, which was similar between the two varieties with potential for industrial application.

Thromboxane A2 receptor deficiency is a qualitative platelet disorder that partially impedes adequate platelet signaling and aggregation. Generally, these patients have mild hemorrhagic manifestations in basal conditions, but may show severe bleeding when faced with a hemostatic challenge. We present the case of a 30-year-old female patient that arrives at the Hematology service with an undiagnosed bleeding disorder. She presented hemorrhagic complications during an augmentation mammoplasty and during an exodontia procedure, yet, during a C-section she presented none. At the first consultation she had normal coagulation factor levels by coagulometry, and normal platelet aggregation test for ADP, ristocetin, collagen and epinephrine. A platelet aggregation test for arachidonic acid confirmed thromboxane A2 deficit disorder. Thromboxane A2 deficit disorder is a rare qualitative platelet disorder that requires an extensive knowledge of coagulation and platelet function and tests, and a high level of clinical suspicion. These tests are especially difficult to interpret during pregnancy due to normal modifications to bodily function during this process.

Abstract Transition metal dichalcogenides have shown great potential for next-generation electronic and optoelectronic devices. However, native oxidation remains a major issue in achieving their long-term stability, especially for Zr-containing materials such as ZrS2. Here, we develop a first principles-informed reactive forcefield for Zr/O/S to study oxidation dynamics of ZrS2. Simulation results reveal anisotropic oxidation rates between (210) and (001) surfaces. The oxidation rate is highly dependent on the initial adsorption of oxygen molecules on the surface. Simulation results also provide reaction mechanism for native oxide formation with atomistic details. Graphic Abstract

Amorphous selenium is one of the best photoconductors with a wide range of applications, from its early use in the photocopy industry to its present application in X-ray imaging. Low melting point and high vapor pressure of amorphous selenium enable uniform and economical deposition of this photoconductive material up to few millimeters thick. However, there is a tradeoff between deposition rate and film uniformity. In this article, a thermal evaporation system for amorphous selenium deposition was developed. The system geometry was simulated to determine the optimized source–substrate throw distance for uniform film thickness of amorphous selenium (a-Se) on a substrate with up to 4-in diameter. Boat and crucible source configurations of equal volume (100 cc) were tested. The film was fabricated, characterized, and the uniformity and thickness were measured and compared with simulation results.