3D printing for space food applications: Advancements, challenges, and prospects.

Space foods closely associate with the performance and mental health of astronauts. Over the years, a range of manufacturing technologies have been explored and advancements in food 3D printing can provide answers to certain existing challenges and revolutionize the way foods are prepared for space exploration missions. Apart from the nutrition and satiety perspective, product shelf-life, variety, personalization, and the need for customized diets are critical considerations. In such long-duration human-crewed space missions, under microgravity conditions and exposure to space, psychological factors heavily affect food consumption patterns. Therefore, there has been a surge in research funding for developing products and methods that offer safe, nutritionally balanced, and delightful food options. 3D food printing could be a creative solution for such requirements. While multiple challenges must be addressed, the technology promises waste minimization and the scope for on-site on-demand food preparation. This article begins with fundamental concepts of this subject, provides a timeline of the advancements in the field, and details the futuristic prospects of the technology for long-duration space missions.

Avenues for non-conventional robotics technology applications in the food industry.

Robots in manufacturing alleviate hazardous environmental conditions, reduce the physical/mental stress of the workers, maintain high precision for repetitive movements, reduce errors, speed up production, and minimize production costs. Although robots have pervaded many industrial sectors and domestic environments, the experiments in the food sectors are limited to pick-and-place operations and meat processing while we are assisting new attention in gastronomy. Given the great performances of the robots, there would be many other intriguing applications to explore which could usher the transition to precision food manufacturing. This review wants open thoughts and opinions on the use of robots in different food operations. First, we reviewed the recent advances in common applications - e.g. novel sensors, end-effectors, and robotic cutting. Then, we analyzed the use of robots in other operations such as cleaning, mixing/kneading, dough manipulation, precision dosing/cooking, and additive manufacturing. Finally, the most recent improvements of robotics in gastronomy with their use in restaurants/bars and domestic environments, are examined. The comprehensive analyses and the critical discussion highlighted the needs of further scientific understanding and exploitation activities aimed to fill the gap between the laboratory-scale results and the validation in the relevant environment.

Density Functional Theory Approximations and Experimental Investigations on Co1-xMoxTe2 Alloy Electrocatalysts Tuning the Overall Water Splitting Reactions.

Understanding the relationship between electronic structure, surface characteristic, and reaction process of a catalyst helps to architect proficient electrodes for sustainable energy development. The highly active and stable catalysts made of earth-abundant materials provide a great endeavor toward green hydrogen production. Herein, we assembled the Co1-xMoxTe (x = 0-1) nanoarray structures into a bifunctional electrocatalyst to achieve high-performance hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) kinetics under alkaline conditions. The designed Co0.75Mo0.25Te and Co0.50Mo0.50 electrocatalysts require minimum overpotential and Tafel slope for high-efficacy HER and OER, respectively. Furthermore, we constructed a Co0.50Mo0.50Te2∥Co0.50Mo0.50Te2 device for overall water splitting with an overpotential of 1.39 V to achieve a current density of 10 mA cm-2, which is superior to noble electrocatalyst performance, with stable reaction throughout the 50 h continuous process. Density functional theory approximations and Gibbs free energy calculations validate the enhanced water splitting reaction catalyzed by the Co0.50Mo0.50Te2 nanoarrays. The partial replacement of Co atoms with Mo atoms in the Co0.50Mo0.50Te2 structure substantially enhances the water electrolysis kinetics through the synergistic effects between the combined metal atoms and the bonded chalcogen.

Silkworm Protein-Derived Nitrogen-Doped Carbon-Coated Li[Ni0.8Co0.15Al0.05]O2 for Lithium-Ion Batteries.

Li[Ni0.8Co0.15Al0.05]O2 (NCA) is a cathode material for lithium-ion batteries and has high power density and capacity. However, this material has disadvantages such as structural instability and short lifespan. To address these issues, herein, we explore the impact of N-doped carbon wrapping on NCA. Sericin, an easily obtained carbon- and nitrogen-rich component of silk cocoons, is utilized as the precursor material. The electrochemical performance evaluation of N-doped carbon-coated NCA shows that the capacity retention of 0.3 NC@NCA at 1C current density is 69.83% after 200 cycles, which is about 19% higher than the 50.65% capacity retention of bare NCA. The results reveal that the sericin-resultant N-doped carbon surface wrapping improves the cycling stability of NC@NCA.

Unveiling the Redox Electrochemistry of MOF-Derived fcc-NiCo@GC Polyhedron as an Advanced Electrode Material for Boosting Specific Energy of the Supercapattery.

Metal organic frameworks (MOFs), which constitute a new class of porous organic-inorganic hybrid materials, have gained considerable attention in the fields of electrochemical energy storage and conversion devices owing to their open topological structures, large surface areas, tunable morphologies, and extreme redox activity. A synthesis protocol that comprises coprecipitation followed by controlled calcination processes to design a battery-type electrode is used. This electrode consists of three-dimensional (3D), ant cave-like polyhedrons of nickel-cobalt alloy on graphitic carbon (GC; NiCo@GC) nanostructures; trimesic acid is used as a potential MOF-linker. The developed NiCo@GC sample exhibits mesoporous characteristics with the maximum surface area of 94.08 m2 g-1 at 77 K. In addition, the redox activity at different sweep rates reveals the battery-type charge storage behavior of the NiCo@GC electrode; its three-electrode assembly provides 444 C g-1 specific capacity at 2 A g-1 with long-term capacity retention. The constructed supercapattery (SC) devices (i.e., AC//NiCo@GC) achieved capacity, specific energy, and specific power are 74.3 mAh g-1 , 39.5 Wh kg-1 , and 665 W kg-1 , respectively. Owing to its reasonable electrochemical characteristics, the prepared NiCo@GC material is a promising candidate for supercapattery electrodes for portable electronic devices.

Bifunctional iron molybdate as highly effective heterogeneous electro-Fenton catalyst and Li-ion battery anode.

Three-dimensional materials have attracted considerable interest in energy and environmental remediation fields. Iron molybdate (FMO) materials have prepared via a facile hydrothermal technique with glycerol assistance, and their structural and chemical composition confirmed using various physico-chemical techniques. The prepared bi-functional material is a strong candidate for energy storage and electrocatalytic degradation of Methylene blue and Congo red. Experimental results confirmed the synthesized FMO-10 catalyst was extremely efficient for methylene blue and Congo red breakdown, achieving 91 % and 96 % degradation in 36 h, respectively. This high catalytic activity was attributed to FMO significant visible light absorption, and reactive OH formation from H2O2 synergistically triggered by both Fe3+ and MoO42-. Prepared FMO samples demonstrated excellent potential as negative electrode material for lithium ion batteries. Electrode specific capacity initially dropped then rebounded to 1265 mAh g-1 after 100 cycles at 100 mA g-1 change rate between 0.01 and 3.0 V.

Influence of selenium precursors on the formation of iron selenide nanostructures (FeSe2): Efficient Electro-Fenton catalysts for detoxification of harmful organic dyestuffs.

In this investigation, a sequences of iron diselenide (FeSe2) nanomaterials as the competent and highly stable catalysts for the detoxification of aqueous organic dye pollutants such as Congo red (CR) and methylene blue (MB) through Electro-Fenton (EF) process using hydrogen peroxide as an initiator have been studied. The utilized selenium precursors include selenium metal, selenious acid (H2SeO3) and selenium dioxide (SeO2) which were employed for the synthesis of FeSe2 catalysts through a wet chemical strategy. It has been observed that based on the employed precursors, different morphologies ranges of the FeSe2 catalysts were obtained: microgranualr particles to nano-stick to nanoflakes. The crystalline nature and phase purity of the obtained FeSe2 catalysts were determined through XRD, Raman and HR-TEM analyses which confirmed their orthorhombic ferroselite structure. Among the prepared FeSe2 catalysts, FS-2 (using H2SeO3) displayed better porous properties as compared to other catalysts and achieved the highest surface area of 74.68 m2g-1. The narrow bandgap (0.88 eV) and fast conversion of Fe2+/Fe3+ cycle of FeSe2 led CR and MB degradation of 93.3% and 90.4%, respectively. The outcome of this study demonstrates improved catalytic properties of FeSe2 nanostructures for the efficient detoxification of hazardous and toxic effluents.

Surface modification of Ni-rich LiNi0.8Co0.1Mn0.1O2 with perovskite LaFeO3 for high voltage cathode materials.

Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) is regarded as a potential cathode material due to its higher capacity. However, the severe capacity fading which occurs above 4.2 V vs. Li/Li+ needs to be addressed to enhance the electrochemical performance. Herein, we report the surface modification of NCM811 cathodes with a perovskite material, i.e., lanthanum iron oxide (LaFeO3), which has drawn attention for various research areas due to its non-toxicity, electric conductivity, chemical stability, and low cost and systematically investigate the influence of the LaFeO3 coating on NCM811. The LaFeO3 coating layer significantly protects the cathode material from corrosion due to the HF formation and restrains the dissolution of other ions into liquid electrolyte during high voltage charge-discharge processes. Even after 80 cycles, 0.5 wt% LaFeO3-coated NCM811 cathode material shows about 13% higher cycling stability when compared to the bare NCM811 and other ratios of coated materials. Furthermore, the 0.5 wt% LaFeO3-coated NCM811 delivers excellent rate capability and demonstrates improved structural stability at 4.6 V vs. Li/Li+ under high voltage conditions with Ni-rich cathode active materials.

Chitosan complements entrapment of silicon inside nitrogen doped carbon to improve and stabilize the capacity of Li-ion batteries.

A facile strategy to entrap milled silicon (m-Si) particles using nitrogen-doped-carbon (N-C@m-Si) to overcome the dramatic volume changes in Si during intercalation of lithium ions and to improve its electronic conductivity is reported here. The only natural nitrogen containing biomaterial alkaline polysaccharide, i.e., chitosan, is used as the carbon source. Simple hydrothermal technique followed by a subsequent carbonization process is used to synthesize N-C and N-C@m-Si particles. N-C@m-Si exhibited significantly improved electrochemical performance as compared to bare m-Si, which is confirmed by the obtained discharge capacity of 942.4 mAh g-1 and columbic efficiency of 97% after 50 cycles at 0.1C rate. With regard to the N-C electrodes, the obtained discharge capacity of 485.34 mAh g-1 and columbic efficiency of 99.78%, after 50 cycles at 0.1C rate is superior to the commercial graphite electrodes. The solid electrolyte interphase (SEI) layer that formed over m-Si and N-C@m-Si electrodes is characterized using X-ray photoelectron spectroscopy. Compared to the SEI layer that formed over m-Si electrode after 10 charge-discharge cycles, the N-C@m-Si electrode had a stable lithium fluoride and carbonate species. Brief reaction mechanisms, representing the formation of different species in the SEI layer, is derived to explain its behavior during the electrochemical processes.

A peptide sequence-YSGVCHTDLHAWHGDWPLPVK [40-60]-in yeast alcohol dehydrogenase prevents the aggregation of denatured substrate proteins.

The structural and functional characteristics of a yeast alcohol dehydrogenase (ADH) peptide (YSGVCHTDLHAWHGDWPLPVK, residues 40-60) have been studied in detail. The peptide is hydrophobic in nature, binds the hydrophobic probe bis-ANS, and is mostly present in a random coil conformation. It shows chaperone-like activity by preventing dithiothreitol (DTT)-induced aggregation of insulin at 27 degrees C, oxidation-induced aggregation of gamma-crystallin at 37 degrees C, and aggregation of thermally denatured ADH and beta(L)-crystallins at 52 degrees C. However, the ADH peptide does not solubilize protein aggregates as do surfactants. Substitution of Pro for His in the ADH peptide leads to diminished anti-aggregation activity. Further, analysis of ADH incubated at 47 degrees C suggests that a significant portion of the enzyme remains as soluble inactive protein with negligible conformational change. Therefore, we propose that the residues 40-60 in native protein may be an intramolecular chaperone site of yeast ADH.

Effect of trifluoroethanol on the structural and functional properties of alpha-crystallin.

Alpha crystallin is an eye lens protein with a molecular weight of approximately 800 kDa. It belongs to the class of small heat shock proteins. Besides its structural role, it is known to prevent the aggregation of beta- and gamma-crystallins and several other proteins under denaturing conditions and is thus believed to play an important role in maintaining lens transparency. In this communication, we have investigated the effect of 2,2,2-trifluoroethanol (TFE) on the structural and functional features of the native alpha-crystallin and its two constituent subunits. A conformational change occurs from the characteristic beta-sheet to the alpha-helix structure in both native alpha-crystallin and its subunits with the increase in TFE levels. Among the two subunits, alphaA-crystallin is relatively stable and upon preincubation prevents the characteristic aggregation of alphaB-crystallin at 20% and 30% (v/v) TFE. The hydrophobicity and chaperone-like activity of the crystallin subunits decrease on TFE treatment. The ability of alphaA-crystallin to bind and prevent the aggregation of alphaB-crystallin, despite a conformational change, could be important in protecting the lens from external stress. The loss in chaperone activity of alphaA-crystallin exposed to TFE and the inability of peptide chaperone--the functional site of alphaA-crystallin--to stabilize alphaB-crystallin at 20-30% TFE suggest that the site(s) involved in subunit interaction and chaperone-like function are quite distinct.

Phe71 is essential for chaperone-like function in alpha A-crystallin.

Experiments with mini-alphaA-crystallin (KFVIFLDVKHFSPEDLTVK) showed that Phe(71) in alphaA-crystallin could be essential for the chaperone-like action of the protein (Sharma, K. K., Kumar, R. S., Kumar, G. S., and Quinn, P. T. (2000) J. Biol. Chem. 275, 3767-3771). In the present study we replaced Phe(71) in rat alphaA-crystallin with Gly by site-directed mutagenesis and then compared the structural and functional properties of the mutant protein with the wild-type protein. There were no differences in molecular size or intrinsic tryptophan fluorescence between the proteins. However, 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid interaction indicated a higher hydrophobicity for the mutant protein. Both wild-type and mutant proteins displayed similar secondary structure during far UV CD experiments. Near UV CD signal showed a slight difference in the tertiary structure around the 285-295 region for the two proteins. The mutant protein was totally inactive in suppressing the aggregation of reduced insulin, heat-denatured citrate synthase, and alcohol dehydrogenase. However, a marginal suppression of beta(L)-crystallin aggregation was observed when mutant alphaA-crystallin was included. These results suggest that Phe(71) contributes to the chaperone-like action of alphaA-crystallin. Therefore we conclude that the 70-88-region in alphaA-crystallin, identified by us earlier, is the functional chaperone site in alphaA-crystallin.

Analysis of alpha-crystallin chaperone function using restriction enzymes and citrate synthase.

PURPOSE: To compare the abilities of [alpha]A-crystallin, [alpha]B-crystallin, and mini-[alpha]A-crystallin (a synthetic peptide chaperone representing the functional unit of [alpha]A-crystallin) to protect against heat-induced inactivation of citrate synthase (CS) and restriction enzymes, SmaI and NdeI. METHODS: Restriction enzymes, SmaI and NdeI were heated at different temperatures in the presence of various amounts of molecular chaperones and tested for their ability to cleave plasmid DNA. The aggregation of CS was measured at 43 degrees C while the loss in activity was monitored at 37 degrees C in the presence of various crystallins. RESULTS: Restriction enzyme activities were protected by the crystallin subunits up to 37 degrees C for SmaI and 43 degrees C for NdeI. However, the mini-[alpha]A-crystallin was unable to protect endonuclease activity. The crystallin subunits and the peptide chaperone were able to suppress thermal aggregation of CS at 43 degrees C, but failed to stabilize its activity at 37 degrees C. CONCLUSIONS: The ability of [alpha]-crystallin subunits to stabilize denaturing proteins varies from enzyme to enzyme as evidenced by the inactivation of CS and protection of SmaI and NdeI activity in the presence of [alpha]-crystallin subunits. Additionally, our results show that there could be more than one site in [alpha]A-crystallin responsible for its chaperone-like action. By addition of crystallin subunits to restriction enzymes prior to or during storage, transport, or assay would maintain or improve their activity thereby decreasing their cost.

In vitro sequestration of two organophosphorus homologs by the rat liver.

Bromophos (Bp) and ethylbromophos (EBp) are two structurally homologous organophosphorus insecticides (OP) which show a 24-fold difference in their toxicity to the laboratory rat (LD50--2215 and 91 mg/kg b.w., respectively). The role of rat liver in the sequestration of the OP oxons was studied based on carboxylesterase (CaE) inhibition in vitro. Bromoxon (Bo) and ethylbromoxon (EBo) were greater inhibitors of rat hepatic CaE than brain acetylcholinesterase (AChE) with IC50 values at nanomolar and picomolar levels, respectively. The capacity of the liver to sequester OPs was determined by measuring AChE inhibition pre-incubated with or without liver homogenate. AChE inhibition by Bo decreased with increasing concentration of liver tissue, whereas it was unaffected in the case of EBo. The results imply that liver tissue contains binding sites, which sequester Bo thereby reducing the number of OP molecules available to inhibit AChE. Although CaE inhibition leads to sequestration, other binding sites in the liver may have a significant role in determining the toxicity of OPs. Differential sequestration of the OPs by hepatic tissue, therefore, could be important in understanding the role of differential saturation of the target molecules, which has a bearing on differential toxicity.

Neurotoxicity and pattern of acetylcholinesterase inhibition in the brain regions of rat by bromophos and ethylbromophos.

Bromophos (Bp) and ethylbromophos (EBp) are two structurally homologous organophosphorus (OP) insecticides which show wide differences in their toxicity as well as neurotoxic symptoms in the laboratory rat. EBp is 24-fold more toxic (LD50 = 91 +/- 14 mg/kg body wt) than Bp (LD50 = 2218 +/- 195 mg/kg body wt) and only EBp produced characteristic tremors and lacrimation. In vivo cholinesterase inhibition was in the order plasma > erythrocytes > brain. Experiments with equitoxic and equimolar doses showed that EBp is a more potent anticholinesterase compound than Bp. Since IC50 values for the brain AChE were similar for both OPs, the target enzyme sensitivity was not a major factor in their differential toxicity. In vitro reactivation of serum ChE was significantly higher in the case of EBp than that of Bp. AChE in the brain regions showed differential inhibition in vivo. The brain stem AChE inhibition was least by Bp, whereas it was highest in the case of EBp. Both the OPs produced high AChE inhibition in the hippocampus. Differential inhibition of AChE in the brain regions and its consequent effects may be important factors in the differential neurotoxicity of OPs.

Differential in vivo inhibition of the foetal and maternal brain acetylcholinesterase by bromophos in the rat.

Bromophos, an organophosphorus compound, is known to cross the placental barrier. The response of the foetal brain acetylcholinesterase (AChE) to in vivo Bromophos exposure is not known. This study measured the in vivo time-course of cholinesterase (ChE) inhibition and recovery in rat maternal serum, brain, and foetal brain after administration of a single acute oral dose of Bromophos (500 mg/kg b.w.) on Day 18 of pregnancy. ChE inhibition in all tissues started as early as 2 h and reached a maximum at 16 h post-exposure. Foetal brain AChE was inhibited least and the first to recover followed by maternal brain and serum. The in vivo ID50 values for the ChE inhibition by Bromophos were 2.02, 205.0, 952.92 mg/kg b.w. and the in vitro IC50 values were 119.12, 115.17, 112.14 microM for the maternal serum, brain, and foetal brain, respectively. The IC50 values show that maternal serum, brain, and foetal brain are equisensitive to Bromophos. However, the ID50 values suggest that they have differential in vivo sensitivity to Bromophos. The foetal brain seems to be protected against the AChE inhibition by Bromophos, probably by detoxication in the maternal, placental, and foetal compartments.