Preservation of Bacillus subtilis' cellular liquid state at deep sub-zero temperatures in perchlorate brines.

Although a low temperature limit for life has not been established, it is thought that there exists a physical limit imposed by the onset of intracellular vitrification, typically occurring at ~-20 °C for unicellular organisms. Here, we show, through differential scanning calorimetry, that molar concentrations of magnesium perchlorate can depress the intracellular vitrification point of Bacillus subtilis cells to temperatures much lower than those previously reported. At 2.5 M Mg(ClO4)2, the peak vitrification temperature was lowered to -83 °C. Our results show that inorganic eutectic salts can in principle maintain liquid water in cells at much lower temperatures than those previously claimed as a lower limit to life, raising the prospects of active biochemical processes in low temperature natural settings. Our results may have implications for the habitability of Mars, where perchlorate salts are pervasive and potentially other terrestrial and extraterrestrial, cryosphere environments.

Analysis and electroanalysis of perchlorate in water and food samples: a critical review.

Perchlorate, ClO4-, with diverse applications, has become one of the major contaminants in surface and groundwater sources. This highly soluble and stable anion poses a considerable threat to human health given that it contaminates drinking water, vegetables, milk, and other contaminated food products. ClO4- can impair the thyroid function; thus, drinking water with high levels of this anion is a severe problem worldwide. However, due to the high solubility, stability, and mobility of ClO4-, its remediation and monitoring remain a major challenge. Considering the various analytical methods, including electrochemistry, each method has advantages and disadvantages in terms of detection sensitivity, selectivity, analysis time, and cost. Also, sample preconcentration and clean-up must be performed for the analysis of more complex matrices such as food and biological samples to ensure a low detection limit and selectivity. Both ion chromatography (IC) and capillary electrophoresis (CE) coupled with electrochemical detection, in addition to liquid chromatography (LC)-mass spectrometry (MS), are expected to play key roles due to their lower detection limit with excellent sensitivities and selectivity. Herein, we also discuss the perspective on various electrode materials for the detection of ClO4- regarding whether ClO4- can be measured at the lowest levels with the highest selectivity.

Perchlorate reduction kinetics and genome-resolved metagenomics identify metabolic interactions in acclimated saline lake perchlorate-reducing consortia.

Perchlorate is a widely detected environmental contaminant in surface and underground water, that seriously impacts human health by inhibiting the uptake of thyroidal radioiodine. Perchlorate reduction due to saline lake microorganisms is not as well understood as that in marine environments. In this study, we enriched a perchlorate-reducing microbial consortium collected from saline lake sediments and found that the perchlorate reduction kinetics of the enriched consortium fit the Michaelis-Menten kinetics well, with a maximum specific substrate reduction rate (qmax) of 0.596 ± 0.001 mg ClO4-/mg DW/h and half-saturation constant (Ks) of 16.549 ± 0.488 mg ClO4-/L. Furthermore, we used improved metagenome binning to reconstruct high-quality metagenome-assembled genomes from the metagenomes of the microbial consortia, including the perchlorate-reducing bacteria (PRB) Dechloromonas agitata and Wolinella succinogenes, with the genome of W. succinogenes harboring complete functional genes for perchlorate reduction being the first recovered. Given that the electrons were directly transferred to the electronic carrier cytochrome c-553 from the quinone pool, the electron transfer pathway of W. succinogenes was shorter and more efficient than the canonical pattern. This finding provides a theoretical basis for microbial remediation of sites contaminated by high concentrations of perchlorate. Metagenomic binning and metatranscriptomic analyses revealed the gene transcription variation of perchlorate reductase pcr and chlorite dismutase cld by PRB and the synergistic metabolic mechanism.

Accurate detection of perchlorate in epoxy resins via chlorine-35 quantitative quadrupolar NMR (qQNMR).

A qQNMR methodology using chlorine-35 as the employed quadrupolar nucleus has been introduced for the first time as a robust and validated method to determine and quantify perchlorate in epoxy resins. The quantification has been carried out by using a calibration curve of lithium perchlorate. The method was validated at seven concentration levels in the range of 0.16 to 2.0 mg mL-1 (1.6 to 20 mM in perchlorate), affording intra- and inter-day accuracies lower than 0.66% (expressed in CV), robustness towards pH, temperature, resin concentration and recycle delay, a limit of detection (LOD) of 0.08 mg mL-1 (0.8 mM in perchlorate), a limit of quantification (LOQ) of 0.16 mg mL-1 (1.6 mM in perchlorate) and probably most important in such applications, having no matrix effect. The method was applied on epoxy resins containing three different types of perchlorate precursors (lithium, potassium and tetramethylammonium), affording excellent quantifications with relative errors below 2.3% compared to the spiked concentrations.

Perchlorate removal by a combined heterotrophic and bio-electrochemical hydrogen autotrophic system.

Here, a novel combined heterotrophic and bio-electrochemical hydrogen autotrophic (CHBHA) system was developed to remove perchlorate under low chemical dosages and energy consumption. The perchlorate removal performance at various hydraulic retention times (HRTs) and acetate dosages was investigated. For influent containing 10 ± 0.10 mg/L perchlorate, the optimal removal efficiency by the CHBHA system was 98.96 ± 1.62 %, 92.99 ± 2.99 %, 97.85 ± 0.41 %, and 98.24 ± 1.56 % at different operating stages. Perchlorate was mainly removed in the heterotrophic part (H-part) at a sufficient HRT (6 h) and acetate dosage (14.75 mg/L). At other stages, perchlorate was synergistically removed by the H-part and electrochemical hydrogen autotrophic part (E-part). Since the H-part removed some perchlorate, the E-part's applied current decreased, thus reducing energy costs. The maximum current efficiency of CHBHA system was 22.09 %. Compared with the single E-part system, the combined system used 65 % less energy. Perchlorate was converted into active chlorine in the E-part, which improved the effluent quality. The bacterial community structures of the two parts were significantly different. Comamonas, Dechloromonas, Acinetobacter, and Chryseobacterium were enriched in the H-part, and the dominant genera in the E-part were Thauera, Azonexus, Hydrogenophaga, and Tissierella.

Screening the Survival of Cyanobacteria Under Perchlorate Stress. Potential Implications for Mars In Situ Resource Utilization.

Cyanobacteria are good candidates for various martian applications as a potential source of food, fertilizer, oxygen, and biofuels. However, the increased levels of highly toxic perchlorates may be a significant obstacle to their growth on Mars. Therefore, in the present study, 17 cyanobacteria strains that belong to Chroococcales, Chroococcidiopsidales, Nostocales, Oscillatoriales, Pleurocapsales, and Synechococcales were exposed to 0.25-1.0% magnesium perchlorate concentrations (1.5-6.0 mM ClO4- ions) for 14 days. The exposure to perchlorate induced at least partial inhibition of growth in all tested strains, although five of them were able to grow at the highest perchlorate concentration: Chroococcidiopsis thermalis, Leptolyngbya foveolarum, Arthronema africanum, Geitlerinema cf. acuminatum, and Cephalothrix komarekiana. Chroococcidiopsis sp. Chroococcidiopsis cubana demonstrated growth up to 0.5%. Strains that maintained growth displayed significantly increased malondialdehyde content, indicating perchlorate-induced oxidative stress, whereas the chlorophyll a/carotenoids ratio tended to be decreased. The results show that selected cyanobacteria from different orders can tolerate perchlorate concentrations typical for the martian regolith, indicating that they may be useful in Mars exploration. Further studies are required to elucidate the biochemical and molecular basis for the perchlorate tolerance in selected cyanobacteria.

Temperature-Induced Change of Water Structure in Aqueous Solutions of Some Kosmotropic and Chaotropic Salts.

The hydrogen bond structure of water was examined by comparing the temperature dependent OH-stretching bands of water and aqueous NaClO4, KClO4, Na2SO4, and K2SO4 solutions. Results called attention to the role of cations on top of the importance of anions determining the emerging structure of a multi-layered system consisting single water rings or multi-ring water-clusters.

Structural responses of model biomembranes to Mars-relevant salts.

Lipid membranes are a key component of contemporary living systems and are thought to have been essential to the origin of life. Most research on membranes has focused on situations restricted to ambient physiological or benchtop conditions. However, the influence of more extreme conditions, such as the deep subsurface on Earth or extraterrestrial environments are less well understood. The deep subsurface environments of Mars, for instance, may harbor high concentrations of chaotropic salts in brines, yet we know little about how these conditions would influence the habitability of such environments for cellular life. Here, we investigated the combined effects of high concentrations of salts, including sodium and magnesium perchlorate and sulfate, and high hydrostatic pressure on the stability and structure of model biomembranes of varying complexity. To this end, a variety of biophysical techniques have been applied, which include calorimetry, fluorescence spectroscopies, small-angle X-ray scattering, dynamic light scattering, and microscopy techniques. We show that the structure and phase behavior of lipid membranes is sensitively dictated by the nature of the salt, in particular its anion and its concentration. We demonstrate that, with the exception of magnesium perchlorate, which can also induce cubic lipid arrangements, long-chain saturated lipid bilayer structures can still persist at high salt concentrations across a range of pressures. The lateral organization of complex heterogeneous raft-like membranes is affected by all salts. For simple, in particular bacterial membrane-type bilayer systems with unsaturated chains, vesicular structures are still stable at Martian brine conditions, also up to the kbar pressure range, demonstrating the potential compatibility of environments containing such ionic and pressure extremes to lipid-encapsulated life.

Sustainable Triazine-Based Dehydro-Condensation Agents for Amide Synthesis.

Conventional methods employed today for the synthesis of amides often lack of economic and environmental sustainability. Triazine-derived quaternary ammonium salts, e.g., 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM(Cl)), emerged as promising dehydro-condensation agents for amide synthesis, although suffering of limited stability and high costs. In the present work, a simple protocol for the synthesis of amides mediated by 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and a tert-amine has been described and data are compared to DMTMM(Cl) and other CDMT-derived quaternary ammonium salts (DMT-Ams(X), X: Cl- or ClO4-). Different tert-amines (Ams) were tested for the synthesis of various DMT-Ams(Cl), but only DMTMM(Cl) could be isolated and employed for dehydro-condensation reactions, while all CDMT/tert-amine systems tested were efficient as dehydro-condensation agents. Interestingly, in best reaction conditions, CDMT and 1,4-dimethylpiperazine gave N-phenethyl benzamide in 93% yield in 15 min, with up to half the amount of tert-amine consumption. The efficiency of CDMT/tert-amine was further compared to more stable triazine quaternary ammonium salts having a perchlorate counter anion (DMT-Ams(ClO4)). Overall CDMT/tert-amine systems appear to be a viable and more economical alternative to most dehydro-condensation agents employed today.

Synthesis of a Series of Dual-Functional Chelated Titanate Bonding Agents and Their Application Performances in Composite Solid Propellants.

Titanate-based bonding agents are a class of efficient bonding agents for improving the mechanical properties of composite solid propellants, a kind of special composite material. However, high solid contents often deteriorate the rheological properties of propellant slurry, which limits the application of bonding agents. To solve this problem, a series of long-chain alkyl chelated titanate binders, N-n-octyl-N, N-dihydroxyethyl-lactic acid-titanate (DLT-8), N-n-dodecyl-N, N-dihydroxyethyl-lactic acid-titanate (DLT-12), N-n-hexadecyl-N, N-Dihydroxyethyl-lactic acid-titanate (DLT-16), were designed and synthesized in the present work. The infrared absorption spectral changes of solid propellants caused by binder coating and adhesion degrees of the bonding agents on the oxidant surface were determined by micro-infrared microscopy (MIR) and X-ray photoelectron spectroscopy (XPS), respectively, to characterize the interaction properties of the bonding agents with oxidants, ammonium perchlorate (AP) and hexogen (RDX), in solid propellants. The further application tests suggest that the bonding agents can effectively interact with the oxidants and effectively improve the mechanical and rheological properties of the four-component hydroxyl-terminated polybutadiene (HTPB) composite solid propellants containing AP and RDX. The agent with longer bond chain length can improve the rheological properties of the propellant slurry more significantly, and the propellant of the best mechanical properties was obtained with DLT-12, consistent with the conclusion obtained in the interfacial interaction study. Our work has provided a new method for simultaneously improving the processing performance and rheological properties of propellants and offered an important guidance for the bonding agent design.

CeIV - and HClO4 -Promoted Assembly of an Fe2IV (µ-O)2 Diamond Core from its Monomeric FeIV =O Precursor at Room Temperature.

Diiron(IV)-oxo species are proposed to effect the cleavage of strong C-H bonds by nonheme diiron enzymes such as soluble methane monooxygenase (sMMO) and fatty acid desaturases. However, synthetic mimics of such diiron(IV) oxidants are rare. Herein we report the reaction of (TPA*)FeII (1) (TPA*=tris(3,5-dimethyl-4-methoxypyridyl-2-methyl)amine) in CH3 CN with 4 equiv CAN and 200 equiv HClO4 at 20 °C to form a complex with an [FeIV2 (µ-O)2 ]4+ core. CAN and HClO4 play essential roles in this unprecedented transformation, in which the comproportionation of FeIII -O-CeIV and FeIV =O/Ce4+ species is proposed to be involved in the assembly of the [FeIV2 (µ-O)2 ]4+ core.

Can Halophilic and Psychrophilic Microorganisms Modify the Freezing/Melting Curve of Cold Salty Solutions? Implications for Mars Habitability.

We present the hypothesis that microorganisms can change the freezing/melting curve of cold salty solutions by protein expression, as it is known that proteins can affect the liquid-to-ice transition, an ability that could be of ecological advantage for organisms on Earth and on Mars. We tested our hypothesis by identifying a suitable candidate, the well-known psycrophile and halotolerant bacteria Rhodococcus sp. JG3, and analyzing its response in culture conditions that included specific hygroscopic salts relevant to Mars-that is, highly concentrated magnesium perchlorate solutions of 20 wt % and 50 wt % Mg(ClO4)2 at both end members of the eutectic concentration (44 wt %)-and subfreezing temperatures (263 K and 253 K). Using a combination of techniques of molecular microbiology and aqueous geochemistry, we evaluated the potential roles of proteins over- or underexpressed as important players in different mechanisms for the adaptability of life to cold environments. We recorded the changes observed by micro-differential scanning calorimetry. Unfortunately, Rhodococcus sp. JG3 did not show our hypothesized effect on the melting characteristics of cold Mg-perchlorate solutions. However, the question remains as to whether our novel hypothesis that halophilic/psychrophilic bacteria or archaea can alter the freezing/melting curve of salt solutions could be validated. The null result obtained after analyzing just one case lays the foundation to continue the search for proteins produced by microorganisms that thrive in very cold, high-saline solutions, which would involve testing different microorganisms with different salt components. The immediate implications for the habitability of Mars are discussed.

Reactivity trends of cobalt(III) complexes towards various amino acids based on the properties of the amino acid alkyl chains.

The reactivity of the cobalt(III) complexes dichlorido[tris(2-aminoethyl)amine]cobalt(III) chloride, [CoCl2(tren)]Cl, and dichlorido(triethylenetetramine)cobalt(III) chloride, [CoCl2(trien)]Cl, towards different amino acids (L-proline, L-asparagine, L-histidine and L-aspartic acid) was explored in detail. This study presents the crystal structures of three amino acidate cobalt(III) complexes, namely, (L-prolinato-κ2N,O)[tris(2-aminoethyl)amine-κ4N,N',N'',N''']cobalt(III) diiodide monohydrate, [Co(C5H8NO2)(C6H18N4)]I2·H2O, I, (L-asparaginato-κ2N,O)[tris(2-aminoethyl)amine-κ4N,N',N'',N''']cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), II, and (L-prolinato-κ2N,O)(triethylenetetramine-κ4N,N',N'',N''')cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), V. The syntheses of the complexes were followed by characterization using UV-Vis spectroscopy of the reaction mixtures and the initial rates of reaction were obtained by calculating the slopes of absorbance versus time plots. The initial rates suggest a stronger reactivity and hence greater affinity of the cobalt(III) complexes towards basic amino acids. The biocompatibility of the complexes was also assessed by evaluating the cytotoxicity of the complexes on cultured normal human fibroblast cells (WS1) in vitro. The compounds were found to be nontoxic after 24 h of incubation at concentrations up to 25 mM.

Study on the bioaccessibility and bioavailability of perchlorate in different food matrices in vitro.

Perchlorate, a persistent pollutant, interferes with iodine uptake by the thyroid. Perchlorate exposure mainly occurs through ingested food; understanding the bioaccessibility and bioavailability of perchlorate in foods facilitate more accurate human health risk assessments. An in vitro digestion/Caco-2 cell model was used for this research. The bioaccessibility of perchlorate in the control group, lettuce, rice and formula was 93.45%, 70.14%, 70.25%, and 63.68%, respectively. The bioavailability of perchlorate was as follows: control group, 43.45%; rice, 37.17%; lettuce, 35.13%; and formula, 30.72%. The absorptive apparent permeability coefficient (Papp) of the control, lettuce, rice, and formula was 30-101 nm/s, 32-65 nm/s, 54-161 nm/s, and 41-88 nm/s, respectively. The results suggested that the risk from perchlorate was overestimated only when considering the content of perchlorate in foods and that the presence of food matrices reduced perchlorate bioavailability by differing degrees.

Development of a Biocompatible Solid Phase Microextraction Thin Film Coating for the Sampling and Enrichment of Peptides.

While currently available methods for peptide sample preparation are mostly suitable for ex situ analysis via exhaustive extraction techniques, these techniques do not allow for in situ extraction of peptides from biological samples, such as blood or plasma collected from patients for routine clinical applications. Biocompatible solid phase microextraction (Bio-SPME) has shown great potential in metabolomics for in situ extraction of metabolites including labile compounds from biological matrices in a biocompatible and non-exhaustive fashion, thus facilitating even in vivo sampling. However, the amounts of peptides extracted by such Bio-SPME chemical biopsy tools are deemed too low for quantification when porous polyacrylonitrile (PAN)-based biocompatible thin film sorbent coatings are used, since such materials have been commonly applied as means to restrict access of high molecular weight compounds such as proteins. Aiming to improve peptide extraction by the SPME sorbent while still preventing protein adsorption, thin films with nanoscale irregularities and mesopores were prepared by inclusion of the porogen lithium perchlorate in the slurries of the coatings. The novel thin film coating method significantly improved extraction of a range of angiotensins known to possess important roles in blood pressure regulation and electrolyte balance. Model low abundance peptides covering a wide range of hydrophobicities were successfully extracted from physiological buffers and human plasma using the increased porosity coating, while the SPME protocol on the tryptic digestion of a protein supported that enzymes were excluded during peptide extraction. Surface rheological analysis, which displayed mesopores on the C18/PAN coatings, confirmed that the porosity of the coating facilitated the mass transport of peptides through the PAN layer, thus enabling extraction of high amounts of peptides by the new C18/PAN coating.

Detection of fuel-oxidizer explosives utilizing portable capillary electrophoresis with wipe-based sampling.

Portable analytical instrumentation that can provide an alarm indication for the presence of explosives and related components is critical for the identification of explosives-based hazards and threats. Many explosives incident reports involve an inorganic oxidizer-fuel mixture which can include pyrotechnics, fireworks, flash powders, black powders, black powder substitutes, and improvised or homemade explosives. A portable CE instrument with targeted analysis of common inorganic oxidizer ions, for example, chlorate, perchlorate, and nitrate, was used here as a rapid detection platform. Unlike frequently used gas-phase separation and detection instrumentation such as ion mobility spectrometry (IMS), an automated liquid extraction mechanism is required for CE separation using acetate paper sample collection wipes. Target inorganic oxidizers were inkjet-printed onto sample wipes to investigate instrument response relative to the collected analyte spatial distribution. Overall, analyte signal intensities increased with off-center sample deposition due to improved sample extraction from wipes and no change in response was observed for varied array distributions across wipes. The system demonstrated sub 200 ng detection limits for all target analytes, with further improvement when normalizing to an internal standard.

Occurrence of perchlorate, chlorate and polar herbicides in different baby food commodities.

The incidence of endocrine disruptors, both possible (glyphosate and glufosinate), and demonstrated (perchlorate and chlorate), was estimated in baby food commodities (meat, fish, cheese, vegetable and fruit). Ion-chromatography coupled to high resolution mass spectrometry analysis of the 105 samples did not show traces of glyphosate, glufosinate or their metabolites, while in 10.5% of the samples a quantifiable amount of perchlorate was found. Some samples based on fruit and vegetables revealed a substantial amount of chlorate, especially the preparations that contained carrots and potatoes: five samples were in a concentration range of 40-120 µg kg-1, while one homogenized pear sample reached 372.2 µg kg-1. The pure meat samples revealed occasional chlorate appearance, with less than 10 µg kg-1. This is the first report of chlorate evaluated in various types of baby food and may serve as symptomatic data regarding its occurrence in infant/toddler diets. Therefore, effective monitoring programs and subsequent strict regulations are strongly required.

Counteranions in the Stimulation Solution Alter the Dynamics of Exocytosis Consistent with the Hofmeister Series.

We show that the Hofmeister series of ions can be used to explain the cellular changes in exocytosis observed by single-cell amperometry for different counteranions. The formation, expansion, and closing of the membrane fusion pore during exocytosis was found to be strongly dependent on the counteranion species in solution. With stimulation of chaotropic anions (e.g., ClO4-), the expansion and closing time of the fusion pore are longer, suggesting chaotropes can extend the duration of exocytosis compared with kosmotropic anions (e.g., Cl-). At a concentration of 30 mM, the two parameters (e.g., t1/2 and tfall) that define the duration of exocytosis vary with the Hofmeister series (Cl- < Br- < NO3- ≤ ClO4- < SCN-). More interestingly, fewer (e.g., Nfoot/Nevents) and smaller (e.g., Ifoot) prespike events are observed when chaotropes are counterions in the stimulation solution, and the values can be sorted by the reverse Hofmeister series (Cl- ≥ Br- > NO3- > ClO4- > SCN-). Based on ion specificity, an adsorption-repulsion mechanism, we suggest that the exocytotic Hofmeister series effect originates from a looser swelling lipid bilayer structure due to the adsorption and electrostatic repulsion of chaotropes on the hydrophobic portion of the membrane. Our results provide a chemical link between the Hofmeister series and the cellular process of neurotransmitter release via exocytosis and provide a better physical framework to understand this important phenomenon.

Allosteric regulation of mammalian Na+/I- symporter activity by perchlorate.

The Na+/I- symporter (NIS), the plasma membrane protein that actively transports I- (stoichiometry 2Na+:1I-) in thyroid physiology and radioiodide-based thyroid cancer treatment, also transports the environmental pollutant perchlorate (stoichiometry 1Na+:1ClO4-), which competes with I- for transport. Until now, the mechanism by which NIS transports different anion substrates with different stoichiometries has remained unelucidated. We carried out transport measurements and analyzed these using a statistical thermodynamics-based equation and electrophysiological experiments to show that the different stoichiometry of ClO4- transport is due to ClO4- binding to a high-affinity non-transport allosteric site that prevents Na+ from binding to one of its two sites. Furthermore, low concentrations of ClO4- inhibit I- transport not only by competition but also, critically, by changing the stoichiometry of I- transport to 1:1, which greatly reduces the driving force. The data reveal that ClO4- pollution in drinking water is more dangerous than previously thought.

Solution-Processed, Electrolyte-Gated In2O3 Flexible Synaptic Transistors for Brain-Inspired Neuromorphic Applications.

Emulating the essential synaptic behaviors using single synaptic transistor has attracted extensive attention for building the brain-inspired neuromorphic systems. However, few reports on synaptic transistors fabricated by solution processes have been reported. In this article, the indium oxide synaptic transistors based on polyimide substrates were fabricated by a nontoxic water-inducement method at a low temperature, and lithium perchlorate (LiClO4) was dissolved in polyethylene oxide as the gate electrolyte. For water-inducement process, comparable electrical properties of the synaptic transistors can be achieved by prolonging the annealing time rather than high-temperature annealing with a relatively short time. The effect of the annealing time on the electrical performance of the electrolyte-gated transistors annealed at various temperatures was investigated. It is found that the electrolyte-gated-synaptic transistor on polyimide substrate annealed at 200 °C exhibits high electrical performance and good mechanical stability. Due to the ion migration relaxation dynamics in the polymer electrolyte, various important synaptic behaviors such as the excitatory postsynaptic current, paired-pulse facilitation, high-pass filtering characteristics, and long-term memory performance were successfully mimicked. The electrolyte-gated synaptic transistors based on solution-processed In2O3 exhibit great potential in neuromorphological applications.