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The continuous effort in making artificial neural networks more alike to human brain calls for the hardware elements to implement biological synapse-like functionalities. The recent experimental demonstration of ferroelectric-like FETs promises low-power operation as compared to the conventional ferroelectric switching devices. This work presents an in-house numerical tool, which self-consistently solves the electrostatics and time-dependent electronic and ionic transport. The tool is exploited to analyze the effect that various physical parameters such as mobility and ion concentration could have on the design of the ferroelectric-like FETs. Their suitability in emulating different functions of the biological synapses is also demonstrated. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) continue to be the "front runner" technology among emerging photovoltaic devices in terms of power conversion efficiency and versatility of applications. However, improving stability and understanding their relationship with their ionic–electronic transport mechanisms continue to be challenging. In this work, a case study of NiOx-based inverted PSCs and the effect of different interface passivating treatments on device performance is presented. Impedance spectroscopy (IS) measurements in short-circuit conditions were performed under different illumination intensities, as well as bias-stress operational stability tests under constant illumination intensity. Surface treatments that involved bulky Lewis bases resulted in better and more stable performance. In contrast, acidic anion donors could induce both an initial performance decrease with a characteristic three-arcs impedance Nyquist plot and a subsequent instability during light exposure. Drift–diffusion simulations suggest strong modifications of surface recombination at the interface with the hole transport material, and for the ion concentration and mobilities in the perovskite. Importantly, capacitance and resistance are shown to peak maximum and minimum values, respectively, around mobile ion concentration (Nion) of 1016 and 1017 cm−3. These features relate to the transition from a drift-, for low Nion below a threshold value, to a diffusion-dominated transport in the bulk of the perovskite, for high Nion beyond the threshold value. Our results introduce a general route for characterization of instability paths in PSCs via IS performed under short-circuit conditions. [ABSTRACT FROM AUTHOR]

When electrolyte solutions are confined in micro- and nanochannels their conductivity is significantly different from those in a bulk phase. Here we revisit the theory of this phenomenon by focusing attention on the reduction in the ion mobility with the concentration of salt and a consequent impact to the conductivity of a monovalent solution, from bulk to confined in a narrow slit. We first give a systematic treatment of electrophoresis of ions and obtain equations for their zeta potentials and mobilities. The latter are then used to obtain a simple expression for a bulk conductivity, which is valid in a concentration range up to a few molars and more accurate than prior analytic theories. By extending the formalism to the electrolyte solution in the charged channel the equations describing the conductivity in different modes are presented. They can be regarded as a generalization of prior work on the channel conductivity to a more realistic case of a nonzero reduction of the electrophoretic mobility of ions with salt concentration. Our analysis provides a framework for interpreting measurements on the conductivity of electrolyte solutions in the bulk and in narrow channels. [ABSTRACT FROM AUTHOR]

BaSnF4 is a prospective solid state electrolyte for fluoride ion batteries. However, the diffusion mechanism of the fluoride ions remains difficult to study, both in experiments and in simulations. In principle, ab initio molecular dynamics could allow to fill this gap, but this method remains very costly from the computational point of view. Using machine learning potentials is a promising method that can potentially address the accuracy issues of classical empirical potentials while maintaining high efficiency. In this work, we fitted a dipole polarizable ion model and trained machine learning potential for BaSnF4 and made comprehensive comparisons on the ease of training, accuracy and efficiency. We also compared the results with the case of a simpler ionic system (NaF). We show that contrarily to the latter, for BaSnF4 the machine learning potential offers much higher versatility. The current work lays foundations for the investigation of fluoride ion mobility in BaSnF4 and provides insight on the choice of methods for atomistic simulations. [ABSTRACT FROM AUTHOR]

Positive-ion laser desorption/ionization (LDI) of fullerenes contained in soot as produced by the Krätschmer-Huffman process delivers a wide range of fullerene molecular ions from C56+• to above C300+•. Here, the collision cross section (CCS) values of those fullerene molecular ions are determined using a trapped ion mobility-quadrupole-time-of-flight (TIMS-Q-TOF) instrument. While CCS values in the range from C60+• to C96+• are already known with high accuracy, those of ions from C98+• onward had yet to be determined. The fullerene molecular ions covered in this work have CCS values from about 200 to 440 Å2. The fullerene molecular ion series is evenly spaced at C2 differences in composition, and thus, small CCS differences of just 2.2–3.5 Å2 were determined across the entire range. Fullerene M+• ions may be employed as mobility calibrants, in particular, when very narrow 1/K0 ranges are being analyzed to achieve high TIMS resolving power. In addition, due to the simple elemental composition, M+• ions of fullerenes could also serve for mass calibration. This study describes the determination of CCS values of fullerene molecular ions from C56+• to C240+• and the application of ions from C56+• to C220+• to calibrate the ion mobility scale of a Bruker timsTOFflex instrument in any combination of LDI, matrix-assisted laser desorption/ionization (MALDI), and electrospray ionization (ESI) modes in the CCS range from about 200 to 420 Å2. This use was exemplified along with ions from Agilent Tune Mix, leucine-enkephalin, angiotensin I, angiotensin II, and substance P. [ABSTRACT FROM AUTHOR]

Due to its soft lattice characteristics, all‐inorganic cesium lead halide (CsPbI3‐xBrx) perovskite is vulnerable to external environmental stress such as moisture, polar solvent, illumination. resulting in structural defects (VI, Ii, etc.) and ion mobility. However, most of the prior arts focus on short‐term and static passivation, which has a negligible effect on defects formed during solar cell operation. Herein, a photoisomerizable molecule, 1,3,3‐trimethylindolino‐8′‐methoxybenzopyrylospiran (OMe‐SP), exhibiting light‐driven pre‐isomeric (SP) and post‐isomeric (PMC) configurations, is employed as an interfacial protective layer on top of CsPbI3‐xBrx. The present strategy not only effectively suppresses migration of halogen ions, but also enables sustainable passivation of defects, thereby significantly reducing interfacial charge recombination and retarding perovskite degradation. Consequently, the OMe‐SP‐modified perovskite solar cells (PSCs) exhibit superior stability, maintaining 91% of their initial efficiency after aging 1032 h under maximum power point (MPP) tracking and continuous one sun illumination. Meanwhile, the OMe‐SP‐modified cell also achieves an impressive power conversion efficiency of 22.20%, which stands as the highest among all‐inorganic perovskite solar cells. Overall, the implementation of this robust strategy provides sustainable defect passivation and continuous suppression of ion migration for achieving both high PCE and stable inorganic perovskite. [ABSTRACT FROM AUTHOR]

Accurate identification of bacterial strains in clinical samples is essential to provide an appropriate antibiotherapy to the patient and reduce the prescription of broad-spectrum antimicrobials, leading to antibiotic resistance. In this study, we utilized the combination of a multidimensional analytical technique, liquid chromatography-ion mobility-tandem mass spectrometry (LC-IM-MS/MS), and machine learning to accurately identify and distinguish 11 Escherichia coli (E. coli) strains in artificially contaminated urine samples. Machine learning was utilized on the LC-IM-MS/MS data of the inoculated urine samples to reveal lipid, metabolite, and peptide isomeric biomarkers for the identification of the bacteria strains. Tandem MS and LC separation proved effective in discriminating diagnostic isomers in the negative ion mode, while IM separation was more effective in resolving conformational biomarkers in the positive ion mode. Using hierarchical clustering, the strains are clustered accurately according to their group highlighting the uniqueness of the discriminating biomarkers to the class of each E. coli strain. These results show the great potential of using LC-IM-MS/MS and machine learning for targeted omics applications to diagnose infectious diseases in various environmental and clinical samples accurately. [ABSTRACT FROM AUTHOR]

The subtle structural variations among carbohydrate isomers pose significant challenges for their identification and quantification. Here, we propose a strategy for rapid identification and quantification of isomeric disaccharides via derivatization with 4-(3-methyl-5-oxo-pyrazolin-1-yl) benzoic acid (CPMP) and analysing by ion mobility spectrometry (IMS). After derivatization, the ionization efficiency of disaccharides was significantly improved. The disaccharide isomers were distinguished by determining the different ion mobilities of CPMP-labelled disaccharides. Among them, [M + 2CPMP + H]+ was separated with a resolution of 1.484, almost achieving baseline separation. Subsequently, [M + CPMP + Na]+ was used for the relative quantification of lactose and maltose, showing a good linear relationship with R2 > 0.990. Finally, the method was successfully applied to the identification of lactose and maltose in beer and milk. The method is fast, accurate and effective for the identification of disaccharide isomers in complex samples. [ABSTRACT FROM AUTHOR]

While operational stability has evolved to be the primary issue for the practical applications of perovskite solar cells (PSCs), the understanding of the origins of device degradation is still limited. Hysteresis is known as a unique and significant feature of PSCs. The hysteresis behavior of the current density-voltage (J–V) curves, governed by the interaction between the evolving ion-induced electric field and the carrier transport/recombination, offers rich and important information about the physical properties of the device. Herein, we propose to establish hysteresis as a diagnostic key to unveil and remedy degradation issues with device physics. With a custom-made ion-incorporated drift-diffusion simulator, we comprehensively investigate the relations between characteristic J–V hysteresis features and critical device issues such as bulk and surface defects, and low mobility of each layer in the PSCs. Ultimately, we derive a fundamental understanding and unveil the origins of the device degradation during the continuous operation of PSCs. This work therefore offers a new way to address and optimize PSC operational stability. The understanding of the origins of device degradation of perovskite solar cells remains limited. Here, the authors establish hysteresis as a diagnostic key to unveil and remedy degradation issues and investigate the relations between characteristic J-V hysteresis features and device deficiencies. [ABSTRACT FROM AUTHOR]

Recent studies have identified an imbalance between the electronic and ionic conductivities as the drivers of inhomogeneous reactions in composite cathodes, which cause the rapid degradation of all‐solid‐state battery (ASSB). To mitigate localized overcharge and utilize isolated active materials, the study proposes the coating of an argyrodite‐type Li6PS5Cl solid electrolyte (SE) with graphene‐like carbon (GLC@LPSCl), a 2D conductive material, to offer a continuous three‐dimensionally connected electron pathway within the composite cathode to facilitate ion mobility and promote homogeneous reactions. Despite reducing the content of the conducting agent, it is observed that the GLC@LPSCl cell exhibits high initial Coulombic efficiency and discharge capacity, reducing the inhomogeneous reactivity after 200 cycles compared with when ordinary conductive agents are deployed. Additionally, the presence of GLC@LPSCI surface suppresses the interfacial reaction between SE–cathode material, thus imparting the cell with excellent capacity retention (≈90%) after 200 cycles. Furthermore, the cell performance improves even after a fourfold increase in the cathode loading amount, demonstrating the criticality of a well‐developed continuous electron pathway to cell performance and highlighting the key role of ensuring a balance between the electron and ion conductivities in the development of high‐energy‐density and high‐power ASSBs. [ABSTRACT FROM AUTHOR]

Ion mobility‐mass spectrometry (IM‐MS) has recently contributed to the structural analysis of molecules, including supramolecules and proteins, by determining the ion arrival time distributions correlated with the collision cross sections (CCSs), as well as the mass‐to‐charge ratios. However, its application range is still limited owing to the lack of general CCSs simulation methods based on possible molecular conformations. Here, a molecular dynamics‐based conformational search method for simulating CCS distributions using projection approximation is reported. As a case study, the gas‐phase conformations of the sodium adducts of conformationally flexible polyketones with 3,3‐dimethylpentane‐2,4‐dione as the monomer are analyzed. The sodium adduct of the hexamer (m/z 781.4 for [1 + Na]+) showed a monomodal arrival time distribution, but that of the octamer sodium adduct (m/z 1033.5 for [2 + Na]+) is multimodal. The conformational analysis indicated an unimodal CCS distribution of simulated [1 + Na]+ conformations in which the sodium cation is mainly bound at the chain terminal. Conversely, four clusters of conformations are obtained for [2 + Na]+ based on the Na+‐coordination sites, which qualitatively reproduced the observed CCS distribution. This approach will extend the utility of IM‐MS for the conformational analysis of flexible molecules in the gas phase. [ABSTRACT FROM AUTHOR]

GNE myopathy, also known as hereditary inclusion body myopathy (HIBM), is a rare genetic muscle disorder marked by a gradual onset of muscle weakness in young adults. GNE myopathy (GNEM) is caused by bi-allelic variants in the UDP-N-acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase)/N-acetylmannosamine kinase (ManNAc kinase) gene (GNE), clinically resulting in the loss of ambulation within 10–20 years from the onset of the initial symptoms. The disease's mechanism is poorly understood and non-invasive biomarkers are lacking, hindering effective therapy development. Based on the available evidence, we employed a lipidomic approach to study the serum lipid profile of GNE patients. The multivariate statistical analysis revealed a downregulation of carnitines, as well as of lysophosphatidylcholines, in sera samples derived from GNEM patients. Furthermore, we identified lower levels of sphingomyelins and, concomitantly, high levels of ceramides in serum samples from GNEM patients when compared to control samples derived from healthy donors. Moreover, the GNEM serum samples showed the upregulation of Krebs cycle intermediates, in addition to a decrease in oxaloacetic acid. The correlated data gathered in this study can offer a promising diagnostic panel of complex lipids and polar metabolites that can be used in clinic for GNEM in terms of a metabolic fingerprint measurable in a minimally invasive manner. [ABSTRACT FROM AUTHOR]

The inherent ion migration in metal halide perovskite materials is known to induce deleterious and highly unstable dark currents in X‐ and γ‐ray detectors based on those compounds upon bias application. Dark current slow drift with time is identified as one of the major drawbacks for these devices to satisfy industrial requirements. Because dark current establishes the detectability limit, current evolution, and eventual growth may mask photocurrent signals produced by incoming X‐ray photons. Relevant information for detector assessment is ion‐related parameters such as ion concentration, ion mobility, and ionic space‐charge zones that are eventually built near the outer contacts upon detector biasing. A combined experimental (simple measurement of dark current transients) and 1D numerical simulation method is followed here using single‐crystal and microcrystalline millimeter‐thick methylammonium‐lead bromide that allows extracting ion mobility within the range of µion ≈ 10−7 cm2 V−1 s−1, while ion concentration values approximate Nion ≈ 1015 cm−3, depending on the perovskite crystallinity. [ABSTRACT FROM AUTHOR]

Over the past few decades, the topic of recycling has become increasingly prominent in the field of sustainable materials and circular economy. One significant challenge is the physical separation of different types of plastics to obtain recyclates of one plastic type as pure as possible with comparable quality and properties to those of virgin material. Given the substantial effort involved in such separation, small amounts of contamination from other plastics may be tolerated. However, these contaminations must be monitored to ensure high-level recyclate quality. In recent years, compact, low-cost ion mobility spectrometers (IMS) with high analytical performance have been developed, and have thus become widely used in a variety of sensing applications. Due to their high sensitivity, IMS are particularly suited for detecting lowest concentration levels of various compounds, as required for the detection of impurities in recyclate quality monitoring. When coupled to a miniature gas chromatograph (GC), GC-IMS reach even higher separation power while being still compact. To bring recyclate samples to the gas phase, pyrolysis (Py) is used in this work. A first feasibility study was conducted to assess the potential of such a pyrolysis–gas chromatography-ion mobility spectrometer (Py-GC-IMS) with the objective of detecting contaminations of polyethylene terephthalate (PET) in polyethylene (PE) recyclates. The study clearly demonstrates the ability to identify PET-related fingerprints while suppressing the PE background matrix by design so that Py-GC-IMS seems a promising approach for in-process monitoring PET contaminations in PE recyclates. [ABSTRACT FROM AUTHOR]

High-resolution ion mobility (resolving power > 200) coupled with mass spectrometry (MS) is a powerful analytical tool for resolving isobars and isomers in complex samples. High-resolution ion mobility is capable of discerning additional structurally distinct features, which are not observed with conventional resolving power ion mobility (IM, resolving power ~ 50) techniques such as traveling wave IM and drift tube ion mobility (DTIM). DTIM in particular is considered to be the "gold standard" IM technique since collision cross section (CCS) values are directly obtained through a first-principles relationship, whereas traveling wave IM techniques require an additional calibration strategy to determine accurate CCS values. In this study, we aim to evaluate the separation capabilities of a traveling wave ion mobility structures for lossless ion manipulation platform integrated with mass spectrometry analysis (SLIM IM-MS) for both lipid isomer standards and complex lipid samples. A cross-platform investigation of seven subclass-specific lipid extracts examined by both DTIM-MS and SLIM IM-MS showed additional features were observed for all lipid extracts when examined under high resolving power IM conditions, with the number of CCS-aligned features that resolve into additional peaks from DTIM-MS to SLIM IM-MS analysis varying between 5 and 50%, depending on the specific lipid sub-class investigated. Lipid CCS values are obtained from SLIM IM (TW(SLIM)CCS) through a two-step calibration procedure to align these measurements to within 2% average bias to reference values obtained via DTIM (DTCCS). A total of 225 lipid features from seven lipid extracts are subsequently identified in the high resolving power IM analysis by a combination of accurate mass-to-charge, CCS, retention time, and linear mobility-mass correlations to curate a high-resolution IM lipid structural atlas. These results emphasize the high isomeric complexity present in lipidomic samples and underscore the need for multiple analytical stages of separation operated at high resolution. [ABSTRACT FROM AUTHOR]

Aberrant lipid metabolism has been widely recognized as a hallmark of various diseases. However, the comprehensive analysis of distinct lipids is challenging due to the complexity of lipid molecular structures, wide concentration ranges, and numerous isobaric and isomeric lipids. Usually, liquid chromatography-mass spectrometry (LC-MS)-based lipidomics requires a long time for chromatographic separation to achieve optimal separation and selectivity. Ion mobility (IM) adds a new separation dimension to LC-MS, significantly enhancing the coverage, sensitivity, and resolving power. We took advantage of the rapid separation provided by ion mobility and optimized a fast and broad-coverage lipidomics method using the LC-IM-MS technology. The method required only 8 minutes for separation and detected over 1000 lipid molecules in a single analysis of common biological samples. The high reproducibility and accurate quantification of this high-throughput lipidomics method were systematically characterized. We then applied the method to comprehensively measure dysregulated lipid metabolism in patients with colorectal cancer (CRC). Our results revealed 115 significantly changed lipid species between preoperative and postoperative plasma of patients with CRC and also disclosed associated differences in lipid classes such as phosphatidylcholines (PC), sphingomyelins (SM), and triglycerides (TG) regarding carbon number and double bond. Together, a fast and broad-coverage lipidomics method was developed using ion mobility-mass spectrometry. This method is feasible for large-scale clinical lipidomic studies, as it effectively balances the requirements of high-throughput and broad-coverage in clinical studies. [ABSTRACT FROM AUTHOR]

The double skeleton interpenetrating network fixed the quaternary ammonium salt, and various internal conduction modes cooperated to promote the transport of hydroxide ions. [Display omitted] The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH− conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (> 300 °C), mechanical property (∼ 34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm−1) and ion mobility number (t ion ∼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the "sandwich"-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm−2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm−2) and stable discharge plateau (12 h, 5 mA cm−2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) represent a category of two-dimensional layered intercalation materials, showing significant potential as electrode materials for the production of high-energy-density supercapacitors due to their tunable composition, ease of synthetic modification, and low cost. Here, we constructed alkali-etched NiAl LDH-OH nanosheets/Ag nanoparticles (NPs) composite material (Ag@NiAl LDH-OH) for high-performance supercapacitors through a simple solvent-thermal reaction. The alkali treatment is employed to selectively etch some Al3+ ions, generating cation vacancies as active sites for energy storage. Additionally, under the simultaneous influence of strong alkalis and vacancies, the interlayer spacing of LDHs expands, aiding in the promotion of interlayer ion mobility. Meanwhile, the decoration of silver nanoparticles ensures excellent electron conductivity in the NiAl-LDH-OH nanosheets, thereby facilitating improved utilization of the active substance and achieving outstanding rate performance. The Ag@NiAl LDH-OH electrode, when prepared, demonstrates a significant increase in specific capacitance, reaching 1790 F g−1 at a current density of 1 A g−1. This represents approximately 7 times the specific capacitance of the pristine NiAl LDH electrode, with a capacity retention of 79 % even under a high current density of 20 A g−1. Moreover, the assembled asymmetric supercapacitor (ASC) attains a maximum energy density of 138.25 Wh kg−1 at a power density of 700 W kg−1, maintaining 81 % of its initial specific capacitance after 20000 cycles. This research introduces novel pathways for advancing high-energy-density SCs. [ABSTRACT FROM AUTHOR]

Atmospheric secondary aerosols are often internally mixed with organic and inorganic components, particularly dicarboxylic acids, ammonium, sulfate, nitrate, and chloride. These complex compositions enable aqueous reaction between organic and inorganic species, significantly complicating aerosol phase behavior during aging and making phase predictions challenging. We investigated carboxylate–ammonium salt mixtures using attenuated total reflection Fourier-transformed infrared spectroscopy (ATR-FTIR). The mono-, di-, and tricarboxylates included sodium pyruvate (SP), sodium tartrate (ST), and sodium citrate (SC), while the ammonium salts included NH4NO3 , NH4Cl , and (NH4)2SO4. Our results demonstrated that aqueous replacement reactions between carboxylates and ammonium salts were promoted by the formation and depletion of NH3 as relative humidity (RH) changed. For SP/ammonium aerosols, NaNO3 and Na2SO4 crystallized from 35.7 % to 12.7 % and from 65.7 % to 60.1 % RH, respectively, which is lower than the values for pure inorganics (62.5 ± 9 %–32 % RH for NaNO3 and 82 ± 7 %–68 ± 5 % RH for Na2SO4). Upon hydration, the crystalline Na2SO4 and NaNO3 deliquesced at 88.8 %–95.2 % and 76.5 ± 2 %–81.9 %, which is higher than the values of pure Na2SO4 (74 ± 4 %–98 % RH) and NaNO3 (65 %–77.1 ± 3 % RH). In contrast, reaction between ST or SC and (NH4)2SO4 was incomplete due to the gel structure at low RH. Unexpectedly, aqueous Na2SO4 crystallized upon humidification in ST/ (NH4)2SO4 particles at 43.6 % RH and then deliquesced with increasing RH. This is attributed to increased ion mobility in viscous particles, leading to nucleation and growth of Na2SO4 crystals. Our findings highlight the intricate interplay between chemical components within organic/inorganic aerosol and the impact of replacement reactions on aerosol aging, phase state, and subsequently atmospheric processes. [ABSTRACT FROM AUTHOR]

Legumain is a cysteine protease broadly associated with inflammation. It has been reported to cleave and activate protease‐activated receptor 2 to provoke pain associated with oral cancer. Outside of gastric and colon cancer, little has been reported on the roles of legumain within the gastrointestinal tract. Using a legumain‐selective activity‐based probe, LE28, we report that legumain is activated within colonocytes and macrophages of the murine colon, and that it is upregulated in models of acute experimental colitis. We demonstrated that loss of legumain activity in colonocytes, either through pharmacological inhibition or gene deletion, had no impact on epithelial permeability in vitro. Moreover, legumain inhibition or deletion had no obvious impacts on symptoms or histological features associated with dextran sulfate sodium‐induced colitis, suggesting its proteolytic activity is dispensable for colitis initiation. To gain insight into potential functions of legumain within the colon, we performed field asymmetric waveform ion mobility spectrometry‐facilitated quantitative proteomics and N‐terminomics analyses on naïve and inflamed colon tissue from wild‐type and legumain‐deficient mice. We identified 16 altered cleavage sites with an asparaginyl endopeptidase signature that may be direct substrates of legumain and a further 16 cleavage sites that may be indirectly mediated by legumain. We also analyzed changes in protein abundance and proteolytic events broadly associated with colitis in the gut, which permitted comparison to recent analyses on mucosal biopsies from patients with inflammatory bowel disease. Collectively, these results shed light on potential functions of legumain and highlight its potential roles in the transition from inflammation to colorectal cancer. [ABSTRACT FROM AUTHOR]

The Journal of Low Temperature Physics published a memorial issue commemorating the life and work of Alexander Fedorovich Andreev, a renowned low-temperature physicist known for his contributions to superconductivity and superfluidity. Andreev's research on Andreev reflection and bound states at interfaces has had a lasting impact on the field. The issue includes articles that build on Andreev's legacy, covering topics such as superconductors, superfluids, quantum crystals, and topological materials, showcasing the breadth of his influence on low-temperature quantum physics. [Extracted from the article]

The study of metal ion's role in the biological processes of Alzheimer's disease has spurred investigations into the coordination chemistry of amyloid beta peptide and its fragments. Nano‐electrospray ionization mass spectrometry (nESI‐MS) has been utilized to examine the stabilization of bound anions on multiprotein complexes without bulk solvent. However, the effects of anions on metal ion binding interactions with amyloid beta peptide have not been explored. This study directly examined metal‐peptide complexes using nESI‐MS and investigated the effects of various anions on the binding ratio and stability of these complexes from ammonium salt solutions. The results indicate that different anions have distinct effects on the binding ratio and stability of various metal‐peptide complexes. Of these, the bicarbonate ion exhibits the highest binding ratios for metal‐peptide complexes, while binding ratios for these complexes in phosphate are comparatively low. Our results suggest that acetate, formate, bicarbonate, and phosphate have weak affinities and act as weak stabilizers of the metal‐peptide complex structure in the gas phase. Intriguingly, chloride and sulfate act as stabilizers of the metal‐peptide complex in the gas phase. The rank order determined from these data is substantially different from the Hofmeister salt series in solution. Although this outcome was anticipated due to the reduced influence of anions and water solvation, our findings correlate well with expected anion binding in solution and emphasize the importance of both hydration layer and anion‐metal‐peptide binding effects for Hofmeister‐type stabilization in solution. This approach proved useful in examining the interactions between metal ions and amyloid beta peptide, which are relevant to Alzheimer's disease, using direct ESI‐MS. [ABSTRACT FROM AUTHOR]

Polystyrene (PS) is a thermoplastic polymer commonly used in various applications due to its bulk properties. Designing functional polystyrenes with well-defined structures for targeted applications is of significant interest due to the rigid and apolar nature of the polymer chain. Progress is hindered to date by the limitations of current analytical methods in defining the atomistic-level folding of the polymer chain. The integration of ion mobility spectrometry and molecular dynamics simulations is beneficial in addressing these challenges. However, data on gas-phase polystyrene ions are rarely reported in the literature. We herein investigate the gas phase structure of polystyrene ions with different end groups to establish how the nature and the rigidity of the monomer unit affect the charge stabilization. We find that, in contrast to polar polymers in which the charges are located deep in the ionic globules, the charges in the PS ions are rather located at the periphery of the polymer backbone, leading to singly and doubly charged PS ions adopting dense elliptic-shaped structures. Molecular dynamics (MD) simulations indicate that the folding of the PS rigid chain is controlled by phenyl ring interactions with the charge ultimately remaining excluded from the core of the globular ions, whereas the folding of polyether ions is initiated by the folding of the flexible polyether chain around the sodium ion that remains deeply enclosed in the core of the ions. [ABSTRACT FROM AUTHOR]

Ion mobility spectroscopy is a technique to characterize compounds based on the differences in the migration of sample ions under the combined action of electric field and air flow. Ions can be separated according to their quantity of electric charge, mass, size and shape. Meanwhile, the collision cross section of the ions can also be calculated to obtain chemical compound structural information, which has shown excellent performance in separating isomers of substances. In recent years, a variety of ion mobility technologies combined with mass spectrometry technology have emerged, and been widely used in food, biology, medicine, environment and other fields. In this paper, the types and working principles of ion mobility spectroscopy are introduced, the advantages and disadvantages of various types of instruments are analyzed, and the application of ion mobility spectrometry, liquid chromatography and mass spectrometry multidimensional combination in analyzing and identifying nutritive and active ingredients and chemical hazards in food is reviewed. The application prospect and development trend of this technology are also prospected. [ABSTRACT FROM AUTHOR]

In view of the characteristics of pesticide residues, such as multiple types, high matrix interference and slow detection speed, in this work, a rapid detection method for pesticide residues in rice was studied by using isoprothiolane, propanil and flutolanil as examples. Improved quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used as rice pretreatment method, and linear range and matrix effect of each pesticide were obtained through analysis of ion mobility spectral data of standard solutions and spiked solutions. Within the linear range, the mixed solutions of the three pesticides were prepared, and concentrations were predicted by partial least squares regression (PLSR) analysis. Feature extraction and data fusion of ion mobility spectra in positive and negative ionization modes were required, and the prediction error was 6.77%. QuEChERS method can rapidly pretreat samples, the measurement speed of ion mobility spectrometry (IMS) is fast, so the combination of them offers advantages that include simple sample preparation, rapid analysis, high sensitivity, robustness, green properties, and low-cost. Feature extraction and data fusion can analyze data from both positive and negative ionization modes, providing more comprehensive information and saving analysis time compared to individual data analysis. PLSR can accurately predict the content of pesticide with similar ion mobility spectra. The combined analysis technology of QuEChERS, IMS, and PLSR established in this work was expected to become a new technology for rapid detection of pesticide residues in rice with the concentration higher than 0.3 mg/kg. [ABSTRACT FROM AUTHOR]

Rationale: Compounds like caffeine metabolites with more than one proton acceptor site can produce a mixture of isomeric protonated ions (protomers) in electrospray ionization and atmospheric pressure chemical ionization (APCI) ion sources. Discrimination between the protomers is of interest as the charge location influences ion structure and chemical and physical properties. Methods: Protonation of caffeine in an APCI ion source was studied using ion mobility spectrometry. The hydronium ions, H3O+(H2O)n, are the main reactant ions in the APCI ion source. Different dopant gases including NO2, NH3, and CH3NH2 were used to produce new reactant ions NO+, NH4+, and CH3NH3+, respectively. Density functional theory was employed to explain the experimental results and calculate the energies of the ionization reactions. Results: The ion mobility spectrum of caffeine showed three peaks. In the presence of NO2 dopant and NO+ reactant ion, caffeine was ionized via charge transfer and formation of M+ ion. As NH3 and CH3NH2 are stronger bases than H2O, the reactant ions NH4+ and CH3NH3+ selectively protonated the more basic site of caffeine, that is, the imidazole nitrogen. Using these dopants, we could attribute the first ion mobility peak to M+ ion, the second peak to the protonation of caffeine at the carbonyl oxygen atom, and the third peak to the protonation of the imidazole nitrogen atom. The calculated collisional cross‐sections of M+ and the protomers of caffeine confirmed the peaks' assignment. Conclusions: The criterion for the selection of an appropriate dopant is that its proton affinity (PA) should be between those of the proton acceptor sites of the molecule studied. [ABSTRACT FROM AUTHOR]

Complex coacervates play essential roles in various biological processes and applications. Although substantial progress has been made in understanding the molecular interactions driving complex coacervation, the mechanisms stabilizing coacervates against coalescence remain experimentally challenging and not fully elucidated. We recently showed that polydiallyldimethylammonium chloride (PDDA) and adenosine triphosphate (ATP) coacervates stabilize upon their transfer to deionized (DI) water. Here, we perform molecular dynamics simulations of PDDA-ATP coacervates in supernatant and DI water, to understand the ion dynamics and structure within stable coacervates. We found that transferring the coacervates to DI water results in an immediate ejection of a significant fraction of small ions (Na+ and Cl−) from the surface of the coacervates to DI water. We also observed a notable reduction in the mobility of these counterions in coacervates when in DI water, both in the cluster-forming and slab simulations, together with a lowered displacement of PDDA and ATP. These results suggest that the initial ejection of the ions from the coacervates in DI water may induce an interfacial skin layer formation, inhibiting further mobility of ions in the skin layer. Transferring coacervates based on polydiallyldimethylammonium chloride and adenosine triphosphate into deionized water has been experimentally demonstrated to stabilize them against coalescence. Here, molecular modeling and simulations are used to study the coacervation and stabilization of the relevant polyelectrolyte mixture, systematically investigating the structural and dynamic properties that lead to stability. [ABSTRACT FROM AUTHOR]

Developing electrolytes with high Mg2+ ion mobility and compatibility with magnesium electrodes is of the utmost importance for the development of next-generation magnesium ion batteries. Here, we report the findings related to the physicochemical properties of the quasi-solid state chitosan biopolymer electrolyte prepared with a highly polar plastic crystal succinonitrile plasticizer. The prepared biopolymer electrolytes exhibited ionic conductivity in the order of 10−2 S cm−1 which is very much comparable to the conductivity of a liquid electrolyte used in commercial batteries. Besides, the prepared electrolyte shows decreased crystallinity ( χ c ) and glass transition temperature (Tg) values, widened electrochemical window (2.5 V), good transference number ( t Mg 2 + ~0.6), reduced activation energy Ea (25 kJ mol−1), and increased dielectric values (ε). These results confirm the enhanced Mg2+ ion kinetics owing to the addition of SCN with high dissociate property and oxidative stability. Furthermore, the interfacial stability of the best-conducting chitosan biopolymer electrolyte is evaluated using CV analysis against Mg electrodes (vs. Mg/Mg2+). Also, a prototype Mg battery is constructed using the prepared electrolyte, MoO3 cathode, and Mg metal anode which showed an initial specific capacity of 277 mAh g−1 analyzed through galvanostatic charge/discharge studies. Therefore, in light of the results, we believe that adding succinonitrile to polymer electrolytes could be a practical approach to enhancing the electrochemical properties suitable for magnesium ion batteries. [ABSTRACT FROM AUTHOR]

This study focuses on developing a perovskite Li 3x La 2/3-x TiO 3 (LLTO) electrolyte using a simple and effective sol-gel technique. This study aims to enable the hopping of lithium ions in lanthanum sites, which enhances the overall ionic conductivity of the material. By employing an ion conduction mechanism, we investigated the conductivity of powdered and pelletized (dense) LLTO materials. Dense-LLTO exhibits a higher grain ionic conductivity of σ = 1.32 × 10−4 S/cm at room temperature, whereas powdered-LLTO gives a significantly lower conductivity. This significant difference in conductivity can be attributed to the closely packed arrangement of ions in the dense-LLTO structure, which minimizes the evaporation of lithium (Li) in lanthanum (La) sites and promotes ion mobility. Therefore, the thermal treatment process plays a crucial role in facilitating the ion(s) movement and its impact on the ionic conductivity of LLTO, which is mainly influenced by the lithium content. To further evaluate the practical application of LLTO as a solid electrolyte, we constructed a solid-state device with LiFePO 4 /LLTO/AC. The LLTO electrolyte is sandwiched between the activated carbon and LiFePO 4 electrodes. This device exhibits an impressive energy density, achieving 2.42 Wh/kg and a power density of 192 W/kg. Moreover, the device demonstrates better rate capability, allowing for efficient charge and discharge processes. Remarkably, the cyclic stability analysis revealed a retention rate of 92 % over 10,000 cycles, indicating the robustness and durability of the LLTO-based solid-state battery system. These findings highlight the potential of LLTO as a promising solid electrolyte material for advanced energy storage devices. The sol-gel synthesis method provides a simple and effective approach for obtaining high-performance LLTO electrolytes. The enhanced ionic conductivity and excellent electrochemical performance of the solid-state LiFePO 4 /LLTO/AC device demonstrate the feasibility and prospects of LLTO-based batteries in practical applications, offering improved energy density, power density, and long-term cycling stability. [ABSTRACT FROM AUTHOR]

Introduction: The introduction of trapped ion mobility spectrometry (TIMS) in combination with fast high-resolution time-of-flight (TOF) mass spectrometry to the proteomics field led to a jump in protein identifications and quantifications, as well as a lowering of the limit of detection for proteins from biological samples. Parallel Accumulation-Serial Fragmentation (PASEF) is a driving force for this development and has been adapted to discovery as well as targeted proteomics. Areas covered: Over the last decade, the PASEF concept has been optimized and led to the implementation of eleven new measurement techniques. In this review, we describe all currently described PASEF measurement techniques and their application to clinical proteomics. Literature was searched using PubMed and Google Scholar search engines. Expert Opinion: The use of a dual TIMS tunnel has revolutionized the depth and the speed of proteomics measurements. Currently, we witness how this technique is pushing clinical proteomics forward. [ABSTRACT FROM AUTHOR]

To enhance the performance and widespread use of solid oxide fuel cells (SOFCs), addressing the low-temperature (< 650 °C) electrochemical performance and operational stability issues of cathode materials is crucial. Here, we propose an innovative approach to enhance oxygen ion mobility and electrochemical performance of perovskite oxide by substituting some oxygen sites with chlorine anions. The designed SrTa0.1Fe0.9O3-δ-xClx (x = 0.05 and 0.10) exhibits improved performance compared to SrTa0.1Fe0.9O3-δ (STF). SrTa0.1Fe0.9O2.95-δCl0.05 (STFCl0.05) shows the lowest area-specific resistance (ASR) value on Sm0.2Ce0.8O1.9 (SDC) electrolyte. At 600 °C, STFCl0.05 achieves an ASR value of 0.084 Ω·cm2, and a single cell with STFCl0.05 reaches a higher peak power density (PPD) value (1143 mW·cm-2) than that with STF (672 mW·cm-2). Additionally, besides exhibiting excellent oxygen reduction reaction (ORR) activity at lower temperatures, the STFCl0.05 cathode demonstrates good CO2 tolerance and operational stability. Symmetrical cell operation lasts for 150 h, and single cell operation endures for 720 h without significant performance decline. The chlorine doping approach effectively enhances ORR activity and stability, making STFCl0.05 a promising cathode material for low-temperature SOFCs. [ABSTRACT FROM AUTHOR]

Understanding and controlling the chemical behavior of iron and iron oxide clusters requires accurate thermochemical data, which, because of the complex electronic structure of transition metal clusters, can be difficult to calculate reliably. Here, dissociation energies for Fe 2 + , Fe2O+, and Fe 2 O 2 + are measured using resonance enhanced photodissociation of clusters contained in a cryogenically cooled ion trap. The photodissociation action spectrum of each species exhibits an abrupt onset for the production of Fe+ photofragments from which bond dissociation energies are deduced for Fe 2 + (2.529 ± 0.006 eV), Fe2O+ (3.503 ± 0.006 eV), and Fe 2 O 2 + (4.104 ± 0.006 eV). Using previously measured ionization potentials and electron affinities for Fe and Fe2, bond dissociation energies are determined for Fe2 (0.93 ± 0.01 eV) and Fe 2 − (1.68 ± 0.01 eV). Measured dissociation energies are used to derive heats of formation ΔfH0( Fe 2 + ) = 1344 ± 2 kJ/mol, ΔfH0(Fe2) = 737 ± 2 kJ/mol, ΔfH0( Fe 2 − ) = 649 ± 2 kJ/mol, ΔfH0(Fe2O+) = 1094 ± 2 kJ/mol, and ΔfH0( Fe 2 O 2 + ) = 853 ± 21 kJ/mol. The Fe 2 O 2 + ions studied here are determined to have a ring structure based on drift tube ion mobility measurements prior to their confinement in the cryogenic ion trap. The photodissociation measurements significantly improve the accuracy of basic thermochemical data for these small, fundamental iron and iron oxide clusters. [ABSTRACT FROM AUTHOR]

Polymer cation exchange membranes (CEMs) are widely used in water treatment processes. The fundamental factors that control the separation and selectivity of cations with different valences in CEMs are not fully understood. In this study, we use atomistic molecular dynamics simulations to investigate the underlying molecular mechanisms that control the mobility of cations with different valences in Nafion membranes. Our results indicate structural differences in binding of monovalent and divalent cations, which gives rise to differences in ion diffusion in Nafion. Monovalent cations are shown to be "territorially" bound, i.e., bound while partially hydrated, to the fixed charge groups whereas divalent cations are shown to be "site" bound, i.e., bound while fully dehydrated, to the charge groups on the polymer. This difference in binding structure gives rise to differences in transport characteristics of cations in Nafion. [ABSTRACT FROM AUTHOR]

Rationale: Mycobacterial species contain high concentrations of mycolic acids in their cell wall. Mycobacteria can pose a threat to both human health and the environment. Mass spectrometry lipidomic characterization can identify bacterial species and suggest targets for microbiological interventions. Due to the complex structures of mycolic acids and the possibility of isobaric isomers, multiple levels of separation are required for complete characterization. In this study, cyclic ion mobility (cIM) mass spectrometry (MS) was used for the analysis, separation and fragmentation of mycolic acids isomers from the bacterial species Gordonia amarae and Mycobacterium bovis. Methods: Mycolic acid isomers were interrogated from cultured G. amarae biomass and commercially available M. bovis mycolic acid extracts. These were infused into a cIM‐enabled quadrupole time‐of‐flight MS. Ions of interest were non‐simultaneously selected with the quadrupole and passed around the cyclic ion mobility device multiple times. Fragment ion analysis was then performed for the resolved isomers of the quadrupole‐selected ions. Results: Repeated passes of the cIM device successfully resolved otherwise overlapping MA isomers, allowing isomer isolation and producing an ion‐specific post‐mobility fragmentation spectrum without isomeric interference. Conclusions: Mycolic acids (MA) isomers from G. amarae and M. bovis were resolved, resulting in a high mobility resolution and low interference fragmentation analysis. These revealed varying patterns of MA isomers in the two species: G. amarae's most abundant ion of each set of MA has 1–2 conformations, while the MA + 2 m/z the most abundant ion of each set has 3–6 conformations. These were resolved after 70 passes of the cyclic device. M. bovis' most abundant ion of each keto‐MA set has 2 conformations, while the keto‐MA + 2 m/z has 1–2 conformations. These were resolved after 75 passes. [ABSTRACT FROM AUTHOR]

Rationale: The 1, 2‐unsaturated derivatives of (1‐4) linked disaccharides serve as versatile building blocks for synthesizing biologically active compounds. Distinguishing between four pairs of stereoisomers in mixtures presents a challenging task. In this study, disaccharide derivatives are analyzed as alkali metal adducts using electrospray ionization tandem mass spectrometry (ESI‐MS/MS), both as individual compounds and in mixtures by ion mobility mass spectrometry (IMS). Methods: Electrospray ionization (ESI) in combination with tandem mass spectrometry (MS/MS) in positive mode was employed to differentiate lithium adduct ions of hexa‐acetyl/hexa‐benzyl‐D‐lactals, and hexa‐acetyl/hexa‐benzyl‐D‐maltals, along with their corresponding 2‐C‐branched malonates. The high resolving power of trapped ion mobility spectrometry (TIMS) with the imeX™ functionality rapidly identified different metal adducts (Li, Na, Cs) as individual isomers and separated mixtures of stereoisomers. The measured collisional cross section (CCS) values were analyzed in relation to predicted CCS values. Results: MS/MS spectra of the [M + Li]+ ions of glycal disaccharide analogues exhibited typical cross‐ring and glycosidic bond cleavages. Collision‐induced dissociation (CID) spectra provided insights into their fragmentation behavior, allowing differentiation of (1‐4) linked disaccharides. TIMS technology delivered adjustable ion mobility resolution for suitable separation of the four sets of stereo isomeric compounds. However, accurately predicting CCS values to differentiate between respective isomeric pairs using the SigmaCCS program for sodium adducts is only partially achievable. Conclusions: ESI CID spectra of [M + Li]+ adduct ions for individual glycal disaccharide analogues facilitate the discrimination between alpha and beta (1‐4) linked unsaturated disaccharides and their 2‐C‐branched analogues. Through optimized experimental conditions, complete baseline ion mobility separation of stereoisomer pairs of the Cs adducts is achieved. [ABSTRACT FROM AUTHOR]

Understanding the ionic conduction mechanisms in solid electrolyte glasses and glass-ceramics is an important task for improving the performance of next-generation all-solid-state batteries. Although many ionic conduction mechanisms have been proposed, the mechanism of increased ionic conductivity in partially crystallized glass is not fully understood. In this study, molecular dynamics was used to analyze the strain and local ion mobility in the glass around the crystal nano-particles of Li 3 PS 4 , which is a promising material for solid electrolytes. From the analysis of the results, we find that a local strain field is generated around the crystal particles and that the tensile strain field decreases the activation energy of ion migration and increases the ionic conductivity. This study opens the possibility of improving the ionic conductivity of glass-ceramics by controlling crystallization and dispersing the tensile strain field, even though the crystalline phase is not a high ionic conducting phase. [ABSTRACT FROM AUTHOR]

Ion Mobility coupled with Mass Spectrometry (IM-MS) is a promising analytical technique that enhances molecular characterization by measuring collision cross-section (CCS) values, which are indicative of the molecular size and shape. However, the effective application of CCS values in structural analysis is still constrained by the limited availability of experimental data, necessitating the development of accurate machine learning (ML) models for in silico predictions. In this study, we evaluated state-of-the-art Graph Neural Networks (GNNs), trained to predict CCS values using the largest publicly available dataset to date. Although our results confirm the high accuracy of these models within chemical spaces similar to their training environments, their performance significantly declines when applied to structurally novel regions. This discrepancy raises concerns about the reliability of in silico CCS predictions and underscores the need for releasing further publicly available CCS datasets. To mitigate this, we introduce Mol2CCS which demonstrates how generalization can be partially improved by extending models to account for additional features such as molecular fingerprints, descriptors, and the molecule types. Lastly, we also show how confidence models can support by enhancing the reliability of the CCS estimates. Scientific contribution We have benchmarked state-of-the-art graph neural networks for predicting collision cross section. Our work highlights the accuracy of these models when trained and predicted in similar chemical spaces, but also how their accuracy drops when evaluated in structurally novel regions. Lastly, we conclude by presenting potential approaches to mitigate this issue. [ABSTRACT FROM AUTHOR]

Developing new enantioselective reactions is an important part of chemical discovery but requires time and resources to test large arrays of potential reaction conditions. New techniques are required to analyse many different reactions quickly and efficiently. Mass spectrometry is a high‐throughput method; when combined with ion‐mobility spectrometry, this technique can monitor diastereomeric reaction intermediates and thus be a handle to study enantioselective reactions. Through this technique and others, it was noted before that in the organocatalytic 1,4‐addition to α,β‐unsaturated aldehydes, the abundance of initial diastereomeric intermediates correlates strongly to that of the final enantiomeric products. This work determines isomeric abundance for various catalysts and aldehydes and uses it to predict the enantiomeric excess of two control reactions. The prediction matches well for one reaction but does not predict the obtained results for the second. This finding confirms that the E/Z ratio of the iminium intermediates can be used as a predictor for some reactions, but the kinetics of the following steps can dramatically change the true enantioselectivity. [ABSTRACT FROM AUTHOR]

This study confirms the sodium lauryl sulfate (SLS) surfactant is effective to enhance water electrolysis performance especially when combined with NaCl. The water electrolysis experiment on different concentrations of SLS and SLS-NaCl mixture electrolyte were performed. The results indicate the presence of NaCl is more effective to enhance the SLS containing electrolyte performance instead of adding more SLS concentration. More SLS concentration is effective to enhance hydrogen evolution reaction (HER) when NaCl is added. The effectiveness of NaCl is shown by the order of final HER SLS 0.5 M + NaCl 3.9212 × 10−7 Mol. L−1, SLS 0.3 M + NaCl 3.8789 × 10−7 Mol. L−1, and, SLS 0.5 M 3.6758 × 10−7 Mol. L−1. The SLS creates positively charged micelles which increases ion mobility and HER. The NaCl accelerates the HER due to the formation of smaller ion clusters that react more quickly with the cathode. Therefore, this study reveals the mechanism of electrolysis enhancement by surfactant mixed electrolyte. [Display omitted] • Sodium Lauryl Sulfate (SLS) forms positively charged micelles. • SLS enhances hydrogen evolution reaction (HER) by carry water to cathode. • NaCl ion clusters improves SLS effectiveness to improve HER. • Na ion cluster has better electrostatic response towards cathode. • Cooperation of NaCl and SLS improves overall efficiency. [ABSTRACT FROM AUTHOR]

Current stage of proteomic research in the field of biology, medicine, development of new drugs, population screening, or personalized approaches to therapy dictates the need to analyze large sets of samples within the reasonable experimental time. Until recently, mass spectrometry measurements in proteomics were characterized as unique in identifying and quantifying cellular protein composition, but low throughput, requiring many hours to analyze a single sample. This was in conflict with the dynamics of changes in biological systems at the whole cellular proteome level upon the influence of external and internal factors. Thus, low speed of the whole proteome analysis has become the main factor limiting developments in functional proteomics, where it is necessary to annotate intracellular processes not only in a wide range of conditions, but also over a long period of time. Enormous level of heterogeneity of tissue cells or tumors, even of the same type, dictates the need to analyze biological systems at the level of individual cells. These studies involve obtaining molecular characteristics for tens, if not hundreds of thousands of individual cells, including their whole proteome profiles. Development of mass spectrometry technologies providing high resolution and mass measurement accuracy, predictive chromatography, new methods for peptide separation by ion mobility and processing of proteomic data based on artificial intelligence algorithms have opened a way for significant, if not radical, increase in the throughput of whole proteome analysis and led to implementation of the novel concept of ultrafast proteomics. Work done just in the last few years has demonstrated the proteome-wide analysis throughput of several hundred samples per day at a depth of several thousand proteins, levels unimaginable three or four years ago. The review examines background of these developments, as well as modern methods and approaches that implement ultrafast analysis of the entire proteome. [ABSTRACT FROM AUTHOR]

Chiral analysis is of high interest in many fields such as chemistry, pharmaceuticals and metabolomics. Mass spectrometry and ion mobility spectrometry are useful analytical tools, although they cannot be used as stand-alone methods. Here, we propose an efficient strategy for the enantiomer characterization of amino acids (AAs) using non-covalent copper complexes. A single ion mobility monitoring (SIM2) method was applied on a TIMS-ToF mass spectrometer to maximize the detection and mobility separation of isomers. Almost all of the 19 pairs of proteinogenic AA enantiomers could be separated with at least one combination with the chiral references L-Phe and L-Pro. Furthermore, we extended the targeted SIM2 method by stitching several mobility ranges, in order to be able to analyze complex mixtures in a single acquisition while maintaining high mobility resolution. Most of the enantiomeric pairs of AAs separated with the SIM2 method were also detected with this approach. The SIM2 stitching method thus opens the way to a more comprehensive chiral analysis with TIMS-ToF instruments. [ABSTRACT FROM AUTHOR]

nH-Perfluoroalkyl carboxylic acids (nH-PFCAs) are emerging pollutants. Their identification by ion mobility is frustrated by the nH-PFCAs having unexpectedly small collision cross sections (CCS). Theory and experiment agree that this is because nH-PFCA ions undergo internal hydrogen bridging, and this insight will help guide the creation of more accurate methods for pollutant identification. [ABSTRACT FROM AUTHOR]

We consider the problem of existence and properties of pulse solutions to a system of equations modeling fast calcium waves in long cells. These waves have the speed up to 1000 μ$$ \upmu $$m/s. They propagate via the inflow of calcium ions from the extracellular space through the mechanically stimulated membrane channels. The channels open due to mechano‐chemical interaction, in which stretching of the cell's membrane at a point opens the calcium channels at neighboring points due to the forces exerted by the actomyosin network. The existence of homoclinic solutions is based on the celebrated exchange lemma, which cannot be applied straightforwardly due to some specificities of the model equations. [ABSTRACT FROM AUTHOR]

Materials with high ion mobility are widely used in many fields of modern science and technology. Over the last 40 years, they have thoroughly changed our world. The paper characterizes the structural features of minerals and their synthetic analogs possessing this property. Special attention is paid to the ionic conductors with tetrahedral (zincite- and wurtzite-like), octahedral (ilmenite-like), and mixed (NASICON-like) frameworks. It is emphasized that the main conditions for fast ionic transport are related to the size and positions occupied by a mobile ion, their activation energy, the presence and diameter of conduction channels running inside the structure, isomorphic impurities, and other structural peculiarities. The results of the studies of solid electrolytes are dispersed in different editions, and the overview of new ideas related to their crystal structures was the focus of this paper. [ABSTRACT FROM AUTHOR]

This study established a simple, rapid, and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous quantification of contezolid and its major metabolite M2 in human plasma and cerebrospinal fluid (CSF). We used isotope-labeled internal standards (IS) along with protein precipitation to efficiently eliminate impurities. The ion transition was m/z 409.1 → 269.1 for contezolid, m/z 414.1 → 269.0 for contezolid-d5, m/z 445.1 → 385.1 for M2, and m/z 450.2 → 390.1 for M2-d5. The flow rate was 0.4 mL/min with a run time of 2.5 min. Validation results demonstrated that the calibration range was 10–5000 ng/mL for contezolid, and 5–2500 ng/mL for M2 in plasma and CSF. Both analytes exhibit excellent linear relationships (all R2 ≥ 0.99). Intra- and inter-batch accuracy and precision for all quality control (QC) levels were within ± 15%, including the lower limit of quantification (LLOQ). The recoveries of contezolid and M2 were 92.60–100.4% and 92.26–99.61% in plasma and 93.33–99.19% and 91.31–98.21% in CSF, respectively. The matrix effects for contezolid and M2 were 97.20–110.3% and 98.27–105.47% in plasma and 105.25–112.99% and 103.35–109.84% in CSF, respectively. The coefficients of variation (CV%) were ≤ 12.58%. Conteozolid and M2 remained stable in plasma and CSF. This study has established a simple and accurate method for determining contezolid and M2 in human plasma and CSF, making it a valuable tool for monitoring the efficacy of central nervous system (CNS) drugs. [ABSTRACT FROM AUTHOR]

Recently, ion mobility spectrometry‐mass spectrometry (IMS‐MS) has become more readily incorporated into various omics‐based workflows. These growing applications are due to developments in instrumentation within the last decade that have enabled higher‐resolution ion mobility separations. Two such platforms are the cyclic (cIMS) and structures for lossless ion manipulations (SLIM), both of which use traveling wave ion mobility spectrometry (TWIMS). High‐resolution separations achieved with these techniques stem from the drastically increased pathlengths, on the order of 10 s of meters to >1 km, in both cIMS‐MS and SLIM IMS‐MS, respectively. Herein, we highlight recent developments and advances, for the period 2019–2023, in high‐resolution traveling wave‐based IMS‐MS through instrumentation, calibration strategies, hyphenated techniques, and applications. Specifically, we will discuss applications including CCS calculations in multipass IMS‐MS separations, coupling of IMS‐MS with chromatography, imaging, and cryogenic infrared spectroscopy, and isomeric separations of glycans, lipids, and other small metabolites. [ABSTRACT FROM AUTHOR]

Human milk oligosaccharides (HMOs) are an important class of biomolecules responsible for the healthy development of the brain‐gut axis of infants. Unfortunately, their accurate characterization is largely precluded due to a variety of reasons – there are over 200 possible HMO structures whereas only 10s of these are available as authentic analytical standards. Furthermore, their isomeric heterogeneity stemming from their many possible glycosidic linkage positions and corresponding α/β anomericities further complicates their analyses. While liquid chromatography coupled to tandem mass spectrometry remains the gold standard for HMO analyses, it often times cannot resolve all possible isomeric species and thus warrants the development of other orthogonal approaches. High‐resolution ion mobility spectrometry coupled to mass spectrometry has emerged as a rapid alternative to condensed‐phase separations but largely has remained limited to qualitative information related to the resolution of isomers. In this work, we have assessed the use of permethylation to improve both the resolution and sensitivity of HMO analyses with cyclic ion mobility separations coupled with mass spectrometry. In addition to this, we have developed the first‐ever high‐resolution collision cross‐section database for permethylated HMOs using our previously established calibration protocol. We envision that this internal reference database generated from high‐resolution cyclic ion mobility spectrometry‐mass spectrometry will greatly aid in the accurate characterization of HMOs and provide a valuable, orthogonal, approach to existing liquid chromatography–tandem mass spectrometry‐based methods. [ABSTRACT FROM AUTHOR]

An ion mobility mass spectrometry (IM‐MS) investigation using a Synapt G2 mass spectrometer was conducted to separate anions generated from the three regioisomers of sulfobenzoic acid. The results revealed that the differences in arrival time distributions (ATDs) were inadequate to differentiate the isomers unambiguously. However, the ATD profiles of the product ions, generated by fragmenting the respective mass‐selected m/z 201 precursor ions in the Trap region of the three‐compartment traveling‐wave ion guide of the Synapt G2 mass spectrometer, were distinctly different, enabling definitive differentiation of the isomers. An arrival‐time peak for an ion of m/z 157 resulting from the loss of CO2 from the respective precursors was common to all three mobilograms. However, only the profile recorded from the para‐isomer exhibited a unique arrival‐time peak for an ion of m/z 137, originating from an SO2 loss. Such a peak corresponding to an SO2 loss was absent in the ATD profiles of the ortho‐ and meta‐isomers. Additionally, the mobilogram of the meta‐isomer displayed a unique peak at 3.42 ms. Based on its product ion spectrum, this peak was attributed to the bisulfite anion (m/z 81; HSO3ˉ). Previously, this meta‐isomer specific m/z 81 ion had been proposed to originate from a two‐step process involving the intermediacy of an m/z 157 ion formed by CO2 loss. However, our detailed tandem mass spectrometric experiments suggest that the m/z 81 is not a secondary product but rather an ion that originated from a direct elimination of a benzyne derivative from the m/z 201 precursor ion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sodium ions inside biomolecular condensates experience heterogeneous dynamics. • An integrative 23Na NMR relaxation-based approach is developed. • This approach allows separating contribution of various sodium ion populations. • Three populations of sodium ions with distinct dynamics detected in agarose gels. Metal ions, including biologically prevalent sodium ions, can modulate electrostatic interactions frequently involved in the stability of condensed compartments in cells. Quantitative characterization of heterogeneous ion dynamics inside biomolecular condensates demands new experimental approaches. Here we develop a 23Na NMR relaxation-based integrative approach to probe dynamics of sodium ions inside agarose gels as a model system. We exploit the electric quadrupole moment of spin-3/2 23Na nuclei and, through combination of single-quantum and triple-quantum-filtered 23Na NMR relaxation methods, disentangle the relaxation contribution of different populations of sodium ions inside gels. Three populations of sodium ions are identified: a population with bi-exponential relaxation representing ions within the slow motion regime and two populations with mono-exponential relaxation but at different rates. Our study demonstrates the dynamical heterogeneity of sodium ions inside agarose gels and presents a new experimental approach for monitoring dynamics of sodium and other spin-3/2 ions (e.g. chloride) in condensed environments. [ABSTRACT FROM AUTHOR]