Fragment Mass Research Articles

Synthesis, anticancer, anti‐inflammatory, antimicrobial activities, molecular docking, and Density functional theory studies of nanometal (IV) glycoconjugates

Oxovanadium (IV) and diphenyltin (IV) complexes were synthesized on the nanoscale based on the Schiff base (H2L) derived from salicylaldehyde and d‐glucosamine. The complexes were formed with a molar ratio of 1:1 and 1:2 (metal: dligand) relative to oxovanadium (IV) and diphenyltin (IV), respectively. Fourier‐transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance, mass fragmentations, electronic transitions, thermogravimetric analysis, and density functional theory were employed to validate the structure of synthesized compounds. The results demonstrated that the ligand (H2L) was successfully attached to oxovanadium (IV) and diphenyltin (IV) as di‐anionic and mono‐anionic ligands, respectively. The size of the complexes was investigated using the transmission scanning microscope. The work presents a prospective concept for the drug design of the targeted anticancer through the glucose moiety. All compounds revealed remarkable anticancer activities against the colorectal (HCT‐116) cell line, recording IC50 values 4.94, 21.73, and 62.5 μg/ml for VO (II)(L), free H2L, and Sn (ph)2(HL)2, respectively. The IC50 value of VO (II)(L) complex was increased after the quercetin inhibitor. Therefore, the sugar‐conjugated compound can be recognized by the glucose recognition binding site of GLUT and their cell‐killing effect depends highly on the GLUT inhibitor, quercetin. The potential GLUT transportability of the compounds was investigated through a molecular docking study. The anti‐migration activity was investigated for VO (II)(L) complex. The free ligand observed the best antimicrobial results. The antibacterial stimulation was investigated and represented different interaction types with the selected ribosyl transferase enzyme.

UHPLC-MS/MS Technique: Applications in Analytical Chemistry

The ultra-high performance liquid chromatography-mass spectrometry/mass spectrometry (UHPLC-MS/MS) is becoming most advanced technique used for analysis of wide range of compounds in analytical chemistry. This technique has been effectively utilized for identifying and quantitatively determining substances in several pharmaceutical analysis fields. The UHPLC technique offers superior sensitivity, selectivity and peak shape in comparison to the conventional HPLC technique. The UHPLC coupled with various mass spectrometers gives accurate mass fragmentations which is ultimately helpful in structural identification and quantitative determination of compounds. The review provides brief introduction on development of UHPLC column packing materials and coupled mass detectors such as single quadrupole, triple quadrupole and time-of-flight mass. This review article also summarizes application of UHPLC-MS/MS technique in various fields of analytical chemistry.

Peeking into the Stingers: A Comprehensive SWATH-MS Study of the European Hornet Vespa crabro (Linnaeus, 1758) (Hymenoptera: Vespidae) Venom Sac Extracts.

This study aimed to investigate the venom sac extracts (VSEs) of the European hornet (EH) Vespa crabro (Linnaeus, 1758) (Hymenoptera: Vespidae), focusing on the differences between stinging females, gynes (G), and workers (W), at the protein level. Using a quantitative "Sequential Window Acquisition of all Theoretical Fragment Ion Mass Spectra" (SWATH-MS) analysis, we identified and quantified a total of 240 proteins. Notably, within the group, 45.8% (n = 110) showed significant differential expression between VSE-G and VSE-W. In this set, 57.3% (n = 63) were upregulated and 42.7% (n = 47) downregulated in the G. Additionally, the two-hundred quantified proteins from the class Insecta belong to sixteen different species, six of them to the Hymenoptera/Apidae lineage, comprising seven proteins with known potential allergenicity. Thus, phospholipase A1 (Vesp v 1), phospholipase A1 verutoxin 2b (VT-2b), hyaluronidase A (Vesp v 2A), hyaluronidase B (Vesp v 2B), and venom allergen 5 (Vesp v 5) were significantly downregulated in the G, and vitellogenin (Vesp v 6) was upregulated. Overall, 46% of the VSE proteins showed differential expression, with a majority being upregulated in G. Data are available via ProteomeXchange with identifier PXD047955. These findings shed light on the proteomic differences in VSE between EH castes, potentially contributing to our understanding of their behavior and offering insights for allergy research.

Enhanced prokaryotic expression, purification, and biological activities of human keratinocyte growth factor

Keratinocyte growth factor (KGF), also known as fibroblast growth factor 7 (FGF7), plays a critical role in embryonic development, cell proliferation, and differentiation. However, efficient production of recombinant KGF remains a challenge due to its low expression levels and high tendency for aggregation in Escherichia coli. This study aimed to enhance the expression and solubility of KGF by employing different protein tags—PDIb'a', MBP, and His—fused to the N-terminus of KGF. Among these, H-PDIb'a'-KGF demonstrated superior stability and was selected for large-scale production and purification. The purified KGF was confirmed through liquid chromatography with tandem mass spectrometry analysis, which showed an 81% fragment mass identification coverage. Biological activity assessments using human breast cancer MCF-7 cells indicated that purified KGF significantly increased cell proliferation, with an EC50 of 6.4 ± 0.5 pM. Interestingly, PDIb'a' alone also exhibited a stimulatory effect on MCF-7 cells. Furthermore, the purified KGF enhanced the wound healing of HaCaT keratinocytes in a dose-dependent manner. These findings provide valuable insights into the efficient production and functional characterization of recombinant KGF for potential applications in therapeutic interventions.

Fabrication and characterization of highly enriched thin 176Yb targets for the reaction dynamic studies on fission mass distribution

The fabrication, transfer, and storage of a highly enriched isotopic target is very much crucial because of air gases and moistures being chemically active at room temperature. One must limit the amount of time that the target surface is exposed to the atmosphere during the transfer of air sensitive targets. The highly interactive targets are not easy to store for longer time and demand an in-vacuum transfer facility. Getting an alternative technique to remove all such imperative is a need of the hour specially for the nuclear physics community, more particularly for reaction dynamic studies of fission fragment mass distribution induced by stable and radioactive ion beams. Highly enriched materials are rare and very expensive, so an effective and highly efficient technique is needed to deal with such materials. Here, an attempt has been made to fabricate 96.63% enriched thin targets of 176Yb by evaporation techniques enabling ≈129.1 μg/cm2 thickness with a ≈25.93 μg/cm2 carbon backing to increase its stability and durability. Numerous trials have been performed using natural Yb to optimize the evaporation setup and associated growth parameters for efficient Yb isotope deposition with thin film deposition unit and diffusion pump based coating unit at Inter University Accelerator Centre (IUAC), New Delhi. Thickness and elemental composition of the targets have been analysed using characterization techniques such as X-ray diffraction, α-energy loss technique, Rutherford backscattering spectroscopy and energy dispersive X-ray spectroscopy. Essentially no significant impurities are found by these measurements, describing high purity and robustness of the fabricated targets. During the nuclear experiments, 30Si and 16O beams of intensity of the order of ≈1010 particles per second were bombarded on the targets for 5–6 days and no ill effects on the target were observed. Isotopic abundance of the target has been obtained experimentally, which ensured the isotopic purity of the target required for the reaction studies. This article will admire our readers about the qualitative nature of the fabrication technique, measurement and characterization citing valuable insights, aiding in a comprehensive understanding of their quality.

Mechanism-Guided Discovery of Cleavable Comonomers for Backbone Deconstructable Poly(methyl methacrylate).

The development of cleavable comonomers (CCs) with suitable copolymerization reactivity paves the way for the introduction of backbone deconstructability into polymers. Recent advancements in thionolactone-based CCs, exemplified by dibenzo[c,e]-oxepine-5(7H)-thione (DOT), have opened promising avenues for the selective deconstruction of multiple classes of vinyl polymers, including polyacrylates, polyacrylamides, and polystyrenics. To date, however, no thionolactone CC has been shown to copolymerize with methacrylates to an appreciable extent to enable polymer deconstruction. Here, we overcome this challenge through the design of a new class of benzyl-functionalized thionolactones (bDOTs). Guided by detailed mechanistic analyses, we find that the introduction of radical-stabilizing substituents to bDOTs enables markedly increased and tunable copolymerization reactivity with methyl methacrylate (MMA). Through iterative optimizations of the molecular structure, a specific bDOT, F-p-CF3PhDOT, is discovered to copolymerize efficiently with MMA. High molar mass deconstructable PMMA-based copolymers (dPMMA, Mn > 120 kDa) with low percentages of F-p-CF3PhDOT (1.8 and 3.8 mol%) are prepared using industrially relevant bulk free radical copolymerization conditions. The thermomechanical properties of dPMMA are similar to PMMA; however, the former is shown to degrade into low molar mass fragments (<6.5 kDa) under mild aminolysis conditions. This work presents the first example of a radical ring-opening CC capable of nearly random copolymerization with MMA without the possibility of cross-linking and provides a workflow for the mechanism-guided design of deconstructable copolymers in the future.

Decaying turbulence in molecular clouds: how does it affect filament networks and star formation?

ABSTRACT The fragmentation of gas to form stars in molecular clouds is intrinsically linked to the turbulence within them. These internal motions are set at the birth of the cloud and may vary with galactic environment and as the cloud evolves. In this paper, we introduce a new suite of 15 high-resolution 3D molecular cloud simulations using the moving mesh code arepo to investigate the role of different decaying turbulent modes (mixed, compressive, and solenoidal) and virial ratios on the evolution of a $10^4\, \mathrm{M}_{\odot }$ molecular cloud. We find that diffuse regions maintain a strong relic of the initial turbulent mode, whereas the initial gravitational potential dominates dense regions. Solenoidal seeded models thus give rise to a diffuse cloud with filament-like morphology, and an excess of brown dwarf mass fragments. Compressive seeded models have an early onset of star-formation, centrally condensed morphologies and a higher accretion rate, along with overbound clouds. 3D filaments identified using disperse and analysed through a new python toolkit we develop and make publicly available with this work called fiesta, show no clear trend in lengths, masses and densities between initial turbulent modes. Overbound clouds, however, produce more filaments and thus have more mass in filaments. The hubs formed by converging filaments are found to favour star-formation, with surprisingly similar mass distributions independent of the number of filaments connecting the hub.

Characterization of PEGylation sites in Neulasta and a biosimilar candidate with a combined fragmentation strategy in mass spectrometry analysis.

In the development of biosimilar products to Neulasta, it is essential to determine the intact molecular mass and confirm precise PEGylation sites. In this study, we applied a combination of techniques, including post-column addition of triethylamine in reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) to determine the intact molecular mass, and in-source fragmentation (ISF) and higher-energy collision dissociation-tandem mass spectrometry (HCD-MS/MS) to identify the PEGylation site. Our results show that both the pegfilgrastim biosimilar candidate and Neulasta lots are mono-PEGylated at the N-terminal end. Furthermore, we show that the combined ISF and HCD-MS/MS method can be used for identifying the PEGylation sites in the diPEGylated variant of pegfilgrastim. The diPEGylated variant has modification sites at the N-terminal end and a lysine at position 35 in the protein sequence.

Prediction of glycopeptide fragment mass spectra by deep learning

Deep learning has achieved a notable success in mass spectrometry-based proteomics and is now emerging in glycoproteomics. While various deep learning models can predict fragment mass spectra of peptides with good accuracy, they cannot cope with the non-linear glycan structure in an intact glycopeptide. Herein, we present DeepGlyco, a deep learning-based approach for the prediction of fragment spectra of intact glycopeptides. Our model adopts tree-structured long-short term memory networks to process the glycan moiety and a graph neural network architecture to incorporate potential fragmentation pathways of a specific glycan structure. This feature is beneficial to model explainability and differentiation ability of glycan structural isomers. We further demonstrate that predicted spectral libraries can be used for data-independent acquisition glycoproteomics as a supplement for library completeness. We expect that this work will provide a valuable deep learning resource for glycoproteomics.

Production and bioprocessing of Taxol from Aspergillus niger, an endophyte of Encephalartos whitelockii, with a plausible biosynthetic stability: antiproliferative activity and cell cycle analysis

The biosynthetic potency of Taxol by fungi raises their prospective to be a platform for commercial production of Taxol, nevertheless, the attenuation of its productivity with the fungal storage, is the challenge. Thus, screening for a novel fungal isolate inhabiting ethnopharmacological plants, with a plausible metabolic stability for Taxol production could be one of the most affordable approaches. Aspergillus niger OR414905.1, an endophyte of Encephalartos whitelockii, had the highest Taxol productivity (173.9 μg/L). The chemical identity of the purified Taxol was confirmed by HPLC, FTIR, and LC–MS/MS analyses, exhibiting the same molecular mass (854.5 m/z) and molecular fragmentation pattern of the authentic Taxol. The purified Taxol exhibited a potent antiproliferative activity against HepG-2, MCF-7 and Caco-2, with IC50 values 0.011, 0.016, and 0.067 μM, respectively, in addition to a significant activity against A. flavus, as a model of human fungal pathogen. The purified Taxol displayed a significant effect against the cellular migration of HepG-2 and MCF-7 cells, by ~ 52–59% after 72 h, compared to the control, confirming its interference with the cellular matrix formation. Furthermore, the purified Taxol exhibited a significant ability to prompt apoptosis in MCF-7 cells, by about 11-fold compared to control cells, suppressing their division at G2/M phase. Taxol productivity by A. niger has been optimized by the response surface methodology with Plackett–Burman Design and Central Composite Design, resulting in a remarkable ~ 1.6-fold increase (279.8 μg/L), over the control. The biological half-life time of Taxol productivity by A. niger was ~ 6 months of preservation at 4 ℃, however, the Taxol yield by A. niger was partially restored in response to ethyl acetate extracts of E. whitelockii, ensuring the presence of plant-derived signals that triggers the cryptic Taxol encoding genes.

Fragmentation of water clusters formed in helium nanodroplets by charge transfer and Penning ionization.

Helium nanodroplets ("HNDs") are widely used for forming tailor-made clusters and molecular complexes in a cold, transparent, and weakly interacting matrix. The characterization of embedded species by mass spectrometry is often complicated by the fragmentation and trapping of ions in the HNDs. Here, we systematically study fragment ion mass spectra of HND-aggregated water and oxygen clusters following their ionization by charge transfer ionization ("CTI") and Penning ionization ("PEI"). While the efficiency of PEI of embedded clusters is lower than for CTI by about factor 10, both the mean sizes of detected water clusters and the relative yields of unprotonated cluster ions are significantly larger, making PEI a "soft ionization" scheme. However, the tendency of ions to remain bound to HNDs leads to a reduced detection efficiency for large HNDs containing >104 helium atoms. These results are instrumental in determining optimal conditions for mass spectrometry and photoionization spectroscopy of molecular complexes and clusters aggregated in HNDs.

Testing the fragmentation of railway ballast material by laboratory methods using Proctor compactor

The physical classification of crushed stone and gravel used in railway construction is based on their strength and endurance and is performed by a laboratory test method using a rotating drum or a mortar method. The values of fracture resistance calculated using the Los Angeles method and abrasion calculated using the Micro-Deval method show a corresponding correlation and require further investigation. Purpose. The development of a new method for measuring rock material fracture that is consistent with widely used standards while also being more comparable to real-world railway operating conditions. Certainly, both standard tests are essential for ensuring product homogeneity during production, so the new recommended method is only a supplement. Methodology. The Proctor device was used to induce so-called shock loads from above, similar to railway loading conditions. Unlike the standard method, the andesite material was placed in a standard cylinder in these tests. The samples were pre-screened and sorted; the specified weight was approximately 1,300 g, and the specified sizes of the individual particles were 6.3, 8.0 and 11.2 mm. Only prewashed and dried materials of NZ (fine crushed stone) or KZ (special crushed stone) from four different quarries (Tállya, Szob, Nógrádkövesd, Recsk) with different rock physics characteristics were considered. The Proctor compactor machine was used because of its calculable labor (19.86 J/impact) and the crushing effect of the calculable impacts (64, 128, 256 and 1,028 blows). Even after loading different numbers of impacts, homogeneous samples from different quarries were sieved to measure the masses of fragments per fraction. Findings. The set of measurements made it possible to establish a series of fragmentation and degradation curves for each of the three repeated measurements based on the composition of the material and the number of blows, which showed the degradation of samples with different physical and mechanical properties of the rock material and particle sizes. With an increasing number of impacts, the amount of crushed material in the sample increased, but the distribution of crushed material did not decrease evenly and proportionally as the number of impacts increased. Parameters and indices were also computed to identify various correlations (i. e., FV, d &lt; 22.4, d &lt; 0.5, d &lt; 0.063 mm, CU, M ratio,  ratio). Some of them (e. g., FV) needed to be changed, but they were predefined due to the nature of the tests. Originality. While many standard and alternative railway track ballast fragmentation test methods and measurement tools are available, this paper proposes a new laboratory method and demonstrates the specific measurement and application effectiveness. Practical value. In addition to standard tests that are already widely used, the new method for measuring the fractional composition of railway ballast can help simulate real-world operating conditions of a railroad track in the laboratory. This method will improve the safety of railway operations.

Development and Validation of Simple and Stable LCMS Method for the Quantification of Potential Genotoxic Impurities in Ozenoxacin Pure Drug and its Commercial Preparations

Ozenoxacin is an antibiotic drug prescribed to treat various skin infections caused by various bacteria. Various chemical mechanisms such as stille coupling, Buchwald–Hartwig coupling, cyclization and saponification are involved during the process of synthesis of Ozenoxacin. In the process of synthesis, there is a possibility of the formation of related impurities and among them, some are genotoxic impurities. To date, in literature, there is no method reported for analysing Potential Genotoxic Impurities (PGIs) in Ozenoxacin and hence this study was initiated to develop an LCMS method for quantification of two genotoxic impurities of Ozenoxacin viz., nitroso impurity, ester impurity. The analytes were resolved on Alltima C18 column (150×4.6mm; 5 μm particle size) using 0.01 mM ammonium acetate at pH 4.8 and methanol in 80:20 (v/v) at 0.5 mL/min flow rate and 10 μ sample injection volume. The multiple reaction monitoring of the mass fragments confirms the parent ion at m/z of 364, 393 and 496 for Ozenoxacin, Nitroso and Ester impurity respectively with characteristic product ion at m/z 196. The method has a linearity range of 0.05 μg/mL to 1.0 μg/mL for three analytes with detection limits of 0.015, 0.011 and 0.015 μg/mL for Ester impurity, Ozenoxacin and Nitroso impurity respectively. The method was validated and produces acceptable results and can successfully separate the potential genotoxic impurities in spiked commercial samples. Based on the findings, it was concluded that this method can be practically useful for the identification and quantification of potential genotoxic impurities and may apply to the safe use of Ozenoxacin in clinical treatment.

Differentiation of isomeric chalcone and dihydroflavone using liquid chromatography coupled with hydrogen-deuterium exchange tandem mass spectrometry (HDX-MS/MS): An application for flavonoids-focused characterization of Snow chrysanthemum

Although the co-occurrences of isomeric chalcones and dihydroflavones widely appear in medicinal plants, the differentiation of such isomerism seldom succeeds using MS/MS, attributing to totally identical MS/MS spectra. Here, efforts were paid to pursue an eligible tool allowing to address the technical challenge. Being inspired by that one more proton signal is observed in 1H NMR spectrum of isoliquiritigenin than liquiritigenin when employing DMSO‑d6 as solvent, hydrogen-deuterium exchange (HDX)-MS/MS was evaluated towards differentiating isomeric chalcones and dihydroflavones through replacing H2O with D2O to prepare the mobile phase. As a result, differences were observed for either MS1 or MS2 spectrum when comparing two pairs of isomers, such as liquiritigenin vs. isoliquiritigenin and liquiritin vs. isoliquiritin, because the isomeric precursor and fragment ion species owned different amounts of hydroxyl protons and those reactive protons could be partially or completely substituted by deuterium protons at the exposure in D2O to result in n × 1.006 mass increments. Moreover, utmost four hydrogen/deuterium exchanges occurred for a single glucosyl moiety. Thereafter, HDX-MS/MS was applied to characterize the flavonoids of Snow chrysanthemum, a precious edible herbal medicine that is rich in isomeric chalcones and dihydroflavones. Through paying special attention to the deuterium labeling styles of (de)protonated molecules as well as those featured fragment ions, five pairs of isomeric chalcones and dihydroflavones were confirmatively differentiated, in addition to that 28 flavonoids were structurally annotated by applying those well-defined mass fragmentation rules. Hence, this study offered an in-depth insight towards the flavonoids-focused characterization of Snow chrysanthemum, and more importantly, HDX-MS/MS is a superior tool to differentiate, but not limited to, isomeric chalcones and dihydroflavones.

High-velocity oblique impact experiments on ice and snow spheres: Implications for the collisional evolution of icy planetesimals at different thermal evolution stages

In order to determine the effect of impact angle on the impact strength of icy planetesimals, we conducted a range of oblique impact experiments for spherical ice and snow targets simulating icy planetesimals at different thermal evolution stages. The ice targets had no porosity and the snow targets had a porosity of 0.5. A polycarbonate or glass sphere impacted the ice targets at 744–1747 m s−1 and the snow targets at 938–5085 m s−1 over a range of impact angles from grazing to head-on collisions. All experiments were conducted using a two-stage light gas gun and a target chamber set in a cold room of −15 °C at Kobe University, Japan. The impact strength, which is a specific energy, Q, when the largest fragment mass is a half of the original target mass, for the ice and snow targets in a head-on collision was determined to be 12 and 520 J kg−1, respectively, whereas it was found that the impact strength depended on the impact velocity. Thus, the normalized largest fragment mass, ml/Mt, could well scale with the velocity dependent Q, that is, Qviγ (where ml and Mt are the masses of largest fragment and target, respectively, and vi is the impact velocity). At high Q, ml/Mt increased drastically with the decrease of impact angle when the impact angle was smaller than a critical angle, θc, and θc~30° for the ice targets and θc~45° for the snow targets. At small Q, ml/Mt continued to increase as the impact angle became smaller for both types of targets. The ml/Mt for oblique impacts had a good correlation with the effective specific energy, Qeff=Qsin2θ, where θ is the impact angle, and the effective impact strength was determined to be 16 J kg−1 and 499 J kg−1 for the ice and snow targets, irrespective of the impact angle. Furthermore, the scaling parameter, Πs_eff, which was proposed by Housen and Holsapple (1990) but includes Qeff instead of Q, multiplied by 1−ϕλ, where ϕ is the porosity, showed even better correlation with ml/Mt, and all ml/Mt data of ice and snow targets could be merged, irrespective of impact velocity and ϕ. Based on our experimental results and a theory on the oblique impact of solar system bodies proposed by Shoemaker (1962), we could estimate the degree of disruption (ml/Mt) at any impact energy and any impact angle for icy planetesimals. Our findings demonstrate that the degree of disruption for icy planetesimals that have experienced sufficient thermal evolution was larger than that for those that did not experience significant thermal evolution.

Integrative Analysis of Cytokine and Lipidomics Datasets Following Mild Traumatic Brain Injury in Rats.

Traumatic brain injury (TBI) is a significant source of disability in the United States and around the world and may lead to long-lasting cognitive deficits and a decreased quality of life for patients across injury severities. Following the primary injury phase, TBI is characterized by complex secondary cascades that involve altered homeostasis and metabolism, faulty signaling, neuroinflammation, and lipid dysfunction. The objectives of the present study were to (1) assess potential correlations between lipidome and cytokine changes after closed-head mild TBI (mTBI), and (2) examine the reproducibility of our acute lipidomic profiles following TBI. Cortices from 54 Sprague Dawley male and female rats were analyzed by ultra-high-performance liquid chromatography mass spectrometry (LC-MS) in both positive and negative ionization modes and multiplex cytokine analysis after single (smTBI) or repetitive (rmTBI) closed-head impacts, or sham conditions. Tissue age was a variable, given that two cohorts (n = 26 and n = 28) were initially run a year-and-a-half apart, creating inter-batch variations. We annotated the lipidome datasets using an in-house data dictionary based on exact masses of precursor and fragment ions and removed features with statistically significant differences between sham control batches. Our results indicate that lipids with high-fold change between injury groups moderately correlate with the cytokines eotaxin, IP-10, and TNF-α. Additionally, we show a significant decrease in the pro-inflammatory markers IL-1β and IP-10, TNF-α, and RANTES in the rmTBI samples relative to the sham control. We discuss the major challenges in correlating high dimensional lipidomic data with functional cytokine profiles and the implications for understanding the biological significance of two related but disparate analysis modes in the study of TBI, an inherently heterogeneous neurological disorder.

Measurement of mass-angle and mass-total kinetic energy distributions from the fission of 190Pt compound nucleus

We have measured the fission fragment mass-angle and mass-total kinetic energy (TKE) distributions for the neutron-deficient 190Pt compound nucleus (CN) populated via 12C + 178Hf reaction, at around and above barrier energies. No mass-angle correlation was observed in the fission of 190Pt signifying the absence of quasi-fission events in the studied reaction. The observed mass-TKE distributions have expected triangular shape and TKE distributions are well described with the single Gaussian fits, and mean TKE shows parabolic dependence on fragment mass as predicted based on liquid drop fission behaviour. The widths of measured TKE distributions agree well with the observed systematics for CN fission in this mass region. Though the CN is relatively neutron deficient, these observations suggest a clear picture of true CN fission behaviour for the chosen reaction in the studied energy domain.

Benchmarking of Coatings for Cathode Active Materials in Solid-State Batteries Using Surface Analysis and Reference Electrodes.

Fast and reliable evaluation of degradation and performance of cathode active materials (CAMs) for solid-state batteries (SSBs) is crucial to help better understand these systems and enable the synthesis of well-performing CAMs. However, there is a lack of well-thought-out procedures to reliably evaluate CAMs in SSBs. Current approaches often rely on X-ray photoelectron spectroscopy (XPS) for the evaluation of degradation. Unfortunately, XPS sensitivity is not very high, and minor but relevant degradation products may not be detected and distinguished. Furthermore, degradation caused by the current collector (CC) itself is usually not distinguished from CAM-induced degradation. This study uses a modified CC, which allows us to separate electrochemical degradation caused by the CC from degradation at the CAM itself. Using this CC, we present an approach using time-of-flight secondary ions mass spectrometry (ToF-SIMS) that offers high sensitivity and reliability. Principal component analysis (PCA) is applied to differentiate secondary ions as well as identify those mass fragments that correlate with degradation products. This approach also enables distinguishing between different pathways of degradation. To evaluate the kinetic performance of the samples, three-electrode rate tests are performed. Electrochemical characterization evaluates the kinetic performance of the samples under investigation. The samples are finally rated with a score that allows a reliable comparison between the different materials and offers a complete picture of the materials' characteristics in terms of electrochemical performance and degradation.

GO@dopamine-Cu as a Green Nanocatalyst for the Efficient Synthesis of Fully Substituted Dihydrofuran-2(5H)-ones

A new nanocatalyst graphene oxide@dopamine-Cu was synthesized, and its structure was characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDX), and thermogravimetric analysis – differential thermal analysis (TGA-DTA) techniques. The three-component one-pot reaction between an arylamine, aromatic aldehyde, and acetylenic carboxylate was achieved and formed methyl 5-oxo-2-aryl-4-(arylamino)-2,5-dihydrofuran-3-carboxylate derivatives (4) in the presence of the catalytic amount of graphene oxide@dopamine-Cu nanocatalyst in high yield. Molecular structures of products were characterized by FT-IR, 1H, 13C nuclear magnetic resonance (NMR), and Mass spectroscopy techniques. Representatively, the mass fragmentation of 4a was discussed, and the structure was confirmed. Easy reaction, high performance, and easy catalyst recyclability are the main advantages of this work. This nanocatalyst is recycled up to five successive runs.

PolyMatch: Novel Libraries, Algorithms, and Visualizations for Discovering Polymers and Chemical Series.

Polymers are integral components of everyday products, ranging from plastics and emulsifiers to lubricants and detergents. Characterization of these materials at the molecular level is essential to understanding their physicochemical properties and potential health impacts, considering factors such as the number of repeating units, chemical moieties, functional groups, and degree of unsaturation. This study introduces a free open-source vendor neutral software, PolyMatch, designed to annotate polysorbates, polysorbides, polyethylene glycols (PEGs), fatty acid esterified species, and related chemical species based on mass spectral and chromatographic patterns inherent in the repeating nature of chemical moieties. PolyMatch facilitates the generation of MS/MS libraries for polymeric chemical species characterization (with over 800 000 structures with associated fragment masses already built in) and covers the entire liquid chromatography-high-resolution mass spectrometry (LC-HRMS/MS) data-processing workflow. PolyMatch covers peak picking, blank filtering, annotation, data visualization, and sharing of interactive data sets via an HTML link to the community. The software was applied to a Tween 80 mixture, using LC-HRMS/MS on an Agilent 6546 Q-TOF instrument with iterative exclusion for comprehensive fragmentation coverage. PolyMatch automatically assigned 86 features with high confidence at the species level, 362 based on PEG containing fragments and accurate mass matching to a simulated polymer database, and over 10 000 based on being a member of a homologous series (three or more) with CH2CH2O repeating units. The ease of use of PolyMatch and comprehensive coverage with species level assignment is expected to contribute to the advancement of materials science, health research, and product development.