Small Peak Research Articles

Defects related vortex dynamics behaviors in the ‘1144’-type iron-based superconductors

Abstract We have synthesized ‘1144’- type (Ca1-xPrxKFe4As4 and CaKFe4As4), and ‘122’-type (Ba0.6K0.4Fe2As2 and Ba0.6Rb0.4Fe2As2) iron-based superconductors. Based on these crystals, we have investigated the vortex dynamics of the ‘1144’- and ‘122’-type iron-based superconductors. The results indicate that the novel flux dynamics behaviors of ‘1144’-type iron-based superconductors are closely related to their defect structures. Firstly, the intergrowths in ‘1144’-type superconductors can function as columnar defects under the applied magnetic field H // ab-plane, which results in a dip structure in the magnetization hysteresis loops (MHLs) near zero field due to the self-field effect. Secondly, the intergrowths as strong pinning sites provide a large pulling force to the flux lines and cause a small magnetization peak at temperatures below 10 K under magnetic fields from about 3 to 7 T in MHLs for the ‘1144’-type superconductors. Thirdly, there may be a vortex entanglement due to the presence of strong pinning centers, which impedes the Elastic to Plastic motion of vortices (E-P phase transition) resulting in a weak second magnetization peak (SMP) effect in the bulk ‘1144’-type superconductors. Fourthly, the intergrowths introduce disorder into the superconductors and accelerate the magnetic 3D-to-2D transition, which causes the thickness-dependent Jc and SMP effect due to the rigidity of flux lines with the reducing sample thickness. The present results are significant for us to understand the relationship between the flux pinning behaviors and the defect structures for a superconductor.

Arabinogalactan-ethyl cellulose films from Pereskia aculeata Miller for pharmaceutical applications

This research aimed to produce and evaluate films containing arabinogalactan, extracted from Pereskia aculeata Miller leaves, combined with ethyl cellulose for potential pharmaceutical applications. Films were prepared using solvent casting with varying concentrations of arabinogalactan (0%, 5%, 10%, 20%) and ethyl cellulose. Crosslinking of arabinogalactan was performed using sodium trimetaphosphate. Films were characterized using FT-IR, XRD, TGA, DSC, SEM, water vapor transmission (WVT), and swelling index (Si%) tests. FT-IR and XRD confirmed successful crosslinking and incorporation of arabinogalactan. Thermal analyses revealed improved stability in arabinogalactan-containing formulations. XRD showed amorphous character in natural arabinogalactan films, while crosslinked samples exhibited small peaks indicating potential crystalline organization. WVT analysis demonstrated increased permeability with higher arabinogalactan concentrations. Si% tests revealed higher swelling in simulated intestinal fluid compared to gastric fluid, with crosslinked formulations showing reduced swelling. SEM confirmed a more expanded polymeric mesh in formulations with higher arabinogalactan content, especially at alkaline pH. These results demonstrate that the ethylcellulose-arabinogalactan composite shows promise for controlled release applications, with properties that can be tailored through arabinogalactan concentration and crosslinking. This study provides a foundation for future research into sustainable materials for modified drug delivery technologies.

Extra-cavity modulating a dark bisoliton

Abstract Although the concept of modulating optical solitons out of fiber laser cavities has already been proposed, to more flexibly change optical solitons’ time or frequency domain properties, compared with traditional intra-cavity modulation. The extra-cavity modulation of dark bisolitons has seldom been touched upon. In this manuscript, we theoretically conduct the research about modulating a dark bisoliton at 1 μm wavelength regime, in an extra-cavity modulation system. The modulation system is composed of different modulation elements. In the simulation, we consider the variations of different parameters. And modulated dark bisoliton’s orthogonal polarization components will show unique variation properties as these soliton parameters vary. For example, as time delay in orthogonal directions varies, a new small pulse peak appears at the position of continuous wave background in vertical polarization direction at output port, when time delay reaches to a specific value. These simulation results further explore the extra-cavity modulation of dark pulses in nonlinear optical fiber modulation systems, which are useful to understand the dark bisolitons’ dynamics in extra-cavity modulation systems. And these results have potential applications in the field of high-speed and long-distance optical fiber communication.

Epidemiological characteristics and influencing factors of public health emergency events of varicella in the Beijing-Tianjin-Hebei region, 2006-2021

To explore the epidemiological characteristics of public health emergency events (PHEE) of varicella in the Beijing-Tianjin-Hebei region and analyze its related influencing factors. Excel was used to organize the varicella data in the Beijing-Tianjin-Hebei region from 2006 to 2021, reported by the management information system of PHEE, to describe the epidemiological characteristics of varicella events. Spatial autocorrelation and spatial scanning methods were used to test and determine its spatial clusters. Geographic detectors were used to analyze the impact of socio-economic factors. From 2006 to 2021, there were 644 reported varicella events in the Beijing-Tianjin-Hebei region, with a total of 18 052 cases and an incidence rate of 2.78%. The number, duration and response time M (Q1, Q3) of each reported event were 22 (15, 35) cases, 19 (7, 34) days and 7 (4, 17) days, respectively. Hebei Province had a shorter response time and duration of events compared to Beijing and Tianjin. The most reported varicella events were in 2006 and 2007, with 112 and 106 events, respectively. By 2014, the number of events had decreased yearly, and there was a small peak from 2017 to 2019 between 2014 and 2021. From 2006 to 2021, the PHEE of varicella showed a seasonal bimodal distribution from March to June and from October to January of the following year, with peaks in May and December. There was a total of 500 reported varicella events in primary schools, including 218 events in rural primary schools (34%), 142 events in county and town primary schools (22%) and 140 events in urban primary schools (22%). The distribution of varicella events showed a positive spatial autocorrelation and strong spatial clustering, with Moran's I of 0.31. The Class 1 clustering area was centered in Kuancheng Manchu Autonomous County, Chengde City, with a radius of 207 km and included 58 districts (LLR=3 550.23, RR=3.78). The most explanatory factor among socio-economic factors was the proportion of the population aged 0-24 years old (q=0.22), and the interaction effect between each factor was stronger than the independent effect. Overall, there are differences in the level of handling varicella events across Beijing, Tianjin and Hebei. The main occurrence of varicella events is in primary schools, especially in rural areas. Varicella events exhibit spatial clustering. Population structure-related factors have a strong impact on the risk of the incidence of varicella events.

Preparation and Characterisations of Acrylic Epoxy/Polyethylene Glycol/Graphene Oxide Nanocomposites for Antibacterial Coating Applications

This study addresses the urgent need for antibacterial coatings amid escalating concerns about pathogen contamination on various surfaces, particularly in healthcare settings and public spaces where infection control is critical. The development of durable and effective antibacterial coatings could significantly reduce harmful bacteria transmission and improve overall hygiene standards. Graphene oxide (GO) had exceptional antibacterial properties against a wide spectrum of bacteria. Here, the researchers explored the composite of GO with acrylic epoxy (AE) through the use of polyethylene glycol (PEG) to become AE/PEG/GO tertiary nanocomposites in enhancing GO’s antibacterial efficacy. The objectives of this study were to prepare and characterise AE/PEG/GO nanocomposites and then investigate their antibacterial abilities against escherichia coli (E. coli) and staphylococcus aureus (S. aureus) bacteria. The GO was prepared using the modified Hummers method, which was mechanically stirred with AE and PEG to produce the AE/PEG/GO nanocomposites. This was followed by characterisations of the nanocomposites via ultraviolet-visible (UV-Vis) spectrophotometer, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometer and scanning electron microscope (SEM). The nanocomposites were then tested against E. coli and S. aureus bacteria by measuring the diameter of the inhibition zone (DIZ). The results showed that the absorption peak of GO was obtained at a wavelength of 236 nm. The diffraction pattern of the AE/PEG/GO nanocomposites showed amorphous structure with a small and wide peak at 2 around 23°. The IR spectrum of the AE/PEG/GO nanocomposites indicated the presence of –OH, –CH3, –CH2, C=O, C–H, C–O and C=C functional groups. The surface morphology showed well-distributed nanocomposite coating onto glass slides with some micro islands. The nanocomposites exhibited promising antibacterial performance revealing higher efficacy against S. aureus compared to E. coli. This was shown by the performance of AE/PEG/GO coating in inhibiting S. aureus bacteria with 1.55 mm larger DIZ compared to the positive control. However, the AE/PEG/GO coating exhibited smaller DIZ than the positive control with a difference of 3.68 mm in inhibiting E. coli bacteria. This study unveiled a simple and straightforward approach in producing nanocomposites for antibacterial coatings shedding light on their potential applications in safeguarding surfaces against bacterial contamination.

Estimates of HIV Incidence, Prevalence, and Mortality in China 2018.

A thorough and precise comprehension understanding of the HIV epidemic is crucial for effective HIV prevention and control. This study aimed to update the estimates of the overall HIV burden in China in 2018 and to assess the trends of HIV prevalence, incidence, and mortality from 1985 to 2018. The Estimation and Projection Package (EPP)/Spectrum software was utilized for estimation, a method highly recommended by UNAIDS. Data were collected from more than 1800 HIV sentinel surveillance sites, population-based seroprevalence surveys, and HIV screening of antenatal clinics and pre-marital medical check-ups across the country. Assumptions about age and sex were used to adapt the parameters of disease progression, including CD4 progression rates and mortality rates for individuals on and off antiretroviral therapy (ART). Joinpoint (version 4.7.0.0) was used to analyze the trends of prevalence, incidence, mortality, and fatality rates from 1985 to 2018. In 2018, the total number of people living with HIV (PLWH) adults in China was estimated to be 1.23 million, corresponding to approximately 106.5/100 000 in the country. A total of 71.8% of adult PLWH were men. Over half of PLWH (58.6%) were infected through heterosexual contact, about one-third (30.2%) through male-to-male transmission, 9.0% through IDU, and 2.3% due to former plasma donation. HIV incidence in adults reached its first small peak in 1992 with 52 400 new infections (95% confidence interval: 2700-920 000). After a brief period of rapid decline between 1992 and 1994, the annual number of new infections among adults increased again and remained relatively stable at 81 000 (95% uncertainty interval [UI]: 60 000-105 000) in 2018. In recent years, the number of new infections through blood donation has been eliminated, and the number of infections through injecting drug use has been kept low. Sexual contact became the predominant transmission route, while casual sexual contact became increasingly common. Overall, HIV mortality has been steadily increasing and has recently begun to decline during the period of 2012-2018. The number of deaths from HIV/AIDS in 2018 was approximately 35 000 (95% UI: 30 000-41 000). The number of estimated PLWH in China has exceeded one million, due to the ongoing occurrence of new infections and longer survival rates. HIV transmission through blood products has been eradicated. Casual sex has become a significant mode of transmission. It is recommended to enhance the implementation of strategies and measures for sexual communication in the general population and to bolster multidisciplinary research.

In-person, virtual visiting and telephone calls in Australia and New Zealand intensive care units: A point prevalence multicentre study mapping daytime and nighttime interactions

BackgroundFamily presence, in-person and via virtual visiting (video calls) and the telephone, is an integral part of patient- and family-centred critical care. Previous studies focussed on visiting policies and their effects. Data mapping the frequency and timing of these interactions are not available. ObjectivesThe aims of this study were to describe the prevalence of in-person visiting and the use of telephone or video conferencing in Australia and New Zealand intensive care units (ICUs). DesignA point prevalence survey was conducted to map visiting policies, hourly family presence at the bedside, telephone or video calls, and reasons for each interaction. SettingThe research was conducted in a 24-h study period in October 2020, corresponding to the end of the 2nd COVID-19 pandemic wave in 40 Australia and New Zealand ICUs. Measurements and main resultsAt the time of survey, 77% of ICUs had restrictions to visiting, median (interquartile range [IQR]) time of 9 (2; 24) hours with permitted visiting per day, a mean of 8 hours less than before the COVID-19 pandemic. There were 532 patients, a median (IQR) of 13 (6; 25) patients per ICU. Two patients had COVID-19. Over 24 h, 65% of patients had at least one in-person visit, median (IQR) of 1 (0; 3) hours with visitors. Telephone calls were received for 52% patients, median (IQR) of 1 (0; 2) calls. Video calls were received for 6% of the patients. In-person visits peaked between 10:00 and 12:00, with a second smaller peak between 16:00 and 17:00. Visiting continued through the evening, and 2% of the patients had visitors overnight. Telephone calls peaked at 10:00, continued through the day and evening, with few calls received overnight. In-person visits were predominantly motivated by family interactions (81%) and telephone calls by clinical updates (51%) and family interactions (47%). ConclusionsIn a low COVID-19 prevalence period, Australia and New Zealand ICUs had partially reopened to visitors. Most visits happened during the day and evening but persisted overnight. ICU resourcing and visiting policies should take these data into account to facilitate family presence at the bedside, virtual visiting, and obtaining clinical updates via telephone.

Study of Some Structural and Optical Properties for Synthesized Graphene/Polyaniline/Zns Nanocomposite

Hybrid graphene (GR)/ polyaniline (PANI) based composites incorporating zinc sulfide (ZnS) nanoparticles were synthesized using the drop-casting method. The weight percentage of ZnS was varied from 0.01 to 0.05%. The optical, structural, and morphological characteristics of the nanocomposite were examined utilizing X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopic (AFM), and UV-Vis spectroscopy. The qualities and dimensions of the GR, PANI, and ZnS NPs and nanoparticle morphology resulting from the nanocomposite process were examined. Utilizing energy dispersive energy X-ray dispersive (EDX), the weight percentage of each element can be verified. The widening sharp peaks in the XRD patterns suggested the creation of a nanocrystalline phase of ZnS with a crystallite size of less than 50 nm. SEM demonstrated the interaction between ZnS nanoparticles and graphene/polyaniline. Surface topography examination using AFM shows that ZnS NPs may be effectively dispersed on top of GR/PANI structures. The ultraviolet-visible absorption spectrum (UV-Vis) showed a small absorption peak at the wavelength of 459.34nm and a broad absorption peak at 652nm.

Seasonal variation in suicide: age group and summer effects in the United States (2015–2020)

BackgroundSuicide is a global public health concern that affects more than 700,000 people globally every year. Seasonal variation in suicide rates is a phenomenon that has been well-documented, but recent data on the seasonality of suicide within specific age groups and sex in the United States remains less well understood.MethodsPublicly available data on monthly suicides was obtained from the Underlying Cause of Death database, CDC WONDER, from 2015–2020. The incidence of summer suicides, from June, July and August, for two groups, 15–24 and ages 25 + , was calculated and a two-sided test was performed. Seasonal Decomposition analysis was performed and time series created from 2015–2020 for every age group then converted into Trend, Seasonality, and Residual respectively.ResultsFor Americans ages 15–24, the highest spike in suicides was in autumn, September–October, with a trough in June. This is the only age group in which this occurred, differing from previous understanding of the seasonality of suicide in the literature. With all other age groups (25–34, 35–44, 45–54, 55–64, 65–74, 75 +) there was a consistent pattern of a peak in late spring/early summer, a small peak in fall, and a trough in late winter.ConclusionsThere is a seasonal variation in suicide deaths in the United States with the youngest group, ages 15–24, presenting a different pattern compared to other ages. There were no significant differences in suicide seasonality by sex.

Blind infrared spectral deconvolution with discrete Radon transform regularization for biomedical applications

Infrared spectrum often suffers from the resolution reduction and random noise. This paper proposes a novel blind infrared spectral reconstruction model that integrates total variation constraint and frequency domain transformation. This model aims to achieve an accurate deconvolution model of infrared spectra by making the coefficient distribution of discrete Radon transform (DRT) of overlapping infrared spectra close to high-resolution infrared spectra. Secondly, we use total variation (TV) as a popular effective spectral prior model, which has been applied in regularization based blind deconvolution of infrared spectra because it can preserve small peaks. In this study, the model fully utilizes spatial information from different image regions and proposes an extended split Bregman iteration method to solve the joint minimization problem. Specifically, the DRT coefficient distribution of overlapping infrared spectra should be close to high-resolution infrared spectra. We believe that there are differences between the DRT coefficient distribution of clean spectra and the distribution of degraded infrared spectra. Extensive experimental results have shown that the proposed method outperforms most existing methods in terms of spectral structure quality and quantitative measurement. The high-resolution infrared spectra after deconvolution can be used for biomedical imaging and clinical applications.

Coordination and Structural Control of Trinuclear Ruthenium Clusters Using Organic Ligands at HOPG Surface

Controlling the self-assembly and nanoarchitectures of metal complexes at the molecular scale is essential for the development of new functional materials and devices. Since two-dimensional (2D) sheets consisting of metal complexes can be designed and controlled with various bonding modes, geometric structures, and chemical functions, they have been studied using various approaches by selecting metal ions and organic ligands. Trinuclear metal clusters contain three metal ions in one complex and are expected to be building blocks for the formation of 2D sheets of metal complexes by selecting their shape and axial ligands. In this study, a trinuclear cluster of ruthenium ions, Ru3O(EtCOO)6(CO)(THF)2:1, was used as the core to form nanostructures on highly oriented pyrolytic graphite (HOPG) substrates via axial ligand exchange with 1,4-Di (4-pyridyl) benzene:2 and 4,4’-di(4-pyridyl) biphenyl: 3. The adlayer structures and electrochemical properties of the nanoarchitectures were investigated by atomic force microscopy (AFM) and cyclic voltammetry (CV). In the experimental procedure, powders of 1, 2, and 3 were dissolved in methanol (MeOH) and tetrahydrofuran (THF), respectively, and a 0.78 µM solution was prepared. A predetermined amount of this was cast on HOPG, dried to form a thin film, and the thin film was observed in air using AFM. Next, equal amounts of 1 and 2 and 1 and 3 solutions were mixed in each solvent, and after heating a water bath at 60°C for 1 h, thin films were prepared in the same manner and observed by AFM. Ultraviolet–visible (UV-vis) absorption spectra and electrochemical measurements by CV were performed before and after heating the mixed solutions. First, in the AFM image of the thin film prepared by casting the MeOH mixture of 1 and 2, two stripe-like domains with different heights were observed, which matched the heights of the structures obtained in the AFM images of the single-domain formation of 1 and 2. In addition, no new absorption peaks were observed in the UV-vis absorption spectrum after mixing the solution; it was inferred that 1and 2 did not exchange ligands. However, when the mixed solution was heated in a water bath for 1 h, a few striped domains were observed, and a new ring-like structure was formed. The CV results also supported the change in the AFM images and absorption spectra after heating the solution. Before heating the mixed solution, a small redox peak was observed around 0.8 V, whereas after the warm bath, a large redox peak was observed around 0.6 V. A dramatic change in the magnitude of the current density was observed, indicating a significant improvement in conductivity. These results suggest that heating the mixed solution replaced THF ligand 1 with 2, forming a cyclic structure consisting of 1 and 2. When the same experiment was carried out in THF solution, a different structure was observed from that of the methanol solution, and a one-dimensional (1D) molecular wire structure was formed after heating the water bath. The absorption spectra and CV results also supported that ligand exchange occurred in the 1D wire structure, revealing the solvent dependence of the nanoarchitecture. When 3 was used as the axial ligand, larger structures were formed compared to 2, and one-dimensional wire structures of several micrometers were observed in the THF solution after the warm bath. Larger current densities and peak separations are also observed in the voltammograms. Thus, the length dependence of the organic ligand for the nanoarchitecture formation on the HOPG surface was demonstrated. Figure 1

Assembling Biodegradable Non-Metal Quinone-Based Supercapacitor with High Energy Density

Quinone-based materials have drawn a lot of attention particularly because of its large ion storage capacities from its low-molecular-weight moiety while having an eco-friendly element structure. Quinones, however, do not show any conductivity and are soluble to in organic solvent. Many reports have shown how to utilize such quinones as electrochemical capacitor’s active material, of which acetone impregnation is the simplest and the most practical method. However, battery cell configuration consisting of, current collector composed of metal, activated carbons (ACs) loaded with quinones synthesized from petroleum, and industrialized carbon black used as a conductive additive, are not eco-friendly. In this study, we conducted a thorough examination of the crucial parameters involved in the impregnation process of ACs to clarify the potential of biomass-based ACs in achieving enhanced electrochemical performance when employed as an organic battery. Subsequently, we applied the ACs to metal-free, organic supercapacitor, utilizing a carbon-based collector and woody biomass-based conductive additives.It was prepared that 7 different AC samples, including a commercially available petroleum-derived AC sample called Maxsorb®, and impregnated chloranil (CHL) and 1,5 dichloroanthraquinone (DCAQ) to each of the samples. Subsequently, a half-cell test was conducted on the sample to determine the extent to what CHL and DCAQ functions as a redox-active material when impregnated into each sample. To characterize each sample, we performed a Brunauer-Emmett-Teller (BET) surface area measurement, Barrett-Joyner-Halenda (BJH) pore distribution measurement, electrical resistivity measurement, and X-ray photoelectron spectroscopy (XPS) analysis to discuss the crucial parameters of quinone impregnation. To create a high-voltage aqueous organic supercapacitor with a metal-free and wood-based structure, we conducted the half-cell on each sample and utilized the best AC sample, a current collector synthesized from natural graphite, a conductive additive derived from a bamboo charcoal to fabricate a practical-sized electrode.From the BET surface area analysis and the half-cell test, one of the AC samples with a great peak in < 5 nm of diameter had a high utilization rate of 95.3% for the 30% CHL impregnated into the AC sample. Though the AC sample had only a surface area of 2271 m2/g compared to that of Maxsorb®which was 2989 m2/g, it achieved the utilization ratio comparable to that of Maxsorb® which was 94.6%. Samples with a peak diameter > 9 nm showed no redox capacity, while samples with a small broad peak in the range of 1–10nm, exhibited an approximately 60% utilization ratio. Hence, the pore size distribution was found to be a crucial aspect for quinone-impregnation, and the specific surface area plays a crucial role in determining the amount of CHL that can be effectively impregnated, as it provides more pore sites with diameters < 5 nm throughout the sample. As for DCAQ, it had a similar result compared to the CHL-impregnation, however in a slightly higher diameter range at about 5 nm for its optimized impregnation pore size. Therefore, identifying the pore size distribution of ACs is crucial in discovering new biomass-based material used for quinone-based supercapacitor.From the half-cell test with CHL, it was observed that the overpotential significantly increased from gold to SUS316 to graphite sheet as current collectors. To reduce the overpotential, we introduced a bamboo charcoal as a conductive additive, which effectively reduced the overpotential from 0.1 V to 0 V for SUS316 and from > 1 V to 0 V for graphite sheet at 1 C, while maintaining > 95% utilization rate. Subsequently, we fabricated a practical sized electrode (9 cm x 9 cm, 1 g) with CHL impregnated cathode and DCAQ impregnated anode from the best biomass-based AC, graphite sheet, and biodegradable 3D-printed battery cell case. The resulting full-cell supercapacitors exhibited a high energy density, demonstrating the feasibility of eco-friendly, metal-free wood-based organic supercapacitors.

Elucidation of the Li Storage State and Dynamics in Various Carbon Electrodes by Using 7Li NMR

In recent years, both soft carbons and hard carbons have been considered as potential anode materials for lithium-ion batteries (LIBs) and lithium-ion capacitors (LICs) because of their high capacity and superior rate performance compared to graphite electrodes. To design high power carbon anode, revealing the Li storage state and dynamics in carbon electrodes is required. However, the effect of carbon microstructure on the Li storage state remains unclear because of the complex microstructures of these carbon materials, which consist of a mixture of graphitic and amorphous domains. 7Li NMR is a useful measurement to know the Li storage state because it provides direct observation of Li atoms in carbon microstructures and has the advantage of seeing the dynamics of Li without the process of de-solvation on the electrode-electrolyte interface, compared to electrochemical measurements. In this study, we investigated the Li storage state in soft and hard carbons with different graphitization degrees using 7Li NMR. We obtained information about the Li species, domain size of Li sites, and motion properties by comparing temperature-dependent NMR spectra and spin relaxation time.Graphite, soft carbon (SC), and hard carbon (HC), as well as their graphitized samples by heat treatment at 1500, 2000, and 2500°C, denoted as SCX or HCX (X: Heat treatment temperatures/°C, HTTs), were prepared. The crystallinity of the carbon materials was evaluated using X-ray diffraction (XRD). These carbon samples were electrochemically lithiated by applying a constant current of 50 mA/g to 0.002 V vs. Li/Li+, followed by keeping the potential until a cut-off current of 5 mA/g. The lithiated carbon samples were characterized using 7Li NMR spectroscopy and spin relaxation measurements at different temperatures (103-353 K). The Li self-diffusion coefficient in SC at 343 K was measured by pulsed gradient spin-echo (PGSE) NMR.The 7Li NMR spectrum of lithiated SC was assigned to Li in the turbostratic structure. As the SC heat-treatment temperature increased, the NMR spectra corresponding to the shrinkage of the carbon layer spacing were obtained. The Li in SC2500 was predominantly stored in a graphitic structure and partially in amorphous structures. On the other hand, the Li state in HC showed intercalated Li in the turbostratic layers and quasi-metallic Li clusters. As the HC heat-treatment temperature increased, the peak of quasi-metallic Li clusters disappeared, and the peak of Li in the turbostratic structures remained. Only HC2500 showed a small peak assigned to Li in the graphitic structure, indicating that HC2500 has a distinct graphitic layer structure, as measured by XRD. The average diffusional displacement in the measurement timescale was estimated to be approximately 1 nm below 200 K 1. The chemical exchange occurring at the temperature suggests that the domain size of the Li sites are a few nanometers.The spin-lattice relaxation time (T1) was measured at different temperatures, and the activation energy of each Li species for motion in carbon electrodes were estimated. Li species intercalated in the turbostratic layers indicated similar activation energy for all amorphous carbons, providing an evidence that these Li species in various carbon electrodes have similar restriction and motion properties. Li in graphitic structures on HC2500 showed higher activation energy than amorphous structures and is considered unsuitable for high-rate charge-discharge performance. Y. Fang, K. Peuvot, A. Gratrex, E. V. Morozov, J. Hagberg, G. Lindbergh, and I. Furó, J. Mater. Chem. A, 10, 10069–10082 (2022). Figure 1

Molecular Oxygen (O2) Artifacts in Tandem Mass Spectra.

Peak annotation plays an important role in mass spectral evaluation of the NIST 2023 tandem mass spectral library. While most fragment ions are formed by neutral losses, there are peaks that represent adduct ions from these fragments. Previously, we have reported two main types of addition reactions in the collision cell, namely addition of H2O and N2. Here we report a different reaction in the collision cell, with addition of O2 leading to a small peak that could only be assigned to a peroxyl radical ion. For example, some protonated iodoaromatics lose an iodine atom to form a radical cation [M+H-I]+•, which reacts with O2 to generate a peroxyl radical ion [M+H-I+O2]+•. Higher concentrations of O2 result in higher peroxyl radical peaks, which become dominant while the precursor ions are consumed, as examined by five compounds under different concentrations of O2. The correlation of the peroxyl radical peak intensities to the concentration of O2 provides a tool to estimate trace amounts of O2 within the instrument. In the NIST 2023 tandem mass spectral library, the peaks for [M+H-X+O2]+· are most abundant in numbers and in intensity for X = NO2 or I, are much less abundant for X = Br, and are rare for X = Cl. Other leaving groups in this library are SO3H, SO2NH2, CSNH2, CO2C6F5, SO2CH3, and COCH3. The O2 addition reaction is also observed with negative ions in this library. While adducts of H2O and N2 often constitute major peaks, the peaks of the peroxyl radicals under standard conditions are mostly very small and may be mistaken for noise, but their correct annotation improves the quality of the spectra and is important when comparing spectra from different instruments or conditions.

Language model-guided anticipation and discovery of unknown metabolites.

Despite decades of study, large parts of the mammalian metabolome remain unexplored. Mass spectrometry-based metabolomics routinely detects thousands of small molecule-associated peaks within human tissues and biofluids, but typically only a small fraction of these can be identified, and structure elucidation of novel metabolites remains a low-throughput endeavor. Biochemical large language models have transformed the interpretation of DNA, RNA, and protein sequences, but have not yet had a comparable impact on understanding small molecule metabolism. Here, we present an approach that leverages chemical language models to discover previously uncharacterized metabolites. We introduce DeepMet, a chemical language model that learns the latent biosynthetic logic embedded within the structures of known metabolites and exploits this understanding to anticipate the existence of as-of-yet undiscovered metabolites. Prospective chemical synthesis of metabolites predicted to exist by DeepMet directs their targeted discovery. Integrating DeepMet with tandem mass spectrometry (MS/MS) data enables automated metabolite discovery within complex tissues. We harness DeepMet to discover several dozen structurally diverse mammalian metabolites. Our work demonstrates the potential for language models to accelerate the mapping of the metabolome.

PEAKO and peakTree: tools for detecting and interpreting peaks in cloud radar Doppler spectra – capabilities and limitations

Abstract. Cloud radar Doppler spectra are of particular interest for investigating cloud microphysical processes, such as ice formation, riming and ice multiplication. When hydrometeor types within a cloud radar observation volume have different terminal fall velocities, they can produce individual Doppler spectrum peaks. The peaks of different particle types can overlap and be further broadened and blended by turbulence and other dynamical effects. If these (sub-)peaks can be separated, properties of the underlying hydrometeor populations can potentially be estimated, such as their fall velocity, number, size and to some extent their shape. However, this task is complex and dependent on the operation settings of the specific cloud radar, as well as atmospheric dynamics and hydrometeor characteristics. As a consequence, there is a need for adjustable tools that are able to detect peaks in cloud radar Doppler spectra to extract the valuable information contained in them. This paper presents the synergistic use of two algorithms used for analyzing the peaks in Doppler spectra: PEAKO and peakTree. PEAKO is a supervised machine learning tool that can be trained to obtain the optimal parameters for detecting peaks in Doppler spectra for specific cloud radar instrument settings. The learned parameters can then be applied by peakTree, which is used to detect, organize and interpret Doppler spectrum peaks. The application of the improved PEAKO–peakTree toolkit is demonstrated in two case studies. The interpretation is supported by forward-simulated cloud radar Doppler spectra by the Passive and Active Microwave TRAnsfer tool (PAMTRA), which are also used to explore the limitations of the algorithm toolkit posed by turbulence and the number of spectral averages chosen in the radar settings. From the PAMTRA simulations, we can conclude that a minimum number of n = 20–40 spectral averages is desirable for Doppler spectrum peak discrimination. Furthermore, small liquid peaks can only be reliably separated for eddy dissipation rate values up to approximately 0.0002 m2 s−3 in the simulation setup which we tested here. The first case study demonstrates that the methods work for different radar systems and settings by comparing the results for two cloud radar systems which were operated simultaneously at a site in Punta Arenas, Chile. Detected peaks which can be attributed to liquid droplets agree well between the two systems, as well as with an independent liquid-predicting neural network. The second case study compares PEAKO–peakTree-detected cloud radar Doppler spectrum peaks to in situ observations collected by a balloon-based holographic imager during a campaign in Ny-Ålesund, Svalbard. This case demonstrates the algorithm toolkit's ability to identify different hydrometeor types but also reveals its limitations posed by strong turbulence and a low n. Despite these challenges, the algorithm toolkit offers a powerful means of extracting comprehensive information from cloud radar observations. In the future, we envision PEAKO–peakTree applications on the one hand for interpreting cloud microphysics in case studies. The identification of liquid cloud peaks emerges as a valuable asset, e.g., in studies on cloud radiative effects, in seeder–feeder processes, or for tracing vertical air motions. Furthermore, the computation of the moments for each subpeak enables the tracking of hydrometeor populations and the observation of growth processes along fallstreaks. On the other hand, PEAKO–peakTree applications could be extended to statistical evaluations of longer data sets. Both algorithms are openly available on GitHub, offering accessibility for the scientific community.

Pattern formation from homogeneous states for an elliptic system with mixed interactions

In this paper, we are interested in the asymptotic behavior of a ground state vector solution for the following coupled nonlinear Schrödinger system { Δ u 1 − λ 1 u 1 + β 11 ( u 1 ) 3 + α β 12 u 1 ( u 2 ) 2 − β β 13 u 1 ( u 3 ) 2 = 0 Δ u 2 − λ 2 u 2 + α β 21 ( u 1 ) 2 u 2 + β 22 ( u 2 ) 3 − β β 23 u 2 ( u 3 ) 2 = 0 Δ u 3 − λ 3 u 3 − β β 31 ( u 1 ) 2 u 3 − β β 32 ( u 2 ) 2 u 3 + β 33 ( u 3 ) 3 = 0 in Ω and ∂ u i ∂ n = 0 on ∂Ω when α , β > 0 are very large. The existence of a ground state vector solution for (1) was proved in Byeon et al. [Pattern formation via mixed interactions for coupled Schrödinger equations under Neumann boundary condition. J Fixed Point Theory Appl. 2017;19:559–583] when α , β , α / β 2 − n 2 are large. We prove that if λ 3 is small, as α , β , α / β 2 − n 2 → ∞ , u 3 converges to a constant, u 1 and u 2 develop a small peak on ∂Ω . Under an additional condition α / β 2 − n 2 + δ → ∞ for some δ > 1 , we show that the peak point converges to a maximum point of the mean curvature of ∂Ω .

Impact of Al3+ substitution on structural, Raman, transport electromagnetic properties of LiFe2O4 nanoparticles

Nanocrystalline Li0.5AlxFe2.5-xO4(x = 0.0 to 0.8 in steps, x = 0.2) compounds were prepared using the sol-gel auto-combustion technique. X-ray diffraction (XRD) analysis confirmed the single-phase cubic spinel structure, which showed that the lattice constant changed significantly, especially in the x = 0.6 sample, where it decreased clearly. The crystallite size decreased with increasing Aluminium content, reaching a small value of about 5 nm for the composition x = 0.8 sample. Raman peaks of pure LiFe2O4 were determined in both phases (alpha and beta), while smaller peaks at 198 and 236 cm−1 that related to the alpha phase were distinguished. All peaks diminished in intensity after Al3+ ions were doped to LiFe2O4 except for the peak at 700, where it became predominantly. The bandgap of the samples was deduced and analyzed from Tauc's plot according to UV–Vis spectra. The change in the electronic structure of the Li-Al ferrites, at which the size of the ferrite becomes close to the de Broglie wavelength, results in a band gap for the Al replaced by LiFe2O4 with different electronic configurations. The variation of the fundamental part of the dielectric constant (ε′), loss tangent (tan δ), and AC conductivity with frequency has been discussed with composition. The increase in Al3+ ion content affected the coercive force, as it decreased, while the saturation magnetism increased when adding Aluminium (x = 0.2) and then began to decline gradually.

Green Synthesis, Characterization and Pharmaceutical Applications of Biocompatible Zinc Oxide Nanoparticles Using Heliotropium rariflorum Stocks.

Background: Zinc oxide nanoparticles are safe, non-toxic, and biocompatible. These NPs are used in food packaging materials, self-cleaning glass, ceramics, deodorants, sunscreens, paints, coatings, ointments, lotions, and as preservatives. This study explored the biological potential of ZnO nanoparticles synthesized using H. rariflorum. Methods: In vitro antibacterial and antifungal activities against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans, Penicillium notatum, Aspergillus flavus, Aspergillus niger and Aspergillus solani were determined. Antioxidant activity was explored using the DPPH radical scavenging method. In vivo analgesic, antipyretic and sedative potential of synthesized nanoparticles was investigated using a mouse model. Results: SEM with various magnification powers showed that some particles were spherical while some were aggregated, flake-shaped, and hexagonal with rough and irregular surfaces. The EDX analysis revealed Zn (12.63%), O (22.83%) and C (63.11%) with trace quantities of Si (0.40%), Ca (0.54%) and P (0.49%). The XRD pattern indicated an amorphous state, with no peaks observed throughout the spectrum. The UV-visible spectrophotometry revealed a characteristic absorption peak at 375 nm, indicating the presence of ZnO nanoparticles. Fourier Transform Infrared Spectroscopy (FTIR) displayed several small peaks between 1793 and 2370 cm-1, providing evidence of the presence of different kinds of organic compounds with different functional groups. ZnO-NPs showed dose-dependent antibacterial and antifungal potential against all strains. Staphylococcus aureus and Candida albicans were the most susceptible strains. The nanoparticles exhibited a maximum antioxidant effect of 85.28% at 100 μg/mL. In this study, the acute toxicity test showed no mortality, and normal behavior was observed in mice at ZnO-NP doses of 5, 10, and 20 mg/kg. For analgesic and antipyretic activities, a two-way ANOVA revealed that dose, time, and the interaction between dose and time were significant. In contrast, the samples had a non-significant effect on sedative activity. Conclusions: This innovative study suggests a potential use of plant resources for managing microbes and treating various diseases, providing a scientific basis for the traditional use of H. rariflorum.

Reproductive biology of fringescale sardinella (Sardinella fimbriata Valenciennes, 1847) from Malampaya Sound, Palawan, Philippines

Reproduction is a fundamental biological process that is essential for the continuous survival of fish species. Understanding their early life history and reproductive biology can explain how the population behave over time. A total of 1,238 fish samples were examined to determine the reproductive patterns and period of fringescale sardinella (Sardinella fimbriata) from Malampaya Sound, Palawan, Philippines. Monthly sampling from April 2023 to March 2024 revealed a 1:1 sex ratio. Gonadal examination of the fish revealed the presence of spawning individuals throughout the study period. The minimum size of matured fish observed was 11.0 cm and 11.1 cm for male and female S. fimbriata, respectively. The peak of spawning was April as indicated by the highest calculated GSI of 7.62% and fecundity of 18,465. A smaller peak was again observed in the month of September. The length at maturity was estimated to be 11.4 and 8.8 cm for males and females, respectively. Fecundity ranged between 2,700 to 36,067 eggs per spawn for size class between 11.1-14.8 cm and weight 13.07-31.93 g. Regression analysis between fecundity and morphometric characteristics such as body length, weight, eviscerated weight, and gonad weight revealed a positive correlation. Very low coefficients of determination were computed, ranging between 0.0028-0.1233. A significant association between fecundity and the morphometric variable gonadal weight was observed, as shown by the p-value of 0.0000. These outcomes are valuable data in the formulation of conservation and management strategies for the area. Implementation of appropriate conservation measures, monitoring of environmental parameters, strict enforcement of fishery regulation, coupled with increased environmental awareness and community participation will guarantee the long-term sustainability of the fringescale sardinella population and the preservation and sustainable use of marine biodiversity in Malampaya Sound.