bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy management strategy of urban rail hybrid energy storage system based on fuzzy logic system
Authors: Meng Qinglu , Wang Siming
Published: February 2024

Energy management is an important link in the effective functioning of hybrid energy storage systems (HESS) within urban rail trains. This factor significantly impacts the operational stability and economic efficiency of urban rail systems. Safety issues arise from DC bus voltage fluctuations due to varying train conditions. To address these issues, this paper proposes an energy management strategy for the urban rail HESS, which builds upon a traditional double closed-loop control strategy. This strategy incorporates a fuzzy logic system to regulate power distribution parameters and discharge thresholds dynamically. Real-time monitoring of the state of charge (SOC) of the energy storage device informs the decision-making process, utilizing a fuzzy inference system to effectively regulate power and energy distribution in response to the distinct characteristics of batteries and super-capacitors. This approach aims to mitigate power fluctuations within the traction network. To validate the effectiveness of the proposed energy management strategy, the study conducts a comprehensive simulation experiment using MATLAB/Simulink. The simulation results confirm the efficacy of the proposed strategy, highlighting its potential to enhance the stability and overall performance of urban rail train operations.
Visualization of the vortex structure formation of a long-lived afterglow arising in a symmetrical pulsed discharge
Authors: Kudryavtsev Anatoly A. , Yuan Chengxun , Zhao Shixin , Astafiev Alexander M. , Shabanov Gennady D. , Chirtsov Alexander S.
Published: February 2024

A visualization of the emerging toroidal vortex in the long-lived afterglow of a high-current symmetrical pulse discharge with an electrolyte anode has been carried out. The visualization of the emerging vortex flow was carried out using the laser knife method using a powerful 10 W laser, which formed a flat divergent beam, which was reflected from dust particles in the atmosphere. For greater contrast, water vapor was let in into the region of the discharge and the emerging afterglow, which moved synchronously with the emerging afterglow vortex. The laser beam reflected from small water vapor droplets made it possible to visualize the gas flow, which was then filmed with a high-speed video camera. The presented data clearly show that the emerging afterglows are able to retain their volume for a long time precisely due to the formation of a vortex structure.
Investigation of lift enhancement through circulation control for distributed propulsion
Authors: Guo Longkai , Zhao Qing , Sun Yunzheng , Zhu Yaowu , Su Shijia , Da Xingya
Published: February 2024

To meet the design requirements for high lift airfoils, an optimization design platform was established using the SNOPT (Sparse Nonlinear Optimizer) method. Two airfoils were designed to achieve both low-speed takeoff/landing and high-speed cruise performance. A comparison between the self-designed airfoils and mature airfoils was carried out at different operating conditions, and the airfoil that met the target requirements was selected. Subsequently, an integrated design of ducted-fan/wing was conducted to study the effect of integrated constraints on the lift augmentation of the wing with the action of the propeller. The results showed that under the integrated layout, the ducted-fan significantly changed the flow velocity field from the front of the inlet and the tail jet, which to some extent changed the upper surface circulation of the wing. Compared with the pure wing, the maximum lift increase was up to 332 %.
Deposition of vertical carbon nanostructures by microwave plasma source on nickel and alumina
Authors: Marinov S , Ivanov I , Popov G , Abrashev M , Kiss’ovski Zh
Published: February 2024

Vertical carbon nanostructures on metal and ceramic substrates are deposited successfully using planar microwave plasma source at frequency of 2.45 GHz. The PECVD (Plasma Enhanced Chemical Vapor Deposition) with microwave surface wave discharge is applied because it produces a dense plasma providing efficient decomposition of the methane and creation of a large number of reactive particles which results in lower substrate temperature for graphene deposition compared to CVD method. Optimization of the gas mixture of H2, Ar and CH4, and the gas pressure in the chamber results in a homogeneous graphene structures deposition on the substrates of Ni-foil, Ni-foam and alumina ceramics at substrate temperatures ∼600 °C. The plasma parameters of surface wave discharge such as gas temperature, electron temperature and density are obtained by measuring OH-band and Ar-lines using optical emission spectroscopy. The morphology of the vertical carbon structures is obtained using SEM analysis and the characteristics of the graphene layers were determined by Raman spectroscopy.
Effect of the beam oscillation on the structure and mechanical properties of electron beam welded joints of Ti6Al4V and Al6082-T6 alloys
Authors: Kaisheva D , Dunchev V , Anchev A , Stoyanov B , Ormanova M , Atanasova M , Todorov V
Published: February 2024

The results of electron beam welding of Ti6Al4V and Al6082-T6 alloys are presented. The influence of electron-beam scanning geometry on the structure and mechanical properties of the welded joint is studied. Two kinds of samples were investigated – the first specimen was welded without beam oscillation and the second one was obtained using an oscillating electron beam following a circular trajectory of scanning with an oscillation radius of 0.2 mm. X-ray diffraction (XRD) method was used for the determination of the phase composition of the welded joints. The microstructure of the welded joints was studied using Scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDX) was applied for the chemical composition investigation. Tensile experiments and microhardness measurements were performed to study the mechanical properties of the welded joints. The sample welded without the application of an oscillating beam showed higher values for the yield strength and tensile strength. The values measured for the microhardness within the welded seam are about 450 HV0.05 in both cases. However, the application of a beam oscillation leads to a significant increase in the micro-hardness of the heat affected zone at the Ti-based alloy. The measured values reached 627 HV0.05.
Spectroscopic ellipsometry modelling of thin AuSn films and nanostructures as plasmonics materials
Authors: Todorov R , Hristova-Vasileva T , Milushev G , Milanov E
Published: February 2024

A considerable interest in nanostructured thin films from intermetallic compounds of noble metals (Ag and Au) and post-transition metals is raised due to their unique plasmonic properties, which makes them potential materials for application in photonics, catalysis and biosensing systems. In this work the possibility for deposition of polycrystalline AuSn thin films was investigated, as thin films with the same composition and different thicknesses (10-100 nm) were obtained by co-depositing of Au and Sn metals. The chemical composition was determined by X-ray microanalysis. The X-ray diffraction patterns indicated formation of the intermetallic compound AuSn in the thin films. The complex permittivity ε = ε′ - i.ε″ of the thin AuSn films as function of the thickness was investigated by spectroscopic ellipsometry. The possibility for application of nanostructures from the AuSn intermetallic compound as suitable substrates for the needs of surface-enhanced Raman and fluorescence spectroscopy in the spectral interval 2.8 - 4.7 eV was analysed.
Investigation of properties of novel multilayer Cr/CrN/CrTiN/CrTiAlN hard coating with four bilayers
Authors: Chitanov V , Zlatareva E , Kolchev S , Cholakova T , Kolaklieva L , Kakanakov R , Pashinski C
Published: February 2024

A novel multilayer Cr/CrN/CrTiN/CrTiAlN hard coating with four bilayers was developed by reactive closed field unbalanced magnetron sputtering (CFUBMS). The substrate temperature was kept in the range of 170 °C to 200 °C. The reactive gas flow was controlled by Optical Emission Monitoring. A thickness of 1.8 μm was determined using a calotester. The morphology and chemical composition were studied by electron microscopy (SEM and EDS). Nanohardness of 34.1 GPa and a modulus of elasticity of 386 GPa were determined using the nanoindentation technique. The scratch test against a diamond Rockwell indenter did not show features indicating poor adhesion. The reciprocating wear test revealed strong resistance to wear, and a coefficient of friction of 0.19 was determined. The developed multilayered hard coating showed optimal mechanical properties for industrial applications on instruments of low-temperature materials.
Structure and mechanical properties of TiCN-ZrCN multilayer coatings
Authors: Kolchev St , Cholakova T , Kolaklieva L , Kakanakov R , Bahchedjiev Ch , Chitanov V , Zlatareva E
Published: February 2024

The present study is focused on the design, deposition and characterization of nanoscale multilayer TiCN/ZrCN coatings obtained by cathodic-arc PVD technique. The multilayer coatings with the bilayer period’s thickness of 12 nm, 20 nm and 32 nm were deposited on stainless steel and high-speed steel substrates at temperature of 320°C in a mixture of N2 and CH4 gases. Scanning electron microscopy equipped with energy dispersive x-ray spectroscopy, was employed to investigate the top surface morphology, cross-sectional morphology, bilayer thickness and structure of the coatings. Mechanical properties were investigated via Calotester, Nanoindentation tester, Scratch tester and Tribometer. The SEM/EDS cross-sectional analysis revealed a columnar morphology and well expressed multi-layered periodic structure. All the multilayer samples demonstrated an increase in hardness and well fracture resistance ability in comparison to TiCN and ZrCN monolayer coatings. The highest nanohardness of 41GPa and better wear resistance for the coatings with bilayer period of 12 nm was determined. The results of the study show that a reduction in the thickness of the individual sub-layers has a significant impact on the mechanical properties of the coatings.
Characterization of program and erase speed of memory capacitors with nanolaminated HfO2/Al2O3 stacks for application in non-volatile memories
Authors: Spassov D , Paskaleva A , Ivanov Tz , Stanchev T
Published: February 2024

The programming and erase performance of atomic layer deposited HfO2/Al2O3 memory stacks is investigated depending on the thickness of the tunnel oxide and the annealing of the structures. The as-grown stacks require applying of voltage pulses with duration of about 10-3 s for a measurable electron trapping (programming). The time dependence of the electron trapping process is quite sharp initially - the increase of the charging time from 4×10-4 s to 4×10-3 s provides more than 80% of the saturation value of the trapped charge obtained at durations above 1 s. The annealing increases the time needed for the onset of the electron trapping. For the chosen voltage amplitudes the programming characteristics does not depend on the tunnel oxide thickness. The electron detrapping (erase) is observed even at durations of ~10-7 s, but with a low efficiency. The erase characteristics is more gradual then the program one, and shows some dependence on tunnel oxide and annealing. The complete erase is achieved for times comparable to those for programming the cell. Erase pulses with duration > 10-2 s results to accumulation of positive charge in the capacitors.
Investigation on the fine structure of the B
1∏ − c
3∑+ complex in KRb
Authors: Stoyanov V , Pashov A
Published: February 2024

The fine structure of the transitions in the (X, υ″ = 0 → (B, c), υ′ = 2) band system in K85Rb is studied by using selective Doppler-free spectroscopy techniques. Energy shifts of the perturbed levels due to spin-spin, spin-rotation and spin-orbit interactions were analyzed and modeled within the effective Hamiltonian approach. Molecular and coupling constants were determined, which successfully model the experimental observations.
A compact frequency-selective absorber with optical transparency
Authors: Deng Kewen , Li Feipeng , Wang Xingyu , Feng Jiqiang , Xu Chen
Published: February 2024

This article proposes a new method for designing an optical transparent frequency-selective surface absorber using indium tin oxide (ITO) conductive film with different sheet resistances. This novel optical transparent frequency-selective absorber exhibits excellent optical transparency, ensuring a visible light transmittance exceeding 76%. Simultaneously, it exhibits broadband absorption characteristics covering the entire X-Ku band, with an absorption rate exceeding 90%. Due to the simplicity of the design, the overall structure is easily processable, and the desired product can be rapidly fabricated using laser etching equipment without adding any lumped elements in the design. Simulation and experimental results indicate that the S11–10 dB frequency range of the frequency-selective absorber is 7.7–18.4 GHz, with a transmission frequency range below −3 dB between 26.7–29.4 GHz. The findings suggest that this structure holds potential applications in microwave stealth design requiring optical transparency and high-throughput satellite communication scenarios.
Influence of the pore size on optical and mechanical properties of ecoflex sponges
Authors: Kocaman Kabil Fatmanur , Oral Ahmet Yavuz
Published: February 2024

Silicone polymers have various applications such as sensors, energy harvesters, soft robotics, prosthetics and implants. Ecoflex has become one of the most remarkable silicone polymers due to its special mechanical properties which include extreme stretchability and biocompatibility. In recent years, interest in porous silicone elastomers has increased in order to improve the absorption, flexibility and chemical activity of the material by increasing the surface area. In this study, porous Ecoflex 00-30 silicone elastomer material was prepared by using the low-cost sugar molding technique and its mechanical, optical and surface properties were investigated. In addition, we report on the influence of pore size on these properties of Ecoflex. Our results demonstrate that the Ecoflex material, which has a porous structure, has a more flexible structure. We have observed that the Ecoflex’s stretchability increased with pore size, especially in the 420–850 μm range.
Nanostructured thin films of TiO2 tailored by anodization
Authors: Luna-Cervantes Marcos , Valdespino-Padilla Duilio , Siqueiros Beltrones Jesús M , Peredo Luis Zamora , Torres Julián Hernández , Cruz-Jáuregui Ma de la Paz
Published: February 2024

Although nanostructured TiO2 layers have been widely prepared by anodization, thin films with thicknesses under 1 μm, over substrate other than Ti foils, with structures beyond the nanopores, had remained a challenge. In this work, such nanostructured TiO2 thin films were synthesized by anodization of Ti films deposited by sputtering on FTO/glass substrates. Anodization was performed in an electrolyte based on 0.6 wt% of NH4F, a graphite cathode and the application of 30 V during lapses ranging from 3 to 14 min. The amorphous TiO2 structures acquired the crystal anatase phase after a post-annealing treatment at 450 °C/4 h. Porous morphologies were observed for anodizing times of 3 and 4 min, sponges were formed with 5 and 6 min and vertical tubular structures were achieved by using 7 up to 9 min; dissolution was observed for longer times. Pore diameters of the structures were in the range of 27 to 47 nm, lengths were within the 330 and 1000 nm interval, transmittance was in the visible range of 70 ± 10%, the energy gap was 3.37 ± 0.02 eV and the wet contact angle was between 20 to 27°. One major contribution of the findings herein developed, is that they can be extended to TiO2 thin films, with a specific nanostructure, grown on a wide gamma of substrates, relevant for particular applications.
Micrometeorological effects and thermal-environmental benefits of cool pavements: findings from a detailed observational field study in Pacoima, California
Authors: Taha Haider
Published: February 2024

Cool pavements represent one of several strategies that can mitigate the effects of urban overheating by increasing albedo. By definition, this means increasing reflected and potentially re-absorbed short-wave radiation but also decreased surface and air temperatures and longwave upwelling, thus reducing radiant temperatures. So far, real-world studies have been inconclusive as to net effects from cool pavements. A project by GAF installed reflective pavements in Pacoima, California, in summer of 2022. This study set out to perform detailed, high spatiotemporal resolution, multi-platform observations to quantify micrometeorological benefits of the cool pavements and address concerns regarding glare, chemistry/air quality, and pedestrian thermal comfort. Results indicated large variability, as expected, but that the dominant effects were beneficial both in direct side-by-side, real-time comparisons (RT) between test and reference areas, as well as in difference-of-difference (DofD) to quantify local changes in test areas. During a heatwave in September 2022, maximum air-temperature differences (averaged over individual street segments) reached up to −1.9 °C RT in the afternoon. During non-heatwave, hot summer days, the largest street-segment-averaged afternoon air-temperature differences reached up to −1.4 °C RT or −2.8 °C DofD, and surface temperature up to −9.2 °C RT or −12.2 °C DofD. Whereas above values represent maximum effects, more typical street-segment averages also showed statistically significant benefits. In the afternoon, the mean of air-temperature differences was −0.2 °C RT and −1.2 °C DofD. The mean of surface-temperature differences was −2.6 °C RT and −4.9 °C DofD. Indicators of pedestrian thermal comfort also showed variability but predominantly a cooling effect. The mean of differences in mean radiant temperature was between −0.9 and −1.3 °C RT, and for physiological equivalent temperature, between −0.2 °C and −0.6 °C RT and −1.7 °C DofD. In terms of predicted mean vote, the mean of differences was −0.09 RT and −0.32 DofD.
Evaluation of the drought resilience of indigenous irrigation water systems: a case study of dry zone Sri Lanka
Authors: Wickramasinghe Romitha , Nakamura Shinichiro
Published: February 2024

The wave of modernization and globalization in the last century has rapidly involved a technological paradigm shift from indigenous irrigation water systems to modern systems in arid regions. Despite interest in the drought resilience of indigenous water systems, the impact of this paradigm shift on drought resilience remains poorly understood because previous studies have focused on fixed irrigation water systems. To fill this gap, we investigated the drought resilience of an indigenous and modern irrigation water system that coexists in the drought-prone Mahaweli H region of the Sri Lankan dry zone. To explain drought resilience, we quantified the historical irrigation system performance (1985–2021) of both water systems using the water duty indicator (i.e., the volume of water required to cultivate a unit land area). The statistical Pettitt test was used to detect significant change points in the time series of water duty, and we divided the time line into few periods based on the change points. Furthermore, a quantitative trend analysis of several socio-hydrological variables and a qualitative analysis of their socio-hydrological backgrounds with triggers of water duty were conducted to explain drought resilience path dependency in modern and indigenous water systems. The results indicated a higher drought resilience is embedded in the indigenous system as the mean water duty increment in drought years compared to non-drought years is 16.4% for the indigenous system and 58.3% for the modern system. In addition, drought resilience pathways that elucidated by water duty change points also demonstrated that indigenous water system features a higher drought resilience compared to the modern water system. The findings of this comparative study can contribute to the design of drought resilience improvement strategies in arid region irrigation water systems in a more comprehensive manner.
Fertilization enhances rice productivity by promoting phosphorus uptake and altering soil microbiota
Authors: Wu Changzhou , Wu Bo , Lin Suhong , Chen Tongying , You Xinxin , Wang Sheng
Published: February 2024

Fertilization can enhance crop yield and improve soil health. However, its effects on nutrient uptake, soil microbiota, and rice yield remain unclear. Herein, we designed a double-cropping system with different fertilization treatments to determine their contributions to paddy soil agroecosystem and rice yield. Soil samples were collected before planting the early rice, after harvesting early rice, and after harvesting the late rice. Soil physicochemical properties, and rice yield, and rice nutrient (total nitrogen, phosphorus, and potassium contents) were determined. Variation of soil microbiota were also determined by high-throughput sequencing. We found that soil potassium content significantly improved during the planting process (P < 0.05), while rice phosphorus displayed significant variation under fertilization (P < 0.05). Notably, late rice yield was significantly higher than early rice yield (P < 0.001) after fertilization treatment. Furthermore, rice yield was positively correlated with available soil phosphorus (P < 0.05), indicating that fertilization promoted phosphorus uptake. Organic fertilizer altered the soil microbiota and increased Chloroflexi phyla abundance, while organic fertilizer combined with a compound microbial agent increased the diversity of soil microbial communities. A partial least squares path model revealed that fertilizer treatment directly positively affected rice yield by influencing phosphorus uptake and Shannon index (P < 0.01). Collectively, this study demonstrates that organic fertilization with compound microbial agents can stabilize soil nutrients, increase soil microbial diversity, and improve rice yield, thereby offering a guide for enhancing fertilizer utilization and improving agroecosystems.
Manipulating optical absorption and polarization using microwave control in an atomic vapor
Authors: Tretiakov A , Potts C A , Lu B , Davis J P , LeBlanc L J
Published: February 2024

The multiplicity of atomic states (and the transitions between them) offer an innate, coherent platform through which microwave and optical fields effectively interact. In an atomic vapor near room temperature, we combine optical and microwave fields to generate a macroscopic internal angular momentum among the atoms—an atomic polarization—at an arbitrary angle with respect to the optical (laser) beam. This geometric freedom enables microwave control over photonic degrees of freedom, which we use in two demonstrations: using microwave-assisted optical pumping, we can rotate linear polarization through several degrees, and we can control the absorption for specific transitions and polarizations, which has applications for microwave-to-optical transduction.
Optimization of responses in single and multi-point machining processes using Dragon-fly algorithm coupled with TOPSIS and VIKOR decision-making approaches
Authors: Ramena Durga Venkata Prasad , Arun Vikram Kothapalli , Maruvada Satya Sankara Srinivas Rao , Sanjana Jagarapu , Balaraju Avija
Published: February 2024

Due to complex production practices, it is becoming crucial to provide greater thermal management and friction reduction in manufacturing processes. Lubricants play a crucial role by effectively reducing friction, minimizing wear and tear thereby extending the lifespan of the tool. It is observed that there is a shortage of studies associated with the machining of hard materials like Ti-6Al-4V. The present work has therefore focused on the machining of high-grade Titanium alloy under dry and Neem oil aerosol-mist spray wet conditions. The machining is performed on two kinds of machining processes, such as plain facing with single point tool and co-axial turn-mill facing with multi-point cutting tools on computer numerical controlled Turn-mill machine tool. Furthermore, there are very few articles reported on usage of Neem oil (AzadirachtaIndicaL.) as a lubricant. This has motivated the authors to use Neem oil in a mist condition to minimize the quantity of coolant, without compromising on the tool temperature, surface quality, and tool-wear. The responses obtained are subjected to regression analysis to evolve the fitness functions. Multi-objective optimization of these functions is than adopted using Dragon-fly algorithm (MODA) under the constraints of the machining parameters. A set of pareto optimal solutions for each of the machining cases are obtained and are further evaluated using TOPSIS and VIKOR decision-making approaches to achieve the optimal values of the cutting parameters. The optimum parameters for single point cutting under wet conditions were observed as speed (592 rpm), feed (0.058 mm rev−1) and depth of cut (1.00 mm).The corresponding values of responses were tool temperature (37.05 °C), surface roughness (0.128 μm) and tool wear (155.19 μm). The equivalent values for multi-point cutting were determined as 510 rpm, 0.086 mm rev−1 and 0.25 mm. The responses for these optimal conditions are 32.17 °C, 0.725 μm and 45.72 μm in that order.
Modeling of compressive stress in AlSi10Mg alloys using feed-forward neural networks
Authors: Rodríguez-Sánchez Alejandro E , Acevedo-Alvarado Mario
Published: February 2024

This study addresses the challenge of modeling compressive stress in AlSi10Mg composites by introducing a method that employs feedforward artificial neural networks (ANNs) and their interpretability, which helps to simulate and analyze material behavior under various conditions. The main objective is to develop a predictive ANN model that can effectively simulate material responses under several factors, incorporating diverse testing parameters and material specifications related with its synthesis. An optimized ANN model, featuring eleven neurons in its hidden layer, was used and demonstrated high predictive accuracy, achieving R
2 values exceeding 0.94. Additionally, a SHAP interpretability analysis was conducted to assess the influence of key factors such as strain and material conditions on the stress response. The results highlight the significant role of material synthesis processes, compared to the strain rate, in the stress response. In conclusion, this method presents a comprehensive tool for studying complex stress behaviors in AlSi10Mg-based composites , offering insights that could guide future material development and research.
Between Prophecy and Apocalypse
Authors: Gabriele Matthew
Published: February 2024

This book maps the movement between two intellectual stances, best described as a shift from prophetic to apocalyptic thinking in medieval Europe. Although the roots of this change lay in late antiquity, the fulcrum of this transition lies in the tenth and eleventh centuries. Biblical commentators in the fourth and fifth centuries enforced a particular understanding of sacred time that held until the ninth century, when exegetes found in their commentaries a different plan for God’s new chosen people. This came into stark relief as the new kingdom of Israel (the Frankish empire under the Carolingians) had splintered in the 840s during the Carolingian civil war. What was perhaps unforeseen was that these commentaries that were written in this specific context would be heavily copied and read for the next 200 years. Ideas that formed in a world that actively lamented the loss of empire had to be translated to a world that could only dream of that empire. As they spread across Europe, these ideas became the basis for monastic educational practices and bled into other types of textual production, such as supposedly “secular” histories. A movement towards surety can be seen in our sources, as in the eleventh century, when medieval Europeans began to try to enact what they thought was God’s plan, often with fire and sword.
Introduction
Authors: Gabriele Matthew
Published: February 2024

The Introduction lays out the parameters of the book as a whole, asking us to question common assumptions about tenth- and eleventh-century Europe. Too often, modern scholars are trapped by the preoccupations of our nineteenth-century forebears who (often explicitly) analyzed the turn of the first millennium within the context of their own contemporary politics. To escape this trap we need to return to a version of medieval Europe that is more honest to our sources and allows our subjects agency. As such, the chapter redefines “prophecy” and “apocalyptic” and suggests a new approach termed “Instrumental History.”
Virtual wards for people with frailty: what works, for whom, how and why—a rapid realist review
Authors: Westby Maggie , Ijaz Sharea , Savović Jelena , McLeod Hugh , Dawson Sarah , Welsh Tomas , Le Roux Hein , Walsh Nicola , Bradley Natasha
Published: February 2024

Background

Virtual wards (VWs) deliver multidisciplinary care at home to people with frailty who are at high risk of a crisis or in crisis, aiming to mitigate the risk of acute hospital admission. Different VW models exist, and evidence of effectiveness is inconsistent.

Aim

We conducted a rapid realist review to identify different VW models and to develop explanations for how and why VWs could deliver effective frailty management.

Methods

We searched published and grey literature to identify evidence on multidisciplinary VWs. Information on how and why VWs might ‘work’ was extracted and synthesised into context-mechanism-outcome configurations with input from clinicians and patient/public contributors.

Results

We included 17 peer-reviewed and 11 grey literature documents. VWs could be short-term and acute (1–21 days), or longer-term and preventative (typically 3–7 months). Effective VW operation requires common standards agreements, information sharing processes, an appropriate multidisciplinary team that plans patient care remotely, and good co-ordination. VWs may enable delivery of frailty interventions through appropriate selection of patients, comprehensive assessment including medication review, integrated case management and proactive care. Important components for patients and caregivers are good communication with the VW, their experience of care at home, and feeling involved, safe and empowered to manage their condition.

Conclusions

Insights gained from this review could inform implementation or evaluation of VWs for frailty. A combination of acute and longer-term VWs may be needed within a whole system approach. Proactive care is recommended to avoid frailty-related crises.
Genome-wide investigation of SQUAMOSA promoter binding protein-like genes in Liriodendron and functional characterization of LcSPL2
Authors: Zhang Yu , Hu Qinghua , Zhai Xinyu , Tu Zhonghua , Wang Jing , Wang Minxin , Li Huogen
Published: February 2024

The plant-specific SQUAMOSA promoter-binding protein-like (SPL) transcription factors play a pivotal role in various developmental processes, including leaf morphogenesis and vegetative to reproductive phase transition. Liriodendron chinense and Liriodendron tulipifera are widely used in landscaping due to their tulip-like flowers and peculiar leaves. However, the SPL gene family in Liriodendron has not been identified and systematically characterized. We systematically identified and characterized the SPL family members in Liriodendron, including phylogeny, gene structure and syntenic analyses. Subsequently, we quantified the expression patterns of LcSPLs across various tissue sites through transcription-quantitative polymerase chain reaction (RT-qPCR) assays and identified the target gene, LcSPL2. Finally, we characterized the functions of LcSPL2 via ectopic transformation. Altogether, 17 LcSPL and 18 LtSPL genes were genome-widely identified in L. chinense and L. tulipifera, respectively. All the 35 SPLs were grouped into 9 clades. Both species had three SPL gene pairs arising from segmental duplication events, and the LcSPLs displayed high collinearity with the L. tulipifera genome. RT-qPCR assays showed that SPL genes were differentially expressed in different tissues, especially. Because LcSPL2 is highly expressed in pistils and leaves, it was selected to describe the SPL gene family of L. chinense by ectopic expression. We showed that overexpression of LcSPL2 in Arabidopsis thaliana resulted in earlier flowering and fewer rosette leaves. Moreover, we observed that overexpression of LcSPL2 in A. thaliana up-regulated the expression levels of four genes related to flower development. This study identified SPL genes in Liriodendron and characterized the function of LcSPL2 in advancing flower development.
BioModME for building and simulating dynamic computational models of complex biological systems
Authors: Womack Justin A , Shah Viren , Audi Said H , Terhune Scott S , Dash Ranjan K
Published: February 2024

Molecular mechanisms of biological functions and disease processes are exceptionally complex, and our ability to interrogate and understand relationships is becoming increasingly dependent on the use of computational modeling. We have developed “BioModME,” a standalone R-based web application package, providing an intuitive and comprehensive graphical user interface to help investigators build, solve, visualize, and analyze computational models of complex biological systems. Some important features of the application package include multi-region system modeling, custom reaction rate laws and equations, unit conversion, model parameter estimation utilizing experimental data, and import and export of model information in the Systems Biology Matkup Language format. The users can also export models to MATLAB, R, and Python languages and the equations to LaTeX and Mathematical Markup Language formats. Other important features include an online model development platform, multi-modality visualization tool, and efficient numerical solvers for differential-algebraic equations and optimization.

Availability and implementation

All relevant software information including documentation and tutorials can be found at https://mcw.marquette.edu/biomedical-engineering/computational-systems-biology-lab/biomodme.php. Deployed software can be accessed at https://biomodme.ctsi.mcw.edu/. Source code is freely available for download at https://github.com/MCWComputationalBiologyLab/BioModME.
imputomics: web server and R package for missing values imputation in metabolomics data
Authors: Chilimoniuk Jarosław , Grzesiak Krystyna , Kała Jakub , Nowakowski Dominik , Krętowski Adam , Kolenda Rafał , Ciborowski Michał , Burdukiewicz Michał
Published: February 2024

Motivation

Missing values are commonly observed in metabolomics data from mass spectrometry. Imputing them is crucial because it assures data completeness, increases the statistical power of analyses, prevents inaccurate results, and improves the quality of exploratory analysis, statistical modeling, and machine learning. Numerous Missing Value Imputation Algorithms (MVIAs) employ heuristics or statistical models to replace missing information with estimates. In the context of metabolomics data, we identified 52 MVIAs implemented across 70 R functions. Nevertheless, the usage of those 52 established methods poses challenges due to package dependency issues, lack of documentation, and their instability.

Results

Our R package, ‘imputomics’, provides a convenient wrapper around 41 (plus random imputation as a baseline model) out of 52 MVIAs in the form of a command-line tool and a web application. In addition, we propose a novel functionality for selecting MVIAs recommended for metabolomics data with the best performance or execution time.

Availability and implementation

‘imputomics’ is freely available as an R package (github.com/BioGenies/imputomics) and a Shiny web application (biogenies.info/imputomics-ws). The documentation is available at biogenies.info/imputomics.
Climate change impact on small mammals from two Neotropical hotspots
Authors: de Castro Evaldt Bruno Henrique , Leite Yuri Luiz Reis , Loss Ana Carolina
Published: February 2024

Current climate change represents the unprecedented change in weather patterns across global and regional scales over a short period due to human activity. It is expected to drive changes in species distributions across the globe. Our goal here was to analyse (i) how climate change can impact the future distribution of species in two Neotropical hotspots, and (ii) how future distribution can impact the threatened status of species. We used ecological niche modelling to estimate suitable areas in the present and four future climate change scenarios (SSPs) for 40 species of nonvolant small mammals endemic to the Atlantic Forest and Cerrado biomes of South America. We also inferred species’ future threat levels according to the IUCN’s A3 criteria using future relative area estimates. We found that species will gradually lose more area in all future scenarios, from the most optimistic Shared Socio-economic Pathway (SSP1-2.6) to the most pessimistic (SSP5-8.5) scenario. Species endemic to the Cerrado will see a greater area reduction than species endemic to the Atlantic Forest. Consequently, the Cerrado will have more threatened species than the Atlantic Forest. Species that occupy both biomes will lose proportionally less area than those endemic to the Cerrado but more area than those endemic to the Atlantic Forest. In conclusion, small mammal species will, in general, be negatively impacted by climate change. However, the degree of impact depends on the trajectory of greenhouse gas concentrations and where the species live.
Inefficient Sox9 upregulation and absence of Rspo1 repression lead to sex reversal in the B6.XYTIR mouse gonad
Authors: Cao Jiangqin , El Mansouri Fatima , Reynoso Sofia , Liu Zongping , Zhu Jiaqiao , Taketo Teruko
Published: February 2024

Sry on the Y-chromosome upregulates Sox9, which in turn upregulates a set of genes such as Fgf9 to initiate testicular differentiation in the XY gonad. In the absence of Sry expression, genes such as Rspo1, Foxl2, and Runx1 support ovarian differentiation in the XX gonad. These two pathways antagonize each other to ensure the development of only one gonadal sex in normal development. In the B6.YTIR mouse, carrying the YTIR-chromosome on the B6 genetic background, Sry is expressed in a comparable manner with that in the B6.XY mouse, yet, only ovaries or ovotestes develop. We asked how testicular and ovarian differentiation pathways interact to determine the gonadal sex in the B6.YTIR mouse. Our results showed that (1) transcript levels of Sox9 were much lower than in B6.XY gonads while those of Rspo1 and Runx1 were as high as B6.XX gonads at 11.5 and 12.5 days postcoitum. (2) FOXL2-positive cells appeared in mosaic with SOX9-positive cells at 12.5 days postcoitum. (3) SOX9-positive cells formed testis cords in the central area while those disappeared to leave only FOXL2-positive cells in the poles or the entire area at 13.5 days postcoitum. (4) No difference was found at transcript levels of all genes between the left and right gonads up to 12.5 days postcoitum, although ovotestes developed much more frequently on the left than the right at 13.5 days postcoitum. These results suggest that inefficient Sox9 upregulation and the absence of Rspo1 repression prevent testicular differentiation in the B6.YTIR gonad.
Long-range connections damage in white matter hyperintensities affects information processing speed
Authors: Lu Tong , Wang Zan , Zhu Yixin , Wang Mengxue , Lu Chun-Qiang , Ju Shenghong
Published: February 2024

White matter hyperintensities, one of the major markers of cerebral small vessel disease, disrupt the integrity of neuronal networks and ultimately contribute to cognitive dysfunction. However, a deeper understanding of how white matter hyperintensities related to the connectivity patterns of brain hubs at the neural network level could provide valuable insights into the relationship between white matter hyperintensities and cognitive dysfunction. A total of 36 patients with moderate to severe white matter hyperintensities (Fazekas score ≥ 3) and 34 healthy controls underwent comprehensive neuropsychological assessments and resting-state functional MRI scans. The voxel-based graph-theory approach-functional connectivity strength was employed to systematically investigate the topological organization of the whole-brain networks. The white matter hyperintensities patients performed significantly worse than the healthy controls in episodic memory, executive function and information processing speed. Additionally, we found that white matter hyperintensities selectively affected highly connected hub regions, predominantly involving the medial and lateral prefrontal, precuneus, inferior parietal lobule, insula and thalamus. Intriguingly, this impairment was connectivity distance-dependent, with the most prominent disruptions observed in long-range connections (e.g. 100–150 mm). Finally, these disruptions of hub connectivity (e.g. the long-range functional connectivity strength in the left dorsolateral prefrontal cortex) positively correlated with the cognitive performance in white matter hyperintensities patients. Our findings emphasize that the disrupted hub connectivity patterns in white matter hyperintensities are dependent on connection distance, especially longer-distance connections, which in turn predispose white matter hyperintensities patients to worse cognitive function.
From tugs to treatments: a systematic review on pharmacological interventions for trichotillomania
Authors: Ghani Hira , Podwojniak Alicia , Tan Isabella J , Fliorent Rebecca , Jafferany Mohammad
Published: February 2024

Background

Trichotillomania (TTM) is a psychiatric disorder with dermatological consequences, characterized by recurrent hair pulling. It affects 1–3% of the population, and often coexists with other psychiatric disorders, leading to emotional distress. Effective management of TTM can be challenging because of underdiagnosis, symptom heterogeneity and stigma. Pharmacological interventions, including selective serotonin reuptake inhibitors and N-acetyl cysteine (NAC) are commonly used.

Objectives

To assess the existing literature on pharmacotherapy for TTM and identify potential avenues for future research and treatment advancements.

Methods

A systematic review of the literature was performed using PubMed and Scopus databases within the past 10 years (PROSPERO: CRD42023454009). Included studies assessed pharmacotherapy for TTM and provided insights into current evidence and potential directions for future research and treatment advancements.

Results

In total, 23 articles were identified that met inclusion criteria. The most successful interventions were NAC, aripiprazole and monoamine oxidase inhibitors. NAC was identified as the most impressive adjunctive therapy to selective serotonin reuptake inhibitors and behavioural therapies in treatment through its mechanism of decreased glutamate-induced excitatory neuronal damage, with adjunctive antioxidant properties. Most of the other therapeutics that were identified require further research and controlled trials to validate their findings.

Conclusions

Even if successful therapeutic outcomes are achieved, it is important to consider the patient’s comorbidities and to combine pharmacological interventions with behavioural therapy interventions to comprehensively manage TTM.
Variants of female pattern hair loss in men
Authors: Awad Andrew , Sharma Prateek , Bhoyrul Bevin
Published: February 2024

Female pattern hair loss (FPHL) presents with hair thinning on the mid-frontal scalp and crown with retention of the anterior hairline. In a proportion of women with FPHL, there is a gradual decrease in hair density from the vertex to the frontal region, resulting in a triangular or ‘Christmas tree’ pattern. Despite what its name may suggest, FPHL can also affect men. However, the Christmas tree pattern has only been used to describe frontal accentuation of hair loss in women. The aim of our study was to determine patterns of FPHL in men.
Functional parcellation of the neonatal cortical surface
Authors: Myers Michael J , Labonte Alyssa K , Gordon Evan M , Laumann Timothy O , Tu Jiaxin C , Wheelock Muriah D , Nielsen Ashley N , Schwarzlose Rebecca F , Camacho M Catalina , Alexopoulos Dimitrios , Warner Barbara B , Raghuraman Nandini , Luby Joan L , Barch Deanna M , Fair Damien A , Petersen Steven E , Rogers Cynthia E , Smyser Christopher D , Sylvester Chad M
Published: February 2024

The cerebral cortex is organized into distinct but interconnected cortical areas, which can be defined by abrupt differences in patterns of resting state functional connectivity (FC) across the cortical surface. Such parcellations of the cortex have been derived in adults and older infants, but there is no widely used surface parcellation available for the neonatal brain. Here, we first demonstrate that existing parcellations, including surface-based parcels derived from older samples as well as volume-based neonatal parcels, are a poor fit for neonatal surface data. We next derive a set of 283 cortical surface parcels from a sample of n = 261 neonates. These parcels have highly homogenous FC patterns and are validated using three external neonatal datasets. The Infomap algorithm is used to assign functional network identities to each parcel, and derived networks are consistent with prior work in neonates. The proposed parcellation may represent neonatal cortical areas and provides a powerful tool for neonatal neuroimaging studies.
Alterations in magnetic properties of crystals of trinuclear copper complexes: isolated entities versus one-dimensional chains
Authors: Hosoya Yosuke , Yoshikawa Hiroki , Tsukamoto Arata , Sugawa Kosuke , Otsuki Joe
Published: February 2024

We obtained two types of crystals of a complex under different crystallization conditions, each exhibiting distinct molecular arrangements and magnetic interactions: one type consists of isolated complexes, while the other forms one-dimensional chains without extra bridging ligands. This approach provides a new avenue for tuning the magnetic properties of metal-complex-based materials.
Durability of Protection Against COVID-19 Through the Delta Surge for the NVX-CoV2373 Vaccine
Authors: Follmann Dean , Mateja Allyson , Fay Michael P , Magaret Craig A , Huang Yunda , Fong Youyi , Angier Heather , Nason Martha , Gay Cynthia L , Kotloff Karen , Woo Wayne , Cho Iksung , Dunkle Lisa M
Published: February 2024

Background

Protein-based vaccines for coronavirus disease 2019 (COVID-19) provide a traditional vaccine platform with long-lasting protection for non–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogens and may complement messenger RNA vaccines as a booster dose. While NVX-CoV2373 showed substantial early efficacy, the durability of protection has not been delineated.

Methods

The PREVENT-19 vaccine trial used a blinded crossover design; the original placebo arm received NVX-CoV2373 after efficacy was established. Using novel statistical methods that integrate surveillance data of circulating strains with post-crossover cases, we estimated placebo-controlled vaccine efficacy and durability of NVX-CoV2373 against both pre-Delta and Delta strains of SARS-CoV-2.

Results

Vaccine efficacy against pre-Delta strains of COVID-19 was 89% (95% CI, 75–95%) and 87% (72–94%) at 0 and 90 days after 2 doses of NVX-CoV2373, respectively, with no evidence of waning (P = .93). Vaccine efficacy against the Delta strain was 88% (71–95%), 82% (56–92%), and 77% (44–90%) at 40, 120, and 180 days, respectively, with evidence of waning (P < .01). In sensitivity analyses, the estimated Delta vaccine efficacy at 120 days ranged from 66% (15–86%) to 89% (74–95%) per various assumptions of the surveillance data.

Conclusions

NVX-CoV2373 has high initial efficacy against pre-Delta and Delta strains of COVID-19 with little evidence of waning for pre-Delta strains through 90 days and moderate waning against Delta strains over 180 days.