bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards an approach to co‐execute system models at the enterprise level
Authors: Bankauskaite Jovita , Strolia Zilvinas , Morkevicius Aurelijus
Published: August 2023

Industry 4, the Internet of Things, and large‐scale system‐to‐system interactions are driving digital transformation in the industry. Model‐based systems engineering (MBSE) is one of the core paradigms behind this transformation. MBSE practices are widely applied to enterprise (including system of systems and mission) architectures, which become a crucial part of successful digital transformation. The core challenge today is not only how digital continuity can be maintained by connecting different layers of models (such as system models to system‐of‐systems models), but also how to perform detailed analysis and simulation at the enterprise level model. This paper studies Systems Modeling Language (SysML) as the standard language to model systems, Unified Architecture Framework (UAF) as the framework, Unified Architecture Framework Modeling Language (UAFML) as the language to model enterprise architectures, and proposes an approach for end‐to‐end co‐execution of the integrated enterprise model.
Applying MBSE in Space Based Systems Development
Authors: Madariaga Chris , Bashir Ahmad , Swickline Chris
Published: August 2023

A core challenge in modern systems engineering is executing the Digital Transformation to produce Digital Engineering (DE) products that meet traditional program needs. Model Based Systems Engineering (MBSE) focuses the formal application of models to support the systems engineering process, but is often difficult to apply in practice due to a lack of a well‐defined methodology. This paper first introduces an openly available MBSE methodology concentrating on a development process for system architecture models, a style guide defining how the process steps are executed, and a validation suite which serves as a tool to help execute development. Then, this paper describes the experience in applying this process to a DoD program developing a space‐based sensor system to a Critical Design Review (CDR) level of maturity. Real‐life successes and lessoned learned are described through model metric data pulled directly from the SysML development model. This paper concludes by identifying opportunities for future research/work from which to further build the DE/MBSE capabilities of the model.
Defining Collaborative Control Interactions Using Systems Theory
Authors: Kopeikin Andrew N. , Leveson Nancy G. , Neogi Natasha A.
Published: August 2023

Human teams collaborate by establishing roles, changing functional authorities, maintaining team cognition, coordinating, and mutually helping one another close control loops. These complex interactions are inspiring novel system concepts to improve human‐machine and multi‐machine collaboration. However, these new systems face engineering gaps in modeling, analysis, design, and assurance. As such, few have been fielded in safety‐critical domains like aerospace. To analyze safety, this paper introduces a system‐theoretic framework to describe interactions that are—or are planned to be—used in multi‐controller systems. It outlines a taxonomy of seven structural dimensions that influence controller interactions and nine dynamics observed in collaborative control that are defined using Systems Theory. An analyzed set of 101 controller interactions in aerospace systems demonstrates how to apply the framework and that designers are trying to create more sophisticated systems. This framework provides the foundation to extend system‐theoretic hazard analysis techniques to systematically find collaborative‐control causal factors.
Vaccination effects on reducing COVID‐19 complications in pregnancy: A large‐scale report from Iran
Authors: Changizi Nasrin , Eshrati Babak , Salehi Mohammadreza , Beheshtian Maryam , Hadipour Jahromy Leila , Emami Afshar Nehzat , Hejazi Saeideh , Hantoushzadeh Sedigheh , Eslamian Laleh , Savaie Mohsen , Raeisi Alireza , Pooransari Parichehr
Published: September 2023

Objective

The objective of this study was to evaluate the effects of maternal coronavirus disease 2019 (COVID‐19) vaccination on preventing severe complications of COVID‐19 in pregnant women.

Methods

A retrospective study was conducted in pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) during pregnancy and/or for up to 6 weeks postpartum between September 1, 2021, to January 30, 2022. The data was retrieved from a national database. The pregnant women were divided into two groups of vaccinated and unvaccinated. The proposed outcomes (the need for hospitalization, intensive care unit admission, and mechanical ventilation and products of conception complications) were compared between the two groups.

Results

Approximately 90 000 pregnant women infected with COVID‐19 were included in the study. The data of the vaccinated (19 922) and unvaccinated (70 147) groups were analyzed and compared. Pregnant patients in the vaccinated group had a significantly lower rate of hospitalization (21.2% vs 29.4%) (odds ratio [OR], 0.648 [95% confidence interval (CI), 0.625–0.673], P = 0.0001) and intensive care unit admission (3.7% vs 7.8%) (OR, 0.453 [95% CI, 0.382–0.535], P = 0.0001). The need for mechanical ventilation was also lower, although not statistically significant, in the vaccinated group than in the unvaccinated group (30 of 155 [19.4%] vs 418 of 1597 [26.2%]) (OR, 0.677 [95% CI, 0.448–1.024], P = 0.063). Cesarean section (54.3% vs 58.1%) (OR, 0.856 [95% CI, 0.751–0.977], P = 0.021) and stillbirth (0.4% vs 3.6%) (OR, 0.097 [95% CI, 0.026–0.252], P = 0.0001) were also significantly lower in the vaccinated patients. Most pregnant women in the vaccinated group (18 484–96.14%) received Sinopharm BIBP COVID‐19 inactivated vaccine. No significant differences were seen in the effect of different types of COVID‐19 vaccines on reducing COVID‐19 complications in infected pregnant patients.

Conclusion

Maternal COVID‐19 immunization is effective in reducing COVID‐19 complications in infected pregnant women.
Sustained Content Teaching in Academic ESL/EFL: A Practical Approach
Authors: Alatriste Lubie G.
Published: August 2023

Marcia Pally (Ed.). Boston, MA: Houghton Mifflin, 2000
Discrimination and school outcomes in first nation youth: The role of positive psychological characteristics
Authors: Schick Melissa R. , Todi Akshiti A. , Nalven Tessa , Spillane Nichea S.
Published: September 2023

Introduction

Positive psychological characteristics have been found to be associated with discrimination and school outcomes separately; however, no work has examined these associations together or in North American Indigenous (NAI) populations. NAI adolescents experience high rates of racial discrimination. Because discrimination has a detrimental impact on academic outcomes it is critical to identify factors that could buffer this impact. The purpose of this study was to examine the indirect effect of racial discrimination on three distinct school outcomes (i.e., attitudes toward school, grades, and educational attainment goals) through the pathway of three positive psychological characteristics (i.e., satisfaction with life, subjective happiness, and self‐compassion).

Methods

First Nation adolescents living on a rural reserve in Eastern Canada (N = 106, Mage = 14.6 years, 50.0% female) completed a pencil‐and‐paper survey in Spring 2017 as part of a larger community‐based participatory research study.

Results

In the model examining school attitudes, indirect effects through subjective happiness (b = −0.21, 95% confidence interval (CI): [−0.53, −0.03]) and self‐compassion (b = −0.19, 95% CI: [−0.39, −0.04]), but not satisfaction with life, were significant. In the model examining grades, only the specific indirect effect through subjective happiness was significant (b = −0.27, 95% CI: [−0.59 −0.07]). Similarly, in the model examining school goals, only the indirect effect through subjective happiness was significant (b = −0.40, 95% CI: [−0.94, −0.08]). The direct effects of discrimination on school attitudes (b = 0.02, 95% CI: [−0.52, 0.56]), grades (b = 0.16, 95% CI: [−0.39, 0.71]), and school goals (b = −0.03, 95% CI: [−0.90, 0.84]) were not significant after controlling for positive psychological characteristics.

Discussion

Schools should foster positive emotions to enhance academic outcomes, especially for NAI youth who are more likely to experience racial discrimination.
Investigation of TGF‐α‐overexpressing mouse hepatocytes (TAMH) cultured as spheroids for use in hepatotoxicity screening of drug candidates
Authors: Beirow Kristin , Schmidt Christian , Jürgen Britta , Schlüter Rabea , Schweder Thomas , Bednarski Patrick J.
Published: September 2023

The immortalized mouse liver cell line TAMH has been described as a valuable tool for studying hepatotoxic mechanisms, but until now, it has only been reported to grow as a monolayer in culture. However, culturing hepatocytes as three‐dimensional (3D) spheroids has been shown to result in improved liver‐specific functions (e.g., metabolic capacity) by better mimicking the in vivo environment. This approach may lead to more reliable detection of drug‐induced liver injury (DILI) in the early phase of drug discovery, preventing post‐marketing drug withdrawals. Here, we investigated the cultivation of TAMH as 3D spheroids, characterizing them with optical and transmission electron microscopy as well as analyzing their gene expression at mRNA level (especially drug‐metabolizing enzymes) compared to TAMH monolayer. In addition, comparisons were made with spheroids grown from the human hepatoblastoma cell line HepG2, another current spheroid model. The results indicate that TAMH spheroids express hepatic structures and show elevated levels of some of the key phase I and II drug‐metabolizing enzymes, in contrast to TAMH monolayer. The in vitro hepatotoxic potencies of the drugs acetaminophen and flupirtine maleate were found to be very similar between TAMH spheroidal and the monolayer cultures. Both the advantages and disadvantages of TAMH spheroids as an in vitro hepatotoxicity model compared to monolayer model are discussed.
Therapeutic effects of low‐color‐temperature light‐emitting diodes on dry eye
Authors: Pang Yulian , Cao Ting , Hu Haijian , Peng Zhida , Xu Ke , Jiang Yi , Wang Feifei , Jin Ming , Zeng Ling , Zhang Xu
Published: September 2023

Background

As a new technology for treating dry eye diseases, phototherapy has attracted great attention, but the research on its safety and effectiveness is limited. In this study, the therapeutic effects of low‐color‐temperature light‐emitting diodes on dry eye in humans, rabbits, and rats were investigated.

Methods

In clinical experiments, subjects in both groups read the same paper for 3 h under light sources of two color temperatures: 1900 K (low‐color‐temperature light‐emitting diodes) or 4000 K (artificial fluorescent white light‐emitting diodes). The differences in the non‐invasive tear film breakup time, tear meniscus height, and conjunctival congestion scores before and after the experiment were compared between the two groups. In animal experiments, corneal epithelial barrier function and tear production of Sprague–Dawley rats and New Zealand white rabbits with dry eye were compared before and after low‐color‐temperature light‐emitting diodes treatment. TUNEL staining and Western blotting were used to detect the apoptosis of corneal and conjunctival cells and the expression of inflammatory factor IL‐1β.

Results

Low‐color‐temperature light‐emitting diodes prolonged tear film breakup time in patients with dry eye. Moreover, it increased tear secretion, decreased fluorescein sodium staining scores, corneal and conjunctival cell apoptosis, and inflammatory factor expression in rabbits and rats with dry eye.

Conclusions

Low‐color‐temperature light‐emitting diodes phototherapy can be used as an effective treatment for dry eye, reducing its symptoms and related ocular surface damage in humans, rabbits, and rats.
Comparison of PLLA‐PEG and PDLLA‐PEG micelles for co‐encapsulation of docetaxel and resveratrol
Authors: Jurczyk Magdalena , Musiał‐Kulik Monika , Foryś Aleksander , Godzierz Marcin , Kaczmarczyk Bożena , Kasperczyk Janusz , Wrześniok Dorota , Beberok Artur , Jelonek Katarzyna
Published: August 2023

The interest in combining chemosensitizers with cytostatics in cancer therapy is growing, which causes also a need to develop their delivery systems. Example of the combination with beneficial therapeutic effects is docetaxel (Dtx) and resveratrol (Res). Although poly(lactide)‐co‐poly(ethylene glycol) (PLA–PEG) micelles have been considered as one of the most promising platforms for drug delivery, their properties may depend on the stereoisomeric form of hydrophobic block. Therefore, the aim of this study was evaluation of the effect of PLA block on co‐encapsulation and release rate of Dtx and Res, which has not been studied so far. This article presents a comparison of single‐ (Dtx or Res) and dual‐drug (Dtx and Res) loaded micelles obtained from poly(l,l‐lactide)‐co‐poly(ethylene glycol) (PLLA‐PEG) and poly(d,l‐lactide)‐co‐poly(ethylene glycol) (PDLLA‐PEG). The analyzes of the micelles have been conducted including morphology, drug(s) encapsulation efficiency, intermolecular interactions, in vitro drug release, and cytotoxicity. Differences in drug loading ability and release profile have been observed between Res and Dtx but also depending on the polymer and number of drugs in micelles (single vs. dual loaded). The PLLA‐PEG micelles have a significantly higher Dtx encapsulation capacity than PDLLA‐PEG micelles. The highest cytotoxicity was shown for Dtx and Res dual‐loaded micelles, regardless of the polymer. The findings may be used for selection of PLA‐based drug delivery systems containing Dtx and Res.
Neophobia, but not perch hopping, is sensitive to long‐term chronic stress intensity
Authors: Beattie Ursula K. , Mikolajczak Lily , Fefferman Nina , Romero L. Michael
Published: September 2023

To further elucidate the role that wear‐and‐tear plays in the transition from acute to chronic stress, we manipulated the intensity and duration of applied chronic stress to determine if behavior would respond proportionately. We brought wild house sparrows into captivity and subjected them to high‐stress, medium‐stress, low‐stress, or captivity‐only. We varied the number of stressors per day and the duration of stress periods to vary wear‐and‐tear, and thus the potential to exhibit chronic stress symptoms. The behaviors we assessed were neophobia (the fear of the new; assessed via food approach latency) and perch hopping (activity). We predicted that our birds would show proportionate decreases in neophobia and activity throughout a long‐term chronic stress paradigm. Our results indicate that neophobia is sensitive to the intensity of chronic stress, however, the birds became more neophobic, which was the opposite of what we expected. Conversely, perch hopping did not differ across treatment groups and is thus not sensitive to the intensity of chronic stress. Together, these data show that different behavioral measurements are impacted differently by chronic stress.
Impact of volume and rate of milk delivery on coordination of respiration and swallowing in infant pigs
Authors: Gould Francois D. H. , Mayerl Christopher J. , Adjerid Khaled , Edmonds Chloe , Charles Nicole , Johnson Maxwell , German Rebecca Z.
Published: September 2023

The coordination of respiration and swallowing is a life‐critical function in infants. Varying volume and rate of milk delivery changes swallowing frequency and bolus volume but any impact on swallow‐respiration coordination is unknown. Five infant pigs were filmed with simultaneous high speed videofluoroscopy and plethysmography while feeding from an automatic system delivering milk across a range of volumes and frequencies. Swallow inspiration delay, respiratory cycle duration, and distribution of inspiratory and expiratory swallows were calculated. At constant volume, there were more inspiratory phase swallows when frequency increased. At high constant frequency, increasing volume changed swallow‐respiration coordination patterns, with increased occurrence of inspiratory phase swallows. Respiratory cycle duration did not change in response to changes in oral milk delivery. These results suggest that the observed pattern of expiratory swallowing in infants is achieved primarily by regulation of milk intake, not modulation of respiratory patterns by oral sensation.
Comparative study of dietary phenols with Tartary buckwheat protein (2S/13S): impact on structure, binding sites and functionality of protein
Authors: Li Dongze , Zhu Ling , Wu Qiming , Chen Yiling , Wu Gangcheng , Zhang Hui
Published: September 2023

Background

This research was to investigate the interaction mechanism between 2S albumin and 13S globulin (2S and 13S, the most important storage proteins in Tartary buckwheat seeds) and three phenols (rutin, quercetin and myricetin) regarding the structural and antioxidant properties of their complexes.

Results

There are differences in the binding affinity of phenols for 2S and 13S. Rutin had a higher binding affinity for 2S, myricetin had a higher binding affinity for 13S, and 13S exhibited a higher affinity toward phenols than did 2S. Binding with phenols significantly changed the secondary and tertiary structures of 2S and 13S, decreased the surface hydrophobic value and enhanced the antioxidant capacity. Molecular docking and isothermal titration calorimetry showed that the binding processes were spontaneous and that there were hydrogen bonds, hydrophobic bonds and van der Waals force interactions between phenols and proteins.

Conclusion

These findings could provide meaningful guidance for the further application of buckwheat protein complex. © 2023 Society of Chemical Industry.
Comprehensive two‐dimensional gas chromatography— A discussion on recent innovations
Authors: Milani Nino B. L. , van Gilst Eric , Pirok Bob W. J. , Schoenmakers Peter J.
Published: September 2023

Although comprehensive 2‐D GC is an established and often applied analytical method, the field is still highly dynamic thanks to a remarkable number of innovations. In this review, we discuss a number of recent developments in comprehensive 2‐D GC technology. A variety of modulation methods are still being actively investigated and many exciting improvements are discussed in this review. We also review interesting developments in detection methods, retention modeling, and data analysis.
Application of one‐step inner‐recycling counter‐current chromatography for the preparative separation and purification of chemical constituents from the rhizome of Bergenia ciliate (haw.) Sternb
Authors: Aziz Shahid , Akhter Faheem , Hussain Hidayat , Liu Jiguo , Yan Huijiao , Cui Li , Chen Qixu , Cheng Wei , Wang Daijie , Wang Xiao
Published: September 2023

Bergenia ciliata (haw.) Sternb, the renowned pharmaceutical plant in Jammu and Kashmir of Pakistan, is widely applied in treating different illnesses including diabetes, diarrhea, and vomiting. This work employed an efficient one‐step inner‐recycling counter‐current chromatography for preparative separating and purifying compounds with similar partition coefficients from the rhizome of Bergenia ciliate (haw.). Five compounds, including quercetin rhamnodiglucoside (1), quercetin‐3‐O‐rutinoside (2), bergenine (3), kaempferol (4), and palmatic acid (5), were successfully separated using the optimized biphasic solvent system that contained ter‐butylmetylether/n‐butanol/acetonitrile/water (2:2:1:5, v/v) with the purities over 98%. Mass spectrometry and nuclear magnetic resonance were conducted for structural identification. As a result, our proposed strategy might be applied in separating compounds with similar partition coefficients, which was advantageous with regard to the less solvent and time consumption, and the increased number of theoretical plates.
Characterization of chemical constituents in Huangqi Guizhi Wuwu decoction using ultra‐high performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry
Authors: Fan Zhuoyu , Guan Jiao , Li Lele , Cui Yue , Tang Xinmiao , Lin Xiaoying , Shen Guanghai , Feng Bo , Zhu Heyun
Published: September 2023

Huangqi Guizhi Wuwu decoction (HGWWD) is a classic traditional Chinese medicine prescription for the treatment of ischemic stroke, etc. However, the material basis of its efficacy remains unclear, seriously affecting drug development and clinical applications. In the present study, an ultra‐high performance liquid chromatography‐quadrupole time‐of‐flight mass spectrometry method was developed to separate and identify the chemical components of HGWWD. A total of 81 compounds were identified and tentatively characterized. Eight compounds were accurately identified by comparing the retention time and mass spectrometry data with those of reference substances, the remaining compounds were characterized by comparing the mass spectrometry data and reference information. Based on the results of compound attribution, 35 compounds were from Astragali Radix, six compounds were from Cinnamomi Ramulus, 23 compounds were from Paeoniae Radix Alba, eight compounds were from Zingiberis Rhizoma Recens and nine compounds were from Jujubae Fructus. The results showed that monoterpenoids, flavonoids, organic acids, triterpenes, amino acids, gingerols, alkaloids, and glycosides were the main chemical components of HGWWD. This analytical method is suitable for characterizing the chemical constituents of HGWWD, and the results provide important information for elucidating its pharmacodynamic material basis and mechanism of action.
Optomechanically Induced Benjamin–Feir Instability
Authors: Xiong Hao
Published: August 2023

Benjamin–Feir instability, which is originally discovered in hydrodynamics and plasma physics, has become a central process of nonlinear physics over the past decades. On‐chip solid‐state devices with controllable Benjamin–Feir instability can exhibit a rich set of spatio‐temporal dynamics that are inherently sensitive to their initial distribution, which are vital for force sensors and information processing. By exploiting the nonlinear photonic evolution and localization in a micro‐fabricated optomechanical chain, the direct signal of optomechanically induced Benjamin–Feir instability is identified within the reach of current experimental techniques. A spatio‐temporal dynamical theory of optomechanically induced Benjamin–Feir instability is represented, which provides a quantitative interpretation of the exponential growth characteristics. Numerical calculations of the spatio‐temporal dynamics in the optomechanical chain are in excellent agreement with this theory. Optomechanically induced Benjamin–Feir instability may entail a wide range of intriguing phenomena and find applications in on‐chip manipulations of light propagation and precision measurements due to their exponential growth characteristics.
Theoretical and experimental investigation of chalcogenide suspended waveguide gas sensor
Authors: Huang Yijun , Wang Xueying , Pi Mingquan , Zhao Huan , Peng Zihang , Min Yuting , Guan Gangyun , Zheng Chuantao , Song Fang , Bai Xue , Wang Yiding
Published: September 2023

To address the issues of low ratio of evanescent field (γ) and high reflectivity between waveguide cross‐section and gas for the mid‐infrared waveguide sensors, we propose a chalcogenide (ChG) suspended waveguide with Ge28Sb12Se60 as the core layer and silica (SiO2) as the buffer layer. The SiO2 beneath the waveguide core ridge structure is removed to create suspended structure. The waveguide sensing performance is obtained using a 10% methane (CH4) sample. The fabricated waveguide exhibits a γ of 112%, which is a 10% improvement compared to a free‐space optical sensor with the same optical path length. The good agreement between the theoretical and experimental results of γ confirms the reliability of our theoretical investigation approach. The influences of fabrication error, environmental temperature, and pressure on sensing performances are discussed. This work provides theoretical guidance for designing waveguide structures with large γ, contributing to the further enhancement of on‐chip sensor performance.
Analysis and application of a local discontinuous Galerkin method for the electromagnetic concentrator model
Authors: Huang Yunqing , Li Jichun , Liu Xin
Published: September 2023

In this paper, we develop a local discontinuous Galerkin (LDG) method to simulate the wave propagation in an electromagnetic concentrator. The concentrator model consists of a coupled system of four partial differential equations and one ordinary differential equation. Discrete stability and error estimate are proved for both semi‐discrete and full‐discrete LDG schemes. Numerical results are presented to justify the theoretical analysis and demonstrate the interesting wave concentration property by the electromagnetic concentrator.
Synthesis and Characterization of Ultra‐Small Gold Nanoparticles in the Ionic Liquid 1‐Ethyl‐3‐methylimidazolium Dicyanamide, [Emim][DCA]
Authors: Hildebrandt Jana , Taubert Andreas , Thünemann Andreas F.
Published: August 2023

We report on gold clusters with around 62 gold atoms and a diameter of 1.15±0.10 nm. Dispersions of the clusters are long‐term stable for two years at ambient conditions. The synthesis was performed by mixing tetrachloroauric acid (HAuCl4 ⋅ 3 H2O) with the ionic liquid 1‐ethyl‐3‐methylimidazolium dicyanamide ([Emim][DCA]) at temperatures of 20 to 80 °C. Characterization was performed with small‐angle X‐ray scattering (SAXS), UV‐Vis spectroscopy, and MALDI‐TOF mass spectrometry. A three‐stage model is proposed for the formation of the clusters, in which cluster growth from gold nuclei takes place according to the Lifshitz‐Slyozov‐Wagner (LSW) model followed by oriented attachment to form colloidal stable clusters.
Ensuring the Future Reliability of a Large‐Diameter Water Main
Authors: Tanzi David J. , Chwiedosiuk Jan
Published: September 2023

A proactive condition assessment was conducted to ensure the long‐term integrity and viability of a critical raw water pipeline, preventing a potential failure and loss of service.
Exploring service‐providing non‐governmental organization perceptions of shifting civic space in Ghana: Impacts of government and international actors
Authors: Zook Sandy , Krawczyk Kelly Ann , Oduro Franklin
Published: September 2023

Civil society space is constantly shifting, either negatively (e.g., shrinking, narrowing) or positively (e.g., expanding). These shifts are predominantly attributed to actions by central government actors, such as the implementation and enforcement of laws. Emergent work, however, also recognizes that in the context of the Global South, the international community can take actions to shrink or expand civil society space. Recently, Ghana in West Africa—known for its democratic stability—has introduced significant legislative and administrative reforms aimed at regulating the NGO sector. We interview 20 Ghanaian service‐providing NGOs to explore perceived shifts in civil society space and the impacts of these shifts, as well as strategies service‐providing NGOs are employing in response to shifting civic space. Findings identify perceived shifts in civic space caused by international actors and the Ghanaian government, as well as strategies for combating and mitigating shifting space.
Numerical simulation of miscible multiphase flow and fluid–fluid interaction in deformable porous media
Authors: Peters Sven , Heider Yousef , Markert Bernd
Published: September 2023

The focus of the underlying research work is on the macroscopic modeling of unstable multiphase fluid flow in deformable porous media, where a lower‐viscous fluid is displaced by a more viscous fluid. This process leads to the formation of channel‐like networks, called viscous fingering. The instability effect is involved in a wide range of different fields in engineering. Some of the most common applications include carbon sequestration to store carbon dioxide (CO2) in underground reservoirs, contaminant transport in geostructures, in industrial processes, such as filtration, catalytic reactions, and in the operation of polymer electrolyte membrane fuel cells with multiphase flow in the gas diffusion layers. In this work, ideal miscible water–glycerin fluids are considered. It is assumed that the interacting fluids in the deformable porous media are incompressible. In addition, a dispersion–diffusion law is applied to capture the fluid–fluid interactions. The presence of a deformable porous material adds additional effects to the problem of the multiphase flow in porous media. The stresses in the porous solid matrix lead to changes in the porosity and influence the flow velocity of the fluids. To couple the deformable porous media with the multiphase flow, a macroscopic approach is used that relies on the theory of porous media. For the porous solid matrix, a linear elastic material model within small strains assumption is applied. The influence of the deformation‐dependent porosity on the instability is studied for 2D simulations, such as a multilayered geometry with different elastic parameters. The presented coupled nonlinear system of differential equations is simulated with the finite element method. Furthermore, a stabilization technique based on the quasi‐compressibility method is used.
Click chemistry‐based azide‐substituted polysulfone/alkynyl‐substituted sulfonated polyvinyl alcohol/nafion blend membranes for direct methanol fuel cells
Authors: Yuan Chengyun , Li Qun , Dong Yunfa , Wang Jiayu , He Weidong , Yan Cenqi , Wang Yinghan , Cheng Pei
Published: August 2023

At present, commercial Nafion membrane is not suitable for proton exchange membrane used in direct methanol fuel cell (DMFC) due to the severe methanol permeation phenomenon. This work reported the preparation and characterization of azide‐substituted polysulfone (PSU‐N3) and alkynyl‐substituted sulfonated polyvinyl alcohol (SAPVA) crosslinked in the matrix of Nafion membrane base on click chemistry applied in DMFC. The compatibility between PSU‐N3 and SAPVA is promoted due to the formation of crosslinked network structure. Key properties, including dimensional stability, oxidative stability, mechanical behavior, methanol permeability and proton conductivity, are compared with those of the recast Nafion membrane. The prepared blend membranes exhibit lower methanol permeability due to the crosslinked network and well‐dispersed microphase structure of PSU‐PVA in the Nafion matrix. The proton selectivity of the Nafion‐PSU‐PVA‐3 membrane is 9.16 × 104 S s/cm3, much higher than that of the recast Nafion membrane (2.82 × 104 S s/cm3). In DMFC single cell tests, the maximum power density of the Nafion‐PSU‐PVA‐3 membrane is 4.6 mW/cm2, about 58.6% higher than that of the recast Nafion membrane. All the results indicate that the prepared blend membranes have the potential to be applied in DMFC.
Rational design of small‐molecule responsive protein switches
Authors: Shui Sailan , Buckley Stephen , Scheller Leo , Correia Bruno E.
Published: September 2023

Small‐molecule responsive protein switches are powerful tools for controlling cellular processes. These switches are designed to respond rapidly and specifically to their inducer. They have been used in numerous applications, including the regulation of gene expression, post‐translational protein modification, and signal transduction. Typically, small‐molecule responsive protein switches consist of two proteins that interact with each other in the presence or absence of a small molecule. Recent advances in computational protein design already contributed to the development of protein switches with an expanded range of small‐molecule inducers and increasingly sophisticated switch mechanisms. Further progress in the engineering of small‐molecule responsive switches is fueled by cutting‐edge computational design approaches, which will enable more complex and precise control over cellular processes and advance synthetic biology applications in biotechnology and medicine. Here, we discuss recent milestones and how technological advances are impacting the development of chemical switches.
Mental health problems in first‐generation university students: A scoping review
Authors: Smith Donna , McLellan Ros
Published: August 2023

Despite growing concern about mental health problems in university students and increasing recognition that first‐generation university students (FGS) may face additional challenges, there has been no previous attempt to map the existing research on FGS mental health. The aim of this scoping review was to elicit current understanding of mental health problems in FGS from the literature. Following database searches and screening, 40 peer‐reviewed articles were included in the scoping review. Findings from these studies were synthesised for: types of mental health problems in FGS; prevalence of mental health problems in FGS compared to continuing‐generation students (CGS); factors associated with mental health problems in FGS; effects of mental health problems on FGS; help‐seeking for mental health problems in FGS; and interventions. Significant gaps were highlighted and recommendations made for future research, particularly outside the United States. True commitment to widening participation demands much more research on mental health problems in FGS to ensure that they thrive not just arrive.

Context and implications

Rationale for this study

The aim of this scoping review was to map the existing international research on mental health problems in first‐generation university students (FGS).

Why do the new findings matter?

The scoping review synthesises findings from 40 empirical studies published in peer‐reviewed journals, giving valuable insights into mental health problems in FGS and highlighting significant gaps in our understanding.

Implications for higher education researchers and universities

The findings of the scoping review are a call to action for future research in this field. More studies are needed, particularly outside the United States, using a variety of research designs to gain a more comprehensive understanding of mental health problems in FGS. This research should be prioritised so that universities are provided with evidence‐based recommendations to mitigate and/or address mental health problems in FGS, thereby helping to ensure that they thrive in higher education.
Adaptive mean‐square consensus of heterogeneous multiagent systems with stochastic switching topologies
Authors: Huang Wenchao , Tu Yuhan , Liu Tiantian , Liu Hailin , Tian Binbin , Huang Yanwei , Chen Shaobin
Published: September 2023

The leader–following consensus of linear heterogeneous multiagent systems is investigated in this paper. To comply with the most practical scenario, the communicating topologies among agents are assumed to switch stochastically and driven by a continuous‐time discrete‐state Markov process, whose state space corresponds to all the possible topologies. A novel distributed adaptive compensator is designed for the followers to reconstruct the exogenous signals without knowing the Laplacian matrix who is regarded as a global information, and sufficient conditions are given to ensure the compensator converges to the dynamic of the leader asymptotically in the mean square sense. Then, based on the compensator, we solved the consensus problem both by distributed state and measurement output feedback control schemes under output regulation framework, which allow followers to have nonidentical state dimensions. Finally, the theoretical results are demonstrated by a numerical example.
Expansion of random 0/1 polytopes
Authors: Leroux Brett , Rademacher Luis
Published: August 2023

A conjecture of Milena Mihail and Umesh Vazirani (Proc. 24th Annu. ACM Symp. Theory Comput., ACM, Victoria, BC, 1992, pp. 26–38.) states that the edge expansion of the graph of every polytope is at least one. Any lower bound on the edge expansion gives an upper bound for the mixing time of a random walk on the graph of the polytope. Such random walks are important because they can be used to generate an element from a set of combinatorial objects uniformly at random. A weaker form of the conjecture of Mihail and Vazirani says that the edge expansion of the graph of a polytope in is greater than one over some polynomial function of . This weaker version of the conjecture would suffice for all applications. Our main result is that the edge expansion of the graph of a random polytope in is at least with high probability.
One‐pot Multicomponent Synthesis of Novel Chromene Derivatives Using New Organic Phosphate Salt Catalysts
Authors: Salmalian Setareh , Mahmoodi Nosrat O. , Sheykhan Mehdi.
Published: September 2023

A new method for synthesizing chromene derivatives as an essential class of heterocyclic compounds has been reported. This research described synthesizing and identifying three new organic salt catalysts based on phosphate moieties. Among the synthesized new phosphate‐based organic salt catalysts, disodium ethyl (phenyl) amino phosphate (DSEAP) plays an essential role and reusable catalyst for the preparation of chromene derivatives under different reaction conditions following the principles of green chemistry. Cost‐effectiveness, non‐toxicity and easy availability are among the salient features of this environmentally friendly catalyst. Furthermore, the catalyst was satisfactorily recycled up to four times without significant performance degradation in the yield of synthesized chromenes. X‐ray diffraction (XRD), infrared spectroscopy (FT‐IR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to illustrate the structural and morphologic characteristics of the catalysts. Some synthesized chromene derivatives, including 4I and 4P, showed good antibacterial and biological antioxidant activity compared to the standard drug, respectively. In this research, DSEAP was used as a heterogeneous catalyst in performing one‐pot 3MCRs of aryl aldehyde, an active methylene group e. g. ethyl acetoacetate or diethyl malonate and 5,5‐dimethyl‐1,3‐cyclohexanedione.
DFT Insight into the Kinetics and Mechanism of OH⋅‐Initiated Atmospheric Oxidation of Catechol: Addition of 3∑g− O2 and Isomerization of Peroxy Radicals
Authors: Rahbar Ali , Zahedi Ehsan , Aghaie Hossein , Giahi Masoud , Zare Karim
Published: September 2023

Atmospheric oxidation mechanism of predominant catechol‐OH adduct [C6H6O2−OH]⋅ (AD2) by oxygen molecule in its triplet electronic ground state and isomerization processes of catechol peroxy radicals [C6H6O2−OH]⋅−O2 into bicyclic peroxy radicals have been studied at the M06‐2X/aug‐cc‐pVTZ level in conjugation with the RRKM theory. The first step begins via the complexation of [C6H6O2−OH]⋅ with oxygen molecule and formation of two pre‐reactive van der Waals complexes in syn and anti modes. Syn mode addition of O2 is more favorable over the anti mode due to the formation of intramolecular hydrogen bond. Kinetically and thermodynamically, addition of O2 at the C5 position in syn mode, namely peroxy radical AD2‐5OO‐syn, is the most efficient process with bimolecular RRKM rate coefficient 2.80×10−16 cm3 molecule−1 s−1 at ambient conditions. Isomerization (cyclization) of peroxy radical AD2‐5OO‐syn into bicyclic peroxy radicals via the formation of −OO− bridge are strongly endothermic and nonspontaneous processes with high activation energies. Ring closure into the bicyclic peroxy radical AD2‐5,6OO‐syn is the most favorable process with unimolecular RRKM rate coefficient 1.41×10−8 s−1 at ambient conditions.
Synthesis and Recognition Properties of Cd(II) Framework for Highly Selective Sensing of Fe3+, Cr2O72− and CrO42− ions
Authors: Gao Ningning , Zhang Yunyun , Huang Jing , Wang Yan
Published: September 2023

In this study, we successfully constructed a high‐performance fluorescent material for the detection of toxic pollutants in water, [Cd(2‐bpmh)(BDC)H2O]n (1) (2‐bpmh=1,4‐bis(2‐pyridyl)‐2,3‐diaza‐1,3‐butadiene, H2BDC=terephthalic acid), which achieved high yield under the condition of solvothermal reaction. Single crystal X‐ray analysis revealed that complex 1 forms a one‐dimensional chain structure, which is further assembled into a three‐dimensional structure through hydrogen bonding interactions. The luminescence sensing research showed that 1 not only displayed excellent luminescence quenching efficiency, but also could specifically recognize Cr2O72−, CrO42− and Fe3+ ions in water.
Zinc‐Doped BiFeO3 Nanoparticles: Synthesis, Characterization and Photocatalytic Activity on Acid Red‐85 Dye
Authors: Ponraj Caroline , Krishnamoorthi C. , Vinitha G. , Manikandan N. , Santhosh kumar P. , Daniel Joseph
Published: September 2023

Photocatalysis has been drawing significant research attention because of its extensive applications in fields such as environmental remediation and renewable energy. In this work, we design a series of BiFe1‐xZnxO3 (x=0, 0.025, 0.05, 0.075, and 0.1) photocatalysts to reveal the photocatalytic mechanism for model Acid Red‐85, a stable textile dye. The bandgap energy of zinc – doped BiFeO3 is ranging from 2.138 to 2.2 eV. We have shown that changing the Fe/Zn ratio by bandgap engineering effectively controls the reaction pathway. Specifically, BiFe0.925Zn0.075O3 (7.5BFZO) presented the best performance for photocatalytic activity (92 %). The magnetic behaviour improves for lower zinc doping concentrations (x=0.025 and 0.05) and declines for higher concentrations (x=0.075 and 0.10). The photocatalytic degradation of Acid Red‐85 dye followed pseudo first order kinetics, with the highest catalytic effect seen in BiFe0.925Zn0.075O3 with 92 % degradation after 2 hours of light exposure.
Development of Resin Based Spherical Activated Carbon with High Performance Derived from Waste Ion‐Exchange Resin and Its High Effective Removal of Tetracycline
Authors: Li Aiduo , Chen Zhiwei , Ma Cheng , Qiao Wenming , Wang Jitong
Published: September 2023

Industrial production brings billions of tons of solid waste every year, which not only leads to resource waste, but also causes threat to the environment. Improving solid waste resource utilization can better meet the needs of environmental protection and sustainable development. Herein, steam activation method were used to transform the waste ion‐exchange resin (IER) into resin based spherical activated carbons (RSACs) with high adsorption properties and mechanical strength to realize the efficient use of waste resources. The porous structures and mechanical strength of RSACs can be adjusted by changing the reaction conditions including activation temperature, activation time and steam input. The largest specific surface area is up to 2047 m2/g with the pore volume of 1.56 cm3/g. The feasibility of utilizing RSACs to remove tetracycline (TC) from aqueous solution was evaluated, and the highest adsorption capacity is 701 mg/g. The pH variation shows some extent effect on the adsorption. The coexisting ions with higher valence state and concentration result in the decrease of the adsorption capacity to some extent. Additionally, the kinetics experimental data fit the pseudo‐second‐order model well, and the equilibrium data are more consistent with the Freundlich model. The adsorbent is promising in wastewater treatment.
X‐Ray Techniques Dedicated to Materials Characterization in Cultural Heritage
Authors: Magdy Mina
Published: September 2023

This article discusses the basic principles, methodological features, instrumental characteristics, and practical applications of X‐ray techniques in cultural heritage. X‐ray techniques are a set of well‐defined methods for determining the chemical composition and properties of samples. In the field of cultural heritage, material characterization provides valuable information on archaeological materials for understanding heritage assets and ensuring their sustainability. X‐ray fluorescence (XRF) is a versatile method for qualitative and semi‐quantitative elemental analysis. X‐ray diffraction (XRD) is a characterization method to define the properties of the crystal structure of materials. X‐ray photoelectron spectroscopy (XPS) is a chemical tool for understanding the surface chemistry of materials. X‐ray absorption fine structure (XAFS) is a powerful probe for determining the local atomic environment of individual atomic species. X‐ray imaging methods are used for visualization and examination of the objects under study, including X‐ray radiography (XRR) for the non‐destructive inspection of objects, X‐ray computed tomography (XCT) for revealing the internal structure of materials, and dual‐energy X‐ray absorptiometry (DEXA) for the diagnosis of bone health. X‐ray techniques represent key analytical techniques in archaeometric investigations and provide valuable insights into the cultural significance of artifacts.
Bromine Migration and Product Analysis of Waste Printed Circuit Boards during Microwave Steam‐Gasification‐Assisted Pyrolysis
Authors: Li Chunyu , Liu Chengfei , Xia Hongying , Zeng Kangqing , Zhang Libo
Published: September 2023

Bromine in waste printed circuit boards has caused serious harm to the environment. How to deal with it safely is a problem. In this paper, the debromination of waste printed circuit boards by microwave gasification pyrolysis was studied, and the properties of pyrolysis products and the migration of bromine were analyzed. The optimum pyrolysis conditions of microwave steam atmosphere were 600 °C, 1000 W, 50 min, 2 mL/min. Compared with conventional pyrolysis and conventional steam pyrolysis, less solid products (60.39 wt %) were obtained, and more metal copper was enriched. The content increased from 27.46 % and 28.35 % to 30.63 %, respectively, and the diffraction peak intensity of copper was also enhanced. There is no obvious change in the type of functional groups of the solid product, and its microscopic morphology is smoother. Compared with conventional pyrolysis, the phenolic compounds in pyrolysis oil decreased, and increased compared with conventional steam pyrolysis. The content of H2 in the pyrolysis gas increased significantly, and the content of CO decreased significantly. Compared with conventional pyrolysis, the bromine content in pyrolysis gas and pyrolysis oil decreased from 94.5 % and 5.5 % to 1 %, respectively, and more bromine (98 %) in the raw material entered the aqueous solution.
Colorimetric Sensor Based AgNPs for the Detection of Cyanide using UV‐Vis Spectrophotometry
Authors: Girgin Ayça , Akbıyık Hilal , Zaman Buse Tuğba , Çetin Gülten , Bakırdere Sezgin
Published: September 2023

Cyanide (CN−) is known to be a very harmful ion that may accumulate in the air, soil and water, and become a critical risk to organisms, even at trace levels. Hence, it is very critical to develop sensitive and accurate analytical methods for the determination of this anion. In this study, a highly sensitive and simple approach was developed for the quantitative determination of cyanide by UV‐Vis spectrophotometry with the aid of synthesized silver nanoparticles (AgNPs) solutions. AgNPs are promising probes frequently used in the determination of both organic and inorganic pollutants. The AgNPs were prepared by reducing silver nitrate (AgNO3) with sodium borohydride (NaBH4) in the presence of Triton X‐100 as a stabilizer. The UV‐Vis absorption spectra showed that the interaction between cyanide ions and AgNPs made significant decreases in the absorption peak of the surface plasmon resonance (SPR) band at 405 nm. The developed colorimetric sensor exhibited exceptional sensing towards cyanide ions with good linearity in the range of 0.5 and 3.5 mM. The limit of detection (LOD) and the limit of quantification (LOQ) were estimated as 0.09 and 0.29 mM, respectively. Moreover, the proposed colorimetric method was successfully applied to different water samples.