bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Melatonin Coating on Physiochemical Qualities and Enzymatic Activities in Banana Pericarp under Cold Storage
Authors: Charoenphun Narin , Chucherd Pakawan , Paulraj Balaji , Venkatachalam Karthikeyan
Published: April 2024

Banana pericarp is highly susceptible to chilling injury (CI), negatively affecting its quality and shelf life. Melatonin (MT), a plant tryptophan derivative, has shown promising effects in mitigating CI and related physiological disorders in tropical and subtropical fruits. This study investigated the efficacy of MT at different concentrations (0, 50, and 100 µM/L) in the coating of banana pericarp to control CI and physicochemical degradation during storage at 7 °C for five days, and on each day, fruits were assessed for quality. The MT100 treatment significantly (p < 0.05) mitigated the severity of the CI index, electrolytic leakage (EL), and malondialdehyde (MDA) levels. Reactive oxygen species (ROS) levels were substantially higher in control samples, whereas MT treatments notably suppressed their increase. Glutathione (GSH) and ascorbic acid (AA) levels were elevated in those banana pericarps treated with higher MT concentrations. Although total phenolic content (TPC) and total carotenoid contents (TCC) were increased in MT-treated samples, the MT concentrations did not significantly affect them. The level of phenolic compounds, such as gallic acid (GA), chlorogenic acid (CA), quinic acid (QA), protocatechuic acid (PA), and catechin (CC), exhibited continuous growth during the storage period, with the highest levels found in MT100-treated samples. Activities of enzymes such as lipoxygenase (LOX), phospholipase D (PLD), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO) were significantly (p < 0.05) higher in control samples and rose continuously over time, yet were effectively reduced in MT-treated pericarps. This study shows that applying a higher MT coating (100 µM/L) to bananas is an effective post-harvest strategy to considerably lower the incidence of CI and associated losses.
IUAutoTimeSVD++: A Hybrid Temporal Recommender System Integrating Item and User Features Using a Contractive Autoencoder
Authors: Azri Abdelghani , Haddi Adil , Allali Hakim
Published: April 2024

Collaborative filtering (CF), a fundamental technique in personalized Recommender Systems, operates by leveraging user–item preference interactions. Matrix factorization remains one of the most prevalent CF-based methods. However, recent advancements in deep learning have spurred the development of hybrid models, which extend matrix factorization, particularly with autoencoders, to capture nonlinear item relationships. Despite these advancements, many proposed models often neglect dynamic changes in the rating process and overlook user features. This paper introduces IUAutoTimeSVD++, a novel hybrid model that builds upon autoTimeSVD++. By incorporating item–user features into the timeSVD++ framework, the proposed model aims to address the static nature and sparsity issues inherent in existing models. Our model utilizes a contractive autoencoder (CAE) to enhance the capacity to capture a robust and stable representation of user-specific and item-specific features, accommodating temporal variations in user preferences and leveraging item characteristics. Experimental results on two public datasets demonstrate IUAutoTimeSVD++’s superiority over baseline models, affirming its effectiveness in capturing and utilizing user and item features for temporally adaptive recommendations.
Literacy in Artificial Intelligence as a Challenge for Teaching in Higher Education: A Case Study at Portalegre Polytechnic University
Authors: Lérias Eduardo , Guerra Cristina , Ferreira Paulo
Published: April 2024

The growing impact of artificial intelligence (AI) on Humanity is unavoidable, and therefore, “AI literacy” is extremely important. In the field of education—AI in education (AIED)—this technology is having a huge impact on the educational community and on the education system itself. The present study seeks to assess the level of AI literacy and knowledge among teachers at Portalegre Polytechnic University (PPU), aiming to identify gaps, find the main opportunities for innovation and development, and seek the degree of relationship between the dimensions of an AI questionnaire, as well as identifying the predictive variables in this matter. As a measuring instrument, a validated questionnaire based on three dimensions (AI Literacy, AI Self-Efficacy, and AI Self-Management) was applied to a sample of 75 teachers in the various schools of PPU. This revealed an average level of AI literacy (3.28), highlighting that 62.4% of responses are at levels 3 and 4 (based on a Likert scale from 1 to 5). The results also demonstrate that the first dimension is highly significant for the total dimensions, i.e., for AI Literacy, and no factor characterizing the sample is a predictor, but finding a below-average result in the learning factor indicates a pressing need to focus on developing these skills.
Recovery of Ni-Co-Mn Oxides from End-of-Life Lithium-Ion Batteries for the Application of a Negative Temperature Coefficient Sensor
Authors: Mhin Sungwook
Published: April 2024

This study demonstrates the current advancements in battery management systems (BMSs), emphasizing the need for precise temperature monitoring within battery packs to enhance safety and performance through efficient thermal management. The increased demand for lithium-ion batteries (LIBs) has driven the development of temperature sensors with improved accuracy and stability. In particular, Ni-Co-Mn-based spinel oxides are commonly used due to their stable negative temperature coefficient (NTC) behavior. However, challenges arise in manufacturing due to the high cost and uncertain supply of critical cathode components (e.g., Co, Ni, and Mn) for LIBs. This research focuses on developing spinel-type (Ni0.6Co0.4Mn2)O4 using recycled Ni-Co-Mn oxides obtained from end-of-life (EOL) LIBs, demonstrating temperature resistance behavior suitable for temperature sensing. The oxides are prepared through hydrometallurgy, oxalate synthesis, and post-heat treatment. Successful integration into spinel-type NTC thermistors suggests broader applications in various industrial fields. A systematic investigation into the synthesis and characterization of recovered Ni-Co-Mn oxides from EOL LIB cathode materials (Li(Ni0.33Co0.33Mn0.33)O2) is presented for NTC thermistor application. Thermogravimetric analysis-derivative thermogravimetry (TGA-DTG) identifies the optimal post-heat treatment temperature. The X-ray diffraction (XRD) patterns confirm a cubic spinel structure of the Ni-Co-Mn oxides, supported by scanning electron microscope (SEM) images showing a uniform microstructure. Also, energy dispersive X-ray spectroscopy (EDS) mapping confirms homogeneous element distribution. Recovered oxide pellets from the sintering process exhibit a single spinel structure, with X-ray photoelectron spectroscopy (XPS) analysis revealing changes in the valence states for Ni and Mn. Resistivity measurements demonstrate semiconductive behavior, which shows a B value (3376.92 K) suitable for NTC thermistor applications. This study contributes valuable insights to black powder recycling from EOL LIBs and its potential in temperature-sensitive electronic devices.
Hypervolume Niche Dynamics and Global Invasion Risk of Phenacoccus solenopsis under Climate Change
Authors: Cui Shaopeng , Zhang Huisheng , Liu Lirui , Lyu Weiwei , Xu Lin , Zhang Zhiwei , Han Youzhi
Published: April 2024

As a globally invasive quarantine pest, the cotton mealybug, Phenacoccus solenopsis, is spreading rapidly, posing serious threats against agricultural and forestry production and biosecurity. In recent years, the niche conservatism hypothesis has been widely debated, which is particularly evident in invasive biology research. Identifying the niche dynamics of P. solenopsis, as well as assessing its global invasion risk, is of both theoretical and practical importance. Based on 462 occurrence points and 19 bioclimatic variables, we used n-dimensional hypervolume analysis to quantify the multidimensional climatic niche of this pest in both its native and invasive ranges. We examined niche conservatism and further optimized the MaxEnt model parameters to predict the global invasion risk of P. solenopsis under both current and future climate conditions. Our findings indicated that the niche hypervolume of this pest in invasive ranges was significantly larger than that in its native ranges, with 99.45% of the niche differentiation contributed by niche expansion, with the remaining less than 1% explained by space replacement. Niche expansion was most evident in Oceania and Eurasia. The area under the receiver operating characteristic curve (0.83) and true skill statistic (0.62) indicated the model’s robust performance. The areas of suitable habitats for P. solenopsis are increasing significantly and the northward spread is obvious in future climate change scenarios. North Africa, northern China, Mediterranean regions, and northern Europe had an increased invasion risk of P. solenopsis. This study provided scientific support for the early warning and control of P. solenopsis.
Advancements in Laser Therapies for Dermal Hyperpigmentation in Skin of Color: A Comprehensive Literature Review and Experience of Sequential Laser Treatments in a Cohort of 122 Indian Patients
Authors: Garg Suruchi , Vashisht Kanya Rani , Garg Diksha , Oberoi Bhavni , Sharma Geeta
Published: April 2024

The heightened awareness of ethnic dermatology aligns with the growing prevalence of skin of color communities globally, where hyperpigmentation disorders pose a common dermatological challenge. Effectively addressing dermal pigmentation is challenging due to its resistance to conventional therapies and its association with impaired quality of life. This underscores the need for effective treatments and a thorough grasp of laser advancements. A relevant literature search spanning the last 7 years across the PubMed database reveals core studies, challenges, and the evolution of laser technologies tailored for various forms of congenital and acquired dermal hyperpigmentation in skin of color. This comprehensive review explores the mechanisms, applications, and recommendations for pigmentary laser technologies, highlighting the key role of Q-switched lasers in their established millisecond/ nanosecond forms and emerging picosecond lasers, fractional non-ablative and ablative lasers, Intense Pulsed Light, etc. The summary of evidence includes studies on dermal melanocytosis (nevus of Ota and Hori’s nevus), tattoos, acquired dermal macular hyperpigmentation, etc., and also entities with mixed epidermal–dermal components, such as melasma and post-inflammatory hyperpigmentation. The review offers valuable insights for clinicians to make informed decisions based on diagnosis, skin type, and the latest technologies to optimize results and minimize complications, especially in darker Fitzpatrick skin types. In their five-year study with 122 Indian patients, the authors applied specific laser combinations for diverse dermal melanoses, including tattoos, dermal/mixed melasma, acquired dermal macular hyperpigmentation, and dermal nevi. Substantial pigmentation reduction, subjectively assessed by both physicians and patients, was observed across all groups. A one-way ANOVA indicated a significant difference in mean improvement scores across various pigmentary conditions (F = 3.39, p = 0.02), with melasma patients exhibiting a significantly higher improvement score than tattoos (p = 0.03). The results affirmed the safety and efficacy of sequential laser therapy for dermal pigmentation in skin of color, advocating for flexibility in approach while maintaining the rationale behind the laser sequences. Despite advancements, challenges persist, and gaps in the current literature are identified. In conclusion, this summary highlights the ongoing pursuit of optimal protocols in dermatological laser treatments for dermal melanoses, offering valuable insights for future research and clinical practice.
Obtaining and Characterizing New Types of Materials Based on Low-Density Polyethylene and Thermoplastic Starch
Authors: Stelescu Maria Daniela , Oprea Ovidiu-Cristian , Motelica Ludmila , Ficai Anton , Trusca Roxana-Doina , Sonmez Maria , Nituica Mihaela , Georgescu Mihai
Published: April 2024

Significant interest is devoted to the development of new polymer blends by using concepts of the circular economy. Such materials have predetermined properties, are easy to recycle, ecological, and have a low carbon footprint. This research presents obtaining and characterization of polymer blends based on low-density polyethylene (LDPE) and thermoplastic starch (TPS). In the first stage, TPS was obtained through the gelatinization process, and, in the second stage, mixtures of LDPE and TPS were obtained through a melt mixing process at 150 °C for 7 min. The physical–mechanical characteristics of the samples, like hardness, elongation at break, rebound resilience, and tensile strength, were determined. The sample containing maleic anhydride grafted low-density polyethylene (LDPE-g-MA) as a compatibilizer shows improvements in elongation at break and tensile strength (by 6.59% and 40.47%, respectively) compared to the test sample. The FTIR microscopy maps show that samples containing LDPE-g-MA are more homogeneous. The SEM micrographs indicate that TPS-s is homogeneously dispersed as droplets in the LDPE matrix. From the thermal analysis, it was observed that both the degree of crystallinity and the mass loss at high temperature are influenced by the composition of the samples. The melt flow index has adequate values, indicating good processability of the samples by specific methods (such as extrusion or injection).
Diagnosis, Treatment, and Outcome of Coccidioidal Osseous Infections: A Systematic Review
Authors: Tsantes Andreas G. , Koutserimpas Christos , Naoum Symeon , Drosopoulou Lida-Paraskevi , Papadogeorgou Ellada , Petrakis Vasileios , Alpantaki Kalliopi , Samonis George , Veizi Enejd , Papadopoulos Dimitrios V.
Published: April 2024

Extrapulmonary infections by Coccidioides spp., though rare, can occur via dissemination, affecting singular or multiple sites, including the skin and musculoskeletal system. Skeletal involvement often manifests as osteomyelitis, particularly in the axial skeleton. The present systematic review evaluates all documented cases of skeletal coccidioidomycosis to assess the diagnostic and treatment strategies alongside the outcomes, drawing insights from an analysis of 163 verified cases. A systematic review following PRISMA guidelines identified all studies reporting skeletal infections by Coccidioides spp. up to 2023 from the PubMed and Scopus databases. Eligible studies evaluated osteoarticular infections from Coccidioides spp. Data extraction included demographics, microbiological data, diagnostic methods, and treatment outcomes. Of the 501 initially identified records, a total of 163 patients from 69 studies met the inclusion criteria. Most cases were from the USA, predominantly males, while the median age of the population was 36 years. Diabetes mellitus was the common comorbidity (14.7%). C. immitis was the most prevalent pathogen. The spine and hand were common sites of infection (17.5% and 15.1%, respectively). Osteomyelitis by Coccidioides spp. was diagnosed, in most cases, by positive cultures (n = 68; 41.7%), while, in 49 (30.9%), both the histological examination and cultures yielded the fungus. Surgical debridement was performed in 80.9% of cases. A total of 118 (72.3%) patients were treated with monotherapy, while combination therapy with two or more antifungal agents was reported in 45 (17.7%). Amphotericin B (either liposomal or deoxycholate) was the most commonly given agent as monotherapy in 51 (31.2%) patients, while 30 (18.4%) patients received itraconazole as monotherapy. The rate of infection’s resolution was higher in patients undergoing surgical debridement (79.5%), compared to those treated only with antifungal agents (51.6%, p = 0.003). Treatment outcomes showed complete resolution in 74.2% of patients, with a mortality rate of 9.2%. Coccidioidal osseous infections present diagnostic and therapeutic challenges. Surgical intervention is often necessary, complementing antifungal therapy. Vigilance for Coccidioides spp. infections, especially in regions with endemicity, is crucial, particularly when bacterial cultures yield negative results.
A Narrative Review of Psychobiotics: Probiotics That Influence the Gut–Brain Axis
Authors: Ķimse Laima , Reinis Aigars , Miķelsone-Jansone Lāsma , Gintere Sandra , Krūmiņa Angelika
Published: April 2024

Mental health disorders and dementia have become a serious public health concern, with a heightened frequency of diagnoses observed in the wake of the global COVID-19 pandemic. Psychobiotics, a novel area of research at the intersection of microbiology and neuroscience, explore the potential of probiotics to influence the nervous system and mental health outcomes. This review explores the intricate mechanisms by which psychobiotics interact with the gut–brain axis, shedding light on their effects on mood, cognition, and the stress response. Through a comprehensive analysis of the current literature and recent advancements, we discuss the therapeutic potential of psychobiotics in various mental health disorders, including depression, anxiety, and neurodegenerative diseases like dementia. The findings from this research highlight the promising potential of psychobiotics as innovative interventions in mental health treatment. Further investigation into their mechanisms of action and clinical applications is warranted to fully realize their therapeutic benefits.
Recent Advances and Challenges in Anion Exchange Membranes Development/Application for Water Electrolysis: A Review
Authors: Liu Lu , Ma Hongyang , Khan Madani , Hsiao Benjamin S.
Published: April 2024

In recent years, anion exchange membranes (AEMs) have aroused widespread interest in hydrogen production via water electrolysis using renewable energy sources. The two current commercial low-temperature water electrolysis technologies used are alkaline water electrolysis (AWE) and proton exchange membrane (PEM) water electrolysis. The AWE technology exhibited the advantages of high stability and increased cost-effectiveness with low hydrogen production efficiency. In contrast, PEM water electrolysis exhibited high hydrogen efficiency with low stability and cost-effectiveness, respectively. Unfortunately, the major challenges that AEMs, as well as the corresponding ion transportation membranes, including alkaline hydrogen separator and proton exchange membranes, still face are hydrogen production efficiency, long-term stability, and cost-effectiveness under working conditions, which exhibited critical issues that need to be addressed as a top priority. This review comprehensively presented research progress on AEMs in recent years, providing a thorough understanding of academic studies and industrial applications. It focused on analyzing the chemical structure of polymers and the performance of AEMs and established the relationship between the structure and efficiency of the membranes. This review aimed to identify approaches for improving AEM ion conductivity and alkaline stability. Additionally, future research directions for the commercialization of anion exchange membranes were discussed based on the analysis and assessment of the current applications of AEMs in patents.
Influence of Citrus sunki and Poncirus trifoliata Root Extracts on Metabolome of Phytophthora parasitica
Authors: Maximo Héros José , Araújo Francisca Diana da Silva , Pagotto Carolina Clepf , Boava Leonardo Pires , Dalio Ronaldo José Durigan , Duarte Gustavo Henrique Bueno , Eberlin Marcos Nogueira , Machado Marcos Antonio
Published: April 2024

Phytophthora parasitica is an oomycete pathogen that infects a broad range of crops of worldwide economic interest; among them are citrus species. In general, some Citrus and the rootstocks of related genera offer considerable resistance against P. parasitica; therefore, understanding the mechanisms involved in the virulence of this pathogen is crucial. In this work, P. parasitica secondary metabolite production was studied using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and ultrahigh-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOF-MS) combined with chemometric tools, and its metabolic profile was evaluated under the influence of Citrus sunki (a highly susceptible host) and Poncirus trifoliata (a resistant genotype) extracts. The root extracts of Citrus sunki had an influence on the growth and hyphae morphology, and the root extracts of P. trifoliata had an influence on the zoospore behavior. In parallel, the spatial distribution of several metabolites was revealed in P. parasitica colonies using MALDI-MSI, and the metabolite ion of m/z 246 was identified as the protonated molecule of Arg-Ala. The MALDI-MSI showed variations in the surface metabolite profile of P. parasitica under the influence of the P. trifoliata extract. The P. parasitica metabolome analysis using UHPLC-ESI-Q-TOF-MS resulted in the detection of Arg-Gln (m/z 303.1775), as well as L-arginine (m/z 175.1191) and other unidentified metabolites. Significant variations in this metabolome were detected under the influence of the plant extracts when evaluated using UHPLC-ESI-Q-TOF-MS. Both techniques proved to be complementary, offering valuable insights at the molecular level when used to assess the impact of the plant extracts on microbial physiology in vitro. The metabolites identified in this study may play significant roles in the interaction or virulence of P. parasitica, but their functional characterization remains to be analyzed. Overall, these data confirm our initial hypotheses, demonstrating that P. parasitica has the capabilities of (i) recognizing host signals and altering its reproductive programing and (ii) distinguishing between hosts with varying responses in terms of reproduction and the production of secondary metabolites.
Plant-Derived Caffeic Acid and Its Derivatives: An Overview of Their NMR Data and Biosynthetic Pathways
Authors: Yu Jiahui , Xie Jingchen , Sun Miao , Xiong Suhui , Xu Chunfang , Zhang Zhimin , Li Minjie , Li Chun , Lin Limei
Published: April 2024

In recent years, caffeic acid and its derivatives have received increasing attention due to their obvious physiological activities and wide distribution in nature. In this paper, to clarify the status of research on plant-derived caffeic acid and its derivatives, nuclear magnetic resonance spectroscopy data and possible biosynthetic pathways of these compounds were collected from scientific databases (SciFinder, PubMed and China Knowledge). According to different types of substituents, 17 caffeic acid and its derivatives can be divided into the following classes: caffeoyl ester derivatives, caffeyltartaric acid, caffeic acid amide derivatives, caffeoyl shikimic acid, caffeoyl quinic acid, caffeoyl danshens and caffeoyl glycoside. Generalization of their 13C-NMR and 1H-NMR data revealed that acylation with caffeic acid to form esters involves acylation shifts, which increase the chemical shift values of the corresponding carbons and decrease the chemical shift values of the corresponding carbons of caffeoyl. Once the hydroxyl group is ester, the hydrogen signal connected to the same carbon shifts to the low field (1.1~1.6). The biosynthetic pathways were summarized, and it was found that caffeic acid and its derivatives are first synthesized in plants through the shikimic acid pathway, in which phenylalanine is deaminated to cinnamic acid and then transformed into caffeic acid and its derivatives. The purpose of this review is to provide a reference for further research on the rapid structural identification and biofabrication of caffeic acid and its derivatives.
Inclusion Complexes of Litsea cubeba (Lour.) Pers Essential Oil into β-Cyclodextrin: Preparation, Physicochemical Characterization, Cytotoxicity and Antifungal Activity
Authors: Pante Giseli Cristina , Castro Juliana Cristina , Lini Renata Sano , Romoli Jéssica Cristina Zoratto , Pires Thiago Yoshioka , Garcia Francielle Pelegrin , Nakamura Celso Vataru , Mulati Ana Claúdia Nogueira , Matioli Graciette , Machinski Junior Miguel
Published: April 2024

The uses of natural compounds, such as essential oils (EOs), are limited due to their instability to light, oxygen and temperature, factors that affect their application. Therefore, improving stability becomes necessary. The objective of this study was to prepare inclusion complexes of Litsea cubeba essential oil (LCEO) with β-cyclodextrin (β-CD) using physical mixing (PM), kneading (KN) and co-precipitation (CP) methods and to evaluate the efficiency of the complexes and their physicochemical properties using ATR-FTIR, FT-Raman, DSC and TG. The study also assessed cytotoxicity against human colorectal and cervical cancer cells and antifungal activity against Aspergillus flavus and Fusarium verticillioides. The complexation efficiency results presented significant evidence of LCEO:β-CD inclusion complex formation, with KN (83%) and CP (73%) being the best methods used in this study. All tested LCEO:β-CD inclusion complexes exhibited toxicity to HT-29 cells. Although the cytotoxic effect was less pronounced in HeLa tumor cells, LCEO-KN was more active against Hela than non-tumor cells. LCEO-KN and LCEO-CP inclusion complexes were efficient against both toxigenic fungi, A. flavus and F. verticillioides. Therefore, the molecular inclusion of LCEO into β-CD was successful, as well as the preliminary biological results, evidencing that the β-CD inclusion process may be a viable alternative to facilitate and increase future applications of this EO as therapeutic medication, food additive and natural antifungal agent.
Computational Binding Study Hints at Ecdysone 20-Mono-Oxygenase as the Hitherto Unknown Target for Ring C-Seco Limonoid-Type Insecticides
Authors: Ramírez Ramsés E. , Buendia-Corona Ricardo E. , Pérez-Xochipa Ivonne , Scior Thomas
Published: April 2024

The insecticidal property of ring C-seco limonoids has been discovered empirically and the target protein identified, but, to date, the molecular mechanism of action has not been described at the atomic scale. We elucidate on computational grounds whether nine C-seco limonoids present sufficiently high affinity to bind specifically with the putative target enzyme of the insects (ecdysone 20-monooxygenase). To this end, 3D models of ligands and the receptor target were generated and their interaction energies estimated by docking simulations. As a proof of concept, the tetrahydro-isoquinolinyl propenamide derivative QHC is the reference ligand bound to aldosterone synthase in the complex with PDB entry 4ZGX. It served as the 3D template for target modeling via homology. QHC was successfully docked back to its crystal pose in a one-digit nanomolar range. The reported experimental binding affinities span over the nanomolar to lower micromolar range. All nine limonoids were found with strong affinities in the range of −9 < ΔG < −13 kcal/mol. The molt hormone ecdysone showed a comparable ΔG energy of −12 kcal/mol, whereas −11 kcal/mol was the back docking result for the liganded crystal 4ZGX. In conclusion, the nine C-seco limonoids were strong binders on theoretical grounds in an activity range between a ten-fold lower to a ten-fold higher concentration level than insecticide ecdysone with its known target receptor. The comparable or even stronger binding hints at ecdysone 20-monooxygenase as their target biomolecule. Our assumption, however, is in need of future experimental confirmation before conclusions with certainty can be drawn about the true molecular mechanism of action for the C-seco limonoids under scrutiny.
Metalloid–Organic Intermolecular Complexes with Charge State-Controlled Conformations
Authors: Naumkin Fedor Y.
Published: April 2024

Shape alterations of molecular systems, induced by their (electric) charging/discharging, could facilitate useful electronic and/or mechanical functions in molecular-scale devices and machines. The present study reports structures, stabilities, charge distributions, and IR spectra for a group of complexes of a main-group metalloid (boron) atom with hydrocarbon molecules. The considered systems include the smallest species demonstrating the basic principle of operation, as well as their size-extended analogues, generalizing it to larger counterparts based on such units. The system geometries vary considerably between neutral and ionic counterparts and exhibit two–three typical conformations related to twisting by up to about 90 degrees. The predicted structures correlate with specific infrared spectra, which can enable their experimental identification and transformation tracking. The above-mentioned characteristics suggest the potential utility of such systems for intermolecular switches, with the possible spectral monitoring of their functioning.
Hybrid-Mechanism Synergistic Flexible Nb2O5@WS2@C Carbon Nanofiber Anode for Superior Sodium Storage
Authors: Zhao Yang , Feng Ziwen , Tan Yipeng , Deng Qinglin , Yao Lingmin
Published: April 2024

Sodium-ion batteries (SIBs) have demonstrated remarkable development potential and commercial prospects. However, in the current state of research, the development of high-energy-density, long-cycle-life, high-rate-performance anode materials for SIBs remains a huge challenge. Free-standing flexible electrodes, owing to their ability to achieve higher energy density without the need for current collectors, binders, and conductive additives, have garnered significant attention across various fields. In this work, we designed and fabricated a free-standing three-dimensional flexible Nb2O5@WS2@C carbon nanofiber (CNF) anode based on a hybrid adsorption–intercalation–conversion mechanism of sodium storage, using electrospinning and hydrothermal synthesis processes. The hybrid structure, aided by synergistic effects, releases the advantages of all materials, demonstrating a superior rate performance (288, 248, 211, 158, 90, and 48 mA h g−1 at the current density of 0.2, 0.5, 1, 2, 5, and 10 A g−1, respectively) and good cycling stability (160 mA h g−1 after 200 cycles at 1 A g−1). This work provides certain guiding significance for future research on hybrid and flexible anodes of SIBs.
Crack Detection of Reinforced Concrete Structure Using Smart Skin
Authors: Jung Yu-Jin , Jang Sung-Hwan
Published: April 2024

The availability of carbon nanotube (CNT)-based polymer composites allows the development of surface-attached self-sensing crack sensors for the structural health monitoring of reinforced concrete (RC) structures. These sensors are fabricated by integrating CNTs as conductive fillers into polymer matrices such as polyurethane (PU) and can be applied by coating on RC structures before the composite hardens. The principle of crack detection is based on the electrical change characteristics of the CNT-based polymer composites when subjected to a tensile load. In this study, the electrical conductivity and electro-mechanical/environmental characterization of smart skin fabricated with various CNT concentrations were investigated. This was performed to derive the tensile strain sensitivity of the smart skin according to different CNT contents and to verify their environmental impact. The optimal CNT concentration for the crack detection sensor was determined to be 5 wt% CNT. The smart skin was applied to an RC structure to validate its effectiveness as a crack detection sensor. It successfully detected and monitored crack formation and growth in the structure. During repeated cycles of crack width variations, the smart skin also demonstrated excellent reproducibility and electrical stability in response to the progressive occurrence of cracks, thereby reinforcing the reliability of the crack detection sensor. Overall, the presented results describe the crack detection characteristics of smart skin and demonstrate its potential as a structural health monitoring (SHM) sensor.
Incidence of the Brownian Relaxation Process on the Magnetic Properties of Ferrofluids
Authors: Vajtai Lili , Nemes Norbert Marcel , Morales Maria del Puerto , Molnár Kolos , Pinke Balázs Gábor , Simon Ferenc
Published: April 2024

Ferrofluids containing magnetic nanoparticles represent a special class of magnetic materials due to the added freedom of particle tumbling in the fluids. We studied this process, known as Brownian relaxation, and its effect on the magnetic properties of ferrofluids with controlled magnetite nanoparticle sizes. For small nanoparticles (below 10 nm diameter), the Néel process is expected to dominate the magnetic response, whereas for larger particles, Brownian relaxation becomes important. Temperature- and magnetic-field-dependent magnetization studies, differential scanning calorimetry, and AC susceptibility measurements were carried out for 6 and 13.5 nm diameter magnetite nanoparticles suspended in water. We identify clear fingerprints of Brownian relaxation for the sample of large-diameter nanoparticles as both magnetic and thermal hysteresis develop at the water freezing temperature, whereas the samples of small-diameter nanoparticles remain hysteresis-free down to the magnetic blocking temperature. This is supported by the temperature-dependent AC susceptibility measurements: above 273 K, the data show a low-frequency Debye peak, which is characteristic of Brownian relaxation. This peak vanishes below 273 K.
Thermal Stability and Crystallization Processes of Pd78Au4Si18 Thin Films Visualized via In Situ TEM
Authors: Yu Bingjiao , Zhao Rui , Lu Zhen , Su Hangbo , Liang Binye , Liu Bingjie , Ma Chunlan , Zhu Yan , Li Zian
Published: April 2024

Amorphous alloys or metallic glasses (MGs) thin films have attracted extensive attention in various fields due to their unique functional properties. Here, we use in situ heating transmission electron microscopy (TEM) to investigate the thermal stability and crystallization behavior of Pd-Au-Si thin films prepared by a pulsed laser deposition (PLD) method. Upon heating treatment inside a TEM, we trace the structural changes in the Pd-Au-Si thin films through directly recording high-resolution images and diffraction patterns at different temperatures. TEM observations reveal that the Pd-Au-Si thin films started to nucleate with small crystalline embryos uniformly distributed in the glassy matrix upon approaching the glass transition temperature Tg=625K, and subsequently, the growth of crystalline nuclei into sub-10 nm Pd-Si nanocrystals commenced. Upon further increasing the temperature to 673K, the thin films transformed to micro-sized patches of stacking-faulty lamellae that further crystallized into Pd9Si2 and Pd3Si intermetallic compounds. Interestingly, with prolonged thermal heating at elevated temperatures, the Pd9Si2 transformed to Pd3Si. Simultaneously, the solute Au atoms initially dissolved in glassy alloys and eventually precipitated out of the Pd9Si2 and Pd3Si intermetallics, forming nearly spherical Au nanocrystals. Our TEM results reveal the unique thermal stability and crystallization processes of the PLD-prepared Pd-Au-Si thin films as well as demonstrate a possibility of producing a large quantity of pure nanocrystals out of amorphous solids for various applications.
Physiologically Based Pharmacokinetic Modeling in Pregnancy, during Lactation and in Neonates: Achievements, Challenges and Future Directions
Authors: Allegaert Karel , Quinney Sara K. , Dallmann André
Published: April 2024

Obstetric subjects represent a special population in pharmacology [...]
Effect of Environmental pH on the Mechanics of Chitin and Chitosan: A Single-Molecule Study
Authors: Zhang Song , Ji Yunxu , He Yiwei , Dong Juan , Li Haohang , Yu Shirui
Published: April 2024

Chitin and chitosan are important structural macromolecules for most fungi and marine crustaceans. The functions and application areas of the two molecules are also adjacent beyond their similar molecular structure, such as tissue engineering and food safety where solution systems are involved. However, the elasticities of chitin and chitosan in solution lack comparison at the molecular level. In this study, the single-molecule elasticities of chitin and chitosan in different solutions are investigated via atomic force microscope (AFM) based single-molecule spectroscopy (SMFS). The results manifest that the two macromolecules share the similar inherent elasticity in DOSM due to their same chain backbone. However, obvious elastic deviations can be observed in aqueous conditions. Especially, a lower pH value (acid environment) is helpful to increase the elasticity of both chitin and chitosan. On the contrary, the tendency of elastic variation of chitin and chitosan in a larger pH value (alkaline environment) shows obvious diversity, which is mainly determined by the side groups. This basic study may produce enlightenment for the design of intelligent chitin and chitosan food packaging and biomedical materials.
Development of Polylactic Acid Films with Alkali- and Acetylation-Treated Flax and Hemp Fillers via Solution Casting Technique
Authors: Pokharel Anamol , Falua Kehinde James , Babaei-Ghazvini Amin , Nikkhah Dafchahi Mostafa , Tabil Lope G. , Meda Venkatesh , Acharya Bishnu
Published: April 2024

This study aims to enhance value addition to agricultural byproducts to produce composites by the solution casting technique. It is well known that PLA is moisture-sensitive and deforms at high temperatures, which limits its use in some applications. When blending with plant-based fibers, the weak point is the poor filler–matrix interface. For this reason, surface modification was carried out on hemp and flax fibers via acetylation and alkaline treatments. The fibers were milled to obtain two particle sizes of <75 μm and 149–210 μm and were blended with poly (lactic) acid at different loadings (0, 2.5%, 5%, 10%, 20%, and 30%) to form a composite film The films were characterized for their spectroscopy, physical, and mechanical properties. All the film specimens showed C–O/O–H groups and the π–π interaction in untreated flax fillers showed lignin phenolic rings in the films. It was noticed that the maximum degradation temperature occurred at 362.5 °C. The highest WVPs for untreated, alkali-treated, and acetylation-treated composites were 20 × 10−7 g·m/m2 Pa·s (PLA/hemp30), 7.0 × 10−7 g·m/m2 Pa·s (PLA/hemp30), and 22 × 10−7 g·m/m2 Pa·s (PLA/hemp30), respectively. Increasing the filler content caused an increase in the color difference of the composite film compared with that of the neat PLA. Alkali-treated PLA/flax composites showed significant improvement in their tensile strength, elongation at break, and Young’s modulus at a 2.5 or 5% filler loading. An increase in the filler loadings caused a significant increase in the moisture absorbed, whereas the water contact angle decreased with an increasing filler concentration. Flax- and hemp-induced PLA-based composite films with 5 wt.% loadings showed a more stable compromise in all the examined properties and are expected to provide unique industrial applications with satisfactory performance.
Mechanically Tough and Conductive Hydrogels Based on Gelatin and Z–Gln–Gly Generated by Microbial Transglutaminase
Authors: Chen Zhiwei , Zhang Ruxin , Zhao Shouwei , Li Bing , Wang Shuo , Lu Wenhui , Zhu Deyi
Published: April 2024

Gelatin-based hydrogels with excellent mechanical properties and conductivities are desirable, but their fabrication is challenging. In this work, an innovative approach for the preparation of gelatin-based conductive hydrogels is presented that improves the mechanical and conductive properties of hydrogels by integrating Z–Gln–Gly into gelatin polymers via enzymatic crosslinking. In these hydrogels (Gel–TG–ZQG), dynamic π–π stacking interactions are created by the introduction of carbobenzoxy groups, which can increase the elasticity and toughness of the hydrogel and improve the conductivity sensitivity by forming effective electronic pathways. Moreover, the mechanical properties and conductivity of the obtained hydrogel can be controlled by tuning the molar ratio of Z–Gln–Gly to the primary amino groups in gelatin. The hydrogel with the optimal mechanical properties (Gel–TG–ZQG (0.25)) exhibits a high storage modulus, compressive strength, tensile strength, and elongation at break of 7.8 MPa at 10 °C, 0.15 MPa at 80% strain, 0.343 MPa, and 218.30%, respectively. The obtained Gel–TG–ZQG (0.25) strain sensor exhibits a short response/recovery time (260.37 ms/130.02 ms) and high sensitivity (0.138 kPa−1) in small pressure ranges (0–2.3 kPa). The Gel–TG–ZQG (0.25) hydrogel-based sensors can detect full-range human activities, such as swallowing, fist clenching, knee bending and finger pressing, with high sensitivity and stability, yielding highly reproducible and repeatable sensor responses. Additionally, the Gel–TG–ZQG hydrogels are noncytotoxic. All the results demonstrate that the Gel–TG–ZQG hydrogel has potential as a biosensor for wearable devices and health-monitoring systems.
Enhanced Photocatalytic and Filtration Performance of TiO2-Ag Composite-Coated Membrane Used for the Separation of Oil Emulsions
Authors: Fazekas Ákos Ferenc , Gyulavári Tamás , Ágoston Áron , Janovák László , Kopniczky Judit , László Zsuzsanna , Veréb Gábor
Published: April 2024

Polyvinylidene fluoride (PVDF) membranes were coated with TiO2 and TiO2-Ag to enhance their efficiency for oil-in-water emulsion separation. The photocatalytic activities of the two modified membranes and their filtration performances were compared in detail. The significantly enhanced photocatalytic activity of the TiO2-Ag composite was proved using a methyl orange (MO) solution (c = 10−5 M) and a crude oil emulsion (c = 50 mg·L−1). The TiO2-Ag-coated membrane reduced the MO concentration by 87%, whereas the TiO2-modified membrane reached only a 46% decomposition. The photocatalytic reduction in the chemical oxygen demand of the emulsion was also ~50% higher using the TiO2-Ag-coated membrane compared to that of the TiO2-coated membrane. The photoluminescence measurements demonstrated a reduced electron/hole recombination, achieved by the Ag nanoparticle addition (TiO2-Ag), which also explained the enhanced photocatalytic activity. A significant improvement in the oil separation performance with the TiO2-Ag-coated membrane was also demonstrated: a substantial increase in the flux and flux recovery ratio (up to 92.4%) was achieved, together with a notable reduction in the flux decay ratio and the irreversible filtration resistance. Furthermore, the purification efficiency was also enhanced (achieving 98.5% and 99.9% COD and turbidity reductions, respectively). Contact angle, zeta potential, scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements were carried out to explain the results. SEM and AFM images revealed that on the TiO2-Ag-coated membrane, a less aggregated, more continuous, homogeneous, and smoother nanolayer was formed due to the ~50% more negative zeta potential of the TiO2-Ag nanocomposite compared to that of the TiO2. In summary, via Ag addition, a sufficiently hydrophilic, beneficially negatively charged, and homogeneous TiO2-Ag-coated PVDF membrane surface was achieved, which resulted in the presented advantageous filtration properties beyond the photocatalytic activity enhancement.
Long-Term Cropping Management Practices Affect the Biochemical Properties of an Alabama Ultisol
Authors: Watts Dexter B. , He Zhongqi , Yin Xinhua , Torbert H. Allen , Senwo Zachary N. , Tewolde Haile
Published: April 2024

Interest in improving the long-term sustainability of agricultural production systems has focused on identifying management practices that promote soil health. No tillage, cover cropping, and amending soils with broiler (Gallus gallus domesticus L.) litter are commonly adopted conservation practices that have been shown to improve soil fertility and crop yield. However, the overall influence of these conservation practices on soil health in the southeastern US are not well understood. Thus, a study was conducted to evaluate the influence of tillage, broiler litter (BL) applications, and cropping systems on soil biochemical properties. Soils were collected from field research plots under long-term management (>than 25 years of tillage, 15 years of broiler litter application, and 15 years of cropping system). Soil microbial biomass, C, N, and P, amidohydrolases, and dissolved organic matter (DOM) were evaluated as indicators of soil health. Adopting tillage and BL into the agricultural management system modified the biochemical parameters of the soils evaluated. Most of these modifications occurred in the 0–5 cm depth. Higher microbial biomass carbon (MBC; 85%) and nitrogen (MBN; 10%) and enzyme activities of asparaginase (65%) and glutaminase (70%) were observed in the 0–5 cm depth under no tillage (NT) compared to conventional tillage (CT), indicating greater biological activities were established in these soil ecosystems. Broiler litter applications increased microbial biomass N and activities of asparaginase and glutaminase in both soil depths. In addition, microbial biomass phosphorus (MBP) was increased following BL application in the 0–5 cm depth. The results suggest that long-term management of NT and BL additions can improve the health of eroded southeastern US soils by altering the soil biochemical parameters.
Dynamical Downscaling of Daily Extreme Temperatures over China Using PRECIS Model
Authors: Guo Junhong , Jia Hongtao , Wang Yuexin , Wang Xiaoxuan , Li Wei
Published: April 2024

As global warming intensifies and the frequency of extreme weather events rises, posing a major threat to the world’s economy and sustainable development, accurate forecasting of future extreme events is of great significance to mankind’s response to extreme weather events and to the sustainable development of society. Global Climate Models (GCMs) have limitations in their applicability at regional scales due to their coarse resolution. Utilizing dynamical downscaling methods based on regional climate models (RCMs) is an essential approach to obtaining high-resolution climate simulation information in future. This study represents an attempt to extend the use of the Providing REgional Climates for Impacts Studies (PRECIS) regional climate model by employing the BCC-CSM2-MR model from the Beijing Climate Center to drive it, conducting downscaling experiments over China at a spatial resolution of 0.22° (25 km). The simulation and prediction of daily maximum and minimum temperatures across the China region are conducted, marking a significant effort to expand the usage of PRECIS with data from alternative GCMs. The results indicate that PRECIS performs well in simulating the daily maximum and minimum temperatures over the China region, accurately capturing their spatial distribution and demonstrating notable simulation capabilities for both cold and warm regions. In the annual cycle, the simulation performance of PRECIS is superior to its driving GCM, particularly during cold months (i.e., December and from January to May). Regarding future changes, the daily extreme temperatures in most regions are projected to increase gradually over time. In the early 21st century, the warming magnitude is approximately 1.5 °C, reaching around 3 °C by the end of the century, with even higher warming magnitudes exceeding 4.5 °C under the SSP585 scenario. Northern regions will experience greater warming magnitudes than southern regions, suggesting faster increases in extreme temperatures in higher latitudes. This paper provides forecasts of extreme temperatures in China, which will be useful for studying extreme events and for the government to make decisions in response to extreme events.