bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Acne-Prone Skin with Reflectance Confocal Microscopy and Optical Coherence Tomography and Modifications Induced by Topical Treatment and Probiotic Supplementation
Authors: Manfredini Marco , Sticchi Alberto , Lippolis Nicola , Pedroni Gioia , Giovani Matteo , Ciardo Silvana , Chello Camilla , Guida Stefania , Farnetani Francesca , Pellacani Giovanni
Published: July 2023

The evaluation of acne-prone skin and absent-to-mild acne is difficult because this condition is not associated with a clinically definable situation. Previous studies showed that apparently healthy skin in patients with previous episodes of acne shows microcomedos and infundibular hyperkeratosis upon reflectance confocal microscopy (RCM) evaluation. Our aim was to characterize the subclinical and microscopic characteristics of acne-prone skin by means of RCM and dynamic optical coherence tomography (D-OCT) and evaluate microscopic changes induced by treatment. A group of 20 patients received a daily combined treatment over a period of 3 months, consisting of probiotic supplementation with three strains of 109 colony-forming units of Lactobacillus (Lactobacillus reuteri, Lactobacillus casei subsp. rhamnosus, Lactobacillus plantarum) and a combined topical product of azelaic and hydroxypinacolone retinoate (HPR). Clinical evaluations and non-invasive imaging acquisitions using VISIA® System, RCM, and D-OCT were performed at baseline, and after 4 and 12 weeks. The total number of clinically evident non-inflammatory lesions decreased during treatment from 11.5 to 7.3 (p < 0.05). There was also an evident reduction in microscopic acne features at RCM and D-OCT, such as the number of small bright follicles, large bright follicles and vascular threshold density at 300 μm and 500 μm depths. The types and extent of microscopic alterations in acne-prone skin patients may not be evident by clinical scores. Patients with low investigator global assessment (IGA) grades are a heterogeneous population, characterized by different microscopic skin features. Acne-prone skin is susceptible to treatment, and RCM and D-OCT imaging are sensitive tools to objectively monitor subclinical skin changes.
Beard Alopecia: An Updated and Comprehensive Review of Etiologies, Presentation and Treatment
Authors: Kaiser Michael , Abdin Rama , Yaghi Marita , Gaumond Simonetta I. , Jimenez Joaquin J. , Issa Naiem T.
Published: July 2023

Facial hair is an important social and psychologic aspect of clinical appearance for men. The purpose of this review is to provide a comprehensive overview of the causes of alopecia of the beard including the prevalence, pathophysiology, clinical presentation, and treatment. In this review, we highlight more common causes of beard alopecia including alopecia areata and pseudofolliculitis barbae, infectious causes such as tinea barbae and herpes simplex folliculitis, and rare causes including dermatopathia pigmentosa reticularis and frontal fibrosing alopecia. This review serves as an important resource for clinicians when faced with patients suffering from beard alopecia.
Catheter-Based Techniques for Addressing Atrioventricular Valve Regurgitation in Adult Congenital Heart Disease Patients: A Descriptive Cohort
Authors: El Bouziani Abdelhak , Witte Lars S. , Bouma Berto J. , Jongbloed Monique R. M. , Robbers-Visser Daniëlle , Straver Bart , Beijk Marcel A. M. , Kiès Philippine , Koolbergen David R. , van der Kley Frank , Schalij Martin J. , de Winter Robbert J. , Egorova Anastasia D.
Published: July 2023

Introduction: Increasing survival of adult congenital heart disease (ACHD) patients comes at the price of a range of late complications—arrhythmias, heart failure, and valvular dysfunction. Transcatheter valve interventions have become a legitimate alternative to conventional surgical treatment in selected acquired heart disease patients. However, literature on technical aspects, hemodynamic effects, and clinical outcomes of percutaneous atrioventricular (AV) valve interventions in ACHD patients is scarce. Method: This is a descriptive cohort from CAHAL (Center of Congenital Heart Disease Amsterdam-Leiden). ACHD patients with severe AV valve regurgitation who underwent a transcatheter intervention in the period 2020–2022 were included. Demographic, clinical, procedural, and follow-up data were collected from patient records. Results: Five ACHD patients with severe or torrential AV valve regurgitation are described. Two patients underwent a transcatheter edge-to-edge repair (TEER), one patient underwent a valve-in-valve procedure, one patient received a Cardioband system, and one patient received both a Cardioband system and TEER. No periprocedural complications occurred. Post-procedural AV valve regurgitation as well as NYHA functional class improved in all patients. The median post-procedural NYHA functional class improved from 3.0 (IQR [2.5–4.0]) to 2.0 (IQR [1.5–2.5]). One patient died 9 months after the procedure due to advanced heart failure with multiorgan dysfunction. Conclusion: Transcatheter valve repair is feasible and safe in selected complex ACHD patients. A dedicated heart team is essential for determining an individualized treatment strategy as well as pre- and periprocedural imaging to address the underlying mechanism(s) of AV regurgitation and guide the transcatheter intervention. Long-term follow-up is essential to evaluate the clinical outcomes of transcatheter AV valve repair in ACHD patients.
Microwave-Assisted Hydrothermal Treatment of Multifunctional Substituted Hydroxyapatite with Prospective Applications in Bone Regeneration
Authors: Burdusel Alexandra-Cristina , Neacsu Ionela Andreea , Birca Alexandra Catalina , Chircov Cristina , Grumezescu Alexandru-Mihai , Holban Alina Maria , Curutiu Carmen , Ditu Lia Mara , Stan Miruna , Andronescu Ecaterina
Published: July 2023

Orthopedic bone graft infections are major complications in today’s medicine, and the demand for antibacterial treatments is expanding because of the spread of antibiotic resistance. Various compositions of hydroxyapatite (HAp) in which Calcium (Ca2+) ions are substituted with Cerium (Ce3+) and Magnesium (Mg2+) are herein proposed as biomaterials for hard tissue implants. This approach gained popularity in recent years and, in the pursuit of mimicking the natural bone mineral’s composition, over 70 elements of the Periodic Table were already reported as substituents into HAp structure. The current study aimed to create materials based on HAp, Hap-Ce, and Hap-Mg using hydrothermal maturation in the microwave field. This route has been considered a novel, promising, and effective way to obtain monodisperse, fine nanoparticles while easily controlling the synthesis parameters. The synthesized HAp powders were characterized morphologically and structurally by XRD diffraction, Dynamic light scattering, zeta potential, FTIR spectrometry, and SEM analysis. Proliferation and morphological analysis on osteoblast cell cultures were used to demonstrate the cytocompatibility of the produced biomaterials. The antimicrobial effect was highlighted in the synthesized samples, especially for hydroxyapatite substituted with cerium. Therefore, the samples of HAp substituted with cerium or magnesium are proposed as biomaterials with enhanced osseointegration, also having the capacity to reduce device-associated infections.
Green-Synthesized Silver Nanoparticles: Antifungal and Cytotoxic Potential for Further Dental Applications
Authors: Klein Widadh , Ismail Enas , Maboza Ernest , Hussein Ahmed A. , Adam Razia Z.
Published: July 2023

Fungal infections caused by Candida albicans (C. albicans) are one of the most prevalent types of oral disorders in the elderly. It has been reported that drug resistance to fungal pathogens poses a severe risk to global healthcare systems and public health. Therefore, the goal of this work is to investigate the cytotoxic and antifungal properties of silver nanoparticles (AgNPs) produced using three different natural extracts: Berzelia lanuginose, Helichrysum cymosum, and Searsia crenata. According to the UV-Vis results, the synthesized AgNPs via B. lanuginose, H. cymosum, and S. crenata show surface plasmonic resonance (SPR) peaks at 430, 440, and 428 nm, respectively. HR-TEM revealed different shapes for the nanoparticles within the size ranges of 16–20, 31–60, and 57–72 nm for B. lanuginose, H. cymosum, and S. crenata, respectively. Using a human oral fibroblast cell line, the cytotoxicity of both AgNPs and plant extracts was tested at concentrations of 0.007, 0.012, 0.025, and 0.062 mg/mL (buccal mucosa fibroblasts). The antifungal activity showed growth inhibition zones of approximately 18 mm, 18.67 mm, and 18.33 mm for the AgNPs conjugated with B. lanuginose, H. cymosum, and S. crenata, respectively. For the studied samples, the minimum inhibitory concentration (MIC50) was less than 0.015 mg/mL. The AgNPs exhibited antifungal activity that was concentration- and size-dependent. The results of this study offer new insights into the cytotoxicity and antifungal activity of the green-synthesized AgNPs.
Nutritional Assessment of Lactarius drassinus and L. controversus from the Cold Desert Region of the Northwest Himalayas for Their Potential as Food Supplements
Authors: Mayirnao Hom-Singli , Gupta Samta , Thokchom Sarda Devi , Sharma Karuna , Mehmood Tahir , Kaur Surinder , Sharma Yash Pal , Kapoor Rupam
Published: July 2023

Kargil is a cold desert with hostile ecological conditions such as low temperature and precipitation, as well as difficult terrains. However, several wild mushrooms thrive well under such an extreme environment. Despite their abundance, the chemical composition of indigenous mushrooms has not been explored. This study aimed to assess the potential of two wild edible mushrooms from Kargil, Lactarius drassinus and Lactarius controversus, as food supplements by evaluating their nutritional and nutraceutical properties. Nutritional attributes such as total protein, available carbohydrates, soluble sugars, and vitamins were found to be high in the mushroom species. Furthermore, high mineral accumulation and relatively lower antinutrient concentrations resulted in higher bioavailabilities of Zn, Fe, Ca, and Mg. Gas-chromatography–mass-spectrometry-based metabolite profiling revealed that although the two mushroom species showed similar metabolite compositions, their relative concentrations differed. Sugars were the predominant compounds identified in both the species, with sugar alcohols being the major contributor. The second most abundant class of compound in L. drassinus was amino acids, with 5-oxoproline as the major contributor. On the other hand, fatty acids were the second most abundant compounds in L. controversus, with high oleic and linoleic acid concentrations. In the ultra-performance-liquid-chromatography-based quantification of phenolic compounds, chlorogenic acid was found to be highest in in terms of its concentration in both the mushrooms studied, followed by quercetin dihydrate and gallic acid in L. drassinus and L. controversus, respectively. Moreover, high antioxidant activities attributable to their high phenol, flavonoid, and carotenoid concentrations were observed. Overall, the two mushrooms offer well-balanced sources of nutritional and nutraceutical compounds, making them healthy foods.
Evaluation of microRNA Expression Features in Patients with Various Types of Arterial Damage: Thoracic Aortic Aneurysm and Coronary Atherosclerosis
Authors: Ekedi Ange Veroniqe Ngo Bilong , Rozhkov Andrey N. , Shchekochikhin Dmitry Yu. , Novikova Nina A. , Kopylov Philippe Yu. , Bestavashvili Afina A. , Ivanova Tatiana V. , Zhelankin Andrey V. , Generozov Eduard V. , Konanov Dmitry N. , Akselrod Anna S.
Published: July 2023

Circulating serum miRNA are increasingly used as biomarkers and potential treatment targets in several clinical scenarios, including cardiovascular diseases. However, the current data on circulating miRNA in thoracic aorta aneurism (TAA) patients are inconclusive. The aim of the present study is to compare the levels of several circulating miRNA in patients with degenerative TAA, coronary artery disease (CAD), and controls for special profile identification. We have identified several candidates for the role of new biomarkers: miR-143-3p, miR-181-5p, miR-126-3p, miR-126-5p, miR-145-5p, miR-150-5p, and miR-195-5p. Materials and methods: Serum samples of 100 patients were analyzed, including 388 TAA patients scheduled for elective surgery, 67 patients with stable CAD and 17 controls, were used for miRNA isolation and identification. Results: More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, miR-29b-5p, miR-126-5p/-3p, miR-181b-5p, and miR-92a-3p, with the latter microRNA being investigated as a novel potential marker of TAA for the first time. Conclusion: TAA and CAD patients demonstrated a significant increase in the levels of circulating miR-126-5p/-3p, miR-181b-5p, and miR-29b-3p. More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, -29b-5p, -126-5p/-3p, 181b-5p, and -92a-3p, with the latter microRNA being investigated as a potential marker of TAA for the first time.
Agricultural Cultivation Structure in Arid Areas Based on Water–Carbon Nexus—Taking the Middle Reaches of the Heihe River as an Example
Authors: Li Boxuan , Niu Meng , Zhao Jing , Zheng Xi , Chen Ran , Ling Xiao , Li Jinxin , Wang Yuxiao
Published: July 2023

China faces challenges of food security and sustainable agricultural production. However, current studies rarely address the spatial distribution patterns of water consumption and carbon emissions. We studied the irrigation water use efficiency and carbon emission differences of crops in arid areas and their spatial distribution using wheat and maize, two major food crops in the middle reaches of the Heihe River, as examples. Furthermore, we have optimized low-carbon cropping of crops under the multiple objectives of water conservation and economic development. The results show that: (1) The carbon emissions per unit of water consumption for maize are 0.03 × 10−6 t mm−1 and 0.49 × 10−6 t mm−1 for wheat. Irrigation water consumption per unit yield is 515.6 mm t−1 for maize and 426.7 mm t−1 for wheat. (2) The spatial distribution patterns of irrigation water consumption were opposites for maize and wheat. The former has lower irrigation water consumption in the planting area upstream of the Heihe River and higher in the lower reaches. In contrast, the pattern of wheat irrigation is the opposite. (3) After optimizing the cropping mix for both crops, the area planted with wheat should be reduced to 59% of the current size, while maize should be expanded to 104%. The results of the research hold immense importance in guiding the future grain crop planting patterns for water-saving agriculture and low-carbon agriculture development in arid zones worldwide, aligning with the United Nations’ Sustainable Development Goals.
Analysis and Evaluation of the Service Capacity of a Waterfront Public Space Using Point-of-Interest Data Combined with Questionnaire Surveys
Authors: Ouyang Pinyue , Wu Xiaowen
Published: July 2023

The analysis and evaluation of the service capacity of an urban public space is of great importance for optimizing spatial design and ensuring sustainable regeneration of the space. Point-of-interest (POI) data analysis is a common method for evaluating the performance of public space since it contains various geographical information about specific facilities. However, this method is incapable of providing intuitive and clear feedback on the usage of the space, such as visitor experience and satisfaction levels. In this paper, we present a hybrid approach that combines POI data with questionnaire surveys to comprehensively analyze and evaluate the service capacity of the facilities in a waterfront public space. By taking the Changning section of the Suzhou Creek in Shanghai as an example, we evaluate and verify the utilization rate and satisfaction level of public facilities based on this hybrid approach with three satisfaction factors: accessibility, landscape visual quality, and service functions. The results reveal that the service space that can be reached on foot provides the most satisfaction in terms of accessibility, followed by the space that can be reached by bicycle. When it comes to landscape visual quality, visitors are more concerned with the view around the facility than with the greenery. Regarding service functions, the service facility with beverage outlets, fitness, and small gatherings is more appealing. The proposed approach will be useful for further developing advanced public space evaluation strategies with real-time feedback capabilities, as well as for the intelligent design and long-term regeneration of future public spaces.
Stereotypes in a Multilingual Film: A Case Study on Issues of Social Injustice
Authors: Eriss Azadeh , Khoshsaligheh Masood
Published: July 2023

Films serve to (re-)create a ‘world’ within the mind of the audience. Additionally, they introduce or reinforce stereotypes portrayed as a reality of the modern world through multiplexity and the strategic use of foreign languages, dialects, and non-native language use, among others. Various concepts of stereotypes can be explored in fiction feature films, especially as film characters are often based on different kinds of stereotypes. Audiovisual texts tend to operate as cultural constructs that reflect and convey certain ideologies within an industry that holds the power to marginalize or belittle voices. Multilingual films highlight the contrasts among and within cultures; hence, they can further exacerbate the marginalization and stereotyping of different cultures and nations, ultimately having damaging effects on society’s perception of different stereotypes, such as race and gender groups, which is shown with the examples from a multilingual film. This article analyzes the marginalization and stereotypes in a Hollywoodian multilingual film through film analysis and critical theory. By doing so, this study aims to provide insight into the stereotypes that have been depicted, covering various clichés and stereotypes, including cultural, gender, political, and religious stereotypes. Furthermore, it seeks to dissect the societal consequences that arise from detrimental portrayals of stereotyping in a purposeful selection of an American multilingual film.
The Role of Blood Oxygen Level Dependent Signal Variability in Pediatric Neuroscience: A Systematic Review
Authors: Dinatolo Michael F. , Pur Daiana Roxana , Eagleson Roy , de Ribaupierre Sandrine
Published: July 2023

Background: As pediatric BOLD Signal Variability (SV) analysis is relatively novel, there is a need to provide a foundational framework that gives researchers an entry point into engaging with the topic. This begins with clarifying the definition of BOLD signal variability by identifying and categorizing the various metrics utilized to measure BOLD SV. Methods: A systematic review of the literature was conducted. Inclusion criteria were restricted to studies utilizing any metric of BOLD SV and with individuals younger than 18 in the study population. The definition of BOLD SV was any measure of intra-individual variability in the BOLD signal. Five databases were searched: Psychinfo, Healthstar, MEDLINE, Embase, and Scopus. Results: A total of 17 observational studies, including male (n = 1796) and female (n = 1324) pediatric participants were included. Eight studies quantified variability as the amount of deviation from the average BOLD signal, seven used complexity-based metrics, three used correlation measures of variability, and one used the structure of the hemodynamic response function. In this study, 10 methods of quantifying signal variability were identified. Associations and trends in BOLD SV were commonly found with age, factors specific to mental and/or neurological disorders such as attention deficit disorder, epilepsy, psychotic symptoms, and performance on psychological and behavioral tasks. Conclusions: BOLD SV is a potential biomarker of neurodevelopmental and neurological conditions and symptom severity in mental disorders for defined pediatric populations. Studies that establish clinical trends and identify the mechanisms underlying BOLD SV with a low risk of bias are needed before clinical applications can be utilized by physicians.
Study on Flexural Behavior of Corroded I-Shaped Steel Beams Strengthened with Hybrid CFRP/GFRP Sheets
Authors: Han Yiming , Li Nan , Zhang Guangxi
Published: July 2023

How to effectively reinforce steel structures with rust and damage is an important research topic in the engineering field. This article takes the rusted I-beam as the research object and analyzes the effects of different CFRP/GFRP reinforcement methods on the bending performance of rusted I-beams through experimental research with a total of 1 unreinforced beam and 7 CFRP/GFRP-reinforced beams. The results show that when the number of CFRP/GFRP-reinforced layers is the same, replacing some of the CFRP with GFRP and using different interlayer mixed laying sequences have little effect on the bending bearing capacity of rusted I-beams. The number of CFRP/GFRP-reinforced layers is the key factor affecting the bending bearing capacity. At the same time, numerical simulation was conducted using finite element software to study the stress distribution and stress development law of the reinforced beam, and the numerical simulation results were consistent with the experimental results.
Interplay of Oxidative Stress, Inflammation, and Autophagy in RAW 264.7 Murine Macrophage Cell Line Challenged with Si/SiO2 Quantum Dots
Authors: Stanca Loredana , Geicu Ovidiu Ionut , Serban Andreea Iren , Dinischiotu Anca
Published: July 2023

Quantum dots (QDs) with photostable fluorescence are recommended for imaging applications; however, their effect on living cells is incompletely understood. We aimed to elucidate the RAW 264.7 murine macrophage cell line’s response to the Si/SiO2 QDs challenge. Cells were exposed to 5 and 15 μg/mL Si/SiO2 QDs for 6 h, 12 h, and 24 h. Cell metabolic activity and viability were assessed by MTT, live/dead, and dye-exclusion assays. Oxidative stress and membrane integrity were assessed by anion superoxide, malondialdehyde, and lactate dehydrogenase activity evaluations. Antioxidative enzyme activities were analyzed by kinetic spectrophotometric methods. Cytokines were analyzed with an antibody-based magnetic bead assay, PGE2 was assessed by ELISA, and Nrf-2, Bcl-2, Beclin 1, and the HSPs were analyzed by western blot. Autophagy levels were highlighted by fluorescence microscopy. The average IC50 dose for 6, 12, and 24 h was 16.1 ± 0.7 μg/mL. Although glutathione S-transferase and catalase were still upregulated after 24 h, superoxide dismutase was inhibited, which together allowed the gradual increase of malondialdehyde, anion superoxide, nitric oxide, and the loss of membrane integrity. G-CSF, IL-6, TNF-α, MIP-1β, MCP-1, Nrf-2, PGE2, and RANTES levels, as well as autophagy processes, were increased at all time intervals, as opposed to caspase 1 activity, COX-2, HSP60, and HSP70, which were only upregulated at the 6-h exposure interval. These results underscore that Si/SiO2 QDs possess significant immunotoxic effects on the RAW 264.7 macrophage cell line and stress the importance of developing effective strategies to mitigate their adverse impact.
Improvement of Plasterboard Properties by the Control of Polymethylhydrosiloxane Dosage, Stirring Time, and Drying Temperature Applied to the Calcium Sulfate Hemihydrate and Water Mixture
Authors: Romano-Matos Victoria , Tundidor-Camba Alain , Vera Sergio , Videla Alvaro R.
Published: July 2023

Plasterboard is an important building material in the construction industry because it allows for quick installation of walls, partitions, and ceilings. Although a common material, knowledge about its performance related to modern polymers and fabrication conditions is still lacking. The present work analyzes how some manufacturing factors applied during the plaster board fabrication impact on some plasterboard properties, including water absorption, flexural strength, and thermal conductivity. The manufacturing variables evaluated are the dose (D) of polymethylhydrosiloxane (PMHS), the agitation time of the mixture (H), and the drying temperature of the plaster boards after setting (T). The results suggest that factors D, H, and T induce changes in the porosity and the morphological structure of the calcium sulfate dihydrate crystals formed. Performance is evaluated at two levels of each factor following a statistical method of factorial experimental design centered on a cube. Morphological changes in the crystals of the resulting boards were evaluated with scanning electron microscopy (SEM) and the IMAGEJ image analysis program. Porosity changes were evaluated with X-ray microcomputed tomography (XMT) and 3D image analysis tools. The length-to-width ratio of the crystals decreases as it goes from low PMHS dosage to high dosage, favoring a better compaction of the plasterboard under the right stirring time and drying temperature. In contrast, the porosity generated by the incorporation of PMHS increases when going from low-level to high-level conditions and affects the maximum size of the pores being generated, with a maximum value achieved at 0.6% dosage, 40 s, and 140 °C conditions. The presence of an optimal PMHS dosage value that is approximately 0.6–1.0% is evidenced. In fact, when comparing trails without and with PMHS addition, a 10% decrease in thermal conductivity is achieved at high H (60 s) and high T (150 °C) level conditions. Water absorption decreases by more than 90% when PMHS is added, mainly due to the hydrophobic action of the PMHS. Minimum water absorption levels can be obtained at high drying temperatures. Finally, the resistance to flexion is not affected by the addition of PMHS because apparently there are two opposing forces acting: on one hand is the decrease in the length–width ratio giving more compactness, and on the other hand is the generation of pores. The maximum resistance to flexion was found around a dosage of 0.6% PMHS. In conclusion, the results suggest that the addition of PMHS, the correct agitation time of the mixture, and the drying temperature reduce the water absorption and the thermal conductivity of the gypsum boards, with no significant changes in the flexural resistance.
Influence of Molecular Weight on the Enzymatic Degradation of PLA Isomer Blends by a Langmuir System
Authors: Im Donghyeok , Gavande Vishal , Lee Hak Yong , Lee Won-Ki
Published: July 2023

Polylactides (PLAs) and lactide copolymers are biodegradable, compostable, and derived from renewable resources, offering a sustainable alternative to petroleum-based synthetic polymers owing to their advantages of comparable mechanical properties with commodity plastics and biodegradability. Their hydrolytic stability and thermal properties can affect their potential for long-lasting applications. However, stereocomplex crystallization is a robust method between isomer PLAs that allows significant amelioration in copolymer properties, such as thermal stability, mechanical properties, and biocompatibility, through substantial intermolecular interactions amid l-lactyl and d-lactyl sequences, which have been the key approach to initial degradation rate and further PLA applications. It was demonstrated that the essential parameters affecting stereocomplexation are the mixing ratio and the chain length of each unit sequence. This study deals with the molecular weight, one of the specific interactions between isomers of PLAs. A solution polymerization method was applied to control molecular weight and chain architecture. The stereocomplexation was monitored with DSC. It was confirmed that the lower molecular weight polymer showed a higher degradation rate, as a hydrolyzed fragment having a molecular weight below a certain length dissolves into the water. To systematically explore the critical contribution of molecular weights, the Langmuir system was used to observe the stereocomplexation effect and the overall degradation rate.
3D Multi-Ion Corrosion Model in Hierarchically Structured Cementitious Materials Obtained from Nano-XCT Data
Authors: Szyszkiewicz-Warzecha Krzysztof , Stec Jakub , Deja Jan , Łagosz Artur , Górska Anna , Kutukova Kristina , Zschech Ehrenfried , Filipek Robert
Published: July 2023

Corrosion of steel reinforcements in concrete constructions is a worldwide problem. To assess the degradation of rebars in reinforced concrete, an accurate description of electric current, potential and concentrations of various species present in the concrete matrix is necessary. Although the concrete matrix is a heterogeneous porous material with intricate microstructure, mass transport has been treated in a homogeneous material so far, modifying bulk transport coefficients by additional factors (porosity, constrictivity, tortuosity), which led to so-called effective coefficients (e.g., diffusivity). This study presents an approach where the real 3D microstructure of concrete is obtained from high-resolution X-ray computed tomography (XCT), processed to generate a mesh for finite element method (FEM) computations, and finally combined with a multi-species system of transport and electric potential equations. This methodology allows for a more realistic description of ion movements and reactions in the bulk concrete and on the rebar surface and, consequently, a better evaluation of anodic and cathodic currents, ultimately responsible for the loss of reinforcement mass and its location. The results of this study are compared with a state-of-the-art model and numerical calculations for 2D and 3D geometries.
Effect of HA Content on Microstructure and Properties of Ti-27Nb-17Ta-8Zr/HA Composite
Authors: Jia Qinggong , Liang Shuhua , Wang Qingxiang
Published: July 2023

In this paper, Ti-27Nb-17Ta-8Zr/HA series composite materials were prepared by spark plasma sintering (SPS) technology. The medical titanium alloy (Ti-27Nb-17Ta-8Zr) with good mechanical properties, wear resistance, and corrosion resistance was combined with the hydroxyapatite (HA) bioactive ceramic with high biological activity and bone-binding ability. Moreover, the density, microstructure evolution, metal/ceramic reaction, mechanical behavior, in vitro bioactivity, and influencing mechanisms of composite materials with different HA contents were studied. The research results indicate that all biological composite materials are composed of β-Ti solution, α-Ti, and ceramic phases (Ti2O, CaTiO3, CaO, TixPy). With the increase of HA content, the compressive strength and yield strength of the composite material show a trend of first increasing, then decreasing, and then slowly increasing. After soaking in SBF artificial simulated body fluid for 5 days, the deposition of elements such as Ca and P on the surface significantly increased, while elements such as Ti, Nb, Ta, and Zr were evenly distributed in the matrix, demonstrating good in vitro mineralization ability and facilitating the attachment and growth of osteoblasts.
Cavitation Erosion Prevention Using Laser Shock Peening: Development of a Predictive Evaluation System
Authors: Li Wenlong , Yao Hongbing , Ding Zhipeng , Zhou Yuanhang , Wei Pengyu , Yue Jiang , Su Wei , Zhu Weihua
Published: July 2023

Marine flow-passing components are susceptible to cavitation erosion (CE), and researchers have worked to find ways to reduce its effects. Laser Shock Peening (LSP), a material strengthening method, has been widely used in aerospace and other cutting-edge fields. In recent years, LSP has been used in cavitation resistance research. However, the current LSP research does not realize a comprehensive predictive assessment of the material’s CE resistance. This paper uses m stresses to develop a comprehensive set of strengthening effect prediction models from LSP to CE using finite element analysis (FEA). Results show that the LSP-1 sample (4 mm spot, 10 J energy) introduced a compressive residual stress value of 37.4 MPa, better than that of 16.6 MPa with the LSP-2 sample (6 mm spot, 10 J energy), which is generally consistent with the experimental findings; the model predicts a 16.35% improvement in the resistance of LSP-1 sample to water jet damage, which is comparable to the experimental result of 14.02%; additionally, interactions between micro-jets do not predominate the cavitation erosion process and the final CE effect of the material is mainly due to the accumulation of jet-material interaction.
Experimental and Numerical Study on Shear Performance of Pitched Screws in Wood–Concrete Composite Beam with Wooden Partitions
Authors: Yuan Shengnan , Du Hao , Sun Zhixiang , Hu Xiamin
Published: July 2023

Wooden partitions are extensively used as formwork for pouring concrete in wood–concrete composite beams, especially in the restoring of wood structures. However, limited research has been conducted on the shear properties of pitched screw connectors in wood–concrete composite beams with wooden partitions. Therefore, this study investigated the shear performance of pitched screws in wood–concrete composite beams with wooden partitions through push-out tests and finite element analysis. The test results revealed that the failure mode of pitched screws was characterized by the pulling failure of the screws under tensile–shear action. The finite element analysis accurately predicted the failure mode, stress distribution, and load–slip behavior of pitched screws. Furthermore, the effects of the screw embedding angle, wooden partition thickness, concrete strength, and the length–diameter ratio of the screw were investigated through parametric analyses. It was found that when the screw diameter was 12 mm, the shearing capacity of the pitched screws with embedding angles of ±45°, ±60°, and ±75° decreased by 3.9%, 11.9%, and 26.9%, respectively, compared to the screws with an embedding angle of ±30°. The shearing capacity of pitched screws improved with the increase in the concrete strength and length–diameter ratio of the screw. However, the improvement in shearing capacity became less significant as the concrete strength and length–diameter ratio of the screw increased. Moreover, an increase in wooden partition thickness reduced the shearing capacity of pitched screws.
Exploring the Structural, Electronic, Magnetic, and Transport Properties of 2D Cr, Fe, and Zr Monoborides
Authors: Arias-Camacho Isabel M. , Gonzalez Szwacki Nevill
Published: July 2023

Compared to other 2D materials, MBenes are at an early stage of investigation in terms of both experimental and theoretical approaches. However, their wide range of possible 2D structures leads to novel and challenging properties and consequent applications. From all the possible stoichiometries, we performed a theoretical study of orthorhombic and hexagonal M2B2 MBenes within the framework of density functional theory. We found that both symmetries of Cr2B2, Fe2B2, and Zr2B2 show metallic behavior and could be grown under certain conditions as they were demonstrated to be dynamically stable. Moreover, the values of the magnetic moment observed, in specific ferromagnetic cases exceeding 2.5μB/M2B2, make them suitable as robust 2D magnets. Our findings represent an important step in the understanding of MBenes and open several windows to future research in fields like energy conversion and storage, sensing, catalysis, biochemistry, and nanotechnology, among others.
Cobalt Phthalocyanine-Doped Polymer-Based Electrocatalyst for Rechargeable Zinc-Air Batteries
Authors: Kumar Yogesh , Akula Srinu , Kibena-Põldsepp Elo , Käärik Maike , Kozlova Jekaterina , Kikas Arvo , Aruväli Jaan , Kisand Vambola , Leis Jaan , Tamm Aile , Tammeveski Kaido
Published: July 2023

Rechargeable zinc-air batteries (RZAB) have gained significant attention as potential energy storage devices due to their high energy density, cost-effectiveness, and to the fact that they are environmentally safe. However, the practical implementation of RZABs has been impeded by challenges such as sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), including poor cyclability. Herein, we report the preparation of cobalt- and nitrogen-doped porous carbon derived from phloroglucinol-formaldehyde polymer networks with 2-methyl imidazole and cobalt phthalocyanine as precursors for nitrogen and cobalt. The CoN-PC-2 catalyst prepared in this study exhibits commendable electrocatalytic activity for both ORR and OER, evidenced by a half-wave potential of 0.81 V and Ej=10 of 1.70 V. Moreover, the catalyst demonstrates outstanding performance in zinc-air batteries, achieving a peak power density of 158 mW cm−2 and displaying excellent stability during charge-discharge cycles. The findings from this study aim to provide valuable insights and guidelines for further research and the development of hierarchical micro-mesoporous carbon materials from polymer networks, facilitating their potential commercialisation and widespread deployment in energy storage applications.
Superconducting State Properties of CuBa2Ca3Cu4O10+δ
Authors: Lynnyk Artem , Puzniak Roman , Shi Luchuan , Zhao Jianfa , Jin Changqing
Published: July 2023

The superconducting state properties of the CuBa2Ca3Cu4O10+δ (Cu-1234) system, with a transition temperature as high as 117.5 K, were investigated. The ac magnetic susceptibility measurements confirmed a very sharp transition to the superconducting state. The upper critical field, Hc2, as high as 91 T, and the irreversibility field, Hirr, as high as 21 T at 77 K, were determined using dc SQUID magnetization measurements. The intragrain critical current density, jc, estimated from a magnetic hysteresis loop, is as high as 5 × 109 A/m2 in a self-generated magnetic field at 77 K. However, the intergrain critical current density in the studied material is smaller by four orders of magnitude due to very weak intergrain connections.
Characterization of PLA Sheets Prepared by Stretching under Different Conditions: Influence of Reprocessing and Establishing Optimal Conditions
Authors: Ortega Zaida , Douglas Paula , Hanna Paul R. , Garrett Graham , Clarke Alan , Cunningham Eoin , Suárez Luis
Published: July 2023

Polylactide (PLA) is one of the most commonly used biomaterials nowadays, with many recognized benefits, particularly in the packaging and single-use products industries. However, little research has been conducted on its stretching behavior. This work investigates the optimal conditions of biaxial stretching of injection-molded PLA samples produced under different processing conditions (pressure, drying, and pre-processing by extrusion, to simulate a recycling step). The injection-molded samples were characterized to determine their mechanical, thermal and thermo-mechanical behavior, water absorption, thermal behavior, and crystallization kinetics. The extruded samples showed reduced thermal stability, lower viscosity, decreased mechanical properties, and higher crystallization rates due to thermal degradation. However, the stretched samples provided similar properties regardless of the materials pre-processing. Regarding the assessment of the biaxial stretching process, processing at lower temperatures provides the films with a higher yield and breaking strength, while the time and strain rates have little influence on such properties. It was then determined that 82 °C is the optimal temperature for stretching the PLA samples. An increase in the stretch ratio provided a higher elastic modulus and higher values of opacity due to an increased crystallinity induced by stress during the process. Films as thin as 50 μm can be obtained by biaxially stretching injection-molded preforms, producing a deformation over 150% and acquiring good mechanical properties: about 90 MPa for the yield and a breaking strength and elastic modulus of 4000 MPa.
Carbon Quantum Dots-Doped Ni3Se4/Co9Se8/Fe3O4 Multilayer Nanosheets Prepared Using the One-Step Solvothermal Method to Boost Electrocatalytic Oxygen Evolution
Authors: Zhang Yao , Wang Runze , Zhu Longqi , Li Xu , Sun Caixia , Liu Haizhen , Zhu Lei , Wang Kuikui
Published: July 2023

Oxygen evolution reaction is a momentous part of electrochemical energy storage and conversion devices such as rechargeable metal–air batteries. It is particularly urgent to develop low-cost and efficient electrocatalysts for oxygen evolution reactions. As a potential substitute for noble metal electrocatalysts, transition metal selenides still prove challenging in improving the activity of oxygen evolution reaction and research into reaction intermediates. In this study, a simple one-step solvothermal method was used to prepare a polymetallic compound carbon matrix composite (Co9Se8/Ni3Se4/Fe3O4@C) with a multilayered nanosheets structure. It exhibited good OER activity in an alkaline electrolyte solution, with an overpotential of 268 mV at 10 mA/cm2. In addition, this catalyst also showed excellent performance in the 24 h stability test. The composite presents a multi-layer sheet structure, which effectively improves the contact between the active site and the electrolyte. The selenide formed by Ni and Co has a synergistic effect, and Fe3O4 and Co9Se8 form a heterojunction structure which can effectively improve the reaction activity by initiating the electronic coupling effect through the interface modification. In addition, carbon quantum dots have rich heteroatoms and electron transferability, which improves the electrochemical properties of the composites. This work provides a new strategy for the preparation of highly efficient OER electrocatalysts utilizing the multi-metal synergistic effect.
Inhomogeneity of the Backward Extruded NdFeB Ring Magnet Prepared from Amorphous Powders
Authors: Huang Weida , Xu Ke , Liao Xuefeng , Zhou Bang , Yu Hongya , Zhong Xichun , Liu Zhongwu
Published: July 2023

Back extrusion is an important process to prepare radially oriented NdFeB ring magnets. In this work, we fabricate the ring magnets using amorphous magnetic powders as the raw material. The microstructure, magnetic properties, corrosion resistance, and mechanical properties of the backward extruded magnet at different positions along the axial direction have been investigated, and the inhomogeneity of the magnet is clarified. The results showed that the grains in the middle region of the ring magnet exhibit a strong c-axis orientation, whereas the grains at the bottom and top regions are disordered with random orientation. The microstructure variation is related to the distribution of the grain boundary phase and the degree of grain deformation. Due to the microstructure difference, the magnetic properties, temperature stability, corrosion resistance, and mechanical properties in the middle region of the magnet are higher than those in the top and bottom regions. The exchange coupling between grains also varies in different regions, which is related to the grain size and grain boundary thickness. In addition, different Co element segregations were observed in different regions, which has a crucial effect on the Curie temperature and thermal stability of the magnet. The microstructure difference also leads to the variation of corrosion resistance and mechanical properties for the samples from different regions of the magnet. This work suggests that the amorphous powder can be used to directly prepare radially oriented ring magnets, and the inhomogeneity of the magnet should be fully understood.
Design, Modelling and Optimization of a High Power Density Axial Flux SRM with Reduced Torque Ripple for Electric Vehicles
Authors: Ajamloo Akbar Mohammadi , Ibrahim Mohamed N. , Sergeant Peter
Published: July 2023

Switched reluctance machines (SRMs) are potential candidates for use in the propulsion systems of electric vehicles. However, they suffer from low power density and high torque ripple. In this paper, a segmented rotor double-sided axial flux SRM (DSAFSRM) is chosen for detailed analysis. A hybrid design algorithm is proposed to take the effects of iron non-linearity into account. The proposed design procedure benefits from simplicity and high accuracy at the same time. A two-step optimization procedure is presented which minimizes the torque ripple of the DSAFSRM without jeopardizing its efficiency. The torque ripple is reduced from 120% to 35% after optimization. In the two-step optimization procedure, both geometrical and switching related parameters are investigated. Moreover, a double-sided radial flux SRM is designed and compared with the proposed DSAFSRM in terms of torque ripple, average torque, efficiency and power density. The results indicate superior performance of the optimized DSAFSRM, especially in terms of average torque, which is 26% higher than the torque produced by the double-sided radial flux SRM.
A Study on Graph Centrality Measures of Different Diseases Due to DNA Sequencing
Authors: Muhiuddin Ghulam , Samanta Sovan , Aljohani Abdulrahman F. , Alkhaibari Abeer M.
Published: July 2023

Rare genetic diseases are often caused by single-gene defects that affect various biological processes across different scales. However, it is challenging to identify the causal genes and understand the molecular mechanisms of these diseases. In this paper, we present a multiplex network approach to study the relationship between human diseases and genes. We construct a human disease network (HDN) and a human genome network (HGN) based on genotype–phenotype associations and gene interactions, respectively. We analyze 3771 rare diseases and find distinct phenotypic modules within each dimension that reflect the functional effects of gene mutations. These modules can also be used to predict novel gene candidates for unsolved rare diseases and to explore the cross-scale impact of gene perturbations. We compute various centrality measures for both networks and compare them. Our main finding is that diseases are weakly connected in the HDN, while genes are strongly connected in the HGN. This implies that diseases are relatively isolated from each other, while genes are involved in multiple biological processes. This result has implications for understanding the transmission of infectious diseases and the development of therapeutic interventions. We also show that not all diseases have the same potential to spread infections to other parts of the body, depending on their centrality in the HDN. Our results show that the phenotypic module formalism can capture the complexity of rare diseases beyond simple physical interaction networks and can be applied to study diseases arising from DNA (Deoxyribonucleic Acid) sequencing errors. This study provides a novel network-based framework for integrating multi-scale data and advancing the understanding and diagnosis of rare genetic diseases.