bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Ni/Y2O3 Nanocomposite through USP and Lyophilisation for Possible Use as Coating
Authors: Švarc Tilen , Stopić Srećko , Jelen Žiga , Zadravec Matej , Friedrich Bernd , Rudolf Rebeka
Published: April 2022

The Ni/Y2O3 catalyst showed high catalytic activity. Based on this, the aim of this study was to create Ni/Y2O3 nanocomposites powder with two innovative technologies, Ultrasonic Spray Pyrolysis (USP) and lyophilisation. In the USP process, thermal decomposition of the generated aerosols in an N2/H2 reduction atmosphere caused a complete decomposition of the nickel (II) nitrate to elemental Ni, which became trapped on the formed Y2O3 nanoparticles. The Ni/Y2O3 nanocomposite particles were captured via gas washing in an aqueous solution of polyvinylpyrrolidone (PVP) in collection bottles. PVP was chosen for its ability to stabilise nano-suspensions and as an effective cryoprotectant. Consequently, there was no loss or agglomeration of Ni/Y2O3 nanocomposite material during the lyophilisation process. The Ni/Y2O3 nanocomposite powder was analysed using ICP-MS, SEM-EDX, and XPS, which showed the impact of different precursor concentrations on the final Ni/Y2O3 nanocomposite particle composition. In a final step, highly concentrated Ni/Y2O3 nanocomposite ink (Ni/Y2O3 > 0.140 g/mL) and test coatings from this ink were prepared by applying them on a white matte photo paper sheet. The reflection curve of the prepared Ni/Y2O3 nanocomposite coating showed a local maximum at 440 nm with a value of 39% reflection. Given that Ni is located on the surface of the Ni/Y2O3 nanocomposite in the elemental state and according to the identified properties, tests of the catalytic properties of this coating will be performed in the future.
Finite Element Analysis of Rubberized Concrete Interlocking Masonry under Vertical Loading
Authors: Al-Fakih Amin , Al-Osta Mohammed A.
Published: April 2022

Fine aggregate and cement have been partially replaced by 10% and 56% crumb rubber and class F-fly ash, respectively, in order to manufacture rubberized concrete interlocking bricks (RCIBs). The newly developed product has been used for masonry construction without the need for mortar (mortarless), and the experimental testing under compression load was investigated by Al-Fakih et al. Therefore, in line with that, this study carried out finite element (FE) analysis for experimental result validation of masonry walls and prisms made of RCIBs. ANSYS software was utilized to implement the FE analysis, and a plasticity detailed micro-modeling approach was adopted. Parametric studies were carried out on masonry prisms to investigate the effect of the slenderness ratio and the elastic modulus of grout on the prism behavior. The results found that the adopted FE model has the ability to predict the structural response, such as compressive strength, stiffness, and failure mechanism, of the interlocking masonry prisms with about a 90% agreement with the experimental results. Based on the parametric studies, the compressive strength for a 6-course prism is approximately 68% less than a 3-course prism and 60% less than a 5-course prism, which means that the slenderness ratio plays a vital role in the behavior of the RCIB masonry prism under the vertical compression load. Moreover, the results showed that the difference between FE and experimental results of the walls was less than 16%, indicating a good match. The findings also reported that masonry walls and prisms experienced higher ductility measured by the post-failure loading under compression. The finite element model can be used for further investigation of masonry systems built with rubberized concrete interlocking bricks.
Interface Mechanism and Splitting Characteristics of Fiber-Reinforced Cement-Solidified Aeolian Sand
Authors: Zhang Xiangdong , Pang Shuai , Li Jun , Zhang Xuefeng , Cai Guanjun , Tian Lijun
Published: April 2022

Experimental studies on reinforcing aeolian sand with cement and fiber are lacking, and the interface mechanism and splitting characteristics thus remain unclear. Herein, the interface mechanism and splitting characteristics of fiber-reinforced, cement-solidified, aeolian sand were experimentally assessed to investigate whether glass fiber exhibits better properties as a reinforcing agent than traditional fiber-free cement-solidified aeolian sand, and whether aeolian sand is applicable as a base material in geotechnical engineering. The splitting experiments involved the use of fiber-reinforced, cement-solidified aeolian sand samples that were differentiated based on the mixing schemes used to formulate them. Based on the strengthening control technology effects on the structural performance of the fiber-reinforced, cement aeolian, sand-mixed matrix material, the internal physical and chemical mechanisms of structural performance evolution were revealed and analyzed using scanning electron microscopy images. The experimental results show that the splitting strength of the sample reaches its maximum value at a combination of 6 mm glass fiber, 3‰ fiber, and 10% cement contents. In fiber-reinforced cement-solidified aeolian sand, cement hydrate forms more needle-shaped crystal products. The crystals adhere to the fiber surfaces that interweave with each other to form a porous and dense network. Although this improves the bonding force between the fiber and aeolian sand particles, the fibers are prone to fracture and slippage during the splitting process. The three-dimensional network structure formed by overlapping fibers is critical for the improvement of the splitting strength. The study’s findings will serve as benchmarks to achieve additional improvements in glass fiber-reinforced cement-solidified aeolian sand.
Effect of Silicon on Dynamic/Static Corrosion Resistance of T91 in Lead–Bismuth Eutectic at 550 °C
Authors: Li Ji , He Xikou , Xu Bin , Tang Zhengxin , Fang Caishun , Yang Gang
Published: April 2022

The 9–12% Cr ferritic–martensitic heat-resistant steel is the main candidate structural material for the Lead-cooled Faster Reactor. The lower Gibbs free energy change of Si oxide can promote the formation of a stable oxide layer, which can improve the corrosion resistance of the material. Therefore, it is of great significance to study the effect of silicon (Si) on the corrosion resistance of T91 steel in lead–bismuth eutectic (LBE). The corrosion resistance of T91 steel with Si contents of 0.5 wt.%, 1.3 wt.%, and 2.0 wt.%, both in dynamic and static LBE at 550 °C, was investigated. The microstructure was analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), while the oxide films were characterized by electron probe microanalysis (EPMA). Results show that the addition of Si is conducive to improving the corrosion resistance of T91 steel in LBE. T91 steel with high Si content has a thinner and more stable oxide film. The change of Si content can change the contact angle between the steel and LBE, and the contact angle is the largest when the Si content is 1.3 wt.%. The Si-rich oxide layer is usually located in the inner oxide layer, which promotes the formation of a Cr oxide layer located in the internal oxidation zone (IOZ). Si will not enter the precipitated phase, but only change the ferrite content. The oxidation model of T91 steel containing Si in LBE was also proposed.
Nucleation of Helium in Liquid Lithium at 843 K and High Pressures
Authors: Martí Jordi , Mazzanti Ferran , Astrakharchik Grigori E. , Batet Lluís , Portos-Amill Laura , Pedreño Borja
Published: April 2022

Fusion energy stands out as a promising alternative for a future decarbonised energy system. In order to be sustainable, future fusion nuclear reactors will have to produce their own tritium. In the so-called breeding blanket of a reactor, the neutron bombardment of lithium will produce the desired tritium, but also helium, which can trigger nucleation mechanisms owing to the very low solubility of helium in liquid metals. An understanding of the underlying microscopic processes is important for improving the efficiency, sustainability and reliability of the fusion energy conversion process. The spontaneous creation of helium droplets or bubbles in the liquid metal used as breeding material in some designs may be a serious issue for the performance of the breeding blankets. This phenomenon has yet to be fully studied and understood. This work aims to provide some insight on the behaviour of lithium and helium mixtures at experimentally corresponding operating conditions (843 K and pressures between 108 and 1010 Pa). We report a microscopic study of the thermodynamic, structural and dynamical properties of lithium–helium mixtures, as a first step to the simulation of the environment in a nuclear fusion power plant. We introduce a new microscopic model devised to describe the formation of helium droplets in the thermodynamic range considered. Our model predicts the formation of helium droplets at pressures around 109 Pa, with radii between 1 and 2 Å. The diffusion coefficient of lithium (2 Å2/ps) is in excellent agreement with reference experimental data, whereas the diffusion coefficient of helium is in the range of 1 Å2/ps and tends to decrease as pressure increases.
Velocity and Singularity Analysis of a 5-DOF (3T2R) Parallel-Serial (Hybrid) Manipulator
Authors: Laryushkin Pavel , Antonov Anton , Fomin Alexey , Essomba Terence
Published: April 2022

This article presents the velocity and singularity analysis for a five-degree-of-freedom (5-DOF) parallel-serial manipulator. The hybrid structure of the manipulator combines a tripod-like parallel part and a serial part, represented as two carriages moving in perpendicular directions. This manipulator provides its end-effector with a 3T2R motion pattern, which includes three independent translations and two independent rotations. First, the study briefly discusses the manipulator design and the results of the position analysis. These results form the basis for the subsequent velocity and singularity analysis, performed by screw theory. The screw coordinates of the unit twists are written for each manipulator joint, and then through the reciprocal screw approach, the actuation and constraint wrenches of the manipulator are obtained by simple inspection. Based on these twists and wrenches, the paper forms the velocity equation and shows an example of the inverse velocity analysis for a given end-effector trajectory. The same example is solved by numerical differentiation to verify the proposed approach. Next, the paper investigates singular configurations by analyzing the wrench system of the manipulator and presents several conditions for serial and parallel singularities. Each condition has both a symbolic representation, given by an equation for screw coordinates of certain wrenches, and a visual representation, which shows the manipulator in a singular configuration.
Mining Campus Big Data: Prediction of Career Choice Using Interpretable Machine Learning Method
Authors: Wang Yuan , Yang Liping , Wu Jun , Song Zisheng , Shi Li
Published: April 2022

The issue of students’ career choice is the common concern of students themselves, parents, and educators. However, students’ behavioral data have not been thoroughly studied for understanding their career choice. In this study, we used eXtreme Gradient Boosting (XGBoost), a machine learning (ML) technique, to predict the career choice of college students using a real-world dataset collected in a specific college. Specifically, the data include information on the education and career choice of 18,000 graduates during their college years. In addition, SHAP (Shapley Additive exPlanation) was employed to interpret the results and analyze the importance of individual features. The results show that XGBoost can predict students’ career choice robustly with a precision, recall rate, and an F1 value of 89.1%, 85.4%, and 0.872, respectively. Furthermore, the interaction of features among four different choices of students (i.e., choose to study in China, choose to work, difficulty in finding a job, and choose to study aboard) were also explored. Several educational features, especially differences in grade point average (GPA) during their college studying, are found to have relatively larger impact on the final choice of career. These results can be of help in the planning, design, and implementation of higher educational institutions’ (HEIs) events.
Identifying Key Risk Factors in Product Development Projects
Authors: Chiu Yu-Jing , Hu Yi-Chung , Yao Chia-Yin , Yeh Chia-Hung
Published: April 2022

In a rapidly changing world, most operational processes of enterprises are conducted in the form of development projects. The development of new products is an important organizational strategy to meet consumer needs. During this process, enterprises often encounter many bottlenecks and risks that can cause delays in, and even the failure of, development projects. In this study, we developed a research framework based on relevant literature and expert interviews and then used the decision making trial and evaluation laboratory (DEMATEL) and the analytic network process (ANP) to determine the relationships among and the importance of risks in the development of new products. The results of a case study show that the six key risks of product development projects include project completion time, mastery of key technical capabilities, controlling the progress of the project, uniqueness and complexity of the project, ability to control the market, and functional integrity of the product. According to the results of importance performance analysis, six key factors were classified in the concentrate quadrant. The optoelectronic manufacturing industry should focus on reducing risks to the project. A cause-and-effect diagram shows that if an enterprise wants to improve performance in terms of these key factors, it should first improve the project completion time or the mastery of key technical capabilities. Therefore, it is appropriate to start by improving the project completion time. In this study, we developed a practical and simple decision support system that allows managers of research and development to examine the risk of projects and assess the relevant risks. A case study was also conducted to test the accuracy of the proposed risk-management method.
Using Markov-Switching Models in US Stocks Optimal Portfolio Selection in a Black–Litterman Context (Part 1)
Authors: De la Torre-Torres Oscar V. , Galeana-Figueroa Evaristo , Del Río-Rama María de la Cruz , Álvarez-García José
Published: April 2022

In this study, we tested the benefit of using Markov-Switching (M-S) models to forecast the views of the 26 most traded stocks in the US in a Black–Litterman (B–L) optimal selection context. With weekly historical data of these stocks from 1 January 1980, we estimated and simulated (from 7 January 2000, to 7 February 2022) three portfolios that used M-S views in each stock and blended them with the market equilibrium views in a B–L context. Our position was that the B–L optimal portfolios could generate alpha (extra return) against a buy-and-hold and an actively managed portfolio with sample portfolio parameters (à la Markowitz, SampP). Our results suggest that the outperformance of the B–L managed portfolios holds only in the short term. In the long-term, the performance of the B–L portfolios, the SampP, and the market portfolio are statistically equal in terms of returns or their mean–variance efficiency in an ex-ante or ex-post analysis.
Late-Onset Hypogonadism in a Male Patient with Long COVID Diagnosed by Exclusion of ME/CFS
Authors: Soejima Yoshiaki , Otsuka Yuki , Tokumasu Kazuki , Nakano Yasuhiro , Harada Ko , Nakamoto Kenta , Sunada Naruhiko , Sakurada Yasue , Hasegawa Kou , Hagiya Hideharu , Ueda Keigo , Otsuka Fumio
Published: April 2022

After the acute phase of COVID-19, some patients have been reported to have persistent symptoms including general fatigue. We have established a COVID-19 aftercare clinic (CAC) to provide care for an increasing number of these patients. Here, we report the case of a 36-year-old man who developed post-COVID fatigue after acute infection with SARS-CoV-2. In the acute phase of COVID-19, the patient’s fever resolved within four days; however, general fatigue persisted for three months, and he visited our CAC 99 days after the initial infection. Examination revealed a high Aging Male’s Symptoms (AMS) score of 44 and low free testosterone (FT) level of 5.5 pg/mL, which meet the Japanese criteria of late-onset hypogonadism (LOH) syndrome. Imaging studies revealed an atrophic pituitary in addition to fatty liver and low bone mineral density. Anterior pituitary function tests showed a low follicle-stimulating hormonelevel and delayed reaction of luteinizing hormone (LH) after gonadotropin-releasing hormone (GnRH) stimulation, indicating the possibility of hypothalamic hypogonadism in addition to primary hypogonadism seen in patients with post-COVID-19 conditions. After the initiation of Japanese traditional medicine (Kampo medicine: hochuekkito followed by juzentaihoto), the patient’s symptoms as well as his AMS score and serum FT level were noticeably improved. Furthermore, follow-up tests of GnRH stimulation revealed improvements in LH responsiveness. Although many patients have been reported to meet the criteria of ME/CFS such as our case, we emphasize the possibility of other underlying pathologies including LOH syndrome. In conclusion, LOH syndrome should be considered a cause of general fatigue in patients with post-COVID-19 conditions and herbal treatment might be effective for long COVID symptoms due to LOH (264 words).
Towards an International Consensus on the Prevention, Treatment, and Management of High-Risk Substance Use and Overdose among Youth
Authors: Krausz Michael , Westenberg Jean N. , Tsang Vivian , Suen Janet , Ignaszewski Martha J. , Mathew Nickie , Azar Pouya , Cabanis Maurice , Elsner Julie , Vogel Marc , Spijkerman Renske , Orsolini Laura , Vo Dzung , Moore Eva , Moe Jessica , Strasser Johannes , Köck Patrick , Marian Calin , Dürsteler Kenneth M. , Backmund Markus , Röhrig Jeanette , Post Marianne , Haltmayer Hans , Wladika Wolfgang , Trabi Thomas , Muller Christian , Rechberger Gerhard , Teesson Maree , Farrell Michael , Christie Grant , Merry Sally , Mamdouh Mostafa , Alinsky Rachel , Levy Sharon , Fishman Marc , Rosenthal Richard , Jang Kerry , Choi Fiona
Published: April 2022

Background and Objectives: Now more than ever, there is an obvious need to reduce the overall burden of disease and risk of premature mortality that are associated with mental health and substance use disorders among young people. However, the current state of research and evidence-based clinical care for high-risk substance use among youth is fragmented and scarce. The objective of the study is to establish consensus for the prevention, treatment, and management of high-risk substance use and overdose among youth (10 to 24 years old). Materials and Methods: A modified Delphi technique was used based on the combination of scientific evidence and clinical experience of a group of 31 experts representing 10 countries. A semi-structured questionnaire with five domains (clinical risks, target populations, intervention goals, intervention strategies, and settings/expertise) was shared with the panelists. Based on their responses, statements were developed, which were subsequently revised and finalized through three iterations of feedback. Results: Among the five major domains, 60 statements reached consensus. Importantly, experts agreed that screening in primary care and other clinical settings is recommended for all youth, and that the objectives of treating youth with high-risk substance use are to reduce harm and mortality while promoting resilience and healthy development. For all substance use disorders, evidence-based interventions should be available and should be used according to the needs and preferences of the patient. Involuntary admission was the only topic that did not reach consensus, mainly due to its ethical implications and resulting lack of comparable evidence. Conclusions: High-risk substance use and overdoses among youth have become a major challenge. The system’s response has been insufficient and needs substantial change. Internationally devised consensus statements provide a first step in system improvement and reform.
Elucidating the Water and Methanol Dynamics in Sulfonated Polyether Ether Ketone Nanocomposite Membranes Bearing Layered Double Hydroxides
Authors: Lufrano Ernestino , Nicotera Isabella , Enotiadis Apostolos , Ur Rehman Muhammad Habib , Simari Cataldo
Published: April 2022

Conventional Nafion membranes demonstrate a strong affinity for methanol, resulting in a high fuel crossover, poor mechanical stability, and thus poor performance in direct methanol fuel cells (DMFCs). This study involves the synthesis and physiochemical characterization of an alternative polymer electrolyte membrane for DMFCs based on sulfonated poly(ether ether ketone) and a layered double hydroxide (LDH) material. Nanocomposite membranes (sPL), with filler loading ranging between 1 wt% and 5 wt%, were prepared by simple solution intercalation and characterized by XRD, DMA, swelling tests, and EIS. For the first time, water and methanol mobility inside the hydrophilic channels of sPEEK-LDH membranes were characterized by NMR techniques. The introduction of LDH nanoplatelets improved the dimensional stability while having a detrimental effect on methanol mobility, with its self-diffusion coefficient almost two orders of magnitude lower than that of water. It is worth noting that anionic lamellae are directly involved in the proton transport mechanism, thus enabling the formation of highly interconnected paths for proton conduction. In this regard, sPL3 yielded a proton conductivity of 110 mS cm−1 at 120 °C and 90% RH, almost attaining the performance of the Nafion benchmark. The nanocomposite membrane also showed an excellent oxidative stability (over more than 24 h) during Fenton’s test at 80 °C. These preliminary results demonstrate that an sPL3 nanocomposite can be potentially and successfully applied in DMFCs.
Influence of Cell Opening Methods on Electrolyte Removal during Processing in Lithium-Ion Battery Recycling
Authors: Werner Denis Manuel , Mütze Thomas , Peuker Urs Alexander
Published: April 2022

Lithium-ion batteries (LIBs) are an important pillar for the sustainable transition of the mobility and energy storage sector. LIBs are complex devices for which waste management must incorporate different recycling technologies to produce high-quality secondary (raw) materials at high recycling efficiencies (RE). This contribution to LIB recycling investigated the influence of different pretreatment strategies on the subsequent processing. The experimental study combined different dismantling depths and depollution temperatures with subsequent crushing and thermal drying. Therein, the removal of organic solvent is quantified during liberation and separation. This allows to evaluate the safety of cell opening according to the initial depollution status. These process steps play a key role in the recycling of LIBs when using the low-temperature route. Therefore, combinations of pretreatment and processing steps regarding technical and economic feasibility are discussed. Moreover, the process medium and equipment properties for a safe cell opening, the technical recycling efficiencies and their consequences on future industrial LIB waste management are pointed out.
Electrochemical Kinetic Analysis of Carbon Steel Powders Produced by High-Energy Ball Milling
Authors: Soliz Alvaro , Guzmán Danny , Cáceres Luis , Madrid Felipe M. Galleguillos
Published: April 2022

This work reports on the electrochemical kinetic analysis of carbon steel powders produced during the milling of carbon steel chips for 2, 3, and 5 h under an air atmosphere in a high-energy ball miller. This work aims to fill the gap in the literature regarding the transformation processes that affect carbon steel powder production. This information can be crucial for specific powder metallurgy systems. The results obtained using the Rietveld refinement method showed a decrease in the crystallite size, an increase in the microstrain, and no changes in the lattice parameter with the milling process. The electrochemical results revealed a strong influence of anodic electroactivity with milling time in NaCl solution, in contrast with NaOH, where the influence of the milling process was not significant. These results clearly show the significant role of chloride ions in preventing the formation of a passive film in milling with NaCl solution and in contrast to the formation of a passive film that notoriously inhibits both the anodic and cathodic reactions in milling with NaOH solution. The novelty of this work lies in the experimental demonstration of milling’s influence on the surface properties of carbon steel powders that directly affect their electrochemical response.
Corrosion Behavior of Passivated CUSTOM450 and AM350 Stainless Steels for Aeronautical Applications
Authors: Samaniego-Gámez Oliver , Almeraya-Calderón Facundo , Chacón-Nava José , Maldonado-Bandala Erick , Nieves-Mendoza Demetrio , Flores-De los Rios Juan Pablo , Jáquez-Muñoz Jesús Manuel , Delgado Anabel D. , Gaona-Tiburcio Citlalli
Published: April 2022

Custom 450 stainless steel and AM 350 stainless steel are both precipitation hardening stainless steels, which are widely used in a variety of aerospace applications. The former steel exhibits very good corrosion resistance with moderate strength, whereas the latter is used for applications requiring high strength along with corrosion resistance. In this study, the corrosion behavior of CUSTOM 450 and AM 350 stainless steels passivated in (a) citric acid and (b) nitric acid solutions for 50 and 75 min at 49 and 70 °C, and subsequently exposed in 5 wt. % NaCl and 1 wt. % H2SO4 solutions are investigated. Two electrochemical techniques were used: electrochemical noise (EN) and electrochemical impedance spectroscopy (EIS) according to ASTM G199-09 and ASTM G106-13, respectively. The results indicated that passivation in nitric acid made the surface prone to localized corrosion. Statistical and PSD values showed a tendency toward pitting corrosion. On the whole, passivated CUSTOM 450 stainless steel showed the best corrosion behavior in both, NaCl and H2SO4 test solutions.
Cyborg Moth Flight Control Based on Fuzzy Deep Learning
Authors: Yang Xiao , Jiang Xun-Lin , Su Zheng-Lian , Wang Ben
Published: April 2022

Cyborg insect control methods can be divided into invasive methods and noninvasive methods. Compared to invasive methods, noninvasive methods are much easier to implement, but they are sensitive to complex and highly uncertain environments, for which classical control methods often have low control accuracy. In this paper, we present a noninvasive approach for cyborg moths stimulated by noninvasive ultraviolet (UV) rays. We propose a fuzzy deep learning method for cyborg moth flight control, which consists of a Behavior Learner and a Control Learner. The Behavior Learner is further divided into three hierarchies for learning the species’ common behaviors, group-specific behaviors, and individual-specific behaviors step by step to produce the expected flight parameters. The Control Learner learns how to set UV ray stimulation to make a moth exhibit the expected flight behaviors. Both the Control Learner and Behavior Learner (including its sub-learners) are constructed using a Pythagorean fuzzy denoising autoencoder model. Experimental results demonstrate that the proposed approach achieves significant performance advantages over the state-of-the-art approaches and obtains a high control success rate of over 83% for flight parameter control.
Sources of Hydrothermal Fluids Inferred from Oxygen and Carbon Isotope Composition of Calcite, Keweenaw Peninsula Native Copper District, Michigan, USA
Authors: Bodden Thomas , Bornhorst Theodore , Bégué Florence , Deering Chad
Published: April 2022

The Mesoproterozoic North American Midcontinent Rift hosts the world’s largest accumulation of native copper in Michigan’s Keweenaw Peninsula. During a regional metamorphogenic-hydrothermal event, native copper was deposited along with spatially zoned main-stage minerals in a thermal high. This was followed by deposition of late-stage minerals including minor copper sulfide. Inferences from the oxygen and carbon isotopic composition of main-stage hydrothermal fluids, as calculated from 296 new and compiled isotopic measurements on calcite, are consistent with existing models that low-sulfur saline native copper ore-forming fluids were dominantly derived by burial metamorphic processes from the very low sulfur basalt-dominated rift fill at depth below the native copper deposits. Co-variation of oxygen and carbon isotopic compositions are consistent with mixing of metamorphic-derived fluids with two additional isotopically different fluids. One of these is proposed to be evolved seawater that provided an outside source of salinity. This fluid mixed at depth and participated in the formation of a well-mixed hybrid metamorphic-dominated ore-forming fluid. Secondary Ion Mass Spectrometry in-situ isotopic analyses of calcite demonstrate a high degree of variability within samples that is attributed to variable degrees of shallow mixing of the hybrid ore-forming fluid with sulfur-poor, reduced evolved meteoric water in the zone of precipitation. The oxygen and carbon isotopic compositions of 100 new and compiled measurements on late-stage calcite are mostly isotopically different than the main-stage hydrothermal fluids. The late-stage hydrothermal fluids are interpreted as various proportions of mixing of evolved meteoric water, main-stage hybrid ore-forming fluid, and shallow, evolved seawater in the relatively shallow zone of precipitation.
Chemical Characterization of the Roman Glass Finds from Muricelle Archaeological Site (Luzzi, Cosenza)
Authors: De Francesco Anna Maria , La Marca Antonio , Colelli Carmelo , Barca Donatella
Published: April 2022

This study reports the results obtained on seventeen glass finds collected from the archaeological site of Muricelle near Cosenza in Calabria (Italy), dated between the first and third century AD. Chemical characterization was undertaken by using an electron probe micro analyser (EPMA). The glasses showed a soda–lime–silica composition indicating the use of the natron as a flux. The comparison between the collected data and those on coeval finds available from the literature allowed us to subdivide the Muricelle glass into three compositional groups: (1) Mn_a, classified as Roman-Mn glasses; (2) Mn_b, which can be compared to the Mn-unintentionally coloured Roman glasses; and (3) Sb + Mn, obtained by the recycling of the Sb and Mn Roman-type glasses. These groups were different not only with respect to the contents and the types of decolourants but also for soda, lime, and aluminium contents, highlighting the use of different raw materials in the primary glass production and also indicating the procedures used in secondary glass production. The compositional characteristics suggested the Levant region as the primary glass source for the Mn_a and Mn_b groups. On the other hand, the Sb + Mn group was obtained through recycling, involving the melting and mixing of two types of primary glass (Sb-decolourised and Mn-decolourised) of Egyptian and Levantine origins, respectively.
Rosmarinus officinalis L. Leaf Extracts and Their Metabolites Inhibit the Aryl Hydrocarbon Receptor (AhR) Activation In Vitro and in Human Keratinocytes: Potential Impact on Inflammatory Skin Diseases and Skin Cancer
Authors: Kallimanis Panagiotis , Chinou Ioanna , Panagiotopoulou Angeliki , Soshilov Anatoly A. , He Guochun , Denison Michael S. , Magiatis Prokopios
Published: April 2022

Aryl hydrocarbon receptor (AhR) activation by environmental agents and microbial metabolites is potentially implicated in a series of skin diseases. Hence, it would be very important to identify natural compounds that could inhibit the AhR activation by ligands of microbial origin as 6-formylindolo[3,2-b]carbazole (FICZ), indirubin (IND) and pityriazepin (PZ) or the prototype ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Five different dry Rosmarinus officinalis L. extracts (ROEs) were assayed for their activities as antagonists of AhR ligand binding with guinea pig cytosol in the presence of [3H]TCDD. The methanolic ROE was further assayed towards CYP1A1 mRNA induction using RT-PCR in human keratinocytes against TCDD, FICZ, PZ, and IND. The isolated metabolites, carnosic acid, carnosol, 7-O-methyl-epi-rosmanol, 4′,7-O-dimethylapigenin, and betulinic acid, were assayed for their agonist and antagonist activity in the presence and absence of TCDD using the gel retardation assay (GRA). All assayed ROE extracts showed similar dose-dependent activities with almost complete inhibition of AhR activation by TCDD at 100 ppm. The methanol ROE at 10 ppm showed 99%, 50%, 90%, and 85% inhibition against TCDD, FICZ, IND, and PZ, respectively, in human keratinocytes. Most assayed metabolites exhibited dose-dependent antagonist activity. ROEs inhibit AhR activation by TCDD and by the Malassezia metabolites FICZ, PZ, and IND. Hence, ROE could be useful for the prevention or treatment of skin diseases mediated by activation of AhR.
Components of Banisteriopsis caapi, a Plant Used in the Preparation of the Psychoactive Ayahuasca, Induce Anti-Inflammatory Effects in Microglial Cells
Authors: Santos Beatriz Werneck Lopes , Moreira Daniel Carneiro , Borges Tatiana Karla dos Santos , Caldas Eloisa Dutra
Published: April 2022

Banisteriopsis caapi is used to prepare the psychoactive beverage ayahuasca, and both have therapeutic potential for the treatment of many central nervous system (CNS) conditions. This study aimed to isolate new bioactive compounds from B. caapi extract and evaluate their biological activity, and that of the known β-carboline components of the plant (harmine, harmaline, and tetrahydroharmine), in BV-2 microglial cells, the in vivo activation of which is implicated in the physiopathology of CNS disorders. B. caapi extract was fractionated using semipreparative liquid chromatography (HPLC-DAD) and the exact masses ([M + H]+m/z) of the compounds in the 5 isolated fractions were determined by high-resolution LC-MS/MS: F1 (174.0918 and 233.1289), F2 (353.1722), F3 (304.3001), F4 (188.1081), and F5 (205.0785). Harmine (75.5–302 µM) significantly decreased cell viability after 2 h of treatment and increased the number of necrotic cells and production of reactive oxygen species at equal or lower concentrations after 24 h. F4 did not impact viability but was also cytotoxic after 24 h. Most treatments reduced proinflammatory cytokine production (IL-2, IL-6, IL-17, and/or TNF), especially harmaline and F5 at 2.5 µM and higher concentrations, tetrahydroharmine (9.3 µM and higher), and F5 (10.7 µM and higher). The results suggest that the compounds found in B. caapi extract have anti-inflammatory potential that could be explored for the development of treatments for neurodegenerative diseases.
A Robust Fermentation Process for Natural Chocolate-like Flavor Production with Mycetinis scorodonius
Authors: Rigling Marina , Heger Fabienne , Graule Maria , Liu Zhibin , Zhang Chen , Ni Li , Zhang Yanyan
Published: April 2022

Submerged fermentation of green tea with the basidiomycete Mycetinis scorodonius resulted in a pleasant chocolate-like and malty aroma, which could be a promising chocolate flavor alternative to current synthetic aroma mixtures in demand of consumer preferences towards healthy natural and ‘clean label’ ingredients. To understand the sensorial molecular base on the chocolate-like aroma formation, key aroma compounds of the fermented green tea were elucidated using a direct immersion stir bar sorptive extraction combined with gas chromatography–mass spectrometry–olfactometry (DI-SBSE-GC-MS-O) followed by semi-quantification with internal standard. Fifteen key aroma compounds were determined, the most important of which were dihydroactinidiolide (odor activity value OAV 345), isovaleraldehyde (OAV 79), and coumarin (OAV 24), which were also confirmed by a recombination study. Furthermore, effects of the fermentation parameters (medium volume, light protection, agitation rate, pH, temperature, and aeration) on the aroma profile were investigated in a lab-scale bioreactor at batch fermentation. Variation of the fermentation parameters resulted in similar sensory perception of the broth, where up-scaling in volume evoked longer growth cycles and aeration significantly boosted the concentrations yet added a green note to the overall flavor impression. All findings prove the robustness of the established fermentation process with M. scorodonius for natural chocolate-like flavor production.
Mechanisms of Penetration Enhancement and Transport Utilizing Skin Keratine Liposomes for the Topical Delivery of Licochalcone A
Authors: Wu Wenfeng , Wang Zhuxian , Wu Yufan , Wu Huiyi , Chen Tingting , Xue Yaqi , Wang Yuan , Jiang Cuiping , Shen Chunyan , Liu Li , Zhu Hongxia , Liu Qiang
Published: April 2022

Keratin liposomes have emerged as a useful topical drug delivery system given theirenhanced ability to penetrate the skin, making them ideal as topical drug vehicles. However, the mechanisms of the drug penetration enhancement of keratin liposomes have not been clearly elucidated. Therefore, licochalcone A(LA)-loaded skin keratin liposomes (LALs) were prepared to investigate their mechanisms of penetration enhancement on the skin and inB16F10 cells. Skin deposition studies, differential scanning calorimetry (DSC), attenuated total reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and skin distribution and intracellular distribution studies were carried out to demonstrate the drug enhancement mechanisms of LALs. We found that the optimal application of LALs enhanced drug permeation via alterations in the components, structure, and thermodynamic properties of the stratum corneum (SC), that is, by enhancing the lipid fluidization, altering the skin keratin, and changing the thermodynamic properties of the SC. Moreover, hair follicles were the main penetration pathways for the LA delivery, which occurred in a time-dependent manner. In the B16F10 cells, the skin keratin liposomes effectively delivered LA into the cytoplasm without cytotoxicity. Thus, LAL nanoparticles are promising topical drug delivery systems for pharmaceutical and cosmetic applications.
Bioactive Hydrolysates from Chlorella vulgaris: Optimal Process and Bioactive Properties
Authors: Cunha Sara A. , Coscueta Ezequiel R. , Nova Paulo , Silva Joana Laranjeira , Pintado Maria Manuela
Published: April 2022

Microalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC50 for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.
Quantification of Structural Integrity and Stability Using Nanograms of Protein by Flow-Induced Dispersion Analysis
Authors: Pedersen Morten E. , Østergaard Jesper , Jensen Henrik
Published: April 2022

In the development of therapeutic proteins, analytical assessment of structural stability and integrity constitutes an important activity, as protein stability and integrity influence drug efficacy, and ultimately patient safety. Existing analytical methodologies solely rely on relative changes in optical properties such as fluorescence or scattering upon thermal or chemical perturbation. Here, we present an absolute analytical method for assessing protein stability, structure, and unfolding utilizing Taylor dispersion analysis (TDA) and LED-UV fluorescence detection. The developed TDA method measures the change in size (hydrodynamic radius) and intrinsic fluorescence of a protein during in-line denaturation with guanidinium hydrochloride (GuHCl). The conformational stability of the therapeutic antibody adalimumab and human serum albumin were characterized as a function of pH. The simple workflow and low sample consumption (40 ng protein per data point) of the methodology make it ideal for assessing protein characteristics related to stability in early drug development or when having a scarce amount of sample available.
Using Big Data Analytics to “Back Engineer” Protein Conformational Selection Mechanisms
Authors: Gupta Shivangi , Baudry Jerome , Menon Vineetha
Published: April 2022

In the living cells, proteins bind small molecules (or “ligands”) through a “conformational selection” mechanism, where a subset of protein structures are capable of binding the small molecules well while most other protein structures are not capable of such binding. The present work uses machine learning approaches to identify, in a very large amount of protein:ligand complexes, what protein properties are associated with their capacity to bind small molecules. In order to do so, we calculate 40 physicochemical properties on about 1.5 millions of protein conformations: ligand and protein conformations. This work describes a machine learning approach to identify the unique physico-chemical descriptors of a protein that maximize the prediction rate of potential protein molecular conformations for the test case proteins ADORA2A (Adenosine A2a Receptor), ADRB2 (Adrenoceptor Beta 2) and OPRK1 (Opioid Receptor Kappa 1). We find adequate machine learning techniques can increase by an order of magnitude the identification of “binding protein conformations” in an otherwise very large ensemble of protein conformations, compared to random selection of protein conformations. This opens the door to the systematic identification of such “binding conformations” for proteins and provides a big data approach to the conformational selection mechanism.
A Consensus Compound/Bioactivity Dataset for Data-Driven Drug Design and Chemogenomics
Authors: Isigkeit Laura , Chaikuad Apirat , Merk Daniel
Published: April 2022

Publicly available compound and bioactivity databases provide an essential basis for data-driven applications in life-science research and drug design. By analyzing several bioactivity repositories, we discovered differences in compound and target coverage advocating the combined use of data from multiple sources. Using data from ChEMBL, PubChem, IUPHAR/BPS, BindingDB, and Probes & Drugs, we assembled a consensus dataset focusing on small molecules with bioactivity on human macromolecular targets. This allowed an improved coverage of compound space and targets, and an automated comparison and curation of structural and bioactivity data to reveal potentially erroneous entries and increase confidence. The consensus dataset comprised of more than 1.1 million compounds with over 10.9 million bioactivity data points with annotations on assay type and bioactivity confidence, providing a useful ensemble for computational applications in drug design and chemogenomics.
The Influence of Ionic Liquids Adsorption on the Electronic and Optical Properties of Phosphorene and Arsenene with Different Phases: A Computational Study
Authors: Zhu Lin , Fu Aiping
Published: April 2022

Density functional theory (DFT) calculations have been performed to investigate the interfacial interactions of ionic liquids (ILs) on the α- and β-phases of phosphorene (P) and arsenene (As). Nine representative ILs based on the combinations of 1-ethyl-3-methylimidazolium ([EMIM]+), N-methylpyridinium ([MPI]+), and trimethylamine ([TMA]+) cations paired to tetrafluoroborate ([BF4]−), trifluoromethanesulfonate ([TFO]−), and chloridion (Cl−) anions were used as adsorbates on the 2D P and As nanosheets with different phases to explore the effect of IL adsorption on the electronic and optical properties of 2D materials. The calculated structure, adsorption energy, and charge transfer suggest that the interaction between ILs and P and As nanosheets is dominated by noncovalent forces, and the most stable adsorption structures are characterized by the simultaneous interaction of the cation and anion with the surface, irrespective of the types of ILs and surfaces. Furthermore, the IL adsorption leads to the larger change in the electronic properties of β-phase P and As than those of their α-phase counterparts, which demonstrates that the adsorption properties are not only related to the chemical elements, but also closely related to the phase structures. The present results provide insight into the further applications of ILs and phosphorene (arsenene) hybrid materials.
Improving Discharge Voltage of Al-Air Batteries by Ga3+ Additives in NaCl-Based Electrolyte
Authors: Gu Yingying , Liu Yingjie , Tong Yunwei , Qin Zhenbo , Wu Zhong , Hu Wenbin
Published: April 2022

The application of NaCl-based aluminum-air batteries is limited due to the passivation of the aluminum anode. In an effort to solve this problem, this work studied the influence of different concentrations of Ga3+ additives on the discharge behavior of Al in the NaCl electrolyte. The results of both experiments and theoretical calculations have shown that commercial purity aluminum could be significantly activated by Ga3+. Based on microstructure observations and electrochemical impedance spectroscopy, the influence activation mechanism of Ga3+ on the discharge behavior of commercial purity Al is clarified. The addition of Ga3+ biased the surface charge of aluminum along the activation direction, forming activation sites, and then destroyed the surface passivation film. Due to the formation of a gallium–aluminum amalgam, the Al-air battery had the best discharge characteristics in the electrolyte with 0.2 M Ga3+, and its discharge voltage reached 0.9734 V with a remarkable increase compared with that of NaCl solution (0.4228 V). Therefore, Ga3+ additive is a promising choice for NaCl-based Al-air batteries to improve their discharge voltage.