bluuebunny/crossref_metadata_2025 huggingface dataset:
BIPMIN: A Gamified Framework for Process Modeling Education
Authors: Bedwell Kylie , Garaccione Giacomo , Coppola Riccardo , Ardito Luca , Morisio Maurizio
Published: December 2022

Business Process Modeling is a skill that is becoming sought after for computer engineers, with Business Process Modeling Notation (BPMN) being one example of the tools used in modeling activities. Students of the Master of Computer Engineering course at Politecnico di Torino learn about BPMN in dedicated courses but often underperform on BPMN-related exercises due to difficulties understanding how to model processes. In recent years, there has been a surge of studies that employ gamification (using game elements in non-recreative contexts to obtain benefits) as a tool in Computer Engineering education to increase students’ engagement with the learning process. This study aims to use the principles of gamification to design a supplementary learning tool for the teaching of information systems technology. In particular, to improve student understanding and use of BPMN diagrams. This study also analyzes the usability and motivation of the participants in using different game elements in increasing student motivation and performance. As part of the study, a prototype web application was developed, which implemented three different designs, each incorporating different game elements relating to either progress, competition, or rewards. An evaluation was then conducted on the prototype to evaluate the performance of the practitioners in performing BPMN modeling tasks with the gamified tool, the usability of the proposed mechanics and the enjoyment of the individual game mechanics that were implemented. With the usage of the gamified tool, the users of the experimental sample were able to complete BPMN modeling tasks with performances compatible with estimates made through expert judgement (i.e., gamification had no negative effect on performance), and were motivated to check the correctness of their models many times during the task execution. The system was evaluated as highly usable (85.8 System Usability Score); the most enjoyed game elements were rewards, levels, progress bars and aesthetics.
Exploiting Polyelectrolyte Complexation for the Development of Adhesive and Bioactive Membranes Envisaging Guided Tissue Regeneration
Authors: Fonseca Mário C. , Vale Ana Catarina , Costa Rui R. , Reis Rui L. , Alves Natália M.
Published: December 2022

Mussels secrete protein-based byssal threads to tether to rocks, ships, and other organisms underwater. The secreted marine mussel adhesive proteins (MAPs) contain the peculiar amino acid L-3,4-dihydroxyphenylalanine (DOPA), whose catechol group content contributes greatly to their outstanding adhesive properties. Inspired by such mussel bioadhesion, we demonstrate that catechol-modified polysaccharides can be used to obtain adhesive membranes using the compaction of polyelectrolyte complexes (CoPEC) method. It is a simple and versatile approach that uses polyelectrolyte complexes as building blocks that coalesce and dry as membrane constructs simply as a result of sedimentation and mild temperature. We used two natural and biocompatible polymers: chitosan (CHI) as a polycation and hyaluronic acid (HA) as a polyanion. The CoPEC technique also allowed the entrapment of ternary bioactive glass nanoparticles to stimulate mineralization. Moreover, combinations of these polymers modified with catechol groups were made to enhance the adhesive properties of the assembled membranes. Extensive physico-chemical characterization was performed to investigate the successful production of composite CoPEC membranes in terms of surface morphology, wettability, stability, mechanical performance, in vitro bioactivity, and cellular behavior. Considering the promising properties exhibited by the obtained membranes, new adhesives suitable for the regeneration of hard tissues can be envisaged.
Impact of Autogenous Demineralized Dentin Matrix on Mandibular Second Molar after Third Molar Extraction: Retrospective Study
Authors: Kim Yesel , Ku Jeong-Kui , Um In-Woong , Seok Hyun , Leem Dae Ho
Published: December 2022

The purpose of this retrospective study was to evaluate bone healing after autogenous demineralized dentin matrix (DDM) grafts, focusing on the distal root of the mandibular second molar after the extraction of the third. We included retrospective data from 20 patients who had undergone molar extractions (15 male, 41.9 ± 12.0 years) between January 2020 and September 2022 and had DDM grafts implanted on the extraction socket, immediately (“immediate graft”) or 6 weeks (“delayed graft”) after the first surgery without primary closure. Patients who underwent grafting on only one side were used as the control group (n = 4). Bone defects at the mandibular second molar were measured preoperatively and 4 months after the graft surgery using cone-beam computed tomography (CBCT). Improvement of bone defect (i.e., the change in the bony defect pre- vs. postoperatively) was compared between the control and graft groups using the Wilcoxon Signed Rank test, and the difference between immediate and delayed grafts was analyzed with the Mann-Whitney U test. Complications such as infections or graft failure did not occur. Although pre-operative defects were smaller in the control than in the graft group (2.98 ± 1.77 and 10.02 ± 3.22 mm, p = 0.001), post-operative defects were similar in both (2.12 ± 0.59 and 2.29 ± 1.67 mm, respectively). The improvement ratio was not statistically significant in the control group (22.68 ± 15.36%) but a difference was observed in the graft group (76.70 ± 15.36%, p = 0.001). The amount of improvement of bone defect was not affected by graft timing or patient sex. In conclusion, DDM can improve bone defect at the distal aspect of the mandibular second molar after third molar extraction.
cMetS Based on Z-Scores as an Accurate and Efficient Scoring System to Determine Metabolic Syndrome in Spanish Adolescents
Authors: Fernández-Aparicio Ángel , Perona Javier S. , Schmidt-RioValle Jacqueline , Montero-Alonso Miguel A. , Navarro-Pérez Carmen Flores , González-Jiménez Emilio
Published: December 2022

The definition of metabolic syndrome (MetS) based on dichotomous cut-off points is efficient in the adult population. However, to date, there is no international consensus on how to define MetS in the pediatric population. For that reason, a continuous MetS score (cMetS) has been proposed for the pediatric population. However, despite multiple attempts, cMetS has not been fully validated as there is no agreement about the most accurate score to calculate it. The purpose of the present study was to compare the validity of different scores (three siMS scores, z-score, principal components analysis (PCA), the sum of PCA, and confirmatory factor analysis) to calculate cMetS and determine MetS in Spanish adolescents. There were 981 subjects, ranging 11–16 years old, recruited for this cross-sectional study. Seven different approaches to pediatric cMetS scores were calculated. All cMetS scores calculated strongly correlated with each other, especially siMS scores. The area under the curve obtained from receiving operating characteristic curves was particularly elevated for z-scores 0.81 (95% CI: 0.784–0.838), showing a specificity of 64.4%. Our study shows that cMetS based on z-scores is accurate and efficient to be used for research instead of the dichotomized definition of MetS in adolescents; and cMetS based on siMS scores is useful for clinical practice.
Bioassay-Guided Fractionation Leads to the Detection of Cholic Acid Generated by the Rare Thalassomonas sp.
Authors: Pheiffer Fazlin , Schneider Yannik , Hansen Espen , Andersen Jeanette , Isaksson Johan , Busche Tobias , Rückert Christian , Kalinowski Jörn , Zyl Leonardo , Trindade Marla
Published: December 2022

Bacterial symbionts of marine invertebrates are rich sources of novel, pharmaceutically relevant natural products that could become leads in combatting multidrug-resistant pathogens and treating disease. In this study, the bioactive potential of the marine invertebrate symbiont Thalassomonas actiniarum was investigated. Bioactivity screening of the strain revealed Gram-positive specific antibacterial activity as well as cytotoxic activity against a human melanoma cell line (A2058). The dereplication of the active fraction using HPLC-MS led to the isolation and structural elucidation of cholic acid and 3-oxo cholic acid. T. actiniarum is one of three type species belonging to the genus Thalassomonas. The ability to generate cholic acid was assessed for all three species using thin-layer chromatography and was confirmed by LC-MS. The re-sequencing of all three Thalassomonas type species using long-read Oxford Nanopore Technology (ONT) and Illumina data produced complete genomes, enabling the bioinformatic assessment of the ability of the strains to produce cholic acid. Although a complete biosynthetic pathway for cholic acid synthesis in this genus could not be determined based on sequence-based homology searches, the identification of putative penicillin or homoserine lactone acylases in all three species suggests a mechanism for the hydrolysis of conjugated bile acids present in the growth medium, resulting in the generation of cholic acid and 3-oxo cholic acid. With little known currently about the bioactivities of this genus, this study serves as the foundation for future investigations into their bioactive potential as well as the potential ecological role of bile acid transformation, sterol modification and quorum quenching by Thalassomonas sp. in the marine environment.
Bactericide Activity of Cellulose Acetate/Silver Nanoparticles Asymmetric Membranes: Surfaces and Porous Structures Role
Authors: Figueiredo Ana Sofia , Ferraria Ana Maria , Botelho do Rego Ana Maria , Monteiro Silvia , Santos Ricardo , Minhalma Miguel , Sánchez-Loredo María Guadalupe , Tovar-Tovar Rosa Lina , de Pinho Maria Norberta
Published: December 2022

The antibacterial properties of cellulose acetate/silver nanoparticles (AgNP) ultrafiltration membranes were correlated with their integral asymmetric porous structures, emphasizing the distinct features of each side of the membranes, that is, the active and porous layers surfaces. Composite membranes were prepared from casting solutions incorporating polyvinylpyrrolidone-covered AgNP using the phase inversion technique. The variation of the ratio acetone/formamide and the AgNP content resulted in a wide range of asymmetric porous structures with different hydraulic permeabilities. Comprehensive studies assessing the antibacterial activity against Escherichia coli (cell death and growth inhibition of bacteria in water) were performed on both membrane surfaces and in E. coli suspensions. The results were correlated with the surface chemical composition assessed by XPS. The silver-free membranes presented a generalized growth of E. coli, which is in contrast with the inhibition patterns displayed by the membranes containing AgNP. For the surface bactericide test, the growth inhibition depends on the accessibility of E. coli to the silver present in the membrane; as the XPS results show, the more permeable membranes (CA30 and CA34 series) have higher silver signal detected by XPS, which is correlated with a higher growth inhibition. On the other hand, the inhibition action is independent of the membrane porous structure when the membrane is deeply immersed in an E. coli inoculated suspension, presenting almost complete growth inhibition.
Investigation of the Therapeutic Effect of Total Alkaloids of Corydalis saxicola Bunting on CCl4-Induced Liver Fibrosis in Rats by LC/MS-Based Metabolomics Analysis and Network Pharmacology
Authors: Wang Qianyi , Luo Zhuo , Li Danfeng , Qin Jinghua , Pan Ziping , Guo Bingjian , Deng Lijun , Nong Yunyuan , Huang Zheng , He Ying , Guo Hongwei , Zhu Dan , Liang Yonghong , Su Zhiheng
Published: December 2022

Liver fibrosis is a pathological result of liver injury that usually leads to a pathophysiological wound healing response. The total alkaloids of Corydalis saxicola Bunting (TACS) have been used for hepatoprotective effects on the liver. However, its exact therapeutic mechanisms of liver fibrosis are not yet well understood. To explore the potential anti-fibrosis mechanism of TACS, metabolomics coupled with network pharmacology were applied to reveal the underlying mechanisms. Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with multivariate statistical analyses were performed to estimate changes in metabolic profiles. As a result, a total of 23 metabolites in rats with liver fibrosis were altered; of these, 11 had been downregulated and 12 had been upregulated compared with the control group. After TACS treatment, the levels of 13 metabolites were significantly restored compared with the CCl4-treated group, of which 4 metabolites were up-regulated and 9 metabolites were down-regulated. Many of these metabolites are involved in the bile acid metabolism, glutathione metabolism, tryptophan metabolism and purine metabolism. Then, three key targets, including cytochrome P450 family1 subfamily A member 1 (CYP1A1), ornithine decarboxylase 1 (OCD1) and monoamine oxidase Type B (MAOB) were predicted as potential therapeutic targets of TACS against liver fibrosis through network pharmacology analysis. Finally, palmatine, tetrahydropalmatine and dehydrocavidine were screened as potential active compounds responsible for the anti-fibrosis effect of TACS by molecular docking analysis. This study reveals that TACS exerted anti-fibrosis effects by regulating the liver metabolic pathway with multiple components and multiple targets, which is helpful to further clarify the hepatoprotective mechanisms of natural plant extracts.
Comprehensive Investigation of Electrical and Optical Characteristics of InGaN-Based Flip-Chip Micro-Light-Emitting Diodes
Authors: Lee Chang-Cheng , Huang Chun-Wei , Liao Po-Hsiang , Huang Yu-Hsin , Huang Ching-Liang , Lin Kuan-Heng , Wu Chung-Chih
Published: December 2022

Micro-light-emitting diodes (micro-LEDs) have been regarded as the important next-generation display technology, and a comprehensive and reliable modeling method for the design and optimization of characteristics of the micro-LED is of great use. In this work, by integrating the electrical simulation with the optical simulation, we conduct comprehensive simulation studies on electrical and optical/emission properties of real InGaN-based flip-chip micro-LED devices. The integrated simulation adopting the output of the electrical simulation (e.g., the non-uniform spontaneous emission distribution) as the input of the optical simulation (e.g., the emission source distribution) can provide more comprehensive and detailed characteristics and mechanisms of the micro-LED operation than the simulation by simply assuming a simple uniform emission source distribution. The simulated electrical and emission properties of the micro-LED were well corroborated by the measured properties, validating the effectiveness of the simulation. The reliable and practical modeling/simulation methodology reported here shall be useful to thoroughly investigate the physical mechanisms and operation of micro-LED devices.
Improved Optical and Electrical Characteristics of GaN-Based Micro-LEDs by Optimized Sidewall Passivation
Authors: Zhu Zhifang , Tao Tao , Liu Bin , Zhi Ting , Chen Yang , Yu Junchi , Jiang Di , Xu Feifan , Sang Yimeng , Yan Yu , Xie Zili , Zhang Rong
Published: December 2022

GaN-based Micro-LED has been widely regarded as the most promising candidate for next generation of revolutionary display technology due to its advantages of high efficiency, high brightness and high stability. However, the typical micro-fabrication process would leave a great number of damages on the sidewalls of LED pixels, especially for Micro-LEDs, thus reducing the light emitting efficiency. In this paper, sidewall passivation methods were optimized by using acid-base wet etching and SiO2 layer passivation. The optical and electrical characteristics of optimized Micro-LEDs were measured and analyzed. The internal quantum efficiency (IQE) of Micro-LED was increased to 85.4%, and the reverse leakage current was reduced down to 10−13 A at −5 V. Optimized sidewall passivation can significantly reduce the non-radiative recombination centers, improving the device performance and supporting the development of high-resolution Micro-LED display.
Research on the Fracture Properties and Mechanism of Carbon Dioxide Blasting Based on Rock-like Materials
Authors: Chang Jian , Sun Lijun , Dai Bibo , Li Helin , Liu Zhenbiao , Zhao Xukun , Ke Bo
Published: December 2022

Liquid carbon dioxide blasting technology has a wide range of applications and is characterized by sound fracturing effects, low vibration hazards, and high safety. In order to investigate the characteristics and mechanism of CO2 phase change rock breaking, liquid CO2 blasting tests on rock-like specimens were carried out in this paper. The results show that 130 MPa is the threshold value at which a CO2 blasting system moves from dynamic tensile stress damage to dynamic pressure stress damage. When blasting pressures of 100 MPa and 70 MPa are used, the lumpiness ratio of the fragments does not change much as the strength of the rock changes, so a suitable blasting pressure should be chosen to improve the blasting effect. Under the impact of blast stress and high-pressure gas flow, cracks develop to form a rough failure surface.
Editorial for the Special Issue “Minerals of Alkaline Igneous Rocks: Chemical and Isotopic Features as Tracers of Magmatic Processes”
Authors: D’Antonio Massimo , Arienzo Ilenia
Published: December 2022

This Special Issue aims to highlight the pivotal role of the minerals found in alkaline igneous rocks in tracing magmatic processes [...]
Discovery of Hepatotoxic Equivalent Markers and Mechanism of Polygonum multiflorum Thunb. by Metabolomics Coupled with Molecular Docking
Authors: Zhang Yinhuan , Liu Lirong , Feng Menghan , Wu Hao , Dai Yihang , Jia Zhixin , Fang Cong , Liu Mingyan , Yan Xiaoning , Zhu Meixia , Huang Beibei , Qu Biqiong , Xiao Hongbin
Published: December 2022

Polygonum multiflorum Thunb. (PMT), a commonly used Chinese herbal medicine for treating diseases such as poisoning and white hair, has attracted constant attention due to the frequent occurrence of liver injury incidents. To date, its hepatotoxic equivalent markers (HEMs) and potential hepatotoxic mechanisms are still unclear. In order to clarify the HEMs of PMT and further explore the potential mechanisms of hepatotoxicity, firstly, the chemical constituents in PMT extract were globally characterized, and the fingerprints of PMT extracts were established along with the detection of their hepatotoxicity in vivo. Then, the correlations between hepatotoxic features and component contents were modeled by chemometrics to screen HEMs of PMT, which were then further evaluated. Finally, the hepatotoxic mechanisms of PMT were investigated using liver metabolomics and molecular docking. The results show that the chemical combination of 2,3,5,4-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) and emodin-8-O-glucoside (EG) was discovered as the HEMs of PMT through pre-screening and verifying process. Liver metabolomics revealed that PMT caused liver injury by interfering with purine metabolism, which might be related to mitochondrial function disorder and oxidative injury via the up-regulations of xanthosine and xanthine, and the down-regulation of 5′ nucleotidase (NT5E) and adenylate kinase 2 (AK2). This study not only found that the HEMs of PMT were TSG and EG, but also clarified that PMT might affect purine metabolism to induce liver injury, which contributed to our understanding of the underlying mechanisms of PMT hepatotoxicity.
Mitochondrial Iron Metabolism: The Crucial Actors in Diseases
Authors: Duan Geyan , Li Jianjun , Duan Yehui , Zheng Changbing , Guo Qiuping , Li Fengna , Zheng Jie , Yu Jiayi , Zhang Peiwen , Wan Mengliao , Long Cimin
Published: December 2022

Iron is a trace element necessary for cell growth, development, and cellular homeostasis, but insufficient or excessive level of iron is toxic. Intracellularly, sufficient amounts of iron are required for mitochondria (the center of iron utilization) to maintain their normal physiologic function. Iron deficiency impairs mitochondrial metabolism and respiratory activity, while mitochondrial iron overload promotes ROS production during mitochondrial electron transport, thus promoting potential disease development. This review provides an overview of iron homeostasis, mitochondrial iron metabolism, and how mitochondrial iron imbalances-induced mitochondrial dysfunction contribute to diseases.
A Novel FTIR-Based Chemometric Solution for the Assessment of Saffron Adulteration with Non-Fresh Stigmas
Authors: Foschi Martina , Tozzi Ludovica , Di Donato Francesca , Biancolillo Alessandra , D’Archivio Angelo Antonio
Published: December 2022

The development of fast, non-destructive, and green methods with adequate sensitivity for saffron authentication has important implications in the quality control of the entire production chain of this precious spice. In this context, the highly suitable sensitivity of a spectroscopic method coupled with chemometrics was verified. A total number of 334 samples were analyzed using attenuated-total-reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy; the collected spectra were processed by partial-least-squares discriminant analysis (PLS-DA) to evaluate the feasibility of this study for the discrimination between compliant saffron (fresh samples produced in 2020) and saffron samples adulterated with non-fresh stigmas produced in 2018 and 2016. PLS-DA was able to classify the saffron samples in accordance with the aging time and to discriminate fresh samples from the samples adulterated with non-fresh (legally expired) stigmas, achieving 100% of both sensitivity and specificity in external prediction. Moreover, PLS regression was able to predict the adulteration level with sufficient accuracy (the root-mean-square error of prediction was approximately 3–5%). In summary, ATR-FTIR and chemometrics can be employed to highlight the illegal blending of fresh saffron with unsold stocks of expired saffron, which may be a common fraudulent practice not yet considered in the scientific literature.
Fabrication and Characterization of β-Cyclodextrin/Mosla Chinensis Essential Oil Inclusion Complexes: Experimental Design and Molecular Modeling
Authors: Liu Hong-Ning , Jiang Xiao-Xia , Naeem Abid , Chen Fu-Cai , Wang Lu , Liu Yan-Xia , Li Zhe , Ming Liang-Shan
Published: December 2022

Essential oils (EOs) are primarily isolated from medicinal plants and possess various biological properties. However, their low water solubility and volatility substantially limit their application potential. Therefore, the aim of the current study was to improve the solubility and stability of the Mosla Chinensis (M. Chinensis) EO by forming an inclusion complex (IC) with β-cyclodextrin (β-CD). Furthermore, the IC formation process was investigated using experimental techniques and molecular modeling. The major components of M. Chinensis ‘Jiangxiangru’ EOs were carvacrol, thymol, o-cymene, and terpinene, and its IC with β-CD were prepared using the ultrasonication method. Multivariable optimization was studied using a Plackett-Burman design (step 1, identifying key parameters) followed by a central composite design for optimization of the parameters (step 2, optimizing the key parameters). SEM, FT-IR, TGA, and dissolution experiments were performed to analyze the physicochemical properties of the ICs. In addition, the interaction between EO and β-CD was further investigated using phase solubility, molecular docking, and molecular simulation studies. The results showed that the optimal encapsulation efficiency and loading capacity of EO in the ICs were 86.17% and 8.92%, respectively. Results of physicochemical properties were different after being encapsulated, indicating that the ICs had been successfully fabricated. Additionally, molecular docking and dynamics simulation showed that β-CD could encapsulate the EO component (carvacrol) via noncovalent interactions. In conclusion, a comprehensive methodology was developed for determining key parameters under multivariate conditions by utilizing two-step optimization experiments to obtain ICs of EO with β-CD. Furthermore, molecular modeling was used to study the mechanisms involved in molecular inclusion complexation.
Conjugative Stabilization versus Anchimeric Assistance in Carbocations
Authors: Shainyan Bagrat A.
Published: December 2022

In this study, an old concept of anchimeric assistance is viewed from a different angle. Primary cations with two different heteroatomic substituents in the α-position to the cationic carbon atom CHXY–CH2+ (X, Y = Me2N, MeO, Me3Si, Me2P, MeS, MeS, Br) can be stabilized by the migration of either the X or Y group to the cation center. In each case, the migration can be either complete, resulting in the transfer of the migrating group to the adjacent carbon atom and the formation of a secondary carbocation stabilized by the remaining heteroatom, or incomplete, leading to an anchimerically assisted iranium ion. For all combinations of the above groups, these transformations have been studied by theoretical analysis at the MP2/aug-cc-pVTZ level and were shown to occur depending on the ability of anchimeric assistance by X and Y, as well as the conformation of the starting primary carbocation. In the conformers of α-amino cations with the p-orbital, C–N bond and the nitrogen lone pair in one plane, the Me2N group migrates to the cationic center to give aziranium ions. Otherwise, the second heteroatom is shifted to give iminium ions, without or with very slight anchimeric assistance. In the α-methoxy cations, the MeO group can be shifted to the cationic center to give the O-anchimerically assisted ions as local minima, the global minima being the ions anchimerically assisted by another heteroatom. The electropositive silicon tends to migrate towards the cationic center, but with the formation of a π-complex of the Me3Si cation with the C=C bond rather than a Si-anchimerically assisted cation. The phosphorus atom can either fully migrate to the cationic center (X = P, Y = S, Se) or form anchimerically stabilized phosphiranium ions (X = P, Y = O, Si, Br). The order of the anchimeric assistance for the heaviest atoms decreases in the order Se >> S > Br.
Magnetic Nanocomposites of Coated Ferrites/MOF as Pesticide Adsorbents
Authors: Lazarou Savvina , Antonoglou Orestis , Mourdikoudis Stefanos , Serra Marco , Sofer Zdeněk , Dendrinou-Samara Catherine
Published: December 2022

Magnetic metal–organic frameworks (MMOFs) are gaining increased attention as emerging adsorbents/water remediation agents. Herein, a facile development of novel MMOFs comprised of coated ferrite nanoparticles (MNPs) and UiO-66 metal–organic framework is reported. In specific, coated Co- and Zn-doped ferrite magnetic nanoparticles were synthesized as building block while the metal–organic framework was grown in the presence of MNPs via a semi-self-assembly approach. The utilization of coated MNPs facilitated the conjugation and stands as a novel strategy for fabricating MMOFs with increased stability and an explicit structure. MMOFs were isolated with 13–25 nm crystallites sizes, 244–332 m2/g specific surface area (SSA) and 22–42 emu/g saturation magnetization values. Establishing the UiO-66 framework via the reported semi-self-assembly resulted in roughly 70% reduction in both magnetic properties and SSA, compared with the initial MNPs building blocks and UiO-66 framework, respectively. Nonetheless, the remaining 30% of the magnetization and SSA was adequate for successful and sufficient adsorption of two different pesticides, 2,4-Dichlorophenoxyacetic acid (2,4-D) and 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T), while the recovery with a commercial magnet and reuse were also found to be effective. Adsorption and kinetic studies for all three MMOFs and both pesticides were performed, and data were fitted to Langmuir–Freundlich isotherm models.
Ultrafast Photocarrier Dynamics in Vertically Aligned SnS2 Nanoflakes Probing with Transient Terahertz Spectroscopy
Authors: Zhang Wenjie , Sun Kaiwen , Suo Peng , Yan Xiaona , Lin Xian , Jin Zuanming , Ma Guohong
Published: December 2022

By employing optical pump Terahertz (THz) probe spectroscopy, ultrafast photocarrier dynamics of a two-dimensional (2D) semiconductor, SnS2 nanoflake film, has been investigated systematically at room temperature. The dynamics of photoexcitation is strongly related to the density of edge sites and defects in the SnS2 nanoflakes, which is controllable by adjusting the height of vertically aligned SnS2 during chemical vapor deposition growth. After photoexcitation at 400 nm, the transient THz photoconductivity response of the films can be well fitted with bi-exponential decay function. The fast and slow processes are shorter in the thinner film than in the thicker sample, and both components are independent on the pump fluence. Hereby, we propose that edge-site trapping as well as defect-assisted electron-hole recombination are responsible for the fast and slow decay progress, respectively. Our experimental results demonstrate that the edge sites and defects in SnS2 nanoflakes play a dominant role in photocarrier relaxation, which is crucial in understanding the photoelectrochemical performance of SnS2 nanoflakes.
Tailoring the Emission Behavior of WO3 Thin Films by Eu3+ Ions for Light-Emitting Applications
Authors: Kavitha V. S. , Biju V. , Gopchandran K. G. , Praveena R. , Jayasankar C. K. , Mekprasart Wanichaya , Boonyarattanakalin Kanokthip , Pecharapa Wisanu , Pillai V. P. Mahadevan
Published: December 2022

The article reports the successful fabrication of Eu3+-doped WO3 thin films via the radio-frequency magnetron sputtering (RFMS) technique. To our knowledge, this is the first study showing the tunable visible emission (blue to bluish red) from a WO3:Eu3+ thin film system using RFMS. X-ray diffractograms revealed that the crystalline nature of these thin films increased upto 3 wt% of the Eu3+ concentration. The diffraction peaks in the crystalline films are matched well with the monoclinic crystalline phase of WO3, but for all the films’, micro-Raman spectra detected bands related to WO3 monoclinic phase. Vibrational and surface studies reveal the amorphous/semi-crystalline behavior of the 10 wt% Eu3+-doped sample. Valence state determination shows the trivalent state of Eu ions in doped films. In the 400–900 nm regions, the fabricated thin films show an average optical transparency of ~51–85%. Moreover, the band gap energy gradually reduces from 2.95 to 2.49 eV, with an enhancement of the Eu3+-doping content. The doped films, except the one at a higher doping concentration (10 wt%), show unique emissions of Eu3+ ions, besides the band edge emission of WO3. With an enhancement of the Eu3+ content, the concentration quenching process of the Eu3+ ions’ emission intensities is visible. The variation in CIE chromaticity coordinates suggest that the overall emission color can be altered from blue to bluish red by changing the Eu3+ ion concentration.
Reduced Potential Barrier of Sodium-Substituted Disordered Rocksalt Cathode for Oxygen Evolution Electrocatalysts
Authors: Singh Aditya Narayan , Hajibabaei Amir , Ha Miran , Meena Abhishek , Kim Hyun-Seok , Bathula Chinna , Nam Kyung-Wan
Published: December 2022

Cation-disordered rocksalt (DRX) cathodes have been viewed as next-generation high-energy density materials surpassing conventional layered cathodes for lithium-ion battery (LIB) technology. Utilizing the opportunity of a better cation mixing facility in DRX, we synthesize Na-doped DRX as an efficient electrocatalyst toward oxygen evolution reaction (OER). This novel OER electrocatalyst generates a current density of 10 mA cm−2 at an overpotential (η) of 270 mV, Tafel slope of 67.5 mV dec−1, and long-term stability >5.5 days’ superior to benchmark IrO2 (η = 330 mV with Tafel slope = 74.8 mV dec−1). This superior electrochemical behavior is well supported by experiment and sparse Gaussian process potential (SGPP) machine learning-based search for minimum energy structure. Moreover, as oxygen binding energy (OBE) on the surface closely relates to OER activity, our density functional theory (DFT) calculations reveal that Na-doping assists in facile O2 evolution (OBE = 5.45 eV) compared with pristine-DRX (6.51 eV).
Rheology of Conductive High Reactivity Carbonaceous Material (HRCM)-Based Ink Suspensions: Dependence on Concentration and Temperature
Authors: Dessi Claudia , Melis Nicola , Desogus Francesco , Pilia Luca , Ricciu Roberto , Grosso Massimiliano
Published: December 2022

The present case study reports a shear rheological characterization in the temperature domain of inks and pastes loaded with conductive High Reactivity Carbonaceous Material (HRCM) consisting mainly of few-layers graphene sheets. The combined effect of filler concentration and applied shear rate is investigated in terms of the shear viscosity response as a function of testing temperature. The non-Newtonian features of shear flow ramps at constant temperature are reported to depend on both the HRCM load and the testing temperature. Moreover, temperature ramps at a constant shear rate reveal a different viscosity–temperature dependence from what is observed in shear flow ramps while maintaining the same filler concentration. An apparent departure from the well-known Vogel–Fulcher–Tamman relationship as a function of the applied shear rate is also reported.
Dissolution Behaviour of Metal-Oxide Nanomaterials in Various Biological Media
Authors: Avramescu Mary-Luyza , Chénier Marc , Beauchemin Suzanne , Rasmussen Pat
Published: December 2022

Toxicological effects of metal-oxide-engineered nanomaterials (ENMs) are closely related to their distinct physical–chemical properties, especially solubility and surface reactivity. The present study used five metal-oxide ENMs (ZnO, MnO2, CeO2, Al2O3, and Fe2O3) to investigate how various biologically relevant media influenced dissolution behaviour. In both water and cell culture medium (DMEM), the metal-oxide ENMs were more soluble than their bulk analogues, with the exception that bulk-MnO2 was slightly more soluble in water than nano-MnO2 and Fe2O3 displayed negligible solubility across all tested media (regardless of particle size). Lowering the initial concentration (10 mg/L vs. 100 mg/L) significantly increased the relative solubility (% of total concentration) of nano-ZnO and nano-MnO2 in both water and DMEM. Nano-Al2O3 and nano-CeO2 were impacted differently by the two media (significantly higher % solubility at 10 mg/L in DMEM vs. water). Further evaluation of simulated interstitial lung fluid (Gamble’s solution) and phagolysosomal simulant fluid (PSF) showed that the selection of aqueous media significantly affected agglomeration and dissolution behaviour. The solubility of all investigated ENMs was significantly higher in DMEM (pH = 7.4) compared to Gamble’s (pH 7.4), attributable to the presence of amino acids and proteins in DMEM. All ENMs showed low solubility in Gamble’s (pH = 7.4) compared with PSF (pH = 4.5), attributable to the difference in pH. These observations are relevant to nanotoxicology as increased nanomaterial solubility also affects toxicity. The results demonstrated that, for the purpose of grouping and read-across efforts, the dissolution behaviour of metal-oxide ENMs should be evaluated using aqueous media representative of the exposure pathway being considered.
Concentration-Dependent Antibacterial Activity of Chitosan on Lactobacillus plantarum
Authors: Kovács Renátó , Erdélyi Lóránd , Fenyvesi Ferenc , Balla Noémi , Kovács Fruzsina , Vámosi György , Klusóczki Ágnes , Gyöngyösi Alexandra , Bácskay Ildikó , Vecsernyés Miklós , Váradi Judit
Published: December 2022

The antimicrobial effect of chitosan and synthetic chitosan derivatives has been confirmed on many Gram-positive and Gram-negative bacteria and fungi. The tests were carried out on pathogenic microorganisms, so the mechanism and concentration dependence of the inhibitory effect of chitosan were revealed. We conducted our tests on a probiotic strain, Lactobacillus plantarum. Commercially available chitosan derivatives of different molecular weights were added to L. plantarum suspension in increasing concentrations. The minimum inhibitory concentration (MIC) value of chitosan was determined and confirmed the viability decreasing effect at concentrations above the MIC with a time-kill assay. The release of bacterium cell content was measured at 260 nm after treatment with 0.001–0.1% concentration chitosan solution. An increase in the permeability of the cell membrane was observed only with the 0.1% treatment. The interaction was also investigated by zeta potential measurement, and the irreversible interaction and concentration dependence were established in all concentrations. The interaction of fluorescein isothiocyanate (FITC) labeled low molecular weight chitosan and bacterial cells labeled with membrane dye (FM® 4–64) was confirmed by confocal microscopy. In conclusion, the inhibitory effect of chitosan was verified on a probiotic strain, which is an undesirable effect in probiotic preparations containing chitosan additives, while the inhibitory effect experienced with pathogenic strains is beneficial.
Preparation of Nano-Mg(OH)2 and Its Flame Retardant and Antibacterial Modification on Polyethylene Terephthalate Fabrics
Authors: Wang Ying , Liu Yanjing , Li Xiyue , Liu Yuezhou , Wang Fuming , Huang Yaping , Lv Lihua , Chu Ying , Qian Yongfang
Published: December 2022

The multifunctional polyethylene terephthalate (PET) fabrics were successfully prepared through a dip-coating technology to endow the flame retardant and antibacterial properties of PET fabrics, which are extensively used in many fields. The flame retardant and antibacterial agent was synthesized by a double drop-reverse precipitation method and surface-modified by the mixtures of titanate coupling agents and stearic acid to result in a good compatibility of the hydrophilic nano-Mg(OH)2 and the hydrophobic PET fabrics. The results indicated that the suitable synthesis conditions of nano-Mg(OH)2 are: Mg2+ concentration 1.5 mg/mL, reaction temperature 50 °C and reaction time 50 min, and the optimal modification conditions of nano-Mg(OH)2 are: modifier ratio 5/5, modification temperature 70 °C and modification time 40 min. The flame retardant test and the antibacterial test showed that the multifunctional PET fabrics had excellent flame retardant and antibacterial properties.
Research Progress in Energy Based on Polyphosphazene Materials in the Past Ten Years
Authors: Zhou Zeping , Jiang Zhen , Chen Feng , Kuang Tairong , Zhou Dapeng , Meng Fuliang
Published: December 2022

With the rapid development of electronic devices, the corresponding energy storage equipment has also been continuously developed. As important components, including electrodes and diaphragms, in energy storage device and energy storage and conversion devices, they all face huge challenges. Polyphosphazene polymers are widely used in various fields, such as biomedicine, energy storage, etc., due to their unique properties. Due to its unique design variability, adjustable characteristics and high chemical stability, they can solve many related problems of energy storage equipment. They are expected to become a new generation of energy materials. This article briefly introduces the research progress in energy based on polyphosphazene materials in the past ten years, on topics such as fuel cells, solar cells, lithium batteries and supercapacitors, etc. The main focus of this work is on the defects of different types of batteries. Scholars have introduced different functional group modification that solves the corresponding problem, thus increasing the battery performance.
Accelerated Laboratory Weathering of Polypropylene/Poly (Lactic Acid) Blends
Authors: Zhou Qihua , Liu Xuan , Lu Yanzhen , Dao Xiaoyao , Qiu Liuqing
Published: December 2022

To solve the pollution problems that result from polypropylene (PP), suitable biopolymers such as poly (lactic acid) (PLA) were selected to blend with PP. Since PP/PLA blends are often exposed to the natural environment, it is necessary to study the photodegradation behavior of PP/PLA blends. In this paper, PP/PLA blends with different compositions were prepared by extrusion and subjected to the accelerated laboratory weathering equipment. The effects of compatibilizers on the degradation behavior of PP/PLA blends were also studied. The weatherability of PP/PLA blends was studied through weight loss, optical microscope, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results revealed that PP is easy to degrade than PLA during accelerated laboratory weathering. PP/PLA blends are susceptible to the accelerated laboratory weathering process, and PP-rich and PLA-rich blends reduce the weathering resistance. Moreover, the results indicate that the initial degradation temperature, melting temperature, and crystallization temperature decrease after weathering related to the decreased thermal stability of PP/PLA blends. For instance, the initial degradation temperature of PP/PLA8.2 reduces from 332.2 °C to 320.2 °C. Moreover, the compatibilized sample is generally more resistant to weathering conditions than the uncompatibilized one due to the higher compatibility of PP and PLA.
Compensation of Thermal Gradients Effects on a Quartz Crystal Microbalance
Authors: Magni Marianna , Scaccabarozzi Diego , Saggin Bortolino
Published: December 2022

Quartz Crystal Microbalances (QCM) are widely used instruments thanks to their stability, low mass, and low cost. Nevertheless, the sensitivity to temperature is their main drawback and is often a driver for their design. Though the crystal average temperature is mostly considered as the only disturbance, temperature affects the QCM measurements also through the in-plane temperature gradients, an effect identified in the past but mostly neglected. Recently, it has been shown that this effect can prevail over that of the average temperature in implementations where the heat for thermal control is released directly on the crystal through deposited film heaters. In this study, the effect of temperature gradients for this kind of crystal is analyzed, the sensitivity of frequency to the average temperature gradient on the electrode border is determined, and a correction is proposed and verified. A numerical thermal model of the QCM has been created to determine the temperature gradients on the electrode borders. The frequency versus temperature-gradient function has been experimentally determined in different thermal conditions. The correction function has been eventually applied to a QCM implementing a crystal of the same manufacturing lot as the one used for the characterization. The residual errors after the implementation of the correction of both average temperature and temperature gradients were always lower than 5% of the initial temperature disturbance. Moreover, using the correlation between the heater power dissipation and the generated temperature gradients, it has been shown that an effective correction strategy can be based on the measurement of the power delivered to the crystal without the determination of the temperature gradient.
The Tacotron-Based Signal Synthesis Method for Active Sonar
Authors: Kim Yunsu , Kim Juho , Hong Jungpyo , Seok Jongwon
Published: December 2022

The importance of active sonar is increasing due to the quieting of submarines and the increase in maritime traffic. However, the multipath propagation of sound waves and the low signal-to-noise ratio due to multiple clutter make it difficult to detect, track, and identify underwater targets using active sonar. To solve this problem, machine learning and deep learning techniques that have recently been in the spotlight are being applied, but these techniques require a large amount of data. In order to supplement insufficient active sonar data, methods based on mathematical modeling are primarily utilized. However, mathematical modeling-based methods have limitations in accurately simulating complicated underwater phenomena. Therefore, an artificial intelligence-based sonar signal synthesis technique is proposed in this paper. The proposed method modified the major modules of the Tacotron model, which is widely used in the field of speech synthesis, in order to apply the Tacotron model to the field of sonar signal synthesis. To prove the validity of the proposed method, spectrograms of synthesized sonar signals are analyzed and the mean opinion score was measured. Through the evaluation, we confirmed that the proposed method can synthesize active sonar data similar to the trained one.
Federated Learning Attacks Revisited: A Critical Discussion of Gaps, Assumptions, and Evaluation Setups
Authors: Wainakh Aidmar , Zimmer Ephraim , Subedi Sandeep , Keim Jens , Grube Tim , Karuppayah Shankar , Sanchez Guinea Alejandro , Mühlhäuser Max
Published: December 2022

Deep learning pervades heavy data-driven disciplines in research and development. The Internet of Things and sensor systems, which enable smart environments and services, are settings where deep learning can provide invaluable utility. However, the data in these systems are very often directly or indirectly related to people, which raises privacy concerns. Federated learning (FL) mitigates some of these concerns and empowers deep learning in sensor-driven environments by enabling multiple entities to collaboratively train a machine learning model without sharing their data. Nevertheless, a number of works in the literature propose attacks that can manipulate the model and disclose information about the training data in FL. As a result, there has been a growing belief that FL is highly vulnerable to severe attacks. Although these attacks do indeed highlight security and privacy risks in FL, some of them may not be as effective in production deployment because they are feasible only given special—sometimes impractical—assumptions. In this paper, we investigate this issue by conducting a quantitative analysis of the attacks against FL and their evaluation settings in 48 papers. This analysis is the first of its kind to reveal several research gaps with regard to the types and architectures of target models. Additionally, the quantitative analysis allows us to highlight unrealistic assumptions in some attacks related to the hyper-parameters of the model and data distribution. Furthermore, we identify fallacies in the evaluation of attacks which raise questions about the generalizability of the conclusions. As a remedy, we propose a set of recommendations to promote adequate evaluations.