bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery and Separation of Dysprosium from Waste Neodymium Magnets through Cyphos IL 104 Extraction
Authors: Chen Wei-Sheng , Jian Guo-Cai , Lee Cheng-Han
Published: August 2022

In the present study, the extraction of rare earth elements (REEs) from waste neodymium magnets using phosphorus ionic liquid Cyphos IL 104 was investigated. The objective was to recover and separate the heavy REE (Dy) from light REEs (Nd and Pr). Therefore, the experimental parameters of ionic liquid extraction, including contacting time, the initial pH value, extractant concentration, and O/A ratio, have been optimized. The highest separation factor αDy/Nd of 45.18 and αDy/Pr of 47.93 has been achieved. Following the ionic liquid extraction, the comparison of different stripping agents and the stripping parameters (the concentration of stripping agent and A/O ratio) were also explored. In short terms, this research demonstrates the optimal parameters of Cyphos IL 104 for selectively extracting high REE (Dy) and reveals its potential for recovering and separating REEs in real waste.
Enhancing Free Cyanide Photocatalytic Oxidation by rGO/TiO2 P25 Composites
Authors: Albiter Elim , Barrera-Andrade Jose M. , Calzada Lina A. , García-Valdés Jesús , Valenzuela Miguel A. , Rojas-García Elizabeth
Published: August 2022

Graphene-TiO2 composites have been investigated in various photocatalytic reactions showing successful synergy compared to pristine TiO2. In the present work, graphene oxide (GO) was synthesized by the Hummers method and then reduced graphene oxide-TiO2 composites (rGO/TiO2) were obtained by an in situ GO photoreduction route. X-ray diffraction, FTIR, Raman, UV–vis DRS, and photoluminescence were the main characterization techniques. The obtained composites containing 1 and 3 wt.% rGO were evaluated in the cyanide (50 mg/L) oxidation and Au-cyanide complex (300 mg/L) degradation under UV-A light. The composites showed higher photocatalytic activity than TiO2, mainly with the 1% rGO content. Cyanate and gold nanoparticles, deposited on the photocatalyst’s surface, were the main byproducts during the photocatalyst assessment. The improved photocatalytic activity of the composites was attributed to a higher rate of electron transfer and a lower rate of charge recombination due to the chemical interaction of rGO with TiO2.
Incorporation of Ethylcellulose Microparticles Containing a Model Drug with a Bitter Taste into Nanofibrous Mats by the Electrospinning Technique—Preliminary Studies
Authors: Olechno Katarzyna , Grilc Nina Katarina , Zupančič Špela , Winnicka Katarzyna
Published: August 2022

Electrospinning is considered a simple and comprehensive technique to formulate ultrafine fibres by using an electric field. Polymeric nanofibers constitute promising materials in biomedical applications as drug delivery systems. For their preparation, both natural and synthetic polymers are utilised. Owing to the potential use of electrospun nanofibers as an orodispersible drug dosage form, ethylcellulose microparticles containing the antihistamine drug rupatadine fumarate, prepared by the spray drying technique to conceal the drug’s bitter taste, were incorporated into nanofibers. The obtained nanofibrous mats were evaluated for morphology, mechanical strength, disintegration time, the drug solid state and acceptability in terms of taste masking efficiency. Preliminary studies showed that hypromellose used as a single polymer was not a suitable substance for the manufacturing of nanofibers. Therefore, in order to facilitate the obtention of homogeneous nonwovens, different grades of polyethylene oxide (2,000,000–2M-Da and 4,000,000–4M-Da) were added, which improved the quality of the prepared mats. Nanofibers of the most satisfactory quality were obtained from hypromellose (6.5% w/v) and PEO (2M, 0.5% w/v). SEM image analysis has shown that the nanofibers were homogeneous and smooth and possessed a fast disintegration time (below 30 s) and an adequate drug content with a simultaneous taste-masking effect (as indicated by the in vivo and in vitro methods). However, further studies are necessary to refine their mechanical characteristics.
Digital Image Correlation Characterization and Formability Analysis of Aluminum Alloy TWB during Forming
Authors: Wu Jie , Hovanski Yuri , Miles Michael
Published: August 2022

The formability of aluminum alloy 5754-O tailor-welded blanks prepared by friction stir welding was studied experimentally. The strain evolution and deformation during limiting dome height experiments were studied using digital image correlation and the ARAMIS software. The influence of the sheet thickness of the base materials on the punch loading, fracture strain and formability were investigated experimentally. It was found that the punch loading, fracture strain and limiting dome height values increase with the increasing sheet thickness of the base materials. A linear relationship between the limiting dome height value and the sheet thickness was demonstrated. An increase of 16.8% in the fracture strain of aluminum tailor-welded blanks was observed for an increase of 36% in sheet thickness. This paper provides a methodology for experimentally determining the forming limits of aluminum alloy tailor-welded blanks accurately.
Template-Mediated Synthesis of Hierarchically Porous Metal–Organic Frameworks for Efficient CO2/N2 Separation
Authors: Qiu Tianjie , Gao Song , Fu Yanchun , Xu Dong , Kong Dekai
Published: August 2022

Carbon dioxide (CO2) is generally unavoidable during the production of fuel gases such as hydrogen (H2) from steam reformation and syngas composed of carbon monoxide (CO) and hydrogen (H2). Efficient separation of CO2 from these gases is highly important to improve the energetic utilization efficiency and prevent poisoning during specific applications. Metal–organic frameworks (MOFs), featuring ordered porous frameworks, high surface areas and tunable pore structures, are emerging porous materials utilized as solid adsorbents for efficient CO2 capture and separation. Furthermore, the construction of hierarchical MOFs with micropores and mesopores could further promote the dynamic separation processes, accelerating the diffusion of gas flow and exposing more adsorptive pore surface. Herein, we report a simple, efficient, one-pot template-mediated strategy to fabricate a hierarchically porous CuBTC (CuBTC-Water, BTC = 1,3,5-benzenetricarboxylate) for CO2 separation, which demonstrates abundant mesopores and the superb dynamic separation ability of CO2/N2. Therefore, CuBTC-Water demonstrated a CO2 uptake of 180.529 cm3 g−1 at 273 K and 1 bar, and 94.147 cm3 g−1 at 298 K and 1 bar, with selectivity for CO2/N2 mixtures as high as 56.547 at 273 K, much higher than microporous CuBTC. This work opens up a novel avenue to facilely fabricate hierarchically porous MOFs through one-pot synthesis for efficient dynamic CO2 separation.
Rheological and Stability Evaluation of Emulsions Containing Fenugreek Galactomannan—Xanthan Gum Mixtures: Effect of Microwave and Ultrasound Treatments
Authors: Niknam Rasoul , Soudi Mohammad Reza , Mousavi Mohammad
Published: August 2022

The effects of treating two biopolymers (Trigonella foenum—graceum galactomannan and xanthan gum mixtures) with microwaves and ultrasound on the rheological aspects of O/W emulsions were investigated. The data obtained from steady shear flow were fitted with various models and the best were chosen due to the values of R2 and RMSE. The oscillatory shear rheology data demonstrated that the emulsions not treated with microwaves or ultrasound had viscous-like behavior and treated samples demonstrated weak gel behavior. The values obtained for various rheological parameters (especially apparent viscosity, storage modulus and loss modulus) indicated that fenugreek galactomannan had more impact on the rheological aspects of emulsions in comparison with xanthan gum. In addition, the synergistic interaction between two biopolymers, particularly in samples treated with ultrasound, resulted in better rheological aspects which could be affiliated with the strong bonds between the hydrocolloids. By treating the samples with microwaves and ultrasound, the emulsion stability values of the samples (especially those with a high ratio of galactomannan) significantly increased, which might be connected with various parameters, especially viscosity.
An Orchestration Perspective on Open Innovation between Industry–University: Investigating Its Impact on Collaboration Performance
Authors: Băban Călin Florin , Băban Marius
Published: August 2022

Since open innovation between industry–university is a highly complex phenomenon, its orchestration may be of great support for better collaboration between these organizations. However, there is a lack of evidence on how an orchestration framework impacts the collaboration performance between these organizations in such a setting. Based on a research model that investigates the influence of the main orchestration dimensions on the performance of collaboration, this study offers one of the first perspectives of an orchestration process between the industry and university actors in open innovation. The developed research model was assessed using a deep learning dual-stage PLS-SEM and artificial neural network (ANN) analysis. In the first stage, the hypotheses of the research model were tested based on a disjoint two-stage approach of PLS-SEM, and the results reveal the orchestration dimensions that have a significant impact on collaboration performance. In the second stage, a deep learning network approach was successfully employed to capture the complex relationships among the significant orchestration dimensions identified through the PLS-SEM analysis. An importance–performance map analysis provided useful insights into the relative importance of the components of each orchestration dimension based on their effects on the collaboration performance.
A Novel Marine Pyran-Isoindolone Compound Enhances Fibrin Lysis Mediated by Single-Chain Urokinase-Type Plasminogen Activator
Authors: Gao Chunli , Tang Simin , Zhang Haixing , Zhang Huishu , Zhang Tian , Bao Bin , Zhu Yuping , Wu Wenhui
Published: August 2022

Fungi fibrinolytic compound 1 (FGFC1) is a rare pyran-isoindolone derivative with fibrinolytic activity. The aim of this study was to further determine the effect of FGFC1 on fibrin clots lysis in vitro. We constructed a fibrinolytic system containing single-chain urokinase-type plasminogen activator (scu-PA) and plasminogen to measure the fibrinolytic activity of FGFC1 using the chromogenic substrate method. After FITC-fibrin was incubated with increasing concentrations of FGFC1, the changes in the fluorescence intensity and D-dimer in the lysate were measured using a fluorescence microplate reader. The fibrin clot structure induced by FGFC1 was observed and analyzed using a scanning electron microscope and laser confocal microscope. We found that the chromogenic reaction rate of the mixture system increased from (15.9 ± 1.51) × 10−3 min−1 in the control group to (29.7 ± 1.25) × 10−3 min−1 for 12.8 μM FGFC1(p < 0.01). FGFC1 also significantly increased the fluorescence intensity and d-dimer concentration in FITC fibrin lysate. Image analysis showed that FGFC1 significantly reduced the fiber density and increased the fiber diameter and the distance between protofibrils. These results show that FGFC1 can effectively promote fibrin lysis in vitro and may represent a novel candidate agent for thrombolytic therapy.
Seroprevalence of Anti-Hepatitis E Virus Antibodies among Patients from a Tertiary Hospital from Northeast Romania
Authors: Mihai Ioana Florina , Anita Dragos , Dorneanu Olivia Simona , Luca Catalina Mihaela , Manciuc Carmen Doina , Budacu Cristian Constantin , Roșu Florin Manuel , Savuta Gheorghe , Anita Adriana , Vâţă Andrei
Published: August 2022

Background and Objectives. Being an enterically transmitted pathogen with a growing prevalence in developed countries, hepatitis E virus (HEV) infection remains an underdiagnosed disease in Eastern Europe. As far as Romania is concerned, only a few studies address this issue. Our goal was to estimate the prevalence of serum anti-HEV IgA/IgM/IgG antibodies in a group of patients admitted to the Clinical Hospital for Infectious Diseases “St. Parascheva” Iasi. Materials and Methods. The cross-sectional study consisted of enrollment of 98 patients admitted to the clinic for COVID-19 over a period of three months in 2020. Results. The median age in our study was 73 years, with an equal gender ratio and with a predominance of people from the urban environment (75%). The overall HEV antibody seroprevalence was 12.2%. The main risk factors associated with HEV infection were consumption of water from unsafe sources (58.3% HEV-positive patients vs. 26.7% HEV-negative patients, p = 0.026) and improperly cooked meat (58.3% HEV-positive patients vs. 23.2% HEV-negative patients, p = 0.01). Zoonotic transmission was an important criterion in our study, with patients reporting contact with pigs, poultry, rats, or other farms animals, but no significant differences were found between HEV antibody positive and negative groups. Conclusions. The seroprevalence rate of HEV antibodies was similar to other previous reports from our area but higher than in most European countries. The fact that HEV antibodies were detected in patients without identifiable risk factors for hepatitis E is evidence of subclinical infection as a silent threat.
Photobiomodulation Treatment in Chemotherapy-Induced Oral Mucositis in Young Haematological Patients—A Pilot Study
Authors: Fiwek Paula , Emerich Katarzyna , Irga-Jaworska Ninela , Pomiecko Dagmara
Published: August 2022

Background and Objectives: One of the most debilitating side effects of chemotherapy is oral mucositis (OM). Photobiomodulation (PBM) demonstrates high efficacy in the management of OM. The aim of the study was to investigate the incidence of oral mucositis and evaluation of the effectiveness of PBM therapy. Materials and Methods: A total of 23 children diagnosed with leukaemia or lymphoma affected by chemotherapy-induced OM were enrolled in the study. OM grade was assessed with the World Health Organization (WHO) scale. Patients completed an approved questionnaire, and blood cell counts were read every 2 days. OM lesions were treated with class IV laser therapy with a frequency of every 48 h and density of 2, 4, 8, 16 or 30 J/cm2. The level of pain was measured with VAS scale. Results: The 23 patients developed a total of 41 OM episodes with a mean duration of 7.61 days ± 4.70. Laser therapy showed a great reduction regarding pain and a better function of patients even with neutropenia. Conclusions: Oral mucositis represents a significant burden to children. PBM brings positive aspects for patients; however, the optimal treatment parameters require further study.
The Effects of Short- and Long-Term Spinal Brace Use with and without Exercise on Spine, Balance, and Gait in Adolescents with Idiopathic Scoliosis
Authors: da Silveira Guilherme Erdmann , Andrade Rodrigo Mantelatto , Guilhermino Gean Gustavo , Schmidt Ariane Verttú , Neves Lucas Melo , Ribeiro Ana Paula
Published: August 2022

Background and Objectives: Adolescent idiopathic scoliosis (AIS) is a prevalent spinal disorder in adolescents. Previous studies have shown biomechanical changes of the gait in the lower limb of AIS patients. To minimize the progression of scoliotic curvature, a spinal brace is used, which has been shown to be efficient. Usually, a brace is worn strictly for 20–22 h every day. To our knowledge, no study has assessed the short- and long-term effects of spinal brace use with or without an exercise program (6 months) to improve clinical and biomechanical parameters. The aim of our study was to verify the effects of short- and long-term spinal brace use, with or without an exercise program on the spine, body balance, and plantar load distribution during gait in AIS. Materials and Methods: A prospective randomized study was conducted with intention-to-treat analysis in forty-five adolescents diagnosed with AIS undergoing conservative treatment at a center specialized in spinal rehabilitation. Adolescents were evaluated at two stages of intervention: (1) spinal orthopedic brace, with acute use 24 h/day (n = 22) and (2) spinal orthopedic brace, with acute use between 15–18 h/day associated with a specific rehabilitation exercise protocol for six consecutive months (six months and 12 total sessions, n = 23). The evaluated parameters were: spine pain, using a visual analog scale (VAS); Cobb angle measurement using radiograph exams, as well as the Risser sign; and static balance and plantar pressure of the feet during gait, carried out using a pressure platform. Results: AIS patients showed significant improvements in the main scoliotic curvature, with a 12-degree reduction in Cobb angle pre- and post-short-term immediate use of spinal brace and a 5.3 degree correction after six months of spinal brace use in combination with specific exercises (long term). In addition, short- and long-term brace use with an exercise program showed a significant increase in anteroposterior and mediolateral balance and a reduction in plantar overload on the heel during gait, with an effect size between moderate and high. Conclusions: Intervention via the short- or long-term use of a spinal brace combined with specific exercises in adolescents with idiopathic scoliosis proved to be effective for correcting scoliotic curvature. In addition, intervention also showed improvements to the antero-posterior and mediolateral body balance and a reduction in the plantar load on the rearfoot region during gait, demonstrating effective mechanical action on the spine.
Multi-Layered Branched Surface Fluorination on PVDF Membrane for Anti-Scaling Membrane Distillation
Authors: Liu Yu-Jing , Lu Yan-Nan , Liang Dong-Qing , Hu Yin-Shuang , Huang Yu-Xi
Published: August 2022

Membrane distillation (MD) has emerged as a promising technology for hypersaline wastewater treatment. However, membrane scaling is still a critical issue for common hydrophobic MD membranes. Herein, we report a multi-layered surface modification strategy on the commercial polyvinylidene fluoride (PVDF) membrane via plasma treatment and surface fluorination cycles. The repeated plasma treatment process generates more reaction sites for the fluorination reaction, leading to higher fluorination density and more branched structures. MD tests with CaSO4 as the scaling agent show that the modification strategy mentioned above improves the membrane scaling resistance. Notably, the PVDF membrane treated with three cycles of plasma and fluorination treatments exhibits the best anti-scaling performance while maintaining almost the same membrane flux as the unmodified PVDF membrane. This study suggests that a highly branched surface molecular structure with low surface energy benefits the MD process in both membrane flux and scaling resistance. Besides, our research demonstrates a universal and facile approach for membrane treatment to improve membrane scaling resistance.
Time-Domain Inversion Method of Impact Loads Based on Strain Monitoring Data
Authors: Wang Fanchao , Zheng Kai , Chen Bihao , Peng Yinghao , Liu Kun , Tang Dewen
Published: August 2022

A helicopter deck is the main load-bearing component under the emergency landing conditions for helicopters. However, it is generally difficult to directly obtain the landing load from measurements due to the high randomness of the landing position. As the main design load of the helicopter deck, the emergency landing load is very important to its structural design. A large design load value leads to an overly conservative structural design and affects the control of the ship’s weight and center of gravity, while a small design load may lead to a lack of security and affect the safety of the helicopter and the ship. As a result, the time domain inversion method, which is based on strain monitoring data, is an important and effective method for obtaining the helicopter emergency landing load. In this study, a grillage model experiment was conducted to study the time domain inversion method. The helicopter impact load was simulated by falling body impact, and the impact load history and structural strain response were recorded by sensors. The grillage model impact load was calculated with different inversion methods, including the direct inverse, truncated singular value decomposition (TSVD), and Tikhonov regularization methods. The solution accuracy of different methods and number of sensors needed were compared. The results demonstrated that the Tikhonov regularization method based on four measurement points along with the L-curve determination criterion showed a better performance for capturing the impact load time history features.
Simultaneous Quantification of Steroid Hormones Using hrLC-MS in Endocrine Tissues of Male Rats and Human Samples
Authors: Bordanaba-Florit Guillermo , Liempd Sebastiaan van , Cabrera Diana , Royo Félix , Falcón-Pérez Juan Manuel
Published: August 2022

Steroid hormones play a vital role in the regulation of cellular processes, and dysregulation of these metabolites can provoke or aggravate pathological issues, such as autoimmune diseases and cancer. Regulation of steroid hormones involves different organs and biological compartments. Therefore, it is important to accurately determine their levels in tissues and biofluids to monitor changes after challenge or during disease. In this work, we have developed and optimized the extraction and quantification of 11 key members of the different steroid classes, including androgens, estrogens, progestogens and corticoids. The assay consists of a liquid/liquid extraction step and subsequent quantification by high-resolution liquid chromatography coupled time-of-flight mass spectrometry. The recoveries range between 74.2 to 126.9% and 54.9 to 110.7%, using a cell culture or urine as matrix, respectively. In general, the signal intensity loss due to matrix effect is no more than 30%. The method has been tested in relevant steroidogenic tissues in rat models and it has also been tested in human urine samples. Overall, this assay measures 11 analytes simultaneously in 6 min runtime and it has been applied in adrenal gland, testis, prostate, brain and serum from rats, and urine and extracellular vesicles from humans.
Thermodynamic Analysis and Experimental Study on the Oxidation of PbX (X = S, Se) Nanostructured Layers
Authors: Maraeva Evgeniya , Maximov Alexander , Permiakov Nikita , Moshnikov Vyacheslav
Published: August 2022

Heat treatment in an oxygen-containing medium is a necessary procedure in the technology of forming photodetectors and emitters based on lead chalcogenides. Lead chalcogenide layers (PbS, PbSe) were prepared via a chemical bath deposition method. Surface oxidation of lead chalcogenide layers was analyzed using X-ray diffraction and Raman spectroscopy methods, and thermodynamic analysis of the oxidation of PbSe and PbS layers was also performed. The calculated phase diagrams from 20 °C to 500 °C showed good agreement with the experimental results. According to the thermodynamic analysis, the oxidation products depend on the initial composition of the layers and temperature of the annealing. In some cases, the formation of a separate metallic phase Pb is possible along with the formation of lead oxide PbO and other oxides. The performed thermodynamic analysis makes it possible to substantiate the two-stage annealing temperature regimes which ensure an increase in the speed of photodetectors.
Laser-Induced Graphene Stretchable Strain Sensor with Vertical and Parallel Patterns
Authors: Yen Yu-Hsin , Hsu Chao-Shin , Lei Zheng-Yan , Wang Hsin-Jou , Su Ching-Yuan , Dai Ching-Liang , Tsai Yao-Chuan
Published: August 2022

In intelligent manufacturing and robotic technology, various sensors must be integrated with equipment. In addition to traditional sensors, stretchable sensors are particularly attractive for applications in robotics and wearable devices. In this study, a piezoresistive stretchable strain sensor based on laser-induced graphene (LIG) was proposed and developed. A three-dimensional, porous LIG structure fabricated from polyimide (PI) film using laser scanning was used as the sensing layer of the strain sensor. Two LIG pattern structures (parallel and vertical) were fabricated and integrated within the LIG strain sensors. Scanning electron microscopy, an X-ray energy dispersive spectrometer, and Raman scattering spectroscopy were used to examine the microstructure of the LIG sensing layer. The performance and strain sensing properties of the parallel and vertical stretchable LIG strain sensors were investigated in tensile tests. The relative resistance changes and the gauge factors of the parallel and vertical LIG strain sensors were quantified. The parallel strain sensor achieved a high gauge factor of 15.79 in the applied strain range of 10% to 20%. It also had high sensitivity, excellent repeatability, good durability, and fast response times during the tensile experiments. The developed LIG strain sensor can be used for the real-time monitoring of human motions such like finger bending, wrist bending, and throat swallowing.
Cuffless Blood Pressure Monitoring: Academic Insights and Perspectives Analysis
Authors: Li Shiyun , Zhang Can , Xu Zhirui , Liang Lihua , Tian Ye , Li Long , Wu Huaping , Zhong Sheng
Published: August 2022

In recent decades, cuffless blood pressure monitoring technology has been a point of research in the field of health monitoring and public media. Based on the web of science database, this paper evaluated the publications in the field from 1990 to 2020 using bibliometric analysis, described the developments in recent years, and presented future research prospects in the field. Through the comparative analysis of keywords, citations, H-index, journals, research institutions, national authors and reviews, this paper identified research hotspots and future research trends in the field of cuffless blood pressure monitoring. From the results of the bibliometric analysis, innovative methods such as machine learning technologies related to pulse transmit time and pulse wave analysis have been widely applied in blood pressure monitoring. The 2091 articles related to cuffless blood pressure monitoring technology were published in 1131 journals. In the future, improving the accuracy of monitoring to meet the international medical blood pressure standards, and achieving portability and miniaturization will remain the development goals of cuffless blood pressure measurement technology. The application of flexible electronics and machine learning strategy in the field will be two major development directions to guide the practical applications of cuffless blood pressure monitoring technology.
A Poly-(ethylene glycol)-diacrylate 3D-Printed Micro-Bioreactor for Direct Cell Biological Implant-Testing on the Developing Chicken Chorioallantois Membrane
Authors: Lutsch Eric , Struber Andreas , Auer Georg , Fessmann Thomas , Lepperdinger Günter
Published: August 2022

Advancements in biomaterial manufacturing technologies calls for improved standards of fabrication and testing. Currently 3D-printable resins are being formulated which exhibit the potential to rapidly prototype biocompatible devices. For validation purposes, 3D-printed materials were subjected to a hierarchical validation onto the chorioallantoic membrane of the developing chicken, better known as the HET CAM assay. Working along these lines, prints made from poly-(ethylene glycol)-diacrylate (PEGDA), which had undergone appropriate post-print processing, outperformed other commercial resins. This material passed all tests without displaying adverse effects, as experienced with other resin types. Based on this finding, the micro bioreactors (MBR) design, first made of PDMS and that also passed with cell tests on the HET-CAM, was finally printed in PEGDA, and applied in vivo. Following this workflow shows the applicability of 3D-printable resins for biomedical device manufacturing, consents to adherence to the present standards of the 3R criteria in material research and development, and provides flexibility and fast iteration of design and test cycles for MBR adaptation and optimization.
Green Production of Functionalized Few-Layer Graphene–Silver Nanocomposites Using Gallnut Extract for Antibacterial Application
Authors: Bu Yingjie , Kushwaha Anamika , Goswami Lalit , Kim Beom-Soo
Published: August 2022

Recently, there has been much attention paid to functionalized few-layer graphene (FFG) owing to its many biomedical applications, such as in bioimaging, biosensors, drug delivery, tissue scaffolds, nanocarriers, etc. Hence, the preparation of FFG has now become of great interest to researchers. The present study systematically investigates the utilization of gallnut extract (GNE) during the process of high-shear exfoliation for the efficient conversion of expanded graphite to FFG. Various parameters, such as GNE concentration, graphite concentration, exfoliation time, and the rotation speed of the high-shear mixer, were initially optimized for FFG production. The prepared FFG was characterized in terms of surface functionality and morphology using Raman spectra, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, and scanning electron microscopy analyses. Further, the conjugation of FFG with Ag was confirmed by XRD, XPS, and energy-dispersive X-ray spectra. The Ag–FFG composite exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria through the agar well diffusion method. This study provides an efficient, economical, and eco-friendly FFG and Ag–FFG production method for biomedical applications.
Bubble Formation in Pulsed Electric Field Technology May Pose Limitations
Authors: Rodriguez Osuna Isaac Aaron , Cobelli Pablo , Olaiz Nahuel
Published: August 2022

Currently, increasing amounts of pulsed electric fields (PEF) are employed to improve a person’s life quality. This technology is based on the application of the shortest high voltage electrical pulse, which generates an increment over the cell membrane permeability. When applying these pulses, an unwanted effect is electrolysis, which could alter the treatment. This work focused on the study of the local variations of the electric field and current density around the bubbles formed by the electrolysis of water by PEF technology and how these variations alter the electroporation protocol. The assays, in the present work, were carried out at 2 KV/cm, 1.2 KV/cm and 0.6 KV/cm in water, adjusting the conductivity with NaCl at 2365 μs/cm with a single pulse of 800 μs. The measurements of the bubble diameter variations due to electrolysis as a function of time allowed us to develop an experimental model of the behavior of the bubble diameter vs. time, which was used for simulation purposes. In the in silico model, we calculated that the electric field and observed an increment of current density around the bubble can be up to four times the base value due to the edge effect around it, while the thermal effects were undesirable due to the short duration of the pulses (variations of ±0.1 °C are undesirable). This research revealed that the rise of electric current is not just because of the shift in electrical conductivity due to chemical and thermal effects, but also varies with the bubble coverage over the electrode surface and variations in the local electric field by edge effect. All these variations can conduce to unwanted limitations over PEF treatment. In the future, we recommend tests on the variation of local current conductivity and electric fields.
Influence of Thermal Boundary Conditions and Number of Channels on the Performance of Heat Sinks with Rectangular Minichannels
Authors: Vocale Pamela
Published: August 2022

This paper aims to contribute to the analysis of a heat sink designed for the active cooling of small flat surfaces. The heat transfer device investigated here consists of a flat square substrate and a cover, separated by parallel channels with a rectangular cross-section. The cold air flowing in the channels is sucked from the environment, and the bottom of the substrate adheres closely to the hot surface of the device to be cooled. The thermal problem is tackled by considering two different conditions: the first one assuming one long side of the channel is heated and the three other sides are adiabatic (version 1L) and the second one assuming high conductivity of the walls (version 4), in both the H1 and H2 boundary conditions. Moreover, to investigate the effect of the number of channels on the performance of the heat sink, the number of channels is changed between 1 and 20. The results, presented in terms of the f Re product, Nusselt number, maximum surface temperature, and thermal resistance, reveal that both the thermal boundary conditions and the number of channels significantly affect the performance of the investigated heat transfer device.
Deformation Monitoring and Shape Reconstruction of Flexible Planer Structures Based on FBG
Authors: Wu Huifeng , Dong Rui , Liu Zheng , Wang Hui , Liang Lei
Published: August 2022

To reduce the dependence of real-time deformation monitoring and shape reconstruction of flexible planar structures on experience, mathematical models, specific structural curvature (shape) sensors, etc., we propose a reconstruction approach based on FBG and a data-driven model; with the aid of ANSYS finite element software, a simulation model was built, and training samples were collected. After the machine learning training, the mapping relationship was established, which is between the strain and the deformation variables (in three directions of the x-, y-, z-axis) of each point of the surface of the flexible planar structure. Four data-driven models were constructed (linear regression, regression tree, integrated tree, and BP neural network) and comprehensively evaluated; the predictive value of the BP neural network was closer to the true value (R2 = 0.9091/0.9979/0.9964). Finally, the replication experiment on the flexible planar structure specimen showed that the maximum predictive error in the x-, y-, and z-axis coordinates were 2.93%, 35.59%, and 16.21%, respectively. The predictive results are highly consistent with the expected results of flexible planar structure deformation monitoring and shape reconstruction in the existing test environment. The method provides a new high-precision method for the real-time monitoring and shape reconstruction of flexible planar structures.
Two Epochs of Mineralization of Orogenic Gold Deposit in the East Kunlun Orogenic Belt: Constraints from Monazite U–Pb Age, In Situ Sulfide Trace Elements and Sulfur Isotopes in Wulonggou Gold Field
Authors: Zhang Zheming , Zeng Qingdong , Pan Tong , Xie Hailin , Wei Zhanhao , Fan Hongrui , Wu Jinjian , Yang Kuifeng , Li Xinghui , Liang Gaizhong
Published: August 2022

The Wulonggou Gold Field is one of the giant gold fields in the East Kunlun Orogenic Belt, northwestern China. Previous studies mainly focused on elementary mineral isotopic studies, fluid inclusions, and geological features in the Wulonggou Gold Field. In this study, we report some research on the precise age and the specific ore-forming process of the WGF: the hydrothermal monazite U–Pb ages; the way of gold precipitation; the composition, evolution, and source of ore-forming fluids of the Wulonggou Gold Field. Finally, we demonstrate a link between two-stage hydrothermal events and sequential episodes of crust-derived magmas, with implications for gold metallogeny in the East Kunlun Orogenic Belt. There are four hydrothermal stages that are recognized: a quartz–pyrite stage (stage 1), a quartz–pyrite–arsenopyrite–chalcopyrite stage (stage 2), a quartz–galena–sphalerite–pyrite stage (stage 3) and a quartz–stibnite–carbonate stage (stage 4). The monazite U–Pb ages of the Huanglonggou and Hongqigou deposits in the Wulonggou Gold Field were 422.2 ± 2.4 Ma and 236.7 ± 3.7 Ma, respectively, which support the opinion of two epochs of mineralization. Stages 1 and 2 are the main gold mineralization stages, wherein Au and As have a close genetic relationship. The Hongqigou and Huanglonggou deposits seem to have been formed in different metallogenic events due to the contrast on the trace element compositions in pyrite. The sources of the ore-forming materials and fluids of the Hongqigou and Huanglonggou deposits show apparent characteristics of orogenic gold deposit, and the magmatic events during Paleozoic and Mesozoic have an important contribution to the formation of the gold deposits. The gold deposits in the Wulonggou Gold Field can be interpreted as an orogenic gold system related to two-epoch tectonic–magmatic events.
Origin of Podiform Chromitites in the Sebuku Island Ophiolite (South Kalimantan, Indonesia): Constraints from Chromite Composition and PGE Mineralogy
Authors: Idrus Arifudin , Zaccarini Federica , Garuti Giorgio , Wijaya I , Swamidharma Yoseph , Bauer Christoph
Published: August 2022

The presence of PGM associated with the podiform chromitites in the Jurassic–Cretaceous ophiolite of Sebuku Island (South Kalimantan, Indonesia) is reported for the first time. Two types of chromitite have been recognized; one with high-Cr composition (Cr/(Cr + Al) > 0.7) occurs in the deep mantle, the other, high-Al (Cr/(Cr + Al) < 0.6), is located close to the Moho transition zone. The TiO2-Al2O3 relations indicate affinity to IAT and MORB, for the high-Cr and high-Al chromitites, respectively. However, both are believed to have formed by mantle/melt reaction and differentiation of a magma characterized by an initial IAT composition related to an SSZ. Primary magmatic inclusions (<10 μm) of laurite characterized by Ru/Os chondritic ratio are the only PGM found in the high-Cr chromitites, indicating crystallization from undifferentiated magma, at low fS2 in the mantle. In contrast, the high-Al to chondrite, suggesting the increase of fS2 in the evolved melt. Besides laurite, the high-Al chromitite contains a complex assemblage of secondary PGM (Pt-Fe, garutiite, iridium, ruthenium–magnetite aggregates, zaccariniite and unnamed Ru and Mn oxides). These secondary PGM have an irregular shape and occur exclusively in the chlorite matrix sometimes associated with Mn-Ni-Fe-Cr hydroxides. They are interpreted to have formed by desulfuration of primary interstitial PGM sulfides or to have precipitated from secondary fluids during low T alteration. The relative abundance of PPGE in the high-Al chromitite is interpreted as a result of PGE fractionation during differentiation of the parent melt of the chromitites.
High-Resolution Transmission Electron Microscopy Study of a Powder River Basin Coal-Derived Fly Ash
Authors: Hower James C. , Berti Debora , Winkler Christopher R. , Qian Dali , Briot Nicolas J.
Published: August 2022

Examination of a fly ash derived from the combustion of a low-S, subbituminous Powder River Basin coal by Scanning Electron Microscopy (SEM) and High-resolution Transmission Electron Microscopy (HRTEM), both supplemented by Energy-dispersive X-ray spectroscopy (EDS), showed that the fly ashes were dominated by amorphous phases, Ca-rich plagioclase feldspars, Mg-rich phases, complex Ca-Mg-Al-Si-Ti-Fe grains, and trace amounts of REE-rich particles. Many of the particles were rimmed by a Ca-S, possibly a sulfate. HRTEM-EDS examination of a REE-rich particle proved it to be a mix of light- and heavy-rare earth minerals mixed with amorphous phases.
Development of a Smart Computational Tool for the Evaluation of Co- and By-Products in Mining Projects Using Chovdar Gold Ore Deposit in Azerbaijan as a Case Study
Authors: Mammadli Anvar , Barakos George , Islam Md Ariful , Mischo Helmut , Hitch Michael
Published: August 2022

Despite their significance in numerous applications, many critical minerals and metals are still considered minor. Since most of them are not found alone in mineral deposits, their co- or by-production depends on the production of base metals and other major commodities. In many cases, the concentration of the minor metals is low enough not to be considered part of the production. Hence, their supply is not always secured, their availability decreases, and their criticality increases. Many researchers have addressed this issue, but no one has set actual impact factors other than economic ones that should determine the production of these minor commodities. This study identified several parameters, the number and diversity of which gave birth to developing a computational tool using a multi-criteria-decision analysis model based on the Analytical Hierarchical Process (AHP) and Python. This unprecedented methodology was applied to evaluate the production status of different commodities in a polymetallic deposit located in Chovdar, Azerbaijan. The evaluation outcomes indicated in quantifiable terms the production potentials for several commodities in the deposit and justified the great perspectives of this tool to evaluate all kinds of polymetallic deposits concerning the co- and by-production of several minor critical raw materials.
Classical Molecular Dynamics Simulations of Surface Modifications Triggered by a Femtosecond Laser Pulse
Authors: Lipp Vladimir , Ziaja Beata
Published: August 2022

This work is devoted to classical molecular dynamics simulations of surface modifications (craters) drilled by single femtosecond laser pulses in silicon and diamond, materials relevant for numerous industrial applications. We propose a methodology paving the way towards a significant decrease in the simulation computational costs, which could also enable a precise estimation of the craters’ size and shape.
Thickness Effect on the Solid-State Reaction of a Ni/GaAs System
Authors: Rabhi Selma , Oueldna Nouredine , Perrin-Pellegrino Carine , Portavoce Alain , Kalna Karol , Benoudia Mohamed Cherif , Hoummada Khalid
Published: August 2022

Ni thin films with different thicknesses were grown on a GaAs substrate using the magnetron sputtering technique followed by in situ X-ray diffraction (XRD) annealing in order to study the solid-state reaction between Ni and GaAs substrate. The thickness dependence on the formation of the intermetallic phases was investigated using in situ and ex situ XRD, pole figures, and atom probe tomography (APT). The results indicate that the 20 nm-thick Ni film exhibits an epitaxial relation with the GaAs substrate, which is (001) Ni//(001) GaAs and [111] Ni//[110] GaAs after deposition. Increasing the film’s thickness results in a change of the Ni film’s texture. This difference has an impact on the formation temperature of Ni3GaAs. This temperature decreases simultaneously with the thickness increase. This is due to the coherent/incoherent nature of the initial Ni/GaAs interface. The Ni3GaAs phase decomposes into the binary and ternary compounds xNiAs and Ni3−xGaAs1−x at about 400 °C. Similarly to Ni3GaAs, the decomposition temperature of the second phase also depends on the initial thickness of the Ni layer.
A Mini Review of Antibacterial Properties of Al2O3 Nanoparticles
Authors: Gudkov Sergey V. , Burmistrov Dmitriy E. , Smirnova Veronika V. , Semenova Anastasia A. , Lisitsyn Andrey B.
Published: August 2022

Bacterial antibiotic resistance is one of the most serious modern biomedical problems that prioritizes the search for new agents to combat bacterial pathogens. It is known that nanoparticles of many metals and metal oxides can have an antibacterial effect. However, the antibacterial efficacy of aluminum oxide nanoparticles has been studied little compared to the well-known antimicrobial properties of nanoparticles of oxides of metals such as zinc, silver, iron, and copper. In this review, we have focused on the experimental studies accumulated to date demonstrating the antibacterial effect of aluminum oxide nanoparticles. The review discusses the main ways of synthesis and modification of these nanoparticles, provides the proposed mechanisms of their antibacterial action against gram-positive and gram-negative bacteria, and also compares the antibacterial efficacy depending on morphological characteristics. We have also partially considered the activity of aluminum oxide nanoparticles against water microalgae and fungi. In general, a more detailed study of the antibacterial properties of aluminum oxide nanoparticles is of great interest due to their low toxicity to eukaryotic cells.
Self-Awareness of Cognitive Efficiency, Cognitive Status, Insight, and Financial Capacity in Patients with Mild AD, aMCI, and Healthy Controls: An Intriguing Liaison with Clinical Implications?
Authors: Giannouli Vaitsa , Tsolaki Magdalini
Published: August 2022

Objectives: This study compares objective measures of cognitive performance with subjective perception of specific performance on neuropsychological tests examining basic cognitive domains, including, for the first time, financial capacity. Additionally, differences in assessment between single- and multiple-domain aMCI, mild AD, and healthy elderly regarding insight are examined. Methods: Participants completed a number of neuropsychological tests and the Legal Capacity for Property Law Transactions Assessment Scale (LCPLTAS). After every test, participants were asked to complete the Clinical Insight Rating scale (CIR) and to self-evaluate their performance by comparing it to what they considered as average for people of their age and educational level. Results: These preliminary findings show significant differences in the self-assessment patterns of the four groups in measures of verbal memory, visuospatial perception and memory, executive functions, tests of attention, and financial capacity. Mild AD expressed the highest overestimations, followed by single- and multiple-domain aMCI as well as controls. Accuracy of self-report is not uniform across groups and functional areas. Conclusions: Unawareness of memory deficits in both MCI subtypes is contradictory to subjective memory complaints as being an important component for clinical diagnosis. Financial capacity is overestimated in MCI and mild AD, a finding that has a plethora of clinical and legal implications.
The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria
Authors: Ashkar Fatemeh , Bhullar Khushwant S. , Wu Jianping
Published: August 2022

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.