bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Water-Soluble Sulfonated Chitin Derivatives for Potential Antioxidant and Antifungal Activity
Authors: Luan Fang , Xu Zhenhua , Wang Kai , Qi Xin , Guo Zhanyong
Published: October 2022

Chitin is a natural renewable and useful biopolymer limited by its insolubility; chemical derivatization can enhance the solubility and bioactivity of chitin. The purpose of this study was to synthesize novel water-soluble chitin derivatives, sulfo-chitin (SCT) and sulfopropyl-chitin (SPCT), as antioxidant and antifungal agents. The target derivatives were characterized by means of elemental analysis, FTIR, 13C NMR, TGA and XRD. Furthermore, the antioxidant activity of the chitin derivatives was estimated by free radical scavenging ability (against DPPH-radical, hydroxyl-radical and superoxide-radical) and ferric reducing power. In addition, inhibitory effects against four fungi were also tested. The findings show that antioxidant abilities and antifungal properties were in order of SPCT > SCT > CT. On the basis of the results obtained, we confirmed that the introduction of sulfonated groups on the CT backbone would help improve the antioxidant and antifungal activity of CT. Moreover, its efficacy as an antioxidant and antifungal agent increased as the chain length of the substituents increased. This derivatization strategy might provide a feasible way to broaden the utilization of chitin. It is of great significance to minimize waste and realize the high-value utilization of aquatic product wastes.
The Impact of Burnout Syndrome on Job Satisfaction among Emergency Department Nurses of Emergency Clinical County Hospital “Sfântul Apostol Andrei” of Galati, Romania
Authors: Moscu Cosmina-Alina , Marina Virginia , Dragomir Liliana , Anghele Aurelian-Dumitrache , Anghele Mihaela
Published: October 2022

Background and Objectives: Burnout syndrome is caused by a number of factors, including personal, organizational, and professional problems. Data from the literature reported a strong relationship between burnout syndrome and job satisfaction among emergency medical personnel. Materials and Methods: We studied a sample of 80 nurses working in the Emergency Department of Emergency Clinical County Hospital “Sfântul Apostol Andrei” of Galati Romania. Participants signed an informed consent and then completed a socio-demographic questionnaire and the MBI-HSS (Maslach Burnout Inventory–Human Services Survey) questionnaire to assess the level of burnout and JSS (Job Satisfaction Survey) to assess the level of professional satisfaction. The aim of this study was to measure the levels of burnout and satisfaction among nurses in the Emergency Department as well as the relationship between these two variables and a group of selected socio-demographic characteristics. Results: This study found that 36.25% of nurses reported a high level of burnout. Additionally, emotional exhaustion is directly proportional to professional experience and age. Participants also reported a sense of ambivalence and satisfaction with the workplace, but were satisfied with the nature of their work. Conclusions: The results of this study suggest the relationship between variables and this could be used to implement psychoactive intervention strategies at both individual and organizational levels, which could lead to a decrease in burnout levels. Burnout is a predictor of job satisfaction for Emergency Department nurses. Personal achievement was relatively commensurate with the nature of the work. Additionally, the increase in burnout among nurses is directly proportional to the nature of the work.
Acute Eosinophilic Pneumonia after Combined Use of Conventional and Heat-Not-Burn Cigarettes: A Case Report
Authors: Kang Bo Hyoung , Lee Dong Hyun , Roh Mee Sook , Um Soo-Jung , Kim Insu
Published: October 2022

Background: Acute eosinophilic pneumonia (AEP) is a rare acute respiratory disease accompanied by fever, shortness of breath, and cough. Although the pathogenesis of the disease is not yet established, the patient’s condition improves with a rapid therapeutic response to systemic corticosteroids. Conventional cigarettes or heat-not-burn cigarettes are the most common cause of AEP among young people. Case Presentation: A 22-year-old woman with dyspnea, cough, and fever did not improve after visiting the local medical center and was admitted to the emergency room. The patient denied having any recent travel history or insect bites. She was treated with appropriate antibiotics according to the community acquired pneumonia, but there was no improvement. Chest radiography showed bilateral patches of pulmonary infiltration, and chest computed tomography revealed bilateral multifocal patchy consolidations with multiple small nodular ground-glass opacities and interlobular septal thickening. The bronchoalveolar lavage result was dominantly eosinophilic. The patient’s condition improved rapidly after the use of intravenous methylprednisolone and then a change to oral methylprednisolone. Finally, the patient was hospitalized for 9 days, and the duration of use of methylprednisolone including outpatient visits was 14 days. Results: The early treatment of AEP yields a good prognosis, but since the symptoms of AEP are similar to those of infectious diseases such as community-acquired pneumonia, physicians should be meticulous in differentiating AEP from other diseases. Conclusions: Since AEP shows a good response to steroids, early detection using an appropriate diagnostic method is recommended. In addition, there should be strong education against smoking in any form.
Growth of the Cycle Life and Rate Capability of LIB Silicon Anodes Based on Macroporous Membranes
Authors: Li Galina , Rumyantsev Aleksander , Astrova Ekaterina , Maximov Maxim
Published: October 2022

This work investigated the possibility of increasing the cycle life and rate capability of silicon anodes, made of macroporous membranes, by adding fluoroethylene carbonate (FEC) to the complex commercial electrolyte. It was found that FEC leads to a decrease in the degradation rate; for a sample without FEC addition, the discharge capacity at the level of Qdch = 1000 mAh/g remained unchanged for 220 cycles and the same sample with 3% FEC added to the electrolyte remained unchanged for over 600 cycles. FEC also improves the power characteristics of the anodes by 5–18%. Studies of impedance hodographs showed that in both electrolytes (with 0% and 3% FEC, respectively) the charge transfer resistance grows with an increasing number of cycles, while Solid Electrolyte Interphase (SEI) parameters, such as its resistance and capacitance, show little change. However, the addition of FEC more than halves the overall system impedance and reduces the resistance of the liquid electrolyte and all current carrying parts as well as the SEI film and charge transfer resistances.
Design of Multi-Layer Graphene Membrane with Descending Pore Size for 100% Water Desalination by Simulation Using ReaxFF
Authors: Ibrahim Qusai , Akbarzadeh Rokhsareh , Gharbia Salem S. , Ndungu Patrick Gathura
Published: October 2022

The performance of a desalination membrane depends on a specific pore size suitable for both water permeability and salt rejection. To increase membrane permeability, the applied pressure should be increased, which creates the need to improve membrane stability. In this research article, a molecular dynamics (MD) simulation was performed using ReaxFF module from Amsterdam Modeling suite (AMS) software to simulate water desalination efficiency using a single and multi-layer graphene membrane. The graphene membrane with different pore sizes and a multi-layer graphene membrane with descending pore size in each layer were designed and studied under different pressures. The stability of the membrane was checked using Material Studio 2019 by studying the dynamics summary. The single-layer graphene membrane was evaluated under pressures ranging from 100 to 500 MPa, with the salt rejection ranging from 95% to 82% with a water permeability of 0.347 × 10−9 to 2.94 × 10−9 (mm.g.cm−2s−1.bar−1), respectively. Almost 100% salt rejection was achieved for the multi-layer graphene membrane. This study successfully demonstrated the design and optimization of graphene membrane performance without functionalization.
From Traditional to Novel Printed Electrochromic Devices: Material, Structure and Device
Authors: Cai Qingyue , Yan Haoyang , Yao Rihui , Luo Dongxiang , Li Muyun , Zhong Jinyao , Yang Yuexin , Qiu Tian , Ning Honglong , Peng Junbiao
Published: October 2022

Electrochromic materials have been considered as a new way to achieve energy savings in the building sector due to their potential applications in smart windows, cars, aircrafts, etc. However, the high cost of manufacturing ECDs using the conventional manufacturing methods has limited its commercialization. It is the advantages of low cost as well as resource saving, green environment protection, flexibility and large area production that make printing electronic technology fit for manufacturing electrochromic devices. This paper reviews the progress of research on printed electrochromic devices (ECDs), detailing the preparation of ECDs by screen printing, inkjet printing and 3D printing, using the scientific properties of discrete definition printing method. Up to now, screen printing holds the largest share in the electrochromic industry due to its low cost and large ink output nature, which makes it suitable especially for printing on large surfaces. Though inkjet printing has the advantages of high precision and the highest coloration efficiency (CE) can be up to 542 ± 10 cm2C–1, it has developed smoothly, and has not shown rigid needs. Inkjet printing is suitable for the personalized printing production of high precision and small batch electronic devices. Since 3D printing is a new manufacturing technology in the 21st century, with the characteristics of integrated molding and being highly controllable, which make it suitable for customized printing of complex devices, such as all kinds of sensors, it has gained increasing attention in the past decade. Finally, the possibility of combining screen printing with inkjet printing to produce high performance ECDs is discussed.
Separation of Soluble Benzene from an Aqueous Solution by Pervaporation Using a Commercial Polydimethylsiloxane Membrane
Authors: Rasheed Salam H. , Ibrahim Salah S. , Alsalhy Qusay F. , Salih Issam K.
Published: October 2022

A developed polydimethylsiloxane (PDMS) membrane was used to separate soluble benzene compounds (C6H6) from an aqueous solution via a pervaporation (PV) process. This membrane was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, contact angle (CA), and energy-dispersive spectroscopy (EDS). To evaluate the performance of the membrane, the separation factor and permeation flux were estimated in various operating conditions, including the feed temperature, initial benzene concentration, and feed flow rate. The experiments to maximize the separation factor and permeation flux were designed using the response surface method (RSM) that is built into Minitab 18. A quadratic model (nonlinear regression equation) was suggested to obtain mathematical expressions to predict the benzene permeation flux and the separation factor according to the effect of the parameters’ interaction. The optimization of the PV was performed using an RSM that was based on the analysis of variance (ANOVA). The optimal values of the benzene permeation flux and separation factor were 6.7 g/m2·h and 39.8, respectively, at the optimal conditions of temperature (30 °C), initial concentration of benzene (1000 ppm), and feed flow rate (3.5 L/min). It was found that the feed concentration was the most influential parameter, leading to a significant increase in the permeation flux and separation factor of the PDMS membrane.
Theoretical Investigation of the Phenomenon of Space Charge Breakdown in Electromembrane Systems
Authors: Kovalenko Anna , Chubyr Natalia , Uzdenova Aminat , Urtenov Makhamet
Published: October 2022

At present, it is customary to consider the overlimit operating modes of electromembrane systems to be effective, and electroconvection as the main mechanism of overlimiting transfer. The breakdown of the space charge is a negative, “destructive” phenomenon, since after the breakdown the size and number of electroconvective vortices are significantly reduced, which leads to a decrease in mass transfer. Therefore, electromembrane desalination processes must be carried out before space charge breakdown occurs. Thus, the actual problem arises of determining at which potential jumps a breakdown of the space charge occurs at a given concentration of the solution. Electromembrane systems are used for desalination at electrolyte solution concentrations ranging from 1 to 100 mol/m3. In a theoretical study of increasing the efficiency of the desalination process, mathematical modeling is used in the form of a boundary value problem for the system of Nernst–Planck and Poisson (NPP) equations, which refers to “hard” problems that are difficult to solve numerically. This is caused by the appearance of a small parameter at the derivative in the Poisson equation in a dimensionless form, and, correspondingly, a boundary layer at ion-exchange membranes, where concentrations and other characteristics of the desalination process change exponentially. It is for this reason that the numerical study of the boundary value problem is currently obtained for initial concentrations of the order of 0.01 mol/m3. The paper proposes a new numerical–analytical method for solving boundary value problems for the system of Nernst–Planck and Poisson equations for real initial concentrations, using which the phenomenon of space charge breakdown (SCB) in the cross section of the desalination channel in potentiostatic and potentiodynamic modes is studied. The main regularities of the appearance and interaction of charge waves, up to their destruction (breakdown), are established. A simple formula is proposed for engineering calculations of the potential jump depending on the concentration of the solution, at which the breakdown of the space charge begins.
Study of Mineralogy and Metallurgical Properties of Lump Ores
Authors: Zhu Deqing , Jiang Yin , Pan Jian , Yang Congcong
Published: October 2022

The ironmaking process in blast furnaces using iron lumps is an energy-efficient and low-carbon initiative that helps lower the cost of the ironmaking process. The physical and chemical properties of raw materials, process mineralogy, and metallurgical properties of three Malaysian iron ore lumps were researched in this paper, with the goal of showing the relationship between metallurgical qualities and mineralogy. The results show that lump ore A has a better decrepitation index, with a DI−6.3mm of only 0.2%; lump ore J has better reducibility and low-temperature reduction disintegration index, with RI and RDI+6.3mm values of 88.39% and 87.55%, respectively; and the three lump ores have excellent softening and melting properties and a high permeability index. The metallurgical properties of lump ore and mineralogical characterizations are generally correlated, the decrepitation performance of lump ore is mostly determined by the presence of goethite, and the original porosity is unrelated. The higher the content, the worse the decrepitation performance; lump ore’s reducibility is mostly determined by the open porosity and the content of newly generating hematite at high temperatures, which has no relationship to its original porosity. The higher the open porosity, the higher the goethite content, the higher the newly generated porous hematite content, and the better the lump ore’s reducibility; the higher the original hematite content in the lump ores, the lower the open porosity at high temperatures and the worse the reduction degradation characteristics.
Thermomechanical and Microstructural Analysis of the Influence of B- and Ti-Content on the Hot Ductility Behavior of Microalloyed Steels
Authors: Gontijo Marina , Chakraborty Arnab , Webster Richard F. , Ilie Sergiu , Six Jakob , Primig Sophie , Sommitsch Christof
Published: October 2022

The effects of the combined addition of B and Ti, as well as the influence of different strain rates on the hot ductility behavior of low carbon, continuously cast, microalloyed steels were investigated in this work. Tensile tests, microstructure analyses, and thermokinetic simulations were performed with in situ melted samples. Furthermore, prior austenite grain evaluations were carried out for the two different microalloyed steels. Increasing the strain rate brought improvements to the ductility, which was more significant in the steel with the leanest composition. The steel containing more B and Ti presented a better hot ductility behavior under all conditions tested. The main causes for the improvements rely on the precipitation behavior and the austenite–ferrite phase transformation. The preferential formation of TiN instead of fine BN and AlN was seen to be beneficial to the ductility, as well as the absence of MnS. Grain boundary segregation of free B that did not form BN retarded the ferrite formation, avoiding the brittleness brought by the thin ferrite films at the austenite grain boundaries. Furthermore, it was revealed that for the steels in question, the prior austenite grains have less influence on the hot ductility behavior than the precipitates and ferrite formation.
Evolution of the Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Sheets during Multi-Pass Lowered-Temperature Rolling
Authors: Miao Qing , Zhu Lantao , Wang Wenke , Wang Zhihao , Shao Bin , Chen Wenzhen , Yu Yang , Zhang Wencong
Published: October 2022

AZ31 magnesium alloy sheets with 2 mm thickness were successfully fabricated by multi-pass lowered-temperature rolling. The evolution of the microstructure, texture, and mechanical properties during the rolling process was investigated. Based on the effect of multiple dynamic recrystallization, multi-pass lowered-temperature rolling not only refined the grain size obviously but also markedly improved the microstructure homogeneity. The resulting sheets had the optimal microstructure morphology with an average grain size of 4.38 μm. For the texture evolution, the stress state of the rolling process made the (0002) basal plane gradually rotate toward the rolling plane. However, the activation of non-basal slips due to the higher rolling temperature slightly rotated the (0002) basal plane point to the rolling direction (RD). As a result, the grain refinement strengthening and the texture strengthening together increased the yield stress to 202 MPa in the transverse direction (TD) and 189.8 MPa in the RD. Importantly, the resulting sheet concurrently exhibited excellent fracture elongation, about 38% in the TD and 39.2% in the RD. This was mainly ascribed to the finer grain size, giving rise to a significant effect of grain boundary sliding and the activation amount of non-basal slips.
A Comparative Study on the Mathematic Models for the Ignition of Titanium Alloy in Oxygen-Enriched Environment
Authors: Wang Congzhen , Li Jianjun , Li Yajun , Dou Caihong , Jin Pengfei , He Guangyu , Song Xiping , Huang Jinfeng , Zhang Cheng
Published: October 2022

Metallic materials are always suffered from the risk of combustion when serviced under some extreme conditions such as high temperature, oxygen-enriched enrichment, and high-speed friction. Although different mathematic models have been proposed but it is still a challenge for accurately describing the ignition conditions of metals under the extreme conditions, which is of great significance for the safety-use of materials. In this paper, the mathematic models based on Semenov and Frank-Kamenetskii theory were introduced into describing the effects of size, oxygen concentration, and oxygen pressure on the ignition temperature and critical oxygen pressure of TC17 alloy. The results showed that the critical oxygen pressure of TC17 alloy increased with the increase of size, which was fitted well with the Frank-Kamenetskii model. As a comparison, the critical oxygen pressure was size independent in the Semenov model, which was inconsistent with the experimental data. For the Frank-Kamenetskii model, the fitting results showed that the activation energy, reaction order, as well as the adsorption coefficient of TC17 alloy were determined to be 99.23 kJ/mol, 1.69, and 4.01 MPa−1.69 respectively. Based on above, the ignition temperature of TC17 samples with different sizes were predicted well by the Frank-Kamenetskii model with the relative error within 3.58%, which could be suitable for describing the critical ignition conditions of bulk metallic materials under complex environment.
Alternative Approach for the Intercritical Annealing of (Cr, Mo, V)-Alloyed TRIP-Assisted Steel before Austempering
Authors: Zurnadzhy Vadym , Efremenko Vasily , Petryshynets Ivan , Dabalà Manuele , Franceschi Mattia , Wu Kaiming , Kováč František , Chabak Yuliia , Puchy Viktor , Brykov Michail
Published: October 2022

TRIP-assisted C-Si-Mn steels are usually subjected to austempering with a preliminary intercritical annealing that is targeted at the multi-phase structure with 40–60 vol.% of proeutectoid ferrite. The kinetics and the mechanism of phase-structural transformations can be impacted due to the additional alloying of TRIP-assisted steel by the strong carbide forming elements, thus necessitating an alternative approach for the selection of intercritical annealing parameters. This issue is analyzed in the present work, which investigates the effect of the temperature of intercritical annealing on the “Structure/Properties” correlations in 0.2 wt.% C-Si-Mn-Nb steel additionally alloyed by 0.55 wt.% Cr, 0.20% Mo, and 0.11 wt.% V. The annealing temperature ranged from 770 °C to 950 °C, and austempering was performed at 350 °C for 20 min. It was observed that the addition of the (Cr, Mo, and V) complex significantly improved the steel hardenability. However, the annealing of steel at 770 °C (to gain 50 vol.% of proeutectoid ferrite) resulted in the precipitation of coarse cementite lamellas during bainite transformation, thus lowering the amount of retained austenite (RA) and decreasing the strength and ductility of the steel. At higher annealing temperatures, carbide-free bainite was formed, which presented a 2.5–3.5 times increase in the RA volume fraction and a 1.5 times increase in the RA carbon content. The optimal combination of the mechanical properties (UTS of 1040 MPa, TEL of 23%, V-notch impact toughness of 95 J/cm2, PSE of 23.9 GPa·%) referred to annealing at a temperature close to the Ac3 point, resulting in a structure with 5 vol.% ferrite and 9 vol.% RA (the residue was carbide-free bainite). This structure presented an extended manifestation of the TRIP effect with an enhanced strain hardening rate due to strain-induced martensite transformation. The impact of the alloying elements on the carbon activity in austenite served as the basis for the analysis of structure formation.
Surface or Internal Fatigue Crack Initiation during VHCF of Tempered Martensitic and Bainitic Steels: Microstructure and Frequency/Strain Rate Dependency
Authors: Krupp Ulrich , Giertler Alexander
Published: October 2022

By means of comparing the VHCF response of heat-treated alloy steel, several factors governing the transition from surface (type I) to internal (type II) VHCF failure, and, in the case of internal inclusion and non-inclusion type II VHCF failure, are discussed: differences in strength, differences in grain size and strength gradients. Therefore, the steel grades (i) 50CrMo4 (0.5 wt%C–1.0 wt%Cr–0.2 wt%Mo) in two different tempering conditions (37HRC and 57HRC) but of the same prior austenite grain size, and (ii) 16MnCrV7 7 (0.16 wt%C–1.25 wt%Mn–1.7 wt%Cr) in the bainitic and martensitic thermomechanical treatment state, were studied. It is concluded that steels of moderate strength (37HRC) exhibit a real endurance limit (109 cycles), while the fatigue strength of high strength (43–57HRC) or coarse-grained steels (37HRC) decreases with increasing number of load cycles.
Synthesis and Catalytic Studies of Nanoalloy Particles Based on Bismuth, Silver, and Rhenium
Authors: Wojtaszek Konrad , Skibińska Katarzyna , Cebula Filip , Tokarski Tomasz , Escribà-Gelonch Marc , Hessel Volker , Wojnicki Marek
Published: October 2022

The work reports the synthesis and characterization of ternary nanoalloy catalysts of silver, bismuth, and rhenium from alkaline solutions containing L–cysteine as a complexing agent and sodium borohydride as a reducing agent. UV–Vis spectra and dynamic light scattering (DLS) analyses of the obtained colloids were performed. Additionally, high-resolution transmission electron microscope (HR–TEM) analysis assisted the former investigations. The influence of a stabilizer (PVA) was demonstrated for bismuth nanoparticles reaching an average size of 8 nm with PVA, whereas they grew large, 514 nm, in the case of synthesis without stabilizing agent. AgReBi nanoalloy particles reach an average size of 19 nm with PVA. The presence of two absorption maxima in the UV–Vis spectrum suggests shape anisotropy of these nanoparticles. TEM micrographs demonstrate the crystal structure of AgReBi nanoparticles. Cyclic voltamaperometry allows for deciphering of the catalytic properties for hydrogen peroxide electro-reduction. Both bismuth and AgReBi nanoalloy catalysts showed relatively high catalytic activity in H2O2 electro-reduction in the amperometric tests.
Rhizophora mucronata Lam. (Mangrove) Bark Extract Reduces Ethanol-Induced Liver Cell Death and Oxidative Stress in Swiss Albino Mice: In Vivo and In Silico Studies
Authors: Jairaman Chitra , Alehaideb Zeyad I. , Yacoob Syed Ali Mohamed , Alghamdi Sahar S. , Suliman Rasha S. , Venkataraman Anuradha , Alghanem Bandar , Sivanesan Senthilkumar , Vijayaraghavan Rajagopalan , Rameshbabu Saranya , Pari Shree Mukilan , Matou-Nasri Sabine
Published: October 2022

The bark extract of Rhizophora mucronata (BERM) was recently reported for its prominent in vitro protective effects against liver cell line toxicity caused by various toxicants, including ethanol. Here, we aimed to verify the in vivo hepatoprotective effects of BERM against ethanol intoxication with the prediction of potential targets employing in silico studies. An oral administration of different concentrations (100, 200 and 400 mg/kg body weight) of BERM before high-dose ethanol via intraperitoneal injection was performed in mice. On day 7, liver sections were dissected for histopathological examination. The ethanol intoxication caused liver injury and large areas of necrosis. The pre-BERM administration decreased the ethanol-induced liver damage marker tumor necrosis factor-alpha (TNF-α) expression, reduced hepatotoxicity revealed by nuclear deoxyribonucleic acid (DNA) fragmentation and decreased oxidative stress indicated by malondialdehyde and glutathione contents. Our in silico studies have identified BERM-derived metabolites exhibiting the highest predicted antioxidant and free radical scavenger activities. Molecular docking studies showed that most of the metabolites were predicted to be enzyme inhibitors such as carbonic anhydrase inhibitors, which were reported to stimulate the antioxidant defense system. The metabolites predominantly presented acceptable pharmacokinetics and safety profiles, suggesting them as promising new antioxidant agents. Altogether, the BERM extract exerts antioxidative activities and shows promising hepatoprotective effects against ethanol intoxication. Identification of related bioactive compounds will be of interest for future use at physiological concentrations in ethanol-intoxicated individuals.
Influence of 24 h Simulated Altitude on Red Blood Cell Deformability and Hematological Parameters in Patients with Fontan Circulation
Authors: Härtel Julian Alexander , Müller Nicole , Breuer Johannes , Jordan Jens , Tank Jens , Bros Janina , Seeger Benedikt , Zollmann Emily , Bloch Wilhelm , Grau Marijke
Published: October 2022

Patients with Fontan circulation are particularly dependent on low pulmonary vascular resistance because their lungs are passively perfused. Hypoxia drives pulmonary vasoconstriction; thus, red blood cell (RBC) deformability and stability of hematological parameters might be of particular importance, because alterations during hypoxia might further influence circulation. This study aimed to measure respective parameters in patients with Fontan circulation exposed to normobaric hypoxia. A total of 18 patients with Fontan circulation (16 to 38 years) were exposed to normobaric hypoxia (15.2% ambient oxygen). Blood samples were taken in normoxia, after 24 h in hypoxia, and 60 min after return to normoxia. Blood count, RBC age distribution, EPO, RBC deformability, marker of RBC nitric oxide, oxidative state, and RBC ATP were measured. Hypoxia increased oxidative stress in RBC, but without affecting RBC deformability. RBC age distribution remained unaffected, although EPO concentrations increased, followed by a rise in reticulocyte count at an already high hematocrit. NO metabolism was not affected by hypoxia. Modest normobaric hypoxia for 24 h did not impair RBC deformability in patients with Fontan circulation; however, the oxidative system seemed to be stressed. Given the high baseline Hct in these patients, hypoxia-induced erythropoiesis could adversely affect rheology with more prolonged hypoxia exposure.
Effects of Proteases from Pineapple and Papaya on Protein Digestive Capacity and Gut Microbiota in Healthy C57BL/6 Mice and Dose-Manner Response on Mucosal Permeability in Human Reconstructed Intestinal 3D Tissue Model
Authors: Kostiuchenko Olha , Kravchenko Nadiia , Markus Jan , Burleigh Stephen , Fedkiv Olexandr , Cao Ling , Letasiova Silvia , Skibo Galyna , Fåk Hållenius Frida , Prykhodko Olena
Published: October 2022

Cysteine proteases obtained from the stem of pineapple or papaya latex, bromelain and papain, respectively, exhibit a broad spectrum of beneficial effects on human health. However, their effects on gut microbiota composition or dose-manner effects on the intestinal integrity of healthy tissue have not been evaluated. In this study, C57BL/6 young, healthy mice were fed bromelain or papain in a dose of 1 mg per animal/day for three consecutive days, followed by the assessment of digestive protein capacity, intestinal morphology and gut microbiota composition. Furthermore, a human reconstructed 3D tissue model EpiIntestinal (SMI-100) was used to study the effects of 1, 0.1 and 10 mg/mL doses of each enzyme on tissue integrity and mucosal permeability using TEER measurements and passage of Lucifer Yellow marker from the apical to the basolateral side of the mucosa. The results indicated that fruit proteases have the potential to modulate gut microbiota with decreasing abundance of Proteobacteria and increasing beneficial Akkermansia muciniphila. The enhancement of pancreatic trypsin was observed in bromelain and papain supplementation, while bromelain also increased the thickness of the ileal mucosa. Furthermore, an in vitro study showed a dose-dependent interruption in epithelial integrity, which resulted in increased paracellular permeability by the highest doses of enzymes. These findings define bromelain and papain as promising enzymatic supplementation for controlled enhancement of paracellular uptake when needed, together with beneficial effects on the gut microbiota.
Magnetic Forces by Permanent Magnets to Manipulate Magnetoresponsive Particles in Drug-Targeting Applications
Authors: Bernad Sandor I. , Bernad Elena
Published: October 2022

This study presents preliminary computational and experimental findings on two alternative permanent magnet configurations helpful for magnetic drug administration in vivo. A numerical simulation and a direct experimental measurement of the magnetic induction on the magnet system’s surface were used to map the magnetic field. In addition, the ferrite-type (grade Y35) and permanent neodymium magnets (grade N52) to produce powerful magnetic forces were also examined analytically and quantitatively. Ansys-Maxwell software and Finite Element Method Magnetism (FEMM) version 4.2 were used for all numerical computations in the current investigation. For both magnets, the generated magnetic fields were comparatively studied for targeting Fe particles having a diameter of 6 μm. The following findings were drawn from the present investigation: (i) the particle deposition on the vessel wall is greatly influenced by the intensity of the magnetic field, the magnet type, the magnet size, and the magnetic characteristics of the micro-sized magnetic particles (MSMPs); (ii) ferrite-type magnets might be employed to deliver magnetoresponsive particles to a target location, even if they are less powerful than neodymium magnets; and (iii) the results from the Computational Fluid Dynamics( CFD) models agree well with the measured magnetic field induction, magnetic field strength, and their fluctuation with the distance from the magnet surface.
Design and Implementation of a Fully-Actuated Integrated Aerial Platform Based on Geometric Model Predictive Control
Authors: Shi Chuanbeibei , Yu Yushu
Published: October 2022

Unlike individual unmanned aerial vehicles (UAVs), integrated aerial platforms (IAPs) containing multiple UAVs do not suffer from underactuation and can move omnidirectionally in six dimensions, providing a basis for constructing aerial manipulation platforms. Compared to single UAVs, multi-UAV IAPs are also advantageous in terms of payload and fault-tolerance capacity, making them promising candidates as platforms with integrated-response, observation, and strike capabilities. Herein, an IAP structure design containing three sub-UAVs connected in a star-like configuration is presented. This form of integration enables the IAP, as a whole, to simultaneously adjust its position and attitude in six dimensions. The dynamics of the overall system of the IAP are modeled. On this basis, an overall system controller is designed. To simplify control, based on stability of cascaded system, the rotational motion of the sub-UAVs is treated as a inner-loop subsystem, whereas the overall motion of the IAP is seen as a outer-loop subsystem. Because the configuration space of the sub-UAVs is non-Euclidean, a controller is designed for the outer-loop subsystem based on model predictive control on the manifold. Subsequently, the stability of the closed-loop system is demonstrated. Fieldbus technology is employed to design a real-time, scalable communication architecture for multiple sub-UAVs, followed by the development of a principle prototype of the multi-UAV IAP that consists of hardware and software systems. The effectiveness of the IAP design and control method is validated through simulation and real-world prototype-based tests. In the simulation and real-world tests, the proposed methodology can make the IAP system converge to the desired configuration at the presence of large initial configuration error. The same test scenario cannot be finished by a baseline PID controller. The advantage of the proposed control scheme in dealing with state and input constraints is shown via such tests.
Genesis of the Beixiang Sb-Pb-Zn-Sn Deposit and Polymetallic Enrichment of the Danchi Sn-Polymetallic Ore Belt in Guangxi, SW China
Authors: Wu Jing , Li Zhi , Zhu Minjie , Huang Wenting , Liao Juan , Zhang Jian , Liang Huaying
Published: October 2022

Antimony deposits contain little Sn, whereas Sb and Pb are not the principally contained metal of granite-related Sn deposits. The Danchi Sn-metallogenic ore belt (DSOB) in southwestern China is characterized by Sn-Sb-Zn-Pb co-enrichment, yet the triggers are poorly constrained. The Beixiang deposit in the southern DSOB consists of stage I Sn-Zn and stage II Sb-Pb-Zn mineralization. Here, we analyzed the cassiterite U-Pb age, fluid inclusion H-O and sulfide Pb-S isotopes, and calcite trace elements of the Beixiang ores. By comparing with the Dachang and Mangchang Sn-polymetallic ore-fields within the DSOB, we constrained the timing of regional mineralization and revealed the processes causing the Sb-Pb co-enrichment. The cassiterite U-Pb dating yielded 90.6 ± 4.5 Ma (MSWD = 2.6), similar to the ages of the Dachang and Mangchang ore fields, indicating the Late Cretaceous mineralization event throughout the DSOB. The fluid inclusions from stage II ore have δ18OH2O (−2.8 to −7.8‰) and δDV-SMOW (−90.5 to −59.3‰), and the synchronous calcite features have low REE contents, upward-convex REE patterns, and weak Eu anomalies. These suggest that the ore fluids were derived from meteoric water and oil field brine, which dissolved S and Pb from local strata as recorded by sulfide sulfur (δ34SV-CDT = −6.2 to −4.0‰) and Pb isotopes. However, calcite from the stage I ore have higher REE contents and (La/Yb)N, with strong positive Eu anomalies, indicating that the Sn-rich ore fluids were released by greisenization of granite. Overall, we suggest that the combination of granitic magma- and oil field brine-derived fluids, rich in Sn-Zn and Sb-Pb-Zn, respectively, caused the co-enrichment of Sn-Sb-Pb-Zn in Beixiang and throughout the DSOB.
Rare Earth Element (REE) and Critical Mineral Fractions of Central Appalachian Coal-Related Strata Determined by 7-Step Sequential Extraction
Authors: Bauer Sophia , Yang Jonathan , Stuckman Mengling , Verba Circe
Published: October 2022

Rare earth elements (REEs) and critical minerals (CMs) are used in many modern industries, including the automotive sector, generation and storage, clean energy, and defense. The demand for REEs is increasing, and the REE supply chain is unpredictable. The US has driven to assess non-conventional sources of REE (such as coal underclay) to identify domestic resources to stabilize this uncertainty in supply. Knowledge of the minerology, distribution, and modes of occurrence of REEs is integral to the assessment of non-conventional sources. Additionally, extraction techniques can be optimized and targeted when REE distribution in different solid fractions from source material is understood. In this study, four bituminous coal-related samples associated with the Lower and Middle Kittanning coal seams in the Appalachian Basin (US) underwent a seven-step sequential extraction procedure, primarily targeting the water-soluble, exchangeable, acid soluble, mildly reducible, moderately reducible, strongly reducible, and oxidizable fractions. The REE and other elements of interest from each extraction step were analyzed, and the percentages of element extracted from raw solids were calculated. REEs extracted from the total seven steps were reported as the extractable fraction, whereas the fractions in the residual solids were reported as the non-extractable fraction. Less than 6% of REE were extracted from three samples. Twenty-one percent of REE was extracted from the fourth sample, mainly from the steps targeting oxidizable and exchangeable phases. Co-extraction of critical metals (Co, Ni, Cu, and Zn) occurred during the oxidizable, exchangeable, acid soluble, and water-soluble steps for the four samples. In the extracted fractions, the four samples all exhibited a middle and heavy REE enrichment relative to light REE. The mobility of major cation (e.g., Ca, Fe, and P) and REE is associated with exchangeable, oxidizable, and acid soluble fractions. Non-extractable REE is likely held in refractory apatitic phases, and/or primary REE-phosphates (e.g., monazite and xenotime).
Natural Radionuclides in Soils of Natural-Technogenic Landscapes in the Impact Zone of Potassium Salt Mining
Authors: Perevoshchikov Roman , Perminova Anna , Menshikova Elena
Published: October 2022

This study considers the contents of natural radionuclides (226Ra, 232Th, and 40K) in the soils of natural–technogenic landscapes in the Verkhnekamskoe potassium–magnesium salt deposit (Perm Krai, Russia). The purpose of the study is to assess the lateral activity distribution of natural radionuclides (226Ra, 232Th, and 40K) in the soils of natural–technogenic landscapes of the mining areas on the territory of the Berezniki–Solikamsk industrial hub. Seventy-five soil samples from depths of 0–0.4 m are examined. The specific activities of the natural radionuclides 226Ra, 232Th, and 40K in the soil samples are measured using gamma spectrometry. The average values of the activity concentrations of 226Ra, 232Th, and 40K are 11.78 Bq/kg, 8.11 Bq/kg, and 246.9 Bq/kg, respectively. A gamma survey is conducted using the MKS/SRP-08A search dosimeter–radiometer over a control point framework covering 50,000 hectares. The research shows that the migration of the studied natural radionuclides is limited to a radius of 10 km. The results of the gamma-radiation measurements in the study area fall within a range of 0.06–0.25 µSv/h, which does not exceed the permissible limits. According to the findings, there is an increase in the concentration of natural radionuclides in transit supra-floodplain terrace landscapes and accumulative floodplain landscapes in the area affected by potash mining.
Eclogite Varieties and Their Positions in the Cratonic Mantle Lithosphere beneath Siberian Craton and Archean Cratons Worldwide
Authors: Ashchepkov Igor , Logvinova Alla , Spetsius Zdislav , Downes Hilary , Ntaflos Theodoros , Ivanov Alexandr , Zinchenko Vladimir , Kostrovitsky Sergey , Ovchinnikov Yury
Published: October 2022

The pressure-temperature (PT) conditions and position of different groups of eclogites in the sub-cratonic lithospheric mantle (SCLM) worldwide were established using clinopyroxene Jd-Di and garnet thermobarometry. Beneath Siberia, Fe-eclogites found within the 3.0–4.0 GPa formed in Early Archean times. In the Middle and Late Archean, eclogites were melted during and after subduction. High-Mg eclogites (partial melts or arc cumulates) are related to low-T (LT) geotherms. Melt-metasomatized eclogites trace a high-temperature (HT) geotherm. Eclogitic diamond inclusions from Siberia mostly belong to the middle SCLM (MSCLM) part. Ca-rich eclogites from Precambrian Indian kimberlites are located in the MSCLM. In Phanerozoic time, they were located in the lithosphere base. In Proterozoic South Africa, Ca-rich eclogites and grospydites occur within 4.0–5.0 GPa and HT eclogite and diamond inclusions from the Premier pipe trace a HT geotherm at depths of 7.0–4.0 GPa, showing an increase in Fe upwards in the mantle section. Similar trends are common for eclogites worldwide. In the Wyoming craton, kimberlites captured eclogite xenoliths from the 4.0–2.5 GPa interval. Mantle eclogites have clinopyroxenes and garnet trace element patterns with high (La/Yb)n determined by KDs with melts and are magmatic. Flatter and bell-like REE patterns with Eu anomalies, HFSE troughs, and U and Pb peaks, are common for clinopyroxenes from MORB-type “basaltic” eclogites. High-Mg eclogites show less fractionated incompatible element branch in patterns. LILE-enrichments and HFSE troughs are typical for kyanite-bearing eclogites. Clinopyroxenes from diamond-bearing eclogites show lower REE, troughs in Nb and Zr, and peaks in Pb and U concentrations, compared to barren eclogites with round smooth trace element patterns and small depressions in Pb and Ba.
Study on the Color-Influencing Factors of Blue Iolite
Authors: Liu Xin , Guo Ying
Published: October 2022

This article explores the factors that influence the color of blue iolite, which is the gem-quality variety of the cordierite mineral. The X-Rite SP62 portable spectrophotometer was used to measure color in the CIELAB color space. ED-XRF and UV–vis were used for analysis. The results show that blue iolite contains the chromophore elements Fe and Mn, but the effect on the color of iolite is not significant due to the low Mn content. The lightness L* and the hue angle h° are mostly determined by its Fe content. UV–vis spectra show that iolite has a broad absorption band near 570 nm caused by the charge transfer between Fe2+ on the octahedron and Fe3+ on the T11 tetrahedron and results in the color of blue iolite. Each different standard light source has different degrees of influence on the color parameters of iolite, and the hue angle h° is the most influenced.
Main Control Factors and Hydrocarbon Accumulation Model of Volcanic Oil Reservoirs with Complex Oil–Water Relationships: A Case Study of the Carboniferous in the Chepaizi Uplift, the Junggar Basin, China
Authors: Li Xiaoshan , Pan Hong , Wu Yuxiao , Luo Guanxing , Song Junqiang , Yang Liu , Gu Kaifang , Jin Ping , Wang Shuo , Li Ting , Zhang Lifeng
Published: October 2022

In order to study the main control factors of volcanic reservoirs with complex oil–water relationships, the Carboniferous in the Chepaizi Uplift of the Junggar Basin was taken as an example and the lithofacies characteristics, main control factors, and hydrocarbon accumulation model of volcanic reservoirs were investigated by combining the petroleum geology with field testing (data of core analysis, well logging, formation testing, and production testing). The results show that the Carboniferous in the Chepaizi Uplift experienced three stages of volcanic activities and developed seven volcanic lithofacies bodies, distributed in a bead-string connected planar form along the Hongche fault. There is no unified oil–water interface across the whole study area and there are multiple oil–water systems within one fault block. The Carboniferous volcanic reservoir experienced two stages of hydrocarbon accumulation from two different source rocks. The distribution of faults penetrating hydrocarbon kitchens and source rocks controls the macro-scale distribution of reservoirs. The physical properties of reservoirs affect the pattern of oil and water differentiation in volcanic rock bodies, while the lithofacies body-controlled hydrocarbon accumulation mode highlighting “one rock body for one reservoir” determines the distribution of reservoirs. The matching between the paleo-structure and hydrocarbon accumulation stage controls the accumulation and adjustment of hydrocarbon distribution. The Permian source rocks in the Shawan Sag serve as the lateral hydrocarbon supply and hydrocarbons accumulate in the Carboniferous structural-lithologic traps, which are summarized as the two stages of hydrocarbon accumulation of newly generated hydrocarbons into older reservoir rocks. This study of the hydrocarbon accumulation pattern in volcanic rocks aims at guiding the development of Carboniferous reservoirs with complex oil and water relationships in this area.
Research on Multi-Objective Ore Blending Optimization Based on Non-Equilibrium Grade Polymetallic Mine of Shizhuyuan
Authors: Wu Ji , Huang Linqi , He Binquan , Li Zhongze , Chen Guohui , Chen Gong , Li Xibing
Published: October 2022

The ore blending of non-equilibrium grade polymetallic ore is affected by various factors such as mineral resources, production technology, and economic efficiency. Aiming at the problems of Shizhuyuan Polymetallic Mine being diverse in nature, uneven in size, having many mining points, with large grade fluctuation, this paper proposes an optimization method for ore blending based on an artificial bee colony (ABC) algorithm. A multi-metal and multi-objective ore-blending optimization model is established with the minimum fluctuation of ore grade, mining transportation cost, and production capacity as the objective function. The ore mining plan was prepared according to the actual production situation of the mine and the optimization results. While ensuring that the average grade of the output ore reaches the minimum selected grade of the beneficiation plant, the recovery rates of tungsten, molybdenum, and bismuth in the beneficiation plant are significantly increased by 8.95%, 12.20%, and 8.33%, respectively. This study has discovered the first refined and high-efficiency blending of polymetallic ore such as tungsten, molybdenum, and bismuth in China, with simultaneous mining of low-and high-grade ore, cost control, balanced selection of grades, and coordinated production tasks.