bluuebunny/crossref_metadata_2025 huggingface dataset:
An Eco-Friendly Acid Leaching Strategy for Dealkalization of Red Mud by Controlling Phase Transformation
Authors: Wu Jiaming , Lei Tianyu , Wang Beibei , Ma Shuwei , Lin Yulong , Lu Xiaolei , Ye Zhengmao
Published: January 2022

The alkaline components in red mud represent one of the crucial factors restricting its application, especially for the construction and building industry. The phase state of alkaline components has a significant influence on the dealkalization of red mud. In this work, an environmentally friendly acid leaching strategy is proposed by controlling the phase transformation of red mud during active roasting pretreatment. With a moderate roasting temperature, the alkaline component is prevented from converting into insoluble phases. After acid leaching with a low concentration of 0.1 M, a high dealkalization rate of 92.8% is obtained. Besides, the leachate is neutral (pH = 7) and the valuable metals in red mud are well preserved, manifesting a high selectivity and efficiency of diluted acid leaching. The calcination experiment further confirms the practicability of the strategy in the construction field, where the cementitious minerals can be formed in large quantities. Compared with the traditional acid leaching routes, the diluted acid leaching strategy in this work is acid saving with low valuable element consumption. Meanwhile, the secondary pollution issue can be alleviated. Hence, the findings in this work provide a feasible approach for the separation and recovery of alkali and resource utilization of red mud.
Influence of Carbon Sorbent Quantity on Breakthrough Time in Absorbent Filters for Antismog Half Mask Application
Authors: Brochocka Agnieszka , Nowak Aleksandra , Kozikowski Paweł
Published: January 2022

In this article, we present polymer non-woven fabrics with the addition of carbon sorbents being tested to estimate the breakthrough time and efficient protection against vapors present in smog. For this purpose, three substances were selected, which constitute an inhalation hazard and are smog components: cyclohexane, toluene, and sulfur dioxide. It was demonstrated that an increased quantity of carbon sorbent in polymeric filters significantly prolongs the breakthrough time. However, high sorbent quantities may increase the filter surface mass and air flow resistance. To optimize the protective parameters with functionality, a compromise between the two has to be found. By comparing the breakthrough times for different carbon sorbent quantities, the optimal filter composition was elaborated. The analyzed non-woven fabrics were manufactured by the melt-blown process and filled with ball-milled carbon sorbents supplied directly into the fabric blowing nozzle. Both protective performance and textural properties were analyzed for two commercially available carbon sorbents. Furthermore, it was proven that high values of sorbent-specific surface area translates directly into greater filter performance.
The Influence of Cutting Parameters on Plastic Deformation and Chip Compression during the Turning of C45 Medium Carbon Steel and 62SiMnCr4 Tool Steel
Authors: Kuruc Marcel , Vopát Tomáš , Peterka Jozef , Necpal Martin , Šimna Vladimír , Milde Ján , Jurina František
Published: January 2022

The paper deals with the issue of cutting zone and chip compression. The aim was to analyse the microstructure transverse section of the cutting zone on a metallographic cut, due to determined values of chip compression and plastic deformation, which affect the cutting process efficiency. The tested cutting tool material was coated with cemented carbide. The selected workpiece materials were C45 medium carbon steel of ISO grade and 62SiMnCr4 tool steel of ISO (W.Nr. 1.2101) grade. In the experiments, a DMG CTX alpha 500 turning centre was used. The cutting speed and feed were varied, and the depth of the cut was kept constant during the turning. The plastic deformation and chip compression determine the efficiency of the cutting process. The higher compression requires more work to perform the process and, therefore, it requires more energy for doing so. With the increase of the cutting speed, the deformation for C45 steel is decreased. The rapid deformation reduction was observed when the cutting speed was increased from 145 m/min to 180 m/min. Generally, deformation is decreasing with the increase of the feed. Only at a cutting speed of 145 m/min was the deformation elevation observed, when the feed was increased from 0.4 mm to 0.6 mm. During the turning of the 62SiMnCr4 tool steel we observed an error value at a cutting speed of 145 m/min and a feed of 0.4 mm was the middle cutting parameter. However, feed dependence was clear: With an increase of the feed, the plastic deformation was decreasing. This decreasing was more rapid with the increasing of the cutting speed. Besides plastic deformation, there was analysed chip compression as well. With the increasing of the cutting speed, there was a decrease of the chip compression. Due to a lack of information in the area of the chip compression and the plastic deformation in the cutting process, we decided to investigate the cutting zone for the turning of tool steels 62SiMnCr4, which was compared with the reference steel C45. The results could be applied to increase the efficiency of the process and improvement of the surface integrity.
Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs
Authors: Zheng Changsong , Ma Zhiwei , Yu Liang , Wang Xu , Zheng Liangjie , Zhu Li’an
Published: January 2022

To study the influence of nano-additives on the friction-wear characteristics of friction materials, the nano-sized silicon carbide particles which have excellent chemical and physical properties are considered to add in composite to form the modified friction material. The influence of the silicon carbide nanoparticles (SCN) on the friction-wear characteristics of copper-based friction materials (CBFM) is investigated via the SAE#2 (made in Hangzhou, China) clutch bench test with the applied pressure, rotating speed, and automatic transmission fluid (ATF) temperature taken into account. Moreover, the variations of friction torque and temperature are considered to evaluate the friction performance, and the variable coefficient is employed to describe the friction stability. The wear characteristics of friction materials are investigated by the disc changes in thickness and micro-morphology. The results show that the CBFM with SCN can provide a higher friction torque, which increased by 30% to 50% compared with CBFM. The variable coefficient of CBFM with SCN changes from 674 to 52 with the rotating speed raised from 600 rpm to 3000 rpm, which shows that the friction stability is relatively worse. Furthermore, the micromorphology shows that the CBFM with SCN has lower porosity and surface roughness, which increases the microscopic contact area and the coefficient of friction (COF). Simultaneously, the reduction in porosity also leads to a decrease in the cooling quality, bringing about a rapid temperature rise. Thus, the wear amount of CBFM with SCN increases significantly, especially for the friction disc in the axial middle position.
Effect of Thermomechanical Treatment of Al-Zn-Mg-Cu with Minor Amount of Sc and Zr on the Mechanical Properties
Authors: Beigi Kheradmand Azam , Mirdamadi Shamseddin , Lalegani Zahra , Hamawandi Bejan
Published: January 2022

In this study, the mechanical and microstructural properties of Al-Zn-Mg-Cu-Zr cast alloy with 0.1% Sc under homogeneous, dissolution, and T6 and thermomechanical treatments with the aim of increasing the volume fraction of MgZn2. Al3(Sc,Zr) reinforcing precipitates were examined by hardness, microscopic examinations, tensile tests and software analysis. The results showed that, firstly, the hardness results are well proportional to the results of the tensile properties of alloys and, secondly, the strength of the alloy with thermomechanical treatments compared to T6 treatments increased from 492 MPa to 620 MPa and the elongation increased from 8% to 17% and was 100% upgraded. Microstructural and fracture cross section investigations showed that Al3(Sc,Zr) nanosize dispersoids were evenly distributed among MgZn2 dispersoids and the alloy fracture was of semi-ductile type and nanosize dispersoids less than 10 nm were observed at the end of the dimples in the fracture section. The volume fraction of nanosize dispersoids in the whole microstructure of thermomechanical treatment samples was also much higher than that of T6 heat treated samples, so that the percentage of Al3(Sc,Zr) precipitates arrived from less than 1% in T6 operation to 8.28% in the quench-controlled thermomechanical operation (with 50% deformation). The quality index (QI) in thermomechanical treatment samples is 19% higher than T6 samples, so that this index has increased from 641 in T6 operation to 760 in samples under thermomechanical treatment due to precipitate morphology, volume fraction of precipitates, their uniform distribution in the matrix, and nano sized precipitates in samples under thermomechanical treatment.
The Influence of Layer Thickness on the Microstructure and Mechanical Properties of M300 Maraging Steel Additively Manufactured by LENS® Technology
Authors: Rońda Natalia , Grzelak Krzysztof , Polański Marek , Dworecka-Wójcik Julita
Published: January 2022

This work investigates the effect of layer thickness on the microstructure and mechanical properties of M300 maraging steel produced by Laser Engineered Net Shaping (LENS®) technique. The microstructure was characterized using light microscopy (LM) and scanning electron microscopy (SEM). The mechanical properties were characterized by tensile tests and microhardness measurements. The porosity and mechanical properties were found to be highly dependent on the layer thickness. Increasing the layer thickness increased the porosity of the manufactured parts while degrading their mechanical properties. Moreover, etched samples revealed a fine cellular dendritic microstructure; decreasing the layer thickness caused the microstructure to become fine-grained. Tests showed that for samples manufactured with the chosen laser power, a layer thickness of more than 0.75 mm is too high to maintain the structural integrity of the deposited material.
The Microstructure, Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives
Authors: Yu Dawei , Feng Jiayao , You Huimin , Zhou Shipeng , Bai Yan , He Jincan , Cao Hua , Che Qishi , Guo Jiao , Su Zhengquan
Published: January 2022

Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.
Risk Factors for Urological Complications Associated with Caesarean Section—A Case-Control Study
Authors: Radu Viorel Dragos , Pristavu Anda Ioana , Vinturache Angela , Onofrei Pavel , Socolov Demetra Gabriela , Carauleanu Alexandru , Boiculese Lucian , Scripcariu Sadyie Ioana , Costache Radu Cristian
Published: January 2022

Background and Objectives: Acute urologic complications, including bladder and/or ureteric injury, are rare but known events occurring at the time of caesarean section (CS). Delayed or inadequate management is associated with increased morbidity and poor long-term outcomes. We conducted this study to identify the risk factors for urologic injuries at CS in order to inform obstetricians and patients of the risks and allow management planning to mitigate these risks. Materials and Methods: We reviewed all cases of urological injuries that occurred at CS surgeries in a tertiary university centre over a period of four years, from January 2016 to December 2019. To assess the risk factors of urologic injuries, a case-control study of women undergoing caesarean delivery was designed, matched 1:3 to randomly selected women who had an uncomplicated CS. Electronic medical records and operative reports were reviewed for socio-demographic and clinical information. Descriptive and univariate analyses were used to characterize the study population and identify the risk factors for urologic complications. Results: There were 36 patients with urologic complications out of 14,340 CS patients, with an incidence of 0.25%. The patients in the case group were older, had a lower gestational age at time of delivery and their newborns had a lower birth weight. Prior CS was more prevalent among the study group (88.2 vs. 66.7%), as was the incidence of placenta accreta and central praevia. In comparison with the control group, the intraoperative blood loss was higher in the case group, although there was no difference among the two groups regarding the type of surgery (emergency vs. elective), uterine rupture, or other obstetrical indications for CS. Prior CS and caesarean hysterectomy were risk factors for urologic injuries at CS. Conclusions: The major risk factor for urological injuries at the time of CS surgery is prior CS. Among patients with previous CS, those who undergo caesarean hysterectomy for placenta previa central and placenta accreta are at higher risk of surgical haemostasis and complex urologic injuries involving the bladder and the ureters.
The Dilemma of Reconstructive Material Choice for Orbital Floor Fracture: A Narrative Review
Authors: Sivam Akash , Enninghorst Natalie
Published: January 2022

The aim of this study is to present a narrative review of the properties of materials currently used for orbital floor reconstruction. Orbital floor fractures, due to their complex anatomy, physiology, and aesthetic concerns, pose complexities regarding management. Since the 1950s, a myriad of materials has been used to reconstruct orbital floor fractures. This narrative review synthesises the findings of literature retrieved from search of PubMed, Web of Science, and Google Scholar databases. This narrative review was conducted of 66 studies on reconstructive materials. Ideal material properties are that they are resorbable, osteoconductive, resistant to infection, minimally reactive, do not induce capsule formation, allow for bony ingrowth, are cheap, and readily available. Autologous implants provide reliable, lifelong, and biocompatible material choices. Allogenic materials pose a threat of catastrophic disease transmission. Newer alloplastic materials have gained popularity. Consideration must be made when deliberating the use of permanent alloplastic materials that are a foreign body with potential body interactions, or the use of resorbable alloplastic materials failing to provide adequate support for orbital contents. It is vital that surgeons have an appropriate knowledge of materials so that they are used appropriately and reduce the risks of complications.
The Optimization of Dispersion and Application Techniques for Nanocarbon-Doped Mixed Matrix Gas Separation Membranes
Authors: Hammerstein Ruben , Schubert Tim , Braun Gerd , Wolf Tobias , Barbe Stéphan , Quade Antje , Foest Rüdiger , Karousos Dionysios S. , Favvas Evangelos P.
Published: January 2022

In this work, supported cellulose acetate (CA) mixed matrix membranes (MMMs) were prepared and studied concerning their gas separation behaviors. The dispersion of carbon nanotube fillers were studied as a factor of polymer and filler concentrations using the mixing methods of the rotor–stator system (RS) and the three-roll-mill system (TRM). Compared to the dispersion quality achieved by RS, samples prepared using the TRM seem to have slightly bigger, but fewer and more homogenously distributed, agglomerates. The green γ-butyrolactone (GBL) was chosen as a polyimide (PI) polymer-solvent, whereas diacetone alcohol (DAA) was used for preparing the CA solutions. The coating of the thin CA separation layer was applied using a spin coater. For coating on the PP carriers, a short parameter study was conducted regarding the plasma treatment to affect the wettability, the coating speed, and the volume of dispersion that was applied to the carrier. As predicted by the parameter study, the amount of dispersion that remained on the carriers decreased with an increasing rotational speed during the spin coating process. The dry separation layer thickness was varied between about 1.4 and 4.7 μm. Electrically conductive additives in a non-conductive matrix showed a steeply increasing electrical conductivity after passing the so-called percolation threshold. This was used to evaluate the agglomeration behavior in suspension and in the applied layer. Gas permeation tests were performed using a constant volume apparatus at feed pressures of 5, 10, and 15 bar. The highest calculated CO2/N2 selectivity (ideal), 21, was achieved for the CA membrane and corresponded to a CO2 permeability of 49.6 Barrer.
Bio-Membrane Internalization Mechanisms of Arginine-Rich Cell-Penetrating Peptides in Various Species
Authors: Liu Betty Revon , Chiou Shiow-Her , Huang Yue-Wern , Lee Han-Jung
Published: January 2022

Recently, membrane-active peptides or proteins that include antimicrobial peptides (AMPs), cytolytic proteins, and cell-penetrating peptides (CPPs) have attracted attention due to their potential applications in the biomedical field. Among them, CPPs have been regarded as a potent drug/molecules delivery system. Various cargoes, such as DNAs, RNAs, bioactive proteins/peptides, nanoparticles and drugs, can be carried by CPPs and delivered into cells in either covalent or noncovalent manners. Here, we focused on four arginine-rich CPPs and reviewed the mechanisms that these CPPs used for intracellular uptake across cellular plasma membranes. The varying transduction efficiencies of them alone or with cargoes were discussed, and the membrane permeability was also expounded for CPP/cargoes delivery in various species. Direct membrane translocation (penetration) and endocytosis are two principal mechanisms for arginine-rich CPPs mediated cargo delivery. Furthermore, the amino acid sequence is the primary key factor that determines the cellular internalization mechanism. Importantly, the non-cytotoxic nature and the wide applicability make CPPs a trending tool for cellular delivery.
Effect of Heat Treatment on the Cyclic Deforming Behavior of As-Extruded ZA81M Magnesium Alloy
Authors: Luo Tianjiao , Feng Jianguang , Liu Chenye , Wang Cong , Li Yingju , Feng Xiaohui , Zheng Ce , Huang Qiuyan , Li Weirong , Yang Yuansheng
Published: January 2022

In the present work, the effect of heat treatment on the cyclic deformation behavior of as-extruded ZA81M magnesium alloy was investigated. Two heat treatment conditions were applied to the as-extruded ZA81M alloy: a solution treatment (T4, 653 K for 40 h and quenched with 298 K water) and a solution treatment plus artificial aging (T6, 348 K for 32 h (pre-aging at low temperature) and 453 K for 8 h (the second aging) and quenched with 353 K water). The results showed that the fine second phase precipitated after the aging treatment, the tensile yield strength of the T6-treated specimens increased, and the stress amplitude of T6-treated specimens was always higher than that of T4-treated specimens. The T6-treated specimens had a higher total strain energy density and a shorter fatigue life at a strain amplitude of 0.4%, and a lower total strain energy density and a longer fatigue life at a strain amplitude of 0.8%, compared to the T4-treated specimens. All fatigue cracks of the T4 and T6 ZA81M alloy were initiated at the second phase or along the grain boundary and propagated perpendicular to the loading direction.
Characterization of Waste Amidoxime Chelating Resin and Its Reutilization Performance in Adsorption of Pb(II), Cu(II), Cd(II) and Zn(II) Ions
Authors: Zheng Chunhui , He Chunlin , Yang Yingjie , Fujita Toyohisa , Wang Guifang , Yang Wenchao
Published: January 2022

The continuous expansion of the market demand and scale of commercial amidoxime chelating resins has caused large amounts of resin to be discarded around the world. In this study, the waste amidoxime chelating resin was reutilized as an adsorbent for the removal and recovery of Pb(II), Cu(II), Cd(II) and Zn(II) ions from aqueous solutions. The physical morphology and chemical composition of the waste amidoxime chelating resin (WAC-resin) from the factory was characterized by the elemental analyzer, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The influence of the initial metal ions concentration, contact time, temperature and the solution pH on the adsorption performance of the metal ions was explored by batch experiments. It was shown that the optimal pH was 4. Kinetic studies revealed that adsorption process corresponded with the pseudo-second-order kinetic model and the adsorption isotherm was consistent with the Langmuir model. At room temperature, the adsorption capacities of WAC-resin for Pb2+, Cu2+, Zn2+ and Cd2+ reached 114.6, 93.4, 24.4 and 20.7 mg/g, respectively.
Corrosion Activity of Carbon Steel B450C and Low Chromium Ferritic Stainless Steel 430 in Chloride-Containing Cement Extract Solution
Authors: Veleva Lucien , Bonfil David , Bacelis Ángel , Feliu Sebastian , Cabrini Marina , Lorenzi Sergio
Published: January 2022

The carbon steel B450C and low chromium SS 430 ferritic samples were exposed for 30 days to chloride-containing (5 g L−1 NaCL) cement extract solution. The initial pH ≈ 13.88 decreased to pH ≈ 9.6, associated mainly with the consumption of OH− ions and the formation of γ-FeOOH, α-FeOOH, Fe3O4 and Cr(OH)3, as suggested by XRD and XPS analysis, in the presence of CaCO3 and NaCl crystals. The deep corrosion damages on B450C were observed around particles of Cu and S as local cathodes, while the first pitting events on the SS 430 surface appeared after 30 days of exposure. The change in the activity of each type of steel was provided by the potentiodynamic polarization curves (PDP). Two equivalent electrical circuits (EC) were proposed for quantitative analysis of EIS (Nyquist and Bode diagrams). The calculated polarization resistance (Rp), as an indicator of the stability of passive films, revealed that SS 430 presented relatively constant values, being two-three orders of magnitude higher than those of the carbon steel B450C. The calculated thickness (d) of the SS 430 passive layers was ≈0.5 nm and, in contrast, that of the B450C passive layers tends to disappear after 30 days.
Structural Optimization and Improving Antitumor Potential of Moreollic Acid from Gamboge
Authors: Cheng Li-Zhi , Huang Dan-Ling , Liao Min , Li Ke-Ming , Wu Zhao-Qiu , Cheng Yong-Xian
Published: January 2022

Moreollic acid, a caged-tetraprenylated xanthone from Gamboge, has been indicated as a potent antitumor molecule. In the present study, a series of moreollic acid derivatives with novel structures were designed and synthesized, and their antitumor activities were determined in multifarious cell lines. The preliminary screening results showed that all synthesized compounds selectively inhibited human colon cancer cell proliferation. TH12-10, with an IC50 of 0.83, 1.10, and 0.79 μM against HCT116, DLD1, and SW620, respectively, was selected for further antitumor mechanism studies. Results revealed that TH12-10 effectively inhibited cell proliferation by blocking cell-cycle progression from G1 to S. Besides, the apparent structure–activity relationships of target compounds were discussed. To summarize, a series of moreollic acid derivatives were discovered to possess satisfactory antitumor potentials. Among them, TH12-10 displays the highest antitumor activities against human colon cancer cells, in which the IC50 values in DLD1 and SW620 are lower than that of 5-fluorouracil.
A New Series of Indeno[1,2-c]pyrazoles as EGFR TK Inhibitors for NSCLC Therapy
Authors: Özdemir Ahmet , Ciftci Halilibrahim , Sever Belgin , Tateishi Hiroshi , Otsuka Masami , Fujita Mikako , Altıntop Mehlika Dilek
Published: January 2022

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death throughout the world. Due to the shortcomings of traditional chemotherapy, targeted therapies have come into prominence for the management of NSCLC. In particular, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy has emerged as a first-line therapy for NSCLC patients with EGFR-activating mutations. In this context, new indenopyrazoles, which were prepared by an efficient microwave-assisted method, were subjected to in silico and in vitro assays to evaluate their potency as EGFR TK-targeted anti-NSCLC agents. Compound 4 was the most promising antitumor agent towards A549 human lung adenocarcinoma cells, with an IC50 value of 6.13 µM compared to erlotinib (IC50 = 19.67 µM). Based on its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), it can be concluded that compound 4 exerts selective antitumor action. This compound also inhibited EGFR TK with an IC50 value of 17.58 µM compared to erlotinib (IC50 = 0.04 µM) and induced apoptosis (56.30%). Taking into account in silico and in vitro data, compound 4 stands out as a potential EGFR TKI for the treatment of NSCLC.
A Double-Site Chemodosimeter for Selective Fluorescence Detection of a Nerve Agent Mimic
Authors: Guo Xin , Liu Chang-Xiang , Lu Yuan , Wang Ya-Wen , Peng Yu
Published: January 2022

A novel two-site chemodosimeter (SWJT-4) based on fluorescein skeleton to detect diethyl chlorophosphate (DCP) was designed and synthesized. It is a turn-on fluorescent probe for DCP with good selectivity and obvious color change in aqueous solution. Interestingly, the two oxime groups of SWJT-4 as dual response sites initiated different reactions with DCP to form a cyano group and an isoxazole ring, respectively. The corresponding mechanism was confirmed by 1H NMR, MS and DFT calculation. Moreover, SWJT-4 could be used as a fluorescent test paper to detect DCP vapor.
Interactions of Linearly Polarized and Unpolarized Light on Kiwifruit Using Aquaphotomics
Authors: Rajkumar Damenraj , Künnemeyer Rainer , Kaur Harpreet , Longdell Jevon , McGlone Andrew
Published: January 2022

Near infrared (NIR) spectroscopy is an important tool for predicting the internal qualities of fruits. Using aquaphotomics, spectral changes between linearly polarized and unpolarized light were assessed on 200 commercially grown yellow-fleshed kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’). Measurements were performed on different configurations of unpeeled (intact) and peeled (cut) kiwifruit using a commercial handheld NIR instrument. Absorbance after applying standard normal variate (SNV) and second derivative Savitzky–Golay filters produced different spectral features for all configurations. An aquagram depicting all configurations suggests that linearly polarized light activated more free water states and unpolarized light activated more bound water states. At depth (≥1 mm), after several scattering events, all radiation is expected to be fully depolarized and interactions for incident polarized or unpolarized light will be similar, so any observed differences are attributable to the surface layers of the fruit. Aquagrams generated in terms of the fruit soluble solids content (SSC) were similar for all configurations, suggesting the SSC in fruit is not a contributing factor here.
Visible Light-Induced Aerobic Oxidative Dehydrogenation of C–N/C–O to C=N/C=O Bonds Using Metal-Free Photocatalysts: Recent Developments
Authors: Torregrosa-Chinillach Alejandro , Chinchilla Rafael
Published: January 2022

Performing synthetic transformation using visible light as energy source, in the presence of a photocatalyst as a promoter, is currently of high interest, and oxidation reactions carried out under these conditions using oxygen as the final oxidant are particularly convenient from an environmental point of view. This review summarizes the recent developments achieved in the oxidative dehydrogenation of C–N and C–O bonds, leading to C=N and C=O bonds, respectively, using air or pure oxygen as oxidant and metal-free homogeneous or recyclable heterogeneous photocatalysts under visible light irradiation.
Au Nanoparticle-Based Amplified DNA Detection on Poly-l-lysine Monolayer-Functionalized Electrodes
Authors: Marti Almudena , Huskens Jurriaan
Published: January 2022

Affinity sensing of nucleic acids is among the most investigated areas in biosensing due to the growing importance of DNA diagnostics in healthcare research and clinical applications. Here, we report a simple electrochemical DNA detection layer, based on poly-l-lysine (PLL), in combination with gold nanoparticles (AuNPs) as a signal amplifier. The layer shows excellent reduction of non-specific binding and thereby high contrast between amplified and non-amplified signals with functionalized AuNPs; the relative change in current was 10-fold compared to the non-amplified signal. The present work may provide a general method for the detection of tumor markers based on electrochemical DNA sensing.
An Innovative Formulation Based on Nanostructured Lipid Carriers for Imatinib Delivery: Pre-Formulation, Cellular Uptake and Cytotoxicity Studies
Authors: Gundogdu Evren , Demir Emine-Selin , Ekinci Meliha , Ozgenc Emre , Ilem-Ozdemir Derya , Senyigit Zeynep , Gonzalez-Alvarez Isabel , Bermejo Marival
Published: January 2022

Imatinib (IMT) is a tyrosine kinase enzyme inhibitor and extensively used for the treatment of gastrointestinal stromal tumors (GISTs). A nanostructured lipid carrier system (NLCS) containing IMT was developed by using emulsification–sonication methods. The characterization of the developed formulation was performed in terms of its particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, loading capacity, sterility, syringeability, stability, in vitro release kinetics with mathematical models, cellular uptake studies with flow cytometry, fluorescence microscopy and cytotoxicity for CRL-1739 cells. The particle size, PDI, loading capacity and zeta potential of selected NLCS (F16-IMT) were found to be 96.63 ± 1.87 nm, 0.27 ± 0.15, 96.49 ± 1.46% and −32.7 ± 2.48 mV, respectively. F16-IMT was found to be stable, thermodynamic, sterile and syringeable through an 18 gauze needle. The formulation revealed a Korsmeyer–Peppas drug release model of 53% at 8 h, above 90% of cell viability, 23.61 µM of IC50 and induction of apoptosis in CRL-1739 cell lines. In the future, F16-IMT can be employed to treat GISTs. A small amount of IMT loaded into the NLCSs will be better than IMT alone for therapy for GISTs. Consequently, F16-IMT could prove to be useful for effective GIST treatment.
Optical Force on a Metal Nanorod Exerted by a Photonic Jet
Authors: Wei Bojian , Gong Shuhong , Li Renxian , Minin Igor , Minin Oleg , Lin Leke
Published: January 2022

In this article, we study the optical force exerted on nanorods. In recent years, the capture of micro-nanoparticles has been a frontier topic in optics. A Photonic Jet (PJ) is an emerging subwavelength beam with excellent application prospects. This paper studies the optical force exerted by photonic jets generated by a plane wave illuminating a Generalized Luneburg Lens (GLLs) on nanorods. In the framework of the dipole approximation, the optical force on the nanorods is studied. The electric field of the photonic jet is calculated by the open-source software package DDSCAT developed based on the Discrete Dipole Approximation (DDA). In this paper, the effects of the nanorods’ orientation and dielectric constant on the transverse force Fx and longitudinal force Fy are analyzed. Numerical results show that the maximum value of the positive force and the negative force are equal and appear alternately at the position of the photonic jet. Therefore, to capture anisotropic nanoscale-geometries (nanorods), it is necessary to adjust the position of GLLs continuously. It is worth emphasizing that manipulations with nanorods will make it possible to create new materials at the nanoscale.
Crosslinked Chitosan Binder for Sustainable Aqueous Batteries
Authors: Bargnesi Luca , Gigli Federica , Albanelli Nicolò , Toigo Christina , Arbizzani Catia
Published: January 2022

The increased percentage of renewable power sources involved in energy production highlights the importance of developing systems for stationary energy storage that satisfy the requirements of safety and low costs. Na ion batteries can be suitable candidates, specifically if their components are economic and safe. This study focuses on the development of aqueous processes and binders to prepare electrodes for sodium ion cells operating in aqueous solutions. We demonstrated the feasibility of a chitosan-based binder to produce freestanding electrodes for Na ion cells, without the use of organic solvents and current collectors in electrode processing. To our knowledge, it is the first time that water-processed, freestanding electrodes are used in aqueous Na ion cells, which could also be extended to other types of aqueous batteries. This is a real breakthrough in terms of sustainability, taking into account low risks for health and environment and low costs.
3-Hydroxyphenylacetic Acid: A Blood Pressure-Reducing Flavonoid Metabolite
Authors: Dias Patrícia , Pourová Jana , Vopršalová Marie , Nejmanová Iveta , Mladěnka Přemysl
Published: January 2022

Regular intake of polyphenol-rich food has been associated with a wide variety of beneficial health effects, including the prevention of cardiovascular diseases. However, the parent flavonoids have mostly low bioavailability and, hence, their metabolites have been hypothesized to be bioactive. One of these metabolites, 3-hydroxyphenylacetic acid (3-HPAA), formed by the gut microbiota, was previously reported to exert vasorelaxant effects ex vivo. The aim of this study was to shed more light on this effect in vivo, and to elucidate the mechanism of action. 3-HPAA gave rise to a dose-dependent decrease in arterial blood pressure when administered i.v. both as a bolus and infusion to spontaneously hypertensive rats. In contrast, no significant changes in heart rate were observed. In ex vivo experiments, where porcine hearts from a slaughterhouse were used to decrease the need for laboratory animals, 3-HPAA relaxed precontracted porcine coronary artery segments via a mechanism partially dependent on endothelium integrity. This relaxation was significantly impaired after endothelial nitric oxide synthase inhibition. In contrast, the blockade of SKCa or IKCa channels, or muscarinic receptors, did not affect 3-HPAA relaxation. Similarly, no effects of 3-HPAA on cyclooxygenase nor L-type calcium channels were observed. Thus, 3-HPAA decreases blood pressure in vivo via vessel relaxation, and this mechanism might be based on the release of nitric oxide by the endothelial layer.
Nutritional Behaviors, Vitamin Supplementation and Physical Activity among Polish Adults during the COVID-19 Pandemic
Authors: Gryszczyńska Bogna , Budzyń Magdalena , Grupińska Joanna , Kasprzak Magdalena Paulina , Gryszczyńska Agnieszka
Published: January 2022

The COVID-19 pandemic and its consequences, including social isolation, movement restrictions and work instability have altered many people’s nutritional behaviors and daily lifestyle. The aim of the study was to evaluate the influence of the COVID-19 pandemic on selected eating habits, physical activity and daily lifestyle changes of Polish adults (n = 145). The self-designed and anonymous questionnaire was available online from the 1 May 2021 to the 15 May 2021. In general, 60% of respondents declared that the COVID-19 pandemic did not affect their dietary habits, whereas 26% of surveyed individuals answered in the affirmative. The effect of the COVID-19 pandemic on changing dietary habits was differentiated by age (Pearson’s χ2 = 12.604; p = 0.0134). The number of meals consumed by respondents per day differed across gender groups (Pearson’s χ2 = 9.653; df = 4; p = 0.0466). An increase in body weight during the COVID-19 pandemic was reported by 43% of women and 7.6% of surveyed men. Additionally, hybrid working women declared most often an increase in body mass independent of age, education level and living place. Moreover, the majority of respondents who reported the effect of the pandemic on changing dietary habits also declared more frequent sweets consumption. The study revealed that respondents who stated more frequent sweets consumption during the COVID-19 pandemic were more likely associated with an increase in body mass (OR = 6.75, 95% CI, 6.75–91.25). No increase in the consumption of vitamin D, C and Mg supplements and pickled products was found.
Intracellular Toxic Advanced Glycation End-Products in 1.4E7 Cell Line Induce Death with Reduction of Microtubule-Associated Protein 1 Light Chain 3 and p62
Authors: Takata Takanobu , Sakasai-Sakai Akiko , Takeuchi Masayoshi
Published: January 2022

Background: The death of pancreatic islet β-cells (β-cells), which are the insulin-producing cells, promote the pathology in both Type 1 and Type 2 diabetes mellitus (DM) (T1DM and T2DM), and they are protected by autophagy which is one of the mechanisms of cell survival. Recently, that some advanced glycation end-products (AGEs), such as methylglyoxial-derived AGEs and Nε-carboxymethyllysine, induced the death of β-cells were revealed. In contrast, we had reported AGEs derived from glyceraldehyde (GA, the metabolism intermediate of glucose and fructose) are considered to be toxic AGEs (TAGE) due to their cytotoxicity and role in the pathogenesis of T2DM. More, serum levels of TAGE are elevated in patients with T1 and T2DM, where they exert cytotoxicity. Aim: We researched the cytotoxicity of intracellular and extracellular TAGE in β-cells and the possibility that intracellular TAGE were associated with autophagy. Methods: 1.4E7 cells (a human β-cell line) were treated with GA, and analyzed viability, quantity of TAGE, microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, and p62. We also examined the viability of 1.4E7 cells treated with TAGE-modified bovine serum albumin, a model of TAGE in the blood. Results: Intracellular TAGE induced death of 1.4E7 cells, decrease of LC3-I, LC3-II, and p62. Extracellular TAGE didn’t show cytotoxicity in the physiological concentration. Conclusion: Intracellular TAGE induced death of β-cells more strongly than extracellular TAGE, and may suppress autophagy via reduction of LC3-I, LC3-II, and p62 to inhibit the degradation of them.
Overexpression of pPLAIIIγ in Arabidopsis Reduced Xylem Lignification of Stem by Regulating Peroxidases
Authors: Jang Jin Hoon , Seo Hae Seong , Lee Ok Ran
Published: January 2022

Patatin-related phospholipases A (pPLAs) are a group of plant-specific acyl lipid hydrolases that share less homology with phospholipases than that observed in other organisms. Out of the three known subfamilies (pPLAI, pPLAII, and pPLAIII), the pPLAIII member of genes is particularly known for modifying the cell wall structure, resulting in less lignin content. Overexpression of pPLAIIIα and ginseng-derived PgpPLAIIIβ in Arabidopsis and hybrid poplar was reported to reduce the lignin content. Lignin is a complex racemic phenolic heteropolymer that forms the key structural material supporting most of the tissues in plants and plays an important role in the adaptive strategies of vascular plants. However, lignin exerts a negative impact on the utilization of plant biomass in the paper and pulp industry, forage digestibility, textile industry, and production of biofuel. Therefore, the overexpression of pPLAIIIγ in Arabidopsis was analyzed in this study. This overexpression led to the formation of dwarf plants with altered anisotropic growth and reduced lignification of the stem. Transcript levels of lignin biosynthesis-related genes, as well as lignin-specific transcription factors, decreased. Peroxidase-mediated oxidation of monolignols occurs in the final stage of lignin polymerization. Two secondary cell wall-specific peroxidases were downregulated following lowered H2O2 levels, which suggests a functional role of peroxidase in the reduction of lignification by pPLAIIIγ when overexpressed in Arabidopsis.
Preliminary Analysis and Evaluation of BDS-3 RDSS Timing Performance
Authors: Guo Rui , Wang Dongxia , Xing Nan , Liu Zhijun , Zhang Tianqiao , Ren Hui , Liu Shuai
Published: January 2022

Radio determination satellite service (RDSS) is one of the characteristic services of Beidou navigation satellite system (BDS), and also distinguishes with other GNSS systems. BDS-3 RDSS adopts new signals, which is compatible with BDS-2 RDSS signals in order to guarantee the services of old users. Moreover, the new signals also separate civil signals and military signals which are modulated on different carriers to improve their isolation and RDSS service performance. Timing is an important part of RDSS service, which has been widely used in the field of the power, transportation, marine and others. Therefore, the timing accuracy, availability and continuity is an important guarantee for RDSS service. This paper summarizes the principle of one-way and two-way timing, and provides the evaluation method of RDSS timing accuracy, availability and continuity. Based on BDS-3 RDSS signal measurements of system, the performance of one-way timing and two-way timing is analyzed and evaluated for the first time. The results show that: (1) the accuracy of one-way timing and two-way timing is better than 30 ns and 8 ns respectively, which are better than the official claimed accuracy; (2) the RMS of one-way timing accuracy is 5.45 ns, which is 20% smaller than BDS-2, and the availability and continuity are 100%; (3) the RMS of two-way timing accuracy is 3.59 ns, which is 34% smaller than one-way timing, and both of the availability and continuity are 100%; (4) the orbit maneuver of GEO satellite make the one-way timing has 7.68 h recovery, but has no affection on the two-way timing.
Using UAV and Field Measurement Technology to Monitor the Impact of Coal Gangue Pile Temperature on Vegetation Ecological Construction
Authors: Ruan Mengying , Hu Zhenqi , Duan Xinyi , Zhou Tao , Nie Xinran
Published: January 2022

Coal gangue is an inevitable product in coal mining and processing and is the most important source of pollution in mines. Vegetation restoration of coal gangue piles must consider its special site conditions. Therefore, we conducted unmanned air vehicle (UAV) temperature monitoring, field investigation and experimental analysis on spontaneous combustion coal gangue piles in Lu’an mining area. In the vegetation construction of coal gangue piles, high-temperature stress affects plant survival. The spontaneous combustion coal gangue piles have abnormal temperature, high surface temperature and few vegetation types. The plant community species diversity index (Shannon–Wiener index, Pielou’s index and Species abundance index) is small, the plant community is single and the plant diversity is low. Spontaneous combustion of coal gangue leads to soil acidification, reducing soil water content, soil organic carbon (SOM), available nitrogen (AN), available potassium (AK) and available phosphorus (AP). These factors are single or interactive in plants and have an impact on plant survival and growth. The research results are of great significance to the vegetation restoration of spontaneous combustion coal gangue piles, ecological reconstruction and the improvement of the ecological environment of coal mine areas.
A Multi-Domain Collaborative Transfer Learning Method with Multi-Scale Repeated Attention Mechanism for Underwater Side-Scan Sonar Image Classification
Authors: Cheng Zhen , Huo Guanying , Li Haisen
Published: January 2022

Due to the strong speckle noise caused by the seabed reverberation which makes it difficult to extract discriminating and noiseless features of a target, recognition and classification of underwater targets using side-scan sonar (SSS) images is a big challenge. Moreover, unlike classification of optical images which can use a large dataset to train the classifier, classification of SSS images usually has to exploit a very small dataset for training, which may cause classifier overfitting. Compared with traditional feature extraction methods using descriptors—such as Haar, SIFT, and LBP—deep learning-based methods are more powerful in capturing discriminating features. After training on a large optical dataset, e.g., ImageNet, direct fine-tuning method brings improvement to the sonar image classification using a small-size SSS image dataset. However, due to the different statistical characteristics between optical images and sonar images, transfer learning methods—e.g., fine-tuning—lack cross-domain adaptability, and therefore cannot achieve very satisfactory results. In this paper, a multi-domain collaborative transfer learning (MDCTL) method with multi-scale repeated attention mechanism (MSRAM) is proposed for improving the accuracy of underwater sonar image classification. In the MDCTL method, low-level characteristic similarity between SSS images and synthetic aperture radar (SAR) images, and high-level representation similarity between SSS images and optical images are used together to enhance the feature extraction ability of the deep learning model. Using different characteristics of multi-domain data to efficiently capture useful features for the sonar image classification, MDCTL offers a new way for transfer learning. MSRAM is used to effectively combine multi-scale features to make the proposed model pay more attention to the shape details of the target excluding the noise. Experimental results of classification show that, in using multi-domain data sets, the proposed method is more stable with an overall accuracy of 99.21%, bringing an improvement of 4.54% compared with the fine-tuned VGG19. Results given by diverse visualization methods also demonstrate that the method is more powerful in feature representation by using the MDCTL and MSRAM.
Swin Transformer and Deep Convolutional Neural Networks for Coastal Wetland Classification Using Sentinel-1, Sentinel-2, and LiDAR Data
Authors: Jamali Ali , Mahdianpari Masoud
Published: January 2022

The use of machine learning algorithms to classify complex landscapes has been revolutionized by the introduction of deep learning techniques, particularly in remote sensing. Convolutional neural networks (CNNs) have shown great success in the classification of complex high-dimensional remote sensing imagery, specifically in wetland classification. On the other hand, the state-of-the-art natural language processing (NLP) algorithms are transformers. Although the transformers have been studied for a few remote sensing applications, the integration of deep CNNs and transformers has not been studied, particularly in wetland mapping. As such, in this study, we explore the potential and possible limitations to be overcome regarding the use of a multi-model deep learning network with the integration of a modified version of the well-known deep CNN network of VGG-16, a 3D CNN network, and Swin transformer for complex coastal wetland classification. Moreover, we discuss the potential and limitation of the proposed multi-model technique over several solo models, including a random forest (RF), support vector machine (SVM), VGG-16, 3D CNN, and Swin transformer in the pilot site of Saint John city located in New Brunswick, Canada. In terms of F-1 score, the multi-model network obtained values of 0.87, 0.88, 0.89, 0.91, 0.93, 0.93, and 0.93 for the recognition of shrub wetland, fen, bog, aquatic bed, coastal marsh, forested wetland, and freshwater marsh, respectively. The results suggest that the multi-model network is superior to other solo classifiers from 3.36% to 33.35% in terms of average accuracy. Results achieved in this study suggest the high potential for integrating and using CNN networks with the cutting-edge transformers for the classification of complex landscapes in remote sensing.