bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Bifurcations Occurring on Red Fixed Components in the λ-Parameter Plane for a Family of Optimal Fourth-Order Multiple-Root Finders under the Möbius Conjugacy Map
Authors: Geum Young Hee , Kim Young Ik
Published: May 2020

Optimal fourth-order multiple-root finders with parameter λ were conjugated via the Möbius map applied to a simple polynomial function. The long-term dynamics of these conjugated maps in the λ -parameter plane was analyzed to discover some properties of periodic, bounded and chaotic orbits. The λ -parameters for periodic orbits in the parameter plane are painted in different colors depending on their periods, and the bounded or chaotic ones are colored black to illustrate λ -dependent connected components. When a red fixed component in the parameter plane branches into a q-periodic component, we encounter geometric bifurcation phenomena whose characteristics determine the desired boundary equation and bifurcation point. Computational results along with illustrated components support the bifurcation phenomena underlying this paper.
Numerical Simulation of Gas–Liquid Two-Phase Flow Characteristics of Centrifugal Pump Based on the CFD–PBM
Authors: Zhang Fan , Zhu Lufeng , Chen Ke , Yan Weicheng , Appiah Desmond , Hu Bo
Published: May 2020

This work seeks to apply the computational fluid dynamics–population balance model (CFD–PBM) to investigate the gas distribution and flow mechanism in the gas–liquid two-phase flow of a centrifugal pump. The findings show that the numerical simulation accurately captures the bubble distribution characteristics in the process of coalescence and breakage evolution. In addition, comparing the CFD–PBM with the Double Euler, the hydraulic head of the pump are similar, but the efficiency using the Double Euler is much higher—even close to single-phase. This is in contrast to previous experimental research. Then, the unsteady flow usually led to the formation of bubbles with larger diameters especially where vortices existed. In addition, the rotor–stator interaction was a main reason for bubble formation. Generally, it was observed that the coalescence rate was greater than the breakage rate; thus, the coalescence rate decreased until it equaled the breakage rate. Thereafter, the average diameter of the bubble in each part tended to be stable during the process of bubble evolution. Finally, the average diameter of bubbles seemed to increase from inlet to outlet. The results of this study may not only enhance the gas–liquid two-phase internal flow theory of centrifugal pumps, but also can serve as a benchmark for optimizations of reliable operation of hydraulic pumps under gas–liquid two-phase flow conditions.
Carrageenan-Based Acyclovir Mucoadhesive Vaginal Tablets for Prevention of Genital Herpes
Authors: Pacheco-Quito Edisson-Mauricio , Ruiz-Caro Roberto , Rubio Juan , Tamayo Aitana , Veiga María-Dolores
Published: May 2020

Women are the most affected by genital herpes, which is one of the most common sexually transmitted infections, affecting more than 400 million people worldwide. The application of vaginal microbicides could provide a safe method of protection. Acyclovir is a safe and effective medication for vaginal administration, and numerous benefits have been observed in the treatment of primary or recurrent lesions due to genital herpes. Vaginal tablets based on a combination of the polymers iota-carrageenan and hydroxypropyl methylcellulose were developed for the controlled release of acyclovir. Swelling, mucoadhesion and drug release studies were carried out in simulated vaginal fluid. The tablets, containing a combination of iota-carrageenan and hydroxypropyl methylcellulose, have an adequate uptake of the medium that allows them to develop the precise consistency and volume of gel for the controlled release of acyclovir. Its high mucoadhesive capacity also allows the formulation to remain in the vaginal area long enough to ensure the complete release of acyclovir. These promising formulations for the prevention of genital herpes deserve further evaluation.
Optimisation of Ultrasound Frequency, Extraction Time and Solvent for the Recovery of Polyphenols, Phlorotannins and Associated Antioxidant Activity from Brown Seaweeds
Authors: Ummat Viruja , Tiwari Brijesh K , Jaiswal Amit K , Condon Kevin , Garcia-Vaquero Marco , O’Doherty John , O’Donnell Colm , Rajauria Gaurav
Published: May 2020

This study investigates ultrasound assisted extraction (UAE) process parameters (time, frequency and solvent) to obtain high yields of phlorotannins, flavonoids, total phenolics and associated antioxidant activities from 11 brown seaweed species. Optimised UAE conditions (35 kHz, 30 min and 50% ethanol) significantly improved the extraction yield from 1.5-fold to 2.2-fold in all seaweeds investigated compared to solvent extraction. Using ultrasound, the highest recovery of total phenolics (TPC: 572.3 ± 3.2 mg gallic acid equivalent/g), total phlorotannins (TPhC: 476.3 ± 2.2 mg phloroglucinol equivalent/g) and total flavonoids (TFC: 281.0 ± 1.7 mg quercetin equivalent/g) was obtained from Fucus vesiculosus seaweed. While the lowest recovery of TPC (72.6 ± 2.9 mg GAE/g), TPhC (50.3 ± 2.0 mg PGE/g) and TFC (15.2 ± 3.3 mg QE/g) was obtained from Laminaria digitata seaweed. However, extracts from Fucus serratus obtained by UAE exhibited the strongest 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity (29.1 ± 0.25 mg trolox equivalent/g) and ferric reducing antioxidant power (FRAP) value (63.9 ± 0.74 mg trolox equivalent/g). UAE under optimised conditions was an effective, low-cost and eco-friendly technique to recover biologically active polyphenols from 11 brown seaweed species.
Inspired by Sea Urchins: Warburg Effect Mediated Selectivity of Novel Synthetic Non-Glycoside 1,4-Naphthoquinone-6S-Glucose Conjugates in Prostate Cancer
Authors: Dyshlovoy Sergey A. , Pelageev Dmitry N. , Hauschild Jessica , Sabutskii Yurii E. , Khmelevskaya Ekaterina A. , Krisp Christoph , Kaune Moritz , Venz Simone , Borisova Ksenia L. , Busenbender Tobias , Denisenko Vladimir A. , Schlüter Hartmut , Bokemeyer Carsten , Graefen Markus , Polonik Sergey G. , Anufriev Victor Ph. , von Amsberg Gunhild
Published: May 2020

The phenomenon of high sugar consumption by tumor cells is known as Warburg effect. It results from a high glycolysis rate, used by tumors as preferred metabolic pathway even in aerobic conditions. Targeting the Warburg effect to specifically deliver sugar conjugated cytotoxic compounds into tumor cells is a promising approach to create new selective drugs. We designed, synthesized, and analyzed a library of novel 6-S-(1,4-naphthoquinone-2-yl)-d-glucose chimera molecules (SABs)—novel sugar conjugates of 1,4-naphthoquinone analogs of the sea urchin pigments spinochromes, which have previously shown anticancer properties. A sulfur linker (thioether bond) was used to prevent potential hydrolysis by human glycoside-unspecific enzymes. The synthesized compounds exhibited a Warburg effect mediated selectivity to human prostate cancer cells (including highly drug-resistant cell lines). Mitochondria were identified as a primary cellular target of SABs. The mechanism of action included mitochondria membrane permeabilization, followed by ROS upregulation and release of cytotoxic mitochondrial proteins (AIF and cytochrome C) to the cytoplasm, which led to the consequent caspase-9 and -3 activation, PARP cleavage, and apoptosis-like cell death. These results enable us to further clinically develop these compounds for effective Warburg effect targeting.
Stroke, Dementia, and Atrial Fibrillation: From Pathophysiologic Association to Pharmacological Implications
Authors: Russo Vincenzo , Vio Riccardo , Proietti Riccardo
Published: May 2020

The impact of stroke and dementia on disability and death is a major contemporary health issue [...]
Purification of Arabinoxylans from Corn Fiber and Preparation of Bioactive Films for Food Packaging
Authors: Serra Maria , Weng Verónica , Coelhoso Isabel M. , Alves Vitor D. , Brazinha Carla
Published: May 2020

Corn fiber, a by-product of the starch industry, is presently incorporated in animal feed. However, it has arabinoxylans as added-value components (besides ferulic acid) that should be valorized. In this work, the raw material, a fraction enriched in arabinoxylans from corn fiber, previously produced by alkaline extraction from corn fiber and pre-concentrated by ultrafiltration, was further purified. The use of ultrafiltration operated in diafiltration mode (dia-ultrafiltration) was evaluated for the purification of the arabinoxylans fraction. The objective was to maximize the removal of the small contaminants from the fraction and to maximize the permeability and/or the permeate flux, by selecting the relevant operating conditions involved in this process. The removal of contaminants (%) was estimated when their apparent rejection stabilized. Edible films were produced, from the resultant purified arabinoxylans fraction, using glycerol as plasticizer (30% dry basis). Additionally, films with the incorporation of ferulic acid were developed, in order to obtain barriers with antioxidant activity. The films were characterized in terms of mechanical properties, antioxidant activity and permeability to water vapor. The films prepared presented a good potential to be used as packaging for food products with low water content.
Effect of Hybrid Ultrasonic and Mechanical Stirring on the Distribution of m-SiCp in A356 Alloy
Authors: Grilo J. , Puga H. , Carneiro V. H. , Tohidi S. D. , Barbosa F. V. , Teixeira J. C.
Published: May 2020

The present study details the micro-scale silicon carbide particle (m-SiCp) homogeneous distribution in an A356 alloy through hybrid ultrasonic-stirring melt treatment under different operation conditions. Ultrasonically excited fluids were studied by particle image velocimetry to estimate the efficiency of the acoustic streaming in different distances to the sonotrode. Distinct particle approaches to introduce the melt and stirring techniques were performed to determine a successful route to promote a homogenous distribution of reinforcement particles. Results showed that the addition of m-SiCp in the semisolid state significantly improved particle wettability, preventing rapid sedimentation. The combination of ultrasonic induced streaming and mechanical stirring is an effective tool for the homogeneous distribution of m-SiCp along the casting specimen.
Magnesium Solubility in Primary α-Al and Heat Treatment Response of Cast Al-7Si-Mg
Authors: Santos Jorge , Dahle Arne K. , Jarfors Anders E. W.
Published: May 2020

Magnesium and silicon concentrations in the interior of primary α-Al of Al-7Si-Mg alloys were studied at temperatures in the liquid-solid range and just after solidification was completed. Analysis of the results showed that the magnesium concentration in the interior of primary α-Al is very low in the temperatures range from the liquidus to the start of the Al-Si eutectic reaction. Formation of silicon-rich phases during eutectic reactions, such as eutectic silicon and β-Al5FeSi, phases trigger a significant increase in the magnesium concentration in the interior of primary α-Al, when sufficient time is allowed for solid-state diffusion to occur. When fast cooling rates are applied during the Al-Si eutectic reaction, most of the magnesium is retained in π-Al8FeMg3Si6 and Mg2Si phases formed during solidification. Semi-solid Al-7Si-Mg castings were produced with varying magnesium contents, and the mechanical properties were evaluated in the as-cast, T5 and T6 conditions. It was found that the 0.2% offset yield strength of the semi-solid Al-7Si-Mg castings in the T5 and T6 conditions increases linearly with the square root of the magnesium concentration in the interior of the α-Al globules formed during the slurry preparation process.
Probabilistic Surface Layer Fatigue Strength Assessment of EN AC-46200 Sand Castings
Authors: Pomberger Sebastian , Oberreiter Matthias , Leitner Martin , Stoschka Michael , Thuswaldner Jörg
Published: May 2020

The local fatigue strength within the aluminium cast surface layer is affected strongly by surface layer porosity and cast surface texture based notches. This article perpetuates the scientific methodology of a previously published fatigue assessment model of sand cast aluminium surface layers in T6 heat treatment condition. A new sampling position with significantly different surface roughness is investigated and the model exponents a 1 and a 2 are re-parametrised to be suited for a significantly increased range of surface roughness values. Furthermore, the fatigue assessment model of specimens in hot isostatic pressing (HIP) heat treatment condition is studied for all sampling positions. The obtained long life fatigue strength results are approximately 6% to 9% conservative, thus proven valid within an range of 30 µm ≤ S v ≤ 260 µm notch valley depth. To enhance engineering feasibility even further, the local concept is extended by a probabilistic approach invoking extreme value statistics. A bivariate distribution enables an advanced probabilistic long life fatigue strength of cast surface textures, based on statistically derived parameters such as extremal valley depth S v i and equivalent notch root radius ρ ¯ i . Summing up, a statistically driven fatigue strength assessment tool of sand cast aluminium surfaces has been developed and features an engineering friendly design method.
Analysis of Different Solution Treatments in the Transformation of β-AlFeSi Particles into α-(FeMn)Si and Their Influence on Different Ageing Treatments in Al–Mg–Si Alloys
Authors: Alvarez-Antolin Florentino , Asensio-Lozano Juan , Cofiño-Villar Alberto , Gonzalez-Pociño Alejandro
Published: May 2020

In the as-cast state, Al–Mg–Si alloys are not suitable for hot forming. They present low ductility due to the presence of intermetallic β-AlFeSi particles that form in the interdendritic regions during the solidification process. Homogenization treatments promote the transformation of these particles into α-(FeMn)Si particles, which are smaller in size and more rounded in shape, thus improving the ductility of the material. This paper analyses the influence of various solution treatments on the transformation of β-AlFeSi particles into α-(FeMn)Si particles in an Al 6063 alloy. Their effect on different ageing treatments in the 150–180 °C temperature range is also studied. An increase in the solution temperature favours greater transformation of the β-AlFeSi particles into α-(FeMn)Si, dissolving a greater amount of Si, thereby having a significant effect on subsequent ageing. We found that as the dwell time at a temperature of 600 °C increases, the rate of dissolution of the Fe atoms from α-(FeMn)Si particles exceeds the rate of incorporation of Mn atoms into said particles. This seems to produce a delay in reaching the peak hardness values in ageing treatments, which warrants further research to model this behaviour. The optimal solution treatment takes place at around 600 °C and the highest obtained peak hardness value is 104 HV after a 2 h solution treatment at said temperature and ageing at 160 °C for 12 h.
Influence of Sand Fines Transport Velocity on Erosion-Corrosion Phenomena of Carbon Steel 90-Degree Elbow
Authors: Khan Rehan , H. Ya Hamdan , Pao William , bin Abdullah Mohamad Zaki , Dzubir Faizul Azly
Published: May 2020

Erosion-corrosion is an ineluctable flow assurance problem confronted in hydrocarbon transportation and production systems. In this work, the effect of sand fines velocity on the erosion-corrosion behavior of AISI 1018 carbon steel long radius 90° elbows was experimentally and numerically investigated for liquid-solid flow conditions. Experiments were effectuated for sand fines of mean diameter 50 µm circulated in a flow loop with three different velocities (0.5, 1 and 2 m/s). To elucidate the erosion-corrosion mechanism and degradation rate, the material loss analysis, multilayer paint modeling (MPM) and microscopic imaging technique were employed, with computational fluid dynamics (CFD) and discrete phase modeling (DPM) also capacitating to evaluate the erosion distribution. It was perceived that increasing slurry velocity significantly changes the particle-wall impaction mechanism, leading to an increase in material degradation in the elbow bottom section up to 2 times in comparison to the low transport velocity. The erosion scars and pits development at the elbows internal surface was found to govern the wear mechanism in the carbon steel and made downstream section susceptible to erosion and corrosion. The material removal mechanisms were ascertained to change from cutting to pitting and plastic deformation with an increase of sand fines transportation velocity from 0.5 m/s to 2 m/s.
Leaching of Oxide Copper Ores by Addition of Weak Acid from Copper Smelters
Authors: Araya Giselle , Toro Norman , Castillo Jonathan , Guzmán Danny , Guzmán Alexis , Hernández Pía , Jeldres Ricardo I. , Sepúlveda Rossana
Published: May 2020

In this study, weak acid in the curing and leaching stages of copper ore was incorporated, and we analyzed its effect on the dissolution of copper and final impurities. The weak acid corresponds to a wastewater effluent from sulfuric acid plants produced in the gas treatment of copper smelting processes. This effluent is basically water with high acidity (pH-value low at 1), which contains several toxic elements and some valuable metals. The results indicated that there is no positive or negative effect on the incorporation of the weak acid in the curing stage, while the case of the leaching stage is favored. Toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) toxicity tests were performed on the solid leaching residues, determining that they accomplish the stability ranges of the impurities (Pb, Cd, Hg, Cr, Ba, Se, As, and Ag).
A Review of MEMS Capacitive Microphones
Authors: Zawawi Siti Aisyah , Hamzah Azrul Azlan , Majlis Burhanuddin Yeop , Mohd-Yasin Faisal
Published: May 2020

This review collates around 100 papers that developed micro-electro-mechanical system (MEMS) capacitive microphones. As far as we know, this is the first comprehensive archive from academia on this versatile device from 1989 to 2019. These works are tabulated in term of intended application, fabrication method, material, dimension, and performances. This is followed by discussions on diaphragm, backplate and chamber, and performance parameters. This review is beneficial for those who are interested with the evolutions of this acoustic sensor.
Additive Manufacturing for Soft Robotics: Design and Fabrication of Airtight, Monolithic Bending PneuNets with Embedded Air Connectors
Authors: Stano Gianni , Arleo Luca , Percoco Gianluca
Published: May 2020

Air tightness is a challenging task for 3D-printed components, especially for fused filament fabrication (FFF), due to inherent issues, related to the layer-by-layer fabrication method. On the other hand, the capability of 3D print airtight cavities with complex shapes is very attractive for several emerging research fields, such as soft robotics. The present paper proposes a repeatable methodology to 3D print airtight soft actuators with embedded air connectors. The FFF process has been optimized to manufacture monolithic bending PneuNets (MBPs), an emerging class of soft robots. FFF has several advantages in soft robot fabrication: (i) it is a fully automated process which does not require manual tasks as for molding, (ii) it is one of the most ubiquitous and inexpensive (FFF 3D printers costs < $200) 3D-printing technologies, and (iii) more materials can be used in the same printing cycle which allows embedding of several elements in the soft robot body. Using commercial soft filaments and a dual-extruder 3D printer, at first, a novel air connector which can be easily embedded in each soft robot, made via FFF technology with a single printing cycle, has been fabricated and tested. This new embedded air connector (EAC) prevents air leaks at the interface between pneumatic pipe and soft robot and replaces the commercial air connections, often origin of leakages in soft robots. A subsequent experimental study using four different shapes of MBPs, each equipped with EAC, showed the way in which different design configurations can affect bending performance. By focusing on the best performing shape, among the tested ones, the authors studied the relationship between bending performance and air tightness, proving how the Design for Additive Manufacturing approach is essential for advanced applications involving FFF. In particular, the relationship between chamber wall thickness and printing parameters has been analyzed, the thickness of the walls has been studied from 1.6 to 1 mm while maintaining air tightness and improving the bending angle by 76.7% under a pressure of 4 bar. It emerged that the main printing parameter affecting chamber wall air tightness is the line width that, in conjunction with the wall thickness, can ensure air tightness of the soft actuator body.
The Influence of Chronic Liver Diseases on Hepatic Vasculature: A Liver-on-a-chip Review
Authors: Özkan Alican , Stolley Danielle , Cressman Erik N. K. , McMillin Matthew , DeMorrow Sharon , Yankeelov Thomas E. , Rylander Marissa Nichole
Published: May 2020

In chronic liver diseases and hepatocellular carcinoma, the cells and extracellular matrix of the liver undergo significant alteration in response to chronic injury. Recent literature has highlighted the critical, but less studied, role of the liver vasculature in the progression of chronic liver diseases. Recent advancements in liver-on-a-chip systems has allowed in depth investigation of the role that the hepatic vasculature plays both in response to, and progression of, chronic liver disease. In this review, we first introduce the structure, gradients, mechanical properties, and cellular composition of the liver and describe how these factors influence the vasculature. We summarize state-of-the-art vascularized liver-on-a-chip platforms for investigating biological models of chronic liver disease and their influence on the liver sinusoidal endothelial cells of the hepatic vasculature. We conclude with a discussion of how future developments in the field may affect the study of chronic liver diseases, and drug development and testing.
All-Optical Formation and Manipulation of Microbubbles on a Porous Gold Nanofilm
Authors: Cao Qin , Wu Tianli , Chen Xixi , Gong Zhiyong , Wen Ahao
Published: May 2020

Microbubble generation and manipulation in aqueous environments are techniques that have attracted considerable attention for their microfluidic and biological applications. Ultrasonic and hydrodynamic methods are commonly used to form and manipulate microbubbles, but these methods are limited by the relatively low precision of the microbubble sizes and locations. Here, we report an all-optical method for generation and manipulation of microbubbles with ~100 nm precision by using “hot spots” on a porous gold nanofilm under the illumination of near-infrared focused laser beam. The microbubble diameter ranged from 700 nm to 100 μm, with a standard deviation of 100 nm. The microbubbles were patterned into two-dimensional arrays, with an average location deviation of 90 nm. By moving the laser beam, the microbubbles could be manipulated to a desired region. This work provides a controllable way to form and manipulate microbubbles with ~100 nm precision, which is expected to have applications in optofluidic and plasmonic devices.
Role of Leaf Litter in Above-Ground Wood Decay
Authors: Kirker Grant T. , Bishell Amy , Cappellazzi Jed , Palmer Jonathan , Bechle Nathan , Lebow Patricia , Lebow Stan
Published: May 2020

The effects of leaf litter on moisture content and fungal decay development in above-ground wood specimens were assessed. Untreated southern pine specimens were exposed with or without leaf litter contact. Two types of leaf litter were evaluated; aged (decomposed) and young (early stages of decomposition). The moisture content of specimens was monitored, and specimens were periodically removed for visual evaluation of decay development. In addition, amplicon-based sequencing analysis of specimens and associated leaf litter was conducted at two time points. Contact with either type of leaf litter resulted in consistently higher moisture contents than those not in contact with leaf litter. Visually, evident decay developed most rapidly in specimens in contact with the aged leaf litter. Analysis of amplicon-based sequencing revealed that leaf litter contributes a significant amount of the available wood decay fungal community with similar communities found in the litter exposed wood and litter itself, but dissimilar community profiles from unexposed wood. Dominant species and guild composition shifted over time, beginning initially with more leaf saprophytes (ascomycetes) and over time shifting to more wood rotting fungi (basidiomycetes). These results highlight the importance of the contributions of leaf litter to fungal colonization and subsequent decay hazard for above-ground wood.
Development and Evaluation of a Single Dye Duplex Droplet Digital PCR Assay for the Rapid Detection and Quantification of Mycobacterium tuberculosis
Authors: Nyaruaba Raphael , Xiong Jin , Mwaliko Caroline , Wang Nuo , Kibii Belindah J. , Yu Junping , Wei Hongping
Published: May 2020

Droplet digital PCR (ddPCR) is a third generation of PCR that was recently developed to overcome the challenges of real-time fluorescence-based quantitative PCR (qPCR) in absolute quantification of pathogens. Few studies have been done on tuberculosis (TB) detection and quantification using ddPCR despite its many advantages over qPCR. From the few studies, none explores a single dye duplex assay for the detection and quantification of TB. In this study, steps toward developing and evaluating a duplex single dye (FAM) assay for detecting two targets (IS6110 and IS1081) are clearly described using simplex and duplex experiments. To achieve this, various parameters are investigated, including annealing temperature, primer and probe concentration, sensitivity and specificity, sample concentration, and inter/intra-assay variability. From the results, primer and probe concentration, annealing temperature, and sample concentration have an effect on the position and separation of droplets in both simplex and duplex assays. The copies of target genes in a duplex assay can be estimated accurately using the threshold tool with little inter-assay (CV <1%) and intra-assay (CV <6%) variability when compared to simplex assays. The ddPCR assay specificity and sensitivity are both 100% when compared to qPCR. This work shows steps toward the detection and quantification of two targets in a single channel, enabling higher multiplexing to include more targets in future works.
Transcriptome Analysis of Gene Expression in Dermacoccus abyssi HZAU 226 under Lysozyme Stress
Authors: Zhang Xinshuai , Ruan Yao , Liu Wukang , Chen Qian , Gu Lihong , Guo Ailing
Published: May 2020

Lysozyme acts as a kind of cationic antimicrobial protein and effectively hydrolyzes bacterial peptidoglycan to have a bactericidal effect, which also plays an important role in protecting eggs from microbial contamination. Dermacoccus abyssi HZAU 226, a Gram-positive bacterium isolated from spoiled eggs, has egg white and lysozyme tolerance, but its survival mechanism is unknown, especially from a transcriptomics point of view. In this study, the high lysozyme tolerance of D. abyssi HZAU 226 was characterized by three independent experiments, and then the Illumina RNA-seq was used to compare the transcriptional profiles of this strain in Luria–Bertani (LB) medium with and without 5 mg/mL lysozyme to identify differentially expressed genes (DEGs); 1024 DEGs were identified by expression analysis, including 544 up-regulated genes and 480 down-regulated genes in response to lysozyme treatment. The functional annotation analysis results of DEGs showed that these genes were mainly involved in glutathione biosynthesis and metabolism, ion transport, energy metabolism pathways, and peptidoglycan biosynthesis. This study is the first report of bacterial-related lysozyme RNA-seq, and our results help in understanding the lysozyme-tolerance mechanism of bacteria from a new perspective and provide transcriptome resources for subsequent research in related fields.
Assessment of the Immunomodulatory Properties of the Probiotic Strain Lactobacillus paracasei K5 In Vitro and In Vivo
Authors: Chondrou Pelagia , Karapetsas Athanasios , Kiousi Despoina Eugenia , Vasileiadis Stavros , Ypsilantis Petros , Botaitis Sotiris , Alexopoulos Athanasios , Plessas Stavros , Bezirtzoglou Eugenia , Galanis Alex
Published: May 2020

Lactobacillus paracasei K5 is a lactic acid bacteria (LAB) strain that has been isolated from dairy products. Previous studies have established its probiotic potential in a series of in vitro tests, including molecular characterization, safety profiling, and tolerability of the gastrointestinal tract conditions. To characterize its beneficial actions on the host, we have shown previously that L. paracasei K5 adheres to Caco-2 cells and exerts anti-proliferative effects through the induction of apoptosis. In the present study, we focused on the immunomodulatory potential of this strain. We employed the dorsal-air-pouch mouse model of inflammation and recorded an eight-fold increase in the recruitment of immune cells in mice treated with the probiotic strain, compared to the control group. Analysis of the exudates revealed significant changes in the expression of pro-inflammatory mediators on site. Treatment of Caco-2 cells with L. paracasei K5 induced significant upregulation of cytokines interleukin-1α (IL-1α), ΙL-1β, IL-6, tumor necrosis factor-alpha (TNF-α), the chemokine C-X-C motif ligand 2 (CXCL2), and the inflammation markers soluble intercellular adhesion molecule (sICAM) and metallopeptidase inhibitor-1 (TIMP-1). Transient induction of the Toll-like receptors (TLRs) 2, 4, 6, and 9 expression levels was recorded by real-time PCR analysis. These results highlight the immunomodulatory potential of this strain and further support its probiotic character.
Petrogenesis of Ultramafic Lamprophyres from the Terina Complex (Chadobets Upland, Russia): Mineralogy and Melt Inclusion Composition
Authors: Prokopyev Ilya , Starikova Anastasiya , Doroshkevich Anna , Nugumanova Yazgul , Potapov Vladislav
Published: May 2020

The mineral composition and melt inclusions of ultramafic lamprophyres of the Terina complex were investigated. The rocks identified were aillikites, mela-aillikites, and damtjernites, and they were originally composed of olivine macrocrysts and phenocrysts, as well as phlogopite phenocrysts in carbonate groundmass, containing phlogopite, clinopyroxene and feldspars. Minor and accessory minerals were fluorapatite, ilmenite, rutile, titanite, and sulphides. Secondary minerals identified were quartz, calcite, dolomite, serpentine, chlorite, rutile, barite, synchysite-(Ce), and monazite-(Ce). Phlogopite, calcite, clinopyroxene, Ca-amphibole, fluorapatite, magnetite, and ilmenite occurred as daughter-phases in melt inclusions. The melt inclusions also contained Fe–Ni sulphides, synchysite-(Ce) and, probably, anhydrite. The olivine macrocrysts included orthopyroxene and ilmenite, and the olivine phenocrysts included Cr-spinel and Ti-magnetite inclusions. Crystal-fluid inclusions in fluorapatite from damtjernites contain calcite, clinopyroxene, dolomite, and barite. The data that were obtained confirm that the ultramafic lamprophyres of the Terina complex crystallized from peridotite mantle-derived carbonated melts and they have not undergone significant fractional crystallization. The investigated rocks are considered to be representative of melts that are derived from carbonate-rich mantle beneath the Siberian craton.
Process Variable Importance Analysis by Use of Random Forests in a Shapley Regression Framework
Authors: Aldrich Chris
Published: May 2020

Linear regression is often used as a diagnostic tool to understand the relative contributions of operational variables to some key performance indicator or response variable. However, owing to the nature of plant operations, predictor variables tend to be correlated, often highly so, and this can lead to significant complications in assessing the importance of these variables. Shapley regression is seen as the only axiomatic approach to deal with this problem but has almost exclusively been used with linear models to date. In this paper, the approach is extended to random forests, and the results are compared with some of the empirical variable importance measures widely used with these models, i.e., permutation and Gini variable importance measures. Four case studies are considered, of which two are based on simulated data and two on real world data from the mineral process industries. These case studies suggest that the random forest Shapley variable importance measure may be a more reliable indicator of the influence of predictor variables than the other measures that were considered. Moreover, the results obtained with the Gini variable importance measure was as reliable or better than that obtained with the permutation measure of the random forest.
Spatial Macroscale Variability of the Role of Mineral Matter in Concentrating Some Trace Elements in Bituminous Coal in a Coal Basin—A Case Study from the Upper Silesian Coal Basin in Poland
Authors: Parzentny Henryk R.
Published: May 2020

As there are numerous claims that the mode of occurrence of trace elements in coal influences the quality of the substrates as well as the course and results of the coal preparation processes, it is necessary to analyse the differences in the mode of occurrence of the elements in coal within a coal basin or a coal deposit. With the use of concentration distribution functions and the Pearson correlation coefficient, it was concluded that (1) mineral matter plays a significant and nearly constant or constant role in concentrating V, Cr, Co, As, Rb, Sr, Ba, and Pb in coal; (2) organic matter plays a stable role in concentrating Sn; and (3) there are significant differences in the role of organic and mineral matter in concentrating Mn, Ni, Cu, Zn, Mo, Cd, and Sb in coal throughout the USCB (Upper Silesian Coal Basin). Moreover, there was observed a difference in the mode of occurrence of Cr, Mn, Co, Ni, Cu, Zn, Mo, Cd, Sn, and Sb in coal in the vertical profile of the USCB. At the same time, there were observed no differences and a stable significant role of mineral matter in concentrating V, As, Rb, Sr, Ba, and Pb in coal, while the role of the petrographic groups of the coal components in concentrating the elements in raw coal was differentiated. It is believed that the difference in the mode of occurrence of the trace elements in coal within coal seams and coal deposits is a geochemical regularity.
Methods of Ore Pretreatment for Comminution Energy Reduction
Authors: Adewuyi Sefiu O. , Ahmed Hussin A. M. , Ahmed Haitham M. A.
Published: May 2020

The comminution of ores consumes a high portion of energy. Therefore, different pretreatment methods of ores prior to their comminution are considered to reduce this energy. However, the results of pretreatment methods and their technological development are scattered in literature. Hence, this paper aims at collating the different ore pretreatment methods with their applications and results from published articles, conference proceedings, and verified reports. It was found that pretreatment methods include thermal (via oven, microwave, or radiofrequency), chemical additive, electric, magnetic, ultrasonic, and bio-milling. Results showed that the chemical pretreatment method has been used at an industrial scale since 1930, mainly in cement production. The microwave pretreatment results showed positive improvements at pilot scale mining applications in 2017. The results of ore pretreatment using electric and ultrasonic methods showed up to 24% and 66% improvement in energy consumption, respectively. The former and the latter have been piloted for gold and carbonate ore, respectively. Findings also showed that magnetic, radiofrequency, and bio-milling methods have not led to significant reductions in comminution energy. Based on energy reduction, safety, costs, stage of application, and downstream benefits, microwave and electrical pretreatment methods may be focused for applications in the mining industry.
Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints
Authors: Pozo-Antonio Jose Santiago , Cardell Carolina , Barral Diana , Dionisio Amelia , Rivas Teresa
Published: May 2020

In order to improve our knowledge of the weathering response of tempera paints exposed to an industrial atmosphere, azurite- and malachite-based paint mock-ups prepared with either rabbit glue or egg yolk binders were artificially aged in an SO2 rich atmosphere. The aim was to identify the different alteration mechanisms and forms of degradation in the paints by observing their physical (color, gloss, reflectance, and roughness), mineralogical, chemical, and micro-textural characteristics. Superficial physical changes were evaluated by stereomicroscopy, spectrophotometry, gloss measurement, hyperspectral imaging, and roughness measurements. Chemical and mineralogical changes were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with microanalysis (SEM-EDS), which was also used to evaluate the micro-texture of the paints. The differences between the fresh temperas were due mainly to the binder (egg yolk or rabbit glue) used in the paint mixture, which also played a crucial role in the different deterioration patterns in the artificially aged paint mock-ups. Thus, the egg yolk-based paints remained physically quite intact after SO2 exposure, although they suffered more significant chemical degradation, above all in the form of copious precipitation of Cu and Ca-rich sulfate salts and the subsequent yellowing of the egg yolk binder. The SO2 aged rabbit glue-based mock-ups showed microscopically important crack formation and binder loss and fewer sulfated salts precipitated on the surface of the paints.
Single Crystal Elastic Properties of Hemimorphite, a Novel Hydrous Silicate
Authors: Li Yingzhe , Bass Jay D.
Published: May 2020

Hemimorphite, with the chemical formula Zn4Si2O7(OH)2·H2O, contains two different types of structurally bound hydrogen: molecular water and hydroxyl. The elastic properties of single-crystal hemimorphite have been determined by Brillouin spectroscopy at ambient conditions, yielding tight constraints on all nine single-crystal elastic moduli (Cij). The Voigt–Reuss–Hill (VRH) averaged isotropic aggregate elastic moduli are KS (VRH) = 74(3) GPa and μ (VRH) = 27(2) GPa, for the adiabatic bulk modulus and shear modulus, respectively. The average of the Hashin–Shtrickman (HS) bounds are Ks (HS) = 74.2(7) GPa and and μ (HS) = 26.5(6) GPa. Hemimorphite displays a high degree of velocity anisotropy. As a result, differences between upper and lower bounds on aggregate properties are large and the main source of uncertainty in Ks and μ. The HS average P wave velocity is VP = 5.61(4) km/s, and the HS S-wave velocity is VS = 2.77(3) km/s. The high degree of elastic anisotropy among the on-diagonal longitudinal and pure shear moduli of hemimorphite are largely explained by its distinctive crystal structure.
Fracture Propagation and Morphology Due to Non-Aqueous Fracturing: Competing Roles between Fluid Characteristics and In Situ Stress State
Authors: Jia Yunzhong , Lu Zhaohui , Liu Hong , Wang Jiehao , Cheng Yugang , Zhang Xinwei
Published: May 2020

Non-aqueous or gaseous stimulants are alternative working fluids to water for hydraulic fracturing in shale reservoirs, which offer advantages including conserving water, avoiding clay swelling and decreasing formation damage. Hence, it is crucial to understand fluid-driven fracture propagation and morphology in shale formations. In this research, we conduct fracturing experiments on shale samples with water, liquid carbon dioxide, and supercritical carbon dioxide to explore the effect of fluid characteristics and in situ stress on fracture propagation and morphology. Moreover, a numerical model that couples rock property heterogeneity, micro-scale damage and fluid flow was built to compare with experimental observations. Our results indicate that the competing roles between fluid viscosity and in situ stress determine fluid-driven fracture propagation and morphology during the fracturing process. From the macroscopic aspect, fluid-driven fractures propagate to the direction of maximum horizontal stress direction. From the microscopic aspect, low viscosity fluid easily penetrates into pore throats and creates branches and secondary fractures, which may deflect the main fracture and eventually form the fracture networks. Our results provide a new understanding of fluid-driven fracture propagation, which is beneficial to fracturing fluid selection and fracturing strategy optimization for shale gas hydraulic fracturing operations.
Forecast of AMD Quantity by a Series Tank Model in Three Stages: Case Studies in Two Closed Japanese Mines
Authors: Tokoro Chiharu , Fukaki Kenichiro , Kadokura Masakazu , Fuchida Shigeshi
Published: May 2020

There are about 100 sites of acid mine drainage (AMD) from abandoned/closed mines in Japan. For their sustainable treatment, future prediction of AMD quantity is crucial. In this study, AMD quantity was predicted for two closed mines in Japan based on a series tank model in three stages. The tank model parameters were determined from the relationship between the observed AMD quantity and the inflow of rainfall and snowmelt by using the Kalman filter and particle swarm optimization methods. The Automated Meteorological Data Acquisition System (AMeDAS) data of rainfall were corrected for elevation and by the statistical daily fluctuation model. The snowmelt was estimated from the AMeDAS data of rainfall, temperature, and sunshine duration by using mass and heat balance of snow. Fitting with one year of daily data was sufficient to obtain the AMD quantity model. Future AMD quantity was predicted by the constructed model using the forecast data of rainfall and temperature proposed by the Max Planck Institute–Earth System Model (MPI–ESM), based on the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) 2.6 and RCP8.5 scenarios. The results showed that global warming causes an increase in the quantity and fluctuation of AMD, especially for large reservoirs and residence time of AMD. There is a concern that for mines with large AMD quantities, AMD treatment will be unstable due to future global warming.
A Comparative Study of Porphyry-Type Copper Deposit Mineralogies by Portable X-ray Fluorescence and Optical Petrography
Authors: Gray Connor , Van Rythoven Adrian
Published: May 2020

Porphyry-type deposits are crucial reserves of Cu and Mo. They are associated with large haloes of hydrothermal alteration that host particular mineral assemblages. Portable X-ray fluorescence analysis (pXRF) is an increasingly common tool used by mineral prospectors to make judgments in the field during mapping or core logging. A total of 31 samples from 13 porphyry copper deposits of the Western Cordillera were examined. Whole-rock composition was estimated over three points of analysis by pXRF. This approach attempts to capture the rapid and sometimes haphazard application of pXRF in mineral exploration. Modes determined by optical petrography were converted into bulk rock compositions and compared with those determined by pXRF. The elements S, Si, Ca, and K all were underestimated by optical mineralogy, and the elements Cu, Mo, Al, Fe, Mg, and Ti were overestimated by optical mineralogy when compared with pXRF results. Most of these porphyry samples occur in veined porphyritic quartz monzonite that is characteristic of these deposits. Sulfide and silicate vein stockworks are pervasive in most of the samples as well as dissemination of sulfides outwards from veinlets. Ore minerals present include chalcopyrite and molybdenite with lesser bornite. Chalcocite, digenite, and covellite are secondary. Potential sources of analytical bias are discussed.
Reconfiguring Nature’s Cholesterol Accepting Lipoproteins as Nanoparticle Platforms for Transport and Delivery of Therapeutic and Imaging Agents
Authors: Chuang Skylar T. , Cruz Siobanth , Narayanaswami Vasanthy
Published: May 2020

Apolipoproteins are critical structural and functional components of lipoproteins, which are large supramolecular assemblies composed predominantly of lipids and proteins, and other biomolecules such as nucleic acids. A signature feature of apolipoproteins is the preponderance of amphipathic α-helical motifs that dictate their ability to make extensive non-covalent inter- or intra-molecular helix–helix interactions in lipid-free states or helix–lipid interactions with hydrophobic biomolecules in lipid-associated states. This review focuses on the latter ability of apolipoproteins, which has been capitalized on to reconstitute synthetic nanoscale binary/ternary lipoprotein complexes composed of apolipoproteins/peptides and lipids that mimic native high-density lipoproteins (HDLs) with the goal to transport drugs. It traces the historical development of our understanding of these nanostructures and how the cholesterol accepting property of HDL has been reconfigured to develop them as drug-loading platforms. The review provides the structural perspective of these platforms with different types of apolipoproteins and an overview of their synthesis. It also examines the cargo that have been loaded into the core for therapeutic and imaging purposes. Finally, it lays out the merits and challenges associated with apolipoprotein-based nanostructures with a future perspective calling for a need to develop “zip-code”-based delivery for therapeutic and diagnostic applications.
High Temperature Stable Anatase Phase Titanium Dioxide Films Synthesized by Mist Chemical Vapor Deposition
Authors: Zhang Qiang , Li Chaoyang
Published: May 2020

Pure anatase-phase titanium dioxide films stable up to high temperatures were successfully fabricated by the mist chemical vapor deposition method. A post-annealing treatment of the synthesized films was carried out in oxygen atmosphere in the temperature range from 600 to 1100 °C and no anatase to rutile transformation was observed up to 1000 °C. Based on the grazing incidence X-ray diffraction data, the average crystallite size of the titanium dioxide films increased gradually with increasing annealing temperature. The structural analysis revealed that the high thermal stability of the anatase phase can be attributed to the small crystallite size and a sheet-like grain structure. An incomplete anatase to rutile transformation was observed after annealing at 1100 °C.
Study on Electron-Induced Surface Plasmon Coupling with Quantum Well Using a Perturbation Method
Authors: Chen Yifan , Feng Yulong , Chen Zhizhong , Jiao Fei , Zhan Jinglin , Chen Yiyong , Nie Jingxin , Pan Zuojian , Kang Xiangning , Li Shunfeng , Wang Qi , Zhang Shulin , Zhang Guoyi , Shen Bo
Published: May 2020

Ag nanoparticles (NPs) are filled in a photonic crystal (PhC) hole array on green light emitting diodes (LEDs). The localized surface plasmon (LSP)–quantum well (QW) coupling effect is studied by measuring the cathodoluminescence (CL) spectra impinging at the specific spots on the Ag NPs. Twenty-six percent and fifty-two percent enhancements of the CL intensities are obtained at the center and edge of the Ag NP, respectively, compared to the result that the electron-beam (e-beam) excites the QW directly. To illustrate the coupling process of the three-body system of e-beam–LSP–QW, a perturbation theory combining a three-dimensional (3D) finite difference time domain (FDTD) simulation is put forward. The effects of the polarization orientation of the dipole and the field symmetry of the LSP on the LSP–QW coupling are also discussed.