bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Electrochemical Performance of Graphene @ Halloysite Nanotubes/Sulfur Composites Cathode Materials for Lithium-Sulfur Batteries
Authors: Cen Tian , Zhang Yong , Tian Yanhong , Zhang Xuejun
Published: November 2020

Natural halloysite nanotubes (HNTs) and reduced graphene oxide (RGO) were introduced into the S cathode material to form HNTs/S and RGO@HNTs/S composite electrode to improve the electrochemical performance of Li-S batteries. The effect of acid etching temperature on the morphology and pore structure of HNTs was explored and the morphological characteristics and electrochemical performance of composite electrodes formed by HNTs that after treatment with different acid etching temperatures and RGO were compared. The result shows that the cycling stability and the utilization rate of active substances of the Li-S battery were greatly improved because the pore structure and surface polarity functional groups of HNTs and the introduction of RGO provide a conductive network for insulating sulfur particles. The RGO@HNTs treated by acid treatment at 80 °C (RGO@HNTs-80/S) composite electrode at 0.1 C has an initial capacity of 1134 mAh g−1, the discharge capacity after 50 cycles retains 20.1% higher than the normal S electrode and maintains a specific discharge capacity of 556 mAh g−1 at 1 C. Therefore, RGO and HNTs can effectively improve the initial discharge specific capacity, cycle performance and rate performance of Li-S batteries.
A Pathway toward a New Era of Open-Cell Polyurethane Foams—Influence of Bio-Polyols Derived from Used Cooking Oil on Foams Properties
Authors: Kurańska Maria , Malewska Elżbieta , Polaczek Krzysztof , Prociak Aleksander , Kubacka Joanna
Published: November 2020

In order to create greener polyurethane (PUR) foams, modified used cooking oils (UCO) were applied as starting resources for the synthesis of bio-polyols. The bio-polyols were produced using transesterification of UCO with diethylene glycol (UCO_DEG) and triethanolamine (UCO_TEA). Next, open-cell PUR foams were synthesized by replacing 20, 40, 60, 80 and 100% of the petrochemical polyol with the bio-polyol UCO_DEG or UCO_TEA. It was observed that an increasing bio-polyol content (up to 60%) led to an increase of the closed cell content. However, a further increase in the bio-polyol content up to 100% resulted in foam cell opening. The bio-foams obtained in the experiment had an apparent density of 13–18 kg/m3. The coefficient of thermal conductivity was determined at three different average temperatures: 10, 0 and −10 °C. The PUR bio-foams modified with bio-polyol UCO_TEA had lower values of thermal conductivity, regardless of the average temperature (35.99–39.57 mW/m·K) than the foams modified with bio-polyol UCO_DEG (36.95–43.78 mW/m·K). The compressive strength of most of the bio-foams was characterized by a higher value than the compressive strength of the reference material (without bio-polyol). Finally, it was observed that the bio-materials exhibited dimensional stability at 70 °C.
Scaled Approach to Designing the Minimum Hybrid Reinforcement of Concrete Beams
Authors: Gorino Andrea , Fantilli Alessandro
Published: November 2020

To study the brittle/ductile behavior of concrete beams reinforced with low amounts of rebar and fibers, a new multi-scale model is presented. It is used to predict the flexural response of an ideal Hybrid Reinforced Concrete (HRC) beam in bending, and it is validated with the results of a specific experimental campaign, and some tests available in the technical literature. Both the numerical and the experimental measurements define a linear relationship between the amount of reinforcement and the Ductility Index (DI). The latter is a non-dimensional function depending on the difference between the ultimate load and the effective cracking load of a concrete beam. As a result, a new design-by-testing procedure can be established to determine the minimum reinforcement of HRC elements. It corresponds to DI = 0, and can be considered as a linear combination of the minimum area of rebar (of the same reinforced concrete beam) and the minimum fiber volume fraction (of the same fiber-reinforced concrete beam), respectively.
Post-Processing Treatment Impact on Mechanical Properties of SLM Deposited Ti-6Al-4 V Porous Structure for Biomedical Application
Authors: Pehlivan Eren , Džugan Jan , Fojt Jaroslav , Sedláček Radek , Rzepa Sylwia , Daniel Matej
Published: November 2020

Additive manufacturing technologies allow producing a regular three-dimensional mesh of interconnected struts that form an open-cell porous structure. Regular porous structures have been used in the orthopedic industry due to outstanding bone anchoring. The aim of the study was to determine how the postprocessing influences the mechanical properties of porous structures made of titanium alloy CL 41TI ELI. The effect of hot isostatic pressing (HIP) as a method of increasing microstructural integrity was investigated here. The influence of surface etching (SE) technique, which was applied to the porous structure for cleaning unmelted titanium powder particles on the surface of connectors from the inner surfaces of a porous structure, was examined in this study. Mechanical properties were investigated by means of compression tests. The results point out that HIP has a minor effect on the mechanical behavior of considered porous structures. The SE is an effective method to clean the surface of a porous structure, which is very important in the case of biomedical applications when loose powder can cause serious health problems. Another effect of the SE is also the strut thickness reduction. Reducing strut thickness of a porous structure with the surface etching decreases its stiffness to the same extent as predicted by the relative density theoretical model but did not result in structural damage.
Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption
Authors: Andrade-Guel Marlene , Ávila-Orta Carlos A. , Cadenas-Pliego Gregorio , Cabello-Alvarado Christian J. , Pérez-Alvarez Marissa , Reyes-Rodríguez Pamela , Inam Fawad , Cortés-Hernández Dora A. , Quiñones-Jurado Zoe V.
Published: November 2020

High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78–82%) and hemocompatibility (1.6–1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood.
Increasing Necking Strain through Corrugation: Identifying Composite Systems That Can Benefit from Corrugated Geometry
Authors: Fraser Mark , Zurob Hatem , Wu Peidong , Bouaziz Olivier
Published: November 2020

Under some circumstances, composites with a corrugated reinforcement geometry show larger necking strains compared to traditional straight reinforced composites. In this work, finite element modeling studies were performed for linearly hardening materials, examining the effect of material parameters on the stress–strain response of both corrugation and straight-reinforced composites. These studies showed that improvements in necking strain depend on the ability of the corrugation to unbend and to provide a boost in work hardening at the right time. It was found that there is a range of matrix yield strengths and hardening rates for which a corrugated geometry will improve the necking strain and also a lower threshold of reinforcement yield strength below which no improvement in necking strain is possible. In addition, benefit maps and surfaces were generated that show which regions of property space benefit through corrugation and the corresponding improvement in necking strain that can be achieved.
Active Optical Fibers and Components for Fiber Lasers Emitting in the 2-μm Spectral Range
Authors: Todorov Filip , Aubrecht Jan , Peterka Pavel , Schreiber Ondřej , Jasim Ali A. , Mrázek Jan , Podrazký Ondřej , Kamrádek Michal , Kanagaraj Nithyanandan , Grábner Martin , Baravets Yauhen , Cajzl Jakub , Koška Pavel , Fišar Adam , Kašík Ivan , Honzátko Pavel
Published: November 2020

Laser sources emitting in the infrared range at around 2 µm are attracting great interest for a variety of applications like processing of transparent thermoplastic polymers in industry as well as plenty of applications in medicine, spectroscopy, gas sensing, nonlinear frequency conversion to the mid-infrared, to mention a few. Of late, fiber lasers compared to other kinds of lasers benefit from their all-fiber design, leading to a compact, robust, and well thermally manageable device. Particularly, thulium- and holmium-doped fiber lasers are the first choice in fiber lasers emitting light around 2 µm. In this paper, we give an overview of our recent results in the research on thulium- and holmium-doped optical fibers, fiber lasers, and related research topics in the 2-µm spectral range. In particular, we present, to our knowledge, the first results of improvement of pump absorption in double-clad fibers thanks to the fiber twist frozen during drawing. Finally, a brief demonstration of material processing by thulium all-fiber laser operating at 2 µm is presented.
The Correlation of Temperature-Mineral Phase Transformation as a Controlling Factor of Thermal and Mechanical Performance of Fly Ash-Based Alkali-Activated Binders
Authors: Kozhukhova Natalia , Kozhukhova Marina , Zhernovskaya Irina , Promakhov Vladimir
Published: November 2020

This research focuses on an evaluation of mineral phase and structure transformations in Class F fly ash-based geopolymer systems. The research also studies the strength response of geopolymers when exposed to temperatures between 25 and 800 °C. The purpose of this research is to understand the processes that occur in alkali-activated systems within a wide range of high-working temperatures. The XRD, SEM, and DTA/TG analyses performed for the alkali-activated compositions after exposure to different temperatures confirmed a direct correlation of structural transformations with strength performance. The detrimental effect of sodium hydrocarbonate Na3(HCO3)(CO3) 2H2O or trona contained in one of the fly ash products was observed for the corresponding alkali-activated composite under high-temperature exposure between 600 and 800 °C. It was also detected that a high-temperature interval of 400–800 °C created favorable conditions that helped to form nanosized nepheline crystals and an additional vitreous substance that also contributed to a denser alkali-activated matrix.
Comparative Investigation of Activated Carbon Electrode and a Novel Activated Carbon/Graphene Oxide Composite Electrode for an Enhanced Capacitive Deionization
Authors: Folaranmi Gbenro , Bechelany Mikhael , Sistat Philippe , Cretin Marc , Zaviska Francois
Published: November 2020

Capacitive deionization is an emerging brackish water desalination technology whose principle lies in the utilization of porous electrodes (activated carbon materials) to temporarily store ions. Improving the properties of carbon material used as electrodes have been the focus of recent research, as this is beneficial for overall efficiency of this technology. Herein, we have synthesized a composite of activated carbon/graphene oxide electrodes by using a simple blending process in order to improve the hydrophilic property of activated carbon. Graphene oxide (GO) of different weight ratios was blended with commercial Activated carbon (AC) and out of all the composites, AC/GO-15 (15 wt.% of GO) exhibited the best electrochemical and salt adsorption performance in all operating conditions. The as prepared AC and AC/GO-x (x = 5, 10, 15 and 20 wt.% of GO) were characterized by cyclic voltammetry and their physical properties were also studied. The salt adsorption capacity (SAC) of AC/GO-15 at an operating window of 1.0 V is 5.70 mg/g with an average salt adsorption rate (ASAR) of 0.34 mg/g/min at a 400 mg/L salt initial concentration and has a capacitance of 75 F/g in comparison to AC with 3.74 mg/g of SAC, ASAR of 0.23 mg/g/min and a capacitance of 56 F/g at the same condition. This approach could pave a new way to produce a highly hydrophilic carbon based electrode material in CDI.
Preparation and Phase Change Performance of Graphene Oxide and Silica Composite Na2SO4·10H2O Phase Change Materials (PCMs) as Thermal Energy Storage Materials
Authors: Tao Wen , Kong Xiangfa , Bao Anyang , Fan Chuangang , Zhang Yi
Published: November 2020

In this study, a novel nucleating agent composed of graphene oxide (GO) and silicon dioxide (SiO2) (GO–SiO2) is developed. GO is used as a skeleton material through which SiO2 nanomaterials are absorbed and subsequently incorporated into Na2SO4·10H2O phase change materials (PCMs). Furthermore, this study examines the phase change performance of the composite Na2SO4·10H2O materials. Fourier-transform infrared (FTIR) spectra confirmed the physical combination of GO with a SiO2 nanoparticles. Scanning electron microscope (SEM) results showed that the GO–SiO2 composite exhibited a layered structure and excellent dispersibility. The GO–SiO2 composite Na2SO4·10H2O PCMs displayed a low level of supercooling, i.e., about 1.2 °C with the addition of GO–SiO2 at 2.45 wt%. This was because the synergistic relation of the GO and the high dispersion SiO2, imparted more nucleation sites for Na2SO4·10H2O. Additionally, the prepared PCMs achieved high phase change latent heat and thermal conductivity, even under these conditions. The results show that the GO–SiO2 in the Na2SO4·10H2O exhibited advantageous application prospects for the improvement of the thermal performance of hydrate salts.
Proteomic Analysis of Porcine-Derived Collagen Membrane and Matrix
Authors: Lee Jung-Seok , Mitulović Goran , Panahipour Layla , Gruber Reinhard
Published: November 2020

Collagen membranes and matrices being widely used in guided bone regeneration and soft tissue augmentation have characteristic properties based on their composition. The respective proteomic signatures have not been identified. Here, we performed a high-resolution shotgun proteomic analysis on two porcine collagen-based biomaterials designed for guided bone regeneration and soft tissue augmentation. Three lots each of a porcine-derived collagen membrane and a matrix derived from peritoneum and/or skin were digested and separated by nano-reverse-phase high-performance liquid chromatography. The peptides were subjected to mass spectrometric detection and analysis. A total of 37 proteins identified by two peptides were present in all collagen membranes and matrices, with 11 and 16 proteins being exclusively present in the membrane and matrix, respectively. The common extracellular matrix proteins include fibrillar collagens (COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL5A3, COL11A2), non-fibrillar collagens (COL4A2, COL6A1, COL6A2, COL6A3, COL7A1, COL16A1, COL22A1), and leucine-rich repeat proteoglycans (DCN, LUM, BGN, PRELP, OGN). The structural proteins vimentin, actin-based microfilaments (ACTB), annexins (ANXA1, ANXA5), tubulins (TUBA1B, TUBB), and histones (H2A, H2B, H4) were also identified. Examples of membrane-only proteins are COL12A1 and COL14A1, and, of matrix only proteins, elastin (ELN). The proteomic signature thus revealed the similarities between but also some individual proteins of collagen membrane and matrix.
Deformation of Bioinspired MXene-Based Polymer Composites with Brick and Mortar Structures: A Computational Analysis
Authors: Srivatsa Shreyas , Paćko Paweł , Mishnaevsky Leon , Uhl Tadeusz , Grabowski Krzysztof
Published: November 2020

In this work, the deformation behavior of MXene-based polymer composites with bioinspired brick and mortar structures is analyzed. MXene/Polymer nanocomposites are modeled at microscale for bioinspired configurations of nacre-mimetic brick-and-mortar assembly structure. MXenes (brick) with polymer matrix (mortar) are modeled using classical analytical methods and numerical methods based on finite elements (FE). The analytical methods provide less accurate estimation of elastic properties compared to the numerical one. MXene nanocomposite models analyzed with the FE method provide estimates of elastic constants in the same order of magnitude as literature-reported experimental results. Bioinspired design of MXene nanocomposites results in an effective increase of Young’s modulus of the nanocomposite by 25.1% and strength (maximum stress capacity within elastic limits) enhanced by 42.3%. The brick and mortar structure of the nanocomposites leads to an interlocking mechanism between MXene fillers in the polymer matrix, resulting in effective load transfer, good strength, and damage resistance. This is demonstrated in this paper by numerical analysis of MXene nanocomposites subjected to quasi-static loads.
Effect of SiC Addition to Al2O3 Ceramics Used in Cutting Tools
Authors: Gevorkyan Edwin , Rucki Mirosław , Panchenko Sergey , Sofronov Dmitry , Chałko Leszek , Mazur Tomasz
Published: November 2020

In this study, the effect of the addition of silicon carbide to alumina ceramics commonly used in cutting tool applications is addressed. Performance of Al2O3–SiC composite cutting inserts during the machining of hardened steels and ductile iron was compared to the results obtained for a cutting tool made out of 99 wt.% Al2O3, Al2O3–TiC, Al2O3–TiC–ZrO2, and Al2O3–TiN. In almost all tests, the composite with silicon carbide demonstrated better wear resistance, longer tool lifetime, and the ability to cut at higher speeds. The enhanced properties of cutting tools with SiC can be attributed to the morphology and dimensions of the inclusions in the matrix as well as to the strength of the interphase boundaries, small porosity, and lack of high inner stresses in the volume.
Bond Strength of Metallic or Ceramic Orthodontic Brackets to Enamel, Acrylic, or Porcelain Surfaces
Authors: Pinho Mónica , Manso Maria C. , Almeida Ricardo Faria , Martin Conchita , Carvalho Óscar , Henriques Bruno , Silva Filipe , Pinhão Ferreira Afonso , Souza Júlio C. M.
Published: November 2020

Bonding strategies within different brackets and dental materials are still a challenge concerning adhesion and dental surface damage. This study compared the shear and tensile bond strength of orthodontic ceramic and metallic brackets to enamel, acrylic, and ceramic surfaces after thermal cycling. Dental surfaces were divided into three groups: enamel, ceramic, and acrylic. Each group received stainless-steel and ceramic brackets. After thermal cycling, specimens were randomly divided into two subgroups considering tensile (TBS) or shear bond strength (SBS) test. After the mechanical testing, scanning electron and optical microscopy were performed, and the adhesive remnant index (ARI) was determined. The two-way ANOVA full factorial design was used to compare TBS, SBS, and ARI on the surface and bracket type (α = 0.05). There were significant differences in TBS, SBS, and ARI values per surface (p < 0.001 and p = 0.009) and type of bracket (p = 0.025 and p = 0.001). The highest mean SBS values were recorded for a ceramic bracket bonded to an acrylic surface (8.4 ± 2.3 MPa). For TBS, a ceramic bracket bonded to acrylic showed the worst performance (5.2 ± 1.8 MPa) and the highest values were found on a metallic bracket bonded to enamel. The adhesion of metallic or ceramic brackets is enough for clinical practice although the damage of the enamel surface after debonding is irreversible and harmful for the aesthetic outcome of the teeth.
Numerical and Experimental Extraction of Dynamic Parameters for Pyramidal Truss Core Sandwich Beams with Laminated Face Sheets
Authors: Wesolowski Miroslaw , Ruchwa Mariusz , Skukis Eduards , Kovalovs Andrejs
Published: November 2020

Sandwich beams that are composed of laminated face sheets and aluminum pyramidal truss cores are considered to be essential elements of building and aerospace structures. In this paper, a methodology for the experimental and numerical analysis of such structures is presented in order to support their industrial application. The scope of the present research covers both the experimental and numerical extraction of the dynamic parameters of the sandwich beams. Vibration tests are performed while using an optical system for three-dimensional vibrations sensing. The in-plane and out-of-plane vibration modes can thus be examined. A detailed numerical model of the sandwich beam is developed, including an adhesive joint (an additional layer of material) between the parent components of the beam. The numerically predicted modal parameters (eigenfrequencies, mode shapes, modal loss factors) are comported with their corresponding experimentally-obtained values. The modal loss factors are predicted based on the strain energy method, for which a brief theoretical introduction is provided. The obtained experimental and numerical results coincide with good accuracy. The circumstances for possible model simplifications are provided depending on the solution objectives.
An Investigation of Softening Laws and Fracture Toughness of Slag-Based Geopolymer Concrete and Mortar
Authors: Ding Yao , Bai Yu-Lei , Dai Jian-Guo , Shi Cai-Jun
Published: November 2020

This paper aimed to determine the softening laws and fracture toughness of slag-based geopolymer (SG) concrete and mortar (SGC and SGM) as compared to those of Portland cement (PC) concrete and mortar (PCC and PCM). Using three-point bending (TPB) tests, the load vs. mid-span displacement, crack mouth opening displacement, and crack tip opening displacement curves (P-d, P-CMOD, and P-CTOD curves) were all recorded. Bilinear softening laws of the PC and SG series were determined by inverse analysis. Furthermore, the cohesive toughness was predicted using an analytical fracture model. The cohesive toughness obtained by experimental study was consistent with that predicted by analytical method, proving the correctness of the tension softening law obtained from inverse analysis. In addition, both initial and unstable fracture toughness values of SG mortar were lower than those of PC mortar given the same compressive strength. Moreover, the initial fracture toughness of SG concrete was generally lower than that of PC concrete, whereas the unstable fracture toughness exhibited an opposite trend.
Multibody-Based Piano Action: Validation of a Haptic Key
Authors: Timmermans Sébastien , Dehez Bruno , Fisette Paul
Published: November 2020

A piano key prototype actuated by a custom-made linear actuator is proposed to enhance the touch of digital pianos by reproducing the force feedback of an acoustic piano action. This paper presents the design and the validation of the haptic device. The approach exploits a multibody model to compute the action dynamics and the corresponding force on the key in real time. More specifically, a grand piano model that includes the five action bodies, its geometry and the specific force laws, is computed in the haptic device. A presizing step along with Finite Element Method (FEM) analysis produced an especially made actuator satisfying the design requirements, in particular the highly dynamic nature of the force to be transmitted. Force peaks, up to 50 (N) in less than 20 (ms), are reachable with low power consumption. Compared to previous solutions: (i) the key physical characteristics are preserved; (ii) the feedback is based on a real-time multibody model that is easily configurable and interchangeable; (iii) an experimental validation of the actuator within the prototype is developed and demonstrates its feasibility. The results confirm that the voice coil can produce suitable haptic feedback. In particular, rendering a grand piano action within the device shows promising haptic force profiles.
Usefulness of Antioxidants as Adjuvant Therapy for Septic Shock: A Randomized Clinical Trial
Authors: Aisa-Alvarez Alfredo , Soto María Elena , Guarner-Lans Verónica , Camarena-Alejo Gilberto , Franco-Granillo Juvenal , Martínez-Rodríguez Enrique A. , Gamboa Ávila Ricardo , Manzano Pech Linaloe , Pérez-Torres Israel
Published: November 2020

Background and objectives: Oxidative stress (OS) participates in the pathophysiology of septic shock, which leads to multiple organ failure (MOF), ischemia-reperfusion injury, and acute respiratory distress syndrome. Therefore, antioxidants have been proposed as therapy. Here, we evaluated the effect of antioxidant treatments in patients with septic shock with MOF and determined levels OS before and after treatment. This study was a randomized, controlled, triple-masked, and with parallel assignment clinical trial with a control group without treatment. Materials and Methods: It included 97 patients of either sex with septic shock. 5 treatments were used each in an independent group of 18 patients. Group 1 received vitamin C (Vit C), group 2 vitamin E (Vit E), group 3 n-acetylcysteine (NAC), group 4 melatonin (MT), and group 5 served as control. All antioxidants were administered orally or through a nasogastric tube for five days as an adjuvant to the standard therapy. Results: The results showed that all patients presented MOF due to sepsis upon admission and that the treatment decreased it (p = 0.007). The antioxidant treatment with NAC increased the total antioxidant capacity (p < 0.05). The patients that received Vit C had decreased levels of the nitrate and nitrite ratio (p < 0.01) and C-reactive protein levels (p = 0.04). Procalcitonin levels were reduced by Vit E (p = 0.04), NAC (p = 0.001), and MT (p = 0.04). Lipid-peroxidation was reduced in patients that received MT (p = 0.04). Conclusions: In conclusion, antioxidant therapy associated with standard therapy reduces MOF, OS, and inflammation in patients with septic shock.
Special Issue: Plant Metabolomics
Authors: Gonda Sándor
Published: November 2020

This Special Issue was initiated to collect a handful of studies on plant chemistry, utilizing metabolomics as the main technique, to show the diversity of possible applications of this approach [...]
Altered Levels of Desaturation and ω-6 Fatty Acids in Breast Cancer Patients’ Red Blood Cell Membranes
Authors: Amézaga Javier , Ugartemendia Gurutze , Larraioz Aitziber , Bretaña Nerea , Iruretagoyena Aizpea , Camba Joana , Urruticoechea Ander , Ferreri Carla , Tueros Itziar
Published: November 2020

Red blood cell (RBC) membrane can reflect fatty acid (FA) contribution from diet and biosynthesis. In cancer, membrane FAs are involved in tumorigenesis and invasiveness, and are indicated as biomarkers to monitor the disease evolution as well as potential targets for therapies and nutritional strategies. The present study provides RBC membrane FA profiles in recently diagnosed breast cancer patients before starting chemotherapy treatment. Patients and controls were recruited, and their dietary habits were collected. FA lipidomic analysis of mature erythrocyte membrane phospholipids in blood samples was performed. Data were adjusted to correct for the effects of diet, body mass index (BMI), and age, revealing that patients showed lower levels of saturated fatty acids (SFA) and higher levels of monounsaturated fatty acid, cis-vaccenic (25%) than controls, with consequent differences in desaturase enzymatic index (∆9 desaturase, –13.1%). In the case of polyunsaturated fatty acids (PUFA), patients had higher values of ω-6 FA (C18:2 (+11.1%); C20:4 (+7.4%)). RBC membrane lipidomic analysis in breast cancer revealed that ω-6 pathways are favored. These results suggest new potential targets for treatments and better nutritional guidelines.
The Genus Ochrobactrum as Major Opportunistic Pathogens
Authors: Ryan Michael P. , Pembroke J. Tony
Published: November 2020

Ochrobactrum species are non-enteric, Gram-negative organisms that are closely related to the genus Brucella. Since the designation of the genus in 1988, several distinct species have now been characterised and implicated as opportunistic pathogens in multiple outbreaks. Here, we examine the genus, its members, diagnostic tools used for identification, data from recent Ochrobactrum whole genome sequencing and the pathogenicity associated with reported Ochrobactrum infections. This review identified 128 instances of Ochrobactrum spp. infections that have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Ochrobactrum spp. outbreaks if these bacteria are clinically isolated in more than one patient and that Ochrobactrum spp. are more important pathogens than previously thought.
Evaluation of a New Topical Treatment for the Control of Cutaneous Leishmaniasis
Authors: Martínez-Salazar Berenice , Carregaro Pereira Vanessa , Hauyon-La-Torre Yazmin , Khamesipour Ali , Tacchini-Cottier Fabienne
Published: November 2020

Leishmania major (L. major) causes cutaneous leishmaniasis in the Old World. The infection mostly induces a localized lesion restricted to the sand fly bite. The costs and the side effects of current treatments render imperative the development of new therapies that are affordable and easy to administrate. Topical treatment would be the ideal option for the treatment of cutaneous leishmaniasis. MF29 is a 3-haloacetamidobenzoate that was shown in vitro to inhibit tubulin assembly in Leishmania. Here, we tested a topical cream formulated with MF29. BALB/c mice were infected in the ear dermis with L. major metacyclic promastigotes and once the lesion appeared, mice were treated with different concentrations of MF29 and compared to the control group treated with the cream used as the vehicle. We observed that topical application of MF29 reduced the progression of the infection while control groups developed an unhealing lesion that became necrotic. The treatment decreased the type 2 immune response. Comparison with SinaAmphoLeish, another topical treatment, revealed that MF29 treatment once a day was sufficient to control lesion development, while application SinaAmphoLeish needed applications twice daily. Collectively, our data suggest that MF-29 topical application could be a promising topical treatment for cutaneous leishmaniasis.
Disrupting Bordetella Immunosuppression Reveals a Role for Eosinophils in Coordinating the Adaptive Immune Response in the Respiratory Tract
Authors: Gestal Monica C. , Blas-Machado Uriel , Johnson Hannah M. , Rubin Lily N. , Dewan Kalyan K. , Bryant Claire , Tiemeyer Michael , Harvill Eric T.
Published: November 2020

Recent findings revealed pivotal roles for eosinophils in protection against parasitic and viral infections, as well as modulation of adaptive immune responses in the gastric mucosa. However, the known effects of eosinophils within the respiratory tract remain predominantly pathological, associated with allergy and asthma. Simulating natural respiratory infections in mice, we examined how efficient and well-adapted pathogens can block eosinophil functions that contribute to the immune response. Bordetella bronchiseptica, a natural pathogen of the mouse, uses the sigma factor btrS to regulate expression of mechanisms that interfere with eosinophil recruitment and function. When btrS is disrupted, immunomodulators are dysregulated, and eosinophils are recruited to the lungs, suggesting they may contribute to much more efficient generation of adaptive immunity induced by this mutant. Eosinophil-deficient mice failed to produce pro-inflammatory cytokines, to recruit lymphocytes, to organize lymphoid aggregates that resemble Bronchus Associated Lymphoid Tissue (BALT), to generate an effective antibody response, and to clear bacterial infection from the respiratory tract. Importantly, the failure of eosinophil-deficient mice to produce these lymphoid aggregates indicates that eosinophils can mediate the generation of an effective lymphoid response in the lungs. These data demonstrate that efficient respiratory pathogens can block eosinophil recruitment, to inhibit the generation of robust adaptive immune responses. They also suggest that some post-infection sequelae involving eosinophils, such as allergy and asthma, might be a consequence of bacterial mechanisms that manipulate their accumulation and/or function within the respiratory tract.
Assessment of Native and Endemic Chilean Plants for Removal of Cu, Mo and Pb from Mine Tailings
Authors: Lazo Pamela , Lazo Andrea
Published: November 2020

In Chile, 85% of tailings impoundments are inactive or abandoned and many of them do not have a program of treatment or afforestation. The phytoremediation of tailings with Oxalis gigantea, Cistanthe grandiflora, Puya berteroniana and Solidago chilensis have been tested in order to find plants with ornamental value and low water requirements, which enable reductions in molybdenum (Mo), copper (Cu) or lead (Pb) concentrations creating an environmentally friendly surrounding. Ex-situ phytoremediation experiments were carried out for seven months and Mo, Cu and Pb were measured at the beginning and at the end of the growth period. The capacity of these species to phyto-remedy was evaluated using the bioconcentration and translocation factors, along with assessing removal efficiency. Solidago chilensis showed the ability to phytoextract Mo while Puya berteroniana showed potential for Cu and Mo stabilization. The highest removal efficiencies were obtained for Mo, followed by Cu and Pb. The maximum values of removal efficiency for Mo, Cu and Pb were 28.7% with Solidago chilensis, 15.6% with Puya berteroniana and 8.8% with Cistanthe grandiflora, respectively. Therefore, the most noticeable results were obtained with Solidago chilensis for phytoextraction of Mo.
Mineralogical and Leaching Characteristics of Altered Ilmenite Beach Placer Sands
Authors: Ramakokovhu Munyadziwa Mercy , Olubambi Peter Apata , Mbaya Richard Kady Kadiambuji , Mojisola Tajudeen , Teffo Moipone Linda
Published: November 2020

In order to have a good understanding of the treatment process and improvement on the market value of ilmenite beach placer sands, knowledge of its mineral composition and phase distribution is fundamental. In this study, a combination of characterization techniques including high-resolution scanning electron microscopy (HR-SEM), high-resolution transmission electron (HR-TEM) microscope, and X-ray diffraction (XRD) techniques was used to understand the mineralogical characteristics of ilmenite beach placer sands obtained from Richards Bay, South Africa. The mineral phase constituents of the ilmenite beach placer sands were studied before pre-oxidation and additive leaching in a chloride environment. During observations using XRD and HR-SEM, the ilmenite beach placer sands exhibited signature rhombohedral crystal form and crescentic pits with evidence of alteration phases. The characterized pre-oxidized ilmenite showed the presence of a ferric oxide film deposit of the particles. The leaching characteristics of both raw and pre-oxidized ilmenite was studied in the presence of additives. The leaching efficiency of the pre-oxidized ilmenite in the presence of additives increased by 20% at atmospheric conditions. The characterized residues show the improved amenability of pre-oxidized leach in chloride media. The formation of new phases containing pseudo-rutile indicated crystallographic disintegration by the movement of atoms during dissolution. Some particles retained the crescentic pit and the subangular grain structure; however, the phase changes were observed at the grain boundaries and grain edges. The leached residue’s EDS results still indicated the presence of pseudo-rutile and some minor unreacted oxides such as SiO2, Al2O3, and other trace metals. The trace metals impurities present in the as-received ilmenite were reduced by 80% in the final residue after the leaching.
Role of Bcl-2 Family Proteins in Photodynamic Therapy Mediated Cell Survival and Regulation
Authors: Aniogo Eric Chekwube , George Blassan Plackal Adimuriyil , Abrahamse Heidi
Published: November 2020

Photodynamic therapy (PDT) is a treatment modality that involves three components: combination of a photosensitizer, light and molecular oxygen that leads to localized formation of reactive oxygen species (ROS). The ROS generated from this promising therapeutic modality can be lethal to the cell and leads to consequential destruction of tumor cells. However, sometimes the ROS trigger a stress response survival mechanism that helps the cells to cope with PDT-induced damage, resulting in resistance to the treatment. One preferred mechanism of cell death induced by PDT is apoptosis, and B-cell lymphoma 2 (Bcl-2) family proteins have been described as a major determinant of life or death decision of the death pathways. Apoptosis is a cellular self-destruction mechanism to remove old cells through the biological event of tissue homeostasis. The Bcl-2 family proteins act as a critical mediator of a life–death decision of cells in maintaining tissue homeostasis. There are several reports that show cancer cells developing resistance due to the increased interaction of the pro-survival Bcl-2 family proteins. However, the key mechanisms leading to apoptosis evasion and drug resistance have not been adequately understood. Therefore, it is critical to understand the mechanisms of PDT resistance, as well as the Bcl-2 family proteins, to give more insight into the treatment outcomes. In this review, we describe the role of Bcl-2 gene family proteins’ interaction in response to disease progression and PDT-induced resistance mechanisms.
Health-Promoting Capacities of In Vitro and Cultivated Goji (Lycium chinense Mill.) Fruit and Leaves; Polyphenols, Antimicrobial Activity, Macro- and Microelements and Heavy Metals
Authors: Kruczek Arleta , Krupa-Małkiewicz Marcelina , Lachowicz Sabina , Oszmiański Jan , Ochmian Ireneusz
Published: November 2020

There is a growing interest among the public in fruit with a positive impact on human health. Two goji berry cultivars (‘No. 1’ and ‘New Big’) were propagated in vitro, grown in an orchard and then evaluated for macro- and microelements and harmful heavy metals (i.e., Pb, Ni, and Cd). The leaves and fruit were also assessed for nutritional value, polyphenols and the antimicrobial activity of the leaves. ‘New Big’ was characterized by a higher content of macro elements in the leaves (in vitro and orchard) and a higher content of microelements in the fruit. The harmful substances content was below the minimum value. Furthermore, neither the fruit nor the leaves contained cadmium. This study also indicated that leaves had a higher content of polyphenols compared to the fruit. The fruits were characterized by their health-promoting capacities, while the leaves were characterized by their antibacterial activity. Among the Gram-positive bacteria, the most sensitive strain was Bacillus subtilis, and among the Gram-negative bacteria, it was Proteus vulgaris. Taking into consideration the Recommended Daily Allowance (RDA) for minerals, goji berries can be declared to be a source of Cu, Fe, Mn, Zn and P.
Molecular Targets Implicated in the Antiparasitic and Anti-Inflammatory Activity of the Phytochemical Curcumin in Trichomoniasis
Authors: Mallo Natalia , Lamas Jesús , Sueiro Rosa Ana , Leiro José Manuel
Published: November 2020

Trichomoniasis, is the most prevalent non-viral sexually transmitted disease worldwide. Although metronidazole (MDZ) is the recommended treatment, several strains of the parasite are resistant to MDZ, and new treatments are required. Curcumin (CUR) is a polyphenol with anti-inflammatory, antioxidant and antiparasitic properties. In this study, we evaluated the effects of CUR on two biochemical targets: on proteolytic activity and hydrogenosomal metabolism in Trichomonas vaginalis. We also investigated the role of CUR on pro-inflammatory responses induced in RAW 264.7 phagocytic cells by parasite proteinases on pro-inflammatory mediators such as the nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1beta (IL-1β), chaperone heat shock protein 70 (Hsp70) and glucocorticoid receptor (mGR). CUR inhibited the growth of T. vaginalis trophozoites, with an IC50 value between 117 ± 7 μM and 173 ± 15 μM, depending on the culture phase. CUR increased pyruvate:ferredoxin oxidoreductase (PfoD), hydrogenosomal enzyme expression and inhibited the proteolytic activity of parasite proteinases. CUR also inhibited NO production and decreased the expression of pro-inflammatory mediators in macrophages. The findings demonstrate the potential usefulness of CUR as an antiparasitic and anti-inflammatory treatment for trichomoniasis. It could be used to control the disease and mitigate the associated immunopathogenic effects.
Antifungal Activity of Alpha-Mangostin against Colletotrichum gloeosporioides In Vitro and In Vivo
Authors: Ye Huochun , Wang Qin , Zhu Fadi , Feng Gang , Yan Chao , Zhang Jing
Published: November 2020

We investigated alpha-mangostin (α-mangostin, α-MG), a xanthone natural product extracted from the pericarp of mangosteen (Garcinia mangostana), for its antifungal activities and possible mechanism against Colletotrichum gloeosporioides, which causes mango anthracnose. The results demonstrated that α-MG had a relatively high in vitro inhibitory activity against C. gloeosporioides among 20 plant pathogenic fungi. The median effective concentration (EC50) values of α-MG against mycelial growth were nearly 10 times higher than those of spore germination inhibition for both strains of C. gloeosporioides, the carbendazim-sensitive (CBD-s) and carbendazim-resistant (CBD-r). The results suggested that α-MG exhibited a better inhibitory effect on spore germination than on the mycelial growth of C. gloeosporioides. Further investigation indicated that the protective effect could be superior to the therapeutic effect for mango leaves for scab development. The morphological observations of mycelium showed that α-MG caused the accumulation of dense bodies. Ultrastructural observation further revealed that α-MG caused a decrease in the quantity and shape of the swelling of mitochondria in the mycelium cells of C. gloeosporioides. In addition, bioassays disclosed that the inhibitory activity of α-MG on spore germination was reduced by adding exogenous adenosine triphosphate (ATP). These results suggested that the mode of action of α-MG could be involved in the destruction of mitochondrial energy metabolism. The current study supports α-MG as a natural antifungal agent in crop protection.
Astaxanthin and its Effects in Inflammatory Responses and Inflammation-Associated Diseases: Recent Advances and Future Directions
Authors: Chang Ming Xian , Xiong Fan
Published: November 2020

Astaxanthin is a natural lipid-soluble and red-orange carotenoid. Due to its strong antioxidant property, anti-inflammatory, anti-apoptotic, and immune modulation, astaxanthin has gained growing interest as a multi-target pharmacological agent against various diseases. In the current review, the anti-inflammation mechanisms of astaxanthin involved in targeting for inflammatory biomarkers and multiple signaling pathways, including PI3K/AKT, Nrf2, NF-κB, ERK1/2, JNK, p38 MAPK, and JAK-2/STAT-3, have been described. Furthermore, the applications of anti-inflammatory effects of astaxanthin in neurological diseases, diabetes, gastrointestinal diseases, hepatic and renal diseases, eye and skin disorders, are highlighted. In addition to the protective effects of astaxanthin in various chronic and acute diseases, we also summarize recent advances for the inconsistent roles of astaxanthin in infectious diseases, and give our view that the exact function of astaxanthin in response to different pathogen infection and the potential protective effects of astaxanthin in viral infectious diseases should be important research directions in the future.
Cardioprotective Activity of Selected Polyphenols Based on Epithelial and Aortic Cell Lines. A Review
Authors: Otręba Michał , Kośmider Leon , Stojko Jerzy , Rzepecka-Stojko Anna
Published: November 2020

Polyphenols have recently gained popularity among the general public as products and diets classified as healthy and containing naturally occurring phenols. Many polyphenolic extracts are available on the market as dietary supplements, functional foods, or cosmetics, taking advantage of clients’ desire to live a healthier and longer life. However, due to the difficulty of discovering the in vivo functions of polyphenols, most of the research focuses on in vitro studies. In this review, we focused on the cardioprotective activity of different polyphenols as possible candidates for use in cardiovascular disease therapy and for improving the quality of life of patients. Thus, the studies, which were mainly based on endothelial cells, aortic cells, and some in vivo studies, were analyzed. Based on the reviewed articles, polyphenols have a few points of action, including inhibition of acetylcholinesterase, decrease in reactive oxygen species production and endothelial tube formation, stimulation of acetylcholine-induced endothelium-derived mediator release, and others, which lead to their cardio- and/or vasoprotective effects on endothelial cells. The obtained results suggest positive effects of polyphenols, but more long-term in vivo studies demonstrating effects on mechanism of action, sensitivity, and specificity or efficacy are needed before legal health claims can be made.
Development of Antioxidant-Loaded Nanoliposomes Employing Lecithins with Different Purity Grades
Authors: Yarce Cristhian J. , Alhajj Maria J. , Sanchez Julieth D. , Oñate-Garzón Jose , Salamanca Constain H.
Published: November 2020

This work focused on comparing the ability of lecithins with two purity grades regarding their performance in the development of nanoliposomes, as well as their ability to contain and release polar (trans-aconitic acid) and non-polar (quercetin) antioxidant compounds. First, the chemical characterization of both lecithins was carried out through infrared spectroscopy (FTIR), electrospray ionization mass spectrometry (ESI/MS), and modulated differential scanning calorimetry (mDSC). Second, nanoliposomes were prepared by the ethanol injection method and characterized by means of particle size, polydispersity, and zeta potential measurements. Third, the encapsulation efficiency and in vitro release profiles of antioxidants were evaluated. Finally, the antioxidant effect of quercetin and trans aconitic acid in the presence and absence of nanoliposomes was assessed through the oxygen radical absorbance capacity (ORAC) assay. The results showed that, although there are differences in the chemical composition between the two lecithins, these allow the development of nanoliposomes with very similar physicochemical features. Likewise, nanoliposomes elaborated with low purity grade lecithins favored the encapsulation and release of trans-aconitic acid (TAA), while the nanoliposomes made with high purity lecithins favored the encapsulation of quercetin (QCT) and modified its release. Regarding the antioxidant effect, the vehiculization of TAA and QCT in nanoliposomes led to an increase in the antioxidant capability, where QCT showed a sustained effect over time and TAA exhibited a rapidly decaying effect. Likewise, liposomal systems were also found to have a slight antioxidant effect.