bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Investigation on Micro End Milling with High-Speed Up Cut Milling for Hardened Die Steel
Authors: Kino Haruki , Imada Takumi , Ogawa Keiji , Nakagawa Heisaburo , Kojima Hitomi
Published: October 2020

The importance of micromachining using small diameter end mills and the dies used for them has been increasing in the machining of small parts. However, the reality is that there are various requirements to improve the machining surface, machining accuracy, machining efficiency, and tool life. Therefore, this paper discusses the possibility of satisfying these requirements by high-speed up cut milling in side cutting. The goal of this study was to solve the aforementioned problems, by conducting a detailed analysis of the machining phenomena in order to understand their mechanisms. In particular, the effects of high-speed cutting using a high-speed air-turbine spindle with highly stiff rolling bearings were analyzed. Moreover, cutting experiments were conducted by measuring the cutting force and flank wear of the tool, to reveal the differences in the cutting phenomena relative to the cutting direction in high-speed micro end milling. Description of the machined surface and the measurement of its profile were also included in the discussions. On the basis of the results, high-speed up cut milling is a better choice than down cut milling; furthermore, a high-feed rate further increases machining efficiency and improves tool life.
Interface Control in Additive Manufacturing of Dissimilar Metals Forming Intermetallic Compounds—Fe-Ti as a Model System
Authors: Cui Di , Mohanta Antaryami , Leparoux Marc
Published: October 2020

Laser metal deposition (LMD) has demonstrated its ability to produce complex parts and to adjust material composition within a single workpiece. It is also a suitable additive manufacturing (AM) technology for building up dissimilar metals directly. However, brittle intermetallic compounds (IMCs) are formed at the interface of the dissimilar metals fabricated by LMD. Such brittle phases often lead to material failure due to thermal expansion coefficient mismatch, thermal stress, etc. In this work, we studied a Fe-Ti system with two brittle phases, such as FeTi and Fe2Ti, as a model system. Fe was grown on top of Ti at various process parameters. The morphologies and microstructures were characterized by optical microscopy (OM) and scanning electron microscopy (SEM). No cracks along the interface between pure Ti and bottom of the solidified melt pool were observed in the cross-sectional images. Chemical composition in the fabricated parts was measured by Energy-dispersive X-ray spectroscopy (EDS). Electron backscatter diffraction (EBSD) was performed in addition to EDS to identify the crystalline phases. The Vickers hardness test was conducted in areas with different phases. The chemical composition in the melt pool region was found to be a determining factor for the occurrence of major cracks.
Impact of DBBM Fragments on the Porosity of the Calvarial Bone: A Pilot Study on Mice
Authors: Kuchler Ulrike , Heimel Patrick , Stähli Alexandra , Strauss Franz Josef , Luza Bernadette , Gruber Reinhard
Published: October 2020

Deproteinized bovine bone mineral (DBBM) is brittle and can break into fragments. Here, we examined whether DBBM fragments have an impact on mice calvarial bone during bone augmentation. DBBM was either randomly crushed (DBBM fragments) or left undisturbed (DBBM granules). Then, DBBM fragments or original DBBM granules were placed onto calvarial bone in 20 BALB/c mice. Following random allocation, ten mice received DBBM fragments and ten mice received original DBBM granules. After fourteen days of healing, micro computed tomography (micro-CT) and histological analysis of the augmented sites were performed. The primary outcome was the porosity of the calvarial bone. The micro-CT analysis revealed that DBBM fragments failed to significantly change the porosity of the calvarial bone as compared with original DBBM granules, despite the slightly higher bone resorption in the DBBM fragment group, 10.3% (CI 6.3–11.6) versus 6.1% (CI 4.1–7.8, p = 0.355), respectively. The cortical bone volume was not altered by DBBM fragments as compared with original DBBM granules, i.e., 79.0% (CI 78.9–81.2) versus 81.5% (CI 80.1–83.3, p = 0.357), respectively. The DBBM fragment group revealed similar bone thickness values as compared with the DBBM granules group, i.e., 0.26 mm (CI 0.23–0.29) versus 0.25 mm (CI 0.22–0.27, p = 0.641), respectively. The histological evaluation supported the micro-CT observations, displaying minor signs of porosity and resorption. The particle-size distribution analysis confirmed a shift towards smaller particle sizes in the DBBM fragment group. These findings suggest that DBBM fragments behave similarly to original DBBM granules in terms of bone morphological changes at augmented sites.
Predicting Ultra-High-Performance Concrete Compressive Strength Using Tabular Generative Adversarial Networks
Authors: Marani Afshin , Jamali Armin , Nehdi Moncef L.
Published: October 2020

There have been abundant experimental studies exploring ultra-high-performance concrete (UHPC) in recent years. However, the relationships between the engineering properties of UHPC and its mixture composition are highly nonlinear and difficult to delineate using traditional statistical methods. There is a need for robust and advanced methods that can streamline the diverse pertinent experimental data available to create predictive tools with superior accuracy and provide insight into its nonlinear materials science aspects. Machine learning is a powerful tool that can unravel underlying patterns in complex data. Accordingly, this study endeavors to employ state-of-the-art machine learning techniques to predict the compressive strength of UHPC using a comprehensive experimental database retrieved from the open literature consisting of 810 test observations and 15 input features. A novel approach based on tabular generative adversarial networks was used to generate 6513 plausible synthetic data for training robust machine learning models, including random forest, extra trees, and gradient boosting regression. While the models were trained using the synthetic data, their ability to generalize their predictions was tested on the 810 experimental data thus far unknown and never presented to the models. The results indicate that the developed models achieved outstanding predictive performance. Parametric studies using the models were able to provide insight into the strength development mechanisms of UHPC and the significance of the various influential parameters.
Influence and Sensitivity of Temperature and Microstructure on the Fluctuation of Creep Properties in Ni-Base Superalloy
Authors: Yao Zhihao , Zhou Biao , Yao Kaijun , Wang Hongying , Dong Jianxin , Davey Theresa
Published: October 2020

In this work, the sensitivity zone of microstructure and temperature for precipitation-strengthened nickel-based superalloys, used for turbine applications in aero-engines, has been firstly established. Heat treatment experiments with different solution temperatures were carried out. The microstructure evolution and creep residual strain sensitivity, low cycle fatigue properties, and tensile properties are analyzed, and the essential reason for the fluctuation of the mechanical properties of nickel-based superalloys was revealed. The main results obtained are as follows: following subsolvus solution heat treatment with a temperature of 1020 °C, samples have a high primary γ′I phase content, which is beneficial to low creep residual strain. Above the supersolvus solution temperature of 1040 °C, the creep residual strain value and low cycle fatigue performance fluctuate significantly. The essential reason for the dramatic fluctuation of performance is the presence of γ′ phases in different sizes and quantities, especially following the solution heat treatment in the temperature-sensitive zone of the γ′I phase, which is likely to cause huge fluctuations in the microstructure of tertiary γ′III phases. A zone of particular sensitivity in terms of temperature and microstructure for the γ′I phase is proposed. The range of suitable solution temperatures are discussed. In order to maintain stable mechanical properties without large fluctuations, the influence of the sensitivity within this temperature and microstructure zone on the γ′ phase should be considered.
Effects of Bacterial Nanocellulose Loaded with Curcumin and Its Degradation Products on Human Dermal Fibroblasts
Authors: Zikmundova Marketa , Vereshaka Maria , Kolarova Katerina , Pajorova Julia , Svorcik Vaclav , Bacakova Lucie
Published: October 2020

Bacterial nanocellulose has found applications in tissue engineering, in skin tissue repair, and in wound healing. Its large surface area enables the adsorption of various substances. Bacterial nanocellulose with adsorbed substances can serve as a substrate for drug-delivery of specific bioactive healing agents into wounds. In this study, we loaded a bacterial nanocellulose hydrogel with curcumin, i.e., an important anti-bacterial and healing agent, and its degradation products. These products were prepared by thermal decomposition of curcumin (DC) at a temperature of 180 °C (DC 180) or of 300 °C (DC 300). The main thermal decomposition products were tumerone, vanillin, and feruloylmethane. Curcumin and its degradation products were loaded into the bacterial nanocellulose by an autoclaving process. The increased temperature during autoclaving enhanced the solubility and the penetration of the agents into the nanocellulose. The aim of this study was to investigate the cytotoxicity and the antimicrobial activity of pure curcumin, its degradation products, and finally of bacterial nanocellulose loaded with these agents. In vitro tests performed on human dermal fibroblasts revealed that the degradation products of curcumin, i.e., DC 180 and DC 300, were more cytotoxic than pure curcumin. However, if DC 300 was loaded into nanocellulose, the cytotoxic effect was not as strong as in the case of DC 300 powder added into the culture medium. DC 300 was found to be the least soluble product in water, which probably resulted in the poor loading of this agent into the nanocellulose. Nanocellulose loaded with pure curcumin or DC 180 exhibited more antibacterial activity than pristine nanocellulose.
The Comparative Study of the State of Conservation of Two Medieval Documents on Parchment from Different Historical Periods
Authors: (Haulică) Maria Boutiuc , Florescu Oana , Vasilache Viorica , Sandu Ion
Published: October 2020

The paper explores the potentiality of an experimental multianalytic protocol with appropriate methodology for determining the chemical and morphostructural characteristics of two old documents on parchment support. Such a protocol can authenticate and assess the state of conservation under the influence of environmental factors during storage and archival documentation, thus advancing preventive and prophylactic measures in “treasure” deposits such as the National Archives of Romania, where these documents are kept. The work methodology consisted of three stages. The first stage consists of visual observation for identifying deteriorations and degradations, alongside the selection of representatives’ areas from where micro-samples were collected. The second stage involves Scanning Electron Microscopy coupled by Energy Dispersive X-ray Spectrometry (SEM-EDX) analysis, for highlighting the morphology and determining the elemental composition; lastly, the Fourier-transform infrared (FTIR) analysis and correlation of results establish the chemical and morphostructural changes. The use of this gradual system of analyses allowed determining the differences between these two documents in terms of the materials used for producing them, their manufacturing technologies, the writing and ornamentation, and the overall state of conservation. The results provided the first accurate picture of the chemical nature and manufacturing of the two parchment documents by determining the main characteristics of the collagen and of the finishing, writing, and decoration materials, in view of the natural aging through the oxidative and gelatinization processes of the collagen. The SEM-EDX results revealed the morphological changes of the parchment that occurred at various levels in the collagen fibrous mesh and established the state of conservation of the support, writing, and decorations.
Comprehensive Biological Evaluation of Biomaterials Used in Spinal and Orthopedic Surgery
Authors: Komorowski Piotr , Siatkowska Małgorzata , Kamińska Marta , Jakubowski Witold , Walczyńska Marta , Walkowiak-Przybyło Magdalena , Szymański Witold , Piersa Katarzyna , Wielowski Patryk , Sokołowska Paulina , Białkowska Kamila , Makowski Krzysztof , Elgalal Marcin , Kierzkowska Agnieszka , Ciupik Lechosław , Walkowiak Bogdan
Published: October 2020

Biological acceptance is one of the most important aspects of a biomaterial and forms the basis for its clinical use. The aim of this study was a comprehensive biological evaluation (cytotoxicity test, bacterial colonization test, blood platelets adhesion test and transcriptome and proteome analysis of Saos-2 cells after contact with surface of the biomaterial) of biomaterials used in spinal and orthopedic surgery, namely, Ti6Al4V ELI (Extra Low Interstitials), its modified version obtained as a result of melting by electron beam technology (Ti6Al4V ELI-EBT), polyether ether ketone (PEEK) and polished medical steel American Iron and Steel Institute (AISI) 316L (the reference material). Biological tests were carried out using the osteoblasts-like cells (Saos-2, ATCC HTB-85) and bacteria Escherichia coli (DH5α). Results showed lack of cytotoxicity of all materials and the surfaces of both Ti6Al4V ELI and PEEK exhibit a significantly higher resistance to colonization with E. coli cells, while the more porous surface of the same titanium alloy produced by electron beam technology (EBT) is more susceptible to microbial colonization than the control surface of polished medical steel. None of the tested materials showed high toxicity in relation to E. coli cells. Susceptibility to platelet adhesion was very high for polished medical steel AISI 316L, whilst much lower for the other biomaterials and can be ranked from the lowest to the highest as follows: PEEK < Ti6Al4V ELI < Ti6Al4V ELI-EBT. The number of expressed genes in Saos-2 cells exposed to contact with the examined biomaterials reached 9463 genes in total (ranging from 8455 genes expressed in cells exposed to ELI to 9160 genes in cells exposed to PEEK). Whereas the number of differentially expressed proteins detected on two-dimensional electrophoresis gels in Saos-2 cells after contact with the examined biomaterials was 141 for PEEK, 223 for Ti6Al4V ELI and 133 for Ti6Al4V ELI-EBT. Finally, 14 proteins with altered expression were identified by mass spectrometry. In conclusion, none of the tested biomaterials showed unsatisfactory levels of cytotoxicity. The gene and protein expression analysis, that represents a completely new approach towards characterization of these biomaterials, showed that the polymer PEEK causes much more intense changes in gene and protein expression and thus influences cell metabolism.
Dielectric Tunability Properties in (110)-Oriented Epitaxial 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 Thin Films Prepared by PLD Method
Authors: Luo Bing , Xu Yiwen , Zhang Fuzeng , Wang Tingting , Yao Yingbang
Published: October 2020

Epitaxial 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) thin films with single-crystal perovskite structure have been grown by pulsed laser deposition (PLD) on the (110) SrRuO3/SrTiO3 substrates. Temperature-dependent dielectric measurements show obvious characteristics of a diffused phase transition. Typical P-E hysteresis loops with a distinct ferroelectric imprint phenomenon are observed in these BZT-BCT thin films with a remnant polarization of 2.0 μC/cm2 and coercive field of 187 kV/cm. Small leakage currents (<1 × 10−6 A/cm2) are obtained in these thin films under an electrical field of 240 MV/m. These BZT-BCT thin films have shown large dielectric tunability values ranging from 75.8% to 85.7%, under a wide temperature range from 200 K to 330 K and a frequency range between 100 Hz and 100 kHz, which shows their good temperature and frequency stability. Such excellent dielectric tunability properties in these (110)-oriented BZT-BCT thin films promise their great potentials in practical phase shifter applications.
Determining the Damage and Failure Behaviour of Textile Reinforced Composites under Combined In-Plane and Out-of-Plane Loading
Authors: Düreth Christian , Weck Daniel , Böhm Robert , Thieme Mike , Gude Maik , Henkel Sebastian , Wolf Carl , Biermann Horst
Published: October 2020

The absence of sufficient knowledge of the heterogeneous damage behaviour of textile reinforced composites, especially under combined in-plane and out-of-plane loadings, requires the development of multi-scale experimental and numerical methods. In the scope of this paper, three different types of plain weave fabrics with increasing areal weight were considered to characterise the influence of ondulation and nesting effects on the damage behaviour. Therefore an advanced new biaxial testing method has been elaborated to experimentally determine the fracture resistance at the combined biaxial loads. Methods in image processing of the acquired in-situ CT data and micrographs have been utilised to obtain profound knowledge of the textile geometry and the distribution of the fibre volume content of each type. Combining the derived data of the idealised geometry with a numerical multi-scale approach was sufficient to determine the fracture resistances of predefined uniaxial and biaxial load paths. Thereby, Cuntze’s three-dimensional failure mode concept was incorporated to predict damage and failure. The embedded element method was used to obtain a structured mesh of the complex textile geometries. The usage of statistical and visualisation methods contributed to a profound comprehension of the ondulation and nesting effects.
Synthesis and Biological Evaluation of Analogues of Butyrolactone I as PTP1B Inhibitors
Authors: Hong Bihong , He Jianlin , Fan Chaochun , Tang Chao , Le Qingqing , Bai Kaikai , Niu Siwen , Xiao Meitian
Published: October 2020

In recent years, a large number of pharmacologically active compounds containing a butenolide functional group have been isolated from secondary metabolites of marine microorganisms. Butyrolactone I was found to be produced by Aspergillus terreus isolated from several marine-derived samples. The hypoglycemic activity of butyrolactone I has aroused our great interest. In this study, we synthesized six racemic butenolide derivatives (namely BL-1–BL-6) by modifying the C-4 side chain of butyrolactone I. Among them, BL-3 and BL-5 improved the insulin resistance of HepG2 cells and did not affect the proliferation of RIN-m5f cell line, which indicated the efficacy and safety of BL-3 and BL-5. Furthermore, BL-3, BL-4, BL-5, and BL-6 displayed a significant protein tyrosine phosphatase 1B (PTP1B) inhibitory effect, while the enantiomers of BL-3 displayed different 50% percentage inhibition concentration (IC50) values against PTP1B. The results of molecular docking simulation of the BLs and PTP1B explained the differences of biological consequences observed between the enantiomers of BL-3, which supported BLs as PTP1B inhibitors, and also indicated that the chirality of C-4 might influence the inhibitory effect of the BLs. Our findings provide a novel strategy for the development of butyrolactone derivatives as potential PTP1B inhibitors for the treatment of type 2 diabetes mellitus.
Disulfides from the Brown Alga Dictyopteris membranacea Suppress M1 Macrophage Activation by Inducing AKT and Suppressing MAPK/ERK Signaling Pathways
Authors: Daskalaki Maria , Bafiti Paraskevi , Kikionis Stefanos , Laskou Maria , Roussis Vassilios , Ioannou Efstathia , Kampranis Sotirios , Tsatsanis Christos
Published: October 2020

Inflammation is part of the organism’s response to deleterious stimuli, such as pathogens, damaged cells, or irritants. Macrophages orchestrate the inflammatory response obtaining different activation phenotypes broadly defined as M1 (pro-inflammatory) or M2 (homeostatic) phenotypes, which contribute to pathogen elimination or disease pathogenesis. The type and magnitude of the response of macrophages are shaped by endogenous and exogenous factors and can be affected by nutrients or therapeutic agents. Multiple studies have shown that natural products possess immunomodulatory properties and that marine algae contain products with such action. We have previously shown that disulfides isolated from Dictyopteris membranacea suppress nitric oxide (NO) production from activated macrophages, suggesting potential anti-inflammatory actions. In this study, we investigated the anti-inflammatory mechanism of action of bis(5-methylthio-3-oxo-undecyl) disulfide (1), 5-methylthio-1-(3-oxo-undecyl) disulfanylundecan-3-one (2) and 3-hexyl-4,5-dithiocycloheptanone (3). Our results showed that all three compounds inhibited M1 activation of macrophages by down regulating the production of pro-inflammatory cytokines TNFα, IL-6 and IL-12, suppressed the expression of the NO converting enzyme iNOS, and enhanced expression of the M2 activation markers Arginase1 and MRC1. Moreover, disulfides 1 and 2 suppressed the expression of glucose transporters GLUT1 and GLUT3, suggesting that compounds 1 and 2 may affect cell metabolism. We showed that this was due to AKT/MAPK/ERK signaling pathway modulation and specifically by elevated AKT phosphorylation and MAPK/ERK signal transduction reduction. Hence, disulfides 1–3 can be considered as potent candidates for the development of novel anti-inflammatory molecules with homeostatic properties.
Incorporation of FGF-2 into Pharmaceutical Grade Fucoidan/Chitosan Polyelectrolyte Multilayers
Authors: Benbow Natalie L. , Karpiniec Samuel , Krasowska Marta , Beattie David A.
Published: October 2020

Biopolymer polyelectrolyte multilayers are a commonly studied soft matter system for wound healing applications due to the biocompatibility and beneficial properties of naturally occurring polyelectrolytes. In this work, a popular biopolymer, chitosan, was combined with the lesser known polysaccharide, fucoidan, to create a multilayer film capable of sequestering growth factor for later release. Fucoidan has been shown to act as a heparin-mimic due to similarities in the structure of the two molecules, however, the binding of fibroblast growth factor-2 to fucoidan has not been demonstrated in a multilayer system. This study assesses the ability of fucoidan to bind fibroblast growth factor-2 within a fucoidan/chitosan polyelectrolyte multilayer structure using attenuated total internal reflectance infrared spectroscopy and quartz crystal microbalance with dissipation monitoring. The fibroblast growth factor-2 was sequestered into the polyelectrolyte multilayer as a cationic layer in the uppermost layers of the film structure. In addition, the diffusion of fibroblast growth factor-2 into the multilayer has been assessed.
Antibacterial Cyclic Tripeptides from Antarctica-Sponge-Derived Fungus Aspergillus insulicola HDN151418
Authors: Sun Chunxiao , Zhang Ziping , Ren Zilin , Yu Liu , Zhou Huan , Han Yaxin , Shah Mudassir , Che Qian , Zhang Guojian , Li Dehai , Zhu Tianjiao
Published: October 2020

Three new aspochracin-type cyclic tripeptides, sclerotiotides M–O (1–3), together with three known analogues, sclerotiotide L (4), sclerotiotide F (5), and sclerotiotide B (6), were obtained from the ethyl acetate extract of the fungus Aspergillus insulicola HDN151418, which was isolated from an unidentified Antarctica sponge. Spectroscopic and chemical approaches were used to elucidate their structures. The absolute configuration of the side chain in compound 4 was elucidated for the first time. Compounds 1 and 2 showed broad antimicrobial activity against a panel of pathogenic strains, including Bacillus cereus, Proteus species, Mycobacterium phlei, Bacillus subtilis, Vibrio parahemolyticus, Edwardsiella tarda, MRCNS, and MRSA, with MIC values ranging from 1.56 to 25.0 µM.
Pasta Supplemented with Opuntia ficus-indica Extract Improves Metabolic Parameters and Reduces Atherogenic Small Dense Low-Density Lipoproteins in Patients with Risk Factors for the Metabolic Syndrome: A Four-Week Intervention Study
Authors: Giglio Rosaria Vincenza , Carruba Giuseppe , Cicero Arrigo F.G. , Banach Maciej , Patti Angelo Maria , Nikolic Dragana , Cocciadiferro Letizia , Zarcone Maurizio , Montalto Giuseppe , Stoian Anca Pantea , Banerjee Yajnavalka , Rizvi Ali A. , Toth Peter P. , Rizzo Manfredi
Published: October 2020

Food supplementation with Opuntia ficus-indica (OFI) has been associated with a significant reduction in total cholesterol, body fat, hyperglycemia and blood pressure. Since OFI may also have antioxidant and anti-atherogenic properties, we hypothesized that its supplementation might reduce atherogenic lipoproteins, including small, dense low-density lipoproteins (sdLDL). Forty-nine patients (13 men and 36 women, mean age: 56 ± 5 years) with one or two criteria for the metabolic syndrome weekly consumed 500 g of pasta supplemented with 3% OFI extract (30% of insoluble polysaccharides with high antioxidant power) for 1 month. The full LDL subclass profile was assessed by gel electrophoresis (Lipoprint, Quantimetrix, Redondo Beach, CA, USA). After 1 month of pasta supplementation, waist circumference (p = 0.0297), plasma glucose (p < 0.0001), triglycerides (p = 0.0137), plasma creatinine (p = 0.0244), urea and aspartate transaminase (p < 0.0001 for each) significantly decreased. A percentage increase in larger, less atherogenic LDL-1 (p = 0.0002), with a concomitant reduction in smaller, denser LDL-2 (p < 0.0001) and LDL-3 (p = 0.0004), were found. LDL-4 and-5 decreased, although not significantly. This is the first intervention study suggesting that pasta enriched with an OFI extract may have beneficial effects on some metabolic parameters and the LDL particle sizes, reducing atherogenic sdLDL. Future studies will help to establish if these findings impact cardiovascular outcomes.
Analysis of the Failure and Performance Variation Mechanism of MEMS Suspended Inductors with Auxiliary Pillars under High-g Shock
Authors: Xu Lixin , Li Yiyuan , Li Jianhua
Published: October 2020

Microelectromechanical systems (MEMS) suspended inductors have excellent radio frequency (RF) performance and they are compatible with integrated circuit (IC). They will be shocked during manufacturing, transportation, and operation; in some applications, the shock amplitude can be as high as tens of thousands of gravitational acceleration (g, 9.8 m/s2). High-g shock will lead to the inductor deformation which affects its performance or even failure of the inductor structure. However, few studies have been carried out on the inductors under high-g shock. In this study, a kind of MEMS suspended inductor with excellent RF and mechanical performance is designed and fabricated. The failure and performance variation mechanism of the inductor under high-g shock is analyzed by measuring and comparing the performance measurement results and the π model parameters extraction results of the inductors before and after air cannon shock test. The results show that the increase of energy loss caused by substrate parasitic effect and the properties variation of the coil material affected by high-g shock are the main reasons for the decrease of RF performance parameters, and the critical stress exceeding the interlayer adhesion is the main reason for the failure of the inductor.
Long-Term Persistence of blaCTX-M-15 in Soil and Lettuce after Introducing Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli via Manure or Water
Authors: Gekenidis Maria-Theresia , Rigotti Serena , Hummerjohann Jörg , Walsh Fiona , Drissner David
Published: October 2020

The number of environmental antibiotic-resistant bacteria (ARB) has increased dramatically since the start of antibiotic mass production for broad bacterial infection treatment in 1944. Nowadays, ARB and their resistance-determining genes (ARGs) are readily detected in all environments, including the human food chain. A highly relevant food group in this context is fresh produce, frequent raw consumption of which facilitates direct transfer of ARB and ARGs to the consumer. Here, we investigate the persistence of an extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) pEK499 and its clinically most important ARG (blaCTX-M-15), after introduction via irrigation water or manure into a lettuce-growing system. Culturable ESBL-producing E. coli persisted longest in soil and when introduced via manure (until 9 weeks after introduction), while being undetectable on lettuce beyond day 7. In contrast, qPCR detection of blaCTX-M-15 was much more frequent: introduction via water significantly increased blaCTX-M-15 on lettuce until week 4, as opposed to manure, which affected the soil in the long-term (9 weeks) while leading to blaCTX-M-15 detection on lettuce until day 7 only. Our findings demonstrate long-term persistence of undesired ARB and ARG after their introduction via both irrigation and amendment. Such an understanding of the persistence kinetics of an ESBL-producing E. coli and plasmid-encoded blaCTX-M-15 aids the determination of critical actions in order to mitigate their transfer to the consumer.
Aspegillus terreus: From Soil to Industry and Back
Authors: Vassileva Maria , Malusá Eligio , Eichler-Löbermann Bettina , Vassilev Nikolay
Published: October 2020

Aspergillus terreus is an important saprophytic filamentous fungus that can be found in soils. Like many other soil microorganisms, A. terreus demonstrates multiple functions and offers various important metabolites, which can be used in different fields of human activity. The first application of A. terreus on an industrial level is the production of itaconic acid, which is now considered as one of the most important bioproducts in the Green Chemistry field. The general schemes for itaconic acid production have been studied, but in this mini-review some lines of future research are presented based on analysis of the published results. A. terreus is also intensively studied for its biocontrol activity and plant growth-promoting effect. However, this microorganism is also known to infect important crops such as, amongst others, rice, wheat, potato, sugar cane, maize, and soybean. It was suggested, however, that the balance between positive vs. negative effects is dependent on the soil-plant-inoculant dose system. A. terreus has frequently been described as an important human pathogen. Therefore, its safety manipulation in biotechnological processes for the production of itaconic acid and some drugs and its use in soil-plant systems should be carefully assessed. Some suggestions in this direction are discussed, particularly concerning the uses in crop production.
Challenges in the Assessment of Mining Process Water Quality
Authors: Le Thi Minh Khanh , Miettinen Hanna , Bomberg Malin , Schreithofer Nóra , Dahl Olli
Published: October 2020

The changes in water quality owing to recirculation of water in mineral processing plants can compromise the plant performance as well as maintenance needs. Therefore, mining process water quality assessment is becoming critical. Nevertheless, very few studies have investigated the suitability of the current analysis methodology practiced in certified laboratories for evaluating mining process water quality. This article presents two case studies to highlight the major issues encountered when performing sampling for physicochemical and chemical parameters in process water at two European mine sites using procedures from two certified laboratories. In addition, microorganisms were shown to be abundant in process waters and likely affect the mining water chemistries. However, the protocols used for microbial studies are not optimal for mining process samples, and need to be improved. The results showed difficulties in providing satisfactory results when analyzing control samples. Additionally, the analysis results presented a strong imbalance in TDS and sulfur compounds. Several potential causes associated with the poor quality of the analysis results have been outlined with a specific focus on the preservation methods. A literature review on the degradation of thiosalts suggested that the current preservation procedures are not suitable for preserving sulfur compounds. Moreover, the results indicated that the water matrix strongly influenced the validity of the chosen analysis method. In conclusion, the analysis methods should be customized for the different mining water matrix types in order to ensure the accuracy and reproducibility of the results.
The Formation of Authigenic Carbonates at a Methane Seep Site in the Northern Part of the Laptev Sea
Authors: Ruban Alexey , Rudmin Maxim , Dudarev Oleg , Mazurov Alexey
Published: October 2020

Authigenic carbonates from cold seeps are unique archives for studying environmental conditions, including biogeochemical processes associated with methane-rich fluid migration through the sediment column. The aim of this research was to study major oxide, mineralogical, and stable isotopic compositions of cold-seep authigenic carbonates collected in the northern part of the Laptev Sea. These carbonates are represented by Mg-calcite with an Mg content of 2% to 8%. The δ13C values range from −27.5‰ to −28.2‰ Vienna Peedee belemnite (VPDB) and indicate that carbonates formed due to anaerobic oxidation of methane, most likely thermogenic in origin. The authigenic pyrite in Mg-calcite is evidence of sulfate reduction during carbonate precipitation. The δ18O values of carbonates vary from 3.5‰ to 3.8‰ VPDB. The calculated δ18Ofluid values show that pore water temperature for precipitated Mg-calcite was comparable to bottom seawater temperature. The presence of authigenic carbonate in the upper horizons of sediments suggests that the sulfate–methane transition zone is shallowly below the sediment–water interface.
A Critical Review of the Role of the Cannabinoid Compounds Δ9-Tetrahydrocannabinol (Δ9-THC) and Cannabidiol (CBD) and their Combination in Multiple Sclerosis Treatment
Authors: Jones Éamon , Vlachou Styliani
Published: October 2020

Many people with MS (pwMS) use unregulated cannabis or cannabis products to treat the symptoms associated with the disease. In line with this, Sativex, a synthetic combination of cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC) has been approved to treat symptoms of spasticity. In animals, CBD is effective in reducing the amounts of T-cell infiltrates in the spinal cord, suggesting CBD has anti-inflammatory properties. By doing this, CBD has shown to delay symptom onset in animal models of multiple sclerosis and slow disease progression. Importantly, combinations of CBD and Δ9-THC appear more effective in treating animal models of multiple sclerosis. While CBD reduces the amounts of cell infiltrates in the spinal cord, Δ9-THC reduces scores of spasticity. In human studies, the results are less encouraging and conflict with the findings in animals. Drugs which deliver a combination of Δ9-THC and CBD in a 1:1 ratio appear to be only moderately effective in reducing spasticity scores, but appear to be almost as effective as current front-line treatments and cause less severe side effects than other treatments, such as baclofen (a GABA-B receptor agonist) and tizanidine (an α2 adrenergic receptor agonist). The findings of the studies reviewed suggest that cannabinoids may help treat neuropathic pain in pwMS as an add-on therapy to already established pain treatments. It is important to note that treatment with cannabinoid compounds may cause significant cognitive dysfunction. Long term double-blind placebo studies are greatly needed to further our understanding of the role of cannabinoids in multiple sclerosis treatment.
Resonant and Sensing Performance of Volume Waveguide Structures Based on Polymer Nanomaterials
Authors: Smirnova Tatiana , Fitio Volodymyr , Sakhno Oksana , Yezhov Pavel , Bendziak Andrii , Hryn Volodymyr , Bellucci Stefano
Published: October 2020

Organic–inorganic photocurable nanocomposite materials are a topic of intensive research nowadays. The wide variety of materials and flexibility of their characteristics provide more freedom to design optical elements for light and neutron optics and holographic sensors. We propose a new strategy of nanocomposite application for fabricating resonant waveguide structures (RWS), whose working principle is based on optical waveguide resonance. Due to their resonant properties, RWS can be used as active tunable filters, refractive index (RI) sensors, near-field enhancers for spectroscopy, non-linear optics, etc. Our original photocurable organic–inorganic nanocomposite was used as a material for RWS. Unlike known waveguide structures with corrugated surfaces, we investigated the waveguide gratings with the volume modulation of the RI fabricated by a holographic method that enables large-size structures with high homogeneity. In order to produce thin photosensitive waveguide layers for their subsequent holographic structuring, a special compression method was developed. The resonant and sensing properties of new resonant structures were experimentally examined. The volume waveguide gratings demonstrate narrow resonant peaks with a bandwidth less than 0.012 nm. The Q-factor exceeds 50,000. The sensor based on waveguide volume grating provides detection of a minimal RI change of 1 × 10−4 RIU. Here we also present the new theoretical model that is used for analysis and design of developed RWS. Based on the proposed model, fairly simple analytical relationships between the parameters characterizing the sensor were obtained.
Hydrothermal Synthesis of Polyhedral Nickel Sulfide by Dual Sulfur Source for Highly-Efficient Hydrogen Evolution Catalysis
Authors: Gao Yuan , Wang Ka , Lin Zixia , Song Haizeng , Duan Xiaomeng , Peng Zehui , Yan Shancheng
Published: October 2020

Transition metal sulfides are cheap and efficient catalysts for water splitting to produce hydrogen; these compounds have attracted wide attention. Nickel sulfide (NiS2) has been studied in depth because of its simple preparation process, excellent performance and good stability. Here, we propose a modification to the hydrothermal synthesis method for the fabrication of a highly efficient and stable NiS2 electrocatalyst prepared by two different sulfur sources, i.e., sulfur powder and C3H7NaO3S2 (MPS), for application in hydrogen evolution reactions. The obtained NiS2 demonstrated excellent HER performance with an overpotential of 131 mV to drive -10 mA cm−1 in 0.5 M H2SO4 solution with 5mV performance change after 1000 cycles of stability testing. We believe that this discovery will promote the industrial development of nonprecious metal catalysts.
Docetaxel-Loaded Poly(3HB-co-4HB) Biodegradable Nanoparticles: Impact of Copolymer Composition
Authors: Faisalina A.F. , Sonvico Fabio , Colombo Paolo , Amirul A.A. , Wahab H.A. , Majid Mohamed Isa Abdul
Published: October 2020

Polyhydroxyalkanoate (PHA) copolymers show a relatively higher in vivo degradation rate compared to other PHAs, thus, they receive a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water-soluble anticancer drug docetaxel (DCX) were produced using poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB), copolymers biosynthesised from Cupriavidus malaysiensis USMAA1020 isolated from the Malaysian environment. Three copolymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX-loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Preformulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in terms of average particle size around 150 nm and narrow particle size distribution (polydispersity index (PDI) below 0.100). The encapsulation efficiency result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticle system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug-to-polymer ratio while for the 30% and 40% drug-to-polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.
Sensitivity-Enhanced SPR Sensor Based on Graphene and Subwavelength Silver Gratings
Authors: Kong Lu , Lv Jiangtao , Gu Qiongchan , Ying Yu , Jiang Xiaoxiao , Si Guangyuan
Published: October 2020

A novel surface plasmon resonance (SPR) sensor with graphene and subwavelength gratings is proposed to improve the sensing performance. A series of numerical analyses were performed to investigate the effect of structural parameters on the sensing performance, such as minimum reflectance at resonance (MRR), full width at half maximum (FWHM), and resonance angle. The results indicated that near-zero MRR (2.9 × 10−6) and narrow FWHM (about 3.5 deg) could be obtained by optimizing the geometrical parameters. Moreover, the influence of the number of graphene layers on sensitivity was also studied. The maximum sensitivity of the designed sensor could reach 192 deg/refractive index unit (RIU), which is a great enhancement compared to the silver-only SPR sensor. In addition, ethylene glycol solutions with different refractive indices were detected. The results showed that the sensitivity of the sensor could reach 220.67 deg/RIU, and the proposed sensor had excellent linearity between the resonance angle and refractive index, enabling extensive potential practical sensing applications.
Vitamin D Supplementation during Winter: Effects on Stress Resilience in a Randomized Control Trial
Authors: Hansen Anita L. , Ambroziak Gina , Thornton David , Mundt James C. , Kahn Rachel E. , Dahl Lisbeth , Waage Leif , Kattenbraker Daniel , Araujo Pedro , Murison Robert , Rypdal Knut , Grung Bjørn
Published: October 2020

Vitamin D status may be important for stress resilience. This study investigated the effects of vitamin D supplements during winter on biological markers of stress resilience such as psychophysiological activity, serotonin, and cortisol in a placebo-controlled, randomized clinical trial. Eighty-six participants were randomly assigned to the Intervention (vitamin D) or Control (placebo) groups. Before and after the intervention participants were exposed to an experimental stress procedure. Psychophysiological activity was measured during three main conditions: baseline, stress, and recovery. Fasting blood samples were taken in the morning and saliva samples were collected at seven different time points across 24 h. Prior to intervention both groups had normal/sufficient vitamin D levels. Both groups showed a normal pattern of psychophysiological responses to the experimental stress procedure (i.e., increased psychophysiological responses from resting baseline to stress-condition, and decreased psychophysiological responses from stress-condition to recovery; all p < 0.009). Post-intervention, the Intervention group showed increased vitamin D levels (p < 0.001) and normal psychophysiological responses to the experimental stress procedure (p < 0.001). Importantly, the Control group demonstrated a classic nadir in vitamin D status post-intervention (spring) (p < 0.001) and did not show normal psychophysiological responses. Thus, physiologically the Control group showed a sustained stress response. No significant effects of vitamin D were found on serotonin and cortisol.
Bifidobacterium longum subsp. infantis CECT7210 (B. infantis IM-1®) Displays In Vitro Activity against Some Intestinal Pathogens
Authors: Ruiz Lorena , Flórez Ana Belén , Sánchez Borja , Moreno-Muñoz José Antonio , Rodriguez-Palmero Maria , Jiménez Jesús , Gavilán Clara G. de los Reyes , Gueimonde Miguel , Ruas-Madiedo Patricia , Margolles Abelardo
Published: October 2020

Certain non-digestible oligosaccharides (NDO) are specifically fermented by bifidobacteria along the human gastrointestinal tract, selectively favoring their growth and the production of health-promoting metabolites. In the present study, the ability of the probiotic strain Bifidobacterium longum subsp. infantis CECT7210 (herein referred to as B. infantis IM-1®) to utilize a large range of oligosaccharides, or a mixture of oligosaccharides, was investigated. The strain was able to utilize all prebiotics screened. However, galactooligosaccharides (GOS), and GOS-containing mixtures, effectively increased its growth to a higher extent than the other prebiotics. The best synbiotic combination was used to examine the antimicrobial activity against Escherichia coli, Cronobacter sakazakii, Listeria monocytogenes and Clostridium difficile in co-culture experiments. C. difficile was inhibited by the synbiotic, but it failed to inhibit E. coli. Moreover, Cr. sakazakii growth decreased during co-culture with B. infantis IM-1®. Furthermore, adhesion experiments using the intestinal cell line HT29 showed that the strain IM-1® was able to displace some pathogens from the enterocyte layer, especially Cr. sakazakii and Salmonella enterica, and prevented the adhesion of Cr. sakazakii and Shigella sonnei. In conclusion, a new synbiotic (probiotic strain B. infantis IM-1® and GOS) appears to be a potential effective supplement for maintaining infant health. However, further studies are needed to go more deeply into the mechanisms that allow B.infantis IM-1® to compete with enteropathogens.
Maternal Compliance to Recommended Iron and Folic Acid Supplementation in Pregnancy, Sri Lanka: A Hospital-Based Cross-Sectional Study
Authors: Pathirathna Malshani L. , Wimalasiri Kuruppu M. S. , Sekijima Kayako , Sadakata Mieko
Published: October 2020

Iron deficiency anaemia during pregnancy is a common public health problem that negatively affects maternal and newborn health. This study aims to identify the rate of maternal compliance with the recommended iron and folic acid (IFA) supplementation during pregnancy and to identify factors associated with maternal compliance and non-compliance. A hospital-based cross-sectional study was conducted among 703 women at 0–4 days postpartum. The prevalence of anaemia at the initial antenatal clinic (ANC) visit and at the third trimester were 20.8% and 44.9%, respectively. The rate of IFA supplementation compliance during pregnancy was 80.1%. Forgetfulness (66.9%) was the major reason for non-compliance, followed by side effects (15.7%). Maternal employment [OR (95%CI): 1.7 (1.00–2.89)], history of a low birth weight infant [OR (95%CI): 0.4 (0.19–0.9)] and history of anaemia [OR (95%CI): 0.4 (0.12–0.98] were significantly associated with maternal compliance with IFA supplementation. Only 26.6% of the participants adhered to dietary recommendations during the period when IFA supplements were provided. The rate of maternal compliance with IFA supplementation was high. However, the prevalence of maternal anaemia during pregnancy was also high, which was presumably due to poor dietary compliance despite high IFA supplementation compliance.