bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptome Analysis Identifies LINC00152 as a Biomarker of Early Relapse and Mortality in Acute Lymphoblastic Leukemia
Authors: Bárcenas-López Diego Alberto , Núñez-Enríquez Juan Carlos , Hidalgo-Miranda Alfredo , Beltrán-Anaya Fredy Omar , May-Hau Didier Ismael , Jiménez-Hernández Elva , Bekker-Méndez Vilma Carolina , Flores-Lujano Janet , Medina-Sansón Aurora , Tamez-Gómez Edna Liliana , López-García Víctor Hugo , Lara-Ramos José Ramón , Núñez-Villegas Nora Nancy , Peñaloza-González José Gabriel , Flores-Villegas Luz Victoria , Amador-Sánchez Raquel , Espinosa-Elizondo Rosa Martha , Martín-Trejo Jorge Alfonso , Velázquez-Aviña Martha Margarita , Merino-Pasaye Laura Elizabeth , Pérez-Saldívar María Luisa , Duarte-Rodríguez David Aldebarán , Torres-Nava José Refugio , Cortés-Herrera Beatriz , Solís-Labastida Karina Anastacia , González-Ávila Ana Itamar , Santillán-Juárez Jessica Denisse , García-Velázquez Alejandra Jimena , Rosas-Vargas Haydee , Mata-Rocha Minerva , Sepúlveda-Robles Omar Alejandro , Mejía-Aranguré Juan Manuel , Jiménez-Morales Silvia
Published: March 2020

Evidence showing the role of long non-coding RNAs (lncRNAs) in leukemogenesis have emerged in the last decade. It has been proposed that these genes can be used as diagnosis and/or prognosis biomarkers in childhood acute lymphoblastic leukemia (ALL). To know if lncRNAs are associated with early relapse and early mortality, a microarray-based gene expression analysis in children with B-lineage ALL (B-ALL) was conducted. Cox regression analyses were performed. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated. LINC00152 and LINC01013 were among the most differentially expressed genes in patients with early relapse and early mortality. For LINC00152 high expression, the risks of relapse and death were HR: 4.16 (95% CI: 1.46–11.86) and HR: 1.99 (95% CI: 0.66–6.02), respectively; for LINC01013 low expression, the risks of relapse and death were HR: 3.03 (95% CI: 1.14–8.05) and HR: 6.87 (95% CI: 1.50–31.48), respectively. These results were adjusted by NCI risk criteria and chemotherapy regimen. The lncRNA–mRNA co-expression analysis showed that LINC00152 potentially regulates genes involved in cell substrate adhesion and peptidyl–tyrosine autophosphorylation biological processes. The results of the present study point out that LINC00152 could be a potential biomarker of relapse in children with B-ALL.
G-quadruplex Stabilization Fuels the ALT Pathway in ALT-positive Osteosarcoma Cells
Authors: Amato Roberta , Valenzuela Martina , Berardinelli Francesco , Salvati Erica , Maresca Carmen , Leone Stefano , Antoccia Antonio , Sgura Antonella
Published: March 2020

Most human tumors maintain telomere lengths by telomerase, whereas a portion of them (10–15%) uses a mechanism named alternative lengthening of telomeres (ALT). The telomeric G-quadruplex (G4) ligand RHPS4 is known for its potent antiproliferative effect, as shown in telomerase-positive cancer models. Moreover, RHPS4 is also able to reduce cell proliferation in ALT cells, although the influence of G4 stabilization on the ALT mechanism has so far been poorly investigated. Here we show that sensitivity to RHPS4 is comparable in ALT-positive (U2OS; SAOS-2) and telomerase-positive (HOS) osteosarcoma cell lines, unlinking the telomere maintenance mechanism and RHPS4 responsiveness. To investigate the impact of G4 stabilization on ALT, the cardinal ALT hallmarks were analyzed. A significant induction of telomeric doublets, telomeric clusterized DNA damage, ALT-associated Promyelocytic Leukaemia-bodies (APBs), telomere sister chromatid exchanges (T-SCE) and c-circles was found exclusively in RHPS4-treated ALT cells. We surmise that RHPS4 affects ALT mechanisms through the induction of replicative stress that in turn is converted in DNA damage at telomeres, fueling recombination. In conclusion, our work indicates that RHPS4-induced telomeric DNA damage promotes overactivation of telomeric recombination in ALT cells, opening new questions on the therapeutic employment of G4 ligands in the treatment of ALT positive tumors.
The Role of School Leaders’ Health Literacy for the Implementation of Health Promoting Schools
Authors: Dadaczynski Kevin , Rathmann Katharina , Hering Thomas , Okan Orkan
Published: March 2020

Background: The promotion of health literacy is seen as an urgent goal in public health and education and, hence, should be integrated in the school context as a component of the holistic health promoting school (HPS) approach. However, only limited empirical studies have addressed health literacy of school staff so far. Hence, this study aimed to examine the level of health literacy among school leaders and its association with the extent of HPS implementation. Methods: A cross-sectional study with n = 680 school principals and members of the school management board from Germany was carried out at the end of 2018. Individual health literacy, attitudes, and competencies towards HPS and occupational self-efficacy served as independent variables and the level of HPS implementation was the dependent variable. Data were analyzed using univariate and bivariate analysis as well as multiple binary logistic regression. Results: 29.3% of school leaders show a limited health literacy with significantly higher values found for male respondents. Regression analyses revealed that male gender (OR: 1.91, 95% CI: 1.22–2.99), HPS attitudes (OR: 3.17, 95% CI: 2.13–4.72), and HPS competencies (OR: 3.66, 95% CI: 2.43–5.50) were associated with a lower level of HPS implementation. Furthermore, regression analyses differentiated by gender showed that limited health literacy is associated with a low level of HPS implementation for male school leaders only (OR: 2.81, 95% CI: 1.22–6.45). Conclusions: The promotion of health literacy especially for male leaders would not only result in positive effects on an individual level but also could contribute to a stronger implementation of activities on school health promotion. We suggest integrating health literacy, HPS attitudes, and competencies more strongly into the qualification and in further training of school leaders.
Home Assessment of Indoor Microbiome (HAIM) in Relation to Lower Respiratory Tract Infections among Under-Five Children in Ibadan, Nigeria: The Study Protocol
Authors: Fakunle Adekunle G. , Olusola Babatunde , Jafta Nkosana , Faneye Adedayo , Heederik Dick , Smit Lidwien A.M. , Naidoo Rajen N.
Published: March 2020

The association between household air pollution and lower respiratory tract infections (LRTI) among children under five years of age has been well documented; however, the extent to which the microbiome within the indoor environment contributes to this association is uncertain. The home assessment of indoor microbiome (HAIM) study seeks to assess the abundance of indoor microbiota (IM) in the homes of under-five children (U-5Cs) with and without LRTI. HAIM is a hospital- and community-based study involving 200 cases and 200 controls recruited from three children’s hospitals in Ibadan, Nigeria. Cases will be hospital-based patients with LRTI confirmed by a pediatrician, while controls will be community-based participants, matched to cases on the basis of sex, geographical location, and age (±3 months) without LRTI. The abundance of IM in houses of cases and controls will be investigated using active and passive air sampling techniques and analyzed by qualitative detection of bacterial 16SrRNA gene (V3–V4), fungal ITS1 region, and viral RNA sequencing. HAIM is expected to elucidate the relationship between exposure to IM and incidence of LRTI among U-5Cs and ultimately provide evidence base for strategic interventions to curtail the burgeoning burden of LRTI on the subcontinent.
Pet Attachment and Wellbeing of Older-Aged Recreational Horseback Riders
Authors: Schwarzmueller-Erber Gabriele , Maier Manfred , Kundi Michael
Published: March 2020

The aim of the study was to determine if and how emotional attachment to their animal of older-aged (45+) horseback riders affects their physical, psychological and social wellbeing in comparison to dog owners. Overall, 124 individuals 45+ years answered questionnaires about pet attachment and wellbeing. Comparisons were carried out using a general linear model with activity group (rider/dog owner) as the main variable of interest. Horseback riders had no significantly lower pet attachment scores compared to dog owners. Gender differences of pet attachment were found in riders, with women having higher love factor scores. Self-reported mood during activities with the animal was significantly correlated with overall pet attachment, pet love and personal growth by contact with the pet in both, riders and dog owners. We observed no correlation of physical wellbeing during and after the activity with the animal and overall pet attachment in dog owners and horseback riders. Psychological wellbeing during the activity was significantly correlated with overall pet attachment in riders and social wellbeing during the activity in both groups. Recreational horseback riders nearly reach pet attachment scores of dog owners, increasing social and psychological wellbeing in a manner similar to that in dog owners.
New Evidences about Subjective Well-Being in Adolescence and Its Links with Neurocognitive Performance
Authors: Ortuño-Sierra Javier , Aritio-Solana Rebeca , Fonseca-Pedrero Eduardo
Published: March 2020

The main purpose of the present work was to study the neurocognitive endophenotypes of adolescents at risk for low personal wellbeing. The sample included a total of 1588 adolescents from stratified random cluster sampling; derived from this sample, a group of high-risk (n = 84) and a control group (n = 84) were selected. The personal well-being index–school children (PWI–SC), the University of Pennsylvania computerized neuropsychological test battery for children (included 14 tasks assessing five neurobehavioral domains: executive functions, episodic memory, complex cognition, social cognition and sensorimotor speed), and the strengths and difficulties questionnaire (SDQ) were used. Adolescents with low personal wellbeing showed statistically significant impairments across the different neurocognitive domains. In particular, adolescents at risk showed lower accuracy scores on executive function and complex cognition and lower speed scores on episodic memory, complex cognition and social cognition scores. The results of the present study contribute relevant information about the nature of neurocognitive impairments associated with subjective wellbeing and allow implementing preventive treatments.
Digital Reconstitution of Road Traffic Accidents: A Flexible Methodology Relying on UAV Surveying and Complementary Strategies to Support Multiple Scenarios
Authors: Pádua Luís , Sousa José , Vanko Jakub , Hruška Jonáš , Adão Telmo , Peres Emanuel , Sousa António , Sousa Joaquim J.
Published: March 2020

The reconstitution of road traffic accidents scenes is a contemporary and important issue, addressed both by private and public entities in different countries around the world. However, the task of collecting data on site is not generally focused on with the same orientation and relevance. Addressing this type of accident scenario requires a balance between two fundamental yet competing concerns: (1) information collecting, which is a thorough and lengthy process and (2) the need to allow traffic to flow again as quickly as possible. This technical note proposes a novel methodology that aims to support road traffic authorities/professionals in activities involving the collection of data/evidences of motor vehicle collision scenarios by exploring the potential of using low-cost, small-sized and light-weight unmanned aerial vehicles (UAV). A high number of experimental tests and evaluations were conducted in various working conditions and in cooperation with the Portuguese law enforcement authorities responsible for investigating road traffic accidents. The tests allowed for concluding that the proposed method gathers all the conditions to be adopted as a near future approach for reconstituting road traffic accidents and proved to be: faster, more rigorous and safer than the current manual methodologies used not only in Portugal but also in many countries worldwide.
Antisense Oligonucleotide in LNA-Gapmer Design Targeting TGFBR2—A Key Single Gene Target for Safe and Effective Inhibition of TGFβ Signaling
Authors: Kuespert Sabrina , Heydn Rosmarie , Peters Sebastian , Wirkert Eva , Meyer Anne-Louise , Siebörger Mareile , Johannesen Siw , Aigner Ludwig , Bogdahn Ulrich , Bruun Tim-Henrik
Published: March 2020

Antisense Oligonucleotides (ASOs) are an emerging drug class in gene modification. In our study we developed a safe, stable, and effective ASO drug candidate in locked nucleic acid (LNA)-gapmer design, targeting TGFβ receptor II (TGFBR2) mRNA. Discovery was performed as a process using state-of-the-art library development and screening. We intended to identify a drug candidate optimized for clinical development, therefore human specificity and gymnotic delivery were favored by design. A staggered process was implemented spanning in-silico-design, in-vitro transfection, and in-vitro gymnotic delivery of small batch syntheses. Primary in-vitro and in-vivo toxicity studies and modification of pre-lead candidates were also part of this selection process. The resulting lead compound NVP-13 unites human specificity and highest efficacy with lowest toxicity. We particularly focused at attenuation of TGFβ signaling, addressing both safety and efficacy. Hence, developing a treatment to potentially recondition numerous pathological processes mediated by elevated TGFβ signaling, we have chosen to create our data in human lung cell lines and human neuronal stem cell lines, each representative for prospective drug developments in pulmonary fibrosis and neurodegeneration. We show that TGFBR2 mRNA as a single gene target for NVP-13 responds well, and that it bears great potential to be safe and efficient in TGFβ signaling related disorders.
Comparative Mitogenome Analysis of the Genus Trifolium Reveals Independent Gene Fission of ccmFn and Intracellular Gene Transfers in Fabaceae
Authors: Choi In-Su , Ruhlman Tracey A. , Jansen Robert K.
Published: March 2020

The genus Trifolium is the largest of the tribe Trifolieae in the subfamily Papilionoideae (Fabaceae). The paucity of mitochondrial genome (mitogenome) sequences has hindered comparative analyses among the three genomic compartments of the plant cell (nucleus, mitochondrion and plastid). We assembled four mitogenomes from the two subgenera (Chronosemium and Trifolium) of the genus. The four Trifolium mitogenomes were compact (294,911–348,724 bp in length) and contained limited repetitive (6.6–8.6%) DNA. Comparison of organelle repeat content highlighted the distinct evolutionary trajectory of plastid genomes in a subset of Trifolium species. Intracellular gene transfer (IGT) was analyzed among the three genomic compartments revealing functional transfer of mitochondrial rps1 to nuclear genome along with other IGT events. Phylogenetic analysis based on mitochondrial and nuclear rps1 sequences revealed that the functional transfer in Trifolieae was independent from the event that occurred in robinioid clade that includes genus Lotus. A novel, independent fission event of ccmFn in Trifolium was identified, caused by a 59 bp deletion. Fissions of this gene reported previously in land plants were reassessed and compared with Trifolium.
Tenogenic Contribution to Skeletal Muscle Regeneration: The Secretome of Scleraxis Overexpressing Mesenchymal Stem Cells Enhances Myogenic Differentiation In Vitro
Authors: Strenzke Maximilian , Alberton Paolo , Aszodi Attila , Docheva Denitsa , Haas Elisabeth , Kammerlander Christian , Böcker Wolfgang , Saller Maximilian Michael
Published: March 2020

Integrity of the musculoskeletal system is essential for the transfer of muscular contraction force to the associated bones. Tendons and skeletal muscles intertwine, but on a cellular level, the myotendinous junctions (MTJs) display a sharp transition zone with a highly specific molecular adaption. The function of MTJs could go beyond a mere structural role and might include homeostasis of this musculoskeletal tissue compound, thus also being involved in skeletal muscle regeneration. Repair processes recapitulate several developmental mechanisms, and as myotendinous interaction does occur already during development, MTJs could likewise contribute to muscle regeneration. Recent studies identified tendon-related, scleraxis-expressing cells that reside in close proximity to the MTJs and the muscle belly. As the muscle-specific function of these scleraxis positive cells is unknown, we compared the influence of two immortalized mesenchymal stem cell (MSC) lines—differing only by the overexpression of scleraxis—on myoblasts morphology, metabolism, migration, fusion, and alignment. Our results revealed a significant increase in myoblast fusion and metabolic activity when exposed to the secretome derived from scleraxis-overexpressing MSCs. However, we found no significant changes in myoblast migration and myofiber alignment. Further analysis of differentially expressed genes between native MSCs and scleraxis-overexpressing MSCs by RNA sequencing unraveled potential candidate genes, i.e., extracellular matrix (ECM) proteins, transmembrane receptors, or proteases that might enhance myoblast fusion. Our results suggest that musculotendinous interaction is essential for the development and healing of skeletal muscles.
Vaccarin Regulates Diabetic Chronic Wound Healing through FOXP2/AGGF1 Pathways
Authors: Liu Yixiao , Sun Jiangnan , Ma Xinyu , Li Shuangshuang , Ai Min , Xu Fei , Qiu Liying
Published: March 2020

Background: Diabetes mellitus is a growing global health issue nearly across the world. Diabetic patients who are prone to develop diabetes-related complications often exhibit progressive neuropathy (painless and sensory loss). It is usual for small wounds to progress to ulceration, which especially worsens with peripheral arterial disease and in the presence of anaerobic bacteria, culminating into gangrene. In our study, vaccarin (VAC), the main active monomer extracted from Chinese herb vaccariae semen, is proven to have a role in promoting diabetic chronic wound healing through a cytoprotective role under high glucose conditions. Materials and methods: We constructed a pressure ulcer on both VAC-treated and control mice based on a type 1 diabetes (T1DM) model. The wound healing index was evaluated by an experimental wound assessment tool (EWAT). We also determined the effect of VAC on the proliferation and cell migration of human microvascular endothelial cells (HMEC-1) by a cell counting kit (CCK-8), a scratch and transwell assay. Results: The results demonstrated that VAC could promote the proliferation and migration of high glucose-stimulated HMEC-1 cells, which depend on the activation of FOXP2/AGGF1. Activation of the angiogenic factor with G patch and FHA domains 1 (AGGF1) caused enhanced phosphorylation of serine/threonine kinase (Akt) and extracellular regulated protein kinases (Erk1/2). By silencing the expression of forkhead box p2 (FOXP2) protein by siRNA, both mRNA and protein expression of AGGF1 were downregulated, leading to a decreased proliferation and migration of HMEC-1 cells. In addition, a diabetic chronic wound model in vivo unveiled that VAC had a positive effect on chronic wound healing, which involved the activation of the above-mentioned pathways. Conclusions: In summary, our study found that VAC promoted chronic wound healing in T1DM mice by activating the FOXP2/AGGF1 pathway, indicating that VAC may be a promising candidate for the treatment of the chronic wounds of diabetic patients.
The Use of Conductive Polymers Embedded Macro Porous Pei and Ionic Liquid Form of Pei Cryogels for Potential Conductometric Sensor Application to CO2
Authors: Demirci Sahin , Sahiner Nurettin
Published: March 2020

Polyethyleneimine (PEI) cryogels with interconnected superporous morphology were synthesized via the cryopolymerization technique. Then, conductive polymers, poly(Aniline) (PANi), poly(Pyrrole) (PPy), and poly(Thiophene) (PTh) were prepared within these PEI cryogels. Then, the conductive polymer embedding PEI composites’ characterization was carried morphologically using scanning electron microscope (SEM) by means of Fourier Transform Infrared Radiation (FT-IR) spectrometer, and by means of electrical conductivity measurements using an electrometer. Among all the prepared cryogel conductive polymer composites, the highest value in terms of conductivity was determined for PEI/PANi cryogel composites with 4.80 × 10−3 S.cm−1. Afterward, to prepare polymeric ionic liquid (PIL) forms of PEI and PEI/PANi composites. To assess the effect of anions on the conductivities of the prepared composites, PEI-based cryogels were anion ex-changed after protonation with HCl by treatment of aqueous solutions of sodium dicyanamide (Na+[N(CN)2]−), ammonium hexafluorophosphate (NH4+[PF6]−), sodium tetrafluoroborate (Na+[BF4]−), and potassium thiocyanate (K+[SCN]−), separately. Furthermore, PEI-based cryogel composites and their PIL forms were tested as a sensor for CO2 gas. The higher conductivity changes were observed on bare PEI cryogel and PEI+[BF4]− PIL cryogels with 1000-fold decrease on conductivity upon 240 min CO2 exposure. The sensitivity and recovery percent of bare PEI and PEI+[BF4]− PIL cryogels were shown almost the same with a two-fold decrease in the presence of 0.009 mole of CO2 gas, and approximately 30% recovery after the fifth consecutive reuse.
Impact of Three Natural Oily Extracts as Pulp Additives on the Mechanical, Optical, and Antifungal Properties of Paper Sheets Made from Eucalyptus camaldulensis and Meryta sinclairii Wood Branches
Authors: Salem Mohamed Z. M. , Abo Elgat Wael A. A. , Taha Ayman S. , Fares Yahia G. D. , Ali Hayssam M.
Published: March 2020

In the pulp and paper industry, several studies have been done to improve and enhance the properties of the mechanical, optical, and antimicrobial activities of pulp produced with different additives. In the present study, pulp of wood branches (WBs) from Eucalyptus camaldulensis Dehnh. and Meryta sinclairii (Hook.f.) Seem. was treated with n-hexane oily extracts (HeOE) from Melia azedarach L. fruits, Magnolia grandiflora L. leaves, and Sinapis alba L. seeds as additives at concentrations of 1%, 3%, and 5% based on oven-dry pulp weight. Measured mechanical properties were higher in paper sheets made from E. camaldulensis than M. sinclairii WB pulp. The highest tensile index values were observed with E. camaldulensis WB pulp treated with 5% HeOEs of S. alba (33.90 N·m/g) and M. grandiflora (33.76 N·m/g) compared to control (32.10 N·m/g); the highest tear index with 5% HeOE of S. alba (4.11 mN·m2/g) compared to control (3.32 mN·m2/g); and the highest burst index with 5% HeOE of S. alba (4.11 kPa·m2/g) compared to control (3.08 kPa·m2/g). The highest double-fold number value (9) was observed with E. camaldulensis WB pulp treated with 5% HeOEs of S. alba, M. azedarach, and M. grandiflora but with no significant difference compared to control treatment (8.33) or other HeOE treatments with E. camaldulensis WB pulp. Scanning electron microscope (SEM) examination showed clear inhibition of the growth of Aspergillus terreus with WB pulp paper discs of E. camaldulensis and M. sinclairii treated with HeOEs of M. azedarach, S. alba, and M. grandiflora at 3% and 5% compared to control treatment, while HeOEs at 5% concentration showed no growth of A. niger and A. terreus. The present findings establish that the HeOEs from M. azedarach, S. alba, and M. grandiflora at 3% and 5% are novel natural products that can be used as alternatives to improve the properties and antifungal activity of WB pulp produced from E. camaldulensis and M. sinclairii.
Phosphate Coatings Enriched with Copper on Titanium Substrate Fabricated Via DC-PEO Process
Authors: Rokosz Krzysztof , Hryniewicz Tadeusz , Kacalak Wojciech , Tandecka Katarzyna , Raaen Steinar , Gaiaschi Sofia , Chapon Patrick , Malorny Winfried , Matýsek Dalibor , Pietrzak Kornel , Dudek Łukasz
Published: March 2020

The present paper covers the possible ways to fabricate advanced porous coatings that are enriched in copper on a titanium substrate through Direct Current Plasma Electrolytic Oxidation (DC-PEO) with voltage control, in electrolytes made of concentrated orthophosphoric acid with the addition of copper(II) nitrate(V) trihydrate. In these studies, solutions containing from 0 to 650 g salt per 1 dm3 of acid and anodic voltages from 450 V up to 650 V were used. The obtained coatings featuring variable porosity could be best defined by the three-dimensional (3D) parameter Sz, which lies in the range 9.72 to 45.18 μm. The use of copper(II) nitrate(V) trihydrate in the electrolyte, resulted, for all cases, in the incorporation of the two oxidation forms, i.e., Cu+ and Cu2+ into the coatings. Detailed X-Ray Photoelectron Spectroscopy (XPS) studies layers allowed for stating that the percentage of copper in the surface layer of the obtained coatings was in the range of 0.24 at% to 2.59 at%. The X-Ray Diffraction (XRD) studies showed the presence of copper (α-Cu2P2O7, and Cu3(PO4)2) and titanium (TiO2-anatase, TiO3, TiP2O7, and Ti0.73O0.91) compounds in coatings. From Energy-Dispersive X-Ray Spectroscopy (EDS) and XPS studies, it was found that the Cu/P ratio increases with the increase of voltage and the amount of salt in the electrolyte. The depth profile analysis by Glow-Discharge Optical Emission Spectroscopy (GDOES) method showed that a three-layer model consisting of a top porous layer, a semi-porous layer, and a transient/barrier layer might describe the fabricated coatings.
The Effect of Service on Microstructure and Mechanical Properties of HR3C Heat-Resistant Austenitic Stainless Steel
Authors: Golański Grzegorz , Zieliński Adam , Sroka Marek , Słania Jacek
Published: March 2020

The physical metallurgical tests were performed on the test samples made of HR3C steel, taken from a section of a pipeline in the as-received condition and after approximately 26,000 h of service at 550 °C. In the as-received condition, the test material had austenitic microstructure with numerous large primary Z-phase precipitates inside the grains. The service of the test steel mainly contributed to the precipitation processes inside the grains and at the grain boundaries. After service, the following precipitates were identified in the microstructure of the test steel: Z-phase (NbCrN) and M23C6 carbides. The Z-phase precipitates were observed inside the grains, whereas M23C6 carbides - at the boundaries where they formed the so-called continuous grid. The service of the test steel contributed to the growth of the strength properties, determined both at room and elevated temperature (550, 600 °C), compared to the as-received condition. Moreover, the creep properties of HR3C steel after service were higher than those of the material in the as-received condition. The increase in the strength properties and creep resistance was connected with the growth of strengthening of the test steel by the precipitation of Z-phase and M23C6 carbides.
A Peridynamics-Based Micromechanical Modeling Approach for Random Heterogeneous Structural Materials
Authors: Nayak Sumeru , Ravinder R , Krishnan N M Anoop , Das Sumanta
Published: March 2020

This paper presents a peridynamics-based micromechanical analysis framework that can efficiently handle material failure for random heterogeneous structural materials. In contrast to conventional continuum-based approaches, this method can handle discontinuities such as fracture without requiring supplemental mathematical relations. The framework presented here generates representative unit cells based on microstructural information on the material and assigns distinct material behavior to the constituent phases in the random heterogenous microstructures. The framework incorporates spontaneous failure initiation/propagation based on the critical stretch criterion in peridynamics and predicts effective constitutive response of the material. The current framework is applied to a metallic particulate-reinforced cementitious composite. The simulated mechanical responses show excellent match with experimental observations signifying efficacy of the peridynamics-based micromechanical framework for heterogenous composites. Thus, the multiscale peridynamics-based framework can efficiently facilitate microstructure guided material design for a large class of inclusion-modified random heterogenous materials.
Medium Energy Carbon and Nitrogen Ion Beam Induced Modifications in Charge Transport, Structural and Optical Properties of Ni/Pd/n-GaN Schottky Barrier Diodes
Authors: Kumar Santosh , Zhang Xiang , Mariswamy Vinay Kumar , Reddy Varra Rajagopal , Kandasami Asokan , Nimmala Arun , Rao S V S Nageswara , Tang Jue , Ramakrishnna Seeram , Sannathammegowda Krishnaveni
Published: March 2020

The irradiation effects of carbon and nitrogen medium energy ions (MEI) on charge transport, structural and optical properties of Ni/Pd/n-GaN Schottky barrier diodes are reported. The devices are exposed to 600 keV C2+ and 650 keV N2+ ions in the fluence range of 1 × 1013 to 1 × 1015 ions cm−2. The SRIM/TRIM simulations provide quantitative estimations of damage created along the trajectories of ion beams in the device profile. The electrical parameters like Schottky barrier height, series resistance of the Ni/Pd/n-GaN Schottky barrier diodes decreases for a fluence of 1 × 1013 ions cm−2 and thereafter increases with an increase in fluence of 600 keV C2+ and 650 keV N2+ ions. The charge transport mechanism is influenced by various current transport mechanisms along with thermionic emission. Photoluminescence studies have demonstrated the presence of yellow luminescence in the pristine samples. It disappears at higher fluences due to the possible occupancy of Ga vacancies. The presence of the green luminescence band may be attributed to the dislocation caused by the combination of gallium vacancy clusters and impurities due to MEI irradiation. Furthermore, X-ray diffraction studies reveal that there is a decrease in the intensity and shift in the diffraction peaks towards the lower side of two thetas. The reductions in the intensity of C2+ ion irradiation is more when compared to N2+ ion irradiation, which may be attributed to change in the mean atomic scattering factor on a given site for light C2+ ion as compared to N2+ ion.
Laminated Wallboard Panels Made with Cellulose Nanofibrils as a Binder: Production and Properties
Authors: Hafez Islam , Tajvidi Mehdi
Published: March 2020

This study explored the development and characterization of laminated wallboard panels using renewable materials for building applications. The panels are based on cellulose nanofibrils (CNFs) as a binder and wood particles. Other additives included FiberLeanTM (microfibrillated cellulose/calcium carbonate composite), starch and fire retardant (boric acid/borax). These panels are also intended to address the environmental concerns of commercial gypsum boards. The manufacturing of the panels is via a wet-based process; hence no initial drying was required to remove the water from the CNF. It was found that the dosage of CNF (and/or FiberLeanTM) binder and the addition of starch had the largest impact upon the quality of the final product. The addition of starch was found more favorable in the presence of FiberLeanTM. The fire retardancy was induced by adding boric acid/borax (1:1). The burning test revealed that the panels treated with the fire retardant exhibited excellent burning properties comparable to that of gypsum board (inherently fire resistant). Interestingly, the addition of the boric acid/borax also appeared to increase the retention of starch in the system, leading to favorable mechanical properties.
New Zr-Ti-Nb Alloy for Medical Application: Development, Chemical and Mechanical Properties, and Biocompatibility
Authors: Mishchenko Oleg , Ovchynnykov Oleksandr , Kapustian Oleksii , Pogorielov Maksym
Published: March 2020

The concept of mechanical biocompatibilities is considered an important factor for orthopedics and dental implants. The high Young modulus of traditional Ti-based alloys can lead to stress-shielding syndrome and late postoperative complications. The development of new Al- and V-free Ti alloys with a low elastic modulus is a critical task for implantology. Despite the relatively low Young modulus and appropriate biological response of metastable beta-Ti alloys, their production requires complex metallurgical solutions and a high final cost that limit commercial application. The current research aimed to develop a Zr-Ti-Nb system with a low Young modulus suitable for biomedical application, including orthopedics and dental implantology. Two different charges were used for new alloy production with melting in a vacuum-arc furnace VDP-1 under atmospheric control (argon + helium) with a non-consumable tungsten electrode and a water-cooled copper crystallizer. Post-treatment included a forging-rolling process to produce a bar suitable for implant production. SEM with EDX and the mechanical parameters of the new alloy were evaluated, and a cell culture experiment provided a biocompatibility assessment. The chemical composition of the new alloy can be represented as 59.57-19.02-21.41 mass% of Zr-Ti-Nb. The mechanical properties are characterized by an extremely low Young modulus—27,27 GPa for the alloy and 34.85 GPa for the bar. The different master alloys used for Zr-Ti-Nb production did not affect the chemical compound and mechanical parameters so it was possible to use affordable raw materials to decrease the final price of the new product. The cell culture experiment demonstrated a full biocompatibility, indicating that this new alloy can be used for dental and orthopedics implant production.
New Resin-Based Bulk-Fill Composites: in vitro Evaluation of Micro-Hardness and Depth of Cure as Infection Risk Indexes
Authors: Colombo Marco , Gallo Simone , Poggio Claudio , Ricaldone Vittorio , Arciola Carla Renata , Scribante Andrea
Published: March 2020

The current in vitro study evaluated the Vickers hardness number (VHN) and hardness ratio of four bulk-fill composites (VisCalor bulk; Admira Fusion x-tra; x-tra fil; and GrandioSO x-tra-Voco, Cuxhaven, Germany) to assess the risk of bacterial colonization in comparison with standard composite materials. Thirty samples were prepared for each group. The VHN of both the external (top) and internal surface (bottom) was determined with a micro-hardness tester (200 g load for 15 s), and the hardness ratio was also calculated for each sample. Subsequently, storage in an acidic soft drink (Coca-Cola, Coca-Cola Company, Milano, Italy) was performed; for each group, 10 samples were stored for 1 day, while another 10 were stored for 7 days and the remaining 10 were kept in water as controls. A significant reduction in VHN was shown for all the groups when comparing the external versus internal side (P < 0.05), although the hardness ratio was greater than 0.80, resulting in an adequate polymerization. Regarding the acid storage, all the groups showed a significant decrease of VHN when compared with the controls, both after 1 day (P < 0.05) and after 7 days (P < 0.001). All the products showed adequate depth of cure without further risk of bacterial colonization. However, acid exposure negatively affected micro-hardness values, which might promote subsequent colonization.
Tensile Properties of <111>-Oriented Nanotwinned Cu with Different Columnar Grain Structures
Authors: Li Yu-Jin , Tu King-Ning , Chen Chih
Published: March 2020

We performed tensile tests on highly <111>-oriented nanotwinned copper (nt-Cu) foils with different columnar grain structures. For a systematic study, we altered the microstructure of the foils by tuning the electroplating electrolyte and annealing temperatures under a nitrogen atmosphere. The results show that the yield strength ranges from 300 to 700 MPa, and elongation spans from 5% to 25%. Knowing the measured twin spacing and average grain size, and combining the confined layer slip with the Hall–Petch equation, we calculated the theoretical yield strength of the nt-Cu with different microstructures, and the theoretic values match the experiment results. Owing to the unique crystal orientation properties of <111>-oriented columnar grains, dislocations induced by slip are very limited. The Schmid factor of grains along the tensile axis direction is highly identical, so the plastic deformation is much more suitably explained by the Schmid factor model. Thus, we replace the Taylor factor with the Schmid factor in the slip model of nt-Cu.
Cytotoxic Thiodiketopiperazine Derivatives from the Deep Sea-Derived Fungus Epicoccum nigrum SD-388
Authors: Chi Lu-Ping , Li Xiao-Ming , Li Li , Li Xin , Wang Bin-Gui
Published: March 2020

Four new thiodiketopiperazine alkaloids, namely, 5’-hydroxy-6’-ene-epicoccin G (1), 7-methoxy-7’-hydroxyepicoccin G (2), 8’-acetoxyepicoccin D (3), and 7’-demethoxyrostratin C (4), as well as a pair of new enantiomeric diketopiperazines, (±)-5-hydroxydiphenylalazine A (5), along with five known analogues (6–10), were isolated and identified from the culture extract of Epicoccum nigrum SD-388, a fungus obtained from deep-sea sediments (−4500 m). Their structures were established on the basis of detailed interpretation of the NMR spectroscopic and mass spectrometric data. X-ray crystallographic analysis confirmed the structures and established the absolute configurations of compounds 1–3, while the absolute configurations for compounds 4 and 5 were determined by ECD calculations. Compounds 4 and 10 showed potent activity against Huh7.5 liver tumor cells, which were comparable to that of the positive control, sorafenib, and the disulfide bridge at C-2/C-2’ is likely essential for the activity.
Establishment of Novel High-Standard Chemiluminescent Assay for NTPase in Two Protozoans and Its High-Throughput Screening
Authors: Harada Masamitsu , Nagai Jun , Kurata Riho , Shimizu Kenji , Cui Xiaofeng , Isagawa Takayuki , Semba Hiroaki , Ishihara Jun , Yoshida Yasuhiro , Takeda Norihiko , Maemura Koji , Yonezawa Tomo
Published: March 2020

Toxoplasma gondii is a major protozoan parasite and infects human and many other warm-blooded animals. The infection leads to Toxoplasmosis, a serious issue in AIDS patients, organ transplant recipients and pregnant women. Neospora caninum, another type of protozoa, is closely related to Toxoplasma gondii. Infections of the protozoa in animals also causes serious diseases such as Encephalomyelitis and Myositis-Polyradiculitis in dogs or abortion in cows. Both Toxoplasma gondii and Neospora caninum have similar nucleoside triphosphate hydrolases (NTPase), NcNTPase and TgNTPase-I in Neospora caninum and Toxoplasma gondii, respectively. These possibly play important roles in propagation and survival. Thus, we targeted the enzymes for drug discovery and tried to establish a novel high-standard assay by a combination of original biochemical enzyme assay and fluorescent assay to determine ADP content. We then validated whether or not it can be applied to high-throughput screening (HTS). Then, it fulfilled criterion to carry out HTS in both of the enzymes. In order to identify small molecules having inhibitory effects on the protozoan enzyme, we also performed HTS using two synthetic compound libraries and an extract library derived from marine bacteria and then, identified 19 compounds and 6 extracts. Nagasaki University collected many extracts from over 18,000 marine bacteria found in local Omura bay, and continues to compile an extensive collection of synthetic compounds from numerous drug libraries established by Japanese chemists.
The Relationship between Selected Bioelements and Depressiveness Associated with Testosterone Deficiency Syndrome in Aging Men
Authors: Rotter Iwona , Wiatrak Adrian , Rył Aleksandra , Kotfis Katarzyna , Ciosek Żaneta , Laszczyńska Maria , Sipak-Szmigiel Olimpia , Szylińska Aleksandra
Published: March 2020

Background and Objectives: Abnormal concentrations of bioelements (magnesium, manganese, chromium, copper, zinc) have been associated with physical and emotional dysfunctions, including depression. This association, however, has not been analyzed in testosterone deficiency syndrome (TDS) or patients with depressiveness, i.e., when individual symptoms do not form the picture of a full-syndrome depressive disorder. This study aimed to assess the relationship between concentrations of selected bioelements and the incidence of depressive symptoms in men aged 50 years and older with a concurrent testosterone deficiency syndrome. Material and Methods: Blood samples were taken from 314 men; the mean age of the population was 61.36 ± 6.38 years. Spectrophotometric method for biochemical analysis of magnesium (Mg), manganese (Mn), chromium (Cr), copper (Cu), and zinc (Zn) was used. The diagnosis of testosterone deficiency syndrome (TDS) was based on the total testosterone (TT), free testosterone (FT), estradiol (E2), and dehydroepiandrosterone sulfate (DHEAS) levels by ELISA. Each participant completed the Androgen Deficiency in Aging Male (ADAM) questionnaire, as well as the Beck Depression Inventory (BDI-Ia) measuring the severity of depressive symptoms. Results: Emotional disturbances manifested as depressive symptoms were diagnosed in 28.7% of all participants and testosterone deficiency syndrome in 49.3%. In the TDS group, the analysis showed a significant correlation between the level of manganese (R = 0.225, p = 0.005) and chromium (R = 0.185, p = 0.021) with the incidence of depression. Conclusions: The results of our study demonstrated a relationship between manganese and chromium concentrations with the incidence of depression in men aged 50 years and older with a concurrent testosterone deficiency syndrome. This may indicate that there is a correlation between these bioelements, as well as emotional disorders manifested as depressive symptoms in aging men with a diagnosed testosterone deficiency.
Hemocompatibility-related Adverse Events Following HeartMate II Left Ventricular Assist Device Implantation between Japan and United States
Authors: Imamura Teruhiko , Ono Minoru , Kinugawa Koichiro , Fukushima Norihide , Shiose Akira , Matsui Yoshiro , Yamazaki Kenji , Saiki Yoshikatsu , Usui Akihiko , Niinami Hiroshi , Matsumiya Goro , Arai Hirokuni , Sawa Yoshiki , Uriel Nir
Published: March 2020

Background: Left ventricular assist device (LVAD) therapy has improved the clinical outcomes in advanced heart failure patients, however, this may differ between countries. We aimed to compare outcomes between Japanese and US LVAD cohorts. Methods: For 416 consecutive LVAD patients who received HeartMate II LVAD implantation and completed a one-year follow-up, age-matched Japanese patients (the Japanese registry for mechanically assisted circulatory support (J-MACS) group) and the US patients were compared for their clinical outcomes. Results: 154 J-MACS patients and 77 US patients were compared. Survival, free from hemocompatibility-related adverse events (HRAEs) in the J-MACS was statistically comparable with the US (75% vs. 63%, p = 0.79). J-MACS had more disabling strokes than the US (0.221 vs. 0.052/patient-year, p = 0.005), whereas there was less nonsurgical bleeding (0.045 vs. 0.117/patient-year, p = 0.024). The net hemocompatibility score was statistically comparable between the groups (1.54 vs. 1.19 points/patient, p = 0.99). Post-LVAD prothrombin time with international normalized ratio (INR) <1.5 (odds ratio 4.07) was a risk factor for HRAEs in J-MACS, whereas INR >3.0 (odds ratio 5.71) was a risk factor in the US (p < 0.05 for both). Conclusion: In the age-matched cohorts, the J-MACS group experienced more strokes, while the US group had more bleedings. “Tailor-made” therapeutic strategy might be required for each country, given the unique variation of HRAE incidence among each country.
A Biomimetic Fish Fin-Like Robot Based on Textile Reinforced Silicone
Authors: Pfeil Sascha , Katzer Konrad , Kanan Anas , Mersch Johannes , Zimmermann Martina , Kaliske Michael , Gerlach Gerald
Published: March 2020

The concept of merging pre-processed textile materials with tailored mechanical properties into soft matrices is so far rarely used in the field of soft robotics. The herein presented work takes the advantages of textile materials in elastomer matrices to another level by integrating a material with highly anisotropic bending properties. A pre-fabricated textile material consisting of oriented carbon fibers is used as a stiff component to precisely control the mechanical behavior of the robotic setup. The presented robotic concept uses a multi-layer stack for the robot’s body and dielectric elastomer actuators (DEAs) on both outer sides of it. The bending motion of the whole structure results from the combination of its mechanically adjusted properties and the force generation of the DEAs. We present an antagonistic switching setup for the DEAs that leads to deflections to both sides of the robot, following a biomimetic principle. To investigate the bending behavior of the robot, we show a simulation model utilizing electromechanical coupling to estimate the quasi-static deflection of the structure. Based on this model, a statement about the bending behavior of the structure in general is made, leading to an expected maximum deflection of 10 mm at the end of the fin for a static activation. Furthermore, we present an electromechanical network model to evaluate the frequency dependent behavior of the robot’s movement, predicting a resonance frequency of 6.385 Hz for the dynamic switching case. Both models in combination lead to a prediction about the acting behavior of the robot. These theoretical predictions are underpinned by dynamic performance measurements in air for different switching frequencies of the DEAs, leading to a maximum deflection of 9.3 mm located at the end of the actuators. The herein presented work places special focus on the mechanical resonance frequency of the robotic setup with regard to maximum deflections.
The Potential of Pandanus amaryllifolius Leaves Extract in Fabrication of Dense and Uniform ZnO Microrods
Authors: Md Akhir Rabiatuladawiyah , Umbaidilah Siti Zulaikha , Abdullah Nurul Afaah , Alrokayan Salman A.H. , Khan Haseeb A. , Soga Tetsuo , Rusop M. , Khusaimi Zuraida
Published: March 2020

Zinc oxide (ZnO) micro and nanorods were successfully prepared using Pandanus amaryllifolius and hexamethylenetetramine (HMTA) separately as stabilizers using the solution immersion method. Two types of ZnO seed layer were prepared using the same pre-cursor with the different stabilizers. The fabricated ZnO microrods exhibit absorption at ~375 nm as revealed from the UV–Visible absorption spectrum, and this is comparable with ZnO nanorods synthesized using HMTA. X-ray diffraction (XRD) measurement displayed a sharp peak corresponding to the hexagonal wurtzite structure of ZnO microrods. Field emission scanning electron microscopy (FESEM) of ZnO microrods showed average diameter at approximately 500 nm compared to 70 nm of those synthesized from HMTA. A new finding is the ability of Pandanus amaryllifolius as a green stabilizer to grow a dense ZnO microrod structure with high crystallinity. Results reveal that both samples from different stabilizers during the preparation of the ZnO seed layer greatly improved the morphological and structural properties and optical absorption of ZnO. The main outcomes from this study will benefit optoelectronic application, such as in ultraviolet (UV) sensors.