bluuebunny/crossref_metadata_2025 huggingface dataset:
Information Management in a Collaboratively-Developed Approach to Enterprise Resource Planning—A Higher Education Perspective
Authors: Almigheerbi Tareq Salahi , Ramsey David , Lamek Anna
Published: March 2020

This paper is a part of an exploratory study with the goal of investigating the applicability of collaboratively-developed enterprise resource planning (the CD-ERP approach) within Libyan public universities. Since it is being proposed in order to overcome the topical issue of information system (IS) development in Libyan higher education (LHE), Libyan universities were investigated to assess IS performance while using the approach of methodological assessment. Accordingly, three public universities were chosen to be studied, namely the University of Tripoli (UOT), Misurata University (MU), and Sirte University (SU). The UOT was run as an initial study to identify practical problems in conducting a formal study. Previous papers have discussed the use of a formal study, in which a methodological assessment of IS performance at Libyan universities was conducted. The findings from all three cases are discussed and analyzed on the basis of selected techniques and models. This analysis indicates the low level of the ISs implemented in LHE at the university level, as well as the lack of system development capabilities within these universities. This paper focuses on the management of information flow between universities during student exchange. Business process maps are presented, and improvements based on the CD-ERP approach are proposed.
Do Not Let the Robot Get too Close: Investigating the Shape and Size of Shared Interaction Space for Two People in a Conversation
Authors: Ruijten Peter A. M. , Cuijpers Raymond H.
Published: March 2020

Robotic and other autonomous systems that need to operate in environments with people should respect social rules. One important aspect of this is personal space, which is the space surrounding a person. When two people are in a conversation, they position themselves such that a so-called shared interaction space is created in the middle of them. The aim of the current research was to experimentally investigate the shape and size of this shared interaction space in different formations. In three experiments, we had a robot approaching two people who were having a conversation from 5 different directions, and those people indicated what would be a comfortable distance for the robot to stop. We expected that people would take the personal space of their conversation partner into account when stopping the robot. Findings of the three studies mostly confirm this expectation. Apart from some exceptions, people tend to stop the robot at a similar distance from their conversation partner as from themselves. If these findings are applied in the behavior of robotic and other autonomous systems, people would be more likely to trust and later accept robots in their physical space, ultimately creating natural social interactions between humans and robots.
Effect of UV-Absorbing Nets on the Performance of the Aphid Predator Sphaerophoria rueppellii (Diptera: Syrphidae)
Authors: Amorós-Jiménez Rocco , Plaza María , Montserrat Marta , Marcos-García M. Ángeles , Fereres Alberto
Published: March 2020

Photoselective nets have proven to be effective for aphid pest control as they limit their dispersal ability. However, little is known on the impact of such nets on natural enemies of aphids. In this work, we study the effect of UV-absorbing nets on the syrphid fly Sphaerophoria rueppellii Wiedemann (Diptera: Syrphidae), a commercially available aphid biocontrol agent in Mediterranean horticultural crops. First, we released mature syrphid adults and evaluated density and dispersal of the resulting immatures in a turnip crop grown under either UV-blocking (Bionet) or standard net. Second, we assessed, under controlled conditions, the impact of UV radiation on fitness-related parameters, and on flight behavior of S. rueppellii adults. Results showed that, while syprhid immature density was higher, their dispersion was reduced under Bionet. UV-absorbing nets are known to influence the dispersion pattern of aphids, which may have indirectly conditioned the distribution of their predator S. rueppellii. On the other hand, the type of net had no influence on the performance of adults. We conclude that the use of photoselective nets and the release of syrphid predators such S. rueppellii are compatible strategies to be used in IPM aphid-control programs.
Treatment of Somatosensory Tinnitus: A Randomized Controlled Trial Studying the Effect of Orofacial Treatment as Part of a Multidisciplinary Program
Authors: van der Wal Annemarie , Michiels Sarah , Van de Heyning Paul , Braem Marc , Visscher Corine M. , Topsakal Vedat , Gilles Annick , Jacquemin Laure , Van Rompaey Vincent , De Hertogh Willem
Published: March 2020

Background: Tinnitus, or ringing in the ears, is a perception of sound in the absence of overt acoustic stimulation. In some cases, tinnitus can be influenced by temporomandibular somatosensory input, then called temporomandibular somatosensory tinnitus (TST). It is, however, not entirely known if orofacial treatment can decrease tinnitus severity. The purpose of this study was to evaluate the effect of orofacial treatment on tinnitus complaints in patients with TST. Methods: Adult patients with TST were included, and all patients received information and advice about tinnitus and conservative orofacial treatment consisting of physical therapy, and, in case of grinding, occlusal splints were applied. Included patients were randomly assigned to an early start group and a delayed start group according to our delayed treatment design. Results: In total, 40 patients were included in each group. The treatment effect on tinnitus severity was investigated using the tinnitus questionnaire (TQ) and Tinnitus Functional Index (TFI). Regarding the TQ score, no clinically relevant reductions were observed, and no significant differences in the decrease were observed between the early start group and delayed start group. Contrarily, a significantly higher percentage of patients showed a decrease in the TQ degree in the early start group compared to the delayed start group (30.0% versus 2.8%, p = 0.006). The TFI score did show a significantly greater and clinically relevant reduction in the early start group compared to the delayed start group (p = 0.042). Conclusion: A multidisciplinary non-invasive orofacial treatment was able to reduce tinnitus severity in patients with temporomandibular related somatosensory tinnitus.
Tantalum Recycling by Solvent Extraction: Chloride Is Better than Fluoride
Authors: Kinsman Luke M. M. , Crevecoeur Rosa A. M. , Singh-Morgan Amrita , Ngwenya Bryne T. , Morrison Carole A. , Love Jason B.
Published: March 2020

The recycling of tantalum (Ta) is becoming increasingly important due to the criticality of its supply from a conflict mineral. It is used extensively in modern electronics, such as in capacitors, and so electronic waste is a potentially valuable secondary source of this metal. However, the recycling of Ta is difficult, not least because of the challenges of its leaching and subsequent separation from other metals. In this work, we show that Ta(V) halides, such as TaCl5 and TaF5, which can potentially be accessed from Ta metal upon acid halide leaching, can be recovered by solvent extraction using a simple primary amide reagent. The need for high halide concentrations in the aqueous phase implies the formation of the hexahalide salts [TaX6]− (X = F, Cl) and that an anion-swing mechanism operates. While extraction of the fluorides is poor (up to 45%), excellent extraction under chloride conditions is found (>99%) and presents an alternative route to Ta recycling.
State-of-the-Art Diffusion Studies in the High Entropy Alloys
Authors: Dąbrowa Juliusz , Danielewski Marek
Published: March 2020

The development of the high entropy alloys (HEAs) is amongst the most important topics in the field of materials science during the last two decades. The concept of multicomponent, near-equimolar systems has been already applied to the number of other systems, including oxides, carbides, diborides, silicides, and it can be expected that other groups of materials will follow. One of the main driving forces for the development of HEAs is the so-called “four core effects”: high entropy effects, severe lattice distortion, cocktail effect, and sluggish diffusion effect. Their existence and extent has been a subject of heated discussion. Probably the least studied of them is the sluggish diffusion effect, which is of the, especially, high importance from the point of view of the most possible applications of HEAs—as high-temperature materials. Its alleged existence carries a promise of obtaining materials with superior mechanical properties, higher creep resistance, and less susceptibility to high-temperature corrosion. In the current review, the state-of-the-art of diffusion studies in HEAs was presented, as well as the resulting conclusions concerning the existence of the sluggish diffusion effect. Based on the literature analysis, it can be stated that there is no experimental evidence, which would support the existence of the sluggish diffusion in HEAs on the level of tracer and self-diffusivities. Nevertheless, it can be pointed out that our current state of knowledge on the diffusion in HEAs is still far from complete; therefore, further directions of studies are proposed.
Volatile Metabolites in Liverworts of Ecuador
Authors: Valarezo Eduardo , Tandazo Oswaldo , Galán Kathia , Rosales Jandry , Benítez Ángel
Published: March 2020

Volatile metabolites from Frullania brasiliensis Raddi, Herbertus juniperoideus (Sw.) Grolle, Leptoscyphus hexagonus (Nees) Grolle, and Syzygiella anomala (Lindenb. & Gottsche) Steph collected in the south of Ecuador were investigated. Volatile secondary metabolites were extracted by hydrodistillation and analyzed by gas chromatography/flame ionization detector (GC/FID) and Gas chromatography/Mass spectrometry (GC/MS). Sixty-seven volatile compounds were identified in the four species, which represent between 80.12–90.17% of the total chemical composition. The major components were τ-muurolol (32.14%) and Germacrene-D (11.98%) in the essential oil of F. brasiliensis, bicyclogermacrene (18.23%), and Caryophyllene oxide (15.29%) in the oil of H. juniperoideus, Cabreuva oxide D (33.77%) and Elemol (18.55%) in the oil of Leptoscyphus hexagonus, and Silphiperfola-5,7(14)-diene (25.22%) and Caryophyllene oxide (8.98%) in the oil of Syzygiella anomala. This is the first report on volatile compounds for the species Herbertus juniperoideus, Leptoscyphus hexagonus, and Syzygiella anomala.
Reliability and Remaining Life Assessment of an Electronic Fuze Using Accelerated Life Testing
Authors: Muhammad Noor , Fang Zhigeng , Shah Syed Yaseen , Haider Daniyal
Published: March 2020

An electronic fuze is a one-shot system that has a long storage life and high mission criticality. Fuzes are designed, developed, and tested for high reliability (over 99%) with a confidence level of more than 95%. The electronic circuit of a fuze is embedded in the fuze assembly, and thus is not visible. Go/NoGo fuze assembly mission critical testing does not provide prognostic information about electrical and electronic circuits and subtle causes of failure. Longer storage times and harsh conditions cause degradation at the component level. In order to calculate accrued damage due to storage and operational stresses, it is necessary to perform sample-based accelerated life testing after a certain time and estimate the remaining useful life of mission critical parts. Reliability studies of mechanical parts of such systems using nondestructive testing (NDT) have been performed, but a thorough investigation is missing with regards to the electronic parts. The objective of this study is to identify weak links and estimate the reliability and remaining useful life of electronic and detonating parts. Three critical components are identified in an electronic fuze circuit (1) a diode, (2) a capacitor, and (3) a squib or detonator. The accelerated test results reveal that after ten years of storage life, there is no significant degradation in active components while passive components need to be replaced. The squib has a remaining useful life (RUL) of more than ten years with reliability over 99%.
The Role of Gangue Mineralogy on Flowsheet Development in Fluorite Processing
Authors: Taguta Jestos , Teme Kebone Carol , Ngobeni Portia
Published: March 2020

Fluorite, CaF2, is considered a strategically important mineral as it is a raw material for many strategic industries. Froth flotation is reported to be the most efficient and economically viable process for the production of an acid-grade product with a CaF2 content of at least 97%. Selective flotation of fluorite from gangue minerals, e.g., calcite and barite, is challenging because these minerals have similar physicochemical properties. This study employed batch flotation tests coupled with mineralogical analysis to design suitable customised flowsheets and efficiently optimised reagent regimes for optimum production of acid-grade fluorite concentrate from two different fluorite ores by the froth flotation process. The effect of pulp temperature on fluorite flotation was investigated in this study with the objective of lowering pulp temperatures in fluorite flotation. The results showed that an acid-grade CaF2 concentrate could be obtained from the flotation of both ores at ambient pulp temperatures. This eliminates the requirement for high-temperature pulp treatment, which would result in a significant reduction in thermal energy costs. This study showed that an understanding of gangue mineralogy is key to process optimisation for acid-grade CaF2 production. Although an acid-grade CaF2 concentrate could be produced from both ores, the flowsheets and reagent regimes were markedly different. For instance, the production of an acid-grade CaF2 product from a high quartz and calcite ore was achieved by employing a simple rougher–multiple cleaner flotation circuit using tannin and sodium silicate as calcite and quartz depressants, respectively. On the other hand, the production of an acid-grade CaF2 product from the flotation of the pyritic ore required a pre-sulphide flotation stage for upfront sulphur removal and the use of a sulphide depressant. Multiple stages of cleaning were required for improved selectivity in the flotation of both ores.
Characterization of the Lipid Oxidation Process of Robusta Green Coffee Beans and Shelf Life Prediction during Accelerated Storage
Authors: Cong Sha , Dong Wenjiang , Zhao Jianping , Hu Rongsuo , Long Yuzhou , Chi Xiaoxing
Published: March 2020

The lipid oxidation process of Robusta green coffee beans was characterized during accelerated storage for 20 days at 40 °C, 50 °C, and 60 °C. The conventional oxidation indexes and fatty acid compositions were evaluated, and the shelf life of the green coffee beans was predicted using the Arrhenius model. The acid value, iodine value, peroxide value, total oxidation value, thiobarbituric acid reactive substances, and free fatty acid content increased throughout storage, while the moisture content, p-anisidine value, and unsaturated fatty acid content decreased, which suggests that lipid oxidation occurred during accelerated storage. The predicted shelf life of green coffee bean samples were 57.39 days, 44.44 days, and 23.12 days when stored at 40 °C, 50 °C, and 60 °C, respectively. This study provided scientific evidence of the impact of lipid oxidation on the loss of quality during the accelerated storage of green coffee beans.
In Vivo Positive Magnetic Resonance Imaging Applications of Poly(methyl vinyl ether-alt-maleic acid)-coated Ultra-small Paramagnetic Gadolinium Oxide Nanoparticles
Authors: Ahmad Mohammad Yaseen , Ahmad Md. Wasi , Yue Huan , Ho Son Long , Park Ji Ae , Jung Ki-Hye , Cha Hyunsil , Marasini Shanti , Ghazanfari Adibehalsadat , Liu Shuwen , Tegafaw Tirusew , Chae Kwon-Seok , Chang Yongmin , Lee Gang Ho
Published: March 2020

The study of ultra-small paramagnetic gadolinium oxide (Gd2O3) nanoparticles (NPs) as in vivo positive (T1) magnetic resonance imaging (MRI) contrast agents is one of the most attractive fields in nanomedicine. The performance of the Gd2O3 NP imaging agents depends on the surface-coating materials. In this study, poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was used as a surface-coating polymer. The PMVEMA-coated paramagnetic ultra-small Gd2O3 NPs with an average particle diameter of 1.9 nm were synthesized using the one-pot polyol method. They exhibited excellent colloidal stability in water and good biocompatibility. They also showed a very high longitudinal water proton spin relaxivity (r1) value of 36.2 s−1mM−1 (r2/r1 = 2.0; r2 = transverse water proton spin relaxivity) under a 3.0 tesla MR field which is approximately 10 times higher than the r1 values of commercial molecular contrast agents. High positive contrast enhancements were observed in in vivo T1 MR images after intravenous administration of the NP solution sample, demonstrating its potential as a T1 MRI contrast agent.
Formation of Tetrahydrofurano-, Aryltetralin, and Butyrolactone Norlignans through the Epoxidation of 9-Norlignans
Authors: Runeberg Patrik A. , Agustin Dominique , Eklund Patrik C.
Published: March 2020

Epoxidation of the C=C double bond in unsaturated norlignans derived from hydroxymatairesinol was studied. The intermediate epoxides were formed in up to quantitative conversions and were readily further transformed into tetrahydrofuran, aryltetralin, and butyrolactone products—in diastereomeric mixtures—through ring-closing reactions and intramolecular couplings. For epoxidation, the classical Prilezhaev reaction, using stoichiometric amounts of meta-chloroperbenzoic acid (mCPBA), was used. As an alternative method, a catalytic system using dimeric molybdenum-complexes [MoO2L]2 with ONO- or ONS-tridentate Schiff base ligands and aqueous tert-butyl hydroperoxide (TBHP) as oxidant was used on the same substrates. Although the epoxidation was quantitative when using the Mo-catalysts, the higher temperatures led to more side-products and lower yields. Kinetic studies were also performed on the Mo-catalyzed reactions.
Characterizations and Assays of α-Glucosidase Inhibition Activity on Gallic Acid Cocrystals: Can the Cocrystals be Defined as a New Chemical Entity During Binding with the α-Glucosidase?
Authors: Xue Na , Jia Yutao , Li Congwei , He Binnan , Yang Caiqin , Wang Jing
Published: March 2020

Cocrystallization with co-former (CCF) has proved to be a powerful approach to improve the solubility and even bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs). However, it is still uncertain whether a cocrystal would exert the pharmacological activity in the form of a new chemical entity, an API-CCF supramolecule. In the present study, gallic acid (GA)-glutaric acid and GA-succinimide cocrystals were screened. The solubility, dissolution rate and oral bioavailability of the two cocrystals were evaluated. As expected, AUCs of GA-glutaric acid and GA-succinimide cocrystals were 1.86-fold and 2.60-fold higher than that of single GA, respectively. Moreover, experimental evaluations on α-glucosidase inhibition activity in vitro and theoretical simulations were used to detect whether the two cocrystals would be recognized as a new chemical entity during binding with α-glucosidase, a target protein in hypoglycemic mechanisms. The enzyme activity evaluation results showed that both GA and glutaric acid displayed α-glucosidase inhibition activity, and GA-glutaric acid cocrystals showed strengthened α-glucosidase inhibition activity at a moderate concentration, which is attributed to synergism of the two components. Molecular docking displayed that the GA-glutaric acid complex deeply entered the active cavity of the α-glucosidase in the form of a supramolecule, which made the guest-enzyme binding configuration more stable. For the GA and succinimide system, succinimide showed no enzyme inhibition activity, however, the GA-succinimide complex presented slightly higher α-glucosidase inhibition activity than that of GA. Molecular docking simulation indicated that the guest molecules entering the active cavity of the α-glucosidase were free GA and succinimide, not the GA-succinimide supramolecule.
Design and Synthesis of Molecular Hybrids of Sophora Alkaloids and Cinnamic Acids as Potential Antitumor Agents
Authors: Shang Hai , Li Lingyu , Ma Liyan , Tian Yu , Jia Hongmei , Zhang Tao , Yu Meng , Zou Zhongmei
Published: March 2020

Twenty-five sophora alkaloids-cinnamic acid hybrids (including matrine-cinnamic acid hybrids, sophoridine-cinnamic acid hybrids, and sophocarpine-cinnamic acid hybrids) were designed, synthesized, and evaluated in vitro against three human tumor cell lines (HeLa, HepG2 and A549) with cisplatin as a positive control. Some matrine-cinnamic acid and sophoridine-cinnamic acid compounds exhibited potent effect against all three cancer cell lines, such as compounds 5b, 5e, 5g, and 6d. The structure-activity relationship study of the synthesized compounds was also performed. Preliminary mechanistic studies indicated that compounds 5e and 6d could induce apoptosis in HepG2 cell line. Further, compounds 5e and 6d altered mitochondrial membrane potential and produced ROS leading to cell apoptosis of HepG2 cells. Overall, our findings suggested that these compounds may provide promising lead compounds for further development as antitumor agents by structural modification.
Redox-Sensitive and Hyaluronic Acid-Functionalized Nanoparticles for Improving Breast Cancer Treatment by Cytoplasmic 17α-Methyltestosterone Delivery
Authors: Rezaei Somayeh , Kashanian Soheila , Bahrami Yadollah , Cruz Luis J. , Motiei Marjan
Published: March 2020

Novel reduction-responsive hyaluronic acid–chitosan–lipoic acid nanoparticles (HACSLA-NPs) were designed and synthesized for effective treatment of breast cancer by targeting Cluster of Differentiation 44 (CD44)-overexpressing cells and reduction-triggered 17α-Methyltestosterone (MT) release for systemic delivery. The effectiveness of these nanoparticles was investigated by different assays, including release rate, 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT), lactate dehydrogenase (LDH), caspase-3 activity, Rhodamine 123 (RH-123), and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). In vitro experiments revealed that Methyltestosterone/Hyaluronic acid–chitosan–lipoic acid nanoparticles (MT/HACSLA-NPs) illustrated a sustained drug release in the absence of glutathione (GSH), while the presence of GSH led to fast MT release. HACSLA-NPs also showed high cellular internalization via CD44 receptors, quick drug release inside the cells, and amended cytotoxicity against positive CD44 BT-20 breast cancer cell line as opposed to negative CD44, Michigan Cancer Foundation-7 (MCF-7) cell line. These findings supported that these novel reduction-responsive NPs can be promising candidates for efficient targeted delivery of therapeutics in cancer therapy.
Novel Tamoxifen Nanoformulations for Improving Breast Cancer Treatment: Old Wine in New Bottles
Authors: Day Candace M. , Hickey Shane M. , Song Yunmei , Plush Sally E. , Garg Sanjay
Published: March 2020

Breast cancer (BC) is one of the leading causes of death from cancer in women; second only to lung cancer. Tamoxifen (TAM) is a hydrophobic anticancer agent and a selective estrogen modulator (SERM), approved by the FDA for hormone therapy of BC. Despite having striking efficacy in BC therapy, concerns regarding the dose-dependent carcinogenicity of TAM still persist, restricting its therapeutic applications. Nanotechnology has emerged as one of the most important strategies to solve the issue of TAM toxicity, owing to the ability of nano-enabled-formulations to deliver smaller concentrations of TAM to cancer cells, over a longer period of time. Various TAM-containing-nanosystems have been successfully fabricated to selectively deliver TAM to specific molecular targets found on tumour membranes, reducing unwanted toxic effects. This review begins with an outline of breast cancer, the current treatment options and a history of how TAM has been used as a combatant of BC. A detailed discussion of various nanoformulation strategies used to deliver lower doses of TAM selectively to breast tumours will then follow. Finally, a commentary on future perspectives of TAM being employed as a targeting vector, to guide the delivery of other therapeutic and diagnostic agents selectively to breast tumours will be presented.
Combination of High Hydrostatic Pressure and Ultrafiltration to Generate a New Emulsifying Ingredient from Egg Yolk
Authors: Giarratano Mélanie , Duffuler Pauline , Chamberland Julien , Brisson Guillaume , House James D. , Pouliot Yves , Doyen Alain
Published: March 2020

Egg yolk granule phosvitin (45 kDa) is a phosphoprotein known for its emulsifying properties. Recently, high hydrostatic pressure (HHP) treatment of granule induced the transfer of phosvitin to the soluble plasma fraction. This project evaluated the performance of the ultrafiltration (UF) used to concentrate phosvitin from the plasma fraction to produce a natural emulsifier. Phosvitin was characterized in plasma from a pressure-treated granule (1.73 ± 0.07% w/w) and in its UF retentate (26.00 ± 4.12% w/w). The emulsifying properties of both retentates were evaluated. The emulsion prepared with phosvitin-enriched retentate was more resistant to flocculation and creaming. Confocal laser scanning microscopy showed a network of aggregated protein similar to a gel, which encapsulated oil droplets in emulsions made with UF-retentate of plasma from pressure-treated granule. However, although sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that β-phosvitin is recovered in the cream, it is difficult to attribute the improved emulsifying properties of the UF-retentate of plasma from pressure-treated granules only to phosvitin.
Development and Characterization of the Shortest Anti-Adhesion Peptide Analogue of B49Mod1
Authors: Lyu Yuan , Mahauad-Fernandez Wadie D. , Okeoma Chioma M.
Published: March 2020

Inhibition of cancer cell adhesion is an effective approach to killing adherent cancer cells. B49 and its analog B49Mod1 peptides, derived from the extracellular domain (ECD) of bone marrow stromal antigen 2 (BST-2), display anti-adhesion activity on breast cancer cells. However, the minimal sequence required for this anti-adhesion activity is unknown. Here, we further characterized the anti-adhesion activity of B49Mod1. We show that the anti-adhesion activity of B49Mod1 may require cysteine-linked disulfide bond and that the peptide is susceptible to proteolytic deactivation. Using structure-activity relationship studies, we identified an 18-Mer sequence (B18) as the minimal peptide sequence mediating the anti-adhesion activity of B49Mod1. Atomistic molecular dynamic (MD) simulations reveal that B18 forms a stable complex with the ECD of BST-2 in aqueous solution. MD simulations further reveal that B18 may cause membrane defects that facilitates peptide translocation across the bilayer. Placement of four B18 chains as a transmembrane bundle results in water channel formation, indicating that B18 may impair membrane integrity and form pores. We hereby identify B18 as the minimal peptide sequence required for the anti-adhesion activity of B49Mod1 and provide atomistic insight into the interaction of B18 with BST-2 and the cell membrane.
Porous Si Microparticles Infiltrated with Magnetic Nanospheres
Authors: Chistè Elena , Ischia Gloria , Gerosa Marco , Marzola Pasquina , Scarpa Marina , Daldosso Nicola
Published: March 2020

Porous silicon (pSi) microparticles obtained by porosification of crystalline silicon wafers have unique optical properties that, together with biodegradability, biocompatibility and absence of immunogenicity, are fundamental characteristics to candidate them as tracers in optical imaging techniques and as drug carriers. In this work, we focus on the possibility to track down the pSi microparticles also by MRI (magnetic resonance imaging), thus realizing a comprehensive tool for theranostic applications, i.e., the combination of therapy and diagnostics. We have developed and tested an easy, quick and low-cost protocol to infiltrate the COOH-functionalized pSi microparticles pores (tens of nanometers about) with magnetic nanospheres (SPIONs—Super Paramagnetic Iron Oxide Nanoparticles, about 5–7 nm) and allow an electrostatic interaction. The structural properties and the elemental composition were investigated by electron microscopy techniques coupled to elemental analysis to demonstrate the effective attachment of the SPIONs along the pores’ surface of the pSi microparticles. The magnetic properties were investigated under an external magnetic field to determine the relaxivity properties of the material and resulting in an alteration of the relaxivity of water due to the SPIONs presence, clearly demonstrating the effectiveness of the easy functionalization protocol proposed.
Visible-Light-Excited Room Temperature Phosphorescent Carbon Dots
Authors: Hu Sizhe , Jiang Kai , Wang Yuci , Wang Sui , Li Zhongjun , Lin Hengwei
Published: March 2020

Carbon dots (CDs) with a room temperature phosphorescent (RTP) feature have attracted considerable interest in recent years due to their fundamental importance and promising applications. However, the reported matrix-free RTP CDs only show short-wavelength (green to yellow) emissions and have to be triggered by ultraviolet (UV) light (below 400 nm), limiting their applications in certain fields. Herein, visible-light-excited matrix-free RTP CDs (named AA-CDs) with a long-wavelength (orange) emission are reported for the first time. The AA-CDs can be facilely prepared via a microwave heating treatment of L-aspartic acid (AA) in the presence of ammonia and they emit unique orange RTP in the solid state with visible light (420 nm) excitation just being switched off. Through the studies of the carbonization process, the C=O and C=N containing moieties in the AA-CDs are confirmed to be responsible for the observed RTP emission. Finally, the applications of AA-CDs in information encryption and anti-counterfeiting were preliminarily demonstrated.
Effects of Titanium Dioxide Nanoparticles on the Hprt Gene Mutations in V79 Hamster Cells
Authors: Kazimirova Alena , El Yamani Naouale , Rubio Laura , García-Rodríguez Alba , Barancokova Magdalena , Marcos Ricard , Dusinska Maria
Published: March 2020

The genotoxicity of anatase/rutile TiO2 nanoparticles (TiO2 NPs, NM105 at 3, 15 and 75 µg/cm2) was assessed with the mammalian in-vitro Hypoxanthine guanine phosphoribosyl transferase (Hprt) gene mutation test in Chinese hamster lung (V79) fibroblasts after 24 h exposure. Two dispersion procedures giving different size distribution and dispersion stability were used to investigate whether the effects of TiO2 NPs depend on the state of agglomeration. TiO2 NPs were fully characterised in the previous European FP7 projects NanoTEST and NanoREG2. Uptake of TiO2 NPs was measured by transmission electron microscopy (TEM). TiO2 NPs were found in cytoplasmic vesicles, as well as close to the nucleus. The internalisation of TiO2 NPs did not depend on the state of agglomeration and dispersion used. The cytotoxicity of TiO2 NPs was measured by determining both the relative growth activity (RGA) and the plating efficiency (PE). There were no substantial effects of exposure time (24, 48 and 72 h), although a tendency to lower RGA at longer exposure was observed. No significant difference in PE values and no increases in the Hprt gene mutant frequency were found in exposed relative to unexposed cultures in spite of evidence of uptake of NPs by cells.
Green and Sustainable Manufacture of Ultrapure Engineered Nanomaterials
Authors: Ortiz de Zárate David , García-Meca Carlos , Pinilla-Cienfuegos Elena , Ayúcar José A. , Griol Amadeu , Bellières Laurent , Hontañón Esther , Kruis Frank E. , Martí Javier
Published: March 2020

Nanomaterials with very specific features (purity, colloidal stability, composition, size, shape, location…) are commonly requested by cutting-edge technologic applications, and hence a sustainable process for the mass-production of tunable/engineered nanomaterials would be desirable. Despite this, tuning nano-scale features when scaling-up the production of nanoparticles/nanomaterials has been considered the main technological barrier for the development of nanotechnology. Aimed at overcoming these challenging frontier, a new gas-phase reactor design providing a shorter residence time, and thus a faster quenching of nanoclusters growth, is proposed for the green, sustainable, versatile, cost-effective, and scalable manufacture of ultrapure engineered nanomaterials (ranging from nanoclusters and nanoalloys to engineered nanostructures) with a tunable degree of agglomeration, composition, size, shape, and location. This method enables: (1) more homogeneous, non-agglomerated ultrapure Au-Ag nanoalloys under 10 nm; (2) 3-nm non-agglomerated ultrapure Au nanoclusters with lower gas flow rates; (3) shape-controlled Ag NPs; and (4) stable Au and Ag engineered nanostructures: nanodisks, nanocrosses, and 3D nanopillars. In conclusion, this new approach paves the way for the green and sustainable mass-production of ultrapure engineered nanomaterials.
Core–Shell Structured Phenolic Polymer@TiO2 Nanosphere with Enhanced Visible-Light Photocatalytic Efficiency
Authors: Xu Xiankui , Zhang Lei , Zhang Shihua , Wang Yanpeng , Liu Baoying , Ren Yanrong
Published: March 2020

Core–shell structured TiO2 is a promising solution to promote the photocatalytic effectiveness in visible light. Compared to metal or semiconductor materials, polymers are rarely used as the core materials for fabricating core–shell TiO2 materials. A novel core–shell structured polymer@TiO2 was developed by using phenolic polymer (PP) colloid nanoparticles as the core material. The PP nanoparticles were synthesized by an enzyme-catalyzed polymerization in water. A subsequent sol–gel and hydrothermal reaction was utilized to cover the TiO2 shell on the surfaces of PP particles. The thickness of the TiO2 shell was controlled by the amount of TiO2 precursor. The covalent connection between PP and TiO2 was established after the hydrothermal reaction. The core–shell structure allowed the absorption spectra of PP@TiO2 to extend to the visible-light region. Under visible-light irradiation, the core–shell nanosphere displayed enhanced photocatalytic efficiency for rhodamine B degradation and good recycle stability. The interfacial C–O–Ti bonds and the π-conjugated structures in the PP@TiO2 nanosphere played a key role in the quick transfer of the excited electrons between PP and TiO2, which greatly improved the photocatalytic efficiency in visible light.
A Universal Method to Weld Individual One-Dimensional Nanostructures with a Tungsten Needle Based on Synergy of the Electron Beam and Electrical Current
Authors: Zhao Peng , Zhang Yu , Tang Shuai , Zhan Runze , She Juncong , Chen Jun , Deng Shaozhi
Published: March 2020

One-dimensional (1D) nanostructures are extensively used in the design of novel electronic devices, sensors, and energy devices. One of the major challenges faced by the electronics industry is the problem of contact between the 1D nanostructure and electrode, which can limit or even jeopardize device operations. Herein, a universal method that can realize good Ohmic and mechanical contact between an individual 1D nanostructure and a tungsten needle at sub-micron or micron scale is investigated and presented in a scanning electron microscope (SEM) chamber with the synergy of an electron beam and electrical current flowing through the welded joint. The linear I‒V curves of five types of individual 1D nanostructures, characterized by in-situ electrical measurements, demonstrate that most of them demonstrate good Ohmic contact with the tungsten needle, and the results of in-situ tensile measurements demonstrate that the welded joints possess excellent mechanical performance. By simulation analysis using the finite element method, it is proved that the local heating effect, which is mainly produced by the electrical current flowing through the welded joints during the welding process, is the key factor in achieving good Ohmic contact.
Fly Ash, from Recycling to Potential Raw Material for Mesoporous Silica Synthesis
Authors: Miricioiu Marius Gheorghe , Niculescu Violeta-Carolina
Published: March 2020

In order to meet the increasing energy demand and to decrease the dependency on coal, environmentally friendly methods for fly ash utilization are required. In this respect, the priority is to identify the fly ash properties and to consider its potential as raw material in the obtaining of high-value materials. The physico-chemical and structural characteristics of the fly ash coming from various worldwide power plants are briefly presented. The fly ash was sampled from power plants where the combustion of lignite and hard coal in pulverized-fuel boilers (PC) and circulating fluidized bed (CFB) boilers was applied. The fly ash has high silica content. Due to this, the fly ash can be considered a potential raw material for the synthesis of nanoporous materials, such as zeolites or mesoporous silica. The samples with the highest content of SiO2 can be used to obtain mesoporous silica materials, such as MCM-41 or SBA-15. The resulting mesoporous silica can be used for removing/capture of CO2 from emissions or for wastewater treatment. The synthesis of various porous materials using wastes would allow a high level of recycling for a sustainable society with low environmental impact.
The Effects of Endoplasmic-Reticulum-Resident Selenoproteins in a Nonalcoholic Fatty Liver Disease Pig Model Induced by a High-Fat Diet
Authors: Wang Pengzu , Lu Zhuang , He Meng , Shi Baoming , Lei Xingen , Shan Anshan
Published: March 2020

The present study aimed to investigate the intervention of selenium in the oxidative stress and apoptosis of pig livers, which were induced by a high-fat diet, and the effects of four endoplasmic reticulum (ER)-resident selenoproteins in the process. A 2 × 4 design trial was conducted that included two dietary fat levels (BD = basal diet and HFD = high-fat diet) and four dietary Se supplementation levels (0, 0.3, 1.0, and 3.0 mg/kg of the diet, in the form of sodium selenite (Na2SeO3)). Our results indicated that the HFD significantly increased the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, as well as the degree of steatosis, the content of malondialdehyde (MDA), the apoptotic rate, and the level of mRNA caspase-3 in the liver compared to their BD counterparts (p < 0.05). Moreover, these parameters in the HFD groups were more significantly reduced (p < 0.05) for a Se concentration of 1.0 mg/kg than for the other concentrations. Further, for both the BD and HFD, the groups supplemented with 1.0 mg/kg Se showed the highest mRNA level of selenoprotein S. In conclusion, the consumption of an HFD can induce oxidative damage and apoptosis in the liver. This shows that the supplementation of Se at 1.0 mg/kg may be the optimum concentration against damage induced by HFD, and Sels may play a key role in this process.
Atypical Presentation of Methicillin-Susceptible Staphylococcus aureus Infection in a Dengue-Positive Patient: A Case Report with Virulence Genes Analysis
Authors: Ngoi Soo Tein , Lee Yee Wan , Niek Wen Kiong , Kan Foong Kee , AbuBakar Sazaly , Ponnampalavanar Sasheela Sri La Sri , Idris Nuryana , Teh Cindy Shuan Ju
Published: March 2020

Concurrent bacteraemia in patients with dengue fever is rarely reported. We report a case of a patient who initially presented with symptoms typical of dengue fever but later succumbed to septic shock caused by hypervirulent methicillin-susceptible Staphylococcus aureus (MSSA). A 50-year-old female patient with hypertension and diabetes mellitus presented with typical symptoms of dengue fever. Upon investigation, the patient reported having prolonged fever for four days prior to hospitalization. Within 24 hours post-admission, the patient developed pneumonia and refractory shock, and ultimately succumbed to multiple-organs failure. Microbiological examination of the blood culture retrieved a pan susceptible MSSA strain. Genomic sequence analyses of the MSSA strain identified genes encoding staphylococcal superantigens (enterotoxin staphylococcal enterotoxin C 3 (SEC3) and enterotoxin-like staphylococcal enterotoxins-like toxin L (SElL)) that have been associated with toxic shock syndrome in human hosts. Genes encoding important toxins (Panton-Valentine leukocidins, alpha-haemolysin, protein A) involved in the development of staphylococcal pneumonia were also present in the MSSA genome. Staphylococcus aureus co-infections in dengue are uncommon but could be exceptionally fatal if caused by a toxin-producing strain. Clinicians should be aware of the risks and signs of sepsis in dengue fever, thus allowing early diagnosis and starting of antibiotic treatment in time to lower the mortality and morbidity rates.
Urinary N-acetyltyramine-O,β-glucuronide in Persons with Onchocerciasis-Associated Epilepsy
Authors: Hotterbeekx An , Dusabimana Alfred , Mandro Michel , Abhafule Germain M , Deogratias Wonya’Rossy , Siewe Fodjo Joseph N. , Abrams Steven , Colebunders Robert
Published: March 2020

We investigated urinary N-acetyltyramine-O,β-glucuronide (NATOG) levels as a biomarker for active Onchocerca volvulus infection in an onchocerciasis-endemic area in the Democratic Republic of Congo with a high epilepsy prevalence. Urinary NATOG was measured in non-epileptic men with and without O. volvulus infection, and in O. volvulus-infected persons with epilepsy (PWE). Urinary NATOG concentration was positively associated with microfilarial density (p < 0.001). The median urinary NATOG concentration was higher in PWE (3.67 µM) compared to men without epilepsy (1.74 µM), p = 0.017; and was higher in persons with severe (7.62 µM) compared to mild epilepsy (2.16 µM); p = 0.008. Non-epileptic participants with and without O. volvulus infection had similar NATOG levels (2.23 µM and 0.71 µM, p = 0.426). In a receiver operating characteristic curve analysis to investigate the diagnostic value of urinary NATOG, the area under the curve was 0.721 (95% CI: 0.633–0.797). Using the previously proposed cut-off value of 13 µM to distinguish between an active O. volvulus infection and an uninfected state, the sensitivity was 15.9% and the specificity 95.9%. In conclusion, an O. volvulus infection is associated with an increased urinary NATOG concentration, which correlates with the individual parasitic load. However, the NATOG concentration has a low discriminating power to differentiate between infected and uninfected individuals.
Chemical Composition, Antimicrobial activity, In Vitro Cytotoxicity and Leukotoxin Neutralization of Essential Oil from Origanum vulgare against Aggregatibacter actinomycetemcomitans
Authors: Akkaoui Sanae , Johansson Anders , Yagoubi Maâmar , Haubek Dorte , El hamidi Adnane , Rida Sana , Claesson Rolf , Ennibi OumKeltoum
Published: March 2020

In this study, the essential oil of Origanum vulgare was evaluated for putative antibacterial activity against six clinical strains and five reference strains of Aggregatibacter actinomycetemcomitans, in comparison with some antimicrobials. The chemical composition of the essential oil was analyzed, using chromatography (CG) and gas chromatography–mass spectrometry coupled (CG–MS). The major compounds in the oil were Carvacrol (32.36%), α-terpineol (16.70%), p-cymene (16.24%), and Thymol (12.05%). The antimicrobial activity was determined by an agar well diffusion test. A broth microdilution method was used to study the minimal inhibitory concentration (MIC). The minimal bactericidal concentration (MBC) was also determined. The cytotoxicity of the essential oil (IC50) was <125 µg/mL for THP-1 cells, which was high in comparison with different MIC values for the A. actinomycetemcomitans strains. O. vulgare essential oil did not interfere with the neutralizing capacity of Psidium guajava against the A. actinomycetemcomitans leukotoxin. In addition, it was shown that the O. vulgare EO had an antibacterial effect against A. actinomycetemcomitans on a similar level as some tested antimicrobials. In view of these findings, we suggest that O.vulgare EO may be used as an adjuvant for prevention and treatment of periodontal diseases associated to A. actinomycetemcomitans. In addition, it can be used together with the previously tested leukotoxin neutralizing Psidium guajava.
Genome-Wide Identification and Expression Profile Analysis of the NF-Y Transcription Factor Gene Family in Petunia hybrida
Authors: Wei Qian , Wen Shiyun , Lan Chuying , Yu Yixun , Chen Guoju
Published: March 2020

Nuclear Factor Ys (NF-Ys) are a class of heterotrimeric transcription factors that play key roles in many biological processes, such as abiotic stress responses, flowering time, and root development. The petunia (Petunia hybrida) is a model ornamental plant, and its draft genome has been published. However, no details regarding the NF-Y gene family in petunias are available. Here, 27 NF-Y members from the petunia genome were identified, including 10 PhNF-YAs, 13 PhNF-YBs, and 4 PhNF-YCs. Multiple alignments showed that all PhNF-Y proteins had clear conserved core regions flanked by non-conserved sequences. Phylogenetic analyses identified five pairs of orthologues NF-YB proteins from Petunia and Arabidopsis, and six pairs of paralogues NF-Y proteins in Petunia. Analysis of the gene structure and conserved motifs further confirmed the closer relationship in each subfamily. Bioinformatics analysis revealed that 16 PhNF-Ys could be targeted by 18 miRNA families. RNA-seq results showed that expression patterns of PhNF-Ys among four major organs (leaf, stem, flower, and root) were clustered into six major groups. The stress response pattern of PhNF-Ys was identified under cold, heat, drought, and salinity treatments. Based on the RNA-seq data, we found that 3 genes responded to drought, 4 genes responded to salt, 10 genes responded to cold, and 9 genes responded to hot. In conclusion, this study provides useful information for further studying the functions of NF-Ys in stress response.
Preparation and Properties of Inherently Black Polyimide Films with Extremely Low Coefficients of Thermal Expansion and Potential Applications for Black Flexible Copper Clad Laminates
Authors: Tan Yao-yao , Zhang Yan , Jiang Gang-lan , Zhi Xin-xin , Xiao Xiao , Wu Lin , Jia Yan-Jiang , Liu Jin-gang , Zhang Xiu-min
Published: March 2020

In the current work, a series of black polyimide (PI) films with excellent thermal and dimensional stability at elevated temperatures were successfully developed. For this purpose, two aromatic diamines including 4,4′-iminodianline (NDA) and 2-(4-aminophenyl)-5- aminobenzimidazole (APBI) were copolymerized with pyromellitic dianhydride (PMDA) to afford PIs containing imino groups (–NH–) in the molecular structures. The referenced PI film, PI-ref, was simultaneously prepared from PMDA and 4,4′-oxydianiline (ODA). The introduction of imino groups endowed the PI films with excellent blackness and opaqueness with the optical transmittance lower than 2% at the wavelength of 600 nm at a thickness of 25 μm and lightness (L*) below 10 for the CIE (Commission International Eclairage) Lab optical parameters. Meanwhile, the introduction of rigid benzimidazole units apparently improved the thermal and dimensional stability of the PI films. The PI-d film based on PMDA and mixed diamines (NDA:APBI = 70:30, molar ratio) showed a glass transition temperature (Tg) of 445.5 °C and a coefficient of thermal expansion (CTE) of 8.9 × 10−6/K in the temperature range of 50 to 250 °C, respectively. It is obviously superior to those of the PI-a (PMDA-NDA, Tg = 431.6 °C; CTE = 18.8 × 10−6/K) and PI-ref (PMDA-ODA, Tg = 418.8 °C; CTE: 29.5 × 10−6/K) films.