bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing Corrosion and Wear Resistance of Ti6Al4V Alloy Using CNTs Mixed Electro-Discharge Process
Authors: Singh Gurpreet , Ablyaz Timur Rizovich , Shlykov Evgeny Sergeevich , Muratov Karim Ravilevich , Bhui Amandeep Singh , Sidhu Sarabjeet Singh
Published: September 2020

This paper presents wear and corrosion resistance analysis of carbon nanotubes coated with Ti-6Al-4V alloy processed by electro-discharge treatment. The reported work is carried out using Taguchi’s L18 orthogonal array to design the experimental matrix by varying five input process parameters i.e., dielectric medium (plain dielectric, multi-walled carbon nanotubes (MWCNTs) mixed dielectric), current (1–4 A), pulse-on-time (30–60 µs), pulse-off-time (60–120 µs), and voltage (30–50 V). The output responses are assessed in terms of microhardness and surface roughness of the treated specimen. X-ray diffraction (XRD) spectra of the coated sample reveal the formation of intermetallic compounds, oxides, and carbides, whereas surface morphology is observed using scanning electron microscopy (SEM) analysis. For the purpose of the in-vitro wear behavior of treated samples, the surface with superior microhardness values in plain dielectric and MWCNTs mixed dielectric is compared using a pin-on-disc type wear test. Furthermore, electrochemical corrosion test is also conducted to portray the dominance of treated substrate of Ti-6Al-4V alloy for biomedical applications. It is concluded that the wear-resistant and the corrosion protection efficiency of the MWCNTs treated substrate enhanced to 95%, and 96.63%, respectively.
Investigation of Monolithic 3D Integrated Circuit Inverter with Feedback Field Effect Transistors Using TCAD Simulation
Authors: Oh Jong Hyeok , Yu Yun Seop
Published: September 2020

The optimal structure and process for the feedback field-effect transistor (FBFET) to operate as a logic device are investigated by using a technology computer-aided design mixed-mode simulator. To minimize the memory window of the FBFET, the channel length (Lch), thickness of silicon body (Tsi), and doping concentration (Nch) of the channel region below the gate are adjusted. As a result, the memory window increases as Lch and Tsi increase, and the memory window is minimum when Nch is approximately 9 × 1019 cm−3. The electrical coupling between the top and bottom tiers of a monolithic 3-dimensional inverter (M3DINV) consisting of an n-type FBFET located at the top tier and a p-type FBFET located at the bottom tier is also investigated. In the M3DINV, we investigate variation of switching voltage with respect to voltage transfer characteristics (VTC), with different thickness values of interlayer dielectrics (TILD), Tsi, Lch, and Nch. The variation of propagation delay of the M3DINV with different TILD, Tsi, Lch, and Nch is also investigated. As a result, the electrical coupling between the stacked FBFETs by TILD can be neglected. The switching voltage gaps increase as Lch and Tsi increase and decrease, respectively. Furthermore, the slopes of VTC of M3DINV increase as Tsi and Nch increase. For transient response, tpHL decrease as Lch, Tsi, and Nch increase, but tpLH increase as Lch and Tsi increase and it is almost the same for Nch.
Degradation of Hydrocarbons and Heavy Metal Reduction by Marine Bacteria in Highly Contaminated Sediments
Authors: Dell’Anno Filippo , Brunet Christophe , van Zyl Leonardo Joaquim , Trindade Marla , Golyshin Peter N. , Dell’Anno Antonio , Ianora Adrianna , Sansone Clementina
Published: September 2020

Investigations on the ability of bacteria to enhance removal of hydrocarbons and reduce heavy metal toxicity in sediments are necessary to design more effective bioremediation strategies. In this study, five bacterial strains, Halomonas sp. SZN1, Alcanivorax sp. SZN2, Pseudoalteromonas sp. SZN3, Epibacterium sp. SZN4, and Virgibacillus sp. SZN7, were isolated from polluted sediments from an abandoned industrial site in the Gulf of Naples, Mediterranean Sea, and tested for their bioremediation efficiency on sediment samples collected from the same site. These bacteria were added as consortia or as individual cultures into polluted sediments to assess biodegradation efficiency of polycyclic aromatic hydrocarbons and heavy metal immobilisation capacity. Our results indicate that these bacteria were able to remove polycyclic aromatic hydrocarbons, with a removal rate up to ca. 80% for dibenzo-anthracene. In addition, these bacteria reduced arsenic, lead, and cadmium mobility by promoting their partitioning into less mobile and bioavailable fractions. Microbial consortia generally showed higher performance toward pollutants as compared with pure isolates, suggesting potential synergistic interactions able to enhance bioremediation capacity. Overall, our findings suggest that highly polluted sediments select for bacteria efficient at reducing the toxicity of hazardous compounds, paving the way for scaled-up bioremediation trials.
Genomics Reveals the Metabolic Potential and Functions in the Redistribution of Dissolved Organic Matter in Marine Environments of the Genus Thalassotalea
Authors: Kim Minji , Cha In-Tae , Lee Ki-Eun , Lee Eun-Young , Park Soo-Je
Published: September 2020

Members of the bacterial genus Thalassotalea have been isolated recently from various marine environments, including marine invertebrates. A metagenomic study of the Deepwater Horizon oil plume has identified genes involved in aromatic hydrocarbon degradation in the Thalassotalea genome, shedding light on its potential role in the degradation of crude oils. However, the genomic traits of the genus are not well-characterized, despite the ability of the species to degrade complex natural compounds, such as agar, gelatin, chitin, or starch. Here, we obtained a complete genome of a new member of the genus, designated PS06, isolated from marine sediments containing dead marine benthic macroalgae. Unexpectedly, strain PS06 was unable to grow using most carbohydrates as sole carbon sources, which is consistent with the finding of few ABC transporters in the PS06 genome. A comparative analysis of 12 Thalassotalea genomes provided insights into their metabolic potential (e.g., microaerobic respiration and carbohydrate utilization) and evolutionary stability [including a low abundance of clustered regularly interspaced short palindromic repeats (CRISPR) loci and prophages]. The diversity and frequency of genes encoding extracellular enzymes for carbohydrate metabolism in the 12 genomes suggest that members of Thalassotalea contribute to nutrient cycling by the redistribution of dissolved organic matter in marine environments. Our study improves our understanding of the ecological and genomic properties of the genus Thalassotalea.
Beneficial Effects of Newly Isolated Akkermansia muciniphila Strains from the Human Gut on Obesity and Metabolic Dysregulation
Authors: Yang Meng , Bose Shambhunath , Lim Sookyoung , Seo JaeGu , Shin JooHyun , Lee Dokyung , Chung Won-Hyong , Song Eun-Ji , Nam Young-Do , Kim Hojun
Published: September 2020

The identification of new probiotics with anti-obesity properties has attracted considerable interest. In the present study, the anti-obesity activities of Akkermansia muciniphila (A. muciniphila) strains isolated from human stool samples and their relationship with the gut microbiota were evaluated using a high fat-diet (HFD)-fed mice model. Three strains of A. muciniphila were chosen from 27 isolates selected based on their anti-lipogenic activity in 3T3-L1 cells. The anti-lipogenic, anti-adipogenic and anti-obesity properties of these three strains were evaluated further in HFD-induced obese mice. The animals were administered these strains six times per week for 12 weeks. The treatment improved the HFD-induced metabolic disorders in mice in terms of the prevention of body weight gain, caloric intake and reduction in the weights of the major adipose tissues and total fat. In addition, it improved glucose homeostasis and insulin sensitivity. These effects were also associated with the inhibition of low-grade intestinal inflammation and restoration of damaged gut integrity, prevention of liver steatosis and improvement of hepatic function. These results revealed a difference in the distribution pattern of the gut microbial communities between groups. Therefore, the gut microbial population modulation, at least in part, might contribute to the beneficial impact of the selected A. muciniphila strains against metabolic disorders.
Larvae of the Clothing Moth Tineola bisselliella Maintain Gut Bacteria that Secrete Enzyme Cocktails to Facilitate the Digestion of Keratin
Authors: Vilcinskas Andreas , Schwabe Michael , Brinkrolf Karina , Plarre Rudy , Wielsch Natalie , Vogel Heiko
Published: September 2020

The evolutionary success of insects is promoted by their association with beneficial microbes that enable the utilization of unusual diets. The synanthropic clothing moth Tineola bisselliella provides an intriguing example of this phenomenon. The caterpillars of this species have adapted to feed on keratin-rich diets such as feathers and wool, which cannot be digested by most other animals and are resistant to common digestive enzymes. Inspired by the hypothesis that this ability may be conferred by symbiotic microbes, we utilized a simple assay to detect keratinase activity and a method to screen gut bacteria for candidate enzymes, which were isolated from feather-fed larvae. The isolation of DNA from keratin-degrading bacterial strains followed by de novo genome sequencing resulted in the identification of a novel bacterial strain related to Bacillus sp. FDAARGOS_235. Genome annotation identified 20 genes with keratinase domains. Proteomic analysis of the culture supernatant from this gut bacterium grown in non-nutrient buffer supplemented with feathers revealed several candidate enzymes potentially responsible for keratin degradation, including a thiol-disulfide oxidoreductase and multiple proteases. Our results suggest that the unusual diet of T. bisselliella larvae promotes their association with keratinolytic microorganisms and that the ability of larvae to feed on keratin can at least partially be attributed to bacteria that produce a cocktail of keratin-degrading enzymes.
Phase Transformations in Fly Ash-Based Solids
Authors: Perná Ivana , Hanzlíček Tomáš , Šupová Monika , Novotná Martina
Published: September 2020

The presented article describes the phase transformations in solid bodies based on fluid fly ash (FFA) over eight years from the initial to the final phases. FFA has been selected as a type of industrial waste whose amount has been growing in recent years. This type of ash has self-hardening properties when watered because of the conditions of its origin. The specific temperature of fluid burning and the addition of calcium carbonate into the burning zone create a mixture of phases which are, even when solidified, ready to form new crystal phases, especially alumina-silicates, relicts of coal clay minerals. For experiments, bricks from the mixture of FFA and quartz sand were industrially produced and left outside. Subsequent mineralogical analyses of samples of various ages confirmed differences in phase compositions. It is supposed that the main role in the presented changes is played by the content of the roentgen-amorphous part of alumina-silicates because they are likely to be transformed into a stable form of feldspar. In addition to that, this article presents the hypothesis of a moving agent, which could explain the transformations in the final bodies.
Microstructure and Pb2+ Adsorption Properties of Blast Furnace Slag and Fly Ash based Geopolymers
Authors: Medina T. J. , Arredondo S. P. , Corral R. , Jacobo A. , Zárraga R. A. , Rosas C. A. , Cabrera F. G. , Bernal J. M.
Published: September 2020

In this study, a blast furnace slag (BFS) and fly ash (FA) based adsorbent geopolymer to be used for removing Pb2+ from aqueous solutions were synthesized using the hydrothermal method at 60 °C for 24 h, and then cured at 25 °C for another six days. The alkali activator applied in this work was a combination of sodium hydroxide and sodium silicate solutions at a mass ratio of 2. The geopolymer slurry was adjusted to a Si/Al molar ratio of 3. A BFS-based geopolymer (GS) having a specific area of 23.56 m2/g and pore size and volume of 7.8 nm and 73 cm3/kg, respectively, surpassed the raw material surface by approximately 13-fold. An FA-based geopolymer (GA) having a specific area of 35.97 m2/g and a size and porous volume of 9 nm and 124 nm, respectively, surpassed the raw material surface by approximately 23-fold. In addition, GS and GA showed a cation exchange capacity (CEC) of 241.30 and 286.96 Meq/100 g, respectively. X-ray diffraction (XRD) determined sample crystallinity and it was proven by scanning electron microscopy (SEM), showing that both geopolymers were constituted of unreacted particles surrounded by amorphous and semi-amorphous products. Through Fourier transform infrared spectroscopy (FTIR), a band that was assigned to the asymmetric stretching vibration of Si-O-M (M = Na+ and/or Ca2+) non-bridging oxygen type was observed, which suggested that Na and Ca could serve as exchangeable ions in the ionic exchange process. Adsorption test data indicated that good adsorption was obtained when a neutral pH was used at room temperature, and the adsorption isotherm showed that GA had more adsorption sites than GS, which meant greater maximum adsorption capacity.
Evaluation of a New 177Lu-Labeled Somatostatin Analog for the Treatment of Tumors Expressing Somatostatin Receptor Subtypes 2 and 5
Authors: Mansi Rosalba , Nicolas Guillaume Pierre , Del Pozzo Luigi , Abid Karim Alexandre , Grouzmann Eric , Fani Melpomeni
Published: September 2020

Targeted radionuclide therapy of somatostatin receptor (SST)-expressing tumors is only partially addressed by the established somatostatin analogs having an affinity for the SST subtype 2 (SST2). Aiming to target a broader spectrum of tumors, we evaluated the bis-iodo-substituted somatostatin analog ST8950 ((4-amino-3-iodo)-d-Phe-c[Cys-(3-iodo)-Tyr-d-Trp-Lys-Val-Cys]-Thr-NH2), having subnanomolar affinity for SST2 and SST5, labeled with [177Lu]Lu3+ via the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). Human Embryonic Kidney (HEK) cells stably transfected with the human SST2 (HEK-SST2) and SST5 (HEK-SST5) were used for in vitro and in vivo evaluation on a dual SST2- and SST5-expressing xenografted mouse model. natLu-DOTA-ST8950 showed nanomolar affinity for both subtypes (IC50 (95% confidence interval): 0.37 (0.22–0.65) nM for SST2 and 3.4 (2.3–5.2) for SST5). The biodistribution of [177Lu]Lu-DOTA-ST8950 was influenced by the injected mass, with 100 pmol demonstrating lower background activity than 10 pmol. [177Lu]Lu-DOTA-ST8950 reached its maximal uptake on SST2- and SST5-tumors at 1 h p.i. (14.17 ± 1.78 and 1.78 ± 0.35%IA/g, respectively), remaining unchanged 4 h p.i., with a mean residence time of 8.6 and 0.79 h, respectively. Overall, [177Lu]Lu-DOTA-ST8950 targets SST2-, SST5-expressing tumors in vivo to a lower extent, and has an effective dose similar to clinically used radiolabeled somatostatin analogs. Its main drawbacks are the low uptake in SST5-tumors and the persistent kidney uptake.
Occurrence of Acrylamide in Italian Baked Products and Dietary Exposure Assessment
Authors: Esposito Francesco , Velotto Salvatore , Rea Teresa , Stasi Tommaso , Cirillo Teresa
Published: September 2020

Acrylamide (AA) is a neo-formed toxic compound that develops in foods during cooking at temperatures above 120 °C. AA shows in vivo neurotoxic and carcinogenic effects, and it is potentially carcinogenic for humans. Its occurrence is common in baked food, such as bread and similar products. This study set out to analyze bread and sweets from the Italian market to evaluate the effects of the benchmark thresholds set by EU Regulation 2017/2158 and to ascertain the exposure of the Italian population to AA, across three age groups, through the consumption of baked products, according to the margin of exposure (MOE) approach. Two hundred samples were tested, and the content of AA ranged from 31 to 454 µg/kg for bread and products thereof and from 204 to 400 µg/kg for the sweets category. The exposure data did not show any neurotoxic health concern, whereas the MOE related to the carcinogenic endpoint is well below the minimum safety value of 10,000.
Production and Characterization of Molecular Dications: Experimental and Theoretical Efforts
Authors: Falcinelli Stefano , Rosi Marzio
Published: September 2020

Molecular dications are doubly charged cations of importance in flames, plasma chemistry and physics and in the chemistry of the upper atmosphere of Planets. Furthermore, they are exotic species able to store a considerable amount of energy at a molecular level. This high energy content of several eV can be easily released as translational energy of the two fragment monocations generated by their Coulomb explosion. For such a reason, they were proposed as a new kind of alternative propellant. The present topic review paper reports on an overview of the main contributions made by the authors’ research groups in the generation and characterization of simple molecular dications during the last 40 years of coupling experimental and theoretical efforts.
Biased Opioid Antagonists as Modulators of Opioid Dependence: Opportunities to Improve Pain Therapy and Opioid Use Management
Authors: Sadee Wolfgang , Oberdick John , Wang Zaijie
Published: September 2020

Opioid analgesics are effective pain therapeutics but they cause various adverse effects and addiction. For safer pain therapy, biased opioid agonists selectively target distinct μ opioid receptor (MOR) conformations, while the potential of biased opioid antagonists has been neglected. Agonists convert a dormant receptor form (MOR-μ) to a ligand-free active form (MOR-μ*), which mediates MOR signaling. Moreover, MOR-μ converts spontaneously to MOR-μ* (basal signaling). Persistent upregulation of MOR-μ* has been invoked as a hallmark of opioid dependence. Contrasting interactions with both MOR-μ and MOR-μ* can account for distinct pharmacological characteristics of inverse agonists (naltrexone), neutral antagonists (6β-naltrexol), and mixed opioid agonist-antagonists (buprenorphine). Upon binding to MOR-μ*, naltrexone but not 6β-naltrexol suppresses MOR-μ*signaling. Naltrexone blocks opioid analgesia non-competitively at MOR-μ*with high potency, whereas 6β-naltrexol must compete with agonists at MOR-μ, accounting for ~100-fold lower in vivo potency. Buprenorphine’s bell-shaped dose–response curve may also result from opposing effects on MOR-μ and MOR-μ*. In contrast, we find that 6β-naltrexol potently prevents dependence, below doses affecting analgesia or causing withdrawal, possibly binding to MOR conformations relevant to opioid dependence. We propose that 6β-naltrexol is a biased opioid antagonist modulating opioid dependence at low doses, opening novel avenues for opioid pain therapy and use management.
Co-administration of Pregabalin and Curcumin Synergistically Decreases Pain-Like Behaviors in Acute Nociceptive Pain Murine Models
Authors: Leksiri Sarinee , Hasriadi Hasriadi , Dasuni Wasana Peththa Wadu , Vajragupta Opa , Rojsitthisak Pornchai , Towiwat Pasarapa
Published: September 2020

Analgesic drugs in a combination-form can achieve greater efficacy with lesser side effects compared to either drug alone. The combination of drugs acting at different targets or mechanisms of action has been recognized as an alternative approach for achieving optimal analgesia. In this study, the analgesic effects of pregabalin (30, 60, 100, 200 mg/kg), curcumin (15, 30, 60, 100, 120 mg/kg), and 1:1 fixed-dose ratio of the pregabalin-curcumin combination were assessed using two acute nociceptive pain models, the acetic acid-induced writhing and tail-flick tests in mice. The pregabalin-curcumin combination produced a dose-dependent decrease in mean of writhes and an increase in the percentage of antinociception by the acetic acid-induced writhing test. In the tail-flick test, the combination also showed an improvement in antinociception indicated by the tail-flick latency, % antinociception, and area under the curve (AUC). Isobolographic analysis of interactions demonstrated a significant synergistic interaction effect between pregabalin and curcumin in both acute nociceptive pain models with the experimental ED50 below the predicted additive line and the combination index < 1. These findings demonstrate that the combination of pregabalin and curcumin exhibits a synergistic interaction in mouse models of acute nociceptive pain.
Verifying the Geographical Origin and Authenticity of Greek Olive Oils by Means of Optical Spectroscopy and Multivariate Analysis
Authors: Kontzedaki Renate , Orfanakis Emmanouil , Sofra-Karanti Georgia , Stamataki Katerina , Philippidis Aggelos , Zoumi Aikaterini , Velegrakis Michalis
Published: September 2020

Olive oil samples from three different Greek regions (Crete, Peloponnese and Lesvos) were examined by optical spectroscopy in a wide spectral region from ultraviolet to near infrared using absorption, fluorescence and Raman spectroscopies. With the aid of machine learning methods, such as multivariate partial least squares discriminant analysis, a clear classification of samples originating from the different Greek geographical regions was revealed. Moreover, samples produced in different subareas of Crete and Peloponnese were also well discriminated. Furthermore, mixtures of olive oils from different geographical origins were studied employing partial least squares as a tool to establish a model between the actual and predicted compositions of the mixtures. The results demonstrated that optical spectroscopy combined with multivariate statistical analysis can be used as an emerging innovative alternative to the classical analytical methods for the identification of the origin and authenticity of olive oils.
Cuticular Chemistry of the Queensland Fruit Fly Bactrocera tryoni (Froggatt)
Authors: Park Soo J. , Pandey Gunjan , Castro-Vargas Cynthia , Oakeshott John G. , Taylor Phillip W. , Mendez Vivian
Published: September 2020

The cuticular layer of the insect exoskeleton contains diverse compounds that serve important biological functions, including the maintenance of homeostasis by protecting against water loss, protection from injury, pathogens and insecticides, and communication. Bactrocera tryoni (Froggatt) is the most destructive pest of fruit production in Australia, yet there are no published accounts of this species’ cuticular chemistry. We here provide a comprehensive description of B. tryoni cuticular chemistry. We used gas chromatography-mass spectrometry to identify and characterize compounds in hexane extracts of B. tryoni adults reared from larvae in naturally infested fruits. The compounds found included spiroacetals, aliphatic amides, saturated/unsaturated and methyl branched C12 to C20 chain esters and C29 to C33 normal and methyl-branched alkanes. The spiroacetals and esters were found to be specific to mature females, while the amides were found in both sexes. Normal and methyl-branched alkanes were qualitatively the same in all age and sex groups but some of the alkanes differed in amounts (as estimated from internal standard-normalized peak areas) between mature males and females, as well as between mature and immature flies. This study provides essential foundations for studies investigating the functions of cuticular chemistry in this economically important species.
p-Aminophenylalanine Involved in the Biosynthesis of Antitumor Dnacin B1 for Quinone Moiety Formation
Authors: Hu Xiaojing , Li Xing , Sheng Yong , Wang Hengyu , Li Xiaobin , Ou Yixin , Deng Zixin , Bai Linquan , Kang Qianjin
Published: September 2020

Actinosynnema species produce diverse natural products with important biological activities, which represent an important resource of antibiotic discovery. Advances in genome sequencing and bioinformatics tools have accelerated the exploration of the biosynthetic gene clusters (BGCs) encoding natural products. Herein, the completed BGCs of dnacin B1 were first discovered in two Actinosynnema pretiosum subsp. auranticum strains DSM 44131T (hereafter abbreviated as strain DSM 44131T) and X47 by comparative genome mining strategy. The BGC for dnacin B1 contains 41 ORFs and spans a 66.9 kb DNA region in strain DSM 44131T. Its involvement in dnacin B1 biosynthesis was identified through the deletion of a 9.7 kb region. Based on the functional gene analysis, we proposed the biosynthetic pathway for dnacin B1. Moreover, p-amino-phenylalanine (PAPA) unit was found to be the dnacin B1 precursor for the quinone moiety formation, and this was confirmed by heterologous expression of dinV, dinE and dinF in Escherichia coli. Furthermore, nine potential PAPA aminotransferases (APAT) from the genome of strain DSM 44131T were explored and expressed. Biochemical evaluation of their amino group transformation ability was carried out with p-amino-phenylpyruvic acid (PAPP) or PAPA as the substrate for the final product formation. Two of those, APAT4 and APAT9, displayed intriguing aminotransferase ability for the formation of PAPA. The proposed dnacin B1 biosynthetic machinery and PAPA biosynthetic investigations not only enriched the knowledge of tetrahydroisoquinoline (THIQ) biosynthesis, but also provided PAPA building blocks to generate their structurally unique homologues.
Gliadin Nanoparticles Pickering Emulgels for β-Carotene Delivery: Effect of Particle Concentration on the Stability and Bioaccessibility
Authors: Cheng Ce , Gao Yi , Wu Zhihua , Miao Jinyu , Gao Hongxia , Ma Li , Zou Liqiang , Peng Shengfeng , Liu Chengmei , Liu Wei
Published: September 2020

β-carotene is a promising natural active ingredient for optimum human health. However, the insolubility in water, low oral bioavailability, and instability in oxygen, heat, and light are key factors to limit its application as incorporation into functional foods. Therefore, gliadin nanoparticles (GNPs) Pickering emulgels were chosen as food-grade β-carotene delivery systems. The objectives of the present study were to investigate the influence of GNPs concentration on the rheological properties, stability, and simulated gastrointestinal fate of β-carotene of Pickering emulgels. The formulations of Pickering emulgels at low GNPs concentration had better fluidity, whereas at high GNPs concentration, they had stronger gel structures. Furthermore, the thermal stability of β-carotene loaded in Pickering emulgels after two pasteurization treatments was significantly improved with the increase of GNPs concentration. The Pickering emulgels stabilized with higher GNPs concentration could improve the protection and bioaccessibility of β-carotene after different storage conditions. This study demonstrated the tremendous potential of GNPs Pickering emulgels to carry β-carotene.
Phenolic Compounds in Extracts of Hibiscus acetosella (Cranberry Hibiscus) and Their Antioxidant and Antibacterial Properties
Authors: Lyu Jae Il , Ryu Jaihyunk , Jin Chang Hyun , Kim Dong-Gun , Kim Jung Min , Seo Kyoung-Sun , Kim Jin-Baek , Kim Sang Hoon , Ahn Joon-Woo , Kang Si-Yong , Kwon Soon-Jae
Published: September 2020

Hibiscus species are rich in phenolic compounds and have been traditionally used for improving human health through their bioactive activities. The present study investigated the phenolic compounds of leaf extracts from 18 different H. acetosella accessions and evaluated their biofunctional properties, focusing on antioxidant and antibacterial activity. The most abundant phenolic compound in H. acetosella was caffeic acid, with levels ranging from 14.95 to 42.93 mg/100 g. The antioxidant activity measured by the ABTS assay allowed the accessions to be classified into two groups: a high activity group with red leaf varieties (74.71–84.02%) and a relatively low activity group with green leaf varieties (57.47–65.94%). The antioxidant activity was significantly correlated with TAC (0.933), Dp3-Sam (0.932), Dp3-Glu (0.924), and Cy3-Sam (0.913) contents (p < 0.001). The H. acetosella phenolic extracts exhibited antibacterial activity against two bacteria, with zones of inhibition between 12.00 and 13.67 mm (Staphylococcus aureus), and 10.67 and 13.33 mm (Pseudomonas aeruginosa). All accessions exhibited a basal antibacterial activity level (12 mm) against the Gram-positive S. aureus, with PI500758 and PI500764 exhibiting increased antibacterial activity (13.67 mm), but they exhibited a more dynamic antibacterial activity level against the Gram-negative P. aeruginosa.
Comparison of Chemical Composition between Kuromoji (Lindera umbellata) Essential Oil and Hydrosol and Determination of the Deodorizing Effect
Authors: Nanashima Naoki , Kitajima Maiko , Takamagi Shizuka , Fujioka Miyuki , Tomisawa Toshiko
Published: September 2020

Kuromoji (Lindera umbellata) is a tree that grows throughout Japan. The components of kuromoji essential oil have antitumor and aromatherapy effects. However, the composition of the hydrosol, obtained as a by-product of the essential oil process, is unknown. Furthermore, it is unknown whether kuromoji essential oil has a deodorizing effect. Therefore, the purpose of the current study was to compare the chemical composition of kuromoji essential oil and hydrosol, as well as evaluate the deodorizing effect of the former. The chemical composition of samples was evaluated using gas chromatography–mass spectrometry (GC-MS). Additionally, the deodorizing effect of Kuromoji essential oil was investigated with the detector tube method using ammonia, hydrogen sulfide, methyl mercaptan, and isovaleric acid. Linalool was the most abundant component in both the essential oil and hydrosol; however, its proportion was higher in the hydrosol (57.5%) than in the essential oil (42.8%). The hydrosol contained fewer chemical components, but higher proportions of trans-geraniol and ethanol. Moreover, the essential oil eliminated 50% of ammonia and 97.6% or more of isovaleric acid. Interestingly, linalool was soluble in the hydrosol and did not irritate the skin. This suggests that the hydrosol may be an effective foot care product.
Measurement of Glutathione as a Tool for Oxidative Stress Studies by High Performance Liquid Chromatography
Authors: Nuhu Faisal , Gordon Andrew , Sturmey Roger , Seymour Anne-Marie , Bhandari Sunil
Published: September 2020

Background: Maintenance of the ratio of glutathione in the reduced (GSH) and oxidised (GSSG) state in cells is important in redox control, signal transduction and gene regulation, factors that are altered in many diseases. The accurate and reliable determination of GSH and GSSG simultaneously is a useful tool for oxidative stress determination. Measurement is limited primarily to the underestimation of GSH and overestimation GSSG as a result of auto-oxidation of GSH. The aim of this study was to overcome this limitation and develop, optimise and validate a reverse-phase high performance liquid chromatographic (HPLC) assay of GSH and GSSG for the determination of oxidant status in cardiac and chronic kidney diseases. Methods: Fluorescence detection of the derivative, glutathione-O-pthaldialdehyde (OPA) adduct was used. The assay was validated by measuring the stability of glutathione and glutathione-OPA adduct under conditions that could affect the reproducibility including reaction time and temperature. Linearity, concentration range, limit of detection (LOD), limit of quantification (LOQ), recovery and extraction efficiency and selectivity of the method were assessed. Results: There was excellent linearity for GSH (r2 = 0.998) and GSSG (r2 = 0.996) over concentration ranges of 0.1 µM–4 mM and 0.2 µM–0.4 mM respectively. The extraction of GSH from tissues was consistent and precise. The limit of detection for GSH and GSSG were 0.34 µM and 0.26 µM respectively whilst their limits of quantification were 1.14 µM and 0.88 µM respectively. Conclusion: These data validate a method for the simultaneous measurement of GSH and GSSG in samples extracted from biological tissues and offer a simple determination of redox status in clinical samples.
Identification of Key Functional Motifs of Native Amelogenin Protein for Dental Enamel Remineralisation
Authors: Dissanayake Shama S. M. , Ekambaram Manikandan , Li Kai Chun , Harris Paul W. R. , Brimble Margaret A.
Published: September 2020

Dental caries or tooth decay is a preventable and multifactorial disease that affects billions of people globally and is a particular concern in younger populations. This decay arises from acid demineralisation of tooth enamel resulting in mineral loss from the subsurface. The remineralisation of early enamel carious lesions could prevent the cavitation of teeth. The enamel protein amelogenin constitutes 90% of the total enamel matrix protein in teeth and plays a key role in the biomineralisation of tooth enamel. The physiological importance of amelogenin has led to the investigation of the possible development of amelogenin-derived biomimetics against dental caries. We herein review the literature on amelogenin, its primary and secondary structure, comparison to related species, and its’ in vivo processing to bioactive peptide fragments. The key structural motifs of amelogenin that enable enamel remineralisation are discussed. The presence of several motifs in the amelogenin structure (such as polyproline, N- and C-terminal domains and C-terminal orientation) were shown to play a critical role in the formation of particle shape during remineralization. Understanding the function/structure relationships of amelogenin can aid in the rational design of synthetic polypeptides for biomineralisation, halting enamel loss and leading to improved therapies for tooth decay.
Short-Term Memory Dynamics of TiN/Ti/TiO2/SiOx/Si Resistive Random Access Memory
Authors: Cho Hyojong , Kim Sungjun
Published: September 2020

In this study, we investigated the synaptic functions of TiN/Ti/TiO2/SiOx/Si resistive random access memory for a neuromorphic computing system that can act as a substitute for the von-Neumann computing architecture. To process the data efficiently, it is necessary to coordinate the information that needs to be processed with short-term memory. In neural networks, short-term memory can play the role of retaining the response on temporary spikes for information filtering. In this study, the proposed complementary metal-oxide-semiconductor (CMOS)-compatible synaptic device mimics the potentiation and depression with varying pulse conditions similar to biological synapses in the nervous system. Short-term memory dynamics are demonstrated through pulse modulation at a set pulse voltage of −3.5 V and pulse width of 10 ms and paired-pulsed facilitation. Moreover, spike-timing-dependent plasticity with the change in synaptic weight is performed by the time difference between the pre- and postsynaptic neurons. The SiOx layer as a tunnel barrier on a Si substrate provides highly nonlinear current-voltage (I–V) characteristics in a low-resistance state, which is suitable for high-density synapse arrays. The results herein presented confirm the viability of implementing a CMOS-compatible neuromorphic chip.
Effect of Nanostructured Scaffold on Human Adipose-Derived Stem Cells: Outcome of In Vitro Experiments
Authors: Borgese Marina , Barone Ludovica , Rossi Federica , Raspanti Mario , Papait Roberto , Valdatta Luigi , Bernardini Giovanni , Gornati Rosalba
Published: September 2020

This work is addressed to provide, by in vitro experiments, results on the repercussion that a nanostructured scaffold could have on viability, differentiation and secretion of bioactive factors of human adipose-derived stem cells (hASCs) when used in association to promote angiogenesis, a crucial condition to favour tissue regeneration. To achieve this aim, we evaluated cell viability and morphology by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and microscopy analysis, respectively. We also investigated the expression of some of those genes involved in angiogenesis and differentiation processes utilizing quantitative polymerase chain reaction (qPCR), whereas the amounts of Vascular Endothelial Growth Factor A, Interleukin 6 and Fatty Acid-Binding Protein 4 secreted in the culture medium, were quantified by enzyme-linked immunosorbent assay (ELISA). Results suggested that, in the presence of the scaffold, cell proliferation and the exocytosis of factors involved in the angiogenesis process are reduced; by contrast, the expression of those genes involved in hASC differentiation appeared enhanced. To guarantee cell survival, the construct dimensions are, generally, smaller than clinically required. Furthermore, being the paracrine event the primary mechanism exerting the beneficial effects on injured tissues, the use of conditioned culture medium instead of cells may be convenient.
Preparation of a g-C3N4/UiO-66-NH2/CdS Photocatalyst with Enhanced Visible Light Photocatalytic Activity for Tetracycline Degradation
Authors: Zhang Hao , Li Jialiang , He Xianglei , Liu Bo
Published: September 2020

A combination of calcination and hydrothermal processing was used to prepare a g-C3N4/UiO-66-NH2/CdS photocatalyst, and the degradation of tetracycline (TC) over this material was assessed. The photocatalytic performance of this nanocomposite was approximately 4.4 and 2.3 times those of CdS and g-C3N4, respectively, and was found to be affected by the CdS loading amount, the pH of the reaction solution and the initial TC concentration. This catalyst also exhibited stable performance over four consecutive reaction cycles. The highly enhanced photoactivity of the g-C3N4/UiO-66-NH2/CdS is attributed to the introduction of CdS, which widens the range over which the material absorbs visible light and inhibits the recombination of electron–hole pairs. The results of this study suggest further applications for this material in the treatment of contaminated wastewater powered by solar energy.
Toxicity of Carbon, Silicon, and Metal-Based Nanoparticles to Sea Urchin Strongylocentrotus intermedius
Authors: Pikula Konstantin , Zakharenko Alexander , Chaika Vladimir , Em Iurii , Nikitina Anna , Avtomonov Evgenii , Tregubenko Anna , Agoshkov Alexander , Mishakov Ilya , Kuznetsov Vladimir , Gusev Alexander , Park Soojin , Golokhvast Kirill
Published: September 2020

With the increasing annual production of nanoparticles (NPs), the risks of their harmful influence on the environment and human health are rising. However, our knowledge about the mechanisms of interaction between NPs and living organisms is limited. Prior studies have shown that echinoderms, and especially sea urchins, represent one of the most suitable models for risk assessment in environmental nanotoxicology. To the best of the authors’ knowledge, the sea urchin Strongylocentrotus intermedius has not been used for testing the toxicity of NPs. The present study was designed to determine the effect of 10 types of common NPs on spermatozoa activity, egg fertilization, and early stage of embryo development of the sea urchin S. intermedius. In this research, we used two types of multiwalled carbon nanotubes (CNT-1 and CNT-2), two types of carbon nanofibers (CNF-1 and CNF-2), two types of silicon nanotubes (SNT-1 and SNT-2), nanocrystals of cadmium and zinc sulfides (CdS and ZnS), gold NPs (Au), and titanium dioxide NPs (TiO2). The results of the embryotoxicity test showed the following trend in the toxicity level of used NPs: Au > SNT-2 > SNT-1 > CdS > ZnS > CNF-2 > CNF-1 > TiO2 > CNT-1 > CNT-2. This research confirmed that the sea urchin S. intermedius can be considered as a sensitive and stable test model in marine nanotoxicology.
Top-Down Reactive Approach for the Synthesis of Disordered ZrN Nanocrystalline Bulk Material from Solid Waste
Authors: El-Eskandarany Mohamed Sherif , Al-Salem Sultan Majed , Ali Naser
Published: September 2020

Transition metal nitrides possess superior mechanical, physical, and chemical properties that make them desirable materials for a broad range of applications. A prime example is zirconium nitride (ZrN), which can be obtained through different fabrication methods that require the applications of high temperature and pressure. The present work reports an interesting procedure for synthesizing disordered face centered cubic (fcc)-ZrN nanoparticles through the reactive ball milling (RBM) technique. One attractive point of this study is utilizing inexpensive solid-waste (SW) zirconium (Zr) rods as feedstock materials to fabricate ZrN nanopowders. The as-received SW Zr rods were chemically cleaned and activated, arc-melted, and then disintegrated into powders to obtain the starting Zr metal powders. The powders were charged and sealed under nitrogen gas using a pressurized milling steel vial. After 86 ks of milling, a single fcc-ZrN phase was obtained. This phase transformed into a metastable fcc-phase upon RBM for 259 ks. The disordered ZrN powders revealed good morphological characteristics of spherical shapes and ultrafine nanosize (3.5 nm). The synthetic ZrN nanopowders were consolidated through a spark plasma sintering (SPS) technique into nearly full-density (99.3% of the theoretical density for ZrN) pellets. SPS has proven to be an integral step in leading to desirable and controlled grain growth. Moreover, the sintered materials were not transformed into any other phase(s) upon consolidation at 1673 K. The results indicated that increasing the RBM time led to a significant decrease in the grain size of the ZrN powders. As a result, the microhardness of the consolidated samples was consequently improved with increasing RBM time.
Dependencies of Surface Condensation on the Wettability and Nanostructure Size Differences
Authors: Liao Ming-Jun , Duan Li-Qiang
Published: September 2020

When changing surface wettability and nanostructure size, condensation behavior displays distinct features. In this work, we investigated evaporation on a flat hydrophilic surface and condensation on both hydrophilic and hydrophobic nanostructured surfaces at the nanoscale using molecular dynamics simulations. The simulation results on hydrophilic surfaces indicated that larger groove widths and heights produced more liquid argon atoms, a quicker temperature response, and slower potential energy decline. These three characteristics closely relate to condensation areas or rates, which are determined by groove width and height. For condensation heat transfer, when the groove width was small, the change of groove height had little effect, while change of groove height caused a significant variation in the heat flux with a large groove width. When the cold wall was hydrophobic, the groove height became a significant impact factor, which caused no vapor atoms to condense in the groove with a larger height. The potential energy decreased with the increase of the groove height, which demonstrates a completely opposing trend when compared with hydrophilic surfaces.
Exciton Dynamics in Droplet Epitaxial Quantum Dots Grown on (311)A-Oriented Substrates
Authors: Abbarchi Marco , Mano Takaaki , Kuroda Takashi , Sakoda Kazuaki
Published: September 2020

Droplet epitaxy allows the efficient fabrication of a plethora of 3D, III–V-based nanostructures on different crystalline orientations. Quantum dots grown on a (311)A-oriented surface are obtained with record surface density, with or without a wetting layer. These are appealing features for quantum dot lasing, thanks to the large density of quantum emitters and a truly 3D lateral confinement. However, the intimate photophysics of this class of nanostructures has not yet been investigated. Here, we address the main optical and electronic properties of s-shell excitons in individual quantum dots grown on (311)A substrates with photoluminescence spectroscopy experiments. We show the presence of neutral exciton and biexciton as well as positive and negative charged excitons. We investigate the origins of spectral broadening, identifying them in spectral diffusion at low temperature and phonon interaction at higher temperature, the presence of fine interactions between electron and hole spin, and a relevant heavy-hole/light-hole mixing. We interpret the level filling with a simple Poissonian model reproducing the power excitation dependence of the s-shell excitons. These results are relevant for the further improvement of this class of quantum emitters and their exploitation as single-photon sources for low-density samples as well as for efficient lasers for high-density samples.
A Novel Experimental Study on the Rheological Properties and Thermal Conductivity of Halloysite Nanofluids
Authors: Le Ba Thong , Alkurdi Ahmed Qani , Lukács István Endre , Molnár János , Wongwises Somchai , Gróf Gyula , Szilágyi Imre Miklós
Published: September 2020

Nanofluids obtained from halloysite and de-ionized water (DI) were prepared by using surfactants and changing pH for heat-transfer applications. The halloysite nanotubes (HNTs) nanofluids were studied for several volume fractions (0.5, 1.0, and 1.5 vol%) and temperatures (20, 30, 40, 50, and 60 °C). The properties of HNTs were studied with a scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), Fourier-transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), Raman spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA). The stability of the nanofluids was proven by zeta potentials measurements and visual observation. With surfactants, the HNT nanofluids had the highest thermal conductivity increment of 18.30% for 1.5 vol% concentration in comparison with the base fluid. The thermal conductivity enhancement of nanofluids containing surfactant was slightly higher than nanofluids with pH = 12. The prepared nanofluids were Newtonian. The viscosity enhancements of the nanofluid were 11% and 12.8% at 30 °C for 0.5% volume concentration with surfactants and at pH = 12, respectively. Empirical correlations of viscosity and thermal conductivity for these nanofluids were proposed for practical applications.
The Cost of Diets According to Their Caloric Share of Ultraprocessed and Minimally Processed Foods in Belgium
Authors: Vandevijvere Stefanie , Pedroni Camille , De Ridder Karin , Castetbon Katia
Published: September 2020

Background: This study estimated the monetary cost of diets with higher and lower caloric shares of ultraprocessed food products (UPF) and unprocessed/minimally processed foods (MPF) in Belgium for various sociodemographic groups. Methods: Data from the latest nationally representative Food Consumption Survey (FCS) 2014–2015 (n = 3146; 3–64 years) were used. Dietary data were collected through two nonconsecutive 24-hour recalls (food diaries for children). Average prices for >2000 food items (year 2014) were derived from GfK ConsumerScan panel data and linked with foods consumed in the FCS. Foods eaten were categorized by their extent of processing using the NOVA classification. The average caloric share (percentage of daily energy intake) of UPF and MPF were calculated. The mean diet cost was compared across the UPF and MPF contribution tertiles, using linear regression. Results: The average price per 100 kcal for UPF was significantly cheaper (EUR 0.55; 95%CI = 0.45–0.64) than for MPF (EUR 1.29; 95% CI = 1.27–1.31). UPF contributed between 21.9% (female adults) and 29.9% (young boys), while MPF contributed between 29.5% (male adolescents) and 42.3% (female adults) to the daily dietary cost. The contribution of MPF to the daily dietary cost was significantly higher for individuals with a higher household education level compared to those with a lower household education level (p < 0.01). Adjusted for covariates, the average dietary cost per 2000 kcal was significantly lower for individuals in the highest compared to the lowest tertile for the proportion of daily energy consumed from UPF (EUR −0.37 ± 0.13; p = 0.006), and significantly higher for individuals in the highest compared to the lowest tertile for proportion of daily energy consumed from MPF (EUR 1.18 ± 0.12, p < 0.001). Conclusion: Diets with a larger caloric share of UPF were significantly cheaper than those with a lower contribution of these products, while the opposite was found for MPF. Policies that improve relative affordability and accessibility of MPF are recommended.