bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanodevices Tend to Be Round
Authors: Pananakakis Georges , Ghibaudo Gérard , Cristoloveanu Sorin
Published: March 2021

Under several circumstances, a nanowire transistor with a square cross-section behaves as a circular. Taking the Gate-All-Around junctionless transistor as a primary example, we investigate the transition of the conductive region from square to circle-like. In this case, the metamorphosis is accentuated by smaller size, lower doping, and higher gate voltage. After defining the geometrical criterion for square-to-circle shift, simulation results are used to document the main consequences. This transition occurs naturally in nanowires thinner than 50 nm. The results are rather universal, and supportive evidence is gathered from inversion-mode Gate-All-Around (GAA) MOSFETs as well as from thermal diffusion process.
Design and Integration of the Single-Lens Curved Multi-Focusing Compound Eye Camera
Authors: Tao Kekai , Lian Gaoge , Liu Yongshun , Xing Huaming , Xing Yi , Su Xiangdong , Feng Xin , Wu Yihui
Published: March 2021

Compared with a traditional optical system, the single-lens curved compound eye imaging system has superior optical performance, such as a large field of view (FOV), small size, and high portability. However, defocus and low resolution hinder the further development of single-lens curved compound eye imaging systems. In this study, the design of a nonuniform curved compound eye with multiple focal lengths was used to solve the defocus problem. A two-step gas-assisted process, which was combined with photolithography, soft photolithography, and ultraviolet curing, was proposed for fabricating the ommatidia with a large numerical aperture precisely. Ommatidia with high resolution were fabricated and arranged in five rings. Based on the imaging experimental results, it was demonstrated that the high-resolution and small-volume single-lens curved compound eye imaging system has significant advantages in large-field imaging and rapid recognition.
A Non-Volatile Tunable Terahertz Metamaterial Absorber Using Graphene Floating Gate
Authors: Bai Jinjun , Shen Wei , Shi Jia , Xu Wei , Zhang Shusheng , Chang Shengjiang
Published: March 2021

Based on the graphene floating gate, a tunable terahertz metamaterial absorber is proposed. Compared with the traditional graphene–dielectric–metal absorber, our absorber has the property of being non-volatile and capacity for anti-interference. Using the finite element method, the paper investigates the absorption spectra, the electric field energy distribution, the tunability and the physical mechanism. In addition, we also analyse the influence of geometry, polarization and incident angles on the absorption. Simulation results show that the bandwidth of the absorption above 90% can reach up to 2.597 THz at the center frequency of 3.970 THz, and the maximum absorption can be tuned continuously from 14.405% to 99.864% by controlling the Fermi level from 0 eV to 0.8 eV. Meanwhile, the proposed absorber has the advantages of polarization insensitivity and a wide angle, and has potential applications in imaging, sensing and photoelectric detection.
A Novel Microfluidic Device for Blood Plasma Filtration
Authors: Al-aqbi Zaidon T. , Albukhaty Salim , Zarzoor Ameerah M. , Sulaiman Ghassan M. , Khalil Khalil A. A. , Belali Tareg , Soliman Mohamed T. A.
Published: March 2021

The use of whole blood and some biological specimens, such as urine, saliva, and seminal fluid are limited in clinical laboratory analysis due to the interference of proteins with other small molecules in the matrix and blood cells with optical detection methods. Previously, we developed a microfluidic device featuring an electrokinetic size and mobility trap (SMT) for on-chip extract, concentrate, and separate small molecules from a biological sample like whole blood. The device was used to on-chip filtrate the whole blood from the blood cells and plasma proteins and then on-chip extract and separate the aminoglycoside antibiotic drugs within 3 min. Herein, a novel microfluidic device featuring a nano-junction similar to those reported in the previous work formed by dielectric breakdown was developed for on-chip filtration and out-chip collection of blood plasma with a high extraction yield of 62% within less than 5 min. The filtered plasma was analyzed using our previous device to show the ability of this new device to remove blood cells and plasma proteins. The filtration device shows a high yield of plasma allowing it to detect a low concentration of analytes from the whole blood.
Optimal n-Type Al-Doped ZnO Overlayers for Charge Transport Enhancement in p-Type Cu2O Photocathodes
Authors: Lee Hak Hyeon , Kim Dong Su , Choi Ji Hoon , Kim Young Been , Jung Sung Hyeon , Sarker Swagotom , Deshpande Nishad G. , Suh Hee Won , Cho Hyung Koun
Published: March 2021

An effective strategy for improving the charge transport efficiency of p-type Cu2O photocathodes is the use of counter n-type semiconductors with a proper band alignment, preferably using Al-doped ZnO (AZO). Atomic layer deposition (ALD)-prepared AZO films show an increase in the built-in potential at the Cu2O/AZO interface as well as an excellent conformal coating with a thin thickness on irregular Cu2O. Considering the thin thickness of the AZO overlayers, it is expected that the composition of the Al and the layer stacking sequence in the ALD process will significantly influence the charge transport behavior and the photoelectrochemical (PEC) performance. We designed various stacking orders of AZO overlayers where the stacking layers consisted of Al2O3 (or Al) and ZnO using the atomically controlled ALD process. Al doping in ZnO results in a wide bandgap and does not degrade the absorption efficiency of Cu2O. The best PEC performance was obtained for the sample with an AZO overlayer containing conductive Al layers in the bottom and top regions. The Cu2O/AZO/TiO2/Pt photoelectrode with this overlayer exhibits an open circuit potential of 0.63 V and maintains a high cathodic photocurrent value of approximately −3.2 mA cm−2 at 0 VRHE for over 100 min.
Adhesion Properties, Biofilm Forming Potential, and Susceptibility to Disinfectants of Contaminant Wine Yeasts
Authors: Perpetuini Giorgia , Rossetti Alessio Pio , Battistelli Noemi , Arfelli Giuseppe , Tofalo Rosanna
Published: March 2021

In this study, yeasts isolated from filter membranes used for the quality control of bottled wines were identified and tested for their resistance to some cleaning agents and potassium metabisulphite, adhesion to polystyrene and stainless-steel surfaces, and formation of a thin round biofilm, referred to as a MAT. A total of 40 strains were identified by rRNA internal transcribed spacer (ITS) restriction analysis and sequence analysis of D1/D2 domain of 26S rRNA gene. Strains belong to Pichia manshurica (12), Pichia kudriavzevii (9), Pichia membranifaciens (1), Candida sojae (6), Candida parapsilosis (3), Candida sonorensis (1), Lodderomyces elongisporus (2), Sporopachydermia lactativora (3), and Clavispora lusitaniae (3) species. Regarding the adhesion properties, differences were observed among species. Yeasts preferred planktonic state when tested on polystyrene plates. On stainless-steel supports, adhered cells reached values of about 6 log CFU/mL. MAT structures were formed only by yeasts belonging to the Pichia genus. Yeast species showed different resistance to sanitizers, with peracetic acid being the most effective and active at low concentrations, with minimum inhibitory concentration (MIC) values ranging from 0.08% (v/v) to 1% (v/v). C. parapsilosis was the most sensible species. Data could be exploited to develop sustainable strategies to reduce wine contamination and establish tailored sanitizing procedures.
Critical Role of 3′-Downstream Region of pmrB in Polymyxin Resistance in Escherichia coli BL21(DE3)
Authors: Xu Fuzhou , Hinenoya Atsushi , Zeng Ximin , Li Xing-Ping , Guan Ziqiang , Lin Jun
Published: March 2021

Polymyxins, such as colistin and polymyxin B, are the drugs used as a last resort to treat multidrug-resistant Gram-negative bacterial infections in humans. Increasing colistin resistance has posed a serious threat to human health, warranting in-depth mechanistic research. In this study, using a functional cloning approach, we examined the molecular basis of colistin resistance in Escherichia coli BL21(DE3). Five transformants with inserts ranging from 3.8 to 10.7 kb displayed significantly increased colistin resistance, three of which containing pmrB locus and two containing pmrD locus. Stepwise subcloning indicated that both the pmrB with a single G361A mutation and at least a 103 bp downstream region of pmrB are essential for conferring colistin resistance. Analysis of the mRNA level and stability showed that the length of the downstream region drastically affected the pmrB mRNA level but not its half-life. Lipid A analysis, by mass spectrometry, revealed that the constructs containing pmrB with a longer downstream region (103 or 126 bp) have charge-altering l-4-aminoarabinose (Ara4N) and phosphoethanolamine (pEtN) modifications in lipid A, which were not observed in both vector control and the construct containing pmrB with an 86 bp downstream region. Together, the findings from this study indicate that the 3′-downstream region of pmrB is critical for the PmrB-mediated lipid A modifications and colistin resistance in E. coli BL21(DE3), suggesting a novel regulatory mechanism of PmrB-mediated colistin resistance in E. coli.
Towards Enhanced MRI Performance of Tumor-Specific Dimeric Phenylboronic Contrast Agents
Authors: Martinelli Jonathan , Tei Lorenzo , Geninatti Crich Simonetta , Alberti Diego , Djanashvili Kristina
Published: March 2021

It is known that phenylboronic acid (PBA) can target tumor tissues by binding to sialic acid, a substrate overexpressed by cancer cells. This capability has previously been explored in the design of targeting diagnostic probes such as Gd- and 68Ga-DOTA-EN-PBA, two contrast agents for magnetic resonance imaging (MRI) and positron emission tomography (PET), respectively, whose potential has already been demonstrated through in vivo experiments. In addition to its high resolution, the intrinsic low sensitivity of MRI stimulates the search for more effective contrast agents, which, in the case of small-molecular probes, basically narrows down to either increased tumbling time of the entire molecule or elevated local concentration of the paramagnetic ions, both strategies resulting in enhanced relaxivity, and consequently, a higher MRI contrast. The latter strategy can be achieved by the design of multimeric GdIII complexes. Based on the monomeric PBA-containing probes described recently, herein, we report the synthesis and characterization of the dimeric analogues (GdIII-DOTA-EN)2-PBA and (GdIII-DOTA-EN)2F2PBA. The presence of two Gd ions in one molecule clearly contributes to the improved biological performance, as demonstrated by the relaxometric study and cell-binding investigations.
Determination of Cytotoxic Activity of Sanguinaria canadensis Extracts against Human Melanoma Cells and Comparison of Their Cytotoxicity with Cytotoxicity of Some Anticancer Drugs
Authors: Tuzimski Tomasz , Petruczynik Anna , Plech Tomasz , Kaproń Barbara , Makuch-Kocka Anna , Szultka-Młyńska Małgorzata , Misiurek Justyna , Buszewski Bogusław
Published: March 2021

Melanoma is an enormous global health burden, and should be effectively addressed with better therapeutic strategies. Therefore, new therapeutic agents are needed for the management of this disease. The aim of this study was the investigation of cytotoxic activity of some isoquinoline alkaloid standards and extracts obtained from Sanguinaria canadensis—collected before, during, and after flowering—against three different human melanoma cells (A375, G361, SK-MEL-3). The cytotoxicity of these extracts was not previously tested on these melanoma cell lines. Determination of alkaloid contents was performed by HPLC-DAD using Polar RP column and mobile phase containing acetonitrile, water, and 1-butyl-3-methylimidazolium tetrafluoroborate. The cytotoxicity of alkaloid standards was investigated by determination of cell viability and calculation of IC50 values. Significant differences were observed in the alkaloids content and cytotoxic activity of the extracts, depending on the season of collection of the plant material. In the Sanguinaria canadensis extracts high contents of sanguinarine (from 4.8543 to 9.5899 mg/g of dry plant material) and chelerythrine (from 42.7224 to 6.8722 mg/g of dry plant material) were found. For both of these alkaloids, very high cytotoxic activity against the tested cell lines were observed. The IC50 values were in the range of 0.11–0.54 µg/mL for sanguinarine and 0.14 to 0.46 µg/mL for chelerythrine. IC50 values obtained for Sanguinaria canadensis extracts against all tested cell lines were also very low (from 0.88 to 10.96 µg/mL). Cytotoxic activity of alkaloid standards and Sanguinaria canadensis extracts were compared with the cytotoxicity of anticancer drugs—etoposide, cisplatin, and hydroxyurea. In all cases except the one obtained for cisplatin against A375, which was similar to that obtained for Sanguinaria canadensis after flowering against the same cell line, IC50 values obtained for anticancer drugs were higher than the IC50 values obtained for sanguinarine, chelerythrine, and Sanguinaria canadensis extracts. Our results showed that Sanguinaria canadensis extracts and isoquinoline alkaloids, especially sanguinarine and chelerythrine, could be recommended for further in vivo experiments in order to confirm the possibility of their application in the treatment of human melanomas.
Parallel G-quadruplex Structures Increase Cellular Uptake and Cytotoxicity of 5-Fluoro-2′-deoxyuridine Oligomers in 5-Fluorouracil Resistant Cells
Authors: Clua Anna , Fàbrega Carme , García-Chica Jesús , Grijalvo Santiago , Eritja Ramon
Published: March 2021

Fluoropyrimidines, such as 5-fluorouracil (5-FU) and related prodrugs have been considered first-line chemotherapy agents for the treatment of colorectal cancer. However, poor specificity and tumor cell resistance remain major limiting bottlenecks. G-quadruplexes, have been suggested as preferred nanostructures for enhancing cellular uptake mediated by G-quadruplex binding proteins which are abundant at the membranes of some tumor cells. In the current study, we propose a new strategy to deliver 5-fluoro-2′-deoxyuridine (5-FdU) monophosphate, the main active drug from 5-FU derivatives that may circumvent the cellular mechanisms of FU-resistant cancer cells. Two G-quadruplexes delivery systems containing four and six G-tetrads ((TG4T) and (TG6T)) linked to a FdU oligonucleotide were synthesized. Biophysical studies show that the G-quadruplex parallel structures are not affected by the incorporation of the 5 units of FdU at the 5’-end. Internalization studies confirmed the ability of such G-quadruplex nanostructures to facilitate the transport of the FdU pentamer and increase its cytotoxic effect relative to conventional FU drug in FU-resistant colorectal cancer cells. These results suggest that FdU oligomers linked to G-quadruplex parallel sequences may be a promising strategy to deliver fluoropyrimidines to cancer cells.
Fast Screening of Biomembrane-Permeable Compounds in Herbal Medicines Using Bubble-Generating Magnetic Liposomes Coupled with LC–MS
Authors: Gu Xiaoting , Wang Dongwu , Wang Xin , Liu Youping , Di Xin
Published: March 2021

A novel strategy based on the use of bionic membrane camouflaged magnetic particles and LC–MS was developed to quickly screen the biomembrane-permeable compounds in herbal medicines. The bionic membrane was constructed by bubble-generating magnetic liposomes loaded with NH4HCO3 (BMLs). The lipid bilayer structure of the liposomes enabled BMLs to capture biomembrane-permeable compounds from a herbal extract. The BMLs carrying the compounds were then separated from the extract by a magnetic field. Upon heat treatment, NH4HCO3 rapidly decomposed to form CO2 bubbles within the liposomal bilayer, and the captured compounds were released from BMLs and analyzed by LC–MS. Jinlingzi San (JLZS), which contains various natural ingredients, was chosen to assess the feasibility of the proposed method. As a result, nine potential permeable compounds captured by BMLs were identified for the first time. Moreover, an in vivo animal study found that most of the compounds screened out by the proposed method were absorbed into the blood. The study provides a powerful tool for rapid and simultaneous prediction of multiple biomembrane-permeable components.
Isomorph Invariance of Higher-Order Structural Measures in Four Lennard–Jones Systems
Authors: Rahman Mahajabin , Carter Benjamin M. G. D. , Saw Shibu , Douglass Ian M. , Costigliola Lorenzo , Ingebrigtsen Trond S. , Schrøder Thomas B. , Pedersen Ulf R. , Dyre Jeppe C.
Published: March 2021

In the condensed liquid phase, both single- and multicomponent Lennard–Jones (LJ) systems obey the “hidden-scale-invariance” symmetry to a good approximation. Defining an isomorph as a line of constant excess entropy in the thermodynamic phase diagram, the consequent approximate isomorph invariance of structure and dynamics in appropriate units is well documented. However, although all measures of the structure are predicted to be isomorph invariant, with few exceptions only the radial distribution function (RDF) has been investigated. This paper studies the variation along isomorphs of the nearest-neighbor geometry quantified by the occurrence of Voronoi structures, Frank–Kasper bonds, icosahedral local order, and bond-orientational order. Data are presented for the standard LJ system and for three binary LJ mixtures (Kob–Andersen, Wahnström, NiY2). We find that, while the nearest-neighbor geometry generally varies significantly throughout the phase diagram, good invariance is observed along the isomorphs. We conclude that higher-order structural correlations are no less isomorph invariant than is the RDF.
A Proteomics Study on the Mechanism of Nutmeg-Induced Hepatotoxicity
Authors: Xia Wei , Cao Zhipeng , Zhang Xiaoyu , Gao Lina
Published: March 2021

Nutmeg is a traditional spice and medicinal plant with a variety of pharmacological activities. However, nutmeg abuse due to its hallucinogenic characteristics and poisoning cases are frequently reported. Our previous metabolomics study proved the hepatotoxicity of nutmeg and demonstrated that high-dose nutmeg can affect the synthesis and secretion of bile acids and cause oxidative stress. In order to further investigate the hepatotoxicity of nutmeg, normal saline, 1 g/kg, 4 g/kg nutmeg were administrated to male Kunming mice by intragastrical gavage for 7 days. Histopathological investigation of liver tissue, proteomics and biochemical analysis were employed to explore the mechanism of liver damage caused by nutmeg. The results showed that a high-dose (4 g/kg) of nutmeg can cause significant increased level of CYP450s and depletion of antioxidants, resulting in obvious oxidative stress damage and lipid metabolism disorders; but this change was not observed in low-dose group (1 g/kg). In addition, the increased level of malondialdehyde and decreased level of glutathione peroxidase were found after nutmeg exposure. Therefore, the present study reasonably speculates that nutmeg exposure may lead to liver injury through oxidative stress and the degree of this damage is related to the exposure dose.
Using Micropropagation to Develop Medicinal Plants into Crops
Authors: Moraes Rita M. , Cerdeira Antonio Luiz , Lourenço Miriam V.
Published: March 2021

Medicinal plants are still the major source of therapies for several illnesses and only part of the herbal products originates from cultivated biomass. Wild harvests represent the major supply for therapies, and such practices threaten species diversity as well as the quality and safety of the final products. This work intends to show the relevance of developing medicinal plants into crops and the use of micropropagation as technique to mass produce high-demand biomass, thus solving the supply issues of therapeutic natural substances. Herein, the review includes examples of in vitro procedures and their role in the crop development of pharmaceuticals, phytomedicinals, and functional foods. Additionally, it describes the production of high-yielding genotypes, uniform clones from highly heterozygous plants, and the identification of elite phenotypes using bioassays as a selection tool. Finally, we explore the significance of micropropagation techniques for the following: a) pharmaceutical crops for production of small therapeutic molecules (STM), b) phytomedicinal crops for production of standardized therapeutic natural products, and c) the micropropagation of plants for the production of large therapeutic molecules (LTM) including fructooligosaccharides classified as prebiotic and functional food crops.
Sugar Containing Compounds and Biological Activities of Lagochilus setulosus
Authors: Akramov Davlat Kh. , Mamadalieva Nilufar Z. , Porzel Andrea , Hussain Hidayat , Dube Mthandazo , Akhmedov Akbar , Altyar Ahmed E. , Ashour Mohamed L. , Wessjohann Ludger A.
Published: March 2021

Phytochemical investigation of the methanolic extract obtained from the aerial parts of Lagochilus setulosus (Lamiaceae) afforded the new compound 1-methoxy-3-O-β-glucopyranosyl-α-l-oliose (1) together with five known glycosides, namely sitosterol-3-O-β-glucoside (2), stigmasterol-3-O-β-glucoside (3), pinitol (4), 6β-hydroxyl-7-epi-loganin (5), and chlorotuberoside (6). The structures of these compounds were elucidated by extensive spectroscopic analyses, especially HR-MS, 1D and 2D NMR spectroscopy. The in vitro cytotoxic activity of the methanolic extract and the isolated compounds was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and crystal violet (CV) staining assays. In addition, the antifungal activities of the components were evaluated against Botrytis cinerea, Septoria tritici, and Phytophthora infestans. The anthelmintic potential was determined against Caenorhabditis elegans nematodes. Neither the extract nor the isolated compounds showed promising activity in all the bioassays.
Influence of Electronic Environment on the Radiative Efficiency of 9-Phenyl-9H-carbazole-Based ortho-Carboranyl Luminophores
Authors: Lee Seok Ho , Lee Ji Hye , Mun Min Sik , Yi Sanghee , Yoo Eunji , Hwang Hyonseok , Lee Kang Mun
Published: March 2021

The photophysical properties of closo-ortho-carboranyl-based donor–acceptor dyads are known to be affected by the electronic environment of the carborane cage but the influence of the electronic environment of the donor moiety remains unclear. Herein, four 9-phenyl-9H-carbazole-based closo-ortho-carboranyl compounds (1F, 2P, 3M, and 4T), in which an o-carborane cage was appended at the C3-position of a 9-phenyl-9H-carbazole moiety bearing various functional groups, were synthesized and fully characterized using multinuclear nuclear magnetic resonance spectroscopy and elemental analysis. Furthermore, the solid-state molecular structures of 1F and 4T were determined by X-ray diffraction crystallography. For all the compounds, the lowest-energy absorption band exhibited a tail extending to 350 nm, attributable to the spin-allowed π–π* transition of the 9-phenyl-9H-carbazole moiety and weak intramolecular charge transfer (ICT) between the o-carborane and the carbazole group. These compounds showed intense yellowish emission (λem = ~540 nm) in rigid states (in tetrahydrofuran (THF) at 77 K and in films), whereas considerably weak emission was observed in THF at 298 K. Theoretical calculations on the first excited states (S1) of the compounds suggested that the strong emission bands can be assigned to the ICT transition involving the o-carborane. Furthermore, photoluminescence experiments in THF‒water mixtures demonstrated that aggregation-induced emission was responsible for the emission in rigid states. Intriguingly, the quantum yields and radiative decay constants in the film state were gradually enhanced with the increasing electron-donating ability of the substituent on the 9-phenyl group (‒F for 1F < ‒H for 2P < ‒CH3 for 3M < ‒C(CH3)3 for 4T). These features indicate that the ICT-based radiative decay process in rigid states is affected by the electronic environment of the 9-phenyl-9H-carbazole group. Consequently, the efficient ICT-based radiative decay of o-carboranyl compounds can be achieved by appending the o-carborane cage with electron-rich aromatic systems.
Assessing Green Methods for Pectin Extraction from Waste Orange Peels
Authors: Benassi Laura , Alessandri Ivano , Vassalini Irene
Published: March 2021

In this work, we assess three different methods for the extraction of pectin from waste orange peels, using water as extracting solvent. “Hot-water”, Rapid Solid Liquid Dynamic (RSLD) and microwave-assisted extractions have been compared and evaluated in terms of amount and quality of extracted pectin, as well as embodied energy. This analysis provides useful guidelines for pectin production from food waste according to green procedures, enabling the identification of acidic “hot-water” as the most sustainable extraction route.
Identification of Potential SARS-CoV-2 Main Protease and Spike Protein Inhibitors from the Genus Aloe: An In Silico Study for Drug Development
Authors: Abouelela Mohamed E. , Assaf Hamdy K. , Abdelhamid Reda A. , Elkhyat Ehab S. , Sayed Ahmed M. , Oszako Tomasz , Belbahri Lassaad , El Zowalaty Ahmed E. , Abdelkader Mohamed Salaheldin A.
Published: March 2021

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease is a global rapidly spreading virus showing very high rates of complications and mortality. Till now, there is no effective specific treatment for the disease. Aloe is a rich source of isolated phytoconstituents that have an enormous range of biological activities. Since there are no available experimental techniques to examine these compounds for antiviral activity against SARS-CoV-2, we employed an in silico approach involving molecular docking, dynamics simulation, and binding free energy calculation using SARS-CoV-2 essential proteins as main protease and spike protein to identify lead compounds from Aloe that may help in novel drug discovery. Results retrieved from docking and molecular dynamics simulation suggested a number of promising inhibitors from Aloe. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) calculations indicated that compounds 132, 134, and 159 were the best scoring compounds against main protease, while compounds 115, 120, and 131 were the best scoring ones against spike glycoprotein. Compounds 120 and 131 were able to achieve significant stability and binding free energies during molecular dynamics simulation. In addition, the highest scoring compounds were investigated for their pharmacokinetic properties and drug-likeness. The Aloe compounds are promising active phytoconstituents for drug development for SARS-CoV-2.
Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review
Authors: Rievaj Miroslav , Culková Eva , Šandorová Damiána , Lukáčová-Chomisteková Zuzana , Bellová Renata , Durdiak Jaroslav , Tomčík Peter
Published: March 2021

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.
Chitosan Films Obtained from Brachystola magna (Girard) and Its Evaluation on Quality Attributes in Sausages during Storage
Authors: Tirado-Gallegos Juan Manuel , Zamudio-Flores Paul Baruk , Espino-Díaz Miguel , Salgado-Delgado René , Vela-Gutiérrez Gilber , Hernández-Centeno Francisco , López-De la Peña Haydee Yajaira , Hernández-González María , Rendón-Villalobos J Rodolfo , Ortega-Ortega Adalberto
Published: March 2021

High molecular weight chitosan (≈322 kDa) was obtained from chitin isolated from Brachystola magna (Girard) to produced biodegradable films. Their physicochemical, mechanical and water vapor permeability (WVP) properties were compared against commercial chitosan films with different molecular weights. Brachystola magna chitosan films (CFBM) exhibited similar physicochemical and mechanical characteristics to those of commercial chitosans. The CFBM films presented lower WVP values (10.01 × 10−11 g/m s Pa) than commercial chitosans films (from 16.06 × 10−11 to 64.30 × 10−11 g/m s Pa). Frankfurt-type sausages were covered with chitosan films and stored in refrigerated conditions (4 °C). Their quality attributes (color, weight loss, pH, moisture, texture and lipid oxidation) were evaluated at 0, 5, 10, 15 and 20 days. Sausages covered with CFMB films presented the lowest weight loss (from 1.24% to 2.38%). A higher increase in hardness (from 22.32 N to 30.63 N) was observed in sausages covered with CFMB films. Compared with other films and the control (uncovered sausages), CFMB films delay pH reduction. Moreover, this film presents the lower lipid oxidation level (0.10 malonaldehyde mg/sample kg). Thus, chitosan of B. magna could be a good alternative as packaging material for meat products with high-fat content.
A Randomized, Double-Blind, Placebo-Controlled Trial to Determine the Effectiveness of a Polyphenolic Extract (Hibiscus sabdariffa and Lippia citriodora) for Reducing Blood Pressure in Prehypertensive and Type 1 Hypertensive Subjects
Authors: Marhuenda Javier , Pérez-Piñero Silvia , Arcusa Raúl , Victoria-Montesinos Desirée , Cánovas Fernando , Sánchez-Macarro Maravillas , García-Muñoz Ana María , Querol-Calderón María , López-Román Francisco Javier
Published: March 2021

Hypertension is an important factor of cardiovascular diseases and contributes to their negative consequences including mortality. The World Health Organization estimated that 54% of strokes and 47% of cases of ischemic heart illness are related to high blood pressure. Recently, Hibiscus sabdariffa (HS) and Lippia citriodora (LC) have attracted scientific interest, and they are recognized for their high content of polyphenols as these may prevent several disease factors, such as hypertension. The aim of the present study is to determine if supplementation with an HS-LC blend (MetabolAid®) may be effective for the treatment of type 1 hypertensive sedentary populations. A total of 80 type 1 hypertensive subjects of both sexes were included in the study and were treated with placebo or the HS-LC extract, and both groups were treated over 84 days. The blood pressure (diastolic, systolic, and pulse pressure) was measured throughout the day, for each of the days of the study duration and determined using Ambulatory Blood Pressure Monitoring (ABPM). Physical activity was determined throughout the study to ensure similar conditions related to exercise. The results showed the capacity for reducing the blood pressure parameters in the case of the HS-LC extract. The daily consumption of the HS-LC extract but not the placebo over 84 days was able to reduce the daytime parameters related to blood pressure. The most remarkable results were observed in the measurements performed during the daytime, especially in the systolic blood pressure showing statistically significant variation.
Solution and Solid State Studies of Urea Derivatives of DITIPIRAM Acting as Powerful Anion Receptors
Authors: Niedbała Patryk , Dąbrowa Kajetan , Cholewiak-Janusz Agnieszka , Jurczak Janusz
Published: March 2021

Herein, we present the synthesis and anion binding studies of a family of homologous molecular receptors 4–7 based on a DITIPIRAM (8-propyldithieno-[3,2-b:2′,3′-e]-pyridine-3,5-di-amine) platform decorated with various urea para-phenyl substituents (NO2, F, CF3, and Me). Solution, X-ray, and DFT studies reveal that the presented host–guest system offers a convergent array of four urea NH hydrogen bond donors to anions allowing the formation of remarkably stable complexes with carboxylates (acetate, benzoate) and chloride anions in solution, even in competitive solvent mixtures such as DMSO-d6/H2O 99.5/0.5 (v/v) and DMSO-d3/MeOH-d3 9:1 (v/v). The most effective derivatives among the series turned out to be receptors 5 and 6 containing electron-withdrawing F- and -CF3para-substituents, respectively.
Needle Trap Device-GC-MS for Characterization of Lung Diseases Based on Breath VOC Profiles
Authors: Monedeiro Fernanda , Monedeiro-Milanowski Maciej , Ratiu Ileana-Andreea , Brożek Beata , Ligor Tomasz , Buszewski Bogusław
Published: March 2021

Volatile organic compounds (VOCs) have been assessed in breath samples as possible indicators of diseases. The present study aimed to quantify 29 VOCs (previously reported as potential biomarkers of lung diseases) in breath samples collected from controls and individuals with lung cancer, chronic obstructive pulmonary disease and asthma. Besides that, global VOC profiles were investigated. A needle trap device (NTD) was used as pre-concentration technique, associated to gas chromatography-mass spectrometry (GC-MS) analysis. Univariate and multivariate approaches were applied to assess VOC distributions according to the studied diseases. Limits of quantitation ranged from 0.003 to 6.21 ppbv and calculated relative standard deviations did not exceed 10%. At least 15 of the quantified targets presented themselves as discriminating features. A random forest (RF) method was performed in order to classify enrolled conditions according to VOCs’ latent patterns, considering VOCs responses in global profiles. The developed model was based on 12 discriminating features and provided overall balanced accuracy of 85.7%. Ultimately, multinomial logistic regression (MLR) analysis was conducted using the concentration of the nine most discriminative targets (2-propanol, 3-methylpentane, (E)-ocimene, limonene, m-cymene, benzonitrile, undecane, terpineol, phenol) as input and provided an average overall accuracy of 95.5% for multiclass prediction.
A Novel Dual Drug Approach That Combines Ivermectin and Dihydromyricetin (DHM) to Reduce Alcohol Drinking and Preference in Mice
Authors: Silva Joshua , Carry Eileen , Xue Chen , Zhang Jifeng , Liang Jing , Roberge Jacques Y. , Davies Daryl L.
Published: March 2021

Alcohol use disorder (AUD) affects over 18 million people in the US. Unfortunately, pharmacotherapies available for AUD have limited clinical success and are under prescribed. Previously, we established that avermectin compounds (ivermectin [IVM] and moxidectin) reduce alcohol (ethanol/EtOH) consumption in mice, but these effects are limited by P-glycoprotein (Pgp/ABCB1) efflux. The current study tested the hypothesis that dihydromyricetin (DHM), a natural product suggested to inhibit Pgp, will enhance IVM potency as measured by changes in EtOH consumption. Using a within-subjects study design and two-bottle choice study, we tested the combination of DHM (10 mg/kg; i.p.) and IVM (0.5–2.5 mg/kg; i.p.) on EtOH intake and preference in male and female C57BL/6J mice. We also conducted molecular modeling studies of DHM with the nucleotide-binding domain of human Pgp that identified key binding residues associated with Pgp inhibition. We found that DHM increased the potency of IVM in reducing EtOH consumption, resulting in significant effects at the 1.0 mg/kg dose. This combination supports our hypothesis that inhibiting Pgp improves the potency of IVM in reducing EtOH consumption. Collectively, we demonstrate the feasibility of this novel combinatorial approach in reducing EtOH consumption and illustrate the utility of DHM in a novel combinatorial approach.
Molecular Dynamics Simulations and Theoretical Model for Engineering Tensile Properties of Single-and Multi-Walled Carbon Nanotubes
Authors: Shirasu Keiichi , Kitayama Shunsuke , Liu Fan , Yamamoto Go , Hashida Toshiyuki
Published: March 2021

To apply carbon nanotubes (CNTs) as reinforcing agents in next-generation composites, it is essential to improve their nominal strength. However, since it is difficult to completely remove the defects, the synthesis guideline for improving nominal strength is still unclear, i.e., the effective strength and the number of nanotube layers required to improve the nominal strength has been undermined. In this study, molecular dynamics simulations were used to elucidate the effects of vacancies on the mechanical properties of CNTs. Additionally, the relationships between the number of layers and effective and nominal strengths of CNTs were discussed theoretically. The presence of extensive vacancies provides a possible explanation for the low nominal strengths obtained in previous experimental measurements of CNTs. This study indicates that the nominal strength can be increased from the experimentally obtained values of 10 GPa to approximately 20 GPa by using six to nine nanotube layers, even if the increase in effective strength of each layer is small. This has advantages over double-walled CNTs, because the effective strength of such CNTs must be approximately 60 GPa to achieve a nominal strength of 20 GPa.
Preparation of Carbon-Covered Phosphorus-Modified Alumina with Large Pore Size and Adsorption of Rhodamine B
Authors: Chen Shuaiqi , Wang Xuhui , Tong Weiyi , Sun Jianchuan , Xu Xiangyu , Song Jiaqing , Gong Jianyi , Chen Wei
Published: March 2021

In this study, phosphorus-modified alumina with large pore size was synthesized through a coprecipitation method. The carbon-covered, phosphorus-modified alumina with large pores was prepared by impregnating with glucose and carbonizing to further improve the adsorption of organic dyes. The morphology and structure of these composites were characterized by various analysis methods, and Rhodamine B (RhB) adsorption was also examined in aqueous media. The results showed that the specific surface area and pore size of the phosphorus-modified alumina sample AP7 (prepared with a P/Al molar ratio of 0.07) reached 496.2 m2·g−1 and 21.9 nm, while the specific surface area and pore size of the carbon-covered phosphorus-modified alumina sample CAP7–27 (prepared by using AP7 as a carrier for glucose at a glucose/Al molar ratio of 0.27) reached 435.3 m2·g−1 and 21.2 nm. The adsorption experiment of RhB revealed that CAP7–27 had not only an equilibrium adsorption capacity of 198 mg·g−1, but also an adsorption rate of 162.5 mg·g−1 in 5 min. These superior adsorption effects can be attributed to the similar pore structures of CAP7–27 with those of alumina and the specific properties with those of carbon materials. Finally, the kinetic properties of these composites were also studied, which were found to be consistent with a pseudo-second-order kinetic model and Langmuir model for isothermal adsorption analysis. This study indicates that the prepared nanomaterials are expected to be promising candidates for efficient adsorption of toxic dyes.
Combined Toxicity of Gas Plasma Treatment and Nanoparticles Exposure in Melanoma Cells In Vitro
Authors: Bekeschus Sander
Published: March 2021

Despite continuous advances in therapy, cancer remains a deadly disease. Over the past years, gas plasma technology emerged as a novel tool to target tumors, especially skin. Another promising anticancer approach are nanoparticles. Since combination therapies are becoming increasingly relevant in oncology, both gas plasma treatment and nanoparticle exposure were combined. A series of nanoparticles were investigated in parallel, namely, silica, silver, iron oxide, cerium oxide, titanium oxide, and iron-doped titanium oxide. For gas plasma treatment, the atmospheric pressure argon plasma jet kINPen was utilized. Using three melanoma cell lines, the two murine non-metastatic B16F0 and metastatic B16F10 cells and the human metastatic B-Raf mutant cell line SK-MEL-28, the combined cytotoxicity of both approaches was identified. The combined cytotoxicity of gas plasma treatment and nanoparticle exposure was consistent across all three cell lines for silica, silver, iron oxide, and cerium oxide. In contrast, for titanium oxide and iron-doped titanium oxide, significantly combined cytotoxicity was only observed in B16F10 cells.
Synthesis of Gold Nanoparticles by Using Green Machinery: Characterization and In Vitro Toxicity
Authors: Al Saqr Ahmed , Khafagy El-Sayed , Alalaiwe Ahmed , Aldawsari Mohammed F. , Alshahrani Saad M. , Anwer Md. Khalid , Khan Salman , Lila Amr S. Abu , Arab Hany H. , Hegazy Wael A. H.
Published: March 2021

Green synthesis of gold nanoparticles (GNPs) with plant extracts has gained considerable interest in the field of biomedicine. Recently, the bioreduction nature of herbal extracts has helped to synthesize spherical GNPs of different potential from gold salt. In this study, a fast ecofriendly method was adopted for the synthesis of GNPs using fresh peel (aqueous) extracts of Benincasa hispida, which acted as reducing and stabilizing agents. The biosynthesized GNPs were characterized by UV–VIS and Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering. In addition, the in vitro antibacterial and anticancer activities of synthesized GNPs were investigated. The formation of gold nanoparticles was confirmed by the existence of a sharp absorption peak at 520 nm, corresponding to the surface plasmon resonance (SPR) band of the GNPs. TEM analysis revealed that the prepared GNPs were spherical in shape and had an average particle size of 22.18 ± 2 nm. Most importantly, the synthesized GNPs exhibited considerable antibacterial activity against different Gram-positive and Gram-negative bacteria. Furthermore, the biosynthesized GNPs exerted remarkable in vitro cytotoxicity against human cervical cancer cell line, while sparing normal human primary osteoblast cells. Such cytotoxic effect was attributed to the increased production of reactive oxygen species (ROS) that contributed to the damage of HeLa cells. Collectively, peel extracts of B. hispida can be efficiently used for the synthesis of GNPs, which can be adopted as a natural source of antimicrobial and anticancer agent.
Clinical Usefulness of Anthropometric Indices to Predict the Presence of Prediabetes. Data from the ILERVAS Cohort
Authors: Sánchez Marta , Sánchez Enric , Bermúdez-López Marcelino , Torres Gerard , Farràs-Sallés Cristina , Pamplona Reinald , Castro-Boqué Eva , Valdivielso José , Purroy Francisco , Martínez-Alonso Montserrat , Godoy Pere , Mauricio Dídac , Fernández Elvira , Hernández Marta , Rius Ferran , Lecube Albert ,   On Behalf of the ILERVAS Project Collaborators
Published: March 2021

Prediabetes is closely related to excess body weight and adipose distribution. For this reason, we aimed to assess and compare the diagnostic usefulness of ten anthropometric adiposity indices to predict prediabetes. Cross-sectional study with 8188 overweight subjects free of type 2 diabetes from the ILERVAS project (NCT03228459). Prediabetes was diagnosed by levels of glycated hemoglobin (HbA1c). Total body adiposity indices [BMI, Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) and Deurenberg’s formula] and abdominal adiposity (waist and neck circumferences, conicity index, waist to height ratio, Bonora’s equation, A body shape index, and body roundness index) were calculated. The area under the receiver-operating characteristic (ROC) curve, the best cutoff and the prevalence of prediabetes around this value were calculated for every anthropometric index. All anthropometric indices other than the A body adiposity were higher in men and women with prediabetes compared with controls (p < 0.001 for all). In addition, a slightly positive correlation was found between indices and HbA1c in both sexes (r ≤ 0.182 and p ≤ 0.026 for all). None of the measures achieved acceptable levels of discrimination in ROC analysis (area under the ROC ≤ 0.63 for all). Assessing BMI, the prevalence of prediabetes among men increased from 20.4% to 36.2% around the cutoff of 28.2 kg/m2, with similar data among women (from 29.3 to 44.8% with a cutoff of 28.6 kg/m2). No lonely obesity index appears to be the perfect biomarker to use in clinical practice to detect individuals with prediabetes.
Ketogenic Diet as a Preventive and Supportive Care for COVID-19 Patients
Authors: Gangitano Elena , Tozzi Rossella , Gandini Orietta , Watanabe Mikiko , Basciani Sabrina , Mariani Stefania , Lenzi Andrea , Gnessi Lucio , Lubrano Carla
Published: March 2021

Severe obesity is associated with an increased risk of admission to intensive care units and need for invasive mechanical ventilation in patients with COVID-19. The association of obesity and COVID-19 prognosis may be related to many different factors, such as chronic systemic inflammation, the predisposition to severe respiratory conditions and viral infections. The ketogenic diet is an approach that can be extremely effective in reducing body weight and visceral fat in the short term, preserving the lean mass and reducing systemic inflammation. Therefore, it is a precious preventive measure for severely obese people and may be considered as an adjuvant therapy for patients with respiratory compromise.
Home Artificial Nutrition in Polish Children: An Analysis of 9-Year National Healthcare Provider Data
Authors: Wyszomirska Karolina , Wyszomirski Adam , Brzeziński Michał , Borkowska Anna , Zagierski Maciej , Kierkuś Jarosław , Książyk Janusz , Romanowska Hanna , Świder Magdalena , Toporowska-Kowalska Ewa , Szlagatys-Sidorkiewicz Agnieszka
Published: March 2021

Background: Home artificial nutrition (HAN) is a developing method of treatment that reduces the need for hospitalizations. The epidemiology of pediatric HAN in Poland has not yet been covered in detail. This study is a longitudinal nationwide analysis of incidence, prevalence, and patients’ profile for HAN in Polish children. Methods: Assessment of National Health Fund (NFZ) data covering all pediatric patients treated with HAN in Poland between 2010 and 2018. Results: HAN was received by 4426 children, 65 patients were on home enteral nutrition (HEN) or home parenteral nutrition (HPN) at different times (HEN n = 3865, HPN n = 626). HAN was most frequently started before the child was 3 years old and long-term HAN programs (5–9 years) were reported. The most common principal diagnosis in HEN was food-related symptoms and signs. In HPN, it was postoperative gastrointestinal disorders. A regionally differentiated prevalence of HAN patients and centers was demonstrated. Mortality among patients was 24.9% for HEN, and 9.6% for HPN, and the main in-hospital cause of death was cardiac arrest. Conclusions: HAN’s use is increasing and evolving in Poland. Uneven distribution of patients and centers results in difficult access to the nutritional procedure which, together with the increasing number of patients, highlights the need for data analysis and development of nutrition centers.