bluuebunny/crossref_metadata_2025 huggingface dataset:
Articulated Structures of D-A Type Dipolar Dye with AIEgen: Synthesis, Photophysical Properties, and Applications
Authors: Kim Na Hee , Kim Byeong Wook , Kim Youngseo , Hur Junho K. , Jung Junyang , Oh Yohan , Park Sungnam , Kim B. Moon , Kim Dokyoung
Published: April 2020

Articulated structures of naphthalene-based donor (D)-acceptor (A) type dipolar dye and aggregation-induced emission luminogen (AIEgen) based on tetraphenylethylene (TPE) were synthesized, and their photophysical properties were analyzed for the first time. There are many fluorophore backbones, which have dipolar structure and AIEgen. However, there has been neither property analysis nor research that closely articulates DA and AIE through non-conjugation linker. We have therefore prepared two representative fluorophores; DA-AIE series (DA-AIE-M and DA-AIE-D), and characterized their UV/vis absorption and emission properties with quantum chemical calculations. In addition, we utilized the unique photophysical properties of DA-AIE-D for monitoring a trace of dimethyl sulfoxide (DMSO) in aqueous media, including real water samples.
Fractionation of Lignin for Selective Shape Memory Effects at Elevated Temperatures
Authors: Nguyen Ngoc , Bowland Christopher , Bonnesen Peter , Littrell Kenneth , Keum Jong , Naskar Amit
Published: April 2020

We report a facile approach to control the shape memory effects and thermomechanical characteristics of a lignin-based multiphase polymer. Solvent fractionation of a syringylpropane-rich technical organosolv lignin resulted in selective lignin structures having excellent thermal stability coupled with high stiffness and melt-flow resistance. The fractionated lignins were reacted with rubber in melt-phase to form partially networked elastomer enabling selective programmability of the material shape either at 70 °C, a temperature that is high enough for rubbery matrix materials, or at an extremely high temperature, 150 °C. Utilizing appropriate functionalities in fractionated lignins, tunable shape fixity with high strain and stress recovery, particularly high-stress tolerance were maintained. Detailed studies of lignin structures and chemistries were correlated to molecular rigidity, morphology, and stress relaxation, as well as shape memory effects of the materials. The fractionation of lignin enabled enrichment of specific lignin properties for efficient shape memory effects that broaden the materials’ application window. Electron microscopy, melt-rheology, dynamic mechanical analysis and ultra-small angle neutron scattering were conducted to establish morphology of acrylonitrile butadiene rubber (NBR)-lignin elastomers from solvent fractionated lignins.
Comparative Study of the Structure, Properties, and Corrosion Behavior of Sr-Containing Biocoatings on Mg0.8Ca
Authors: Sedelnikova Mariya B. , Sharkeev Yurii P. , Tolkacheva Tatiana V. , Khimich Margarita A. , Bakina Olga V. , Fomenko Alla N. , Kazakbaeva Aigerim A. , Fadeeva Inna V. , Egorkin Vladimir S. , Gnedenkov Sergey V. , Schmidt Juergen , Loza Kateryna , Prymak Oleg , Epple Matthias
Published: April 2020

A comparative analysis of the structure, properties and the corrosion behavior of the micro-arc coatings based on Sr-substituted hydroxyapatite (Sr-HA) and Sr-substituted tricalcium phosphate (Sr-TCP) deposited on Mg0.8Ca alloy substrates was performed. The current density during the formation of the Sr-HA coatings was higher than that for the Sr-TCP coatings. As a result, the Sr-HA coatings were thicker and had a greater surface roughness Ra than the Sr-TCP coatings. In addition, pore sizes of the Sr-HA were almost two times larger. The ratio (Ca + Sr + Mg)/P were equal 1.64 and 1.47 for Sr-HA and Sr-TCP coatings, respectively. Thus, it can be assumed that the composition of Sr-HA and Sr-TCP coatings was predominantly presented by (Sr,Mg)-substituted hydroxyapatite and (Sr,Mg)-substituted tricalcium phosphate. However, the average content of Sr was approximately the same for both types of the coatings and was equal to 1.8 at.%. The Sr-HA coatings were less soluble and had higher corrosion resistance than the Sr-TCP coatings. Cytotoxic tests in vitro demonstrated a higher cell viability after cultivation with extracts of the Sr-HA coatings.
Influence of Grains Shape Irregularity in Porous Ceramics—Numerical Study
Authors: Miedzińska Danuta
Published: April 2020

The presented study deals with the analysis of the stochastic geometry of grains on ceramic foam strength behavior. A microstructural finite element (FE) model of a grainy structure of such a material was developed and stochastic changes to the grain geometry (initially of a regular cubic shape) were introduced. The numerical compression test of a series of finite element models was carried out with the use of LS Dyna computer code. To consider the ceramic specific behavior, the Johnson Holmquist constitutive model was implemented with parameters for alumina. The influence of the stochastic irregularities on the ceramic foam strength was observed—the geometry changes caused an increase in the maximum stress, which could be the basis for the indication that the production of the energy absorbing material should be based on mostly irregular grains.
From Complex Modulus E* to Creep Compliance D(t): Experimental and Modeling Study
Authors: Daoudi Abdeldjalil , Perraton Daniel , Dony Anne , Carter Alan
Published: April 2020

Creep compliance (D(t)) is a very important input for the thermal cracking resistance in the Mechanistic-Empirical Pavement Design Guide (MEPDG). The aim of the work presented here is to predict the results of creep compliance D(t) from the result of complex modulus E*(ω). The work plan is divided in two main parts: an experimental part consisting of creep tests, and a modeling part. Three configurations were compared together, namely direct tensile, direct compression and indirect tensile tests. The modelling part consists of using a 2S2P1D model coupled to Kopelman approximation to switch from the frequency domain to the time domain. Additionally, 2S2P1D was used to calibrate the generalized Kelvin–Voigt model and get the creep compliance directly from E* results. The experimental results show that D(t) from direct tensile and direct compression are the same in the viscoelastic domain and are greater than D(t) from the indirect tensile test. The indirect tensile test (IDT) seems to be very difficult to achieve compared to the other two variants. The converted results using the 2S2P1D model coupled to Kopelman approximation and the results from the GKV model describe the experimental points very well.
Two New Strategies for Pricing Freight Options by Means of a Valuation PDE and by Functional Bounds
Authors: Gómez-Valle Lourdes , López-Marcos Miguel Angel , Martínez-Rodríguez Julia
Published: April 2020

Freight derivative prices have been modeled assuming that the spot freight follows a particular stochastic process in order to manage them, like freight futures, forwards and options. However, an explicit formula for pricing freight options is not known, not even for simple spot freight processes. This is partly due to the fact that there is no valuation equation for pricing freight options. In this paper, we deal with this problem from two independent points of view. On the one hand, we provide a novel theoretical framework for pricing these Asian-style options. In this way, we build a partial differential equation whose solution is the freight option price obtained from stochastic delay differential equations. On the other hand, we prove lower and upper bounds for those freight options which enables us to estimate the option price. In this work, we consider that the spot freight rate follows a general stochastic diffusion process without restrictions in the drift and volatility functions. Finally, using recent data from the Baltic Exchange, we compare the described bounds with the freight option prices.
Spectrally Sparse Tensor Reconstruction in Optical Coherence Tomography Using Nuclear Norm Penalisation
Authors: Assoweh Mohamed Ibrahim , Chrétien Stéphane , Tamadazte Brahim
Published: April 2020

Reconstruction of 3D objects in various tomographic measurements is an important problem which can be naturally addressed within the mathematical framework of 3D tensors. In Optical Coherence Tomography, the reconstruction problem can be recast as a tensor completion problem. Following the seminal work of Candès et al., the approach followed in the present work is based on the assumption that the rank of the object to be reconstructed is naturally small, and we leverage this property by using a nuclear norm-type penalisation. In this paper, a detailed study of nuclear norm penalised reconstruction using the tubal Singular Value Decomposition of Kilmer et al. is proposed. In particular, we introduce a new, efficiently computable definition of the nuclear norm in the Kilmer et al. framework. We then present a theoretical analysis, which extends previous results by Koltchinskii Lounici and Tsybakov. Finally, this nuclear norm penalised reconstruction method is applied to real data reconstruction experiments in Optical Coherence Tomography (OCT). In particular, our numerical experiments illustrate the importance of penalisation for OCT reconstruction.
Growth-Inhibitory Effect of Chitosan-Coated Liposomes Encapsulating Curcumin on MCF-7 Breast Cancer Cells
Authors: Hasan Mahmoud , Elkhoury Kamil , Belhaj Nabila , Kahn Cyril , Tamayol Ali , Barberi-Heyob Muriel , Arab-Tehrany Elmira , Linder Michel
Published: April 2020

Current anticancer drugs exhibit limited efficacy and initiate severe side effects. As such, identifying bioactive anticancer agents that can surpass these limitations is a necessity. One such agent, curcumin, is a polyphenolic compound derived from turmeric, and has been widely investigated for its potential anti-inflammatory and anticancer effects over the last 40 years. However, the poor bioavailability of curcumin, caused by its low absorption, limits its clinical use. In order to solve this issue, in this study, curcumin was encapsulated in chitosan-coated nanoliposomes derived from three natural lecithin sources. Liposomal formulations were all in the nanometric scale (around 120 nm) and negatively charged (around −40 mV). Among the three lecithins, salmon lecithin presented the highest growth-inhibitory effect on MCF-7 cells (two times lower growth than the control group for 12 µM of curcumin and four times lower for 20 µM of curcumin). The soya and rapeseed lecithins showed a similar growth-inhibitory effect on the tumor cells. Moreover, coating nanoliposomes with chitosan enabled a higher loading efficiency of curcumin (88% for coated liposomes compared to 65% for the non-coated liposomes) and a stronger growth-inhibitory effect on MCF-7 breast cancer cells.
Astaxanthin Attenuates Fish Oil-Related Hepatotoxicity and Oxidative Insult in Juvenile Pacific White Shrimp (Litopenaeus vannamei)
Authors: Yu Yingying , Liu Yang , Yin Peng , Zhou Weiwen , Tian Lixia , Liu Yongjian , Xu Donghui , Niu Jin
Published: April 2020

The present study investigated the effect of dietary astaxanthin (AX) on the growth performance, antioxidant parameters, and repair of hepatopancreas damage in Pacific white shrimp (Litopenaeus vannamei). To evaluate the hepatopancreas protective function of AX in shrimps, we compared the effect of five isonitrogenous and isoenergetic diets under oxidized fish oil conditions with varying AX levels during the 50-day experimental period. The formulated diets were as follows: (i) OFO (oxidized fish oil); (ii) OFO/AX150 (oxidized fish oil + AX150 mg/kg); (iii) OFO/AX250 (oxidized fish oil + AX250 mg/kg); (iv) OFO/AX450 (oxidized fish oil + AX450 mg/kg); and, (v) control group (fresh fish oil). Results showed that the oxidized fish oil with 275.2 meq/kg peroxide value (POV) resulted in a substantial decrease in the final body weight of L. vannamei (P > 0.05) and induced some visible histopathological alterations in the hepatopancreas. Growth performance was significantly higher in shrimps fed with the OFO/AX450 diet than those fed with the OFO diet (p < 0.05). However, no significant difference was observed when the OFO/AX450 diet was compared to the control diet containing fresh fish oil (p > 0.05). Moreover, shrimps under the OFO/AX450 diet displayed a significant improvement in hepatopancreatic health and showed a reduction of malondialdehyde (MDA) compared to those under the OFO diet (p < 0.05). Dietary AX improved the antioxidant capacity of L. vannamei by increasing the catalase (CAT) activity in the hemolymph. Acute salinity change test showed a higher shrimp survival rate under OFO/AX450 diet than the OFO diet (p < 0.05), suggesting that AX can contribute to enhanced stress tolerance. In conclusion, our data suggest that AX confers dose-dependent protection against OFO-induced oxidative insults and hepatopancreatic damage in shrimp.
In Vivo Evaluation of the Wound Healing Activity of Extracts and Bioactive Constituents of the Marine Isopod Ceratothoa oestroides
Authors: Sofrona Evgenia , Tziveleka Leto-Aikaterini , Harizani Maria , Koroli Panagiota , Sfiniadakis Ioannis , Roussis Vassilios , Rallis Michail , Ioannou Efstathia
Published: April 2020

Wound healing is a fundamental response to tissue injury and a number of natural products has been found to accelerate the healing process. Herein, we report the preparation of a series of different polarity (organic and aqueous) extracts of the marine isopod Ceratothoa oestroides and the in vivo evaluation of their wound healing activity after topical administration of ointments incorporating the various extracts on wounds inflicted on SKH-hr1 hairless mice. The most active extract was fractionated for enrichment in the bioactive constituents and the fractions were further evaluated for their wound healing activity, while their chemical profiles were analyzed. Wound healing was evaluated by clinical assessment, photo-documentation, histopathological analysis and measurement of biophysical skin parameters, such as transepidermal water loss (TEWL), hydration, elasticity, and skin thickness. The highest levels of activity were exerted by treatment of the wounds with a fraction rich in eicosapentaenoic acid (EPA), as well as myristic and palmitoleic acids. Topical application of the bioactive fraction on the wounds of mice resulted in complete wound closure with a skin of almost normal architecture without any inflammatory elements.
Fucoidan Induces Apoptosis of HT-29 Cells via the Activation of DR4 and Mitochondrial Pathway
Authors: Bai Xu , Wang Yu , Hu Bo , Cao Qi , Xing Maochen , Song Shuliang , Ji Aiguo
Published: April 2020

Fucoidan has a variety of pharmacological activities, but the understanding of the mechanism of fucoidan-induced apoptosis of colorectal cancer cells remains limited. The results of the present study demonstrated that the JNK signaling pathway is involved in the activation of apoptosis in colorectal cancer-derived HT-29 cells, and fucoidan induces apoptosis by activation of the DR4 at the transcriptional and protein levels. The survival rate of HT-29 cells was approximately 40% in the presence of 800 μg/mL of fucoidan, but was increased to 70% after DR4 was silenced by siRNA. Additionally, fucoidan has been shown to reduce the mitochondrial membrane potential and destroy the integrity of mitochondrial membrane. In the presence of an inhibitor of cytochrome C inhibitor and DR4 siRNA or the presence of cytochrome C inhibitor only, the cell survival rate was significantly higher than when cells were treated with DR4 siRNA only. These data indicate that both the DR4 and the mitochondrial pathways contribute to fucoidan-induced apoptosis of HT-29 cells, and the extrinsic pathway is upstream of the intrinsic pathway. In conclusion, the current work identified the mechanism of fucoidan-induced apoptosis and provided a novel theoretical basis for the future development of clinical applications of fucoidan as a drug.
Syntheses and Glycosidase Inhibitory Activities, and in Silico Docking Studies of Pericosine E Analogs Methoxy-Substituted at C6
Authors: Usami Yoshihide , Higuchi Megumi , Mizuki Koji , Yamamoto Mizuki , Kanki Mao , Nakasone Chika , Sugimoto Yuya , Shibano Makio , Uesawa Yoshihiro , Nagai Junko , Yoneyama Hiroki , Harusawa Shinya
Published: April 2020

Inspired by the significant α-glucosidase inhibitory activities of (+)- and (−)-pericosine E, we herein designed and synthesized 16 analogs of these marine natural products bearing a methoxy group instead of a chlorine atom at C6. Four of these compounds exhibited moderate α-glucosidase inhibitory activities, which were weaker than those of the corresponding chlorine-containing species. The four compounds could be prepared by coupling reactions utilizing the (−)-pericosine B moiety. An additional in silico docking simulation suggested that the reason of reduced activity of the C6-methoxylated analogs might be an absence of hydrogen bonding between a methoxy group with the surrounding amino acid residues in the active site in α-glucosidase.
Detailed Thermo-Kinematic Analysis of Face Grinding Operations with Straight Wheels
Authors: Urgoiti Lander , Barrenetxea David , Sánchez Jose Antonio , Lanzagorta Jose Luis
Published: April 2020

This paper presents a new model that relates thermal aspects with process kinematics in face grinding applications with straight wheels. Changes in chip thickness along the contact area were considered in the model, which allows for taking into account local thermal effects. The model was validated through grinding tests conducted with conventional alumina wheels. Power signals were used as input for the model. Thermal damage on the ground surface was detected using eddy current technology and revealed by acid etching. Both the model and experimental findings provide the basis for developing an approach for process optimization.
Liquid Metal Flow Under Traveling Magnetic Field—Solidification Simulation and Pulsating Flow Analysis
Authors: Shvydkiy Evgeniy , Baake Egbert , Köppen Diana
Published: April 2020

Non steady applied magnetic field impact on a liquid metal has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. The ability of the pulsating force to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance was found numerically. The obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field.
Effect of Proton Irradiation on the Defect Evolution of Zr/Nb Nanoscale Multilayers
Authors: Laptev Roman , Lomygin Anton , Krotkevich Dmitriy , Syrtanov Maxim , Kashkarov Egor , Bordulev Yuriy , Siemek Krzysztof , Kobets Andrey
Published: April 2020

Nanoscale multilayer coatings (NMCs) with different crystal structures are considered as capable of self-healing after radiation damage due to the recombination of vacancies and interstitials. This work is focused on a defect distribution study of NMCs based on Zr/Nb layers (25/25 nm and 100/100 nm) after proton irradiation. Coatings with a total thickness of 1.05 ± 0.05 µm were irradiated by 900-keV protons using a pelletron-type electrostatic accelerator with an ion current of 2 µA for durations of 60 min to 120 min. The influence of the irradiation effect was studied by X-ray diffraction analysis (XRD), glow discharge optical emission spectrometry (GD–OES), and Doppler broadening spectroscopy using a variable energy positron beam. The results obtained by these methods are compatible and indicate that defect concentration of Zr/Nb NMCs remains unchanged or slightly decreases with increasing irradiation time.
Effect of Inoculum Pretreatment on the Composition of Microbial Communities in Anaerobic Digesters Producing Volatile Fatty Acids
Authors: Blasco Lucia , Kahala Minna , Tampio Elina , Vainio Markku , Ervasti Satu , Rasi Saija
Published: April 2020

Volatile fatty acids (VFAs) are intermediates in the methane formation pathway of anaerobic digestion and can be produced through the fermentation of organic wastes. VFAs have become an anticipated resource- and cost-effective way to replace fossil resources with higher added value and more versatile fuels and chemicals. However, there are still challenges in the production of targeted compounds from diverse and complex biomasses, such as urban biowastes. In this study, the aim was to modulate the microbial communities through inoculum treatment to enhance the production of green chemicals. Thermal and freeze-thaw treatments were applied to the anaerobic digester inoculum to inhibit the growth of methanogens and to enhance the performance of acidogenic and acetogenic bacteria. VFA fermentation after different inoculum treatments was studied in batch scale using urban biowaste as the substrate and the process performance was assessed with chemical and microbial analyses. Inoculum treatments, especially thermal treatment, were shown to increase VFA yields, which were also correlating with the dynamics of the microbial communities and retention times of the test. There was a strong correlation between VFA production and the relative abundances of the microbial orders Clostridiales (families Ruminococcaceae, Lachnospiraceae and Clostridiaceae), and Lactobacillales. A syntrophic relationship of these taxa with members of the Methanobacteriales order was also presumed.
Mycobacterium tuberculosis YrbE3A Promotes Host Innate Immune Response by Targeting NF-κB/JNK Signaling
Authors: Wang Jieru , Zhu Xiaojie , Peng Yongchong , Zhu Tingting , Liu Han , Zhu Yifan , Xiong Xuekai , Chen Xi , Hu Changmin , Chen Huanchun , Chen Yingyu , Guo Aizhen
Published: April 2020

Mycobacterium tuberculosis is considered a successful pathogen with multiple strategies to undermine host immunity. The YrbE3A is encoded by Rv1964 within the RD15 region present in the genome of Mtb, but missing in M. bovis, M. bovis BCG (Pasteur) strain, and M. smegmatis (Ms). However, little is known about its function. In this study, the YrbE3A gene was cloned into pMV261 and expressed in Ms and BCG, while the strains with the vector served as the controls. The YrbE3A was expressed on the mycobacterial membrane, and the purified protein could stimulate RAW264.7 cells to produce IL-6. Furthermore, the effect of the recombinant strains on cytokine secretion by RAW264.7 was confirmed, which varied with the host strains. Ms_YrbE3A increased significantly higher levels of TNF-α and IL-6 than did Ms_vec, while BCG_YrbE3A enhanced higher TNF-α than BCG_vec. The pathways associated with NF-κB p65 and MAPK p38/JNK, other than Erk1/2, regulated this process. In addition, mice were infected with Ms_YrbE3A and Ms-vec and were kinetically examined. Compared to Ms-vec, Ms_YrbE3A induced more serious inflammatory damage, higher levels of TNF-α and IL-6, higher numbers of lymphocytes, neutrophils, and monocytes in a time-dependent way, but lower lung bacterial load in lung. These findings may contribute to a better understanding of Mtb pathogenesis.
Biological Activity of Endophytic Fungi from the Roots of the Medicinal Plant Vernonia anthelmintica
Authors: Rustamova Nigora , Gao Yanhua , Zhang Yong , Yili Abulimiti
Published: April 2020

Endophytic fungi were first isolated from the fresh root of the Chinese medicinal plant Vernonia anthelmintica collected from the Hotan Prefecture within the Xinjiang Autonomous region of the People’s Republic of China. This plant has been used in Uyghur traditional medicine to treat vitiligo, a skin condition characterized by patches of the skin losing their pigment. In total, fifteen fungal strains were isolated. Among these, four endophytic fungi were identified by their DNA sequences and registered to GenBank with accession numbers. The isolates were identified as Schizophyllum commune XJA1, Talaromyces sp. XJA4, Aspergillus sp. XJA6, Aspergillus terreus XJA8. Ethyl acetate extracts of all fungal strains were used to quantify melanin content and to identify in vitro biological activity assays including antimicrobial, antioxidant, cytotoxic, antidiabetic and tyrosinase activity on B16 cells. Among the extracts of all four identified strains, the ethyl acetate extract of the Aspergillus sp. XJA6 was chosen for further characterization because it presented the highest biological activity against these tests. In addition, twenty four volatile compounds from the petroleum ether fraction were characterized by GC–MS.
Genome-Wide Analysis of Sugar Transporters Identifies the gtsA Gene for Glucose Transportation in Pseudomonas stutzeri A1501
Authors: Liu Yaqun , Shang Liguo , Zhan Yuhua , Lin Min , Liu Zhu , Yan Yongliang
Published: April 2020

Pseudomonas stutzeri A1501 possesses an extraordinary number of transporters which confer this rhizosphere bacterium with the sophisticated ability to metabolize various carbon sources. However, sugars are not a preferred carbon source for P. stutzeri A1501. The P. stutzeri A1501 genome has been sequenced, allowing for the homology-based in silico identification of genes potentially encoding sugar-transport systems by using established microbial sugar transporters as a template sequence. Genomic analysis revealed that there were 10 sugar transporters in P. stutzeri A1501, most of which belong to the ATP-binding cassette (ABC) family (5/10); the others belong to the phosphotransferase system (PTS), major intrinsic protein (MIP) family, major facilitator superfamily (MFS) and the sodium solute superfamily (SSS). These systems might serve for the import of glucose, galactose, fructose and other types of sugar. Growth analysis showed that the only effective medium was glucose and its corresponding metabolic system was relatively complete. Notably, the loci of glucose metabolism regulatory systems HexR, GltR/GtrS, and GntR were adjacent to the transporters ABCMalEFGK, ABCGtsABCD, and ABCMtlEFGK, respectively. Only the ABCGtsABCD expression was significantly upregulated under both glucose-sufficient and -limited conditions. The predicted structure and mutant phenotype data of the key protein GtsA provided biochemical evidence that P. stutzeri A1501 predominantly utilized the ABCGtsABCD transporter for glucose uptake. We speculate that gene absence and gene diversity in P. stutzeri A1501 was caused by sugar-deficient environmental factors and hope that this report can provide guidance for further analysis of similar bacterial lifestyles.
Effect of Cobalt, Nickel, and Selenium/Tungsten Deficiency on Mesophilic Anaerobic Digestion of Chemically Defined Soluble Organic Compounds
Authors: Šafarič Luka , Yekta Sepehr Shakeri , Svensson Bo H. , Schnürer Anna , Bastviken David , Björn Annika
Published: April 2020

Trace elements (TEs) are vital for anaerobic digestion (AD), due to their role as cofactors in many key enzymes. The aim of this study was to evaluate the effects of specific TE deficiencies on mixed microbial communities during AD of soluble polymer-free substrates, thus focusing on AD after hydrolysis. Three mesophilic (37 °C) continuous stirred-tank biogas reactors were depleted either of Co, Ni, or a combination of Se and W, respectively, by discontinuing their supplementation. Ni and Se/W depletion led to changes in methane kinetics, linked to progressive volatile fatty acid (VFA) accumulation, eventually resulting in process failure. No significant changes occurred in the Co-depleted reactor, indicating that the amount of Co present in the substrate in absence of supplementation was sufficient to maintain process stability. Archaeal communities remained fairly stable independent of TE concentrations, while bacterial communities gradually changed with VFA accumulation in Ni- and Se-/W-depleted reactors. Despite this, the communities remained relatively similar between these two reactors, suggesting that the major shifts in composition likely occurred due to the accumulating VFAs. Overall, the results indicate that Ni and Se/W depletion primarily lead to slower metabolic activities of methanogenic archaea and their syntrophic partners, which then has a ripple effect throughout the microbial community due to a gradual accumulation of intermediate fermentation products.
Multitarget Approach to Drug Candidates against Alzheimer’s Disease Related to AChE, SERT, BACE1 and GSK3β Protein Targets
Authors: Ivanova Larisa , Karelson Mati , Dobchev Dimitar A.
Published: April 2020

Alzheimer’s disease is a neurodegenerative condition for which currently there are no drugs that can cure its devastating impact on human brain function. Although there are therapeutics that are being used in contemporary medicine for treatment against Alzheimer’s disease, new and more effective drugs are in great demand. In this work, we proposed three potential drug candidates which may act as multifunctional compounds simultaneously toward AChE, SERT, BACE1 and GSK3β protein targets. These candidates were discovered by using state-of-the-art methods as molecular calculations (molecular docking and molecular dynamics), artificial neural networks and multilinear regression models. These methods were used for virtual screening of the publicly available library containing more than twenty thousand compounds. The experimental testing enabled us to confirm a multitarget drug candidate active at low micromolar concentrations against two targets, e.g., AChE and BACE1.
Syntheses and Structure–Activity Relationships in Growth Inhibition Activity against Human Cancer Cell Lines of 12 Substituted Berberine Derivatives
Authors: Wang Bo , Deng An-Jun , Li Zhi-Hong , Wang Nan , Qin Hai-Lin
Published: April 2020

In this study, quaternary berberine chloride is used as a lead compound to design and synthesize a series of berberine-12-amine derivatives to evaluate the growth inhibition activity against human cancer cell lines. Forty-two compounds of several series were obtained. The quaternary berberine-12-N,N-di-n-alkylamine chlorides showed the targeted activities with the IC50 values of most active compounds being dozens of times those of the positive control. A significant structure–activity relationship (SAR) was observed. The activities of quaternary berberine-12-N,N-di-n-alkylamine chlorides are significantly stronger than those of the reduced counterparts. In the range of about 6-8 carbon atoms, the activities increase with the elongation of n-alkyl carbon chain of 12-N,N-di-n-alkylamino, and when the carbon atom numbers are more than 6-8, the activities decrease with the elongation of n-alkyl carbon chain. The activities of the tertiary amine structure are significantly higher than that of the secondary amine structure.
Effects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis
Authors: Pérez-Gómez Jorge , Villafaina Santos , Adsuar José Carmelo , Merellano-Navarro Eugenio , Collado-Mateo Daniel
Published: April 2020

The purpose of this study was to systematically review the scientific literature about the effects of supplementation with Ashwagandha (Withania somnifera) on maximum oxygen consumption (VO2max), as well as to provide directions for clinical practice. A systematic search was conducted in three electronic databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). The inclusion criteria were: (a) VO2max data, with means ± standard deviation before and after the supplement intervention, (b) the study was randomized controlled trial (RCT), (c) the article was written in English. The quality of evidence was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. A meta-analysis was performed to determine effect sizes. Five studies were selected in the systematic review (162 participants) and four were included in the meta-analysis (142 participants). Results showed a significant enhancement in VO2max in healthy adults and athletes (p = 0.04). The mean difference was 3.00 (95% CI from 0.18 to 5.82) with high heterogeneity. In conclusion, Ashwagandha supplementation might improve the VO2max in athlete and non-athlete people. However, further research is need to confirm this hypothesis since the number of studies is limited and the heterogeneity was high.
Saccharin Supplementation Inhibits Bacterial Growth and Reduces Experimental Colitis in Mice
Authors: Sünderhauf Annika , Pagel René , Künstner Axel , Wagner Anika E. , Rupp Jan , Ibrahim Saleh M. , Derer Stefanie , Sina Christian
Published: April 2020

Non-caloric artificial sweeteners are frequently discussed as components of the “Western diet”, negatively modulating intestinal homeostasis. Since the artificial sweetener saccharin is known to depict bacteriostatic and microbiome-modulating properties, we hypothesized oral saccharin intake to influence intestinal inflammation and aimed at delineating its effect on acute and chronic colitis activity in mice. In vitro, different bacterial strains were grown in the presence or absence of saccharin. Mice were supplemented with saccharin before or after induction of acute or chronic colitis using dextran sodium sulfate (DSS) and the extent of colitis was assessed. Ex vivo, intestinal inflammation, fecal bacterial load and composition were studied by immunohistochemistry analyses, quantitative PCR, 16 S RNA PCR or next generation sequencing in samples collected from analyzed mice. In vitro, saccharin inhibited bacterial growth in a species-dependent manner. In vivo, oral saccharin intake reduced fecal bacterial load and altered microbiome composition, while the intestinal barrier was not obviously affected. Of note, DSS-induced colitis activity was significantly improved in mice after therapeutic or prophylactic treatment with saccharin. Together, this study demonstrates that oral saccharin intake decreases intestinal bacteria count and hence encompasses the capacity to reduce acute and chronic colitis activity in mice.
The Sun’s Vitamin in Adult Patients Affected by Prader–Willi Syndrome
Authors: Barrea Luigi , Muscogiuri Giovanna , Pugliese Gabriella , Aprano Sara , de Alteriis Giulia , Di Somma Carolina , Colao Annamaria , Savastano Silvia
Published: April 2020

Prader–Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia with progressive, severe obesity, and an increased risk of obesity-related comorbidities in adult life. Although low dietary vitamin D intake and low 25-hydroxy vitamin D (25OHD) levels are commonly reported in PWS in the context of bone metabolism, the association of low 25OHD levels with fat mass has not been extensively evaluated in PWS adults. The aims of this study were to investigate the following in PWS adults: (1) 25OHD levels and the dietary vitamin D intake; (2) associations among 25OHD levels with anthropometric measurements and fat mass; (3) specific cut-off values for body mass index (BMI) and fat mass predictive of the 25OHD levels. In this cross-sectional, single-center study we enrolled 30 participants, 15 PWS adults (age 19–41 years and 40% males) and 15 control subjects matched by age, sex, and BMI from the same geographical area (latitude 40° 49’ N; elevation 17 m). Fat mass was assessed using a bioelectrical impedance analysis (BIA) phase-sensitive system. The 25OHD levels were determined by a direct competitive chemiluminescence immunoassay. Dietary vitamin D intake data was collected by three-day food records. The 25OHD levels in the PWS adults were constantly lower across all categories of BMI and fat mass compared with their obese counterpart. The 25OHD levels were negatively associated with BMI (p = 0.04), waist circumference (p = 0.03), fat mass (p = 0.04), and dietary vitamin D intake (p < 0.001). During multiple regression analysis, dietary vitamin D intake was entered at the first step (p < 0.001), thus explaining 84% of 25OHD level variability. The threshold values of BMI and fat mass predicting the lowest decrease in the 25OHD levels were found at BMI ≥ 42 kg/m2 (p = 0.01) and fat mass ≥ 42 Kg (p = 0.003). In conclusion, our data indicate that: (i) 25OHD levels and dietary vitamin D intake were lower in PWS adults than in the control, independent of body fat differences; (ii) 25OHD levels were inversely associated with BMI, waist circumference, and fat mass, but low dietary vitamin D intake was the major determinant of low vitamin D status in these patients; (iii) sample-specific cut-off values of BMI and fat mass might help to predict risks of the lowest 25OHD level decreases in PWS adults. The presence of trained nutritionists in the integrated care teams of PWS adults is strongly suggested in order to provide an accurate nutritional assessment and tailored vitamin D supplementations.
Space Dimension Renormdynamics
Authors: Bures Martin , Makhaldiani Nugzar
Published: April 2020

We aim to construct a potential better suited for studying quarkonium spectroscopy. We put the Cornell potential into a more geometrical setting by smoothly interpolating between the observed small and large distance behaviour of the quarkonium potential. We construct two physical models, where the number of spatial dimensions depends on scale: one for quarkonium with Cornell potential, another for unified field theories with one compactified dimension. We construct point charge potential for different dimensions of space. The same problem is studied using operator fractal calculus. We describe the quarkonium potential in terms of the point charge potential and identify the strong coupling fine structure constant dynamics. We formulate renormdynamics of the structure constant in terms of Hamiltonian dynamics and solve the corresponding motion equations by numerical and graphical methods, we find corresponding asymptotics. Potentials of a nonlinear extension of quantum mechanics are constructed. Such potentials are ingredients of space compactification problems. Mass parameter effects are motivated and estimated.
Novel Coronavirus: Current Understanding of Clinical Features, Diagnosis, Pathogenesis, and Treatment Options
Authors: Mungroo Mohammad Ridwane , Khan Naveed Ahmed , Siddiqui Ruqaiyyah
Published: April 2020

Since December 2019, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in devastating consequences worldwide and infected more than 350,000 individuals and killed more than 16,000 people. SARS-CoV-2 is the seventh member of the coronavirus family to affect humans. Symptoms of COVID-19 include fever (88%), cough (68%), vomiting (5%) and diarrhoea (3.7%), and transmission of SARS-CoV-2 is thought to occur from human to human via respiratory secretions released by the infected individuals when coughing and sneezing. COVID-19 can be detected through computed tomography scans and confirmed through molecular diagnostics tools such as polymerase chain reaction. Currently, there are no effective treatments against SARS-CoV-2, hence antiviral drugs have been used to reduce the development of respiratory complications by reducing viral load. The purpose of this review is to provide a comprehensive update on the pathogenesis, clinical aspects, diagnosis, challenges and treatment of SARS-CoV-2 infections.
Nonreciprocal Wavefront Manipulation in Synthetically Moving Metagratings
Authors: Ra’di Younes , Alù Andrea
Published: April 2020

We introduce a metasurface platform for nonreciprocal wave manipulation. We study metagratings composed of nonreciprocal bianisotropic particles supporting synthetic motion, which enable nonreciprocal energy transfer between tailored Floquet channels with unitary efficiency. Based on this framework, we derive the required electromagnetic polarizabilities to realize a metagrating supporting space wave circulation with unitary efficiency for free-space radiation and design a microwave metagrating supporting this functionality. The proposed concept opens new research venues to control free-space radiation with high efficiency beyond the limits dictated by Lorentz reciprocity.
Cycas micronesica Stem Carbohydrates Decline Following Leaf and Male Cone Growth Events
Authors: Marler Thomas E. , Cruz Gil N.
Published: April 2020

The growth of synchronized leaf flushes or male cones on Cycas trees is an ephemeral event, and non-structural carbohydrates (NSCs) are likely deployed from stem and root storage tissues to support their construction. The relationships among various stem NSCs and these rapid growth events have not been studied to date. Monosaccharides, disaccharides, and starch were quantified in Cycas micronesica stem tissue prior to and immediately after the growth of leaf flushes or male cones to determine the influences on the concentration of these carbohydrates. The pre-existing leaves were removed from half of the plants to determine if the elimination of this carbon source would influence the NSC behaviors. Starch and sucrose dominated the NSC profiles, and these two NSCs declined following cone or new leaf growth. Removal of pre-existing leaves generated a greater decline in starch and sucrose for cone growth, and a greater decline in sucrose, but not starch following new leaf growth than in control trees with no leaf removal. The initial differences in starch and sucrose among cortex, vascular, and pith tissues disappeared as the concentrations declined in all three tissue categories to reach similar post-growth concentrations among the stem tissue categories. The fructose, glucose, and maltose behaviors were not consistent, and their concentrations were low such that their influence on the total NSC behaviors was minimal. These results provided indirect evidence that stem NSCs were mobilized to support ephemeral male cone and new leaf growth for this arborescent cycad. Growth of female strobili is slow and lengthy, so we did not include female trees in this study. The contributions of stem NSCs to female strobili growth remain to be studied with alternative methods.
Effects of NtSPS1 Overexpression on Solanesol Content, Plant Growth, Photosynthesis, and Metabolome of Nicotiana tabacum
Authors: Yan Ning , Gai Xiaolei , Xue Lin , Du Yongmei , Shi John , Liu Yanhua
Published: April 2020

Nicotiana tabacum solanesyl diphosphate synthase 1 (NtSPS1) is the key enzyme in solanesol biosynthesis. However, changes in the solanesol content, plant growth, photosynthesis, and metabolome of tobacco plants after NtSPS1 overexpression (OE) have not been previously reported. In the present study, these parameters, as well as photosynthetic gas exchange, chlorophyll content, and chlorophyll fluorescence parameters, were compared between NtSPS1 OE and wild type (WT) lines of tobacco. As expected, NtSPS1 OE significantly increased solanesol content in tobacco leaves. Although NtSPS1 OE significantly increased leaf growth, photosynthesis, and chlorophyll content, the chlorophyll fluorescence parameters in the leaves of the NtSPS1 OE lines were only slightly higher than those in the WT leaves. Furthermore, NtSPS1 OE resulted in 64 differential metabolites, including 30 up-regulated and 34 down-regulated metabolites, between the OE and WT leaves. Pathway enrichment analysis of these differential metabolites identified differentially enriched pathways between the OE and WT leaves, e.g., carbon fixation in photosynthetic organisms. The maximum carboxylation rate of RuBisCO and the maximum rate of RuBP regeneration were also elevated in the NtSPS1 OE line. To our knowledge, this is the first study to confirm the role of NtSPS1 in solanesol biosynthesis and its possible functional mechanisms in tobacco.
Severe Plastid Genome Size Reduction in a Mycoheterotrophic Orchid, Danxiaorchis singchiana, Reveals Heavy Gene Loss and Gene Relocations
Authors: Lee Shiou Yih , Meng Kaikai , Wang Haowei , Zhou Renchao , Liao Wenbo , Chen Fang , Zhang Shouzhou , Fan Qiang
Published: April 2020

Danxiaorchis singchiana (Orchidaceae) is a leafless mycoheterotrophic orchid in the subfamily Epidendroideae. We sequenced the complete plastome of D. singchiana. The plastome has a reduced size of 87,931 bp, which includes a pair of inverted repeat (IR) regions of 13,762 bp each that are separated by a large single copy (LSC) region of 42,575 bp and a small single copy (SSC) region of 17,831 bp. When compared to its sister taxa, Cremastra appendiculata and Corallorhiza striata var. involuta, D. singchiana showed an inverted gene block in the LSC and SSC regions. A total of 61 genes were predicted, including 21 tRNA, 4 rRNA, and 36 protein-coding genes. While most of the housekeeping genes were still intact and seem to be protein-coding, only four photosynthesis-related genes appeared presumably intact. The majority of the presumably intact protein-coding genes seem to have undergone purifying selection (dN/dS < 1), and only the psaC gene was positively selected (dN/dS > 1) when compared to that in Cr. appendiculata. Phylogenetic analysis of 26 complete plastome sequences from 24 species of the tribe Epidendreae had revealed that D. singchiana diverged after Cr. appendiculata and is sister to the genus Corallorhiza with strong bootstrap support (100%).
Bamboo Plantations for Phytoremediation of Pig Slurry: Plant Response and Nutrient Uptake
Authors: Piouceau Julien , Panfili Frédéric , Bois Grégory , Anastase Matthieu , Feder Frédéric , Morel Julien , Arfi Véronique , Dufossé Laurent
Published: April 2020

On Réunion Island, a French overseas territory located in the western Indian Ocean, increasing pig livestock farming is generating large quantities of slurry. Most of it is spread on a little agricultural land due to the insular context. Considering the limitation of the quantities that can be spread on agricultural areas (European “Nitrate Directive” 91/676/EEC), the use of wastewater treatment systems using phytoremediation principles is an attractive option for the pig slurry treatment. A wastewater treatment system using bamboo groves was assessed for the pig slurry treatment. Three field plots were designed on an agricultural area and planted with 40 bamboo clumps on each plot. A total of 67 m3 of pig slurry was spread on two plots in two forms: raw slurry and centrifuged slurry. The latter plot was watered with tap water. The total amount of nitrogen, phosphorus and potassium was 5.3, 1.4 and 5.5 t·ha−1, respectively, for the raw slurry treatment and 4.2, 0.4 and 5.1 t·ha−1, respectively, for the centrifuged slurry treatment. The response of bamboo species to pig slurry application was determined using morphologic parameters, Chlorophyll a fluorescence measurements and biomass yield. Compared to the control, the biomass increased by 1.8 to 6 times, depending on the species and the form of slurry. Depending on the species, the average biomass ranged from 52 to 135 t.DM.ha−1 in two years of experiment.