bluuebunny/crossref_metadata_2025 huggingface dataset:
Alleviation of Multidrug Resistance by Flavonoid and Non-Flavonoid Compounds in Breast, Lung, Colorectal and Prostate Cancer
Authors: Costea Teodora , Vlad Oana Cezara , Miclea Luminita-Claudia , Ganea Constanta , Szöllősi János , Mocanu Maria-Magdalena
Published: January 2020

The aim of the manuscript is to discuss the influence of plant polyphenols in overcoming multidrug resistance in four types of solid cancers (breast, colorectal, lung and prostate cancer). Effective treatment requires the use of multiple toxic chemotherapeutic drugs with different properties and targets. However, a major cause of cancer treatment failure and metastasis is the development of multidrug resistance. Potential mechanisms of multidrug resistance include increase of drug efflux, drug inactivation, detoxification mechanisms, modification of drug target, inhibition of cell death, involvement of cancer stem cells, dysregulation of miRNAs activity, epigenetic variations, imbalance of DNA damage/repair processes, tumor heterogeneity, tumor microenvironment, epithelial to mesenchymal transition and modulation of reactive oxygen species. Taking into consideration that synthetic multidrug resistance agents have failed to demonstrate significant survival benefits in patients with different types of cancer, recent research have focused on beneficial effects of natural compounds. Several phenolic compounds (flavones, phenolcarboxylic acids, ellagitannins, stilbens, lignans, curcumin, etc.) act as chemopreventive agents due to their antioxidant capacity, inhibition of proliferation, survival, angiogenesis, and metastasis, modulation of immune and inflammatory responses or inactivation of pro-carcinogens. Moreover, preclinical and clinical studies revealed that these compounds prevent multidrug resistance in cancer by modulating different pathways. Additional research is needed regarding the role of phenolic compounds in the prevention of multidrug resistance in different types of cancer.
Effect of Unloading Condition on the Healing Process and Effectiveness of Platelet Rich Plasma as a Countermeasure: Study on In Vivo and In Vitro Wound Healing Models
Authors: Cialdai Francesca , Colciago Alessandra , Pantalone Desiré , Rizzo Angela Maria , Zava Stefania , Morbidelli Lucia , Celotti Fabio , Bani Daniele , Monici Monica
Published: January 2020

Wound healing is a very complex process that allows organisms to survive injuries. It is strictly regulated by a number of biochemical and physical factors, mechanical forces included. Studying wound healing in space is interesting for two main reasons: (i) defining tools, procedures, and protocols to manage serious wounds and burns eventually occurring in future long-lasting space exploration missions, without the possibility of timely medical evacuation to Earth; (ii) understanding the role of gravity and mechanical factors in the healing process and scarring, thus contributing to unravelling the mechanisms underlying the switching between perfect regeneration and imperfect repair with scarring. In the study presented here, a new in vivo sutured wound healing model in the leech (Hirudo medicinalis) has been used to evaluate the effect of unloading conditions on the healing process and the effectiveness of platelet rich plasma (PRP) as a countermeasure. The results reveal that microgravity caused a healing delay and structural alterations in the repair tissue, which were prevented by PRP treatment. Moreover, investigating the effects of microgravity and PRP on an in vitro wound healing model, it was found that PRP is able to counteract the microgravity-induced impairment in fibroblast migration to the wound site. This could be one of the mechanisms underlying the effectiveness of PRP in preventing healing impairment in unloading conditions.
Preparation of PCI Balloons: What Is the Best Method to Avoid Air in the Balloon? A Comparison of Different Methods of Connecting PCI Balloons and the Inflation Syringe while Removing Air from the Balloon
Authors: Kreuser Laura , Laugwitz Karl-Ludwig , Tiemann Klaus , Lewalter Thorsten , Jilek Clemens
Published: January 2020

As the techniques to connect percutaneous coronary intervention (PCI) balloons and the inflation syringe vary in the instructions for use and in practice, we measured the amount of air in PCI balloons after testing three connection methods to an inflation syringe. Following the preparation using one of the three methods, 114 balloons and stent balloons were tested four times. Method 1 connected the syringe and the balloon catheter directly after purging and filling the lumen, while method 3 omitted the purging and filling process. With method 2, the catheter lumen was purged, filled and fully vented via a three-way valve. The primary endpoint answered whether air remained in the balloon, and if so, the secondary endpoint indicated the total volume of remaining air. The connection with a three-way valve achieved significantly less air in the inflated balloon as compared with either direct connection approach (27% vs. 44% and 51%; p = 0.015). For the direct connection, no significant difference between purging and filling the lumen prior to making the connection or not existed. According to these findings, the best method to connect a PCI balloon to the inflation syringe while removing air involves using a three-way valve.
Novel Reliable and Energy-Efficient Routing Protocols for Wireless Sensor Networks
Authors: Almazaideh Mohammed , Levendovszky Janos
Published: January 2020

In this paper, novel energy-aware and reliable routing protocols are proposed. The aim is to maximize the lifespan of wireless sensor networks (WSNs) subject to predefined reliability constraints by using multi-hop routing schemes, in which the source node forwards the packet to the base station (BS) via other nodes as relays. In the first proposed protocol, energy efficiency is achieved by maximizing the minimum residual energy of the path subject to fulfilling a predefined reliability constraints. The second protocol is an optimized version of the first one with respect to lifespan and complexity. The optimal path is the one in which the residual energy distribution of the nodes along the path is as close to uniform as possible and the packet arrives at the base station with a given success probability. To measure the uniformity of the residual energy distribution, we use an entropy like measure. The information about the current energy state of the network is maintained by using a look-up-table from which the optimal routes are computed on the BS. The BS broadcasts the updated optimal paths to each node after each round of packet transmission.
Experimental Investigation of Impact Concrete Slab on the Bending Behavior of Composite Bridge Girders with Sinusoidal Steel Web
Authors: Górecki Marcin , Śledziewski Krzysztof
Published: January 2020

Until recently, steel plate girders with corrugated steel members were used primarily as poles and girders in the construction of industrial buildings. Currently, they are also being used in the construction of bridges. Compared to traditional steel and rolled girders, steel plate girders weigh less and are more stiff, while also having a neater appearance. In this paper, the results of an experimental study are present. The aim of the study was to determine the behavior of a bridge girder with sinusoidal web geometry when subjected to a bending moment. The study was focused on a composite steel and concrete structure with pin connections, which is currently the most common solution. Three near-real scale beams were subjected to bending tests. The study found that composite corrugated-web steel beams and non-composite corrugated-web steel beams showed similar forms of failure. A reinforced concrete slab did not prevent web stress concentration at the point of connection with the flange. Furthermore, the study indicates that corrugated steel webs in bridge girders can have a much smaller thickness (less than 8 mm) compared with the traditional solution.
Study on the Dissolution Mechanism of Cellulose by ChCl-Based Deep Eutectic Solvents
Authors: Zhang Heng , Lang Jinyan , Lan Ping , Yang Hongyan , Lu Junliang , Wang Zhe
Published: January 2020

Four deep eutectic solvents (DESs), namely, glycerol/chlorocholine (glycerol/ChCl), urea/ChCl, citric acid/ChCl, and oxalic acid/ChCl, were synthesized and their performance in the dissolution of cellulose was studied. The results showed that the melting point of the DESs varied with the proportion of the hydrogen bond donor material. The viscosity of the DESs changed considerably with the change in temperature; as the temperature increased, the viscosity decreased and the electrical conductivity increased. Oxalic acid/ChCl exhibited the best dissolution effects on cellulose. The microscopic morphology of cellulose was observed with a microscope. The solvent system effectively dissolved the cellulose, and the dissolution method of the oxalic acid/ChCl solvent on cellulose was preliminarily analyzed. The ChCl solvent formed new hydrogen bonds with the hydroxyl groups of the cellulose through its oxygen atom in the hydroxyl group and its nitrogen atom in the amino group. That is to say, after the deep eutectic melt formed an internal hydrogen bond, a large number of remaining ions formed a hydrogen bond with the hydroxyl groups of the cellulose, resulting in a great dissolution of the cellulose. Although the cellulose and regenerated cellulose had similar structures, the crystal form of cellulose changed from type I to type II.
Molecular Coverage Determines Sliding Wear Behavior of n-Octadecylphosphonic Acid Functionalized Cu–O Coated Steel Disks against Aluminum
Authors: Prünte Stephan , Music Denis , Terziyska Velislava L. , Mitterer Christian , Schneider Jochen M.
Published: January 2020

The sliding wear behavior of Cu–O coated steel disks functionalized with n-octadecyl-phosphonic acids was evaluated against aluminum in ball-on-disk tribometer experiments. After 5 m of sliding the friction coefficient of the functionalized sample with maximum molecular coverage is ≤0.3 ± 0.1. Surfaces with lower coverage mitigate friction and wear as well exhibiting initially similar low friction coefficients but reveal the breakdown of lubrication for sliding distances <5 m. The length of the low friction sliding distance before breakdown scales with the coverage of n-octadecylphosphonic acids on the Cu–O surface. Coverage hence determines the tribological behavior of the functionalized surface against sliding aluminum. As the coverage is increased, detrimental asperity contacts between the rubbing surfaces are reduced.
Fabrication, Structure, and Mechanical and Ultrasonic Properties of Medical Ti6Al4V Alloys Part II: Relationship between Microstructure and Mechanical Properties and Ultrasonic Properties of Ultrasonic Scalpel
Authors: He Zheyu , He Hao , Lou Jia , Li Yimin , Li Dongyang , Chen Yongzhi , Liu Shaojun
Published: January 2020

In this study, the ultrasonic resonance parameters of Ti6Al4V alloys under different heat treatments are measured by an impedance analyzer. The amplitude of the specimens is measured experimentally by means of optical microscope and image analysis software. These results show that the ultrasonic properties of Ti6Al4V alloys are closely related to β phase content and elastic modulus of the alloys. The highest volume fraction of the β phase appears in the specimen treated by solid solution treatment at 960 °C is 40.2%. These alloys present the lowest average elastic modulus (~99.69 GPa) and the minimum resonant frequency (55.06 kHz) and the highest average amplitude (21.48 µm) when the testing sample length is 41.25 mm. These findings can be used to guide the design of medical Ti6Al4V alloys for ultrasonic scalpels.
Analysis of Strain Field Heterogeneity at the Microstructure Level and Inverse Identification of Composite Constituents by Means of Digital Image Correlation
Authors: Ogierman Witold , Kokot Grzegorz
Published: January 2020

The present paper is devoted to the theoretical study on the estimation of the full-field strain at the microstructural level of composite materials by means of Digital Image Correlation (DIC). The main aim of the paper is to investigate the influence of speckle size on the accuracy of the strain field measurement at the microscale. The DIC analysis was conducted based on artificial speckle patterns generated numerically and the deformation behavior of the composites was simulated by using the finite element method (FEM). This approach gives the opportunity to compare the results of the DIC in terms of speckle size with the reference FEM solution. Moreover, the paper focuses on the inverse identification of the material constants of the composite constituents by using information associated with the measured strain field. The inverse problem is solved by using a novel two-step optimization procedure, which reduces the problem complexity. The feasibility and accuracy of the proposed approach are presented by analysis of two exemplary microgeometries representing the microstructures of fiber reinforced composites.
TiO2 Modified with Organic Acids for the Decomposition of Chlorfenvinphos under the Influence of Visible Light: Activity, Performance, Adsorption, and Kinetics
Authors: Zawadzki Piotr
Published: January 2020

Photocatalytic decomposition of chlorfenvinphos (CFVP) in the presence of titanium dioxide (TiO2) modified with organic acids: pyruvic (PA) and succinic (SA) under the visible light radiation has been studied. The following tests were examined: dose of photocatalysts, adsorption time, pH of the model solution, deactivation of catalysts, the role of oxygen, identification of free radicals for the CFVP decomposition, Langmuir-Hinshelwood kinetics. The synthesized materials were characterized by Scanning Electron Microscopy (SEM) and UV-Vis. At 10 wt.% of acid (90:10) decomposition of chlorfenvinphos was the most effective in the following conditions: dose of catalyst 50.0 mg/L, time of adsorption = 20 min, pH of model solution = 3.0. Under these conditions the order of photocatalyst efficiency has been proposed: TiO2/PA/90:10 > TiO2/SA/90:10 > TiO2 with the removal degree of 85, 72 and 48%. The mathematically calculated half-life at this conditions was 27.0 min and 39.0 min for TiO2/PA/90:10 and TiO2/SA/90:10 respectively, compared to 98 min for pure TiO2. It has been determined that the O2•− radicals and holes (h+) are the main reactive species involved in the photodegradation of chlorfenvinphos. The results of this study showed that method may be an interesting alternative for the treatment of chlorfenvinphos contaminated wastewater.
Vaginal Polyelectrolyte Layer-by-Layer Films Based on Chitosan Derivatives and Eudragit® S100 for pH Responsive Release of Tenofovir
Authors: Cazorla-Luna Raúl , Martín-Illana Araceli , Notario-Pérez Fernando , Bedoya Luis Miguel , Tamayo Aitana , Ruiz-Caro Roberto , Rubio Juan , Veiga María-Dolores
Published: January 2020

Women are still at high risk of contracting the human immunodeficiency virus (HIV) virus due to the lack of protection methods under their control, especially in sub-Saharan countries. Polyelectrolyte multilayer smart vaginal films based on chitosan derivatives (chitosan lactate, chitosan tartate, and chitosan citrate) and Eudragit® S100 were developed for the pH-sensitive release of Tenofovir. Films were characterized through texture analysis and scanning electron microscopy (SEM). Swelling and drug release studies were carried out in simulated vaginal fluid and a mixture of simulated vaginal and seminal fluids. Ex vivo mucoadhesion was evaluated in bovine vaginal mucosa. SEM micrographs revealed the formation of multilayer films. According to texture analysis, chitosan citrate was the most flexible compared to chitosan tartrate and lactate. The swelling studies showed a moderate water uptake (<300% in all cases), leading to the sustained release of Tenofovir in simulated vaginal fluid (up to 120 h), which was accelerated in the simulated fluid mixture (4–6 h). The films had high mucoadhesion in bovine vaginal mucosa. The multilayer films formed by a mixture of chitosan citrate and Eudragit® S100 proved to be the most promising, with zero toxicity, excellent mechanical properties, moderate swelling (<100%), high mucoadhesion capacity, and Tenofovir release of 120 h and 4 h in vaginal fluid and the simulated fluid mixture respectively.
Predictive Factors of Adrenal Insufficiency in Outpatients with Indeterminate Serum Cortisol Levels: A Retrospective Study
Authors: Manosroi Worapaka , Phimphilai Mattabhorn , Khorana Jiraporn , Atthakomol Pichitchai , Pipanmekaporn Tanyong
Published: January 2020

Background and Objectives: To diagnose adrenal insufficiency (AI), adrenocorticotropic hormone (ACTH) stimulation tests may need to be performed, but those tests may not be available in some institutions. In addition, they may not be necessary for some patients. The objective of this study was to identify clinical and biochemical factors that could facilitate AI diagnosis in outpatient departments and decrease the number of unnecessary dynamic tests. Materials and Methods: This seven-year retrospective study was performed in a tertiary care medical center. A total of 517 patients who had undergone ACTH stimulation tests in the outpatient department were identified. AI was described as a peak serum cortisol level of <18 µg/dL at 30 or 60 min after stimulation. The associations between clinical factors, biochemical factors, and AI were analyzed using the Poisson regression model and reported by the risk ratio (RR). Results: AI was identified in 128 patients (24.7%). Significant predictive factors for the diagnosis of AI were chronic kidney disease (RR = 2.52, p < 0.001), Cushingoid appearance (RR = 3.44, p < 0.001), nausea and/or vomiting (RR = 1.84, p = 0.003), fatigue (RR = 1.23, p < 0.001), serum basal cortisol <9 µg/dL (RR = 3.36, p < 0.001), serum cholesterol <150 mg/dL (RR = 1.26, p < 0.001), and serum sodium <135 mEq/L (RR = 1.09, p = 0.001). The predictive ability of the model was 83% based on the area under the curve. Conclusion: The easy-to-obtain clinical and biochemical factors identified may facilitate AI diagnosis and help identify patients with suspected AI. Using these factors in clinical practice may also reduce the number of nonessential dynamic tests for AI.
Electrothermally Driven Hydrogel-on-Flex-Circuit Actuator for Smart Steerable Catheters
Authors: Selvaraj Madeshwaran , Takahata Kenichi
Published: January 2020

This paper reports an active catheter-tip device functionalized by integrating a temperature-responsive smart polymer onto a microfabricated flexible heater strip, targeting at enabling the controlled steering of catheters through complex vascular networks. A bimorph-like strip structure is enabled by photo-polymerizing a layer of poly(N-isopropylacrylamide) hydrogel (PNIPAM), on top of a 20 × 3.5 mm2 flexible polyimide film that embeds a micropatterned heater fabricated using a low-cost flex-circuit manufacturing process. The heater activation stimulates the PNIPAM layer to shrink and bend the tip structure. The bending angle is shown to be adjustable with the amount of power fed to the device, proving the device’s feasibility to provide the integrated catheter with a controlled steering ability for a wide range of navigation angles. The powered device exhibits uniform heat distribution across the entire PNIPAM layer, with a temperature variation of <2 °C. The operation of fabricated prototypes assembled on commercial catheter tubes demonstrates their bending angles of up to 200°, significantly larger than those reported with other smart-material-based steerable catheters. The temporal responses and bending forces of their actuations are also characterized to reveal consistent and reproducible behaviors. This proof-of-concept study verifies the promising features of the prototyped approach to the targeted application area.
Autonomous and In Situ Ocean Environmental Monitoring on Optofluidic Platform
Authors: Wang Fang , Zhu Jiaomeng , Chen Longfei , Zuo Yunfeng , Hu Xuejia , Yang Yi
Published: January 2020

Determining the distributions and variations of chemical elements in oceans has significant meanings for understanding the biogeochemical cycles, evaluating seawater pollution, and forecasting the occurrence of marine disasters. The primary chemical parameters of ocean monitoring include nutrients, pH, dissolved oxygen (DO), and heavy metals. At present, ocean monitoring mainly relies on laboratory analysis, which is hindered in applications due to its large size, high power consumption, and low representative and time-sensitive detection results. By integrating photonics and microfluidics into one chip, optofluidics brings new opportunities to develop portable microsystems for ocean monitoring. Optofluidic platforms have advantages in respect of size, cost, timeliness, and parallel processing of samples compared with traditional instruments. This review describes the applications of optofluidic platforms on autonomous and in situ ocean environmental monitoring, with an emphasis on their principles, sensing properties, advantages, and disadvantages. Predictably, autonomous and in situ systems based on optofluidic platforms will have important applications in ocean environmental monitoring.
Facile Fabrication of Highly Perforated Hollow Metallic Cylinder with Changeable Micro-Orifices by Electroforming-Extrusion Molding Hybrid Process
Authors: Zhang Junzhong , Ming Pingmei , Zhang Xinmin , Qin Ge , Yan Liang , Zhao Xiaokang , Zheng Xingshuai
Published: January 2020

A seamless thin-walled hollow metallic cylinder with array of micro-perforations is one of the key components for some products. Normally, these micro-perforations are formed by removing material from the given metallic hollow cylinder (pipe or tube) one by one or row by row. To efficiently and flexibly manufacture such a highly perforated hollow cylinder, this paper proposed a hybrid technique combining extrusion moulding process and electroforming process. In the hybrid technique, the extrusion moulding process was used to create polymer extrusion patterns on the outside surface of the given stainless steel (SS) pipe, and then the electroforming process was carried out using the SS pipe as the mandrel. The formation of the polymer extrusion patterns was simulated and extruding molding experiments were carried out to examine the feasibility of the various mandrels. Electroforming experiments were implemented to verify the achievement of the seamless perforated thin-walled hollow cylinder. It was found that five different types of polymer extrusion pattern were able to be obtained on the same extruding pipe just by adjusting some extruding conditions and parameters, and correspondingly four types of perforated hollow cylinder with different tapered orifices are produced after the electroforming process. The obtainable perforations are: perforation with double conic-orifices, perforation with hemispheric orifice and conic orifice, unidirectionally tapered perforation, and straight-walled perforation. The geometric profile of the extrusion patterns is highly dependent on the processing conditions and parameters. The proposed hybrid process represents a promising alternative process to fabricate seamless thin-walled perforated hollow metallic cylinder efficiently, flexibly, and with low cost.
Structural Disorder in High-Spin {CoII9WV6} (Core)-[Pyridine N-Oxides] (Shell) Architectures
Authors: Liberka Michal , Kobylarczyk Jedrzej , Podgajny Robert
Published: January 2020

The combinations of Co(II), octacyanidotungstate(V), and monodentate pyridine N-oxide (pyNO) or 4-phenylpyridine N-oxide (4-phpyNO) led to crystallization of novel crystalline phases {CoII[CoII8(pyNO)12(MeOH)12][WV(CN)8]6} (1) and {CoII[CoII8(4-phpyNO)7(MeOH)17][WV(CN)8]6}·7MeOH·(4-phpyNO)3 (2). In both architectures, metal–cyanide clusters are coordinated by N-oxide ligands in a simple monodentate manner to give the spherical objects of over 1 nm core diameter and about 2.2 nm (1) and 3 nm (2) of the total diameter, terminated with the aromatic rings. The supramolecular architecture is dominated by dense and rich π–π interaction systems. Both structures are characterized by a significant structural disorder in ligand shell, described with the suitable probability models. For 1, the π–π interactions between the pyNO ligands attached to the same metal centers are suggested for the first time. In 2, 4-phpyNO acts as monodentate ligand and as the crystallization molecule. Magnetic studies indicate the high-spin ground state due to the ferromagnetic interactions Co(II)–W(V) through the cyanido bridges. Due to the high symmetry of the clusters, no signature of slow magnetic relaxation was observed. The characterization is completed by solid-state IR and UV–Vis–NIR spectroscopy. The conditions for the stable M9M’6-based crystals formation are synthetically discussed in terms of the type of capping ligands: monodentate, bridging, and chelating. The potential of the related polynuclear forms toward the magnetism-based functional properties is critically indicated.
An Investigation of the Organoborane/Lewis Base Pairs on the Copolymerization of Propylene Oxide with Succinic Anhydride
Authors: Hu Lan-Fang , Chen Dan-Jing , Yang Jia-Liang , Zhang Xing-Hong
Published: January 2020

The copolymerization of biorenewable succinic anhydride (SA) with propylene oxide (PO) is a promising way to synthesize biodegradable aliphatic polyesters. However, the catalytic systems for this reaction still deserve to be explored because the catalytic activity of the reported catalysts and the molecular weights of produced polyesters are unsatisfied. Herein, we investigate the copolymerization of SA with PO catalyzed by the organoborane/base pairs. The types of Lewis bases, organoboranes, and their loadings all have a large impact on the activity and selectivity of the copolymerization. High ester content of >99% was achieved when performed the PO/SA copolymerization using triethyl borane (TEB)/phosphazene base P1-t-Bu (t-BuP1) pair with a molar ratio of 1/1 at 30–80 °C. Using TEB/t-BuP1 pair with the molar ratio of 4/1 at 80 °C, the turnover of frequency (TOF) was up to 128 h−1 and clearly higher than the known TOF values (0.5–34 h−1) of the PO/SA copolymerization by previously reported catalysts. The number-average molecular weights (Mns) of the resultant polyesters reached up to 20.4 kg/mol when copolymerization was carried out using TEB/t-BuP1 (1/1, in molar ratio) at 30 °C.
One-Pot Multicomponent Synthesis and Cytotoxic Evaluation of Novel 7-Substituted-5-(1H-Indol-3-yl)Tetrazolo[1,5-a] Pyrimidine-6-Carbonitrile
Authors: Radwan Mohamed A. A. , Alminderej Fahad M. , Awad Hanem M.
Published: January 2020

A series of novel 7-substituted-5-(1H-indol-3-yl)tetrazolo[1,5-a]pyrimidine-6-carbonitrile was synthesized via a one-pot, three-multicomponent reaction of appropriate aldehydes, 1H-tetrazole-5-amine and 3-cyanoacetyl indole in catalytic triethylamine. The cytotoxic activity of the new synthesized tetrazolopyrimidine-6-carbonitrile compounds was investigated against HCT-116, MCF-7, MDA-MB-231, A549 human cancer cell lines and one human healthy normal cell line (RPE-1) using the MTT cytotoxicity assay. Compounds 4h, 4b, 4c, 4i and 4a showed potent anticancer activities against human colon cancer. Additionally, all the compounds showed potent anticancer activities on human lung cancer.
Ultrashort Cationic Lipopeptides–Effect of N-Terminal Amino Acid and Fatty Acid Type on Antimicrobial Activity and Hemolysis
Authors: Neubauer Damian , Jaśkiewicz Maciej , Bauer Marta , Gołacki Krzysztof , Kamysz Wojciech
Published: January 2020

Ultrashort cationic lipopeptides (USCLs) are promising antimicrobial agents that hypothetically may be alternatively used to combat pathogens such as bacteria and fungi. In general, USCLs consist of fatty acid chains and a few basic amino acid residues. The main shortcoming of USCLs is their relatively high cytotoxicity and hemolytic activity. This study focuses on the impact of the hydrophobic fatty acid chain, on both antimicrobial and hemolytic activities. To learn more about this region, a series of USCLs with different straight-chain fatty acids (C8, C10, C12, C14) attached to the tripeptide with two arginine residues were synthesized. The amino acid at the N-terminal position was exchanged for proteinogenic and non-proteinogenic amino acid residues (24 in total). Moreover, the branched fatty acid residues were conjugated to N-terminus of a dipeptide with two arginine residues. All USCLs had C-terminal amides. USCLs were tested against reference bacterial strains (including ESKAPE group) and Candida albicans. The hemolytic potential was tested on human erythrocytes. Hydrophobicity of the compounds was evaluated by RP-HPLC. Shortening of the fatty acid chain and simultaneous addition of amino acid residue at N-terminus were expected to result in more selective and active compounds than those of the reference lipopeptides with similar lipophilicity. Hypothetically, this approach would also be beneficial to other antimicrobial peptides where N-lipidation strategy was used to improve their biological characteristics.
Δ-FeOOH as Support for Immobilization Peroxidase: Optimization via a Chemometric Approach
Authors: Tavares Tássia Silva , da Rocha Eduardo Pereira , Esteves Nogueira Francisco Guilherme , Torres Juliana Arriel , Silva Maria Cristina , Kuca Kamil , Ramalho Teodorico C.
Published: January 2020

Owing to their high surface area, stability, and functional groups on the surface, iron oxide hydroxide nanoparticles have attracted attention as enzymatic support. In this work, a chemometric approach was performed, aiming at the optimization of the horseradish peroxidase (HRP) immobilization process on Δ-FeOOH nanoparticles (NPs). The enzyme/NPs ratio (X1), pH (X2), temperature (X3), and time (X4) were the independent variables analyzed, and immobilized enzyme activity was the response variable (Y). The effects of the factors were studied using a factorial design at two levels (−1 and 1). The biocatalyst obtained was evaluated for the ferulic acid (FA) removal, a pollutant model. The materials were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The SEM images indicated changes in material morphology. The independent variables X1 (−0.57), X2 (0.71), and X4 (0.42) presented the significance effects estimate. The variable combinations resulted in two significance effects estimates, X1*X2 (−0.57) and X2*X4 (0.39). The immobilized HRP by optimized conditions (X1 = 1/63 (enzyme/NPs ratio, X2 = pH 8, X4 = 60 °C, and 30 min) showed high efficiency for FA oxidation (82%).
Meroterpene-Like α-Glucosidase Inhibitors Based on Biomimetic Reactions Starting from β-Caryophyllene
Authors: Yan Da-Wei , Huang Cheng-Di , Zheng Hang-Hang , Zhao Na , Feng Xiao-Lan , Ma Shuang-Jiang , Zhang An-Ling , Zhang Qiang
Published: January 2020

Background: Natural meroterpenes derived from phloroglucinols and β-caryophyllene have shown high inhibitory activity against α-glucosidase or cancer cells, however, the chemical diversity of this type of skeletons in Nature is limited. Methods: To expand the chemical space and explore their inhibitory activities against α-glucosidase (EC 3.2.1.20), we employed β-caryophyllene and some natural moieties (4-hydroxycoumarins, lawsone or syncarpic acid) to synthesize new types of meroterpene-like skeletons. All the products (including side products) were isolated and characterized by NMR, HR-MS, and ECD. Results: In total, 17 products (representing seven scaffolds) were generated through a one-pot procedure. Most products (12 compounds) showed more potential activity (IC50 < 25 μM) than the positive controls (acarbose and genistein, IC50 58.19, and 54.74 μM, respectively). Compound 7 exhibited the most potent inhibition of α-glucosidase (IC50 3.56 μM) in a mixed-type manner. The CD analysis indicated that compound 7 could bind to α-glucosidase and influence the enzyme’s secondary structure. Conclusions: Compound 7 could serve as a new type of template compound to develop α-glucosidase inhibitors. Full investigation of a biomimic reaction can be used as a concise strategy to explore diverse natural-like skeletons and search for novel lead compounds.
Fabrication and Plasma Modification of Nanofibrous Tissue Engineering Scaffolds
Authors: Asadian Mahtab , Chan Ke Vin , Norouzi Mohammad , Grande Silvia , Cools Pieter , Morent Rino , De Geyter Nathalie
Published: January 2020

This paper provides a comprehensive overview of nanofibrous structures for tissue engineering purposes and the role of non-thermal plasma technology (NTP) within this field. Special attention is first given to nanofiber fabrication strategies, including thermally-induced phase separation, molecular self-assembly, and electrospinning, highlighting their strengths, weaknesses, and potentials. The review then continues to discuss the biodegradable polyesters typically employed for nanofiber fabrication, while the primary focus lies on their applicability and limitations. From thereon, the reader is introduced to the concept of NTP and its application in plasma-assisted surface modification of nanofibrous scaffolds. The final part of the review discusses the available literature on NTP-modified nanofibers looking at the impact of plasma activation and polymerization treatments on nanofiber wettability, surface chemistry, cell adhesion/proliferation and protein grafting. As such, this review provides a complete introduction into NTP-modified nanofibers, while aiming to address the current unexplored potentials left within the field.
Suppression of DNCB-Induced Atopic Skin Lesions in Mice by Wikstroemia indica Extract
Authors: Lee So-Yeon , Park No-June , Jegal Jonghwan , Jo Beom-Geun , Choi Sangho , Lee Sang Woo , Uddin Md. Salah , Kim Su-Nam , Yang Min Hye
Published: January 2020

Wikstroemia indica (L.) C.A. Mey. is used in traditional Chinese medicine to treat inflammatory diseases such as arthritis and bronchitis. In this study, we aimed to investigate the effects of an ethanolic extract of W. indica on cutaneous inflammation in mice with 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD). Dermal administration of W. indica ethanolic extract to DNCB-sensitized hairless mice with dermatitis, for two weeks, reduced erythema, scaling, and edema. Skin hydration was improved and transepidermal water loss was reduced at a W. indica concentration of 1%. Furthermore, W. indica also significantly reduced serum IgE and IL-4 concentrations in our mouse model. These results suggest that W. indica has potential as a topical treatment for AD and as an adjunctive agent to control AD.
Theanine, the Main Amino Acid in Tea, Prevents Stress-Induced Brain Atrophy by Modifying Early Stress Responses
Authors: Unno Keiko , Sumiyoshi Akira , Konishi Tomokazu , Hayashi Michiko , Taguchi Kyoko , Muguruma Yoshio , Inoue Koichi , Iguchi Kazuaki , Nonaka Hiroi , Kawashima Ryuta , Hasegawa-Ishii Sanae , Shimada Atsuyoshi , Nakamura Yoriyuki
Published: January 2020

Chronic stress can impair the health of human brains. An important strategy that may prevent the accumulation of stress may be the consumption of functional foods. When senescence-accelerated mice prone 10 (SAMP10), a stress-sensitive strain, were loaded with stress using imposed male mouse territoriality, brain volume decreased. However, in mice that ingested theanine (6 mg/kg), the main amino acid in tea leaves, brain atrophy was suppressed, even under stress. On the other hand, brain atrophy was not clearly observed in a mouse strain that aged normally (Slc:ddY). The expression level of the transcription factor Npas4 (neuronal PAS domain protein 4), which regulates the formation and maintenance of inhibitory synapses in response to excitatory synaptic activity, decreased in the hippocampus and prefrontal cortex of stressed SAMP10 mice, but increased in mice that ingested theanine. Lipocalin 2 (Lcn2), the expression of which increased in response to stress, was significantly high in the hippocampus and prefrontal cortex of stressed SAMP10 mice, but not in mice that ingested theanine. These data suggest that Npas4 and Lcn2 are involved in the brain atrophy and stress vulnerability of SAMP10 mice, which are prevented by the consumption of theanine, causing changes in the expression of these genes.
Parents’ Perceptions about Salt Consumption in Urban Areas of Peru: Formative Research for a Social Marketing Strategy
Authors: Ponce-Lucero Vilarmina , Saavedra-Garcia Lorena , Cateriano-Arévalo Erik , Perez-Leon Silvana , Villarreal-Zegarra David , Horna-Alva Diego , Miranda J. Jaime
Published: January 2020

Background: Salt intakes in Latin America currently double the World Health Organization’s recommendation of 5 g/day. Various strategies to reduce the population’s salt consumption, such as raising awareness using social marketing, have been recommended. This study identified parents’ perceptions of salt consumption to inform a social marketing strategy focused on urban areas in Peru. Methods: Using a sequential exploratory methods design, parents of pre-school children, of high and low socioeconomic status, provided qualitative data in the form of interviews and focus groups. Following this, quantitative data was obtained via questionnaires, which were sent to all parents. The information was analyzed jointly. Results: 296 people (mean age 35.4, 82% women) participated, 64 in the qualitative and 232 in the quantitative phase of the study. Qualitative data from the first phase revealed that the majority of mothers were in charge of cooking, and female participants expressed that cooking was “their duty” as housewives. The qualitative phase also revealed that despite the majority of the participants considered their salt intake as adequate, half of them mentioned that they have tried to reduce salt consumption, and the change in the flavor of the food was stated as the most difficult challenge to continue with such practice. Quantitative data showed that 67% of participants would be willing to reduce their salt intake, and 79.7% recognized that high salt intake causes hypertension. In total, 84% of participants reaffirmed that mothers were in charge of cooking. There were no salient differences in terms of responses provided by participants from high versus low socioeconomic groups. Conclusions: The results point towards the identification of women as a potential target-audience of a social marketing strategy to promote reductions in salt intake in their families and, therefore, a gender-responsive social marketing intervention is recommended.
The Effect of a Low GI Diet on Truncal Fat Mass and Glycated Hemoglobin in South Indians with Type 2 Diabetes—A Single Centre Randomized Prospective Study
Authors: Pavithran Nivedita , Kumar Harish , Menon Arun Somasekharan , Pillai Gopala Krishna , Sundaram Karimassery Ramaiyer , Ojo Omorogieva
Published: January 2020

Background: There has been no previous study that has investigated the effect of a low glycemic index (LGI) diet with local recipes of South Indian cuisine on the body fat composition using dual-energy X-ray absorptiometry (DXA). Truncal obesity has been associated with the risk of metabolic disorders and cardiovascular diseases. Aim: The aim of this study was to examine the effect of a low GI diet on glycemic control and body composition in people with type 2 diabetes in South India. Method: This was a prospective and randomized controlled study that was conducted over a period of 24 weeks. A total of 40 participants were recruited from the Department of Endocrinology and Diabetes Outpatient in Kerala, South India. All the patients had type 2 diabetes and were randomly assigned and given advice and instructions to follow either a low GI diet plan (n = 18) or their usual diet, which served as control (n = 18). The advice was reinforced throughout the study period. Dietary compliance was evaluated based on a 24 h dietary recall at weeks 3, 11, 12, 18, 23, and 24. The age of the subjects ranged from 35 to 65 years. Anthropometric, body composition, and cardio-metabolic parameters were measured according to standard procedures. T-tests were conducted to compare differences between intervention and control groups and the Pearson correlation coefficient was used to evaluate associations between the variables. Results: There were significant reductions (p < 0.05) in the low GI diet compared to the control group with respect to weight, body mass index (BMI), and triceps skinfold thickness. Similarly, significant reductions were observed in the low GI diet group with respect to region, total fat, android, and gynoid fat mass and the differences between the groups were significant at p < 0.05. There was also a positive correlation between BMI and android fat mass (r = 0.745), total fat mass (r = 0.661), total truncal mass (r = 0.821), and truncal fat (r = 0.707). There was a significant reduction in glycated hemoglobin in the low GI diet group compared to the control group at p < 0.05. Conclusion: This study has demonstrated that there was a significant reduction (p < 0.05) of truncal obesity and glycated hemoglobin in patients with type 2 diabetes on a local diet of South Indian cuisine with low GI compared with the control.
Comparison as a Provisional Activity
Authors: Hoel Nikolas O.
Published: January 2020

The careers of many scholars in various disciplines have been focused on the study of hagiography, including that of the author. Yet, as those scholars have uncovered new knowledge and employed new interpretations of the materials at hand, the very notions of “hagiography” and “hagiology” have become deeply problematized. The issues become more complex as multiple religious traditions are examined. The scholarly work that forms the basis of the essays in this volume has explored the effects of taking a comparative and collaborative approach to “hagiography”. This piece responds to the core essays by showing first how personal the study of such sources and act of comparison can be, and then exploring how knowledge changes through the processes of comparison and collaboration. In the end, this response argues that comparison is by its very nature a provisional activity in that the knowledge it creates constantly changes as comparative methods and theories are re-applied again and again over time. This process is only aided by collaborative efforts which make the act of comparison even more effective and productive.
Temporal Patterns in Illumination Conditions and Its Effect on Vegetation Indices Using Landsat on Google Earth Engine
Authors: Martín-Ortega Pablo , García-Montero Luis Gonzaga , Sibelet Nicole
Published: January 2020

Vegetation indices (VI) describe vegetation structure and functioning but they are affected by illumination conditions (IC). Moreover, the fact that the effect of the IC on VI can be stronger than other biophysical or seasonal processes is under debate. Using Google Earth Engine and the latest Landsat Surface Reflectance level 1 data, we evaluated the temporal patterns of IC and two VI, the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) in a mountainous tropical forest during the years 1984–2017. We evaluated IC and VI at different times, their relationship with the topography and the correlations between them. We show that IC is useful for understanding the patterns of variation between VI and IC at the pixel level using Landsat sensors. Our findings confirmed a strong correlation between EVI and IC and less between NDVI and IC. We found a significant increase in IC, EVI, and NDVI throughout time due to an improvement in the position of all Landsat sensors. Our results reinforce the need to consider IC to interpret VI over long periods using Landsat data in order to increase the precision of monitoring VI in irregular topography.
Moreau-Enhanced Total Variation and Subspace Factorization for Hyperspectral Denoising
Authors: Yang Yanhong , Chen Shengyong , Zheng Jianwei
Published: January 2020

Hyperspectral images (HSIs) denoising aims at recovering noise-free images from noisy counterparts to improve image visualization. Recently, various prior knowledge has attracted much attention in HSI denoising, e.g., total variation (TV), low-rank, sparse representation, and so on. However, the computational cost of most existing algorithms increases exponentially with increasing spectral bands. In this paper, we fully take advantage of the global spectral correlation of HSI and design a unified framework named subspace-based Moreau-enhanced total variation and sparse factorization (SMTVSF) for multispectral image denoising. Specifically, SMTVSF decomposes an HSI image into the product of a projection matrix and abundance maps, followed by a ‘Moreau-enhanced’ TV (MTV) denoising step, i.e., a nonconvex regularizer involving the Moreau envelope mechnisam, to reconstruct all the abundance maps. Furthermore, the schemes of subspace representation penalizing the low-rank characteristic and ℓ 2 , 1 -norm modelling the structured sparse noise are embedded into our denoising framework to refine the abundance maps and projection matrix. We use the augmented Lagrange multiplier (ALM) algorithm to solve the resulting optimization problem. Extensive results under various noise levels of simulated and real hypspectral images demonstrate our superiority against other competing HSI recovery approaches in terms of quality metrics and visual effects. In addition, our method has a huge advantage in computational efficiency over many competitors, benefiting from its removal of most spectral dimensions during iterations.
Coarse-to-Fine Deep Metric Learning for Remote Sensing Image Retrieval
Authors: Yun Min-Sub , Nam Woo-Jeoung , Lee Seong-Whan
Published: January 2020

Remote sensing image retrieval (RSIR) is the process of searching for identical areas by investigating the similarities between a query image and the database images. RSIR is a challenging task owing to the time difference, viewpoint, and coverage area depending on the shooting circumstance, resulting in variations in the image contents. In this paper, we propose a novel method based on a coarse-to-fine strategy, which makes a deep network more robust to the variations in remote sensing images. Moreover, we propose a new triangular loss function to consider the whole relation within the tuple. This loss function improves the retrieval performance and demonstrates better performance in terms of learning the detailed information in complex remote sensing images. To verify our methods, we experimented with the Google Earth South Korea dataset, which contains 40,000 images, using the evaluation metric Recall@n. In all experiments, we obtained better performance results than those of the existing retrieval training methods. Our source code and Google Earth South Korea dataset are available online.
Analysis of the Influence of Foggy Weather Environment on the Detection Effect of Machine Vision Obstacles
Authors: Liu Zhaohui , He Yongjiang , Wang Chao , Song Runze
Published: January 2020

This study is to analyze the influence of visibility in a foggy weather environment on the accuracy of machine vision obstacle detection in assisted driving. We present a foggy day imaging model and analyze the image characteristics, then we set up the faster region convolutional neural network (Faster R-CNN) as the basic network for target detection in the simulation experiment and use Karlsruhe Institute of Technology and Toyota Technological Institute (KITTI) data for network detection and classification training. PreScan software is used to build weather and traffic scenes based on a foggy imaging model, and we study object detection of machine vision in four types of weather condition—clear (no fog), light fog, medium fog, and heavy fog—by simulation experiment. The experimental results show that the detection recall is 91.55%, 85.21%, 72.54~64.79%, and 57.75% respectively in no fog, light fog, medium fog, and heavy fog environments. Then we used real scenes in medium fog and heavy fog environment to verify the simulation experiment. Through this study, we can determine the influence of bad weather on the detection results of machine vision, and hence we can improve the safety of assisted driving through further research.