bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Nitrogen Sources on Omega-3 Polyunsaturated Fatty Acid Biosynthesis and Gene Expression in Thraustochytriidae sp.
Authors: Li Siting , Hu Zhangli , Yang Xuewei , Li Yan
Published: December 2020

The molecular mechanism that contributes to nitrogen source dependent omega-3 polyunsaturated fatty acid (n-3 PUFA) synthesis in marine oleaginous protists Thraustochytriidae sp., was explored in this study. The fatty acid (FA) synthesis was significantly influenced by the supplement of various levels of sodium nitrate (SN) (1–50 mM) or urea (1–50 mM). Compared with SN (50 mM) cultivation, cells from urea (50 mM) cultivation accumulated 1.16-fold more n-3 PUFAs (49.49% docosahexaenoic acid (DHA) (w/w, of total FAs) and 5.28% docosapentaenoic acid (DPA) (w/w, of total FAs)). Strikingly higher quantities of short chain FAs (<18 carbons) (52.22-fold of that in urea cultivation) were produced from SN cultivation. Ten candidate reference genes (RGs) were screened by using four statistical methods (geNorm, NormFinder, Bestkeeper and RefFinder). MFT (Mitochondrial folate transporter) and NUC (Nucleolin) were determined as the stable RGs to normalize the RT-qPCR (real-time quantitative polymerase chain reaction) data of essential genes related to n-3 PUFAs-synthesis. Our results elucidated that the gene transcripts of delta(3,5)-delta(2,4)-dienoyl-CoA isomerase, enoyl-CoA hydratase, fatty acid elongase 3, long-chain fatty acid acyl-CoA ligase, and acetyl-CoA carboxylase were up-regulated under urea cultivation, contributing to the extension and unsaturated bond formation. These findings indicated that regulation of the specific genes through nitrogen source could greatly stimulate n-3 PUFA production in Thraustochytriidae sp.
Candida Species (Volatile) Metabotyping through Advanced Comprehensive Two‐Dimensional Gas Chromatography
Authors: Costa Carina Pedrosa , Bezerra Ana Rita , Almeida Adelaide , Rocha Sílvia M.
Published: December 2020

Microbial metabolomics is a challenge strategy that allows a comprehensive analysis of metabolites within a microorganism and may support a new approach in microbial research, including the microbial diagnosis. Thus, the aim of this research was to in-depth explore a metabolomics strategy based on the use of an advanced multidimensional gas chromatography for the comprehensive mapping of cellular metabolites of C. albicans and non-C. albicans (C. glabrata and C. tropicalis) and therefore contributing for the development of a comprehensive platform for fungal detection management and for species distinction in early growth times (6 h). The volatile fraction comprises 126 putatively identified metabolites distributed over several chemical families: acids, alcohols, aldehydes, hydrocarbons, esters, ketones, monoterpenic and sesquiterpenic compounds, norisoprenoids, phenols and sulphur compounds. These metabolites may be related with different metabolic pathways, such as amino acid metabolism and biosynthesis, fatty acids metabolism, aromatic compounds degradation, mono and sesquiterpenoid synthesis and carotenoid cleavage. These results represent an enlargement of ca. 70% of metabolites not previously reported for C. albicans, 91% for C. glabrata and 90% for C. tropicalis. This study represents the most detailed study about Candida species exometabolome, allowing a metabolomic signature of each species, which signifies an improvement towards the construction of a Candida metabolomics platform whose application in clinical diagnostics can be crucial to guide therapeutic interventions.
Contrasting Environmental Drivers Determine Biodiversity Patterns in Epiphytic Lichen Communities along a European Gradient
Authors: Hurtado Pilar , Prieto María , de Bello Francesco , Aragón Gregorio , López-Angulo Jesús , Giordani Paolo , Díaz-Peña Eva María , Vicente Rebeca , Merinero Sonia , Košuthová Alica , Benesperi Renato , Bianchi Elisabetta , Mayrhofer Helmut , Nascimbene Juri , Grube Martin , Wedin Mats , Westberg Martin , Martínez Isabel
Published: December 2020

Assessing the ecological impacts of environmental change on biological communities requires knowledge of the factors driving the spatial patterns of the three diversity facets along extensive environmental gradients. We quantified the taxonomic (TD), functional (FD), and phylogenetic diversity (PD) of lichen epiphytic communities in 23 beech forests along Europe to examine their response to environmental variation (climate, habitat quality, spatial predictors) at a continental geographic scale. We selected six traits related to the climatic conditions in forest ecosystems, the water-use strategy and the nutrient uptake, and we built a phylogenetic tree based on four molecular markers. FD and climate determined TD and PD, with spatial variables also affecting PD. The three diversity facets were primarily shaped by distinct critical predictors, with the temperature diurnal range affecting FD and PD, and precipitation of the wettest month determining TD. Our results emphasize the value of FD for explaining part of TD and PD variation in lichen communities at a broad geographic scale, while highlighting that these diversity facets provide complementary information about the communities’ response under changing environmental conditions. Furthermore, traits such as growth form, photobiont type, and reproductive strategy mediated the response of lichen communities to abiotic factors emerging as useful indicators of macroclimatic variations.
Metabolite Characterization and Correlations with Antioxidant and Wound Healing Properties of Oil Palm (Elaeis guineensis Jacq.) Leaflets via 1H-NMR-Based Metabolomics Approach
Authors: Che Zain Mohamad Shazeli , Lee Soo Yee , Nasir Nadiah Mad , Fakurazi Sharida , Shaari Khozirah
Published: December 2020

Oil palm (Elaeis guineensis Jacq.) leaflets (OPLs) are one of the major agricultural by-products generated from the massive cultivation of Malaysian palm oil. This biomass is also reported to be of potential value based on its health-improving effects. By employing proton nuclear magnetic resonance (1H-NMR) spectroscopy combined with multivariate data analysis (MVDA), the metabolite profile of OPLs was characterized and correlated with their antioxidant and wound healing properties. Principal component analysis (PCA) classified four varieties of extracts, prepared using solvents ranging from polar to medium polarity, into three distinct clusters. Cumulatively, six flavonoids, eight organic acids, four carbohydrates, and an amine were identified from the solvent extracts. The more polar extracts, such as, the ethyl acetate-methanol, absolute methanol, and methanol-water, were richer in phytochemicals. Based on partial least square (PLS) analysis, the constituents in these extracts, such as (+)-catechin, (−)-epicatechin, orientin, isoorientin, vitexin, and isovitexin, were strongly correlated with the measured antioxidant activities, comprising ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide (NO) free radical scavenging activities, as well as with cell proliferation and migration activities. This study has provided crucial evidence on the importance of these natural antioxidant compounds on the wound healing properties of OPL.
Activity and Diversity of Microorganisms in Root Zone of Plant Species Spontaneously Inhabiting Smelter Waste Piles
Authors: Siebielec Sylwia , Siebielec Grzegorz , Sugier Piotr , Woźniak Małgorzata , Grządziel Jarosław , Gałązka Anna , Stuczyński Tomasz
Published: December 2020

The aim was to assess plant driven changes in the activity and diversity of microorganisms in the top layer of the zinc and lead smelter waste piles. The study sites comprised two types (flotation waste—FW and slag waste—SW) of smelter waste deposits in Piekary Slaskie, Poland. Cadmium, zinc, lead, and arsenic contents in these technosols were extremely high. The root zone of 8 spontaneous plant species (FW—Thymus serpyllum, Silene vulgaris, Solidago virgaurea, Echium vulgare, and Rumex acetosa; and SW—Verbascum thapsus; Solidago gigantea, Eupatorium cannabinum) and barren areas of each waste deposit were sampled. We observed a significant difference in microbial characteristics attributed to different plant species. The enzymatic activity was mostly driven by plant-microbial interactions and it was significantly greater in soil affected by plants than in bulk soil. Furthermore, as it was revealed by BIOLOG Ecoplate analysis, microorganisms inhabiting barren areas of the waste piles rely on significantly different sources of carbon than those found in the zone affected by spontaneous plants. Among phyla, Actinobacteriota were the most abundant, contributing to at least 25% of the total abundance. Bacteria belonging to Blastococcus genera were the most abundant with the substantial contribution of Nocardioides and Pseudonocardia, especially in the root zone. The contribution of unclassified bacteria was high—up to 38% of the total abundance. This demonstrates the unique character of bacterial communities in the smelter waste.
Activation and Delivery of Tetrazine-Responsive Bioorthogonal Prodrugs
Authors: Wang Yayue , Zhang Chang , Wu Haoxing , Feng Ping
Published: December 2020

Prodrugs, which remain inert until they are activated under appropriate conditions at the target site, have emerged as an attractive alternative to drugs that lack selectivity and show off-target effects. Prodrugs have traditionally been activated by enzymes, pH or other trigger factors associated with the disease. In recent years, bioorthogonal chemistry has allowed the creation of prodrugs that can be chemically activated with spatio-temporal precision. In particular, tetrazine-responsive bioorthogonal reactions can rapidly activate prodrugs with excellent biocompatibility. This review summarized the recent development of tetrazine bioorthogonal cleavage reaction and great promise for prodrug systems.
An Enantioselective Approach to 4-Substituted Proline Scaffolds: Synthesis of (S)-5-(tert-Butoxy carbonyl)-5-azaspiro[2.4]heptane-6-carboxylic Acid
Authors: López Blanca , Bartra Martí , Berenguer Ramon , Ariza Xavier , Garcia Jordi , Gómez Roberto , Torralvo Hèctor
Published: December 2020

A catalytic and enantioselective preparation of the (S)-4-methyleneproline scaffold is described. The key reaction is a one-pot double allylic alkylation of an imine analogue of glycine in the presence of a chinchonidine-derived catalyst under phase transfer conditions. These 4-methylene substituted proline derivatives are versatile starting materials often used in medicinal chemistry. In particular, we have transformed tert-butyl (S)-4-methyleneprolinate (12) into the N-Boc-protected 5-azaspiro[2.4]heptane-6-carboxylic acid (1), a key element in the industrial synthesis of antiviral ledipasvir.
Efficient Expression of Soluble Recombinant Protein Fused with Core-Streptavidin in Bacterial Strain with T7 Expression System
Authors: Tarar Ammar , Alyami Esmael M. , Peng Ching-An
Published: December 2020

The limited amount of fusion protein transported into cytosol milieu has made it challenging to obtain a sufficient amount for further applications. To avoid the laborious and expensive task, T7 promoter-driving pET-30a(+) coding for chimeric gene of thymidine phosphorylase and core streptavidin as a model system was constructed and transformed into a variety of E. coli strains with T7 expression system. Our results demonstrated that the pET-30a(+)-TP-coreSA/Lemo21(DE3) system is able to provide efficient expression of soluble TP-coreSA fusion protein for purification. Moreover, the eluted TP-coreSA fusion protein tethered on biotinylated A549 carcinoma cells could effectively eliminate these malignant cells after administrating prodrug 5′-DFUR.
Nitrogen Cycling and Mass Balance in the World’s Mangrove Forests
Authors: Alongi Daniel M.
Published: December 2020

Nitrogen (N) cycling in mangroves is complex, with rapid turnover of low dissolved N concentrations, but slow turnover of particulate N. Most N is stored in soils. The largest sources of N are nearly equal amounts of mangrove and benthic microalgal primary production. Dissolved N fluxes between the forests and tidal waters show net uptake, indicating N conservation. N2-fixation is underestimated as rapid rates measured on tree stems, aboveground roots and cyanobacterial mats cannot currently be accounted for at the whole-forest scale due to their extreme patchiness and the inability to extrapolate beyond a localized area. Net immobilization of NH4+ is the largest ecosystem flux, indicating N retention. Denitrification is the largest loss of N, equating to 35% of total N input. Burial equates to about 29% of total inputs and is the second largest loss of N. Total inputs slightly exceed total outputs, currently suggesting net N balance in mangroves. Mangrove PON export equates to ≈95% of PON export from the world’s tropical rivers, but only 1.5% of the entire world’s river discharge. Mangrove N2O emissions, denitrification, and burial contribute 0.4%, 0.5–2.0% and 6%, respectively, to the global coastal ocean, which are disproportionate to their small worldwide area.
ASC-Mediated Inflammation and Pyroptosis Attenuates Brucella abortus Pathogenesis Following the Recognition of gDNA
Authors: Tupik Juselyn D. , Coutermarsh-Ott Sheryl L. , Benton Angela H. , King Kellie A. , Kiryluk Hanna D. , Caswell Clayton C. , Allen Irving C.
Published: December 2020

Brucella abortus is a zoonotic pathogen that causes brucellosis. Because of Brucella’s unique LPS layer and intracellular localization predominately within macrophages, it can often evade immune detection. However, pattern recognition receptors are capable of sensing Brucella pathogen-associated molecular patterns (PAMPS). For example, NOD-like receptors (NLRs) can form a multi-protein inflammasome complex to attenuate Brucella pathogenesis. The inflammasome activates IL-1β and IL-18 to drive immune cell recruitment. Alternatively, inflammasome activation also initiates inflammatory cell death, termed pyroptosis, which augments bacteria clearance. In this report, we assess canonical and non-canonical inflammasome activation following B. abortus infection. We conducted in vivo studies using Asc−/− mice and observed decreased mouse survival, immune cell recruitment, and increased bacteria load. We also conducted studies with Caspase-11−/− mice and did not observe any significant impact on B. abortus pathogenesis. Through mechanistic studies using Asc−/− macrophages, our data suggests that the protective role of ASC may result from the induction of pyroptosis through a gasdermin D-dependent mechanism in macrophages. Additionally, we show that the recognition of Brucella is facilitated by sensing the PAMP gDNA rather than the less immunogenic LPS. Together, these results refine our understanding of the role that inflammasome activation and pyroptosis plays during brucellosis.
The Surface Protein Fructose-1, 6 Bisphosphate Aldolase of Klebsiella pneumoniae Serotype K1: Role of Interaction with Neutrophils
Authors: Lee Chen-Hsiang , Chuah Seng-Kee , Chang Chia-Chi , Chen Fang-Ju
Published: December 2020

Hypermucoviscosity phenotypic Klebsiella pneumoniae (HV-Kp) serotype K1 is the predominant pathogen of a pyogenic liver abscess, an emerging infectious disease that often complicates septic metastatic syndrome in diabetic patients with poor sugar control. HV-Kpisolates were more resistant to neutrophil phagocytosis than non-HV-Kpisolates because of different pathogen-associated molecular patterns. The protein expression of HV-Kp after interaction with neutrophils is unclear. We studied KP-M1 (HV phenotype; serotype K1), DT-X (an acapsularmutant strain of KP-M1), and E. coli (ATCC 25922) with the model of Kp-infected neutrophils, using a comparative proteomic approach. One the identified protein, namely fructose-1, 6-bisphosphate aldolase (FBA), was found to be distributed in the KP-M1 after infecting neutrophils. Cell fractionation experiments showed that FBA is localized both to the cytoplasm and the outer membrane. Flow cytometry demonstrated that outer membrane-localized FBA was surface-accessible to FBA-specific antibody. The fba gene expression was enhanced in high glucose concentrations, which leads to increasing bacterial resistance to neutrophils phagocytosis and killing. The KP-M1 after FBA inhibitors and FBA-specific antibody treatment showed a significant reduction in bacterial resistance to neutrophils phagocytosis and killing, respectively, compared to KP-M1 without treatment. FBA is a highly conserved surface-exposed protein that is required for optimal interaction of HV-Kp to neutrophils.
Drug-Loaded Lipid-Core Micelles in Mucoadhesive Films as a Novel Dosage Form for Buccal Administration of Poorly Water-Soluble and Biological Drugs
Authors: Chou Wai-Houng , Galaz Ariel , Jara Miguel O. , Gamboa Alexander , Morales Javier O.
Published: December 2020

The aim of the study was to develop a novel buccal dosage form to transport rhodamine 123 and human insulin as models for poorly water-soluble and biological drugs, using lipid-core micelles (LCMs)-loaded mucoadhesive films. LCMs were synthesized by a low-energy hot emulsification process, yielding spherically shaped, small-sized, monodispersed and negatively charged carriers with high entrapment efficiency. In vitro release studies demonstrated a higher release of insulin rather than rhodamine from LCMs in simulated physiological conditions, due to an initial burst release effect; however, both release profiles are mainly explained by a diffusion mechanism. Furthermore, LCMs-loaded mucoadhesive films were manufactured and preserved with similar mechanical properties and optimal mucoadhesive behavior compared to nonloaded films. Ex vivo permeation experiments using excised porcine buccal epithelium reveal that both rhodamine and insulin-loaded LCM films elicited a significantly enhanced permeation effect compared to LCMs in suspension and free drugs in solution as controls. Hence, LCMs-loaded mucoadhesive films are suitable as buccal dosage form for the transport and delivery of rhodamine 123 and insulin, as models for poorly water-soluble and biological drugs, respectively.
Semi-Solid Pharmaceutical Formulations for the Delivery of Papain Nanoparticles
Authors: Lima Caroline S. A. de , Varca Justine P. R. O. , Nogueira Kamila M. , Fazolin Gabriela N. , Freitas Lucas F. de , Souza Eliseu W. de , Lugão Ademar B. , Varca Gustavo. H. C.
Published: December 2020

Papain is a therapeutic enzyme with restricted applications due to associated allergenic reactions. Papain nanoparticles have shown to be safe for biomedical use, although a method for proper drug loading and release remains to be developed. Thus, the objective of this work was to develop and assess the stability of papain nanoparticles in a prototype semi-solid formulation suitable for dermatological or topical administrations. Papain nanoparticles of 7.0 ± 0.1 nm were synthesized and loaded into carboxymethylcellulose- and poly(vinyl alcohol)-based gels. The formulations were then assayed for preliminary stability, enzyme activity, cytotoxicity studies, and characterized according to their microstructures and protein distribution. The formulations were suitable for papain nanoparticle loading and provided a stable environment for the nanoparticles. The enzyme distribution along the gel matrix was homogeneous for all the formulations, and the proteolytic activity was preserved after the gel preparation. Both gels presented a slow release of the papain nanoparticles for four days. Cell viability assays revealed no potential cytotoxicity, and the presence of the nanoparticles did not alter the microstructure of the gel. The developed systems presented a potential for biomedical applications, either as drug delivery systems for papain nanoparticles and/or its complexes.
Exploring Antioxidant Activity, Organic Acid, and Phenolic Composition in Strawberry Tree Fruits (Arbutus unedo L.) Growing in Morocco
Authors: Zitouni Hafida , Hssaini Lahcen , Ouaabou Rachida , Viuda-Martos Manuel , Hernández Francisca , Ercisli Sezai , Ennahli Said , Messaoudi Zerhoune , Hanine Hafida
Published: December 2020

This study aimed to explore the main biochemical components and the antioxidant capacity of five strawberry tree fruits using three antioxidant essays within the ecotypic comparison scheme, to find out the most valuable fruit presenting disease-preventing properties. Total phenols, total flavonoids, total anthocyanins, antioxidant activity (DPPH, ABTS, and β-Carotene bleaching assays), pH, titratable acidity, soluble solids, and moisture content were investigated in five strawberry tree genotypes belonging to several areas in Morocco. Phenolic compounds were also identified using high performance chromatography (HPLC), with a diode array detector (DAD). High significant differences (p ˂ 0.05) were revealed among the examined genotypes regarding their total phenols (25.37–39.06 mg gallic acid equivalents (GAE)/g Dry weight (DW), total flavonoids (3.30–7.07 mg RE/g Dry weight (DW), total anthocyanins (0.15–0.64 mg cya-3-glu/100g Dry weight (DW), pH (2.44–3.92), titratable acidity (0.65–1.01 g malic acid/100g Fresh weight (FW), and soluble solids (14.83–18.53%). The average radical scavenging capacity, assessed using three methods, exhibited the following concentration ranges: 3.33–21.08, 2.25–19.58, and 1.08–13 mg Ascorbic Equivalent (AAE/g Dry weight(DW) for the DPPH scavenging test, ABTS, and β-carotene bleaching, respectively. Seventeen phenolic compounds were identified in sampled cultivars. Gallocatechol and catechin were found to be the major phenolic compounds. The correlation matrix revealed significant correlations among investigated variables, particularly ABTS and DPPH. The principal component analysis showed that the first three components formed 90.25% of the total variance. The following variables: chlorogenic acid, ellagic acid derivative, ellagic acid, rutin, and cyanidin−30.5-diglucoside, were the most involved in the total variance. The results revealed highly promising physico-biochemical profiles within the studied strawberry tree genotypes.
Contribution to the Orophilous Cushion-Like Vegetation of Central-Southern and Insular Greece
Authors: Musarella Carmelo Maria , Brullo Salvatore , del Galdo Gianpietro Giusso
Published: December 2020

The results of a phytosociological investigation regarding the orophilous cushion-like vegetation occurring in the top of the high mountains of central-southern Greece and in some Ionian (Lefkas, Cephalonia) and Aegean Islands (Euboea, Samos, Lesvos, Chios and Thassos) are provided. Based on 680 phytosociological relevès (460 unpublished and 220 from literature), a new syntaxonomical arrangement is proposed with the description of a new class, including two new orders, eight new alliances, and several associations (many of them new). Compared to the previous hierarchical framework usually followed in the literature, this study provides a more realistic and clear phytosociological characterization of this peculiar and archaic vegetation type, which is exclusive to the high mountains of the north-eastern Mediterranean. The new arrangement is mainly based on the phytogeographical role of the orophytes featuring this very specialized vegetation, which is essentially represented by endemics or rare species belonging to the ancient Mediterranean Tertiary flora. In addition, taxonomic research on the orophilous flora occurring in these plant communities allowed to identify six species new to science (i.e., Astragalus corinthiacus, Allium cremnophilum, A. cylleneum, A. orosamium, A. karvounis, and A. lefkadensis) and a new subspecies (i.e., Allium hirtovaginatum subsp. samium), and two new combinations (i.e., Astragalus rumelicus subsp. euboicus and subsp. taygeticus) are proposed.
Induction of Hairy Roots on Somatic Embryos of Rhizoclones from Typha domingensis Seedlings
Authors: Hernández-Piedra Guadalupe , Ruiz-Carrera Violeta , Sánchez Alberto J. , Azpeitia-Morales Alfonso , Calva-Calva Graciano
Published: December 2020

A protocol for the induction of hairy roots on somatic embryos of rhizoclones from Typha domingensis seedlings grown in hydroponic rhizotron systems was established for the first time. Rhizogenesis was induced through the agrotransformation of somatic embryos in oblong and scutellar states of development using the K599, LBA9402, and A4 strains of Agrobacterium rhizogenes. The transfection to the embryos was performed by cocultivation of rhizoclones on a Murashige and Skoog mineral medium at 50% strength (MS0.5), in the dark, at 28 ± 2 °C for 72 h. In contrast to nontransformed embryos that did not exhibit any root tissue, transformed embryos presented hairy roots that varied in number, length, and density depending on the bacterial strain, and K599 was the most effective strain. After analysis via optical microscopy, the transformed embryos were collected and transferred to fresh culture media supplemented with 400 mg mL−1 cefotaxime and 10 mg L−1 ascorbic acid. The efficiency of transformation and survival of the oblong and scutellar embryos were similar among the three bacterial strains. The results show that agrotransformation of somatic embryos of rhizoclones from T. domingensis is a novel and viable strategy for the generation of genetic transformants of Typha that have potential applications in bioremediation technologies.
Thermally Conductive Polyethylene/Expanded Graphite Composites as Heat Transfer Surface: Mechanical, Thermo-Physical and Surface Behavior
Authors: Sobolčiak Patrik , Abdulgader Asma , Mrlik Miroslav , Popelka Anton , A. Abdala Ahmed , A. Aboukhlewa Abdelnasser , Karkri Mustapha , Kiepfer Hendrik , Bart Hans-Jörg , Krupa Igor
Published: December 2020

Composites of high-density polyethylene (HDPE) and expanded graphite (EG) are prepared for heat exchangers in multi-effect distillation (MED) desalination. At 50 wt.% EG loading, the thermal conductivity of HDPE was increased by 372%. Moreover, the surface wettability of the HDPE/EG composite was enhanced by corona and RF plasma treatment as demonstrated by the increase in surface free energy from 28.5 mJ/m2 for untreated HDPE/EG to 55.5 and 54.5 mJ/m2 for HDPE/EG treated by corona and RF plasma, respectively. This enhanced surface wettability was retained over a long time with only a 9% and 18% decrease in RF and corona plasma-treated samples’ surface energy after two months. The viscoelastic moduli and the complex viscosity profiles indicated that EG content dictates the optimum processing technique. At loading below 30 wt.%, the extrusion process is preferred, while above 30 wt.% loading, injection molding is preferred. The plasma treatment also improved the HDPE/EG composite overall heat transfer coefficient with an overall heat transfer coefficient of the composite reaching about 98% that of stainless steel. Moreover, the plasma-treated composite exhibited superior resistance to crystallization fouling in both CaSO4 solution and artificial seawater compared to untreated composites and stainless-steel surfaces.
Adsorption Thermodynamics and Kinetics of Resin for Metal Impurities in Bis(2-hydroxyethyl) Terephthalate
Authors: Fatima Noor , Zhang Qi , Chen Ruru , Yan Dongxia , Zhou Qing , Lu Xingmei , Xin Jiayu
Published: December 2020

Adsorption of heavy metals from degraded of Polyethylene terephthalate (PET) products by strong cation exchange resin AmberliteIR-120 under optimized conditions toward the selectivity removal of metals are in the following order: Al3+ > Zn2+ > Mg2+ > Fe2+ > Ni2+. Therefore, kinetic and adsorption isotherm models were applied for fitting experimental data. Comparatively, adsorption isotherm study revealed that Langmuir isotherm model better fits adsorption on surface of resin over than the Freundlich model. In summary, AmberliteIR-120 strong acid cation exchange resin can be used as an efficient adsorbent for heavy metals removal from depolymerized products bis(2-hydroxyethyl) terephthalate.
Deformable Polyurethane Joints and Fibre Grids for Resilient Seismic Performance of Reinforced Concrete Frames with Orthoblock Brick Infills
Authors: Rousakis Theodoros , Ilki Alper , Kwiecien Arkadiusz , Viskovic Alberto , Gams Matija , Triller Petra , Ghiassi Bahman , Benedetti Andrea , Rakicevic Zoran , Colla Camilla , Halici Omer Faruk , Zając Bogusław , Hojdys Łukasz , Krajewski Piotr , Rizzo Fabio , Vanian Vachan , Sapalidis Anastasios , Papadouli Efthimia , Bogdanovic Aleksandra
Published: December 2020

The behaviour of reinforced concrete frames with masonry wall infills is influenced a lot by the stiffness and strength difference between the frame and the infill, causing early detrimental damage to the infill or to the critical concrete columns. The paper reports the results from shake table seismic tests on a full-scale reinforced concrete (RC) frame building with modified hollow clay block (orthoblock brick) infill walls, within INMASPOL SERA Horizon 2020 project. The building received innovative resilient protection using Polyurethane Flexible Joints (PUFJs) made of polyurethane resin (PU), applied at the frame-infill interface in different schemes. Further, PUs were used for bonding of glass fibre grids to the weak masonry substrate to form Fibre Reinforced Polyurethanes (FRPUs) as an emergency repair intervention. The test results showed enhancement in the in-plane and out-of-plane infill performance under seismic excitations. The results confirmed remarkable delay of significant infill damages at very high RC frame inter-story drifts as a consequence of the use of PUFJs. Further, the PUFJ protection enabled the resilient repair of the infill even after very high inter-story drift of the structure up to 3.7%. The applied glass FRPU system efficiently protected the damaged infills against collapse under out-of-plane excitation while they restored large part of their in-plane stiffness.
Synthesis and Characterization of Polyaniline-Chitosan Patches with Enhanced Stability in Physiological Conditions
Authors: Rahman Sami Ur , Bilal Salma , ul Haq Ali Shah Anwar
Published: December 2020

Electroconductive polymeric patches are being developed in the hope to interface with the electroresponsive tissues. For these constructs, conjugated polymers are considered as conductive components for their electroactive nature. Conversely, the clinical applications of these conductive polymeric patches are limited due to their short operational time, a decrease in their electroactivity occurs with the passage of time. This paper reports on the polymerization of aniline on prefabricated chitosan films on microscopic glass slides in the presence of sodium phytate. The strong chelation among sodium phytate, aniline and chitosan led to the formation of electoconductive polymeric patch. We assume that immobilization of sodium phytate in the polymeric patch helps to prevent electric deterioration, extend its electronic stability and reduce sheet resistance. The patch oxidized after three weeks (21 days) of incubation in phosphate buffer (pH 7.4 as physiological medium). This feasible fabrication technique set the foundation to design electronically stable, conjugated polymer-based patches, by providing a robust system of conduction that could be used with electroactive tissues such as cardiac muscles at the interface.
Micellar Carriers Based on Amphiphilic PEG/PCL Graft Copolymers for Delivery of Active Substances
Authors: Odrobińska Justyna , Neugebauer Dorota
Published: December 2020

Amphiphilic copolymers of alkyne functionalized 2-hydroxyethyl methacrylate (AlHEMA) and poly(ethylene glycol) methyl ether methacrylate (MPEGMA) with graft or V-shaped graft topologies were synthesized. The functionalization of poly(ε-caprolactone) (PCL) with azide group enabled attachment to P(AlHEMA-co-MPEGMA) copolymers via a “click” alkyne-azide reaction. The introduction of PCL as a second side chain type in addition to PEG resulted in heterografted copolymers with modified properties such as biodegradability. “Click” reactions were carried out with efficiencies between 17–70% or 32–50% (for lower molecular weight PCL, 4000 g/mol, or higher molecular weight PCL, 9000 g/mol, respectively) depending on the PEG grafting density. The graft copolymers were self-assembled into micellar superstructures with the ability to encapsulate active substances, such as vitamin C (VitC), arbutin (ARB) or 4-n-butylresorcinol (4nBRE). Drug loading contents (DLC) were obtained in the range of 5–55% (VitC), 39–91% (ARB) and 42–98% (4nBRE). In vitro studies carried out in a phosphate buffer saline (PBS) solution (at pH 7.4 or 5.5) gave the maximum release levels of active substances after 10–240 min depending on the polymer system. Permeation tests in Franz chambers indicated that the bioactive substances after release by micellar systems penetrated through the artificial skin membrane in small amounts, and a majority of the bioactive substances remained inside the membrane, which is satisfactory for most cosmetic applications.
An Overview of Current Knowledge on the Properties, Synthesis and Applications of Quaternary Chitosan Derivatives
Authors: Freitas Emanuelle Dantas , Moura Jr. Celso Fidelis , Kerwald Jonas , Beppu Marisa Masumi
Published: December 2020

Chitosan, a chitin-derivative polysaccharide, known for its non-toxicity, biocompatibility and biodegradability, presents limited applications due to its low solubility in neutral or basic pH medium. Quaternization stands out as an alternative to modify this natural polymer, aiming to improve its solubility over a wide pH range and, consequently, expand its range of applications. Quaternization occurs by introducing a quaternary ammonium moiety onto or outside the chitosan backbone, via chemical reactions with primary amino and hydroxyl groups, under vast experimental conditions. The oldest and most common forms of quaternized chitosan involve N,N,N-trimethyl chitosan (TMC) and N-[(2-hydroxy-3-trimethyl ammonium) propyl] chitosan (HTCC) and, more recently, quaternized chitosan by insertion of pyridinium or phosphonium salts. By modifying chitosan through the insertion of a quaternary moiety, permanent cationic charges on the polysaccharide backbone are achieved and properties such as water solubility, antimicrobial activity, mucoadhesiveness and permeability are significantly improved, enabling the application mainly in the biomedical and pharmaceutical areas. In this review, the main quaternized chitosan compounds are addressed in terms of their structure, properties, synthesis routes and applications. In addition, other less explored compounds are also presented, involving the main findings and future prospects regarding the field of quaternized chitosans.
Antimicrobial Activity and GC-MS Profile of Copaiba Oil for Incorporation into Xanthosoma mafaffa Schott Starch-Based Films
Authors: Rodrigues Giovana de Menezes , Filgueiras Cristina Tostes , Garcia Vitor Augusto dos Santos , Carvalho Rosemary Aparecida de , Velasco José Ignacio , Fakhouri Farayde Matta
Published: December 2020

The present study evaluated the effect of the incorporation of copaiba oil, in direct and in microencapsulated form, into films based on Xanthosoma mafaffa Schott starch. Initially, the characterization of copaiba oil by gas chromatograph coupled with mass spectrometry (GC-MS) and its antimicrobial activity against gram-positive and gram-negative bacteria was performed. The films were produced by the casting technique and characterized in relation to physical, chemical, structural, and antimicrobial activity. Sesquiterpenes, mainly β-caryophyllene, were the predominant compounds in copaiba oil, showing antimicrobial activity against B. subtilis and S. aureus. The films showed forming capacity, however, was observed a decrease in solubility and revealed an increase in hydrophobic characteristics. However, the oil reduced the tensile strength and elongation, while the microcapsules did not influence the mechanical properties in comparison to the control film. From microstructure analysis, changes in the films roughness and surface were observed after the addition of oil both directly and in microencapsulated form. Films incorporated with microparticles were able to inhibit the gram-positive bacteria tested, forming inhibition zones, indicating that the encapsulation of copaiba oil was more efficient for protecting bioactive compounds from the oil, suggesting the possible application of mangarito starch-based films incorporated with copaiba oil as biodegradable packaging.
5-Fluorouracil Loaded Biogenic and Albumin Capped Gold Nanoparticles Using Bacterial Enzyme—In Vitro-In Silico Gastroplus® Simulation and Prediction
Authors: Mahdi Wael A. , Hussain Afzal , Ramzan Mohd.
Published: December 2020

The study investigated in situ biosynthesis of albumin capped 5-fluorouracil (5-FU) loaded gold nanoparticles (NPs) using bacterial extract for enhanced efficacy against MCF-7 and in silico prediction using a GastroPlus® software. The optimized formulations were characterized for morphology, size, zeta potential, drug loading (%DL) and entrapment (%EE), compatibility, in vitro drug release, in vitro hemolysis, cellular toxicity and apoptosis studies. The results exhibited highly dispersed albumin capped mono-metallic stable NPs. Spherical size, negative zeta potential and polydispersity index were in range of 38.25–249.62 nm, 18.18–29.87 mV and 0.11–0.283, respectively. F11, F7 and F3 showed a progressive increase in %DL and %EE with increased concentration of the cellular lysate (100% > 50% > 10%). The drug release was relatively extended over 48 h as compared to drug solution (96.64% release within 5 h). The hemolysis result ensured hemocompatibility (<14%) at the explored concentration. The biogenic F11 was more cytotoxic (81.99% inhibition by F11 and 72.04% by pure 5-FU) to the MCF-7 cell lines as compared to others which may be attributed to the preferential accumulation by the tumor cell and capped albumin as the source of energy to the cancer cells. Finally, GastroPlus® predicted the key factors responsible for improved pharmacokinetics parameters and regional absorption from various segments of human intestine. Thus, the approach can be more efficacious and suitable to control breast cancer when administered transdermally or orally.
Optimal Sizing of an Island Hybrid Microgrid Based on Improved Multi-Objective Grey Wolf Optimizer
Authors: Zhu Wenqiang , Guo Jiang , Zhao Guo , Zeng Bing
Published: December 2020

The hybrid renewable energy system is a promising and significant technology for clean and sustainable island power supply. Among the abundant ocean energy sources, tidal current energy appears to be very valuable due to its excellent predictability and stability, particularly compared with the intermittent wind and solar energy. In this paper, an island hybrid energy microgrid composed of photovoltaic, wind, tidal current, battery and diesel is constructed according to the actual energy sources. A sizing optimization method based on improved multi-objective grey wolf optimizer (IMOGWO) is presented to optimize the hybrid energy system. The proposed method is applied to determine the optimal system size, which is a multi-objective problem including the minimization of annualized cost of system (CACS) and deficiency of power supply probability (DPSP). MATLAB software is utilized to program and simulate the hybrid energy system. Optimization results confirm that IMOGWO is feasible to optimally size the system, and the energy management strategy effectively matches the requirements of system operation. Furthermore, comparison of hybrid systems with and without tidal current turbines is undertaken to confirm that the utilization of tidal current turbines can contribute to enhancing system reliability and reducing system investment, especially in areas with abundant tidal energy sources.
Extreme Learning Machine Based on Firefly Adaptive Flower Pollination Algorithm Optimization
Authors: Liu Ting , Fan Qinwei , Kang Qian , Niu Lei
Published: December 2020

Extreme learning machine (ELM) has aroused a lot of concern and discussion for its fast training speed and good generalization performance, and it has been used diffusely in both regression and classification problems. However, on account of the randomness of input parameters, it requires more hidden nodes to obtain the desired accuracy. In this paper, we come up with a firefly-based adaptive flower pollination algorithm (FA-FPA) to optimize the input weights and thresholds of the ELM algorithm. Nonlinear function fitting, iris classification and personal credit rating experiments show that the ELM with FA-FPA (FA-FPA-ELM) can obtain significantly better generalization performance (such as root mean square error, classification accuracy) than traditional ELM, ELM with firefly algorithm (FA-ELM), ELM with flower pollination algorithm (FPA-ELM), ELM with genetic algorithm (GA-ELM) and ELM with particle swarm optimization (PSO-ELM) algorithms.
Integrating Ministerial Visions: Lessons from Campus Ministry
Authors: Day Maureen K. , McCrabb Barbara H.
Published: December 2020

In recent years, colleges and universities have seen an increase in a relatively new model of Catholic campus ministry: missionary organizations. As these missionaries grow in number, there is also an increase in the number of campuses that simultaneously use missionaries and long-term, professional ministers with graduate degrees. Drawing upon two national studies of Catholic campus ministers and the work of a national task force, this article will illuminate the obstacles these blended teams face in crafting a more holistic engagement with the Catholic tradition. It will also outline the steps to promote a more integrated ministerial vision and to become more pastorally effective. Implications for ministry more broadly are discussed.
Observer-Based Event-Triggered Predictive Control for Networked Control Systems under DoS Attacks
Authors: Lu Weifan , Yin Xiuxia , Fu Yichuan , Gao Zhiwei
Published: December 2020

This paper studies the problem of DoS attack defense based on static observer-based event-triggered predictive control in networked control systems (NCSs). First, under the conditions of limited network bandwidth resources and the incomplete observability of the state of the system, we introduce the event-triggered function to provide a discrete event-triggered transmission scheme for the observer. Then, we analyze denial-of-service (DoS) attacks that occur on the network transmission channel. Using the above-mentioned event-triggered scheme, a novel class of predictive control algorithms is designed on the control node to proactively save network bandwidth and compensate for DoS attacks, which ensures the stability of NCSs. Meanwhile, a closed-loop system with an observer-based event-triggered predictive control scheme for analysis is created. Through linear matrix inequality (LMI) and the Lyapunov function method, the design of the controller, observer and event-triggered matrices is established, and the stability of the scheme is analyzed. The results show that the proposed solution can effectively compensate DoS attacks and save network bandwidth resources by combining event-triggered mechanisms. Finally, a smart grid simulation example is employed to verify the feasibility and effectiveness of the scheme’s defense against DoS attacks.
A ppm Ethanol Sensor Based on Fabry–Perot Interferometric Surface Stress Transducer at Room Temperature
Authors: Takahashi Toshiaki , Choi Yong-Joon , Sawada Kazuaki , Takahashi Kazuhiro
Published: December 2020

Disease screening by exhaled breath diagnosis is less burdensome for patients, and various devices have been developed as promising diagnostic methods. We developed a microelectromechanical system (MEMS) optical interferometric surface stress sensor to detect volatile ethanol gas at room temperature (26~27 °C) with high sensitivity. A sub-micron air gap in the optical interferometric sensor reduces interference orders, leading to increased spectral response associated with nanomechanical deflection caused by ethanol adsorption. The sub-micron cavity was embedded in a substrate using a transfer technique of parylene-C nanosheet. The sensor with a 0.4 µm gap shows a linear stable reaction, with small standard deviations, even at low ethanol gas concentrations of 5–110 ppm and a reversible reaction to the gas concentration change. Furthermore, the possibility of detecting sub-ppm ethanol concentration by optimizing the diameter and thickness of the deformable membrane is suggested. Compared with conventional MEMS surface stress gas sensors, the proposed optical interferometric sensor demonstrated high-sensitivity gas detection with exceeding the detection limit by two orders of magnitude while reducing the sensing area.
Characteristics of a Hybrid Detector Combined with a Perovskite Active Layer for Indirect X-ray Detection
Authors: Liu Hailiang , Lee Jehoon , Kang Jungwon
Published: December 2020

In this study, we investigated the characteristics of an organic-inorganic hybrid indirect-type X-ray detector with a CH3NH3PbI3 (MAPbI3) perovskite active layer. A layer with a thickness of 192 nm annealed at 100 °C showed higher absorption, higher crystallinity, and lower surface roughness than did perovskite layers made under different conditions. In the indirect X-ray detector, a scintillator coupled with the detector to convert X-ray photons to visible photons, and the converted photons were absorbed by the active layer to generate charge carriers. The detector with the optimized MAPbI3 (192 nm thick and 100 °C annealing condition) active layer was coupled with a CsI(Tl) scintillator which consisted of 400 μm thick CsI and 0.5 mm thick Al, and achieved the highest sensitivity, i.e., 2.84 mA/Gy·cm2. In addition, the highest short-circuit current density (JSC), i.e., 18.78 mA/cm2, and the highest mobility, i.e., 2.83 × 10−4 cm2/V·s, were obtained from the same detector without the CsI(Tl) scintillator.
Magnetic Position System Design Method Applied to Three-Axis Joystick Motion Tracking
Authors: Malagò Perla , Slanovc Florian , Herzog Stefan , Lumetti Stefano , Schaden Thomas , Pellegrinetti Andrea , Moridi Mohssen , Abert Claas , Suess Dieter , Ortner Michael
Published: December 2020

This manuscript discusses the difficulties with magnetic position and orientation (MPO) system design and proposes a general method for finding optimal layouts. The formalism introduces a system quality measure through state separation and reduces the question “How to design an MPO system?” to a global optimization problem. The latter is then solved by combining differential evolution algorithms with magnet shape variation based on analytical computations of the field. The proposed formalism is then applied to study possible realizations of continuous three-axis joystick motion tracking, realized with just a single magnet and a single 3D magnetic field sensor. The computations show that this is possible when a specific design condition is fulfilled and that large state separations as high as 1mT/∘ can be achieved under realistic conditions. Finally, a comparison to state-of-the-art design methods is drawn, computation accuracy is reviewed critically, and an experimental validation is presented.