bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Cycling of (RE)BCO-Based Superconducting Tapes Joined by Lead-Free Solders
Authors: Skarba Michal , Pekarčíková Marcela , Frolek Lubomír , Cuninková Eva , Necpal Martin
Published: February 2021

We prepared overlap soldered joints of high-temperature superconducting tapes, using various materials and preparation conditions. In order to select the joints with optimal performance, we correlated their electrical properties (derived from current–voltage curves) with the microstructure of the respective joint cross-section by scanning electron microscopy. With the first group of joints, we focused on the effect of used materials on joint resistivity and critical current, and we found that the dominant role was played by the quality of the internal interfaces of the superconducting tape. Initial joint resistivities ranged in the first group from 41 to 341 nΩ·cm2. The second group of joints underwent a series of thermal cyclings, upon which the initial resistivity range of 35–49 nΩ·cm2 broadened to 25–128 nΩ·cm2. After the total of 135 thermal cycles, three out of four joints showed no signs of significant degradation. Within the limit of 100 thermal cycles, reliable soldered joints can be thus prepared, with normalized resistivity not exceeding 1.4 and with normalized critical current above the value of 0.85.
On Unification of Methods in Theories of Fuzzy Sets, Hesitant Fuzzy Set, Fuzzy Soft Sets and Intuitionistic Fuzzy Sets
Authors: Močkoř Jiří , Hýnar David
Published: February 2021

The main goal of this publication is to show that the basic constructions in the theories of fuzzy sets, fuzzy soft sets, fuzzy hesitant sets or intuitionistic fuzzy sets have a common background, based on the theory of monads in categories. It is proven that ad hoc defined basic concepts in individual theories, such as concepts of power set structures in these theories, relations or approximation operators defined by these relations are only special examples of applications of the monad theory in categories. This makes it possible, on the one hand, to unify basic constructions in all these theories and, on the other hand, to verify the legitimacy of ad hoc definitions of these constructions in individual theories. This common background also makes it possible to transform these basic concepts from one theory to another.
Heuristic Design of Advanced Martensitic Steels That Are Highly Resistant to Hydrogen Embrittlement by ε-Carbide
Authors: Shimotomai Michio
Published: February 2021

Many advanced steels are based on tempered martensitic microstructures. Their mechanical strength is characterized by fine sub-grain structures with a high density of free dislocations and metallic carbides and/or nitrides. However, the strength for practical use has been limited mostly to below 1400 MPa, owing to delayed fractures that are caused by hydrogen. A literature survey suggests that ε-carbide in the tempered martensite is effective for strengthening. A preliminary experimental survey of the hydrogen absorption and hydrogen embrittlement of a tempered martensitic steel with ε-carbide precipitates suggested that the proper use of carbides in steels can promote a high resistance to hydrogen embrittlement. Based on the surveys, martensitic steels that are highly resistant to hydrogen embrittlement and that have high strength and toughness are proposed. The heuristic design of the steels includes alloying elements necessary to stabilize the ε-carbide and procedures to introduce inoculants for the controlled nucleation of ε-carbide.
Synthesis of Printable Polyvinyl Alcohol for Aerosol Jet and Inkjet Printing Technology
Authors: Monne Mahmuda Akter , Howlader Chandan Qumar , Mishra Bhagyashree , Chen Maggie Yihong
Published: February 2021

Polyvinyl Alcohol (PVA) is a promising polymer due to its high solubility with water, availability in low molecular weight, having short polymer chain, and cost-effectiveness in processing. Printed technology is gaining popularity to utilize processible solution materials at low/room temperature. This work demonstrates the synthesis of PVA solution for 2.5% w/w, 4.5% w/w, 6.5% w/w, 8.5% w/w and 10.5% w/w aqueous solution was formulated. Then the properties of the ink, such as viscosity, contact angle, surface tension, and printability by inkjet and aerosol jet printing, were investigated. The wettability of the ink was investigated on flexible (Kapton) and non-flexible (Silicon) substrates. Both were identified as suitable substrates for all concentrations of PVA. Additionally, we have shown aerosol jet printing (AJP) and inkjet printing (IJP) can produce multi-layer PVA structures. Finally, we have demonstrated the use of PVA as sacrificial material for micro-electro-mechanical-system (MEMS) device fabrication. The dielectric constant of printed PVA is 168 at 100 kHz, which shows an excellent candidate material for printed or traditional transistor fabrication.
The Energy Conversion behind Micro-and Nanomotors
Authors: Wang Yingmeng , Tu Yingfeng , Peng Fei
Published: February 2021

Inspired by the autonomously moving organisms in nature, artificially synthesized micro-nano-scale power devices, also called micro-and nanomotors, are proposed. These micro-and nanomotors that can self-propel have been used for biological sensing, environmental remediation, and targeted drug transportation. In this article, we will systematically overview the conversion of chemical energy or other forms of energy in the external environment (such as electrical energy, light energy, magnetic energy, and ultrasound) into kinetic mechanical energy by micro-and nanomotors. The development and progress of these energy conversion mechanisms in the past ten years are reviewed, and the broad application prospects of micro-and nanomotors in energy conversion are provided.
Numerical Analysis of Thermophoresis of a Charged Spheroidal Colloid in Aqueous Media
Authors: Zhou Yi , Yang Yang , Zhu Changxing , Yang Mingyuan , Hu Yi
Published: February 2021

Thermophoresis of charged colloids in aqueous media has wide applications in biology. Most existing studies of thermophoresis focused on spherical particles, but biological compounds are usually non-spherical. The present paper reports a numerical analysis of the thermophoresis of a charged spheroidal colloid in aqueous media. The model accounts for the strongly coupled temperature field, the flow field, the electric potential field, and the ion concentration field. Numerical simulations revealed that prolate spheroids move faster than spherical particles, and oblate spheroids move slower than spherical particles. For the arbitrary electric double layer (EDL) thickness, the thermodiffusion coefficient of prolate (oblate) spheroids increases (decreases) with the increasing particle’s dimension ratio between the major and minor semiaxes. For the extremely thin EDL case, the hydrodynamic effect is significant, and the thermodiffusion coefficient for prolate (oblate) spheroids converges to a fixed value with the increasing particle’s dimension ratio. For the extremely thick EDL case, the particle curvature’s effect also becomes important, and the increasing (decreasing) rate of thermodiffusion coefficient for prolate (oblate) spheroids is reduced slightly.
A Combined Soda Sintering and Microwave Reductive Roasting Process of Bauxite Residue for Iron Recovery
Authors: Cardenia Chiara , Balomenos Efthymios , Wai Yin Tam Pritii , Panias Dimitrios
Published: February 2021

In this study an integrated process is presented as a suitable method to transform Fe3+ oxides present in bauxite residue into magnetic oxides and metallic iron through a microwave roasting reduction, avoiding the formation of hercynite (FeAl2O4). In the first step, all the alumina phases were transformed into sodium aluminates by adding sodium carbonate as a flux to BR and then leached out through alkali-leaching to recover alumina. Subsequently, the leaching residue was mixed with carbon and roasted by using a microwave furnace at the optimum conditions. The iron oxide present in the sinter was converted into metallic iron (98%). In addition, hercynite was not detected. The produced cinder was subjected to a wet high intensity magnetic separation process to separate iron from the other elements.
Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts
Authors: Tessema Eskedar , Elakkat Vijayanath , Chiu Chiao-Fan , Zheng Jing-Hung , Chan Ka Long , Shen Chia-Rui , Zhang Peng , Lu Norman
Published: February 2021

Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In this work, two kinds of basic pyridine-based organo-catalysts were used to efficiently catalyze phospha-Michael addition reactions, the 4-N,N-dimethylaminopyridinium saccharinate (DMAP·Hsac) salt and a fluorous long-chained pyridine (4-Rf-CH2OCH2-py, where Rf = C11F23). These catalysts have been synthesized and characterized by Lu’s group. The phospha-Michael addition of diisopropyl, dimethyl or triethyl phosphites to α, β-unsaturated malonates in the presence of those catalysts showed very good reactivity with high yield at 80–100 °C in 1–4.5 h with high catalytic recovery and reusability. With regard to significant catalytic recovery, sometimes more than eight cycles were observed for DMAP·Hsac adduct by using non-polar solvents (e.g., ether) to precipitate out the catalyst. In the case of the fluorous long-chained pyridine, the thermomorphic method was used to efficiently recover the catalyst for eight cycles in all the reactions. Thus, the easy separation of the catalysts from the products revealed the outstanding efficacy of our systems. To our knowledge, these are good examples of the application of recoverable organo-catalysts to the DMAP·Hsac adduct by using non-polar solvent and a fluorous long-chained pyridine under the thermomorphic mode in phospha-Michael addition reactions.
New Bifunctional Bis(azairidacycle) with Axial Chirality via Double Cyclometalation of 2,2′-Bis(aminomethyl)-1,1′-binaphthyl
Authors: Sato Yasuhiro , Kawata Yuichi , Yasui Shungo , Kayaki Yoshihito , Ikariya Takao
Published: February 2021

As a candidate for bifunctional asymmetric catalysts containing a half-sandwich C–N chelating Ir(III) framework (azairidacycle), a dinuclear Ir complex with an axially chiral linkage is newly designed. An expedient synthesis of chiral 2,2′-bis(aminomethyl)-1,1′-binaphthyl (1) from 1,1-bi-2-naphthol (BINOL) was accomplished by a three-step process involving nickel-catalyzed cyanation and subsequent reduction with Raney-Ni and KBH4. The reaction of (S)-1 with an equimolar amount of [IrCl2Cp*]2 (Cp* = η5–C5(CH3)5) in the presence of sodium acetate in acetonitrile at 80 °C gave a diastereomeric mixture of new dinuclear dichloridodiiridium complexes (5) through the double C–H bond cleavage, as confirmed by 1H NMR spectroscopy. A loss of the central chirality on the Ir centers of 5 was demonstrated by treatment with KOC(CH3)3 to generate the corresponding 16e amidoiridium complex 6. The following hydrogen transfer from 2-propanol to 6 provided diastereomers of hydrido(amine)iridium retaining the bis(azairidacycle) architecture. The dinuclear chlorido(amine)iridium 5 can serve as a catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with a substrate to a catalyst ratio of 200 in the presence of KOC(CH3)3 in 2-propanol, leading to (S)-1-phenylethanol with up to an enantiomeric excess (ee) of 67%.
Synthesis of New Brassinosteroid 24-Norcholane Type Analogs Conjugated in C-3 with Benzoate Groups
Authors: Ferrer Karoll , Díaz Katy , Kvasnica Miroslav , Olea Andrés F. , Cuellar Mauricio , Espinoza Luis
Published: February 2021

The metabolism of brassinosteroid leads to structural modifications in the ring skeleton or the side alkyl chain. The esterification and glycosylation at C-3 are the most common metabolic pathways, and it has been suggested that conjugate brassinosteroids are less active or inactive. In this way, plants regulate the content of active brassinosteroids. In this work, the synthesis of brassinosteroid 24-norcholane type analogs conjugated at C-3 with benzoate groups, carrying electron donor and electron attractant substituents on the aromatic ring, is described. Additionally, their growth-promoting activities were evaluated using the Rice Lamina Inclination Test (RLIT) and compared with that exhibited by brassinolide (used as positive control) and non-conjugated analogs. The results indicate that at the lowest tested concentrations (10−8–10−7 M), all analogs conjugated at C-3 exhibit similar or higher activities than brassinolide, and the diasteroisomers with S configuration at C-22 are the more active ones. Increasing concentration (10−6 M) reduces the biological activities of analogs as compared to brassinolide.
Simultaneous Quantification of 3′- and 6′-Sialyllactose in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Pharmacokinetic Study
Authors: Jang Seok-In , Eom Han Young , Hwang Jeong Ho , Kim Lila , Lee Jong-Hwa
Published: February 2021

Sialyllactose (SL), an acidic oligosaccharide, has immune-protective effects against pathogens and helps with the development of the immune system and intestinal microorganisms. To elucidate the pharmacokinetic characterization after oral administration to rats, the simultaneous quantification method for 3′-SL and 6′-SL in rat plasma was validated, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in an electrospray ionization (ESI) mode. Several types of columns [C18, amide, and hydrophilic interaction liquid chromatography (HILIC) phase] were used to separate the peaks of 3′-SL and 6′-SL, which improved chromatographic selectivity. Ultimately, the HILIC phase column had a good peak shape and quick resolution, with a mobile phase comprising ammonium acetate buffer and acetonitrile obtained by gradient elution. In addition, the simultaneous quantification of 3′-SL and 6′-SL in rat plasma samples were adequately applied to pharmacokinetic study.
Chemical Fingerprinting of Cryptic Species and Genetic Lineages of Aneura pinguis (L.) Dumort. (Marchantiophyta, Metzgeriidae)
Authors: Wawrzyniak Rafał , Wasiak Wiesław , Jasiewicz Beata , Bączkiewicz Alina , Buczkowska Katarzyna
Published: February 2021

Aneura pinguis (L.) Dumort. is a representative of the simple thalloid liverworts, one of the three main types of liverwort gametophytes. According to classical taxonomy, A. pinguis represents one morphologically variable species; however, genetic data reveal that this species is a complex consisting of 10 cryptic species (named by letters from A to J), of which four are further subdivided into two or three evolutionary lineages. The objective of this work was to develop an efficient method for the characterisation of plant material using marker compounds. The volatile chemical constituents of cryptic species within the liverwort A. pinguis were analysed by GC-MS. The compounds were isolated from plant material using the HS-SPME technique. Of the 66 compounds examined, 40 were identified. Of these 40 compounds, nine were selected for use as marker compounds of individual cryptic species of A. pinguis. A guide was then developed that clarified how these markers could be used for the rapid identification of the genetic lineages of A. pinguis. Multivariate statistical analyses (principal component and cluster analysis) revealed that the chemical compounds in A. pinguis made it possible to distinguish individual cryptic species (including genetic lineages), with the exception of cryptic species G and H. The classification of samples based on the volatile compounds by cluster analysis reflected phylogenetic relationships between cryptic species and genetic lineages of A. pinguis revealed based on molecular data.
Constructing an Efficient Bacillus subtilis Spore Display by Using Cohesin−Dockerin Interactions
Authors: Wang He , Jiang Xiaomin , Qian Yongchang , Yin Lianghong
Published: February 2021

Bacillus subtilis spore display has become a field of increasing interest in the past two decades. To improve the efficiency of B. subtilis spore display, its directed modification was performed based on the cellulosome architecture by introducing onto them divergent cohesin (Coh) modules that can specifically bind to the target enzyme bearing the matching dockerins (Doc). In this study, five different pairs of cohesins and dockerins, selected from four cellulolytic microbes, were examined for their capabilities in displaying a tetrameric enzyme β-galactosidase from Bacillus stearothermophilus IAM11001 on the surface of B. subtilis WB600 spores. Immunofluorescence microscopy, western blotting, dot blotting, and enzyme assay was applied to confirm its surface expression. All the resultant five Coh–Doc based spore display can hydrolyze o-nitrophenyl-β-D-galactopyranoside. Further, the optimized Coh–Doc based spore display exhibited the highest display efficiency. Overall, the results of current study may open new perspectives on the use of Coh–Doc interaction, which will find application in improving the efficiency of B. subtilis spore display.
Impact of In Vitro Gastrointestinal Digestion on the Bioaccessibility of Phytochemical Compounds from Eight Fruit Juices
Authors: Mihaylova Dasha , Desseva Ivelina , Stoyanova Magdalena , Petkova Nadezhda , Terzyiska Margarita , Lante Anna
Published: February 2021

Fruits contain a number of useful substances including antioxidants. Their bio-accessibility after passing through the digestive tract is of primary importance when considering their benefits. In this respect, we investigated the effect of in vitro digestion on the phytochemicals of eight fruit juices. Freshly prepared juices from pomegranate, orange and grapefruit were used as well as commercially available juices from cherry, black grapes and aloe vera, blackberry and chokeberry, and two types of chokeberry and raspberries. Spectrophotometric and HPLC methods were used in order to analyse the sugar content, the total phenolic (TPC) and flavonoid contents (TFC), anthocyanins, phenolic acids and antioxidant activity. Principle component analysis was used to explain the differentiation among the types of fruit juice. Sugar recovery variation was between 4–41%. The bio-accessibility of TPC ranged from 13.52–26.49% and of flavonoids between 24.25–67.00%. The pomegranate juice and the juice of black grapes and aloe vera kept 58.12 and 50.36% of their initial anthocyanins content, while for the other samples less than 1.10% was established. As a result, a maximum of 30% remaining antioxidant activity was measured for some of the samples, but for most this was less than 10%. In conclusion, fruit juices are a rich source of biologically active substances, but a more detailed analysis of food transformation during digestion is needed.
Slow Relaxation of the Magnetization in Anilato-Based Dy(III) 2D Lattices
Authors: Benmansour Samia , Hernández-Paredes Antonio , Bayona-Andrés María , Gómez-García Carlos J.
Published: February 2021

The search for two- and three-dimensional materials with slow relaxation of the magnetization (single-ion magnets, SIM and single-molecule magnets, SMM) has become a very active area in recent years. Here we show how it is possible to prepare two-dimensional SIMs by combining Dy(III) with two different anilato-type ligands (dianions of the 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone: C6O4X22−, with X = H and Cl) in dimethyl sulfoxide (dmso). The two compounds prepared, formulated as: [Dy2(C6O4H2)3(dmso)2(H2O)2]·2dmso·18H2O (1) and [Dy2(C6O4Cl2)3(dmso)4]·2dmso·2H2O (2) show distorted hexagonal honeycomb layers with the solvent molecules (dmso and H2O) located in the interlayer space and in the hexagonal channels that run perpendicular to the layers. The magnetic measurements of compounds 1, 2 and [Dy2(C6O4(CN)Cl)3(dmso)6] (3), a recently reported related compound, show that the three compounds present slow relaxation of the magnetization. In compound 1 the SIM behaviour does not need the application of a DC field whereas 2 and 3 are field-induced SIM (FI-SIM) since they show slow relaxation of the magnetization when a DC field is applied. We discuss the differences observed in the crystal structures and magnetic properties based on the X group of the anilato ligands (H, Cl and Cl/CN) in 1–3 and in the recently reported derivative [Dy2(C6O4Br2)3(dmso)4]·2dmso·2H2O (4) with X = Br, that is also a FI-SIM.
Therapeutic Intervention of COVID-19 by Natural Products: A Population-Specific Survey Directed Approach
Authors: Gomez Christian , Espinoza Ingrid , Faruque Fazlay , Hasan Md. Mahbub , Rahman Khondaker , Walker Larry , Muhammad Ilias
Published: February 2021

To date very few promising leads from natural products (NP) secondary metabolites with antiviral and immunomodulatory properties have been identified for promising/potential intervention for COVID-19. Using in-silico docking studies and genome based various molecular targets, and their in vitro anti-SARS CoV-2 activities against whole cell and/or selected protein targets, we select a few compounds of interest, which can be used as potential leads to counteract effects of uncontrolled innate immune responses, in particular those related to the cytokine storm. A critical factor for prevention and treatment of SARS-CoV-2 infection relates to factors independent of viral infection or host response. They include population-related variables such as concurrent comorbidities and genetic factors critically relevant to COVID-19 health disparities. We discuss population risk factors related to SARS-CoV-2. In addition, we focus on virulence related to glucose-6-phosphate dehydrogenase deficiency (G6PDd), the most common human enzymopathy. Review of data on the response of individuals and communities with high prevalence of G6PDd to NP, prompts us to propose the rationale for a population-specific management approach to rationalize design of therapeutic interventions of SARS-CoV-2 infection, based on use of NP. This strategy may lead to personalized approaches and improve disease-related outcomes.
Induction of Low Temperature Tolerance in Wheat by Pre-Soaking and Parental Treatment with Melatonin
Authors: Zhang Hua , Liu Lei , Wang Zongshuai , Feng Guozhong , Gao Qiang , Li Xiangnan
Published: February 2021

Low temperatures seriously depress germination and seedling establishment in wheat and it is of great significance to explore approaches to improve wheat tolerance to low temperatures. In this study, the effects of seed pre-soaking and parental treatment with melatonin on seed germination and low temperature tolerance during the early growing stage in wheat were studied. The results showed that pre-soaking with melatonin increased the germination rate, improved antioxidant capacity and accelerated starch degradation under low temperature, which alleviated low temperature-induced damage to the chloroplasts in coleoptiles of wheat seedlings. Parental melatonin treatment during grain filling stage significantly decreased the grain weight. Seeds from parental melatonin-treated plants showed higher germination rates and higher antioxidant enzyme activity than the control seeds under low temperature. In addition, parental treatment with melatonin modulated the activities of carbohydrate metabolism enzymes, which contributes to enhanced low temperature tolerance in wheat offspring. It was suggested that both seed pre-soaking and parental treatment with melatonin could be the effective approaches for low temperature tolerance induction in wheat.
Nanomaterials for the Diagnosis and Treatment of Urinary Tract Infections
Authors: Qindeel Maimoona , Barani Mahmood , Rahdar Abbas , Arshad Rabia , Cucchiarini Magali
Published: February 2021

The diagnosis and treatment of urinary tract infections (UTIs) remain challenging due to the lack of convenient assessment techniques and to the resistance to conventional antimicrobial therapy, showing the need for novel approaches to address such problems. In this regard, nanotechnology has a strong potential for both the diagnosis and therapy of UTIs via controlled delivery of antimicrobials upon stable, effective and sustained drug release. On one side, nanoscience allowed the production of various nanomaterial-based evaluation tools as precise, effective, and rapid procedures for the identification of UTIs. On the other side, nanotechnology brought tremendous breakthroughs for the treatment of UTIs based on the use of metallic nanoparticles (NPs) for instance, owing to the antimicrobial properties of metals, or of surface-tailored nanocarriers, allowing to overcome multidrug-resistance and prevent biofilm formation via targeted drug delivery to desired sites of action and preventing the development of cytotoxic processes in healthy cells. The goal of the current study is therefore to present the newest developments for the diagnosis and treatment of UTIs based on nanotechnology procedures in relation to the currently available techniques.
One-Pot Synthesis of SiO2@Ag Mesoporous Nanoparticle Coating for Inhibition of Escherichia coli Bacteria on Various Surfaces
Authors: Gankhuyag Sukhbayar , Bae Dong Sik , Lee Kyoung , Lee Seunghyun
Published: February 2021

Silver nanoparticles (Ag NPs) as antibacterial agents are of considerable interest owing to their simplicity, high surface area to volume ratio, and efficient oligodynamic properties. Hence, we investigated the synthesis of silica-supported Ag NPs (SiO2@Ag) as an effective antibacterial agent by using a wet-impregnation method. The formation of SiO2@Ag with Ag NP (5–15 nm diameter) on the silica particle (100–130 nm diameter) was confirmed with transmission electron microscopy (TEM). The study on antibacterial activity was performed in a liquid culture to determine the minimum inhibitory concentration (MIC) against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria. Both bacteria are chosen to understand difference in the effect of Ag NPs against Gram-negative (E. coli) and Gram-positive (B. subtilis) bacteria. SiO2@Ag mesoporous nanoparticles had excellent antibacterial activity against E. coli bacteria and fully restricted the bacterial growth when the material concentration was increased up to 1.00 mg/mL. In addition, the obtained material had good adhesion to both steel and polyethylene substrates and exhibited a high inhibition effect against E. coli bacteria.
Spin-Orbit Coupling Effects in Au 4f Core-Level Electronic Structures in Supported Low-Dimensional Gold Nanoparticles
Authors: Sahoo Smruti R. , Ke Shyue-Chu
Published: February 2021

Despite their many advantages, issues remain unresolved over the variability in catalytic activities in supported gold nanoparticle (AuNP)-based catalysts, which requires precise characterization to unravel the presence of any fine features. Herein, upon analyzing the Au 4f core-level spin-orbit components in many as-synthesized AuNP-based catalysts, we observed that like deviations in the Au 4f7/2 binding energy positions, both the Au 4f7/2-to-Au 4f5/2 peak intensity and linewidth ratios varied largely from the standard statistical bulk reference values. These deviations were observed in all the as-synthesized supported AuNPs irrespective of different synthesis conditions, variations in size, shape or morphology of the gold nanoparticles, and different support materials. On the other hand, the spin-orbit-splitting values remained almost unchanged and did not show any appreciable deviations from the atomic or bulk standard gold values. These deviations could originate due to alterations in the electronic band structures in the supported AuNPs and might be present in other NP-based catalyst systems as well, which could be the subject of future research interest.
Role of Vitamin C in Prophylaxis and Treatment of Gout—A Literature Review
Authors: Brzezińska Olga , Styrzyński Filip , Makowska Joanna , Walczak Konrad
Published: February 2021

Gout, known as “the disease of the kings”, is the most frequent type of arthritis. It results from sustained hyperuricemia that leads to monosodium urate crystal deposition in joint structures and soft tissue. Environmental factors such as diet affect the incidence of gout; there is a known relationship between the occurrence of an acute attack of gout and the consumption of alcohol and meat; and a low purine diet is a widely recognized nonpharmacological method of supplementing the treatment and preventing recurrence of arthritis. This review aims to summarize the current knowledge about the role of vitamin C in prevention and treatment of gout. A PubMed/Medline database search on the role of vitamin C in purine metabolism was done. Reports from in vitro and animal studies seem to be promising and to allow explanation of the physiological relationship between vitamin C and uric acid. Most epidemiological studies indicate a significant correlation between high vitamin C intake and lower serum uric acid levels. Despite promising observations, there are few observational and interventional studies, and their results do not clearly define the benefits of a high daily intake of vitamin C in preventing the development and recurrence of gout.
The Sum of Plasma Fatty Acids iso16:0, iso17:0, trans11-18:1, cis9, trans11-CLA, and cis6-18:1 as Biomarker of Dairy Intake Established in an Intervention Study and Validated in the EPIC Cohort of Gipuzkoa
Authors: Berriozabalgoitia Alaitz , Gordoa Juan Carlos Ruiz de , Renobales Mertxe de , Amores Gustavo , Barron Luis Javier R. , Amiano Pilar , Dorronsoro Miren , Perea Zelai , Virto Mailo
Published: February 2021

The questioned reliability of 15:0, 17:0, and trans9-16:1 acids as biomarkers of dairy fat intake also questions the relationship between the intake of these products and their health effects. Two studies were conducted in the same geographical region. In an intervention study, volunteers followed a diet rich in dairy products followed by a diet without dairy products. Plasma and erythrocyte fatty acids (FA) were analyzed, and their correlations with dairy product intakes were tested. The FA biomarkers selected were validated in the Gipuzkoa cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) observational study. The correlation coefficients between plasma concentrations of iso16:0, iso17:0, trans11-18:1, cis9, trans11-18:2, and cis6-18:1 and the dairy fat ingested are similar in both studies, indicating that their concentration increases by 0.8 µmol/L per gram of dairy fat ingested. The biomarkers are positively related to plasma triglycerides (r = 0.324 and 0.204 in the intervention and observational studies, respectively) and total cholesterol (r = 0.459 and 0.382), but no correlation was found between the biomarkers and atherogenicity indexes. In conclusion, the sum of the plasma concentration of the selected FAs can be used as biomarkers of dairy product consumption. A linear relationship exists between their plasma concentrations and ruminant product intake. These biomarkers allow for obtaining consistent relationships between dairy intake and plasma biochemical parameters.
Vitamin D Deficiency Cause Gender Specific Alterations of Renal Arterial Function in a Rodent Model
Authors: Sipos Miklós , Péterffy Borbála , Sziva Réka Eszter , Magyar Péter , Hadjadj Leila , Bányai Bálint , Süli Anita , Soltész-Katona Eszter , Gerszi Dóra , Kiss Judit , Szekeres Mária , Nádasy György L. , Horváth Eszter Mária , Várbíró Szabolcs
Published: February 2021

Vitamin D deficiency shows positive correlation to cardiovascular risk, which might be influenced by gender specific features. Our goal was to examine the effect of Vitamin D supplementation and Vitamin D deficiency in male and female rats on an important hypertension target organ, the renal artery. Female and male Wistar rats were fed with Vitamin D reduced chow for eight weeks to induce hypovitaminosis. Another group of animals received normal chow with further supplementation to reach optimal serum vitamin levels. Isolated renal arteries of Vitamin D deficient female rats showed increased phenylephrine-induced contraction. In all experimental groups, both indomethacin and selective cyclooxygenase-2 inhibition (NS398) decreased the phenylephrine-induced contraction. Angiotensin II-induced contraction was pronounced in Vitamin D supplemented males. In both Vitamin D deficient groups, acetylcholine-induced relaxation was impaired. In the female Vitamin D supplemented group NS398, in males the indomethacin caused reduced acetylcholine-induced relaxation. Increased elastic fiber density was observed in Vitamin D deficient females. The intensity of eNOS immunostaining was decreased in Vitamin D deficient females. The density of AT1R staining was the highest in the male Vitamin D deficient group. Although Vitamin D deficiency induced renal vascular dysfunction in both sexes, female rats developed more extensive impairment that was accompanied by enzymatic and structural changes.
Advances and Future Directions in the Clinical Utility of Food Addiction
Authors: Cassin Stephanie E. , Sockalingam Sanjeev
Published: February 2021

The body of research examining the validity of food addiction and eating addiction far exceeds the research examining their clinical utility [...]
Suprachoroidal Delivery of Small Molecules, Nanoparticles, Gene and Cell Therapies for Ocular Diseases
Authors: Wan Chen-rei , Muya Leroy , Kansara Viral , Ciulla Thomas A.
Published: February 2021

Suprachoroidal drug delivery technology has advanced rapidly and emerged as a promising administration route for a variety of therapeutic candidates, in order to target multiple ocular diseases, ranging from neovascular age-related macular degeneration to choroidal melanoma. This review summarizes the latest preclinical and clinical progress in suprachoroidal delivery of therapeutic agents, including small molecule suspensions, polymeric entrapped small molecules, gene therapy (viral and nonviral nanoparticles), viral nanoparticle conjugates (VNCs), and cell therapy. Formulation customization is critical in achieving favorable pharmacokinetics, and sustained drug release profiles have been repeatedly observed for multiple small molecule suspensions and polymeric formulations. Novel therapeutic agents such as viral and nonviral gene therapy, as well as VNCs, have demonstrated promise in animal studies. Several of these suprachoroidally-administered therapies have been assessed in clinical trials, including small molecule suspensions of triamcinolone acetonide and axitinib, viral vector RGX-314 for gene therapy, and VNC AU-011. With continued drug delivery research and optimization, coupled with customized drug formulations, suprachoroidal drug delivery may address large unmet therapeutic needs in ophthalmology, targeting affected tissues with novel therapies for efficacy benefits, compartmentalizing therapies away from unaffected tissues for safety benefits, and achieving durability to relieve the treatment burden noted with current agents.
Recovered Energy from Salinity Gradients Utilizing Various Poly(Acrylic Acid)-Based Hydrogels
Authors: Bui Tri Quang , Cao Vinh Duy , Wang Wei , Kjøniksen Anna-Lena
Published: February 2021

Hydrogels can be utilized to extract energy from salinity gradients when river water mixes with seawater. Saline-sensitive hydrogels exhibit a reversible swelling/shrinking process when they are, alternately, exposed to fresh and saline water. We present a comparison of several poly(acrylic acid)-based hydrogels, including poly(acrylic acid) (PAA), poly(acrylic acid-co-vinylsulfonic acid) (PAA/PVSA), and poly(4-styrenessulfonic acid-co-maleic acid) interpenetrated in a poly(acrylic acid) network (PAA/PSSA-MA). The hydrogels were synthesized by free radical polymerization, copolymerization, and by semi-IPN (interpenetrating polymer network). The hydrogels were placed in a piston-like system to measure the recovered energy. Semi-IPN hydrogels exhibit a much higher recovered energy compared to the copolymer and PAA hydrogel. The recovered energy of 60 g swollen gel was up to 4 J for the PAA/PSSA-MA hydrogel. The obtained energy per gram dried gel was up to 13.3 J/g. The swelling volume of the hydrogels was maintained for 30 cycles without decline in recovered energy.
A Review on Natural Fiber Reinforced Polymer Composite for Bullet Proof and Ballistic Applications
Authors: Nurazzi N. M. , Asyraf M. R. M. , Khalina A. , Abdullah N. , Aisyah H. A. , Rafiqah S. Ayu , Sabaruddin F. A. , Kamarudin S. H. , Norrrahim M. N. F. , Ilyas R. A. , Sapuan S. M.
Published: February 2021

Even though natural fiber reinforced polymer composites (NFRPCs) have been widely used in automotive and building industries, there is still a room to promote them to high-level structural applications such as primary structural component specifically for bullet proof and ballistic applications. The promising performance of Kevlar fabrics and aramid had widely implemented in numerous ballistic and bullet proof applications including for bullet proof helmets, vest, and other armor parts provides an acceptable range of protection to soldiers. However, disposal of used Kevlar products would affect the disruption of the ecosystem and pollutes the environment. Replacing the current Kevlar fabric and aramid in the protective equipment with natural fibers with enhanced kinetic energy absorption and dissipation has been significant effort to upgrade the ballistic performance of the composite structure with green and renewable resources. The vast availability, low cost and ease of manufacturing of natural fibers have grasped the attention of researchers around the globe in order to study them in heavy armory equipment and high durable products. The possibility in enhancement of natural fiber’s mechanical properties has led the extension of research studies toward the application of NFRPCs for structural and ballistic applications. Hence, this article established a state-of-the-art review on the influence of utilizing various natural fibers as an alternative material to Kevlar fabric for armor structure system. The article also focuses on the effect of layering and sequencing of natural fiber fabric in the composites to advance the current armor structure system.
Self-Healing Polymer Nanocomposite Materials by Joule Effect
Authors: Orellana Jaime , Moreno-Villoslada Ignacio , Bose Ranjita K. , Picchioni Francesco , Flores Mario E. , Araya-Hermosilla Rodrigo
Published: February 2021

Nowadays, the self-healing approach in materials science mainly relies on functionalized polymers used as matrices in nanocomposites. Through different physicochemical pathways and stimuli, these materials can undergo self-repairing mechanisms that represent a great advantage to prolonging materials service-life, thus avoiding early disposal. Particularly, the use of the Joule effect as an external stimulus for self-healing in conductive nanocomposites is under-reported in the literature. However, it is of particular importance because it incorporates nanofillers with tunable features thus producing multifunctional materials. The aim of this review is the comprehensive analysis of conductive polymer nanocomposites presenting reversible dynamic bonds and their energetical activation to perform self-healing through the Joule effect.
Injectable Hydrogels: From Laboratory to Industrialization
Authors: Alonso Jose Maria , Andrade del Olmo Jon , Perez Gonzalez Raul , Saez-Martinez Virginia
Published: February 2021

The transfer of some innovative technologies from the laboratory to industrial scale is many times not taken into account in the design and development of some functional materials such as hydrogels to be applied in the biomedical field. There is a lack of knowledge in the scientific field where many aspects of scaling to an industrial process are ignored, and products cannot reach the market. Injectable hydrogels are a good example that we have used in our research to show the different steps needed to follow to get a product in the market based on them. From synthesis and process validation to characterization techniques used and assays performed to ensure the safety and efficacy of the product, following regulation, several well-defined protocols must be adopted. Therefore, this paper summarized all these aspects due to the lack of knowledge that exists about the industrialization of injectable products with the great importance that it entails, and it is intended to serve as a guide on this area to non-initiated scientists. More concretely, in this work, the characteristics and requirements for the development of injectable hydrogels from the laboratory to industrial scale is presented in terms of (i) synthesis techniques employed to obtain injectable hydrogels with tunable desired properties, (ii) the most common characterization techniques to characterize hydrogels, and (iii) the necessary safety and efficacy assays and protocols to industrialize and commercialize injectable hydrogels from the regulatory point of view. Finally, this review also mentioned and explained a real example of the development of a natural hyaluronic acid hydrogel that reached the market as an injectable product.
Lignin-Based Polyols with Controlled Microstructure by Cationic Ring Opening Polymerization
Authors: Perez-Arce Jonatan , Centeno-Pedrazo Ander , Labidi Jalel , Ochoa-Gomez Jose R. , Garcia-Suarez Eduardo J.
Published: February 2021

Lignin-based polyols (LBPs) with controlled microstructure were obtained by cationic ring opening polymerization (CROP) of oxiranes in an organosolv lignin (OL) tetrahydrofuran (THF) solution. The control on the microstructure and consequently on the properties of the LBPs such as hydroxyl number, average molecular weight, melting, crystallization and decomposition temperatures, are crucial to determine the performance and application of the derived-products. The influence of key parameters, for example, molar ratio between the oxirane and the hydroxyl groups content in OLO, initial OL concentration in THF, temperature, specific flow rate and oxirane nature has been investigated. LBPs with hydroxyl numbers from 35 to 217 mg KOH/g, apparent average Mw between 5517 and 52,900 g/mol and melting temperatures from −8.4 to 18.4 °C were obtained. The CROP procedure allows obtaining of tailor-made LBPs for specific applications in a very simple way, opening the way to introduce LBPs as a solid alternative to substitute currently used fossil-based polyols.
Role of Doping Agent Degree of Sulfonation and Casting Solvent on the Electrical Conductivity and Morphology of PEDOT:SPAES Thin Films
Authors: Tomasino Daniela Valeria , Wolf Mario , Farina Hermes , Chiarello Gianluca , Feldhoff Armin , Ortenzi Marco Aldo , Sabatini Valentina
Published: February 2021

Poly(3,4-ethylenedioxythiophene) (PEDOT) plays a key role in the field of electrically conducting materials, despite its poor solubility and processability. Various molecules and polymers carrying sulfonic groups can be used to enhance PEDOT’s electrical conductivity. Among all, sulfonated polyarylether sulfone (SPAES), prepared via homogenous synthesis with controlled degree of sulfonation (DS), is a very promising PEDOT doping agent. In this work, PEDOT was synthesized via high-concentration solvent-based emulsion polymerization using 1% w/w of SPAES with different DS as dopant. It was found that the PEDOT:SPAESs obtained have improved solubility in the chosen reaction solvents, i.e., N, N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone and, for the first time, the role of doping agent, DS and polymerization solvents were investigated analyzing the electrical properties of SPAESs and PEDOT:SPAES samples and studying the different morphology of PEDOT-based thin films. High DS of SPAES, i.e., 2.4 meq R-SO3−× g−1 of polymer, proved crucial in enhancing PEDOT’s electrical conductivity. Furthermore, the DMSO capability to favor PEDOT and SPAES chains rearrangement and interaction results in the formation of a polymer film with more homogenous morphology and higher conductivity than the ones prepared from DMAc, DMF, and NMP.
Development of Antibacterial Protective Coatings Active against MSSA and MRSA on Biodegradable Polymers
Authors: Rezić Iva , Majdak Mislav , Ljoljić Bilić Vanja , Pokrovac Ivan , Martinaga Lela , Somogyi Škoc Maja , Kosalec Ivan
Published: February 2021

In this work the in vitro antimicrobial activity of colloidal solutions of nine different commercially available nanoparticles were investigated against Staphylococcus aureus strains, both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA). Research covered antimicrobial investigation of different metal and metal-oxide nanoparticles, including Ag 10 nm, Ag 40 nm, Al2O3 100 nm, Au 20 nm, Pt 4 nm, TiO2 100 nm, Y2O3 100 nm, ZnO 100 nm and ZrO2 100 nm nanoparticles. Such materials were foreseen to be applied as coatings on 3D-printed biodegradable polymers: i.e., catheters, disposable materials, hospital bedding items, disposable antimicrobial linings and bandages for chronic wounds. Therefore, the antimicrobial activity of the nanoparticles was determined by agar well diffusion assays and serial microdilution broth assays. In addition, the chromatographic characterization of elements present in trace amounts was performed as a method for tracing the nanoparticles. Moreover, the potential of preparing the rough surface of biodegradable polymers for coating with antimicrobial nanoparticles was tested by 3D-printing fused deposition methodology. The in vitro results have shown that particular nanoparticles provided powerful antimicrobial effects against MSSA and MRSA strains, and can be easily applied on different biopolymers.
New Spectrophotometric Method for Quantitative Characterization of Density-Driven Convective Instability
Authors: Teng Ying , Wang Pengfei , Jiang Lanlan , Liu Yu , Wei Yang
Published: February 2021

CO2 convective dissolution has been regarded as one of the fundamental mechanisms to accelerate the mass transfer of CO2 into brine. We present a new spectrophotometric method to characterize the convective instability and measure the dissolved CO2 mass, which enables the real-time quantitative visualization of CO2/brine transport mechanisms. Successive images were captured to identify the finger development regimes, and the convection morphologies were analyzed by the fingers length and affected area. CO2 solubility was experimentally studied, and the results are in agreement with the theoretical calculations. CO2 mass transfer flux was investigated as the Sherwood number changed. The increase in salinity and temperature has a negative effect on CO2 dissolution; here, numerical simulation and experimental phenomena are qualitatively consistent. In general, these findings confirm the feasibility of the method and improve the understanding of the physical process of CO2 convective dissolution, which can help assess the CO2 solubility trapping mass.