bluuebunny/crossref_metadata_2025 huggingface dataset:
Daily Prediction of the Arctic Sea Ice Concentration Using Reanalysis Data Based on a Convolutional LSTM Network
Authors: Liu Quanhong , Zhang Ren , Wang Yangjun , Yan Hengqian , Hong Mei
Published: March 2021

To meet the increasing sailing demand of the Northeast Passage of the Arctic, a daily prediction model of sea ice concentration (SIC) based on the convolutional long short-term memory network (ConvLSTM) algorithm was proposed in this study. Previously, similar deep learning algorithms (such as convolutional neural networks; CNNs) were frequently used to predict monthly changes in sea ice. To verify the validity of the model, the ConvLSTM and CNNs models were compared based on their spatiotemporal scale by calculating the spatial structure similarity, root-mean-square-error, and correlation coefficient. The results show that in the entire test set, the single prediction effect of ConvLSTM was better than that of CNNs. Taking 15 December 2018 as an example, ConvLSTM was superior to CNNs in simulating the local variations in the sea ice concentration in the Northeast Passage, particularly in the vicinity of the East Siberian Sea. Finally, the predictability of ConvLSTM and CNNs was analysed following the iteration prediction method, demonstrating that the predictability of ConvLSTM was better than that of CNNs.
Complete Utilization of the Major Carbon Sources Present in Sugar Beet Pulp Hydrolysates by the Oleaginous Red Yeasts Rhodotorula toruloides and R. mucilaginosa
Authors: Martins Luís C. , Palma Margarida , Angelov Angel , Nevoigt Elke , Liebl Wolfgang , Sá-Correia Isabel
Published: March 2021

Agro-industrial residues are low-cost carbon sources (C-sources) for microbial growth and production of value-added bioproducts. Among the agro-industrial residues available, those rich in pectin are generated in high amounts worldwide from the sugar industry or the industrial processing of fruits and vegetables. Sugar beet pulp (SBP) hydrolysates contain predominantly the neutral sugars d-glucose, l-arabinose and d-galactose, and the acidic sugar d-galacturonic acid. Acetic acid is also present at significant concentrations since the d-galacturonic acid residues are acetylated. In this study, we have examined and optimized the performance of a Rhodotorula mucilaginosa strain, isolated from SBP and identified at the molecular level during this work. This study was extended to another oleaginous red yeast species, R. toruloides, envisaging the full utilization of the C-sources from SBP hydrolysate (at pH 5.0). The dual role of acetic acid as a carbon and energy source and as a growth and metabolism inhibitor was examined. Acetic acid prevented the catabolism of d-galacturonic acid and l-arabinose after the complete use of the other C-sources. However, d-glucose and acetic acid were simultaneously and efficiently metabolized, followed by d-galactose. SBP hydrolysate supplementation with amino acids was crucial to allow d-galacturonic acid and l-arabinose catabolism. SBP valorization through the production of lipids and carotenoids by Rhodotorula strains, supported by complete catabolism of the major C-sources present, looks promising for industrial implementation.
Financial Crises, Macroeconomic Variables, and Long-Run Risk: An Econometric Analysis of Stock Returns Correlations (2000 to 2019)
Authors: Tronzano Marco
Published: March 2021

This paper focuses on four major aggregate stock price indexes (SP 500, Stock Europe 600, Nikkei 225, Shanghai Composite) and two “safe-haven” assets (Gold, Swiss Franc), and explores their return co-movements during the last two decades. Significant contagion effects on stock markets are documented during almost all financial crises; moreover, in line with the recent literature, the defensive role of gold and the Swiss Franc in asset portfolios is highlighted. Focusing on a new set of macroeconomic and financial series, a significant impact of these variables on stock returns correlations is found, notably in the case of the world equity risk premium. Finally, long-run risks are detected in all asset portfolios including the Chinese stock market index. Overall, this empirical evidence is of interest for researchers, financial risk managers and policy makers.
Solution Blow Spinning of Polycaprolactone—Rheological Determination of Spinnability and the Effect of Processing Conditions on Fiber Diameter and Alignment
Authors: Czarnecka Katarzyna , Wojasiński Michał , Ciach Tomasz , Sajkiewicz Pawel
Published: March 2021

The growing popularity of solution blow spinning as a method for the production of fibrous tissue engineering scaffolds and the vast range of polymer–solvent systems available for the method raises the need to study the effect of processing conditions on fiber morphology and develop a method for its qualitative assessment. Rheological approaches to determine polymer solution spinnability and image analysis approaches to describe fiber diameter and alignment have been previously proposed, although in a separate manner and mostly for the widely known, well-researched electrospinning method. In this study, a series of methods is presented to determine the processing conditions for the development of submicron fibrous scaffolds. Rheological methods are completed with extensive image analysis to determine the spinnability window for a polymer–solvent system and qualitatively establish the influence of polymer solution concentration and collector rotational speed on fiber morphology, diameter, and alignment. Process parameter selection for a tissue engineering scaffold target application is discussed, considering the varying structural properties of the native extracellular matrix of the tissue of interest.
Spectral Dependence of the Photoplastic Effect in CdZnTe and CdZnTeSe
Authors: Franc Jan , Dědič Václav , Moravec Pavel , Rejhon Martin , Grill Roman , Elhadidy Hassan , Šíma Vladimír , Cieslar Miroslav , Bratko Maroš , Roy Utpal , James Ralph B.
Published: March 2021

We studied the spectral dependence of the Vickers microhardness HV0.025 of CdZnTe and CdZnTeSe samples upon illumination and found out that it increases over the entire applied spectral range of 1540–750 nm. We also found out that the photoconductivity and microhardness are correlated. We observed changes in the correlation diagram (change of slope and an abrupt change of HV0.025 at several wavelengths of the illuminating light). Based on measurements of the relative changes of the space charge upon illumination using the Pockels effect, we suggest that the observed spectral dependence of positive photoplastic effect in CdZnTe and CdZnTeSe can be explained by the trapping of photoinduced electrons and holes, which affects the motion of the partial dislocations. The underlying physical explanation relies on the assumption that reconstructed bonds break before dislocation glide.
Study of Selected Physical-Mechanical Properties of Corn Grains Important from the Point of View of Mechanical Processing Systems Designing
Authors: Kruszelnicka Weronika
Published: March 2021

Mechanical properties of corn grains are of key importance in a design of processing machines whose energy demand depends on these properties. The aim of this study is to determine the selected mechanical properties of corn grains and the rupture energy. The research problem was formulated as questions: (1) How much force and energy is needed to induce a rupture of corn grain maintaining good quality of the product of processing (mixing, grinding transport)? (2) Can empirical distributions of the studied physical-mechanical properties be described by means of probability distributions provided by the literature? (3) Is there a relationship between the corn grain size and the selected mechanical properties, as well as rupture energy? In order to achieve the goals, the selected physical properties (size, volume) of corn grains have been distinguished and a static compression test has been carried out on an Instron 5966 testing machine. The results indicate a significant scatter of the results in terms of size, grain shape, forces, energy, and deformation corresponding to the point of inflection, bioyiled point, and rupture point. It has also been indicated that empirical distributions of the analyzed properties can be described by means of distributions known from the literature, e.g., gamma, Weibull or lognormal distributions. It has been confirmed that mechanical properties such as force, energy, and stress that cause rupture depend on the grain size, more precisely, the grain thickness—there are negative relations between thickness and force, energy and stress in relation to the point of inflection, bioyiled point, and rupture point.
Functionalization of PET with Phosphazene Grafted Graphene Oxide for Synthesis, Flammability, and Mechanism
Authors: Wei Lifei , Wang Rui , Zhu Zhiguo , Wang Wenqing , Wu Hanguang
Published: March 2021

Significant improvement in the fire resistance of polyethylene terephthalate (PET) while ensuring its mechanical properties is a tremendous challenge. A novel flame retardant (GO-HCCP, graphene oxide-hexachlorocyclotriphosphazene) was synthesized by nucleophilic substitution of the graphene oxide (GO) and hexachlorocyclotriphosphazene (HCCP) and then applied in PET by an in situ polymerization technique. The scanning electron microscope (SEM) showed a better dispersion of GO-HCCP than GO in the PET matrix. The char yield at 700 °C increased by 32.5% with the addition of GO-HCCP. Moreover, the peak heat release rate (pHRR), peak smoke produce rate (pSPR)and carbon monoxide production (COP)values significantly decreased by 26.0%, 16.7% and 37.5%, respectively, which indicates the outstanding fire and smoke suppression of GO-HCCP. In addition, the composites exhibited higher elastic modulus and tensile strength without compromising the toughness of PET matrix. These significantly reduced fire hazards properties are mainly attributed to the catalytic carbonation of HCCP and the barrier effect of GO. Thus, PET composites with good flame-retardant and mechanical properties were prepared, which provides a new strategy for further flame retardant PET preparation.
The Role of Supplementary Cementitious Materials (SCMs) in Ultra High Performance Concrete (UHPC): A Review
Authors: Park Sungwoo , Wu Siyu , Liu Zhichao , Pyo Sukhoon
Published: March 2021

Although ultra high-performance concrete (UHPC) has great performance in strength and durability, it has a disadvantage in the environmental aspect; it contains a large amount of cement that is responsible for a high amount of CO2 emissions from UHPC. Supplementary cementitious materials (SCMs), industrial by-products or naturally occurring materials can help relieve the environmental burden by reducing the amount of cement in UHPC. This paper reviews the effect of SCMs on the properties of UHPC in the aspects of material properties and environmental impacts. It was found that various kinds of SCMs have been used in UHPC in the literature and they can be classified as slag, fly ash, limestone powder, metakaolin, and others. The effects of each SCM are discussed mainly on the early age compressive strength, the late age compressive strength, the workability, and the shrinkage of UHPC. It can be concluded that various forms of SCMs were successfully applied to UHPC possessing the material requirement of UHPC such as compressive strength. Finally, the analysis on the environmental impact of the UHPC mix designs with the SCMs is provided using embodied CO2 generated during the material production.
A Unifying Framework for Perturbative Exponential Factorizations
Authors: Arnal Ana , Casas Fernando , Chiralt Cristina , Oteo José Angel
Published: March 2021

We propose a framework where Fer and Wilcox expansions for the solution of differential equations are derived from two particular choices for the initial transformation that seeds the product expansion. In this scheme, intermediate expansions can also be envisaged. Recurrence formulas are developed. A new lower bound for the convergence of the Wilcox expansion is provided, as well as some applications of the results. In particular, two examples are worked out up to a high order of approximation to illustrate the behavior of the Wilcox expansion.
Effects of Variable Punch Speed and Blank Holder Force in Warm Superplastic Deep Drawing Process
Authors: Manabe Ken-ichi , Soeda Kentaro , Shibata Akinori
Published: March 2021

A cylindrical deep drawing test was conducted for the purpose of improving the drawability, product accuracy, and quality in warm deep drawing using a superplastic material with large strain rate dependence. Then, the effects of blank holding force (BHF) and punch speed (SPD) on the flange wrinkle behavior and wall thickness distribution were investigated by experiments and theoretical analysis. A Zn-22Al-0.5Cu-0.01Mg alloy superplastic material SPZ2 with a sheet thickness of 1 mm was employed as the experimental material, and a cylindrical deep drawing experiment with the drawing ratio (DR) of 3.1 and 5 was performed at 250 °C. A good agreement was qualitatively obtained between the elementary theory on the flange wrinkle limit, the fracture limit, and the experimental results. In addition, the authors examined each variable BHF and SPD method obtained from the theory and experimentally demonstrated that the variable BHF method has a great effect on uniform wall thickness distribution and that variable SPD has a great effect on shortening the processing time for superplastic materials. Furthermore, the authors demonstrated the effectiveness of the variable BHF/SPD deep drawing method that varies both BHF and SPD simultaneously.
Salt Sensation and Regulation
Authors: Puri Sonali , Lee Youngseok
Published: March 2021

Taste sensation and regulation are highly conserved in insects and mammals. Research conducted over recent decades has yielded major advances in our understanding of the molecular mechanisms underlying the taste sensors for a variety of taste sensations and the processes underlying regulation of ingestion depending on our internal state. Salt (NaCl) is an essential ingested nutrient. The regulation of internal sodium concentrations for physiological processes, including neuronal activity, fluid volume, acid–base balance, and muscle contraction, are extremely important issues in animal health. Both mammals and flies detect low and high NaCl concentrations as attractive and aversive tastants, respectively. These attractive or aversive behaviors can be modulated by the internal nutrient state. However, the differential encoding of the tastes underlying low and high salt concentrations in the brain remain unclear. In this review, we discuss the current view of taste sensation and modulation in the brain with an emphasis on recent advances in this field. This work presents new questions that include but are not limited to, “How do the fly’s neuronal circuits process this complex salt code?” and “Why do high concentrations of salt induce a negative valence only when the need for salt is low?” A better understanding of regulation of salt homeostasis could improve our understanding of why our brains enjoy salty food so much.
Rapid Development of an Injection Mold with High Cooling Performance Using Molding Simulation and Rapid Tooling Technology
Authors: Kuo Chil-Chyuan , Nguyen Trong-Duc , Zhu Yi-Jun , Lin Shi-Xun
Published: March 2021

Rapid tooling technology (RTT) provides an alternative approach to quickly provide wax injection molds for the required products since it can reduce the time to market compared with conventional machining approaches. Removing conformal cooling channels (CCCs) is the key technology for manufacturing injection mold fabricated by rapid tooling technology. In this study, three different kinds of materials were used to fabricate CCCs embedded in the injection mold. This work explores a technology for rapid development of injection mold with high cooling performance. It was found that wax is the most suitable material for making CCCs. An innovative method for fabricating a large intermediary mold with both high load and supporting capacities for manufacturing a large rapid tooling using polyurethane foam was demonstrated. A trend equation for predicting the usage amount of polyurethane foam was proposed. The production cost savings of about 50% can be obtained. An optimum conformal cooling channel design obtained by simulation is proposed. Three injection molds with different cooling channels for injection molding were fabricated by RTT. Reductions in the cooling time by about 89% was obtained. The variation of the results between the experiment and the simulation was investigated and analyzed.
Characterization of an Electrode-Type Tactile Display Using Electrical and Electrostatic Friction Stimuli
Authors: Komurasaki Seiya , Kajimoto Hiroyuki , Shimokawa Fusao , Ishizuka Hiroki
Published: March 2021

Unlike tactile displays that use mechanical actuators, electrode-type tactile displays can be easily integrated and miniaturized because they consist of electrodes and insulators. Electrical tactile displays only require electrodes and use an electric current to stimulate vibration or pressure. Likewise, electrostatic friction tactile displays also only require electrodes and an insulator and can induce changes in friction between the display and a fingerpad. We have developed a tactile display that integrates electrical and electrostatic friction stimulation owing to their affinity to microfabrication techniques. This tactile display can provide both pressure and friction at the same time. In this study, we presented an elongated bar shape via the tactile display to experimental participants. The experimental results showed that a tactile display employing multiple stimuli as opposed to a single stimulus can induce the perception of larger shapes.
Combinatorial Effects of Protective Agents on Survival Rate of the Yeast Starter, Saccharomyces cerevisiae 88-4, after Freeze-Drying
Authors: Chin Young-Wook , Lee Saerom , Yu Hwan Hee , Yang Seung Jae , Kim Tae-Wan
Published: March 2021

A yeast starter is formulated for commercial practices, including storage and distribution. The cell viability of the yeast starter is one of the most important factors for manufacturing alcoholic beverages to ensure their properties during the fermentation and formulation processes. In this study, 64 potential protective agents were evaluated to enhance the survival rate of the brewing yeast Saccharomyces cerevisiae 88-4 after freeze-drying. In addition, the optimized combination of protective agents was assessed for long-term storage. Finally, response surface methodology was applied to investigate the optimal concentration of each protectant. Twenty of the 64 additives led to an increase in the survival rate of freeze-dried S. cerevisiae 88-4. Among the various combinations of protectants, four had a survival rate >95%. The combination of skim milk, maltose, and maltitol exhibited the best survival rate of 61% after 42 weeks in refrigerated storage, and the composition of protectants optimized by response surface methodology was 6.5–10% skim milk, 1.8–4.5% maltose, and 16.5–18.2% maltitol. These results demonstrated that the combination of multiple protectants could alleviate damage to yeasts during freeze-drying and could be applied to the manufacturing starters for fermented foods.
A Review on the Biotechnological Applications of the Operational Group Bacillus amyloliquefaciens
Authors: Ngalimat Mohamad Syazwan , Yahaya Radin Shafierul Radin , Baharudin Mohamad Malik Al-adil , Yaminudin Syafiqah Mohd. , Karim Murni , Ahmad Siti Aqlima , Sabri Suriana
Published: March 2021

Bacteria under the operational group Bacillus amyloliquefaciens (OGBa) are all Gram-positive, endospore-forming, and rod-shaped. Taxonomically, the OGBa belongs to the Bacillus subtilis species complex, family Bacillaceae, class Bacilli, and phylum Firmicutes. To date, the OGBa comprises four bacterial species: Bacillus amyloliquefaciens, Bacillus siamensis, Bacillus velezensis and Bacillus nakamurai. They are widely distributed in various niches including soil, plants, food, and water. A resurgence in genome mining has caused an increased focus on the biotechnological applications of bacterial species belonging to the OGBa. The members of OGBa are known as plant growth-promoting bacteria (PGPB) due to their abilities to fix nitrogen, solubilize phosphate, and produce siderophore and phytohormones, as well as antimicrobial compounds. Moreover, they are also reported to produce various enzymes including α-amylase, protease, lipase, cellulase, xylanase, pectinase, aminotransferase, barnase, peroxidase, and laccase. Antimicrobial compounds that able to inhibit the growth of pathogens including non-ribosomal peptides and polyketides are also produced by these bacteria. Within the OGBa, various B. velezensis strains are promising for use as probiotics for animals and fishes. Genome mining has revealed the potential applications of members of OGBa for removing organophosphorus (OPs) pesticides. Thus, this review focused on the applicability of members of OGBa as plant growth promoters, biocontrol agents, probiotics, bioremediation agents, as well as producers of commercial enzymes and antibiotics. Here, the bioformulations and commercial products available based on these bacteria are also highlighted. This review will better facilitate understandings of members of OGBa and their biotechnological applications.
Diversity of Bacterioplankton and Bacteriobenthos from the Veracruz Reef System, Southwestern Gulf of Mexico
Authors: Rodríguez-Gómez Citlali , Durán-Riveroll Lorena María , Okolodkov Yuri B. , Oliart-Ros Rosa María , García-Casillas Andrea M. , Cembella Allan D.
Published: March 2021

Bacterial diversity was explored among field samples and cultured isolates from coral reefs within the Veracruz Reef System. Bacterioplankton and bacteriobenthos were characterized by pyrosequencing 16S rRNA genes. Identified sequences belonged to the kingdom Bacteria and classified into 33 phyla. Proteobacteria (likely SAR11 clade) dominated in collective field samples, whereas Firmicutes were the most abundant taxa among cultured isolates. Bioinformatic sorting of sequences to family level revealed 223 bacterial families. Pseudomonadaceae, Exiguobacteraceae and Bacillaceae were dominant among cultured isolates. Vibrionaceae, Alteromonadaceae, and Flavobacteriaceae dominated in reef-associated sediments, whereas Rickettsiaceae and Synechoccaceae were more highly represented in the water column. Bacterial communities from sediments were more diverse than from the water column. This study reveals cryptic bacterial diversity among microenvironmental components of marine microbial reef communities subject to differential influence of anthropogenic stressors. Such investigations are critical for constructing scenarios of environmentally induced shifts in bacterial biodiversity and species composition.
Obesity and Energy Substrate Transporters in Ovarian Cancer—Review
Authors: Baczewska Marta , Bojczuk Klaudia , Kołakowski Adrian , Dobroch Jakub , Guzik Paweł , Knapp Paweł
Published: March 2021

Ovarian cancer is the seventh most common cancer in women. It is characterized by a high mortality rate because of its aggressiveness and advanced stage at the time of diagnosis. It is a nonhomogenous group of neoplasms and, of which the molecular basics are still being investigated. Nowadays, the golden standard in the treatment is debulking cytoreductive surgery combined with platinum-based chemotherapy. We have presented the interactions and the resulting perspectives between fatty acid transporters, glucose transporters and ovarian cancer cells. Studies have shown the association between a lipid-rich environment and cancer progression, which suggests the use of correspondent transporter inhibitors as promising chemotherapeutic agents. This review summarizes preclinical and clinical studies highlighting the role of fatty acid transport proteins and glucose transporters in development, growth, metastasizing and its potential use in targeted therapies of ovarian cancer.
The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen
Authors: Adamiak Katarzyna , Lewandowska Katarzyna , Sionkowska Alina
Published: March 2021

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.
On-Line Preconcentration and Simultaneous Determination of Cu and Mn in Water Samples Using a Minicolumn Packed with Sisal Fiber by MIP OES
Authors: Silva Javier , Pistón Mariela
Published: March 2021

An on-line preconcentration system for the simultaneous determination of Copper (Cu) and manganese (Mn) in water samples was developed and coupled to a microwave-induced plasma optical emission spectrometer (MIP OES). The flow injection system was designed with a minicolumn packed with sisal fiber (Agave sisalana). A multivariate experimental design was performed to evaluate the influence of pH, preconcentration time, and eluent concentration. Optimal conditions for sample preparation were pH 5.5, preconcentration time was 90 s, and HCl 0.5 mol L−1 was the eluent. The main figures of merit were detection limits 3.7 and 9.0 µg L−1 for Cu and Mn, respectively. Precision was expressed as a relative standard deviation better than 10%. Accuracy was evaluated via spiked recovery assays with recoveries between 75–125%. The enrichment factor was 30 for both analytes. These results were adequate for water samples analysis for monitoring purposes. The preconcentration system was coupled and synchronized with the MIP OES nebulizer to allow simultaneous determination of Cu and Mn as a novel sample introduction strategy. The sampling rate was 20 samples/h. Sisal fiber resulted an economical biosorbent for trace element preconcentration without extra derivatization steps and with an awfully time of use without replacement complying with the principles of green analytical methods.
The Fascinating Flexibility and Coordination Modes of a Pentamethylene Connected Macrocyclic CNC Pincer Ligand
Authors: Jordan Ronja , Kunz Doris
Published: March 2021

The coordination chemistry of an electron-rich macrocyclic CNC pincer-ligand consisting of two pentamethylene tethered N-heterocyclic carbene moieties on a carbazole backbone (bimcaC5) is investigated by mainly NMR spectroscopy and X-ray crystal structure analysis. A bridging coordination mode is found for the lithium complex. With the larger and softer potassium ion, the ligand adopts a facial coordination mode and a polymeric structure by intermolecular potassium nitrogen interactions. The facial coordination is also confirmed at a Cp*Ru fragment, while C-H activation under dehydrogenation at the alkyl chain is observed upon reaction with [Ru(PPh3)3Cl2]. In contrast, Pd(OAc)2 reacts under C-H activation at the central carbon atom of the pentamethylene tether to an alkyl-pincer macrocycle.
Selective Styrene Oxidation to Benzaldehyde over Recently Developed Heterogeneous Catalysts
Authors: Andrade Marta A. , Martins Luísa M. D. R. S.
Published: March 2021

The selective oxidation of styrene under heterogeneous catalyzed conditions delivers environmentally friendly paths for the production of benzaldehyde, an important intermediate for the synthesis of several products. The present review explores heterogeneous catalysts for styrene oxidation using a variety of metal catalysts over the last decade. The use of several classes of supports is discussed, including metal–organic frameworks, zeolites, carbon materials and silicas, among others. The studied catalytic systems propose as most used oxidants tert-butyl hydroperoxide, and hydrogen peroxide and mild reaction conditions. The reaction mechanism proceeds through the generation of an intermediate reactive metal–oxygen species by catalyst-oxidant interactions. Overall, most of the studies highlight the synergetic effects among the metal and support for the activity and selectivity enhancement.
Theasaponin E1 Inhibits Platinum-Resistant Ovarian Cancer Cells through Activating Apoptosis and Suppressing Angiogenesis
Authors: Li Bo , Tong Tuantuan , Ren Ning , Rankin Gary O. , Rojanasakul Yon , Tu Youying , Chen Yi Charlie
Published: March 2021

Novel therapeutic strategies for ovarian cancer treatment are in critical need due to the chemoresistance and adverse side effects of platinum-based chemotherapy. Theasaponin E1 (TSE1) is an oleanane-type saponin from Camellia sinensis seeds. Its apoptosis-inducing, cell cycle arresting and antiangiogenesis activities against platinum-resistant ovarian cancer cells were elucidated in vitro and using the chicken chorioallantoic membrane (CAM) assay. The results showed that TSE1 had more potent cell growth inhibitory effects on ovarian cancer OVCAR-3 and A2780/CP70 cells than cisplatin and was lower in cytotoxicity to normal ovarian IOSE-364 cells. TSE1 significantly induced OVCAR-3 cell apoptosis via the intrinsic and extrinsic apoptotic pathways, slightly arresting cell cycle at the G2/M phase, and obviously inhibited OVCAR-3 cell migration and angiogenesis with reducing the protein secretion and expression of vascular endothelial growth factor (VEGF). Western bolt assay showed that Serine/threonine Kinase (Akt) signaling related proteins including Ataxia telangiectasia mutated kinase (ATM), Phosphatase and tensin homolog (PTEN), Akt, Mammalian target of rapamycin (mTOR), Ribosome S6 protein kinase (p70S6K) and e IF4E-binding protein 1(4E-BP1) were regulated, and Hypoxia inducible factor-1α (HIF-1α) protein expression was decreased by TSE1 in OVCAR-3 cells. Moreover, TSE1 treatment potently downregulated protein expression of the Notch ligands including Delta-like protein 4 (Dll4) and Jagged1, and reduced the protein level of the intracellular domain (NICD) of Notch1. Combination treatment of TSE1 with the Notch1 signaling inhibitor tert-butyl (2S)-2-[[(2S)-2-[[2-(3,5-difluorophenyl)acetyl]amino]propanoyl]amino]-2-phenylacetate (DAPT), or the Akt signaling inhibitor wortmannin, showed a stronger inhibition toward HIF-1α activation compared with single compound treatment. Taken together, TSE1 might be a potential candidate compound for improving platinum-resistant ovarian cancer treatment via Dll4/Jagged1-Notch1-Akt-HIF-1α axis.
Chrysophanol Attenuates Manifestations of Immune Bowel Diseases by Regulation of Colorectal Cells and T Cells Activation In Vivo
Authors: Lee Hyun-Su , Jeong Gil-Saeng
Published: March 2021

Inflammatory bowel disease (IBD) is an immune disorder that develops due to chronic inflammation in several cells. It is known that colorectal and T cells are mainly involved in the pathogenesis of IBD. Chrysophanol is an anthraquinone family member that possesses several bioactivities, including anti-diabetic, anti-tumor, and inhibitory effects on T cell activation. However, it is unknown whether chrysophanol suppresses the activity of colorectal cells. In this study, we found that chrysophanol did not induce cytotoxicity in HT-29 colorectal cells. Pre-treatment with chrysophanol inhibited the mRNA levels of pro-inflammatory cytokines in tumor necrosis factor-α (TNF-α)-stimulated HT-29 cells. Western blot analysis revealed that pre-treatment with chrysophanol mitigates p65 translocation and the mitogen-activated protein kinase (MAPK) pathway in activated HT-29 cells. Results from the in vivo experiment confirmed that oral administration of chrysophanol protects mice from dextran sulfate sodium (DSS)-induced IBD. Chrysophanol administration attenuates the expression of pro-inflammatory cytokines in colon tissues of the DSS-induced IBD model. In addition, we found that oral administration of chrysophanol systemically decreased the expression of effector cytokines from mesenteric lymph nodes. Therefore, these data suggest that chrysophanol has a potent modulatory effect on colorectal cells as well as exhibiting a beneficial potential for curing IBD in vivo.
TiO2 as a Photocatalyst for Water Splitting—An Experimental and Theoretical Review
Authors: Eidsvåg Håkon , Bentouba Said , Vajeeston Ponniah , Yohi Shivatharsiny , Velauthapillai Dhayalan
Published: March 2021

Hydrogen produced from water using photocatalysts driven by sunlight is a sustainable way to overcome the intermittency issues of solar power and provide a green alternative to fossil fuels. TiO2 has been used as a photocatalyst since the 1970s due to its low cost, earth abundance, and stability. There has been a wide range of research activities in order to enhance the use of TiO2 as a photocatalyst using dopants, modifying the surface, or depositing noble metals. However, the issues such as wide bandgap, high electron-hole recombination time, and a large overpotential for the hydrogen evolution reaction (HER) persist as a challenge. Here, we review state-of-the-art experimental and theoretical research on TiO2 based photocatalysts and identify challenges that have to be focused on to drive the field further. We conclude with a discussion of four challenges for TiO2 photocatalysts—non-standardized presentation of results, bandgap in the ultraviolet (UV) region, lack of collaboration between experimental and theoretical work, and lack of large/small scale production facilities. We also highlight the importance of combining computational modeling with experimental work to make further advances in this exciting field.
Application of Elicitors in Two Ripening Periods of Vitis vinifera L. cv Monastrell: Influence on Anthocyanin Concentration of Grapes and Wines
Authors: Paladines-Quezada Diego F. , Fernández-Fernández José I. , Moreno-Olivares Juan D. , Bleda-Sánchez Juan A. , Gómez-Martínez José C. , Martínez-Jiménez José A. , Gil-Muñoz Rocío
Published: March 2021

In recent years, it has been demonstrated that the application of elicitors such as methyl-jasmonate (MeJ) and benzothiadiazole (BTH) to wine grapes can increase their phenolic and aromatic compounds if they are treated at the beginning of ripening (veraison). However, the veraison period is short, and it is not always possible to apply the treatments in a few days. Therefore, it would be of great interest to optimize the moment of elicitor application or extend the treatment period. The aim of this paper was to analyze during two consecutive years (2016–2017) the foliar application of MeJ, BTH, and a combination of both, during two different ripening periods of Monastrell grapes (veraison and mid-ripening), and determine the more appropriate moment to increase the concentration of anthocyanins. To carry out this aim, analysis of anthocyanins by HPLC in grapes and wines was mainly performed. The most suitable period for the application of MeJ, BTH, and MeJ + BTH was at mid-ripening, since the grapes showed a greater accumulation of anthocyanins at harvest. However, the MeJ + BTH treatment applied during veraison also obtained similar results, which would allow extending the application period if necessary. However, the increase in the anthocyanin content of grapes was not reflected in all the wines, which may have been due to reinforcement of the skin cell wall as a result of the application of elicitors. Further analysis is needed to improve the maceration process of the Monastrell grapes and the extraction of the anthocyanins that were increased by the treatments applied in the vineyard.
Crystallization Kinetics in BaTiO3 Synthesis from Hydrate Precursors via Microwave-Assisted Heat Treatment
Authors: Yun Han-Sol , Yun Byeong-Gyu , Shin So-Young , Jeong Dae-Yong , Cho Nam-Hee
Published: March 2021

The crystallization kinetics in BaTiO3 synthesis from hydrate precursors via microwave-assisted heating (MWH) were investigated. The structural and chemical features of powders synthesized via MWH and conventional heating (CH) were compared. The charged radicals generated under microwave irradiation were identified by chemical analysis and real-time charge flux measurements. Using Ba(OH)2∙H2O (BH1), Ba(OH)2 (BH0), and BaCO3 (BC) as the precursors for a Ba source, and TiO2∙4H2O (TH) for a Ti source, three different mixture samples, BH1TH (BH1 + TH), BH0TH (BH0 + TH), and BCTH (BC + TH), were heat-treated in the temperature range of 100–900 °C. BaTiO3 powders were synthesized at temperatures as low as 100 °C when sample BH1TH was subjected to MWH. Based on the growth exponent (n), the synthesis reactions were inferred to be diffusion-controlled processes (3 ≤ n ≤ 4) for MWH and interface-controlled processes (2 ≤ n ≤ 3) for CH. Current densities of approximately 0.073 and 0.022 mA/m2 were measured for samples BH1TH and BH0TH, respectively, indicating the generation of charged radicals by the interaction between the precursors and injected microwaves. The radicals were determined as OH− groups by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.
Optimization of Glutathione Adhesion Process to Modified Graphene Surfaces
Authors: Jakubowski Witold , Atraszkiewicz Radomir , Nowak Dorota , Batory Damian , Szymański Witold , Sobczyk-Guzenda Anna , Kaczmarek Łukasz , Kula Piotr , Cłapa Marian , Warga Tomasz , Czerniak-Reczulska Małgorzata
Published: March 2021

The presented work shows the results of the functionalization of the graphene surface obtained by the growth on the liquid bimetallic matrices method. We used glutathione (GSH) as a peptide model, which allowed us to optimize the procedure to obtain high process efficiency. To establish the amount of GSH attached to the graphene surface, the Folina-Ciocalteu method was used, which allows the assessment of the concentration of colored reaction products with peptide bonds without the disadvantages of most methods based on direct colored reaction of peptide bonds. Samples surface morphology, quality of graphene and chemical structure in the subsequent stages of surface modification were tested—for this purpose Raman spectroscopy, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) were used.
Human Milk Oligosaccharide Profiles and Associations with Maternal Nutritional Factors: A Scoping Review
Authors: Biddulph Caren , Holmes Mark , Kuballa Anna , Davies Peter S. W. , Koorts Pieter , Carter Roger J. , Maher Judith
Published: March 2021

Human milk oligosaccharides (HMOs) are complex unconjugated glycans associated with positive infant health outcomes. This study has examined current knowledge of the effect of maternal diet and nutritional status on the composition of HMOs in breast milk. Using the PRISMA-ScR guidelines, a comprehensive, systematic literature search was conducted using Scopus, Web of Science, Global Health (CABI), and MEDLINE. Titles and abstracts were screened independently by two reviewers against predefined inclusion and exclusion criteria. Fourteen studies met the inclusion criteria and reported on maternal dietary intake (n = 3), maternal body composition indices (n = 9), and dietary supplementation interventions (n = 2). In total, data from 1388 lactating mothers (4011 milk samples) were included. Design methodologies varied substantially across studies, particularly for milk sample collection, HMO analysis, dietary and body composition assessment. Overall, this review has identified potential associations between maternal dietary intake and nutritional status and the HMO composition of human milk, though an abundance and sufficiency of evidence is lacking. Standardised procedures for human milk sample collection and HMO analysis, along with robust and validated nutrition assessment techniques, should be employed to further investigate the impact of maternal nutritional factors on HMO composition.
Using a Paleo Ratio to Assess Adherence to Paleolithic Dietary Recommendations in a Randomized Controlled Trial of Individuals with Type 2 Diabetes
Authors: Mårtensson Alexander , Stomby Andreas , Tellström Anna , Ryberg Mats , Waling Maria , Otten Julia
Published: March 2021

This study is a secondary analysis of a randomized controlled trial using Paleolithic diet and exercise in individuals with type 2 diabetes. We hypothesized that increased adherence to the Paleolithic diet was associated with greater effects on blood pressure, blood lipids and HbA1c independent of weight loss. Participants were asked to follow a Paleolithic diet for 12 weeks and were randomized to supervised exercise or general exercise recommendations. Four-day food records were analyzed, and food items characterized as “Paleolithic” or “not Paleolithic”. Foods considered Paleolithic were lean meat, poultry, fish, seafood, fruits, nuts, berries, seeds, vegetables, and water to drink; “not Paleolithic” were legumes, cereals, sugar, salt, processed foods, and dairy products. A Paleo ratio was calculated by dividing the Paleolithic calorie intake by total calorie intake. A multiple regression model predicted the outcome at 12 weeks using the Paleo ratio, group affiliation, and outcome at baseline as predictors. The Paleo ratio increased from 28% at baseline to 94% after the intervention. A higher Paleo ratio was associated with lower fat mass, BMI, waist circumference, systolic blood pressure, and serum triglycerides at 12 weeks, but not with lower HbA1c levels. The Paleo ratio predicted triglyceride levels independent of weight loss (p = 0.046). Moreover, an increased monounsaturated/saturated fatty acids ratio and an increased polyunsaturated/saturated fatty acids ratio was associated with lower triglyceride levels independent of weight loss. (p = 0.017 and p = 0.019 respectively). We conclude that a higher degree of adherence to the Paleolithic diet recommendations improved fat quality and was associated with improved triglyceride levels independent of weight loss among individuals with type 2 diabetes.
Influence of Micronutrient Intake, Sociodemographic, and Behavioral Factors on Periodontal Status of Adults Assisted by a Public Health Care System in Brazil: A Cross-Sectional Multivariate Analysis
Authors: Costa Patrícia , Canaan Juliana , Midori Castelo Paula , Campideli Fonseca Douglas , Márcia Pereira-Dourado Stela , Mendonça Murata Ramiro , Pardi Vanessa , Pereira Luciano José
Published: March 2021

The lack of access to a balanced diet, rich in vitamins and minerals, can predispose people to inflammatory diseases such as obesity, diabetes mellitus, and periodontitis. We aimed to evaluate the relationship between micronutrient intake, sociodemographic behavioral characteristics, and periodontal health in adults assisted by a public health care system. Participants (n = 450) answered a food frequency questionnaire and were submitted to anthropometric and oral clinical examinations. Principal component analysis was used to summarize the number of components emerging from 17-micronutrient intake. Subsequently, cluster analysis was employed. The prevalence of at least one periodontal pocket ≥ 4 mm was 67.4%. Three clusters were identified according to periodontal status. Cluster 1 “poor periodontal status” was characterized by older individuals (n = 202; 85% females) with poor periodontal status, lower education level, mainly smokers with non-transmissible chronic diseases (NTCD), with lower energy, omega-3, fiber, Zn, K, Cu, and vitamin C intake. Cluster 3 “healthy periodontal status” included younger individuals (n = 54) with the healthiest periodontal status, a higher education level, without NTCD, and with higher energy, omega-3, fiber, Zn, calcium, retinol, and riboflavin intake. Cluster 2 was labeled as “intermediate periodontal status”. Micronutrient ingestion was associated with periodontal status and may be considered in health promotion actions for low-income populations.
Plant Phenolics and Extracts in Animal Models of Preeclampsia and Clinical Trials—Review of Perspectives for Novel Therapies
Authors: Ożarowski Marcin , Karpiński Tomasz M. , Szulc Michał , Wielgus Karolina , Kujawski Radosław , Wolski Hubert , Seremak-Mrozikiewicz Agnieszka
Published: March 2021

The current health requirements set the direction in pharmacological research, especially as regards diseases that require improvement of existing therapeutic regimens. Such diseases include preeclampsia, which is a hypertensive disorder of pregnancy during which there occurs progressive increasing activation of the immune system through elevation of pro-inflammatory cytokines and antiangiogenic factors, which is dangerous for the mother and fetus. A promising field of research for new drugs to treat this disease is the study of natural phenolic compounds of plant origin and herbal extracts, which are complex matrices of chemical compounds with broad biological activities. Many plant substances with anti‑inflammatory and anti‑hypertensive properties are known, but studies in animal models of preeclampsia and clinical trials concerning this disease constitute a new and developing research trend of significant medical importance. The aim of our research review was to identify and analyze the results of already available studies on baicalin, curcumin, epigallocatechin gallate, punicalagin, quercetin, resveratrol, salvianolic acid A (danshensu), silibinin, and vitexin, as well as plant extracts from Brassica oleracea L., Euterpe oleracea Mart., Moringa oleifera Lam., Punica granatum L., Silybum marianum (L.) Gaertner, Thymus schimperi Ronniger, Uncaria rhynchophylla (Miq.) Miq. ex Havil., and Vitis vinifera L., which are potential and promising candidates for further research and for potential new therapies.
Pharmacokinetics and Pharmacogenetics of Cyclophosphamide in a Neonate and Infant Childhood Cancer Patient Population
Authors: Barnett Shelby , Errington Julie , Sludden Julieann , Jamieson David , Poinsignon Vianney , Paci Angelo , Veal Gareth J.
Published: March 2021

Infants and young children represent an important but much understudied childhood cancer patient population. The pharmacokinetics and pharmacogenetics of the widely used anticancer prodrug cyclophosphamide were investigated in children <2 years of age. Concentrations of cyclophosphamide and selected metabolites were determined in patients administered cyclophosphamide at doses ranging from 100–1500 mg/m2 (5–75 mg/kg), with various infusion times as determined by the standard treatment regimen that each patient was receiving. Polymorphisms in genes including CYP2B6 and CYP2C19 were investigated. Data generated for cyclophosphamide were analysed using a previously published population pharmacokinetic model. Cyclophosphamide pharmacokinetics was assessed in 111 samples obtained from 25 patients ranging from 4–23 months of age. The average cyclophosphamide clearance for the patients was 46.6 mL/min/m2 (ranging from 9.4–153 mL/min/m2), with marked inter-patient variability observed (CV 41%). No significant differences in cyclophosphamide clearance or exposure (AUC) were observed between patient groups as separated by age or body weight. However, marked differences in drug clearance and metabolism were noted between the current data in children <2 years of age and recently published results from a comparable study conducted by our group in older children, which reported significantly lower cyclophosphamide clearance values and metabolite exposures using the same population pharmacokinetic model for analysis. Whilst this study demonstrates no significant differences in cyclophosphamide clearance in patients <2 years, it highlights large differences in dosing protocols across tumour types. Furthermore, the study suggests marked differences in cyclophosphamide clearance in children less than two years of age as compared to older patients.