bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Properties and Damage Evolution of Concrete Materials Considering Sulfate Attack
Authors: Wu Qianyun , Ma Qinyong , Huang Xianwen
Published: April 2021

In order to study the durability of concrete materials subjected to sulfate attack, in a sulfate attack environment, a series of concrete tests considering different fly ash contents and erosion times were conducted. The mechanical properties and the micro-structure of concrete under sulfate attack were studied based on the following: uniaxial compressive strength test, split tensile test, ultrasonic impulse method, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical properties were compressive strength, splitting tensile strength, and relative dynamic elastic modulus, respectively. Additionally, according to the damage mechanical theory, experimental results and micro-structure analysis, the damage evolution process of concrete under a sulfate attack environment were studied in detail. Finally, according to the sulfate attack time and fly ash content, a damage model of the sulfate attack of the binary surface was established. The specific results are as follows: under the action of sulfate attack, the change law of the rate of mass change, relative dynamic modulus of elasticity, corrosion resistance coefficient of compressive strength, and the corrosion resistance coefficient of the splitting tensile strength of concrete all increase first and then decrease. Under the same erosion time, concrete mixed with 10% fly ash content has the best sulfate resistance. Through data regression, the damage evolution equation of the sulfate attack was developed and there is an exponential function relationship among the different damage variables. The binary curved surface regression effect of the concrete damage and the erosion time and the amount of fly ash is significant, which can predict deterioration of concrete damage under sulfate attack. During the erosion time, the combined expansion of ettringite and gypsum caused micro cracks. With an increase of corrosion time, micro cracks developed and their numbers increased.
Curdlan-Based Hydrogels for Potential Application as Dressings for Promotion of Skin Wound Healing—Preliminary In Vitro Studies
Authors: Nurzynska Aleksandra , Klimek Katarzyna , Palka Krzysztof , Szajnecki Łukasz , Ginalska Grazyna
Published: April 2021

The aim of this work was to establish whether novel curdlan-based hydrogels enriched with Ca2+ ions may be considered as potential candidates for dressings, for the acceleration of skin wound healing. Firstly, biomaterials were allocated for evaluation of structural and mechanical properties. Subsequently, the ability of hydrogels to absorb simulated wound fluid and water vapor permeability, as well their capacity to release calcium ions, was evaluated. The biocompatibility of biomaterials was assessed using normal human skin fibroblasts. Importantly, the main features of the obtained curdlan-based hydrogels were compared with those of KALTOSTAT® (a commercial calcium sodium alginate wound dressing). The obtained results showed that curdlan-based biomaterials possessed a mesoporous structure (pore diameter ranged from 14–48 nm) and exhibited a good ability to absorb simulated wound fluid (swelling ratio close to 974–1229%). Moreover, in a wet state, they enabled proper water vapor transmission rate (>2000 g/m2/day), thanks to their hydrogel structure. Finally, it was found that biomaterial composed of 11 wt.% of curdlan (Cur_11%) possessed the most desirable biological properties in vitro. It released a beneficial amount of calcium ions to the aqueous environment (approximately 6.12 mM), which significantly enhanced fibroblast viability and proliferation. Taking into account the beneficial properties of Cur_11% biomaterial, it seems justified to subject it to more advanced cell culture experiments in vitro and to in vivo studies in order to determine its precise influence on skin wound healing.
Impact of Fly Ashes from Combustion in Fluidized Bed Boilers and Siliceous Fly Ashes on Durability of Mortars Exposed to Seawater and Carbonation Process
Authors: Janowska-Renkas Elżbieta , Kaliciak Agnieszka
Published: April 2021

This article presents test results of aggressive environment impact, i.e., seawater, acid solutions and carbonation, on the durability of cement–ash mortars. Tests were conducted on CEM I 42.5R-based mortars containing 35 to 70% by mass of FBC fly ash from brown and black coal combustion in a homogeneous form and mixtures of 35% by mass of siliceous fly ashes (CFA) and 35% by mass of FBC fly ash. It was demonstrated that in normal conditions (20 °C), FBC ashes showed higher pozzolanic activity than CFA, except when their curing temperature was increased to 50 °C. FBC ashes increased mortars’ water demands, which led to an accelerated carbonation process. In an environment of Cl- ions, cement–ash mortars showed more Ca2+ ions leached and no expansive linear and mass changes, which, with their increased strength, might be an argument in favour for their future use in construction of coastal structures resistant to seawater. FBC ash content may be increased to 35% by mass, maintaining mortars’ resistance to seawater, acid rain and carbonation. A favourable solution turned out to be a FBC and CFA mixed addition to cement of 35% by mass each, in contrast to mortars containing 70% of FBC fly ash in homogeneous form.
Enhanced NO2 Sensing Performance of Graphene with Thermally Induced Defects
Authors: Lim Namsoo , Kim Hyeonghun , Pak Yusin , Byun Young Tae
Published: April 2021

This paper demonstrates the enhanced NO2 sensing performance of graphene with defects generated by rapid thermal annealing (RTA). A high temperature of RTA (300–700 °C) was applied to graphene under an argon atmosphere to form defects on sp2 carbon lattices. The density of defects proportionally increased with increasing the RTA temperature. Raman scattering results confirmed significant changes in sp2 bonding. After 700 °C RTA, ID/IG, I2D/IG, and FWHM (full width at half maximum)(G) values, which are used to indirectly investigate carbon-carbon bonds’ chemical and physical properties, were markedly changed compared to the pristine graphene. Further evidence of the thermally-induced defects on graphene was found via electrical resistance measurements. The electrical resistance of the RTA-treated graphene linearly increased with increasing RTA temperature. Meanwhile, the NO2 response of graphene sensors increased from 0 to 500 °C and reached maximum (R = ~24%) at 500 °C. Then, the response rather decreased at 700 °C (R = ~14%). The results imply that rich defects formed at above a critical temperature (~500 °C) may damage electrical paths of sp2 chains and thus deteriorate NO2 response. Compared to the existing functionalization process, the RTA treatment is very facile and allows precise control of the NO2 sensing characteristics, contributing to manufacturing commercial low-cost, high-performance, integrated sensors.
Non-Doped Deep-Blue OLEDs Based on Carbazole-π-Imidazole Derivatives
Authors: Yu Pengfei , Xiao Yin
Published: April 2021

In this work, we designed and synthesized four bipolar blue-emitting materials with carbazole, imidazole, and biphenyl as donor, acceptor, and p bridge, respectively. The twisted phenylimidazole acceptor leads to a wider band-gap and hence deeper blue emission than the conjugated phenanthrimidazole acceptor. For the substituents on the carbazole donor, the t-butyl group could prevent the intramolecular charge transfer (ICT) process more effectively than the methoxy group. A non-doped deep-blue organic light-emitting diodes (OLED) is obtained with CIE coordinates of (0.159, 0.080), a maximum luminance of 11,364 cd/m2, and a maximum EQE of 4.43%.
Unexpected Light-Induced Thermal Hysteresis in Matrix Embedded Low Cooperative Spin Crossover Microparticles
Authors: Plesca Diana , Railean Anastasia , Tanasa Radu , Stancu Alexandru , Laisney Jérôme , Boillot Marie-Laure , Enachescu Cristian
Published: April 2021

The embedding of spin-crossover micro- or nanocrystals in various surroundings dramatically changes their functionalities based on first-order spin transitions. The dampening of their internal cooperativity, together with introducing a new kind of interactions occurring at interfaces between spin-crossover particles and their environment, results in spectacular effects, as an enhanced hysteresis with non-cooperative transitions. In this work, we deal with the influence of the embedding matrix on the light-induced thermal hysteresis (LITH) in the case of spin-crossover microparticles of Fe(phen)2(NCS)2. Despite the low cooperativity of this compound, the competition between the continuous photoexcitation towards the metastable high spin state and the relaxation down to low spin ground state leads to a light-induced thermal hysteresis, with a quasi-static width of around 10 K. This unexpected hysteresis is explained by considering a switch-on/cutoff mechanism of the particle–matrix interactions in the framework of a mean-field approach based on negative external pressures, with Gaussian distributed variations and of an Ising-like model with various interactions with the environment. Additional first-order reversal curves measurements and corresponding calculated distributions are in line with relaxations under light and confirm the existence of a non-kinetic LITH.
An Overview of the Foundations of the Hypergroup Theory
Authors: Massouros Christos , Massouros Gerasimos
Published: April 2021

This paper is written in the framework of the Special Issue of Mathematics entitled “Hypercompositional Algebra and Applications”, and focuses on the presentation of the essential principles of the hypergroup, which is the prominent structure of hypercompositional algebra. In the beginning, it reveals the structural relation between two fundamental entities of abstract algebra, the group and the hypergroup. Next, it presents the several types of hypergroups, which derive from the enrichment of the hypergroup with additional axioms besides the ones it was initially equipped with, along with their fundamental properties. Furthermore, it analyzes and studies the various subhypergroups that can be defined in hypergroups in combination with their ability to decompose the hypergroups into cosets. The exploration of this far-reaching concept highlights the particularity of the hypergroup theory versus the abstract group theory, and demonstrates the different techniques and special tools that must be developed in order to achieve results on hypercompositional algebra.
Modification of Newton-Househölder Method for Determining Multiple Roots of Unknown Multiplicity of Nonlinear Equations
Authors: Sariman Syahmi Afandi , Hashim Ishak , Samat Faieza , Alshbool Mohammed
Published: April 2021

In this study, we propose an extension of the modified Newton-Househölder methods to find multiple roots with unknown multiplicity of nonlinear equations. With four functional evaluations per iteration, the proposed method achieves an optimal eighth order of convergence. The higher the convergence order, the quicker we get to the root with a high accuracy. The numerical examples have shown that this scheme can compete with the existing methods. This scheme is also stable across all of the functions tested based on the graphical basins of attraction.
Probing the Anti-Cancer Potency of Sulfated Galactans on Cholangiocarcinoma Cells Using Synchrotron FTIR Microspectroscopy, Molecular Docking, and In Vitro Studies
Authors: Boonsri Boonyakorn , Choowongkomon Kiattawee , Kuaprasert Buabarn , Thitiphatphuvanon Thanvarin , Supradit Kittiya , Sayinta Apinya , Duangdara Jinchutha , Rudtanatip Tawut , Wongprasert Kanokpan
Published: April 2021

Sulfated galactans (SG) isolated from red alga Gracilaria fisheri have been reported to inhibit the growth of cholangiocarcinoma (CCA) cells, which was similar to the epidermal growth factor receptor (EGFR)-targeted drug, cetuximab. Herein, we studied the anti-cancer potency of SG compared to cetuximab. Biological studies demonstrated SG and cetuximab had similar inhibition mechanisms in CCA cells by down-regulating EGFR/ERK pathway, and the combined treatment induced a greater inhibition effect. The molecular docking study revealed that SG binds to the dimerization domain of EGFR, and this was confirmed by dimerization assay, which showed that SG inhibited ligand-induced EGFR dimer formation. Synchrotron FTIR microspectroscopy was employed to examine alterations in cellular macromolecules after drug treatment. The SR-FTIR-MS elicited similar spectral signatures of SG and cetuximab, pointing towards the bands of RNA/DNA, lipids, and amide I vibrations, which were inconsistent with the changes of signaling proteins in CCA cells after drug treatment. Thus, this study demonstrates the underlined anti-cancer mechanism of SG by interfering with EGFR dimerization. In addition, we reveal that FTIR signature spectra offer a useful tool for screening anti-cancer drugs’ effect.
Green Propolis Compounds (Baccharin and p-Coumaric Acid) Show Beneficial Effects in Mice for Melanoma Induced by B16f10
Authors: Gastaldello Gabriel H. , Cazeloto Ana Caroline V. , Ferreira Juliana C. , Rodrigues Débora Munhoz , Bastos Jairo Kennup , Campo Vanessa L. , Zoccal Karina F. , Tefé-Silva Cristiane
Published: April 2021

Background: Cutaneous melanoma is the most aggressive form of skin cancer, with the worst prognosis, and it affects a younger population than most cancers. The high metastatic index, in more advanced stages, and the high aggressiveness decrease the effectiveness of currently used therapies, such as surgical removal, radiotherapy, cryotherapy, and chemotherapy, used alone or in combination. Based on these disadvantages, research focused on alternative medicine offers great potential for therapeutic innovation. Medicinal plants represent a remarkable source of compounds for the treatment of various diseases. Methods: In this study, we investigated the tumoral behavior of melanoma under treatment with the compounds baccharin and p-coumaric acid, extracted from green propolis, in mice inoculated with B16F10 cells for 26 days. Results: A significant modulation in the number of inflammatory cells recruited to the tumor region and blood in the groups treated with the compounds was observed. In addition, a significant reduction in the amount of blood vessels and mitosis in the neoplastic area was noticed. Conclusions: Through our research, we confirmed that baccharin and coumaric acid, isolated substances from Brazilian green propolis, have a promising anticarcinogenic potential to be explored for the development of new antitumor agents, adhering to the trend of drugs with greater tolerance and biological effectiveness.
Characteristics of Passive Solute Transport across Primary Rat Alveolar Epithelial Cell Monolayers
Authors: Kim Yong Ho , Kim Kwang-Jin , D’Argenio David Z. , Crandall Edward D.
Published: April 2021

Primary rat alveolar epithelial cell monolayers (RAECM) were grown without (type I cell-like phenotype, RAECM-I) or with (type II cell-like phenotype, RAECM-II) keratinocyte growth factor to assess passive transport of 11 hydrophilic solutes. We estimated apparent permeability (Papp) in the absence/presence of calcium chelator EGTA to determine the effects of perturbing tight junctions on “equivalent” pores. Papp across RAECM-I and -II in the absence of EGTA are similar and decrease as solute size increases. We modeled Papp of the hydrophilic solutes across RAECM-I/-II as taking place via heterogeneous populations of equivalent pores comprised of small (0.41/0.32 nm radius) and large (9.88/11.56 nm radius) pores, respectively. Total equivalent pore area is dominated by small equivalent pores (99.92–99.97%). The number of small and large equivalent pores in RAECM-I was 8.55 and 1.29 times greater, respectively, than those in RAECM-II. With EGTA, the large pore radius in RAECM-I/-II increased by 1.58/4.34 times and the small equivalent pore radius increased by 1.84/1.90 times, respectively. These results indicate that passive diffusion of hydrophilic solutes across an alveolar epithelium occurs via small and large equivalent pores, reflecting interactions of transmembrane proteins expressed in intercellular tight junctions of alveolar epithelial cells.
ECMO Support and Operator Safety in the Context of COVID-19 Outbreak: A Regional Center Experience
Authors: Montrucchio Giorgia , Sales Gabriele , Urbino Rosario , Simonetti Umberto , Bonetto Chiara , Cura Stura Erik , Simonato Erika , Fuoco Giovanni , Fanelli Vito , Brazzi Luca
Published: April 2021

Since the beginning of the COVID-19 emergency, the referral Intensive Care Unit for the Extracorporeal Membrane Oxygenation (ECMO) support of Piedmont Region (Italy), in cooperation with infectious disease specialists, perfusionists and cardiac surgeons, developed a protocol to guarantee operator safety during invasive procedures, among which the ECMO positioning or inter-hospital transport. The use of powered air-purifying respirators, filtering facepiece particles (FFP) 2–3 masks, protective suits, disposable sterile surgical gowns, and two pairs of sterile gloves as a part of a protocol seemed effective and feasible for trained healthcare workers and allow all the complex activities connected with the positioning of the ECMO support to be completed effectively. The simulation training on donning and doffing procedures and the presence of a dedicated team member to verify the compliance with the safety procedure effectively reassured operators and likely reduced the risk of self-contamination. From 1 March to 31 December 2020, we used the procedure in 35 severe acute respiratory distress syndrome (ARDS) patients and one acute respiratory failure caused by neoplastic total tracheal obstruction, all positive to COVID-19, to be connected to veno-venous ECMO in peripheral hospitals and centralized for ECMO management. This preliminary experience seems to confirm that the use of ECMO during COVID-19 outbreaks is feasible and the risks associated with its positioning and management are sustainable for the health-care workers and safe for patients.
Quo Vadis Caenorhabditis elegans Metabolomics—A Review of Current Methods and Applications to Explore Metabolism in the Nematode
Authors: Salzer Liesa , Witting Michael
Published: April 2021

Metabolomics and lipidomics recently gained interest in the model organism Caenorhabditis elegans (C. elegans). The fast development, easy cultivation and existing forward and reverse genetic tools make the small nematode an ideal organism for metabolic investigations in development, aging, different disease models, infection, or toxicology research. The conducted type of analysis is strongly depending on the biological question and requires different analytical approaches. Metabolomic analyses in C. elegans have been performed using nuclear magnetic resonance (NMR) spectroscopy, direct infusion mass spectrometry (DI-MS), gas-chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) or combinations of them. In this review we provide general information on the employed techniques and their advantages and disadvantages in regard to C. elegans metabolomics. Additionally, we reviewed different fields of application, e.g., longevity, starvation, aging, development or metabolism of secondary metabolites such as ascarosides or maradolipids. We also summarised applied bioinformatic tools that recently have been used for the evaluation of metabolomics or lipidomics data from C. elegans. Lastly, we curated metabolites and lipids from the reviewed literature, enabling a prototypic collection which serves as basis for a future C. elegans specific metabolome database.
Control of n-Butanol Induced Lipidome Adaptations in E. coli
Authors: Jeucken Aike , Zhou Miaomiao , Wösten Marc M. S. M. , Brouwers Jos F.
Published: April 2021

The versatile compound n-butanol is one of the most promising biofuels for use in existing internal combustion engines, contributing to a smooth transition towards a clean energy society. Furthermore, n-butanol is a valuable resource to produce more complex molecules such as bioplastics. Microbial production of n-butanol from waste materials is hampered by the biotoxicity of n-butanol as it interferes with the proper functioning of lipid membranes. In this study we perform a large-scale investigation of the complete lipid-related enzyme machinery and its response to exposure to a sublethal concentration of n-butanol. We profiled, in triplicate, the growth characteristics and phospholipidomes of 116 different genetic constructs of E. coli, both in the presence and absence of 0.5% n-butanol (v/v). This led to the identification of 230 lipid species and subsequently to the reconstruction of the network of metabolites, enzymes and lipid properties driving the homeostasis of the E. coli lipidome. We were able to identify key lipids and biochemical pathways leading to altered n-butanol tolerance. The data led to new conceptual insights into the bacterial lipid metabolism which are discussed.
Features of the Metabolic Profile of Saliva in Lung Cancer and COPD: The Effect of Smoking Status
Authors: Bel’skaya Lyudmila V. , Sarf Elena A. , Solomatin Denis V. , Kosenok Victor K.
Published: April 2021

The aim of the study was to compare the metabolic characteristics of the salivary composition in lung cancer, chronic obstructive pulmonary disease (COPD) and their combination, depending on the smoking history. The study group included 392 patients with lung cancer of various histological types. The division into subgroups was carried out in accordance with the severity of COPD and smoking experience. Salivary biochemical composition was determined according to 34 indicators. For data processing, the principal component method was used. Different groups of biochemical saliva markers are informative when separately accounting for the smoking factor and the presence of COPD in lung cancer. For smoking, antioxidant enzymes and electrolyte components of saliva are informative; for COPD metabolic enzymes, lipid peroxidation products, sialic acids and electrolyte components are informative. While taking into account the smoking factor and the presence of COPD, biochemical markers corresponding to the presence/absence and severity of COPD are the priority. Changes occurring in the background of smoking are of a secondary nature, manifesting as much as possible with a smoking history of more than 50 pack-years. Thus, the metabolic changes that occur in lung cancer in combination with COPD, depending on the smoking factor, can be estimated using saliva.
A Direct-Writing Approach for Fabrication of CNT/Paper-Based Piezoresistive Pressure Sensors for Airflow Sensing
Authors: Chen Jinyan , Tran Van-Thai , Du Hejun , Wang Junshan , Chen Chao
Published: April 2021

Airflow sensor is a crucial component for monitoring environmental airflow conditions in many engineering fields, especially in the field of aerospace engineering. However, conventional airflow sensors have been suffering from issues such as complexity and bulk in structures, high cost in fabrication and maintenance, and low stability and durability. In this work, we developed a facile direct-writing method for fabricating a low-cost piezoresistive element aiming at high-performance airflow sensing, in which a commercial pen was utilized to drop solutions of single-walled carbon nanotubes onto tissue paper to form a piezoresistive sensing element. The encapsulated piezoresistive element was tested for electromechanical properties under two loading modes: one loading mode is the so-called pressure mode in which the piezoresistive element is pressed by a normal pressure, and another mode is the so-called bending mode in which the piezoresistive element is bended as a cantilever beam. Unlike many other developed airflow sensors among which the sensing elements are normally employed as cantilever beams for facing winds, we designed a fin structure to be incorporated with the piezoresistive element for airflow sensing; the main function of the fin is to face winds instead of the piezoresistive element, and subsequently transfer and enlarge the airflow pressure to the piezoresistive element for the normal pressure loading mode. With this design, the piezoresistive element can also be protected by avoiding experiencing large strains and direct contact with external airflows so that the stability and durability of the sensor can be maintained. Moreover, we experimentally found that the performance parameters of the airflow sensor could be effectively tuned by varying the size of the fin structure. When the fin sizes of the airflow sensors were 20 mm, 30 mm, and 40 mm, the detection limits and sensitivities of the fabricated airflow sensors were measured as 8.2 m/s, 6.2 m/s, 3.2 m/s, 0.0121 (m/s)−2, 0.01657 (m/s)−2, and 0.02264 (m/s)−2, respectively. Therefore, the design of the fin structure could pave an easy way for adjusting the sensor performance without changing the sensor itself toward different application scenarios.
Biaxial Angular Acceleration Sensor with Rotational-Symmetric Spiral Channels and MEMS Piezoresistive Cantilevers
Authors: Nakashima Rihachiro , Takahashi Hidetoshi
Published: April 2021

Angular acceleration sensors are attracting attention as sensors for monitoring rotational vibration. Many angular acceleration sensors have been developed; however, multiaxis measurement is still in a challenging stage. In this study, we propose a biaxial angular acceleration sensor with two uniaxial sensor units arranged orthogonally. The sensor units consist of two rotational-symmetric spiral channels and microelectromechanical system (MEMS) piezoresistive cantilevers. The cantilever is placed to interrupt the flow at the junctions of parallelly aligned spirals in each channel. When two cantilevers are used as the resistance of the bridge circuit in the two-gauge method, the rotational-symmetric spiral channels enhance the sensitivity in the target axis, while the nontarget axis sensitivities are canceled. The fabricated device responds with approximately constant sensitivity from 1 to 15 Hz, with a value of 3.86 × 10−5/(rad/s2), which is equal to the theoretical value. The nontarget axis sensitivity is approximately 1/400 of the target axis sensitivity. In addition, we demonstrate that each unit responds according to the tilt angle when the device is tilted along the two corresponding rotational axis planes. Thus, it is concluded that the developed device realizes biaxial angular acceleration measurement with low crosstalk.
Evaluation of the Infectious Potential of Neoparamoeba perurans Following Freshwater Bathing Treatments
Authors: Taylor Richard S. , Slinger Joel , Stratford Chris , Rigby Megan , Wynne James W.
Published: April 2021

Freshwater bathing for 2–3 h is the main treatment to control amoebic gill disease of marine-farmed Atlantic salmon. Recent in vitro studies have demonstrated that amoebae (Neoparamoeba perurans) detach when exposed to freshwater and that some eventually reattach to culture plates when returned to seawater. Here, we evaluated the potential for gill-detached N. perurans to survive a commercially relevant treatment and infect AGD-naïve fish and whether holding used bathwater for up to 6 h post treatment would lower infectivity. AGD-affected fish were bathed in freshwater for 2 h. Naïve salmon were exposed to aliquots of the used bathwater after 2, 4, 6 and 8 h. The inoculation was performed at 30 ppt for 2 h, followed by gradual dilution with seawater. Sampling at 20 days post inoculation (dpi) and 40 dpi confirmed rapid AGD development in fish inoculated in 2 h used bathwater, but a slower AGD development following exposure to 4 h bathwater. AGD signs were variable and reduced following longer bathwater holding times. These results suggest that viable amoebae are likely returned to seawater following commercial freshwater treatments, but that the risk of infection can be reduced by retention of bathwater before release.
Serological and Molecular Evidence of Bartonella henselae in Stray Cats from Southern Italy
Authors: Grippi Francesca , Galluzzo Paola , Guercio Annalisa , Blanda Valeria , Santangelo Francesco , Sciortino Sonia , Vicari Domenico , Arcuri Francesca , Di Bella Santina , Torina Alessandra
Published: April 2021

Bartonella henselae is a slow growing and facultative intracellular pathogen mainly transmitted by arthropod vectors adapted to domestic and wild mammalian reservoir hosts. Since cats are the major source of the B. henselae infection, this study aimed to evaluate the seroprevalence and the DNA presence in randomly sampled stray cats. Blood samples of 429 cats were collected from shelter of Palermo (Southern Italy) and sera and whole blood were analyzed for the presence of antibodies against B. henselae by indirect immunofluorescence assay (IFA) and by real-time polymerase chain reaction (PCR), respectively. Two hundred and three sera (47.3%) were positive to IFA and 148 blood samples (34.5%) to real-time PCR. Based on serological results, the evaluation of the potential risk factors (sex, age, coat color) was carried out. The multivariate analysis indicated that cats more than 12 months old were more likely to be seropositive to B. henselae than cats <12 months. These data will add useful information to the understanding of the spread of B. henselae in stray cats in Southern Italy.
Evolution of Syenite Magmas: Insights from the Geology, Geochemistry and O-Nd Isotopic Characteristics of the Ordovician Saibar Intrusion, Altai-Sayan Area, Russia
Authors: Vorontsov Alexander A. , Izoh Andrey E. , Yarmolyuk Vladimir V. , Komaritsyna Tatyana Y. , Nikiforov Anatoly V. , Perfilova Olga Y. , Dril Sergei I. , Rizvanova Nailya G. , Dushkin Egor P.
Published: April 2021

In this paper, we provide insight into the evolution of syenite magmas based on geological data and petrographic, geochemical, and O-Nd isotope parameters of rocks of the Saibar intrusion located within the Minusinsk Trough, Altay-Sayan area. The intrusive suite includes predominant syenites, few bodies of melanocratic and leucocratic nepheline syenites (foyaites), and granites. In addition, dykes of granites and mafic rocks are present. The U-Pb zircon age from the melanocratic foyaites was determined to be 457 ± 10 Ma? Examined rocks show fractionated light rare earth element patterns, normalized to chondrite, with (La/Sm)n varying from 4 to 9, and a weakly fractionated distribution of medium and heavy rare elements, with (Dy/Yb)n from 0.35 to 1.23 and (Sm/Yb)n from 0.63 to 2.62. The spidergram normalized to the primitive mantle shows negative Ba, Sr, Nb, Ta, Ti, and Eu anomalies (Eu* = 0.48–0.60) and positive Rb, Th, and U anomalies. The δ18O values vary within 6.3 to 10.2‰, and εNd(t) from +4.1 to +5.0. We observe gradual transitions from syenites to foyaites. Assimilation by syenite magma of the host carbonate rocks was followed to transition from silica-saturated to silica-undersaturated conditions and removal of anorthite from the melt, which then led to nepheline. Granites of the main phase show depleted lithophile incompatible elements in comparison with syenites and foyaites. They originate via interaction of magmas at the marginal part (endocontact zone) of the intrusion, corresponding to north contact of the granites with the host felsic rocks. In comparison, the rock composition of granite dykes is enriched in lithophile incompatible elements, except for Zr, Hf, and Ti. These rocks are formed due to the differentiation of syenite magma without a significant effect of host rock assimilation. Mantle magmas must be used as parent magmas for syenites based on analysis of the formation model of other alkaline intrusions, which are similar in age to the Saibar intrusion. In the line of syenite intrusions of the Altai-Sayan province, the Saibar intrusion is no exception, and its origin is related to the evolution of mafic magmas that arose during the melting of the mantle under the influence of a mantle plume.
The Potency of Seaweed Sulfated Polysaccharides for the Correction of Hemostasis Disorders in COVID-19
Authors: Kuznetsova Tatyana A. , Andryukov Boris G. , Makarenkova Ilona D. , Zaporozhets Tatyana S. , Besednova Natalya N. , Fedyanina Ludmila N. , Kryzhanovsky Sergey P. , Shchelkanov Mikhail Yu.
Published: April 2021

Hemostasis disorders play an important role in the pathogenesis, clinical manifestations, and outcome of COVID-19. First of all, the hemostasis system suffers due to a complicated and severe course of COVID-19. A significant number of COVID-19 patients develop signs of hypercoagulability, thrombocytopenia, and hyperfibrinolysis. Patients with severe COVID-19 have a tendency toward thrombotic complications in the venous and arterial systems, which is the leading cause of death in this disease. Despite the success achieved in the treatment of SARS-CoV-2, the search for new effective anticoagulants, thrombolytics, and fibrinolytics, as well as their optimal dose strategies, continues to be relevant. The wide therapeutic potential of seaweed sulfated polysaccharides (PSs), including anticoagulant, thrombolytic, and fibrinolytic activities, opens up new possibilities for their study in experimental and clinical trials. These natural compounds can be important complementary drugs for the recovery from hemostasis disorders due to their natural origin, safety, and low cost compared to synthetic drugs. In this review, the authors analyze possible pathophysiological mechanisms involved in the hemostasis disorders observed in the pathological progression of COVID-19, and also focus the attention of researchers on seaweed PSs as potential drugs aimed to correction these disorders in COVID-19 patients. Modern literature data on the anticoagulant, antithrombotic, and fibrinolytic activities of seaweed PSs are presented, depending on their structural features (content and position of sulfate groups on the main chain of PSs, molecular weight, monosaccharide composition and type of glycosidic bonds, the degree of PS chain branching, etc.). The mechanisms of PS action on the hemostasis system and the issues of oral bioavailability of PSs, important for their clinical use as oral anticoagulant and antithrombotic agents, are considered. The combination of the anticoagulant, thrombolytic, and fibrinolytic properties, along with low toxicity and relative cheapness of production, open up prospects for the clinical use of PSs as alternative sources of new anticoagulant and antithrombotic compounds. However, further investigation and clinical trials are needed to confirm their efficacy.
Metal-Promoted Heterocyclization: A Heterosynthetic Approach to Face a Pandemic Crisis
Authors: Rossi Federico Vittorio , Gentili Dario , Marcantoni Enrico
Published: April 2021

The outbreak of SARS-CoV-2 has drastically changed our everyday life and the life of scientists from all over the world. In the last year, the scientific community has faced this worldwide threat using any tool available in order to find an effective response. The recent formulation, production, and ongoing administration of vaccines represent a starting point in the battle against SARS-CoV-2, but they cannot be the only aid available. In this regard, the use of drugs capable to mitigate and fight the virus is a crucial aspect of the pharmacological strategy. Among the plethora of approved drugs, a consistent element is a heterocyclic framework inside its skeleton. Heterocycles have played a pivotal role for decades in the pharmaceutical industry due to their high bioactivity derived from anticancer, antiviral, and anti-inflammatory capabilities. In this context, the development of new performing and sustainable synthetic strategies to obtain heterocyclic molecules has become a key focus of scientists. In this review, we present the recent trends in metal-promoted heterocyclization, and we focus our attention on the construction of heterocycles associated with the skeleton of drugs targeting SARS-CoV-2 coronavirus.
Preventive Effects of Green Tea Extract against Obesity Development in Zebrafish
Authors: Zang Liqing , Shimada Yasuhito , Nakayama Hiroko , Katsuzaki Hirotaka , Kim Youngil , Chu Djong-Chi , Juneja Lekh Raj , Kuroyanagi Junya , Nishimura Norihiro
Published: April 2021

Various natural products (NPs) have been used to treat obesity and related diseases. However, the best way to fight obesity is preventive, with accurate body weight management through exercise, diet, or bioactive NPs to avoid obesity development. We demonstrated that green tea extract (GTE) is an anti-obesity NP using a zebrafish obesity model. Based on a hypothesis that GTE can prevent obesity, the objective of this study was to assess GTE’s ability to attenuate obesity development. Juvenile zebrafish were pretreated with GTE for seven days before obesity induction via a high-fat diet; adult zebrafish were pretreated with GTE for two weeks before obesity induction by overfeeding. As a preventive intervention, GTE significantly decreased visceral adipose tissue accumulation in juveniles and ameliorated visceral adiposity and plasma triglyceride levels in adult zebrafish obesity models. RNA sequencing analysis was performed using liver tissues from adult obese zebrafish, with or without GTE administration, to investigate the underlying molecular mechanism. Transcriptome analysis revealed that preventive GTE treatment affects several pathways associated with anti-obesity regulation, including activation of STAT and downregulation of CEBP signaling pathways. In conclusion, GTE could be used as a preventive agent against obesity.
Inorganic Elements in Mytilus galloprovincialis Shells: Geographic Traceability by Multivariate Analysis of ICP-MS Data
Authors: Forleo Tiziana , Zappi Alessandro , Melucci Dora , Ciriaci Martina , Griffoni Francesco , Bacchiocchi Simone , Siracusa Melania , Tavoloni Tamara , Piersanti Arianna
Published: April 2021

The international seafood trade is based on food safety, quality, sustainability, and traceability. Mussels are bio-accumulative sessile organisms that need regular control to guarantee their safe consumption. However, no well-established and validated methods exist to trace mussel origin, even if several attempts have been made over the years. Recently, an inorganic multi-elemental fingerprint coupled to multivariate statistics has increasingly been applied in food quality control. The mussel shell can be an excellent reservoir of foreign inorganic chemical species, allowing recording long-term environmental changes. The present work investigates the multi-elemental composition of mussel shells, including Al, Cu, Cr, Zn, Mn, Cd, Co, U, Ba, Ni, Pb, Mg, Sr, and Ca, determined by inductively-coupled plasma mass-spectrometry in Mytilus galloprovincialis collected along the Central Adriatic Coast (Marche Region, Italy) at 25 different sampling sites (18 farms and 7 natural banks) located in seven areas. The experimental data, coupled with chemometric approaches (principal components analysis and linear discriminant analysis), were used to create a statistical model able to discriminate samples as a function of their production site. The LDA model is suitable for achieving a correct assignment of >90% of individuals sampled to their respective harvesting locations and for being applied to counteract fraud.
Solubility and Stability of Some Pharmaceuticals in Natural Deep Eutectic Solvents-Based Formulations
Authors: Mustafa Natali , Spelbos Vincent , Witkamp Geert-Jan , Verpoorte Robert , Choi Young
Published: April 2021

Some medicines are poorly soluble in water. For tube feeding and parenteral administration, liquid formulations are required. The discovery of natural deep eutectic solvents (NADES) opened the way to potential applications for liquid drug formulations. NADES consists of a mixture of two or more simple natural products such as sugars, amino acids, organic acids, choline/betaine, and poly-alcohols in certain molar ratios. A series of NADES with a water content of 0–30% (w/w) was screened for the ability to solubilize (in a stable way) some poorly water-soluble pharmaceuticals at a concentration of 5 mg/mL. The results showed that NADES selectively dissolved the tested drugs. Some mixtures of choline-based NADES, acid-neutral or sugars-based NADES could dissolve chloral hydrate (dissociated in water), ranitidine·HCl (polymorphism), and methylphenidate (water insoluble), at a concentration of up to 250 mg/mL, the highest concentration tested. Whereas a mixture of lactic-acid–propyleneglycol could dissolve spironolacton and trimethoprim at a concentration up to 50 and 100 mg/mL, respectively. The results showed that NADES are promising solvents for formulation of poorly water-soluble medicines for the development of parenteral and tube feeding administration of non-water-soluble medicines. The chemical stability and bioavailability of these drug in NADES needs further studies.
Caffeic Acid, Quercetin and 5-Fluorocytidine-Functionalized Au-Fe3O4 Nanoheterodimers for X-ray-Triggered Drug Delivery in Breast Tumor Spheroids
Authors: Klein Stefanie , Distel Luitpold V. R. , Neuhuber Winfried , Kryschi Carola
Published: April 2021

Au-Fe3O4 nanoheterodimers (NHD) were functionalized with the natural and synthetic anticancer drugs caffeic acid (CA), quercetin (Q) and 5-fluorocytidine (5FC). Their X-radiation dose-enhancing potential and chemotherapeutic efficacy for bimodal cancer therapy were investigated by designing multicellular tumor spheroids (MCTS) to in vitro avascular tumor models. MCTS were grown from the breast cancer cell lines MCF-7, MDA-MB-231, and MCF-10A. The MCF-7, MDA-MB-231 and MCF-10A MCTS were incubated with NHD-CA, NHD-Q, or NHD-5FC and then exposed to fractionated X-radiation comprising either a single 10 Gy dose, 2 daily single 5 Gy doses or 5 daily single 2 Gy doses. The NHD-CA, NHD-Q, and NHD-5FC affected the growth of X-ray irradiated and non-irradiated MCTS in a different manner. The impact of the NHDs on the glycolytic metabolism due to oxygen deprivation inside MCTS was assessed by measuring lactate secretion and glucose uptake by the MCTS. The NHD-CA and NHD-Q were found to act as X-radiation dose agents in MCF-7 MCTS and MDA-MB-231 MCTS and served as radioprotector in MCF-10A MCTS. X-ray triggered release of CA and Q inhibited lactate secretion and thereupon disturbed glycolytic reprogramming, whereas 5FC exerted their cytotoxic effects on both, healthy and tumor cells, after their release into the cytosol.
The Effect of Quasi-Spherical Gold Nanoparticles on Two-Photon Induced Reactive Oxygen Species for Cell Damage
Authors: Liaw Jiunn-Woei , Kuo Chia-Yu , Tsai Shiao-Wen
Published: April 2021

The performance of quasi-spherical gold nanoparticles (GNPs) on the generation of reactive oxygen species (ROS) to cause cell damage, as irradiated by a two-photon laser, is studied. In this mechanism, hot electrons are generated from GNPs as irradiated by the two-photon laser, reacting with the molecules in the medium to produce ROS. We used laser scanning confocal microscopy with a low-fluence femtosecond Ti:Sapphire laser of 800 nm to observe the generated ROS in A431 cells, which were incubated with GNPs in advance. Subsequently, the cell morphology, cytoskeleton, and viability were investigated. In comparison with the control (no GNPs), the expression of ROS in these GNP-treated cells was enhanced after irradiation by the two-photon laser. Additionally, the disruption of cytoskeletons and the follow-up apoptosis of these GNP-treated cells are significantly increased as the number of laser shots increases. Moreover, we used N-acetyl-L-cysteine (NAC), an antioxidant, to inhibit the formation of ROS, to clarify whether the cytoskeletal disruption is caused by ROS rather than photothermal effects. Our results show that after two-photon irradiation, the ROS expression in these cells treated with GNPs plus NAC was significantly reduced. In addition, the cytoskeletal damage of these cells treated with GNPs and NAC was less than that of those treated with GNPs but without NAC; their cell viability after three days was almost the same with the control. These results illustrate that the induced ROS from the two-photon excited GNPs is the main cause of cell damage. The study may pave a way for the use of GNPs as a photosensitized therapeutic agent for two-photon photodynamic therapy on tumor treatment.
Charge-Order on the Triangular Lattice: A Mean-Field Study for the Lattice S = 1/2 Fermionic Gas
Authors: Kapcia Konrad Jerzy
Published: April 2021

The adsorbed atoms exhibit tendency to occupy a triangular lattice formed by periodic potential of the underlying crystal surface. Such a lattice is formed by, e.g., a single layer of graphane or the graphite surfaces as well as (111) surface of face-cubic center crystals. In the present work, an extension of the lattice gas model to S=1/2 fermionic particles on the two-dimensional triangular (hexagonal) lattice is analyzed. In such a model, each lattice site can be occupied not by only one particle, but by two particles, which interact with each other by onsite U and intersite W1 and W2 (nearest and next-nearest-neighbor, respectively) density-density interaction. The investigated hamiltonian has a form of the extended Hubbard model in the atomic limit (i.e., the zero-bandwidth limit). In the analysis of the phase diagrams and thermodynamic properties of this model with repulsive W1>0, the variational approach is used, which treats the onsite interaction term exactly and the intersite interactions within the mean-field approximation. The ground state (T=0) diagram for W2≤0 as well as finite temperature (T>0) phase diagrams for W2=0 are presented. Two different types of charge order within 3×3 unit cell can occur. At T=0, for W2=0 phase separated states are degenerated with homogeneous phases (but T>0 removes this degeneration), whereas attractive W2<0 stabilizes phase separation at incommensurate fillings. For U/W1<0 and U/W1>1/2 only the phase with two different concentrations occurs (together with two different phase separated states occurring), whereas for small repulsive 0<U/W1<1/2 the other ordered phase also appears (with tree different concentrations in sublattices). The qualitative differences with the model considered on hypercubic lattices are also discussed.
Probing the Intracellular Bio-Nano Interface in Different Cell Lines with Gold Nanostars
Authors: Spedalieri Cecilia , Szekeres Gergo Péter , Werner Stephan , Guttmann Peter , Kneipp Janina
Published: April 2021

Gold nanostars are a versatile plasmonic nanomaterial with many applications in bioanalysis. Their interactions with animal cells of three different cell lines are studied here at the molecular and ultrastructural level at an early stage of endolysosomal processing. Using the gold nanostars themselves as substrate for surface-enhanced Raman scattering, their protein corona and the molecules in the endolysosomal environment were characterized. Localization, morphology, and size of the nanostar aggregates in the endolysosomal compartment of the cells were probed by cryo soft-X-ray nanotomography. The processing of the nanostars by macrophages of cell line J774 differed greatly from that in the fibroblast cell line 3T3 and in the epithelial cell line HCT-116, and the structure and composition of the biomolecular corona was found to resemble that of spherical gold nanoparticles in the same cells. Data obtained with gold nanostars of varied morphology indicate that the biomolecular interactions at the surface in vivo are influenced by the spike length, with increased interaction with hydrophobic groups of proteins and lipids for longer spike lengths, and independent of the cell line. The results will support optimized nanostar synthesis and delivery for sensing, imaging, and theranostics.