bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Dentistry Materials on Chemical Remineralisation/Infiltration versus Salivary Remineralisation of Enamel—In Vitro Study
Authors: Damian Lia-Raluca , Dumitrescu Ramona , Alexa Vlad Tiberiu , Focht David , Schwartz Cristoph , Balean Octavia , Jumanca Daniela , Obistioiu Diana , Lalescu Dacian , Stefaniga Sebastian-Aurelian , Berbecea Adina , Fratila Aurora Doris , Scurtu Alexandra Denisa , Galuscan Atena
Published: October 2022

The aim of this study is to evaluate salivary remineralisation versus chemical remineralisation/infiltration of enamel, using different dentistry materials. The enamel changes were studied using confocal laser scanning microscopy (CLSM), and the depth of lesions and demineralisation/remineralisation/infiltration percentage were calculated. Additionally, the macro elemental composition of the teeth was performed using atomic absorption spectroscopy (AAS). Two studies were performed: (i) demineralisation of enamel in 3% citric acid and infiltration treatment with infiltration resin (Icon, DMG), remineralisation with Fluor Protector (Ivoclar Vivadent) and artificial saliva pH 8; and (ii) enamel demineralisation in saliva at pH 3 and remineralisation at salivary pH 8. The results showed that, firstly, for the remineralisation of demineralised enamel samples, Fluor Protector (Ivoclar Vivadent) was very effective for medium demineralised lesions followed by saliva remineralisation. In cases of deep demineralisation lesions where fluoride could not penetrate, low viscosity resin (Icon, DMG, Hamburg) effectively infiltrated to stop the demineralisation process. Secondly, remineralisation in salivary conditions needed supplementary study over a longer period, to analyse the habits, diet and nutrition of patients in detail. Finally, demineralisation/remineralisation processes were found to influence the macro elemental composition of enamel demineralisation, with natural saliva proving to be less aggressive in terms of decreasing Ca and Mg content.
Highlighting Bacteria with Calcifying Abilities Suitable to Improve Mortar Properties
Authors: Răut Iuliana , Constantin Mariana , Petre Ionela , Raduly Monica , Radu Nicoleta , Gurban Ana-Maria , Doni Mihaela , Alexandrescu Elvira , Nicolae Cristi-Andi , Jecu Luiza
Published: October 2022

Biomineralization, the use of microorganisms to produce calcium carbonate, became a green solution for application in construction materials to improve their strength and durability. The calcifying abilities of several bacteria were investigated by culturing on a medium with urea and calcium ions. The characterization of the precipitates from bacterial cultures was performed using X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The formation of carbonate crystals was demonstrated by optical and scanning electron microscopy. Water absorption and compressive strength measurements were applied to mortars embedded with sporal suspension. The efficiency of the supplementation of mortar mixtures with bacterial cells was evaluated by properties, namely the compressive strength and the water absorption, which are in a relationship of direct dependence, the increase in compressive strength implying the decrease in water absorption. The results showed that Bacillus subtilis was the best-performing bacterium, its introduction into the mortar producing an increase in compressive strength by 11.81% and 9.50%, and a decrease in water absorption by 11.79% and 10.94%, after 28 and 56 days of curing, respectively, as compared to standards. The exploitation of B. subtilis as a calcifying agent can be an interesting prospect in construction materials.
Multi-Server Queuing Production Inventory System with Emergency Replenishment
Authors: Shajin Dhanya , Krishnamoorthy Achyutha , Melikov Agassi Z. , Sztrik Janos
Published: October 2022

We consider a multi-server production inventory system with an unlimited waiting line. Arrivals occur according to a non-homogeneous Poisson process and exponentially distributed service time. At the service completion epoch, one unit of an item in the on-hand inventory decreases with probability δ, and the customer leaves the system without taking the item with probability (1−δ). The production inventory system adopts an (s,S) policy where the processing of inventory requires a positive random amount of time. The production time for a unit item is phase-type distributed. Furthermore, assume that an emergency replenishment of one item with zero lead time takes place when the on-hand inventory level decreases to zero. The emergency replenishment is incorporated in the system to ensure customer satisfaction. We derive the stationary distribution of the system and some main performance measures, such as the distribution of the production on/off time in a cycle and the mean emergency replenishment cycle time. Numerical experiments are conducted to illustrate the system performance. A cost function is constructed, and we examine the optimal number of servers to be employed. Furthermore, we numerically calculate the optimal values of the production starting level and maximum inventory level.
Using Probabilistic Models for Data Compression
Authors: Iatan Iuliana , Drăgan Mihăiţă , Dedu Silvia , Preda Vasile
Published: October 2022

Our research objective is to improve the Huffman coding efficiency by adjusting the data using a Poisson distribution, which avoids the undefined entropies too. The scientific value added by our paper consists in the fact of minimizing the average length of the code words, which is greater in the absence of applying the Poisson distribution. Huffman Coding is an error-free compression method, designed to remove the coding redundancy, by yielding the smallest number of code symbols per source symbol, which in practice can be represented by the intensity of an image or the output of a mapping operation. We shall use the images from the PASCAL Visual Object Classes (VOC) to evaluate our methods. In our work we use 10,102 randomly chosen images, such that half of them are for training, while the other half is for testing. The VOC data sets display significant variability regarding object size, orientation, pose, illumination, position and occlusion. The data sets are composed by 20 object classes, respectively: aeroplane, bicycle, bird, boat, bottle, bus, car, motorbike, train, sofa, table, chair, tv/monitor, potted plant, person, cat, cow, dog, horse and sheep. The descriptors of different objects can be compared to give a measurement of their similarity. Image similarity is an important concept in many applications. This paper is focused on the measure of similarity in the computer science domain, more specifically information retrieval and data mining. Our approach uses 64 descriptors for each image belonging to the training and test set, therefore the number of symbols is 64. The data of our information source are different from a finite memory source (Markov), where its output depends on a finite number of previous outputs. When dealing with large volumes of data, an effective approach to increase the Information Retrieval speed is based on using Neural Networks as an artificial intelligent technique.
Some Fejér-Type Inequalities for Generalized Interval-Valued Convex Functions
Authors: Khan Muhammad Bilal , Macías-Díaz Jorge E. , Treanțǎ Savin , Soliman Mohamed S.
Published: October 2022

The goal of this study is to create new variations of the well-known Hermite–Hadamard inequality (HH-inequality) for preinvex interval-valued functions (preinvex I-V-Fs). We develop several additional inequalities for the class of functions whose product is preinvex I-V-Fs. The findings described here would be generalizations of those found in previous studies. Finally, we obtain the Hermite–Hadamard–Fejér inequality with the support of preinvex interval-valued functions. Some new and classical special cases are also obtained. Moreover, some nontrivial examples are given to check the validity of our main results.
Multitask Image Splicing Tampering Detection Based on Attention Mechanism
Authors: Zeng Pingping , Tong Lianhui , Liang Yaru , Zhou Nanrun , Wu Jianhua
Published: October 2022

In today’s modern communication society, the authenticity of digital media has never been of such importance as it is now. In this aspect, the reliability of digital images is of paramount importance because images can be easily manipulated by means of sophisticated software, such as Photoshop. Splicing tampering is a commonly used photographic manipulation for modifying images. Detecting splicing tampering remains a challenging task in the area of image forensics. A new multitask model based on attention mechanism, densely connected network, Atrous Spatial Pyramid Pooling (ASPP) and U-Net for locating splicing tampering in an image, AttDAU-Net, was proposed. The proposed AttDAU-Net is basically a U-Net that incorporates the spatial rich model filtering, an attention mechanism, an ASPP module and a multitask learning framework, in order to capture more multi-scale information while enlarging the receptive field and improving the detection precision of image splicing tampering. The experimental results on the datasets of CASIA1 and CASIA2 showed promising performance metrics for the proposed model (F1-scores of 0.7736 and 0.6937, respectively), which were better than other state-of-the-art methods for comparison, demonstrating the feasibility and effectiveness of the proposed AttDAU-Net in locating image splicing tampering.
Magnesium-Doped Sr2(Fe,Mo)O6−δ Double Perovskites with Excellent Redox Stability as Stable Electrode Materials for Symmetrical Solid Oxide Fuel Cells
Authors: Zheng Kun , Lach Jakub , Zhao Hailei , Huang Xiubing , Qi Kezhen
Published: October 2022

In this work, magnesium-doped Sr2Fe1.2Mg0.2Mo0.6O6−δ and Sr2Fe0.9Mg0.4Mo0.7O6−δ double perovskites with excellent redox stability have been successfully obtained. The physicochemical properties including: crystal structure properties, redox stability, thermal expansion properties in oxidizing and reducing conditions, oxygen content as a function of temperature and transport properties, as well as the chemical compatibility with typical electrolytes have been systematically investigated. The in situ oxidation of reduced samples using high-temperature XRD studies shows the crystal structure of materials stable at up to a high-temperature range. The in situ reduction and oxidation of sinters with dilatometer measurements prove the excellent redox stability of materials, with the thermal expansion coefficients measured comparable with electrolytes. The oxygen nonstoichiometry δ of compounds was determined and recorded in air and argon up to 900 °C. Sr2Fe1.2Mg0.2Mo0.6O6−δ oxide presents satisfactory values of electrical conductivity in air (56.2 S·cm−1 at 600 °C) and reducing conditions (10.3 S·cm−1 at 800 °C), relatively high coefficients D and k, and good ionic conductivity (cal. 0.005 S·cm−1 at 800 °C). The stability studies show that both compounds are compatible with Ce0.8Gd0.2O1.9 but react with the La0.8Sr0.2Ga0.8Mg0.2O3−d electrolyte. Therefore, the magnesium-doped double perovskites with excellent redox stability can be potentially qualified as electrode materials for symmetrical SOFCs and are of great interest for further investigations.
Influence of the Processing Parameters on the Aroma Profile and Chemical Composition of Conventional and Ecological Cabernet Sauvignon Red Wines during Concentration by Reverse Osmosis
Authors: Ivić Ivana , Kopjar Mirela , Obhođaš Jasmina , Vinković Andrija , Babić Jurislav , Mesić Josip , Pichler Anita
Published: October 2022

Wine aroma represents one of the most important quality parameters and it is influenced by various factors, such as climate conditions, viticulture and vinification techniques, storage conditions, etc. Wines produced from conventionally and ecologically grown grapes of the same variety have different chemical compositions and aroma profiles. The composition of wine can also be influenced by the additional treatment of wine, such as the concentration of wine by reverse osmosis (RO). The aim of this study was to investigate the influence of four different pressures (2.5, 3.5, 4.5 and 5.5 MPa) and two temperature regimes (with and without cooling) on the aroma profile and chemical composition of conventional and ecological Cabernet Sauvignon red wine during concentration by reverse osmosis. The results showed that different processing parameters influenced the permeate flux, the retentate temperature and the compounds retention. Higher working pressures (4.5 and 5.5 MPa) and the regime, with cooling, resulted in a higher retention of the total aroma compounds than the opposite processing parameters. The retention of individual compounds depended also on their chemical properties and their interactions with the membrane surface. The reverse osmosis membranes proved to be permeable for ethanol, acetic acid or undesirable 4-ethylphenol and 4-ethylguaiacol that made them applicable for their correction or removal.
Influence of Pulse Current on Inclusion Properties of Alumina in Molten Steel
Authors: Yang Xin , Zhang Liguo , Cao Dong , Han Xiao , Zhang Yuanyuan , He Zhijun
Published: October 2022

In the process of metal purification, the study of controlling the morphology and size distribution of non-metallic inclusions in steel based on electric fields has attracted extensive attention. However, the action mechanism of electric fields on inclusions in liquid steel has not been clearly identified. In this paper, the influence of pulse current on the quantity, size, and distribution of alumina inclusions in liquid steel was explored through a high-temperature energization experiment, and the action mechanism of pulse current was expounded based on the angle of interface free energy. The results show that the number of small alumina inclusions in the steel after electric pulse treatment (the pulse current density was 0.1–3 A/cm2, the frequency was 100 Hz, and the pulse waveform was a square wave) was significantly increased compared with the sample without electric pulse treatment, and the particle size was concentrated at 2–5 μm, and the inclusions were concentrated in the upper and lower parts of the sample. However, in the samples without electrification treatment, the large particles of inclusions are the majority, the particle size was concentrated at about 10 μm, and the inclusions were concentrated in the upper and middle parts of the samples. When the pulse current was applied to the molten steel, the interfacial free energy of the internal system of liquid steel alumina inclusion was reduced, the nucleation of alumina inclusion was promoted, the aggregation growth between alumina particles was inhibited, and then the migration and distribution of inclusions were also affected. The experimental results could provide technical support for high-quality steel smelting production to a certain extent.
Experimental Investigation of Isothermal Section in the La–Co–Ni System at 723 K
Authors: Huang Kailin , Xiao Liming , Yang Qingkai , Yang Lu , Li Zhuobin , Lu Zhao , Yao Qingrong , Deng Jianqiu , Cheng Lichun , Huang Caimin , Long Qianxin , Wang Jiang , Zhou Huaiying
Published: October 2022

The isothermal section of the La–Co–Ni ternary system at 723 K has been constructed in this work by using X-ray diffraction (XRD), scanning electron microscopy, and energy dispersion spectroscopy techniques (SEM-EDS). The experimental results show no existence of ternary compounds at 723 K. The isothermal section consists of 16 two-phase regions and 8 three-phase regions. La3Co and La3Ni, La2Co3 and La2Ni3, La2Co7 and La2Ni7, and LaCo5 and LaNi5 form a continuous solid solution. The ternary solid solubility of Ni in LaCo13 phase and La2Co1.7 phase was determined to be 15.61 at.% and 9.61 at.%, respectively. The solid solubility of Co in the LaNi3, La7Ni3, and LaNi phases was 18.07 at.%, 5.62 at.%, and 8.49 at.%, respectively. The present experimental results are important for the design of La(Fe,Si)13-based magnetic refrigeration materials.
The Cardiovascular Benefits and Infections Risk of SGLT2i versus Metformin in Type 2 Diabetes: A Systemic Review and Meta-Analysis
Authors: Xu Chunmei , He Liping , Zhang Jing , Xu Lusi , Dong Jianjun , Liao Lin
Published: October 2022

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and metformin are both widely accepted anti-hyperglycemic agents. However, there is still no systematic review evaluating the cardiovascular benefits and risk of infections of SGLT2i versus metformin. To make that clear, we designed this study. Public databases, including the Cochrane library database, PubMed, and Embase were searched for randomized clinical trials (RCTs) fitting the inclusion criteria. Two reviewers extracted the data and appraised the study quality independently. Thirteen RCTs enrolling 4189 patients were eligible for this analysis. Our results showed that compared with metformin, SGLT2i increased the risk of genitourinary tract infections (p < 0.00001). Further subgroup analysis suggested that the occurrence of urinary tract infections (UTI) was not statistically significant (p = 0.18), but the incidence of reproductive tract infections (RTI) was significantly increased in patients in the SGLT2i group compared with that in the metformin group (p < 0.00001). In addition, SGLT2i markedly decreased the levels of cardiovascular risk factor, including body weight, blood pressure, and triglyceride level, and significantly increased the HDL-cholesterol level (p < 0.00001) in patients versus that of metformin. For type 2 diabetes patients with obesity, SGLT2i was associated with more significant reductions in weight and blood pressure compared to metformin without an increased risk of genitourinary infections, and the reduction in fasting plasma glucose was superior in the SGLT2i group; the decrease in HbA1c was similar in both groups. Additionally, no significant publication bias was seen. Based on these findings, SGLT2i provided the similar antihyperglycemic effects, additional cardiovascular benefits, and a potential RTI risk compared with that of metformin. Our results indicate that SGLT2i is a good choice for those patients with metformin intolerance or resistance.
Cheminformatics Bioprospection of Broad Spectrum Plant Secondary Metabolites Targeting the Spike Proteins of Omicron Variant and Wild-Type SARS-CoV-2
Authors: Aribisala Jamiu Olaseni , Aruwa Christiana Eleojo , Uthman Taofik Olatunde , Nurain Ismaila Olanrewaju , Idowu Kehinde , Sabiu Saheed
Published: October 2022

The spike protein (SP) of SARS-CoV-2 (SC-2) is susceptible to high mutation and has contributed to the multiple waves of COVID-19 being experienced. Hence, targeting the SP remains a logical approach in the development of potent therapeutics against SARS-CoV-2. Here, a computational technique was adopted to identify broad-spectrum plant secondary metabolites with indigenous relevance in the management of respiratory infections against the SPs of the SC-2 wild- type (SC-2WT) and omicron variants. Following 100 ns molecular dynamic (MD) simulation and binding free energy calculation of the top five compounds identified through molecular docking, maysin (SC-2WT (−34.85 kcal/mol), omicron (−38.88 kcal/mol)) and geraniin (SC-2WT (−36.90 kcal/mol) omicron (−31.28 kcal/mol)) had better broad-spectrum activities for the investigated SPs than zafirlukast (SC-2WT (−33.73 kcal/mol) omicron (−22.38 kcal/mol)). Furthermore, 6-hydroxycyanidin-3-rutinoside (−42.97 kcal/mol) and kaempferol-7-glucoside (−37.11 kcal/mol) had the best affinity for the SPs of omicron and SC-2WT, respectively. Interestingly, except for Kaempferol-7-glucoside against omicron SP, all the top-ranked compounds were thermodynamically stable with the SP of both variants, and this observation was linked to the number, nature, and bond length in the resulting complexes in each case. Also, except for geraniin, all the top-ranked compounds had lower toxicity profiles compared to zafirlukast and this could be attributed to their phenolic moieties. Nevertheless, the in vitro and in vivo confirmation of the activities observed in this study is recommended, especially for maysin and geraniin with the best broad-spectrum activity, towards development of COVID-19 drug candidates.
A Marked Low-Grade Inflammation and a Significant Deterioration in Metabolic Status in First-Episode Schizophrenia: A Five-Year Follow-Up Study
Authors: Parksepp Madis , Haring Liina , Kilk Kalle , Taalberg Egon , Kangro Raul , Zilmer Mihkel , Vasar Eero
Published: October 2022

The objective of this study was to evaluate how schizophrenia spectrum disorders and applied long-term (5.1 years) antipsychotic (AP) treatment affect the serum level of acylcarnitines (ACs), cytokines and metabolic biomarkers and to characterize the dynamics of inflammatory and metabolic changes in the early course of the disorder. A total of 112 adults participated in the study (54 patients with first-episode psychosis (FEP) and 58 control subjects). Biomolecule profiles were measured at the onset of first-episode psychosis and 0.6 years and 5.1 years after the initiation of APs. The results of the present study confirmed that specific metabolic–inflammatory imbalance characterizes AP-naïve patients. Short-term (0.6-years) AP treatment has a favourable effect on psychotic symptoms, as well as the recovery of metabolic flexibility and resolution of low-level inflammation. However, 5.1 years of AP treatment resulted in weight gain and increased serum levels of interleukin (IL)-2, IL-4, IL-6, IL-10, interferon-γ, hexoses, acetylcarnitine, short-chain ACs (C3, C4) and long-chain ACs (C16:2, C18:1, C18:2). In conclusion, despite the improvement in psychotic symptoms, 5.1 years of AP treatment was accompanied by a pronounced metabolic–inflammatory imbalance, which was confirmed by the presence of enhanced pro-inflammatory activity and increased obesity with changes in the metabolism of carbohydrates, lipids, and their metabolites.
Study on the Regulation of Exogenous Hormones on the Absorption of Elements and the Accumulation of Secondary Metabolites in the Medicinal Plant Artemisia argyi Leaves
Authors: Yang Linlin , Yan Yueci , Zhao Boyu , Xu Huaming , Su Xiuhong , Dong Chengming
Published: October 2022

As an important medicinal plant, we still do not know the effect of exogenous hormones on absorption of elements and accumulation of secondary metabolites in Artemisia argyi leaves. In this work, we analyzed the difference in 21 elements absorbed by A. argyi leaves under three exogenous hormone (MeJA, SA and ABA) treatments, and also clarified the correlation between 21 elements and eight bioactive components. Different hormone treatments changed the absorption and enrichment of elements, and the composition also changed significantly. The contents of eight bioactive components changed significantly under different hormone treatments. When A. argyi was stimulated by exogenous hormones, the content of secondary metabolites was adjusted in the leaves through changes in the absorption and enrichment of elements. The widely untargeted metabolomic analysis further confirmed that ABA changes the metabolic direction of secondary metabolites in A. argyi leaves and stimulates the biosynthesis of multiple secondary metabolites including phenylpropanoids, flavonoids, terpenoids, alkaloids and others. These results provide a new perspective for the changes in element absorption and the mechanism of secondary metabolic components in A. argyi leaves under exogenous hormone treatments, and also deepen people’s understanding of the interaction mechanism between medicinal plants and hormones.
Use of Slightly Pressurized Carbon Dioxide to Enhance the Antimicrobial Properties of Brines in Naturally Processed Black Table Olives
Authors: Zullo Biagi Angelo , Ciafardini Gino
Published: October 2022

Naturally fermented black table olives are processed at low pH in the presence of high sodium chloride concentrations ranging from 8 to 12% (w v−1). Reducing the salt content of brine has become an urgent issue as it is responsible for several health and environmental problems. The study aim was to evaluate slightly pressurized CO2 (spCO2) as a third barrier to microbial growth in naturally processed black table olives with low pH and a reduced NaCl concentration. Based on the assessments performed on a pilot plant scale, an spCO2 of 1 bar completely inhibited the growth of the bacteria and molds in the presence of reduced saline concentrations. Furthermore, the amount of yeast decreased in the brine as a function of the NaCl content. Laboratory tests performed under spCO2 conditions using a single yeast species from the same habitat confirmed the high sensitivity of some oxidizing yeasts and indicated that the fermenting yeast, Saccharomyces cerevisiae, is the most tolerant species. Overall, in the brine of naturally processed olives with a low pH between 4 and 4.2, the antimicrobial properties observed with the high concentrations of NaCl can be achieved with a lower salt dose of 5% (w v−1) when combined with spCO2.
Mineralogical, Geochronological, and Geochemical Characteristics of Early Cretaceous Granite in South China: Implications for Tectonic Evolution and REE Mineralization
Authors: Qin Yue , Cai Yongfeng , Fu Wei , Han Zhixuan , Liu Panfeng , Lao Changling , Zhao Yongshan , Han Zhengchao , Zhou Yun
Published: October 2022

One of the most important geological features of South China are the widespread Mesozoic igneous rocks that play a key role in revealing the tectonic evolution of South China. Due to the thick covering of vegetation and Quaternary sediments, the early Cretaceous magmatism in southwestern South China is still not well constrained. In this paper, we report newly identified early Cretaceous granites in Guangxi, South China. Zircon U–Pb dating results showed that representative fine-grained and coarse-grained granites in northeastern Guangxi indicate the early Cretaceous ages of 141 ± 3 Ma and 141 ± 4 Ma, respectively. Geochemically, both fine-grained and coarse-grained granites had high 10,000 × Ga/Al ratios and belonged to A-type granite. They had undergone high degrees of magma differentiation, as evidenced by extremely negative Sr, Ba, and Eu anomalies. They had high REE (rare earth elements) contents (>451 ppm). The fine-grained granites were characterized by higher HREE (heavy rare earth elements) contents, lower LREE (light rare earth elements) contents, and lower LREE/HREE ratios than the coarse-grained granites. Integrated with regional geological data, the early Cretaceous granites were likely formed in a back-arc extensional environment in response to the increased subduction angle of the Paleo-Pacific plate. Different REE contents in the fine- and coarse-grained granites may be a result of fractional crystallization. Magma differentiation and hydrothermal alteration might have played an important role in REE mineralization of the early Cretaceous granites in Guangxi.
Nipecotic Acid Derivatives as Potent Agents against Neurodegeneration: A Preliminary Study
Authors: Papagiouvannis Georgios , Theodosis-Nobelos Panagiotis , Rekka Eleni A.
Published: October 2022

Alzheimer’s Disease (AD) is a common neurodegenerative disorder characterized by memory loss and cognitive impairment. Its pathology has not been fully clarified and therefore highly effective treatments have not been obtained yet. Almost all the current treatment options aim to alleviate only the symptoms and not to eliminate the disease itself. Acetylcholinesterase inhibitors are the main therapeutic agents against AD, whereas oxidative stress and inflammation have been found to be of great significance for the development and progression of neurodegeneration. In this work, ethyl nipecotate (ethyl-piperidine-3-carboxylate), a heterocyclic carboxylic acid derivative, which acts as a GABA reuptake inhibitor and has been used in research for diseases involving GABAergic neurotransmission dysfunction, was amidated with various carboxylic acids bearing antioxidant and/or anti-inflammatory properties (e.g., ferulic acid, sinapic acid, butylated hydroxycinnamic acid). Most of our compounds have significant antioxidant potency as lipid peroxidation inhibitors (IC50 as low as 20 μΜ), as oxidative protein glycation inhibitors (inhibition up to 57%), and act as DPPH reducing agents. Moreover, our compounds are moderate LOX inhibitors (up to 33% at 100 μΜ) and could reduce rat paw edema induced by carrageenan by up to 61%. Finally, some of them possessed inhibitory activity against acetylcholinesterase (IC50 as low as to 47 μΜ). Our results indicate that our compounds could have the potentiality for further optimization as multi-targeting agents directed against AD.
Biopolymeric Ni3S4/Ag2S/TiO2/Calcium Alginate Aerogel for the Decontamination of Pharmaceutical Drug and Microbial Pollutants from Wastewater
Authors: Kumar Rajeev , Oves Mohammad , Ansari Mohammad , Taleb Md. , Barakat Mohamed , Alghamdi Mansour , Makishah Naief
Published: October 2022

The ubiquitous presence of pharmaceutical drugs and microbes in the water is leading to the development of drug resistant microbes. Therefore, efficient materials that can remove or inactivate the drug and microbe contaminants are required. In this work, nickel sulfide/calcium alginate (Ni3S4/CA), silver sulfide/calcium alginate (Ag2S/CA), modified titanium dioxide/calcium alginate (TiO2/CA), and Ni3S4/Ag2S/TiO2/calcium alginate (Ni3S4/Ag2S/TiO2/CA) aerogels have been synthesized for the removal of the oxytetracycline (OTC) drug and microbial contaminants from real beverage industry wastewater. The results revealed that Ni3S4/Ag2S/TiO2/CA aerogel is highly efficient for OTC adsorption and inactivation of microbes compared to Ni3S4/CA, Ag2S/CA and TiO2/CA aerogels. The OTC adsorption depends greatly on the solution pH, and optimum OTC removal was observed at pH 6 in its zwitterionic (OTC±) form. The formation of H-bonding and n-π electron donor-acceptors is possible to a considerable extent due to the presence of the double bond benzene ring, oxygen and nitrogen, sulfur-containing functional groups on the OTC molecules, and the Ni3S4/Ag2S/TiO2/CA aerogel. Based on the statistical analysis, root-mean-square deviation (RMSD), chi square (χ2) values, and higher correlation coefficient (R2) values, the Redlich–Peterson isotherm model and Elovich kinetic model are most suited to modelling the OTC adsorption onto Ni3S4/Ag2S/TiO2/CA. The prepared aerogels’ excellent antimicrobial activity is observed in the dark and with solar light irradiation. The zone of inhibition analysis revealed that the antimicrobial activity of the aerogels is in the following order: Ni3S4/Ag2S/TiO2/CA > TiO2/CA > Ag2S/CA > Ni3S4/CA, respectively. Moreover, the antimicrobial results demonstrated that reactive oxygen species, electrons, and active radical species are responsible for growth inhibition and killing of the microbes. These results indicated that Ni3S4/Ag2S/TiO2/CA aerogel is highly efficient in decontaminating pollutants from wastewater.
Chemical Composition and Antimicrobial Potential of Essential Oil of Acritopappus confertus (Gardner) R.M.King & H.Rob. (Asteraceae)
Authors: da Cruz Rafael Pereira , Castro José Walber Gonçalves , Leite Débora Odília Duarte , de Carvalho Natália Kelly Gomes , Almeida-Bezerra José Weverton , Pereira Raimundo Luiz Silva , Rodrigues Fázia Fernandes Galvão , Bezerra José Jailson Lima , Costa Adrielle Rodrigues , Mori Edna , de Farias Pablo Antonio Maia , Coutinho Henrique Douglas Melo , Morais-Braga Maria Flaviana Bezerra , Iriti Marcello , da Costa José Galberto Martins , Rodrigues Fabíola Fernandes Galvão
Published: October 2022

Microbial resistance has become a worrying problem in recent decades after the abusive use of antibiotics causing the selection of resistant microorganisms. In order to circumvent such resistance, researchers have invested efforts in the search for promising natural substances, such as essential oils. Thus, the objective of this work was to determine the chemical composition of the essential oil of Acritopappus confertus leaves, to evaluate its intrinsic effect and its effects in combination with drugs against pathogenic fungi and bacteria, in addition to verifying the inhibition of virulence in Candida strains. To this end, the oil was verified by gas chromatography coupled with mass spectrometry (GC/MS). Candida strains were used for antifungal assays by means of the serial microdilution technique, in order to determine the average inhibitory concentration (IC50), and for the modification assays, sub-inhibitory concentrations (MIC/8) were used. Finally, the natural product’s ability to inhibit the formation of filamentous structures was evaluated. In antibacterial tests, the MIC of the oil against strains of Staphylococcus aureus and Escherichia coli and its modifying effects in association with gentamicin, erythromycin, and norfloxacin were determined. The major constituent of the essential oil was the monoterpene myrcene (54.71%). The results show that the essential oil has an antifungal effect, with C. albicans strains being the most susceptible. Furthermore, the oil can potentiate the effect of fluconazole against strains of C. tropicalis and C. albicans. Regarding its effect on micromorphology, the oil was also able to inhibit the filaments in all strains. In combination with antibiotics, the oil potentiated the drug’s action by reducing the MIC against E. coli and S. aureus. It can be concluded that the essential oil of A. confertus has potential against pathogenic fungi and bacteria, making it a target for the development of an antimicrobial drug.
Integrated Omic Approaches Reveal Molecular Mechanisms of Tolerance during Soybean and Meloidogyne incognita Interactions
Authors: Arraes Fabricio B. M. , Vasquez Daniel D. N. , Tahir Muhammed , Pinheiro Daniele H. , Faheem Muhammed , Freitas-Alves Nayara S. , Moreira-Pinto Clídia E. , Moreira Valdeir J. V. , Paes-de-Melo Bruno , Lisei-de-Sa Maria E. , Morgante Carolina V. , Mota Ana P. Z. , Lourenço-Tessutti Isabela T. , Togawa Roberto C. , Grynberg Priscila , Fragoso Rodrigo R. , de Almeida-Engler Janice , Larsen Martin R. , Grossi-de-Sa Maria F.
Published: October 2022

The root-knot nematode (RKN), Meloidogyne incognita, is a devastating soybean pathogen worldwide. The use of resistant cultivars is the most effective method to prevent economic losses caused by RKNs. To elucidate the mechanisms involved in resistance to RKN, we determined the proteome and transcriptome profiles from roots of susceptible (BRS133) and highly tolerant (PI 595099) Glycine max genotypes 4, 12, and 30 days after RKN infestation. After in silico analysis, we described major defense molecules and mechanisms considered constitutive responses to nematode infestation, such as mTOR, PI3K-Akt, relaxin, and thermogenesis. The integrated data allowed us to identify protein families and metabolic pathways exclusively regulated in tolerant soybean genotypes. Among them, we highlighted the phenylpropanoid pathway as an early, robust, and systemic defense process capable of controlling M. incognita reproduction. Associated with this metabolic pathway, 29 differentially expressed genes encoding 11 different enzymes were identified, mainly from the flavonoid and derivative pathways. Based on differential expression in transcriptomic and proteomic data, as well as in the expression profile by RT–qPCR, and previous studies, we selected and overexpressed the GmPR10 gene in transgenic tobacco to assess its protective effect against M. incognita. Transgenic plants of the T2 generation showed up to 58% reduction in the M. incognita reproduction factor. Finally, data suggest that GmPR10 overexpression can be effective against the plant parasitic nematode M. incognita, but its mechanism of action remains unclear. These findings will help develop new engineered soybean genotypes with higher performance in response to RKN infections.
Modulation of Photosynthesis and ROS Scavenging Response by Beneficial Bacteria in Olea europaea Plantlets under Salt Stress Conditions
Authors: Galicia-Campos Estrella , García-Villaraco Velasco Ana , Montero-Palmero Mᵃ Belén , Gutiérrez-Mañero F. Javier , Ramos-Solano Beatriz
Published: October 2022

Climate change consequences for agriculture involve an increase of saline soils which results in lower crop yields due to increased oxidative stress in plants. The present study reports the use of Plant Growth Promoting Bacteria (PGPB) as a tool to modulate plant innate mechanisms of adaptation to water stress (salinity and drought) in one year-old olive plantlets var. Arbosana and Arbequina. Integration of external changes in plants involve changes in Reactive Oxygen Species (ROS) that behave as signals to trigger plant adaptative mechanisms; however, they become toxic in high concentrations. For this reason, plants are endowed with antioxidant systems to keep ROS under control. So, the working hypothesis is that specific beneficial strains will induce a systemic response able to modulate oxidative stress and improve plant adaptation to water stress. Ten strains were assayed, evaluating changes in photosynthesis, pigments, ROS scavenging enzymes and antioxidant molecules, osmolytes and malondialdehyde, as oxidative stress marker. Photosynthesis and photosynthetic pigments were the most affected variables. Despite the specific response of each variety, the favorite targets of PGPBs to improve plant fitness were photosynthetic pigments and the antioxidant pools of glutathione and ascorbate. Our results show the potential of PGPBs to improve plant fitness modulating oxidative stress.
Bioprospecting of Essential Oil-Bearing Plants: Rapid Screening of Volatile Organic Compounds Using Headspace Bubble-in-Drop Single-Drop Microextraction for Gas Chromatography Analysis
Authors: Letseka Thabiso E. , Sepheka Ntjana J. , Dubery Ian A. , George Mosotho J.
Published: October 2022

Essential oils are vital constituents of oil-bearing plants. However, their screening still demands harvesting of the plant for laboratory analysis. We report herein a simple, rapid and robust headspace bubble-in-drop microextraction screening technique (BID-SPME) requiring only small amounts of plant material. The optimised method uses 0.5 g of the crushed plant leaves sample obtained in a 2 mL capped chromatography vial, heated to 55 °C and sampled with 2 µL heptadecane in a Hamilton gastight syringe equilibrated for 15 min exposed to the headspace volume. The method was applied to three plants, Pinus radiata, Tagetes minuta and Artemisia afra, which are known for their essential oil content. The method was able to extract at least 80% of the oil constituents in such abundance that they could be easily annotated using the gas chromatography–mass spectrometry (GC–MS) mass spectral libraries. The major volatile organic compounds (VOCs) detected included tagetone, terpinen-4-ol, ocimenone, caryophyllene, dihydrotagetone, terpinolene and artemisia ketone, just to mention a few, at different concentrations in different plants. Importantly, these annotated VOCs were also reported in other studies in the same and even different plants, extracted using normal steam distillation and importantly those reported in the literature for different extraction techniques.
Synthetic Thermo-Responsive Terpolymers as Tunable Scaffolds for Cell Culture Applications
Authors: Lizana-Vasquez Gaby D. , Arrieta-Viana Luis F. , Mendez-Vega Janet , Acevedo Aldo , Torres-Lugo Madeline
Published: October 2022

The use of tailored synthetic hydrogels for in vitro tissue culture and biomanufacturing provides the advantage of mimicking the cell microenvironment without issues of batch-to-batch variability. To that end, this work focused on the design, characterization, and preliminary evaluation of thermo-responsive, transparent synthetic terpolymers based on N-isopropylacrylamide, vinylphenylboronic acid, and polyethylene glycol for cell manufacturing and in vitro culture applications. Polymer physical properties were characterized by FT-IR, 1H-NMR, DLS, rheology, and thermal-gravimetric analysis. Tested combinations provided polymers with a lower critical solution temperature (LCST) between 30 and 45 °C. Terpolymer elastic/shear modulus varied between 0.3 and 19.1 kPa at 37 °C. Cellular characterization indicated low cell cytotoxicity on NIH-3T3. Experiments with the ovarian cancer model SKOV-3 and Jurkat T cells showed the terpolymers’ capacity for cell encapsulation without interfering with staining or imaging protocols. In addition, cell growth and high levels of pluripotency demonstrated the capability of terpolymer to culture iPSCs. Characterization results confirmed a promising use of terpolymers as a tunable scaffold for cell culture applications.
Characterization of a Translucent Material Produced from Paulownia tomentosa Using Peracetic Acid Delignification and Resin Infiltration
Authors: Park Kyoung-Chan , Kim Byeongho , Park Hanna , Kim Yesun , Park Se-Yeong
Published: October 2022

Paulownia tomentosa, a tree species that allows for efficient production of translucent wood, was selected as an experimental wood species in this study, and a two-step process of delignification and polymer impregnation was performed. For delignification, 2–4 mm thick specimens were immersed in peracetic acid for 8 h. The delignified-wood specimens were impregnated using epoxy, a commercial transparent polymer. To identify the characteristics of the resulting translucent wood, the transmittance and haze of each type of wood section (cross- and tangential) were measured, while bending strength was measured using a universal testing machine. The translucent wood varied in properties according to the wood section, and the total transmittance and haze were 88.0% and 78.5% for the tangential section and 91.3% and 96.2% for the cross-section, respectively. For the bending strength, untreated wood showed values of approximately 4613.5 MPa modulus of elasticity (MOE), while the epoxy impregnation to improve the strength of the wood had increased the MOE up to approximately 6089.9 MPa, respectively. A comparative analysis was performed in this study with respect to the substitution of balsa, which is used widely in the production of translucent wood. The results are anticipated to serve as baseline data for the functionalization of translucent wood.
High-Dielectric PVP@PANI/PDMS Composites Fabricated via an Electric Field-Assisted Approach
Authors: Wei Huaixiao , Yuan Yuan , Ren Tianli , Zhou Lijuan , Liu Xueqing , Saeed Haroon A. M. , Jin Pingliang , Chen Yuwei
Published: October 2022

Polymer-based composite films with multiple properties, such as low dielectric loss tangent, high dielectric constant, and low cost are promising materials in the area of electronics and electric industries. In this study, flexible dielectric films were fabricated via an electric field-assisted method. Polyaniline (PANI) was modified by polyvinylpyrrolidone (PVP) to form a core–shell structure to serve as functional particles and silicone rubber polydimethylsiloxane (PDMS) served as the matrix. The dielectric constant of the composites prepared under electric fields was improved by the micro-structures formed by external electric fields. With the addition of 2.5 wt% PVP@PANI, the dielectric constant could be significantly enhanced, up to 23; the dielectric loss tangent is only 1, which is lower than that of the aligned PANI samples. This new processing technology provides important insights for aligning fillers in polymer matrix to form composites with enhanced dielectric properties.
The Effect of Flame Retardant—Aluminum Trihydroxide on Mixed Mode I/II Fracture Toughness of Epoxy Resin
Authors: Zielonka Paweł , Duda Szymon , Lesiuk Grzegorz , Błażejewski Wojciech , Wiśniewska Magdalena , Warycha Joanna , Stabla Paweł , Smolnicki Michał , Babiarczuk Bartosz
Published: October 2022

Fire resistance is a major issue concerning composite materials for safe operation in many industrial sectors. The design process needs to meet safety requirements for buildings and vehicles, where the use of composites has increased. There are several solutions to increasing the flame resistance of polymeric materials, based on either chemical modification or physical additions to the material’s composition. Generally, the used flame retardants affect mechanical properties either in a positive or negative way. The presented research shows the influence of the mixed-mode behavior of epoxy resin. Fracture toughness tests on epoxy resin samples were carried out, to investigate the changes resulting from different inorganic filler contents of aluminum trihydroxide (ATH). Three-point bending and asymmetric four-point bending tests, with different loading modes, were performed, to check the fracture behavior in a complex state of loading. The results showed that the fracture toughness of mode I and mode II was reduced by over 50%, compared to neat resin. The experimental outcomes were compared with theoretical predictions, demonstrating that the crack initiation angle for higher values of KI/KII factor had a reasonable correlation with the MTS prediction. On the other hand, for small values of the factor KI/KII, the results of the crack initiation angle had significant divergences. Additionally, based on scanning electron microscopy images, the fracturing of the samples was presented.
Satellite-Derived Photosynthetically Available Radiation at the Coastal Arctic Seafloor
Authors: Singh Rakesh Kumar , Vader Anna , Mundy Christopher J. , Søreide Janne E. , Iken Katrin , Dunton Kenneth H. , Castro de la Guardia Laura , Sejr Mikael K. , Bélanger Simon
Published: October 2022

Climate change has affected the Arctic Ocean (AO) and its marginal seas significantly. The reduction of sea ice in the Arctic region has altered the magnitude of photosynthetically available radiation (PAR) entering the water column, impacting primary productivity. Increasing cloudiness in the atmosphere and rising turbidity in the coastal waters of the Arctic region are considered as the major factors that counteract the effect of reduced sea ice on underwater PAR. Additionally, extreme solar zenith angles and sea-ice cover in the AO increase the complexity of retrieving PAR. In this study, a PAR algorithm based on radiative transfer in the atmosphere and satellite observations is implemented to evaluate the effect of these factors on PAR in the coastal AO. To improve the performance of the algorithm, a flag is defined to identify pixels containing open-water, sea-ice or cloud. The use of flag enabled selective application of algorithms to compute the input parameters for the PAR algorithm. The PAR algorithm is validated using in situ measurements from various coastal sites in the Arctic and sub-Arctic seas. The algorithm estimated daily integrated PAR above the sea surface with an uncertainty of 19% in summer. The uncertainty increased to 24% when the algorithm was applied year-round. The PAR values at the seafloor were estimated with an uncertainty of 76%, with 36% of the samples under sea ice and/or cloud cover. The robust performance of the PAR algorithm in the pan-Arctic region throughout the year will help to effectively study the temporal and spatial variability of PAR in the Arctic coastal waters. The calculated PAR data are used to quantify the changing trend in PAR at the seafloor in the coastal AO with depth < 100 m using MODIS-Aqua data from 2003 to 2020. The general trends calculated using the pixels with average PAR > 0.415 mol m−2 day−1 at the seafloor during summer indicate that the annual average of PAR entering the water column in the coastal AO between 2003 and 2020 increased by 23%. Concurrently, due to increased turbidity, the attenuation in the water column increased by 22%. The surge in incident PAR in the water column due to retreating sea ice first led to increased PAR observed at the seafloor (∼12% between 2003 and 2014). However, in the last decade, the rapid increase in light attenuation of the water column has restricted the increase in average annual PAR reaching the bottom in the coastal AO.