bluuebunny/crossref_metadata_2025 huggingface dataset:
Osteoblast Attachment Compromised by High and Low Temperature of Titanium and Its Restoration by UV Photofunctionalization
Authors: Ikeda Takayuki , Okubo Takahisa , Saruta Juri , Hirota Makoto , Kitajima Hiroaki , Yanagisawa Naoki , Ogawa Takahiro
Published: September 2021

Titanium implants undergo temperature fluctuations during manufacturing, transport, and storage. However, it is unknown how this affects their bioactivity. Herein, we explored how storage (six months, dark conditions) and temperature fluctuations (5–50 °C) affected the bioactivity of titanium implants. Stored and fresh acid-etched titanium disks were exposed to different temperatures for 30 min under wet or dry conditions, and their hydrophilicity/hydrophobicity and bioactivity (using osteoblasts derived from rat bone marrow) were evaluated. Ultraviolet (UV) treatment was evaluated as a method of restoring the bioactivity. The fresh samples were superhydrophilic after holding at 5 or 25 °C under wet or dry conditions, and hydrophilic after holding at 50 °C. In contrast, all the stored samples were hydrophobic. For both fresh and stored samples, exposure to 5 or 50 °C reduced osteoblast attachment compared to holding at 25 °C under both wet and dry conditions. Regression analysis indicated that holding at 31 °C would maximize cell attachment (p < 0.05). After UV treatment, cell attachment was the same or better than that before temperature fluctuations. Overall, titanium surfaces may have lower bioactivity when the temperature fluctuates by ≥20 °C (particularly toward lower temperatures), independent of the hydrophilicity/hydrophobicity. UV treatment was effective in restoring the temperature-compromised bioactivity.
Mechanical Properties of Crumb Rubber Mortar Containing Nano-Silica Using Response Surface Methodology
Authors: Shahrul Syafiqah , Mohammed Bashar S. , Wahab M. M. A. , Liew M. S.
Published: September 2021

Crumb rubber (CR) from scrap tires is used as a partial replacement of fine aggregates in cement paste. This promotes the sustainable development of the environment, economy, and society, as waste tires are non-biodegradable and flammable. They occupy large landfill areas and are breeding grounds for mosquitoes and rodents. Inclusion of CR in mortar leads to several improvements on the mixture properties such as ductility, toughness, and impact resistance. However, it exhibits lower strengths and Modulus of Elasticity (ME). Therefore, to promote the use of mortar containing CR, it is vital to improve its mechanical strength. Past studies proved that nano-silica (NS) improves the strength of concrete due to the physico-chemical effects of NS. This study aims to examine the mechanical properties of crumb rubber mortar containing nano-silica (NS-CRM) and to develop models to predict these properties using Response Surface Methodology (RSM). Two variables were considered, CR as partial replacement to sand by volume (0%, 7.5%, 15%), and NS as partial replacement to cement by weight (0%, 2.5%, 5%). The results demonstrated a significant improvement in the mechanical properties of CRM when incorporating NS, and the models developed using RSM were acceptable with a 2% to 3% variation.
Cobalt Content Effect on the Magnetic Properties of Ni50-xCoxMn35.5In14.5 Annealed Ribbons
Authors: Dubiel Łukasz , Wal Andrzej , Stefaniuk Ireneusz , Żywczak Antoni , Potera Piotr , Maziarz Wojciech
Published: September 2021

We present a study of the annealing effect and its influence on magnetic and structural properties for a series of Heusler alloys Ni50−xCoxMn35.5In14.5 (x=0,3,5) prepared in ribbon form. We studied the morphology and composition using scanning electron microscopy (SEM) equipped with an X-ray microanalyzer (EDX). The magnetic properties were determined by two methods: electron magnetic resonance (EMR) and vibrating sample magetometer (VSM). We found that cobalt content in the annealed samples reveals an additional magnetic phase transition at lower temperatures.
Tie Rod-Equivalent Non-Linear Constitutive Law for Uniformly Loaded Cables
Authors: Croce Pietro
Published: September 2021

Cables are typically used in engineering applications as tensile members. Relevant examples are the main cables of suspension bridges, the stays of cable-stayed bridges, the load-bearing and stabilizing cables of tensile structures, the anchor cables of floating mooring structures, the guy-ropes for ship masts, towers, and wind turbines, the copper cables of electrical power lines. Since cables are characterized by non-linear behavior, analysis of cable structures often requires advanced techniques, like non-linear FEM, able to consider geometric non-linearity. Nevertheless, a traditional simplified approach consists in replacing the cable with an equivalent tie rod, characterized by a suitable non-linear constitutive law. Currently used equivalent constitutive laws have been derived by Dischinger, Ernst and Irvine. Since the equivalence is restricted to taut cables, characterized by small sag to chord ratios, these traditional formulae are not appropriate for uniformly loaded sagging cables: the main cables of suspension bridges are a particularly emblematic case. Despite some recent attempts to find more refined solutions, the problem is still open, since closed form solutions of general validity are not available. In the paper, general analytical formulae of the non-linear constitutive law of the equivalent tie rod are proposed, distinguishing two relevant cases, according as the length of the cable can vary or not. The expressions, derived by applying the general form of the theorem of virtual work, can be applied independently on the material, on the sag to chord ratio, on the load intensity and on the stress level, so allowing the replacement of the whole cable with a single equivalent tie rod. The expressions are critically discussed referring to a wide parametric study also in comparison with the existing formulae, stressing the influence of the most relevant parameters.
Material Monitoring of a Composite Dome Pavilion Made by Robotic Coreless Filament Winding
Authors: Mindermann Pascal , Rongen Bas , Gubetini Drilon , Knippers Jan , Gresser Götz T.
Published: September 2021

A hemispherical research demonstration pavilion was presented to the public from April to October 2019. It was the first large-scale lightweight dome with a supporting roof structure primarily made of carbon- and glass-fiber-reinforced composites, fabricated by robotic coreless filament winding. We conducted monitoring to ascertain the sturdiness of the fiber composite material of the supporting structure over the course of 130 days. This paper presents the methods and results of on-site monitoring as well as laboratory inspections. The thermal behavior of the pavilion was characterized, the color change of the matrix was quantified, and the inner composition of the coreless wound structures was investigated. This validated the structural design and revealed that the surface temperatures of the carbon fibers do not exceed the guideline values of flat, black façades and that UV absorbers need to be improved for such applications.
Research on Flashover Prediction Method of Large-Space Timber Structures in a Fire
Authors: Zhang Yongwang , Wang Lu
Published: September 2021

Due to the flammability of materials and the vastness of space, flashover fires of large-space timber structures pose a huge threat to lives as well as the structures themselves. Therefore, it is necessary to study the critical conditions, control factors and prediction methods of flashover fires. To address this issue, hundreds of design conditions were simulated by Fire Dynamics Simulator (FDS) with variations in space size, the heat release rate (HRR) of fire source and fire growth type. A temperature–time model of the maximum temperature of the smoke layer near the ceiling (Tmax) was established, and the critical condition that uses this model to predict the occurrence of flashover was determined. Furthermore, a mathematical formula was established that can accurately predict the flashover induction time when the Tmax exceeds 400 °C. This research can provide a reference for the performance-based fire safety design of large-space timber structures.
Curve Fitting for Damage Evolution through Regression Analysis for the Kachanov–Rabotnov Model to the Norton–Bailey Creep Law of SS-316 Material
Authors: Sattar Mohsin , Othman Abdul Rahim , Akhtar Maaz , Kamaruddin Shahrul , Khan Rashid , Masood Faisal , Alam Mohammad Azad , Azeem Mohammad , Mohsin Sumiya
Published: September 2021

In a number of circumstances, the Kachanov–Rabotnov isotropic creep damage constitutive model has been utilized to assess the creep deformation of high-temperature components. Secondary creep behavior is usually studied using analytical methods, whereas tertiary creep damage constants are determined by the combination of experiments and numerical optimization. To obtain the tertiary creep damage constants, these methods necessitate extensive computational effort and time to determine the tertiary creep damage constants. In this study, a curve-fitting technique was proposed for applying the Kachanov–Rabotnov model into the built-in Norton–Bailey model in Abaqus. It extrapolates the creep behaviour by fitting the Kachanov–Rabotnov model to the limited creep data obtained from the Omega-Norton–Bailey regression model and then simulates beyond the available data points. Through the Omega creep model, several creep strain rates for SS-316 were calculated using API-579/ASME FFS-1 standards. These are dependent on the type of the material, the flow stress, and the temperature. In the present work, FEA creep assessment was carried out on the SS-316 dog bone specimen, which was used as a material coupon to forecast time-dependent permanent plastic deformation as well as creep behavior at elevated temperatures and under uniform stress. The model was validated with the help of published experimental creep test data, and data optimization for sensitivity study was conducted by applying response surface methodology (RSM) and ANOVA techniques. The results showed that the specimen underwent secondary creep deformation for most of the analysis period. Hence, the method is useful in predicting the complete creep behavior of the material and in generating a creep curve.
Magnetic Nanomaterials as Biocatalyst Carriers for Biomass Processing: Immobilization Strategies, Reusability, and Applications
Authors: Mariño Mayra A. , Fulaz Stephanie , Tasic Ljubica
Published: September 2021

Environmental concerns, along with oil shortages, have increased industrial interest in biomass conversion to produce biofuels and other valuable chemicals. A green option in biomass processing is the use of enzymes, such as cellulases, hemicellulases, and ligninolytic (laccase and peroxidases), which have outstanding specificity toward their substrates and can be reused if immobilized onto magnetic nanocarriers. Numerous studies report the biocatalysts’ performance after covalent binding or adsorption on differently functionalized magnetic nanoparticles (MNPs). Functionalization strategies of MNPs include silica-based surfaces obtained through a sol–gel process, graphene oxide-based nanocomposites, polymer-coated surfaces, grafting polymer brushes, and others, which have been emphasized in this review of the immobilization and co-immobilization of enzymes used for biomass conversion. Careful analysis of the parameters affecting the performance of enzyme immobilization for new hybrid matrices has enabled us to achieve wider tolerance to thermal or chemical stress by these biosystems during saccharification. Additionally, it has enabled the application of immobilized laccase to remove toxic organic compounds from lignin, among other recent advances addressed here related to the use of reusable magnetic carriers for bioderived chemical manufacturing.
Control Techniques for a Class of Fractional Order Systems
Authors: Ivanescu Mircea , Dumitrache Ioan , Popescu Nirvana , Popescu Decebal
Published: September 2021

The paper discusses several control techniques for a class of systems described by fractional order equations. The paper presents the unit frequency criteria that ensure the closed loop control for: Fractional Order Linear Systems, Fractional Order Linear Systems with nonlinear components, Time Delay Fractional Order Linear Systems, Time Delay Fractional Order Linear Systems with nonlinear components. The stability criterion is proposed for the systems composed of fractional order subsystems. These techniques are used in two applications: Soft Exoskeleton Glove Control, studied as a nonlinear model with time delay and Disabled Man-Wheelchair model, analysed as a fractional-order multi-system.
A Randomized Greedy Algorithm for Piecewise Linear Motion Planning
Authors: Ortiz Carlos , Lara Adriana , González Jesús , Borat Ayse
Published: September 2021

We describe and implement a randomized algorithm that inputs a polyhedron, thought of as the space of states of some automated guided vehicle R, and outputs an explicit system of piecewise linear motion planners for R. The algorithm is designed in such a way that the cardinality of the output is probabilistically close (with parameters chosen by the user) to the minimal possible cardinality.This yields the first automated solution for robust-to-noise robot motion planning in terms of simplicial complexity (SC) techniques, a discretization of Farber’s topological complexity TC. Besides its relevance toward technological applications, our work reveals that, unlike other discrete approaches to TC, the SC model can recast Farber’s invariant without having to introduce costly subdivisions. We develop and implement our algorithm by actually discretizing Macías-Virgós and Mosquera-Lois’ notion of homotopic distance, thus encompassing computer estimations of other sectional category invariants as well, such as the Lusternik-Schnirelmann category of polyhedra.
A ResNet50-Based Method for Classifying Surface Defects in Hot-Rolled Strip Steel
Authors: Feng Xinglong , Gao Xianwen , Luo Ling
Published: September 2021

Hot-rolled strip steel is widely used in automotive manufacturing, chemical and home appliance industries, and its surface quality has a great impact on the quality of the final product. In the manufacturing process of strip steel, due to the rolling process and many other reasons, the surface of hot rolled strip steel will inevitably produce slag, scratches and other surface defects. These defects not only affect the quality of the product, but may even lead to broken strips in the subsequent process, seriously affecting the continuation of production. Therefore, it is important to study the surface defects of strip steel and identify the types of defects in strip steel. In this paper, a scheme based on ResNet50 with the addition of FcaNet and Convolutional Block Attention Module (CBAM) is proposed for strip defect classification and validated on the X-SDD strip defect dataset. Our solution achieves a classification accuracy of 94.11%, higher than more than a dozen other compared deep learning models. Moreover, to adress the problem of low accuracy of the algorithm in classifying individual defects, we use ensemble learning to optimize. By integrating the original solution with VGG16 and SqueezeNet, the recognition rate of oxide scale of plate system defects improved by 21.05 percentage points, and the overall defect classification accuracy improved to 94.85%.
Secure and Optimal Secret Sharing Scheme for Color Images
Authors: Shankar K. , Taniar David , Yang Eunmok , Yi Okyeon
Published: September 2021

Due to contemporary communication trends, the amount of multimedia data created and transferred in 5G networks has reached record levels. Multimedia applications communicate an enormous quantity of images containing private data that tend to be attacked by cyber-criminals and later used for illegal reasons. Security must consider and adopt the new and unique features of 5G/6G platforms. Cryptographic procedures, especially secret sharing (SS), with some extraordinary qualities and capacities, can be conceived to handle confidential data. This paper has developed a secured (k, k) multiple secret sharing (SKMSS) scheme with Hybrid Optimal SIMON ciphers. The proposed SKMSS method constructs a set of noised components generated securely based on performing hash and block ciphers over the secret image itself. The shares are created and safely sent after encrypting them through the Hybrid Optimal SIMON ciphers based on the noised images. This is a lightweight cryptography method and helps reduce computation complexity. The hybrid Particle Swarm Optimization-based Cuckoo Search Optimization Algorithm generates the keys based on the analysis of the peak signal to noise ratio value of the recovered secret images. In this way, the quality of the secret image is also preserved even after performing more computations upon securing the images.
Power Grid Dynamic Performance Enhancement via STATCOM Data-Driven Control
Authors: Rivera David , Guillen Daniel , Mayo-Maldonado Jonathan C. , Valdez-Resendiz Jesus E. , Escobar Gerardo
Published: September 2021

This work proposes a data-driven approach to controlling the alternating current (AC) voltage via a static synchronous compensator (STATCOM). This device offers a fast dynamic response injecting reactive power to compensate the voltage profile, not only during load variations but also depending on the operating point established by the grid. The proposed control scheme is designed to improve the dynamic grid performance according to the defined operating point into the grid. The mathematical fundamentals of the proposed control strategy are described according to a (model-free) data-driven-based controller. The robustness of the proposed scheme is proven with several tests carried out using Matlab/Simulink software. The analysis is performed with the well-known test power system of two areas, demonstrating that the proposed controller can enhance the dynamic performance under transient scenarios. As the main strength of the present work with respect to the current state-of-the-art, we highlight the fact that no prior knowledge of the system is required for the controller implementation, that is, a model or a system representation. The synthesis of the controller is obtained in a pure numerical way from data, while it can simultaneously ensure stability in a rigorous way, by satisfying Lyapunov conditions.
RFID: A Fuzzy Linguistic Model to Manage Customers from the Perspective of Their Interactions with the Contact Center
Authors: Marín Díaz Gabriel , Carrasco Ramón Alberto , Gómez Daniel
Published: September 2021

In an increasingly globalized market, the relationship between the customer and the brand goes beyond the purchasing process. It is very important to understand the customer, to know their needs and to propose actions to increase the value of the brand for them. In the literature, there are several models capable of determining and segmenting customers according to variables dependent on the purchasing process. However, we have not found any study that applies to the business case of classifying customers according to their relationship with the contact centre. In this paper, we establish a working model that allows us to define the value of the customer in the process of interaction with the contact centre, so that we can propose actions both in the sales phase and during the post-sales service, so that the value and perception of the brand is increased. In this model, we propose using the value of recency, frequency, importance and duration of customer interactions with the post-sales service, thus obtaining a ranking, and grouping of customers to help establish personalized communication strategies. We have verified this model by presenting a business case applied to the telecom sector.
Modified Artificial Ecosystem-Based Optimization for Multilevel Thresholding Image Segmentation
Authors: Ewees Ahmed A. , Abualigah Laith , Yousri Dalia , Sahlol Ahmed T. , Al-qaness Mohammed A. A. , Alshathri Samah , Elaziz Mohamed Abd
Published: September 2021

Multilevel thresholding is one of the most effective image segmentation methods, due to its efficiency and easy implementation. This study presents a new multilevel thresholding method based on a modified artificial ecosystem-based optimization (AEO). The differential evolution (DE) is applied to overcome the shortcomings of the original AEO. The main idea of the proposed method, artificial ecosystem-based optimization differential evolution (AEODE), is to employ the operators of the DE as a local search of the AEO to improve the ecosystem of solutions. We used benchmark images to test the performance of the AEODE, and we compared it to several existing approaches. The proposed AEODE achieved a high performance when evaluated by the structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), and fitness values. Moreover, the AEODE outperformed the basic version of the AEO concerning SSIM and PSNR by 78% and 82%, respectively, which reserves the best features for each of AEO and DE.
Risk of More Advanced Lesions at Hysterectomy after Initial Diagnosis of Non-Atypical Endometrial Hyperplasia in Patients with Postmenopausal Bleeding and Oral Anticoagulant Treatment
Authors: Carabineanu Adrian , Zaharia Claudia , Blidisel Alexandru , Ilina Razvan , Miclaus Codruta , Ardelean Ovidiu , Preda Marius , Mazilu Octavian
Published: September 2021

Background and Objectives: Endometrial hyperplasia (EH) is a precursor lesion to endometrial cancer (EC), and when cellular atypia is present, in 40% of cases, they are diagnosed with EC on hysterectomy. Usually, EH is clinically manifested by uterine bleeding. In patients with oral anticoagulant therapy (OAT), the uterus is the second most common source of bleeding. The aim of the study was to show that uterine bleeding in postmenopausal patients undergoing OAT may reveal precancerous endometrial lesions with atypia, or neoplastic lesions in patients with an initial diagnosis of endometrial hyperplasia without atypia (non-atypical endometrial hyperplasia, NAEH) on dilation and curettage (D&C). We will be able to estimate the risk of a postmenopausal female patient with uterine bleeding during an OAT to have a precancerous endometrial lesion. Materials and Methods: The subjects of the study were 173 female patients with uterine bleeding, who have had total hysterectomy with bilateral salpingoovarectomy, of whom 99 underwent an OAT. There were 101 female patients initially diagnosed with NAEH, of which 60 did not have anticoagulant treatment (mean age 57.36 ± 6.51) and 41 had anticoagulant treatment (mean age 60.39 ± 7.35) (p = 0.006). From the pathology diagnosis moment, the surgery was performed at 42.09 ± 14.54 days in patients without OAT and after 35.39 ± 11.29 days in those who received such treatment (p = 0.724). Results: Initial diagnosis of NAEH established at D&C was changed at the final diagnosis after hysterectomy in EH with cellular atypia (atypical endometrial hyperplasia AEH) or EC in 18.18% of patients without OAT, and in 40.54% of patients who received this treatment. Conclusions: Based on a logistic regression model, it is estimated that female patients with an initial histopathological diagnosis of NAEH and who underwent OAT have, on average, 4.85 times greater odds (OR = 4.85, 95% CI 1.79–14.06) than the others of being identified postoperatively with more advanced lesions.
Pustular Psoriasis and Acute Generalized Exanthematous Pustulosis
Authors: Sussman Morgan , Napodano Anthony , Huang Simo , Are Abhirup , Hsu Sylvia , Motaparthi Kiran
Published: September 2021

The similarity between pustular psoriasis (PP) and acute generalized exanthematous pustulosis (AGEP) poses problems in the diagnosis and treatment of these two conditions. Significant clinical and histopathologic overlap exists between PP and AGEP. PP is an inflammatory disorder that has numerous clinical subtypes, but all with sterile pustules composed of neutrophils. AGEP is a severe cutaneous adverse reaction that is also characterized by non-follicular sterile pustules. Clinical features that suggest a diagnosis of PP over AGEP include a history of psoriasis and the presence of scaling plaques. Histologically, eosinophilic spongiosis, vacuolar interface dermatitis, and dermal eosinophilia favor a diagnosis of AGEP over PP. Importantly, PP and AGEP vary in clinical course and treatment. PP treatment involves topical steroids, oral retinoids, and systemic immunosuppressants. Newer therapies targeting IL-36, IL-23, IL-1, and PDE-4 have been investigated. The removal of the offending agent is a crucial part of the treatment of AGEP.
Effect of Titanium Addition on the Structure, Microstructure, and Selected Mechanical Properties of As-Cast Zr-25Ta-xTi Alloys
Authors: Kuroda Pedro Akira Bazaglia , Pedroso Barbara Letícia Tomaz , Pontes Fenelon Martinho Lima , Grandini Carlos Roberto
Published: September 2021

Ti alloys are the most used metallic materials in the biomedical field due to their excellent biocompatibility associated with good corrosion resistance in body fluids and relatively low elastic modulus. However, the alloys used in the orthopedic area have an elastic modulus that is 2 to 4 times higher than that of human cortical bone. Searching for new alloys for biomedical applications and with low elastic modulus, zirconium gained prominence due to its attractive properties, especially its biocompatibility. The purpose of this paper is to present novel as-cast alloys of the Zr-25Ta-xTi system and analyze the influence of titanium on the structure, microstructure, microhardness, and elastic modulus of the alloys. The alloys were prepared using an arc-melting furnace. X-ray diffraction measurements and microscopy techniques were used to characterize the crystalline structure and microstructure. From structural and microstructural characterizations, it was observed that titanium acted as an α-stabilizing element since its increase in the precipitation of the orthorhombic α” phase, an intermediate phase from β to α phases, in the alloys. Regarding microhardness measurements, the alloys have higher hardness than pure zirconium due to solid solution hardening that detaches the Zr-25Ta alloy, which has a high hardness value of the precipitation of the ω phase. Among the studied alloys, the Zr-25Ta-25Ti alloy is highlighted, demonstrating the lowest result of modulus of elasticity, which is approximately 2 times higher than the human cortical bone, but many alloys used in the biomedical field, such as pure titanium, have elastic modulus values almost 3 times higher than that of human bone.
Twin Roll Casting and Secondary Cooling of 6.0 wt.% Silicon Steel
Authors: Müller Max , Czempas Dorothea , Bailly David , Hirt Gerhard
Published: September 2021

Iron–silicon alloys with up to 6.5 wt.% Si offer an improvement of soft magnetic properties in electrical steels compared to conventional electrical steel grades. However, steels with high Si contents are very brittle and cannot be produced by cold rolling. In addition to solid solution hardening, it is assumed that the B2- and DO3-superlattice structures are responsible for the poor cold workability. In this work, two cast strips with 6.0 wt.% Si were successfully produced by the twin roll strip casting process and cooled differently by secondary cooling. The aim of the different cooling strategies was to suppress the formation of the embrittling superlattice structures and thus enable further processing by cold rolling. A comprehensive material characterization allows for the understanding of the influence of casting parameters and cooling strategies on segregation, microstructure and superlattice structure. The results show that both cooling strategies are not sufficient to prevent the formation of B2- and DO3-structures. Although the dark field images show a condition which is far from equilibrium, the achieved condition is not sufficient to ensure cold processing of the material.
Phenazine-1-carboxylic Acid Produced by Pseudomonas chlororaphis YL-1 Is Effective against Acidovorax citrulli
Authors: Liu Youzhou , Zhou Yaqiu , Qiao Junqing , Yu Wenjie , Pan Xiayan , Zhang Tingting , Liu Yongfeng , Lu Shi-En
Published: September 2021

The bacterial pathogen Acidovorax citrulli causes the destructive fruit blotch (BFB) on cucurbit plants. Pseudomonas chlororaphis YL-1 is a bacterial strain isolated from Mississippi soil and its genome harbors some antimicrobial-related gene clusters, such as phenazine, pyrrolnitrin, and pyoverdine. Here, we evaluated the antimicrobial activity of strain YL-1 as compared with its deficient mutants of antimicrobial-related genes, which were obtained using a sacB-based site-specific mutagenesis strategy. We found that only phenazine-deficient mutants ΔphzE and ΔphzF almost lost the inhibitory effects against A. citrulli in LB plates compared with the wild-type strain YL-1, and that the main antibacterial compound produced by strain YL-1 in LB medium was phenazine-1-carboxylic acid (PCA) based on the liquid chromatography-mass spectrometry (LC-MS) analysis. Gene expression analyses revealed that PCA enhanced the accumulation of reactive oxygen species (ROS) and increased the activity of catalase (CAT) in A. citrulli. The inhibition effect of PCA against A. citrulli was lowered by adding exogenous CAT. PCA significantly upregulated the transcript level of katB from 6 to 10 h, which encodes CAT that helps to protect the bacteria against oxidative stress. Collectively, the findings of this research suggest PCA is one of the key antimicrobial metabolites of bacterial strain YL-1, a promising biocontrol agent for disease management of BFB of cucurbit plants.
Can Human Handling Increase the Presence of Multidrug Resistance (MDR) in Salmonella spp. Isolated from Food Sources?
Authors: Gargano Valeria , Gambino Delia , Migliore Sergio , Vitale Maria , Sciortino Sonia , Costa Antonella , Vicari Domenico
Published: September 2021

The spread of antibiotic resistance (AR) among zoonotic pathogens is a serious health problem, especially because in the last decade the massive use of antibiotics has favored the emergence of Multidrug Resistance (MDR) strains. Some species of the Salmonella genus are among the major causes of foodborne infections worldwide and could represent reservoirs of AR. For these reasons, the susceptibility to six antibiotic classes of 63 strains isolated from animals and food was determined to assess the presence of MDR strains. In addition, the detection of resistance genes was done for strains that resulted in MDR. A statistically significant difference was found when comparing the presence of Salmonella spp. MDR strains between strains isolated from animals and strains isolated from food. Our data seem to indicate that MDR occurs mostly in Salmonella strains isolated from food.
Ionic Liquid-Assisted Grinding: An Electrophilic Fluorination Benchmark
Authors: Zaikin Pavel A. , Dyan Ok Ton , Elanov Innokenty R. , Borodkin Gennady I.
Published: September 2021

We demonstrated the influence of liquid additives on the rate and selectivity of mechanochemical fluorination of aromatic and 1,3-dicarbonyl compounds with F-TEDA-BF4. Substoichiometric catalytic quantities of ionic liquids speed up the reaction. We proposed an improved protocol for ionic liquids-assisted fluorination that allows easy and efficient isolation of fluorinated products by vacuum sublimation. A careful choice of additive results in high yields of fluorinated products and low E-factor for the overall process. Here, we report a benchmarking study of various ionic liquids in comparison with representative molecular solvents. A lower viscosity of ionic liquid additive is typically associated with higher yields and a higher degree of difluorination. Ionic liquids with fluorous anions (triflate and triflimide) are shown to be the most efficient catalysts for ionic liquid-assisted grinding.
Sage, Salvia officinalis L., Constituents, Hepatoprotective Activity, and Cytotoxicity Evaluations of the Essential Oils Obtained from Fresh and Differently Timed Dried Herbs: A Comparative Analysis
Authors: Mohammed Hamdoon A. , Eldeeb Hussein M. , Khan Riaz A. , Al-Omar Mohsen S. , Mohammed Salman A. A. , Sajid Mohammed S. M. , Aly Mohamed S. A. , Ahmad Adel M. , Abdellatif Ahmed A. H. , Eid Safaa Yehia , El-Readi Mahmoud Zaki
Published: September 2021

Sage, Salvia officinalis L., is used worldwide as an aromatic herb for culinary purposes as well as a traditional medicinal agent for various ailments. Current investigations exhibited the effects of extended dryings of the herb on the yields, composition, oil quality, and hepatoprotective as well as anti-cancer biological activities of the hydrodistillation-obtained essential oils from the aerial parts of the plant. The essential oils’ yields, compositions, and biological activities levels of the fresh and differently timed and room-temperature dried herbs differed significantly. The lowest yields of the essential oil were obtained from the fresh herbs (FH, 631 mg, 0.16%), while the highest yield was obtained from the two-week dried herbs (2WDH, 1102 mg, 0.28%). A notable decrease in monoterpenes, with increment in the sesquiterpene constituents, was observed for the FH-based essential oil as compared to all the other batches of the essential oils obtained from the different-timed dried herbs. Additionally, characteristic chemotypic constituents of sage, i.e., α-pinene, camphene, β-pinene, myrcene, 1, 8-cineole, α-thujone, and camphor, were present in significantly higher proportions in all the dried herbs’ essential oils as compared to the FH-based essential oil. The in vivo hepatoprotective activity demonstrated significant reductions in the levels of AST, ALT, and ALP, as well as a significant increase in the total protein (p < 0.05) contents level, as compared to the acetaminophen (AAP) administered experimental group of rats. A significant reduction (p < 0.05) in the ALT level was demonstrated by the 4WDH-based essential oil in comparison to the FH-based essential oil. The levels of creatinine, cholesterol, and triglycerides were reduced (p < 0.05) in the pre-treated rats by the essential oil batches, with non-significant differences found among them as a result of the herbs dryings based oils. A notable increase in the viability of the cells, and total antioxidant capacity (TAOxC) levels, together with the reduction in malondialdehyde (MDA) levels were observed by the essential oils obtained from all the batches as compared with the AAP-treated cell-lines, HepG-2, HeLa, and MCF-7, that indicated the in vitro hepatoprotective effects of the sage essential oils. However, significant improvements in the in vivo and in vitro hepatoprotective activities with the 4WDH-based oil, as compared to all other essential oil-batches and silymarin standard demonstrated the beneficial effects of the drying protocol for the herb for its medicinal purposes.
Psychrotolerant Mesorhizobium sp. Isolated from Temperate and Cold Desert Regions Solubilizes Potassium and Produces Multiple Plant Growth Promoting Metabolites
Authors: Baba Zahoor Ahmad , Hamid Basharat , Sheikh Tahir Ahmad , Alotaibi Saad H. , El Enshasy Hesham A. , Ansari Mohammad Javed , Zuan Ali Tan Kee , Sayyed R. Z.
Published: September 2021

Soil potassium (K) supplement depends intensively on the application of chemical fertilizers, which have substantial harmful environmental effects. However, some bacteria can act as inoculants by converting unavailable and insoluble K forms into plant-accessible forms. Such bacteria are an eco-friendly approach for enhancing plant K absorption and consequently reducing utilization of chemical fertilization. Therefore, the present research was undertaken to isolate, screen, and characterize the K solubilizing bacteria (KSB) from the rhizosphere soils of northern India. Overall, 110 strains were isolated, but only 13 isolates showed significant K solubilizing ability by forming a halo zone on solid media. They were further screened for K solubilizing activity at 0 °C, 1 °C, 3 °C, 5 °C, 7 °C, 15 °C, and 20 °C for 5, 10, and 20 days. All the bacterial isolates showed mineral K solubilization activity at these different temperatures. However, the content of K solubilization increased with the upsurge in temperature and period of incubation. The isolate KSB (Grz) showed the highest K solubilization index of 462.28% after 48 h of incubation at 20 °C. The maximum of 23.38 µg K/mL broth was solubilized by the isolate KSB (Grz) at 20 °C after 20 days of incubation. Based on morphological, biochemical, and molecular characterization (through the 16S rDNA approach), the isolate KSB (Grz) was identified as Mesorhizobium sp. The majority of the strains produced HCN and ammonia. The maximum indole acetic acid (IAA) (31.54 µM/mL) and cellulase (390 µM/mL) were produced by the isolate KSB (Grz). In contrast, the highest protease (525.12 µM/mL) and chitinase (5.20 µM/mL) activities were shown by standard strain Bacillus mucilaginosus and KSB (Gmr) isolate, respectively.
Active Flavonoids from Colubrina greggii var. greggii S. Watson against Clinical Isolates of Candida spp.
Authors: Melchor-Martínez Elda M. , Tamez-Fernández Juan F. , González-González Gloria María , Silva-Mares David A. , Waksman-Minsky Noemí , Pérez-López Luis Alejandro , Rivas-Galindo Verónica M.
Published: September 2021

Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.
Regioselective C-H Functionalization of the Six-Membered Ring of the 6,5-Fused Heterocyclic Systems: An Overview
Authors: Faarasse Soukaina , El Brahmi Nabil , Guillaumet Gérald , El Kazzouli Saïd
Published: September 2021

The regioselective C-H functionalization of the five-membered ring of the 6,5-fused heterocyclic systems is nowadays well documented due to its high reactivity compared to the six-membered ring. So, developing new procedures of C-H functionalization of the six-membered ring “by thinking out of the box” is extremely challenging, which explains the limited number of reports published to date. This review paper aims to highlight advances achieved in this emerging chemistry research and discusses recently reported methods.
Importance of Conjugation of the Bile Salt on the Mechanism of Lipolysis
Authors: Łozińska Natalia , Jungnickel Christian
Published: September 2021

We aim to advance the discussion on the significance of the conjugation of bile salts (BS) in our organism. We hypothesize that conjugation influences the rate of lipolysis. Since the rate of lipolysis is a compound parameter, we compare the effect of conjugation on four surface parameters, which contribute to the rate. Since deconjugation is due to gut microbiota, we hypothesize that microbiota may affect the rate of lipolysis. A meta-analysis of literature data of critical micelle concentration, β, aggregation number, and molar solubilization ratio has been performed for the first time. In addition, critical micelle concentration (CMC), interfacial tension, and lipolysis rate measurements were performed. It was found that the unconjugated BS in mixed micelles increases the antagonism between the BS, therefore, increasing the CMC. This correlated with the effect of unconjugated BS on the solubilization capacity of mixed micelles. The collected literature information indicates that the role of the BS and its conjugation in our organism is a key factor influencing the functioning of our organism, where too high levels of unconjugated BS may lead to malabsorption of fat-soluble nutrients. The experimental lipolysis results irrevocably showed that conjugation is a significant factor influencing the rate.
Virtual Screening for Biomimetic Anti-Cancer Peptides from Cordyceps militaris Putative Pepsinized Peptidome and Validation on Colon Cancer Cell Line
Authors: Chantawannakul Jarinyagon , Chatpattanasiri Paninnuch , Wattayagorn Vichugorn , Kongsema Mesayamas , Noikaew Tipanart , Chumnanpuen Pramote
Published: September 2021

Colorectal cancer is one of the leading causes of cancer-related death in Thailand and many other countries. The standard practice for curing this cancer is surgery with an adjuvant chemotherapy treatment. However, the unfavorable side effects of chemotherapeutic drugs are undeniable. Recently, protein hydrolysates and anticancer peptides have become popular alternative options for colon cancer treatment. Therefore, we aimed to screen and select the anticancer peptide candidates from the in silico pepsin hydrolysate of a Cordyceps militaris (CM) proteome using machine-learning-based prediction servers for anticancer prediction, i.e., AntiCP, iACP, and MLACP. The selected CM-anticancer peptide candidates could be an alternative treatment or co-treatment agent for colorectal cancer, reducing the use of chemotherapeutic drugs. To ensure the anticancer properties, an in vitro assay was performed with “CM-biomimetic peptides” on the non-metastatic colon cancer cell line (HT-29). According to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results from peptide candidate treatments at 0–400 µM, the IC50 doses of the CM-biomimetic peptide with no toxic and cancer-cell-penetrating ability, original C. militaris biomimetic peptide (C-ori), against the HT-29 cell line were 114.9 µM at 72 hours. The effects of C-ori compared to the doxorubicin, a conventional chemotherapeutic drug for colon cancer treatment, and the combination effects of both the CM-anticancer peptide and doxorubicin were observed. The results showed that C-ori increased the overall efficiency in the combination treatment with doxorubicin. According to the acridine orange/propidium iodine (AO/PI) staining assay, C-ori can induce apoptosis in HT-29 cells significantly, confirmed by chromatin condensation, membrane blebbing, apoptotic bodies, and late apoptosis which were observed under a fluorescence microscope.
Novel Marine Secondary Metabolites Worthy of Development as Anticancer Agents: A Review
Authors: Mbaoji Florence Nwakaego , Nweze Justus Amuche , Yang Liyan , Huang Yangbin , Huang Shushi , Onwuka Akachukwu Marytheresa , Peter Ikechukwu Emmanuel , Mbaoji Cynthia Chioma , Jiang Mingguo , Zhang Yunkai , Pan Lixia , Yang Dengfeng
Published: September 2021

Secondary metabolites from marine sources have a wide range of biological activity. Marine natural products are promising candidates for lead pharmacological compounds to treat diseases that plague humans, including cancer. Cancer is a life-threatening disorder that has been difficult to overcome. It is a long-term illness that affects both young and old people. In recent years, significant attempts have been made to identify new anticancer drugs, as the existing drugs have been useless due to resistance of the malignant cells. Natural products derived from marine sources have been tested for their anticancer activity using a variety of cancer cell lines derived from humans and other sources, some of which have already been approved for clinical use, while some others are still being tested. These compounds can assault cancer cells via a variety of mechanisms, but certain cancer cells are resistant to them. As a result, the goal of this review was to look into the anticancer potential of marine natural products or their derivatives that were isolated from January 2019 to March 2020, in cancer cell lines, with a focus on the class and type of isolated compounds, source and location of isolation, cancer cell line type, and potency (IC50 values) of the isolated compounds that could be a guide for drug development.
Utilisation of Non-Edible Source (Pongamia pinnata Seeds Shells) for Producing Methyl Esters as Cleaner Fuel in the Presence of a Novel Heterogeneous Catalyst Synthesized from Waste Eggshells
Authors: Al-Muhtaseb Ala’a H.
Published: September 2021

Waste eggshells were considered for synthesising a precursor (CaO) for a heterogeneous catalyst, further impregnated by alkali caesium oxide (Cs2O). The following techniques were used to characterise the synthesised catalysts: X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (CO2-TPD). The synthesised catalyst revealed its suitability for transesterification to produce biodiesel. The biodiesel production process was optimised, and it showed that the optimal biodiesel yield is 93.59%. The optimal set of process parameters is process temperature 80 °C, process time 90 min, methanol-to-oil molar ratio 8 and catalyst loading 3 wt.%. It has been found that the high basicity of the catalyst tends to give a high biodiesel yield at low methanol-to-oil ratio 8 when the reaction time is also less (90 min). The fuel properties of biodiesel also satisfied the standard limits defined by ASTM and the EN standards. Thus, the synthesised catalyst from waste eggshells is highly active, improved the biodiesel production conditions and PPSS oil is a potential nonedible source.
Validation and Evaluation of Selected Organic Pollutants in Shrimp and Seawater Samples from the NW Portuguese Coast
Authors: Maia Maria Luz , Delerue-Matos Cristina , Calhau Conceição , Domingues Valentina Fernandes
Published: September 2021

The development of coastal regions has contributed to the intensification of environmental contamination, which can accumulate in aquatic biota, such as shrimps. These crustaceans, besides being delicious and being a good source of nutrients, can also accumulate environmental pollutants. Amongst others, these include organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and synthetic musks (SMs). These pollutants, classified as endocrine disruptors, are related to adverse effects in humans and since one of the major routes of exposition is ingestion, this is a cause for concern regarding their presence in food. The aim of the present study was to quantify the presence of environmental pollutants in shrimp samples and in the water from their habitat along the northwest Portuguese coast. In seawater samples, only two OCPs (lindane and DDD) and one BFR (BTBPE) were detected, and in shrimp samples, one OCP (DDD) and three SMs (HHCB, AHTN and ketone) were found. Bioaccumulation and the risk assessment of dietary exposure of SMs in shrimp samples were investigated. It was observed that all shrimp samples analyzed significantly presented bioaccumulation of the three SMs found. Concentrations of SMs detected in shrimp samples do not present a health risk for the adult Portuguese population.