bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Design of Solid Particle Wear Behavior of Ni-Based Composite Coatings
Authors: Senapati Pragyan , Sutar Harekrushna , Murmu Rabiranjan , Bajpai Shubhra
Published: May 2021

The composition of nickel-based metal matrix NiCrBSi was varied with 5%, 10% and 15% of Al2O3 particles to obtain high wear resistant coatings by means of a high-velocity oxy fuel (HVOF) thermal spraying process. The coating was characterized by optical microscope, scanning electron microscope (SEM) and X-ray diffractometer (XRD). The physical properties of coatings such as porosity, thickness, surface roughness, surface hardness, fracture toughness, bond strength and density were measured and compared. The experimental design of Taguchi L27 orthogonal array was employed to study and compare the effect of parameters such as impingement angle, impact velocity and alumina per cent in the coating on erosion. The coating containing 15 wt.% of Al2O3 and erodent speed of 33 m/s striking at inclination angle of 30° proved to be the best arrangement in preventing volume loss to a minimum of 0.00015 cc due to low-impact energy, high bond strength and high surface hardness. Analysis of variance (ANOVA) supported the assertion that the impact angle (A) of erodent and composition (C) were the factors contributing most to the volumetric loss as indicated by their combined effect A × C leading to the highest combined factor of 7.34. The scanning electron microscopy (SEM) images of the eroded coatings reveal that the mechanisms of erosion were the fracturing of splats, development of craters, micro cutting and ploughing action.
Endothelial Cell Responses to a Highly Deformable Titanium Alloy Designed for Vascular Stent Applications
Authors: Ion Raluca , Cabon Gaëtan , Gordin Doina-Margareta , Ionica Elena , Gloriant Thierry , Cimpean Anisoara
Published: May 2021

Titanium alloys are widely used for biomedical applications due to their good biocompatibility. Nevertheless, they cannot be used for balloon expandable stents due to a lack of ductility compared to cobalt-chromium (Co-Cr) alloys and stainless steels. In this study, a new highly deformable Ti-16Nb-8Mo alloy was designed for such an application. However, the biological performance of a stent material is strongly influenced by the effect exerted on the behavior of endothelial cells. Therefore, the cellular responses of human umbilical vein endothelial cells (HUVECs), including morphological characteristics, cell viability and proliferation, and functional markers expression, were investigated to evaluate the biocompatibility of the alloy in the present study. The in vitro results demonstrated the suitability of this alloy for use as endovascular stents.
Feature Extraction for Finger-Vein-Based Identity Recognition
Authors: Sidiropoulos George K. , Kiratsa Polixeni , Chatzipetrou Petros , Papakostas George A.
Published: May 2021

This paper aims to provide a brief review of the feature extraction methods applied for finger vein recognition. The presented study is designed in a systematic way in order to bring light to the scientific interest for biometric systems based on finger vein biometric features. The analysis spans over a period of 13 years (from 2008 to 2020). The examined feature extraction algorithms are clustered into five categories and are presented in a qualitative manner by focusing mainly on the techniques applied to represent the features of the finger veins that uniquely prove a human’s identity. In addition, the case of non-handcrafted features learned in a deep learning framework is also examined. The conducted literature analysis revealed the increased interest in finger vein biometric systems as well as the high diversity of different feature extraction methods proposed over the past several years. However, last year this interest shifted to the application of Convolutional Neural Networks following the general trend of applying deep learning models in a range of disciplines. Finally, yet importantly, this work highlights the limitations of the existing feature extraction methods and describes the research actions needed to face the identified challenges.
Differential Expression of Amanitin Biosynthetic Genes and Novel Cyclic Peptides in Amanita molliuscula
Authors: Lüli Yunjiao , Zhou Shengwen , Li Xuan , Chen Zuohong , Yang Zhuliang , Luo Hong
Published: May 2021

Amanita molliuscula is a basal species of lethal Amanita and intrigues the field because it does not produce discernable α-amanitin when inspected by High Performance Liquid Chromatography (HPLC), which sets it apart from all known amanitin-producing (lethal) Amanita species. In order to study the underlining genetic basis of the phenotype, we sequenced this species through PacBio and Illumina RNA-Seq platforms. In total, 17 genes of the “MSDIN” family (named after the first five amino acid residues of the precursor peptides) were found in the genome and 11 of them were expressed at the transcription level. The expression pattern was not even but in a differential fashion: two of the MSDINs were highly expressed (FPKM value > 100), while the majority were expressed at low levels (FPKM value < 1). Prolyl oligopeptidease B (POPB) is the key enzyme in the amanitin biosynthetic pathway, and high expression of this enzyme was also discovered (FPKM value > 100). The two MSDINs with highest transcription further translated into two novel cyclic peptides, the structure of which is distinctive from all known cyclic peptides. The result illustrates the correlation between the expression and the final peptide products. In contrast to previous HPLC result, the genome of A. molliuscula harbors α-amanitin genes (three copies), but the product was in trace amount indicated by MS. Overall, transcription of MSDINs encoding major toxins (α-amanitin, β-amanitin, phallacidin and phalloidin) were low, showing that these toxins were not actively synthesized at the stage. Collectively, our results indicate that the amanitin biosynthetic pathway is highly active at the mature fruiting body stage in A. molliuscula, and due to the differential expression of MSDIN genes, the pathway produces only a few cyclic peptides at the time.
Diversity, Ecological Role and Biotechnological Potential of Antarctic Marine Fungi
Authors: Varrella Stefano , Barone Giulio , Tangherlini Michael , Rastelli Eugenio , Dell’Anno Antonio , Corinaldesi Cinzia
Published: May 2021

The Antarctic Ocean is one of the most remote and inaccessible environments on our planet and hosts potentially high biodiversity, being largely unexplored and undescribed. Fungi have key functions and unique physiological and morphological adaptations even in extreme conditions, from shallow habitats to deep-sea sediments. Here, we summarized information on diversity, the ecological role, and biotechnological potential of marine fungi in the coldest biome on Earth. This review also discloses the importance of boosting research on Antarctic fungi as hidden treasures of biodiversity and bioactive molecules to better understand their role in marine ecosystem functioning and their applications in different biotechnological fields.
Candida albicans/Macrophage Biointerface on Human and Porcine Decellularized Adipose Matrices
Authors: Cicuéndez Mónica , Casarrubios Laura , Feito María José , Madarieta Iratxe , Garcia-Urkia Nerea , Murua Olatz , Olalde Beatriz , Briz Nerea , Diez-Orejas Rosalía , Portolés María Teresa
Published: May 2021

Macrophages, cells effective in sensing, internalizing and killing Candida albicans, are intertwined with the extracellular matrix (ECM) through different signals, which include the release of specific cytokines. Due to the importance of these interactions, the employment of in vitro models mimicking a fungal infection scenario is essential to evaluate the ECM effects on the macrophage response. In this work, we have analyzed the effects of human and porcine decellularized adipose matrices (DAMs), obtained by either enzymatic or organic solvent treatment, on the macrophage/Candida albicans interface. The present study has allowed us to detect differences on the activation of macrophages cultured on either human- or porcine-derived DAMs, evidencing changes in the macrophage actin cytoskeleton, such as distinct F-actin-rich membrane structures to surround the pathogen. The macrophage morphological changes observed on these four DAMs are key to understand the defense capability of these cells against this fungal pathogen. This work has contributed to the knowledge of the influence that the extracellular matrix and its components can exert on macrophage metabolism, immunocompetence and capacity to respond to the microenvironment in a possible infection scenario.
The Molecular Mechanism of Fludioxonil Action Is Different to Osmotic Stress Sensing
Authors: Bersching Katharina , Jacob Stefan
Published: May 2021

The group III two-component hybrid histidine kinase MoHik1p in the filamentous fungus Magnaporthe oryzae is known to be a sensor for external osmotic stress and essential for the fungicidal activity of the phenylpyrrole fludioxonil. The mode of action of fludioxonil has not yet been completely clarified but rather assumed to hyperactivate the high osmolarity glycerol (HOG) signaling pathway. To date, not much is known about the detailed molecular mechanism of how osmotic stress is detected or fungicidal activity is initiated within the HOG pathway. The molecular mechanism of signaling was studied using a mutant strain in which the HisKA signaling domain was modified by an amino acid change of histidine H736 to alanine A736. We found that MoHik1pH736A is as resistant to fludioxonil but not as sensitive to osmotic stress as the null mutant ∆Mohik1. H736 is required for fludioxonil action but is not essential for sensing sorbitol stress. Consequently, this report provides evidence of the difference in the molecular mechanism of fludioxonil action and the perception of osmotic stress. This is an excellent basis to understand the successful phenylpyrrole-fungicides’ mode of action better and will give new ideas to decipher cellular signaling mechanisms.
Personalized Medicine Based on Nasal Epithelial Cells: Comparative Studies with Rectal Biopsies and Intestinal Organoids
Authors: Silva Iris A. L. , Railean Violeta , Duarte Aires , Amaral Margarida D.
Published: May 2021

As highly effective CFTR modulator therapies (HEMT) emerge, there is an unmet need to find effective drugs for people with CF (PwCF) with ultra-rare mutations who are too few for classical clinical trials and for whom there are no drug discovery programs. Therefore, biomarkers reliably predicting the benefit from CFTR modulator therapies are essential to find effective drugs for PwCF through personalized approaches termed theranostics. Here, we assess CFTR basal function and the individual responses to CFTR modulators in primary human nasal epithelial (pHNE) cells from PwCF carrying rare mutations and compare these measurements with those in native rectal biopsies and intestinal organoids, respectively, in the same individual. The basal function in pHNEs shows good correlation with CFTR basal function in rectal biopsies. In parallel, CFTR rescue in pHNEs by CFTR modulators correlates to that in intestinal organoids. Altogether, results show that pHNEs are a bona fide theranostic model to assess CFTR rescue by CFTR modulator drugs, in particular for PwCF and rare mutations.
Short-Term Capital Flows, Exchange Rate Expectation and Currency Internationalization: Evidence from China
Authors: Li Mingming , Qin Fengming , Zhang Zhaoyong
Published: May 2021

This paper intended to employ a portfolio approach to assess the effect of exchange rate expectation on Chinese RMB internationalization and empirically test the interactive effects among short-term capital flows, RMB appreciation expectation and the internationalization process using a VAR model with monthly data ranging from February 2004 to December 2020. The results suggest that RMB exchange rate appreciation could lead to an increase in the foreign demand for RMB and RMB denominated assets, while RMB internationalization would attract more short-term capital inflow due to the reduced transaction costs. The empirical evidence from the VAR model estimation confirms the finding that expected RMB appreciation induces short-term capital inflow and promotes RMB internationalization. The robustness checks confirm the evidence. The results have important policy implication for RMB internationalization and for maintaining a sound and stable financial system.
Agents and Robots for Reliable Engineered Autonomy:A Perspective from the Organisers of AREA 2020
Authors: Cardoso Rafael C. , Ferrando Angelo , Briola Daniela , Menghi Claudio , Ahlbrecht Tobias
Published: May 2021

Multi-agent systems, robotics and software engineering are large and active research areas with many applications in academia and industry. The First Workshop on Agents and Robots for reliable Engineered Autonomy (AREA), organised the first time in 2020, aims at encouraging cross-disciplinary collaborations and exchange of ideas among researchers working in these research areas. This paper presents a perspective of the organisers that aims at highlighting the latest research trends, future directions, challenges, and open problems. It also includes feedback from the discussions held during the AREA workshop. The goal of this perspective is to provide a high-level view of current research trends for researchers that aim at working in the intersection of these research areas.
The Eastern Nebraska Salt Marsh Microbiome Is Well Adapted to an Alkaline and Extreme Saline Environment
Authors: Athen Sierra R. , Dubey Shivangi , Kyndt John A.
Published: May 2021

The Eastern Nebraska Salt Marshes contain a unique, alkaline, and saline wetland area that is a remnant of prehistoric oceans that once covered this area. The microbial composition of these salt marshes, identified by metagenomic sequencing, appears to be different from well-studied coastal salt marshes as it contains bacterial genera that have only been found in cold-adapted, alkaline, saline environments. For example, Rubribacterium was only isolated before from an Eastern Siberian soda lake, but appears to be one of the most abundant bacteria present at the time of sampling of the Eastern Nebraska Salt Marshes. Further enrichment, followed by genome sequencing and metagenomic binning, revealed the presence of several halophilic, alkalophilic bacteria that play important roles in sulfur and carbon cycling, as well as in nitrogen fixation within this ecosystem. Photosynthetic sulfur bacteria, belonging to Prosthecochloris and Marichromatium, and chemotrophic sulfur bacteria of the genera Sulfurimonas, Arcobacter, and Thiomicrospira produce valuable oxidized sulfur compounds for algal and plant growth, while alkaliphilic, sulfur-reducing bacteria belonging to Sulfurospirillum help balance the sulfur cycle. This metagenome-based study provides a baseline to understand the complex, but balanced, syntrophic microbial interactions that occur in this unique inland salt marsh environment.
Update on Biomarkers Associated to Cardioembolic Stroke: A Narrative Review
Authors: Fonseca Ana Catarina , Coelho Pedro
Published: May 2021

Background: In the last years, several studies were conducted that evaluated biomarkers that could be helpful for cardioembolic stroke diagnosis, prognosis, and the determination of risk of stroke recurrence. Methods: We performed a narrative review of the main studies that evaluated biomarkers related to specific cardioembolic causes: atrial fibrillation, patent foramen ovale, atrial cardiomyopathy, and left ventricular wall motion abnormalities. Results: BNP and NT-proBNP are, among all biomarkers of cardioembolic stroke, the ones that have the highest amount of evidence for their use. NT-proBNP is currently used for the selection of patients that will be included in clinical trials that aim to evaluate the use of anticoagulation in patients suspected of having a cardioembolic stroke and for the selection of patients to undergo cardiac monitoring. NT-proBNP has also been incorporated in tools used to predict the risk of stroke recurrence (ABC-stroke score). Conclusions: NT-proBNP and BNP continue to be the biomarkers most widely studied in the context of cardioembolic stroke. The possibility of using other biomarkers in clinical practice is still distant, mainly because of the low methodological quality of the studies in which they were evaluated. Both internal and external validation studies are rarely performed for most biomarkers.
Plantar Stimulations during 3-Day Hindlimb Unloading Prevent Loss of Neural Progenitors and Maintain ERK1/2 Activity in the Rat Hippocampus
Authors: Berezovskaya Anna S. , Tyganov Sergey A. , Nikolaeva Svetlana D. , Naumova Alexandra A. , Shenkman Boris S. , Glazova Margarita V.
Published: May 2021

Adult neurogenesis is a flexible process that depends on the environment and correlates with cognitive functions. Cognitive functions are impaired by various factors including space flight conditions and reduced physical activity. Physically active life significantly improves both cognition and the hippocampal neurogenesis. Here, we analyzed how 3-day simulated microgravity caused by hindlimb unloading (HU) or dynamic foot stimulation (DFS) during HU can affect the hippocampal neurogenesis. Adult Wistar rats were recruited in the experiments. The results demonstrated a decrease in the number of doublecortine (DCX) positive neural progenitors, but proliferation in the subgranular zone of the dentate gyrus was not changed after 3-day HU. Analysis of the effects of DFS showed restoration of neural progenitor population in the subgranular zone of the dentate gyrus. Additionally, we analyzed activity of the cRaf/ERK1/2 pathway, which is one of the major players in the regulation of neuronal differentiation. The results demonstrated inhibition of cRaf/ERK1/2 signaling in the hippocampus of HU rats. In DFS rats, no changes in the activity of cRaf/ERK1/2 were observed. Thus, we demonstrated that the process of neurogenesis fading during HU begins with inhibition of the formation of immature neurons and associated ERK1/2 signaling activity, while DFS prevents the development of mentioned alterations.
Trigonometric Embeddings in Polynomial Extended Mode Decomposition—Experimental Application to an Inverted Pendulum
Authors: Garcia-Tenorio Camilo , Delansnay Gilles , Mojica-Nava Eduardo , Vande Wouwer Alain
Published: May 2021

The extended dynamic mode decomposition algorithm is a tool for accurately approximating the point spectrum of the Koopman operator. This algorithm provides an approximate linear expansion of non-linear discrete-time systems, which can be useful for system analysis and controller design. The accuracy of this algorithm depends heavily on the availability of a set of basis functions that provide the ability to capture the nonlinear dynamics of the underlying system. Recently, the use of orthogonal polynomials, along with reduction techniques for the dimension and maximum order of the polynomial basis, have been successfully used to approximate nonlinear systems with the additional benefit of using smaller datasets. This paper expands the current methods for selecting the set of observables for nonlinear systems with periodic behavior, which is prone to a representation in terms of trigonometric functions. The benefit of working with orthogonal polynomials is preserved by embedding the trigonometric functions into the orthogonal basis. The algorithm is illustrated with the data-driven modelling of an inverted pendulum in simulation and real-life experiments.
Reverse Causality between Fiscal and Current Account Deficits in ASEAN: Evidence from Panel Econometric Analysis
Authors: Marimuthu Maran , Khan Hanana , Bangash Romana
Published: May 2021

This study aims to explore the causal relationship between fiscal deficit (FD) and current account deficit (CAD) along with policy recommendations based on long-run and short-run dynamics and sensitivities. A panel data span from 1990 to 2019 is analyzed based on panel unit root tests, panel co-integration with auto-regressive distributed lag (ARDL), panel co-integration regression with fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS), and causal analysis with the Dumitrescu and Hurlin (DH) technique. The results disclosed that all tested variables are stationary at the first difference I(1) except the real interest rate (IR), which is stationary at level I(0). The ARDL estimates suggested that there is a long-run relationship between tested variables and 92% annual convergence is possible for long-run equilibrium. The FMOLS and DOLS estimates indicated that the CAD is sensitive towards the FD and the exchange rate. The DH causality test showed that the CAD is significantly affecting the FD, supporting the current account targeting hypothesis. Furthermore, it is observed that the interest rate is acting as a moderating factor between the FD and the CAD because it causes both the deficits. Thus, reverse causality is concluded from the CAD to the FD. These results have macroeconomic implications for fiscal policy in the Association of South-East Asian Nations (ASEAN-10).
Image Denoising Using Adaptive and Overlapped Average Filtering and Mixed-Pooling Attention Refinement Networks
Authors: Lin Ming-Hao , Hou Zhi-Xiang , Cheng Kai-Han , Wu Chin-Hsien , Peng Yan-Tsung
Published: May 2021

Cameras are essential parts of portable devices, such as smartphones and tablets. Most people have a smartphone and can take pictures anywhere and anytime to record their lives. However, these pictures captured by cameras may suffer from noise contamination, causing issues for subsequent image analysis, such as image recognition, object tracking, and classification of an object in the image. This paper develops an effective combinational denoising framework based on the proposed Adaptive and Overlapped Average Filtering (AOAF) and Mixed-pooling Attention Refinement Networks (MARNs). First, we apply AOAF to the noisy input image to obtain a preliminarily denoised result, where noisy pixels are removed and recovered. Next, MARNs take the preliminary result as the input and output a refined image where details and edges are better reconstructed. The experimental results demonstrate that our method performs favorably against state-of-the-art denoising methods.
On the Paired-Domination Subdivision Number of Trees
Authors: Wei Shouliu , Hao Guoliang , Sheikholeslami Seyed Mahmoud , Khoeilar Rana , Karami Hossein
Published: May 2021

A paired-dominating set of a graph G without isolated vertices is a dominating set of vertices whose induced subgraph has perfect matching. The minimum cardinality of a paired-dominating set of G is called the paired-domination number γpr(G) of G. The paired-domination subdivision number sdγpr(G) of G is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the paired-domination number. Here, we show that, for each tree T ≠ P5 of order n ≥ 3 and each edge e ∉ E(T), sdγpr(T) + sdγpr(T + e) ≤ n + 2.
Q or R Factor Analysis for Subjectiveness Measurement in Consumer Behavior? A Study Case on Durable Goods Buying Behavior in Romania
Authors: Gabor Manuela Rozalia , Cristache Nicoleta
Published: May 2021

The complexity of consumer behavior requires new research methods to overcome the limitations of conventional evident-based research. The aim of this paper is the comparison between two types of factor analyses, Q and R (PCA and cluster analysis) for subjectiveness measurement in the case of durable goods buying behavior in Romanian households with different levels of education and occupancy. Our study explores different subjective patterns of stimulus of 30 statements (Q-sample) by 30 Romanian households (P-sample) using the Q-sort method for collecting data. For the Q-sample inputs, results from the literature were used. Based on the 30 Q-sorts, we discovered four factors for both Q and R factor analysis, mostly different according to specific results from different methods. For the Q method, we used the labels “pragmatic”, “modern”, “traditionalist”, and “innovator. For R factor analysis and cluster, we used “traditional Romanian brands”, “real needs and power purchasing”, “sceptic versus optimistic subjectiveness”, and “negative subjectiveness”. This paper suggests the Q methodology as a structured and transparent approach to consumer behavior research by combining the in-depth subjectivity of qualitative methods and statistical rigor of factor analysis to identify groups in consumers. The research provides useful suggestions for selecting and approaching target consumer segments in the Romanian durable goods industry.
Efficient Processing of All Nearest Neighbor Queries in Dynamic Road Networks
Authors: Bhandari Aavash , Hasanov Aziz , Attique Muhammad , Cho Hyung-Ju , Chung Tae-Sun
Published: May 2021

The increasing trend of GPS-enabled smartphones has led to the tremendous usage of Location-Based Service applications. In the past few years, a significant amount of studies have been conducted to process All nearest neighbor (ANN) queries. An ANN query on a road network extracts and returns all the closest data objects for all query objects. Most of the existing studies on ANN queries are performed either in Euclidean space or static road networks. Moreover, combining the nearest neighbor query and join operation is an expensive procedure because it requires computing the distance between each pair of query objects and data objects. This study considers the problem of processing the ANN queries on a dynamic road network where the weight, i.e., the traveling distance and time varies due to various traffic conditions. To address this problem, a shared execution-based approach called standard clustered loop (SCL) is proposed that allows efficient processing of ANN queries on a dynamic road network. The key concept behind the shared execution technique is to exploit the coherence property of road networks by clustering objects that share common paths and processing the cluster as a single path. In an empirical study, the SCL method achieves significantly better performance than competitive methods and efficiently reduces the computational cost to process ANN queries in various problem settings.
Production Strategies of TiNx Coatings via Reactive High Power Impulse Magnetron Sputtering for Selective H2 Separation
Authors: Mortalò Cecilia , Deambrosis Silvia Maria , Montagner Francesco , Zin Valentina , Fabrizio Monica , Pasquali Luca , Capelli Raffaella , Montecchi Monica , Miorin Enrico
Published: May 2021

This scientific work aims to optimize the preparation of titanium nitride coatings for selective H2 separation using the Reactive High Power Impulse Magnetron Sputtering technology (RHiPIMS). Currently, nitride-based thin films are considered promising membranes for hydrogen. The first series of TiNx/Si test samples were developed while changing the reactive gas percentage (N2%) during the process. Obtained coatings were extensively characterized in terms of morphology, composition, and microstructure. A 500 nm thick, dense TiNx coating was then deposited on a porous alumina substrate and widely investigated. Moreover, the as-prepared TiNx films were heat-treated in an atmosphere containing hydrogen in order to prove their chemical and structural stability; which revealed to be promising. This study highlighted how the RHiPIMS method permits fine control of the grown layer’s stoichiometry and microstructure. Moreover, it pointed out the need for a protective layer to prevent surface oxidation of the nitride membrane by air and the necessity to deepen the study of TiNx/alumina interface in order to improve film/substrate adhesion.
Excellent Ductility in the Extruded AZ61 Magnesium Alloy Tube Induced by Electropulsing Treatment during Tension
Authors: Jiang Bo , Zhang Dongdong , Xu Hong , Liu Yongbing , Cao Zhanyi , Yang Xiaohong
Published: May 2021

In this work, we reported the high ductility of an extruded AZ61 magnesium alloy tube achieved by electropulsing current-assisted tension. The elongation of the alloy reached up to about 45%, which is largely superior to the majority of AZ61 wrought Mg alloys. We found that the hardening capacity of the alloy seemed to slightly increase as the electropulsing frequency increased. Furthermore, electropulsing can arouse the serrated flow phenomenon. Here we proposed an equation describing the correlation between the average amplitude and frequency: Aa = C − 6 × 10−3f, where Aa is the average amplitude, f is the frequency, and C is the constant. In addition, introducing electropulsing current pronouncedly reduced the tendency of twinning, but the twinning fraction seemed to fail depending on the electropulsing frequency. Based on microstructure analysis, we concluded that the outstanding ductility of the studied alloy was mainly due to the combined role of the thermal effects from Joule heating, the athermal effects from electron wind, and the magnetic effects from the electropulsing current. The serrated flow phenomenon occurred along stress–strain curves after electropulsing treatment, and the underlying reasons also were uncovered.
An Overview of Metabolic Activity, Beneficial and Pathogenic Aspects of Burkholderia Spp.
Authors: Elshafie Hazem S. , Camele Ippolito
Published: May 2021

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.
High-Efficiency Parallel Cryptographic Accelerator for Real-Time Guaranteeing Dynamic Data Security in Embedded Systems
Authors: Zhang Zhun , Wang Xiang , Hao Qiang , Xu Dongdong , Zhang Jinlei , Liu Jiakang , Ma Jinhui
Published: May 2021

Dynamic data security in embedded systems is raising more and more concerns in numerous safety-critical applications. In particular, the data exchanges in embedded Systems-on-Chip (SoCs) using main memory are exposing many security vulnerabilities to external attacks, which will cause confidential information leakages and program execution failures for SoCs at key points. Therefore, this paper presents a security SoC architecture with integrating a four-parallel Advanced Encryption Standard-Galois/Counter Mode (AES-GCM) cryptographic accelerator for achieving high-efficiency data processing to guarantee data exchange security between the SoC and main memory against bus monitoring, off-line analysis, and data tampering attacks. The architecture design has been implemented and verified on a Xilinx Virtex-5 Field Programmable Gate Array (FPGA) platform. Based on evaluation of the cryptographic accelerator in terms of performance overhead, security capability, processing efficiency, and resource consumption, experimental results show that the parallel cryptographic accelerator does not incur significant performance overhead on providing confidentiality and integrity protections for exchanged data; its average performance overhead reduces to as low as 2.65% on typical 8-KB I/D-Caches, and its data processing efficiency is around 3 times that of the pipelined AES-GCM construction. The reinforced SoC under the data tampering attacks and benchmark tests confirms the effectiveness against external physical attacks and satisfies a good trade-off between high-efficiency and hardware overhead.
Selective Direct Laser Writing of Pyrolytic Carbon Microelectrodes in Absorber-Modified SU-8
Authors: Ludvigsen Emil , Pedersen Nina Ritter , Zhu Xiaolong , Marie Rodolphe , Mackenzie David M. A. , Emnéus Jenny , Petersen Dirch Hjorth , Kristensen Anders , Keller Stephan Sylvest
Published: May 2021

Pyrolytic carbon microelectrodes (PCMEs) are a promising alternative to their conventional metallic counterparts for various applications. Thus, methods for the simple and inexpensive patterning of PCMEs are highly sought after. Here, we demonstrate the fabrication of PCMEs through the selective pyrolysis of SU-8 photoresist by irradiation with a low-power, 806 nm, continuous wave, semiconductor-diode laser. The SU-8 was modified by adding Pro-Jet 800NP (FujiFilm) in order to ensure absorbance in the 800 nm range. The SU-8 precursor with absorber was successfully converted into pyrolytic carbon upon laser irradiation, which was not possible without an absorber. We demonstrated that the local laser pyrolysis (LLP) process in an inert nitrogen atmosphere with higher laser power and lower scan speed resulted in higher electrical conductance. The maximum conductivity achieved for a laser-pyrolyzed line was 14.2 ± 3.3 S/cm, with a line width and thickness of 28.3 ± 2.9 µm and 6.0 ± 1.0 µm, respectively, while the narrowest conductive line was just 13.5 ± 0.4 µm wide and 4.9 ± 0.5 µm thick. The LLP process seemed to be self-limiting, as multiple repetitive laser scans did not alter the properties of the carbonized lines. The direct laser writing of adjacent lines with an insulating gap down to ≤5 µm was achieved. Finally, multiple lines were seamlessly joined and intersected, enabling the writing of more complex designs with branching electrodes and the porosity of the carbon lines could be controlled by the scan speed.
Reciprocal Inhibition of Immunogenic Performance in Mice of Two Potent DNA Immunogens Targeting HCV-Related Liver Cancer
Authors: Jansons Juris , Skrastina Dace , Kurlanda Alisa , Petkov Stefan , Avdoshina Darya , Kuzmenko Yulia , Krotova Olga , Trofimova Olga , Gordeychuk Ilya , Sominskaya Irina , Isaguliants Maria
Published: May 2021

Chronic HCV infection and associated liver cancer impose a heavy burden on the healthcare system. Direct acting antivirals eliminate HCV, unless it is drug resistant, and partially reverse liver disease, but they cannot cure HCV-related cancer. A possible remedy could be a multi-component immunotherapeutic vaccine targeting both HCV-infected and malignant cells, but also those not infected with HCV. To meet this need we developed a two-component DNA vaccine based on the highly conserved core protein of HCV to target HCV-infected cells, and a renowned tumor-associated antigen telomerase reverse transcriptase (TERT) based on the rat TERT, to target malignant cells. Their synthetic genes were expression-optimized, and HCV core was truncated after aa 152 (Core152opt) to delete the domain interfering with immunogenicity. Core152opt and TERT DNA were highly immunogenic in BALB/c mice, inducing IFN-γ/IL-2/TNF-α response of CD4+ and CD8+ T cells. Additionally, DNA-immunization with TERT enhanced cellular immune response against luciferase encoded by a co-delivered plasmid (Luc DNA). However, DNA-immunization with Core152opt and TERT mix resulted in abrogation of immune response against both components. A loss of bioluminescence signal after co-delivery of TERT and Luc DNA into mice indicated that TERT affects the in vivo expression of luciferase directed by the immediate early cytomegalovirus and interferon-β promoters. Panel of mutant TERT variants was created and tested for their expression effects. TERT with deleted N-terminal nucleoli localization signal and mutations abrogating telomerase activity still suppressed the IFN-β driven Luc expression, while the inactivated reverse transcriptase domain of TERT and its analogue, enzymatically active HIV-1 reverse transcriptase, exerted only weak suppressive effects, implying that suppression relied on the presence of the full-length/nearly full-length TERT, but not its enzymatic activity. The effect(s) could be due to interference of the ectopically expressed xenogeneic rat TERT with biogenesis of mRNA, ribosomes and protein translation in murine cells, affecting the expression of immunogens. HCV core can aggravate this effect, leading to early apoptosis of co-expressing cells, preventing the induction of immune response.
Editorial for Special Issue “Microtexture Characterization of Rocks and Minerals”
Authors: Song Yungoo
Published: May 2021

Microtextures, the physical or structural aspects of minerals and rocks, may include the interrelationships of minerals, the preferred orientation of grains, the internal textures of minerals, etc [...]
Intrinsic Dynamic and Static Nature of Halogen Bonding in Neutral Polybromine Clusters, with the Structural Feature Elucidated by QTAIM Dual-Functional Analysis and MO Calculations
Authors: Hayashi Satoko , Nishide Taro , Tanaka Eiichiro , Nakanishi Waro
Published: May 2021

The intrinsic dynamic and static nature of noncovalent Br-∗-Br interactions in neutral polybromine clusters is elucidated for Br4–Br12, applying QTAIM dual-functional analysis (QTAIM-DFA). The asterisk (∗) emphasizes the existence of the bond critical point (BCP) on the interaction in question. Data from the fully optimized structures correspond to the static nature of the interactions. The intrinsic dynamic nature originates from those of the perturbed structures generated using the coordinates derived from the compliance constants for the interactions and the fully optimized structures. The noncovalent Br-∗-Br interactions in the L-shaped clusters of the Cs symmetry are predicted to have the typical hydrogen bond nature without covalency, although the first ones in the sequences have the vdW nature. The L-shaped clusters are stabilized by the n(Br)→σ*(Br–Br) interactions. The compliance constants for the corresponding noncovalent interactions are strongly correlated to the E(2) values based on NBO. Indeed, the MO energies seem not to contribute to stabilizing Br4 (C2h) and Br4 (D2d), but the core potentials stabilize them, relative to the case of 2Br2; this is possibly due to the reduced nuclear–electron distances, on average, for the dimers.
1,2,3-Triazoles as Biomimetics in Peptide Science
Authors: Agouram Naima , El Hadrami El Mestafa , Bentama Abdeslem
Published: May 2021

Natural peptides are an important class of chemical mediators, essential for most vital processes. What limits the potential of the use of peptides as drugs is their low bioavailability and enzymatic degradation in vivo. To overcome this limitation, the development of new molecules mimicking peptides is of great importance for the development of new biologically active molecules. Therefore, replacing the amide bond in a peptide with a heterocyclic bioisostere, such as the 1,2,3-triazole ring, can be considered an effective solution for the synthesis of biologically relevant peptidomimetics. These 1,2,3-triazoles may have an interesting biological activity, because they behave as rigid link units, which can mimic the electronic properties of amide bonds and show bioisosteric effects. Additionally, triazole can be used as a linker moiety to link peptides to other functional groups.
Effects of Thai Local Ingredient Odorants, Litsea cubeba and Garlic Essential Oils, on Brainwaves and Moods
Authors: Sattayakhom Apsorn , Songsamoe Sumethee , Yusakul Gorawit , Kalarat Kosin , Matan Narumol , Koomhin Phanit
Published: May 2021

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor and fragrance of the famous tom yum and massaman dishes. While the biological activities of these ingredients have been investigated, including the antioxidant, anti-inflammatory, and antimicrobial activities, there is still a lack of understanding regarding the responses to the essential oils of these plants. To investigate the effects of essential oil inhalation on the brain and mood responses, electroencephalography was carried out during the non-task resting state, and self-assessment of the mood state was performed. The essential oils were prepared in several dilutions in the range of the supra-threshold level. The results show that Litsea cubeba oil inhalation showed a sedative effect, observed from alpha and beta wave power reductions. The frontal and temporal regions of the brain were involved in the wave alterations. Garlic oil increased the alpha wave power at lower concentrations; however, a sedative effect was also observed at higher concentrations. Lower dilution oil induced changes in the fast alpha activity in the frontal region. The alpha and beta wave powers were decreased with higher dilution oils, particularly in the temporal, parietal, and occipital regions. Both Litsea cubeba and turmeric oils resulted in better positive moods than garlic oil. Garlic oil caused more negative moods than the others. The psychophysiological activities and the related brain functions require further investigation. The knowledge obtained from this study may be used to design functional food products.
Molecular Structure, Thermodynamic and Spectral Characteristics of Metal-Free and Nickel Complex of Tetrakis(1,2,5-thiadiazolo)porphyrazine
Authors: Zhabanov Yuriy A. , Eroshin Alexey V. , Ryzhov Igor V. , Kuzmin Ilya A. , Finogenov Daniil N. , Stuzhin Pavel A.
Published: May 2021

The Knudsen effusion method with mass spectrometric control of the vapor composition was used to study the possibility of a congruent transition to the gas phase and to estimate the enthalpy of sublimation of metal-free tetrakis(1,2,5-thiadiazolo)porphyrazine and its nickel complex (H2TTDPz and NiTTDPz, respectively). The geometrical and electronic structure of H2TTDPz and NiTTDPz in ground and low-lying excited electronic states were determined by DFT calculations. The electronic structure of NiTTDPz was studied by the complete active space (CASSCF) method, following accounting dynamic correlation by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D2h and D4h symmetry was obtained for H2TTDPz and NiTTDPz, respectively. According to data obtained by the MCQDPT2 method, the nickel complex possesses the ground state 1A1g, and the wave function of the ground state has the form of a single determinant. Electronic absorption and vibrational (IR and resonance Raman) spectra of H2TTDPz and NiTTDPz were studied experimentally and simulated theoretically.
Inter- and Intra-Molecular Organocatalysis of SN2 Fluorination by Crown Ether: Kinetics and Quantum Chemical Analysis
Authors: Oh Young-Ho , Yun Wonhyuck , Kim Chul-Hee , Jang Sung-Woo , Lee Sung-Sik , Lee Sungyul , Kim Dong-Wook
Published: May 2021

We present the intra- and inter-molecular organocatalysis of SN2 fluorination using CsF by crown ether to estimate the efficacy of the promoter and to elucidate the reaction mechanism. The yields of intramolecular SN2 fluorination of the veratrole substrates are measured to be very small (<1% in 12 h) in the absence of crown ether promoters, whereas the SN2 fluorination of the substrate possessing a crown ether unit proceeds to near completion (~99%) in 12 h. We also studied the efficacy of intermolecular rate acceleration by an independent promoter 18-crown-6 for comparison. We find that the fluorinating yield of a veratrole substrate (leaving group = −OMs) in the presence of 18-crown-6 follows the almost identical kinetic course as that of intramolecular SN2 fluorination, indicating the mechanistic similarity of intra- and inter-molecular organocatalysis of the crown ether for SN2 fluorination. The calculated relative Gibbs free energies of activation for these reactions, in which the crown ether units act as Lewis base promoters for SN2 fluorination, are in excellent agreement with the experimentally measured yields of fluorination. The role of the metal salt CsF is briefly discussed in terms of whether it reacts as a contact ion pair or as a “free” nucleophile F−.
The Potential Effects of Phytoestrogens: The Role in Neuroprotection
Authors: Gorzkiewicz Justyna , Bartosz Grzegorz , Sadowska-Bartosz Izabela
Published: May 2021

Phytoestrogens are naturally occurring non-steroidal phenolic plant compounds. Their structure is similar to 17-β-estradiol, the main female sex hormone. This review offers a concise summary of the current literature on several potential health benefits of phytoestrogens, mainly their neuroprotective effect. Phytoestrogens lower the risk of menopausal symptoms and osteoporosis, as well as cardiovascular disease. They also reduce the risk of brain disease. The effects of phytoestrogens and their derivatives on cancer are mainly due to the inhibition of estrogen synthesis and metabolism, leading to antiangiogenic, antimetastatic, and epigenetic effects. The brain controls the secretion of estrogen (hypothalamus-pituitary-gonads axis). However, it has not been unequivocally established whether estrogen therapy has a neuroprotective effect on brain function. The neuroprotective effects of phytoestrogens seem to be related to both their antioxidant properties and interaction with the estrogen receptor. The possible effects of phytoestrogens on the thyroid cause some concern; nevertheless, generally, no serious side effects have been reported, and these compounds can be recommended as health-promoting food components or supplements.
Adsorptive Cathodic Stripping Voltammetry for Quantification of Alprazolam
Authors: Boonmee Waree , Samoson Kritsada , Yodrak Janjira , Thiagchanya Adul , Phonchai Apichai , Limbut Warakorn
Published: May 2021

A simple and highly sensitive electrochemical sensor was developed for adsorptive cathodic stripping voltammetry of alprazolam. Based on an electrochemically pretreated glassy carbon electrode, the sensor demonstrated good adsorption and electrochemical reduction of alprazolam. The morphology of the glassy carbon electrode and the electrochemically pretreated glassy carbon electrode were characterized by scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrochemical behaviors of alprazolam were determined by cyclic voltammetry, and the analytical measurements were studied by adsorptive cathodic stripping voltammetry. Optimized operational conditions included the concentration and deposition time of sulfuric acid in the electrochemical pretreatment, preconcentration potential, and preconcentration time. Under optimal conditions, the developed alprazolam sensor displayed a quantification limit of 0.1 mg L−1, a detection limit of 0.03 mg L−1, a sensitivity of 67 µA mg−1 L cm−2 and two linear ranges: 0.1 to 4 and 4 to 20 mg L−1. Sensor selectivity was excellent, and repeatability (%RSD < 4.24%) and recovery (82.0 ± 0.2 to 109.0 ± 0.3%) were good. The results of determining alprazolam in beverages with the developed system were in good agreement with results from the gas chromatography–mass spectrometric method.
Asymmetric Synthesis of Tetrahydroisoquinoline Derivatives through 1,3-Dipolar Cycloaddition of C,N-Cyclic Azomethine Imines with Allyl Alkyl Ketones
Authors: Feng Guipeng , Ma Guoyang , Chen Wenyan , Xu Shaohong , Wang Kaikai , Wang Shaoyan
Published: May 2021

A [3 + 2] 1,3-Dipolar cycloaddition of C,N-cyclic azomethine imines with allyl alkyl ketones has been achieved. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. An array of tetrahydroisoquinoline derivatives is generally constructed with good diastereoselectivities and enantioselectivities (up to >25:1 dr, >95% ee). Moreover, the absolute configuration of the product was previously determined by using the quantum electronic circular dichroism calculation and ECD spectrum method.