bluuebunny/crossref_metadata_2025 huggingface dataset:
Statins Associated with Better Long-Term Outcomes in Aged Hospitalized Patients with COPD: A Real-World Experience from Pay-for-Performance Program
Authors: Chen Ying-Yi , Li Tsai-Chung , Li Chia-Ing , Lin Shih-Pin , Fu Pin-Kuei
Published: February 2022

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally. Previous studies have addressed the impact of comorbidity on short-term mortality in patients with COPD. However, the prevalence of cardiovascular disease (CVD) and the association of statins prescription with mortality for aged COPD patients remains unclear. We enrolled 296 aged, hospitalized patients who were monitored in the pay-for-performance (P-4-P) program of COPD. Factors associated with long-term mortality were identified by Cox regression analysis. The median age of the study cohort was 80 years old, and the prevalence of coronary artery disease (CAD) and statins prescriptions were 16.6% and 31.4%, respectively. The mortality rate of the median 3-year follow-up was 51.4%. Through multivariate analysis, body mass index (BMI), statin prescription, and events of respiratory failure were associated with long-term mortality. A Cox analysis showed that statins prescription was associated with lower mortality (hazard ratio (HR): 0.5, 95% Confident interval, 95% CI: 0.34–0.73, p = 0.0004) and subgroup analysis showed that rosuvastatin prescription had protective effect on long-term mortality (HR: 0.44; 95% CI: 0.20–0.97; p < 0.05). Statin prescriptions might be associated with better long-term survival in aged COPD patients, especially those who experienced an acute exacerbation of COPD (AECOPD) who require hospitalization.
Land Use/Cover Change Reduces Elephant Habitat Suitability in the Wami Mbiki–Saadani Wildlife Corridor, Tanzania
Authors: Ntukey Lucas Theodori , Munishi Linus Kasian , Kohi Edward , Treydte Anna Christina
Published: February 2022

Wildlife corridors are critical for maintaining the viability of isolated wildlife populations and conserving ecosystem functionality. Anthropogenic pressure has negatively impacted wildlife habitats, particularly in corridors between protected areas, but few studies have yet quantitatively assessed habitat changes and corresponding wildlife presence. We quantified land use/land cover and human–elephant conflict trends over the past two decades in the Wami Mbiki–Saadani (WMS) wildlife corridor, Tanzania, using RS and GIS combined with human–wildlife conflict reports. We designed landscape metrics and habitat suitability models for the African savanna elephant (Loxodonta africana) as a large mammal key species in the WMS ecosystem. Our results showed that forest cover, a highly suitable habitat for elephants, decreased by 3.0% between 1998 and 2008 and 20.3% between 2008 and 2018. Overall, the highly suitable habitat for elephants decreased by 22.4% from 1998 to 2018, when it was scarcely available and when small fragmented patches dominated the unprotected parts of the corridor. Our findings revealed that large mammalian habitat conservation requires approaches beyond habitat-loss detection and must consider other facets of landscape patterns. We suggest strengthening elephant habitat conservation through community conservation awareness, wildlife corridor mapping, and restoration practices to ensure a sustainable pathway to human–wildlife coexistence.
On the Nature of Syntactic Satiation
Authors: Snyder William
Published: February 2022

In syntactic satiation, a linguist initially judges a sentence type to be unacceptable but begins to accept it after judging multiple examples over time. When William Snyder first brought this phenomenon to the attention of linguists, he proposed satiation as a data source for linguistic theory and showed it can be induced experimentally. Here, three new studies indicate (i) satiation is restricted to a small, stable set of sentence types; (ii) after satiation on one sentence type (e.g., wh-movement across … wonder whether … or … believe the claim …), acceptability sometimes increases for distinct but syntactically related sentence types (… wonder why …; … accept the idea …); (iii) for sentence types susceptible to satiation, the difficulty of inducing it (e.g., number of exposures required) varies systematically; and (iv) much as satiation in linguists persists over time, experimentally induced satiation can persist for at least four weeks. These findings suggest a role for satiation in determining whether the perceived unacceptability of two sentence types has a common source.
Nasal Symptoms in Patients with Obstructive Sleep Apnoea and Their Association with Continuous Positive Airway Pressure Usage
Authors: Chaidas Konstantinos , Lamprou Kallirroi , Munnings Amberley , Stradling John R. , Nickol Annabel H.
Published: February 2022

The role of nasal symptoms in continuous positive airway pressure (CPAP) tolerance is not completely clear. This study aimed to investigate the association between CPAP usage and nasal symptoms, either prior to, or developing during, CPAP use in patients with obstructive sleep apnoea (OSA). Two hundred thirty patients were studied and divided into high-, low-, and non-CPAP users. Nasal symptoms and related quality of life parameters were evaluated prior to CPAP initiation and after three months. We also investigated predictive factors for CPAP usage. Non-CPAP users had significantly worse baseline scores for runny nose compared with high and low users (1.34 vs. 0.68 and 0.75, respectively, p = 0.006). There were no other significant differences between the groups. Runny nose was an independent predictive factor for lower CPAP usage (p = 0.036). An evaluation after three months showed worsening in runny nose score in high-CPAP users (p = 0.025) but not in low- and non-users. There were no significant changes in other nasal symptoms. Our study demonstrates that nasal symptoms were very common in this population but rhinorrhoea was the only symptom associated with poorer CPAP adherence. Moreover, rhinorrhoea worsened after a three-month trial of high-CPAP usage.
Dentin Biomodification with Flavonoids and Calcium Phosphate Ion Clusters to Improve Dentin Bonding Stability
Authors: Paik Youna , Kim Jae-Hoon , Yoo Kyung-Hyeon , Yoon Seog-Young , Kim Yong-Il
Published: February 2022

The purpose of this study was to evaluate the effects of flavonoids and calcium phosphate ion clusters (CPIC) on dentin bonding stability. Seven experimental solutions were synthesized using icaritin (ICT), fisetin (FIS), silibinin (SIB), CPIC, and combinations of one of three flavonoids and CPIC (ICT + C, FIS + C, SIB + C). The experimental solutions were applied to demineralized dentin prior to the application of a universal adhesive. A group without any experimental solution served as a control. Dentin specimens pretreated with the experimental solutions were assayed using Fourier transform infrared (FTIR) spectroscopy. The microtensile bond strength (µTBS) and nanoleakage were evaluated at 24 h and after 10,000 thermocycles. FIS and ICT + C showed significantly higher µTBS than the control group at 24 h. CPIC, ICT + C, FIS + C, and SIB + C showed significantly higher µTBS than the control group after thermocycling. After thermocycling, silver infiltration into the hybrid layer and interfacial gaps was more noticeable in the control group than in the other groups. The FTIR spectra revealed the formation of apatitic minerals in the demineralized dentin in the flavonoid and CPIC combination groups. The pretreatment of demineralized dentin with flavonoids and CPIC improved dentin bonding stability. The flavonoid and CPIC combinations preserved dentin bond strength.
Contribution of Interfacial Bonding towards Geopolymers Properties in Geopolymers Reinforced Fibers: A Review
Authors: Yazid Muhd Hafizuddin , Faris Meor Ahmad , Abdullah Mohd Mustafa Al Bakri , Nabiałek Marcin , Rahim Shayfull Zamree Abd , Salleh Mohd Arif Anuar Mohd , Kheimi Marwan , Sandu Andrei Victor , Rylski Adam , Jeż Bartłomiej
Published: February 2022

There is a burgeoning interest in the development of geopolymers as sustainable construction materials and incombustible inorganic polymers. However, geopolymers show quasi-brittle behavior. To overcome this weakness, hundreds of researchers have focused on the development, characterization, and implementation of geopolymer-reinforced fibers for a wide range of applications for light geopolymers concrete. This paper discusses the rapidly developing geopolymer-reinforced fibers, focusing on material and geometrical properties, numerical simulation, and the effect of fibers on the geopolymers. In the section on the effect of fibers on the geopolymers, a comparison between single and hybrid fibers will show the compressive strength and toughness of each type of fiber. It is proposed that interfacial bonding between matrix and fibers is important to obtain better results, and interfacial bonding between matrix and fiber depends on the type of material surface contact area, such as being hydrophobic or hydrophilic, as well as the softness or roughness of the surface.
Long Spiky Au-Ag Nanostar Based Fiber Probe for Surface Enhanced Raman Spectroscopy
Authors: He Guangyuan , Han Xiaoyu , Cao Shiyi , Cui Kaimin , Tian Qihang , Zhang Jihong
Published: February 2022

The detection performances of noble metal-based surface enhanced Raman spectroscopy (SERS) devices are determined by the compositions and geometries of the metal nanostructures, as well as the substrates. In the current study, long spiky Au-Ag alloy nanostars were synthesized, and both core diameters and spike lengths were controlled by Lauryl sulfobetaine concentrations (as the nanostructure growth skeleton). The long spiky star geometries were confirmed by transmission electron micrograph images. Elements energy dispersive spectrometer mapping confirmed that Au and Ag elements were inhomogeneously distributed in the nanostructures and demonstrated a higher Ag content at surface for potential better SERS performance. Selected synthesized spiky nanostars were uniformly assembled on multi-mode silica fiber for probe fabrication by silanization. The SERS performance were characterized using crystal violet (CV) and rhodamine 6G (R6G) as analyte molecules. The lowest detection limit could reach as low as 10−8 M, with a 6.23 × 106 enhancement factor, and the relationship between analyte concentrations and Raman intensities was linear for both CV and R6G, which indicated the potential qualitative and quantitative molecule detection applications. Moreover, the fiber probes also showed good reproducibility and stability in the ambient atmosphere.
Effect of Expanded Graphite on the Reaction Sintering of Boron Carbide
Authors: Gubernat Agnieszka , Kornaus Kamil , Lach Radosław , Zientara Dariusz , Dyl Patryk
Published: February 2022

This paper presents novel results of research focused on reaction sintering of a mixture of expanded graphite and amorphous boron. It has been shown that as a result of combining the synthesis from the elements with sintering under pressure, dense boron carbide polycrystals (95% TD) can be obtained in which stable structures dominate, i.e., boron carbides of stoichiometry B13C2 and B4C. Sintering was carried out on boron excess systems, and reaction mixtures with the following mass ratios (B:C = 5:1; 10:1; and 15:1) were used. Boron excess systems were used due to the presence of additional carbon during sintering since the matrix, reactor lining, and heating elements were made of graphite. 1850 °C was considered to be the optimum reaction sintering temperature for all of the systems tested. This shows that a reduction in the sintering temperature of 200–300 °C was observed with respect to traditional sintering techniques. Micro-cracks are present in the sinters, the presence of which is most likely due to the difficulty in removing the gaseous products which accompany the boron carbide synthesis reaction. The elimination of these defects of sintering requires further research.
Effect of Crumb Rubber, Fly Ash, and Nanosilica on the Properties of Self-Compacting Concrete Using Response Surface Methodology
Authors: Rahim Nurul Izzati , Mohammed Bashar S. , Abdulkadir Isyaka , Dahim Mohammed
Published: February 2022

Producing high-strength self-compacting concrete (SCC) requires a low water-cement ratio (W/C). Hence, using a superplasticizer is necessary to attain the desired self-compacting properties at a fresh state. The use of low W/C results in very brittle concrete with a low deformation capacity. This research aims to investigate the influence of crumb rubber (CR), fly ash (FA), and nanosilica (NS) on SCC’s workability and mechanical properties. Using response surface methodology (RSM), 20 mixes were developed containing different levels and proportions of FA (10–40% replacement of cement), CR (5–15% replacement of fine aggregate), and NS (0–4% addition) as the input variables. The workability was assessed through the slump flow, T500, L-box, and V-funnel tests following the guidelines of EFNARC 2005. The compressive, flexural, and tensile strengths were determined at 28 days and considered as the responses for the response surface methodology (RSM) analyses. The results revealed that the workability properties were increased with an increase in FA but decreased with CR replacement and the addition of NS. The pore-refining effect and pozzolanic reactivity of the FA and NS increased the strengths of the composite. Conversely, the strength is negatively affected by an increase in CR, however ductility and deformation capacity were significantly enhanced. Response surface models of the mechanical strengths were developed and validated using ANOVA and have high R2 values of 86–99%. The optimization result produced 36.38%, 4.08%, and 1.0% for the optimum FA, CR, and NS replacement levels at a desirability value of 60%.
Processing Laue Microdiffraction Raster Scanning Patterns with Machine Learning Algorithms: A Case Study with a Fatigued Polycrystalline Sample
Authors: Rong Peng , Zhang Fengguo , Yang Qing , Chen Han , Shi Qiwei , Zhong Shengyi , Chen Zhe , Wang Haowei
Published: February 2022

The massive amount of diffraction images collected in a raster scan of Laue microdiffraction calls for a fast treatment with little if any human intervention. The conventional method that has to index diffraction patterns one-by-one is laborious and can hardly give real-time feedback. In this work, a data mining protocol based on unsupervised machine learning algorithm was proposed to have a fast segmentation of the scanning grid from the diffraction patterns without indexation. The sole parameter that had to be set was the so-called “distance threshold” that determined the number of segments. A statistics-oriented criterion was proposed to set the “distance threshold”. The protocol was applied to the scanning images of a fatigued polycrystalline sample and identified several regions that deserved further study with, for instance, differential aperture X-ray microscopy. The proposed data mining protocol is promising to help economize the limited beamtime.
The Stability and Electronic Structure of Cu(200)/AuCu(200) Interface: An Insight from First-Principle Calculation
Authors: Li Zihao , Feng Junli , Wu Zhangxi , Pang Mingjun , Liu Dong , Yang Wenchao , Zhan Yongzhong
Published: February 2022

AuCu phase had a significant effect on the bonding strength of Au80Sn20 alloy and Cu substrate. The formation of the AuCu(200)/Cu(200) interface significantly improves the shear strength of solder joints. Therefore, it is particularly important to analyze the strengthening mechanism of the AuCu phase in the Cu matrix. The atomic structure, interfacial stability, and interfacial bonding properties of the Cu(200)/AuCu(200) interface were investigated using first-principle calculation. The layer spacing convergence results show that seven layers of Cu(200) surface and seven layers of AuCu(200) surface are enough thick to be chosen for the interface model. The calculation shows that the surface energies are 1.463 J/m2 and 1.081 J/m2 for AuCu(200) surface and Cu(200) surface, respectively. Four interface combinations of Top sit, Long bridge, Short bridge, and Hollow were investigated by considering four stacking methods of AuCu(200). It is shown that the interfacial configuration of the Long bridge is the most stable and favorable structure, which has the largest adhesion work, the smallest interfacial energy, and the smallest interfacial spacing. The density of states and electron difference density were calculated for the four interfacial configurations, and the results showed that the main bonding mode of the Long bridge interface is composed of both Cu-Cu covalent bonds and Au-Cu covalent bonds.
Structural Characterization of Multicomponent Crystals Formed from Diclofenac and Acridines
Authors: Mirocki Artur , Sikorski Artur
Published: February 2022

Multicomponent crystals containing diclofenac and acridine (1) and diclofenac and 6,9-diamino-2-ethoxyacridine (2) were synthesized and structurally characterized. The single-crystal XRD measurements showed that compound 1 crystallizes in the triclinic P-1 space group as a salt cocrystal with one acridinium cation, one diclofenac anion, and one diclofenac molecule in the asymmetric unit, whereas compound 2 crystallizes in the triclinic P-1 space group as an ethanol solvate monohydrate salt with one 6,9-diamino-2-ethoxyacridinium cation, one diclofenac anion, one ethanol molecule, and one water molecule in the asymmetric unit. In the crystals of the title compounds, diclofenac and acridines ions and solvent molecules interact via N–H⋯O, O–H⋯O, and C–H⋯O hydrogen bonds, as well as C–H⋯π and π–π interactions, and form heterotetramer bis[⋯cation⋯anion⋯] (1) or heterohexamer bis[⋯cation⋯ethanol⋯anion⋯] (2). Moreover, in the crystal of compound 1, acridine cations and diclofenac anions interact via N–H⋯O hydrogen bond, C–H⋯π and π–π interactions to produce blocks, while diclofenac molecules interact via C–Cl⋯π interactions to form columns. In the crystal of compound 2, the ethacridine cations interact via C–H⋯π and π–π interactions building blocks, while diclofenac anions interact via π–π interactions to form columns.
Hierarchical Reinforcement Learning: A Survey and Open Research Challenges
Authors: Hutsebaut-Buysse Matthias , Mets Kevin , Latré Steven
Published: February 2022

Reinforcement learning (RL) allows an agent to solve sequential decision-making problems by interacting with an environment in a trial-and-error fashion. When these environments are very complex, pure random exploration of possible solutions often fails, or is very sample inefficient, requiring an unreasonable amount of interaction with the environment. Hierarchical reinforcement learning (HRL) utilizes forms of temporal- and state-abstractions in order to tackle these challenges, while simultaneously paving the road for behavior reuse and increased interpretability of RL systems. In this survey paper we first introduce a selection of problem-specific approaches, which provided insight in how to utilize often handcrafted abstractions in specific task settings. We then introduce the Options framework, which provides a more generic approach, allowing abstractions to be discovered and learned semi-automatically. Afterwards we introduce the goal-conditional approach, which allows sub-behaviors to be embedded in a continuous space. In order to further advance the development of HRL agents, capable of simultaneously learning abstractions and how to use them, solely from interaction with complex high dimensional environments, we also identify a set of promising research directions.
Novel Analysis of the Fractional-Order System of Non-Linear Partial Differential Equations with the Exponential-Decay Kernel
Authors: Alesemi Meshari , Iqbal Naveed , Botmart Thongchai
Published: February 2022

This article presents a homotopy perturbation transform method and a variational iterative transform method for analyzing the fractional-order non-linear system of the unsteady flow of a polytropic gas. In this method, the Yang transform is combined with the homotopy perturbation transformation method and the variational iterative transformation method in the sense of Caputo–Fabrizio. A numerical simulation was carried out to verify that the suggested methodologies are accurate and reliable, and the results are revealed using graphs and tables. Comparing the analytical and actual solutions demonstrates that the proposed approaches are effective and efficient in investigating complicated non-linear models. Furthermore, the proposed methodologies control and manipulate the achieved numerical solutions in a very useful way, and this provides us with a simple process to adjust and control the convergence regions of the series solution.
Continuous Hybrid BCI Control for Robotic Arm Using Noninvasive Electroencephalogram, Computer Vision, and Eye Tracking
Authors: Xu Baoguo , Li Wenlong , Liu Deping , Zhang Kun , Miao Minmin , Xu Guozheng , Song Aiguo
Published: February 2022

The controlling of robotic arms based on brain–computer interface (BCI) can revolutionize the quality of life and living conditions for individuals with physical disabilities. Invasive electroencephalography (EEG)-based BCI has been able to control multiple degrees of freedom (DOFs) robotic arms in three dimensions. However, it is still hard to control a multi-DOF robotic arm to reach and grasp the desired target accurately in complex three-dimensional (3D) space by a noninvasive system mainly due to the limitation of EEG decoding performance. In this study, we propose a noninvasive EEG-based BCI for a robotic arm control system that enables users to complete multitarget reach and grasp tasks and avoid obstacles by hybrid control. The results obtained from seven subjects demonstrated that motor imagery (MI) training could modulate brain rhythms, and six of them completed the online tasks using the hybrid-control-based robotic arm system. The proposed system shows effective performance due to the combination of MI-based EEG, computer vision, gaze detection, and partially autonomous guidance, which drastically improve the accuracy of online tasks and reduce the brain burden caused by long-term mental activities.
An Improved Intellectual Capital Management Method for Selecting and Prioritizing Intangible-Related Aspects: A Case Study of Small Enterprise in Thailand
Authors: Wudhikarn Ratapol , Pongpatcharatorntep Danaitun
Published: February 2022

This study develops a new integrated approach for improving deficiencies relating to executives’ intuitive or illogical decisions, mainly found in past intellectual capital management (ICM) methods. To simultaneously rectify several flaws, the process model of intellectual capital (IC), a traditional ICM method, is integrated using decision science methods—the analytic network process (ANP) and quality function deployment (QFD). The process model of IC is adopted as a core procedure of the proposed ICM approach. ANP is integrated to improve the ability to consider relationships among the IC critical factors and their impacts, while QFD is included to facilitate the systematic consideration and identification of correlations, linkages, and impacts between all IC-related elements from the business concept to strategic plans. The proposed method was applied to two case studies in one real enterprise in Thailand. The results of the implementation reveal the priorities of all IC-related aspects, and the first priority of key success factors (KSFs), key performance indicators (KPIs), and action plans (APs) are all associated with the organization in the structural capital dimension. The results demonstrate that the method may offer advantages with respect to the conceptual expectations and may prioritize critical IC factors and identify their weights. Furthermore, the improved method could indicate the correlations and impacts between related elements, such as critical factors and associated indicators. This study proposes a new comprehensive and systematic management framework by integrating different concepts—decision science methods and the ICM method. To the best of the authors’ knowledge, this improved approach has not been explored or proposed in earlier studies.
A Novel α4/7-Conotoxin QuIA Selectively Inhibits α3β2 and α6/α3β4 Nicotinic Acetylcholine Receptor Subtypes with High Efficacy
Authors: Wang Liujun , Wu Xixi , Zhu Xiaopeng , Zhangsun Dongting , Wu Yong , Luo Sulan
Published: February 2022

α6β4 nAChR is expressed in the peripheral and central nervous systems and is associated with pain, addiction, and movement disorders. Natural α-conotoxins (α-CTxs) can effectively block different nAChR subtypes with higher efficacy and selectivity. However, the research on α6β4 nAChR is relatively poor, partly because of the lack of available target-specific α-CTxs. In this study, we synthesized a novel α-4/7 conotoxin QuIA that was found from Conus quercinus. We investigated the efficacy of this peptide to different nAChR subtypes using a two-electrode voltage-clamp technique. Remarkably, we found α-QuIA inhibited the neuronal α3β2 and α6/α3β4 nAChR subtypes with significantly high affinity (IC50 was 55.7 nM and 90.68 nM, respectively), and did not block other nAChR subtypes even at a high concentration of 10 μM. In contrast, most α-CTxs have been determined so far to effectively block the α6/α3β4 nAChR subtype while also maintaining a similar higher efficacy against the closely related α6β2β3 and/or α3β4 subtypes, which are different from QuIA. In conclusion, α-QuIA is a novel α4/7-CTx, which has the potential to develop as an effective neuropharmacology tool to detect the function of α6β4 nAChR.
COVID-19 and Postural Control—A Stabilographic Study Using Rambling-Trembling Decomposition Method
Authors: Żychowska Magdalena , Jaworecka Kamila , Mazur Ewelina , Słomka Kajetan , Marszałek Wojciech , Rzepko Marian , Czarny Wojciech , Reich Adam
Published: February 2022

Background and Objectives: Some respiratory viruses demonstrate neurotropic capacities. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently taken over the globe, causing coronavirus disease 2019 (COVID-19). The aim of the study was to evaluate the impact of COVID-19 on postural control in subjects who have recently recovered from the infection. Materials and Methods: Thirty-three convalescents who underwent COVID-19 within the preceding 2–4 weeks, and 35 healthy controls were enrolled. The ground reaction forces were registered with the use of a force platform during quiet standing. The analysis of the resultant center of foot pressure (COP) decomposed into rambling (RAMB) and trembling (TREMB) and sample entropy was conducted. Results: Range of TREMB was significantly increased in subjects who experienced anosmia/hyposmia during COVID-19 when the measurement was performed with closed eyes (p = 0.03). In addition, subjects who reported dyspnea during COVID-19 demonstrated significant increase of length and velocity of COP (p < 0.001), RAMB (p < 0.001), and TREMB (p < 0.001), indicating substantial changes in postural control. Conclusions: Subjects who had experienced olfactory dysfunction or respiratory distress during COVID-19 demonstrate symptoms of balance deficits after COVID-19 recovery, and the analysis using rambling-trembling decomposition method might point at less efficient peripheral control. Monitoring for neurological sequelae of COVID-19 should be considered.
Structures and Dynamics of Dengue Virus Nonstructural Membrane Proteins
Authors: Li Qingxin , Kang Congbao
Published: February 2022

Dengue virus is an important human pathogen threating people, especially in tropical and sub-tropical regions. The viral genome has one open reading frame and encodes one polyprotein which can be processed into structural and nonstructural (NS) proteins. Four of the seven nonstructural proteins, NS2A, NS2B, NS4A and NS4B, are membrane proteins. Unlike NS3 or NS5, these proteins do not harbor any enzymatic activities, but they play important roles in viral replication through interactions with viral or host proteins to regulate important pathways and enzymatic activities. The location of these proteins on the cell membrane and the functional roles in viral replication make them important targets for antiviral development. Indeed, NS4B inhibitors exhibit antiviral activities in different assays. Structural studies of these proteins are hindered due to challenges in crystallization and the dynamic nature of these proteins. In this review, the function and membrane topologies of dengue nonstructural membrane proteins are presented. The roles of solution NMR spectroscopy in elucidating the structure and dynamics of these proteins are introduced. The success in the development of NS4B inhibitors proves that this class of proteins is an attractive target for antiviral development.
Fabrication, Performance, Characterization and Experimental Calibration of Embedded Thin-Film Sensor for Tool Cutting Force Measurement
Authors: Cheng Yunping , Wu Wenge , Liu Lijuan , Zhang Yuntao , He Zhenyu , Song Ding
Published: February 2022

Thin-film strain sensors are widely used because of their small volume, fast strain response and high measurement accuracy. Among them, the thin-film material and preparation process of thin-film strain sensors for force measurement are important aspects. In this paper, the preparation process parameters of the transition layer, insulating layer and Ni-Cr alloy layer in a thin-film strain sensor are analyzed and optimized, and the influence of each process parameter on the properties of the thin film are discussed. The surface microstructure of the insulating layer with Al2O3 or Si3N4 transition layers and the film without transition layer were observed by atomic force microscopy. It is analyzed that adding a transition layer between the stainless steel substrate and insulation layer can improve the adhesion and flatness of the insulation layer. The effects of process parameters on elastic modulus, nanohardness and strain sensitivity coefficient of the Ni-Cr resistance layer are discussed, and electrical parameters such as the resistance strain coefficient are analyzed and characterized. The static calibration of the thin-film strain sensor is carried out, and the relationship between the strain value and the output voltage is obtained. The results show that the thin-film strain sensor can obtain the strain generated by the cutting tool and transform it into an electrical signal with good linearity through the bridge, accurately measuring the cutting force.
Power Performance Comparison of SiC-IGBT and Si-IGBT Switches in a Three-Phase Inverter for Aircraft Applications
Authors: Abdalgader Ibrahim A. S. , Kivrak Sinan , Özer Tolga
Published: February 2022

The converters used to integrate the ground power station of planes with the utility grid are generally created with silicon-insulated gate bipolar transistor (Si-IGBT)-based semiconductor technologies. The Si-IGBT switch-based converters are inefficient, oversized, and have trouble achieving pure sine wave voltages requirements. The efficiency of the aircraft ground power units (AGPU) can be increased by replacing existing Si-IGBT transistors with silicon carbide (SiC) IGBTs because of the physical constraints of Si-IGBT switches. The primary purpose of this research was to prove that the efficiency increase could be obtained in the case of using SiC-IGBTs in conventional AGPU systems with the realized experimental studies. In this study, three different experimental systems were discussed for this purpose. The first system was the traditional APGU system. The other two systems were single-phase test (SPT) and three-phase inverter systems, respectively. The SPT system and three-phase inverter systems were designed and implemented to compare and make analyses of Si-IGBTs and SiC-IGBTs performance. The efficiency and detailed hard switching behavior comparison were performed between the 1200-V SiC-IGBT- and 1200-V Si-IGBT-based experimental systems. The APGU system and Si-IGBT modules were examined, the switching characteristic and efficiency of the system were obtained in the first experimental study. The second experimental study was carried out on the SPT system. The single-pulse test system was created using Si-IGBTs and SiC-IGBTs switches in the second experimental system. The third experiment included a three-phase-inverter-based test system. The system was created with Si-IGBTs and SiC-IGBTs to compare the two different switch-based inverters under RL loads. The turning off and turning on processes of the IGBT switches were examined and the results were presented. The Si-IGBT efficiency was 77% experimentally in the SPT experimental system. The efficiency of the third experimental system was increased up to 95% by replacing the old Si transistor with a SiC. The efficiency of the three-phase Si-IGBT-based system was 86% for the six-switch case. The efficiencies of the SiC-IGBT-based system were increased to around 92% in the three-phase inverter system experimentally. The findings of the experimental results demonstrated that the SiC-IGBT had a faster switching speed and a smaller loss than the classical Si-IGBT. As a result of the experimental studies, the efficiency increase that could be obtained in the case of using SiC-IGBTs in conventional AGPU systems was revealed.
Culture-Free Enumeration of Mycobacterium tuberculosis in Mouse Tissues Using the Molecular Bacterial Load Assay for Preclinical Drug Development
Authors: Evangelopoulos Dimitrios , Shoen Carolyn M. , Honeyborne Isobella , Clark Simon , Williams Ann , Mukamolova Galina V. , Cynamon Michael H. , McHugh Timothy D.
Published: February 2022

Background: The turnaround times for phenotypic tests used to monitor the bacterial load of Mycobacterium tuberculosis, in both clinical and preclinical studies, are delayed by the organism’s slow growth in culture media. The existence of differentially culturable populations of M.tuberculosis may result in an underestimate of the true number. Moreover, culture methods are susceptible to contamination resulting in loss of critical data points. Objectives: We report the adaptation of our robust, culture-free assay utilising 16S ribosomal RNA, developed for sputum, to enumerate the number of bacteria present in animal tissues as a tool to improve the read-outs in preclinical drug efficacy studies. Methods: Initial assay adaptation was performed using naïve mouse lungs spiked with known quantities of M. tuberculosis and an internal RNA control. Tissues were homogenised, total RNA extracted, and enumeration performed using RT-qPCR. We then evaluated the utility of the assay, in comparison to bacterial counts estimated using growth assays on solid and liquid media, to accurately inform bacterial load in tissues from M. tuberculosis-infected mice before and during treatment with a panel of drug combinations. Results: When tested on lung tissues derived from infected mice, the MBL assay produced comparable results to the bacterial counts in solid culture (colony forming units: CFU). Notably, under specific drug treatments, the MBL assay was able to detect a significantly higher number of M. tuberculosis compared to CFU, likely indicating the presence of bacteria that were unable to produce colonies in solid-based culture. Additionally, growth recovery in liquid media using the most probable number (MPN) assay was able to account for the discrepancy between the MBL assay and CFU number, suggesting that the MBL assay detects differentially culturable sub-populations of M. tuberculosis. Conclusions: The MBL assay can enumerate the bacterial load in animal tissues in real time without the need to wait for extended periods for cultures to grow. The readout correlates well with CFUs. Importantly, we have shown that the MBL is able to measure specific populations of bacteria not cultured on solid agar. The adaptation of this assay for preclinical studies has the potential to decrease the readout time of data acquisition from animal experiments and could represent a valuable tool for tuberculosis drug discovery and development.
Long-Term Application of Bio-Compost Increased Soil Microbial Community Diversity and Altered Its Composition and Network
Authors: Liu Xiayan , Shi Yu , Kong Lingyu , Tong Lihong , Cao Haoxuan , Zhou Hu , Lv Yizhong
Published: February 2022

The influence of bio-compost on the diversity, composition and structure of soil microbial communities is less understood. Here, Illumina MiSeq sequencing and a network analysis were used to comprehensively characterize the effects of 25 years of bio-compost application on the microbial diversity of soil and community composition. High dosages of bio-compost significantly increased the bacterial and fungal richness. The compositions of bacterial and fungal communities were significantly altered by bio-compost addition. Bio-compost addition enriched the relative abundance of beneficial microorganisms (such as Sphingomonas, Acidibacter, Nocardioides, etc.) and reduced the relative abundance of harmful microorganisms (such as Stachybotrys and Aspergillus). Electrical conductivity, soil organic matter and total phosphorus were the key factors in shaping soil microbial community composition. The bacterial network was more complex than fungal network, and bacteria were more sensitive to changes in environmental factors than fungi. Positive interactions dominated both the bacterial and fungal networks, with stronger positive interactions found in the bacterial network. Functional prediction suggested that bio-composts altered the soil bacterial-community metabolic function with respect to carbon, nitrogen and phosphorus cycles and fungal community trophic modes. In conclusion, suitable bio-compost addition is beneficial to the improvement of soil health and crop quality and therefore the sustainability of agriculture.
Probiotic Potentiality from Versatile Lactiplantibacillus plantarum Strains as Resource to Enhance Freshwater Fish Health
Authors: Iorizzo Massimo , Albanese Gianluca , Letizia Francesco , Testa Bruno , Tremonte Patrizio , Vergalito Franca , Lombardi Silvia Jane , Succi Mariantonietta , Coppola Raffaele , Sorrentino Elena
Published: February 2022

Dietary probiotic supplementation has the potential to enhance the health of fish and their disease resistance. In this study, some properties of ten Lactiplantibacillus plantarum strains have been evaluated, for their potential use as probiotics in freshwater fish diet. In particular, antimicrobial activity, antioxidant activity, the potentiality to survive the gastrointestinal transit and persist in the intestine, were evaluated in vitro. The experimental tests were carried out at 15 °C and 30 °C to determine the suitability of these lactic acid bacteria to be used as probiotics in the diet of fish grown at different temperatures. The results demonstrated that the evaluated Lp. plantarum strains, which often have significant differences among themselves, are characterized by important functional characteristics such as cell surface properties (auto-aggregation and hydrophobicity), ability to produce antioxidant substances, capacity to survive in the presence of 0.3% bile salts and acidic environment (2.5 pH), antagonistic activity against some fish opportunistic pathogens (A. salmonicida, Ps. aeruginosa, E. coli and C. freundii) and other unwanted bacteria present in fish products (S. aureus and L. innocua). The outcomes suggest that these Lp. plantarum strains may be candidates as probiotics in warm- and cold-water aquaculture.
Evolution of Ore-Forming Fluids and Gold Deposition of the Sanakham Lode Gold Deposit, SW Laos: Constrains from Fluid Inclusions Study
Authors: Liu Shusheng , Guo Linnan , Ding Jun , Hou Lin , Xu Siwei , Shi Meifeng , Liang Huimin , Nie Fei , Cui Xiaoyu
Published: February 2022

The Sanakham gold deposit is a newly discovered gold deposit in the Luang Prabang (Laos)–Loei (Thailand) metallogenic belt. It consists of a series of auriferous quartz-sulfide veins, which is distinguished from the regional known porphyry-related skarn and epithermal gold deposits. There are four mineralization stages identified in Sanakham, with native gold grains mainly occurring in stages II and III. Evolution of ore-forming fluids and gold deposition mechanisms in Sanakham are discussed based on fluid inclusion petrography, microthermometry, and Laser Raman spectroscopy. The original ore-forming fluids belong to a medium-high temperature (>345 °C) CH4-rich CH4–CO2–NaCl–H2O system. In stages II and III, the ore fluids evolve into a NaCl–H2O–CO2 ± CH4 system characterized by medium temperature (~300 °C), medium salinity (~10 wt% NaCl eq.), and CO2-rich (~10% mol). They might finally evolve into a NaCl–H2O system with temperature decreasing and salinity increasing in stage IV. Two fluid immiscibility processes occurred in stages II and III, which created high-CH4 & low-CO2 and low-CH4 & high-CO2 end-members, and CO2-poor and CO2-rich endmembers, respectively. Gold-deposition events are suggested to be associated with the fluid immiscibility processes, with P–T conditions and depth of 236–65 MPa, 337–272 °C, and 8.7–6.5 km, respectively.
Synthesis, Characterization, Biological Evaluation and DNA Interaction Studies of 4-Aminophenol Derivatives: Theoretical and Experimental Approach
Authors: Rafique Bushra , Kalsoom Saima , Sajini Abdulrahim A. , Ismail Hammad , Iqbal Mudassir
Published: February 2022

In the present study, five 4-aminophenol derivatives (4-chloro-2-(((4-hydroxyphenyl)imino)methyl)phenol(S-1), 4-((4-(dimethylamino)benzylidene)amino)phenol(S-2), 4-((3-nitrobenzylidene)amino)phenol(S-3), 4-((thiophen-2-ylmethylene)amino)phenol(S-4) and 4-(((E)-3-phenylallylidene)amino)phenol(S-5)) were synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analyses. The synthesized compounds were tested for their antimicrobial (Gram-positive and Gram-negative bacteria and Saccharomyces cervesea fungus) and antidiabetic (α-amylase and α-glucosidase inhibitory) activities. All the compounds showed broad-spectrum activities against the Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 4698), Staphylococcus epidermidis (ATCC 12228), Bacillus subtilis sub. sp spizizenii (ATCC 6633), Bordetella bronchiseptica (ATCC 4617) and Saccharomyces cerevisiae (ATCC 9763) strains. The newly synthesized compounds showed a significant inhibition of amylase (93.2%) and glucosidase (73.7%) in a concentration-dependent manner. Interaction studies of Human DNA with the synthesized Schiff bases were also performed. The spectral bands of S-1, S-2, S-3 and S-5 all showed hyperchromism, whereas the spectral band of S-4 showed a hypochromic effect. Moreover, the spectral bands of the S-2, S-3 and S-4 compounds were also found to exhibit a bathochromic shift (red shift). The present studies delineate broad-spectrum antimicrobial and antidiabetic activities of the synthesized compounds. Additionally, DNA interaction studies highlight the potential of synthetic compounds as anticancer agents. The DNA interaction studies, as well as the antidiabetic activities articulated by the molecular docking methods, showed the promising aspects of synthetic compounds.
Photodynamic Effect of Riboflavin on Chitosan Coatings and the Application in Pork Preservation
Authors: Pei Jiliu , Zhu Shengyu , Liu Yu , Song Yukang , Xue Feng , Xiong Xiaohui , Li Chen
Published: February 2022

Riboflavin (RF) was considered to be possessed of photoactivity to generate reactive oxygen species (ROS) under ultraviolet (UV) light, which is thought to be a favorable antibacterial candidate. Herein, RF was incorporated into chitosan (CS) coatings and treated under UV with different exposure times (2, 4, and 6 h) to improve the physicochemical and antibacterial properties. The results showed that the light transmittance and antibacterial performance of chitosan coatings gradually increased with the extension of the UV irradiation time. The antibacterial ability of chitosan coatings correlated with the generation of ROS: ∙OH and H2O2, which achieved 1549.08 and 95.48 μg/g, respectively, after 6 h irradiation. Furthermore, the chitosan coatings with UV irradiation also reduced the pH value, total volatile basic nitrogen (TVB-N), ΔE, and total viable counts (TVC) and improved sensory attributes of pork. In conclusion, the UV irradiated chitosan coatings could be used as an environmentally friendly antimicrobial packaging material to effectively delay the spoilage of pork, maintain its sensory quality and prolong its shelf life.
Comparison of Phenolic Profile of Balsamic Vinegars Determined Using Liquid and Gas Chromatography Coupled with Mass Spectrometry
Authors: Kašpar Michal , Bajer Tomáš , Bajerová Petra , Česla Petr
Published: February 2022

Balsamic vinegar is one of the best known and most popular types of vinegar, and it is a rich source of polyphenolic compounds. The quality of balsamic vinegar as well as the content of phenolic substances vary depending on the production method. In the present work, we have developed a method for comprehensive characterization of the content of phenolic compounds in balsamic vinegars based on the combination of gas chromatography (GC) and high-performance liquid chromatography (HPLC) coupled with mass spectrometric detection in single mode (MS) and tandem mode (MS/MS). In total, 14 samples of different types of balsamic vinegar were analyzed without difficulty in sample preparation. The separation conditions and detection parameters of HPLC-MS/MS were optimized and used for the determination of 29 phenolic compounds and 6 phenolic acids. The profile of phenolic compounds was completed by semi-quantitative analysis of volatile organic compounds using GC-MS after optimized headspace solid-phase microextraction. Gallic acid, protocatechuic acid, caffeic acid, and p-coumaric acid have been identified as the major phenolic compounds in balsamic vinegars.
The Effect of Antiretroviral Therapy on SIRT1, SIRT3 and SIRT6 Expression in HIV-Infected Patients
Authors: Jurkowska Karolina , Szymańska Beata , Knysz Brygida , Piwowar Agnieszka
Published: February 2022

Human Immunodeficiency Virus (HIV) infection and the chronic use of combined antiretroviral therapy (cART) may affect the occurrence of certain disturbances in the body. There is growing interest in sirtuins–enzymes involved in the regulation of many metabolic processes in the organism and in the pathogenesis of many diseases which also exhibit potential antiviral activity. The aim of the study was to investigate the connection of cART to the expression of Sirtuin 1 (SIRT1), Sirtuin 3 (SIRT3) and Sirtuin 6 (SIRT6) in HIV-infected men. The plasma levels of sirtuins were measured before and one year after cART, and related to HIV viral load, lymphocytes T CD4+ and CD8+ count as well as the applied cART. The levels of sirtuins in plasma were measured in HIV-infected patients (n = 53) and the control group (n = 35) by immunoassay methods. There were statistically significant (p < 0.05) differences between SIRT6 in the HIV-infected patients before therapy and in the subgroups, depending on the count of lymphocytes T CD8+. There were significant differences in the levels of SIRT1 depending on the applied treatment regimen. The obtained results indicate the most significant changes in the expression of SIRT6 in the course of HIV infection and suggest an influence of the type of cART on the level of SIRT1, which indicates its important role in the course of HIV.