bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of the Novel Cardiac Biomarkers sST2, GDF-15, suPAR, and H-FABP in HFpEF Patients Compared to ICM, DCM, and Controls
Authors: Jirak Peter , Pistulli Rudin , Lichtenauer Michael , Wernly Bernhard , Paar Vera , Motloch Lukas J. , Rezar Richard , Jung Christian , Hoppe Uta C. , Schulze P. Christian , Kretzschmar Daniel , Braun-Dullaeus Rüdiger C. , Bekfani Tarek
Published: April 2020

Background: Heart failure with preserved ejection fraction (HFpEF) remains an ongoing therapeutic and diagnostic challenge to date. In this study we aimed for an analysis of the diagnostic potential of four novel cardiovascular biomarkers, GDF-15, H-FABP, sST2, and suPAR in HFpEF patients compared to controls as well as ICM, and DCM. Methods: In total, we included 252 stable outpatients and controls (77 DCM, 62 ICM, 18 HFpEF, and 95 controls) in the present study. All patients were in a non-decompensated state and on a stable treatment regimen. Serum samples were obtained and analyzed for GDF-15 (inflammation, remodeling), H-FABP (ischemia and subclinical ischemia), sST2 (inflammation, remodeling) and suPAR (inflammation, remodeling) by means of ELISA. Results: A significant elevation of GDF-15 was found for all heart failure entities compared to controls (p < 0.005). Similarly, H-FABP evidenced a significant elevation in all heart failure entities compared to the control group (p < 0.0001). Levels of sST2 were significantly elevated in ICM and DCM patients compared to the control group and HFpEF patients (p < 0.0001). Regarding suPAR, a significant elevation in ICM and DCM patients compared to the control group (p < 0.0001) and HFpEF patients (p < 0.01) was observed. An AUC analysis identified H-FABP (0.792, 95% CI 0.713–0.870) and GDF-15 (0.787, 95% CI 0.696–0.878) as paramount diagnostic biomarkers for HFpEF patients. Conclusion: Based on their differences in secretion patterns, novel cardiovascular biomarkers might represent a promising diagnostic tool for HFpEF in the future.
Velocity Vector Imaging Assessment of Functional Change in the Right Ventricle during Transcatheter Closure of Atrial Septal Defect by Intracardiac Echocardiography
Authors: Jung Se Yong , Shin Jae Il , Choi Jae Young , Park Su-Jin , Kim Nam Kyun
Published: April 2020

The functional change of the right ventricle (RV) after atrial septal defect (ASD) via transcatheter closure is well known. We assessed the immediate RV functional change using velocity vector imaging (VVI) with intracardiac echocardiography (ICE). Seventy-four patients who underwent transcatheter closure of an ASD were enrolled. VVI in the “home view” of ICE showing the RV was obtained before and after the procedure. Velocity, strain, strain rate (SR), and longitudinal displacement were analyzed from VVI data, and the changes of these parameters before and after the procedure were compared. The velocity of the RV decreased after ASD transcatheter closure (3.97 ± 1.48 to 3.56 ± 1.4, p = 0.024), especially in the RV inlet and outlet. The average strain decreased (−19.21 ± 5.79 to −16.87 ± 5.03, p = 0.002), as did the average SR (−2.28 ± 0.64 to −2.03 ± 0.61, p = 0.006). The average longitudinal displacement did not differ. With the VVI technique, we could clearly observe RV functional change immediately after transcatheter closure of the ASD. RV functional change with regional difference may reflect the heterogeneity of volume reduction and suggest subclinical RV dysfunction. These findings can enhance our understanding of the physiologic changes in the RV during reverse remodeling.
The Anatomy of the Tibial Nutrient Artery Canal—An Investigation of 106 Patients Using Multi-Detector Computed Tomography
Authors: Almansour Haidara , Armoutsis Eleftherios , Reumann Marie K. , Nikolaou Konstantin , Springer Fabian
Published: April 2020

Radiologic evaluation of the tibial nutrient artery is clinically important as disruption of tibial blood supply is a risk factor for delayed or non-union of tibial fractures. Damage to the tibial nutrient artery canal (TNAC) may occur by a traversing fracture or iatrogenic cause in the context of pin/screw placement. Furthermore, TNAC could be misdiagnosed as a stress fracture. The aim of this study was to characterize the normal anatomy of TNAC and to delineate its gender and side-specific differences. Patients who underwent contrast-enhanced computed-tomography encompassing the pelvis and lower extremities were included. TNAC was identified with an external and internal foramen and a traversing intercortical canal. Various anatomical morphometrics were evaluated: total number of nutrient canals, angular position of the outer and inner nutrient foramina, absolute and relative position of the nutrient foramina, as well as the intercortical canal length with respect to tibial length. The majority of patients of both genders had only one tibial nutrient canal, multiple canals or complete absence were rare. In most cases, the outer nutrient foramen was found on the posterolateral aspect of the upper-third of tibia at about 32% of tibial length; the inner foramen was found at the middle third of the tibia (41% of tibial length). The course of nutrient canal was mostly cranio-caudal with a small, but significant difference in relative canal length: 8.5% vs. 10% of tibial length for females and males, respectively. The angular location of the outer and inner foramen was between 20–30° and did not reveal a statistically significant difference between genders. No statistically significant side specific differences were found for all analyzed parameters and both genders. The clinical relevance of this anatomical study pertains to establishing “safe corridors” of pin/screw insertion in the context of surgical management of tibial fractures in order to avoid iatrogenic disruption of tibial blood supply.
Global Spread of Coronavirus Disease 2019 and Malaria: An Epidemiological Paradox in the Early Stage of A Pandemic
Authors: Napoli Pietro Emanuele , Nioi Matteo
Published: April 2020

In the current work, we discovered and analyzed the epidemiological paradox between coronavirus disease 2019 (COVID-19) and malaria in the initial phase of the ongoing pandemic. From the analysis of distribution data, the endemic presence of malaria seems to protect some populations from COVID-19 outbreak, particularly in the least developed countries. In this sense, molecular and genetic variations associated with malaria (e.g., in ACE2) might play a protective role against coronavirus infection. Moreover, the mechanism of action of some antimalarial drugs, e.g., the antiviral function, suggests their potential role in the chemoprophylaxis of coronavirus epidemics, despite possible adverse effects (e.g., retinal toxicity). All these data provide important insights to understand the spreading mechanisms of COVID-19, and to direct scientific research toward the study of some currently available medications.
Dynamic Behavior of the Deepwater Flexible Pipeline during Pipe Laying Process
Authors: Wang Liquan , Ju Ming , Xing Xiaodong , Yun Feihong , Wang Xiangyu
Published: April 2020

The dynamic behavior of the flexible pipeline during deepwater Flex-lay directly determines the structures of laying facilities and the actual installation process. A coupled dynamic model considering the effects of different factors was established in this paper. Based on the model, the initial attitude of the flexible pipeline during the laying process was determined by using the natural catenary theory and Morison equation. The hydrodynamic analysis of the HYSY201 pipelaying vessel was carried out by using the finite element software AQWA. Under the specific sea condition, a flexible pipeline with outer-diameter of 352.42 mm being laid onto the 3000 m deep seabed was simulated by using the software OrcaFlex to study the pipeline dynamic behaviors including axial tension, bending moment and stress-strain in the laying process, and the factors affecting the dynamic behavior of the pipeline were analyzed. The results show a significant correlation between the marine loads, vessel motion and the dynamic response of the pipeline. Compared with the static state case, the maximum axial tension, bending moment and stress-strain of the pipeline under the interaction of the marine loads and the vessel motion increased by 42.7%, 220%, 52% and 18.7%, separately. Among the marine loads, the surface wave had the most significant effect on the dynamic performance of the pipeline. When the wave direction acts on the width of the ship, the wave height is greater than 2 m and the spectrum period is eight seconds, the wave has the greatest influence on the dynamic response of the pipeline.
Experimental and Estimation Studies of Resilient Modulus of Marine Coral Sand under Cyclic Loading
Authors: He Shao-Heng , Zhang Qiong-Fang , Ding Zhi , Xia Tang-Dai , Gan Xiao-Lu
Published: April 2020

Coral sand is an important filler resource that can solve the shortage of terrestrial fillers in coastal areas. Recently, the foundations of many infrastructures in the South China Sea have been built with coral sand as fillers, which have been subjected to wave and traffic cyclic loads. Resilient modulus (Mr) is an important design parameter in marine engineering, but there are few studies on the resilient modulus response of coral sand under cyclic loading. A series of drained cyclic triaxial tests were carried out to investigate the effects of the initial mean effective stress (p0) and cyclic stress ratio (ζ) on the resilient modulus response of the coral sand from the South China Sea. The change of fractal dimension (αc) can reflect the rule of particle breakage evolution. The αc of coral sand shows a tendency of almost maintaining stable and then increasing rapidly with the increase of mean effective stress p0 under each cyclic stress ratio ζ. There is a threshold of p0, when the p0 exceeds this threshold, αc will increase significantly with the increase of p0. The increase of p0 has a beneficial effect on the improvement of the Mr, while the increase of ζ has both beneficial and detrimental effects on the improvement of the Mr. A new prediction model of the Mr considering particle breakage was established, which can better predict the Mr of coral sand in the whole stress interval. The research results can provide guidance for the design of marine transportation infrastructures, which can promote the development of marine transportation industry and energy utilization.
The Costs and Benefits of Bank Capital—A Review of the Literature
Authors: Birn Martin , de Bandt Olivier , Firestone Simon , Gutiérrez Girault Matías , Hancock Diana , Krogh Tord , Mio Hitoshi , Morgan Donald , Palvia Ajay , Scalone Valerio , Straughan Michael , Uluc Arzu , von Hafften Alexander , Warusawitharana Missaka
Published: April 2020

In 2010, the Basel Committee on Banking Supervision published an assessment of the long-term economic impact (LEI) of stronger capital and liquidity requirements. This paper considers this assessment in light of estimates from later studies of the macroeconomic benefits and costs of higher capital requirements. Consistent with the Basel Committee’s original assessment, this paper finds that the net macroeconomic benefits of capital requirements are positive over a wide range of capital levels. Under certain assumptions, the literature finds that the net benefits of higher capital requirements may have been understated in the original committee assessment. Put differently, the range of estimates for the theoretically optimal level of capital requirements—where marginal benefits equal marginal costs—is likely either similar to, or higher than was originally estimated by the Basel Committee. The above conclusion is however subject to a number of important considerations. First, estimates of optimal capital are sensitive to a number of assumptions and design choices. For example, the literature differs in judgments made about the permanence of crisis effects as well as assumptions about the efficacy of post crisis reforms, such as liquidity regulations and bank resolution regimes, in reducing the probability and costs of future banking crisis. In some cases, these judgements can offset the upward tendency in the range of optimal capital. Second, differences in (net) benefit estimates can reflect different conditioning assumptions such as starting levels of capital or default thresholds (the capital ratio at which firms are assumed to fail) when estimating the impact of capital in reducing crisis probabilities. Finally, the estimates are based on capital ratios that are measured in different units. For example, some studies provide optimal capital estimates in risk-weighted ratios, others in leverage ratios. And, across the risk-weighted ratio estimates, the definition of capital and risk-weighted assets (RWAs) can also differ (e.g., tangible common equity (TCE) or Tier 1 or common equity tier 1 (CET1) capital; Basel II RWAs vs. Basel III measures of RWAs). A full standardisation of the different estimates across studies to allow for all of these considerations is not possible on the basis of the information available and lies beyond the scope of this paper. This paper also suggests a set of issues which warrant further monitoring and research. This includes the link between capital and the cost and probability of crises, accounting for the effects of liquidity regulations, resolution regimes and counter-cyclical capital buffers, and the impact of regulation on loan quantities.
Towards Modeling Second Dialect Speech Learning: The Production of Bogota [s] in Ciudad Bolivar by Speakers of Three Different Varieties of Colombian Spanish
Authors: Gómez Cenaida , Tennant Jeff , Rafat Yasaman
Published: April 2020

This study investigates the second dialect production of Bogota Spanish /s/ in coda position by speakers of three different varieties of Colombian Spanish, who have been in contact in Ciudad Bolivar, a community located in Bogota, Colombia. The study has three aims. First, it will examine the role of phonetic distance in the acquisition of /s/ production. Second, it will determine the linguistic factors that constrain the realization of /s/ sound by the speakers of the three varieties studied. Third, it will look into the role of extralinguistic factors in the production of /s/. A total of 2322 tokens extracted from sociolinguistic interviews with 50 participants were acoustically analyzed in PRAAT. Statistical analyses were conducted using GoldVarb. The results showed the highest rate of [s] was produced by the speakers of the Eastern Andean variety, followed by the Western Andean, and then by the Coastal variety, suggesting that first dialect phonological processes may affect the acquisition of second dialect sounds. Consistent with previous studies that have examined /s/ variation and change, the linguistic factors position in the word, following segment, and syllable stress were also predictors of /s/ in second dialect production. The extralinguistic factors of age of arrival, age, and gender also had a significant effect on /s/ production in this study. Implications are discussed for models of second dialect speech learning.
R-Silsesquioxane-Based Network Polymers by Fluoride Catalyzed Synthesis: An Investigation of Cross-Linker Structure and Its Influence on Porosity
Authors: Hu Nai-hsuan , Furgal Joseph C.
Published: April 2020

Silsesquioxane-based networks are an important class of materials that have many applications where high thermal/oxidative stability and porosity are needed simultaneously. However, there is a great desire to be able to design these materials for specialized applications in environmental remediation and medicine. To do so requires a simple synthesis method to make materials with expanded functionalities. In this article, we explore the synthesis of R-silsesquioxane-based porous networks by fluoride catalysis containing methyl, phenyl and vinyl corners (R-Si(OEt)3) combined with four different bis-triethoxysilyl cross-linkers (ethyl, ethylene, acetylene and hexyl). Synthesized materials were then analyzed for their porosity, surface area, thermal stability and general structure. We found that when a specified cage corner (i.e., methyl) is compared across all cross-linkers in two different solvent systems (dichloromethane and acetonitrile), pore size distributions are consistent with cross-linker length, pore sizes tended to be larger and π-bond-containing cross-linkers reduced overall microporosity. Changing to larger cage corners for each of the cross-linkers tended to show decreases in overall surface area, except when both corners and cross-linkers contained π-bonds. These studies will enable further understanding of post-synthesis modifiable silsesquioxane networks.
Combined Optical-Electrical Optimization of Cd1−xZnxTe/Silicon Tandem Solar Cells
Authors: Koç Mehmet , Kartopu Giray , Yerci Selcuk
Published: April 2020

Although the fundamental limits have been established for the single junction solar cells, tandem configurations are one of the promising approaches to surpass these limits. One of the candidates for the top cell absorber is CdTe, as the CdTe photovoltaic technology has significant advantages: stability, high performance, and relatively inexpensive. In addition, it is possible to tune the CdTe bandgap by introducing, for example, Zn into the composition, forming Cd1−xZnxTe alloys, which can fulfill the Shockley–Queisser limit design criteria for tandem devices. The interdigitated back contact (IBC) silicon solar cells presented record high efficiencies recently, making them an attractive candidate for the rear cell. In this work, we present a combined optical and electrical optimization of Cd1−xZnxTe/IBC Si tandem configurations. Optical and electrical loss mechanisms are addressed, and individual layers are optimized. Alternative electron transport layers and transparent conductive electrodes are discussed for maximizing the top cell and tandem efficiency.
Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer
Authors: Rycewicz Michał , Macewicz Łukasz , Kratochvil Jiri , Stanisławska Alicja , Ficek Mateusz , Sawczak Mirosław , Stranak Vitezslav , Szkodo Marek , Bogdanowicz Robert
Published: April 2020

The physicochemical and mechanical properties of thin and freestanding heavy boron-doped diamond (BDD) nanosheets coated with a thin C:H:N:O plasma polymer were studied. First, diamond nanosheets were grown and doped with boron on a Ta substrate using the microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Next, the BDD/Ta samples were covered with nylon 6.6 to improve their stability in harsh environments and flexibility during elastic deformations. Plasma polymer films with a thickness of the 500–1000 nm were obtained by magnetron sputtering of a bulk target of nylon 6.6. Hydrophilic nitrogen-rich C:H:N:O was prepared by the sputtering of nylon 6.6. C:H:N:O as a film with high surface energy improves adhesion in ambient conditions. The nylon–diamond interface was perfectly formed, and hence, the adhesion behavior could be attributed to the dissipation of viscoelastic energy originating from irreversible energy loss in soft polymer structure. Diamond surface heterogeneities have been shown to pin the contact edge, indicating that the retraction process causes instantaneous fluctuations on the surface in specified microscale regions. The observed Raman bands at 390, 275, and 220 cm−1 were weak; therefore, the obtained films exhibited a low level of nylon 6 polymerization and short-distance arrangement, indicating crystal symmetry and interchain interactions. The mechanical properties of the nylon-on-diamond were determined by a nanoindentation test in multiload mode. Increasing the maximum load during the nanoindentation test resulted in a decreased hardness of the fabricated structure. The integration of freestanding diamond nanosheets will make it possible to design flexible chemical multielectrode sensors.
A Review on Reconfigurable Liquid Dielectric Antennas
Authors: Motovilova Elizaveta , Huang Shao Ying
Published: April 2020

The advancements in wireless communication impose a growing range of demands on the antennas performance, requiring multiple functionalities to be present in a single device. To satisfy these different application needs within a limited space, reconfigurable antennas are often used which are able to switch between a number of states, providing multiple functions using a single antenna. Electronic switching components, such as PIN diodes, radio-frequency micromechanical systems (RF-MEMS), and varactors, are typically used to achieve antenna reconfiguration. However, some of these approaches have certain limitations, such as narrow bandwidth, complex biasing circuitry, and high activation voltages. In recent years, an alternative approach using liquid dielectric materials for antenna reconfiguration has drawn significant attention. The intrinsic conformability of liquid dielectric materials allows us to realize antennas with desired reconfigurations with different physical constraints while maintaining high radiation efficiency. The purpose of this review is to summarize different approaches proposed in the literature for the liquid dielectric reconfigurable antennas. It facilitates the understanding of the advantages and limitations of this technology, and it helps to draw general design principals for the development of reconfigurable antennas in this category.
Tribocorrosion Properties of NiCrAlY Coating in Different Corrosive Environments
Authors: Li Bo , Gao Yimin , Li Cong , Guo Hongjian , Zheng Qiaoling , Li Yefei , Kang Yunchuan , Zhao Siyong
Published: April 2020

Atmospheric plasma spraying (APS) was taken to fabricate the NiCrAlY coating. The corrosion-wear properties of NiCrAlY coating was measured respectively under deionized water, artificial seawater, NaOH solution and HCl solution. Experimental results presented that the as-sprayed NiCrAlY coating consisted of Ni3Al, nickel-based solid solution, NiAl and Y2O3. In deionized water, the coating with the lowest corrosion current density (icorr) of 7.865 × 10−8 A/cm2 was hard to erode. Meanwhile, it presented a lower friction coefficient and the lowest wear rate. In HCl solution, NiCrAlY coating gave the highest corrosion current density (icorr) of 3.356 × 10−6 A/cm2 and a higher wear rate of 6.36 × 10−6 mm3/Nm. Meanwhile, the emergence of Al(OH)3 on the coating surface could reduce the direct contact between the counter ball and sample effectively, which was conducive to the lowest friction coefficient of 0.24.
Seismic Performance of Bridge Piers Constructed with PP-ECC at Potential Plastic Hinge Regions
Authors: Jia Yi , Zhao Renda , Li Fuhai , Zhou Zhidong , Wang Yongbao , Zhan Yulin , Shi Xianming
Published: April 2020

This work presents an experimental investigation on the seismic performance of bridge piers constructed with polypropylene fiber reinforced engineered cementitious composite (PP-ECC) at potential plastic hinge regions. Eight solid square bridge piers are tested under a combination of reversed cyclic lateral loading and constant axial vertical loading. The test variables include the reinforcement stirrup ratio (0 vol.%, 0.46 vol.%, and 0.79 vol.%), axial compression ratio (0.1 and 0.3) and height of the PP-ECC regions (0, 250, and 500 mm). Seismic performance of eight specimens is presented and interpreted, including the failure mode, hysteretic curves, loading–resistance capacity, ductility, stiffness degradation, energy dissipation, and equivalent viscous damping ratio. The material test on the PP-ECC plate specimen suggests that the PP-ECC has obvious strain-hardening behavior and multiple fine-cracking characteristics, with the tensile strength and strain capacity greater than 3.2 MPa and 2.6%, respectively. The PP-ECC material applied at the potential plastic hinge regions notably improves the seismic performance and damage tolerance of bridge piers. The influence of the aforementioned crucial parameters has also been investigated in detail. The axial compression ratio and the height of PP-ECC region have a major influence on the seismic performance of PP-ECC piers. In comparison, the stirrup ratio has a limited effect on the seismic behavior of PP-ECC piers. The experimental findings shed light on the mechanism of the PP-ECC that contributes to the seismic performance of bridge piers and provide some valuable guidance in the seismic design of PP-ECC piers.
The Effect of Laser Power on the Properties of M3B2-Type Boride-Based Cermet Coatings Prepared by Laser Cladding Synthesis
Authors: Hu Zhaowei , Li Wenge , Zhao Yuantao
Published: April 2020

Boride-based cermet can serve as a good protective coating for low-corrosion and wear-resistant materials, such as carbon steels, due to their mechanical and chemical properties. In this study, M3B2 (M: Mo, Ni, Fe, and Cr) boride-based cermet coatings were fabricated on Q235 steel with mixed powders of Mo, B, Ni60, and Cr by laser cladding synthesis, and the effects of laser power on the properties of the cermet layer were investigated. Three laser powers (2200, 2500, and 2800 W) were used at the same scanning speed. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis confirmed that all the coatings were composed of M3B2-type borides and {Fe, Ni} alloys. The micro-hardness, corrosion, and frictional experiments showed that the cermet coatings enhanced the corresponding performances of the Q235 steels at the three laser powers. However, the micro-hardness of the coatings decreased as the power increased, and the maximum micro-hardness value was 1166.3 HV (Vickers Hardness). The results of the corrosion and frictional experiments showed that the best performance was obtained at a laser power of 2500 W, followed by 2800 and 2200 W.
Experimental Study on Mechanical Properties of the Sandwich Composite Structure Reinforced by Basalt Fiber and Nomex Honeycomb
Authors: Li Zongwen , Ma Jianxun
Published: April 2020

The new sandwich composite structure formed by basalt fiber resin-based sheets and Nomex honeycomb has the advantages of being lightweight and environmentally friendly, as well as having excellent electromagnetic performance. It has very important application prospects in traditional and emerging fields. In this paper, the mechanical properties of this new sandwich composite structure are studied. The results show that, under the condition of flatwise compression, increasing the height of the honeycomb is conducive to improving the compressive capacity of the structure. However, the height should be controlled within a certain range in case of instability and yield of the honeycomb; under the bending conditions, the bending failure mode of the composite structure has gone through five stages. Owing to the honeycomb manufacturing process, the orientation of the honeycomb also has a great influence on the bending strength of the structure. After further analysis, it is found that basalt fiber sheets contribute the most to the bending stiffness of the structure, and the main role of honeycomb is to provide out-of-plane support. In both cases, the failure of specimens is ductile, and the combined structure still has a small amount of bearing capacity and maintains structural integrity. Research on this new type of composite structural material is very beneficial for promoting the application and development of green and lightweight special functional materials.
Preparation of Cu3N/MoS2 Heterojunction through Magnetron Sputtering and Investigation of Its Structure and Optical Performance
Authors: Zhu Liwen , Cao Xiu , Gong Chenyang , Jiang Aihua , Cheng Yong , Xiao Jianrong
Published: April 2020

Cu3N/MoS2 heterojunction was prepared through magnetron sputtering, and its optical band gap was investigated. Results showed that the prepared Cu3N/MoS2 heterojunction had a clear surface heterojunction structure, uniform surface grains, and no evident cracks. The optical band gap (1.98 eV) of Cu3N/MoS2 heterojunction was obtained by analyzing the ultraviolet-visible transmission spectrum. The valence and conduction band offsets of Cu3N/MoS2 heterojunction were 1.42 and 0.82 eV, respectively. The Cu3N film and multilayer MoS2 formed a type-II heterojunction. After the two materials adhered to form the heterojunction, the interface electrons flowed from MoS2 to Cu3N because the latter had higher Fermi level than the former. This behavior caused the formation of additional electrons in the Cu3N and MoS2 layers and the change in optical band gap, which was conducive to the charge separation of electrons in MoS2 or MoS2 holes. The prepared Cu3N/MoS2 heterojunction has potential application in various high-performance photoelectric devices, such as photocatalysts and photodetectors.
Dynamic Model of Polished Stone Value Attenuation in Coarse Aggregate
Authors: Liu Jingyi , Guan Bowen , Chen Huaxin , Liu Kaiping , Xiong Rui , Xie Chao
Published: April 2020

The polished stone value (PSV) of coarse aggregate is closely related to pavement skid resistance and traffic safety. However, the determination of the PSV of coarse aggregate is conventionally a time- and energy-intensive process. To facilitate the test process of PSV in materials selection and pavement design and for the prediction of the service life of aggregate materials in practical service, here a new mathematical model of PSV attenuation in coarse aggregate, which employs a physical polishing process analysis, is proposed. The PSVs of four types of coarse aggregates (calcined bauxite, granite, basalt, and limestone) were analyzed through a polishing experiment, and the corresponding mechanism was investigated via scanning electron microscopy analysis. The modeling results are in good agreement with experimental results. The aggregate PSV is affected by both the macrotexture and microtexture of the aggregate surface. The PSV due to the macrotexture exhibits a strong negative correlation with the Vickers hardness of the aggregates and decreases exponentially as the polishing time increases. The attenuation rate decreases as the fractal box dimension in the aggregate surface morphology increases. The primary factor influencing the macrotexture service life and the half-life is the aggregate surface morphology. The PSV due to the microtexture exhibits a strong positive correlation with the Vickers hardness of the aggregates, whereas there is a poor correlation with the aggregate surface morphology and polishing time. The proportion of the aggregate PSV due to the microtexture increases as the aggregate hardness increases. These results highlight the effectiveness of a new modeling approach that may potentially assist in predicting the anti-slip performance and durability of coarse aggregates.
The Temperature Mode of the Carbon-Carbon Multi-Disc Brake in the View of the Interrelations of Its Operating Characteristics
Authors: Yevtushenko Aleksander A. , Grzes Piotr , Adamowicz Adam
Published: April 2020

In this paper, a methodology for conducting a computer simulation of the frictional heating process of a multi-disc braking system is proposed. The single braking of a system of three identical discs made of carbon–carbon (C/C) carbon frictional composite material (CFCM) is considered. In order to determine the operational characteristics of the brake, a heat dynamics of friction (HDF) system of equations is formulated, which takes into account the contact pressure rise time, thermal sensitivity of the C/C material, the change in the coefficient of friction during braking, the parameters of the friction surface’s microgeometry and the mutual influence of sliding velocity and temperature. A numerical solution using the finite element method (FEM) of the HDF system of equations allows us to determine changes in key braking process characteristics, such as work done, braking torque, friction coefficient, heat transfer coefficient, velocity and temperature. Finally, a comparative analysis of the results obtained for three different time profiles of the coefficient of friction is carried out.
Secure Total Domination in Rooted Product Graphs
Authors: Cabrera Martínez Abel , Estrada-Moreno Alejandro , Rodríguez-Velázquez Juan A.
Published: April 2020

In this article, we obtain general bounds and closed formulas for the secure total domination number of rooted product graphs. The results are expressed in terms of parameters of the factor graphs involved in the rooted product.
Longitudinal Analysis of Cardiovascular Risk Factors in Active and Sedentary Kidney Transplant Recipients
Authors: Totti Valentina , Fernhall Bo , Di Michele Rocco , Todeschini Paola , La Manna Gaetano , Cappuccilli Maria , Angelini Maria Laura , De Fabritiis Marco , Merni Franco , Benedetti Enrico , Roi Giulio Sergio , Nanni Costa Alessandro , Mosconi Giovanni
Published: April 2020

Background: Despite the benefits of physical activity on cardiovascular risk in kidney transplant recipients (KTRs), the long-term effects of exercise have been poorly investigated. This is a three-year observational study comparing graft function and cardiovascular risk factors in active KTRs (AKTRs) vs. sedentary KTRs (SKTRs). Methods: KTRs with stable renal function were assigned to active or sedentary group in relation to the level of daily physical activity based on World Health Organization (WHO) recommendations (<150 or >150 minutes/week, respectively). Complete blood count, renal function indices, lipid profile, blood pressure and anthropometric measures were collected yearly for an observation period of three years. The comparisons between the two groups were performed by repeated measures analyses of covariance (ANCOVAs), with age as a covariate. Results: Fifty-four subjects were included in the study. Thirty of them were identified as AKTRs (M/F 26/4, aged 45 ± 12 years) and 24 as SKTRs (M/F 18/6, aged 51 ± 14 years). Baseline characteristics were similar between the groups except body mass index (BMI) that was significantly higher in SKTRs (p = 0.043). Furthermore, over the three-year observation period, BMI decreased in AKTRs and increased in SKTRs (p = 0.006). Graft function was stable in AKTRs, while it showed a decline over time in SKTRs, as indicated by the rise in serum creatinine levels (p = 0.006) and lower eGFR (p = 0.050). Proteinuria, glucose and uric acid levels displayed a decrease in AKTRs and an increase in SKTRs during the three-year period (p = 0.015, p = 0.004 and p = 0.013, respectively). Finally, concerning lipid profiles, AKTRs had a significant reduction over time of triglycerides levels, which conversely showed a clinically relevant increase in SKTRs (p = 0.014). Conclusions: Our findings indicate that regular weekly exercise training may counteract the increased cardiovascular risks and also prevent graft function decline in KTRs.
Effect of an Eleven-Day Altitude Training Program on Aerobic and Anaerobic Performance in Adolescent Runners
Authors: Bahenský Petr , Bunc Václav , Tlustý Pavel , Grosicki Gregory J.
Published: April 2020

Background and Objectives: We evaluated the effect of an eleven-day altitude training camp on aerobic and anaerobic fitness in trained adolescent runners. Materials and Methods: Twenty adolescent (14–18 yrs) middle- and long-distance runners (11 males and 9 females; 16.7 ± 0.8 yrs), with at least two years of self-reported consistent run training, participated in this study. Eight of the subjects (4 females/4 males) constituted the control group, whereas twelve subjects (5 females/7 males) took part in a structured eleven-day altitude training camp, and training load was matched between groups. Primary variables of interest included changes in aerobic (VO2max) and anaerobic (30 s Wingate test) power. We also explored the relationships between running velocity and blood lactate levels before and after the altitude training camp. Results: Following 11 days of altitude training, desirable changes (p < 0.01) in VO2max (+13.6%), peak relative work rate (+9.6%), and running velocity at various blood lactate concentrations (+5.9%–9.6%) were observed. Meanwhile, changes in Wingate anaerobic power (+5.1%) were statistically insignificant (p > 0.05). Conclusions: Short duration altitude appears to yield meaningful improvements in aerobic but not anaerobic power in trained adolescent endurance runners.
Modeling and Simulation of the Simultaneous Absorption/Stripping of CO2 with Potassium Glycinate Solution in Membrane Contactor
Authors: Ghasem Nayef
Published: April 2020

Global warming is an environmental problem caused mainly by one of the most serious greenhouse gas, CO2 emissions. Subsequently, the capture of CO2 from flue gas and natural gas is essential. Aqueous potassium glycinate (PG) is a promising novelty solvent used in the CO2 capture compared to traditional solvents; simultaneous solvent regeneration is associated with the absorption step. In present work, a 2D mathematical model where radial and axial diffusion are considered is developed for the simultaneous absorption/stripping process. The model describes the CO2/PG absorption/stripping process in a solvent–gas membrane absorption process. Regeneration data of rich potassium glycinate solvent using a varied range of acid gas loading (mol CO2 per mol PG) were used to predict the reversible reaction rate constant. A comparison of simulation results and experimental data validated the accuracy of the model predictions. The stripping reaction rate constant of rich potassium glycinate was determined experimentally and found to be a function of temperature and PG concentration. Model predictions were in good agreement with the experimental data. The results reveal that the percent removal of CO2 is directly proportional to CO2 loading and solvent stripping temperature.
MHz-Order Surface Acoustic Wave Thruster for Underwater Silent Propulsion
Authors: Zhang Naiqing , Wen Yue , Friend James
Published: April 2020

High frequency (MHz-order) surface acoustic waves (SAW) are able to generate intense fluid flow from the attenuation of acoustic radiation in viscous fluids as acoustic streaming. Though such flows are known to produce a force upon the fluid and an equivalent and opposing force upon the object producing the acoustic radiation, there is no convenient method for measuring this force. We describe a new method to accomplish this aim, noting the potential of these devices in providing essentially silent underwater propulsion by virtue of their use of the sound itself to generate fluid momentum flux. Our example employs a 40 MHz SAW device as a pendulum bob while immersed in a fluid, measuring a 1.5 mN propulsion force from an input power of 5 W power to the SAW device. Supporting details regarding the acoustic streaming profile via particle image velocimetry and an associated theoretical model are provided to aid in the determination of the propulsion force knowing the applied power and fluid characteristics. Finally, a simple model is provided to aid the selection of the acoustic device size to maximize the propulsion force per unit device area, a key figure of merit in underwater propulsion devices. Using this model, a maximum force of approximately 10 mN/cm 2 was obtained from 1 W input power using 40 MHz SAW in water and producing a power efficiency of approximately 50%. Given the advantages of this technology in silent propulsion with such large efficiency and propulsion force per unit volume, it seems likely this method will be beneficial in propelling small autonomous submersibles.
Optoelectronic Properties of Monolayer Hexagonal Boron Nitride on Different Substrates Measured by Terahertz Time-Domain Spectroscopy
Authors: Bilal Muhammad , Xu Wen , Wang Chao , Wen Hua , Zhao Xinnian , Song Dan , Ding Lan
Published: April 2020

Monolayer (ML) hexagonal boron nitride (hBN) is an important material in making, e.g., deep ultraviolet optoelectronic and power devices and van der Waals heterojunctions in combination with other two-dimensional (2D) electronic systems such as graphene and ML MoS 2 . In this work, we present a comparative study of the basic optoelectronic properties of low resistance ML hBN placed on different substrates such as SiO 2 /Si, quartz, PET, and sapphire. The measurement is carried out by using terahertz (THz) time-domain spectroscopy (TDS) in a temperature regime from 80 to 280 K. We find that the real and imaginary parts of the optical conductivity obtained experimentally for low resistance ML hBN on different substrates can fit well to the Drude–Smith formula. Thus, we are able to determine optically the key sample and material parameters (e.g., the electronic relaxation time or mobility, the carrier density, the electronic localization factor, etc.) of ML hBN. The effect of temperature on these parameters is also examined and analyzed. The results obtained from this study enable us to suggest the appropriate substrate for ML hBN based electronic and optoelectronic devices. This work is relevant to the application to a newly developed 2D electronic system as advanced electronic and optoelectronic materials.
Long-Term Effects of Vitamin D Supplementation in Obese Children During Integrated Weight–Loss Programme—A Double Blind Randomized Placebo–Controlled Trial
Authors: Brzeziński Michał , Jankowska Agnieszka , Słomińska-Frączek Magdalena , Metelska Paulina , Wiśniewski Piotr , Socha Piotr , Szlagatys-Sidorkiewicz Agnieszka
Published: April 2020

Background: Vitamin D was studied in regards to its possible impact on body mass reduction and metabolic changes in adults and children with obesity yet there were no studies assessing the impact of vitamin D supplementation during a weight management program in children and adolescence. The aim of our study was to assess the influence of 26 weeks of vitamin D supplementation in overweight and obese children undergoing an integrated 12–months’ long weight loss program on body mass reduction, body composition and bone mineral density. Methods: A double–blind randomized placebo–controlled trial. Vitamin D deficient patients (<30 ng/ml level of vitamin D) aged 6–14, participating in multidisciplinary weight management program were randomly allocated to receiving vitamin D (1200 IU) or placebo for the first 26 weeks of the intervention. Results: Out of the 152 qualified patients, 109 (72%) completed a full cycle of four visits scheduled in the program. There were no difference in the level of BMI (body mass index) change – both raw BMI and BMI centiles. Although the reduction of BMI centiles was greater in the vitamin D vs. placebo group (−4.28 ± 8.43 vs. −2.53 ± 6.10) the difference was not statistically significant (p = 0.319). Similarly the reduction in fat mass—assessed both using bioimpedance and DEXa was achieved, yet the differences between the groups were not statistically significant. Conclusions: Our study ads substantial results to support the thesis on no effect of vitamin D supplementation on body weight reduction in children and adolescents with vitamin D insufficiency undergoing a weight management program.
Dietary Intake of Free Sugars is Associated with Disease Activity and Dyslipidemia in Systemic Lupus Erythematosus Patients
Authors: Correa-Rodríguez María , Pocovi-Gerardino Gabriela , Callejas-Rubio José-Luis , Ríos Fernández Raquel , Martín-Amada María , Cruz-Caparros María-Gracia , Medina-Martínez Irene , Ortego-Centeno Norberto , Rueda-Medina Blanca
Published: April 2020

Diet has been closely associated with inflammatory autoimmune diseases, including systemic lupus erythematosus (SLE). Importantly, the consumption of dietary sugars has been positively linked to elevated levels of some inflammation markers, but the potential role of their consumption on the prognosis of autoimmune diseases has not yet been examined. The aim of this study was to evaluate the association between the dietary intake of free sugars and clinical parameters and cardiovascular (CVD) risk markers in patients with SLE. A cross-sectional study including a total of 193 patients with SLE (aged 48.25 ± 12.54 years) was conducted. The SLE Disease Activity Index (SLEDAI-2K) and the SDI Damage Index were used to asses disease activity and disease-related damage, respectively. Levels of C-reactive protein (CRP; mg/dL), homocysteine (Hcy; µmol/L), anti-double stranded DNA antibodies (anti-dsDNA) (IU/mL), complement C3 (mg/dL), and complement C4 (mg/dL), among other biochemical markers, were measured. The main factors we considered as risk factors for CVD were obesity, diabetes mellitus, hypertension, and blood lipids. The dietary-intrinsic sugar and added-sugar content participants consumed were obtained via a 24-h patient diary. Significant differences were observed in dietary sugar intake between patients with active and inactive SLE (in grams: 28.31 ± 24.43 vs. 38.71 ± 28.87; p = 0.035) and free sugar intake (as a percentage: 6.36 ± 4.82 vs. 8.60 ± 5.51; p = 0.020). Linear regression analysis revealed a significant association between free sugars intake (by gram or percentage) and the number of complications (β (95% CI) = 0.009 (0.001, 0.0018), p = 0.033)); (β (95% CI) = 0.046 (0.008, 0.084), p = 0.018)), and SLEDAI (β (95% CI) = 0.017 (0.001, 0.034), p = 0.043)); (β (95% CI) = 0.086 (0.011, 0.161), p = 0.024)) after adjusting for covariates. Free sugars (g and %) were also associated with the presence of dyslipidaemia (β (95% CI) = −0.003 (−0.005, 0.000), p = 0.024)) and (β (95% CI) = −0.015 (−0.028, −0.002), p = 0.021)). Our findings suggest that a higher consumption of free sugars might negatively impact the activity and complications of SLE. However, future longitudinal research on SLE patients, including dietary intervention trials, are necessary to corroborate these preliminary data.
Ubiquinol Ameliorates Endothelial Dysfunction in Subjects with Mild-to-Moderate Dyslipidemia: A Randomized Clinical Trial
Authors: Sabbatinelli Jacopo , Orlando Patrick , Galeazzi Roberta , Silvestri Sonia , Cirilli Ilenia , Marcheggiani Fabio , Dludla Phiwayinkosi V. , Giuliani Angelica , Bonfigli Anna Rita , Mazzanti Laura , Olivieri Fabiola , Antonicelli Roberto , Tiano Luca
Published: April 2020

In this randomized, double-blind, single-center trial (ANZCTR number ACTRN12619000436178) we aimed to investigate changes in endothelium-dependent vasodilation induced by ubiquinol, the reduced form of coenzyme Q10 (CoQ10), in healthy subjects with moderate dyslipidemia. Fifty-one subjects with low-density lipoprotein (LDL) cholesterol levels of 130–200 mg/dL, not taking statins or other lipid lowering treatments, moderate (2.5%–6.0%) endothelial dysfunction as measured by flow-mediated dilation (FMD) of the brachial artery, and no clinical signs of cardiovascular disease were randomized to receive either ubiquinol (200 or 100 mg/day) or placebo for 8 weeks. The primary outcome measure was the effect of ubiquinol supplementation on FMD at the end of the study. Secondary outcomes included changes in FMD on week 4, changes in total and oxidized plasma CoQ10 on week 4 and week 8, and changes in serum nitrate and nitrite levels (NOx), and plasma LDL susceptibility to oxidation in vitro on week 8. Analysis of the data of the 48 participants who completed the study demonstrated a significantly increased FMD in both treated groups compared with the placebo group (200 mg/day, +1.28% ± 0.90%; 100 mg/day, +1.34% ± 1.44%; p < 0.001) and a marked increase in plasma CoQ10, either total (p < 0.001) and reduced (p < 0.001). Serum NOx increased significantly and dose-dependently in all treated subjects (p = 0.016), while LDL oxidation lag time improved significantly in those receiving 200 mg/day (p = 0.017). Ubiquinol significantly ameliorated dyslipidemia-related endothelial dysfunction. This effect was strongly related to increased nitric oxide bioavailability and was partly mediated by enhanced LDL antioxidant protection.