bluuebunny/crossref_metadata_2025 huggingface dataset:
Greenhouse Gas Emission Transfer of Inter-Provincial Electricity Trade in China
Authors: Li Wenbo , Long Ruyin , Zhang Linling , He Zhengxia , Chen Feiyu , Chen Hong
Published: November 2020

Inter-regional electricity trade is an important way to mitigate the imbalance between regional electricity generation and consumption. With the increasing amount of inter-regional electricity trade in China, the emission transfer problem is more severe. By using Quasi-Input-Output model, which can consider the ripple effect of electricity trade network, this study analyzed embodied greenhouse gas emissions of electricity trade among 30 provinces in China. Results indicated that, in 2017, the national transfer volumes of CO2, CH4, and N2O embodied in inter-provincial electricity trade were 603.25 Mt, 6803.81 t, and 9899.25 t, respectively. Emissions are mainly transferred from the eastern to the western regions, especially to those with high proportion of electricity generated from fossil fuels. The amount of emission transfer is not consistent with that of purchased electricity, since some regions are rich in clean energy. Although direct emission transfer plays the dominant role for most province, indirect emission transfer should also be noticed. Provinces with larger indirect emission transfer generally purchase electricity from provinces with a lot of electricity inflows. The findings could help policy makers coordinate regional energy utilization strategies and issue more effective emission reduction policies in the electricity industry.
“Children Are Not Children Anymore; They Are a Lost Generation”: Adverse Physical and Mental Health Consequences on Syrian Refugee Children
Authors: Rizkalla Niveen , Mallat Nour K. , Arafa Rahma , Adi Suher , Soudi Laila , Segal Steven P.
Published: November 2020

This research examines Syrian refugee mothers’ accounts of the physical and mental health of their children being affected by war traumas and displacement challenges. Open-ended audio-recorded interviews were conducted in Arabic with 23 mothers residing in Jordan. Using a narrative approach in the data collection and analysis, five major themes were identified: (1) children were exposed to diverse war traumatic experiences in Syria; (2) the escape journey and refugee camps threatened children’s lives; (3) displacement and family stressors exposed children to poverty, hostility from local peers, educational and recreational challenges, child labor, and domestic violence (these three major themes were considered as trauma related variables); (4) children were not only directly affected physically and mentally by their own traumatic experiences and displacement stressors, but these experiences were mediated and magnified by familial interrelated processes, evidenced in intergenerational transmission of trauma, harsh parenting style, parental control, and parentification; and (5) adverse consequences of both trauma related variables and family processes directly and indirectly traumatized children and adversely impacted their physical and mental health. We examined the themes that emerged from the data in view of three theoretical frameworks and the impact of trauma in the family system on child development. To conclude, humanitarian organizations that provide services and interventions to refugees need to take into account familial processes and not only individual factors affecting refugee children’s physical and mental health. Further implications on policies and trauma research are discussed.
Rural–Urban Transition of Hanoi (Vietnam): Using Landsat Imagery to Map Its Recent Peri-Urbanization
Authors: Mauro Giovanni
Published: November 2020

The current trend towards global urbanization presents new environmental and social challenges. For this reason, it is increasingly important to monitor urban growth, mainly in those regions undergoing the fastest urbanization, such as Southeast Asia. Hanoi (Vietnam) is a rapidly growing medium-sized city: since new economic policies were introduced in 1986, this area has experienced a rapid demographic rise and radical socio-economic transformation. In this study, we aim to map not only the recent urban expansion of Hanoi, but also of its surroundings. For this reason, our study area consists of the districts within a 30km radius of the city center. To analyze the rural–urban dynamics, we identified three hypothetical rings from the center: the core (within a 10 km radius), the first ring (the area between 10 and 20 km) and, finally, the outer zone (over 20 km). To map land use/land cover (LULC) changes, we classified a miniseries of Landsat images, collected approximately every ten years (1989, 2000, 2010 and 2019). To better define the urban dynamics, we then applied the following spatial indexes: the rate of urban expansion, four landscape metrics (the number of patches, the edge length, the mean patch area and the largest patch index) and the landscape expansion index. The results show how much the city’s original shape has changed over the last thirty years: confined for hundreds of years in a limited space on the right bank of the Red River, it is now a fringed city which has developed beyond the river into the surrounding periurban areas. Moreover, the region around Hanoi is no longer solely rural: in just thirty years, urbanization has converted this territory into an industrial and commercial region.
Colony-Level Effects of Amygdalin on Honeybees and Their Microbes
Authors: Tauber James P. , Tozkar Cansu Ö. , Schwarz Ryan S. , Lopez Dawn , Irwin Rebecca E. , Adler Lynn S. , Evans Jay D.
Published: November 2020

Amygdalin, a cyanogenic glycoside, is found in the nectar and pollen of almond trees, as well as in a variety of other crops, such as cherries, nectarines, apples and others. It is inevitable that western honeybees (Apis mellifera) consistently consume amygdalin during almond pollination season because almond crops are almost exclusively pollinated by honeybees. This study tests the effects of a field-relevant concentration of amygdalin on honeybee microbes and the activities of key honeybee genes. We executed a two-month field trial providing sucrose solutions with or without amygdalin ad libitum to free-flying honeybee colonies. We collected adult worker bees at four time points and used RNA sequencing technology and our HoloBee database to assess global changes in microbes and honeybee transcripts. Our hypothesis was that amygdalin will negatively affect bee microbes and possibly immune gene regulation. Using a log2 fold-change cutoff at two and intraday comparisons, we show no large change of bacterial counts, fungal counts or key bee immune gene transcripts, due to amygdalin treatment in relation to the control. However, relatively large titer decreases in the amygdalin treatment relative to the control were found for several viruses. Chronic bee paralysis virus levels had a sharp decrease (−14.4) with titers then remaining less than the control, Black queen cell virus titers were lower at three time points (<−2) and Deformed wing virus titers were lower at two time points (<−6) in amygdalin-fed compared to sucrose-fed colonies. Titers of Lotmaria passim were lower in the treatment group at three of the four dates (<−4). In contrast, Sacbrood virus had two dates with relative increases in its titers (>2). Overall, viral titers appeared to fluctuate more so than bacteria, as observed by highly inconstant patterns between treatment and control and throughout the season. Our results suggest that amygdalin consumption may reduce several honeybee viruses without affecting other microbes or colony-level expression of immune genes.
Rearing Trissolcus japonicus and Trissolcus mitsukurii for Biological Control of Halyomorpha halys
Authors: Sabbatini-Peverieri Giuseppino , Dieckhoff Christine , Giovannini Lucrezia , Marianelli Leonardo , Roversi Pio Federico , Hoelmer Kim
Published: November 2020

Halyomorpha halys is a severe agricultural pest of Asian origin that has invaded many countries throughout the world. Pesticides are currently the favored control methods, but as a consequence of their frequent use, often disrupt Integrated Pest Management. Biological control with egg parasitoids is seen as the most promising control method over the long-term. Knowledge of the reproductive biology under laboratory conditions of the most effective candidates (Trissolcus japonicus and Trissolcus mitsukurii) for optimizing production for field releases is strongly needed. Rearing of these egg parasitoids was tested by offering three different host supply regimes using new emerged females and aged, host-deprived females in different combinations. Results showed a mean progeny per female ranging from 80 to 85 specimens for T. japonicus and from 63 to 83 for T. mitsukurii. Sex ratios were strongly female biased in all combinations and emergence rates exceeded 94% overall. Cumulative curves showed that longer parasitization periods beyond 10–14 days (under the adopted rearing regimes) will not lead to a significantly increase in progeny production. However, ageing females accumulate eggs in their ovaries that can be quickly laid if a sufficient number of host eggs are supplied, thus optimizing host resources. Our data showed that offering H. halys egg masses to host-deprived female Trissolcus once a week for three weeks allowed its eggs to accumulate in the ovary, providing the greatest number of offspring within a three week span.
Atmospheric Cold Front-Generated Waves in the Coastal Louisiana
Authors: Cao Yuhan , Li Chunyan , Dong Changming
Published: November 2020

Atmospheric cold front-generated waves play an important role in the air–sea interaction and coastal water and sediment transports. In-situ observations from two offshore stations are used to investigate variations of directional waves in the coastal Louisiana. Hourly time series of significant wave height and peak wave period are examined for data from 2004, except for the summer time between May and August, when cold fronts are infrequent and weak. The intra-seasonal scale variations in the wavefield are significantly affected by the atmospheric cold frontal events. The wave fields and directional wave spectra induced by four selected cold front passages over the coastal Louisiana are discussed. It is found that significant wave height generated by cold fronts coming from the west change more quickly than that by other passing cold fronts. The peak wave direction rotates clockwise during the cold front events. The variability of the directional wave spectrum shows that the largest spectral density is distributed at low frequency in the postfrontal phase associated with migrating cyclones (MC storms) and arctic surges (AS storms).
Two-Dimensional Modelling of a Quayside Floating System
Authors: Neuvéglise Sixtine , Perret Gaële , Smaoui Hassan , Marin François , Sergent Philippe
Published: November 2020

This paper studies the behaviour of a quayside floater oscillating in front of a vertical dike. In order to study the floater motion and the impact of the dike on the floater, a linear analytical model based on 2D potential flow theory in intermediate water depth conditions and a numerical model resolving 2D Navier–Stokes equations are developed. Physical tests performed for different floater dimensions in a wave tank are used as references for the analytical and numerical models. The comparison of the results obtained analytically, numerically and experimentally leads to the validity domain of the potential model. A correction of this model is proposed, based on the optimization of the radiated coefficients, and a quadratic drag term is added according to Morison equation. The impact of the different parameters of the system on floater behaviour is considered. Results show that the draft has the most important impact on floater motion.
The Impact of Wind on Flow and Sediment Transport over Intertidal Flats
Authors: Colosimo Irene , de Vet Paul L. M. , van Maren Dirk S. , Reniers Ad J. H. M. , Winterwerp Johan C. , van Prooijen Bram C.
Published: November 2020

Sediment transport over intertidal flats is driven by a combination of waves, tides, and wind-driven flow. In this study we aimed at identifying and quantifying the interactions between these processes. A five week long dataset consisting of flow velocities, waves, water depths, suspended sediment concentrations, and bed level changes was collected at two locations across a tidal flat in the Wadden Sea (The Netherlands). A momentum balance was evaluated, based on field data, for windy and non-windy conditions. The results show that wind speed and direction have large impacts on the net flow, and that even moderate wind can reverse the tidal flow. A simple analytical tide–wind interaction model shows that the wind-induced reversal can be predicted as a function of tidal flow amplitude and wind forcing. Asymmetries in sediment transport are not only related to the tide–wind interaction, but also to the intratidal asymmetries in sediment concentration. These asymmetries are influenced by wind-induced circulation interacting with the large scale topography. An analysis of the shear stresses induced by waves and currents revealed the relative contributions of local processes (resuspension) and large-scale processes (advection) at different tidal flat elevations.
Tensile Bending Stresses in Mortar-Grouted Riprap Revetments Due to Wave Loading
Authors: Kreyenschulte Moritz , Schüttrumpf Holger
Published: November 2020

One of the most common revetment types in Germany is the mortar-grouted riprap revetment (MGRR), which is constructed by placing riprap on a filter or separation layer and subsequent grouting with mortar. Existing technical standards and guidelines for MGRRs do not consider the interaction between dynamic wave loading and structural response. To date, scientifically sound design approaches verified by model tests are missing. Therefore, the aim of this work is to establish a process-based model for the calculation of the acting bending tensile stresses during wave attack for MGRRs to asses crack formation. To this end, MGRRs were modelled as plates on an elastic foundation (PEF). Hydraulic boundary conditions were determined with full-scale hydraulic model tests. Model parameters of the PEF model were established by investigations into the mechanical parameters of the constituents of MGRRs. The results show that tensile bending stresses are particularly dependent on the pressure difference between the top and bottom edge of the top layer, which varies significantly for MGRRs as their porosity and permeability varies significantly depending on the amount of mortar used for grouting. Enveloping functions for maximum relative tensile bending stress σx,max/(ρwgHm0) are given for four configurations of MGRRs that are of great practical relevance.
Lignin Degradation and Its Use in Signaling Development by the Coprophilous Ascomycete Podospora anserina
Authors: Dicko Moussa , Ferrari Roselyne , Tangthirasunun Narumon , Gautier Valérie , Lalanne Christophe , Lamari Farida , Silar Philippe
Published: November 2020

The filamentous fungus Podospora anserina is a good model to study the breakdown of lignocellulose, owing to its ease of culture and genetical analysis. Here, we show that the fungus is able to use a wide range of lignocellulosic materials as food sources. Using color assays, spectroscopy and pyrolysis–gas chromatography mass spectrometry, we confirm that this ascomycete is able to degrade lignin, primarily by hydrolyzing β–O-4 linkages, which facilitates its nutrient uptake. We show that the limited weight loss that is promoted when attacking Miscanthus giganteus is due to a developmental blockage rather than an inefficiency of its enzymes. Finally, we show that lignin, and, more generally, phenolics, including degradation products of lignin, greatly stimulate the growth and fertility of the fungus in liquid cultures. Analyses of the CATΔΔΔΔΔ mutant lacking all its catalases, pro-oxidants and antioxidants indicate that improved growth and fertility of the fungus is likely caused by augmented reactive oxygen species levels triggered by the presence of phenolics.
Fungal Infections Complicating COVID-19: With the Rain Comes the Spores
Authors: Talento Alida Fe , Hoenigl Martin
Published: November 2020

Within the last 12 months, coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spread globally to pandemic proportions [...]
Will the Aviation Industry Have a Bright Future after the COVID-19 Outbreak? Evidence from Chinese Airport Shipping Sector
Authors: Liu Jingxuan , Qiao Ping , Ding Jian , Hankinson Luke , Harriman Elodie H. , Schiller Edward M. , Ramanauskaite Ieva , Zhang Haowei
Published: November 2020

Due to the lockdown regulations worldwide during the COVID-19 pandemic, the global aviation industry has been severely hit. This study focuses on the volatility estimation of stock indexes in the Chinese Airport Shipping Set (ASS) at industry-enterprise levels and identifies possible business behavior that may cause fluctuating differences. Depending on the Generalized Autoregressive Conditional Heteroskedasticity (GARCH) model, text mining method and Word Cloud Views, results show that (1) the holistic volatility of Airport Shipping Set Index (ASSI) increases relative to the pre-COVID period; (2) volatility of airport stocks has crucial differences, while the volatility of shipping stocks is similar; (3) there are different responses to the pandemic between Shenzhen Airport and Shanghai Airport shown in their semiannual financial reports. Compared to the latter, the former had a more positive attitude and took various measures to mitigate risks, providing evidence of the volatility differences between firms.
Outmigration Drives Cropland Decline and Woodland Increase in Rural Regions of Southwest China
Authors: Yu Yi , Xu Tingbao , Wang Tao
Published: November 2020

Rapid urbanisation in China has led to massive outmigration in rural regions, which has changed the regional labour force structure and can have various profound impacts as a result. This research used a case study in Southwest China to investigate how regional land use patterns have been changed in the context of rural outmigration and assessed the resulting dynamics on local ecological environment. The key findings include: (1) The local land conversion process was mainly characterised by the conversion of farmland (−18.3%) to residential area (+268.3%) and woodland (+55.6%) during 2000–2018; (2) about 83.7% of area showed a statistically significant increase in the normalised difference vegetation index (NDVI), which was not due to human interference factors (e.g., afforestation). Correlation analyses showed that depopulation (R = −0.514, p < 0.01) and local mild temperature (R = 0.505, p < 0.01) could be the main contributors. Only 2.5% of the area had decreased NDVI and this was directly caused by human activities (e.g., urban area expansion). These results implied that vegetation improvement can occur in the context of depopulation and farmland reduction, which did not significantly threaten the local agricultural sector. It then could be a good choice to allow those high-slope and biophysically poor farmlands to undergo forest succession rather than cultivation. Farmers in Southwest China should make a full use of the existing low-slope arable land to curb the declining trend of local farmland amount, in order to meet the future challenges brought by urbanisation. Enhanced agricultural infrastructure, mechanised farming and guide from local government can help achieve this goal. This study provided new insights and more realistic scenarios for rural development in Southwest China. The research findings are expected to provide a better understanding to enable sustainable land use management in Southwest China.
Metabolic Alterations Caused by Defective Cardiolipin Remodeling in Inherited Cardiomyopathies
Authors: Wasmus Christina , Dudek Jan
Published: November 2020

The heart is the most energy-consuming organ in the human body. In heart failure, the homeostasis of energy supply and demand is endangered by an increase in cardiomyocyte workload, or by an insufficiency in energy-providing processes. Energy metabolism is directly associated with mitochondrial redox homeostasis. The production of toxic reactive oxygen species (ROS) may overwhelm mitochondrial and cellular ROS defense mechanisms in case of heart failure. Mitochondria are essential cell organelles and provide 95% of the required energy in the heart. Metabolic remodeling, changes in mitochondrial structure or function, and alterations in mitochondrial calcium signaling diminish mitochondrial energy provision in many forms of cardiomyopathy. The mitochondrial respiratory chain creates a proton gradient across the inner mitochondrial membrane, which couples respiration with oxidative phosphorylation and the preservation of energy in the chemical bonds of ATP. Akin to other mitochondrial enzymes, the respiratory chain is integrated into the inner mitochondrial membrane. The tight association with the mitochondrial phospholipid cardiolipin (CL) ensures its structural integrity and coordinates enzymatic activity. This review focuses on how changes in mitochondrial CL may be associated with heart failure. Dysfunctional CL has been found in diabetic cardiomyopathy, ischemia reperfusion injury and the aging heart. Barth syndrome (BTHS) is caused by an inherited defect in the biosynthesis of cardiolipin. Moreover, a dysfunctional CL pool causes other types of rare inherited cardiomyopathies, such as Sengers syndrome and Dilated Cardiomyopathy with Ataxia (DCMA). Here we review the impact of cardiolipin deficiency on mitochondrial functions in cellular and animal models. We describe the molecular mechanisms concerning mitochondrial dysfunction as an incitement of cardiomyopathy and discuss potential therapeutic strategies.
Impacts of Multilayer Hybrid Coating on PSF Hollow Fiber Membrane for Enhanced Gas Separation
Authors: Roslan Rosyiela Azwa , Lau Woei Jye , Lai Gwo Sung , Zulhairun Abdul Karim , Yeong Yin Fong , Ismail Ahmad Fauzi , Matsuura Takeshi
Published: November 2020

One of the most critical issues encountered by polymeric membranes for the gas separation process is the trade-off effect between gas permeability and selectivity. The aim of this work is to develop a simple yet effective coating technique to modify the surface properties of commonly used polysulfone (PSF) hollow fiber membranes to address the trade-off effect for CO2/CH4 and O2/N2 separation. In this study, multilayer coated PSF hollow fibers were fabricated by incorporating a graphene oxide (GO) nanosheet into the selective coating layer made of polyether block amide (Pebax). In order to prevent the penetration of Pebax coating solution into the membrane substrate, a gutter layer of polydimethylsiloxane (PDMS) was formed between the substrate and Pebax layer. The impacts of GO loadings (0.0–1.0 wt%) on the Pebax layer properties and the membrane performances were then investigated. XPS data clearly showed the existence of GO in the membrane selective layer, and the higher the amount of GO incorporated the greater the sp2 hybridization state of carbon detected. In terms of coating layer morphology, increasing the GO amount only affected the membrane surface roughness without altering the entire coating layer thickness. Our findings indicated that the addition of 0.8 wt% GO into the Pebax coating layer could produce the best performing multilayer coated membrane, showing 56.1% and 20.9% enhancements in the CO2/CH4 and O2/N2 gas pair selectivities, respectively, in comparison to the membrane without GO incorporation. The improvement is due to the increased tortuous path in the selective layer, which created a higher resistance to the larger gas molecules (CH4 and N2) compared to the smaller gas molecules (CO2 and O2). The best performing membrane also demonstrated a lower degree of plasticization and a very stable performance over the entire 50-h operation, recording CO2/CH4 and O2/N2 gas pair selectivities of 52.57 (CO2 permeance: 28.08 GPU) and 8.05 (O2 permeance: 5.32 GPU), respectively.
Hydrogen Purification from Compact Palladium Membrane Module Using a Low Temperature Diffusion Bonding Technology
Authors: Oh Duck-Kyu , Lee Kwan-Young , Park Jong-Soo
Published: November 2020

This study investigates a compact palladium membrane module (CPMM) for hydrogen purification, assembled by diffusion bonding at a low-temperature (450 °C). This CPMM resulted in hydrogen (H2) flux of 18.3 mL cm−2 min−1 with H2/N2 selectivity of over 1100. The H2 purification test using a 60% H2/40% CO2 mixed gas confirmed that the CPMM can separate H2 with a concentration of more than 99%, with a pressure difference of 5 bar. Moreover, the volume of the diffusion bonded membrane module is decreased by 81.4% than the flame-type membrane module pre-studied in our laboratory.
Potential of High Compressive Ductility of Ultrafine Grained Copper Fabricated by Severe Plastic Deformation
Authors: Asano Mayu , Yuasa Motohiro , Miyamoto Hiroyuki , Tanaka Tatsuya , Erdogan Can , Yalçinkaya Tuncay
Published: November 2020

Severe plastic deformation (SPD) can fabricate high-strength materials by forming an ultrafine grained (UFG) microstructure. Low elongation to failure of UFG materials in tensile tests, which has often been regarded as a measure of ductility of materials, has been attributed to low strain hardening of UFG structures where dislocation slip and its accumulation is very limited. In the present work, it is shown that the compressive extensibility of UFG materials can be comparable or potentially superior to that of annealed materials by using a parallel round-bar compression (PRBC) test which was designed for imposing an appropriate stress state preferable for high ductility using the shear mode. The high compressive extensibility of UFG materials can be a result of high accommodation of local strain incompatibility at non-equilibrium grain boundaries and a grain boundary-mediated deformation mechanism, which result in high damage tolerance against void formation and growth. Low strain rate sensitivity indicated that the superplastic viscous nature of deformation is not involved in the high compressive ductility of UFG materials using SPD.
Effect of Turning on the Surface Integrity and Fatigue Life of a TC11 Alloy in Very High Cycle Fatigue Regime
Authors: Gao Tao , Sun Zhidan , Xue Hongqian , Bayraktar Emin , Qin Zhi , Li Bin , Zhang Han
Published: November 2020

In this work, the effect of a turning process on fatigue performance of a Ti-6.5Al-3.5Mo-1.5Zr-0.3Si (TC11) titanium alloy is studied in the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regimes. For this purpose, the surface characteristics including surface morphology, surface roughness and residual stress were investigated. Moreover, axial fatigue tests were conducted with an ultrasonic fatigue testing system working at a frequency of 20 kHz. The results show that the turning process deteriorated the fatigue properties in both HCF and VHCF regimes. The fatigue strength at 1 × 108 cycles of turned samples is approximately 6% lower than that of electropolished ones. Fracture surface observations indicate that turning marks play a crucial role in the fatigue damage process, especially in the crack initiation stage. It was observed that the crack of all the turned samples originated from turning marks. In addition, the compressive residual stress induced by the turning process played a more effective role in resisting crack propagation in the VHCF regime than in the HCF regime.
A RE Methodology to achieve Accurate Polygon Models and NURBS Surfaces by Applying Different Data Processing Techniques
Authors: Pascual Alejandro , Ortega Naiara , Plaza Soraya , Holgado Ibon , Arrizubieta Jon Iñaki
Published: November 2020

The scope of this work is to present a reverse engineering (RE) methodology to achieve accurate polygon models for 3D printing or additive manufacturing (AM) applications, as well as NURBS (Non-Uniform Rational B-Splines) surfaces for advanced machining processes. The accuracy of the 3D models generated by this RE process depends on the data acquisition system, the scanning conditions and the data processing techniques. To carry out this study, workpieces of different material and geometry were selected, using X-ray computed tomography (XRCT) and a Laser Scanner (LS) as data acquisition systems for scanning purposes. Once this is done, this work focuses on the data processing step in order to assess the accuracy of applying different processing techniques. Special attention is given to the XRCT data processing step. For that reason, the models generated from the LS point clouds processing step were utilized as a reference to perform the deviation analysis. Nonetheless, the proposed methodology could be applied for both data inputs: 2D cross-sectional images and point clouds. Finally, the target outputs of this data processing chain were evaluated due to their own reverse engineering applications, highlighting the promising future of the proposed methodology.
Comparison of DNA Extraction Methods and Real-Time PCR Assays for the Detection of Blastocystis sp. in Stool Specimens
Authors: Nourrisson Céline , Brunet Julie , Flori Pierre , Moniot Maxime , Bonnin Virginie , Delbac Frédéric , Poirier Philippe
Published: November 2020

Diagnosis of Blastocystis in stool may be challenging, as microscopic examination and culture-based methods have demonstrated low sensitivity. Molecular detection assays are now available for this enteric parasite, based on “in-house” or commercial-developed techniques. The aim of this study was to assess and compare the performance of (i) two DNA extraction methods (manual versus automated), and (ii) four qPCR assays (three “in-house” and one commercialized), for detection of Blastocystis sp. in human stools. One hundred and forty stools were included, among which 76 were confirmed to be positive for Blastocystis. The manual DNA extraction method allowed for the identification of significantly more positive specimens than the automated method (p < 0.05). In particular, specimens with a low parasite load were negative when DNA was extracted with the automated process. The four qPCR assays also had variable performances, with the commercialized assay being the most sensitive (84%) but the least specific (82%). Overall, for all qPCR assays, the specificity decreased when the sensitivity increased. Blastocystis’ subtype, notably the subtype 4, influenced these performances. Our results indicate that the positivity rate for the detection of Blastocystis in stools could be variable according to the DNA extraction method and the qPCR assay used. These pitfalls need to be considered for the selection of method and interpretation of results, particularly considering the search of this intestinal parasite in a donor before fecal microbiota transplantation.
Soybean Viromes in the Republic of Korea Revealed by RT-PCR and Next-Generation Sequencing
Authors: Jo Yeonhwa , Yoon Young Nam , Jang Yun-Woo , Choi Hoseong , Lee Yeong-Hoon , Kim Sang-Min , Choi Soo Yeon , Lee Bong Choon , Cho Won Kyong
Published: November 2020

Soybean (Glycine max L.) is one of the most important crop plants in the Republic of Korea. Here, we conducted a soybean virome study. We harvested a total of 172 soybean leaf samples showing disease symptoms from major soybean-growing regions in the Republic of Korea. Individual samples were examined for virus infection by RT-PCR. Moreover, we generated eight libraries representing eight provinces by pooling samples and four libraries from single samples. RNA-seq followed by bioinformatics analyses revealed 10 different RNA viruses infecting soybean. The proportion of viral reads in each transcriptome ranged from 0.2 to 31.7%. Coinfection of different viruses in soybean plants was very common. There was a single dominant virus in each province, and this geographical difference might be related to the soybean seeds that transmit viruses. In this study, 32 viral genome sequences were assembled and successfully used to analyze the phylogenetic relationships and quasispecies nature of the identified RNA viruses. Moreover, RT-PCR with newly developed primers confirmed infection of the identified viruses in each library. Taken together, our soybean virome study provides a comprehensive overview of viruses infecting soybean in eight geographical regions in the Republic of Korea and four single soybean plants in detail.
Geodynamic Emplacement Setting of Late Jurassic Dikes of the Yana–Kolyma Gold Belt, NE Folded Framing of the Siberian Craton: Geochemical, Petrologic, and U–Pb Zircon Data
Authors: Yu. Fridovsky Valery , Yakovleva Kyunney Yu. , Vernikovskaya Antonina E. , Vernikovsky Valery A. , Matushkin Nikolay Yu. , Kadilnikov Pavel I. , Rodionov Nickolay V.
Published: November 2020

We present the results of geostructural, mineralogic–petrographic, geochemical, and U–Pb geochronological investigations of mafic, intermediate, and felsic igneous rocks from dikes in the Yana–Kolyma gold belt of the Verkhoyansk–Kolyma folded area (northeastern Asia). The dikes of the Vyun deposit and the Shumniy occurrence intruding Mesozoic terrigenous rocks of the Kular–Nera and Polousniy–Debin terranes were examined in detail. The dikes had diverse mineralogical and petrographic compositions including trachybasalts, andesites, trachyandesites, dacites, and granodiorites. The rocks showed significant similarities in distributions of REE, and their concentrations of most HFSEs were close to the intermediate ones between ocean islands basalts and enriched middle ocean ridge basalts. We propose that the subduction that was ongoing during the collision of the Kolyma–Omolon superterrane with Siberia led to melting in the asthenospheric wedge and in the lithosphere, which formed a mixed source for the dike systems from both an enriched and a depleted mantle source. The U–Pb SHRIMP-II dates obtained for the dikes corresponded to the Late Jurassic interval of 151–145 Ma. We present a geodynamic model for the northeastern margin of the Siberian Craton for the Tithonian age of the Late Jurassic.
The Impact of Coal Fly Ash Purification on Its Antibacterial Activity
Authors: Alterary Seham , Marei Narguess H.
Published: November 2020

Fly ash (FA) is produced from coal power plants’ combustion. FA is used in the concrete industry, as an ingredient in the brick and paving. Knowledge of the chemical composition and toxic metal content in FA is essential for evaluating its environmental risks. This study aimed to assess FA purification effect on its antibacterial activity against Escherichia coli and Bacillus cereus, by calculating percent bacterial reduction. Moreover, centrifugation time effect on the purification process was evaluated. Chemical composition and properties of purified FA were determined and compared with raw FA, using Fourier transform Infrared (FTIR); X-ray diffraction (XRD); X-ray photoelectron spectroscopy (XPS); energy-dispersive X-ray (EDXA); carbon, hydrogen, nitrogen, and sulfur (CHNS) elemental analysis; moisture content; and loss-of-ignition. Particle size was predicted by using dynamic laser scattering, BET and scanning electron microscopy (SEM). The CHNS results showed that purified FA contains the highest carbon content (88.9%), as compared to raw FA (82.1%). The particle size distribution (PSD) of FA microspheres ranges from 48.53 ± 17.9 to 52.98 ± 19.4 µm by using SEM. PSD, using dynamic laser scattering, showed polydispersed and non-uniform size in raw FA, ranging in size from 107.1 to 1027 nm, while purified FA manifests a monodispersed size from 103.3 to 127.3 nm. FA showed the least bacterial growth reduction %, while the purified fly ash (FA2) showed the highest bacterial growth reduction %, as compared to the control bacterial broth culture without fly ash.
Raman Spectroscopy Imaging of Exceptional Electronic Properties in Epitaxial Graphene Grown on SiC
Authors: Ben Gouider Trabelsi A. , V. Kusmartsev F. , Kusmartseva A. , H. Alkallas F. , AlFaify S. , Shkir Mohd
Published: November 2020

Graphene distinctive electronic and optical properties have sparked intense interest throughout the scientific community bringing innovation and progress to many sectors of academia and industry. Graphene manufacturing has rapidly evolved since its discovery in 2004. The diverse growth methods of graphene have many comparative advantages in terms of size, shape, quality and cost. Specifically, epitaxial graphene is thermally grown on a silicon carbide (SiC) substrate. This type of graphene is unique due to its coexistence with the SiC underneath which makes the process of transferring graphene layers for devices manufacturing simple and robust. Raman analysis is a sensitive technique extensively used to explore nanocarbon material properties. Indeed, this method has been widely used in graphene studies in fundamental research and application fields. We review the principal Raman scattering processes in SiC substrate and demonstrate epitaxial graphene growth. We have identified the Raman bands signature of graphene for different layers number. The method could be readily adopted to characterize structural and exceptional electrical properties for various epitaxial graphene systems. Particularly, the variation of the charge carrier concentration in epitaxial graphene of different shapes and layers number have been precisely imaged. By comparing the intensity ratio of 2D line and G line—“I2D/IG”—the density of charge across the graphene layers could be monitored. The obtained results were compared to previous electrical measurements. The substrate longitudinal optical phonon coupling “LOOPC” modes have also been examined for several epitaxial graphene layers. The LOOPC of the SiC substrate shows a precise map of the density of charge in epitaxial graphene systems for different graphene layers number. Correlations between the density of charge and particular graphene layer shape such as bubbles have been determined. All experimental probes show a high degree of consistency and efficiency. Our combined studies have revealed novel capacitor effect in diverse epitaxial graphene system. The SiC substrate self-compensates the graphene layer charge without any external doping. We have observed a new density of charge at the graphene—substrate interface. The located capacitor effects at epitaxial graphene-substrate interfaces give rise to an unexpected mini gap in graphene band structure.
Characterization and Manipulation of Carbon Precursor Species during Plasma Enhanced Chemical Vapor Deposition of Graphene
Authors: Zietz Otto , Olson Samuel , Coyne Brendan , Liu Yilian , Jiao Jun
Published: November 2020

To develop a synthesis technique providing enhanced control of graphene film quality and uniformity, a systematic characterization and manipulation of hydrocarbon precursors generated during plasma enhanced chemical vapor deposition of graphene is presented. Remote ionization of acetylene is observed to generate a variety of neutral and ionized hydrocarbon precursors, while in situ manipulation of the size and reactivity of carbon species permitted to interact with the growth catalyst enables control of the resultant graphene morphology. Selective screening of high energy hydrocarbon ions coupled with a multistage bias growth regime results in the production of 90% few-to-monolayer graphene on 50 nm Ni/Cu alloy catalysts at 500 °C. Additionally, synthesis with low power secondary ionization processes is performed and reveals further control during the growth, enabling a 50% reduction in average defect densities throughout the film. Mass spectrometry and UV-Vis spectroscopy monitoring of the reaction environment in conjunction with Raman characterization of the synthesized graphene films facilitates correlation of the carbon species permitted to reach the catalyst surface to the ultimate quality, layer number, and uniformity of the graphene film. These findings reveal a robust technique to control graphene synthesis pathways during plasma enhanced chemical vapor deposition.
Reduced Graphene Oxide Sheets as Inhibitors of the Photochemical Reactions of α-Lipoic Acid in the Presence of Ag and Au Nanoparticles
Authors: Toulbe N’ghaya , Stroe Malvina , Daescu Monica , Cercel Radu , Mogos Alin , Dragoman Daniela , Socol Marcela , Mercioniu Ionel , Baibarac Mihaela
Published: November 2020

The influence of Ag and Au nanoparticles and reduced graphene oxide (RGO) sheets on the photodegradation of α-lipoic acid (ALA) was determined by UV-VIS spectroscopy. The ALA photodegradation was explained by considering the affinity of thiol groups for the metallic nanoparticles synthesized in the presence of trisodium citrate. The presence of excipients did not induce further changes when ALA interacts with Ag and Au nanoparticles with sizes of 5 and 10 nm by exposure to UV light. Compared to the Raman spectrum of ALA powder, changes in Raman lines’ position and relative intensities when ALA has interacted with films obtained from Au nanoparticles with sizes between 5 and 50 nm were significant. These changes were explained by considering the chemical mechanism of surface-enhanced Raman scattering (SERS) spectroscopy. The photodegradation of ALA that had interacted with metallic nanoparticles was inhibited in the presence of RGO sheets.
Synthesis of Core–Double Shell Nylon-ZnO/Polypyrrole Electrospun Nanofibers
Authors: Beregoi Mihaela , Preda Nicoleta , Costas Andreea , Enculescu Monica , Negrea Raluca , Iovu Horia , Enculescu Ionut
Published: November 2020

Core–double shell nylon-ZnO/polypyrrole electrospun nanofibers were fabricated by combining three straightforward methods (electrospinning, sol–gel synthesis and electrodeposition). The hybrid fibrous organic–inorganic nanocomposite was obtained starting from freestanding nylon 6/6 nanofibers obtained through electrospinning. Nylon meshes were functionalized with a very thin, continuous ZnO film by a sol–gel process and thermally treated in order to increase its crystallinity. Further, the ZnO coated networks were used as a working electrode for the electrochemical deposition of a very thin, homogenous polypyrrole layer. X-ray diffraction measurements were employed for characterizing the ZnO structures while spectroscopic techniques such as FTIR and Raman were employed for describing the polypyrrole layer. An elemental analysis was performed through X-ray microanalysis, confirming the expected double shell structure. A detailed micromorphological characterization through FESEM and TEM assays evidenced the deposition of both organic and inorganic layers. Highly transparent, flexible due to the presence of the polymer core and embedding a semiconducting heterojunction, such materials can be easily tailored and integrated in functional platforms with a wide range of applications.
Hypoglycemic Effect of Prolamin from Cooked Foxtail Millet (Setaria italic) on Streptozotocin-Induced Diabetic Mice
Authors: Fu Yongxia , Yin Ruiyang , Liu Zhenyu , Niu Yan , Guo Erhu , Cheng Ruhong , Diao Xianmin , Xue Yong , Shen Qun
Published: November 2020

Millet proteins have been demonstrated to possess glucose-lowering and lipid metabolic disorder modulation functions against diabetes; however, the molecular mechanisms underlying their anti-diabetic effects remain unclear. The present study aimed to investigate the hypoglycemic effect of prolamin from cooked foxtail millet (PCFM) on type 2 diabetic mice, and explore the gut microbiota and serum metabolic profile changes that are associated with diabetes attenuation by PCFM. Our diabetes model was established using a high-fat diet combined with streptozotocin before PCFM or saline was daily administrated by gavage for 5 weeks. The results showed that PCFM ameliorated glucose metabolism disorders associated with type 2 diabetes. Furthermore, the effects of PCFM administration on gut microbiota and serum metabolome were investigated. 16S rRNA gene sequencing analysis indicated that PCFM alleviated diabetes-related gut microbiota dysbiosis in mice. Additionally, the serum metabolomics analysis revealed that the metabolite levels disturbed by diabetes were partly altered by PCFM. Notably, the decreased D-Glucose level caused by PCFM suggested that its anti-diabetic potential can be associated with the activation of glycolysis and the inhibition of gluconeogenesis, starch and sucrose metabolism and galactose metabolism. In addition, the increased serotonin level caused by PCFM may stimulate insulin secretion by pancreatic β-cells, which contributed to its hypoglycemic effect. Taken together, our research demonstrated that the modulation of gut microbiota composition and the serum metabolomics profile was associated with the anti-diabetic effect of PCFM.
Anti-Obesity Effect of an Ethanol Extract of Cheongchunchal In Vitro and In Vivo
Authors: Kawk Hye Won , Nam Gun-He , Kim Myeong Jin , Kim Sang-Yong , Kim Gi No , Kim Young-Min
Published: November 2020

Cheongchunchal (CE) is a developed crop more highly enriched in cyanidin-3-O-glucoside chloride (anthocyanin) than conventional waxy corn. Anthocyanin has been proven to have anti-oxidant, anti-inflammatory, anti-obesity, and anti-cancer effects. In this study, using high-performance liquid chromatography (HPLC), Cheongchunchal was confirmed to contain 8.99 mg/g anthocyanin. The inhibitory effect of an ethanol extract of Cheongchunchal (CE) on adipocyte differentiation was demonstrated using Oil Red O staining and a triglyceride assay. By conducting Western blotting, we also confirmed the regulatory effect of CE on adipocyte differentiation factors by assessing changes in the levels of factors that play a significant role in the differentiation of 3T3-L1 preadipocytes. A C57BL/6N mouse model of obesity was induced with a high-fat diet, and CE (400, 600, and 800 mg/kg/day) or Garcinia (245 mg/kg/day) was orally administered to verify the anti-obesity effect of CE. As a result of CE administration, the food efficiency ratio (FER), weight gain, and weight of tissues decreased. Additionally, blood biochemical changes were observed. Furthermore, the inhibitory effect of CE on adipocytes was confirmed through morphological observation and the expression of adipocyte differentiation-related factors in the liver and fat tissues. Therefore, in this study, we verified the anti-obesity effects of anthocyanin-rich CE both in vitro and in vivo.