bluuebunny/crossref_metadata_2025 huggingface dataset:
Nine-Year Nationwide Environmental Surveillance of Hepatitis E Virus in Urban Wastewaters in Italy (2011–2019)
Authors: Iaconelli Marcello , Bonanno Ferraro Giusy , Mancini Pamela , Suffredini Elisabetta , Veneri Carolina , Ciccaglione Anna Rita , Bruni Roberto , Della Libera Simonetta , Bignami Francesco , Brambilla Massimo , De Medici Dario , Brandtner David , Schembri Pietro , D’Amato Stefania , La Rosa Giuseppina
Published: March 2020

Hepatitis E virus (HEV) is an emerging causative agent of acute hepatitis worldwide. To provide insights into the epidemiology of HEV in Italy, a large-scale investigation was conducted into urban sewage over nine years (2011–2019), collecting 1374 sewage samples from 48 wastewater treatment plants located in all the 20 regions of Italy. Broadly reactive primers targeting the ORF1 and ORF2 regions were used for the detection and typing of HEV, followed by Sanger and next generation sequencing (NGS). Real-time RT-qPCR was also used to attempt quantification of positive samples. HEV RNA detection occurred in 74 urban sewage samples (5.4%), with a statistically significant higher frequency (7.1%) in central Italy. Fifty-six samples were characterized as G3 strains and 18 as G1. While the detection of G3 strains occurred in all the surveillance period, G1 strains were mainly detected in 2011–2012, and never in 2017–2019. Typing was achieved in 2 samples (3f subtype). Viral concentrations in quantifiable samples ranged from 1.2 × 103 g.c./L to 2.8 × 104 g.c./L. Our results suggest the considerable circulation of the virus in the Italian population, despite a relatively small number of notified cases, a higher occurrence in central Italy, and a noteworthy predominance of G3 strains.
Dengue Surveillance System in Brazil: A Qualitative Study in the Federal District
Authors: Angelo Marco , Ramalho Walter Massa , Gurgel Helen , Belle Nayara , Pilot Eva
Published: March 2020

Dengue’s increasing trends raise concerns over global health and pose a challenge to the Brazilian health system, highlighting the necessity of a strong surveillance system to reduce morbidity, mortality, and the economic burden of this disease. Although the Brazilian surveillance system reports more dengue cases than any other country, recent studies suggest that non-reported cases are the majority. The aim of the study is to explore the strengths and weaknesses of the Brazilian surveillance system, particularly looking at the functioning of data collection and reporting. This was done through qualitative semi-structured interviews with 17 experts in dengue surveillance, supported by quantitative data from the official notification system. To select the interviewees, purposive and theoretical sampling were used. Data were analyzed through thematic analysis. The research highlighted that a lack of human and technological resources in healthcare units and surveillance departments slows down the notification process and data analysis. Due to a lack of integration in the private sector, the surveillance system fails to detect the socioeconomic profile of the patients. Investments in public healthcare, human and technological resources for surveillance and better integration in the private healthcare system, and vector surveillance may improve dengue surveillance.
Use of Fuzzy Analytic Hierarchy Process and Environmental Gini Coefficient for Allocation of Regional Flood Drainage Rights
Authors: Zhang Dandan , Shen Juqin , Liu Pengfei , Zhang Qian , Sun Fuhua
Published: March 2020

To solve the flood drainage conflict among different regions of the water basin when the flood occurs, it is of great significance to study the allocation of flood drainage rights. The allocation of flood drainage rights requires flood management departments to consider the influences of socioeconomic differences among different regions on flood control operations to realize sustainable development. Under the pattern of the total amount allocation of “watershed–administrative regions”, the evaluation index system of flood drainage rights allocation incorporated four aspects: natural conditions, level of social development, level of economic development, and technology and management. The fuzzy analytic hierarchy process (FAHP) was used to calculate the weight coefficient of each allocation index and the initial distribution’s proportion of the total amount in each region. Land area, population, gross domestic product (GDP), and sewage treatment capacity were selected as the evaluation indexes of the environmental Gini coefficient, and the environmental Gini coefficient method was used to evaluate and adjust the initial allocation of each region. Taking the allocation of flood drainage rights in the Taihu Basin as a case study, the final allocation results were obtained after initial allocation and feedback optimization. By evaluating the environmental Gini coefficient of each evaluation index, it is concluded that the final allocation could meet the requirements of fair allocation in each administrative region and be effectively implemented. Optimal allocation of the flood drainage rights in the Taihu Basin can contribute to overall flood control management, the reduction of flood disasters, and the stable development of society in the basin.
Synthesis of Biochar-Supported K-doped g-C3N4 Photocatalyst for Enhancing the Polycyclic Aromatic Hydrocarbon Degradation Activity
Authors: Li Fayun , Lin Meixia
Published: March 2020

The development of novel and green photocatalysts have attracted considerable attentions due to their excellent performance for environmental remediation, especially for the degradation of persistent pollutants. In this work, the biochar-supported K-doped g-C3N4 composites with the high photocatalytic activity under visible light irradiation was prepared by the calcination-impregnation method. The crystal structure, apparent morphology and functional group composition of the as-prepared photocatalytic materials were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscope (FTIR). Moreover, the characterization of UV-Vis diffuse reflectance spectra (UV-Vis DRS) and photoluminescence technique (PL) verified the good optical properties of resultant samples. Naphthalene was selected as the representative compound to evaluate the photocatalytic performance of the prepared photocatalysts under visible light irradiation. The evaluation results showed that the biochar-supported K-doped g-C3N4 composites exhibited excellent photocatalytic activity (82.19%). Moreover, the photocatalytic degradation rate basically remained unchanged after five cycles, indicating the good stability of the prepared photocatalysts. In addition, a possible mechanism for the photodegradation process was proposed on the basis of the main intermediates detected by gas chromatography-mass spectrometer (GC-MS). This study may provide a promising approach for the polycyclic aromatic hydrocarbon degradation by waste utilization of agricultural biomass and increasing the photocatalytic performance of pure g-C3N4.
Valuation Impacts of Environmental Protection Taxes and Regulatory Costs in Heavy-Polluting Industries
Authors: Tu Wen-Jun , Yue Xiao-Guang , Liu Wei , Crabbe M. James C.
Published: March 2020

In 2016, the issue of the Environmental Protection Tax Law indicated the enhancement of environmental protection in China. This study examines the market reaction to firms in heavy-polluting industries, and the effects of external legal institutional quality and internal environmental disclosure on firm value around the passage of Environmental Protection Tax Law. Using an event study approach coupled with ordinary least square regressions, the researchers find a significantly negative market reaction to firms in heavy-polluting industries, but this negative reaction varies depending on the expected increase in future regulatory costs. Specifically, the above negative reaction is stronger when the firm reveals that itself or its subsidiary belongs to heavy-polluting industry, however it would be mitigated when a firm is in a region with better quality of legal institutions or discloses environmental improvement activities. Overall, the results are consistent with the market perceiving that the environmental protection tax law enacted would increase regulatory costs for firms in heavy-polluting industries, and also show the higher-quality regional legal institutions and more efforts on environmental protection could relieve the market’s pessimism caused by uncertainty.
Short- and Long-Term Structural Characterization of Cured-in-Place Pipe Liner with Reinforced Glass Fiber Material
Authors: Ji Hyon Wook , Koo Dan Daehyun , Kang Jeong-Hee
Published: March 2020

Cured-in-place pipe (CIPP), as a kind of trenchless sewer rehabilitation technology, is a method to repair sewer pipe using unsaturated polyester resin. This study develops a CIPP liner using hot water or steam curing as well as glass fiber, in contrast to traditional methods, which use nonwoven fabric. Composite material samples were fabricated by combining liner materials using various methods, and the structural characteristics of the liners were compared and analyzed through short- and long-term flexural strength tests. A long-term test was conducted for 10,000 h, and the results revealed 13.3 times higher flexural strength and 8 times higher flexural modulus than the American Society for Testing Materials minimum criteria for CIPP short-term properties. The maximum creep retention factor was 0.64, thereby reducing the design thickness of the CIPP by up to 54%. The structural characteristics also improved when glass fibers were mixed with traditional CIPP liner, making it possible to reduce the thickness by 30%. Glass fibers result in high structural strength when combined with unsaturated polyester resin. Structural strength increased, even when glass fibers were mixed with traditional CIPP liner. The main contribution of this research is the development of a high strength CIPP liner and improvement of the structural properties of CIPP lining without using the specially formulated resin or lining materials.
Legionella Detection in Water Networks as per ISO 11731:2017: Can Different Filter Pore Sizes and Direct Placement on Culture Media Influence Laboratory Results?
Authors: De Giglio Osvalda , Diella Giusy , Trerotoli Paolo , Consonni Michela , Palermo Roberta , Tesauro Marina , Laganà Pasqualina , Serio Gabriella , Montagna Maria Teresa
Published: March 2020

Determination of Legionella concentrations in water networks is useful for predicting legionellosis risks. The standard culture technique using concentration with membranes filters is the most commonly used method for environmental surveillance of Legionella. The aim of this study was to verify whether filtration with different filter pore sizes (0.2 and 0.45 µm) according to (ISO) 11731:2017, followed by directly placing them on culture media, can influence Legionella detection. Three laboratories participated in an experimental study that tested a known suspension of Legionella pneumophila (Lpn) serogroup 1 (ATCC 33152) (approximate final cell density of 15 CFU/mL). E. coli (ATCC 11775) and Pseudomonas aeruginosa (ATCC 25668) were included as control tests. The average (95% CI) percentage of recovery of Lpn was 65% using 0.45-µm filters and 15% using 0.2-µm filters (p < 0.0001). For control tests, the average (95% CI) percentage of recovery was higher with 0.45 vs. 0.2 µm filters: 97% vs. 64% for Escherichia coli (p < 0.00001) and 105% vs. 97% (p = 0.0244) for P. aeruginosa. Our results showed that the 0.45-µm filters provided the greatest detection of Legionella. Because the current national guidelines leave the choice of membrane porosity to the operator, experimental studies are important for directing operators towards a conscious choice to standardize Legionella environmental surveillance methods.
Human Enteric Pathogens in Eight Rivers Used as Rural Household Drinking Water Sources in the Northern Region of South Africa
Authors: Potgieter Natasha , Karambwe Simbarashe , Mudau Lutendo Sylvia , Barnard Tobias , Traore Afsatou
Published: March 2020

People living in rural areas still rely on the use of environmental water that is contaminated by human and animal activities. This study assessed the occurrence of human enteric pathogens in rivers that are used by rural communities Vhembe District of South Africa as a source of drinking water covering two seasons (winter and summer) over a one-year period. Water quality was assessed using physico characteristics and indicator organisms (total coliforms, E. coli, Clostridium perfringens). Pathogens tested included bacteria (Pathogenic E. coli, Salmonella-, Shigella- and Vibrio spp.), protozoa (Cryptosporidium- and Giardia spp.), and enteric viruses (Rota-, Noro-, Entero-, and Adenoviruses) while using published molecular protocols. The results showed that the indicator bacteria counts exceeded South African drinking water quality guideline limits and pathogenic E. coli was detected in the samples. No Shigella spp. were isolated, while Vibrio spp. and Salmonella spp. were present; parasites were detected in four rivers and Enteric viruses were predominantly detected in the winter season. The results indicated the poor condition of water and the potential health risks to consumers highlighting the need for implementing river catchment management strategies for continued sustainability in these rivers.
Methodological Approach to Incorporate the Involve of Stakeholders in the Geodesign Workflow of Transmission Line Projects
Authors: Moreno-Marimbaldo Francisco-Javier , Manso-Callejo Miguel-Ángel
Published: March 2020

Any artificial infrastructure built in a territory causes changes in its environment, especially when it is a question of large or extensive infrastructures such as high-voltage transmission lines (HVTLs). Such changes are perceived unevenly by the different groups affected or involved. However, all of them can obstruct the development of a project of this type of infrastructure. For this reason, it is increasingly necessary to manage the stakeholders in the different phases of the development of an HVTL project. This article presents the methodological proposal designed to add the management of stakeholders’ opinions by integrating it into the geodesign-based workflow for the development of HVTL projects, giving geographic meaning to each of their opinions, allowing their analysis together with the rest of the geospatial information of the project, reusing the “feedback-iteration-consensus” mechanisms, discovering interactions and synergies or incompatibilities, improving the understanding and finally facilitating the consensus of all parties. In this way, it is possible to manage the development of the projects with a single workflow, in which the results are obtained (development stages) and the decisions that are adopted are used both for the technical part and for the management of the project’s stakeholders.
Sperm Cohort-Specific Zinc Signature Acquisition and Capacitation-Induced Zinc Flux Regulate Sperm-Oviduct and Sperm-Zona Pellucida Interactions
Authors: Kerns Karl , Sharif Momal , Zigo Michal , Xu Wei , Hamilton Lauren E. , Sutovsky Miriam , Ellersieck Mark , Drobnis Erma Z. , Bovin Nicolai , Oko Richard , Miller David , Sutovsky Peter
Published: March 2020

Building on our recent discovery of the zinc signature phenomenon present in boar, bull, and human spermatozoa, we have further characterized the role of zinc ions in the spermatozoa’s pathway to fertilization. In boar, the zinc signature differed between the three major boar ejaculate fractions, the initial pre-rich, the sperm-rich, and the post-sperm-rich fraction. These differences set in the sperm ejaculatory sequence establish two major sperm cohorts with marked differences in their sperm capacitation progress. On the subcellular level, we show that the capacitation-induced Zn-ion efflux allows for sperm release from oviductal glycans as analyzed with the oviductal epithelium mimicking glycan binding assay. Sperm zinc efflux also activates zinc-containing enzymes and proteases involved in sperm penetration of the zona pellucida, such as the inner acrosomal membrane matrix metalloproteinase 2 (MMP2). Both MMP2 and the 26S proteasome showed severely reduced activity in the presence of zinc ions, through studies using by gel zymography and the fluorogenic substrates, respectively. In the context of the fertilization-induced oocyte zinc spark and the ensuing oocyte-issued polyspermy-blocking zinc shield, the inhibitory effect of zinc on sperm-borne enzymes may contribute to the fast block of polyspermy. Altogether, our findings establish a new paradigm on the role of zinc ions in sperm function and pave the way for the optimization of animal semen analysis, artificial insemination (AI), and human male-factor infertility diagnostics.
Hydrophobin-Protein A Fusion Protein Produced in Plants Efficiently Purified an Anti-West Nile Virus Monoclonal Antibody from Plant Extracts via Aqueous Two-Phase Separation
Authors: Jugler Collin , Joensuu Jussi , Chen Qiang
Published: March 2020

The development of monoclonal antibodies (mAbs) has provided vast opportunities to treat a wide range of diseases from cancer to viral infections. While plant-based production of mAbs has effectively lowered the upstream cost of mAb production compared to mammalian cell cultures, further optimization of downstream processing, especially in extending the longevity of Protein A resin by an effective bulk separation step, will further reduce the overall prohibitive cost of mAb production. In this study, we explored the feasibility of using aqueous two-phase separation (ATPS) in capturing and separating plant-made mAbs from host proteins. Our results demonstrated that an anti-West Nile virus mAb (E16) was efficiently separated from most plant host proteins by a single ATPS step, comprising the mixing of plant extracts containing Hydrophobin-Protein A fusion protein (HPA) and E16 and the subsequent incubation with an inexpensive detergent. This simple ATPS step yielded a highly enriched E16 mAb preparation with a recovery rate comparable to that of Protein A chromatography. The ATPS-enriched E16 retained its structural integrity and was fully functional in binding its target antigen. Notably, HPA-based ATPS was also effective in enriching E16 from plant host proteins when both HPA and E16 were produced in the same leaves, supporting the potential of further streamlining the downstream purification process. Thus, ATPS based on plant-produced HPA in unpurified extract is a cost-effective yet efficient initial capture step for purifying plant-made mAbs, which may significantly impact the approach of mAb purification.
Huntingtin Lowering Strategies
Authors: Marxreiter Franz , Stemick Judith , Kohl Zacharias
Published: March 2020

Trials using antisense oligonucleotide technology to lower Huntingtin levels in Huntington’s disease (HD) are currently ongoing. This progress, taking place only 27 years after the identification of the Huntingtin gene (HTT) in 1993 reflects the enormous development in genetic engineering in the last decades. It is also the result of passionate basic scientific work and large worldwide registry studies that have advanced the understanding of HD. Increased knowledge of the pathophysiology of this autosomal dominantly inherited CAG-repeat expansion mediated neurodegenerative disease has led to the development of several putative treatment strategies, currently under investigation. These strategies span the whole spectrum of potential targets from genome editing via RNA interference to promoting protein degradation. Yet, recent studies revealed the importance of huntingtin RNA in the pathogenesis of the disease. Therefore, huntingtin-lowering by means of RNA interference appears to be a particular promising strategy. As a matter of fact, these approaches have entered, or are on the verge of entering, the clinical trial period. Here, we provide an overview of huntingtin-lowering approaches via DNA or RNA interference in present clinical trials as well as strategies subject to upcoming therapeutic options. We furthermore discuss putative implications for future treatment of HD patients.
Crystal Structure and Thermal Behavior of SbC2O4OH and SbC2O4OD
Authors: Kohlmann Holger , Rauchmaul Anne , Keilholz Simon , Franz Alexandra
Published: March 2020

The order of OH groups in the crystal structure of SbC2O4OH, a potential precursor in the synthesis of ternary oxides, was debated. Neutron diffraction on the deuteride SbC2O4OD revealed disordered OD groups with half occupation for deuterium atoms on either side of a mirror plane (SbC2O4OD at T = 298(1) K: Pnma, a = 582.07(3) pm, b = 1128.73(5) pm, c = 631.26(4) pm). O–H stretching frequencies are shifted by a factor of 1.35 from 3390 cm−1 in the hydride to 2513 cm−1 in the deuteride as seen in infrared spectra. SbC2O4OH suffers radiation damage in a synchrotron beam, which leaves a dark amorphous residue. Thermal decomposition at 564 K yields antimony oxide, carbon dioxide, carbon oxide, and water in an endothermic reaction. When using SbC2O4OH as a precursor in reactions, however, ternary oxides are only formed at much higher temperatures.
Approaches to Identify the Value of Seminatural Habitats for Conservation Biological Control
Authors: Holland John , Jeanneret Philippe , Moonen Anna-Camilla , van der Werf Wopke , Rossing Walter , Antichi Daniele , Entling Martin , Giffard Brice , Helsen Herman , Szalai Mark , Rega Carlo , Gibert Caroline , Veromann Eve
Published: March 2020

Invertebrates perform many vital functions in agricultural production, but many taxa are in decline, including pest natural enemies. Action is needed to increase their abundance if more sustainable agricultural systems are to be achieved. Conservation biological control (CBC) is a key component of integrated pest management yet has failed to be widely adopted in mainstream agriculture. Approaches to improving conservation biological control have been largely ad hoc. Two approaches are described to improve this process, one based upon pest natural enemy ecology and resource provision while the other focusses on the ecosystem service delivery using the QuESSA (Quantification of Ecological Services for Sustainable Agriculture) project as an example. In this project, a predictive scoring system was developed to show the potential of five seminatural habitat categories to provide biological control, from which predictive maps were generated for Europe. Actual biological control was measured in a series of case studies using sentinel systems (insect or seed prey), trade-offs between ecosystem services were explored, and heatmaps of biological control were generated. The overall conclusion from the QuESSA project was that results were context specific, indicating that more targeted approaches to CBC are needed. This may include designing new habitats or modifying existing habitats to support the types of natural enemies required for specific crops or pests.
Temperature Tolerance and Thermal Environment of European Seed Bugs
Authors: Käfer Helmut , Kovac Helmut , Simov Nikolay , Battisti Andrea , Erregger Bettina , Schmidt Arne K. D. , Stabentheiner Anton
Published: March 2020

Heteroptera, or true bugs populate many climate zones, coping with different environmental conditions. The aim of this study was the evaluation of their thermal limits and derived traits, as well as climatological parameters which might influence their distribution. We assessed the thermal limits (critical thermal maxima, CTmax, and minima, CTmin) of eight seed bug species (Lygaeidae, Pyrrhocoridae) distributed over four Köppen–Geiger climate classification types (KCC), approximately 6° of latitude, and four European countries (Austria, Italy, Croatia, Bulgaria). In test tubes, a temperature ramp was driven down to −5 °C for CTmin and up to 50 °C for CTmax (0.25 °C/min) until the bugs’ voluntary, coordinated movement stopped. In contrast to CTmin, CTmax depended significantly on KCC, species, and body mass. CTmax showed high correlation with bioclimatic parameters such as annual mean temperature and mean maximum temperature of warmest month (BIO5), as well as three parameters representing temperature variability. CTmin correlated with mean annual temperature, mean minimum temperature of coldest month (BIO6), and two parameters representing variability. Although the derived trait cold tolerance (TC = BIO6 − CTmin) depended on several bioclimatic variables, heat tolerance (TH = CTmax − BIO5) showed no correlation. Seed bugs seem to have potential for further range shifts in the face of global warming.
Increased Amygdala Activations during the Emotional Experience of Death-Related Pictures in Complicated Grief: An fMRI Study
Authors: Fernández-Alcántara Manuel , Verdejo-Román Juan , Cruz-Quintana Francisco , Pérez-García Miguel , Catena-Martínez Andrés , Fernández-Ávalos María Inmaculada , Pérez-Marfil María Nieves
Published: March 2020

Complicated grief (CG) is associated with alterations in various components of emotional processing. The main aim of this study was to identify brain activations in individuals diagnosed with CG while they were observing positive, negative, and death-related pictures. The participants included 19 individuals with CG and 19 healthy non-bereaved (NB) individuals. Functional magnetic resonance imaging (fMRI) scans were obtained during an emotional experience task. The perception of death-related pictures differed between the CG group and the NB group, with a greater activation in the former of the amygdala, putamen, hypothalamus, middle frontal gyrus, and anterior cingulate cortex. Amygdala and putamen activations were significantly correlated with Texas Revised Inventory of Grief scores in the CG group, suggesting that the higher level of grief in this group was associated with a greater activation in both brain areas while watching death-related pictures. A significant interaction between image type and group was observed in the amygdala, midbrain, periaqueductal gray, cerebellum, and hippocampus, largely driven by the greater activation of these areas in the CG group when watching death-related pictures and the lower activation when watching positive-valence pictures. In this study, individuals with CG showed significantly distinct brain activations in response to different emotional images.
Review of Through-the-Thickness Reinforced z-Pinned Composites
Authors: Kostopoulos Vassilis , Sarantinos Nikolaos , Tsantzalis Stavros
Published: March 2020

This work reviews the effects of z-Pins used in composite laminates as through-the-thickness reinforcement to increase the composite’s properties in the out-of-plane direction. The paper presents the manufacture and microstructure of this reinforcement type while also incorporating the impact of z-Pins on the mechanical properties of the composite. Mechanical properties include tensile, compression, flexure properties in static, dynamic and fatigue loads. Additionally, mode I and mode II properties in both static and fatigue loading are presented, as well as hygrothermal, impact and compression after impact properties.
Numerical Simulation of Large Wave Heights from Super Typhoon Nepartak (2016) in the Eastern Waters of Taiwan
Authors: Hsiao Shih-Chun , Chen Hongey , Wu Han-Lun , Chen Wei-Bo , Chang Chih-Hsin , Guo Wen-Dar , Chen Yung-Ming , Lin Lee-Yaw
Published: March 2020

Super Typhoon Nepartak (2016) was used for this case study because it is the most intense typhoon that made landfall in Taiwan in the past decade. Winds extracted from the Climate Forecast System version 2 (CFSV2) and ERA5 datasets and merged with a parametric typhoon model using two hybrid techniques served as the meteorological conditions for driving a coupled wave-circulation model. The computed significant wave heights were compared with the observations recorded at three wave buoys in the eastern waters of Taiwan. Model performance in terms of significant wave height was also investigated by employing the CFSV2 winds under varying spatial and temporal resolutions. The results of the numerical experiments reveal that the simulated storm wave heights tended to decrease significantly due to the lower spatial resolution of the hourly winds from the CFSV2 dataset; however, the variations in the storm wave height simulations were less sensitive to the temporal resolution of the wind field. Introducing the combination of the CFSV2 and the parametric typhoon winds greatly improved the storm wave simulations, and similar phenomena can be found in the exploitation of the ERA5 dataset blended into the parametric wind field. The overall performance of the hybrid winds derived from ERA5 was better than that from the CFSV2, especially in the outer region of Super Typhoon Nepartak (2016).
2,4,6-Tris(4-Iodophenyl)-1,3,5-trimethylbenzene
Authors: Bejan Dana , Marangoci Narcisa Laura , Rotaru Alexandru , Trandabat Alexandru Florentin , Bahrin Lucian Gabriel
Published: March 2020

2,4,6-Tris(4-iodophenyl)-1,3,5-trimethylbenzene was synthesized from 2,4,6-triphenyl-1,3,5-trimethylbenzene, using [bis(trifluoroacetoxy)iodo]benzene as the iodinating agent. The title compound was characterized by means of NMR, IR, and mass spectrometry, as well as TG analysis.
In-situ X-ray Differential Micro-tomography for Investigation of Water-weakening in Quasi-brittle Materials Subjected to Four-point Bending
Authors: Koudelka Petr , Fila Tomas , Rada Vaclav , Zlamal Petr , Sleichrt Jan , Vopalensky Michal , Kumpova Ivana , Benes Pavel , Vavrik Daniel , Vavro Leona , Vavro Martin , Drdacky Milos , Kytyr Daniel
Published: March 2020

Several methods, including X-ray radiography, have been developed for the investigation of the characteristics of water-saturated quasi-brittle materials. Here, the water content is one of the most important factors influencing their strength and fracture properties, in particular, as regards to porous building materials. However, the research concentrated on the three-dimensional fracture propagation characteristics is still significantly limited due to the problems encountered with the instrumentation requirements and the size effect. In this paper, we study the influence of the water content in a natural quasi-brittle material on its mechanical characteristics and fracture development during in-situ four-point bending by employing high-resolution X-ray differential micro-tomography. The cylindrical samples with a chevron notch were loaded using an in-house designed four-point bending loading device with the vertical orientation of the sample. The in-house designed modular micro-CT scanner was used for the visualisation of the specimen’s behaviour during the loading experiments. Several tomographic scans were performed throughout the force-displacement diagrams of the samples. The reconstructed 3D images were processed using an in-house developed differential tomography and digital volume correlation algorithms. The apparent reduction in the ultimate strength was observed due to the moisture content. The crack growth process in the water-saturated specimens was identified to be different in comparison with the dry specimens.
Phase Solubility Changes during Hydration of Monocalciumaluminate and Calcite—The Influence of Alkali Accumulation
Authors: Manninger Tanja , Jansen Daniel , Neubauer Jürgen , Goetz-Neunhoeffer Friedlinde
Published: March 2020

The reaction of CA (monocalcium aluminate) with calcite was closely monitored with regard to phase development, pore water ion content and heat flow. Calcite acts as filler and reactant, finally leading to thermodynamically stable products after hydration at ambient conditions. For better understanding the mechanism taking place, a CA-cement and a commercial calcite mix were compared to a pure CA and pure calcite mix. Both reaction paths were compared. Thermodynamic modeling with PhreeqC gave insight about factors that can influence the course of the hydration reaction. Alkali ions in pore solution of the CA-cement relocate solubility curves of hydration products. Taking into account as many of the alkaline ions as possible, resulted in the closest representation of the measured phase content, confirming thermodynamic modeling. The high dynamics that develop during reaction could only be addressed if a concentration of alkalis in the pore solution at later points in time was respected, thus leading to a shift of solubility curves over time. This was not observed with the pure CA in absence of alkalis.
NiO Pseudocapacitance and Optical Properties: Does The Shape Win?
Authors: Carbone Marilena , Missori Mauro , Micheli Laura , Tagliatesta Pietro , Bauer Elvira Maria
Published: March 2020

In the present paper, we investigate the effects of alkali and operational temperature on NiO capacitive and optical properties. The NiO samples were prepared by a straightforward, surfactant-free hydrothermal synthesis, employing Ni(NO3)2 and either urea or moderately sterically hindered triethylamine (TEA). The syntheses were followed by calcinations at either 400 or 600 °C. NiO samples were characterized by XRD, scanning electron microscopy, and nitrogen adsorption isotherms. The optical properties were investigated by reflectance spectroscopy, and the pseudocapacitance was studied by cyclic voltammetry and galvanostatic charge charge-discharge measurements. We found that the synthesis with TEA yielded nanoflowers whereas the morphology of the synthesis with urea varied with the calcination temperature and resulted in nanoparticles or nanoslices at calcination temperatures of 400 and 600 °C, respectively. The NiO samples prepared at a lower temperature displayed a favorable combination of surface area and porosity that allowed for high performance with capacitances of 502 and 520 F g−1 at a current density of 1 A g−1 for nanoflowers and nanoparticles, respectively. The band gaps of all the samples were compatible with the estimated nanoparticle sizes. Finally, we used the synthesized NiO samples for the preparation of screen-printed electrodes (SPEs) modified by drop-casting and probed them against a [Fe(CN)6]3−/4− probe.
Characterization and Properties of Mg-xGd-1.5Nd-0.5Zn-0.5Zr Alloys for Biodegradation Applications
Authors: Gui Zhenzhen , Zhang Junyi , Kang Zhixin
Published: March 2020

The differences in microstructural characteristics, mechanical properties, and corrosion behavior of the as-cast and solution-treated Mg-xGd-1.5Nd-0.5Zn-0.5Zr alloys (Mg-xGd, x = 1, 3, and 5) were studied and discussed. The as-cast Mg-xGd alloys mainly consisted of an α-Mg and island-like eutectic (Mg,Zn)3RE phase, a few cuboidal phases (REH2), and a ZnZr phase. With the increase of Gd content, the grain sizes of the as-cast Mg-xGd alloys decreased. Compared to the microstructure of the as-cast Mg-xGd alloys, the eutectic (Mg,Zn)3RE phase disappeared and the cuboidal REH2 phases existed in the solution-treated Mg-xGd alloys. A large amount of ZnZrx phase was precipitated from α-Mg in the Mg-3Gd alloy and demonstrates a flower-like distribution. The ultimate tensile strength (UTS) and yield strength (YS) of the solution-treated Mg-xGd alloys increased with an increasing Gd content, with the UTS and YS of the Mg-5Gd alloys reaching 217.5 and 125.2 MPa, respectively. Immersion and electrochemical tests showed that the as-cast Mg-3Gd alloy presented the best corrosion resistance with a corrosion rate of 0.285 mm/yr. The corrosion resistance of the solution-treated Mg-3Gd alloy attained the lowest value (0.973 mm/yr), due to the large quantities of ZnZrx with a flower-like phase distribution, forming series of galvanic couple groups with the α-Mg.
Inventive Microstructural and Durability Investigation of Cementitious Composites Involving Crystalline Waterproofing Admixtures and Portland Limestone Cement
Authors: Azarsa Pejman , Gupta Rishi , Biparva Alireza
Published: March 2020

The durability of a cement-based material is mainly dependent on its permeability. Modifications of porosity, pore-structure and pore-connectivity could have significant impacts on permeability improvement, which eventually leads to more durable materials. One of the most efficient solutions in this regard is to use permeability reducing admixtures (PRA). Among these admixtures for those structures exposed to hydro-static pressure, crystalline waterproofing admixtures (CWA) have been serving in the construction industries for decades and according to ACI 212—chemical admixtures’ report, it has proven its capability in permeability reduction and durability-enhancement. However, there is substantial research being done on its durability properties at the macro level but very limited information available regarding its microstructural features and chemical characteristics at the micro level. Hence, this paper presents one of the first reported attempts to characterize microstructural and chemical elements of hydration products for cementitious composites with CWA called K, P and X using Scanning Electron Microscopy (SEM). Backscattered SEM images taken from a polished-section of one CWA type—K—admixture were analyzed in ImageJ to obtain paste matrix porosity, indicating a lower value for the CWA-K mixture. X-ray analysis and SEM micrographs of polished sections were examined to identify chemical compositions based on atomic ratio plots and brightness differences in backscatter-SEM images. To detect chemical elements and the nature of formed crystals, the fractured surfaces of three different CWA mixtures were examined. Cementitious composites with K admixture indicated needle-like crystal formation—though different from ettringite; X and P admixtures showed sulfur peaks in Energy Dispersive Spectrum (EDS) spectra, like ettringite. SEM images and X-ray analyses of mixtures incorporating Portland Limestone Cement (PLC) indicated lower-than-average porosity but showed different Si/Ca and Al/Ca atomic ratios.
TPLVM: Portfolio Construction by Student’s t-Process Latent Variable Model
Authors: Uchiyama Yusuke , Nakagawa Kei
Published: March 2020

Optimal asset allocation is a key topic in modern finance theory. To realize the optimal asset allocation on investor’s risk aversion, various portfolio construction methods have been proposed. Recently, the applications of machine learning are rapidly growing in the area of finance. In this article, we propose the Student’s t-process latent variable model (TPLVM) to describe non-Gaussian fluctuations of financial timeseries by lower dimensional latent variables. Subsequently, we apply the TPLVM to portfolio construction as an alternative of existing nonlinear factor models. To test the performance of the proposed method, we construct minimum-variance portfolios of global stock market indices based on the TPLVM or Gaussian process latent variable model. By comparing these portfolios, we confirm the proposed portfolio outperforms that of the existing Gaussian process latent variable model.
Resonance Enhancement by Suitably Chosen Frequency Detuning
Authors: Dutykh Denys , Tobisch Elena
Published: March 2020

The theory of exact resonances (kinematics and dynamics) is well developed while even the very concept of detuned resonance is ambiguous and only studies of their kinematic characteristics (that is, those not depending on time) are available in the literature. In this paper, we report novel effects enforced by the resonance detuning on solutions of the dynamical system describing interactions of three spherical planetary waves. We establish that the energy variation range can significantly exceed the range of the exact resonance for suitably chosen values of the detuning. The asymmetry of system’s solutions with respect to the sign of the detuning parameter is demonstrated. Finally, a non-monotonic dependence of the energy oscillation period with respect to detuning magnitude is discovered. These results have direct implications in physics of atmosphere, e.g., for prediction of weather extremes in the Northern Hemisphere midlatitudes (Proc. Nat. Acad. Sci. USA 2016, 133(25), 6862–6867). Moreover, similar study can be conducted for a generic three-wave system taken in the Hamiltonian form which makes our results applicable for an arbitrary Hamiltonian three-wave system met in climate prediction theory, geophysical fluid dynamics, plasma physics, etc.
Corporate Performance and Economic Convergence between Europe and the US: A Cluster Analysis Along Industry Lines
Authors: Vâlsan Călin , Druică Elena
Published: March 2020

We investigate the extent to which the United States and the countries of Europe have achieved economic convergence of their corporate sector. We define convergence as the homogenization of economic performance, institutional arrangements, and market valuation taking place at the meso-economic level. We perform a cluster analysis along industry lines and find that industries and corporations on both continents cluster in four groups, based on six variables measuring operating performance, ownership, and market valuation. The clusters resulted from the US data are more unstable than those resulted from European data. We are also able to pair a handful of highly similar clusters between the US and European data. These findings suggest a complex dynamic. It seems that the US corporate sector is more homogeneous than the European one. Moreover, some degree of convergence between the European Union and the United States appears to have already occurred.
Role of Functional Biomarkers to Identify Early Vitamin B12 Deficiency in Patients with Sleeve Gastrectomy: A Cross-Sectional Study
Authors: Al-Dirbashi Osama Y. , Sharma Charu , Al Dahouri Nahid , Al Aidaros Anas , Al-Muhairi Shamma , Beiram Rami , Gariballa Salah , Al Kaabi Juma
Published: March 2020

Background and objectives: Although laparoscopic sleeve gastrectomy (LSG) is effective for obesity management, postoperative vitamin B12 (B12) deficiency is of major concern. In this cross-sectional study, we assessed the levels of B12 and its related functional biomarkers, namely, total homocysteine (tHcy), methylmalonic acid (MMA), folate, methylcitric acid (MCA), and hemoglobin (Hb), in one-year postoperative LSG patients and matched controls. Materials and Methods: Plasma B12, tHcy, MMA, folate, and MCA were measured in matched controls (n = 66) and patients (n = 71) using validated liquid chromatography-tandem mass spectrometry techniques and protocols in the United Arab Emirates (UAE). Results: The median B12 concentration in patients (177 pmol/L) was significantly lower (p < 0.001) than in the controls (334.7 pmol/L). The tHcy and MMA levels were significantly increased (p < 0.001 and p = 0.011, respectively) and folate levels were significantly decreased (p = 0.001) in the LSG patients compared to the controls. Interestingly, no significant difference in MCA levels were observed between the two groups. The levels of tHcy and MMA were concomitantly increased with the decreased folate levels in postoperative LSG patients when compared with the controls. The Hb levels were significantly lower in males and females in the patient group compared with those in the control group, respectively (p = 0.005 and p = 0.043). Conclusions: This is the first report of serum levels of B12 and its functional biomarkers in postoperative LSG patients among a local population from the UAE. Our findings revealed significant alterations of the B12 biomarkers, total B12, MMA, and tHcy in one-year postoperative LSG patients.
Preparation of Ultrafine-Grained Continuous Chips by Cryogenic Large Strain Machining
Authors: Chen Haitao , Zhang Baoyu , Zhang Jiayang , Deng Wenjun
Published: March 2020

Conventional orthogonal machining is an effective severe plastic deformation (SPD) method to fabricate ultrafine-grained (UFG) materials. However, UFG materials produced by room temperature-free machining (RT-FM) are prone to dynamic recovery, which decreases the mechanical properties of UFG materials. In this study, the cryogenic orthogonal machining technique was implemented to fabricate chips that have an abundant UFG microstructure. Solution-treated Al-7075 bulk has been processed in cryogenic temperature (CT) and room temperature (RT) with various machining parameters, respectively. The microstructure, chip morphology and mechanical properties of CT and RT samples have been investigated. CT samples can reach a microhardness of 167.46 Hv, and the hardness of CT samples is higher than that of the corresponding RT samples among all parameters, with an average difference of 5.62 Hv. Piecemeal chip obtained under RT has cracks on its free surface, and elevated temperature aggravates crack growth, whereas all CT samples possess smoother surfaces and continuous shape. CT suppresses dynamic recovery effectively to form a heavier deformation microstructure, and with a higher dislocation density in CT samples, they further improve the chips’ hardness. Also, CT inhibits the formation of solute cluster and precipitation to enhance the formability of material, so that continuous chips are formed.
Molecular Ecological Network Complexity Drives Stand Resilience of Soil Bacteria to Mining Disturbances among Typical Damaged Ecosystems in China
Authors: Ma Jing , Lu Yongqiang , Chen Fu , Li Xiaoxiao , Xiao Dong , Wang Hui
Published: March 2020

Understanding the interactions of soil microbial species and how they responded to disturbances are essential to ecological restoration and resilience in the semihumid and semiarid damaged mining areas. Information on this, however, remains unobvious and deficiently comprehended. In this study, based on the high throughput sequence and molecular ecology network analysis, we have investigated the bacterial distribution in disturbed mining areas across three provinces in China, and constructed molecular ecological networks to reveal the interactions of soil bacterial communities in diverse locations. Bacterial community diversity and composition were classified measurably between semihumid and semiarid damaged mining sites. Additionally, we distinguished key microbial populations across these mining areas, which belonged to Proteobacteria, Acidobacteria, Actinobacteria, and Chloroflexi. Moreover, the network modules were significantly associated with some environmental factors (e.g., annual average temperature, electrical conductivity value, and available phosphorus value). The study showed that network interactions were completely different across the different mining areas. The keystone species in different mining areas suggested that selected microbial communities, through natural successional processes, were able to resist the corresponding environment. Moreover, the results of trait-based module significances showed that several environmental factors were significantly correlated with some keystone species, such as OTU_8126 (Acidobacteria), OTU_8175 (Burkholderiales), and OTU_129 (Chloroflexi). Our study also implied that the complex network of microbial interaction might drive the stand resilience of soil bacteria in the semihumid and semiarid disturbed mining areas.