bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of a pump unit and geothermal pump use on soil condition
Authors: Orlov K P , Orlova V A , Kupriyanov S V , Bojkov Y N
Published: October 2020

The article considers the advantages of air heat pump use. Their positive impact on ecology compared to other types of similar pumps, in particular geothermal ones, is shown. The author aims to focus on the problems of gross interference with the soil structure. In the majority of sources, geothermal pumps are presented as environmentally friendly and recommended pumps. The task of the study is to prove analytically, as well as using general scientific methods, that these sources are wrong. The use of geothermal heat pumps causes damage to the environment, since well drilling in the vast majority of cases is followed by formation segregation, interstratal insulation violation, change in natural processes of water bodies self-purification, rate of mineralization flow, kinetics of microflora and fauna development and die-away. Significant areas of uninhabitable trees and plants are formed due to subsoil cooling and freezing. Various heat pump layouts were analyzed and conclusion on the most environmentally friendly integrated use of heat air pump and solar energy was made.
Dynamic stress-strain state of earth dam considering an inhomogeneous base
Authors: Salyamova K D
Published: October 2020

The design, construction and operation of important water retaining structures (high earth dams) in seismic regions, such as the territory of the Republic of Uzbekistan, require constant improvement of the methods to calculate their behavior under various loads, including seismic ones. A variational statement of the problem of natural vibrations of a plane elastic earth dam with and without an adjacent base is given. The problem is solved numerically by the finite element method. The aim of this study is to determine the effect of a piecewise-inhomogeneous section at the base of an earth dam on the stress-strain state of the dam itself. The result of solving the problem lies in the analysis of eigenfrequencies, vibration modes, stresses of a concrete earth dam.
Method for justification options for housing stock reconstruction
Authors: Biryukov Yu , Makarov R , Dobryshkin E
Published: October 2020

The main contradictions in the theory and practice of housing stock objects reconstruction are revealed. The technical condition of housing stock reconstruction facilities is analysed and a study of the organization and planning of housing stock reconstruction in the North-western federal district is performed. A method of substantiating options for reconstruction of housing stock in the North-Western federal district has been developed. Its practical significance lies in its application to justify the reconstruction option for technical re-equipment and modernization of housing facilities in Federal and municipal authorities implementing state policy in the field of providing the population with comfortable living conditions, as well as in regional departments of contractors, which perform housing facilities repair work, at the stage of design estimates development for the reconstruction of facilities. Thus, the purpose of the study (to improve the efficiency of planning the housing facilities reconstruction in the North-western federal district on the basis of the developed scientific and methodological apparatus) has been achieved.
Human resources for BIM jobs in the AEC industry in Vietnam: an investigation on job positions and requirements
Authors: Nguyen The-Quan , Dau-Thi Nguyet-Anh , Dao Thuy-Ninh
Published: October 2020

The paper presents research results from 90 BIM jobs vacancies for the AEC industry in Vietnam which were advertised on popular recruitment channels. The results show that BIM jobs in the South are more popular than in the North and the Central. BIM-related job positions are different from company to company, but this study groups those positions into three basic positions according to the international best practice approach: BIM Manager, BIM Coordinator, BIM Modeler. For BIM Modelers, their main job is to develop 3D models, deploy design documents, and coordinate with stakeholders to perform the work. BIM Coordinator’s on-demand job is to coordinate models across disciplines, check conflict and report, control models, support project management. The main task of a BIM Manager is to manage and develop BIM uses, to ensure the information to be communicated among the parties in the projects, and train BIM human resources in the company. There are many requirements for these positions, among them are the two basic requirements of “experience” and “software” (organisations may use different software for the BIM uses they apply). The article also emphasizes the need to have more involvement of professional associations, state management agencies, etc. to standardize job positions, then later they can award BIM licenses to the proper human resources appropriately.
Theoretical aspects of using fragments of destroyed buildings and structures of Iraq
Authors: Ahmed Ahmed Ahmed Anees
Published: October 2020

The relevance of the work is determined with the search for alternative sources of raw materials for the construction industry, associated with the utilization of technogenic waste. The novelty of the paper is to identify the scientific regularities of the influence of concrete scrap from fragments of destroyed buildings and structures on the formation of the micro-structure of light and heavy concrete. Concrete scrap was prepared as both fillers of cement materials and small aggregates, based on which concretes with high mechanical properties were created. The compositions were designed from the point of view of geonics (geodaetica), in particular, taking into account the law of affinity of structures. The strength characteristics of concrete mixes were studied in accordance with EN 12390-3. In addition, microstructural, morphological and thermal properties of raw materials and concretes were determined during 28-day of curing. For the first time, a dense microstructure of the composite was provided, both by products of Portland cement and hydration, and, in part, by products of hydration of previously unreacted clinker, whose minerals are present in concrete waste and are activated when they are crushed. The use of fragments of destroyed buildings and structures as a filler of cementing material when replacing Portland cement up to 20% allows getting better compressive strength, both heavy and light concretes.
Plane model of particle separation in disintegrators with internal circulation of the grinding material
Authors: Orekhova T N , Kachaev A E , Prokopenko V S
Published: October 2020

The paper offers a method for evaluating the separation process of fine particles in the design of a classifier of a disintegrator with internal circulation of the dispersed material. Disintegrator type mills are fairly common in the construction materials industry and related industries. However, there are a number of technological problems with this type of equipment, which hinder their wider use in the production of dispersed powders with a high specific surface area. One of these problems is the presence of under-ground (coarse) particles in the volume of the finished product of a given fraction. The quality of classification is evaluated taking into account the velocity parameters of fine particles in the classifier device built into the disintegrator body. A new design of a gravity-type classifying device is considered, which contributes to the efficient return of large substandard particles to the finishes grinding in the disintegrator grinding chamber. The publication provides a method for determining the speed parameters of particle dynamics in the chamber of the classifier device of a disintegrator mill, and also presents a model for numerical calculation of the efficiency of the classifier device. This theoretical method of assessing the quality of separation of particles in the disintegrator is to define a measure of the degree of separation, to assess the effectiveness of recycle coarse fractions of grinding material powder: degree of operational separation shows the ability of disintegrator to operate in various process modes, and sets the granulometric boundaries for obtaining a particular fraction after grinding in the disintegrator.
Energy characteristics of sands of deposits in the Ivanovo region
Authors: Morozova M V , Akulova M V , Frolova M A
Published: October 2020

It is proposed to use the energy potential of rock-forming minerals obtained in the process of rock synthesis as an energy criterion for ranking raw materials for the production of construction materials. The energy of atomization and its specific values calculated based on the principles of crystal energy are used as a quantitative parameter. The estimation of two deposits of sands of the Ivanovo region on energy of atomization, specific mass energy of atomization, specific volume of energy of atomization (energy density) is carried out. It was found that, despite the difference in the chemical, mineral composition and origin of rocks, macroenergy parameters have similar values. The energy density value allows classifying the considered sands as high-energy-dense. The possible level of use of this energy reserve due to mechanical crushing of raw material is established. Quantifying potential energy of the system that fallen after crushing the material in the surface was carried out based on the values of critical surface tension and specific surface area of raw materials (formed after the process of mechanical grinding). The level of possible use of the potential energy reserve due to the formation of a new material surface was characterized by the activity of the surface of fine samples. The obtained values of surface tension and surface activity showed that the sands of the Nekhtskoe deposit, in comparison with the sands of the Khromtsovskoye deposit, are preferable to be used as an active fine-dispersed component for obtaining binding compositions.
The advantages of using polymer-bituminous concentrate for the production of polymer-bituminous binders
Authors: Denisov V P , Akimov A E , Yadykina V V
Published: October 2020

Construction of road surfaces with an extended service life, as well as the transition to methods of volumetric and functional design of asphalt concrete mixtures, leads to the need for the use of polymer-bituminous binders, as bitumen without polymer modifiers does not provide the required physical and mechanical characteristics and durability. Traditional PBB production technologies involve the use of complex technological processes and equipment. In addition, existing technological features lead to a significant decrease in the quality of the resulting polymer-bituminous binder. In this paper, we consider the possibility of obtaining PBB with high physical and mechanical parameters by using the PBC modifier (polymer-bituminous concentrate). The modifier under study is a polymer dispersed in an oil base and stabilized with active components. When added to bitumen, a colloid mill and complex processes of preparation and maturation of the binder are not required. Experiments have shown that the resulting binder has the characteristics of PBB, in particular, an extended temperature range of plasticity, elasticity and resistance to cyclic loads. At the same time, gentle heating modes provide increased resistance to aging during the preparation of asphalt concrete mixture and its operation. The ease of use of this modifier makes it possible to obtain PBB with a wide range of characteristics that correspond to the operating conditions.
The acceleration of the peat secondary consolidation due to the sorption of bound water with disperse clay
Authors: Ivakhnova G Yu , Nevzorov A L
Published: October 2020

According to observations at the experimental site, the primary consolidation of the 6-6.5 m peat layer completed in 3-5 years after the sandy embankment was filled on. Secondary consolidation of peat caused by the removal of bound water from micropores and channels within vegetation remains is the cause of settlement that has not stabilized for decades. The aim of laboratory research was to evaluate the effects of two methods for peat settlement stabilization at the stage of secondary consolidation – vacuuming and sorption of bound water of disperse clay. Tests were carried out with peat, which has a degree of decomposition of 40-45 %, a density of 0.98–1.12 g/cm3, a void ratio of 11.8–13.8. Samples with a diameter of 87 mm and a height of 30, 50 and 70 mm were set into odometers and maintained under a load of 25, 50 and 100 kPa for 5-6 months, after that experiments to stabilize secondary consolidation were started. In contrast to vacuuming, the use of pre-dried clay with the following properties turned out to be very effective: maximum hygroscopic water content 43%, liquid limit 198%, plastic limit 58%, specific surface area 411 m2/g. The volume of clay was about 20% of the volume of peat samples. Deformations of samples due to water sorption by clay increased within 2-4 days and reached 0.09-0.11 of their initial height. The penetration of clay into the peat can be performed by drilling of boreholes, vibration stamping and other methods.
The research of different types of clays of the Kazakhstan for the production of wall ceramic products
Authors: Sarsenbayev B K , Karshyga G O , Budikova A M , Shakey A M
Published: October 2020

The manuscript presents the results of analysis and synthesis of researches of scientists of the CIS and Kazakhstan on the use of various clays for the production of wall ceramic products. There was investigated the application of refractory and brown clays, loam to optimize the composition of the furnace charge and the choice of technological parameters of the production of wall ceramic products. The drying and burning properties of the samples burned at 850 °C, 900 °C, 950 °C, 1000 °C and 1050°C, 1100÷1150 °C with determination of strength, shrinkage, water absorption of the material at all specified burning temperatures were studied. The optimal burning temperatures for the study of the burning properties of the above three clays are determined. In many regions of the Republic of Kazakhstan the problem of production of high-quality wall ceramic manufacture is particularly acute. Most seasonal plants turns out low-branded products (the M75-100, B < 25), often not conforming to requirements of normative documents, does not have the expanded range, the decorative brick necessary for construction of low houses (country, cottage buildings) as implementation of the similar program requires, first of all, detailed studying of technological and physical and chemical features of clay raw materials is not issued.
Binders from gypsum-containing waste and products based on them
Authors: Alfimova N I , Pirieva S Yu , Elistratkin M Yu , Nikulin I S , Titenko A A
Published: October 2020

Gypsum binders are among the most environmentally friendly from the point of view of their production. The raw material base for their production is represented not only by natural raw materials, but also by a wide variety of technogenic materials, phosphogypsum is the most multi-ton and studied of them. At the same time, citrogypsum is also a promising raw material for the production of gypsum binders and, in comparison with phosphogypsum, does not contain toxic impurities that require the development of additional measures for their removal. Synthesis of the binder from gypsum-containing waste is possible with the use of various technologies using autoclaves, chemical reagents and at elevated temperature and atmospheric pressure. Each method has its own advantages and disadvantages. The most acceptable from the point of view of industrial production is the method of calcination at atmospheric pressure, but it does not allow producing high-strength binders and products based on them. It is possible to increase the efficiency of using such binders for the production of small-piece products by applying special molding modes with increased pressing pressure. The possibility of obtaining a binder from the waste of citric acid – citrogypsum production by calcination in a semi-industrial plant is shown. Using standard methods, a complete analysis of the resulting binder was performed: granulometry, grain shape and morphology, normal density and setting time. A comparison was made with construction gypsum (G5) and high-strength gypsum (G16). The possibility of obtaining small – piece products from a synthesized binder with a dry compressive strength of 20 MPa is shown by using the semi-dry pressing method at high pressures.
The use of augmented reality technology in the reconstruction of a lost cultural heritage site
Authors: Tomilina E M , Gontar E V , Frolova M A
Published: October 2020

The paper is devoted to the study of the possibility of using augmented reality technology in the process of hypothetical (virtual) restoration of the authentic appearance of lost cultural heritage structures on the example of an object of regional significance - the cinema “Sever”. Based on the collected archival data and field studies, a historical and retrospective analysis of the cultural heritage object and its territory is presented, the construction history of the monument site is developed, dimensional drawings are restored and three-dimensional models of the object in various historical periods of the monument life are created. A detailed description of actions for creating an augmented reality object and exporting its animated model to an accessible digital platform (Instagram) was developed. The expediency of using the augmented reality approach in the reconstruction of lost cultural heritage objects is shown. This technology allows recreating the appearance of the lost monument in conjunction with the actual architectural component of the urban space. Successful implementation of this approach will allow for more detailed cultural, historical, archaeological, ethnographic, anthropological and other research.
Employment of vacation queueing models for maintenance of engineering systems of residential buildings
Authors: Afanasyev G A
Published: October 2020

We consider two main functions for servicing the housing stock-scheduled prophylactic inspection and repair of technical objects and the elimination of sudden malfunctions of technical equipment. An approach to analysis based on vacation queueing systems is proposed. We introduce two vacation queueing models in which during vacations the team relizes the prophylactic inspection and repair of technical objects. In the first model during vacation the elimination of sudden malfunctions of technical equipment stops and the second model has a working vacation scheme. For each model the characteristics which determine the quality of the work of the server (team), as well as the boundaries of the change of parameters at which the team copes with the work from the standpoint of a particular criterion are defined.
Influence of design and technological parameters of a high-speed paddle mixer on the quality of dry building mixes
Authors: Brazhnik Yu V , Nesmeyanov N P , Brazhnik A A
Published: October 2020

Today, one of the most promising building materials is dry building mixes. Their production is not only a large segment of the construction market, but also a kind of testing ground for promising developments of modern technological equipment. The paper discusses the design of a high-speed fixed drum paddle mixer for producing modified dry building mixes with a complex recipe. The question is raised about the complexity of the uniform distribution of components in the total volume of the mix. A number of existing factors affecting the distribution of components of the prepared mix are determined. Criteria for evaluating the quality of the finished mix are given. The method for determining the influence of design and technological parameters on the quality indicators of the finished product is described. The method of experimental research that allows evaluating the influence of the design and technological parameters of the mixer on the inhomogeneity coefficient of the resulting dry construction mix is presented. The obtained results confirm the effectiveness of the proposed design of a high speed paddle mixer to obtain high-quality modified dry building mixes at a minimum rate of heterogeneity of the mixture, as well as other indicators to measure the quality of the final product, diagrams of dependence of inhomogeneity coefficient of structural and technological parameters of the mixer are given. Rational values of the main design and technological parameters of the mixer for the production of dry building mixes are given.
Numerical simulation of perimeter drainage system considering peat water permeability change over time
Authors: Nikitin A V , Zaborskaya O M
Published: October 2020

A reliable forecast of water depression in waterlogged areas depends on the due consideration of specific peat properties: a considerable change in the water permeability of peat once water hydrostatic uplift is removed, clogging over time, decomposition and other factors. The article presents an example of numerical simulation in Plaxis software of a perimeter drainage system, where groundwater level has been monitored for 1 year. Piezometers were installed on site at the distance of 7, 17 and 30 m from the drain pipe of a building under construction. Deformation-strength properties and filtration properties of peat were determined on samples taken from excavated pits. Besides, the samples were tested using filtration tubes to identify changes in water permeability of peat over time and depending on the amount of water filtered through peat. The survey took 90 days at the ambient temperature of 6 to 12 °C, which allowed avoiding rapid peat decomposition. The laboratory test results have shown that water permeability of natural-state peat samples has decreased by a factor of 2.7 to 3.1 with 450 to 580 liters of water filtered. The deviation of the design groundwater level calculated in Plaxis from its actual position did not exceed 0.07 m. Numerical simulation with due consideration of decreased water permeability of peat over time allows obtaining forecast results closer to the actual groundwater level.
Calculation of energy parameters of fixed drum concrete mixer with helicoid-type blades
Authors: Nesmyanov N P , Matusov M G
Published: October 2020

Currently, one of the most important areas in the construction industry is the production of high-quality concrete and construction mixes used in the manufacture of reinforced concrete products and structures, road, foundation, monolithic works, as well as used in the laying of bricks, blocks, etc. Concrete mixes are able to ensure high quality of the resulting products and structures when solidified. The scope of their use is the most extensive of all building materials, and production volumes are among the largest. The practice of using concrete in world and domestic construction has shown that it is effective, i.e. it has a number of advantages over new types of building materials, provides high productivity during construction work, is universal and easy to obtain. Initial components for the production of concrete are very common, easily accessible and transportable over long distances, which allows for the production of concrete mix in remote locations using mobile plants. To date, the enterprises of building industry is the production of equipment of various designs and principles of operation used for mixing. In the construction industry, a variety of mixing machines with both advantages and disadvantages have been used in the production of concrete mixes.
Use of glauconitic sand as a filler in the concrete mixes production
Authors: Botsman L N , Lunev R S , Ageeva M S , Nerovnaya S V
Published: October 2020

In recent years, any production tries to minimize labor costs by automating processes. Because of the high rate of automation, machines have come to replace people. In addition to reducing the share of human labor and increasing machine labor, any manufacturer seeks to reduce the cost of raw materials, which contributes to the search for new solutions in the use of old materials. Russia’s natural resource base is quite diverse, with special attention paid to the processing of technogenic waste and the creation of resource-saving technologies. Waste generation occurs at all stages of the movement of raw materials: from the moment of its extraction, when it is still a natural resource, to the end of operation of the product made from it. Waste dumps are a rich source of raw materials for the construction materials industry, as many of them are close to natural raw materials in their composition and properties. The complex physical and chemical composition and structure of waste from a number of industrial productions allow considering them as a real raw material base for the construction materials industry. The paper describes the principles of selecting the composition of concrete on glauconitic sand. Glauconitic sand is a waste product, which is why its use reduces the cost of concrete mixes and products made from them.
Stabilization of metallurgical slug from arc steel-making furnaces
Authors: Bodyakov A N , Meshkova K V , Dukhovny G S
Published: October 2020

At the present time the deficit of stone construction materials for transport construction points to the need for improving the range of used materials. The experience of motorway construction in economically advanced countries shows that the deficit of materials and construction costs can be significantly reduced through extensive use of industrial wastes. One promising avenue of researches is the use of metallurgical production wastes. Main methods on the prevention of slag decomposition by its stabilization are considered. The principle of increasing the stability of stone slag materials by adding a stabilizer to the steel-making slag composition during slag removal from the arc steel-making furnace, ensuring slag stabilization and prevention of the silicate decomposition after cooling, is established. Processes of the slag structure formation during its stabilization are studied. Processes of crystallisation and change of structure of dicalcium silicate are shown. The decomposition of steel-making slag can be prevented by adding a chemical stabilizer into its composition. It is established that a stabilizing agent shall consist of metallurgical production wastes that allows to fully stabilize slag and keep high-temperature modifications of belite in it when cooled. The possibility of obtaining crushed slag with a stable structure achieved by a chemical stabilization of melted slag is shown.
Digital design of a cable-driven parallel robot
Authors: Anciferov S I , Gaponenko E V , Karachevtseva A V , Kholoshevskaya L R
Published: October 2020

The paper analyzes various computer-aided design systems. It is shown that the use of CAD / CAM / CAE-system NX allows to reduce the cost of the final product, increase the level of quality, and reduce the time to market. The article discusses the digital design of a cable-driven parallel robot (CDPR) for various applications using the NX CAD / CAM / CAE system. The mechanism is a rigidly fixed frame connected through tensioned cables to a platform. CDPRs have such advantages as a large working area, ease of assembly and disassembly, high mobility, large lifting capacity, and reconfiguration. The kinematic diagram of the device is presented. Based on the terms of reference and sketch documentation, a preliminary composition of the CDPR has been developed. During the design, the Top-Down method was used. The characteristics are analyzed, and the workspace of the mechanism is formed, taking into account the factors of limitation. Shown is a detailed design of the basic structure of a CDPR with an indication of the main operations. An electronic-digital model of the basic structure of a CDPR, which will later be used for kinematic and static calculations, as well as for making an experimental sample, is presented.
Solid State Device from Plant Extracts
Authors: Emetere M.E. , Chijuo C. , Afolalu S.A.
Published: October 2020

The infusion of green solution into solid-state technology is timely at a time where land, air, and water pollution (from electronic waste) is high in most parts of the globe. At the moment, several research works have proven that plant extract doped with metallic compound exhibits high electrical, optical and chemical properties. In this research we examine two different plant extracts with different dopant. The special opto-transport property of the synthesized compounds was examined using an unconventional characterization technique. It was observed that both compounds can be identified as solid-state device with remarkable optical properties.
Application of Smart Materials in Civil Engineering and Architecture
Authors: Jerzy SZOLOMICKI
Published: October 2020

Smart materials are the result of great advancements in material engineering and have different practical applications. This paper presents a review of selected smart materials applied in modern building structures from civil engineering and architecture perspective and determines what advantages they can bring.These benefits include building structure, interior design and façade solution. A very important causative factor resulting from the use of intelligent materials is obtaining a new aesthetic effect. This effect can be achieved through refined patterns, change of shape, presentation of interactive images.
In-vitro investigation of green synthesized gold nanoparticle’s role in combined photodynamic and radiation therapy of cancerous cells
Authors: Neshastehriz Ali , Amini Seyed Mohammad , Mohammadi Amir , Mahdavi Seyed Rabi , Mahabadi Vahid Pirhajati , Akbari Abolfazl
Published: October 2020

Gold nanoparticles (AuNPs) have been introduced for increasing the effectiveness of various cancer treatments such as radiation and photodynamic therapy. Instead of toxic chemicals, various natural compounds have been introduced for AuNPs synthesis. Here, gallic acid-coated AuNPs (Ga@AuNPs) with the average diameter of 17.9 ± 10 nm and surface charge of −16.2 ± 3.2 mV have been synthesised through easy and single-step chemical route and were characterised with transmission electron microscopy (TEM), dynamic light scattering (DLS) and UV–Vis spectroscopy. The interaction of Ga@AuNPs and methylene blue (MB) photosensitisers was confirmed through various techniques such as FTIR spectroscopy, zeta potential investigation, and UV–vis spectroscopy. Based on our results, methylene blue was adsorbed to the surface of Ga@AuNPs through various amine and thiol functional groups. Upon laser radiation, a release of singlet oxygen species (ROS) from nanoformulation of methylene blue was more gradual than free methylene blue based on the determination of singlet oxygen in the present of 1,3-diphenylisobenzofuran (DPBF) radical scavenger. The Ga@AuNPs nanoparticles were not representing significant toxic effects toward cells. However, the synthesised nanoparticles could increase the effectiveness of radiation therapy or combined treatment of methylene blue mediated photodynamic and radiation therapy in an in-vitro investigation.
Influence of temperature and dimension in a 4H-SiC vertical power MOSFET
Authors: Alqaysi M H , Martinez A , Ubochi B , Batcup S , Ahmeda K
Published: October 2020

A study of the impact of dimension and temperature on a state of the art 4H-SiC power vertical DMOSFET has been carried out using drift-diffusion calculations in conjunction with electrical characterizations to extract physical parameters and doping profiles in a 6 μm channel length device. The model presented in this paper includes the effect of trapping in the channel/oxide interface. Using these parameters, the performance of corresponding lateral and vertical scaled devices are studied. Electrothermal simulations showing self-heating effects are also carried out. The results are qualitatively discussed with the help of an analytical physical model, which considers the interplay between the different device resistances. At low drain bias, the drain current is increased by 42.86% (I
D
 = 5 A at V
G
 = 20 V) when reducing the dimension vertically, whereas it is decreased by 28.57% (I
D
 = 2.5 A at V
G
 = 20 V) when reducing the dimension laterally. These effects are enhanced at high drain bias. In addition, the effect of dimension reduction for breakdown voltage, electric field and impact ionization is investigated. A substantial reduction in breakdown voltage was found when the vertical dimensions were decreased as compared to the lateral dimensions.
Do I lose cognitive function as fast as my twin partner? Analyses based on classes of MMSE trajectories of twins aged 80 and older
Authors: Muniz-Terrera Graciela , Robitaille Annie , Goerdten Jantje , Massa Fernando , Johansson Boo
Published: October 2020

Background

Aging is associated with an increasing risk of decline in cognitive abilities. The decline is, however, not a homogeneous process. There are substantial differences across individuals although previous investigations have identified individuals with distinct cognitive trajectories. Evidence is accumulating that lifestyle contributes significantly to the classification of individuals into various clusters. How and whether genetically related individuals, like twins, change in a more similar manner is yet not fully understood.

Methods

In this study, we fitted growth mixture models to Mini Mental State Exam (MMSE) scores from participants of the Swedish OCTO twin study of oldest-old monozygotic and same-sex dizygotic twins with the purpose of investigating whether twin pairs can be assigned to the same class of cognitive change.

Results

We identified four distinct groups (latent classes) whose MMSE trajectories followed different patterns of change over time: two classes of high performing individuals who remained stable and declined slowly, respectively, a group of mildly impaired individuals with a fast decline and a small group of impaired individuals who declined more rapidly. Notably, our analyses show no association between zygosity and class assignment.

Conclusions

Our study provides evidence for a more substantial impact of environmental, rather than genetic, influences on cognitive change trajectories in later life.
Impact of COVID-19 Confinement on Alcohol Purchases in Great Britain: Controlled Interrupted Time-Series Analysis During the First Half of 2020 Compared With 2015–2018
Authors: Anderson Peter , Llopis Eva Jané , O’Donnell Amy , Kaner Eileen
Published: October 2020

Aims

To investigate if COVID-19 confinement led to excess alcohol purchases by British households.

Methods

We undertake controlled interrupted time series analysis of the impact of COVID-19 confinement introduced on 26 March 2020, using purchase data from Kantar Worldpanel’s of 23,833 British households during January to early July 2020, compared with 53,428 British households for the same time period during 2015–2018.

Results

Excess purchases due to confinement during 2020 were 178 g of alcohol per 100 households per day (adjusted for numbers of adults in each household) above an expected base of 438 g based on averaged 2015–2018 data, representing a 40.6% increase. However, when adjusting for expected normal purchases from on-licenced premises (i.e. bars, restaurants, etc.), there was evidence for no excess purchases of grams of alcohol (a 0.7% increase). With these adjustments, beer purchases dropped by 40%, wine purchases increased by 15% and spirits purchases by 22%. Excess purchases increased the richer the household and the lower the age of the main shopper. Confinement was associated with a shift in purchases from lower to higher strength beers.

Conclusion

During the COVID-19 confinement, the evidence suggests that households did not buy more alcohol for the expected time of the year, when adjusting for what they normally would have purchased from on-licenced premises.
A review of COVID-19 biomarkers and drug targets: resources and tools
Authors: Caruso Francesca P , Scala Giovanni , Cerulo Luigi , Ceccarelli Michele
Published: October 2020

The stratification of patients at risk of progression of COVID-19 and their molecular characterization is of extreme importance to optimize treatment and to identify therapeutic options. The bioinformatics community has responded to the outbreak emergency with a set of tools and resource to identify biomarkers and drug targets that we review here. Starting from a consolidated corpus of 27 570 papers, we adopt latent Dirichlet analysis to extract relevant topics and select those associated with computational methods for biomarker identification and drug repurposing. The selected topics span from machine learning and artificial intelligence for disease characterization to vaccine development and to therapeutic target identification. Although the way to go for the ultimate defeat of the pandemic is still long, the amount of knowledge, data and tools generated so far constitutes an unprecedented example of global cooperation to this threat.
Simulating intervertebral disc cell behaviour within 3D multifactorial environments
Authors: Baumgartner L , Reagh J J , González Ballester M A , Noailly J
Published: October 2020

Motivation

Low back pain is responsible for more global disability than any other condition. Its incidence is closely related to intervertebral disc (IVD) failure, which is likely caused by an accumulation of microtrauma within the IVD. Crucial factors in microtrauma development are not entirely known yet, probably because their exploration in vivo or in vitro remains tremendously challenging. In silico modelling is, therefore, definitively appealing, and shall include approaches to integrate influences of multiple cell stimuli at the microscale. Accordingly, this study introduces a hybrid Agent-based (AB) model in IVD research and exploits network modelling solutions in systems biology to mimic the cellular behaviour of Nucleus Pulposus cells exposed to a 3D multifactorial biochemical environment, based on mathematical integrations of existing experimental knowledge. Cellular activity reflected by mRNA expression of Aggrecan, Collagen type I, Collagen type II, MMP-3 and ADAMTS were calculated for inflamed and non-inflamed cells. mRNA expression over long periods of time is additionally determined including cell viability estimations. Model predictions were eventually validated with independent experimental data.

Results

As it combines experimental data to simulate cell behaviour exposed to a multifactorial environment, the present methodology was able to reproduce cell death within 3 days under glucose deprivation and a 50% decrease in cell viability after 7 days in an acidic environment. Cellular mRNA expression under non-inflamed conditions simulated a quantifiable catabolic shift under an adverse cell environment, and model predictions of mRNA expression of inflamed cells provide new explanation possibilities for unexpected results achieved in experimental research.

Availabilityand implementation

The AB model as well as used mathematical functions were built with open source software. Final functions implemented in the AB model and complete AB model parameters are provided as Supplementary Material. Experimental input and validation data were provided through referenced, published papers. The code corresponding to the model can be shared upon request and shall be reused after proper training.

Supplementary information

Supplementary data are available at Bioinformatics online.
Gender Equality and Public Policy during COVID-19
Authors: Profeta Paola
Published: October 2020

The outbreak of COVID-19 has affected men and women worldwide. The gender dimension of COVID-19 has attracted the attention of researchers and policymakers: while women seem to be less severely hit by the virus and are more compliant with the restricting rules imposed to reduce the spread of the contagion, they risk to suffer more the economic consequences of the pandemic, because they are more vulnerable on the labor market and because they are carrying on most of the burden of housework and childcare which increased substantially during the lockdown. Public policies are required to address the emergency and to deal with its gender implications. Anecdotal evidence suggests that women leaders have performed better than men in dealing with the emergency. This paper explores the evidence on the gender dimension of the pandemic under a new perspective proposed by Profeta (2020), focused on the double relationship between gender equality and public policy: on one side, I show which policies can support gender equality in times of COVID-19 and, on the other side, I explore whether women leadership can promote successful measures. While the evidence provided is only suggestive, future studies should assess causal relationships. (JEL codes: J16 and J18)
Determination of Trace Bromate in Drinking Water with High Chloride Matrix by Cyclic Ion Chromatography
Authors: Ye Mingli , Nesterenko Pavel N , Lu Ying , Huang Xueting , Jin Xiaoling , Chen Meilan
Published: October 2020

An ion chromatography (IC) system with switching recycling column was developed for the determination of bromate in drinking water with high chloride content. The system included a pump, two switching valves, guard column and analytical column, suppressor and a conductivity detector. In this method, the single eluent was used for both online collection and matrix elimination, and bromate was eluted from the concentrator column to the analytical column circularly. Under the optimized separation conditions, the method showed good linearity (r = 0.9995) in the range of 1–100 μg/L and repeatability (RSD ≤ 4.80%, n = 6). The limit of detection was 0.2 μg/L (S/N = 3) with 1000 μL sample volume injections. The method was applied to analysis of drinking and tap waters, and satisfactory recoveries of spiked samples between 96.8% and 108.7% were obtained. The result showed that the recycling column-switching system can be useful for the determination of traces of bromate in high-chloride samples, which is required in production of the drinking water and quality control of the final product.
Determination of Verapamil Hydrochloride and Norverapamil Hydrochloride in Rat Plasma by Capillary Electrophoresis With End-Column Electrochemiluminescence Detection and Their Pharmacokinetics Study
Authors: Sun Shuangjiao , Wei Yanfen , Wang Hao , Tang Lifu , Deng Biyang
Published: October 2020

In this study, we developed a new method for simultaneous determination of verapamil hydrochloride (VerHCl) and its metabolite norverapamil hydrochloride (NorHCl) by using the capillary electrophoresis–electrochemiluminescence. Under optimized experimental conditions, the linear ranges of the VerHCl and NorHCl concentrations were 0.015–10.0 and 0.060–10.0 μg/mL, respectively. The linearity relations were determined using the respective regression equations y = 581.2x + 19.94 and y = 339.4x + 29.16. The respective limits of detection (S/N = 3) were 0.006 and 0.024 μg/mL. The proposed method was used to study the pharmacokinetics of both agents in rat plasma. The maximum concentration (Cmax), half-life time (T1/2) and time to peak (Tmax) were 683.21 ± 74.81 ng/mL, 0.52 ± 0.21 h and 2.49 ± 0.32 h for VerHCl and 698.42 ± 71.45 ng/mL, 1.14 ± 0.26 h and 2.83 ± 0.23 h for NorHCl, respectively, following oral administration of 10 mg/kg VerHCl.
Dose-response Relation Deduced for Coronaviruses From Coronavirus Disease 2019, Severe Acute Respiratory Syndrome, and Middle East Respiratory Syndrome: Meta-analysis Results and its Application for Infection Risk Assessment of Aerosol Transmission
Authors: Zhang Xiaole , Wang Jing
Published: October 2020

Background

A comprehensive understanding of the transmission routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great importance to effectively control the spread of coronavirus disease 2019 (COVID-19). However, the fundamental dose-response relation is missing for evaluation of the infection risk.

Methods

We developed a simple framework to integrate the a priori dose-response relation for SARS-CoV-2 based on mice experiments, the recent data on infection risk from a meta-analysis, and respiratory virus shedding in exhaled breath to shed light on the dose-response relation for humans. The aerosol transmission infection risk was evaluated based on the dose-response model for a typical indoor environment.

Results

The developed dose-response relation is an exponential function with a constant k in the range of about 6.4 × 104 to 9.8 × 105 virus copies, which means that the infection risk caused by 1 virus copy in viral shedding is on the order of 10–6 to 10–5. The median infection risk via aerosol transmission with 1-hour exposure (10–6 to 10–4) was significantly lower than the risk caused by close contact (10–1) in a room with an area of 10 to 400 m2 with 1 infected individual in it and with a typical ventilation rate of 1 air change per hour.

Conclusions

The infection risk caused by aerosol transmission was significantly lower than the risk caused by close contact. It is still necessary to be cautious for the potential aerosol transmission risk in small rooms with prolonged exposure duration.
Fabry disease and COVID-19: international expert recommendations for management based on real-world experience
Authors: Laney Dawn A , Germain Dominique P , Oliveira João Paulo , Burlina Alessandro P , Cabrera Gustavo Horacio , Hong Geu-Ru , Hopkin Robert J , Niu Dau-Ming , Thomas Mark , Trimarchi Hernán , Wilcox William R , Politei Juan Manuel , Ortiz Alberto
Published: October 2020

The rapid spread of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 has raised questions about Fabry disease (FD) as an independent risk factor for severe COVID-19 symptoms. Available real-world data on 22 patients from an international group of healthcare providers reveals that most patients with FD experience mild-to-moderate COVID-19 symptoms with an additional complication of Fabry pain crises and transient worsening of kidney function in some cases; however, two patients over the age of 55 years with renal or cardiac disease experienced critical COVID-19 complications. These outcomes support the theory that pre-existent tissue injury and inflammation may predispose patients with more advanced FD to a more severe course of COVID-19, while less advanced FD patients do not appear to be more susceptible than the general population. Given these observed risk factors, it is best to reinforce all recommended safety precautions for individuals with advanced FD. Diagnosis of FD should not preclude providing full therapeutic and organ support as needed for patients with FD and severe or critical COVID-19, although a FD-specific safety profile review should always be conducted prior to initiating COVID-19-specific therapies. Continued specific FD therapy with enzyme replacement therapy, chaperone therapy, dialysis, renin–angiotensin blockers or participation to clinical trials during the pandemic is recommended as FD progression will only increase susceptibility to infection. In order to compile outcome data and inform best practices, an international registry for patients affected by Fabry and infected by COVID-19 should be established.