bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Rates and Duration of Stress Waves on Residual Strength of Adhesively Bonded Joints After Single Impact or Repeated Impacts
Authors: Sato Chiaki , Ikegami Kozo
Published: December 2021

Residual strength after Impact (RSAI) of adhesively bonded joints was investigated experimentally. Impact Loads were applied to the joints using a split Hopkinson bar equipment. Residual strength of the joints was measured by static tests after a single impact or repeated impacts. Tubular specimens, which included tubular butt joints, were used for the experiments. Since the shape of the specimens was similar to hats, they were called ‘hat specimens’. Materials for the specimens were carbon steel adherends and an epoxy resin adhesive.

The hat specimens were subjected to impact loads by the split Hopkinson bar equipment that consisted of an input bar, an output tube and an air gun. The collision of strikers, which were accelerated by the air gun, to the end of the input bar caused compressive stress waves in the input bar. The compressive stress waves were changed to tensile stress waves in the hat specimen, and consequently high rate tensile loads could be applied to the joints.

The impact tests were conducted with several conditions of maximum stress, duration and rate of impact loading. The maximum stress and the duration of the stress waves depended on the velocity and the length of the strikes, which could be selected. Stress rates were chosen by using buffers, which were inserted between the strikes and the input bar.

Residual strengths of the joints after impact tests were smaller than the strength without impacts. However, the decrease of the strength was relatively small. The influence of the repeated impacts was remarkable on the decreases of the joint strength although the influence of the maximum stress, the duration and the rate of the impact loading were very small.
Estimation of Yield Clamping Force Based on Rigid-Plastic Model
Authors: Tsuji Hirokazu , Maruyama Kazuo
Published: December 2021

Yield clamping force of a bolt in plastic region tightening depends on yield point load of the bolt under combined loads of axial tension and thread torque induced by the tightening process. A new estimation method using interaction curve for yield is proposed, which is applied to the yield clamping force and maximum additional tension under external force. This estimation method utilizes the general yield criterion based on the rigid-plastic solution for combined loads of tension and torsion. The yield of the bolt is expressed by the point of the intersection between the interaction curve and loading path of the bolt in tightening or external loading. Considering the coefficient of friction at the flank of the thread and the residual thread torque after tightening, yield clamping force and maximum additional tension are obtained respectively by the simple formulas. The yield clamping force and the maximum additional tension of the bolt are examined experimentally by a combined load testing machine which can apply combined tensile and torsional loads on the threaded portion of the bolt. Estimated values by the proposed method shows good agreement with the experimental results. The proposed estimation method is superior to the conventional one which takes into account only the local yield criterion. Finally, the target zones of initial clamping force controlled by elastic region tightening, yield point tightening and plastic region tightening are examined. Usefulness of the yield clamping force is demonstrated based on the rigid-plastic model.
An Alternative Mechanical Peel Testing Method for Composite Fiberglass Foam Core Sandwiches
Authors: Zych John L. , Adamick Scott A. , Jones Daniel K. , Wilson Dru M. , Boyer Wayne A.
Published: December 2021

Nondestructive and destructive testing are vital in the composite material industry to determine the mechanical properties of different designs. This paper presents a novel approach to measuring the mechanical peel strength that may be used for a variety of fiberglass foam core sandwiches. The objective of this study was to develop a testing method that was simple and easily reproduced in other laboratories. The goal was to measure the mechanical peel strength using a device that may be used for a variety of sample sizes and materials. An additional goal was to provide benchmark data on the mechanical peel strength of two particular composite designs. The new testing method may have applications to a wide range of composite structures, and it may eventually lead to a new ASTM standard.
In-Situ Continuous Process for Bonding Glass-Fiber Reinforced Polypropylene to Wood
Authors: Ramani Karthik , Smith Michael , Dai Heming
Published: December 2021

Process conditions are developed for the manufacture of composite reinforcement for oak. Commingled glass and polypropylene fibers are consolidated in-situ on the surface of oak. Processing times from 30 to 120 seconds and pressures from .34 MPa to 1.4 MPa are tested. Micrographs of the composite and bond line reveal anisotropic fiber distribution in the composite, dry reinforcing fibers, voids, and incomplete consolidation. These microstructures are correlated with the processing problems which cause them, including insufficient heating time, poor matrix/glass mixing, and insufficient pressure to suppress void development. Lap shear strength and failure modes are related to microstructural features.
Development and Characterisation of a Oxazolidone-Isocyanurate-Urethane Modified Diglycidyl Ether of Bisphenol A Epoxy Resin
Authors: Chian K. S. , Yi S.
Published: December 2021

Epoxy resins are very versatile polymers generally known not only for their adhesive and mechanical strengths but also their inherent thermo-oxidative stability. These properties have been widely exploited in many applications ranging from composites used aerospace components to electronics packaging. However neat epoxy materials suffer from relatively poor strain bearing ability and attempts to improve this brittle behaviour have been an area of many research interests. Toughening of epoxy using elastomers is not new and this is reflected in numerous publications and some have been successfully commercialised.

This paper presents a relatively new method of incorporating a rubber modifier into Diglycidyl ether of Bisphenol A (DEGBA) epoxy resin via the formation of an isocyanurate-oxazolidone-urethane structure. The synthesis involves several simultaneous reactions involving the following reactions: (a) epoxide and the isocyanate to form the oxazolidone, (b) trimerisation of the isocyanate to form isocyanurate and (c) isocyanate with polyols to form polyurethane. The synthesis and characterisation of the modified DEGBA resin will be presented. In addition, the effects of rubber content on the thermomechanical behaviour of the cured resin will also be discussed. In summary, it was found that the introduction of the isocyanurate-oxazolidone-urethane chemical groups into the epoxy molecular chain not only enhances the fracture toughness of the final resin but also improves on the thermal stability. This rubber-modified epoxy system shows excellent promise for adhesive and structural applications where thermal stability and fracture toughness are pre-requisites.
Design and Analysis Techniques for Filament-Wound Composite Pressure Vessel Domes
Authors: Howard William E. , Widera G. E. O.
Published: December 2021

The use of filament-wound composite pressure vessels has expanded into many new markets in recent years, creating the need for better design and analysis techniques, particularly for the end domes. In this paper, design and analysis techniques are developed for elliptical-conical dome profiles with planar filament winding patterns. The effects of wide winding bandwidth are included by dividing the band into sub-bands and considering any point on the dome contour to be a laminate made up of the sub-bands. The slippage tendency of the band at its edges is also calculated.
Strengthening of Cracked Reinforced Concrete Beams Through Crackfilling With Polymeric Materials
Authors: Ayyar R. S. , Burgul S. P.
Published: December 2021

In this paper, an attempt is made to study the nature of weakening of R.C.C. beams due to crack formations and the extent of strengthening of the beam achieved through filling of the cracks by polymeric materials having high bond and flexural strength in tension. The study of crack formation is carried out through a sequence of incremental loading till the stage of impending failure. The progressive reduction in flexural rigidity with the growth of cracks is compared with the improvement in the same after crack filling. A finite element method has been developed for this study.
Flow Image Compression Using Wavelets
Authors: Li Hui , Lu Yan , Takei Masahiro , Ochi Mitsuaki , Saito Yoshifuru , Horii Kiyoshi
Published: December 2021

The wavelet compression technique was applied to turbulent image processing for reducing physical storage and extracting the compact dominant features in this study. The two compression methods, called zone and threshold compression, were employed. It was found that a high order wavelet basis provided good compression performance for compressing turbulent images and two compression methods exhibited almost same performance. It was realized that the compressed image had both lower compress ratio and larger correlation coefficients. By changing compression ratio the compressed images exhibited different scale structures in turbulent jet. This indicated clear that large-scale structure dominates the jet.
Hydrodynamics of Pulse-Stabilized Fluidization at Incipient Fluidization
Authors: Gan Subhadeep , Beasley Donald E.
Published: December 2021

A laboratory scale experimental facility which models a Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) has been developed; this facility is designed to examine the effect of an opposing secondary flow having an oscillatory component on a bubbling fluidized bed. The secondary flow is oriented in a vertical direction. The secondary flow is introduced into the bubbling bed through a tailpipe that extends through the bed and ends just above the porous polyethylene distributor. A pulsed flow simulator that employs a small displacement of a relatively large piston with variable drive radius and speed provides the oscillatory component of the secondary flow. The fluidized bed test section has a cross-sectional flow area of 30.5 by 30.5 cm with a height of 53 cm. Heat exchanger surfaces are modeled by two symmetric horizontal cylinders housed in the test section. The following test parameters are controlled: the primary flow rate, the mean secondary flow rate, the pulsation frequency and the amplitude of the secondary flow. Pressure taps are located just above the distributor and in the freeboard region to measure overall bed pressure drop. The facility is operated with a range of particles from 345 μm to 715 μm and a range of superficial fluidization velocities corresponding to the bubble flow regime.

Fluidization curves were generated for traditional fluidization, using the primary flow through the porous distributor, with both primary and a steady secondary flow, and with primary and a pulsed secondary flow. Significant departures from the linear Darcy flow curves in the fixed bed region were observed, and attributed to significant local fluidization. Time resolved measurements of the overall bed pressure drop clearly indicate phase-locking behavior of the overall bed pressure drop with imposed frequency. Bubbles formed in pulse-stabilized fluidization are significantly smaller than in traditional fluidization, as observed through video recording of the present bed.
Numerical Modeling of Thermal Materials Processing Systems
Authors: Jaluria Yogesh
Published: December 2021

The numerical modeling of the heat and mass transfer and of the fluid flow processes in manufacturing, particularly in the thermal processing of materials, is discussed in this paper. Several important processes such as polymer extrusion, glass fiber drawing, chemical vapor deposition, and casting are considered in detail. The governing equations, the relevant boundary conditions and the basic approach to numerically model many of these processes are presented. The importance of material properties in an accurate mathematical and numerical modeling is brought out, along with the coupling between the process and the resulting characteristics. The concerns and computational difficulties that arise due to various aspects such as the non-Newtonian behavior of plastics, exponential temperature dependence of glass viscosity, complex geometry, free surface flow, conjugate transport, material movement, chemical reactions, and phase change are considered. Some of the important methods to treat these complexities are presented. A few typical numerical results are presented on some important materials processing systems.
Eulerian Finite Element Analysis of 3D Machining
Authors: Madhavan V. , Olovsson L. , Swargam S. C. , Agarwal R.
Published: December 2021

We describe here the development and testing of a capability for finite element simulation of practical machining operations such as turning and milling, using 3D multi-material, explicit dynamic, Eulerian finite element analysis. In these simulations the workpiece material and the air surrounding it are modeled using Eulerian finite elements and the flow of the workpiece material into the air as a result of the action of the Lagrangian tool can be freely tracked.

Tension tests and Taylor impact tests are simulated using the traditional Lagrangian approach as well as the Eulerian approach. Comparison of the results is used to understand the factors affecting the solution accuracy. Simulations of orthogonal machining using this technique show that the side flow of the chip is simulated realistically. Simulations of oblique machining with various rake and inclination angles confirm that the chip flow angle is independent of the rake angle. Inertial effects cause the chip flow angle to differ from the inclination angle as the weight of the chip increases. Simulations of turning and end milling show that chip formation and flow can be simulated ab-initio. The simulation capability described here can provide accurate results for various outputs of interest and is also computationally efficient, allowing a typical analysis to be completed within a day.
A Study of Multiple Heat Sources on a Flat Plate Heat Pipe Using Point Source Approach
Authors: Keng Tan Boon
Published: December 2021

An analytical approach has been employed to study liquid flows in an isotropic wick structure of a flat plate heat pipe with multiple heat sources so as to determine the optimum heat pipe performance. In this study, the heat sources have been modeled as point sources using the Dirac Delta function to describe the heat distribution. The two dimensional pressure and velocity distribution are shown and discussed. The study has been extended to locate the positions of the multiple heat sources for optimum heat pipe performance. The optimum performance of the heat pipe is accomplished when the minimum pressure drop is attained across the wick structure.
Modelling the Rolling Motion of a Momentum Driven Droplet
Authors: Khan Aman M. , Holdo Arne E.
Published: December 2021

Free surfaces, with their associated surface tension energy, play a prominent role in many areas of fluid dynamics. The motions of these free surfaces and the effects of the controlling forces become particularly relevant when considering small droplets or small scale flows in micro-structural domains. Surface tension, in conjunction with structural interaction (as characterised by the contact angle), may also give rise to tractions that are capable of driving the motion of the fluid (as seen in porous media).

The effects of surface tension on the momentum driven motion of a small droplet of honey were first investigated by Dussan and Davis (1974). The qualitative experimental observations made by these authors led to the formulation of a kinematic analysis in which the basic assumption was that the interface rolls onto or off of the solid substrate. In the present work we initially look at how numerical Computational Fluid Dynamic (CFD) modelling can be used to repeat the previous authors’ work, and subsequently, we use the basic model to extend their analysis.

The motion of a small droplet of honey (1 cm3), moving under the influence of gravity, is modelled. The droplet is initially at rest in a semi-hemispherical configuration upon a plane inclined at 30° to the horizontal. Massless computational particles are introduced in a semicircular configuration close to the droplet surface. The particles are at a constant radial distance from the centre of the droplet and are used to mimic dye or marker particles at the free surface. The motion of the droplet and associated particles, in time, is presented. The resulting motions are compared with existing experimental data (Dussan and Davis, 1974).

Using CFD modelling and marker particles we represent numerically the experimental work of Dussan and Davis (1974). Using CFD modelling, dimensional analysis and marker particles within the fluid domain gives an improved insight into the tractions and motions present within the droplet fluid flow.
An Investigation of Reactor Core Isolation Cooling (RCIC) Turbine Exhaust Line Dynamics at LaSalle Nuclear Generating Station
Authors: Ramsden Kevin B. , Randels Raubin
Published: December 2021

The RELAP5 Mod 3.1 computer code has been utilized to study the causes of exhaust line rupture disk actuation that occurred without indication of overpressure conditions. A series of cases have been investigated to determine the conditions in the RCIC upstream steam supply as well as the exhaust piping that would lead to dynamic behavior capable of causing exhaust system rupture disk failure. It has been demonstrated that the presence of moisture in the turbine and/or its immediate exhaust piping, are necessary to achieve the pressures necessary to fail the rupture disk. The upstream steam supply conditions can significantly influence the transient, particularly if saturated water is able to enter the turbine. Saturated water ingestion to the turbine can lead to significantly higher exhaust pressure behavior. The upstream supply conditions cannot, however, result in rupture disk failure if there is not water present in the turbine/exhaust line at startup. This paper discusses the modeling methods, as well as the results obtained from the computer simulation.
Analysis of Passive Water Hammer
Authors: Husaini Syed M. , Arastu Asif H. , Qashu Riyad
Published: December 2021

This paper presents a methodology for the calculation of the severity a type of water hammer called “passive water hammer”. The passage of a cold water column followed by hot saturated water through a restricting orifice causes a reduction in flow velocity and a corresponding increase in pressure. The term passive water hammer was given to this mechanism because there is no active flow intervention required for its initiation. This type of water hammer has been observed in heater drain systems of power plants. An example is given for the calculation of pressure surge and pipe segment forces due to this mechanism.
An Adaptive Domain Decomposition Scheme for Parallel Smooth Particle Hydrodynamics Regional Weather Model
Authors: Kumar Gopal N.
Published: December 2021

Smooth Particle Hydrodynamics (SPH) method is a lagrangian technique used to describe and model complex fluid flows. Being a lagrangian method, it is gridless and the particles themselves carry all the information relating to the flow. By nature of its formulation, SPH method can easily incorporate complex physics of particle interactions. This makes it an attractive candidate for modeling regional weather and weather forecasting. As the SPH method deals with particle interactions in a local sense, it is good for domain decomposition. This makes SPH ideal for parallel computations. The main bottleneck arises from the need to find neighboring particles to determine local interactions. Finding neighbors is achieved by sorting the particles based on some appropriate key value. In order to have high parallel efficiency, one would have to allocate the particles equally amongst the available processors for good load balancing. This calls for an adaptive domain reallocation and for a sorting methodology that is specifically tailored for this. This paper presents a new parallel sorting scheme that guarantees that the available processors have close to equal number of particles.
Cavity Pressure and Part Quality in the Injection Molding Process
Authors: Angstadt David C. , Coulter John P.
Published: December 2021

Extensive research has been conducted in an attempt to develop reliable models or indicators for determining product quality based on process information. Relationships between part quality and process variables such as nozzle temperature, hydraulic pressure and cavity pressure have been established using methods such as statistical process control, regression analysis and artificial neural networks. Ideally, these models would be used to determine part quality without direct inspection. If a level of confidence equivalent to that obtained by traditional methods (e.g., SQC) could be achieved, “quality by inspection” could be eliminated. Two drawbacks to these models are that they are specific to the machine/mold/polymer (M/M/P) combination being studied and they require a significant amount of “up-front” process data for model formulation. A method for “normalizing” pressure data obtained from a range of machine/mold/polymer configurations to yield essentially one curve or attribute denoting acceptable part quality would greatly enhance the utility of P-t data in a manufacturing setting. The objective of the present research is to examine the effects on the temporal cavity pressure due to changes in the mold geometry and to investigate methods for obtaining generic pressure data for various geometries. Cavity pressure data was collected using geometric inserts fitted into a standard ASTM tensile specimen cavity. The pressure data was analyzed to determine the correlation between cavity pressure and part quality for three part geometries studied. A discussion of the utility of the pressure is presented and an attempt is made to find a geometry independent cavity pressure attribute for use in determining part quality.
Experimental Analysis of Particle Filtration in Resin Transfer Molding of Preceramic Polymer Based Ceramic Composites
Authors: Erdal Merve , Ambrosoni Letizia A.
Published: December 2021

The study of particle filtration in resin transfer molding of liquid preceramic polymer (PCP) based ceramic composites with filler particles is the topic of our current research, in order to prevent particle filtering during impregnation and to achieve a uniform particle distribution within the composite. This study targets an experimental analysis of filtration that will be coupled to previously developed filtration models. For reliable filtration data, the properties of the particle-PCP suspension must be known (predictable) and the suspension quality reproducible. This paper presents the initial stage of the experimental work, which consists of standardization of particle-polymer suspension preparation and its characterization. A methodology for optimal (homogeneous suspension with low agglomeration) steric stabilization of polymer / SiC particle suspensions is presented. The results Blackglas™1 preceramic of the characterization of the suspensions through visual inspection (SEM) and rheological measurements are reported. With the achievement of well-dispersed, low viscosity suspensions with reproducible properties, our current work is in the adaptation of electrostatic spraying and laser particle counting technology for the detection of particle size distribution and concentration to be used in subsequent filtration experiments.
Application of a Bubble-Induced Turbulence Model to Subcooled Boiling in a Vertical Pipe
Authors: Mat Mahmut D. , Kaplan Yüksel , Ilegbusi Olusegun J.
Published: December 2021

Subcooled boiling of water in a vertical pipe is numerically investigated. The mathematical model involves solution of transport equations for vapor and liquid phase separately. Turbulence model considers the turbulence production and dissipation by the motion of the bubbles. The radial and axial void fractions, temperature and velocity profiles in the pipe are calculated. The estimated results are compared to experimental data available in the literature. It is found that while present study satisfactorily agrees with experimental data in the literature, it improves the prediction at lower void fractions.
Characterization of Permeability for Solid Freeform Fabricated Porous Structures
Authors: Erdal Merve , Ertoz Levent , Güçeri Selçuk
Published: December 2021

Fused deposition based solid freeform fabrication technique allows manufacturing of potential functional preforms for subsequent Resin Transfer Molding. In this study, the transport property (permeability) of solid freeform fabricated porous preform geometries are investigated. Specifically the effect of pore geometry and network on the permeability is sought. Wet (saturated) permeability experiments were performed for various pore geometries with different viscosity liquids. For all fluids and preform structures investigated in this study, the porous flow exhibited Darcian behavior. The permeability is affected by changes in order of magnitude of fluid viscosity, the effect considerably significant in low porosity preforms. Current work concentrates on dry permeability measurement and development of numerical permeability models for ordered pore geometries (as produced through SFF) that will be compared with experimental results.
Towards Controllability of Injection Molding
Authors: Kazmer David , Hatch David
Published: December 2021

Process control has been recognized as an important means of improving the performance and consistency of thermoplastic parts. However, no single control strategy or system design has been universally accepted, and molding systems continue to produce defective components during production. The capability of the injection molding process is limited by the thermal and flow dynamics of the heated polymer melt.

This paper discusses some of the difficulties posed by complex and distributed nature of the injection molding process. The flow and thermal dynamics of the process are analyzed with respect to transport and rheology. Then, two novel processing methods are described to enable in-cycle flow, pressure, and thermal control. Simulation and experimental results demonstrate effectiveness of these innovations to increase the consistency and flexibility in polymer processing. Such system design changes simplify the requisite control structures while improving the process robustness and productivity.
Conditional Wasserstein generative adversarial networks applied to acoustic metamaterial design
Authors: Lai Peter , Amirkulova Feruza , Gerstoft Peter
Published: December 2021

This work presents a method for the reduction of the total scattering cross section (TSCS) for a planar configuration of cylinders by means of generative modeling and deep learning. Currently, the minimization of TSCS requires repeated forward modelling at considerable computer resources, whereas deep learning can do this more efficiently. The conditional Wasserstein generative adversarial networks (cWGANs) model is proposed for minimization of TSCS in two dimensions by combining Wasserstein generative adversarial networks with convolutional neural networks to simulate TSCS of configuration of rigid scatterers. The proposed cWGAN model is enhanced by adding to it a coordinate convolution (CoordConv) layer. For a given number of cylinders, the cWGAN model generates images of 2D configurations of cylinders that minimize the TSCS. The proposed generative model is illustrated with examples for planar uniform configurations of rigid cylinders.
Examination of Korean stop perception in Quebec French listeners through the lens of assimilation overlap
Authors: Nam Youngja , Paul Marianne J. , Safi Dima
Published: December 2021

This study assessed the perceptual assimilation model (PAM) predictions about assimilation types and discrimination performance through the lens of assimilation overlap in Quebec French listeners' perception of nine non-native Korean stop consonants. The consonants varied in voicing (fortis, lenis, and aspirated) and place of articulation (labials, coronals, and velars). In the identification experiment, the Korean three-way voicing contrasts were found to undergo an assimilation overlap to correspond to the French two-way equivalent contrasts across places of articulation. In the discrimination experiment, assimilation overlap tended to hinder detection of non-native speech distinctions, which is in line with the PAM-based suggestion.
State of a State: Results From the Wyoming Physical Education and Physical Activity Policy Survey
Authors: Kern Ben D. , Malinowski Paul , Hunt Kim , McIlnay Shawna , Powell Brian , Stephenson Deb
Published: December 2021

Purpose: To examine Wyoming physical education (PE) and physical activity (PA) policy and report current district-, school-, and classroom-level data. Method: A total of 175 public preK-12 PE teachers completed the 30-item Wyoming PE and PA Policy survey in April 2021. Results: Participants reported PE offered in elementary school was 73.1 (±34.3) min/week over 1.96 (±0.720) days, middle school 161.2 (±68.2) min/week over 3.13 (±1.29) days, and 229.8 (±85.3) min/week over 3.79 (±1.34) days in high school. Weekly recess minutes averaged 152.75 (±51.21). Recess was withheld as punishment in 51.8% of schools. About 10.2% of students earn PE credits for non-PE activities. Students earn online outsourced PE credits online in 12.5% of schools. Conclusions: PE in Wyoming schools is offered less than half the recommended weekly minutes, while recess is offered considerably more than the recommended amount.
An atlas of intratumoral T cells
Authors: van der Leun Anne M. , Schumacher Ton N.
Published: December 2021

Intratumoral T cell composition is relevant for disease outcome across tumor types
Breakdowns of the year
Authors: Voosen Paul , Servick Kelly , O’Grady Cathleen
Published: December 2021

What went wrong in the world of science
In Other Journals
Authors: Hurtley Stella M. , Ash Caroline , Vignieri Sacha , Sugden Andrew M. , Smith Keith T. , Lavine Marc S. , McCartney Melissa
Published: December 2021

Editors’ selections from the current scientific literature
Quantitative SARS-CoV-2 Viral-Load Curves in Paired Saliva Samples and Nasal Swabs Inform Appropriate Respiratory Sampling Site and Analytical Test Sensitivity Required for Earliest Viral Detection
Authors: Savela Emily S. , Viloria Winnett Alexander , Romano Anna E. , Porter Michael K. , Shelby Natasha , Akana Reid , Ji Jenny , Cooper Matthew M. , Schlenker Noah W. , Reyes Jessica A. , Carter Alyssa M. , Barlow Jacob T. , Tognazzini Colten , Feaster Matthew , Goh Ying-Ying , Ismagilov Rustem F.
Published: December 2021

Early detection of SARS-CoV-2 infection is critical to reduce asymptomatic and presymptomatic transmission, curb the spread of variants, and maximize treatment efficacy. Low-analytical-sensitivity nasal-swab testing is commonly used for surveillance and symptomatic testing, but the ability of these tests to detect the earliest stages of infection has not been established.
Biomarkers That Correlate with Active Pulmonary Tuberculosis Treatment Response: a Systematic Review and Meta-analysis
Authors: Zimmer Alexandra J. , Lainati Federica , Aguilera Vasquez Nathaly , Chedid Carole , McGrath Sean , Benedetti Andrea , MacLean Emily , Ruhwald Morten , Denkinger Claudia M. , Kohli Mikashmi
Published: December 2021

Current WHO recommendations for monitoring treatment response in adult pulmonary tuberculosis (TB) are sputum smear microscopy and/or culture conversion at the end of the intensive phase of treatment. These methods either have suboptimal accuracy or a long turnaround time.
Draft Genome Sequence of Rhodococcus qingshengii (Formerly
erythropolis
) TA37, a First-Generation Biocatalyst for Synthesis of Functionalized Acrylamides
Authors: Lavrov Konstantin V. , Novikov Andrey D. , Kasianov Artem S. , Toshchakov Stepan V. , Korzhenkov Aleksei A. , Yanenko Alexander S.
Published: December 2021

We describe here the 7.0-Mb draft genome sequence of
Rhodococcus qingshengii
strain TA37, which was obtained from samples of nitrile-contaminated soil collected in the Saratov Region (Russian Federation). This genomic resource will support the further development of biocatalysts for the inexpensive and green production of acrylic monomers.
Crustal thickness of the Grenville orogen: A Mesoproterozoic Tibet?
Authors: Brudner Adam , Jiang Hehe , Chu Xu , Tang Ming
Published: December 2021

The Grenville Province on the eastern margin of Laurentia is a remnant of a Mesoproterozoic orogenic plateau that comprised the core of the ancient supercontinent Rodinia. As a protracted Himalayan-style orogen, its orogenic history is vital to understanding Mesoproterozoic tectonics and paleoenvironmental evolution. In this study, we compared two geochemical proxies for crustal thickness: whole-rock [La/Yb]N ratios of intermediate-to-felsic rocks and europium anomalies (Eu/Eu*) in detrital zircons. We compiled whole-rock geochemical data from 124 plutons in the Laurentian Grenville Province and collected trace-element and geochronological data from detrital zircons from the Ottawa and St. Lawrence River (Canada) watersheds. Both proxies showed several episodes of crustal thickening and thinning during Grenvillian orogenesis. The thickest crust developed in the Ottawan phase (~60 km at ca. 1080 Ma and ca. 1045 Ma), when the collision culminated, but it was still up to 20 km thinner than modern Tibet. We speculate that a hot crust and several episodes of crustal thinning prevented the Grenville hinterland from forming a high Tibet-like plateau, possibly due to enhanced asthenosphere-lithosphere interactions in response to a warm mantle beneath a long-lived supercontinent, Nuna-Rodinia.
When did the North Anatolian fault reach southern Marmara, Turkey?
Authors: Karabacak Volkan , Sançar Taylan , Yildirim Gökhan , Uysal I. Tonguç
Published: December 2021

We dated syntectonic calcites on fault planes from the southern branch of the western North Anatolian fault (NAF) in northern Turkey using U-Th geochronology. We selected strike-slip faults that are kinematically related to the current regional strain field. The isotopic ages cluster around different periods during the past ~700 k.y. The most prominent cluster peak of 510.5 ± 9.5 ka (1σ) is consistent with the maximum cumulative strike-slip offset data and tectonic plate motions measured by GPS data, highlighting the fact that the present configuration of the NAF in the southern Marmara region started at ca. 500 ka or earlier. These new isotopic ages, combined with previous considerations of regional tectonics, reveal that faulting along the western NAF initiated primarily in the southern Marmara region at least a few hundred thousand years earlier than the timing suggested for the northern branch of the western NAF. This study presents an innovative approach to constrain the timing of initiation of currently active fault segments along the NAF in southern Marmara. U-Th geochronology of fault-hosted calcite thus has a wide application in determining absolute ages of fault episodes in wider shear zones along plate boundaries.
Mimetics of the Arg-Gly-Asp Sequence: Synthesis and Studies of the Antiaggregative Properties
Authors: Gribovskaya O. V. , Martinovich V. P. , Rodko E. V. , Rasyuk E. D. , Ryabtseva T. V. , Golubovich V. P.
Published: December 2021

Abstract—

It is known that the Arg-Gly-Asp sequence in the fibrinogen molecule is key in binding to the receptors on the surface of platelets. We searched for the compounds which were able to inhibit the binding and synthesized the following analogs of this sequence: 2-acetoxybenzoyl-Arg-βAla-Asp, 4-piperidinecarbonyl-βAla-Asp, and 4-aminobezoyl-βAla-Asp. These compounds were shown to inhibit the platelets aggregation in a different degree. The 2-acetoxybenzoyl-Arg-βAla-Asp analog demonstrated the highest inhibitory activity. A decrease in the expression of the CD62p and CD63 markers on platelets was also found after the action of the Arg-Gly-Asp analogs, confirming the ability of these compounds to block the fibrinogen binding sites for the GP IIb/IIIa glycoprotein receptors.
Molecular Dynamics Study of Escherichia coli Thymidine Phosphorylase in a Complex with 3'-Azidothymidine Inhibitor and Phosphate
Authors: Timofeev V. I. , Zhukhlistova N. E. , Kuranova I. P.
Published: December 2021

Abstract—

Using a molecular dynamics method, the state of the dimeric thymidine phosphorylase molecule fromEscherichia coliin a complex with noncompetitive enzyme inhibitor 3'-azidothymidine and phosphate ion was studied on a trajectory of 50 ns. Previously obtained atomic coordinates of a complex of thymidine phosphorylase with azidothymidine and sulfate at a resolution of 1.52 Å were used as a starting model. It was demonstrated that both subunits of a dimeric enzyme molecule function asynchronously in a given time interval; moreover, each subunit maintains an open conformation. It was found that the nature of ligand at the nucleoside center affects the binding strength of phosphate in the phosphate center. In a complex with an inhibitor, both ligands over the entire time interval remain bound to the enzyme, while the release of phosphate from the active center is observed when simulating the behavior of thymidine phosphorylase in the presence of phosphate and thymidine substrate. The stabilizing effect of azidothymidine on phosphate binding is consistent with the behavior of azidothymidine as a noncompetitive inhibitor of thymidine phosphorylase.
Heavy metal toxicity and mortality—association between density of heavy metal bands and cause specific hospital admissions and mortality: population based cohort study
Authors: Martikainen Pekka , Korhonen Kaarina , Tarkiainen Lasse
Published: December 2021

Objective

To assess the association between area level density of heavy metal bands and cause specific hospital admissions and mortality.

Design

Longitudinal register based cohort study.

Setting

311 municipalities in Finland.

Participants

3 644 944 people aged 15 to 70 residing in Finland at the end of 2001.

Main outcome measures

Hospital admission and mortality from all causes, internal causes, alcohol attributable causes, accidental injury and violence, suicide or self-harm, and mental health related causes. Appendicitis and toxic effects of metals were negative control outcomes.

Results

During 50.4 million person years of follow-up in 2002-17, 4 237 807 person years with hospital admissions were observed and 221 912 individuals died. Mortality in municipalities with a moderate density of heavy metal bands (<5.7 per 10 000 inhabitants) was lower than in municipalities with no heavy metal bands. Hospital admission rates were lower in municipalities with heavy metal bands compared with those with none. These associations could be explained partly by differences in the sociodemographic characteristics of residents in these municipalities. After adjustment for individual characteristics and area level cultural and economic characteristics—proportion of the population with no religious affiliation, unemployment rate, and per capita expenditure on culture and education—large cities with a high density of heavy metal bands (8.2-11.2 per 10 000) showed a mortality advantage (hazard ratio 0.92, 95% confidence interval 0.88 to 0.96). In contrast, the association for hospital admission was fully attenuated (incidence rate ratio 0.99, 95% confidence interval 0.92 to 1.06). The cause specific analysis showed similar results, with the association most pronounced for alcohol attributable mortality (hazard ratio 0.83, 95% confidence interval 0.75 to 0.93 for cities with a high density of heavy metal bands) and alcohol attributable hospital admissions (incidence rate ratio 0.84, 95% confidence interval 0.74 to 0.97 for cities with a high density of heavy metal bands) in the fully adjusted models. No association with heavy metal band density was found for the analysis using appendicitis as a negative control outcome.

Conclusions

The study found no evidence for adverse health outcomes with increasing density of heavy metal bands. Cities with a high density of heavy metal bands showed slightly lower rates of mortality and of hospital admissions for alcohol related problems and self-harm. Although residual confounding remains a problem in observational studies, vibrant local heavy metal scenes—comparable to many other forms of cultural capital—might help to promote health through healthier lifestyles, better coping mechanisms, and a stronger sense of community.
Computerised analysis of writing and drawing by essential tremor phenotype
Authors: Peters James , Motin Mohammod Abdul , Perju-Dumbrava Laura , Ali Sheik Mohammed , Ding Catherine , Eller Michael , Raghav Sanjay , Kumar Dinesh Kant , Kempster Peter
Published: December 2021

We investigated whether computerised analysis of writing and drawing could discriminate essential tremor (ET) phenotypes according to the 2018 Consensus Statement on the Classification of Tremors. The Consensus scheme emphasises soft additional findings, mainly motor, that do not suffice to diagnose another tremor syndrome. Ten men and nine women were classified by blinded assessors according to Consensus Axis 1 definitions of ET and ET plus. Blinded scoring of tremor severity and alternating limb movement was also conducted. Twenty healthy participants acted as controls. Four writing and three drawing tasks were performed on a Wacom Intuos Pro Large digital tablet with a pressure-sensor mounted ink pen. Sixty-seven computerised measurements were obtained, comprising static (dimensional and temporal), kinematic and pen pressure features. The mean age of ET participants was 67.2±13.0 years and mean tremor duration was 21.7±19.0 years. Six were classified as ET, five had one plus feature and eight had two plus features. The computerised analysis could predict the presence and number of ET plus features. Measures of acceleration and variation of pen pressure performed strongly to separate ET phenotypes (p<0.05). Plus features were associated with higher scores on the Fahn-Tolosa-Marin Tremor Rating Scale (p=0.001) and it appeared that ET groups were mainly being separated according to severity of tremor and by compensatory manoeuvres used by participants with more severe tremor. There were, in addition, a small number of negative kinematic correlations suggesting some slowness with ET plus. Abnormal repetitive limb movement was also correlated with tremor severity (R=0.57) by clinical grading. Critics of the Consensus Statement have drawn attention to weaknesses of the ET plus concept in relation to duration and severity of ET. This classification of ET may be too biased towards tremor severity to assist in distinguishing underlying biological differences by clinical measurement.
Efficacy of neoadjuvant hyperthermic intraperitoneal chemotherapy in advanced high-grade serous ovarian cancer (the NHIPEC trial): study protocol for a randomised controlled trial
Authors: Wu Miao-Fang , Wang Li-Juan , Ye Yan-Fang , Liu Chang-Hao , Lu Huai-Wu , Yao Ting-Ting , Zhang Bing-Zhong , Chen Qing , Li Ji-Bin , Peng Yong-Pai , Zhou Hui , Lin Zhong-Qiu , Li Jing
Published: December 2021

Background

Neoadjuvant chemotherapy (NACT) is an important treatment option for patients with ovarian cancer. Although intravenous NACT can improve optimal resection rates and decrease surgical morbidity and mortality, these advantages do not translate into a survival benefit. Ovarian carcinoma is mainly confined to the peritoneal cavity, which makes it a potential target for hyperthermic intraperitoneal chemotherapy (HIPEC). Our previous study showed that HIPEC could be used in the neoadjuvant setting, which was named neoadjuvant HIPEC (NHIPEC). Since hyperthermia is an excellent chemosensitiser, we hypothesised that the combination of NHIPEC and intravenous NACT could show superior efficacy to intravenous NACT alone.

Methods

This study is a single-centre, open-label, randomised (1:1 allocation ratio) phase 2 trial. A total of 80 patients will be randomly assigned into an experimental group (NHIPEC+intravenous NACT) or a control group (intravenous NACT). Patients in the experimental group will receive NHIPEC following laparoscopic evaluation, and four tubes will be placed via the laparoscopic ports, which will be used to administer NHIPEC. Then, perfusion with docetaxel (60–75 mg/m2) will be performed (43°C for 60 min, Day 0) followed by cisplatin (75 mg/m2, Day 1) infusion (43°C for 60 min) 24 hours later. After NHIPEC, two cycles of intravenous NACT will be given. Patients in the control group will receive three cycles of intravenous NACT. The primary endpoint is the proportion of patients who achieve a Chemotherapy Response Score (CRS) of 3 according to the CRS system. The secondary endpoints include progression-free survival, overall survival and the rates of complete resection and NHIPEC-related adverse events.

Ethics approval and dissemination

This study was approved by the Ethics Committee of Sun Yat-sen Memorial Hospital (approval number: 2020-ky-050). Results will be submitted to peer-reviewed journals and presented at national and international conferences.

Trial registration number

ChiCTR2000038173.
Impact of COVID-19 on mobility and participation of older adults living in Hamilton, Ontario, Canada: a multimethod cohort design protocol
Authors: Beauchamp Marla K , Vrkljan Brenda , Kirkwood Renata , Vesnaver Elisabeth , Macedo Luciana G , Keller Heather , Astephen-Wilson Janie , Sohel Nazmul , Noble Tara , Dietrich Nicholas , Gardner Paula , Newbold K Bruce , Scott Darren
Published: December 2021

Introduction

The novel COVID-19 required many countries to impose public health measures that likely impacted the participation and mobility of community-dwelling older adults. This protocol details a multimethod cohort design undertaken to describe short-term and medium-term changes to the mobility and participation of older Canadians living in the community rather than retirement facilities during the COVID-19 pandemic.

Methods and analysis

A longitudinal telephone (or online)-administered survey is being conducted with a random sample of older adults living within 20 km of McMaster University, Hamilton, Ontario, Canada, identified from census dissemination areas. Baseline data collection of community-dwelling older adults aged 65 years and over began in May 2020 with follow-ups at 3, 6, 9 and 12 months. The Late-Life Function and Disability Instrument and global rating of change anchors are the primary outcomes of interest. A subsample of respondents will participate in open-ended, semistructured interviews conducted over the telephone or through video-conference, to explore participants’ lived experiences with respect to their mobility and participation during the pandemic. Descriptive statistics and quantitative approaches will be used to determine changes in mobility and social and personal participation, and associated personal and environmental factors. For the interviews, qualitative data will be analysed using descriptive phenomenology.

Ethics and dissemination

Approval was obtained from the Hamilton Integrated Research Ethics Board of McMaster University (2020-10814-GRA). This study may inform the design of programmes that can support community-dwelling older adults during and after the COVID-19 pandemic. Findings will be disseminated through peer-reviewed publications and conferences focused on ageing.