bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural modelling of multilayer skis with an open source FEM software
Authors: Fraccaroli L , Gorla C , Concli F
Published: March 2021

The development process of mountaineering skis is characterized by a rapid design phase due to the continuous changes in materials, customer’s requirements and manufacturing processes. Nowadays, this type of ski is still characterized by a design process based on a basilar trials and error technique. Finite Elements Analysis (FEA) could introduce a different approach to overcome main disadvantages, such as time, of this actual design method. For this reason, the main purpose of this work is centered on the development of a reliable FE model of an existing mountaineering ski, capable to forecast the mechanical behavior of the real tool. Firstly, all mechanical properties of materials that were composing the ski were characterized. Tensile tests in the two principal directions were performed on flat dog-bones shaped specimens. Secondly, Digital Image Correlation (DIC) was combined with results obtained from tensile tests in order to approximate the four in-plane (XY) elastic properties, namely, the two elastic modules, the shear module and the Poisson ratio (Ex, Ey, Gxy, νxy). Results of the cross-correlation process were after checked with the help of numerical simulations. FEA simulations were reproducing the tensile-tests configuration. Finally, geometry, mesh and simulations-run of the ski were performed in the open source environment Code_Aster/Salome-Meca. The results of simulations of the ski were compared with the response of the real ski in three-point bending tests. Differences of 2.5%-10% with respect to the real ski were observed for the different modelling techniques.
Computational studies on cycloidal gearboxes: a systematic literature review
Authors: Maccioni L , Mastrone M N , Concli F
Published: March 2021

The high compactness of cycloidal gearboxes, their low backlash and their capability to withstand overloads are just some of the factors that have led the research to focus on these solutions for reducing speed. These types of gearboxes have very complex geometries, architectures and dynamics, and the contact between the various components occurs simultaneously in different areas of them. Therefore, numerical simulations can represent an essential tool for the design of these systems. The objective of this study is to understand in what and how numerical simulations can support the design of cycloidal reduction systems and make a review of the literature to understand to date, who, why and how has conducted these of studies. The reviewed contributions, collected through Scopus, are analyzed and classified according to, among others, the component modelled and analyzed, the scope of the analysis and if the analysis has been validated with experimental results. Bibliometric analyses show that the topic is of growing interest to the international scientific community but remains almost an Asian monopoly since most of the results are not shared in English. It has emerged that the study of the contact between cycloidal disk and rollers remains the most widespread study. The research showed that only a small number of analyses have been validated by experimental results.
Finite element modelling of a truck crashing into a new form of mobile vehicle blocker
Authors: Arcieri E V , Baragetti S
Published: March 2021

In the last years, a new form of terrorist attack has sowed panic in western countries: vehicles have been run into crowded places injuring and killing many people. The first solution to preventing the vehicle ramming attack has been the placement of concrete barriers around areas that are potential terrorist targets. The performance of these systems is questionable and the design of new, effective and good-looking protection devices is a hot topic. The authors have already presented a new certified mobile barrier, which is able to stop a 3500 kg vehicle run at 64 km/h in a few meters thank to its high deformability and the adoption of water as a filler. The water flows out and removes an appreciable amount of the impact energy. In this paper, the crashes of a 7500 kg truck running at 64 km/h against a concrete block and a single barrier designed by the authors are analysed with the help of finite element (FE) calculations in Abaqus Explicit. The water in the barrier is modelled using Smooth Particle Hydrodynamics (SPH). Due to the complexity of the truck modelling, a very simplified geometry is adopted, which is a consequence of the different versions tested. According to the results, compared to the concrete blocks, the designed barrier is overall more effective, even in a single configuration.
Validation of a multi-scale simulation strategy based on the Pointwise Strain Superposition Method
Authors: Moda M , Monelli B D , Benassi M , Palladino M
Published: March 2021

This paper details the experimental validation of a multi-scale simulation strategy that we developed for predicting the stresses and distortions induced by Powder Bed Fusion processes. The strategy comprises a meso-scale model, a macro-scale model, and a scaling method named Pointwise Strain Superposition. The first model evaluates the temperature, stress, and strain fields produced by a single scan line. The scaling method transfers the meso-scale results to the macro-scale model, which is then able to simulate the entire manufacturing process with a reasonable computational cost. The simulation strategy was validated by comparing its results with the stresses and distortions measured on several specimens made of selective laser melted Inconel 718. Stresses were measured through the blind hole drilling method on a cylindrical specimen printed with two different scanning strategies, while distortions were measured on a hollow cylinder and on a cantilever-shaped specimen after removing its supports. In both cases the simulation showed first- or higher-order accuracy despite the significant uncertainties regarding the input parameters and material properties. This robustness, coupled with its computational efficiency, leads us to believe that our simulation strategy could enhance the process optimization and provide a better understanding of the underlying physical phenomena along with their effects on the manufactured parts.
Influence of data input in the evaluation of Stress Intensity Factors from Thermoelastic Stress Analysis
Authors: Pitarresi Giuseppe , Cappello Riccardo , Calsi Giovanni Li , Catalanotti Giuseppe
Published: March 2021

Thermoelastic Stress Analysis (TSA) is applied to evaluate the Stress Intensity Factor (SIF), T-stress and J-Integral in a Single-Edge-Notched-Tension sample undergoing fatigue cycling. The Williams’ series stress formulation and a least-square fitting (LSF) procedure are used to obtain the SIF and the T-stress. The evaluation is carried out with the aim to investigate the influence of the input data in the system of equations solved with the LSF, and in particular: the number of coefficients used in the Williams’ series and the choice and position of the fitted experimental data points. Three algorithms for the determination of the crack tip position are also evaluated: a coarse grid method with pixel resolution, a refined grid method and a patternsearch method with sub-pixel resolution. In order to establish a criterion for the choice of input parameters for the LSF, the theoretical case of an infinite plate with a central crack has been analysed, for which an exact solution of the isopachics, SIF and T-stress is available. Finally, the stress separation obtained with the fully characterised Williams’ model is also used to evaluate the J-Integral by applying an Energy-Domain-Integral formulation, and the SIF retrieved from the J-Integral is compared with SIF obtained from the first coefficient of the Williams’ series.
Evaluation of the Energetic Release During Tensile tests in Notched Specimens by means of Experimental and Numerical Techniques
Authors: Foti P , Risitano G , Berto F , Santonocito D
Published: March 2021

Static Thermographic Method is a rapid test procedure able to predict the fatigue limit of the material evaluating the end of the thermoelastic phase during a static tensile test. In order to investigate the energetic release of the material, experimental tests have been carried out on double edge steel notched specimens. During the test, the surface temperature was monitored with an infrared camera and the true stress-strain curve of the material was retrieved. Numerical simulations have been carried out to predict the temperature evolution of the material under monotonic load. The relationship between the elasto-plastic behavior and the energetic release has been investigated comparing numerical and experimental data. The rise of irreversible plastic deformation severally affects the temperature trend introducing an additional heat amount that leads to a deviation from the linearity of the thermoelastic effect. The analysis of the temperature evolution during a static tensile test may be adopted as a novel approach to relate the local stress state with a macroscopic stress value that introduce in the material the first micro plasticization.
A novel method for the evaluation of driving simulator performances
Authors: Cianetti F , Cavallaro M , Palmieri M , Ambrogi F
Published: March 2021

The use of driving-simulator is increasing wide-spreading in the whole automotive sector. The adoption of driving simulator indeed allows evaluating the design choices directly during the design stage thought the man-machine interaction, where “man” means the driver while “machine” means the mathematical model of the car traduced to the driver thought a different machine: the driving simulator. In this research activity a questionnaire was developed to evaluate the performances of a driving simulator focusing on two main aspects. The first one regards the ability of the driving simulator to accurately reproduce the driving feelings without inducing motion sickness sensations. The second instead regards the ability of the driver to objectively judge the vehicle performances throughout a set of parameters. All these aspects were firstly numerically investigated implementing different models showing different dynamics characteristics and successively verified by experimental test at the driving simulator. The drivers scores, about both the accuracy of the mathematical model and the driving simulator, were analysed in order to understand if their feelings match the real behaviour imposed to the car.
Structural design of the optical bench and enclosure for MAORY, adaptive optics module for the ELT
Authors: Andolfo A , Belperio A , Cianniello V , Eredia C , De Caprio V , Armentani E
Published: March 2021

This paper outlines an overview of the mechanical design of the optical bench and the enclosure for MAORY (Multi-conjugate Adaptive Optics RelaY) for the Extremely Large Telescope. MAORY will enable high-angular resolution observations in the near infrared by employing real-time compensation of the wave-front distortions due to atmospheric turbulence and other disturbances on the telescope. The main purpose of the optical bench is to provide support to the opto-mechanical mountings and subsystems that will be integrated on it. The design philosophy behind the proposed architecture is a truss spatial structure with the aim of optimizing the mass of the Main Structure. The enclosure has to protect the optomechanical elements and to achieve a uniform temperature distribution in its internal environment. The mechanical design of the bench and the enclosure was supported by a set of structural FE analyses, to verify the design compliance with ESO (European Southern Observatory) requirements.
Stress corrosion cracking behavior of welding joint of high strength steel
Authors: Sepe R , Bollino F , Caiazzo F , Berto F
Published: March 2021

Nowadays, high-strength steel structures are increasingly being used in marine or soil environments, but low attention has been paid on the corrosion and stress corrosion cracking problem. In this paper, the susceptibility to stress corrosion cracking (SCC) of butt-welding joints of Strenx® 700 (S690QL high strength steel) both in marine and acid-polluted marine atmospheres was studied, by using slow strain rate tensile (SSRT) test. The seawater corrosion environment was considered and it was prepared following the ASTM D1141. To study the influence of the environment pH, NaOH 0,1M solutions and pure H2SO4 were used to adjust the pH of the simulated seawater solution to 8 and 4, respectively. The slow strain rate tensile tests (SSRT) with a crosshead speed of 0.000017 mm/s were carried out at room temperature (approximately 25 °C). After failure, the SCC susceptibility was evaluated acquiring the elongation loss rate and the reduction-in-area loss rate. The fracture surfaces were analyzed by SEM observation.
MEMS sensors for sport engineer applications
Authors: Russo C , Mocera F , Somà A
Published: March 2021

In this paper it is presented a brief introduction about the Micro ElectroMechanical Systems (MEMS) sensors technology and their application and use in healthcare and sport activity in the literature. In these two fields, our research group’s applications will then be analyzed with the support of a numerical tool able to replicate human body behavior performing a sport activity, in particular Nordic Walking and Alpine Skiing. The main goal was to obtain a comparison between the numerical and experimental results, in order to validate of the numerical tool and to better understand the sport gesture. The integrated monitoring systems enable a new interpretation of the sport gesture providing the athletes the maximum freedom of movement and allowing them to better perform in their natural training environment.
A crashworthiness optimisation procedure for the design of full-composite fuselage section
Authors: Manzo M , Perfetto D , Caputo F , Di Palma L , Chiariello A , Waimer M
Published: March 2021

Crashworthiness of composites is a key-point in the design of new aeronautical structures. Special attention has been addressed in the last years to the energy absorption mechanisms of dedicated components in order to limit the structural damages and to preserve the occupants’ safety. Remarkable progress has been made in this field. Despite this, to further improve the design of crashworthy composite structures, components modification, sensitivity analysis, design of experiments and optimisation procedures are needed. In this work, crashworthiness improvements, related to a simplified finite element model of a full-composite fuselage section subjected to a vertical drop-test, have been introduced. The genesis of the model has been described together with its main features and details and a high-speed vertical fall has been simulated, paying attention to velocity and payload. In addition, sensitivity analyses of some components and a discussion on the main crashworthiness characteristics have been carried out. Finally, the parent fuselage section and its simplified model have been compared under both energy and deformation points of view, showing a good results agreement.
Design and validation of low-cost handling equipment for the use of Barkhausen Noise Testing in worm gears grinding burn detection
Authors: Citti P , Molinari P , Giorgetti A , Polidoro A , Pompei L , Arcidiacono G
Published: March 2021

Worm gears in high-performance gearboxes are often exposed to extreme loads, which requires assuring high production quality. Therefore the most important final characteristics of the workpieces are provided by grinding. One of the most investigated issues of this machining method is grinding burns, who change locally the properties of the material. In many industrial applications, nital etching is used to detect grinding burn. Although it is considered a standard, new types of tests are of great interest in order to reduce costs and make online control possible. One of the Non-Destructive Testing methods is Barkhausen Noise Testing (BNT), which is utilized to assess changes in the surface layer of ferromagnetic materials, especially to monitor changes in their hardness and residual stresses. To obtain accurate measures using this technology the Barkhausen probe handling system is essential. Typically the sensor handling system is an Inline/robot component, an automated component, a semi-automated component, or a manual handling system. Considering this scenario, the use of a manual system could allow having important cost savings but has to be correctly developed to obtain reliable measures. The aim of this paper is to develop a handling equipment for the BNT probe able to assure an adequate level of accuracy and repeatability.
Experimental and numerical analysis of roll bending process of thick metal sheets
Authors: Mercuri A , Fanelli P , Giorgetti F , Rubino G , Stefanini C
Published: March 2021

In metalworking, bending forming processes are used extensively for a wide range of applications referring to several industrial fields, such as oil&gas field, naval field or automotive field. In cylinders and truncated cones bending process, three-point roll forming of metal sheets represents a concrete option, which mainly consists of pyramid-type machines made of two lower rolls and a top roll. Each roll can be designed to work as a driven roll or as an idler and to move both vertically and horizontally during the rolling process, depending on the sheet and final product features (mechanical properties, thickness and final curvature mainly). Final products can be affected by defects, which represent a concrete problem for metalworking industries because of the further works to be done to meet customers needs; in three-point roll bending, warping defect and hourglass (or barrel) defect represent two of the most common problems. In this paper, an experimental and numerical analysis is proposed to detect defects on roll-bent thick cylinders referring to several companies experiences; the occurrence of thickness variability and circumferences variability along cylinder length and considerable differences between the internal and external length of cylinders themselves, referable to the so-called ”hourglass defect” represents a common problem in this industrial field and a major cost for metalworking companies. A Finite Element (FE) 3D model of both the roll-bending machine and the metal sheet is used to simulate the mechanical behaviour of the metal sheet during the forming process, checking for the influence of the spring-back effect and the bending moments from the rolls. Both the pre-bending and the roll bending phases have been simulated. Rolls are modelled as rigid. Both rolls and sheet have been modelled using solid elements and contact elements to take into account rolls/sheet friction. Obtained results are compared with experimental results to check the reliability of the FE model and the simulation. The model itself is then implemented with a central lower roll which serves as an idler and is placed half-way between the original ones. The updated model is then used to simulate the process again and test the central idler as an hourglass-defect solution.
A territorial round-robin experiment for the evaluation of mechanical properties of FDM PLA produced by distributed facilities
Authors: Vettori M , Bergonzi L
Published: March 2021

Mechanical characteristics of the produced materials through additive manufacturing (AM) are influenced by a multitude of parameters. In particular, Free Filament Fabrication (FFF) is one of the most adopted technologies due to low machine cost and its simplicity. In recent years, a lot of printer manufacturers emerged as well as many printer control software. This proliferation led to the development of non-standardized ways of printing, such as different machines architecture or software algorithms to control the printing process: in this way, the object produced with a combination of a printer and software is rarely directly comparable (in terms of mechanical characteristics) with the same object produced using a different combination. This work aims to investigate possible variations in material mechanical properties due to different combinations of printers and filament manufacturers: to do so, different makers in Parma area have been involved to produce specimens with their equipment maintaining the same geometry and identical printing settings.
Multiaxial cyclic plasticity model including elastic modulus variation
Authors: Barsanti M , Beghini M , Loffredo M , Macoretta G , Monelli B D , Bagattini A
Published: March 2021

In the present work a multiaxial model is proposed to describe the elastoplastic behaviour of a structural steel in the presence of loading-unloading cycles. The activity is a part of a more estensive research carried out in collaboration with Baker & Hughes aimed at developing an accurate model for accurately predicing residual stresses caused by autofrettage processes in thick cylinders and its experimental verification. It has been demostrated that in order to obtain estimates of the residual stress with errors within a few percent, the constitutive behavior of the material has to be reproduced very accurately. To this purpose, both the Bauschinger effect and the variation of the elastic modulus with the accumulated plastic deformation have to be accurately measured and properly included in the constitutive model.
Deterministic fatigue crack-growth simulations for a railway axle by Dual Boundary Element Method
Authors: Giannella V , Sepe R , De Michele G , Esposito R
Published: March 2021

The maintenance of railway axles requires an optimization of their inspection intervals in order to reduce costs. Such components can endure more than 30 years of service life and are subjected to scheduled Non Destructive Testing (NDT) inspections. It is therefore important to assess the influence of the severe in-service loads on the propagation of cracks in the axles. This manuscript reports deterministic fracture calculations, for the simulation of cracks propagating through a railway axle, by the Dual Boundary Element Method. Once Stress Intensity Factors along the crack front are obtained, the residual fatigue life estimates were calculated through a user made spreadsheet, taking into account the complex loading conditions of the axles. The presented results support the application of the crack propagation simulation for the determination of axle NDT intervals under different loading conditions.
CAD model update on as-built geometries with morphing technique: ITER winding pack
Authors: Pompa E , Porziani S , Groth C , Chiappa A , D’Amico G , Costa E , Sorrentino S , Ferrante E , Portone A , Semeraro L , Biancolini M E
Published: March 2021

CAD and CAE model update on manufactured shapes is a key process in the industry 4.0, where design, manufacturing and maintenance are integrated elements. Digital Twin models, together with Reverse Engineering (RE) techniques, allow tracking components performances during production and verifying the compliance with design requirements during the component lifetime. The need to have RE processes with a small impact on the production is driving the development of these models towards numerical techniques with fast computing performances. In this context, morphing techniques, largely deployed in the field of CAE models update, represent a valuable alternative to conventional RE techniques, because of their reduced computational time and capability to preserve the initial topology of the model. In the work presented in this paper, Radial Basis Function morphing technique has been used for the update of ITER Winding Pack CAD model on scan data acquired from the manufactured component.
Modeling flexible/curved PCBs using RBF mesh morphing
Authors: Biancolini M E , Medikonda S , Morgan K , Porziani S
Published: March 2021

In the recent past, flexible printed circuit board (PCB) electronics have seen a significant surge in many electronics products ranging from smartphone/watches that wrap around our wrists, displays that fold out as large television sets, reconfigurable electronics that conform to the roofs/trunks of cars or as flexible implants that can monitor and treat diseases. Whatever the need is, it is quite evident that the near future is bound to see a significant uptick in day-to-day usage of such electronic products and hence as a direct result there is a need for numerical modeling, simulation and analysis of PCB’s that conform to different shapes. However, given the complexity of PCB’s, numerical modeling of such structures remains a challenge and there is a need for a clear and simple methodology to accomplish this. In addition, the developed methodology should also be applicable to both the trace mapping and trace modeling techniques typically used while working with Electronic-CAD files. In this work, the RBF (Radial Basis Function) method has been presented as a capable technology that can morph the flat mesh electronic data to a curved space which can be further used for analysis purposes. Since the morphing is being directly implemented at the mesh level, a lot of obstacles and complexity typically encountered while generating curved PCB CAD files can be avoided. The RBF Morph ACT Extension has been the tool of choice in the current context. This extension was built on the modular architecture of the ANSYS Workbench and is hence deeply integrated into Mechanical which makes it easy to work with. While RBF Morph offers a wide range of morphing capabilities, a 2-step morph process which relies on an auxiliary body and 2D coordinate filtering technique has been identified as most reliable technique of choice for most curved geometries. The morph technique developed has been successfully applied to a wide range of curved structures which include solid PCBs as well.
The study of self-assembly behavior of phthalocyanine-before (PCB) molecules on Au(111) substrate
Authors: Guo Hailong , Ruan Zilin , Ren Xiang , Lu Jianchen , Yan Cuixia
Published: March 2021

The PCB molecules have been self-assembled on Au(111) surface and the self-assembly behavior has been studied based on the first principle calculation. The results show that the PCB molecules are antiparallel phase between line and line observed by scanning tunneling microscopy (STM). Moreover, the lattice parameter are matched between the PCB molecules and the Au(111) substrate. Based on the first-principle calculation, it is found that the self-assembly behavior are affected by the molecule–substrate (MS) and molecule–molecule (MM) interactions (cyano coupling force), in which the molecule–substrate (MS) interactions is stronger than that of between the molecules. And the effect of MS interaction plays a dominate role during the PCB molecules self-assembly. This work is helpful to achieve rational design, accurate prediction, and controllable construction of assembled molecular nanostructures.
System size identification from sinusoidal probing in diffusive complex networks
Authors: Tyloo Melvyn , Delabays Robin
Published: March 2021

One of the most fundamental characteristic of a complex system is its size (or volume), which, in many modelling, is represented by the number of its individual components. Complex systems under investigation nowadays are typically large and/or time-varying, rendering their identification challenging. We propose here an accurate and efficient method to determine the size of (i.e., number of agents in) a complex, diffusively coupled dynamical system, that leverages the response of the system to an injected probing signal. For our method to be applicable, we rely on some assumptions on system’s characteristics, namely, on the spectrum of the coupling graph and on the basin stability of its steady state(s). Even though such assumptions imply that our method cannot be applied to any instance of diffusively coupled group of dynamical agents, we argue that it covers relevant and interesting examples. Furthermore, the simplicity of the approach and its low computational complexity renders it very interesting for the systems to which it applies.
Volumes of line bundles on schemes
Authors: Cutkosky Steven , Núñez Roberto
Published: March 2021

Volumes of line bundles are known to exist as limits on generically reduced projective schemes. However, it is not known if they always exist as limits on more general projective schemes. We show that they do always exist as a limit on a codimension one subscheme of a nonsingular projective variety.
The non-linear Cousin problem for 𝐽-holomorphic maps
Authors: Kuzman Uroš
Published: March 2021

We solve a non-linear Cousin problem for

J
J

-holomorphic maps. That is, we provide a gluing method for the pseudoholomorphic maps defined on a Cartan pair of domains in

C

\mathbb {C}

.
Light Chain–Restricted Plasmacytoid Cells in Hyperplastic Germinal CentersA Clinicopathologic Investigation
Authors: Wang Xuan J , Moore Erika M , Swerdlow Steven H , Aggarwal Nidhi
Published: March 2021

Objectives

Follicular hyperplasias (FHs) with light chain–restricted (LCR) plasmacytoid/plasma cells (PCs) within germinal centers (GCs) based on immunohistochemistry (IHC)/in situ hybridization (ISH) can potentially lead to diagnostic error. This study aims to better characterize such cases, including their clinical implications.

Methods

LC expression by IHC/ISH was quantitatively assessed in GCs of 17 FHs with LCRGCs. BCL2, CD10, BCL6, BCL2, immunoglobulin (Ig) heavy chains, IgG4, and Epstein-Barr encoding region stains were performed. In total, 8 cases had polymerase chain reaction (PCR)–based clonality studies.

Results

All cases showed FH, including 4 with progressively transformed GCs (PTGCs); 0.8% to 52% (median, 21%) of the GCs were LCR; 13 of 17 had both κ- and λ-LCRGCs, and 4 of 17 had only κ-LCRGCs; 7 of 16 had prominent intrafollicular IgG4-positive cells. One case demonstrated BCL2-positive cells in focal LCRGCs but lacked BCL2 rearrangement. B-cell monoclonality was demonstrated in 3 of 8 cases (only after microdissection). Seven patients had autoimmune disorders, and 1 had had a transplant. Three patients had a history of lymphoma, 1 developed lymphoma, and 1 developed lymphomatoid granulomatosis subsequently.

Conclusions

FHs with LCRGC by IHC/ISH are typically not associated with the development of lymphoma, even though they can express BCL2 and show monoclonality by PCR. They may be associated with increased intrafollicular IgG4-positive cells, PTGC, and autoimmunity.
RFC1 expansions are a common cause of idiopathic sensory neuropathy
Authors: Currò Riccardo , Salvalaggio Alessandro , Tozza Stefano , Gemelli Chiara , Dominik Natalia , Galassi Deforie Valentina , Magrinelli Francesca , Castellani Francesca , Vegezzi Elisa , Businaro Pietro , Callegari Ilaria , Pichiecchio Anna , Cosentino Giuseppe , Alfonsi Enrico , Marchioni Enrico , Colnaghi Silvia , Gana Simone , Valente Enza Maria , Tassorelli Cristina , Efthymiou Stephanie , Facchini Stefano , Carr Aisling , Laura Matilde , Rossor Alexander M , Manji Hadi , Lunn Michael P , Pegoraro Elena , Santoro Lucio , Grandis Marina , Bellone Emilia , Beauchamp Nicholas J , Hadjivassiliou Marios , Kaski Diego , Bronstein Adolfo M , Houlden Henry , Reilly Mary M , Mandich Paola , Schenone Angelo , Manganelli Fiore , Briani Chiara , Cortese Andrea
Published: March 2021

After extensive evaluation, one-third of patients affected by polyneuropathy remain undiagnosed and are labelled as having chronic idiopathic axonal polyneuropathy, which refers to a sensory or sensory-motor, axonal, slowly progressive neuropathy of unknown origin. Since a sensory neuropathy/neuronopathy is identified in all patients with genetically confirmed RFC1 cerebellar ataxia, neuropathy, vestibular areflexia syndrome, we speculated that RFC1 expansions could underlie a fraction of idiopathic sensory neuropathies also diagnosed as chronic idiopathic axonal polyneuropathy. We retrospectively identified 225 patients diagnosed with chronic idiopathic axonal polyneuropathy (125 sensory neuropathy, 100 sensory-motor neuropathy) from our general neuropathy clinics in Italy and the UK. All patients underwent full neurological evaluation and a blood sample was collected for RFC1 testing. Biallelic RFC1 expansions were identified in 43 patients (34%) with sensory neuropathy and in none with sensory-motor neuropathy. Forty-two per cent of RFC1-positive patients had isolated sensory neuropathy or sensory neuropathy with chronic cough, while vestibular and/or cerebellar involvement, often subclinical, were identified at examination in 58%. Although the sensory ganglia are the primary pathological target of the disease, the sensory impairment was typically worse distally and symmetric, while gait and limb ataxia were absent in two-thirds of the cases. Sensory amplitudes were either globally absent (26%) or reduced in a length-dependent (30%) or non-length dependent pattern (44%). A quarter of RFC1-positive patients had previously received an alternative diagnosis, including Sjögren’s syndrome, sensory chronic inflammatory demyelinating polyneuropathy and paraneoplastic neuropathy, while three cases had been treated with immune therapies.
Ethnic differences in excretion of butadiene–DNA adducts by current smokers
Authors: Jokipii Krueger Caitlin C , Park S Lani , Madugundu Guru , Patel Yesha , Le Marchand Loic , Stram Daniel O , Tretyakova Natalia
Published: March 2021

1,3-Butadiene (BD) is a known human carcinogen used in the synthetic polymer industry and also found in cigarette smoke, automobile exhaust and wood burning smoke. BD is metabolically activated by cytochrome P450 monooxygenases (CYP) 2E1 and 2A6 to 3,4-epoxy-1-butene (EB), which can be detoxified by GST-catalyzed glutathione conjugation or hydrolysis. We have previously observed ethnic differences in urinary levels of EB–mercapturic acids in white, Japanese American and Native Hawaiian smokers. In the present study, similar analyses were extended to urinary BD–DNA adducts. BD-induced N7-(1-hydroxy-3-buten-2-yl) guanine (EB–GII) adducts were quantified in urine samples obtained from smokers and non-smokers belonging to three racial/ethnic groups: white, Japanese American and Native Hawaiian. After adjusting for sex, age, nicotine equivalents, body mass index and batch, we found that Japanese American smokers excreted significantly higher amounts of urinary EB–GII than whites [1.45 (95% confidence interval: 1.12–1.87) versus 0.68 (95% confidence interval: 0.52–0.85) fmol/ml urine, P = 4 × 10−5]. Levels of urinary EB–GII in Native Hawaiian smokers were not different from those in whites [0.67 (95% confidence interval: 0.51–0.84) fmol/ml urine, P = 0.938]. There were no racial/ethnic differences in urinary EB–GII adduct levels in non-smokers. Racial/ethnic differences in urinary EB–GII adduct levels in smokers could not be explained by GSTT1 gene deletion or CYP2A6 enzymatic activity. Urinary EB–GII adduct levels in smokers were significantly associated with concentrations of BD metabolite dihyroxybutyl mercapturic acid. Overall, our results reveal that urinary EB–GII adducts in smokers differ across racial/ethnic groups. Future studies are required to understand genetic and epigenetic factors that may be responsible for these differences.
Association of Intensity of Antipseudomonal Antibiotic Therapy With Risk of Treatment-Emergent Organisms in Children With Cystic Fibrosis and Newly Acquired Pseudomonas Aeruginosa
Authors: Cogen Jonathan D , Onchiri Frankline M , Hamblett Nicole Mayer , Gibson Ronald L , Morgan Wayne J , Rosenfeld Margaret
Published: March 2021

Background

While Pseudomonas aeruginosa (Pa) eradication regimens have contributed to a decline in Pa prevalence in people with cystic fibrosis (CF), this antibiotic exposure might increase the risk of acquisition of drug-resistant organisms. This study evaluated the association between antipseudomonal antibiotic exposure intensity and acquisition risk of drug-resistant organisms among children with CF and new Pa infection.

Methods

We utilized data from the Early Pseudomonas Infection Control Clinical Trial (EPIC CT), a randomized controlled trial comparing Pa eradication strategies in children with CF and new Pa. The exposure was the number of weeks of oral or inhaled antipseudomonal antibiotics or ever versus never treatment with intravenous antipseudomonal antibiotics during the 18 months of EPIC CT participation. Primary outcomes were risks of acquisition of several respiratory organisms during 5 years of follow-up after EPIC CT estimated using Cox proportional hazards models separately for each specific organism.

Results

Among 249 participants, there was no increased acquisition risk of any organism associated with greater inhaled antibiotic exposure. With each additional week of oral antibiotics, there was an increased hazard of Achromobacter xylosoxidans acquisition (HR, 1.24; 95% CI: 1.02–1.50; P = .03). Treatment with intravenous antibiotics was associated with an increased hazard of acquisition of multidrug-resistant Pa (HR, 2.47; 95% CI: 1.28–4.78; P = .01) and MRSA (HR, 1.57; 95% CI: 1.03–2.40; P = .04).

Conclusions

Results from this study illustrate the importance of making careful antibiotic choices to balance the benefits of antibiotics in people with CF while minimizing risk of acquisition of drug-resistant organisms.
Echocardiographic guidance for HARPOON beating-heart mitral valve repair
Authors: Gackowski Andrzej , D'Ambra Michael N , Diprose Paul , Szymański Piotr , Duncan Alison , Bartus Krzysztof , Gammie James S
Published: March 2021

The HARPOON mitral valve (MV) repair system has been shown to safely and effectively treat a degenerative MV prolapse with transventricular implantation of artificial cords on a beating heart. The low profile system is introduced and precisely steered under 3D TEE guidance towards the previously selected target on a prolapsing MV segment. It allows puncture and deployment of a knot on the leaflet. The procedure is repeated until desired number of knots are implanted and the cords are optimally tensioned to restore coaptation. The cords are then tied down on the epicardium over a felt pledget.

State of the art echocardiographic imaging is a crucial part of the procedure. It starts from patients screening, pre-procedural analysis and planning, access selection, navigation, deployment, optimal cordal tensioning, and final MV assessment and is continued during the follow-up assessment.

This article illustrates the specific echocardiographic aspects of the HARPOON procedure including 2D and advanced 3D TEE techniques. The echocardiographic protocol was developed based on initial experience in 60 procedures. Detailed training of the echocardiographer and surgical team, is mandatory to achieve excellent results of this procedure, being now introduced in the clinical practice.
Evaluating the direct effects of childhood adiposity on adult systemic metabolism: a multivariable Mendelian randomization analysis
Authors: Richardson Tom G , Mykkänen Juha , Pahkala Katja , Ala-Korpela Mika , Bell Joshua A , Taylor Kurt , Viikari Jorma , Lehtimäki Terho , Raitakari Olli , Davey Smith George
Published: March 2021

Background

Individuals who are obese in childhood have an elevated risk of disease in adulthood. However, whether childhood adiposity directly impacts intermediate markers of this risk, independently of adult adiposity, is unclear. In this study, we have simultaneously evaluated the effects of childhood and adulthood body size on 123 systemic molecular biomarkers representing multiple metabolic pathways.

Methods

Two-sample Mendelian randomization (MR) was conducted to estimate the causal effect of childhood body size on a total of 123 nuclear magnetic resonance-based metabolic markers using summary genome-wide association study (GWAS) data from up to 24 925 adults. Multivariable MR was then applied to evaluate the direct effects of childhood body size on these metabolic markers whilst accounting for adult body size. Further MR analyses were undertaken to estimate the potential mediating effects of these circulating metabolites on the risk of coronary artery disease (CAD) in adulthood using a sample of 60 801 cases and 123 504 controls.

Results

Univariable analyses provided evidence that childhood body size has an effect on 42 of the 123 metabolic markers assessed (based on P < 4.07 × 10−4). However, the majority of these effects (35/42) substantially attenuated when accounting for adult body size using multivariable MR. We found little evidence that the biomarkers that were potentially influenced directly by childhood body size (leucine, isoleucine and tyrosine) mediate this effect onto adult disease risk. Very-low-density lipoprotein markers provided the strongest evidence of mediating the long-term effect of adiposity on CAD risk.

Conclusions

Our findings suggest that childhood adiposity predominantly exerts its detrimental effect on adult systemic metabolism along a pathway that involves adulthood body size.
A study of the skylight coverage ratio for air-conditioned atriumsin the hot and humid regions
Authors: Lou Siwei , Huang Yu , Xia Dawei , Lun Isaac Y F , Li Danny H W
Published: March 2021

The skylight on the roof of an atrium can be popular for commercial malls to illuminate the core area of the building. However, the solar radiation and its heat can get into the building together with the daylight, causing excessive cooling load. This paper studies the daylighting and energy performances of skylight coverage area for the air-conditioned atriums in the hot and humid regions. The energy performance with different atrium heights, glass types and the coverage ratios of the skylight are studied. The daylight performance was simulated by the ray-tracing Radiance and was transferred into EnergyPlus for energy evaluations. The finding suggested that, for hot and humid climates, the skylight coverage ratio should be controlled carefully to prevent the excessive solar heat gain. When the on/off lighting control is applied, the total energy consumption of the single-floor cases (or of the top floor for the multi-floor cases) leveled off when the coverage ratio of the skylight reached 9%. Thus, the skylight is favorable to the energy saving of the low-rise or single-floor commercial buildings only under the current assumptions, as the ground of the atrium cannot be well illuminated while the excessive solar radiation gets into the building. The skylight should be shaded in cooling seasons to prevent the excessive solar heat gains.
From Cattle Brand to Corporate Brand: Blue Jean Trademarks in Mid-century America
Authors: Abrego Sonya
Published: March 2021

Cattle brands are physical imprints of ownership applied to the flesh of animals. They were, in the nineteenth century, indispensable to ranchers for differentiating their cattle from a competitors’ stock on the open range. The branding symbol’s utility as a legible marker of property ownership declined after widespread fencing delimited the plains. Yet cattle brands remained present in vernacular visual and material culture as decorative features and motifs signifying the Old West into the twentieth century. Cattle brand imagery, largely divorced from its functional origins, was recombined and repurposed to add decorative flourish to a variety of garments, wearable accessories, and domestic objects. This article explores the persistence of cattle brands as a popular trope in mid-century America and focuses on denim jeans, manufactured by Levi Strauss & Co., and, in particular, Lee, companies that fashioned their company logos in the guise of a brand. Through material culture analysis I will examine how clothing companies employed cattle brand iconography in advertising, promotions, and product design to consider a historical moment in the cattle brand’s semiotic shift from indexical trace of property ownership to corporate brand logo.
Retroperitoneal ganglioneuroma presenting as an obstructive pyelonephritis: a case report
Authors: Kora Christine , Oulad Amar Asmae , El Arabi Soumia , Rockson Obed , Nasri Siham , Skiker Imane
Published: March 2021

Ganglioneuroma is a nerve tumor arising from the sympathetic neural crest. It is a rare benign tumor. Retroperitoneum is its second location after the posterior mediastinum. Usually asymptomatic, it is discovered incidentally on imaging. Surgical resection is the sole treatment. The prognosis is good if the diagnosis is made early with quality R0 surgical excision. We report a case in a 14-year-old female admitted to the emergency department for obstructive pyelonephritis. Imaging features found a retroperitoneal mass with characteristics suggestive of a retroperitoneal ganglioneuroma, which was confirmed by histological study. Ganglioneuroma should be a part of differential diagnoses for any retroperitoneal mass in children and young adults.
Mechanisms of damage tolerance and repair during DNA replication
Authors: Ashour Mohamed Elsaid , Mosammaparast Nima
Published: March 2021

Accurate duplication of chromosomal DNA is essential for the transmission of genetic information. The DNA replication fork encounters template lesions, physical barriers, transcriptional machinery, and topological barriers that challenge the faithful completion of the replication process. The flexibility of replisomes coupled with tolerance and repair mechanisms counteract these replication fork obstacles. The cell possesses several universal mechanisms that may be activated in response to various replication fork impediments, but it has also evolved ways to counter specific obstacles. In this review, we will discuss these general and specific strategies to counteract different forms of replication associated damage to maintain genomic stability.
Solubility of Monazite–Cheralite and Xenotime in Granitic Melts, and Experimental Evidence of Liquid–Liquid Immiscibility in Concentrating REE
Authors: Van Lichtervelde Marieke , Goncalves Philippe , Eglinger Aurélien , Colin Aurélia , Montel Jean-Marc , Dacheux Nicolas
Published: March 2021

We provide new experimental data on monazite, xenotime and U–Th-bearing cheralite solubility in slightly peralkaline to peraluminous granitic melts using dissolution and reverse (i.e. recrystallization after dissolution) experiments in water-saturated and flux-bearing (P + F + Li) granitic melts, at 800 °C and 200 MPa. Although a positive correlation between rare earth element (REE) solubility and melt peralkalinity is confirmed, monazite solubilities reported here are much lower than the values previously published. We suggest that the presence of elevated phosphorus concentrations in our melts depresses monazite solubility, principally because phosphorus complexes with Al and alkali, which normally depolymerize the melt through the formation of non-bridging oxygens. The new solubility data provide an explanation for the very low REE concentrations generally encountered in phosphorus-bearing peraluminous granites and pegmatites. This accounts for the compatibility of REE in peraluminous systems, as the early crystallization of REE-bearing minerals (mainly monazite and zircon) leads to progressive REE depletion during liquid differentiation. In addition, dissolution and reverse experiments on U–Th-bearing cheralite–monazite display liquid–liquid immiscibility processes in our slightly peralkaline glass. The immiscible liquid forms droplets up to 10 µm in diameter and hosts on average 35 wt% P2O5, 25–30 wt% F, 22 wt% Al2O3, 4 wt% CaO, 5 wt% Na2O, 2 wt% La2O3, and 12 wt% ThO2 + UO2. We believe that the droplets formed during the runs and may have coalesced to larger droplets during quenching. We suggest that liquid–liquid immiscibility is a possible mechanism of REE concentration in highly fluxed melts and should be considered in natural systems where REE are extremely concentrated (up to thousands of µg g–1) in magmatic rocks.