bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Characterization, and 3D Printing of Silver Nanoparticles/Photopolymer Resin Composites
Authors: Ikram H , Al Rashid A , Koç M
Published: August 2022

Recent advancements in the synthesis, functionalization, and processing of metal nanoparticles to enhance the properties of polymers have gained interest in the research community. Researchers have conducted several studies to exploit the extraordinary properties of metal nanoparticles, especially when mixed with polymers. This study investigates the adaptability of synthesized polymer resin nanocomposites, tailoring the physical and thermal properties of photopolymer resins with controlled dispersion of silver nanoparticles (AgNPs) for stereolithography (SLA) 3D printing (3DP). SLA resin composed of polymethylmethacrylate (PMMA) was altered with varying concentrations of AgNPs (0.2%, 0.5%, 2%) through ultrasonication and mechanical mixing. The synthesized photopolymer resin nanocomposites were optimized for 3DP process parameters (i.e., layer resolution, laser power, and exposure time) to 3D print the samples successfully for customized photopolymer resins. The 3D printed samples were then analyzed for thermal stability using thermogravimetric analysis (TGA), while the viscosity variation was observed through a dynamic viscosimeter. It was concluded that optimization of 3DP process parameters is vital to achieving successful 3DP of metal nanoparticles reinforced photopolymer resins, which highly depends upon the physical properties of the resins. In addition, the introduction of AgNPs to photopolymer resins has considerably increased the thermal performance and heat flow characteristics.
Mathematical modelling for prediction of Young’s modulus in compositionally complex alloys
Authors: Nikaran K M , Sathiskumar R , Dharani R , Kovileeswaran C , Kumar D Naveen
Published: August 2022

A generic mathematical model-based bottom-up approach for high throughput materials development of compositionally complex alloys is established in this study. A general bottom-up technique, in contrast to a top-down approach, entails property selection, element screening, structure identification, and fabrication. The application is used to guide the property selection. The alloy design depends on the screening of contributing elements depending on the necessary property. The usage of mathematical models could help with element screening to meet the property requirement. The properties of the resulting compound alloys may be determined by the attributes of compositionally complex alloys. As a result, developing a model that links the needed attribute to the most important aspects of compositionally complex alloys is critical. The Young’s modulus, which is the considered attribute, is predicted using a predictive mathematical modelling approach based on its relationship with the features: valence electron concentration and average melting temperature. Monte Carlo Simulation is also used to discover the optimum feasible composition in order to improve Young’s modulus.
Creep curve modelling of Austenitic Steel 316LN
Authors: Kumar Nilesh , Yadav Surya D.
Published: August 2022

Physical based creep models that elucidate the creep deformation behaviour with ongoing microstructural evolution can be a useful tool for the components life assessment as well as the design of improved materials, deployed at high temperature and pressure. In this research work, a creep model that is a combination of physical based model and CDM approach is employed to predict the creep curves of steel 316LN. The microstructure based variables those are different dislocation densities (mobile and forest) are the input parameters. The model provides a provision for the assessment of each microstructural variable, in each time step of the creep deformation. Consequently, other than creep curves, the model also demonstrates the evolution of dislocation density (mobile and forest), dislocation velocity, dislocation mobility and mean free path. Initial values of input parameters (various dislocation densities and mean free path) are obtained from the literature for initializing the model. It can be observed that the predicted creep curves are in reasonable agreement with experimental ones and the evolution of other involved parameters is discussed thoroughly.
Finite Element Analysis of Impression Creep on P91
Authors: Teja Vishnu , Bedi Raman , Kumar Manoj
Published: August 2022

Impression creep is a versatile technique that is used nowadays for studying the creep deformation of different materials and there is no tertiary stage in this method; it's a non-destructive process. The present work deals with finite element analysis of plastic deformation corresponding to the impression creep deformation of P91 steel. In the FE model, a 3D deformable body is used as a specimen along with a rigid hollow cylindrical indenter with a 0.07 fillet. The effect of sizes of the specimen and indenter was studied, the diameter of the specimen was changed from 10mm,15mm, and 20mm whereas the indenter diameter was changed from 1mm,1.5mm, and 2mm respectively. Moreover, it was found that when punch diameter is increased the induced stress is reduced. It is observed that there is no effect on the diameter of the specimen, however, when the diameter of the indenter is increased from 1mm to 1.5mm and 1.5mm to 2mm, induced stress is reduced by approximately 10% and 20%, respectively. The simulation was run for 100 hours. Furthermore, the optimum distance between two impressions in P91 steel was studied and the distance between two indenters was altered from 10mm,8mm,6mm and 4mm respectively with the same loading and boundary conditions, and the same mesh size. It was observed that for P91 there is no contact between two deformations at 4mm.For P91 steel we can perform two impression creep tests from 4mm apart.
Synthesis and Characterization of Manganese dioxide Agglomerated Nanoparticles for Supercapacitor Application
Authors: Kumar Prabhat , Kaur Jaspinder , Tiwari Anurag Kumar
Published: August 2022

Manganese dioxide (MnO2) nanoflakes were effectively produced at ambient temperature using a solution technique. The SEM, XRD, BET, and electrochemical tests were used to investigate the characteristics of the produced materials (MnO2). The XRD pattern of the manganese oxide sample obtained reveals that it possesses crystal structure. The morphology was examined using a scanning electron microscope image, which confirmed the development of nanoflakes in the 70-100 nm diameter range. The higher specific capacitance achieves 200 Fg-1 at current density and at scan rate of 0.5 A/g and 5 mv/s respectively. For the highest specific capacitance, the obtained value of power density and energy density are of 257.14 w/kg and 25 w.h/kg respectively.
Structural and functional study of fluorescent carbon dots synthesized from lemon-peel via one step microwave irradiation method
Authors: Singh Lovepreet , Kishore Kunal , Singh Vishal
Published: August 2022

In the current research work, green synthesis of Carbon Dots (CDs) from lemon peels via one step microwave irradiation method has been reported. The synthesis technique for CDs is environmental friendly and economical. Green synthesized fluorescent CDs showed high quantum yield of 16.9% obtained from Photo-luminescent (PL) analysis. Structural and functional properties of CDs have been carefully studied with the help of different spectroscopic techniques such as UV-Vis, FT-IR, XPS and XRD. CDs were comprised of sun-flower like morphology with an average size of 20.5 nm. CDs were found to be amorphous in nature. The effect of pH and ionic strength on the synthesized CDs was also explored. All the studies indicate that green CDs can have potential applications in novel biological and opto-electronic devices.
Molecular dynamics simulation of graphene-oxide/natural rubber composites
Authors: Srivastava Aviral , Sharma Sumit
Published: August 2022

Molecular dynamics modelling was used to calculate the improved mechanical characteristics of graphene oxide (GO) reinforced natural rubber (NR) composites at the molecular level. The mechanical characteristics of constructed structures are calculated using the constant strain approach. After creating composites of GO/NR with different volume fractions of GO calculations for mechanical properties have been done. The incorporation of graphene oxide to the NR matrix at 3.5 percent and 7.5 percent vol fraction results in a considerable improvement in Young's, bulk and shear modulus, and overall mechanical characteristics.
Piezoelectric Cantilever Sensor Design with Improved Sensing and Self-actuation performance
Authors: Chauhan Shivanku , Ansari Mohd. Zahid
Published: August 2022

This work aims to improve the sensing and self-actuation performance of a piezoelectric cantilever sensor. Firstly the performance of a rectangular piezoelectric cantilever sensor (M1 model) is analysed for its resonant frequency as well as the deflection and the voltage generation in response to a particular stimulus. Further the profile of the cantilever is modified by providing the holes on its profile at different location (M2 and M3 model) for better performance. M2 model provides better deflection and voltage generation compared to the base model M1 but with the reduced resonant frequency. M3 model is found best from the point of view of resonant frequency, higher deflection and corresponding higher voltage generation in response to a particular stimulus.
A molecular dynamics study of adhesion of polyvinyl-chloride coatings to the aluminum surface
Authors: Sharma Amit , Sharma Sumit
Published: August 2022

Metal polymer interaction are difficult to measure experimentally, hence MD simulations are helpful in such problems to provide the vital information. Polyvinyl chloride is widely used in engineering applications due to its chemical and thermal stability and its barrier properties due to the C-Cl polar bond. Aluminum is also widely used in engineering structures as well as food and pharmaceutical packaging. Hence interaction or bonding between PVC and Al2O3 is studied using MD simulations and interaction energy is calculated at different temperature to check the influence of temperature on adhesion between the two. The higher the absolute magnitude of interaction energy, the stronger the adhesion or bonding between metal and polymer. It was revealed that for the case of PVC coating on Al2O3 the adhesion energy increases as temperature rises.
Structural phase transitions and elastic properties of TiO2 polymorphs: Ab-initio study
Authors: Basavaraj K. , Nyayban Anupriya , Panda Subhasis
Published: August 2022

TiO2 has tremendously drawn the attention of researchers from the photocatalytic to photovoltaic groups. To explore further avenues of applications, it is important to understand various properties and the phase transformations of TiO2 polymorphs at ambient conditions. The detailed study on the phase transitions (pressure induced) of the low-pressure polymorphs (rutile, anatase, brookite and columbite) of TiO2 is surprisingly missing in the literature. In view of the above, we have carried out ab-initio calculations on these four polymorphs of TiO2 using full potential linearized augmented plane wave [FP-LAPW] method to study the structural phase transitions and elastic properties. The transition pressures at 0 K among anatase (A), rutile (R), brookite (B) and columbite (C) are found out to be -2.4 GPa (A-B), 5.3 GPa (A-R), 5.7 GPa (A-C), 8.7 GPa (R-C), 10.7 GPa (B-C) and 11.6 GPa (B-R) respectively. The elastic properties at P = 0 GPa are examined through computation of elastic constants for all polymorphs. All the polymorphs are found to be mechanically stable. The anisotropy in shear moduli and directional dependence of Young's modulus are also investigated for all the polymorphs.
Vibration response of shear deformable functionally graded material plate with parabolic variable thickness
Authors: Kumar V. , Singh S. J. , Saran V. H. , Harsha S. P.
Published: August 2022

This work presents the semi-analytical solution of vibration response for functionally graded materials (FGM) plates with bi-linear and parabolic variable thickness. Continuous thickness variation may affect the design of plate structure which permits to modify the stiffness properties in the utmost stressed area within the domain, considering the overall weight parameter of the structure. As a result, a better dynamic response may be revealed. The first order shear deformation theory (FSDT) has been applied for a kinematic model of the variable thick plate. The material properties were calculated by the simple power law. Accuracy of this model is confirmed by various comparisons with outcomes available in the preceding literature. Frequency factor of the plates with boundary conditions are found by changing the various parameter like material volume exponent, aspect ratio, tapered ratio and thickness ratio.
Effect of different types of nanoparticles on thermophysical properties of water based hybrid nanofluids
Authors: Rajiv  , Kumar Hemant , Sokhal Gurpreet Singh
Published: August 2022

Cooling of micro-electro-mechanical components is the requirement of many industries in today's era. Fluids that are used for the cooling of micro components have low thermal conductivity (k) which is the major limitation that leads to a low heat transfer rate. To overcome such issues, nanofluids come into the picture which plays a vibrant role to raise the heat transfer rate. The suspension of nanoparticles (size below 100nm) into host fluids (oil, ethylene glycol (EG), and water) is used to prepare nanofluids. To understand the basic importance of nanofluids, the thermophysical characteristics of nanofluids have to be studied. Transport (viscosity and density) and thermal (k and specific heat) properties at different temperatures and volume (vol.) concentrations are studied. Hybrid nanofluids (hnf) are important to study for further improvement of heat transfer and also to stabilize the pressure drop. Aluminium oxide (Al2O3,) Copper oxide (CuO) and hybrid (Al2O3:CuO) (40:60) nanoparticles has been taken for the preparation of nanofluids in this present experimentation.
AC conductivity and modulus studies on (1-x)β-PbF2:xCeO2 composite solid electrolytes
Authors: Govinda Reddy Y , Chandrasekhar M , Sadananda Chary A , Narender Reddy S
Published: August 2022

Cubic Lead fluoride [β-PbF2] composite solid electrolyte systems are prepared by dispersing nano CeO2 (< 100nm) in different mol% (5, 10, 15, 20, 25) through the mechanical milling method. XRD and FTIR (ATR method) studies confirm that these are formed in two-phase systems. Scanning Electron Microscope (SEM) images of dispersed systems showed a change in surface morphology with respect to the host. Complex impedance spectroscopy is employed in the frequency range 0.5 to 10 MHz by varying temperatures from 30 to 350°C to study the electric and dielectric properties. Analysis of impedance and modulus spectra revealed the non-Debye nature of these composites. Conductivity measurements on these composites suggest that the frequency exponent (n) in Jonscher’s power law is found to be temperature dependent. The overlapping large polaron tunneling (OLPT) model could be suggested as a suitable hopping mechanism. The variation of the ‘β’ value obtained from the Kohlrausch-Williams-Watts (KWW) function shows a similar variation of ‘n’ in the Jonscher’s power law with temperature.
Finite element modeling of fatigue properties of polymer nanocomposites
Authors: Yadav Vinay Kumar , Shukla Dharmendra Kumar , Verma Neeraj
Published: August 2022

This paper presents a 3-dimensional finite element modeling of fatigue properties of polymer nanocomposites with a Representative Volume Element (RVE) approach using ANSYS. Epoxy was used as a matrix, and alumina nanoparticles of spherical shape (diameter 33 nm) were used as reinforcement. Convergence analysis was conducted to select the proper size of RVE. A geometric model of a flat dog bone specimen was created to model the fatigue properties. MATLAB code was used to generate randomly distributed nanoparticles. The sample was loaded in uniaxial tension-tension fatigue loading with a stress ratio of 0.1. S-N data for epoxy and alumina were given as input to determine the fatigue life of polymer nanocomposites. The results obtained from modeling were compared with experimental data. The fatigue life was determined by taking the average life at five different locations in the gauge region for a sample. The average of five different samples was calculated for each wt.% (0.5, 1.0, and 1.5). Reinforcement of nanoparticles up to 1 wt.% caused an increment in the fatigue life of nanocomposites, and fatigue life decreased at 1.5 wt.% of nanoparticles. The finite element modeling was able to predict the trend of improvement provided by the alumina nanoparticles (similar to experimental data).
Optimisation of Slurry Compositions for Improving the Mechanical Properties of Low Temperature Co-Fired Ceramic (LTCC) Tapes
Authors: Aishwarya K P , Darve Rohan , Gadde Janardhan Rao , Kale Hrithik , Hawaldar Ranjit , Giramkar Vijaya , Kashid Ranjit , Joseph Shany
Published: August 2022

In the era of miniaturization and hybridization, the quest for novel materials for multilayer packaging had been increased. The multilayer packaging includes High Temperature Co-Fired Ceramics (HTCC), LTCC and ULTCC. LTCC which is the mixture of ceramic and glass (which reduces the firing temperature of ceramics) has attracted many researchers due to its lower firing temperature(<900°C). Due to this lower sintering temperature, it can be cofired with the low resistance metals like Ag and Au which increases its value in multilayer packaging field. The standard package fabrication process uses LTCC in the form of tapes. Each layer can be processed separately for punching, via filling and Screen printing and then stacked, laminated and sintered to get a multilayer package. The green sheet of LTCC should have sufficient adhesion to carrier film as well as mechanical properties to withstand the fabrication processes that it undergoes. These properties are mainly affected by the organic compositions used in the slurry preparation. The tape casting slurry was prepared by blending the LTCC powder with solvents, dispersants and binders for a predefined time in ball mill. The as prepared slurry was casted on a Mylar sheet in a continuous tape caster for varied thickness. The present study aims at reporting the effect of plasticizers and binders on the adhesion and mechanical properties of the tape. The starting material which was the mixture of Cordierite and Anorthite based recrystallizable glass was prepared through solid-state method. The powder was then characterised for its phase purity, microstructure and elemental compositions using XRD, FESEM and EDAX. The green tapes were characterised for its thickness, uniformity, green and sintered density, surface defects such as pinholes and cracks, adhesion and tensile strength. The dielectric properties as well as thermal properties are also evaluated. The results are reported.
Predicted Tensile Properties of Natural Fibre Reinforced Acrylonitrile Butadiene Styrene Composites Comparison of Experimental and Standard Equations
Authors: Kumar Piyush , Palsule Sanjay
Published: August 2022

Natural fibre (NF) reinforced acrylonitrile butadiene styrene (ABS) composites (NF/ABS) have many applications that are governed by their mechanical properties, and in particular, by their tensile properties. This study exhibits the comparison of the literature reported measured tensile strength and tensile modulus values of some natural fibre reinforced ABS composites with the values predicted by the following equations: Rule and Inverse Rule of Mixtures and Halpin-Tsai, Nielsen, Hirsch and Palsule equations and evaluates the applicability of these equations for the natural fibre reinforced ABS composites.
Structural insights into some sterically demanding heterocyclic β-diketones: Optimized molecular structure, optimized energy, stability and Mulliken charge distribution based on DFT analysis
Authors: Budania Suchitra , Saxena Sanjiv , Jain Asha
Published: August 2022

Density functional theory is a quantum chemical theory based computational tool for theoretical analysis of molecular structures and electronic properties of organic compounds and new materials. The present synergistic investigation between experimental spectroscopic data and theoretical data is focused to gain structural insights and to study the optimized molecular structures, optimized energies, stabilities and Mulliken charge distribution based on DFT analysis of some sterically demanding heterocyclic β-diketones. The B3LYP functionals with 6-31G* basis set was used for calculations in gas phase as well as in polar and nonpolar solvents. The experimental spectroscopic data (1H and 13C NMR) of sterically demanding heterocyclic β-diketones were compared with the corresponding theoretical data (in gas phase and polar solvent). There was a synergy between experimental spectroscopic data and theoretical data of these organic compounds. The atomic charges at all the atoms were calculated to ascertain the electrophilic and nucleophilic centres in these compounds. Global reactivity descriptors have also been calculated from the energies of frontier molecular orbitals (HOMO-LUMO energy values). The presence of various groups such as -CH3, -CH2CH3, - C6H5 and p-ClC6H4- in these compounds provided an opportunity to examine the steric and electronic effects of these groups on the stability, optimized energy, Mulliken charge distribution and spectroscopic properties of these sterically demanding heterocyclic β-diketones.
Bio-inspired shape morphing soft magnetic locomotion actuators - a novel method of preparation and testing
Authors: Chand Dharmi , Srinivasan Sivakumar M
Published: August 2022

Soft magnetic materials have drawn the attention of researchers worldwide due to their field response actuation, reversible shape morphing capability, remote controllability, an extensive penetration range in numerous circumstances, and diverse applications in the field of engineering, robotics, and medical science. The fabrication and programming of these actuators have been difficult, expensive, and complex, specifically in generating locomotion. This work aims at achieving the kinetic locomotion in actuators inspired by the caterpillar, inchworm, and centipede using a very simplistic approach. To achieve this, a programming technique has been developed through which a magnetic elastomer can be programmed on the curing bed to mimic the motion of the organisms mentioned above. The Carbonyl Iron (CI) particles dispersed in a viscous thermoplastic polyurethane (TPU) solution are cured under a magnetic field generated using a rotating permanent magnet. In the presence of a magnetic field, the magnetic particles tend to align in the direction of the magnetic field in the matrix. After curing, the actuator has an initial shape that changes to the programmed shape upon applying the magnetic field. The change in shape depends on the intensity of the magnetic field, i.e. if the magnetic field during programming was 0.5 T, then to achieve the programmed shape, we need to maintain the field value greater than or equal to 0.5 T. At the lower field values, the change in shape is slow. Thus, locomotion of the sample has been achieved by controlling the magnetic field intensity.
Pan-cancer distribution of cleaved cell-surface amphiregulin, the target of the GMF-1A3 antibody drug conjugate
Authors: Lofgren Kristopher A , Reker Nicolette C , Sreekumar Sreeja , Kenny Paraic A
Published: August 2022

Amphiregulin is a transmembrane protein which, when cleaved by the TACE/ADAM17 protease, releases a soluble epidermal growth factor receptor ligand domain that promotes proliferation of normal and malignant cells. We previously described a rabbit monoclonal antibody, GMF-1A3, that selectively recognizes the cell-associated cleaved amphiregulin epitope. Antibody-drug conjugates had anti-tumor activity against human breast cancer xenografts. Several tumor types express amphiregulin, but evidence for a functional requirement for amphiregulin in these malignancies is limited. By directly evaluating amphiregulin cleavage with immunohistochemistry, GMF-1A3 provides a more direct measure of amphiregulin activity. Using 370 specimens from 10 tumor types (as well as normal controls), we demonstrate that cleaved amphiregulin is widely expressed in solid tumors and is especially common (> 50% of cases) in breast, prostate, liver and lung cancer. As a potential companion diagnostic for this antibody-drug conjugate, this assay allows identification of tumors with high levels of the cleaved amphiregulin target.
Spatiotemporal Trends in Norovirus Outbreaks in the United States, 2009–2019
Authors: Kambhampati Anita K , Calderwood Laura , Wikswo Mary E , Barclay Leslie , Mattison Claire P , Balachandran Neha , Vinjé Jan , Hall Aron J , Mirza Sara A
Published: August 2022

Background

Globally, noroviruses cause infections year-round but have recognized winter seasonality in the Northern Hemisphere and yearly variations in incidence. With candidate norovirus vaccines in development, understanding temporal and geographic trends in norovirus disease is important to inform potential vaccination strategies and evaluate vaccine impact.

Methods

We analyzed data from the National Outbreak Reporting System (NORS) and CaliciNet on single-state norovirus outbreaks that occurred during August 2009–July 2019 in the contiguous United States. We defined norovirus season onset and offset as the weeks by which 10% and 90% of norovirus outbreaks in a surveillance year occurred, respectively, and duration as the difference in weeks between onset and offset. We compared norovirus seasons across surveillance years and geographic regions.

Results

During August 2009–July 2019, 24 995 single-state norovirus outbreaks were reported to NORS and/or CaliciNet. Nationally, the median norovirus season duration was 24 weeks, with onset occurring between October and December and offset occurring between April and May. Across all years combined, we observed a west-to-east trend in seasonality, with the earliest onset (October) and latest offset (May) occurring in western regions and the latest onset (December) and earliest offset (April) occurring in northeastern regions.

Conclusions

Timing and duration of the US norovirus season varied annually but generally occurred during October–May. Norovirus wintertime seasonality was less distinct in western regions and was progressively more pronounced moving east. Further understanding the drivers of spatiotemporal dynamics of norovirus could provide insights into factors that promote virus transmission and help guide future interventions.
Validity of Self-testing at Home With Rapid Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Detection by Lateral Flow Immunoassay
Authors: Atchison Christina J , Moshe Maya , Brown Jonathan C , Whitaker Matthew , Wong Nathan C K , Bharath Anil A , McKendry Rachel A , Darzi Ara , Ashby Deborah , Donnelly Christl A , Riley Steven , Elliott Paul , Barclay Wendy S , Cooke Graham S , Ward Helen
Published: August 2022

Background

We explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody lateral flow immunoassay (LFIA) performance under field conditions compared to laboratory-based electrochemiluminescence immunoassay (ECLIA) and live virus neutralization.

Methods

In July 2021, 3758 participants performed, at home, a self-administered Fortress LFIA on finger-prick blood, reported and submitted a photograph of the result, and provided a self-collected capillary blood sample for assessment of immunoglobulin G (IgG) antibodies using the Roche Elecsys® Anti-SARS-CoV-2 ECLIA. We compared the self-reported LFIA result to the quantitative ECLIA and checked the reading of the LFIA result with an automated image analysis (ALFA). In a subsample of 250 participants, we compared the results to live virus neutralization.

Results

Almost all participants (3593/3758, 95.6%) had been vaccinated or reported prior infection. Overall, 2777/3758 (73.9%) were positive on self-reported LFIA, 2811/3457 (81.3%) positive by LFIA when ALFA-reported, and 3622/3758 (96.4%) positive on ECLIA (using the manufacturer reference standard threshold for positivity of 0.8 U mL–1). Live virus neutralization was detected in 169 of 250 randomly selected samples (67.6%); 133/169 were positive with self-reported LFIA (sensitivity 78.7%; 95% confidence interval [CI]: 71.8, 84.6), 142/155 (91.6%; 95% CI: 86.1, 95.5) with ALFA, and 169 (100%; 95% CI: 97.8, 100.0) with ECLIA. There were 81 samples with no detectable virus neutralization; 47/81 were negative with self-reported LFIA (specificity 58.0%; 95% CI: 46.5, 68.9), 34/75 (45.3%; 95% CI: 33.8, 57.3) with ALFA, and 0/81 (0%; 95% CI: 0, 4.5) with ECLIA.

Conclusions

Self-administered LFIA is less sensitive than a quantitative antibody test, but the positivity in LFIA correlates better than the quantitative ECLIA with virus neutralization.
Reduced Incidence of Long Coronavirus Disease Referrals to the Cambridge University Teaching Hospital Long Coronavirus Disease Clinic
Authors: Krishna Benjamin A , Metaxaki Marina , Wills Mark R , Sithole Nyaradzai
Published: August 2022

Long coronavirus disease (COVID [LC]) constitutes a potential health emergency as millions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections lead to chronic symptoms. We must understand whether vaccines reduce LC because this has major implications for health policy. We report a 79% reduction in LC referrals correlating with vaccination in the United Kingdom.
Riociguat in pulmonary hypertension and heart failure with preserved ejection fraction: the haemoDYNAMIC trial
Authors: Dachs Theresa Marie , Duca Franz , Rettl René , Binder-Rodriguez Christina , Dalos Daniel , Ligios Luciana Camuz , Kammerlander Andreas , Grünig Ekkehard , Pretsch Ingrid , Steringer-Mascherbauer Regina , Ablasser Klemens , Wargenau Manfred , Mascherbauer Julia , Lang Irene M , Hengstenberg Christian , Badr-Eslam Roza , Kastner Johannes , Bonderman Diana
Published: August 2022

Aims

The presence of pulmonary hypertension (PH) severely aggravates the clinical course of heart failure with preserved ejection fraction (HFpEF). To date, neither established heart failure therapies nor pulmonary vasodilators proved beneficial. This study investigated the efficacy of chronic treatment with the oral soluble guanylate cyclase stimulator riociguat in patients with PH-HFpEF.

Methods and Results

The phase IIb, randomized, double-blind, placebo-controlled, parallel-group, multicentre DYNAMIC trial assessed riociguat in PH-HFpEF. Patients were recruited at five hospitals across Austria and Germany. Key eligibility criteria were mean pulmonary artery pressure ≥25 mmHg, pulmonary arterial wedge pressure >15 mmHg, and left ventricular ejection fraction ≥50%. Patients were randomized to oral treatment with riociguat or placebo (1:1). Patients started at 0.5 mg three times daily (TID) and were up-titrated to 1.5 mg TID. The primary efficacy endpoint was change from baseline to week 26 in cardiac output (CO) at rest, measured by right heart catheterization. Primary efficacy analyses were performed on the full analysis set. Fifty-eight patients received riociguat and 56 patients placebo. After 26 weeks, CO increased by 0.37 ± 1.263 L/min in the riociguat group and decreased by −0.11 ± 0.921 L/min in the placebo group (least-squares mean difference: 0.54 L/min, 95% confidence interval 0.112, 0.971; P = 0.0142). Five patients dropped out due to riociguat-related adverse events but no riociguat-related serious adverse event or death occurred.

Conclusion

The vasodilator riociguat improved haemodynamics in PH-HFpEF. Riociguat was safe in most patients but led to more dropouts as compared to placebo and did not change clinical symptoms within the study period.
Repeat expansions nested within tandem CNVs: a unique structural change in GLS exemplifies the diagnostic challenges of non-coding pathogenic variation
Authors: Fazal Sarah , Danzi Matt C , van Kuilenburg André B P , Reich Selina , Traschütz Andreas , Bender Benjamin , Leen René , Toro Camilo , Usdin Karen , Hayward Bruce , Adams David R , van Karnebeek Clara D M , Ferreira Carlos R , D’Sousa Precilla , Network Undiagnosed Diseases , Tekin Mustafa , Züchner Stephan , Synofzik Matthis
Published: August 2022

Glutaminase deficiency has recently been associated with ataxia and developmental delay due to repeat expansions in the 5′UTR of the glutaminase (GLS) gene. Patients with the described GLS repeat expansion may indeed remain undiagnosed due to the rarity of this variant, the challenge of its detection and the recency of its discovery. In this study, we combined advanced bioinformatics screening of ~3000 genomes and ~1500 exomes with optical genome mapping and long-read sequencing for confirmation studies. We identified two GLS families, previously intensely and unsuccessfully analyzed. One family carries an unusual and complex structural change involving a homozygous repeat expansion nested within a quadruplication event in the 5′UTR of GLS. Glutaminase deficiency and its metabolic consequences were validated by in-depth biochemical analysis. The identified GLS patients showed progressive early-onset ataxia, cognitive deficits, pyramidal tract damage and optic atrophy, thus demonstrating susceptibility of several specific neuron populations to glutaminase deficiency. This large-scale screening study demonstrates the ability of bioinformatics analysis—validated by latest state-of-the-art technologies (optical genome mapping and long-read sequencing)—to effectively flag complex repeat expansions using short-read datasets and thus facilitate diagnosis of ultra-rare disorders.
Thermal stress and selection for growth affect myogenic satellite cell lipid accumulation and adipogenic gene expression through mechanistic target of rapamycin pathway
Authors: Xu Jiahui , Strasburg Gale M , Reed Kent M , Velleman Sandra G
Published: August 2022

Satellite cells (SCs) are multipotential stem cells having the plasticity to convert to an adipogenic lineage in response to thermal stress during the period of peak mitotic activity (the first week after hatch in poultry). The mechanistic target of rapamycin (mTOR) pathway, which regulates cellular function and fate of SCs, is greatly altered by thermal stress in turkey pectoralis major muscle SCs. The objective of the present study was to determine the effects of thermal stress, selection for growth, and the role of the mTOR pathway on SC intracellular lipid accumulation and expression of adipogenic regulatory genes. These effects were analyzed using SCs isolated from the pectoralis major muscle of 1-wk-old modern faster-growing commercial turkey line (NC) selected for increased growth and breast muscle yield as compared with SCs of a historic slower-growing Randombred Control Line 2 (RBC2) turkey. Heat stress (43 °C) of SCs during proliferation increased intracellular lipid accumulation (P < 0.001), whereas cold stress (33 °C) showed an inhibitory effect (P < 0.001) in both lines. Knockdown of mTOR reduced the intracellular lipid accumulation (P < 0.001) and suppressed the expression of several adipogenic regulatory genes: peroxisome proliferator-activated receptor-γ (PPARγ; P < 0.001), CCAAT/enhancer-binding protein-β (C/EBPβ; P < 0.001), and neuropeptide-Y (NPY; P < 0.001) during both proliferation and differentiation. The NC line SCs showed fewer reductions in lipid accumulation compared with the RBC2 line independent of temperature. Both intracellular lipid accumulation (P < 0.001) and PPARγ expression (P < 0.001) were greater at 72 h of proliferation than at 48 h of differentiation in both the RBC2 and NC lines independent of temperature. Thus, hot and cold thermal stress affected intracellular lipid accumulation in the pectoralis major muscle SCs, in part, through the mTOR pathway in wea growth-dependent manner. Altered intracellular lipid accumulation could eventually affect intramuscular fat deposition, resulting in a long-lasting effect on the structure and protein to fat ratio of the poultry pectoralis major muscle.
Supplementation with artificial sweetener and capsaicin alters metabolic flexibility and performance in heat-stressed and feed-restricted pigs
Authors: Kroscher Kellie A , Fausnacht Dane W , McMillan Ryan P , El-Kadi Samer W , Wall Emma H , Bravo David M , Rhoads Robert P
Published: August 2022

Substantial economic losses in animal agriculture result from animals experiencing heat stress (HS). Pigs are especially susceptible to HS, resulting in reductions in growth, altered body composition, and compromised substrate metabolism. In this study, an artificial high-intensity sweetener and capsaicin (CAPS-SUC; Pancosma, Switzerland) were supplemented in combination to mitigate the adverse effects of HS on pig performance. Forty cross-bred barrows (16.2 ± 6 kg) were assigned to one of five treatments: thermal neutral controls (TN) (22 ± 1.2 °C; 38%–73% relative humidity) with ad libitum feed, HS conditions with ad libitum feed with (HS+) or without (HS−) supplementation, and pair-fed to HS with (PF+) or without supplementation (PF−). Pigs in heat-stressed treatments were exposed to a cyclical environmental temperature of 12 h at 35 ± 1.2 °C with 27%–45% relative humidity and 12 h at 30 ± 1.1 °C with 24%–35% relative humidity for 21 d. Supplementation (0.1 g/kg feed) began 7 d before and persisted through the duration of environmental or dietary treatments (HS/PF), which lasted for 21 d. Rectal temperatures and respiration rates (RR; breaths/minute) were recorded thrice daily, and feed intake (FI) was recorded daily. Before the start and at the termination of environmental treatments (HS/PF), a muscle biopsy of the longissimus dorsi was taken for metabolic analyses. Blood samples were collected weekly, and animals were weighed every 3 d during treatment. Core temperature (TN 39.2 ± 0.02 °C, HS− 39.6 ± 0.02 °C, and HS+ 39.6 ± 0.02 °C, P < 0.001) and RR (P < 0.001) were increased in both HS− and HS+ groups, but no difference was detected between HS− and HS+. PF− pigs exhibited reduced core temperature (39.1 ± 0.02 °C, P < 0.001), which was restored in PF+ pigs (39.3 ± 0.02 °C) to match TN. Weight gain and feed efficiency were reduced in PF− pigs (P < 0.05) but not in the PF+ or the HS− or HS+ groups. Metabolic flexibility was decreased in the HS− group (−48.4%, P < 0.05) but maintained in the HS+ group. CAPS-SUC did not influence core temperature or weight gain in HS pigs but did restore core temperature, weight gain, and feed efficiency in supplemented PF pigs. In addition, supplementation restored metabolic flexibility during HS and improved weight gain and feed efficiency during PF, highlighting CAPS-SUC’s therapeutic metabolic effects.
Cattle breed type and anabolic implants impact calpastatin expression and abundance of mRNA associated with protein turnover in the longissimus thoracis of feedlot steers
Authors: Reichhardt Caleb C , Stafford Chandler D , Cuthbert Jocelyn M , Dang David S , Motsinger Laura A , Taylor Mackenzie J , Briggs Reganne K , Brady Tevan J , Thomas Aaron J , Garcia Matthew D , Matarneh Sulaiman K , Thornton Kara J
Published: August 2022

Two methods that the beef cattle industry can use to improve efficiency, sustainability, and economic viability are growth promotants and crossbreeding cattle of different breed types. In the United States, over 90% of cattle receive an anabolic implant at some point during production resulting in an overall increase in skeletal muscle growth. Recent research suggests that the two main cattle breed types, Bos indicus and Bos taurus, respond differently to anabolic implants. The objective of this study was to characterize changes that occur in skeletal muscle following implanting in Bos indicus influenced steers or Bos taurus steers. Twenty steers were stratified by initial weight in a 2 × 2 factorial design examining two different breeds: Angus (AN; n = 10) or Santa Gertrudis influenced (SG; n = 10), and two implant strategies: no implant (CON; n = 10) or a combined implant containing 120 mg TBA and 24 mg E2 (IMP; n = 10; Revalor-S, Merck Animal Health). Skeletal muscle biopsies were taken from the longissimus thoracis (LT) 2 and 10 d post-implantation. The mRNA abundance of 24 genes associated with skeletal muscle growth were examined, as well as the protein expression of µ-calpain and calpastatin. Succinate dehydrogenase mRNA abundance was impacted (P = 0.05) by a breed × treatment interaction 2 d post-implanting, with SG-CON having a greater increased abundance than all other steers. A tendency for a breed × treatment interaction was observed for calpain-6 mRNA (P = 0.07), with SG-CON having greater abundance than AN-CON and SG-IMP. Additionally, calpastatin protein expression was altered (P = 0.01) by a breed × treatment interaction, with SG-CON and SG-IMP steers having increased expression (P = 0.01) compared with AN-CON steers. At 2 d post-implanting, a breed × treatment interaction was observed with SG-CON steers having greater (P = 0.05) mRNA abundance of mitogen-activated protein kinase compared with AN-CON steers. Furthermore, breed affected (P = 0.05) calpastatin abundance with AN steers having increased (P = 0.05) abundance 2 d post-implanting compared with SG steers. Meanwhile, implants tended to affect (P = 0.09) muscle RING finger protein-1 mRNA abundance, with CON steers having increased (P = 0.09) abundance compared with that of IMP steers. These findings suggest that cattle breed type and anabolic implants impact calpastatin expression and mRNA abundance associated with protein turnover in the LT of feedlot steers 2 and 10 d post-implantation.
Short Communication: Beta-adrenergic agonists alter oxidative phosphorylation in primary myoblasts
Authors: Sieck Renae L , Treffer Leah K , Fuller Anna M , Ponte Viana Martonio , Khalimonchuk Oleh , Schmidt Ty B , Yates Dustin T , Petersen Jessica L
Published: August 2022

Beta-adrenergic agonists (β-AAs) are widely used supplements in beef and pork production to improve feed efficiency and increase lean muscle mass, yet little is known about the molecular mechanism by which β-AAs achieve this outcome. Our objective was to identify the influence of ractopamine HCl and zilpaterol HCl on mitochondrial respiratory activity in muscle satellite cells isolated from crossbred beef steers (N = 5), crossbred barrows (N = 2), Yorkshire-cross gilts (N = 3), and commercial weather lambs (N = 5). Real-time measurements of oxygen consumption rates (OCRs) were recorded using extracellular flux analyses with a Seahorse XFe24 analyzer. After basal OCR measurements were recorded, zilpaterol HCl, ractopamine HCl, or no β-AA was injected into the assay plate in three technical replicates for each cell isolate. Then, oligomycin, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone, and rotenone were injected into the assay plate sequentially, each inducing a different cellular state. This allowed for the measurement of OCR at these states and for the calculation of the following measures of mitochondrial function: basal respiration, non-mitochondrial respiration, maximal respiration, proton leak, adenosine triphosphate (ATP)-linked respiration, and spare respiratory capacity. Incubation of bovine cells with either zilpaterol HCl or ractopamine HCl increased maximal respiration (P = 0.046) and spare respiratory capacity (P = 0.035) compared with non-supplemented counterparts. No difference (P > 0.05) was observed between zilpaterol HCl and ractopamine HCl for maximal respiration and spare respiratory capacity in bovine cell isolates. No measures of mitochondrial function (basal respiration, non-mitochondrial respiration, maximal respiration, proton leak, ATP-linked respiration, and spare respiratory capacity) were altered by β-AA treatment in ovine or porcine cells. These findings indicate that β-AAs in cattle may improve the efficiency of oxidative metabolism in muscle satellite cells by modifying mitochondrial respiratory activity. The lack of response by ovine and porcine cells to β-AA incubation also demonstrates differing physiological responses to β-AA across species, which helps to explain the variation in its effectiveness as a growth supplement.
Impact of the COVID-19 pandemic on the diagnosis of cancer in Japan: analysis of hospital-based cancer registries
Authors: Okuyama Ayako , Watabe Mari , Makoshi Riko , Takahashi Hirokazu , Tsukada Yoichiro , Higashi Takahiro
Published: August 2022

Background

There is significant concern that cancer care is adversely impacted due to the coronavirus disease pandemic. Using the national database, we document the impact of the pandemic on cancer diagnosis in Japan.

Methods

Data from 735 hospital-based cancer registries, covering >70% of newly diagnosed cases, were analysed. We compared trends during 2016–2019 and those in 2020 by the type of cancer, diagnostic process, stage and 13 prefectures as requiring special precautions to prevent the spread of infection.

Results

Overall, the number of patients who began treatment decreased by 1.9% in 2020 as compared with the average number during 2016–2019. A sharp decline of 13.8% was observed for stomach cases. The decline in cases (22.0% decrease for all cancers) was more pronounced in May. Cancer screening and resulting detection decreased significantly in 2020 (8.1–24.3%). Case registrations of stage I and II gastric cancer, stage II intrahepatic cholangiocarcinoma, stage II oesophageal cancer, stage 0 and I laryngeal cancer and stage II gallbladder cancer decreased by >10% compared with those in 2018 and 2019. The trends in cancer cases by area of residence indicated a decline in 13 prefectures in May 2020 compared with other areas.

Conclusions

The number of cancer diagnoses decreased during the year 2020 under coronavirus pandemic, especially right after the Japanese government declared the first state of emergency in April. We need to carefully observe the consequences of these decrease in diagnosis, or perhaps the delay in care, on patient survival or population mortality.