bluuebunny/crossref_metadata_2025 huggingface dataset:
Microalloyed Steels for Car Parts
Authors: Mukhametzyanova G F , Shveyova T V , Astaschenko V I
Published: November 2020

The composition and properties of three constructional microalloyed steel with vanadium, niobium and nitrogen is investigated. High strength and ductility steel in rolling mill products and in forgings were revealed, manufactured according to various flow diagram. The resistance of microalloyed steels to grain growth during heating to 1300 °C has been established. The opportunity of realization of the forging heat forgings in their heat treatment is shown. Output testing was carried out of steels in the manufacturing crankshaft and engine connecting rods. For heavily loaded machine components, the use of 38G2AF, AC40H2NMAF and AC30X3NMAFB steels is recommended. High resistance to grain growth is shown when heating steels microalloyed with vanadium, niobium and nitrogen. High properties of the steel AC40H2NMAF, AC30X3NMAFB and 38G2AF make it possible to recommend them for the manufacture of heavily loaded parts - crankshafts and connecting rods. The possibility of realizing forging heat of forgings made microalloyed steels with vanadium, niobium and nitrogen during their heat treatment to ensure a high level properties and structural requirements.
Application of the Polymeric Material RIMAMID for Production of Machine Parts
Authors: Shaparev A V , Savin I A , Ptichkin S N
Published: November 2020

Modern polymeric materials have properties that, in some respects, exceed the properties of traditionally used materials (steel, aluminum and titanium alloys, wood). The uniqueness of the Rimamide polymer material is that it is possible to pre-design the material in such a way as to give the product from it the properties necessary for a particular application.

The production of blanks and the use of Rimamide material for the manufacture of sliding and rolling bearings, bushings for wheels and rollers, pulleys, blocks, brackets, wheel hubs, gears, sprockets, gears and worm wheels and other parts to reduce weight, noise and vibrations. The characteristics of the material, examples of the manufacture of blanks, the advantages and disadvantages of the RIMAMID material for the manufacture of machine parts, prospects for use in mechanical engineering are shown.

Due to their properties, they can be used in almost all industries. For example, modern aviation and space technology is characterized by the intensive use of new materials, technologies, and promising designs based on them. When using RIMAMID material using antifriction components (molybdenum sulfide, graphite, etc.), the friction coefficient is significantly reduced and the friction units can be operated without lubrication.

The main advantages of this material is a low coefficient of friction for steel, which provides a 3-4-fold increase in the service life of parts in the friction units, as well as low weight, high strength, good machinability on metal cutting machines, resistance to aggressive environments, and environmental safety.
Study of Physical Properties and Physical Processes in Nano-thin Spatial Dissipative Structures
Authors: Malkov V B , Chemezov O V , Malkov A V
Published: November 2020

Two-dimensional geometric object “neutral surface” - successfully used to study thin plates. The use of this two-dimensional geometric object is not possible for the study of physical properties and physical processes in nano-thin SDS (spatial dissipative structures). The SDS lattice undergoes a rotational curvature around three mutually perpendicular directions, and the nano-thin SDS itself remains flat. We have developed a method for the study of nano-thin SDS with rotary lattice curvature. We used as a basis the method of visualizing the rotational curvature of the lattice by constructing a two-dimensional geometric object - the surface of the lattice curvature by nano-thin SDS. This method of investigation involves application of the lattice curvature surface with nano-thin SDS for the selected crystallographic direction as a “neutral surface”. The method will find application in nanotechnology.
Investigation of Microwave Characteristics of a Composite Based on Copper-Substituted Nickel-Zinc Ferrite
Authors: Zhivulin V , Zezyulina P , Vasijeva A
Published: November 2020

The results of ferrite synthesis and composite preparation and investigation are presented. The Cu substituted Ni-Zn ferrite was prepared in single phase form. The morphology and chemical composition were obtained. The composites on the base of experimental Ni0.28Zn0.62Cu0.1Fe2O4 and commercially available one were prepared. The microwave properties of all samples were investigated. It was checked that the used synthesis method (temperature and time range) can be used for ferrite producing for industry. The microwave properties of composites made of synthesized ferrites are very close to those of composites based on commercially available one. All samples exhibit broad magnetic loss peaks associated with a natural ferrimagnetic resonance.
On the Efficiency of Nitrogen-Containing Gaseous Waste Plasma Afterburning
Authors: Matushkin A V , Anakhov S V , Kharina G V
Published: November 2020

The paper is devoted to the study of the plasma neutralization technology for toxic waste in the gaseous phase. It is noted that for effective implementation of plasma processes in waste processing technologies, it is necessary to search the optimal solutions taking into account the criteria of quality, productivity, cost and safety. In order to determine the feasibility of using plasma incineration technology, attention is paid to the definition of the appropriate nomenclature for gaseous toxic waste. The technology of plasma neutralization for thermal waste processing products - superoxicants (dioxins) and nitrogen-containing gas emissions (ammonia and nitrogen oxides) is studied. A modernized design of the plasma torch for the gaseous waste utilization is proposed. The known methods of thermal destruction for ammonia and nitrogen oxides are considered. Temperature approximations of their decomposition duration and efficiency in the range of plasma heating temperatures are found. The gas-dynamic parameters of the air-plasma flow in the process of nitrogen-containing gases thermal heating by plasma jet are determined using machine modelling methods. The effectiveness of the considered plasma neutralization technology is proved. The results of these studies should allow us to further formulate commonly used in engineering practice principles and methods for designing high-performance plasma heating technology.
Thermal and Physical Properties of Methane Family Hydrocarbon and Oxygen Combustion Products in State-of-the-Art Arc Steel Furnace
Authors: Voronov G V , Glukhov I V
Published: November 2020

The work deals with the particular combustion characteristics of methane family hydrocarbons (methane, ethane, propane, butane) and wet natural gas with process oxygen at carbon dioxide and water steam dissociation in a state-of-the-art arc steelmaking furnace. An algorithm is developed to calculate chemistry, the amount and concentration of combustion products at carbon dioxide and hydrogen dissociation, their physical and thermophysical parameters; heating power, balance and actual temperature, heat and pyrometric factors are evaluated considering heat transfer by radiation into unbounded medium. Based on the calculation results the recommendations are given for development of cold charge material heating conditions in order to minimize dusting, carbon oxide and hydrogen and charge material loss.
Thermodynamic Simulation of Reduction Processes at the Production of Ferrochrome
Authors: Salina V A , Zhuchkov V I , Zayakin O V
Published: November 2020

The possibility of reduction process of chromium from the Cr2O3 – FeO – CaO – SiO2 – MgO – Al2O3 system by carbon using the method of thermodynamic simulation was showed in the article. The compositions of chromium ore of the deposit Rai-Iz and dust of cyclones of the low-carbon ferrochrome in an amount of 0; 5; 10; 20% were used as a components of the system. The carbon was used a reducing agent. The thermodynamic simulation was performed using the HSC Chemistry 6.12 software package developed from Outokumpu, Finland. The thermodynamic characteristics of CrO (II) compound were entered into the software package’s database. The thermochemical data of compounds CaCr2O4, Fe3C, Cr3C2, Cr7C3, Cr23C6, SiC were refined. The calculations were performed using the “Equilibrium Compositions” module in the temperature range 1500 – 1700°C at a temperature increment of 100°C, at a total pressure of 0.1 MPa in the system and 2.24 m3of N2. It was determined that the increase in the dust amount from 5 to 20% did not affect practically at the reduction degree of chromium which is equal 90.2; 93.4; 94.6% respectively at the temperatures of 1500, 1600 and 1700°C. The chemical composition of the metal is, %: 65.6 – 65.1 Cr; 22.7 – 23.2 Fe; 11.5 – 11.6 C; 0.2 – 0.26 Si at the temperature of 1700°C. The thermodynamic simulation results can be used to develop technology for producing ferrochrome using wastes of metallurgical production.
Hydrometallurgical Technology for Processing of Galvanic Sludges
Authors: Yu Makoskaya O , Kostromin K S , Bryantseva N I
Published: November 2020

The problem of processing galvanic sludges, formed as a result of neutralization of technological solutions and wastewater containing heavy non-ferrous metals is considered. At present, sludges are transported to disposal area and are not used in any way. Typically, such sludges contain significant amounts of chromium and nickel, which creates environmental hazard. Investigated sludge contains up to 6.6% Ni and up to 7.4% Cr. The hydrometallurgical technology for processing of these sludges has been developed. Solutions of sulfuric acid and ammonia were used as lixiviants. It is shown that when using a solution of sulfuric acid with pH=1.5, extraction of up to 93.3% Cu, 70.2 Ni, 90.3 Zn is achieved. For selective recovery of nickel from leachates the process of sorption concentration by Lewatit TP207 is proposed.
Study of the Mechanism for Forming a Passivating Layer under Electrochemical Oxidation of Copper (I) Sulfide
Authors: Nechvoglod O V , Pikalov S M
Published: November 2020

In this study the patterns of anodic oxidation of copper (I) sulfide were considered. It was shown that during the crystallization of copper sulfide, the formation of both the chalcosine (Cu2S) phase and the jarleite (Cu31S16) phase is possible, which is characterized by a deficiency of copper in the crystal lattice and deviation from the stoichiometric composition. The electrochemical oxidation of the sample in a solution of sulfuric acid was carried out. During oxidation, intermediate non-stoichiometric sulfides (Cu174S, Cu1.8S) were formed in the following sequence: Cu2S (Cu31S16) → Cu1.81S → Cu1.74S → Cu1.6S → CuS → S + Cu2+. The process was accompanied by the transition of copper cations into solution. As elemental sulfur and copper sulfides accumulated on the reaction surface of the sample and, as a result, the rate of electrochemical oxidation decreased due to the difficulty of the product removal and the reagent supply to the reaction zone.
Increasing the Strength Properties of Gray Iron Castings without Introducing Additional Modifying and Alloying Additives into Its Composition
Authors: Gabelchenko N I , Kidalov N A , Belov A A
Published: November 2020

The effect of the differential cooling regimes on the structure and strength properties of gray iron castings in sand molds was investigated. The experimental foundry equipment was developed and assembled in order to produce experimental and control castings. This equipment allows to investigate the crystallization of two castings under initially equal pouring conditions: chemical composition, temperature and speed of mold filling with molten metal. It was shown that due to the using of the differential cooling regimes the experimental castings tensile strength was increased by 13.8% and hardness reduced by 12.3% via excluding the formation of ledeburite in the structure, which leads to increase in the quality index of cast iron by 33%.
The Impact of the Production Stages of Grade D Steel on its Contamination and the Chemical Composition of Nonmetallic Inclusions
Authors: Rutskii D V , Zyuban N A , Babin G V
Published: November 2020

Optical and electronic microscopy methods are used to evaluate the contamination of grade D carbon steel with nonmetallic inclusions in steel samples taken at various stages of steelmaking (electric arc furnace (EAF) discharge -> ladle furnace (LF) -> vacuum deoxidation (VD) -> continuous casting) at an electric furnace melting shop. Steel contamination with nonmetallic inclusions and inclusion chemical composition are assessed. It is demonstrated that the aluminum deoxidation of the semiproduct leads to the formation of corundum nonmetallic inclusions (Al2O3) in molten steel. The total amount of corundum reaches 52% for all the stages of steelmaking process. The identification and evaluation of nonmetallic inclusions demonstrates that deoxidation performed at all the stages of secondary steelmaking reduce the amount of inclusions. After vacuum deoxidation and adding Al and SiCa, corundum inclusions become globular in shape with a particle size less than 6 urn. When the continuously cast billet has solidified, the total amount of nonmetallic inclusions does not change, whereas silicate inclusion content decreases and corundum contamination grows, with corundum inclusions being of an irregular shape. A heavy corundum contamination is caused by aluminum secondary deoxidation during steel casting as well as by the fact that the molten residue in the pouring nozzle is carried into the solidifying continuously cast billet.
Increasing the Service Lifetime of a Working Elements of Mixer-Pneumosuperchargers for the Building Mixtures Preparation
Authors: Gabelchenko N I , Belov A A , Gabelchenko A I
Published: November 2020

Comparative studies of the blade’s materials for mixer-pneumosuperchargers operated under abrasive conditions were carried out. For this purpose in the production environment at the construction site the service lifetime of the blades offered by various manufacturers was measured on four “SO – 241” mixer-pneumosuperchargers. Production of building mixture in quantity declared by the manufacturer was used as a control period. It is shown that blades made of 110G13L steel retained their service properties almost until the completion of the control period. Also, the composition and technology for producing the working elements of mixer-pneumosuperchargers from wear-resistant white cast iron alloyed with chromium and manganese was developed. The test results showed that the blades made of the proposed material exceeded the service lifetime of the blades made of 110G13L steel.
On the Issue of Heat Balance of Molds for Injection Molding of Non-Ferrous Metal Alloys
Authors: Gavariev R V , Gavarieva K N
Published: November 2020

The article presents a study of the thermal balance of injection molding molds. The main components of the balance equation are indicated, as well as the factors that affect them. It is revealed that the most important factor affecting the thermal balance is the material of the mold. The use of coatings applied by the method of physical vapor deposition on the forming surfaces of molds is proposed. These coatings provide a reduction in friction between the forming surface and the poured melt at the time of filling, which reduces the temperature of the forming surface by 10-12°C. Among the considered options, the most optimal indicators were for titanium and molybdenum metal nitride (Ti, Mo) N.
Investigation of Lateral Surface Contour at Forging of Billets with Upsetting Ratio Above 2.5
Authors: Anishchenko O , Kukhar V , Klimov E
Published: November 2020

List of the most used functions (circle, parabola, ellipse, hyperbola, cosine, hyperbolic cosine), which are applied to approximate of billets contours at upsetting and pointed to the lack of a universal equation for these purposes, was analyzed. The advantages and disadvantages of each type of equations are pointed. The paper presents the results of upsetting of lead cylindrical specimens with a upsetting ratio 2.0-4.0. The experiment shows the stages of a “double barrel” forming on the lateral surface of a billet and its subsequent transition to a single one. The authors propose to use the “superformula” recently invented by Johan Gielis as a universal equation that allows to approximate the contour of the lateral surface of a billet at all stages of upsetting. The paper presents comparative initial data necessaries to determine upsetting force and pressure, taking into account the barrel-shape calculated by the superformula, and the coefficient of friction determined by Gubkin’s method. The equations coefficients have find, which give approximately the same results comparables to upsetting of specimens from lead, and these equations proposed for the calculation of the forming at upsetting from double-barrel to single-barrel workpiece.
Research of the Influence of the Rarefaction Degree on the Metal Protection Quality and Geometric Welding Parameters During Arc Welding in the Controlled Atmosphere
Authors: Sitnikov I V , Trushnikov D N , Permyakov G L
Published: November 2020

This article is devoted to the urgent issue of welding metals and alloys that are widely used in modern aerospace industry. The paper describes the effect of the degree of rarefaction of the controlled atmosphere on the quality of protection of the weld metal and the weld zone, as well as on the change in the geometric parameters of the weld during arc welding in a controlled atmosphere. The main advantages of arc welding in a controlled atmosphere of refractory, heat-resistant, heat-resistant, corrosion-resistant metals and their alloys are indicated. The welding modes used and the welds obtained with these modes are presented. The influence of the degree of rarefaction on the change in the quality of protection of the weld metal and the heat-affected zone is described. The degree of rarefaction of the controlled atmosphere ranged from 200 to 1000 mbar. Dependencies are obtained that describe the effect of the degree of rarefaction on the geometric parameters of welds.
Effect of Welding Speed on Electron Beam Welding Thermal Efficiency
Authors: Terentyev E V , Sliva A P , Santalova Yu V
Published: November 2020

The results of thermal efficiency evaluation during electron beam welding of alloys with different thermophysical properties in the range of welding speeds from 20 m/h to 120 m/h are presented. It was shown that the thermal efficiency increased in accordance with the rising welding speed. Also, the thermal efficiency greatly depends on the thermal conductivity: the lower the thermal conductivity, the higher the thermal efficiency. Thus, with an increase in welding speed from 20 m/h to 120 m/h, the thermal efficiency grew steadily for all three considered types of alloys: values for a titanium alloy 5 V went up from 54% to 67%, while for the steel 40Kh13 values rose from 46% to 63% and the most significant increment related to duralumin D16, the thermal efficiency for this alloy increased from 18% to 40%. The equation which established the ratio between the thermal efficiency, welding speed and thermal conductivity for electron beam welding with full penetration was derived.
A Method of Managing Technological Heredity in the Additive Growing of Objects from Cold-Resistant Materials on a Machine with Technology for Electric Arc Welding
Authors: Shatagin D , Kabaldin Y , Kolchin P
Published: November 2020

The article considers the issue of managing print parameters to minimize the impact of technological heredity on the layers of the formed object. An analysis of the stability of the 3D printing process was carried out using acoustic emission data. The fractal dimensions of the acoustic emission attractor for a stable and unstable 3D printing process have been obtained. A method for controlling process stability by tracking 3D printing modes and assessing their stability using an artificial neural network is proposed. The mechanical properties of printed samples were evaluated under normal conditions and at low temperatures in the Arctic and the far north.
Changes in the Structure and Properties of Nickel-Zinc Spinel Nanoferrites Series for 3D-Printing
Authors: Shamray I I , Yu Buz’ko V , Goryachko A I
Published: November 2020

The family of nickel-zinc nanoferrites with general formula NixZn1 – xFe2O4 for 3D printing were synthesized via pyrochemical urea-nitrate method and annealed at temperatures of up to 770 K. The ferrite powder microstructure was studied by SEM and XRD methods. Average nanocrystallite sizes of 21 to 32 nm and average nanoparticles sizes of 22 to 50 nm were determined. The DC electrical conductivity of NixZn1 – xFe2O4 clearly shows the change in conduction behavior of samples with increase in nickel content. The observed low electrical conductivity with values at 0.l-0.3 and 0.8-0.9 parts of nickel ion for NixZn1 – xFe2O4 is due to change in cation distribution in spinel structure. The microwave absorbing properties of ferrites at 9.15 GHz were analyzed by FMR and maximum microwave absorption is that of compositions NixZn1 – xFe2O4 with x = 0.15 – 0.30. Additive manufacturing FDM 3D-printing process with PLA-nanoferrite filament for fabricating magnetic components also was demonstrated.
Development of a Mathematical Model of an Arc Plasma Discharge in Vacuum, Describing the Joint Solution of the Navier-Stokes Equations, Heat Transfer, with Equations of Plasma Theory
Authors: Sitnikov I V , Trushnikov D N , Permyakov G L
Published: November 2020

This article is devoted to the description of arc processes in a vacuum, relevant today for the melting of wire materials in the implementation of hybrid technologies of layer-by-layer synthesis. The directions of using an electric arc as a source of heat in creating arc additive technologies are indicated. One of the most promising methods for creating an arc discharge in vacuum using a non-consumable thermoelectronic hollow cathode is presented. A two-dimensional model has been developed for studying a hollow-cathode arc discharge in vacuum, where argon was used as the plasma-forming gas. All calculations were carried out in an axisymmetric formulation. To obtain a numerical solution, the COMSOL Multiphysics application software package was used. The obtained simulation results showed a satisfactory agreement with the literature and experimental data.
Interpolation in model spaces
Authors: Gorkin Pamela , Wick Brett
Published: November 2020

In this paper we consider interpolation in model spaces,

H
2

⊖
B

H
2

H^2 \ominus B H^2

with

B
B

a Blaschke product. We study unions of interpolating sequences for two sequences that are far from each other in the pseudohyperbolic metric as well as two sequences that are close to each other in the pseudohyperbolic metric. The paper concludes with a discussion of the behavior of Frostman sequences under perturbations.
Áine O'Brien Chair, RAS Early Career Network
Authors: Johnson Paul , O'Brien Áine
Published: November 2020

The former physics teacher, now studying martian meteorites at Glasgow, explains why early-career scientists need support now more than ever. Interview by Paul Johnson.
Index to ‘A&G’ vol. 61
Authors: Johnson Paul
Published: November 2020

All articles published this year, searchable by author and type
Current challenges for unseen-epitope TCR interaction prediction and a new perspective derived from image classification
Authors: Moris Pieter , De Pauw Joey , Postovskaya Anna , Gielis Sofie , De Neuter Nicolas , Bittremieux Wout , Ogunjimi Benson , Laukens Kris , Meysman Pieter
Published: November 2020

The prediction of epitope recognition by T-cell receptors (TCRs) has seen many advancements in recent years, with several methods now available that can predict recognition for a specific set of epitopes. However, the generic case of evaluating all possible TCR-epitope pairs remains challenging, mainly due to the high diversity of the interacting sequences and the limited amount of currently available training data. In this work, we provide an overview of the current state of this unsolved problem. First, we examine appropriate validation strategies to accurately assess the generalization performance of generic TCR-epitope recognition models when applied to both seen and unseen epitopes. In addition, we present a novel feature representation approach, which we call ImRex (interaction map recognition). This approach is based on the pairwise combination of physicochemical properties of the individual amino acids in the CDR3 and epitope sequences, which provides a convolutional neural network with the combined representation of both sequences. Lastly, we highlight various challenges that are specific to TCR-epitope data and that can adversely affect model performance. These include the issue of selecting negative data, the imbalanced epitope distribution of curated TCR-epitope datasets and the potential exchangeability of TCR alpha and beta chains. Our results indicate that while extrapolation to unseen epitopes remains a difficult challenge, ImRex makes this feasible for a subset of epitopes that are not too dissimilar from the training data. We show that appropriate feature engineering methods and rigorous benchmark standards are required to create and validate TCR-epitope predictive models.
Concatenating plasma p-tau to Alzheimer’s disease
Authors: Tijms Betty M , Teunissen Charlotte E
Published: November 2020

This scientific commentary refers to ‘Time course of phosphorylated-tau181 in blood across the Alzheimer’s disease spectrum’, by Moscoso et al. (doi:10.1093/brain/awaa399).
DNA Methyltransferase 3A Is Involved in the Sustained Effects of Chronic Stress on Synaptic Functions and Behaviors
Authors: Wei Jing , Cheng Jia , Waddell Nicholas J , Wang Zi-Jun , Pang Xiaodong , Cao Qing , Liu Aiyi , Chitaman Javed M , Abreu Kristen , Jasrotia Rahul Singh , Duffney Lara J , Zhang Jinfeng , Dietz David M , Feng Jian , Yan Zhen
Published: November 2020

Emerging evidence suggests that epigenetic mechanisms regulate aberrant gene transcription in stress-associated mental disorders. However, it remains to be elucidated about the role of DNA methylation and its catalyzing enzymes, DNA methyltransferases (DNMTs), in this process. Here, we found that male rats exposed to chronic (2-week) unpredictable stress exhibited a substantial reduction of Dnmt3a after stress cessation in the prefrontal cortex (PFC), a key target region of stress. Treatment of unstressed control rats with DNMT inhibitors recapitulated the effect of chronic unpredictable stress on decreased AMPAR expression and function in PFC. In contrast, overexpression of Dnmt3a in PFC of stressed animals prevented the loss of glutamatergic responses. Moreover, the stress-induced behavioral abnormalities, including the impaired recognition memory, heightened aggression, and hyperlocomotion, were partially attenuated by Dnmt3a expression in PFC of stressed animals. Finally, we found that there were genome-wide DNA methylation changes and transcriptome alterations in PFC of stressed rats, both of which were enriched at several neural pathways, including glutamatergic synapse and microtubule-associated protein kinase signaling. These results have therefore recognized the potential role of DNA epigenetic modification in stress-induced disturbance of synaptic functions and cognitive and emotional processes.
Cost-effectiveness of a Novel Lipoarabinomannan Test for Tuberculosis in Patients With Human Immunodeficiency Virus
Authors: Reddy Krishna P , Denkinger Claudia M , Broger Tobias , McCann Nicole C , Gupta-Wright Ankur , Kerkhoff Andrew D , Pei Pamela P , Shebl Fatma M , Fielding Katherine L , Nicol Mark P , Horsburgh C Robert , Meintjes Graeme , Freedberg Kenneth A , Wood Robin , Walensky Rochelle P
Published: November 2020

Background

A novel urine lipoarabinomannan assay (FujiLAM) has higher sensitivity and higher cost than the first-generation AlereLAM assay. We evaluated the cost-effectiveness of FujiLAM for tuberculosis testing among hospitalized people with human immunodeficiency virus (HIV), irrespective of symptoms.

Methods

We used a microsimulation model to project clinical and economic outcomes of 3 testing strategies: (1) sputum Xpert MTB/RIF (Xpert), (2) sputum Xpert plus urine AlereLAM (Xpert+AlereLAM), (3) sputum Xpert plus urine FujiLAM (Xpert+FujiLAM). The modeled cohort matched that of a 2-country clinical trial. We applied diagnostic yields from a retrospective study (yields for Xpert/Xpert+AlereLAM/Xpert+FujiLAM among those with CD4 <200 cells/µL: 33%/62%/70%; among those with CD4 ≥200 cells/µL: 33%/35%/47%). Costs of Xpert/AlereLAM/FujiLAM were US$15/3/6 (South Africa) and $25/3/6 (Malawi). Xpert+FujiLAM was considered cost-effective if its incremental cost-effectiveness ratio (US$/year-of-life saved) was <$940 (South Africa) and <$750 (Malawi). We varied key parameters in sensitivity analysis and performed a budget impact analysis of implementing FujiLAM countrywide.

Results

Compared with Xpert+AlereLAM, Xpert+FujiLAM increased life expectancy by 0.2 years for those tested in South Africa and Malawi. Xpert+FujiLAM was cost-effective in both countries. Xpert+FujiLAM for all patients remained cost-effective compared with sequential testing and CD4-stratified testing strategies. FujiLAM use added 3.5% (South Africa) and 4.7% (Malawi) to 5-year healthcare costs of tested patients, primarily reflecting ongoing HIV treatment costs among survivors.

Conclusions

FujiLAM with Xpert for tuberculosis testing in hospitalized people with HIV is likely to increase life expectancy and be cost-effective at the currently anticipated price in South Africa and Malawi. Additional studies should evaluate FujiLAM in clinical practice settings.
Letermovir and Maribavir for the Treatment and Prevention of Cytomegalovirus Infection in Solid Organ and Stem Cell Transplant Recipients
Authors: Imlay Hannah N , Kaul Daniel R
Published: November 2020

Until recently, available drugs for cytomegalovirus (CMV) prevention and treatment in transplant patients included (val)ganciclovir, foscarnet, and cidofovir. Use of these drugs is limited by toxicity and the development of resistance. The 2017 approval of letermovir for prevention of CMV after stem cell transplant marked the first approval of an anti-CMV agent since 2003. The role of letermovir in treatment of established CMV infection or disease remains largely unstudied, although early reports suggest that a low barrier to resistance will likely limit efficacy as primary therapy for patients with refractory or resistant disease. The investigational agent maribavir has shown promise as preemptive treatment; in patients with refractory or resistant disease the emergence of resistance while on treatment has been observed and ongoing studies will define efficacy in this population. Both agents have unique mechanisms of action limiting cross resistance, and neither exhibit myelotoxicity or nephrotoxicity.
Comparative Effectiveness of Influenza Vaccines Among US Medicare Beneficiaries Ages 65 Years and Older During the 2019–2020 Season
Authors: Izurieta Hector S , Lu Michael , Kelman Jeffrey , Lu Yun , Lindaas Arnstein , Loc Julie , Pratt Douglas , Wei Yuqin , Chillarige Yoganand , Wernecke Michael , MaCurdy Thomas E , Forshee Richard
Published: November 2020

Background

Approximately 50 000 influenza-associated deaths occur annually in the United States, overwhelmingly among individuals aged ≥65 years. Although vaccination is the primary prevention tool, investigations have shown low vaccine effectiveness (VE) in recent years, particularly among the elderly. We analyzed the relative VE (RVE) of all influenza vaccines among Medicare beneficiaries aged ≥65 years to prevent influenza hospital encounters during the 2019–2020 season.

Methods

Retrospective cohort study using Poisson regression and inverse probability of treatment weighting (IPTW). Exposures included egg-based high-dose trivalent (HD-IIV3), egg-based adjuvanted trivalent (aIIV3), egg-based standard dose (SD) quadrivalent (IIV4), cell-based SD quadrivalent (cIIV4), and recombinant quadrivalent (RIV4) influenza vaccines.

Results

We studied 12.7 million vaccinated beneficiaries. Following IPTW, cohorts were well balanced for all covariates and health-seeking behavior indicators. In the adjusted analysis, RIV4 (RVE, 13.3%; 95% CI, 7.4–18.9%), aIIV3 (RVE, 8.2%; 95% CI, 4.2–12.0%), and HD-IIV3 (RVE, 6.8%; 95% CI, 3.3–10.1%) were significantly more effective in preventing hospital encounters than the reference egg-based SD IIV4, while cIIV4 was not significantly more effective than IIV4 (RVE, 2.8%; 95% CI, −2.8%, 8.2%). Our results were consistent across all analyses.

Conclusions

In this influenza B-Victoria and A(H1N1)–dominated season, RIV4 was moderately more effective than other vaccines, while HD-IIV3 and aIIV3 were more effective than the IIV4 vaccines, highlighting the contributions of antigen amount and adjuvant use to VE. Egg adaptation likely did not substantially affect our RVE evaluation. Our findings, specific to the 2019–2020 season, should be evaluated in other studies using virological case confirmation.
Impact of Age on Outcome of Rifapentine-Based Weekly Therapy for Latent Tuberculosis Infection
Authors: Huang Hung-Ling , Lee Meng-Rui , Cheng Meng-Hsuan , Lu Po-Liang , Huang Chun-Kai , Sheu Chau-Chyun , Lai Ping-Chang , Chen Tun-Chieh , Wang Jann-Yuan , Chong Inn-Wen
Published: November 2020

Background

Weekly rifapentine and isoniazid (3HP) is gaining popularity for latent tuberculosis infection treatment because of its short course and high completion rate. Prior to widespread use, comprehensive 3HP treatment assessment covering an all-age population is essential.

Methods

Participants receiving ≥1 3HP dose from September 2014 to December 2019 were stratified into elderly (≥65 years), middle-aged (>35 & <65 years), and younger (≤35 years) age groups. This study investigated the impact of age on treatment outcome, particularly systemic drug reactions (SDRs) and 3HP discontinuation.

Results

Overall, 134 of 579 (23.1%) participants were elderly. The completion rate was 83.1% overall and was highest and lowest in the younger group (94.5%) and elderly (73.9%) group, respectively. However, the 3HP discontinuation rate was not significantly different among the 3 groups in multivariate logistic regression analysis. In total, 362 (62.5%) participants experienced 1 or more adverse drug reactions (ADRs), of which 38 (10.5%) and 98 (27.1%) required temporary and permanent treatment interruption, respectively. The SDR risk was 11.2% in overall and 17.1% in the middle-aged group, 3.04-fold higher than that in the elderly group (P = .025). This finding was consistently observed in different clinical settings. Hypertensive events accompanied with flu-like symptoms occurred in 11.2% of elderly participants, and accounted for 50% of grade ≥3 ADRs.

Conclusions

With proper medical support and programmatic follow-up, the 3HP completion rate is >70% even in elderly participants. In middle-aged and elderly individuals, 3HP should be employed with caution because of risk of SDRs and hypertensive events, respectively.

Summary: Under programmatic medical support, widespread use of weekly rifapentine and isoniazid (3HP) for latent tuberculosis treatment is possible for its high completion rate. 3HP should be employed with caution for risk of systemic drug reactions and hypertensive events in middle-aged and elderly individuals, respectively.
Biomarkers for Risk Assessment in Atrial Fibrillation
Authors: Berg David D , Ruff Christian T , Morrow David A
Published: November 2020

Background

Atrial fibrillation (AF) is associated with an increased risk of thromboembolism, which can be significantly reduced with anticoagulant treatment. Key goals in the clinical management of AF are the identification of patients at high risk for developing AF and accurate stratification of the risk of stroke and systemic embolic events (S/SEE) as well as treatment-related major bleeding.

Content

In this review, we describe the expanding evidence regarding the use of circulating biomarkers for predicting the risks of both incident AF and its clinically important complications of S/SEE and treatment-related major bleeding. We also review emerging biomarker-based scores for assessing these risks.

Patients with AF undergo progressive cardiac structural remodeling, which may precede the onset of the arrhythmia. Abnormal concentrations of circulating biomarkers reflecting the underlying pathophysiologic mechanisms of hemodynamic stress (i.e., natriuretic peptides), inflammation (i.e., C-reactive protein), and myocardial fibrosis identify patients at higher risk of developing AF. Circulating biomarkers can also be used to identify patients with AF who are at greatest risk for developing S/SEE or major bleeding. In particular, biomarkers of hemodynamic stress, myocardial injury (i.e., cardiac troponin), and coagulation activity (i.e., D-dimer) are key indicators of thromboembolic risk, and cardiac troponin and growth-differentiation factor-15 are strongly associated with risk of anticoagulant-related major bleeding. The biomarker-based age, biomarker, clinical history (ABC)-stroke and ABC-bleeding risk scores improve risk stratification for S/SEE and major bleeding, respectively, when compared with traditional clinical risk scores like the CHA2DS2-VASc and HAS-BLED scores.
School choice during a period of radical school reform. Evidence from academy conversion in England
Authors: Bertoni Marco , Gibbons Stephen , Silva Olmo
Published: November 2020

We study how demand responds to the rebranding of existing state schools as autonomous ‘academies’ in the context of a radical and large-scale reform to the English education system. The academy programme encouraged schools to opt out of local state control and funding, but provided parents and students with limited information on the expected benefits. We use administrative data on school applications for three cohorts of students to estimate whether this rebranding changes schools’ relative popularity. We find that families – particularly higher income, White British – are more likely to rank converted schools above non-converted schools on their applications. We also find that it is mainly schools that are high-performing, popular and proximate to families’ homes that attract extra demand after conversion. Overall, the patterns we document suggest that families read academy conversion as a signal of future quality gains – although this signal is in part misleading as we find limited evidence that conversion causes improved performance.
Quantifying the impact of pre-existing conditions on the stage of oesophagogastric cancer at diagnosis: a primary care cohort study using electronic medical records
Authors: Quiroga Myra , Shephard Elizabeth A , Mounce Luke T A , Carney Madeline , Hamilton William T , Price Sarah J
Published: November 2020

Background

Pre-existing conditions interfere with cancer diagnosis by offering diagnostic alternatives, competing for clinical attention or through patient surveillance.

Objective

To investigate associations between oesophagogastric cancer stage and pre-existing conditions.

Methods

Retrospective cohort study using Clinical Practice Research Datalink (CPRD) data, with English cancer registry linkage. Participants aged ≥40 years had consulted primary care in the year before their incident diagnosis of oesophagogastric cancer in 01/01/2010–31/12/2015. CPRD records pre-diagnosis were searched for codes denoting clinical features of oesophagogastric cancer and for pre-existing conditions, including those providing plausible diagnostic alternatives for those features. Logistic regression analysed associations between stage and multimorbidity (≥2 conditions; reference category: no multimorbidity) and having ‘diagnostic alternative(s)’, controlling for age, sex, deprivation and cancer site.

Results

Of 2444 participants provided, 695 (28%) were excluded for missing stage, leaving 1749 for analysis (1265/1749, 72.3% had advanced-stage disease). Multimorbidity was associated with stage [odds ratio 0.63, 95% confidence interval (CI) 0.47–0.85, P = 0.002], with moderate evidence of an interaction term with sex (1.76, 1.08–2.86, P = 0.024). There was no association between alternative explanations and stage (odds ratio 1.18, 95% CI 0.87–1.60, P = 0.278).

Conclusions

In men, multimorbidity is associated with a reduced chance of advanced-stage oesophagogastric cancer, to levels seen collectively for women.
Extent of contraception methods practised by unmet need couples after counselling: a cross-sectional follow-up study in Puducherry, South India
Authors: Saya Ganesh Kumar , Premarajan Kariyarath Cheriyath , Roy Gautam , Sarkar Sonali , Kar Sitanshu Sekhar , Olickal Jeby Jose
Published: November 2020

Background

Information is paucity about the extent of contraception practise among the unmet need eligible couples after counselling.

Objective

To assess the prevalence and associated factors of unmet need for family planning (FP), the extent to which they practise desired contraception methods after baseline counselling and the reasons for not practicing it.

Methods

A community-based cross-sectional analytical study was conducted between 2016 and 2019 among 2228 currently married couples with periodic follow ups of unmet need group. Baseline data on unmet need were collected based on the National Family Health Survey questionnaire. Individual and couple counselling were performed through informing choice and the support for decision making was based on the unmet need reasons with follow-ups. The data were analysed using Stata software version 12.0 (StataCorp, College Station, TX).

Results

The total study population was 1924. The prevalence of unmet need for FP was 7.1% (137) with 2.9% (55) of unmet need for spacing and 4.3% (82) of limiting births. Age groups between 18 and 24 [adjusted odds ratio (AOR) = 4.463], 25–29 (AOR = 2.339), not having a child (AOR = 0.250), having one child (AOR = 2.369) and having lower socioeconomic status (AOR = 0.155) were significantly associated with unmet need. During the follow-ups, 37.2% (29/78) received who desired limiting births, while 43.6% (34/78) changed to spacing methods. In fact, the main reason for not adopting limiting births is the fear of post-operative surgery-related health problems.

Conclusions

This study emphasizes the need for follow-up counselling for guiding contraceptive use and recorded that majority of the unmet need couples started practicing contraception methods during the follow-ups. Besides, change in desired contraception methods was observed.
Federalism’s radical potential
Authors: Webber Jeremy
Published: November 2020

The ability to rely on federalism as an effective response to deep divisions in post-conflict societies is often impaired by parties requiring too great a consensus on the ideological premises of the re-founded state: on the nation’s essential character; on who bears the right of self-determination; and on the historical foundations of the political community. As a result, the radical potential of federalism—its ability to accommodate, within a single political order, political communities possessing substantially different conceptions of foundational political legitimacy—is lost. This article reviews the nature and history of federations in order to establish that this radical potential is at the very heart of federalism. It describes the dynamics of allegiance in federal societies and suggests why federal states can flourish even in the presence of such significant differences. It then notes seven approaches that can facilitate the success of such federations.
Postoperative outcomes of lung transplant recipients with preformed donor-specific antibodies
Authors: Kayawake Hidenao , Chen-Yoshikawa Toyofumi F , Gochi Fumiaki , Tanaka Satona , Yurugi Kimiko , Hishida Rie , Yutaka Yojiro , Yamada Yoshito , Ohsumi Akihiro , Hamaji Masatsugu , Nakajima Daisuke , Date Hiroshi
Published: November 2020

OBJECTIVES

Few studies have evaluated the outcomes of lung transplantation (LTx) in recipients with preformed donor-specific antibodies (DSAs). This study investigated the postoperative changes in preformed DSAs based on prospectively collected data of DSAs, and the influences of preformed DSAs on postoperative outcomes among LTx recipients.

METHODS

Between July 2010 and December 2019, 216 recipients underwent LTx (81 living-donor lobar lung transplants and 135 deceased-donor lung transplants). We reviewed 8 cases with preformed DSAs to determine postoperative changes in DSAs and compared postoperative outcomes between recipients with and without DSAs.

RESULTS

The preoperative mean fluorescence intensity of preformed DSAs ranged from 1141 to 14 695. Two recipients experienced antibody-mediated rejection within 2 weeks after LTx. DSAs disappeared in 7 recipients; however, 1 recipient experienced the relapse of DSAs and died from chronic lung allograft syndrome (CLAD), whereas 1 recipient had persisting DSAs within the study period and died from CLAD. Neither overall survival (OS) nor CLAD-free survival was significantly different between recipients with and without DSAs (P = 0.26 and P = 0.17, respectively). However, both OS and CLAD-free survival were significantly lower in recipients with DSAs against HLA class II than in those without these antibodies {5-year OS: 25.0% [95% confidence interval (CI): 0.9–66.5%] vs 72.1% (95% CI: 63.8–78.9%), P = 0.030 and 5-year CLAD-free survival: 26.7% (95% CI: 1.0–68.6%) vs 73.7% (95% CI: 66.5–79.5%), P = 0.002}.

CONCLUSIONS

Prognosis in recipients experiencing the relapse of preformed DSAs and those with persisting DSAs may be poor. The recipients with anti-HLA class II preformed DSAs had a significantly worse prognosis.
Screening for coronary artery disease in early surgical treatment of acute aortic valve infective endocarditis
Authors: Knol Wiebe G , Wahadat Ali R , Roos-Hesselink Jolien W , Van Mieghem Nicolas M , Tanis Wilco , Bogers Ad J J C , Budde Ricardo P J
Published: November 2020

OBJECTIVES

In patients with unknown coronary status undergoing surgery for acute infective endocarditis (IE), the need to screen for coronary artery disease (CAD) and the risk of embolization during invasive coronary angiography (ICA) are debated. Coronary computed tomography angiography (CCTA) is a non-invasive alternative in these patients. We aimed to evaluate the safety and feasibility of ICA and CCTA to diagnose CAD, and the necessity to treat CAD to prevent CAD-related postoperative complications.

METHODS

In this single-centre retrospective cohort study, all patients with acute aortic IE between 2009 and 2019 undergoing surgery were selected. Outcomes were any clinically evident embolization after preoperative ICA, in-hospital mortality, perioperative myocardial infarction or unplanned revascularization and postoperative renal function.

RESULTS

Of the 159 included patients, CAD status was already known in 14. No preoperative diagnostics for CAD was done in 46/145, a CCTA was performed in 54/145 patients and an ICA in 52/145 patients. Significant CAD was found after CCTA in 22% and after ICA in 21% of patients. In 1 of the 52 (2%) patients undergoing preoperative ICA, a cerebral embolism occurred. The rate of perioperative myocardial infarction or unplanned revascularization in patients not screened for CAD was 2% (1 out of 46 patients).

CONCLUSIONS

Although the risk of embolism after preoperative ICA is low, it should be carefully weighed against the estimated risk of CAD-related perioperative complications. CCTA can serve as a gatekeeper for ICA in most patients with acute aortic IE.