Root size and architecture are important crop plant traits, as they determine access to water and soil nutrients. The plant hormone cytokinin is a negative regulator of root growth and branching. ...Here, we generated transgenic barley (Hordeum vulgare) plants with an enlarged root system by enhancing cytokinin degradation in roots to explore the potential of cytokinin modulations in improving root functions. This was achieved through root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE gene. Enhanced biomass allocation to roots did not penalize shoot growth or seed yield, indicating that these plants were not source limited. In leaves of transgenic lines, the concentrations of several macroelements and microelements were increased, particularly those with low soil mobility (phosphorus, manganese, and zinc). Importantly, seeds contained up to 44% more zinc, which is beneficial for human nutrition. Transgenic lines also demonstrated dampened stress responses to long-term drought conditions, indicating lower drought sensitivity. Taken together, this work demonstrates that root engineering of cereals is a promising strategy to improve nutrient efficiency, biofortification, and drought tolerance.
Recombinant cysteine peptidase vaccine can induce protective immunity against cutaneous leishmaniasis. However, the antigenic diversity and variable immunogenicity prevents them from being approved ...for general vaccination. Different approaches like adjuvant application and antigen delivery systems are studied to increase their efficacy. Nanoparticles can both stimulated antigen uptakes and affect direction of immune response. In this study the effect of PLGA nanoparticles were considered to enhance the immune response against recombinant CPA (CPA) and CPB (CPB). For this purpose, L. major CPA and CPB were prepared. PLGA were conjugated to the proteins using Aldehyde/Hydrazine Reaction. Conjugation efficacy and created nanoparticle morphology were determined by FTIR and SEM methods, respectively. BALB/c mice were received intraperitoneally three boosts of 7 μg/mouse of each antigen alone (CPA/CPB/CPA + CPB) or as PLGA conjugated form in different Study groups, at 3 weeks interval. After vaccination, mice were challenged with 106L. major, subcutaneously. Time course study of lesion development demonstrated nanoparticle efficacy in parasite dissemination control that confirmed by spleen parasite burden assay. Significant induction of nitric oxide production by peritoneal macrophages and increase in splenocyte IFN-γ production showed the protective effect of PLGA-CPA/CPB vaccination in comparison to CPA and CPB alone. Current study demonstrated that the conjugation of the antigen with the PLGA can activate immune responses against L. major. However, further study is necessary to assess the long-term effect and other aspects of immune response.
•PLGA–CPA/CPB immunization reduces L. major parasite burden in the spleen of BALB/c mice.•PLGA–CPA/CPB immunization induces IFN-γ production by splenocytes of L. major infected BALB/c mice.•PLGA–CPA/CPB immunization enhances nitric oxide production by peritoneal macrophages of L. major infected BALB/c mice.
Introduction
The increasing evidence of SARS‐CoV‐2 impact on the central nervous system (CNS) raises key questions on its impact for risk of later life cognitive decline, Alzheimer's disease (AD), ...and other dementia.
Methods
The Alzheimer's Association and representatives from more than 30 countries—with technical guidance from the World Health Organization—have formed an international consortium to study the short‐and long‐term consequences of SARS‐CoV‐2 on the CNS—including the underlying biology that may contribute to AD and other dementias. This consortium will link teams from around the world covering more than 22 million COVID‐19 cases to enroll two groups of individuals including people with disease, to be evaluated for follow‐up evaluations at 6, 9, and 18 months, and people who are already enrolled in existing international research studies to add additional measures and markers of their underlying biology.
Conclusions
The increasing evidence and understanding of SARS‐CoV‐2's impact on the CNS raises key questions on the impact for risk of later life cognitive decline, AD, and other dementia. This program of studies aims to better understand the long‐term consequences that may impact the brain, cognition, and functioning—including the underlying biology that may contribute to AD and other dementias.
Haynes 282 is a Ni-based gamma prime (γ′) strengthening alloy with a balanced combination of high temperature properties and fabricability. This paper aims to study the evolution of the ...microstructure and hardness using a novel physical simulation method called arc heat treatment, followed by thermodynamic modeling of γ′ precipitation. For the arc heat treatment, a steady state temperature gradient was generated using a stationary tungsten inert gas arc on a sample mounted onto a water-cooled chamber. The steady state condition ranged from room temperature to the liquidus and was achieved within the first few seconds. Aged and solutionized samples were arc heat treated for 1.5 min, 30 min, and 4 h. The experiments were complemented with temperature modeling, equilibrium calculations, and γ′ precipitation simulations. A unique graded microstructure formed in the arc heat-treated samples. It consisted of a fusion zone with a dendritic microstructure; a region with the dissolution of all secondary phases (MC carbides, grain boundary carbides, and γ′); a region with MC and grain boundary carbides; a γ′ precipitation zone; and the base metal. The temperature range of the dissolution area extended to lower temperatures with increasing arc heat treatment dwell time. The γ′ precipitation zone showed a distinct etching response coupled with high hardness. The hardness and the temperature range of the γ′ precipitation zone increased with increasing arc heat treatment time. The γ′ radii increased with increasing time and temperature. The γ′ precipitation model, simulated with TC Prisma, showed very good agreement with the experimental results. Finally, the results were used to develop time-temperature precipitation and hardness diagrams.
•Phase transformations were studied in Haynes® 282® in aged and solutionized conditions.•A novel arc heat treatment produced the temperature gradient for desired times.•A graded microstructure showed different regions in a singles sample.•Precipitation simulation predicted gamma prime coarsening in the samples.•Time-temperature diagrams were drawn for the alloy.
•Development of Single Relaxation Time Advection-Diffusion lattice Boltzmann model capable of handling density and heat capacity variations.•Multi-scale expansion of the model and derivation of ...recovered PDE (up to second order).•Validation through a variety of test-cases involving variable thermal conductivity, heat capacity, pure diffusion and coupled convection -diffusion.•Application of model to large scale turbulent flow in channel involving heat obstacle with conjugate heat transfer.
Many practical flow configurations involve energy transfer in fluids, or in solids and fluids with different thermo-physical properties. The classical advection-diffusion lattice Boltzmann (LB) solver admits some errors when dealing with such configurations. Given that the macroscopic equation recovered by this model is only valid in the limit of incompressible flows with constant heat capacities, one would, for example, observe inconsistent fluxes at the interface of a fluid and solid with different densities or specific heat capacities. This inconsistency being second-order in space, it will have non-negligible effects on the final results. In this work, a modified equilibrium distribution function (EDF) is proposed to overcome these issues. The proposed scheme recovers the correct partial differential equation (PDE) describing energy transfer, as shown by a multi-scale Chapman–Enskog analysis. The performance of the model is checked through a variety of test-cases, involving conjugate heat transfer and variable specific heat capacities in both steady and unsteady configurations. In all cases the obtained results are in excellent agreement with reference data.
Super duplex stainless steel (SDSS) weld metal microstructures, covering the complete temperature range from ambient to liquidus, were produced by arc heat treatment for 1 and 10 min. Temperature ...modeling and thermodynamic calculations complemented microstructural studies, hardness mapping and sensitization testing. After 1 min, intermetallics such as sigma and chi phase had precipitated, resulting in moderate sensitization at 720–840 °C. After 10 min, larger amounts of intermetallics resulted in hardness up to 400 HV0.5 and more severe sensitization at 580–920 °C. Coarse and fine secondary austenite precipitated at high and low temperatures, respectively: The finer secondary austenite was more detrimental to corrosion resistance due to its lower content of Cr, Mo, and N as predicted by thermodynamic calculations. Increased hardness and etching response suggest that 475 °C embrittlement had occurred after 10 min. Results are summarized as time-temperature-precipitation and property diagrams for hardness and sensitization.
The usage of passive cooling systems such as wind catchers can reduce the energy usage in buildings and provide natural ventilation and comfort to its occupants, particularly in hot and dry regions ...of Iran and neighboring countries where it was traditionally used. The purpose of this study was to investigate the airflow and thermal comfort in six different designs of wind catchers using computational fluid dynamics (CFD) technique. Simulations of airflow in the wind catcher and the building were done under steady state and turbulent flow regime with boundary conditions based on typical conditions found in Yazd city, Iran. Several commonly used turbulence models were evaluated to assess the accuracy of the simulation. First, the proposed CFD model was validated through comparison of wind tunnel data available in the literature, and then the model was used for design purposes. It was found that the k−ω turbulence model can accurately predict the airflow velocity in the range of parameters studied. The design and performance of wind catcher were evaluated based on the thermal comfort levels using the Center for the Built Environment (CBE) thermal comfort tool and numerical data. Width and height of the wind catcher were varied in the simulations and optimal values were determined. It was found that varying the width of the wind catcher had the greatest impact on the airflow speed and distribution inside the room. Reducing the width from 2.5m to 2m showed that airflow velocity in the middle area was increased up to 34%. While reducing the width from 2m to 1.5m showed an entirely different flow pattern inside the building and also increase airflow speed in the middle area up to 50%. The addition of curved wall at the bottom of the inlet channel showed that it could increase the airflow speed of the inflow stream, however, it also caused the airflow to be directed towards the lower levels of the room and very large rotating flows in the upper levels. Finally, the results showed that the wind catcher may be optimized for improving comfort for various climates using the tools presented in this work.
•Different turbulence models were evaluated for thermal comfort analysis of wind catchers.•Standard k−ω turbulence model provided most accurate prediction of airflow in wind catcher and building.•Various wind catcher geometries focusing on width and height of tower were studied.•Optimum design of wind catcher for ventilation and thermal comfort were evaluated.
A new version of the ERICA Tool (version 1.2) was released in November 2014; this constitutes the first major update of the Tool since release in 2007. The key features of the update are presented in ...this article. Of particular note are new transfer databases extracted from an international compilation of concentration ratios (CRwo-media) and the modification of ‘extrapolation’ approaches used to select transfer data in cases where information is not available. Bayesian updating approaches have been used in some cases to draw on relevant information that would otherwise have been excluded in the process of deriving CRwo-media statistics. All of these efforts have in turn led to the requirement to update Environmental Media Concentration Limits (EMCLs) used in Tier 1 assessments. Some of the significant changes with regard to EMCLs are highlighted.
•The ERICA Tool for performing environmental risk assessment has been updated.•The new version is underpinned by an internationally supported transfer database.•The Tool provides coverage for many organism groups and radioisotopes.•New calculations were required to derive environmental media concentration limits.•Modified approaches to deriving missing transfer parameters are elaborated.
This study deals with the application of tire derived aggregate (TDA) mixed with ballast material as an approach for enhancing the ballasted track performance in the presence of sand fouling. In ...order to assess the TDA influence on sand-fouled ballast, a series of ballast box tests was conducted on various mixtures of TDA, ballast material with AREMA 4A gradation and the Tabas desert windy sand with particle size range of 0.075–4.75mm. A total number of 36 cyclic uniaxial tests were performed by considering four TDA weight percentages of 0%, 5%, 10% and 15% as well as three weight percentages of 0%, 50% and 100% for windy sand as the contaminant. The gradation of TDAs was similar to that of ballast particles so as not to disturb the ballast layer drainage. On the basis of the laboratory outputs, the settlement, ballast breakage and damping ratio of samples were discussed. The experimental results indicate that increasing the sand percentage decreases the damping ratio, while leading to an increase in the settlement and ballast breakage of samples. Alternatively, these parameters escalated with the increase of TDA percentage. Overall, the 5%-TDA sample was determined as the most suitable mixture in terms of breakage and stiffness, whereas the more TDAs continuously increased the damping ratio of samples. Three regression equations were also derived to evaluate these parameters as functions of the number of loading cycles, TDA and sand percentages.
•A review on preventive measures against incoming sand particles into railway track.•Influence of tire derived aggregates (TDAs) on performance of fouled ballast layer.•TDA and sand weight percentages of 0%, 5%, 10% and 15% as well as 0%, 50% and 100%.•Cyclic loading on twelve ballast-TDA-sand samples using ballast box apparatus.•Settlement, ballast breakage index, damping ratio, optimum TDA percentage of samples.
Since the advent of 3D printing in the mid-1980s, additive manufacturing has grown steadily and found numerous applications across all types of industries. More recently, the industry has seen a spur ...of growth as the terms of the original patents expired and new companies entered the market. While there exist several different methods of additive manufacturing, polymer-based material extrusion 3D printing (also known as fused filament fabrication) has become one of the most widely used ones due to its lower cost, ease of use, and versatility. While development has greatly expanded the material availability and improved the quality of prints, material extrusion 3D printers have often faced a challenge in physical scaling. There are inherent design hurdles to the extrusion process when the print starts to grow larger. This paper aims to study the market landscape of extrusion-based 3D printing technology for polymer-based material as well as challenges faced in upscaling this technology for industrial applications. A prototype large-scale material extrusion 3D printer has been designed, constructed, and then tested to gain experimental data on large-scale 3D printing using thermoplastic polymers as a printing material. Results of testing and experimentation verified certain key design elements and how they can improve large-scale 3D printing. Testing also revealed how large diameter nozzles for the hot end introduce challenges not seen in small-scale 3D printers. This paper also seeks to consolidate available information pertaining to large-scale 3D printing into one comprehensive document.
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