The Experts below are selected from a list of 15453 Experts worldwide ranked by ideXlab platform
Ralph Spolenak - One of the best experts on this subject based on the ideXlab platform.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the...
Stefano Danzi - One of the best experts on this subject based on the ideXlab platform.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the...
Axel T Brunger - One of the best experts on this subject based on the ideXlab platform.
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botulinum neurotoxin b recognizes its protein receptor with high affinity and specificity
Nature, 2006Co-Authors: Andreas Rummel, Thomas Binz, Axel T BrungerAbstract:Botulinum toxins, produced by Clostridia botulinum, are a potential Biological Hazard to humans and a potential bioweapons threat. The toxins are potent inhibitors of neurotransmitter release at synapses, and it is this property that causes the neuroparalytic syndrome known as botulism. Two related papers now report the crystal structure of botulinum toxin B bound to its receptor on the exposed surface of the neuron. This will provide insight into the high affinity and specificity of this interaction, and aid in the development of antibotulism vaccines and drugs. One of two papers that describe how botulinum toxins produced by Clostridium botulinum are potent inhibitors of neurotransmitter release by elucidating the crystal structure of botulinum toxin B bound to its receptor. Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and cause the neuroparalytic syndrome of botulism. With a lethal dose of 1 ng kg-1, they pose a Biological Hazard to humans and a serious potential bioweapon threat1. BoNTs bind with high specificity at neuromuscular junctions and they impair exocytosis of synaptic vesicles containing acetylcholine through specific proteolysis of SNAREs (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors), which constitute part of the synaptic vesicle fusion machinery2,3. The molecular details of the toxin–cell recognition have been elusive. Here we report the structure of a BoNT in complex with its protein receptor: the receptor-binding domain of botulinum neurotoxin serotype B (BoNT/B) bound to the luminal domain of synaptotagmin II, determined at 2.15 A resolution. On binding, a helix is induced in the luminal domain which binds to a saddle-shaped crevice on a distal tip of BoNT/B. This crevice is adjacent to the non-overlapping ganglioside-binding site of BoNT/B. Synaptotagmin II interacts with BoNT/B with nanomolar affinity, at both neutral and acidic endosomal pH. Biochemical and neuronal ex vivo studies of structure-based mutations indicate high specificity and affinity of the interaction, and high selectivity of BoNT/B among synaptotagmin I and II isoforms. Synergistic binding of both synaptotagmin and ganglioside imposes geometric restrictions on the initiation of BoNT/B translocation after endocytosis. Our results provide the basis for the rational development of preventive vaccines or inhibitors against these neurotoxins.
Byron D Goracke - One of the best experts on this subject based on the ideXlab platform.
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ground level ozone following astrophysical ionizing radiation events an additional Biological Hazard
Astrobiology, 2016Co-Authors: Brian Thomas, Byron D GorackeAbstract:Abstract Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional Hazard. Using previously completed atmospheric chemistry modeling, we examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and found that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, incl...
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ground level ozone following astrophysical ionizing radiation events an additional Biological Hazard
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Brian Thomas, Byron D GorackeAbstract:Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to-date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional Hazard. Using previously completed atmospheric chemistry modeling we have examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and find that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, including supernovae and extreme solar proton events.
Volker Schnabel - One of the best experts on this subject based on the ideXlab platform.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.
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architecture independent reactivity tuning of ni al multilayers by solid solution alloying
Applied Physics Letters, 2019Co-Authors: Stefano Danzi, Volker Schnabel, Xuanhe Zhao, J Kach, Ralph SpolenakAbstract:Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the reaction. The results of this study will expand the field of application of reactive multilayers as integrated heat sources, thermal batteries, or microheaters.Reactive multilayers are energetic nanostructures that are able to deliver a large amount of chemical energy via an exothermic reaction. These materials have been a subject of growing interest as they have been shown to provide effective local heat delivery for microscale propulsion or Biological Hazard neutralization. Nonetheless, their use as heat sources remains narrow because of the limits in tuning their intrinsic reactivity without altering their architecture. Here, we propose a method for the adjustment of reaction kinetics in Ni/Al multilayers via solid solution alloying with elements having different reactivities toward aluminum. Nickel layers were alloyed with copper and platinum, resulting in strong modification of the properties of the heat front, temperature, and propagation velocity, while at the same time leaving the multilayer architecture unaltered. This effect hails from a shift in the rate limiting mechanism during intermixing of the reacting species that promotes the propagation of the...