159 research outputs found
Generating Bipolar Nanosecond Pulsed Electric Field using Open Circuit Transmission Line Technique and Avalanche Transistors
Island disaster para-diplomacy in the commonwealth
This chapter covers one particular aspect of the foreign relations of non-sovereign
island jurisdictions (SNIJs), namely relations arising from disaster-related activities.
Islands are among the territories most seriously affected by calamities, including the
spectre of rising seas that may come with climate change. Yet non-sovereign islands
are not so well equipped to speak and act effectively for themselves in the face of such
threats. This may be true even within the governing structures in which these islands
find themselves, but it is even more serious given the weaknesses that may exist in
their capacity to speak to and act in the international community on disaster-related
activities.peer-reviewe
Contextually aware suggestions for online information resources
Novice users often find it challenging to realize the full potential of available information resources. One approach to help such users is to present them with a categorized directory of ranked recommendations for useful information resources, such as apps or websites. However, such a directory may not help discover new resources that can be particularly relevant at specific times based on the user’s current location. This disclosure describes techniques to provide a personalized catalog of suggestions for information resources relevant to a user’s current context, which is obtained with user permission. A personalized catalog of contextual suggestions can help novices broaden their awareness and understanding of available online resources and expose them to a range of tasks that can be accomplished online. In addition to standalone operation, the catalog functionality can be embedded in various commonly used systems and can serve as a mechanism for entities to provide relevant information to individuals in their vicinity
Push–pull configuration of high-power MOSFETs for generation of nanosecond pulses for electropermeabilization of cells
Super-heavy fermion material as metallic refrigerant for adiabatic demagnetization cooling
Low-temperature refrigeration is of crucial importance in fundamental
research of condensed matter physics, as the investigations of fascinating
quantum phenomena, such as superconductivity, superfluidity and quantum
criticality, often require refrigeration down to very low temperatures.
Currently, cryogenic refrigerators with He gas are widely used for cooling
below 1 Kelvin. However, usage of the gas is being increasingly difficult due
to the current world-wide shortage. Therefore, it is important to consider
alternative methods of refrigeration. Here, we show that a new type of
refrigerant, super-heavy electron metal, YbCoZn, can be used for
adiabatic demagnetization refrigeration, which does not require 3He gas. A
number of advantages includes much better metallic thermal conductivity
compared to the conventional insulating refrigerants. We also demonstrate that
the cooling performance is optimized in YbScCoZn by
partial Sc substitution with 0.19. The substitution induces chemical
pressure which drives the materials close to a zero-field quantum critical
point. This leads to an additional enhancement of the magnetocaloric effect in
low fields and low temperatures enabling final temperatures well below 100 mK.
Such performance has up to now been restricted to insulators. Since nearly a
century the same principle of using local magnetic moments has been applied for
adiabatic demagnetization cooling. This study opens new possibilities of using
itinerant magnetic moments for the cryogen-free refrigeration
A structural model for K2P potassium channels based on 23 pairs of interacting sites and continuum electrostatics
K2PØ, the two-pore domain potassium background channel that determines cardiac rhythm in Drosophila melanogaster, and its homologues that establish excitable membrane activity in mammals are of unknown structure. K2P subunits have two pore domains flanked by transmembrane (TM) spans: TM1-P1-TM2-TM3-P2-TM4. To establish spatial relationships in K2PØ, we identified pairs of sites that display electrostatic compensation. Channels silenced by the addition of a charge in pore loop 1 (P1) or P2 were restored to function by countercharges at specific second sites. A three-dimensional homology model was determined using the crystal structure of KV1.2, effects of K2PØ mutations to establish alignment, and compensatory charge–charge pairs. The model was refined and validated by continuum electrostatic free energy calculations and covalent linkage of introduced cysteines. K2P channels use two subunits arranged so that the P1 and P2 loops contribute to one pore, identical P loops face each other diagonally across the pore, and the channel complex has bilateral symmetry with a fourfold symmetric selectivity filter
Mammalian Stem Cells Reprogramming in Response to Terahertz Radiation
We report that extended exposure to broad-spectrum terahertz radiation results in specific changes in cellular functions that are closely related to DNA-directed gene transcription. Our gene chip survey of gene expression shows that whereas 89% of the protein coding genes in mouse stem cells do not respond to the applied terahertz radiation, certain genes are activated, while other are repressed. RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes detail the gene specific effect. The response was not only gene specific but also irradiation conditions dependent. Our findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG). Finally, our molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the THz radiation. We propose that THz radiation is a potential tool for cellular reprogramming
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The 2018 report of the Lancet Countdown on health and climate change: shaping the health of nations for centuries to come
The Lancet Countdown: tracking progress on health and climate change was established to provide an independent, global monitoring system dedicated to tracking the health dimensions of the impacts of, and the response to, climate change. The Lancet Countdown tracks 41 indicators across five domains: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; finance and economics; and public and political engagement. This report is the product of a collaboration of 27 leading academic institutions, the UN, and intergovernmental agencies from every continent. The report draws on world-class expertise from climate scientists, ecologists, mathematicians, geographers, engineers, energy, food, livestock, and transport experts, economists, social and political scientists, public health professionals, and. doctors. The Lancet Countdown’s work builds on decades of research in this field, and was first proposed in the 2015 Lancet Commission on health and climate change,1 which documented the human impacts of climate change and provided ten global recommendations to respond to this public health emergency and secure the public health benefits available (panel 1)
Mechanism based heparanase inhibitors reduce cancer metastasis in vivo
Heparan sulfate proteoglycans (HSPGs) mediate essential interactions throughout the extracellular matrix (ECM), providing signals that regulate cellular growth and development. Altered HSPG composition during tumorigenesis strongly aids cancer progression. Heparanase (HPSE) is the principal enzyme responsible for extracellular heparan sulfate catabolism and is markedly up-regulated in aggressive cancers. HPSE overactivity degrades HSPGs within the ECM, facilitating metastatic dissemination and releasing mitogens that drive cellular proliferation. Reducing extracellular HPSE activity reduces cancer growth, but few effective inhibitors are known, and none are clinically approved. Inspired by the natural glycosidase inhibitor cyclophellitol, we developed nanomolar mechanism-based, irreversible HPSE inhibitors that are effective within physiological environments. Application of cyclophellitol-derived HPSE inhibitors reduces cancer aggression in cellulo and significantly ameliorates murine metastasis. Mechanism-based irreversible HPSE inhibition is an unexplored anticancer strategy. We demonstrate the feasibility of such compounds to control pathological HPSE-driven malignancies.NWO"Endoglycoprobe”714.018.002Bio-organic Synthesi
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