4,328 research outputs found

    Unlocking the potential of RNA interference as a therapeutic tool

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    The existence of an intrinsic biochemical pathway enabling specified regulation of gene expression was unheard of until the final years of the last decade. The identification of ribonucleic acid interference (RNAi) in mammalian cells has nowadays become of extreme importance in the field of functional genomics and translational medicine. The advent of RNAi technology has brought to the scientific research and pharmaceutical communities the ability to regulate expression of any desired gene in a reproducible manner. Consequently, such technology may be utilised in the design of novel therapeutics for clinical conditions having dys-regulated gene expression. Since most RNAi-based therapies in the drug development pipeline of pharmaceutical companies utilise short interfering RNA (siRNA), this review will focus on the role of siRNA in drug development.peer-reviewe

    Electrode for biological recording

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    Electrochemically reversible silver-silver chloride electrode for detecting bioelectric potential differences generated by human muscles and organ

    San Marco D/L solar array system design and performance

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    The design and performance of the solar array system for the San Marco D/L spacecraft is described in detail. The solar array system design is shown to be suitable for spacecraft which have elastically sensitized outer surfaces to measure aerodynamic forces. However, the performance of this solar array system is shown to be at least 30 percent less efficient than conventional spacecraft solar array designs. An on-board experiment to compare the in-flight performances of Si and GaAs solar cell panels is also described. Preflight performance data show that at beginning-of-life, air mass zero solar illumination, 28 C and peak power output the Si panels are at last 20 percent less efficient than the GaAs panels

    Income Taxation--Basis for Depletion Allowance

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    Impact of Senior Service College Education on Naval Officer Promotion

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    In the spring of 1960 some 160 naval officers received orders to attend one of the senior serviette colleges. Commanders were in the majority I but many selectees were already captains. Most were probably surprised, although pleased, with the orders. Surprised because the war college list is one of those closely held document\u27s at the Bureau of Naval Personnel, and pleased because natural reaction is that such orders are indicative of high standing among contemporaries. poraries

    International ultraviolet explorer solar array power degradation

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    The characteristic electrical performance of each International Ultraviolet Explorer (IUE) solar array panel is evaluated as a function of several prevailing variables (namely, solar illumination, array temperature and solar cell radiation damage). Based on degradation in the current-voltage characteristics of the array due to solar cell damage accumulated over time by space charged particle radiations, the available IUE solar array power is determined for life goals up to 10 years. Best and worst case calculations are normalized to actual IUE flight data (available solar array power versus observatory position) to accurately predict the future IUE solar array output. It is shown that the IUE solar array can continue to produce more power than is required at most observatory positions for at least 5 more years

    The Importance of Pulsed Physical Events for Sustainability of Louisiana Coastal Forested Wetlands

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    A number of freshwater diversions from the Mississippi River into Louisiana’s coastal wetlands are currently in operation or in the planning stage. These diversions have multiple objectives including maintaining a desirable salinity gradient, restoring deteriorating wetlands, and enhancing fisheries. The extensive freshwater forested wetlands surrounding the western end of Lake Pontchartrain receive little or no sediment input and are currently deteriorating due to continuous flooding. Diverting nutrient-rich water through wetlands can lead to substantial nutrient removal and to enhanced accretion. The objective of this paper is to compare the impacts on freshwater wetland ecology, accretion, and water quality of several scenarios for diverting freshwater from the Mississippi River. Accretion will be increased so that the area will become progressively less flooded, enhancing productivity and seedling recruitment. With overland flow, about 73% of N and 48% of P will be retained in the wetland, while other alternatives are estimated to remove 0-33% of N and 0-40% of P. Productivity of the forested wetland will decrease by at least 20-50% over the next 50 years if nothing is done, but there would be a substantial increase in productivity if river water is diverted into the area. We recommend that a 45-55 m3/s diversion be placed in the southern portion of the swamps of Lake Maurepas and that the diversion be operated annually from winter to early spring. There are indications that a diversion in late summer and fall would be beneficial, as that is when salt pulses typically occur

    Developing Controlled Conductive Boundaries for JWST Cryogenic Testing

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    In 2017, the James Webb Space Telescope (JWST) underwent functional testing and optical metrology verification of the combined Optical Telescope Element and Integrated Science Instrument Module (OTIS) under cryogenic vacuum conditions in Chamber A at the Johnson Space Center. Maintaining flight-like thermal boundary conditions was a critical requirement for optical testing and required unique and challenging Ground Support Equipment (GSE) design solutions. Two such GSE systems, the Integrated Science Instrument Module (ISIM) Precool Straps and the Hardpoint Struts were direct conduction interfaces to the flight hardware. Hardware safety during cooldown required detailed design of their conductivity, and thermal balance testing required "zero-Q" (0-Q) heater implementation to bring the heat flow to zero, thereby cutting off these non-flight conductive links after operating temperatures were achieved. This paper describes the design considerations and approach implemented to achieve the required flight hardware cool down and return to ambient conditions, ensure flight hardware safety, and minimize the non-flight-like heat flows to or from the observatory during cryo-stable testing
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