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Comparison of Reflective Properties of Materials Exposed to Ultraviolet-C Radiation
No full textThe reflectivity of material lining the inside of a disinfection chamber can have a dramatic effect on the ultraviolet-C (UV-C) radiation dose received across all sides of a contaminated object. Because minimum UV-C dosages are required to reliably inactivate microorganisms, it is crucial for the disinfection chamber to have either multiple UV-C sources or a highly reflective internal surface. This article describes an experimental comparison of four different materials, polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene, silver gloss self-adhesive aluminum, and Rosco matte black Cinefoil, to determine their efficacy as UV-C reflectors by using a custom-designed testing apparatus utilizing a UV-C radiation-emitting diode alongside photochromic UV-C indicators, allowing for a full 360� analysis of a target object and its received UV-C dose. Results determined that UV-C radiation received at the photochromic indicators varied greatly among the chosen materials, with PTFE providing the most uniform levels of radiation across all sides of the test object
Dataset from HDX-MS Studies of IgG1 Glycoforms and Their Interactions with the Fc__RIa (CD64) Receptor
No full text(Unedited Transcript) NIST Oral History Interview about the Boulder Microfabrication (Cleanroom) Facility - June 24, 2021
No full textNote: this transcript is unedited. Current and former NIST employees gathered on June 24, 2021, to share an oral history interview about NIST's Microfabrication (Cleanroom) in Boulder, Colorado. Those recorded for this oral history included Jim Beall, Richard (Dick) Harris, Don McDonald, Richard (Dick) Kautz, Clark Hamilton, Robert (Bob) Phelan, Jr., Dave Redmund. Rebecca Jacobson of the NIST Boulder Public Affairs Office faclitated the interview
SARS-CoV-2 Ultraviolet Radiation Dose-Response Behavior
No full textUltraviolet (UV) radiation in the wavelength range 200 nm � _ � 320 nm, which includes both the UV-C and UV-B portions of the spectrum, is known to be effective for inactivation of a wide range of microbial pathogens, including viruses. Previous research has indicated UV-C radiation to be effective for inactivation of severe acute respiratory syndrome coronavirus (SARS-CoV), the virus that caused an outbreak of SARS in 2003. Given the structural similarities of SARS-CoV and SARS-CoV-2, the cause of coronavirus disease 2019 (COVID-19), it is anticipated that UV radiation should be effective for inactivation of SARS-CoV-2 too. Recently published data support this assertion, but only for a narrow set of exposure and matrix conditions. Models based on genomic and other characteristics of viruses have been developed to provide predictions of viral inactivation responses to UV exposure at _ = 254 nm. The predictions of these models are consistent with reported measurements of viral inactivation, including for SARS-CoV-2. As such, current information indicates that UV-C irradiation should be effective for control of SARS-CoV-2, as well as for control of other coronaviruses; however, additional research is needed to quantify the effects of several important process variables, including the wavelength of radiation, the effects of relative humidity on airborne and surface-associated viruses, and the effects of the medium of exposure
DNA Origami Design: A How-To Tutorial
No full textWhile the design and assembly of DNA origami are straightforward, its relative novelty as a nanofabrication technique means that the tools and methods for designing new structures have not been codified as well as they have for more mature technologies, such as integrated circuits. While design approaches cannot be truly formalized until design-property relationships are fully understood, this document attempts to provide a step-by-step guide to designing DNA origami nanostructures using the tools available at the current state of the art
Decision Tree for Key Comparisons
No full textThis contribution describes a Decision Tree intended to guide the selection of statistical models and data reduction procedures in key comparisons (KCs). The Decision Tree addresses a specific need of the Inorganic Analysis Working Group (IAWG) of the Consultative Committee (CC) for Amount of Substance, Metrology in Chemistry and Biology (CCQM), of the International Committee for Weights and Measures (CIPM), and it is likely to address similar needs of other working groups and consultative committees. Because the portfolio of KCs previously organized by the CCQM-IAWG affords a full range of opportunities to demonstrate the capabilities of the Decision Tree, the majority of the illustrative examples of application of the Decision Tree are from this working group. However, the Decision Tree is widely applicable in other areas of metrology, as illustrated in examples of application to measurements of radionuclides and of the efficiency of a thermistor power sensor. The Decision Tree is intended for use after choices will have been made about the measurement results that qualify for inclusion in the calculation of the key comparison reference value (KCRV), and about the measurement results for which degrees of equivalence should be produced. Both these choices should be based on substantive considerations, not on purely statistical criteria. However, the Decision Tree does not require that the measurement results selected for either purpose be mutually consistent. The Decision Tree should be used as a guide, not as the sole and autonomous determinant of the model that should be selected for the measurement results obtained in a KC, or of the procedure that should be employed to reduce these results. The scientists running the KCs ultimately have the freedom and responsibility to make the corresponding choices that they deem most appropriate and that best fit the purpose of each KC. The Decision Tree involves three statistical tests, and comprises five terminal leaves, which correspond to as many alternative ways in which the KCRV, its associated uncertainty, and the degrees of equivalence (DoEs) may be computed. This contribution does not purport to suggest that any of the KCRVs, associated uncertainties, or DoEs, presented in previously approved final reports issued by working groups of the CCs should be modified. Neither do the alternative results question existing, demonstrated calibration and measurement capabilities (CMCs), nor do they support any new CMCs
Encounter Metrics and Exposure Notification
No full textWe discuss the measurement of aggregate levels of encounters in a population, a concept we call encounter metrics. Encounter metrics are designed so that they can be deployed while preserving the privacy of individuals. To this end, encounters are labeled with a random number that cannot be linked to anything that is broadcast at the time of the encounter. Among the applications of encounter metrics is privacy-preserving exposure notification, a system that allows people to obtain a measure of their risk due to past encounters with people who have self-reported to be positive with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-19), the cause of coronavirus disease 2019 (COVID-19). The precise engineering of a system for exposure notification should be targeted to particular environments. We outline a system for use in the context of a workplace such as the National Institute of Standards and Technology (NIST)
Methods and Mechanisms of Photonic Disinfection
No full textHealthcare-associated infections (HAIs) are a growing social and economic problem in the United States. A HAI is an infection that develops as a result of medical care and is typically contracted in a hospital, outpatient surgery center, nursing home, rehabilitation facility, or while receiving wound care services. One new tool to fight the increasing threat of HAIs is photonic disinfection (optical light-based disinfection). Photonic disinfection of air, surfaces, and liquids has witnessed rapid adoption within many industries (e.g., drinking water purification, wastewater treatment, indoor air purification) over the past 20 years. More recently, light-based disinfection technologies have started to make their way into hospitals, clinics, and medical centers to aid in the disinfection of air and surfaces. Two photonic disinfection methods of interest are the use of ultraviolet-C wavelengths (200 nm to 280 nm) and blue wavelengths (400 nm to 420 nm). These wavelengths of interest have been proven to be effective disinfection tools and should be put into use to augment traditional infection-prevention techniques."
NIST Oral History Interview about the Boulder Microfabrication (Cleanroom) Facility - June 24, 2021
No full textCurrent and former NIST employees gathered on June 24, 2021, to share an oral history interview about NIST's Microfabrication (Cleanroom) in Boulder, Colorado. Those recorded for this oral history included Jim Beall, Richard (Dick) Harris, Don McDonald, Richard (Dick) Kautz, Clark Hamilton, Robert (Bob) Phelan, Jr., Dave Redmund. Rebecca Jacobson of the NIST Boulder Public Affairs Office faclitated the interview. Note: The interview transcript has not been edited
Oral History Interview of Robin "Tuck" Stebbins, July 6, 2021
No full textRobin “Tuck” Stebbins discusses his involvement in the Poor Man mine located west of Boulder, CO. Dr. Stebbins was a graduate student at the Joint Institute of Laboratory Astrophysics from 1970 to 1973. He then worked at the National Solar Observatory and in the Physics Department at the University of Colorado/Boulder. In 2001 he became a Senior Research Scientist for NASA at the Goddard Space Flight Center. He describes his involvement in the research done with the laser interferometer located in the Poor Man mine. He explains the significance of that research and the many developments that subsequently evolved from that project