WorldWideScience

Sample records for 510k bk080002 eprogesa

  1. 75 FR 4402 - Strengthening the Center for Devices and Radiological Health's 510(k) Review Process; Public...

    Science.gov (United States)

    2010-01-27

    ... advantages and disadvantages of each of these practices, as related to the quality and timeliness of 510(k... should address only one discussion topic. FDA will do its best to accommodate requests to speak... devices, (2) issues related to new technologies and scientific evidence, (3) issues related to practices...

  2. 76 FR 45825 - Center for Devices and Radiological Health 510(k) Clearance Process; Institute of Medicine Report...

    Science.gov (United States)

    2011-08-01

    ... Process; Institute of Medicine Report: ``Medical Devices and the Public's Health, The FDA 510(k) Clearance... Medicine (IOM) report entitled: ``Medical Devices and the Public's Health, The FDA 510(k) Clearance Process.... ADDRESSES: See the SUPPLEMENTARY INFORMATION section for electronic access to the document....

  3. 76 FR 81510 - Draft Guidance for Industry and Food and Drug Administration Staff; the 510(k) Program...

    Science.gov (United States)

    2011-12-28

    ... titled ``The New 510(k) Paradigm--Alternate Approaches to Demonstrating Substantial Equivalence in...) Paradigm Guidance. FDA recognizes and supports efforts for global convergence of regulatory systems, and in... draft guidance, when finalized, will represent the Agency's current thinking on the 510(k) decision...

  4. 78 FR 100 - Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for 510(k)s...

    Science.gov (United States)

    2013-01-02

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for 510(k)s; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of the...

  5. Direct Determination of the Rate Coefficient for the Reaction of OH Radicals with Monoethanol Amine (MEA) from 296 to 510 K.

    Science.gov (United States)

    Onel, L; Blitz, M A; Seakins, P W

    2012-04-05

    Monoethanol amine (H2NCH2CH2OH, MEA) has been proposed for large-scale use in carbon capture and storage. We present the first absolute, temperature-dependent determination of the rate coefficient for the reaction of OH with MEA using laser flash photolysis for OH generation, monitoring OH removal by laser-induced fluorescence. The room-temperature rate coefficient is determined to be (7.61 ± 0.76) × 10(-11) cm(3) molecule(-1) s(-1), and the rate coefficient decreases by about 40% by 510 K. The temperature dependence of the rate coefficient is given by k1= (7.73 ± 0.24) × 10(-11)(T/295)(-(0.79±0.11)) cm(3) molecule(-1) s(-1). The high rate coefficient shows that gas-phase processing in the atmosphere will be competitive with uptake onto aerosols.

  6. 78 FR 26786 - 510(k) Device Modifications: Deciding When To Submit a 510(k) for a Change to an Existing Device...

    Science.gov (United States)

    2013-05-08

    ... and resolve the following concerns. 1. Risk Management is a Process--Published risk management... Ways to do Risk Management--FDA's risk analysis process is described in the preamble to 21 CFR part 820.... Although FDA's risk analysis process is similar to some documented risk management processes, there are...

  7. 76 FR 50230 - Center for Devices and Radiological Health 510(k) Clearance Process; Recommendations Proposed in...

    Science.gov (United States)

    2011-08-12

    ... public meeting will be held at the Silver Spring Hilton Hotel, 8727 Colesville Rd., Silver Spring, MD....gov . Submit written comments to the Division of Dockets Management (HFA-305), Food and Drug... Division of Dockets Management between 9 a.m. and 4 p.m., Monday through Friday. SUPPLEMENTARY INFORMATION...

  8. 78 FR 14097 - Pulse Oximeters-Premarket Notification Submissions [510(k)s]; Guidance for Industry and Food and...

    Science.gov (United States)

    2013-03-04

    ... HUMAN SERVICES Food and Drug Administration Pulse Oximeters--Premarket Notification Submissions... availability of the guidance entitled ``Pulse Oximeters--Premarket Notification Submissions .'' This guidance document pertains to non-invasive pulse oximeters intended for prescription use to measure arterial...

  9. 21 CFR 878.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  10. 21 CFR 874.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  11. 21 CFR 864.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  12. 21 CFR 882.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  13. 21 CFR 890.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  14. 21 CFR 880.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  15. 21 CFR 884.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  16. 21 CFR 872.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  17. 21 CFR 892.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  18. 21 CFR 870.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  19. 21 CFR 866.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  20. 21 CFR 886.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  1. 21 CFR 862.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... deficiency syndrome (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor... intended: (1) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired...

  2. 21 CFR 888.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  3. 21 CFR 868.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk of... immunoassay technology; or (c) The device is an in vitro device that is intended: (1) For use in the diagnosis... use in screening or diagnosis of familial or acquired genetic disorders, including inborn errors...

  4. 21 CFR 876.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4...) For use in the diagnosis, monitoring, or screening of neoplastic diseases with the exception of immunohistochemical devices; (2) For use in screening or diagnosis of familial or acquired genetic...

  5. #DDOD: Establishment Registration & Device Listing

    Data.gov (United States)

    U.S. Department of Health & Human Services — SUMMARY DDOD use case to request means on consolidating multiple data sources (MDR, PMA, 510(k), R&L) in order to build a list of all marketed medical devices....

  6. 78 FR 73553 - Prospective Grant of Exclusive License: Development of Cripto-1 Point of Care (POC) Tests and...

    Science.gov (United States)

    2013-12-06

    ... 510K cleared Point of Care (POC) tests and kits for the purpose of disease state recognition, detection..., pancreas, stomach, gallbladder, breast, lung, endometrium and cervix. Current methodologies of...

  7. Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically GuidedFeeding Tube

    Science.gov (United States)

    2017-06-01

    pneumonias. Tube placement does not require costly fluroscopy or endoscopy. Any nurse who can place a nasogastric tube can place this feeding tube without...time required to secure FDA 510K 160787 clearance. FDA clearance was awarded August 9, 2016 for 510K160787 Table of Contents I. Introduction...small bowel feeding tube and developing a smaller version of the technology (8 Fr.). The basic design of the technology is to provide an easy and

  8. Orthopaedic Device Approval Through the Premarket Approval Process: A Financial Feasibility Analysis for a Single Center.

    Science.gov (United States)

    Yang, Brian W; Iorio, Matthew L; Day, Charles S

    2017-03-15

    The 2 main routes of medical device approval through the U.S. Food and Drug Administration are the premarket approval (PMA) process, which requires clinical trials, and the 510(k) premarket notification, which exempts devices from clinical trials if they are substantially equivalent to an existing device. Recently, there has been growing concern regarding the safety of devices approved through the 510(k) premarket notification. The PMA process decreases the potential for device recall; however, it is substantially more costly and time-consuming. Investors and medical device companies are only willing to invest in devices if they can expect to recoup their investment within a timeline of roughly 7 years. Our study utilizes financial modeling to assess the financial feasibility of approving various orthopaedic medical devices through the 510(k) and PMA processes. The expected time to recoup investment through the 510(k) process ranged from 0.585 years to 7.715 years, with an average time of 2.4 years; the expected time to recoup investment through the PMA route ranged from 2.9 years to 24.5 years, with an average time of 8.5 years. Six of the 13 orthopaedic device systems that we analyzed would require longer than our 7-year benchmark to recoup the investment costs of the PMA process. With the 510(k) premarket notification, only 1 device system would take longer than 7 years to recoup its investment costs. Although the 510(k) premarket notification has demonstrated safety concerns, broad requirements for PMA authorization may limit device innovation for less-prevalent orthopaedic conditions. As a result, new approval frameworks may be beneficial. Our report demonstrates how current regulatory policies can potentially influence orthopaedic device innovation.

  9. 78 FR 14015 - Medical Devices; Exemption From Premarket Notification; Class II Devices; Powered Patient Transport

    Science.gov (United States)

    2013-03-04

    ... chairs (which are different from wheelchairs) continue to require submission of 510(k)s. FDA is... known as stairway chair lifts. These devices are used to assist in the transfer of a person with a... stairway chair lifts, class II devices, from premarket notification and establishes conditions for...

  10. 77 FR 71173 - Proposed Collection; Comment Request

    Science.gov (United States)

    2012-11-29

    ... Corporation's ] HCLL TM (Transfusion) and KnowledgeTrak TM (Learning Management). BMBB/TS is an effort... Devices. The EBMS Mediware Corporation developed COTS are FDA 510K cleared Medical Devices that provides... blood donors (both in-house and at mobile collection sites), manage blood products both fresh and...

  11. Structural studies of disordered Mg2NiH4 formed by mechanical grinding

    DEFF Research Database (Denmark)

    Rönnebro, Ewa; Jensen, Jens Oluf; Noréus, Dag;

    1999-01-01

    The low temperature phase of Mg2NiH4 was mechanically ground in argon atmosphere. The ordered monoclinic structure was destroyed to form the disordered cubic structure, previously only found above 510 K. With a Guinier-Hagg X-ray camera the cell parameter was determined to be a=6.492(3) Angstrom....

  12. 77 FR 48159 - Draft Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for...

    Science.gov (United States)

    2012-08-13

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for 510(k)s; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of...

  13. 21 CFR 870.3450 - Vascular graft prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular graft prosthesis. 870.3450 Section 870... prosthesis. (a) Identification. A vascular graft prosthesis is an implanted device intended to repair... Prostheses 510(k) Submissions.”...

  14. 76 FR 7220 - Medical Device Innovation Initiative; Request for Comments

    Science.gov (United States)

    2011-02-09

    ... timely access to important new technologies and next-generation products without compromising their... suffering, treat previously untreatable conditions, extend lives, and improve public health. CDRH is... 510(k) program--and increase its use of emerging science to foster innovation and improve...

  15. Medical devices; exemption from premarket notification; class II devices; wheelchair elevator. Final order.

    Science.gov (United States)

    2013-03-04

    The Food and Drug Administration (FDA) is publishing an order granting a petition requesting exemption from premarket notification requirements for wheelchair elevator devices commonly known as inclined platform lifts and vertical platform lifts. These devices are used to provide a means for a person with a mobility impairment caused by injury or other disease to move from one level to another, usually in a wheelchair. This order exempts wheelchair elevators, class II devices, from premarket notification and establishes conditions for exemption for this device that will provide a reasonable assurance of the safety and effectiveness of the device without submission of a premarket notification (510(k)). This exemption from 510(k), subject to these conditions, is immediately in effect for wheelchair elevators. All other devices classified under FDA's wheelchair elevator regulations, including attendant-operated stair climbing devices for wheelchairs and portable platform lifts, continue to require submission of 510(k)s. FDA is publishing this order in accordance with the section of the Food, Drug, and Cosmetic Act (the FD&C Act) permitting the exemption of a device from the requirement to submit a 510(k).

  16. Dosimetric characteristics of ultraviolet and x-ray-irradiated KBr:Eu{sup 2+} thermoluminescence crystals

    Energy Technology Data Exchange (ETDEWEB)

    Melendrez, R.; Perez-Salas, R. [Programa de Posgrado en Fisica de Materiales, Centro de Investigacion, Cientifica y de Educacion Superior de Ensenada, Apartado Postal 2681, Ensenada, Baja California, 22800 (Mexico); Aceves, R.; Piters, T.M.; Barboza-Flores, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora, 83190 (Mexico)

    1996-08-01

    Thermoluminescence (TL) characteristics of KBr:Eu{sup 2+} (150 ppm) previously exposed to ultraviolet (UV) light (200{endash}300 nm) and x-ray radiation at room temperature have been determined. The TL glow curve of UV-irradiated samples is composed of six peaks located at 337, 384, 402, 435, 475, and 510 K. The TL glow curves of x-irradiated samples show mainly a TL peak around 384 K. The TL intensities of UV-irradiated (402 and 510 K glow peaks) and x-irradiated specimens present a linear dependence as a function of radiation dose as well as fading stability 300 s after irradiation. These results further enhance the possibilities of using europium-doped materials in nonionizing (actinic region) and ionizing radiation detection and dosimetry applications. {copyright} {ital 1996 American Institute of Physics.}

  17. 美国FDA对医疗器械标识的要求%FDA Labeling Requirements for Medical Devices

    Institute of Scientific and Technical Information of China (English)

    马琳榕; 甄辉

    2006-01-01

    分析了标识对医疗器械的重要性,介绍了美国FDA对医疗器械标识的要求,包括通用要求以及对体外诊断试剂产品、临床研究用器械、510(K)、GMP、以及辐射类器械的特定要求.

  18. Medicolegal issues surrounding devices and mesh for surgical treatment of prolapse and incontinence.

    Science.gov (United States)

    Nosti, Patrick A; Iglesia, Cheryl B

    2013-06-01

    Legal issues related to vaginal mesh devices for prolapse and incontinence include abnormal injury and inadequate informed consent. Although vaginal mesh devices are currently cleared through the 510(k) process, new developments at the US Food and Drug Administration requiring additional postmarket studies (522 studies) for transvaginal mesh for prolapse and mini-suburethral synthetic slings have been issued to ensure product safety and effectiveness. New initiatives including unique device identification numbers and the Pelvic Floor Disorders Registry have been developed to improve surveillance throughout the total product/device life cycle.

  19. Innovating in the medical device industry - challenges & opportunities ESB 2015 translational research symposium.

    Science.gov (United States)

    Bayon, Y; Bohner, M; Eglin, D; Procter, P; Richards, R G; Weber, J; Zeugolis, D I

    2016-09-01

    The European Society for Biomaterials 2015 Translational Research Symposium focused on 'Innovating in the Medical Device Industry - Challenges & Opportunities' from different perspectives, i.e., from a non-profit research organisation to a syndicate of small and medium-sized companies and large companies. Lecturers from regulatory consultants, industry and research institutions described the innovation process and regulatory processes (e.g., 510K, PMA, combination product) towards market approval. The aim of the present article is to summarise and explain the main statements made during the symposium, in terms of challenges and opportunities for medical device industries, in a constantly changing customer and regulatory environment.

  20. Modeling and simulation of a residential micro-CHP system based on HT-PEMFC technology

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    Combined-heat-and-power (CHP) technology is a well known and proved method to produce simultaneously power and heat at high efficiencies. This can be further improved by the introduction of a novel micro-CHP residential system based on High Temperature-Proton Exchange Membrane Fuel Cell (HT......-PEMFC). The HT-PEMFC (based on PBI-membrane technology) operates at temperatures near 200oC, and this can be an ideal match for cogeneration residential systems. The proposed system provides electric power, hot water, and space heating for a typical household (1-5 kWe, 5-10 kWth). The micro-CHP system...

  1. Superconductivity in novel Ge-based skutterudites: {Sr,Ba}pt4Ge12.

    Science.gov (United States)

    Bauer, E; Grytsiv, A; Chen, Xing-Qiu; Melnychenko-Koblyuk, N; Hilscher, G; Kaldarar, H; Michor, H; Royanian, E; Giester, G; Rotter, M; Podloucky, R; Rogl, P

    2007-11-23

    Combining experiments and ab initio models we report on SrPt4Ge12 and BaPt4Ge12 as members of a novel class of superconducting skutterudites, where Sr or Ba atoms stabilize a framework entirely formed by Ge atoms. Below T(c)=5.35 and 5.10 K for BaPt4Ge12 and SrPt4Ge12, respectively, electron-phonon coupled superconductivity emerges, ascribed to intrinsic features of the Pt-Ge framework, where Ge-p states dominate the electronic structure at the Fermi energy.

  2. New treatments for restoring impaired epidermal barrier permeability: skin barrier repair creams.

    Science.gov (United States)

    Draelos, Zoe Diana

    2012-01-01

    Skin health depends on an intact barrier composed of protein-rich corneocytes surrounded by the lamellar intercellular lipids. This barrier provides waterproof protection for the body, preventing infection, regulating electrolyte balance, maintaining body temperature, and providing a mechanism for sensation. Damage to the skin barrier results in skin disease that can be treated by a variety of externally applied substances, such as ceramides, hyaluronic acid, licorice extracts, dimethicone, petrolatum, and paraffin wax. These substances are found in moisturizers that are sold as cosmetics and in prescriptions as 510(k) devices. This contribution examines the formulation and effect of skin barrier creams.

  3. Hardware/Software Issues for Video Guidance Systems: The Coreco Frame Grabber

    Science.gov (United States)

    Bales, John W.

    1996-01-01

    The F64 frame grabber is a high performance video image acquisition and processing board utilizing the TMS320C40 and TMS34020 processors. The hardware is designed for the ISA 16 bit bus and supports multiple digital or analog cameras. It has an acquisition rate of 40 million pixels per second, with a variable sampling frequency of 510 kHz to MO MHz. The board has a 4MB frame buffer memory expandable to 32 MB, and has a simultaneous acquisition and processing capability. It supports both VGA and RGB displays, and accepts all analog and digital video input standards.

  4. Response of the middle atmosphere to the geomagnetic storm of November 2004

    Science.gov (United States)

    Hocke, Klemens

    2017-02-01

    Ozone and temperature profiles of the satellite microwave limb sounder Aura/MLS are used for the derivation of the middle atmospheric response to the geomagnetic superstorm of 9 November 2004. We find a destruction of the tertiary ozone layer at 0.022 hPa (77 km) in the northern winter hemisphere lasting for about one week. This effect is surely due to the solar proton event (SPE) of November 2004. At the same time, the zonal mean temperature is enhanced by 5-10 K in the northern polar mesosphere. On the other hand, the zonal mean temperature is decreased by 5-10 K in the northern polar stratosphere. We do not think that the strong temperature perturbations are directly related to the SPE. It seems that the polar vortex was moved by the geomagnetic storm, and this vortex movement caused the strong temperature variations in the zonal mean. However, internal variability of temperature in the polar middle atmosphere in winter without any significant link to the geomagnetic storm cannot be excluded.

  5. Nanofocus: an ultra-miniature dense pinch plasma focus device with submillimetric anode operating at 0.1 J

    Energy Technology Data Exchange (ETDEWEB)

    Soto, Leopoldo; Pavez, Cristian; Moreno, Jose [Comision Chilena de Energia Nuclear, Casilla 188-D, Santiago (Chile); Barbaglia, Mario; Clausse, Alejandro [CNEA-CONICET and Universidad Nacional del Centro, 7000 Tandil (Argentina)], E-mail: lsoto@cchen.cl

    2009-02-01

    As a method for investigating the minimum energy to produce a pinch plasma focus (PF) discharge, an ultra-miniature device for pinch discharges has been designed, constructed and characterized (nanofocus (NF): 5 nF, 5-10 kV, 5-10 kA, 60-250 mJ, 16 ns time to peak current). Submillimetric anode radii (0.8 and 0.21 mm) covered by coaxial insulators were used for experiments in hydrogen. Evidence of pinch was observed in electrical signals in discharges operating at 3 mbar and {approx}100 mJ. A single-frame image converter camera (4 ns exposure) was used to obtain plasma images in the visible range. The dynamics observed from the photographs is consistent with (a) the formation of a plasma sheath close to the insulator surface, (b) the plasma covering the anode, (c) radial compression over the anode; (d) finally the plasma is detached from the anode in the axial direction. The total time from stages (a) to (d) was observed in {approx}30 ns. This ultra-miniature device has a value for the 'plasma energy density parameter' and for the 'drive parameter' of the same order or greater than PF devices operating at energies several orders of magnitude higher.

  6. Nanofocus of tenth of joules and a portable plasma focus of few joules for field applications

    Science.gov (United States)

    Soto, Leopoldo; Pavéz, Cristian; Moreno, José; Tarifeño, Ariel; Pedreros, José; Altamirano, Luis

    2009-01-01

    A repetitive pinch plasma focus that works with stored energy less than 1 J per shot has be developed at the Chilean Nuclear Energy Commission. The main features of this device, repetitive Nanofocus, are 5 nF of capacity, 5 nH of inductance, 5-10 kV charging voltage, 60-250 mJ stored energy, 5-10 kA current peak, per shot. The device has been operated at 20 Hz in hydrogen and deuterium. X-ray radiographs of materials of different thickness were obtained. Neutrons were detected using a system based upon 3He proportional counter in chare integrated mode. However, the reproducibility of this miniaturized device is low and several technological subjects have to be previously solved in order to produce neutrons for periods greater than minutes. Further studies in the Nanofocus are being carried out. In addition, a device with a stored energy of a few joules is being explored. A preliminary compact, low weight (3 kg), portable PF device (25 cm×5 cm×5 cm) for field applications has been designed. This device was designed to operate with few kilovolts (10 kV or less) with a stored energy of 2 J and a repetition rate of 10 Hz without cooling. A neutron flux of the order of 104-105 n/s is expected.

  7. Medical devices: US medical device regulation.

    Science.gov (United States)

    Jarow, Jonathan P; Baxley, John H

    2015-03-01

    Medical devices are regulated by the US Food and Drug Administration (FDA) within the Center for Devices and Radiological Health. Center for Devices and Radiological Health is responsible for protecting and promoting the public health by ensuring the safety, effectiveness, and quality of medical devices, ensuring the safety of radiation-emitting products, fostering innovation, and providing the public with accurate, science-based information about the products we oversee, throughout the total product life cycle. The FDA was granted the authority to regulate the manufacturing and marketing of medical devices in 1976. It does not regulate the practice of medicine. Devices are classified based on complexity and level of risk, and "pre-1976" devices were allowed to remain on the market after being classified without FDA review. Post-1976 devices of lower complexity and risk that are substantially equivalent to a marketed "predicate" device may be cleared through the 510(k) premarket notification process. Clinical data are typically not needed for 510(k) clearance. In contrast, higher-risk devices typically require premarket approval. Premarket approval applications must contain data demonstrating reasonable assurance of safety and efficacy, and this information typically includes clinical data. For novel devices that are not high risk, the de novo process allows FDA to simultaneously review and classify new devices. Devices that are not legally marketed are permitted to be used for clinical investigation purposes in the United States under the Investigational Device Exemptions regulation.

  8. High-Temperature Thermochemical Storage with Redox-Stable Perovskites for Concentrating Solar Power, CRADA Number: CRD-14-554

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-05

    As part of a Federal Opportunity Announcement (FOA) Award, the project will be led by Colorado School of Mines (CSM) to explore and demonstrate the efficacy of highly reducible, redox-stable oxides to provide efficient thermochemical energy storage for heat release at temperatures of 900 degrees Celcius or more. NREL will support the material development for its application in a concentrating solar power (CSP) plant. In the project, NREL will provide its inventive system design, chemical looping for CSP, and use it as a platform to accommodate the chemical processes using a cost effective perovskite materials identified by CSM. NREL will design a 5-10kW particle receiver for perovskite reduction to store solar energy and help the development of a fluidized-bed reoxidation reactor and system integration. NREL will develop the demonstration receiver for on-sun test in the 5-10 kWt range in NREL's high flux solar furnace. NREL will assist in system analysis and provide techno-economic inputs for the overall system configuration.

  9. An ultra miniature pinch-focus discharge

    Energy Technology Data Exchange (ETDEWEB)

    Soto, L.; Pavez, C.; Moreno, J. [Comision Chilena de Energia Nuclear, Santiago (Chile); Pavez, C. [Universidad de Concepcion (Chile); Barbaglia, M.; Clausse, A. [Universidad Nacional del Centro, Pladema-CNEA-Conicet, Tandil (Argentina)

    2004-07-01

    As a way to investigate the minimum energy to produce a pinch plasma focus discharge, an ultra miniature device has been designed and constructed (nano focus NF: 5 nF, 5-10 kV, 5-10 kA, 60-250 mJ, 16 ns time to peak current). Sub-millimetric anode radius covered by a coaxial insulator were used for experiments in hydrogen. Evidence of pinch was observed in electrical signals in discharges operating at 60 mJ. A single-frame image converter camera (4 ns exposure) was used to obtain plasma images in the visible range. The dynamics observed from the photographs is consistent with: a) formation of a plasma sheath close to the insulator surface, b) fast axial motion of the plasma sheath, c) radial compression over the anode, and d) finally the plasma is detached from the anode in the axial direction. The total time since stage a) to d) was observed to be about 30 ns. X ray and neutron emission is being studied. Neutron yield of the order of 10{sup 3} neutrons per shot is expected for discharges operating in deuterium at 10 kA. (authors)

  10. Ferromagnetism and crystalline electric field effects in cubic UX2Zn20 (X=Co, Rh, Ir)

    Science.gov (United States)

    Bauer, E. D.; Thompson, J. D.; Sarrao, J. L.; Hundley, M. F.

    2007-03-01

    The physical properties of a new family of cubic UX2Zn20 (X=Co, Rh, Ir) heavy-fermion compounds are presented. Both UCo2Zn20 and URh2Zn20 show peaks in specific heat and magnetic susceptibility at ˜5-10 K suggesting the presence of crystalline electric field (CEF) effects in these materials, i.e., a localized 5f2 configuration of uranium. UIr2Zn20 exhibits a first-order ferromagnetic transition at Tc=2.1 K with a saturation moment μsat=0.4 μB at 2 K indicating itinerant ferromagnetism. All compounds in this series are heavy-fermion materials with enhanced electronic specific heat coefficients γ˜100-450 mJ/mol K2.

  11. Patient and healthcare professional satisfaction with a new, high accuracy blood glucose meter with color range indicator and wireless connectivity.

    Science.gov (United States)

    Katz, Laurence B; Grady, Mike; Stewart, Lorna; Cameron, Hilary

    2016-07-01

    Accurate self-monitoring of blood glucose is a key component of effective self-management of glycemic control. The OneTouch VerioFlex(™) (OTVF) blood glucose monitoring system (BGMS) was evaluated for accuracy in a clinical setting. Patients also used OTVF for a 1-wk trial period and reported their level of satisfaction with meter features. In a separate study, healthcare professionals used an on-line simulator of the BGMS and answered questions about its potential utility to their patients. OTVF was accurate over a wide glucose range and met lay user and system accuracy blood glucose standards described in ISO15197:2013 as well as the accuracy requirements to fulfill US FDA expectations for 510(k) clearance of BGMS. Patients and healthcare professionals felt the features of OTVF, which has the capability to connect wirelessly to mobile devices and interact wirelessly with diabetes management software, could provide significant benefits to them or their patients.

  12. 福特GT:压力及动力

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    福特GT强大吗?没人会怀疑超过370kW的轰鸣不为你带来纯粹的美国肌肉式的感受。但是有些人不满足于原装动力,为这款5.4L的发动机装上机械增压,并鼓作气的将功率升华到510kW的境界。改装工作由Geiger、Cars主持完成,成效显著。百公里加速3.5s,四分之一英里冲刺仅需10.9s。这无疑是款完美的速度机器。

  13. An industry update: what is new in the field of therapeutic delivery this month?

    Science.gov (United States)

    Harris, Elaine

    2017-01-01

    The present industry update covers the period of 1-30 November 2016, with information sourced primarily from company press releases, regulatory and patent agencies, scientific literature and various news websites. There was positive news on the clinical trials front for both EyeNovia and Glaxo SmithKline, but this month also saw Innocol release disappointing Phase IIb results for its Cogenzia product. In regulatory news, it was announced that the US FDA indicated that EyeGate may use the 510(k) De Novo Path for their device, the Ocular Bandage Gel. Also this month, Glaxo SmithKline announced that it filed a regulatory submission with the FDA for its novel triple-combination therapy product, utilizing its Ellipta(®) inhaler.

  14. Scientific Opinion on the essential composition of total diet replacements for weight control

    DEFF Research Database (Denmark)

    Tetens, Inge

    to induce a substantial energy deficit in overweight or obese adults who wish to lose weight and replace the whole diet in the context of energy-restricted diets for weight reduction. In this opinion, the Panel proposed a minimum protein content based on a Population Reference Intake for protein adjusted......Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the essential composition of total diet replacements for weight control. Total diet replacements for weight control are intended...... or authoritative bodies. Derived from the minimum content of macronutrients, the Panel proposed a minimum energy content of total diet replacements for weight control of 2 510 kJ/day (600 kcal/day). The Panel also advised on potential conditions and restrictions of use for these products....

  15. On-line monitoring of the transesterification reaction between triglycerides and ethanol using near infrared spectroscopy combined with gas chromatography.

    Science.gov (United States)

    Richard, Romain; Li, Ying; Dubreuil, Brigitte; Thiebaud-Roux, Sophie; Prat, Laurent

    2011-06-01

    Many analytical procedures have been developed to determine the composition of reaction mixtures during transesterification of vegetable oils with alcohols. However, despite their accuracy, these methods are time consuming and cannot be easily used for on-line monitoring. In this work, a fast analytical method was developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol using Near InfraRed spectroscopy and a multivariate approach. The reactions were monitored through sequential scans of the reaction medium with a probe in a one-liter batch reactor without collecting and preparing samples. To calibrate the NIR analytical method, gas chromatography-flame ionization detection was used as a reference method. The method was validated by studying the kinetics of the EtONa-catalyzed transesterification reaction. Activation energy (51.0 kJ/mol) was also determined by considering a pseudo second order kinetics model. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Regulation of UHMWPE biomaterials in total hip arthroplasty.

    Science.gov (United States)

    Kasser, Michael J

    2013-04-01

    This manuscript provides a brief history of the development of ultrahigh molecular weight polyethylene (UHWMPE) biomaterials and how the U.S. Food and Drug Administration (FDA) regulates medical devices. The flowchart used to decide whether a device is medium or high risk, known as the 510(k) flowchart, is illustrated by taking several examples through the flowchart. In order to demonstrate how changes to UHWMPE material used in the acetabular liners of total hips have been regulated, two major modifications to UHMWPE, highly crosslinked polyethylene and Vitamin E polyethylene, are taken through the flowchart. This manuscript describes the testing that has been provided to demonstrate safety and effectiveness of these modifications, as well as an explanation why the testing was supplied to the FDA.

  17. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products-

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Han Ok; Byun, Myung Woo; Cho, Sung Kee; Kand, Il Joon; Yook, Hong Sun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    Gamma irradiation was applied to red ginseng powder for improving microbiological and physicochemical quality. Irradiation at 5-10 kGy was effective for sterilizing all contaminated microorganisms of red ginseng powder. At the dose levels, major physicochemical properties (saponin, amino acids, sugars, proximate composition, color, pH, acidity, hydrogen donating activity, fatty acids and minerals) were not changed by gamma irradiation upto 10 kGy. Based upon the results, it is concluded that gamma irradiation can effectively improve the microbiological quality of red ginseng powders without significant unfavorable changes. Therefore, it is suggested that irradiation technology is a viable alternative method to other sanitary process containing chemical fumigant and will be useful for the improvement of the quality of red ginseng powders and their products. 5 figs, 18 tabs, 92 refs. (Author).

  18. Quantitative mid-infrared spectra of allene and propyne from room to high temperatures

    KAUST Repository

    Es-sebbar, Et-touhami

    2014-11-01

    Allene (a-C3H4; CH2CCH2) and propyne (p-C3H4; CH3C2H) have attracted much interest because of their relevance to the photochemistry in astrophysical environments as well as in combustion processes. Both allene and propyne have strong absorption in the infrared region. In the present work, infrared spectra of a-C3H4 and p-C3H4 are measured in the gas phase at temperatures ranging from 296 to 510 K. The spectra are measured over the 580-3400 cm-1 spectral region at resolutions of 0.08 and 0.25 cm-1 using Fourier Transform Infrared spectroscopy. Absolute integrated intensities of the main infrared bands are determined at room temperature and compared with values derived from literature for both molecules. Integrated band intensities are also determined as a function of temperature in various spectral regions.

  19. Rayleigh Lidar observed atmospheric temperature characteristics over a western Indian location: intercomparison with satellite observations and models

    Science.gov (United States)

    Sharma, Som; Vaishnav, Rajesh; Shukla, Krishna K.; Lal, Shyam; Chandra, Harish; Acharya, Yashwant B.

    2017-07-01

    General characteristics of sub-tropical middle atmospheric temperature structure over a high altitude station, Mt. Abu (24.5°N, 72.7°E, altitude 1670 m, above mean sea level (amsl)) are presented using about 150 nights observational datasets of Rayleigh Lidar. The monthly mean temperature contour plot shows two distinct maxima in the stratopause region ( 45-55 km), occurring during February-March and September-October, a seasonal dependence similar to that reported for mid- and high-latitudes respectively. Semi-Annual Oscillation (SAO) are stronger at an altitude 60 km in the mesospheric temperature in comparison to stratospheric region. A comparison with the satellite (Halogen Occultation Experiment, (HALOE)) data shows qualitative agreement, but quantitatively a significant difference is found between the observation and satellite. The derived temperatures from Lidar observations are warmer 2-3 K in the stratospheric region and 5-10 K in the mesospheric region than temperatures observed from the satellite. A comparison with the models, COSPAR International Reference Atmosphere (CIRA)-86 and Mass Spectrometer Incoherent Scatter Extended (MSISE)-90, showed differences of 3 K in the stratosphere and 5-10 K in the mesosphere, with deviations somewhat larger for CIRA-86. In most of the months and in all altitude regions model temperatures were lower than the Lidar observed temperature except in the altitude range of 40-50 km. MSISE-90 Model temperature overestimates as compared to Lidar temperature during December-February in the altitude region of 50-60 km. In the altitude region of 55-70 km both models deviate significantly, with differences exceeding 10-12 K, particularly during equinoctial periods. An average heating rate of 2.5 K/month during equinoxes and cooling rate of 4 K/month during November-December are found in altitude region of 50-70 km, relatively less heating and cooling rates are found in the altitude range of 30-50 km. The stratospheric temperature derived from the Lidar and columnar ozone observed by the Total Ozone Mapping Spectrometer (TOMS) over Mt. Abu shows good correlation (r2 = 0.61) and indicates the association of ozone with the temperature. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic and B. Sivaraman.

  20. Chlorine diffusion in uranium dioxide under heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pipon, Y. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France) and Universite Claude Bernard Lyon-1, Institut Universitaire de Technologie (IUT A), 94, boulevard Niels Bohr, 69622 Villeurbanne cedex (France)]. E-mail: pipon@ipnl.in2p3.fr; Bererd, N. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France); Universite Claude Bernard Lyon-1, Institut Universitaire de Technologie (IUT A), 94, boulevard Niels Bohr, 69622 Villeurbanne cedex (France); Moncoffre, N. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France); Peaucelle, C. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France); Toulhoat, N. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France); Commissariat a l' Energie Atomique (CEA), DEN/Saclay, 91191 Gif sur Yvette cedex (France); Jaffrezic, H. [Universite Claude Bernard Lyon-1/Institut de Physique Nucleaire de Lyon (IPNL), 4, rue Enrico Fermi, 69622 Villeurbanne cedex (France); Raimbault, L. [Ecole des Mines de Paris, Centre de Geosciences, 35 rue Saint Honore, F-77305 Fontainebleau cedex (France); Sainsot, P. [Institut National des Sciences Appliquees de Lyon (INSA), UMR 5514, F-69621 Villeurbanne cedex (France); Carlot, G. [Commissariat a l' Energie Atomique (CEA), Centre de Cadarache, DEN/DEC/SESC/LLCC, 13108 Saint-Paul lez Durance (France)

    2007-04-15

    The radiation enhanced diffusion of chlorine in UO{sub 2} during heavy ion irradiation is studied. In order to simulate the behaviour of {sup 36}Cl, present as an impurity in UO{sub 2}, {sup 37}Cl has been implanted into the samples (projected range 200 nm). The samples were then irradiated with 63.5 MeV {sup 127}I at two fluxes and two temperatures and the chlorine distribution was analyzed by SIMS. The results show that, during irradiation, the diffusion of the implanted chlorine is enhanced and slightly athermal with respect to pure thermal diffusion. A chlorine gain of 10% accumulating near the surface has been observed at 510 K. This corresponds to the displacement of pristine chlorine from a region of maximum defect concentration. This behaviour and the mean value of the apparent diffusion coefficient found for the implanted chlorine, around 2.5 x 10{sup -14} cm{sup 2} s{sup -1}, reflect the high mobility of chlorine in UO{sub 2} during irradiation with fission products.

  1. Chlorine diffusion in uranium dioxide under heavy ion irradiation

    Science.gov (United States)

    Pipon, Y.; Bérerd, N.; Moncoffre, N.; Peaucelle, C.; Toulhoat, N.; Jaffrézic, H.; Raimbault, L.; Sainsot, P.; Carlot, G.

    2007-04-01

    The radiation enhanced diffusion of chlorine in UO2 during heavy ion irradiation is studied. In order to simulate the behaviour of 36Cl, present as an impurity in UO2, 37Cl has been implanted into the samples (projected range 200 nm). The samples were then irradiated with 63.5 MeV 127I at two fluxes and two temperatures and the chlorine distribution was analyzed by SIMS. The results show that, during irradiation, the diffusion of the implanted chlorine is enhanced and slightly athermal with respect to pure thermal diffusion. A chlorine gain of 10% accumulating near the surface has been observed at 510 K. This corresponds to the displacement of pristine chlorine from a region of maximum defect concentration. This behaviour and the mean value of the apparent diffusion coefficient found for the implanted chlorine, around 2.5 × 10-14 cm2 s-1, reflect the high mobility of chlorine in UO2 during irradiation with fission products.

  2. Evaporation rates and vapor pressures of individual aerosol species formed in the atmospheric oxidation of alpha- and beta-pinene.

    Science.gov (United States)

    Bilde, M; Pandis, S N

    2001-08-15

    The semivolatile oxidation products (trans-norpinic acid, pinic acid, cis-pinonic acid, etc.) of the biogenic monoterpenes (alpha-pinene, beta-pinene, etc.) contribute to the atmospheric burden of particulate matter. Using the tandem differential mobility analysis (TDMA) technique evaporation rates of glutaric acid, trans-norpinic acid, and pinic acid particles were measured in a laminar flow reactor. The vapor pressure of glutaric acid was found to be log(p0 glutaric/Pa) = - 3,510 K/T + 8.647 over the temperature range 290-300 K in good agreement with the values previously reported by Tao and McMurry (1989). The measured vapor pressure of trans-norpinic acid over the temperature range 290-312 K is log(p0 norpinic/Pa) = - 2,196.9 K/T + 3.522, and the vapor pressure of pinic acid is log(p0 pinic/ Pa) = - 5,691.7 K/T + 14.73 over the temperature range 290-323 K. The uncertainty on the reported vapor pressures is estimated to be approximately +/- 50%. The vapor pressure of cis-pinonic acid is estimated to be of the order of 7 x 10(-5) Pa at 296 K.

  3. Impact of Organic and Inorganic Fertilizers Application on the Phytochemical and Antioxidant Activity of Kacip Fatimah (Labisia pumila Benth

    Directory of Open Access Journals (Sweden)

    Ehsan Karimi

    2013-09-01

    Full Text Available A study was conducted to compare secondary metabolites and antioxidant activity of Labisia pumila Benth (Kacip Fatimah in response to two sources of fertilizer [i.e., organic (chicken dung; 10% N:10% P2O5:10% K2O and inorganic fertilizer (NPK green; 15% N, 15% P2O5, 15% K2O] under different N rates of 0, 90, 180 and 270 kg N/ha. The experiment was arranged in a randomized complete block design replicated three times. At the end of 15 weeks, it was observed that the application of organic fertilizer enhanced the production of total phenolics, flavonoids, ascorbic acid, saponin and gluthathione content in L. pumila, compared to the use of inorganic fertilizer. The nitrate content was also reduced under organic fertilization. The application of nitrogen at 90 kg N/ha improved the production of secondary metabolites in Labisia pumila. Higher rates in excess of 90 kg N/ha reduced the level of secondary metabolites and antioxidant activity of this herb. The DPPH and FRAP activity was also highest at 90 kg N/ha. The results indicated that the use of chicken dung can enhance the production of secondary metabolites and improve antioxidant activity of this herb.

  4. An experiment study of homogeneous charge compression ignition combustion and emission in a gasoline engine

    Directory of Open Access Journals (Sweden)

    Zhang Jianyong

    2014-01-01

    Full Text Available Homogenous charge compression ignition (HCCI technology has exhibited high potential to reduce fuel consumption and NOx emissions over normal spark ignition engines significantly. Optimized kinetic process (OKP technology is implemented to realize HCCI combustion in a port fuel injection gasoline engine. The combustion and emission characteristics are investigated with variation of intake air temperature, exhaust gas recirculation (EGR rate and intake air pressure. The results show that intake air temperature has great influence on HCCI combustion characteristic. Increased intake air temperature results in advance combustion phase, shorten combustion duration, and lower indicated mean effective pressure (IMEP. Increased EGR rate retards combustion start phase and prolongs combustion duration, while maximum pressure rising rate and NOx emission are reduced with increase of EGR rate. In the condition with constant fuel flow quantity, increased air pressure leads to retarded combustion phase and lower pressure rising rate, which will reduce the engine knocking tendency. In the condition with constant air fuel ratio condition, fuel injection quantity increases as intake air pressure increases, which lead to high heat release rate and high emission level. The optimal intake air temperature varies in different operating area, which can be tuned from ambient temperature to 220℃ by heat management system. The combination of EGR and air boost technology could expand operating area of HCCI engine, which improve indicated mean effective pressure from maximum 510kPa to 720kPa.

  5. Metabolic engineering of Ralstonia eutropha for the biosynthesis of 2-hydroxyacid-containing polyhydroxyalkanoates.

    Science.gov (United States)

    Park, Si Jae; Jang, Young-Ah; Lee, Hyuk; Park, A-Reum; Yang, Jung Eun; Shin, Jihoon; Oh, Young Hoon; Song, Bong Keun; Jegal, Jonggeon; Lee, Seung Hwan; Lee, Sang Yup

    2013-11-01

    Polyhydroxyalkanoates (PHAs) are bio-based and biodegradable polyesters synthesized by numerous microorganisms. PHAs containing 2-hydroxyacids as monomer units have attracted much attention, but their production has not been efficient. Here, we metabolically engineered Ralstonia eutropha strains for the in vivo synthesis of PHAs containing 2-hydroxyacids as monomers. This was accomplished by replacing the R. eutropha phaC gene in the chromosome with either the R. eutropha phaC S506G A510K gene, which contains two point mutations, or the Pseudomonas sp. MBEL 6-19 phaC1437 gene. In addition, the R. eutropha phaAB genes in the chromosome were replaced with the Clostridium propionicum pct540 gene. All of the engineered R. eutropha strains produced PHAs containing 2-hydroxyacid monomers, including lactate and 2-hydroxybutyrate (2HB), along with 3-hydroxybutyrate (3HB) and/or 3-hydroxyvalerate (3HV), when they were cultured in nitrogen-free medium containing 5 g/L lactate or 4 g/L 2HB and 20 g/L glucose as carbon sources. Expression of the Escherichia coli ldhA gene in engineered R. eutropha strains allowed production of poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] from glucose as the sole carbon source. This is the first report on the production of 2-hydroxyacid-containing PHAs by metabolically engineered R. eutropha.

  6. ELF/VLF wave generation from the beating of two HF ionospheric heating sources

    Science.gov (United States)

    Cohen, M. B.; Moore, R. C.; Golkowski, M.; Lehtinen, N. G.

    2012-12-01

    It is well established that Extremely Low Frequency (ELF, 0.3-3 kHz) and Very Low Frequency (VLF, 3-30 kHz) radio waves can be generated via modulated High Frequency (HF, 3-10 MHz) heating of the lower ionosphere (60-100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, creates an `antenna in the sky.' We utilize a theoretical model of the HF to ELF/VLF conversion and the ELF/VLF propagation, and calculate the amplitudes of the generated ELF/VLF waves when two HF heating waves, separated by the ELF/VLF frequency, are transmitted from two adjacent locations. The resulting ELF/VLF radiation pattern exhibits a strong directional dependence (as much as 15 dB) that depends on the physical spacing of the two HF sources. This beat wave source can produce signals 10-20 dB stronger than those generated using amplitude modulation, particularly for frequencies greater than 5-10 kHz. We evaluate recent suggestions that beating two HF waves generates ELF/VLF waves in the F-region (>150 km), and conclude that those experimental results may have misinterpreted, and can be explained strictly by the much more well established D region mechanism.

  7. Fluorescence lifetime plate reader: resolution and precision meet high-throughput.

    Science.gov (United States)

    Petersen, Karl J; Peterson, Kurt C; Muretta, Joseph M; Higgins, Sutton E; Gillispie, Gregory D; Thomas, David D

    2014-11-01

    We describe a nanosecond time-resolved fluorescence spectrometer that acquires fluorescence decay waveforms from each well of a 384-well microplate in 3 min with signal-to-noise exceeding 400 using direct waveform recording. The instrument combines high-energy pulsed laser sources (5-10 kHz repetition rate) with a photomultiplier and high-speed digitizer (1 GHz) to record a fluorescence decay waveform after each pulse. Waveforms acquired from rhodamine or 5-((2-aminoethyl)amino) naphthalene-1-sulfonic acid dyes in a 384-well plate gave lifetime measurements 5- to 25-fold more precise than the simultaneous intensity measurements. Lifetimes as short as 0.04 ns were acquired by interleaving with an effective sample rate of 5 GHz. Lifetime measurements resolved mixtures of single-exponential dyes with better than 1% accuracy. The fluorescence lifetime plate reader enables multiple-well fluorescence lifetime measurements with an acquisition time of 0.5 s per well, suitable for high-throughput fluorescence lifetime screening applications.

  8. Temperature-Sensing Behavior Based on Upconversion Luminescence at the Rhombohedral-Tetragonal Phase Boundary

    Science.gov (United States)

    Zou, Hua; Hu, Yifeng; Zhu, Xiaoqin; Zhang, Jianhao; Wang, Xusheng; Song, Zhitang

    2016-10-01

    In this work, (1- x)(K0.48Na0.52)(Nb0.95Sb0.05)O3- x - xEr0.5(Na0.82K0.18)0.5ZrO3 ( x = 0-0.05) ceramics were fabricated by solid-state reaction techniques. The rhombohedral-tetragonal (R-T) phase boundary of the ceramics was identified at 0.04 ≤ x, thus providing an opportunity to investigate the upconversion emission derived from the Er3+ ions at the R-T phase boundary. Under 980 nm laser excitation, the R-T phase ceramics exhibited a strong green emission. In addition, the fluorescence intensity ratios of green emissions at 530 nm and 550 nm were investigated in a temperature range of 180-510 K, and maximum sensing sensitivity was found to be 0.0037 K-1. The results indicate that Er3+-doped ceramics with R-T phase boundaries can be applied to new multifunctional electro-optical temperature sensors. Laser excitation heating effects were also observed in detail.

  9. Accuracy of the Lifebox pulse oximeter during hypoxia in healthy volunteers.

    Science.gov (United States)

    Dubowitz, G; Breyer, K; Lipnick, M; Sall, J W; Feiner, J; Ikeda, K; MacLeod, D B; Bickler, P E

    2013-12-01

    Pulse oximetry is a standard of care during anaesthesia in high-income countries. However, 70% of operating environments in low- and middle-income countries have no pulse oximeter. The 'Lifebox' oximetry project set out to bridge this gap with an inexpensive oximeter meeting CE (European Conformity) and ISO (International Organization for Standardization) standards. To date, there are no performance-specific accuracy data on this instrument. The aim of this study was to establish whether the Lifebox pulse oximeter provides clinically reliable haemoglobin oxygen saturation (Sp O2 ) readings meeting USA Food and Drug Administration 510(k) standards. Using healthy volunteers, inspired oxygen fraction was adjusted to produce arterial haemoglobin oxygen saturation (Sa O2 ) readings between 71% and 100% measured with a multi-wavelength oximeter. Lifebox accuracy was expressed using bias (Sp O2 - Sa O2 ), precision (SD of the bias) and the root mean square error (Arms). Simultaneous readings of Sa O2 and Sp O2 in 57 subjects showed a mean (SD) bias of -0.41% (2.28%) and Arms 2.31%. The Lifebox pulse oximeter meets current USA Food and Drug Administration standards for accuracy, thus representing an inexpensive solution for patient monitoring without compromising standards.

  10. Scientific Opinion on the essential composition of total diet replacements for weight control

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA

    2015-01-01

    Full Text Available Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA was asked to deliver a scientific opinion on the essential composition of total diet replacements for weight control. Total diet replacements for weight control are intended to induce a substantial energy deficit in overweight or obese adults who wish to lose weight and replace the whole diet in the context of energy-restricted diets for weight reduction. In this opinion, the Panel proposed a minimum protein content based on a Population Reference Intake for protein adjusted for the overweight or obese (75 g/day, a minimum carbohydrate content based on the obligatory glucose demands of the brain (30 g/day and minimum contents of linoleic acid (11 g/day, α-linolenic acid (1.4 g/day and micronutrients based on reference values established either by the Panel or by other scientific or authoritative bodies. Derived from the minimum content of macronutrients, the Panel proposed a minimum energy content of total diet replacements for weight control of 2 510 kJ/day (600 kcal/day. The Panel also advised on potential conditions and restrictions of use for these products.

  11. NeutroPhase(®) in chronic non-healing wounds.

    Science.gov (United States)

    Crew, John; Varilla, Randell; Rocas, Thomas Allandale; Debabov, Dmitri; Wang, Lu; Najafi, Azar; Rani, Suriani Abdul; Najafi, Ramin Ron; Anderson, Mark

    2012-01-01

    Chronic non-healing wounds, such as venous stasis ulcers, diabetic ulcers, and pressure ulcers are serious unmet medical needs that affect a patient's morbidity and mortality. Common pathogens observed in chronic non-healing wounds are Staphylococcus including MRSA, Pseudomonas, Enterobacter, Stenotrophomonas, and Serratia spp. Topical and systemically administered antibiotics do not adequately decrease the level of bacteria or the associated biofilm in chronic granulating wounds and the use of sub-lethal concentrations of antibiotics can lead to resistant phenotypes. Furthermore, topical antiseptics may not be fully effective and can actually impede wound healing. We show 5 representative examples from our more than 30 clinical case studies using NeutroPhase(®) as an irrigation solution with chronic non-healing wounds with and without the technique of negative pressure wound therapy (NPWT). NeutroPhase(®) is pure 0.01% hypochlorous acid (i.e. >97% relative molar distribution of active chlorine species as HOCl) in a 0.9% saline solution at pH 4-5 and is stored in glass containers. NovaBay has three FDA cleared 510(k)s. Patients showed a profound improvement and marked accelerated rates of wound healing using NeutroPhase(®) with and without NPWT. NeutroPhase(®) was non-toxic to living tissues.

  12. NeutroPhase® in chronic non-healing wounds

    Science.gov (United States)

    Crew, John; Varilla, Randell; Rocas, Thomas Allandale; Debabov, Dmitri; Wang, Lu; Najafi, Azar; Rani, Suriani Abdul; Najafi, Ramin (Ron); Anderson, Mark

    2012-01-01

    Chronic non-healing wounds, such as venous stasis ulcers, diabetic ulcers, and pressure ulcers are serious unmet medical needs that affect a patient’s morbidity and mortality. Common pathogens observed in chronic non-healing wounds are Staphylococcus including MRSA, Pseudomonas, Enterobacter, Stenotrophomonas, and Serratia spp. Topical and systemically administered antibiotics do not adequately decrease the level of bacteria or the associated biofilm in chronic granulating wounds and the use of sub-lethal concentrations of antibiotics can lead to resistant phenotypes. Furthermore, topical antiseptics may not be fully effective and can actually impede wound healing. We show 5 representative examples from our more than 30 clinical case studies using NeutroPhase® as an irrigation solution with chronic non-healing wounds with and without the technique of negative pressure wound therapy (NPWT). NeutroPhase® is pure 0.01% hypochlorous acid (i.e. >97% relative molar distribution of active chlorine species as HOCl) in a 0.9% saline solution at pH 4-5 and is stored in glass containers. NovaBay has three FDA cleared 510(k)s. Patients showed a profound improvement and marked accelerated rates of wound healing using NeutroPhase® with and without NPWT. NeutroPhase® was non-toxic to living tissues. PMID:23272294

  13. Heat Capacities and Thermodynamic Properties of 3-(2,2-Dichloroethenyl ) -2,2-dimethylcyclopropanecarboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    XUE Bin; WANG Jian-ya; TAN Zhi-cheng; WU Tong-hao

    2007-01-01

    The heat capacities of 3 - (2,2-dichloroethenyl) -2,2-dimethylcyclopropanecarboxylic acid ( a racemic mixture,molar ratio of cis-/trans-structure is 35/65) in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% ( molar fraction). A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and entropy of fusion, △fusHm, △fusSm, of the acid were determined to be ( 331.48 ± 0.03 ) K, ( 16. 321 ± 0.031 ) kJ/mol,and (49.24 ± 0.19) J/( K·mol), respectively. The thermodynamic functions of the sample, HT - H298.15, ST -S298.15 and GT - G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric (TG) analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7. 3 × 107 min -1, E =70.64 KJ/mol, respectively.

  14. Vibration-induced electrical noise in a cryogen-free dilution refrigerator: Characterization, mitigation, and impact on qubit coherence

    Science.gov (United States)

    Kalra, Rachpon; Laucht, Arne; Dehollain, Juan Pablo; Bar, Daniel; Freer, Solomon; Simmons, Stephanie; Muhonen, Juha T.; Morello, Andrea

    2016-07-01

    Cryogen-free low-temperature setups are becoming more prominent in experimental science due to their convenience and reliability, and concern about the increasing scarcity of helium as a natural resource. Despite not having any moving parts at the cold end, pulse tube cryocoolers introduce vibrations that can be detrimental to the experiments. We characterize the coupling of these vibrations to the electrical signal observed on cables installed in a cryogen-free dilution refrigerator. The dominant electrical noise is in the 5-10 kHz range and its magnitude is found to be strongly temperature dependent. We test the performance of different cables designed to diagnose and tackle the noise, and find triboelectrics to be the dominant mechanism coupling the vibrations to the electrical signal. Flattening a semi-rigid cable or jacketing a flexible cable in order to restrict movement within the cable, successfully reduces the noise level by over an order of magnitude. Furthermore, we characterize the effect of the pulse tube vibrations on an electron spin qubit device in this setup. Coherence measurements are used to map out the spectrum of the noise experienced by the qubit, revealing spectral components matching the spectral signature of the pulse tube.

  15. Modelling the stability of maltodextrin-encapsulated grape skin phenolics used as a new ingredient in apple puree.

    Science.gov (United States)

    Lavelli, V; Sri Harsha, P S C; Spigno, G

    2016-10-15

    Highly soluble maltodextrin-encapsulated grape skin phenolics comprising anthocyanins and less hydrophilic flavonoids were added as an ingredient to apple puree. Upon formulation, heat treatments were applied to achieve 3-14 decimal reductions (D) of the target microorganism (Alicyclobacillus acidoterrestris). A storage study was performed at 15-35°C for 1month. Monomeric anthocyanins were retained at 100% after the 3 D treatment, while anthocyanin retention decreased to 72% with increasing heating intensity until 14 D. During storage, the concentration of monomeric anthocyanins decreased following first-order kinetics (k25°C=34.4d(-1), activation energy=51.0kJ/mol). The flavanols were more stable than the monomeric anthocyanins. The hydroxycinnamic acid, dihydrochalcone and flavonol contents did not change. The fortified puree had a two-fold higher reducing capacity with respect to apple puree. Overall, this ingredient could meet the industrial demand for sustainable colouring agents and health promoting compounds.

  16. Morphology and N2 Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes

    Directory of Open Access Journals (Sweden)

    Ekain Fernandez

    2016-02-01

    Full Text Available The influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM, and the results indicate an increase of the grain size from 120 to 250–270 nm and film surface roughness from 4–5 to 10–12 nm when increasing the temperature from around 360–510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.5–2-µm thick films were deposited onto different types of porous supports to study the influence of the porous support, layer thickness and target power on the selective layer microstructure and membrane properties. The Pd-Ag layers deposited onto ZrO2 3-nm top layer supports (smallest pore size among all tested present high N2 permeance in the order of 10−6 mol·m−2·s−1·Pa−1 at room temperature.

  17. Enhancement of antioxidant properties and increase of content of vitamin D2 and non-volatile components in fresh button mushroom, Agaricus bisporus (higher Basidiomycetes) by γ-irradiation.

    Science.gov (United States)

    Tsai, Shu-Yao; Mau, Jeng-Leun; Huang, Shih-Jeng

    2014-01-01

    Agaricus bisporus is a popular culinary-medicinal mushroom in Taiwan, and γ-irradiation could extend its shelf life. Our objective was to study the content of vitamin D2 and the taste components and antioxidant properties of ethanolic extracts from A. bisporus with various doses of γ-irradiation. After irradiation, the vitamin D2 content of 5-10 kGy irradiated mushrooms was in the range of 5.22-7.90 µg/g, higher than that of the unirradiated control (2.24 µg/g). For all treatments, the total content of soluble sugars and polyols ranged from 113 to 142 mg/g, and the monosodium glutamate-like components ranged from 6.57 to 13.50 mg/g, among which the 2.5 kGy irradiated sample has the highest content of flavor 5'-nucleotide. About antioxidant properties, 10 kGy irradiated samples exhibited lower EC50 values than did other samples. EC50 values were less than 5 mg/mL for ethanolic extracts. Total phenols were the major antioxidant components and the total content was 13.24-22.78 mg gallic acid equivalents/g. Based on the results obtained, γ-irradiation could be used to improve the vitamin D2 content and intensity of umami taste in fresh mushrooms. In addition, γ-irradiation not only maintained the antioxidant properties of mushrooms but also enhanced the antioxidant properties to some extent.

  18. Reduction of mercury(II) by tropical river humic substances (Rio Negro)-Part II. Influence of structural features (molecular size, aromaticity, phenolic groups, organically bound sulfur).

    Science.gov (United States)

    Rocha, Julio Cesar; Sargentini, Ezio; Zara, Luiz Fabricio; Rosa, André Henrique; Dos Santos, Ademir; Burba, Peter

    2003-12-04

    The influence of structural features of tropical river humic substances (HS) on their capability to reduce mercury(II) in aqueous solutions was studied. The HS investigated were conventionally isolated from Rio Negro water-Amazonas State/Brazil by means of the collector XAD 8. In addition, the isolated HS were on-line fractionated by tangential-flow multistage ultrafiltration (nominal molecular-weight cut-offs: 100, 50, 30, 10, 5 kDa) and characterized by potentiometry and UV/VIS spectroscopy. The reduction of Hg(II) ions to elemental Hg by size-fractions of Rio Negro HS was assessed by cold-vapor AAS (CVAAS). UV/VIS spectrometry revealed that the fractions of high molecular-size (F(1)>100 kDa and F(2): 50-100 kDa) have a higher aromaticity compared to the fractions of small molecular-size (F(5): 5-10 kDa, F(6): F(2)>F(1)>F(3)>F(4)>F(6)). Accordingly, Hg(II) ions were preferably reduced by HS molecules having a relatively high ratio of phenolic/carboxylic groups and a small concentration of sulfur. From these results a complex 'competition' between reduction and complexation of mercury(II) by aquatic HS occurring in tropical rivers such as the Rio Negro can be suggested.

  19. Experimental investigation of plasma relaxation using a compact coaxial magnetized plasma gun in a background plasma

    Science.gov (United States)

    Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott; University of New Mexico Collaboration; Los Alamos National Laboratory Collaboration

    2013-10-01

    A compact coaxial plasma gun is employed for experimental studies of plasma relaxation in a low density background plasma. Experiments are being conducted in the linear HelCat device at UNM. These studies will advance the knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets/radio lobes within the intergalactic medium. The gun is powered by a 120pF ignitron-switched capacitor bank which is operated in a range of 5-10 kV and ~100 kA. Multiple diagnostics are employed to investigate plasma relaxation process. Magnetized Argon plasma bubbles with velocities ~1.2Cs and densities ~1020 m-3 have been achieved. Different distinct regimes of operation with qualitatively different dynamics are identified by fast CCD camera images, with the parameter determining the operation regime. Additionally, a B-dot probe array is employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify detached plasma bubble configurations. Experimental data and analysis will be presented.

  20. Are mussels able to distinguish underwater sounds? Assessment of the reactions of Mytilus galloprovincialis after exposure to lab-generated acoustic signals.

    Science.gov (United States)

    Vazzana, Mirella; Celi, Monica; Maricchiolo, Giulia; Genovese, Lucrezia; Corrias, Valentina; Quinci, Enza Maria; de Vincenzi, Giovanni; Maccarrone, Vincenzo; Cammilleri, Gaetano; Mazzola, Salvatore; Buscaino, Giuseppa; Filiciotto, Francesco

    2016-11-01

    This study examined the effects of lab-generated acoustic signals on the behaviour and biochemistry of Mediterranean mussels (Mytilus galloprovincialis). The experiment was carried out in a tank equipped with a video-recording system using six groups of five mussels exposed to five acoustic treatments (each treatment was replicated three times) for 30min. The acoustic signals, with a maximum sound pressure level of 150dB rms re 1μPa, differed in frequency range as follows: low (0.1-5kHz), mid-low (5-10kHz), mid (10-20kHz), mid-high (20-40kHz) and high (40-60kHz). The exposure to sweeps did not produce any significant changes in the mussels' behaviour. Conversely, the specimens exposed to the low frequency band treatment showed significantly higher values of the following biochemical stress parameters measured in their plasma and tissues: glucose, total proteins, total haemocyte number (THC), heat shock protein 70 (Hsp70) expression, and Acetylcholinesterase (AChE) activity. The responses observed in the mussels exposed to low frequency sweeps enable us to suppose a biological and ecological role for this sound, which contains the main frequencies produced by both shipping traffic and the acoustic emissions of fish.

  1. Nuclear magnetic and quadrupole resonance in metallic powders in the presence of strong quadrupole interaction: Rhenium metal

    Energy Technology Data Exchange (ETDEWEB)

    Dimitropoulos, C.; Maglione, M.; Borsa, F.

    1988-03-01

    The nuclear-magnetic-resonance and nuclear-quadrupole-resonance (NQR-NMR) spectra of /sup 187/Re and /sup 185/Re in a powder of rhenium metal were measured in the temperature range 5--10 K both in zero field and with an external magnetic field. The zero-field NQR spectrum is severely broadened by a nonuniform distribution of quadrupole interactions. The average quadrupole coupling frequencies measured at 5 K are, for the two isotopes, ..nu../sub Q/ = 39 +- 0.2 MHz (/sup 187/Re) and ..nu../sub Q/ = 40.8 +- 0.3 MHz (/sup 185/Re). The spectra obtained in the presence of an external magnetic field can be interpreted satisfactorily in terms of transitions among the eigenstates of the full Hamiltonian (Zeeman plus quadrupolar). Measurements of relaxation rates yield T/sub 1/T = 0.03 sK, indicating a relaxation mechanism driven by the hyperfine interaction with the conduction electrons. The feasibility of NQR-NMR studies in small metal particles in the presence of strong inhomogeneous quadrupole interactions is assessed

  2. Class 1 devices case studies in medical devices design

    CERN Document Server

    Ogrodnik, Peter J

    2014-01-01

    The Case Studies in Medical Devices Design series consists of practical, applied case studies relating to medical device design in industry. These titles complement Ogrodnik's Medical Device Design and will assist engineers with applying the theory in practice. The case studies presented directly relate to Class I, Class IIa, Class IIb and Class III medical devices. Designers and companies who wish to extend their knowledge in a specific discipline related to their respective class of operation will find any or all of these titles a great addition to their library. Class 1 Devices is a companion text to Medical Devices Design: Innovation from Concept to Market. The intention of this book, and its sister books in the series, is to support the concepts presented in Medical Devices Design through case studies. In the context of this book the case studies consider Class I (EU) and 510(k) exempt (FDA) . This book covers classifications, the conceptual and embodiment phase, plus design from idea to PDS. These title...

  3. Evaluation of the new cesium-131 seed for use in low-energy x-ray brachytherapy.

    Science.gov (United States)

    Murphy, Mark K; Piper, R Kim; Greenwood, Lawrence R; Mitch, Michael G; Lamperti, Paul J; Seltzer, Stephen M; Bales, Matt J; Phillips, Mark H

    2004-06-01

    Characterization measurements and calculations were performed on a new medical seed developed by IsoRay Inc. in Richland, Washington, that utilizes the short-lived isotope 131Cs. This model has recently received FDA 510(k) clearance. The objective of this work was to characterize the dosimetric properties of the new seed according to the AAPM Task Group 43 recommendations. Cesium-131 is a low-energy x-ray emitter, with the most prominent peaks in the 29 keV to 34 keV region. The intended application is brachytherapy for treating cancers in prostate, breast, head and neck, lung, and pancreas. The evaluations performed included air-kerma strength, radial dose function, anisotropy in phantom, half-life, energy spectra, and internal activity. The results indicate the CS-1 seeds have a dose-rate constant of 0.915 cGy hr(-1) U(-1) in water, dose penetration characteristics similar to 125I and 103Pd, anisotropy function values on the order of 0.71 at short distances and small angles, and an average anisotropy factor of 0.964. The overall dosimetric characteristics are similar to 125I and 103Pd seeds with the exception of half-life, which is 9.7 days, as compared to 17 days for 103Pd and 60 days for 125I. The shorter half-life may offer significant advantages in biological effectiveness.

  4. Tunnelling and barrier-less motions in the 2-fluoroethanol-water complex: a rotational spectroscopic and ab initio study.

    Science.gov (United States)

    Huang, Wenyuan; Thomas, Javix; Jäger, Wolfgang; Xu, Yunjie

    2017-05-17

    The pure rotational spectrum of the 2-fluoroethanol (2-FE)water complex was measured using a chirped pulse Fourier-transform microwave spectrometer and a cavity-based Fourier-transform microwave spectrometer. In the detected 2-FEwater conformer, 2-FE serves as a proton donor, in contrast to its role in the observed ethanolwater conformer, while water acts simultaneously as a hydrogen bond donor and acceptor, forming a hydrogen-bonded ring with an OHO and an OHF hydrogen bond. Comparison to the calculated dipole moment components suggests that the observed structure sits between the two most stable minima identified theoretically. This conclusion is supported by extensive deuterium isotopic data. Further analysis shows that these two minima are connected by a barrier-less wagging motion of the non-bonded hydrogen of the water subunit. The observed narrow splitting with a characteristic 3 : 1 intensity ratio is attributed to an exchange of the bonded and non-bonded hydrogen atoms of water. The tunneling barrier of a proposed tunneling path is calculated to be as low as 5.10 kJ mol(-1). A non-covalent interaction analysis indicates that the water rotation motion along the tunneling path has a surprisingly small effect on the interaction energy between water and 2-FE.

  5. Low-voltage gyrotrons

    Science.gov (United States)

    Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S.; Nusinovich, G. S.

    2013-03-01

    For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).

  6. Antioxidant activities of bambara groundnut (Vigna subterranea) protein hydrolysates and their membrane ultrafiltration fractions.

    Science.gov (United States)

    Arise, Abimbola K; Alashi, Adeola M; Nwachukwu, Ifeanyi D; Ijabadeniyi, Oluwatosin A; Aluko, Rotimi E; Amonsou, Eric O

    2016-05-18

    In this study, the bambara protein isolate (BPI) was digested with three proteases (alcalase, trypsin and pepsin), to produce bambara protein hydrolysates (BPHs). These hydrolysates were passed through ultrafiltration membranes to obtain peptide fractions of different sizes (fractions were investigated for antioxidant activities. The membrane fractions showed that peptides with sizes 3 kDa. This is in agreement with the result obtained for the ferric reducing power, metal chelating and hydroxyl radical scavenging activities where higher molecular weight peptides exhibited better activity (p fractions. However, for all the hydrolysates, the low molecular weight peptides were more effective diphenyl-1-picrylhydrazyl (DPPH) radical scavengers but not superoxide radicals when compared to the bigger peptides. In comparison with glutathione (GSH), BPHs and their membrane fractions had better (p fractions that did not show any metal chelating activity. However, the 5-10 kDa pepsin hydrolysate peptide fractions had greater (88%) hydroxyl scavenging activity than GSH, alcalase and trypsin hydrolysates (82%). These findings show the potential use of BPHs and their peptide fraction as antioxidants in reducing food spoilage or management of oxidative stress-related metabolic disorders.

  7. Adsorption, desorption, and film formation of quinacridone and its thermal cracking product indigo on clean and carbon-covered silicon dioxide surfaces

    Science.gov (United States)

    Scherwitzl, Boris; Lassnig, Roman; Truger, Magdalena; Resel, Roland; Leising, Günther; Winkler, Adolf

    2016-09-01

    The evaporation of quinacridone from a stainless steel Knudsen cell leads to the partial decomposition of this molecule in the cell, due to its comparably high sublimation temperature. At least one additional type of molecules, namely indigo, could be detected in the effusion flux. Thermal desorption spectroscopy and atomic force microscopy have been used to study the co-deposition of these molecules on sputter-cleaned and carbon-covered silicon dioxide surfaces. Desorption of indigo appears at temperatures of about 400 K, while quinacridone desorbs at around 510 K. For quinacridone, a desorption energy of 2.1 eV and a frequency factor for desorption of 1 × 1019 s-1 were calculated, which in this magnitude is typical for large organic molecules. A fraction of the adsorbed quinacridone molecules (˜5%) decomposes during heating, nearly independent of the adsorbed amount, resulting in a surface composed of small carbon islands. The sticking coefficients of indigo and quinacridone were found to be close to unity on a carbon covered SiO2 surface but significantly smaller on a sputter-cleaned substrate. The reason for the latter can be attributed to insufficient energy dissipation for unfavorably oriented impinging molecules. However, due to adsorption via a hot-precursor state, the sticking probability is increased on the surface covered with carbon islands, which act as accommodation centers.

  8. Structural and Immunological Activity Characterization of a Polysaccharide Isolated from Meretrix meretrix Linnaeus.

    Science.gov (United States)

    Li, Li; Li, Heng; Qian, Jianying; He, Yongfeng; Zheng, Jialin; Lu, Zhenming; Xu, Zhenghong; Shi, Jinsong

    2015-12-29

    Polysaccharides from marine clams perform various biological activities, whereas information on structure is scarce. Here, a water-soluble polysaccharide MMPX-B2 was isolated from Meretrix meretrix Linnaeus. The proposed structure was deduced through characterization and its immunological activity was investigated. MMPX-B2 consisted of d-glucose and d-galctose residues at a molar ratio of 3.51:1.00. The average molecular weight of MMPX-B2 was 510 kDa. This polysaccharide possessed a main chain of (1→4)-linked-α-d-glucopyranosyl residues, partially substituted at the C-6 position by a few terminal β-d-galactose residues or branched chains consisting of (1→3)-linked β-d-galactose residues. Preliminary immunological tests in vitro showed that MMPX-B2 could stimulate the murine macrophages to release various cytokines, and the structure-activity relationship was then established. The present study demonstrated the potential immunological activity of MMPX-B2, and provided references for studying the active ingredients in M. meretrix.

  9. Formation and stability of Al-Nd and Al-Nd-Fe metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Battezzati, Livio (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy)); Baricco, Marcello (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy)); Antonione, Carlo (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy))

    1994-07-01

    Partially amorphous Al[sub 91]Nd[sub 9] and Al[sub 86]Nd[sub 9]Fe[sub 5] ribbons were prepared by melt spinning. Metastable crystalline phases were found in both alloys. Complete amorphization of Al[sub 86]Nd[sub 9]Fe[sub 5] was also achieved. Crystallization was monitored by differential scanning calorimetry (DSC). It occurs in two stages at 440 and 510 K for Al[sub 91]Nd[sub 9]. Al[sub 86]Nd[sub 9]Fe[sub 5] presented a eutectic crystallization at 550 K. Microscopy observations, combined with Johnson-Mehl-Avrami (JMA) analyses performed in isothermal DSC traces, showed that Al[sub 91]Nd[sub 9] transforms via growth on pre-existing crystals. Al[sub 86]Nd[sub 9]Fe[sub 5] transformed via heterogeneous nucleation on sites unevenly distributed through the ribbon. The fitting of isothermal peaks by means of the JMA equation was less satisfactory. The limits of this approach are discussed. ((orig.))

  10. 含氮化合物碱性强弱的量子力学研究%Quantum mechanical studies on basieity of nitrogen-containing compounds

    Institute of Scientific and Technical Information of China (English)

    王丽新; 沈喜洲; 周涵; 代振宇

    2009-01-01

    利用密度泛函理论的量子力学从头算法,计算原油及石油产品中不同含氮化合物与H+的结合能,并采用COSMO(conductor-like screen model)模型模拟溶剂的介质环境.结果表明,在水溶剂中,含氮化合物与H+结合的强弱与碱性强弱具有密切关系;与H+结合得越强,其碱性就越强;反之,则越弱.因此,可以算出它们在水溶剂中与H+结合能的高低,判断其碱件的强弱.脂肪胺、非芳香杂环氮化物与H+质子的结合能约在-660~-640 kJ/mol之间,吡啶、芳香胺和吡咯类氮化物分别约为-620、-600、-510 kJ/mol,它们的碱性依次减弱.随着N-烷基苯胺烷基链中碳原子数从0增长到6,与H+结合能从-595 kJ/mol降低到-610 kJ/mol,碱性不断增强;烷基链继续增长,结合能变化很小,对碱性影响不大.芳香环的并入以及芳香环的连接方式,对五员和六员杂环氮化物碱性的影响有所不同.不同氮化物碱性的强弱和其结构有关,尤其电子密度的分布状态,其中电子共轭结构对碱性有很大的影响.%DFT-hased (density functional theory) ab initio quantum mechanical methods have been applied to calculate the pmtonation energies of various nitrogen-containing compounds in petroleum and its products. COSMO (conductor-like screen model) is selected to simulate aqueous solution in the quantum mechanical calculation. The results show that there is a distinct relationship between the pro-tonation energies of nitrogen-containing compounds in aqueous solution and their basicities. The stronger the combination of nitrogen-containing compounds with H + , the higher their basicities. Therefore, the relative basicities of these compounds can be effectively characterized by their protonation energies. The protonation energies of aliphatic amines and nonaromatic heterocycles are about -660 - -640 kJ/mol. Those of pyridines, aromatic amines and pyrroles are about -620 kJ/mol, -600 kJ/mol, and -510 kJ/mol, re

  11. Enhancement of localization phenomena driven by covalency in the SrBiMn{sub 1.75}Ti{sub 0.25}O{sub 6} manganite

    Energy Technology Data Exchange (ETDEWEB)

    Asensio de Lucas, E.; Alvarez-Serrano, I. [Depto. Quimica Inorganica I, Facultad Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Cuello, G.J. [Institut Laue-Langevin, 6 rue Jules Horowitz, F-38042 Grenoble (France); Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, E-28049 Cantoblanco, Madrid (Spain); Lopez, M.L., E-mail: marisal@quim.ucm.es [Depto. Quimica Inorganica I, Facultad Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Pico, C.; Veiga, M.L. [Depto. Quimica Inorganica I, Facultad Ciencias Quimicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2012-05-05

    Graphical abstract: Enhancement of localization phenomena driven by covalency in the BiSrMn{sub 1.75}Ti{sub 0.25}O{sub 6} manganite. The CO/OO phenomena and magnetic clusters (Mn{sub 4}) stabilization at temperatures up to 520 K in BiSrMn{sub 1.75}Ti{sub 0.25}O{sub 6} are connected to a structural transition. The observed enhancement of electronic localization is interpreted considering covalent effects of Ti{sup 4+} and Bi{sup 3+} cations as the main driving force. Highlights: Black-Right-Pointing-Pointer The structural, electronic and magnetic behaviour of the new SrBiMn{sub 1.75}Ti{sub 0.25}O{sub 6} manganite is reported. Black-Right-Pointing-Pointer A structural transition above 520 K takes place, coinciding with relevant changes in the transport properties. Black-Right-Pointing-Pointer The electronic behavior is interpreted in terms of a remarkably high orbital and charge ordering temperature and cluster models. Black-Right-Pointing-Pointer The observed features are explained considering a scenario in which bonds covalence is enhanced by the Bi{sup 3+} and Ti{sup 4+} cations. - Abstract: Manganites are materials that show remarkable phenomena related to charge orbital ordering (CO/OO) and it is extremely important to understand the fundamental nature of this behaviour. This paper reports on the structural, electronic and magnetic behaviour of the new SrBiMn{sub 1.75}Ti{sub 0.25}O{sub 6} manganite and the dependence of these properties with temperature. A detailed structural analysis has been carried out by electron, X-ray, neutron diffraction between 4 and 700 K. The electron diffraction patterns obtained at room temperature (RT) evidence that the average structure (a{approx}b{approx}{radical}(2)a{sub p} and c {approx} 2a{sub p}) presents a modulation that doubles the a and c lattice parameters. A very high charge ordering (CO) transition temperature of 510 K, similar to that found for the non-doped material, SrBiMn{sub 2}O{sub 6}, is observed. Above this

  12. Perception and coding of high-frequency spectral notches: potential implications for sound localization.

    Science.gov (United States)

    Alves-Pinto, Ana; Palmer, Alan R; Lopez-Poveda, Enrique A

    2014-01-01

    The interaction of sound waves with the human pinna introduces high-frequency notches (5-10 kHz) in the stimulus spectrum that are thought to be useful for vertical sound localization. A common view is that these notches are encoded as rate profiles in the auditory nerve (AN). Here, we review previously published psychoacoustical evidence in humans and computer-model simulations of inner hair cell responses to noises with and without high-frequency spectral notches that dispute this view. We also present new recordings from guinea pig AN and "ideal observer" analyses of these recordings that suggest that discrimination between noises with and without high-frequency spectral notches is probably based on the information carried in the temporal pattern of AN discharges. The exact nature of the neural code involved remains nevertheless uncertain: computer model simulations suggest that high-frequency spectral notches are encoded in spike timing patterns that may be operant in the 4-7 kHz frequency regime, while "ideal observer" analysis of experimental neural responses suggest that an effective cue for high-frequency spectral discrimination may be based on sampling rates of spike arrivals of AN fibers using non-overlapping time binwidths of between 4 and 9 ms. Neural responses show that sensitivity to high-frequency notches is greatest for fibers with low and medium spontaneous rates than for fibers with high spontaneous rates. Based on this evidence, we conjecture that inter-subject variability at high-frequency spectral notch detection and, consequently, at vertical sound localization may partly reflect individual differences in the available number of functional medium- and low-spontaneous-rate fibers.

  13. Effects of direct current on the wetting behavior and interfacial morphology between molten Sn and Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yan; Shen, Ping, E-mail: shenping@jlu.edu.cn; Yang, Nan-Nan; Cao, Kang-Zhan

    2014-02-15

    Highlights: • Applying DC has a noticeable effect on the wetting of oxidized Cu by molten Sn. • Current polarity does not have a strong effect on wettability but on microstructure. • The IMC layer greatly thickens with increasing current intensity. • An unusual morphology was formed at the interface under a larger current intensity. -- Abstract: The effect of applying a direct electric current on the wetting behavior of molten Sn on Cu substrates at a nominal temperature of 510 K was investigated using a sessile drop method. The final stable contact angles were 37 ± 5° without employing a direct current (DC) while they decreased from 29 ± 3° to 16 ± 2° when the current increased from 2.5 A to 7.5 A. The current polarity does not have a noticeable effect on the wetting behavior but on interfacial morphology. Cross-sectional microstructure observations revealed that applying a current promoted the dissolution of the Cu substrate in molten Sn and the effect was enhanced with increasing current intensity. An unusual morphology with Cu{sub 3}Sn being the principal phase and Cu{sub 6}Sn{sub 5} being the secondary phase was observed under a relatively large current intensity, particularly for the case of electrons flowing from the Cu substrate to the molten Sn side. Joule heat-induced Marangoni convection in the liquid droplet and electromigration are likely to play significant roles in determining the wettability and interfacial microstructure under the application of a direct electric current.

  14. Sediment Source-to-Sink Processes in the Indus River since the Last Glacial Maximum

    Science.gov (United States)

    Clift, P. D.; Giosan, L.

    2012-04-01

    The Indus River drains the western Himalaya and Karakoram and feeds sediment to the second largest submarine sediment body on Earth. Erosion in the catchment is controlled by rock uplift rates but also by climatic variability that has caused erosional patterns to migrate as the SW monsoon first strengthened then weakened during the Holocene. The tributaries of the Indus have incised the flood plain extending >500 km from the mountain front since 10 ka recycling older deposits. This erosion accounts for about 20% of the total flux to the ocean. Much greater volumes were released from river terraces in the mountains, especially along the major river valleys and from the region within 100 km of the Nanga Parbat syntaxis. Very little new bedrock erosion is required to account for the sediment flux. About half the sediment load has been deposited onshore either in the delta or under the southern flood plains where the river sits on a major accretionary ridge. The remainder of the sediment is in the upper canyon and shelf clinoforms because no sediment has reached the deep sea since at least 7 ka. Comparison of different provenance proxies shows that zircon grains travel slowly through the river, taking 5-10 k.y. longer to travel to the river mouth than clays or micas, whose transport times are within the uncertainties for the dating methods. This slower bed load transport introduces a lag time between a change in erosion patterns and the appearance of the sediment at the river mouth. A further lag of at least 7 ka is assumed for sediments in the Indus Canyon and >11 ka for the upper fan.

  15. Field-induced transition of the magnetic ground state from A-type antiferromagnetic to ferromagnetic order in CsCo2Se2

    Science.gov (United States)

    von Rohr, Fabian; Krzton-Maziopa, Anna; Pomjakushin, Vladimir; Grundmann, Henrik; Guguchia, Zurab; Schnick, Wolfgang; Schilling, Andreas

    2016-07-01

    We report on the magnetic properties of CsCo2Se2 with ThCr2Si2 structure, which we have characterized through a series of magnetization and neutron diffraction measurements. We find that CsCo2Se2 undergoes a phase transition to an antiferromagnetically ordered state with a Néel temperature of {{T}\\text{N}}≈ 66 K. The nearest neighbour interactions are ferromagnetic as observed by the positive Curie-Weiss temperature of \\Theta≈ 51.0 K. We find that the magnetic structure of CsCo2Se2 consists of ferromagnetic sheets, which are stacked antiferromagnetically along the tetragonal c-axis, generally referred to as A-type antiferromagnetic order. The observed magnitude of the ordered magnetic moment at T  =  1.5 K is found to be only 0.20(1){μ\\text{Bohr}}  / Co. Already in comparably small magnetic fields of {μ0}H{{}\\text{MM}}(5~K)≈ 0.3 T, we observe a metamagnetic transition that can be attributed to spin-rearrangements of CsCo2Se2, with the moments fully ferromagnetically saturated in a magnetic field of {μ0}{{H}\\text{FM}}(5~K)≈ 6.4 T. We discuss the entire experimentally deduced magnetic phase diagram for CsCo2Se2 with respect to its unconventionally weak magnetic coupling. Our study characterizes CsCo2Se2, which is chemically and electronically posed closely to the A x Fe2-y Se2 superconductors, as a host of versatile magnetic interactions.

  16. EPR study of polyaniline synthesized enzymatically in the presence of submicrometer-sized AOT vesicles.

    Science.gov (United States)

    Rakvin, Boris; Carić, Dejana; Andreis, Mladen; Junker, Katja; Walde, Peter

    2014-02-27

    EPR spectroscopy was used to examine the magnetic properties of two enzymatically synthesized polyaniline (PANI) samples obtained in the presence of submicrometer-sized vesicles formed from sodium bis(2-ethylhexyl)sulfosuccinate (AOT) as templates. PANI-HRPC-AOT was synthesized with horseradish peroxidase isoenzyme C (HRPC) and hydrogen peroxide (H2O2) as oxidant while PANI-TvL-AOT was prepared with Trametes versicolor laccase (TvL) and dioxygen (O2) as oxidant. A commercial conductive sample of the emeraldine salt form of polyaniline (PANI-ES) was also used for comparison in order to correlate the experimental data obtained for PANI-HRPC-AOT and PANI-TvL-AOT with the properties of the well-characterized PANI-ES. It was shown that a model based on the concept of correlated polaronic bands could be applied for the interpretation of the EPR spectra of all three examined samples, although PANI-HRPC-AOT and PANI-TvL-AOT were significantly less conductive than PANI-ES. The magnetic properties of the PANI samples could be related to their conductivities, whereby a low conductivity was ascribed to decreased interchain spin interactions which were detectable from a splitting of the triplet spectrum at low temperatures (5-10 K). The obtained effective distance between the polyaniline chains is larger for enzymatically synthesized PANI than for PANI-ES, most likely mainly due to the presence of AOT which could not be removed completely during the work-up. AOT influences the chain conformation and the average chain-chain distance.

  17. TiO2 effect on crystallization mechanism and physical properties of nano glass-ceramics of MgO-Al2O3-SiO2 glass system.

    Science.gov (United States)

    Jo, Sinae; Kang, Seunggu

    2013-05-01

    The effect of TiO2 on the degree of crystallization, thermal properties and microstructure for MgO-Al2O3-SiO2 glass-ceramics system containing 0-13 wt% TiO2 and 0-1.5 wt% B2O3 in which the cordierite is the main phase was studied. Using Kissinger and Augis-Bennett equations, the activation energy, 510 kJ/mol and Avrami constant, 1.8 were calculated showing the surface-oriented crystallization would be preferred. The alpha-cordierite phase was generated in the glass-ceramics of containing TiO2 of 0-5.6 wt%. However, for the glass-ceramics of TiO2 content above 7 wt%, an alpha-cordierite disappeared and micro-cordierite phase was formed. The glass-ceramics of no TiO2 added had spherical crystals of few tens nanometer size spread in the matrix. As TiO2 content increased up to 5.6 wt%, a lump of dendrite was formed. In the glass-ceramics containing TiO2 7-13 wt%, in which the main phase is micro-cordierite, the dendrite crystal disappeared and a few hundred nanometer sized crystal particles hold tightly each other were generated. The thermal conductivity of glass-ceramics of both a-cordierite and micro-cordierite base decreased with TiO2 contend added. The thermal conductivity of glass-ceramics of 1.5 wt% TiO2 added was 3.4 W/mK which is 36% higher than that of glass-ceramics of no TiO2 added. The sintering temperature for 1.5 wt% TiO2 glass-ceramics was 965 degrees C which could be concluded as to apply to LTCC process for LED packaging.

  18. High average power CO II laser MOPA system for Tin target LPP EUV light source

    Science.gov (United States)

    Ariga, Tatsuya; Hoshino, Hideo; Endo, Akira

    2007-02-01

    Extreme ultraviolet lithography (EUVL) is the candidate for next generation lithography to be introduced by the semiconductor industry to HVM (high volume manufacturing) in 2013. The power of the EUVL light source has to be at least 115W at a wavelength of 13.5nm. A laser produced plasma (LPP) is the main candidate for this light source but a cost effective laser driver is the key requirement for the realization of this concept. We are currently developing a high power and high repetition rate CO II laser system to achieve 50 W intermediate focus EUV power with a Tin droplet target. We have achieved CE of 2.8% with solid Tin wire target by a transversely excited atmospheric (TEA) CO II laser MOPA system with pulse width, pulse energy and pulse repetition rate as 10~15 ns, 30 mJ and 10 Hz, respectively. A CO II laser system with a short pulse length less than 15 ns, a nominal average power of a few kW, and a repetition rate of 100 kHz, based on RF-excited, fast axial flow CO II laser amplifiers is under development. Output power of about 3 kW has been achieved with a pulse length of 15 ns at 130 kHz repletion rate in a small signal amplification condition with P(20) single line. The phase distortion of the laser beam after amplification is negligible and the beam can be focused to about 150μm diameter in 1/e2. The CO II laser system is reported on short pulse amplification performance using RF-excited fast axial flow lasers as amplifiers. And the CO II laser average output power scaling is shown towards 5~10 kW with pulse width of 15 ns from a MOPA system.

  19. Observations of cloud and rainfall enhancement over irrigated agriculture in an arid environment

    Science.gov (United States)

    Garcia-Carreras, Luis; Marsham, John H.; Spracklen, Dominick V.

    2017-04-01

    The impact of irrigated agriculture on clouds and rainfall remains uncertain, particularly in less studied arid regions. Irrigated crops account for 20% of global cropland area, and non-renewable groundwater accounts for 20% of global irrigation water demand. Quantifying the feedbacks between agriculture and the atmosphere are therefore not only necessary to better understand the climate impacts of land-use change, but are also crucial for predicting long-term water use in water-scarce regions. Here we use high spatial-resolution satellite data to show the impact of irrigated crops in the arid environment of northern Saudi Arabia on cloud cover and rainfall patterns. Land surface temperatures over the crops are 5-10 K lower than their surroundings, linked to evapotranspiration rates of up to 20 mm/ month. Daytime cloud cover is up to 30% higher over the cropland compared to its immediate surroundings, and this enhancement is highly correlated with the seasonal variability in leaf area index. The cloud enhancement is associated with a much more rapid cloud cloud development during the morning. Afternoon rainfall is 85% higher over, and just downwind, of the cropland during the growing season, although rainfall remains very low in absolute terms. The feedback sign we find is the opposite to what has been observed in tropical and semiarid regions, where temperature gradients promote convergence and clouds on the warmer side of land-surface type discontinuities. This suggests that different processes are responsible for the land-atmosphere feedback in very dry environments, where lack of moisture may be a stronger constraint. Increased cloud and rainfall, and associated increases in diffuse radiation and reductions in temperature, can affect vegetation growth thus producing an internal feedback. These effects will therefore need to be taken into account to properly assess the impact of climate change on crop productivity and water use, as well as how global land-use change affects climate.

  20. Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

    Science.gov (United States)

    DSouza, Alisha V.; Lin, Huiyun; Henderson, Eric R.; Samkoe, Kimberley S.; Pogue, Brian W.

    2016-08-01

    There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here.

  1. Light-Driven Contact Hearing Aid for Broad-Spectrum Amplification: Safety and Effectiveness Pivotal Study.

    Science.gov (United States)

    Gantz, Bruce J; Perkins, Rodney; Murray, Michael; Levy, Suzanne Carr; Puria, Sunil

    2017-03-01

    Demonstrate safety and effectiveness of the light-driven contact hearing aid to support FDA clearance. A single-arm, open-label investigational-device clinical trial. Two private-practice and one hospital-based ENT clinics. Forty-three subjects (86 ears) with mild-to-severe bilateral sensorineural hearing impairment. Bilateral amplification delivered via a light-driven contact hearing aid comprising a Tympanic Lens (Lens) with a customized platform to directly drive the umbo and a behind-the-ear sound processor (Processor) that encodes sound into light pulses to wirelessly deliver signal and power to the Lens. The primary safety endpoint was a determination of "no change" (PTA4 hearing at the 120-day measurement interval. The primary efficacy endpoint was improvement in word recognition using NU-6 at the 30-day measurement interval over the baseline unaided case. Secondary efficacy endpoints included functional gain from 2 to 10 kHz and speech-in-noise improvement over the baseline unaided case using both omnidirectional and directional microphones. The results for the 86 ears in the study determined a mean change of -0.40 dB in PTA4, indicating no change in residual hearing (p Hearing in Noise Test was 0.75 dB (p = 0.028) and 3.14 dB (p < 0.0001) for the omnidirectional and directional microphone modes, respectively. The safety and effectiveness data supported a de novo 510(k) submission that received clearance from the FDA.

  2. Structure and anti-influenza A (H1N1) virus activity of three polysaccharides from Eucheuma denticulatum

    Science.gov (United States)

    Yu, Guangli; Li, Miaomiao; Wang, Wei; Liu, Xin; Zhao, Xiaoliang; Lv, Youjing; Li, Guangsheng; Jiao, Guangling; Zhao, Xia

    2012-12-01

    Three polysaccharides (EW, EH and EA) were prepared from a red alga Eucheuma denticulatum by sequential extraction with cold water, hot water and sodium hydroxide water solution. Their monosaccharide compositions, relative molecular mass and structural characterization were determined by gas chromatography, high performance 1iquid chromatography, fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy methods. EW was hybrid ı/κ/ν-carrageenan (70 ı/17κ/13ν-carrabiose), EH was mainly ı-carrageenan, and EA was mainly α-1,4-Glucan (88%) but mixed with small amount of ı-carrageenan (12%). The relative molecular mass of EW, EH and EA was 480, 580 and 510 kDa, respectively. The anti-influenza A (H1N1) virus activity of these three polysaccharides was evaluated using the Madin-Darby canine kidney cells model. EW showed good anti-H1N1 virus activity, its IC50 was 276.5 μg mL-1, and the inhibition rate to H1N1 virus was 52% when its concentration was 250 μg mL-1. The IC50 of ı-carrageenan EH was 366.4 μg mL-1, whereas EA showed lower anti-H1N1 virus activity (IC50>430 μg mL-1). Available data obtained give positive evidence that the hybrid carrageenan EW from Eucheuma denticulatum can be used as potential anti-H1N1 virus inhibitor in future.

  3. Pulsed microwave discharges in powder mixtures: Status, problems, and prospects

    Science.gov (United States)

    Batanov, G. M.; Kossyi, I. A.

    2015-10-01

    Results of experiments on the excitation of pulsed microwave discharges by gyrotron radiation (λ = 4 mm, P 0 = 100-500 kW, τ = 1-10 ms) in the volumes and on the surfaces of metal-dielectric powder mixtures are presented. It is shown that there are two phases of discharge development: the spark phase, accompanied by a partial evaporation of the powder material, and the phase of a developed discharge, characterized by a plasma density of ˜1017 cm-3, high absorption, and high temperatures (˜5-10 kK) in a thin layer (˜0.1-0.2 mm) of plasma and vapor. It is demonstrated that the conductivity induced in the targets by UV radiation play an important role in the microwave absorption by powder grains. It is found that, in the course of the discharge, a conductive metal mesh forms in the powder volume as a result of metal evaporation. Reactions of high-temperature synthesis were initiated in various powder mixtures (Ti + B, Al + Fe2O3, Mo + B, etc.). It is shown that the reactions of high-temperature synthesis last for up to 0.1 s and are accompanied by the evaporation of powder grains and the formation of an aerosol cloud due to free expansion of reactants from the sample surface. The possibility of experimentally studying the kinetics of reactions of high-temperature synthesis is demonstrated. It is noticed that microwave discharges can be used to initiate plasmachemical reactions on the surfaces of radioparent materials in active gaseous media.

  4. Ab Initio Study of the Rotational-Torsional Spectrum of Methyl Formate

    Science.gov (United States)

    Senent, M. L.; Villa, M.; Meléndez, F. J.; Domínguez-Gómez, R.

    2005-07-01

    The molecular structure of methyl formate is determined from ab initio calculations. The molecule presents two conformers (cis and trans) with a 5.3 kcal mol-1 difference in energy. In the most stable cis conformer, the carbonyl group eclipses the methyl group. The internal rotation barriers are V3(cis)=368 cm-1 and V3(trans)=26 cm-1 for the methyl group and VCO=4826 cm-1 for the CO group. The dependence of the spectroscopic parameters on the torsional motions is detailed. The rotational-torsional energy levels have been calculated variationally up to J=6 using a flexible model depending on the two torsional modes. Far-infrared frequencies and intensities are determined at room temperature. The rotational parameters have been computed to be A=20,040.473 MHz, B=6974.140 MHz, C=5350.705 MHz, DJ=-0.510 kHz, DJK=1.566 kHz, and DK=-0.619 kHz; and A=20,040.492 MHz, B=6974.399 MHz, C=5350.851 MHz, DJ=2.070 kHz, DJK=14.712 kHz, and DK=5.898 kHz at the symmetric and E components of the cis ground state, respectively. The corresponding values for trans-methyl formate are A=47,380.066 MHz, B=4738.781 MHz, and C=4430.339 MHz; and A=47,389.697 MHz, B=4737.751 MHz, and C=4429.607 MHz.

  5. RX Herculink Elite® renal stent system: a review of its use for the treatment of renal artery stenosis

    Directory of Open Access Journals (Sweden)

    Colyer Jr

    2012-08-01

    Full Text Available William R Colyer JrDivision of Cardiovascular Medicine, University of Toledo Medical Center, Toledo, OH, USAAbstract: The management of renal artery stenosis (RAS remains controversial. While some evidence suggests that treatment with stent placement is beneficial, randomized trials have failed to demonstrate a significant benefit. Ongoing clinical trials should help to better define the role for stenting of RAS while avoiding limitations seen with earlier trials. When it comes to stenting for RAS, several stents have been used; however, many stents which have been used previously and which are still being used are biliary stents that are used “off-label.” These stents have typically come onto the market through the 510(k pathway. To date, a total of five stents have been approved by the United States Food and Drug Administration for use in the renal arteries. Of the five stents that have received approval, the Bridge™ Extra Support (Medtronic CardioVascular, Santa Rosa, CA and the Palmaz® (Cordis Corporation, Bridgewater, NJ stents are no longer available. Currently, the Express® SD (Boston Scientific, Natick, MA, Formula™ (Cook Medical, Bloomington, IN, and Herculink Elite® (Abbott Vascular, Santa Clara, CA stents are Food and Drug Administration approved and available for use. The Herculink Elite is the most recently approved of the renal stents, having received approval in late 2011. The Herculink Elite stent is the only cobalt chromium stent approved for use in the renal arteries. Although trial data are limited and direct comparisons among renal stents is not possible, the Herculink Elite stent has demonstrated good performance. Additionally, the design of the Herculink Elite offers some advantages that may translate into improved outcomes.Keywords: renal artery stenosis, stenting, FDA approval

  6. Astrochemical Laboratory Experiments as Analogs to Plutonian Chemistry: Using FTIR Spectroscopy to Monitor the Sublimation of Irradiated 1:1:100 CO+H_{2}O+N_{2} and 1:1:100 CH_{4}+H_{2}O+N_{2} Ices

    Science.gov (United States)

    Stelmach, Kamil Bartlomiej; Yarnall, Yukiko; Cooper, Paul

    2017-06-01

    Pluto is a large icy body composed of N_{2}, CH_{4}, and H_{2}O ices. In many ways, Pluto can be seen as one large matrix isolation experiment where N_{2} is the inert matrix that can act to trap and isolate reactive species. The temperature changes on the dwarf planet induce sublimation of N_{2} from the surface. Any previously trapped reactive species could then react with the new ice or neighboring molecules. To see if this process might lead to a significant formation of molecules, Fourier-Transform Infrared (FTIR) Spectroscopy (4 cm^{-1} resolution) was used to study and monitor the sublimation of ices created from irradiated gas mixtures of 1:1:100 CO+H_{2}O+N_{2} or 1:1:100 CH_{4}+H_{2}O+N_{2}. The gas mixtures were initially prepared and deposited on a cold finger at a temperature of 6 K and a baseline vacuum of about 1 x 10^{-7} Torr. Gas mixtures were irradiated using an electric discharge or a microwave discharge before deposition to create the unstable chemical species. To sublimate the matrix, the temperature was brought up step-wise in 5-10 K intervals to 45 K. Slow sublimation (10 min per step) resulted in the new species being trapped in a water ice. In addition to (FTIR) spectroscopy, chemical species were also identified or monitored using ultraviolet-visible (UV-Vis) spectroscopy and a residual gas analyzer (RGA). Carbon suboxide (C_{3}O_{2}), a common component found in meteorites and a potentially important prebiotic molecule, was formed only after the sublimation step. Other products formed included deprotonated versions of products formed in the original matrix ice. C_{3}O_{2}'s potential importance in Pluto's surface chemistry and its overall astrobiological significance will be discussed.

  7. 关于骨科脊柱产品申报美国上市前通告和国内注册申报资料的要求对比研究%A Comparative Study on the Premarket Notiifcation in the United States and the Requirements for Domestic Registration for Orthopedic Spinal Products

    Institute of Scientific and Technical Information of China (English)

    孔玮娜; 程云章

    2016-01-01

    The newly revised Provisions forMedical Device Registration (CFDA No.4) andRequirements and Instructions for Medical Device Registration Application (CFDA No.43) introduced the idea of premarket notiifcation 510k of US Food and Drug Administration (FDA). This study made a comparison between the Requirements and Instructions for Medical Device Registration Application and theGuidance for Industry with the Guidance for Industry and FDA Staff Format for Traditional and Abbreviated 510ks. By using the orthopedic spinal products as examples, this paper analyzes the similarities and differences between the two documents, in order to provide guidance and assistance for the medical device registration dossiers preparation.%新修订的《医疗器械注册管理办法》(食品药品监督管理总局令第4号)及配套的《关于公布医疗器械注册申报资料要求和批准证明文件格式的公告》(食品药品监督管理总局令第43号)引入了美国FDA申报510k的思路,本文通过将《医疗器械注册申报资料要求及说明》和美国FDA《传统和简化510k的格式指导原则》(Guidance for Industry and FDA Staff Format for Traditional and Abbreviated 510ks)做对比,以骨科脊柱产品为例,浅析二者之间的异同点,以期对医疗器械注册申报资料的准备工作提供指导和帮助。

  8. Isolation, purification and characterization of beta-1,3-glucan binding protein from the plasma of marine mussel Perna viridis.

    Science.gov (United States)

    Jayaraj, S S; Thiagarajan, R; Arumugam, M; Mullainadhan, P

    2008-06-01

    A beta-1,3-glucan binding protein (betaGBP) specific for laminarin (a beta-1,3-glucan) was detected for the first time in a mollusc, Perna viridis. betaGBP was isolated and purified from the plasma using laminarin precipitation and affinity chromatography on laminarin-Sepharose 6B, respectively. It agglutinated bakers yeast, bacteria, and erythrocytes and enhanced prophenoloxidase (proPO) activity of the plasma in a dose-dependent manner. The purified betaGBP appeared as a single band in native-PAGE and the purity was conformed by HPLC. The protein has a molecular weight estimate of 510kDa as determined by SDS-PAGE and in isoelectric focusing the purified betaGBP was focused as a single band at pI 5.3. betaGBP was found to possess inherent serine protease activity but lacked beta-1,3-glucanase activity and all these results suggest that plasma betaGBP of P. viridis functions as a recognition molecule for beta-1,3-glucan on the surface of microbial cell walls. This recognition and binding lead to the activation of the prophenoloxidase cascade mediated by the inherent serine protease activity of betaGBP. Presence of agglutinating activity and serine protease activity shows that betaGBP is a bifunctional protein. The findings are discussed in light of the importance of this protein in the innate immune response of P. viridis, and they implicate evolutionary link with similar proteins found in other invertebrates.

  9. Magnetospheric solitary structure maintained by 3000 km/s ions as a cause of westward moving auroral bulge at 19 MLT

    Directory of Open Access Journals (Sweden)

    M. Yamauchi

    2009-07-01

    Full Text Available In the evening equatorial magnetosphere at about 4 RE geocentric distance and 19 MLT, the four Cluster spacecraft observed a solitary structure with a width of about 1000~2000 km in the propagation direction. The solitary structure propagates sunward with about 5~10 km/s carrying sunward electric field (in the propagation direction of up to about 10 mV/m (total potential drop of about 5~10 kV, depletion of magnetic field of about 25%, and a duskward E×B convection up to 50 km/s of He+ rich cold plasma without O+. At the same time, auroral images from the IMAGE satellite together with ground based geomagnetic field data showed a westward (sunward at this location propagating auroral bulge at the magnetically conjugate ionosphere with the solitary structure. The solitary structure is maintained by flux enhancement of selectively 3000 km/s ions (about 50 keV for H+, 200 keV for He+, and 750 keV for O+. These ions are the main carrier of the diamagnetic current causing the magnetic depletion, whereas the polarization is maintained by different behavior of energetic ions and electrons. Corresponding to aurora, field-aligned accelerated ionospheric plasma of several keV appeared at Cluster from both hemispheres simultaneously. Together with good correspondence in location and propagation velocity between the auroral bulge and the solitary structure, this indicates that the sunward moving auroral bulge is caused by the sunward propagation of the solitary structure which is maintained by energetic ions. The solitary structure might also be the cause of Pi2-like magnetic variation that started simultaneously at Cluster location.

  10. Perception and coding of high-frequency spectral notches: Potential implications for sound localization

    Directory of Open Access Journals (Sweden)

    Ana eAlves-Pinto

    2014-05-01

    Full Text Available The interaction of sound waves with the human pinna introduces high-frequency notches (5-10 kHz in the stimulus spectrum that are thought to be useful for vertical sound localization. A common view is that these notches are encoded as rate profiles in the auditory nerve (AN. Here, we review previously published psychoacoustical evidence in humans and computer-model simulations of inner hair cell responses to noises with and without high-frequency spectral notches that dispute this view. We also present new recordings from guinea pig AN and ‘ideal observer’ analyses of these recordings that suggest that discrimination between noises with and without high-frequency spectral notches is probably based on the information carried in the temporal pattern of AN discharges. The exact nature of the neural code involved remains nevertheless uncertain: computer model simulations suggest that high-frequency spectral notches are encoded in spike timing patterns that may be operant in the 4-7 kHz frequency regime, while ‘ideal observer’ analysis of experimental neural responses suggest that an effective cue for high-frequency spectral discrimination may be based on sampling rates of spike arrivals of AN fibers using non-overlapping time binwidths of between 4 and 9 ms. Neural responses show that sensitivity to high-frequency notches is greatest for fibers with low and medium spontaneous rates than for fibers with high spontaneous rates. Based on this evidence, we conjecture that inter-subject variability at high-frequency spectral notch detection and, consequently, at vertical sound localization may partly reflect individual differences in the available number of functional medium- and low-spontaneous-rate fibers.

  11. Comparison of thermal properties of fish collagen and bovine collagen in the temperature range 298-670K.

    Science.gov (United States)

    Gauza-Włodarczyk, Marlena; Kubisz, Leszek; Mielcarek, Sławomir; Włodarczyk, Dariusz

    2017-11-01

    The increased interest in fish collagen is a consequence of the risk of exposure to Creutzfeld-Jacob disease (CJD) and the bovine spongiform encephalopathy (BSE), whose occurrence is associated with prions carried by bovine collagen. Collagen is the main biopolymer in living organisms and the main component of the skin and bones. Until the discovery of the BSE, bovine collagen had been widely used. The BSE epidemic increased the interest in new sources of collagen such as fish skin collagen (FSC) and its properties. Although the thermal properties of collagen originating from mammals have been well described, less attention has been paid to the thermal properties of FSC. Denaturation temperature is a particularly important parameter, depending on the collagen origin and hydration level. In the reported experiment, the free water and bound water release processes along with thermal denaturation process were studied by means of the differential scanning calorimetry (DSC). Measurements were carried out using a DSC 7 instrument (Elmer-Perkin), in the temperature range 298-670K. The study material was FSC derived by acidic hydration method. The bovine Achilles tendon (BAT) collagen type I was used as the control material. The thermograms recorded revealed both, exothermic and endothermic peaks. For both materials, the peaks in the temperature range of 330-360K were assigned to the release of free water and bound water. The denaturation temperatures of FSC and BAT collagen were determined as 420K and 493K, respectively. Thermal decomposition process was observed at about 500K for FSC and at about 510K for BAT collagen. These results show that FSC is less resistant to high temperature than BAT collagen. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Simplification of intradermal skin testing in Hymenoptera venom allergic children.

    Science.gov (United States)

    Cichocka-Jarosz, Ewa; Stobiecki, Marcin; Brzyski, Piotr; Rogatko, Iwona; Nittner-Marszalska, Marita; Sztefko, Krystyna; Czarnobilska, Ewa; Lis, Grzegorz; Nowak-Węgrzyn, Anna

    2017-03-01

    The direct comparison between children and adults with Hymenoptera venom anaphylaxis (HVA) has never been extensively reported. Severe HVA with IgE-documented mechanism is the recommendation for venom immunotherapy, regardless of age. To determine the differences in the basic diagnostic profile between children and adults with severe HVA and its practical implications. We reviewed the medical records of 91 children and 121 adults. Bee venom allergy was exposure dependent, regardless of age (P venom allergic group, specific IgE levels were significantly higher in children (29.5 kUA/L; interquartile range, 11.30-66.30 kUA/L) compared with adults (5.10 kUA/L; interquartile range, 2.03-8.30 kUA/L) (P venom were higher in bee venom allergic children compared with the wasp venom allergic children (P venom. At concentrations lower than 0.1 μg/mL, 16% of wasp venom allergic children and 39% of bee venom allergic children had positive intradermal test results. The median tryptase level was significantly higher in adults than in children for the entire study group (P = .002), as well as in bee (P = .002) and wasp venom allergic groups (P = .049). The basic diagnostic profile in severe HVA reactors is age dependent. Lower skin test reactivity to culprit venom in children may have practical application in starting the intradermal test procedure with higher venom concentrations. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  13. Regulation and Device Development: Tips for Optimizing Your Experience With the Food and Drug Administration.

    Science.gov (United States)

    Brooks, Steven S

    2017-06-01

    Physician-inventors are in a unique position to identify unserved patient needs, and innovate solutions to clinical problems. These solutions may also have associated commercial opportunities. The logistics of developing these medical products, however, can seem a daunting task. One of the primary barriers in the United States is the regulatory process of the Food and Drug Administration (FDA). In this article, we will explore the risk-based approach used by the FDA which forms a framework to consider the regulatory pathway and the process to gain regulatory clearance or approval for medical devices. Inherent device properties and the procedural risk of the devices will determine the rigor with which they are scrutinized by FDA, and the evidentiary requirements to legally market them. Data and evidentiary development will vary depending on risk and regulatory precedent and may or may not require clinical data This regulatory paradigm will determine into which risk-based device class they fit, and whether they are regulated under the 510(k) or premarket approval application pathways. The FDA, although gatekeeper of the US market and tasked with determining which products are safe and effective, can be a powerful ally for product development. They have significant scientific and medical expertise, and mechanisms to both provide guidance, and also to consider novel approaches to product development and evidence development. Early interaction for routine and novel products alike can result in expedited and efficient development. This collaborative approach can be best practice to most expeditiously develop the next generation of products, getting them into the hands of US doctors and into the treatment of US patients. Copyright © 2017. Published by Elsevier Inc.

  14. Crystal Structure and Ionic Conductivity of Three Polymorphic Phases of Rubidium Trefluoromethyl Sulfonate, RbSO3CF3

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt,L.; Dinnebier, R.; Jansen, M.

    2006-01-01

    The crystal structures of three polymorphic phases of rubidium trifluoromethyl sulfonate (RbSO{sub 3}CF{sub 3}, rubidium 'triflate') were solved from X-ray powder diffraction data. At room temperature, rubidium triflate crystallizes in the monoclinic space group Cm with lattice parameters of a = 19.9611(5) Angstroms, b = 23.4913(7) Angstroms, c = 5.1514(2) Angstroms, = 102.758(2); Z = 16. At T = 321 K, a first-order phase transition occurs toward a monoclinic phase in space group P2{sub 1} with lattice parameters at T = 344 K of a = 10.3434(5) Angstroms, b = 5.8283(3) Angstroms, c = 5.1982(3) Angstroms, = 104.278(6); Z = (2). At T = 461 K, another phase transition, this time of second order, occurs toward an orthorhombic phase in space group Cmcm with lattice parameters at T = 510 K of a = 5.3069(2) Angstroms, b = 20.2423(10) Angstroms, c = 5.9479(2) Angstroms; Z = 4. As a common feature within all three crystal structures of rubidium triflate, the triflate anions are arranged in double layers with the lipophilic CF{sub 3} groups facing each other. The rubidium ions are located between the SO{sub 3} groups. The general packing is similar to the packing in cesium triflate. Rubidium triflate can be classified as a solid electrolyte with a specific ionic conductivity of = 9.89 x 10{sup -9} S/cm at T = 384 K and = 3.84 x 10{sup -6} S/cm at T = 481 K.

  15. Crystal structure and ionic conductivity of three polymorphic phases of rubidium trifluoromethyl sulfonate, RbSO3CF3.

    Science.gov (United States)

    Hildebrandt, Lars; Dinnebier, Robert; Jansen, Martin

    2006-04-17

    The crystal structures of three polymorphic phases of rubidium trifluoromethyl sulfonate (RbSO3CF3, rubidium 'triflate') were solved from X-ray powder diffraction data. At room temperature, rubidium triflate crystallizes in the monoclinic space group Cm with lattice parameters of a = 19.9611(5) A, b = 23.4913(7) A, c = 5.1514(2) A, beta = 102.758(2) degrees; Z = 16. At T = 321 K, a first-order phase transition occurs toward a monoclinic phase in space group P2(1) with lattice parameters at T = 344 K of a = 10.3434(5) A, b = 5.8283(3) A, c = 5.1982(3) A, beta = 104.278(6) degrees; Z = 2). At T = 461 K, another phase transition, this time of second order, occurs toward an orthorhombic phase in space group Cmcm with lattice parameters at T = 510 K of a = 5.3069(2) A, b = 20.2423(10) A, c = 5.9479(2) A; Z = 4. As a common feature within all three crystal structures of rubidium triflate, the triflate anions are arranged in double layers with the lipophilic CF3 groups facing each other. The rubidium ions are located between the SO3 groups. The general packing is similar to the packing in cesium triflate. Rubidium triflate can be classified as a solid electrolyte with a specific ionic conductivity of sigma = 9.89 x 10(-9) S/cm at T = 384 K and sigma = 3.84 x 10(-6) S/cm at T = 481 K.

  16. Effect of size and shape dependent anisotropy on superparamagnetic property of CoFe2O4 nanoparticles and nanoplatelets

    Science.gov (United States)

    Chandekar, Kamlesh V.; Kant, K. Mohan

    2017-09-01

    Superparamagnetic cobalt ferrite (CoFe2O4) spherical nanoparticles and rhomboidal nanoplatelets were synthesized by co-precipitation at 80 °C (S1) and hydrothermal route at 150 °C (S2). X-ray diffraction (XRD) pattern confirms formation of cubic inverse spinel structure of as prepared cobalt ferrite samples (S1 and S2) with average crystallite size of 13 nm and 18.7 nm for S1 and S2 respectively. Transmission electron microscopy (TEM) reveals spherical and rhomboidal shaped with average particle size 16.7 nm (S1) and 19.8 nm (S2). The zero field cooled magnetization MZFCvs. T exhibit a broad maxima at 400 K and 510 K for S1 and S2 respectively. The blocking temperature TB is obtained as 310 K and 341 K for S1 and S2 respectively, by fitting coercive field at different temperatures to T 1 / 2 law. The morphology of S1 and S2 corresponds to shape dependence of continuum approach. The effective demagnetization factors estimated as ΔN1 = 0 and ΔN2 = 0 . 749 for S1 and S2 samples respectively. The uniaxial anisotropy and shape anisotropy observed to be dominant in spherical shaped and rhomboidal shaped CoFe2O4 nanoparticles respectively. The uniaxial anisotropy constant of S1 sample is estimated as 56 (kJ/m3) at TB = 310 K whereas the effective anisotropy constant for S2 sample is 627 (kJ/m3) at TB = 341 K , in which shape anisotropy constant 605 (kJ/m3) dominates over contribution from uniaxial anisotropy constant 22 (kJ/m3) in S2 sample.

  17. Kinetically driven self-assembly of a binary solute mixture with controlled phase separation via electro-hydrodynamic flow of corona discharge.

    Science.gov (United States)

    Jung, Hee Joon; Huh, June; Park, Cheolmin

    2012-10-21

    This feature article describes a new and facile process to fabricate a variety of thin films of non-volatile binary solute mixtures suitable for high performance organic electronic devices via electro-hydrodynamic flow of conventional corona discharge. Both Corona Discharge Coating (CDC) and a modified version of CDC, Scanning Corona Discharge Coating (SCDC), are based on utilizing directional electric flow, known as corona wind, of the charged uni-polar particles generated by corona discharge between a metallic needle and a bottom plate under a high electric field (5-10 kV cm(-1)). The electric flow rapidly spreads out the binary mixture solution on the bottom plate and subsequently forms a smooth and flat thin film in a large area within a few seconds. In the case of SCDC, the static movement of the bottom electrode on which a binary mixture solution is placed provides further control of thin film formation, giving rise to a film highly uniform over a large area. Interesting phase separation behaviors were observed including nanometer scale phase separation of a polymer-polymer binary mixture and vertical phase separation of a polymer-organic semiconductor mixture. Core-shell type phase separation of either polymer-polymer or polymer-colloidal nanoparticle binary mixtures was also developed with a periodically patterned microstructure when the relative location of the corona wind was controlled to a binary solution droplet on a substrate. We also demonstrate potential applications of thin functional films with controlled microstructures by corona coating to various organic electronic devices such as electroluminescent diodes, field effect transistors and non-volatile polymer memories.

  18. Domain wall motion and precursor dynamics in PbZrO3

    Science.gov (United States)

    Puchberger, S.; Soprunyuk, V.; Majchrowski, A.; Roleder, K.; Schranz, W.

    2016-12-01

    Single crystals of PbZrO3 have been studied by dynamic mechanical analysis measurements in the low-frequency range f =0.02 -50 Hz. The complex Young's modulus exhibits a quite rich behavior and depends strongly on the direction of the applied dynamic force. In pseudocubic [100] c direction, we found intrinsic elastic behavior as expected from the Landau theory; at the antiferroelectric transition Tc≈510 K, a downwards cusp anomaly in Y' accompanied by a peak in Y'' points to a quadratic/linear order parameter/strain coupling in the Landau free energy. Both anomalies are increasing with decreasing frequency showing that the measurements are performed in the limit ω τth>1 . Frequency scans around Tc show energy dissipation, which could result from interphase boundary motion and/or heat diffusion. Above Tc, we observe a pronounced precursor softening, quite similar as it was found in other perovskites, which can be perfectly fitted including isotropic order parameter fluctuations. The low-frequency elastic response in [110] c direction is different. Below Tc, we find in addition to the intrinsic anomaly a strong contribution from ferroelastic domains, which leads to an additional softening in Y'. With decreasing temperatures this superelastic softening gradually disappears, due to an increasing relaxation time τDW for domain wall motion, indicating glassy behavior of domain freezing in PbZrO3. In contrast to the [100] c direction, for forces along [110] c, we found a pronounced precursor hardening, starting at about 60 K above Tc. Since this anomaly is of dynamic nature, starting at the same temperature as the observed birefringence and piezoelectric anomalies [Ko et al. Phys. Rev. B 87, 184110 (2013), 10.1103/PhysRevB.87.184110], we conclude that it originates from slow dynamic polar clusters, which freeze at T*≈550 K>Tc .

  19. Numerical simulations of the subsurface structure of sunspots

    Science.gov (United States)

    Rempel, M.; Cheung, M.; Birch, A. C.; Braun, D. C.

    2011-12-01

    Knowledge of the subsurface magnetic field and flow structure of sunspots is essential for understanding the processes involved in their formation, dynamic evolution and decay. Information on the subsurface structure can be obtained by either direct numerical modeling or helioseismic inversions. Numerical simulations have reached only in recent years the point at which entire sunspots or even active regions can be modeled including all relevant physical processes such as 3D radiative transfer and a realistic equation of state. We present in this talk results from a series of different models: from simulations of individual sunspots (with and without penumbrae) in differently sized computational domains to simulations of the active region formation process (flux emergence). It is found in all models that the subsurface magnetic field fragments on an intermediate scale (larger than the scale of sunspot fine structure such as umbral dots); most of these fragmentations become visible as light bridges or flux separation events in the photosphere. The subsurface field strength is found to be in the 5-10 kG range. The simulated sunspots are surrounded by large scale flows, the most dominant and robust flow component is a deep reaching outflow with an amplitude reaching about 50% of the convective RMS velocity at the respective depth. The simulated sunspots show helioseismic signatures (frequency dependent travel time shifts) similar to those in observed sunspots. On the other hand it is clear from the simulations that these signatures originate in the upper most 2-3 Mm of the convection zone, since only there substantial perturbations of the wave speed are present. The contributions from deeper layers are insignificant, in particular a direct comparison between an 8 Mm and 16 Mm deep simulation leads to indiscernible helioseismic differences. The National Center for Atmospheric Research is sponsored by the National Science Foundation. This work is in part supported through the NASA SDO Science Center.

  20. Fit testing respirators for public health medical emergencies.

    Science.gov (United States)

    Brosseau, Lisa M

    2010-11-01

    Concerns about limiting pandemic infectious disease transmission when vaccines are not yet available prompted the Food and Drug Administration (FDA) to develop guidance for marketing respirators for use in public health medical emergencies. This project describes the results of filtering facepiece fit tests using 35 untrained, inexperienced subjects meeting the face size criteria of the National Institute for Occupational Safety and Health bivariate panel, in preparation for an FDA 510(k) application. Quantitative fit factors were measured for each subject on two replicates of each of two N95 filtering facepiece respirators (A and B) using the TSI Portacount Plus with N95 Companion. Subjects received no training or assistance with donning and had no prior experience with wearing respirators. The panel consisted of 20 females and 15 males; 80% were between 18 and 34 years of age. Almost all subjects properly placed the respirator on the face and formed the nose clip. Straps were improperly placed 25% of the time. Users reviewed the donning instructions 73% of the time and performed a seal check 80% of the time. Leaks were observed during 80% of the fit tests, most frequently at the chin during the head up and down exercise. For Respirator A, all but one subject had a 95% fit factor greater than 2 (the minimum required by FDA); one subject had a 95% fit factor of 1.5. All subjects had a 95% fit factor greater than 2.5 for Respirator B. Geometric mean fit factors ranged from 19-28 for these two respirators, and a majority of subjects were able to achieve a fit factor of 10 most of the time. However, fewer than 25% of subjects received the fit factor of 100 expected in workplace settings.

  1. Point-Counterpoint: The FDA Has a Role in Regulation of Laboratory-Developed Tests.

    Science.gov (United States)

    Caliendo, Angela M; Hanson, Kimberly E

    2016-04-01

    Since the Food and Drug Administration (FDA) released its draft guidance on the regulation of laboratory-developed tests (LDTs) in October 2014, there has been a flurry of responses from commercial and hospital-based laboratory directors, clinicians, professional organizations, and diagnostic companies. The FDA defines an LDT as an "in vitrodiagnostic device that is intended for clinical use and is designed, manufactured, and used within a single laboratory." The draft guidance outlines a risk-based approach, with oversight of high-risk and moderate-risk tests being phased in over 9 years. High-risk tests would be regulated first and require premarket approval. Subsequently, moderate-risk tests would require a 510(k) premarket submission to the FDA and low-risk tests would need only to be registered. Oversight discretion would be exercised for LDTs focused on rare diseases (defined as fewer than 4,000 tests, not cases, per year nationally) and unmet clinical needs (defined as those tests for which there is no alternative FDA-cleared or -approved test). There was an open comment period followed by a public hearing in early January of 2015, and we are currently awaiting the final decision regarding the regulation of LDTs. Given that LDTs have been developed by many laboratories and are essential for the diagnosis and monitoring of an array of infectious diseases, changes in their regulation will have far-reaching implications for clinical microbiology laboratories. In this Point-Counterpoint, Angela Caliendo discusses the potential benefits of the FDA guidance for LDTs whereas Kim Hanson discusses the concerns associated with implementing the guidance and why these regulations may not improve clinical care.

  2. Utilization of biogas produced by anaerobic digestion of agro-industrial waste: Energy, economic and environmental effects.

    Science.gov (United States)

    Hublin, Andrea; Schneider, Daniel Rolph; Džodan, Janko

    2014-07-01

    Anaerobic digestion of agro-industrial waste is of significant interest in order to facilitate a sustainable development of energy supply. Using of material and energy potentials of agro-industrial waste, in the framework of technical, economic, and ecological possibilities, contributes in increasing the share of energy generated from renewable energy sources. The paper deals with the benefits arising from the utilization of biogas produced by co-digestion of whey and cow manure. The advantages of this process are the profitability of the plant and the convenience in realizing an anaerobic digestion plant to produce biogas that is enabled by the benefits from the sale of electric energy at favorable prices. Economic aspects are related to the capital cost (€ 2,250,000) of anaerobic digestion treatment in a biogas plant with a 300 kW power and 510 kW heating unit in a medium size farm (450 livestock units). Considering the optimum biogas yield of 20.7 dm(3) kg(-1) of wet substrate and methane content in the biogas obtained of 79%, the anaerobic process results in a daily methane production of 2,500 kg, with the maximum power generation of 2,160,000 kWh y(-1) and heat generation of 2,400,000 kWh y(-1) The net present value (NPV), internal rate of return (IRR) and payback period for implementation of profitable anaerobic digestion process is evaluated. Ecological aspects related to carbon dioxide (CO2) and methane (CH4) emission reduction are assessed.

  3. Structure and Anti-influenza A (H1N1) Virus Activity of Three Polysaccharides from Eucheuma denticulatum

    Institute of Scientific and Technical Information of China (English)

    YU Guangli; LI Miaomiao; WANG Wei; LIU Xin; ZHAO Xiaoliang; LV Youjing; LI Guangsheng; JIAO Guangling; ZHAO Xia

    2012-01-01

    Three polysaccharides (EW,EH and EA) were prepared from a red alga Eucheuma denticulatum by sequential extraction with cold water,hot water and sodium hydroxide water solution.Their monosaccharide compositions,relative molecular mass and structural characterization were determined by gas chromatography,high performance liquid chromatography,fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy methods.EW was hybrid ι/κ/v-carrageenan (70ι/17κ/13v-carrabiose),EH was mainly ι-carrageenan,and EA was mainly α-1,4-Glucan (88%) but mixed with small amount of ι-carrageenan (12%).The relative molecular mass of EW,EH and EA was 480,580 and 510kDa,respectively.The anti-influenza A (H1N1) virus activity of these three polysaccharides was evaluated using the Madin-Darby canine kidney cells model.EW showed good anti-H1N1 virus activity,its IC50 was 276.5 μg mL-1,and the inhibition rate to H1N1 virus was 52% when its concentration was 250 μg mL-1.The IC50 of ι-carrageenan EH was 366.4 μgmL-1,whereas EA showed lower anti-H1N1 virus activity (IC50>430 μgmL-1).Available data obtained give positive evidence that the hybrid carrageenan EW from Eucheuma denticulatum can be used as potential anti-H1N1 virus inhibitor in future.

  4. High-resolution label-free vascular imaging using a commercial, clinically approved dermatological OCT scanner

    Science.gov (United States)

    Byers, R. A.; Tozer, G.; Brown, N. J.; Matcher, S. J.

    2016-02-01

    Background and Aim: Recently developed decorrelative techniques such as speckle-variance optical coherence tomography (svOCT) have demonstrated non-invasive depth-resolved imaging of the microcirculation in-vivo. However, bulk tissue motion (BTM) originating from the subject's breathing or heartbeat remains problematic at low imaging speeds, often resulting in full frame decorrelation and a loss of vascular contrast. The aim of this study was to build upon existing svOCT techniques through utilisation of a commercially available, probe-based VivoSight OCT system running at 20 kHz Axial-scan rate. Methods and results: Custom four-dimensional scanning strategies were developed and utilised in order to maximise the interframe correlation during image acquisition. Volumes of structural OCT data were collected from various anatomical regions and processed using the aforementioned svOCT algorithm to reveal angiographic information. Following data collection, three dimensional image registration and novel filtering algorithms were applied to each volume in order to ensure that BTM artefacts were sufficiently suppressed. This enabled accurate visualisation of the microcirculation within the papillary dermis, to a depth of approximately 2mm. Applications of this technique, including quantitative capillary loop density measurement and visualisation of wound healing are demonstrated and enhanced through widefield mosaicing of the svOCT data. Conclusions: Non-invasive microcirculation imaging using an FDA 510(k) approved OCT scanner such as the VivoSight allows direct clinical utilisation of these techniques, in particular for the pathological analysis of skin diseases. This research was supported by BBSRC Doctoral Training Grant: BB/F016840/1. The authors also gratefully acknowledge the use of equipment funded by MRC grant: MR/L012669/1.

  5. Effects of Medium,NPK Proportion and Nitrogen Concentration on Vegetative Growth of Oncidium%基质、氮磷钾比例和氮肥浓度对文心兰生长的影响

    Institute of Scientific and Technical Information of China (English)

    刘晓荣; 廖飞雄; 王碧青; 徐晔春

    2011-01-01

    为提高文心兰的栽培管理水平,为合理施肥提供参考依据,以文心兰切花品种'黄金二号'为试验材料,对不同基质、不同氮磷钾配比及氮肥浓度3个因素进行组合筛选.试验结果显示,水苔与木炭等比例混合基质有利于促进一年生文心兰植株生长,与对照相比,对次代新芽生长达到显著性差异.有利于芽高生长发育的组合是水苔+木炭(1:1),氮磷钾施肥比例30:10:10,氮肥浓度200 mg/L;假球茎发育阶段以水苔+木炭(1:1),氮磷钾施肥比例20:20:20,氮肥浓度100 mg/L为最好;次代新芽以水苔+木炭(1:1),氮磷钾肥比例为20:20:20,氮肥浓度为200 mg/L时生长好.%In order to improve cultivation management level and provide reference for fertilization of Oncidium reasonably, research was conducted to investigate the interaction of different medium, NPK Proportion and nitrogen concentration combinations on growth of ‘ Oncidium Goldiana × O. Guiena Gold’. Plants grown in the sphagnum moss: charcoal (1:1) promoted shoot, pseudobulb and significantly enhanced secondary shoot growth.Combinations of sphagnum moss: charcoal (1:1), 30 N:10 P2O5:10 K2O and 200 mg/L nitrogen accelerated shoot growth. While giving combinations of sphagnum moss: charcoal(1:1), 20 N:20 P2O5:20 K2O and 100 mg/L nitrogen boosted pseudobulb growth, at the same time enhanced secondary shoot growth only increasing nitrogen from 100 mg/L to 200 mg/L.

  6. Utility of Real-Time Shear Wave Elastography in the Assessment of Testicular Torsion.

    Directory of Open Access Journals (Sweden)

    Zhenxing Sun

    Full Text Available Real-time shear-wave elastography (SWE is a newly developed method which can obtain the stiffness of tissues and organs based on tracking of shear wave propagation through a structure. Several studies have demonstrated its potential in the differentiation between diseased and normal tissue in clinical practices, however the applicability to testicular disease has not been well elucidated. We investigated the feasibility and reproducibility of SWE in the detection of testicular torsion. This prospective study comprised 15 patients with complete testicular torsion. Results obtained from SWE along with conventional gray-scale and color Doppler sonography and post-operative pathology were compared. The results revealed that (i the size of injured testis was increased and the twisted testis parenchyma was heterogeneous. The blood flow signals in injured testis were barely visible or absent; (ii The Young's modulus, including Emean, Emax, Emin and SD values in the border area of torsional testis were higher than those of normal testis (Emean, 78.07±9.01 kPa vs 22.0±5.10 kPa; Emax, 94.07±6.53 kPa vs 27.87±5.78 kPa; Emin, 60.73±7.84 kPa vs 18.90±4.39 kPa; SD, 7.67±0.60 kPa vs 2.30±0.36 kPa, [P<0.05]; The Emax and SD values in the central area of the torsional testis were higher than the corresponding area of the normal testis (Emax, 8.23±0.30 kPa vs 3.97±0.95 kPa; SD, 1.5±0.26 kPa vs 0.67±0.35 kPa,[P<0.05] and Emin values was lower than those of normal testicles (0.93±0.51 kPa vs 1.6±0.36 kPa; [P<0.05]; (iii The Young's modulus measurement between two physicians showed good agreement. The pathological findings were accordance with SWE measurement. SWE is a non-invasive, convenient and high reproducible method and may serve as an important alternative tool in the diagnosis and monitoring the progression of the acute scrotums, in additional to conventional Doppler sonography.

  7. Sediment provenance, reworking and transport processes in the Indus River by U-Pb dating of detrital zircon grains

    Science.gov (United States)

    Alizai, Anwar; Carter, Andrew; Clift, Peter D.; VanLaningham, Sam; Williams, Jeremy C.; Kumar, Ravindra

    2011-03-01

    We present new major and trace element data, together with U-Pb ages for zircon sand grains from the major tributaries of the Indus River, as well as the adjacent Ghaggar and Yamuna Rivers and from bedrocks within the Sutlej Valley, in order to constrain the origin of the sediment reaching the Arabian Sea. Zircon grains from the upper Indus are generally younger than 200 Ma and contrast with those from the eastern tributaries eroded from Himalayan sources. Grains younger than 15 Ma, which typify the Nanga Parbat Massif, comprise no more than 1-2% of the total, even in the upper Indus, showing that this terrain is not a major sediment producer, in contrast with the Namche Barwe Massif in the eastern Himalayan syntaxis. The Sutlej and Yamuna Rivers in particular are very rich in Lesser Himalayan-derived 1500-2300 Ma zircons, while the Chenab is dominated by 750-1250 Ma zircons, mostly eroded from the Greater Himalaya. The upper Indus, Chenab and Ravi yield zircon populations broadly consistent with the outcrop areas, but the Jhelum and the Sutlej contain many more 1500-2300 Ma zircons than would be predicted from the area of Lesser Himalayan rock within their drainages. A significant population of grains younger than 200 Ma in the sands of the Thar Desert indicates preferential eolian, monsoon-related transport from the Indus lower reaches, rather than reworking from the local rivers. Modelling of observed zircon ages close to the delta contrasts with modern water discharge. The delta is rich in zircons dating 1500-2300 Ma, while discharge from modern rivers carrying such grains is low. The modest size of the Sutlej, the richest source of these materials in the modern system, raises the possibility that the compositionally similar Yamuna used to flow westwards in the recent past. Our data indicate a non-steady state river with zircon transport times of 5-10 k.y. inferred from earlier zircon dating of delta sands. The modern delta zircons image an earlier, likely Early-Mid Holocene, erosional state, in which the Lesser Himalaya were more important as sediment suppliers. Early-Mid Holocene sands show much less erosion from the Karakoram-Transhimalaya compared to those deposited at the Last Glacial Maximum, or calculated from the modern discharge. We favour variations in summer monsoon intensity as the primary cause of these temporal changes.

  8. Bioproduction of L-Aspartic Acid and Cinnamic Acid by L-Aspartate Ammonia Lyase from Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Patel, Arti T; Akhani, Rekha C; Patel, Manisha J; Dedania, Samir R; Patel, Darshan H

    2017-06-01

    Aspartase (L-aspartate ammonia lyase, EC 4.3.1.1) catalyses the reversible amination and deamination of L-aspartic acid to fumaric acid which can be used to produce important biochemical. In this study, we have explored the characteristics of aspartase from Pseudomonas aeruginosa PAO1 (PA-AspA). To overproduce PA-AspA, the 1425-bp gene was introduced in Escherichia coli BL21 and purified. A 51.0-kDa protein was observed as a homogenous purified protein on SDS-PAGE. The enzyme was optimally active at pH 8.0 and 35 °C. PA-AspA has retained 56% activity after 7 days of incubation at 35 °C, which displays the hyperthermostablility characteristics of the enzyme. PA-AspA is activated in the presence of metal ions and Mg2+ is found to be most effective. Among the substrates tested for specificity of PA-AspA, L-phenylalanine (38.35 ± 2.68) showed the highest specific activity followed by L-aspartic acid (31.21 ± 3.31) and fumarate (5.42 ± 2.94). K m values for L-phenylalanine, L-aspartic acid and fumarate were 1.71 mM, 0.346 μM and 2 M, respectively. The catalytic efficiency (k cat/K m) for L-aspartic acid (14.18 s(-1) mM(-1)) was higher than that for L-phenylalanine (4.65 s(-1) mM(-1)). For bioconversion, from an initial concentration of 1000 mM of fumarate and 30 mM of L-phenylalanine, PA-AspA was found to convert 395.31 μM L-aspartic acid and 3.47 mM cinnamic acid, respectively.

  9. Influence of gamma radiation on the biosynthesis of indoles and gibberellins in barley. The action of zinc on the restitution of growth substance level in irradiated plants

    Energy Technology Data Exchange (ETDEWEB)

    Kutacek, M.; Masev, N.; Oplistilova, K.; Bulgakov, R.

    1966-01-01

    Investigations were made on the effect of exposing barley seeds to gamma-radiation (5-10kR), alone and in combination with the application of zinc (soaking the seeds in solutions containing 5.10/sup -5/ - 5.10/sup -1/% Zn for 12 hours before sowing) on growth and on the content of tryptophan, indole auxins and gibberellin-like substances in seven-day plants. Radiation decreased both growth and the content of tryptophan (e.g. by about 53% at 30 kR), of indole auxins (by about 60% auxin in the zone of IAA on the chromatogram at 30 kR), and also the content of gibberellin-like substances (by about 67% gibberellin content in the zone of GA, on the chromatogram) of plants. The irradiation of standard samples of tryptophan, indolylacetic acid and gibberellic acid alone with many times greater doses (up to 1000 kR) did not lead to marked radiochemical degradation of these substances. It can be assumed that radiation damages the enzyme systems synthesizing natural growth substances in plants. The damaging effect of radiation on auxins is already displayed in the synthesis of tryptophan, which is inhibited. Zinc interacts with the damaging effect of radiation on growth. Optimum concentrations of zinc (5.10/sup -/number% Zn) counteract the effect of radiation, up to doses of about 12 kR, on the growth in height in 7-day plants so that it is equal to the controls. Normal content of tryptophan and auxin in the position of indolylacetic acid on chromatograms can only be reached by the addition of zinc when the dose of radiation was not greater than about 8 kR, which is less than the influence exerted by zinc on the restitution of growth. On the other hand, the biosynthesis of gibberellin-like substances at the position of gibberellic acid on chromatograms can be restored by zinc to their original level to doses of up to 30 kR. 18 references, 7 figures, 2 tables.

  10. Study of the degradation process of polyimide induced by high energetic ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Severin, Daniel

    2008-09-19

    The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions. To study ion-beam induced modifications, Kapton foils were irradiated at the GSI linear accelerator UNILAC using several projectiles (e.g. Ti, Mo, Au, and U) within a large fluence regime (1 x 10{sup 10}-5 x 10{sup 12} ions/cm{sup 2}). The irradiated Kapton foils were analysed by means of infrared and UV/Vis spectroscopy, tensile strength measurement, mass loss analysis, and dielectric relaxation spectroscopy. For testing the radiation stability of Kapton at the cryogenic operation temperature (5-10 K) of the superconducting magnets, additional irradiation experiments were performed at the Grand Accelerateur National d' Ions Lourds (GANIL, France) focusing on the online analysis of the outgassing process of small volatile degradation fragments. The investigations of the electrical properties analysed by dielectric relaxation spectroscopy exhibit a different trend: high fluence irradiations with light ions (e.g. Ti) lead to a slight increase of the conductivity, whereas heavy ions (e.g. Sm, Au) cause a drastic change already in the fluence regime of nonoverlapping tracks (5 x 10{sup 10} ions/cm{sup 2}). Online analysis of the outgassing process during irradiation at cryogenic temperatures shows the release of a variety of small gaseous molecules (e.g. CO, CO{sub 2}, and short hydro carbons). Also a small amount of large polymer fragments is identified. The results allow the following conclusions which are of special interest for the application of Kapton as insulating material in a high-energetic particle radiation environment. a) The material degradation measured with the optical spectroscopy and tensile strength tests are scalable with the dose deposited by the ions. The high correlation of the results allows the prediction of the mechanical degradation with the simple and non-destructive infrared spectroscopy. The degradation curve points to a critical material degradation which has to be expected above a dose of 1 MGy. b) The dielectric relaxation spectroscopy indicates a dramatic increase in the conductivity induced by irradiation with heavy ions which pass a threshold of mass and deposited energy (dE/dx). The phenomenon indicates that only a few hits (fluences of 10{sup 10} ion/cm{sup 2}) of a heavy high energetic ion leads to a significant increase of conductivity. c) The degradation induced formation of small molecules and their outgassing even at cryogenic temperature cause a gas release during irradiation. At temperatures below 20 K, an additional accumulation of these molecules in the bulk material occurs and leads to a critical gas evolution during heat-up cycles. (orig.)

  11. Three-dimensional numerical analysis of convection and conduction cooling of spherical biocrystals with localized heating from synchrotron X-ray beams.

    Science.gov (United States)

    Mhaisekar, Ashutosh; Kazmierczak, Michael J; Banerjee, Rupak

    2005-05-01

    The differential momentum and thermal energy equations for fluid flow and convective heat-transfer around the sample biocrystal, with coupled internal heat conduction, are solved using advanced computational fluid dynamics techniques. Average \\bar{h} as well as local h(theta) values of the convective heat-transfer coefficients are obtained from the fundamental equations. The results of these numerical solutions show the three-dimensional fluid flow field around the sample in conjunction with the detailed internal temperature distribution inside the crystal. The external temperature rise and maximum internal temperature increase are reported for various cases. The effect of the important system parameters, such as gas velocity and properties, crystal size and thermal conductivity and incident beam conditions (intensity and beam size), are all illustrated with comparative examples. For the reference case, an external temperature rise of 7 K and internal temperature increase of 0.5 K are calculated for a 200 microm-diameter cryocooled spherical biocrystal subjected to a 13 keV X-ray beam of 4 x 10(14) photons s(-1) mm(-2) flux density striking half the sample. For all the cases investigated, numerical analysis shows that the controlling thermal resistance is the rate of convective heat-transfer and not internal conduction. Thermal diffusion results in efficient thermal spreading of the deposited energy and this results in almost uniform internal crystal temperatures (DeltaT(internal) approximately 0.5 K), in spite of the non-uniform h(theta) with no more than 1.3 K internal temperature difference for the worst case of localized and focused beam heating. Rather, the major temperature variation occurs between the outer surface of the crystal/loop system and the gas stream, T(s) - T(gas), which itself is only about DeltaT(external) approximately 5-10 K, and depends on the thermal loading imposed by the X-ray beam, the rate of convection and the size of the loop/crystal system.

  12. An implantable wireless neural interface for recording cortical circuit dynamics in moving primates

    Science.gov (United States)

    Borton, David A.; Yin, Ming; Aceros, Juan; Nurmikko, Arto

    2013-04-01

    Objective. Neural interface technology suitable for clinical translation has the potential to significantly impact the lives of amputees, spinal cord injury victims and those living with severe neuromotor disease. Such systems must be chronically safe, durable and effective. Approach. We have designed and implemented a neural interface microsystem, housed in a compact, subcutaneous and hermetically sealed titanium enclosure. The implanted device interfaces the brain with a 510k-approved, 100-element silicon-based microelectrode array via a custom hermetic feedthrough design. Full spectrum neural signals were amplified (0.1 Hz to 7.8 kHz, 200× gain) and multiplexed by a custom application specific integrated circuit, digitized and then packaged for transmission. The neural data (24 Mbps) were transmitted by a wireless data link carried on a frequency-shift-key-modulated signal at 3.2 and 3.8 GHz to a receiver 1 m away by design as a point-to-point communication link for human clinical use. The system was powered by an embedded medical grade rechargeable Li-ion battery for 7 h continuous operation between recharge via an inductive transcutaneous wireless power link at 2 MHz. Main results. Device verification and early validation were performed in both swine and non-human primate freely-moving animal models and showed that the wireless implant was electrically stable, effective in capturing and delivering broadband neural data, and safe for over one year of testing. In addition, we have used the multichannel data from these mobile animal models to demonstrate the ability to decode neural population dynamics associated with motor activity. Significance. We have developed an implanted wireless broadband neural recording device evaluated in non-human primate and swine. The use of this new implantable neural interface technology can provide insight into how to advance human neuroprostheses beyond the present early clinical trials. Further, such tools enable mobile

  13. Development of β-lactoglobulin-specific chimeric human IgEκ monoclonal antibodies for in vitro safety assessment of whey hydrolysates.

    Directory of Open Access Journals (Sweden)

    Karen Knipping

    Full Text Available Cow's milk-derived whey hydrolysates are nutritional substitutes for allergic infants. Safety or residual allergenicity assessment of these whey hydrolysates is crucial. Currently, rat basophilic leukemia RBL-2H3 cells expressing the human IgE receptor α-chain (huFcεRIα-RBL-2H3, sensitized with serum IgE from cow's milk allergic children, are being employed to assess in vitro residual allergenicity of these whey hydrolysates. However, limited availability and inter-lot variation of these allergic sera impede standardization of whey hydrolysate safety testing in degranulation assays.An oligoclonal pool of chimeric human (chuIgE antibodies against bovine β-lactoglobulin (a major allergen in whey was generated to increase sensitivity, specificity, and reproducibility of existing degranulation assays.Mice were immunized with bovine β-lactoglobulin, and subsequently the variable domains of dissimilar anti-β-lactoglobulin mouse IgG antibodies were cloned and sequenced. Six chimeric antibodies were generated comprising mouse variable domains and human constant IgE/κ domains.After sensitization with this pool of anti-β-lactoglobulin chuIgEs, huFcεRIα-expressing RBL-2H3 cells demonstrated degranulation upon cross-linking with whey, native 18 kDa β-lactoglobulin, and 5-10 kDa whey hydrolysates, whereas a 3 kDa whey hydrolysate and cow's milk powder (mainly casein showed no degranulation. In parallel, allergic serum IgEs were less sensitive. In addition, our pool anti-β-lactoglobulin chuIgEs recognized multiple allergenic immunodominant regions on β-lactoglobulin, which were also recognized by serum IgEs from cow's milk allergic children.Usage of our 'unlimited' source and well-defined pool of β-lactoglobulin-specific recombinant chuIgEs to sensitize huFcεRIα on RBL-2H3 cells showed to be a relevant and sensitive alternative for serum IgEs from cow's milk allergic patients to assess safety of whey-based non-allergic hydrolyzed formula.

  14. Thermodynamic analysis of cavity creating mutations in an engineered leucine zipper and energetics of glycerol-induced coiled coil stabilization.

    Science.gov (United States)

    Dürr, E; Jelesarov, I

    2000-04-18

    Protein stability in vitro can be influenced either by introduction of mutations or by changes in the chemical composition of the solvent. Recently, we have characterized the thermodynamic stability and the rate of folding of the engineered dimeric leucine zipper A(2), which has a strengthened hydrophobic core [Dürr, E., Jelesarov, I., and Bosshard, H. R. (1999) Biochemistry 38, 870-880]. Here we report on the energetic consequences of a cavity introduced by Leu/Ala substitution at the tightly packed dimeric interface and how addition of 30% glycerol affects the folding thermodynamics of A(2) and the cavity mutants. Folding could be described by a two-state transition from two unfolded monomers to a coiled coil dimer. Removal of six methylene groups by Leu/Ala substitutions destabilized the dimeric coiled coil by 25 kJ mol(-1) at pH 3.5 and 25 degrees C in aqueous buffer. Destabilization was purely entropic at around room temperature and became increasingly enthalpic at elevated temperatures. Mutations were accompanied by a decrease of the unfolding heat capacity by 0.5 kJ K(-1) mol(-1). Addition of 30% glycerol increased the free energy of folding of A(2) and the cavity mutants by 5-10 kJ mol(-1) and lowered the unfolding heat capacity by 25% for A(2) and by 50% for the Leu/Ala mutants. The origin of the stabilizing effect of glycerol varied with temperature. Stabilization of the parent leucine zipper A(2) was enthalpic with an unfavorable entropic component between 0 and 100 degrees C. In the case of cavity mutants, glycerol induced enthalpic stabilization below 50 degrees C and entropic stabilization above 50 degrees C. The effect of glycerol could not be accounted for solely by the enthalpy and entropy of transfer or protein surface from water to glycerol/water mixture. We propose that in the presence of glycerol the folded coiled coil dimer is better packed and displays less intramolecular fluctuations, leading to enhanced enthalpic interactions and to an increase of the entropy of folding. This work demonstrates that mutational and solvent effects on protein stability can be thermodynamically complex and that it may not be sufficient to only analyze changes of enthalpy and entropy at the unfolding temperature (T(m)) to understand the mechanisms of protein stabilization.

  15. Development of a Conceptual Process for Selective CO 2 Capture from Fuel Gas Streams Using [hmim][Tf 2 N] Ionic Liquid as a Physical Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Basha, Omar M.; Keller, Murphy J.; Luebke, David R.; Resnik, Kevin P.; Morsi, Badie I.

    2013-06-04

    The Ionic Liquid (IL) [hmim][Tf2N] was used as a physical solvent in an Aspen Plus simulation, employing the Peng-Robinson Equation of State (P-R EOS) with Boston-Mathias (BM) alpha function and standard mixing rules, to develop a conceptual process for CO2 capture from a shifted warm fuel gas stream produced from Pittsburgh # 8 coal for a 400 MWe power plant. The physical properties of the IL, including density, viscosity, surface tension, vapor pressure and heat capacity were obtained from literature and modeled as a function of temperature. Also, available experimental solubility values for CO2, H2, H2S, CO, and CH4 in this IL were compiled and their binary interaction parameters (Δij and lij) were optimized and correlated as functions of temperature. The Span-Wager Equation-of-State EOS was also employed to generate CO2 solubilities in [hmim][Tf2N] at high pressures (up to 10 MPa) and temperatures (up to 510 K). The conceptual process developed consisted of 4 adiabatic absorbers (2.4 m ID, 30 m high) arranged in parallel and packed with Plastic Pall Rings of 0.025 m for CO2 capture; 3 flash drums arranged in series for solvent (IL) regeneration with the pressure-swing option; and a pressure-intercooling system for separating and pumping CO2 up to 153 bar to the sequestration sites. The compositions of all process streams, CO2 capture efficiency, and net power were calculated using Aspen Plus simulator. The results showed that, based on the composition of the inlet gas stream to the absorbers, 95.67 mol% of CO2 was captured and sent to sequestration sites; 99.5 mol% of H2 was separated and sent to turbines; the solvent exhibited a minimum loss of 0.31 mol%; and the net power balance of the entire system was 30.81 MW. These results indicated that [hmim][Tf2N] IL could be used as a physical

  16. FDA & digital mammography: why has FDA required full field digital mammography systems to be regulated as potentially dangerous devices for more than 10 years?

    Science.gov (United States)

    Nields, Morgan W

    2010-05-01

    Digital mammography is routinely used in the US to screen asymptomatic women for breast cancer and currently over 50% of US screening centers employ the technology. In spite of FDAs knowledge that digital mammography requires less radiation than film mammography and that its equivalence has been proven in a prospective randomized trial, the agency has failed to allow the technology market access via the 510(k) pre market clearance pathway. As a result of the restrictive Pre Market Approval process, only four suppliers have received FDA approval. The resulting lack of a competitive market has kept costs high, restricted technological innovation, and impeded product improvements as a result of PMA requirements. Meanwhile, at least twelve companies are on the market in the EU and the resulting competitive market has lowered costs and provided increased technological choice. A cultural change with new leadership occurred in the early 90's at FDA. The historical culture at the Center for Devices and Radiological Health of collaboration and education gave way to one characterized by a lack of reliance on outside scientific expertise, tolerance of decision making by unqualified reviewers, and an emphasis on enforcement and punishment. Digital mammography fell victim to this cultural change and as a result major innovations like breast CT and computer aided detection technologies are also withheld from the market. The medical device law, currently under review by the Institute of Medicine, should be amended by the Congress so that new technologies can be appropriately classified in accordance with the risk based assessment classification system detailed in Chapter V of the Federal Food, Drug, and Cosmetic Act. A panel of scientific experts chartered by the NIH or IOM should determine the classification appropriate for new technologies that have no historical regulatory framework. This would be binding on FDA. Unless the law is changed we will likely again experience

  17. Review on magnetic and related properties of RTX compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sachin, E-mail: gsachin55@gmail.com; Suresh, K.G., E-mail: suresh@phy.iitb.ac.in

    2015-01-05

    RTX (R = rare earths, T = 3d/4d/5d, transition metals such as Sc, Ti, Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, Au, and X = p-block elements such as Al, Ga, In, Si, Ge, Sn, As, Sb, Bi) series is a huge family of intermetallics compounds. These compounds crystallize in different crystal structures depending on the constituents. Though these compounds have been known for a long time, they came to limelight recently in view of the large magnetocaloric effect (MCE) and magnetoresistance (MR) shown by many of them. Most of these compounds crystallize in hexagonal, orthorhombic and tetragonal crystal structures. Some of them show crystal structure modification with annealing temperature; while a few of them show iso-structural transition in the paramagnetic regime. Their magnetic ordering temperatures vary from very low temperatures to temperatures well above room temperature (∼510 K). Depending on the crystal structure, they show a variety of magnetic and electrical properties. These compounds have been characterized by means of a variety of techniques/measurements such as X-ray diffraction, neutron diffraction, magnetic properties, heat capacity, magnetocaloric properties, electrical resistivity, magnetoresistance, thermoelectric power, thermal expansion, Hall effect, optical properties, XPS, Mössbauer spectroscopy, ESR, μSR, NMR, and NQR. Some amount of work on theoretical calculations on electronic structure, crystal field interaction and exchange interactions has also been reported. The interesting aspect of this series is that they show a variety of physical properties such as Kondo effect, heavy fermion behavior, spin glass state, intermediate valence, superconductivity, multiple magnetic transitions, metamagnetism, large MCE, large positive as well as negative MR, spin orbital compensation, magnetic polaronic behavior, and pseudo gap effect. Except Mn, no other transition metal in these compounds possesses considerable magnetic moments. Because of this

  18. Antioxidant, ACE-Inhibitory and antibacterial activities of Kluyveromyces marxianus protein hydrolysates and their peptide fractions

    Directory of Open Access Journals (Sweden)

    Mahta Mirzaeia

    2016-07-01

    Full Text Available Background: There has been evidence that proteins are potentially excellent source of antioxidants, antihypertensive and antimicrobial peptides, and that enzymatic hydrolysis is an effective method to release these peptides from protein molecules. The functional properties of protein hydrolysates depends on the protein substrate, the specificity of the enzymes, the conditions used during proteolysis, degree of hydrolysis, and the nature of peptides released including molecular weight, amino acid composition, and hydrophobicity. Context and purpose of this study: The biomass of Kluyveromyces marxianus was considered as a source of ACE inhibitory, antioxidant and antimicrobial peptides. Results: Autolysis and enzymatic hydrolysis were completed respectively, after 96 h and 5 h. Overall, trypsin (18.52% DH and chymotrypsin (21.59% DH treatments were successful in releasing antioxidant and ACE inhibitory peptides. Autolysate sample (39.51% DH demonstrated poor antioxidant and ACE inhibitory activity compared to trypsin and chymotrypsin hydrolysates. The chymotrypsin 3-5 kDa (301.6±22.81 μM TE/mg protein and trypsin < 3 kDa (280.16±39.16 μM TE/mg protein permeate peptide fractions showed the highest DPPH radical scavenging activity. The trypsin <3 kDa permeate peptide fraction showed the highest ABTS radical scavenging (1691.1±48.68 μM TE/mg protein and ACE inhibitory (IC50=0.03±0.001 mg/mL activities. The fraction (MW=5-10 kD obtained after autolysis treatment showed antibacterial activity against St. aureus and Lis. monocytogenes in well diffusion screening. The minimum inhibitory concentration (MIC value was 13.3 mg/mLagainst St. aureus and Lis. monocytogenes calculated by turbidimetric assay and it showed bactericidal activity against St. aureus at 21.3 mg/mL protein concentration. Conclusions: Altogether, the results of this study reveal that K. marxianus proteins contain specific peptides in their sequences which can be released by enzymatic hydrolysis and autolysis.

  19. Overview of high-risk medical device recalls in obstetrics and gynecology from 2002 through 2016: implications for device safety.

    Science.gov (United States)

    Janetos, Timothy M; Ghobadi, Comeron W; Xu, Shuai; Walter, Jessica R

    2017-07-01

    The field of women's health has endured numerous recent controversies involving medical devices such as pelvic meshes, laparoscopic morcellators, and a hysteroscopic sterilization device. With the recent passage of the 21st Century Cures Act, new legislation will change how the Food and Drug Administration regulates medical devices. Given these controversies and new changes, we investigated high-risk, class I recalls in women's health from 2002 through 2016. Class I recalls for medical devices are defined by the Food and Drug Administration as the most serious recall events and are designated for situations when there is a reasonable probability of serious adverse health consequences or death. We defined a recall event as a group of unique Food and Drug Administration recalls that share a similar reason for recall and occurred within a 1-month time frame. In total, 7 class I recall events were identified encompassing 83 unique recalls affecting >88,000 medical devices in distribution. Recalls involved a broad range of devices used in women's health including diagnostic assays for chlamydia and gonorrhea, a laparoscopic tissue morcellator, and obstetrical/gynecological surgical kits. Four of 7 (57%) recall events were due to postmarketing problems such as improper packaging and labeling while the remaining 3 (43%) recalls were due to premarketing problems (eg, software issues). Additionally, 3 of 7 (43%) recall events were cleared via the 510(k) pathway, while the remaining were essentially exempt from any form of premarket approval. Two recall events involved sterility concerns of 71 surgical kits used in obstetrics and gynecological surgeries representing the majority of affected devices (78,423) in distribution. Class I medical device recalls are rare but serious events. Most recalled devices in women's health had minimal preapproval regulation and were recalled due to both premarketing and postmarketing reasons. Future regulatory efforts to improve postmarketing

  20. Evaluation of the Tibial Nerve with Shear-Wave Elastography: A Potential Sonographic Method for the Diagnosis of Diabetic Peripheral Neuropathy.

    Science.gov (United States)

    Dikici, Atilla Suleyman; Ustabasioglu, Fethi Emre; Delil, Sakir; Nalbantoglu, Mecbure; Korkmaz, Bektas; Bakan, Selim; Kula, Osman; Uzun, Nurten; Mihmanli, Ismail; Kantarci, Fatih

    2017-02-01

    Purpose To evaluate the value of shear-wave elastography (SWE) in the detection of diabetic peripheral neuropathy (DPN) of the tibial nerve. Materials and Methods This study was approved by the institutional review board, and written informed consent was obtained from all study participants. The study included 20 diabetic patients with DPN (10 men, 10 women), 20 diabetic patients without DPN (eight men, 12 women), and 20 healthy control subjects (nine men, 11 women). The tibial nerve was examined at 4 cm proximal to the medial malleolus with gray-scale ultrasonography and SWE. The nerve cross-sectional area (in square centimeters) and the mean nerve stiffness (in kilopascals) within the range of the image were recorded. Inter- and intrareader variability, differences among groups, and correlation of clinical and electrophysiologic evaluation were assessed with intraclass correlation coefficients, the Mann Whitney U test, and the Wilcoxon signed rank test. Results Between diabetic patients with and diabetic patients without DPN, mean age (60 years [range, 38-79 years] vs 61 years [range, 46-75 years], respectively), mean duration of diabetes (10 years [range, 1-25 years] vs 10 years [range, 2-26 years]), and mean body mass index (31.4 kg/m(2) [range, 24.7-48.1 kg/m(2)] vs 29.8 kg/m(2) [range, 22.9-44.0 kg/m(2)]) were not significantly different. Diabetic patients without DPN had significantly higher stiffness values on the right side compared with control subjects (P < .001). Patients with DPN had much higher stiffness values on both sides compared with both diabetic patients without DPN (P < .001) and healthy control subjects (P < .001). A cutoff value of 51.0 kPa at 4 cm proximal to the medial malleolus revealed a sensitivity of 90% (95% confidence interval [CI]: 75.4%, 96.7%) and a specificity of 85.0% (95% CI: 74.9%, 91.7%). Conclusion Tibial nerve stiffness measurements appear to be highly specific in the diagnosis of established DPN. The increased stiffness in subjects without DPN might indicate that the nerve is affected by diabetes. (©) RSNA, 2016 Online supplemental material is available for this article.

  1. Non-Contact Thermal Properties Measurement with Low-Power Laser and IR Camera System

    Science.gov (United States)

    Hudson, Troy L.; Hecht, Michael H.

    2011-01-01

    As shown by the Phoenix Mars Lander's Thermal and Electrical Conductivity Probe (TECP), contact measurements of thermal conductivity and diffusivity (using a modified flux-plate or line-source heat-pulse method) are constrained by a number of factors. Robotic resources must be used to place the probe, making them unavailable for other operations for the duration of the measurement. The range of placement is also limited by mobility, particularly in the case of a lander. Placement is also subject to irregularities in contact quality, resulting in non-repeatable heat transfer to the material under test. Most important from a scientific perspective, the varieties of materials which can be measured are limited to unconsolidated or weakly-cohesive regolith materials, rocks, and ices being too hard for nominal insertion strengths. Accurately measuring thermal properties in the laboratory requires significant experimental finesse, involving sample preparation, controlled and repeatable procedures, and, practically, instrumentation much more voluminous than the sample being tested (heater plates, insulation, temperature sensors). Remote measurements (infrared images from orbiting spacecraft) can reveal composite properties like thermal inertia, but suffer both from a large footprint (low spatial resolution) and convolution of the thermal properties of a potentially layered medium. In situ measurement techniques (the Phoenix TECP is the only robotic measurement of thermal properties to date) suffer from problems of placement range, placement quality, occupation of robotic resources, and the ability to only measure materials of low mechanical strength. A spacecraft needs the ability to perform a non-contact thermal properties measurement in situ. Essential components include low power consumption, leveraging of existing or highly-developed flight technologies, and mechanical simplicity. This new in situ method, by virtue of its being non-contact, bypasses all of these problems. The use of photons to both excite and measure the thermal response of any surface material to a high resolution (estimated footprint = 10 square centimeters) is a generational leap in physical properties measurements. The proposed method consists of spot-heating the surface of a material with a low (less than 1 W) power laser. This produces a moderate (5-10 K) temperature increase in the material.

  2. A hantavirus pulmonary syndrome (HPS) DNA vaccine delivered using a spring-powered jet injector elicits a potent neutralizing antibody response in rabbits and nonhuman primates.

    Science.gov (United States)

    Kwilas, Steve; Kishimori, Jennifer M; Josleyn, Matthew; Jerke, Kurt; Ballantyne, John; Royals, Michael; Hooper, Jay W

    2014-01-01

    Sin Nombre virus (SNV) and Andes virus (ANDV) cause most of the hantavirus pulmonary syndrome (HPS) cases in North and South America, respectively. The chances of a patient surviving HPS are only two in three. Previously, we demonstrated that SNV and ANDV DNA vaccines encoding the virus envelope glycoproteins elicit high-titer neutralizing antibodies in laboratory animals, and (for ANDV) in nonhuman primates (NHPs). In those studies, the vaccines were delivered by gene gun or muscle electroporation. Here, we tested whether a combined SNV/ANDV DNA vaccine (HPS DNA vaccine) could be delivered effectively using a disposable syringe jet injection (DSJI) system (PharmaJet, Inc). PharmaJet intramuscular (IM) and intradermal (ID) needle-free devices are FDA 510(k)-cleared, simple to use, and do not require electricity or pressurized gas. First, we tested the SNV DNA vaccine delivered by PharmaJet IM or ID devices in rabbits and NHPs. Both IM and ID devices produced high-titer anti-SNV neutralizing antibody responses in rabbits and NHPs. However, the ID device required at least two vaccinations in NHP to detect neutralizing antibodies in most animals, whereas all animals vaccinated once with the IM device seroconverted. Because the IM device was more effective in NHP, the Stratis(®) (PharmaJet IM device) was selected for follow-up studies. We evaluated the HPS DNA vaccine delivered using Stratis(®) and found that it produced high-titer anti-SNV and anti-ANDV neutralizing antibodies in rabbits (n=8/group) as measured by a classic plaque reduction neutralization test and a new pseudovirion neutralization assay. We were interested in determining if the differences between DSJI delivery (e.g., high-velocity liquid penetration through tissue) and other methods of vaccine injection, such as needle/syringe, might result in a more immunogenic DNA vaccine. To accomplish this, we compared the HPS DNA vaccine delivered by DSJI versus needle/syringe in NHPs (n=8/group). We found

  3. A Hantavirus Pulmonary Syndrome (HPS) DNA Vaccine Delivered Using a Spring-powered Jet Injector Elicits a Potent Neutralizing Antibody
Response in Rabbits and Nonhuman Primates

    Science.gov (United States)

    Kwilas, Steve; Kishimori, Jennifer M.; Josleyn, Matthew; Jerke, Kurt; Ballantyne, John; Royals, Michael; Hooper, Jay W.

    2014-01-01

    Sin Nombre virus (SNV) and Andes virus (ANDV) cause most of the hantavirus pulmonary syndrome (HPS) cases in North and South America, respectively. The chances of a patient surviving HPS are only two in three. Previously, we demonstrated that SNV and ANDV DNA vaccines encoding the virus envelope glycoproteins elicit high-titer neutralizing antibodies in laboratory animals, and (for ANDV) in nonhuman primates (NHPs). In those studies, the vaccines were delivered by gene gun or muscle electroporation. Here, we tested whether a combined SNV/ANDV DNA vaccine (HPS DNA vaccine) could be delivered effectively using a disposable syringe jet injection (DSJI) system (PharmaJet, Inc). PharmaJet intramuscular (IM) and intradermal (ID) needle-free devices are FDA 510(k)-cleared, simple to use, and do not require electricity or pressurized gas. First, we tested the SNV DNA vaccine delivered by PharmaJet IM or ID devices in rabbits and NHPs. Both IM and ID devices produced high-titer anti-SNV neutralizing antibody responses in rabbits and NHPs. However, the ID device required at least two vaccinations in NHP to detect neutralizing antibodies in most animals, whereas all animals vaccinated once with the IM device seroconverted. Because the IM device was more effective in NHP, the Stratis® (PharmaJet IM device) was selected for follow-up studies. We evaluated the HPS DNA vaccine delivered using Stratis® and found that it produced high-titer anti-SNV and anti-ANDV neutralizing antibodies in rabbits (n=8/group) as measured by a classic plaque reduction neutralization test and a new pseudovirion neutralization assay. We were interested in determining if the differences between DSJI delivery (e.g., high-velocity liquid penetration through tissue) and other methods of vaccine injection, such as needle/syringe, might result in a more immunogenic DNA vaccine. To accomplish this, we compared the HPS DNA vaccine delivered by DSJI versus needle/syringe in NHPs (n=8/group). We found that