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Sample records for polymethylmethacrylate dosimeter radix

  1. Application of clear polymethylmethacrylate dosimeter Radix W to a few MeV electron in radiation processing

    NASA Astrophysics Data System (ADS)

    Seito, Hajime; Ichikawa, Tatsuya; Hanaya, Hiroaki; Sato, Yoshishige; Kaneko, Hirohisa; Haruyama, Yasuyuki; Watanabe, Hiroshi; Kojima, Takuji

    2009-11-01

    Characteristics of clear PMMA dosimeter (Radix W) were studied for electron irradiation and compared with the response for gamma irradiation. The dose-response curves were nearly linear up to 30 kGy and become sublinear at higher doses. The radiation-induced absorbance was reduced with 6% within 4 h after irradiation. Dose comparisons were performed for 2, 3, 4 and 5 MeV electron irradiation using cellulose triacetate dosimeter (CTA) (FTR-125) and Radix W dosimeters which were independently calibrated for 2 MeV electrons and 60Co gamma-rays using calorimeter and ionizing chamber, respectively. The doses estimated by CTA and Radix W were different by about 20%. The magnitude of this difference was, however, independent of electron energy.

  2. The shelf life of dyed polymethylmethacrylate dosimeters

    NASA Astrophysics Data System (ADS)

    Bett, R.; Watts, M. F.; Plested, M. E.

    2002-03-01

    The long-term stability of the radiation response of Harwell Red 4034 and Amber 3042 Perspex Dosimeters has been monitored for more than 15 years, and the resulting data used in the justification of their shelf-life specifications.

  3. Radiation dosimeters

    DOEpatents

    Hoelsher, James W.; Hegland, Joel E.; Braunlich, Peter F.; Tetzlaff, Wolfgang

    1992-01-01

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  4. Wristwatch dosimeter

    DOEpatents

    Wolf, M.A.; Waechter, D.A.; Umbarger, C.J.

    1986-08-26

    The disclosure is directed to a wristwatch dosimeter utilizing a CdTe detector, a microprocessor and an audio and/or visual alarm. The dosimeter is entirely housable with a conventional digital watch case having an additional aperture enabling the detector to receive radiation. 10 figs.

  5. Wristwatch dosimeter

    DOEpatents

    Wolf, Michael A.; Waechter, David A.; Umbarger, C. John

    1986-01-01

    The disclosure is directed to a wristwatch dosimeter utilizing a CdTe detector, a microprocessor and an audio and/or visual alarm. The dosimeter is entirely housable with a conventional digital watch case having an additional aperture enabling the detector to receive radiation.

  6. RADIATION DOSIMETER

    DOEpatents

    Balkwell, W.R. Jr.; Adams, G.D. Jr.

    1960-05-10

    An improvement was made in the determination of amounts of ionizing radiation, particularly low-energy beta particles of less than 1000 rad total dose by means of fluid-phase dosimeter employing a stabilized-- sensitized ferrous-ferric colorimetric system in a sulphuric acid medium. The improvement in the dosimeter consists of adding to the ferrous-ferric system in concentrations of 10/sub -2/ to 10/sup -4/M an organic compound having one or more carboxylic or equivalent groups, such compounds being capable of chelating or complexing the iron ions in the solution. Suitable sensitizing and stabilizing agents are benzoic, phthalic, salicylic, malonic, lactic, maleic, oxalic, citric, succinic, phenolic tartaric, acetic, and adipic acid, as well as other compounds which are added to the solution alone or in certain combinations. As in conventional fluid-phase dosimeters, the absorbed dosage is correlated with a corresponding change in optical density at particular wavelengths of the solution.

  7. PERSONNEL DOSIMETER

    DOEpatents

    Birkhoff, R.D.; Hubbell, H.H. Jr.; Johnson, R.M.

    1959-02-24

    A personnel dosimeter sensitive to both gamma and beta radiation is described. The dosimeter consists of an electrical conductive cylinder having a wall thickness of substantially 7 milligrams per square centimeter and an electrode disposed axially within the cylinder and insulated therefrom to maintain a potential impressed between the electrode and the cylinder. A cylindrical perforated shield provided with a known percentage of void area is disposed concentrically about the cylinder. The shield is formed of a material which does not contain more than 15 percent of an element higher than atomic weight 13. The dose actually received is at most the gamma dose plus the beta dose indicated by discharge of the dosimeter divided by the known percentage.

  8. Durable antistatic coating for polymethylmethacrylate

    NASA Technical Reports Server (NTRS)

    Hadek, V.; Somoano, R. B.; Rembaum, A. (Inventor)

    1977-01-01

    A durable antistatic coating is achieved on polymethylmethacrylate plastic without affecting its optical clarity by applying to the surface of the plastic a low molecular weight solvent having a high electron affinity and a high dipole moment, such as acentonitrile or nitromethane alone or in the presence of photopolymerizable monomer. The treated polymethylmethacrylate plastic dissipates most of the induced electrostatic charge and retains its optical clarity. The antistatic behavior persists after washing, rubbing and vacuum treatment.

  9. Composite material dosimeters

    DOEpatents

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  10. Composite material dosimeters

    DOEpatents

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  11. Thermoluminescence dosimeter

    DOEpatents

    Zendle, Robert

    1985-01-01

    A thermoluminescence dosimeter having a very small rate of decline of sensitivity during subsequent uses after heating is disclosed. The dosimeter includes a detector crystal and a glass enclosure in which the detector crystal is located. The glass enclosure is air tight and is filled with a super dry inert fill gas. The inert fill gas is nonreactive with the detector crystal when the detector crystal is heated to thermoluminescence. The fill gas is selected from the group consisting of air, nitrogen, and argon, suitable admixed with 5 to 25 percent helium. The detector crystal consists essentially of calcium fluoride. The fill gas is preferably contained at a subatmospheric pressure in the glass enclosure.

  12. Thermoluminescence dosimeter

    DOEpatents

    Zendle, R.

    1983-11-03

    A thermoluminescence dosimeter having a very small rate of decline of sensitivity during subsequent uses after heating is disclosed. The dosimeter includes a detector crystal and a glass enclosure in which the detector crystal is located. The glass enclosure is air tight and is filled with a super dry inert fill gas. The inert fill gas is nonreactive with the detector crystal when the detector crystal is heated to thermoluminescence. The fill gas is selected from the group consisting of air, nitrogen, and argon, suitable admixed with 5 to 25 percent helium. The detector crystal consists essentially of calcium fluoride. The fill gas is preferably contained at a subatmospheric pressure in the glass enclosure.

  13. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  14. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.” ...

  15. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.” ...

  16. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.” ...

  17. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.” ...

  18. The effects of squalene on the PMMA dosimeter: focusing on a ``chronodosimeter''

    NASA Astrophysics Data System (ADS)

    Duroux, J. L.; Trihi, M.; Hyvernaud, M. J.; Bernard, M.

    1996-02-01

    A polymethylmethacrylate-based plastic material doped with squalene according to our laboratory protocol, has been tested by spectrophotometric measurements as a dosimeter of γ-radiation. The spectrophotometric characterization shows responses in time of which the modelization allows us to find the duration separating the irradiation and the measurement.

  19. Fundamentals of gel dosimeters

    NASA Astrophysics Data System (ADS)

    McAuley, K. B.; Nasr, A. T.

    2013-06-01

    Fundamental chemical and physical phenomena that occur in Fricke gel dosimeters, polymer gel dosimeters, micelle gel dosimeters and genipin gel dosimeters are discussed. Fricke gel dosimeters are effective even though their radiation sensitivity depends on oxygen concentration. Oxygen contamination can cause severe problems in polymer gel dosimeters, even when THPC is used. Oxygen leakage must be prevented between manufacturing and irradiation of polymer gels, and internal calibration methods should be used so that contamination problems can be detected. Micelle gel dosimeters are promising due to their favourable diffusion properties. The introduction of micelles to gel dosimetry may open up new areas of dosimetry research wherein a range of water-insoluble radiochromic materials can be explored as reporter molecules.

  20. Pocket radiation dosimeter--dosimeter charger assembly

    DOEpatents

    Manning, Frank W.

    1984-01-01

    This invention is a novel pocket-type radiation dosimeter comprising an electrometric radiation dosimeter and a charging circuit therefor. The instrument is especially designed to be amenable to mass production, to have a long shelf life, and to be compact, lightweight, and usable by the layman. The dosimeter proper may be of conventional design. The charging circuit includes a shake-type electrostatic generator, a voltage doubler for integrating generator output voltages of one polarity, and a switch operated by an external permanent magnet.

  1. Pocket radiation dosimeter: dosimeter charger assembly

    DOEpatents

    Manning, F.W.

    1982-03-17

    This invention is a novel pocket-type radiation dosimeter comprising an electrometric radiation dosimeter and a charging circuit therefor. The instrument is especially designed to be amenable to mass production, to have a long shelf life, and to be compact, lightweight, and usable by the layman. The dosimeter proper may be of conventional design. The charging circuit includes a shake-type electrostatic generator, a voltage doubler for integrating generator output voltages of one polarity, and a switch operated by an external permanent magnet.

  2. Smart Radiological Dosimeter

    SciTech Connect

    Kosslow, William J.; Bandzuch, Gregory S.

    2004-07-20

    A radiation dosimeter providing an indication of the dose of radiation to which the radiation sensor has been exposed. The dosimeter contains features enabling the monitoring and evaluating of radiological risks so that a user can concentrate on the task at hand. The dosimeter provides an audible alarm indication that a predetermined time period has elapsed, an audible alarm indication reminding the user to check the dosimeter indication periodically, an audible alarm indicating that a predetermined accumulated dose has been prematurely reached, and an audible alarm indication prior or to reaching the 3/4 scale point.

  3. Thermal neutron dosimeter by synthetic single crystal diamond devices.

    PubMed

    Almaviva, S; Marinelli, Marco; Milani, E; Prestopino, G; Tucciarone, A; Verona, C; Verona-Rinati, G; Angelone, M; Pillon, M

    2009-07-01

    We report on a new solid state dosimeter based on chemical vapor deposition (CVD) single crystal diamond fabricated at Roma "Tor Vergata" University laboratories. The dosimeter has been specifically designed for direct neutron dose measurements in boron neutron capture therapy (BNCT). The response to thermal neutrons of the proposed diamond dosimeter is directly due to (10)B and, therefore, the dosimeter response is directly proportional to the boron absorbed doses in BNCT. Two single crystal diamond detectors are fabricated in a p-type/intrinsic/metal configuration and are sandwiched together with a boron containing layer in between the metallic contacts (see Fig.1). Neutron irradiations were performed at the Frascati Neutron Generator (FNG) using the 2.5 MeV neutrons produced through the D(d,n)(3)He fusion reaction. Thermal neutrons were then produced by slowing down the 2.5 MeV neutrons using a cylindrical polymethylmethacrylate (PMMA) moderator. The diamond dosimeter was placed in the center of the moderator. The products of (10)B(n,alpha)Li nuclear reaction were collected simultaneously giving rise to a single peak. Stable performance, high reproducibility, high efficiency and good linearity were observed.

  4. Wrist-watch dosimeter

    DOEpatents

    Wolf, M.A.; Waechter, D.A.; Umbarger, C.J.

    1982-04-16

    The disclosure is directed to a wristwatch dosimeter utilizing a CdTe detector, a microprocessor and an audio and/or visual alarm. The dosimeter is entirely housable within a conventional digital watch case having an additional aperture enabling the detector to receive radiation.

  5. DNA UVB dosimeters.

    PubMed

    Regan, J D; Yoshida, H

    1995-11-01

    DNA can be used to establish and monitor solar UVB dose. Since the principal molecular site of UVB damage in living organisms is DNA, it is logical to quantitate biologically effective solar UVB in DNA dosimeters. In addition to their particular sensitivity to UVB, DNA dosimeters have the advantage of a 2 pi geometry for collecting diffuse UVB radiation from all vectors, low cost, small size and portability, and no moving parts. Both molecular (cyclobutane pyrimidine dimers) and biological (bacteriophage plaques) dosimeters can be quantitated as endpoints to yield the total dose. DNA dosimeters integrate the absorbed energy of all UVB wavelengths (290-320 nm), are highly sensitive to the differential biological effectiveness of these wavelengths, and also integrate over time in hours, days or weeks of exposure. Our experiments have focused on the demonstration of DNA solar dosimeters in the ocean at various depths, the application of the dosimeters to the terrestrial monitoring of solar UVB under various conditions, and the development of a mini-dosimeter which uses nanograms of DNA and is assayed by polymerase chain reaction.

  6. Electronic UV dosimeters.

    PubMed

    Wulf, H C; Gniadecka, M

    1996-08-01

    The pathogenic role of ultraviolet (UV) in the development of skin cancer, skin ageing and immunosuppression makes it important to monitor human exposure to UV radiation. In a previous study we constructed UVB and UVC dosimeters based on a thermoluminescent phenomenon induced by UV in CaF2 :Dy and CaF2 crystals. However, these dosimeters were insensitive to UVA radiation and readout was time-consuming. In the present study we aimed to develop an electronic dosimeter suitable for UVA, UVB and UVC. The principle of this dosimeter is a measure of accumulated electric current induced by UV on a photodetector. Electric current induced by UV on a photodetector was accumulated in a Plessey's E-cell coulometer. A special reading device was constructed to quantify total charge of the coulometer. Sensitivity for UVA, UVB and UVC was achieved by the use of appropriate filters in front of the photodetector. The sensitivity of the electronic dosimeter increased with increasing wavelength of UV radiation; therefore, in UVB and UVC dosimeters the use of amplifiers was necessary. A linear response to UVA, UVB and UVC was achieved. Dosimeters with a linear response to increasing doses of UVA, UVB and UVC have been constructed for personal monitoring of UV exposure.

  7. Temporal dosimeter and method

    DOEpatents

    Warner, Benjamin P.; Lopez, Thomas A.

    2003-09-30

    The invention includes a temporal dosimeter. One dosimeter embodiment includes a housing that is opaque to visible light but transparent to ionizing radiation. The dosimeter also includes a sensor for recording dosages of ionizing radiation, a drive mechanism, a power source, and rotatable shields that work together to produce a compound aperture to unveil different portions of the sensor at different times to ionizing radiation. Another dosimeter embodiment includes a housing, a sensor, a shield with an aperture portion, and a linear actuator drive mechanism coupled to the sensor for moving the sensor past the aperture portion. The sensor turns as it moves past the aperture, tracing a timeline record of exposure to ionizing radiation along a helical path on the sensor.

  8. ULTRASONIC NEUTRON DOSIMETER

    DOEpatents

    Truell, R.; de Klerk, J.; Levy, P.W.

    1960-02-23

    A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

  9. Magnetic field dosimeter development

    SciTech Connect

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation.

  10. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact... Polymethylmethacrylate (PMMA) diagnostic contact lens. (a) Identification. A polymethylmethacrylate (PMMA) diagnostic contact lens is a device that is a curved shell of PMMA intended to be applied for a short period of...

  11. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact... Polymethylmethacrylate (PMMA) diagnostic contact lens. (a) Identification. A polymethylmethacrylate (PMMA) diagnostic contact lens is a device that is a curved shell of PMMA intended to be applied for a short period of...

  12. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact... Polymethylmethacrylate (PMMA) diagnostic contact lens. (a) Identification. A polymethylmethacrylate (PMMA) diagnostic contact lens is a device that is a curved shell of PMMA intended to be applied for a short period of...

  13. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact... Polymethylmethacrylate (PMMA) diagnostic contact lens. (a) Identification. A polymethylmethacrylate (PMMA) diagnostic contact lens is a device that is a curved shell of PMMA intended to be applied for a short period of...

  14. 21 CFR 886.1385 - Polymethylmethacrylate (PMMA) diagnostic contact lens.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Polymethylmethacrylate (PMMA) diagnostic contact... Polymethylmethacrylate (PMMA) diagnostic contact lens. (a) Identification. A polymethylmethacrylate (PMMA) diagnostic contact lens is a device that is a curved shell of PMMA intended to be applied for a short period of...

  15. Length of stain dosimeter

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (Inventor)

    1994-01-01

    Payload customers for the Space Shuttle have recently expressed concerns about the possibility of their payloads at an adjacent pad being contaminated by plume effluents from a shuttle at an active pad as they await launch on an inactive pad. As part of a study to satisfy such concerns a ring of inexpensive dosimeters was deployed around the active pad at the inter-pad distance. However, following a launch, dosimeters cannot be read for several hours after the exposure. As a consequence factors such as different substrates, solvent systems, and possible volatilization of HCl from the badges were studied. This observation led to the length of stain (LOS) dosimeters of this invention. Commercial passive LOS dosimeters are sensitive only to the extent of being capable of sensing 2 ppm to 20 ppm if the exposure is 8 hours. To map and quantitate the HCl generated by Shuttle launches, and in the atmosphere within a radius of 1.5 miles from the active pad, a sensitivity of 2 ppm HCl in the atmospheric gases on an exposure of 5 minutes is required. A passive length of stain dosimeter has been developed having a sensitivity rendering it capable of detecting a gas in a concentration as low as 2 ppm on an exposure of five minutes.

  16. [Quality specification of Curcumae Radix].

    PubMed

    Zhu, Jingjing; Zhang, Qingzhe; Wang, Zhimin; Zhang, Qiwei

    2010-08-01

    To establish and revise the quality specification of Curcumae Radix. TLC identification was carried out by the method in Appendix VI B in Chinese pharmacopoeia (2005th Edition) and the contents of volatile oil was determined by the method describing in Appendix XD. Twenty-four Samples from four different curcuma species were performed TLC qualitative analysis and volatile determination, respectively. The established method can be used for the quality control of Curcumae Radix.

  17. Dose equivalent neutron dosimeter

    DOEpatents

    Griffith, Richard V.; Hankins, Dale E.; Tomasino, Luigi; Gomaa, Mohamed A. M.

    1983-01-01

    A neutron dosimeter is disclosed which provides a single measurements indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer containing conversion material such as .sup.6 Li and .sup.10 B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet. The density of conversion material in the radiator layer is of an amount which is chosen so that the density of tracks produced in the detecting sheet is proportional to the biological damage done by neutrons, regardless of whether the tracks are produced as the result of moderate energy neutrons striking the radiator layer or as the result of higher energy neutrons striking the sheet of track etch material.

  18. Dosimeter Badge Detects Hydrazines

    NASA Technical Reports Server (NTRS)

    Young, Rebecca C.; Travis, Joshua C.; Moore, Gerald; Rose-Pehrsson, Susan; Carver, Patricia; Brenner, Karen

    1993-01-01

    Disposable dosimeter badge indicates approximate cumulative exposure to hydrazine or monomethyl hydrazine in air. Indication is change in colors of both paper tapes; one coated with para-N, N-dimethylaminobenzaldehyde. Colors of exposed tapes compared with colors on two preprinted color wheels to obtain estimate of exposure. Badges help minimize risks associated with exposure of personnel to hydrazine or monomethyl hydrazine, or suspected carcinogens. Also used as stationary monitors by taping them on walls or equipment at strategic locations.

  19. Dosimeter Design Program

    DTIC Science & Technology

    2015-01-05

    Configure pins for start - up : SysTimerSetupFast(); // Start the system tick timer com_initialize...be utilized. Non-hardened parts can often be an order of magnitude less in cost .  Design a dosimeter that is radiation hardened. We will use...prototype developed under this activity since the cost for the radiation hardened parts would be prohibitive. Various chips that are radiation

  20. Photoacoustical radiation dosimeter

    SciTech Connect

    Mascarenhas, S.; Vargas, H.; Cesar, C.L.

    1984-01-01

    A new type of radiation dosimeter using the photoacoustical effect is described. The photoacoustical radiation dosimeter (PARD) is capable of directly measuring the energy absorbed in the detecting element. For a completely absorbing element, the energy fluence rate in the radiation beam is measured. It is thus a calorimetric dosimeter. Since the energy sensor can be calibrated with another form of energy, it has the potential for being an absolute radiation dosemeter. Measurements were made using 50 to 100 kVp x rays with exposure rates at the detector of 2.6 x 10/sup -6/ C/kg/s (10 mR/s) to 5 x 10/sup -5/ C/kg/s (200 mR/s). The minimum measurable exposure rate at 90 kVp is 5 x 10/sup -7/ C/kg/s (2 mR/s). For a given x-ray spectrum, the PARD has a linear response with radiation intensity and an inverse response with chopping frequency. With appropriate design parameters, we believe the PARD may be used to measure any photon energy or any type of radiation particle.

  1. Hanford personnel dosimeter supporting studies FY-1981

    SciTech Connect

    Not Available

    1982-08-01

    This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies.

  2. PERSONNEL NEUTRON DOSIMETER

    DOEpatents

    Fitzgerald, J.J.; Detwiler, C.G. Jr.

    1960-05-24

    A description is given of a personnel neutron dosimeter capable of indicating the complete spectrum of the neutron dose received as well as the dose for each neutron energy range therein. The device consists of three sets of indium foils supported in an aluminum case. The first set consists of three foils of indium, the second set consists of a similar set of indium foils sandwiched between layers of cadmium, whereas the third set is similar to the second set but is sandwiched between layers of polyethylene. By analysis of all the foils the neutron spectrum and the total dose from neutrons of all energy levels can be ascertained.

  3. Ionization chamber dosimeter

    DOEpatents

    Renner, Tim R.; Nyman, Mark A.; Stradtner, Ronald

    1991-01-01

    A method for fabricating an ion chamber dosimeter collecting array of the type utilizing plural discrete elements formed on a uniform collecting surface which includes forming a thin insulating layer over an aperture in a frame having surfaces, forming a predetermined pattern of through holes in the layer, plating both surfaces of the layer and simultaneously tilting and rotating the frame for uniform plate-through of the holes between surfaces. Aligned masking and patterned etching of the surfaces provides interconnects between the through holes and copper leads provided to external circuitry.

  4. Pistol-shaped dosimeter charger

    DOEpatents

    Maples, R.A.

    A pistol-shaped charger assembly clamps a cylindrical radiation dosimeter against one edge thereof. A triggerlike lever on the handgrip of the assembly is manually pivoted to actuate a piezoelectric current generator held in the handgrip and thereby charge the dosimeter.

  5. Pistol-shaped dosimeter charger

    DOEpatents

    Maples, Robert A.

    1985-01-01

    A pistol-shaped charger assembly clamps a cylindrical radiation dosimeter against one edge thereof. A triggerlike lever on the handgrip of the assembly is manually pivoted to actuate a piezoelectric current generator held in the handgrip and thereby charge the dosimeter.

  6. A new radiochromic dosimeter film

    NASA Astrophysics Data System (ADS)

    Sidney, L. N.; Lynch, D. C.; Willet, P. S.

    By employing acid-sensitive leuco dyes in a chlorine-containing polymer matrix, a new radiochromic dosimeter film has been developed for gamma, electron beam, and ultraviolet radiation. These dosimeter films undergo a color change from colorless to royal blue, red fuchsia, or black, depending on dye selection, and have been characterized using a visible spectrophotometer over an absorbed dose range of 1 to 100 kGy. The primary features of the film are improved color stability before and after irradiation, whether stored in the dark or under artificial lights, and improved moisture resistance. The effects of absorbed dose, dose rate, and storage conditions on dosimeter performance are discussed. The dosimeter material may be produced as a free film or coated onto a transparent substrate and optionally backed with adhesive. Potential applications for these materials include gamma sterilization indicator films for food and medical products, electron beam dosimeters, and in-line radiation monitors for electron beam and ultraviolet processing.

  7. Personnel electronic neutron dosimeter

    DOEpatents

    Falk, R.B.; Tyree, W.H.

    1982-03-03

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  8. Personnel electronic neutron dosimeter

    DOEpatents

    Falk, Roger B.; Tyree, William H.

    1984-12-18

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  9. Miniature spectrally selective dosimeter

    NASA Technical Reports Server (NTRS)

    Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr. (Inventor)

    1980-01-01

    A miniature spectrally selective dosimeter capable of measuring selected bandwidths of radiation exposure on small mobile areas is described. This is achieved by the combination of photovoltaic detectors, electrochemical integrators (E-cells) and filters in a small compact case which can be easily attached in close proximity to and substantially parallel to the surface being measured. In one embodiment two photovoltaic detectors, two E-cells, and three filters are packaged in a small case with attaching means consisting of a safety pin. In another embodiment, two detectors, one E-cell, three filters are packaged in a small case with attaching means consisting of a clip to clip over a side piece of an eye glass frame.

  10. Miniature spectrally selective dosimeter

    NASA Astrophysics Data System (ADS)

    Adams, R. R.; MacConochie, I. O.; Poole, B. D., Jr.

    1980-10-01

    A miniature spectrally selective dosimeter capable of measuring selected bandwidths of radiation exposure on small mobile areas is described. This is achieved by the combination of photovoltaic detectors, electrochemical integrators (E-cells) and filters in a small compact case which can be easily attached in close proximity to and substantially parallel to the surface being measured. In one embodiment two photovoltaic detectors, two E-cells, and three filters are packaged in a small case with attaching means consisting of a safety pin. In another embodiment, two detectors, one E-cell, three filters are packaged in a small case with attaching means consisting of a clip to clip over a side piece of an eye glass frame.

  11. Silver nitrate based gel dosimeter

    NASA Astrophysics Data System (ADS)

    Titus, D.; Samuel, E. J. J.; Srinivasan, K.; Roopan, S. M.; Madhu, C. S.

    2017-05-01

    A new radiochromic gel dosimeter based on silver nitrate and a normoxic gel dosimeter was investigated using UV-Visible spectrophotometry in the clinical dose range. Gamma radiation induced the synthesis of silver nanoparticles in the gel and is confirmed from the UV-Visible spectrum which shows an absorbance peak at around 450 nm. The dose response function of the dosimeter is found to be linear upto12Gy. In addition, the gel samples were found to be stable which were kept under refrigeration.

  12. SU-E-T-643: Pure Alanine Dosimeter for Verification Dosimetry in IMRT

    SciTech Connect

    Al-Karmi, Anan M.; Zraiqat, Fadi

    2015-06-15

    Purpose: The objective of this study was evaluation of accuracy of pure alanine dosimeters measuring intensity-modulated radiation therapy (IMRT) dose distributions in a thorax phantom. Methods: Alanine dosimeters were prepared in the form of 110 mg pure L-α-alanine powder filled into clear tissue-equivalent polymethylmethacrylate (PMMA) plastic tubes with the dimensions 25 mm length, 3 mm inner diameter, and 1 mm wall thickness. A dose-response calibration curve was established for the alanine by placing the dosimeters at 1.5 cm depth in a 30×30×30 cm{sup 3} solid water phantom and then irradiating on a linac with 6 MV photon beam at 10×10 cm{sup 2} field size to doses ranging from 1 to 5 Gy. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the absorbed dose in alanine. An IMRT treatment plan was designed for a commercial heterogeneous CIRS thorax phantom and the dose values were calculated at three different points located in tissue, lung, and bone equivalent materials. A set of dose measurements was carried out to compare measured and calculated dose values by placing the alanine dosimeters at those selected locations inside the thorax phantom and delivering the IMRT to the phantom. Results: The alanine dose measurements and the IMRT plan dose calculations were found to be in agreement within ±2%. Specifically, the deviations were −0.5%, 1.3%, and −1.7% for tissue, lung, and bone; respectively. The slightly large deviations observed for lung and bone may be attributed to tissue inhomogeneity, steep dose gradients in these regions, and uncontrollable changes in spectrometer conditions. Conclusion: The results described herein confirmed that pure alanine dosimeter was suitable for in-phantom dosimetry of IMRT beams because of its high sensitivity and acceptable accuracy. This makes the dosimeter a promising option for quality control of the therapeutic beams, complementing the commonly used ionization chambers, TLDs, and films.

  13. Brachytherapy dosimeter with silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Moutinho, L. M.; Castro, I. F. C.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2015-07-01

    In-vivo and in-situ measurement of the radiation dose administered during brachytherapy faces several technical challenges, requiring a very compact, tissue-equivalent, linear and highly sensitive dosimeter, particularly in low-dose rate brachytherapy procedures, which use radioactive seeds with low energy and low dose deposition rate. In this work we present a scintillating optical fiber dosimeter composed of a flexible sensitive probe and a dedicated electronic readout system based on silicon photomultiplier photodetection, capable of operating both in pulse and current modes. The performance of the scintillating fiber optic dosimeter was evaluated in low energy regimes, using an X-ray tube operating at voltages of 40-50 kV and currents below 1 mA, to assess minimum dose response of the scintillating fiber. The dosimeter shows a linear response with dose and is capable of detecting mGy dose variations like an ionization chamber. Besides fulfilling all the requirements for a dosimeter in brachytherapy, the high sensitivity of this device makes it a suitable candidate for application in low-dose rate brachytherapy. According to Peralta and Rego [1], the BCF-10 and BCF-60 scintillating optical fibers used in dosimetry exhibit high variations in their sensitivity for photon beams in the 25-100 kVp energy range. Energy linearity for energies below 50 keV needs to be further investigated, using monochromatic X-ray photons.

  14. Polymethylmethacrylate membrane with a series of serendipity.

    PubMed

    Sakai, Yoshitada

    2011-01-01

    Forty years have passed since the polymethylmethacrylate (PMMA) membrane was first developed. This article reviews its history and explains its longevity. The membrane was developed through application of a stereocomplex phenomenon that is observed upon mixture of isotactic and syndiotactic PMMA polymers. Filtryzer(TM) B1 and B2 were approved in Japan in 1977. B1 was the pioneer high-performance membrane model and B2 was a model that simulated a low-flux cellulosic membrane. The development of B1 led to the development of the dialysis machine with an ultrafiltration rate (UFR)-controlling function because the UFR of B1 was too high to control using transmembrane pressure control. B1 was used not only as a dialyzer but also as a hemodiafilter by combination with a UFR controller. Biocompatibility of the dialysis membrane, complement activation and/or transient leukopenia was studied with B2. Cooperative studies between Niigata University and Toray resulted in Gejyo's finding regarding the harmfulness of β(2)-microglobulin (BMG). Long-term follow-up of patients dialyzed using the BK membrane revealed that plasma BMG levels were significantly low and that the occurrence ratio of carpal tunnel syndrome was suppressed. These results were obtained by the adsorptive removal of BMG onto a PMMA membrane. Several papers have discussed new aspects in succession mainly based on clinical experiences that were not aimed at a development stage, i.e. they were kinds of serendipity. For the BK-F membrane with the largest pore size, this includes anemia and removal or modification of furancarboxylic acid, homocysteine, pentosidine and soluble CD40. For the BG membrane with a slightly anionic component, this includes pruritus and removal of free immunoglobulin light chains. Even patients' prognoses may be modified by the use of PMMA membrane. The mechanisms of these findings have been clarified bit by bit and the membrane will further open new frontiers in dialysis treatment.

  15. [Quality regionalization study on Gentianae Macrophyllae Radix].

    PubMed

    Lu, You-Yuan; Zhang, Xiao-Bo; Yang, Yan-Mei; Ma, Xiao-Hui; Zhu, Tian-Tian; Yu, Xiao-Hui; Jin, Ling

    2016-09-01

    The 79 samples of Gentianae Macrophyllae Radix were collected based on the distributed information by document literature. Based on sample information, and using the regression model of Gentianae Macrophyllae Radix index component and environmental factors, and combined with the prediction results of ecological suitability by MaxEnt and principal component analysis results of index component, the space distribution of Gentianae Macrophyllae Radix was estimated with the spatial analysis function of ArcGIS. The results showed that it had a higher comprehensive quality in south of Shaanxi, south of Gansu, middle of Sichuan and southeast of Xizang. The study results were coinciding with the producing regions of Gentianae Macrophyllae Radix. It can provide reference for Gentianae Macrophyllae Radix resource conservation, development and utilization. Copyright© by the Chinese Pharmaceutical Association.

  16. Proton dosimeter design for distributed body organs.

    NASA Technical Reports Server (NTRS)

    Khandelwal, G. S.; Wilson, J. W.

    1973-01-01

    The design of a real-time rem-rad dosimeter with sufficient generality for inclusion of dose distribution factors for space applications is discussed. This generalized dosimetric system is only slightly more complex than dosimeters in current use.

  17. Dose-equivalent neutron dosimeter

    DOEpatents

    Griffith, R.V.; Hankins, D.E.; Tomasino, L.; Gomaa, M.A.M.

    1981-01-07

    A neutron dosimeter is disclosed which provides a single measurement indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer contaning conversion material such as /sup 6/Li and /sup 10/B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet.

  18. Spectrophotometry of PRESAGETM polyurethane dosimeters

    NASA Astrophysics Data System (ADS)

    Krstajic, N.; Wai, P.; Adamovics, J.; Doran, S.

    2004-01-01

    Preliminary optical density results on irradiated PRESAGE dosimeter are outlined in this article. PRESAGE is a solid dosimeter, based on a clear polyurethane combined with the leuco-dye leuco-malachite green. The purpose of these measurements was a) to obtain spectra for optimizing the wavelength of a new light source for the equipment and b) to obtain a dose-response relation. 10 PRESAGE cuvettes were given uniform doses from 0.1 to 40 Gy and later read out by spectrophotometer. The instrument used was CAMSPEC M350 Double Beam Spectrophotometer.

  19. Miniature personal UV solar dosimeter

    NASA Technical Reports Server (NTRS)

    Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr.

    1981-01-01

    Small light-powered meter measures accumulated radiation in ultraviolet or other selected regions. Practical advantages are device's low cost, small size, accuracy, and adaptability to specific wave-band measurements. Medical applications include detection of skin cancer, vitamin D production, and jaundice. Dosimeter also measures sunlight for solar energy designs, agriculture and meteorology, and monitors stability of materials and environmental and occupational lighting.

  20. Miniature personal UV solar dosimeter

    NASA Technical Reports Server (NTRS)

    Adams, R. R.; Macconochie, I. O.; Poole, B. D., Jr.

    1981-01-01

    Small light-powered meter measures accumulated radiation in ultraviolet or other selected regions. Practical advantages are device's low cost, small size, accuracy, and adaptability to specific wave-band measurements. Medical applications include detection of skin cancer, vitamin D production, and jaundice. Dosimeter also measures sunlight for solar energy designs, agriculture and meteorology, and monitors stability of materials and environmental and occupational lighting.

  1. Calculation of Computational Complexity for Radix-2 (p) Fast Fourier Transform Algorithms for Medical Signals.

    PubMed

    Amirfattahi, Rassoul

    2013-10-01

    Owing to its simplicity radix-2 is a popular algorithm to implement fast fourier transform. Radix-2(p) algorithms have the same order of computational complexity as higher radices algorithms, but still retain the simplicity of radix-2. By defining a new concept, twiddle factor template, in this paper, we propose a method for exact calculation of multiplicative complexity for radix-2(p) algorithms. The methodology is described for radix-2, radix-2 (2) and radix-2 (3) algorithms. Results show that radix-2 (2) and radix-2 (3) have significantly less computational complexity compared with radix-2. Another interesting result is that while the number of complex multiplications in radix-2 (3) algorithm is slightly more than radix-2 (2), the number of real multiplications for radix-2 (3) is less than radix-2 (2). This is because of the twiddle factors in the form of which need less number of real multiplications and are more frequent in radix-2 (3) algorithm.

  2. RADIATION DOSIMETER AND DOSIMETRIC METHODS

    DOEpatents

    Taplin, G.V.

    1958-10-28

    The determination of ionizing radiation by means of single fluid phase chemical dosimeters of the colorimetric type is presented. A single fluid composition is used consisting of a chlorinated hydrocarbon, an acidimetric dye, a normalizer and water. Suitable chlorinated hydrocarbons are carbon tetrachloride, chloroform, trichloroethylene, trichlorethane, ethylene dichioride and tetracbloroethylene. Suitable acidimetric indicator dyes are phenol red, bromcresol purple, and creosol red. Suitable normallzers are resorcinol, geraniol, meta cresol, alpha -tocopberol, and alpha -naphthol.

  3. Fast-neutron solid-state dosimeter

    DOEpatents

    Kecker, K.H.; Haywood, F.F.; Perdue, P.T.; Thorngate, J.H.

    1975-07-22

    This patent relates to an improved fast-neutron solid-state dosimeter that does not require separation of materials before it can be read out, that utilizes materials that do not melt or otherwise degrade at about 300$sup 0$C readout temperature, that provides a more efficient dosimeter, and that can be reused. The dosimeters are fabricated by intimately mixing a TL material, such as CaSO$sub 4$:Dy, with a powdered polyphenyl, such as p-sexiphenyl, and hot- pressing the mixture to form pellets, followed by out-gassing in a vacuum furnace at 150$sup 0$C prior to first use dosimeters. (auth)

  4. Scleroderma en coup de sabre treated with polymethylmethacrylate - Case report*

    PubMed Central

    Franco, Joanna Pimenta de Araujo; Serra, Márcio Soares; Lima, Ricardo Barbosa; D’Acri, Antônio Macedo; Martins, Carlos José

    2016-01-01

    The scleroderma en coup de sabre is a variant of localized scleroderma that occurs preferentially in children. The disease progresses with a proliferative and inflammatory phase and later atrophy and residual deformity, which are treated with surgical techniques such as injectable fillers, transplanted or autologous fat grafting and resection of the lesion. Among the most widely used fillers is hyaluronic acid. However, there are limitations that motivate the search for alternatives, such as polymethylmethacrylate, a permanent filler that is biocompatible, non-toxic, non-mutagenic and immunologically inert. In order to illustrate its application, a case of scleroderma en coup de sabre in a 17-year-old patient, who was treated with polymethylmethacrylate with excellent aesthetic results, is reported. PMID:27192521

  5. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, David A.; Erkkila, Bruce H.; Vasilik, Dennis G.

    1985-01-01

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  6. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, D.A.; Erkkila, B.H.; Vasilik, D.G.

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  7. BETA-GAMMA PERSONNEL DOSIMETER

    DOEpatents

    Davis, D.M.; Gupton, E.D.; Hart, J.C.; Hull, A.P.

    1961-01-17

    A personnel dosimeter is offered which is sensitive to both gamma and soft beta radiations from all directions within a hemisphere. The device is in the shape of a small pill box which is worn on a worker-s wrist. The top and sides of the device are provided with 50 per cent void areas to give 50 per cent response to the beta rays and complete response to the gamma rays. The device is so constructed as to have a response which will approximate the dose received by the basal layer of the human epidermis.

  8. [Traditional Chinese medicine pairs (III)--effect of extract of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix on intestinal absorption in rats].

    PubMed

    Chen, Yi-hang; Li, Meng-xuan; Meng, Zhao-qing; Yang, Jiao-jiao; Huang, Wen-zhe; Wang, Zhen-zhong; Wang, Yue-sheng; Xiao, Wei

    2015-08-01

    This study focused on the intestinal absorption of traditional Chinese medicines (TCM) to reveal the scientific connotation of the compatibility of TCM pairs. The single pass intestinal perfusion (SPIP) was used in rats to compare the absorption of single extracts from Puerariae Lobatae Radix, single extracts from Ginseng Radix et Rhizoma, combined extracts from Puerariae Lobatae Radix and Ginseng Radix et Rhizoma and Puerariae Lobatae Radix and Ginseng Radix et Rhizoma mixture in rats. The content of puerarin, ginsenoside Rg1, ginsenoside Re and ginsenoside Rb1 in liquid were tested by HPLC. The speed constant (Ka) and apparent permeability coefficients (Papp) were calculated and compared. Specifically, the order of puerarin Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Puerariae Lobatae Radix > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix; the order of ginsenosides Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Ginseng Radix et Rhizoma > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix. The combined administration of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix may improve the absorption in the intestinal tract.

  9. [Fingerprint analysis of Glehniae Radix by TLC].

    PubMed

    Su, Xing; Li, Xiang-kun; Wu, Tao; Zhang, Tong; Wang, Zhen-tao

    2012-02-01

    To establish TLC fingerprint of Glehniae Radix for the identification and quality control of the drug. 10 batches of Glehniae Radix commercial drugs collected from different gathering areas and 3 batches from Laiyang, Shandong were used as qualitative identification samples. Falcarindiol, scopoletin umbelliferone and isoimperatorin were used as the chemical reference substances. Double wavelength TLCS was performed with petroleum and ethyl acetate (4:1) as developer,detection wavelength at 300 nm and reference wavelength at 260 nm. TLC chromatogram of 13 samples had 8 well-resolved characteristic peaks, in which 4 peaks were falcarindiol, umbelliferone, scopoletin and isoimperatorin, respectively. The method is accurate and simple, and can be used for the quality control of Glehniae Radix.

  10. Dosimeter and method for using the same

    DOEpatents

    Warner, Benjamin P.; Johns, Deidre M.

    2003-06-24

    A very sensitive dosimeter that detects ionizing radiation is described. The dosimeter includes a breakable sealed container. A solution of a reducing agent is inside the container. The dosimeter has an air-tight dosimeter body with a transparent portion and an opaque portion. The transparent portion includes a transparent chamber that holds the breakable container with the reducing agent. The opaque portion includes an opaque chamber that holds an emulsion of silver salt (AgX) selected from silver chloride, silver bromide, silver iodide, and combinations of them. A passageway in the dosimeter provides fluid communication between the transparent chamber and the opaque chamber. The dosimeter may also include a chemical pH indicator in the breakable container that provides a detectable color change to the solution for a pH of about 3-10. The invention also includes a method of detecting ionizing radiation that involves producing the dosimeter, breaking the breakable container, allowing the solution to flow through the passageway and contact the emulsion, detecting any color change in the solution and using the color change to determine a radiation dosage.

  11. TL and OSL dose response of LiF:Mg,Ti and Al2O3:C dosimeters using a PMMA phantom for IMRT technique quality assurance.

    PubMed

    Matsushima, Luciana C; Veneziani, Glauco R; Sakuraba, Roberto K; Cruz, José C; Campos, Letícia L

    2015-06-01

    The principle of IMRT is to treat a patient from a number of different directions (or continuous arcs) with beams of nonuniform fluences, which have been optimized to deliver a high dose to the target volume and an acceptably low dose to the surrounding normal structures (Khan, 2010). This study intends to provide information to the physicist regarding the application of different dosimeters type, phantoms and analysis technique for Intensity Modulated Radiation Therapy (IMRT) dose distributions evaluation. The measures were performed using dosimeters of LiF:Mg,Ti and Al2O3:C evaluated by techniques of thermoluminescent (TL) and Optically Stimulated Luminescence (OSL). A polymethylmethacrylate (PMMA) phantom with five cavities, two principal target volumes considered like tumours to be treated and other three cavities to measure the scattered radiation dose was developed to carried out the measures.

  12. Radiation Monitoring Equipment Dosimeter Experiment

    NASA Technical Reports Server (NTRS)

    Hardy, Kenneth A.; Golightly, Michael J.; Quam, William

    1992-01-01

    Spacecraft crews risk exposure to relatively high levels of ionizing radiation. This radiation may come from charged particles trapped in the Earth's magnetic fields, charged particles released by solar flare activity, galactic cosmic radiation, energetic photons and neutrons generated by interaction of these primary radiations with spacecraft and crew, and man-made sources (e.g., nuclear power generators). As missions are directed to higher radiation level orbits, viz., higher altitudes and inclinations, longer durations, and increased flight frequency, radiation exposure could well become a major factor for crew stay time and career lengths. To more accurately define the radiological exposure and risk to the crew, real-time radiation monitoring instrumentation, which is capable of identifying and measuring the various radiation components, must be flown. This presentation describes a radiation dosimeter instrument which was successfully flown on the Space Shuttle, the RME-3.

  13. Comparative study of some new EPR dosimeters

    NASA Astrophysics Data System (ADS)

    Alzimami, K. S.; Maghraby, Ahmed M.; Bradley, D. A.

    2014-02-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (WPP) and peak-to-peak signal height (HPP). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic.

  14. Fiber-type dosimeter with improved illuminator

    DOEpatents

    Fox, Richard J.

    1987-01-01

    A single-piece, molded plastic, Cassigrainian-type condenser arrangement is incorporated in a tubular-shaped personal pocket dosimeter of the type which combines an ionization chamber with an optically-read fiber electrometer to provide improved illumination of the electrometer fiber. The condenser routes incoming light from one end of the dosimeter tubular housing around a central axis charging pin assembly and focuses the light at low angles to the axis so that it falls within the acceptance angle of the electrometer fiber objective lens viewed through an eyepiece lens disposed in the opposite end of the dosimeter. This results in improved fiber illumination and fiber image contrast.

  15. Fiber-type dosimeter with improved illuminator

    DOEpatents

    Fox, R.J.

    1985-12-23

    A single-piece, molded plastic, Cassigrainian-type condenser arrangement is incorporated in a tubular-shaped personal pocket dosimeter of the type which combines an ionization chamber with an optically-read fiber electrometer to provide improved illumination of the electrometer fiber. The condenser routes incoming light from one end of the dosimeter tubular housing around a central axis charging pin assembly and focuses the light at low angles to the axis so that it falls within the acceptance angle of the electrometer fiber objective lens viewed through an eyepiece lens disposed in the opposite end of the dosimeter. This results in improved fiber illumination and fiber image contrast.

  16. Diffusion properties of a radiochromic hydrogel dosimeter

    NASA Astrophysics Data System (ADS)

    Skyt, P. S.; Kinnari, T. S.; Wahlstedt, I.; Yates, E. S.; Muren, L. P.; Petersen, J. B. B.; Balling, P.

    2013-06-01

    The aim of this study was to investigate the diffusion properties of a radiochromic hydrogel dosimeter based on leuco malachite green dye in a gelatine matrix. One half of each dosimeter was irradiated while the other half was left un-irradiated creating dose gradients over which diffusion could be investigated. Read-out of the optical response was performed with a high-resolution optical scanner. The dosimeters were found to exhibit a low diffusion rate but a high auto-oxidation level leading to a fading of the contrast in the dose response with time.

  17. [Metabolomics study of anti-platelet effect of Radix Paeoniae Rubra and Radix Paeoniae Alba by UPLC-MS].

    PubMed

    Yang, Qiwei; Yang, Li; Xiong, Aizhen; Wang, Rui; Wang, Zhengtao

    2011-03-01

    To study the anti-platelet effect and influence of Radix Paeoniae Rubra and Radix Paeoniae Alba on rat's endogenous metabolites by animal experiment and UPLC-MS based metabolomic method. After administration of 80% ethanol extracts of Radix Paeoniae Rubra and Radix Paeoniae Alba for 6 d, the serum samples were analyzed by ultra-performance liquid chromatography- mass spectrometry (UPLC-MS) and partial least squares-discriminant analysis (PLS-DA) to find out the potential biomarker. Both of the extracts of Radix Paeoniae Rubra and Radix Paeoniae Alba have good effects of inhibition on platelet coacervation, and the effect of Radix Paeoniae Alba is better than that of Radix Paeoniae Rubra. Malic acid, alpha-acetone dicarboxylic acid, leukotrieneA4 (LTA4), prostaglandinE2 (PGE2) and prostaglandin F2alpha (PGF2alpha) are proved to be significant expressed biomarkers. Metabolomics is helpful for the further research of the mechanism of anti-platelet action of Radix Paeoniae Rubra and Radix Paeoniae Alba.

  18. [The influences of ultrafiltration and alcohol sedimentation on protective effects of Radix Astragali and Radix Hedyseri against rat's cerebral ischemia].

    PubMed

    Liu, Yong-qi; Wang, Zhi-wang; Wei, Shu-chang; Yan, Chun-lu; Wang, Rui-qiong; Li, Ying-dong

    2015-03-01

    To investigate the influences of ultrafiltration and alcohol sedimentation on protective effects of Radix Astragali and Radix Hedyseri against rat's cerebral ischemia. Using dexamethasone (im.) and ligating common carotid artery, the rat stasis model combined transient cerebral ischemia was established to evaluate the effects of the ultrafiltration and alcohol sedimentation through detecting antioxidant system and other indexes in brain tissue. The results showed that the 6 g/kg water extract(crude drug), ultrafiltration and alcohol sedimentation of Radix Astragali and Radix Hedyseri could upgrade adenosine-triphosphate (ATP), superoxide dismutase (SOD) and catalase (CAT), and degrade malondialdehyde(MDA) and water content of brain tissue in rat stasis model combined transient cerebral ischemia, the water extract and ultrafiltration of them could degrade lactic acid (LD) of brain tissue, and the effects of alcohol sedimentation of Radix Astragali and Radix Hedyseri become weaker than water extract of them. The water extract, ultrafiltration and alcohol sedimentation of Radix Astragali and Radix Hedyseri have some protective effects on cerebral ischemia in rats, the effective differences of the extract through the same extraction method are not remarkable, and alcohol precipitation method has obvious influences effect on Radix Astragali and Radix Hedyseri.

  19. Performance criteria for dosimeter angular response

    SciTech Connect

    Roberson, P.L.; Fox, R. A.; Cummings, F. M.; McDonald, J. C.; Jones, K.L.

    1988-06-01

    This report provides criteria for evaluating the response of personnel dosimeters to radiation at nonperpendicular incidence. The US Department of Energy Laboratory Accreditation Program (DOELAP) ensures that dosimetry systems at DOE facilities meet acceptable standards for precision and accuracy. In the past, these standards were limited to tests for system variability, energy dependence, and level of detection. The proposed criteria will broaden the scope of DOELAP to include the angular response of personnel dosimeters. Because occupational exposures in the workplace are rarely due to radiation from only one direction, dosimeters must accurately assign individual dose equivalent from irradiation at any forward angle of incidence. Including an angular response criterion in DOELAP would improve the quality of personnel monitoring provided that the criterion is developed from appropriate dose quantities. This report provides guidance for assigning individual dose equivalents for radiation fields at nonperpendicular incidence to the dosimeter. 21 refs., 10 figs., 10 tabs.

  20. Use of wrist albedo neutron dosimeters

    SciTech Connect

    Hankins, D.E.

    1983-01-01

    We are developing a wrist dosimeter that can be used to measure the exposure at the wrist to x-rays, gamma rays, beta-particles, thermal neutrons and fast neutrons. It consists of a modified Hankins Type albedo neutron dosimeter and also contains three pieces of CR-39 plastic. ABS plastic in the form of an elongated hemisphere provides the beta and low energy x-ray shielding necessary to meet the requirement of depth dose measurements at 1 cm. The dosimeter has a beta window located in the side of the hemisphere oriented towards an object being held in the hands. A TLD 600 is positioned under the 1 cm thick ABS plastic and is used to measure the thermal neutron dose. At present we are using Velcro straps to hold the dosimeter on the inside of the wrist. 9 figures.

  1. Intercomparison of high energy neutron personnel dosimeters

    SciTech Connect

    McDonald, J.C.; Akabani, G.; Loesch, R.M.

    1993-03-01

    An intercomparison of high-energy neutron personnel dosimeters was performed to evaluate the uniformity of the response characteristics of typical neutron dosimeters presently in use at US Department of Energy (DOE) accelerator facilities. It was necessary to perform an intercomparison because there are no national or international standards for high-energy neutron dosimetry. The testing that is presently under way for the Department of Energy Laboratory Accreditation Program (DOELAP) is limited to the use of neutron sources that range in energy from about 1 keV to 2 MeV. Therefore, the high-energy neutron dosimeters presently in use at DOE accelerator facilities are not being tested effectively. This intercomparison employed neutrons produced by the {sup 9}Be(p,n){sup 9}B interaction at the University of Washington cyclotron, using 50-MeV protons. The resulting neutron energy spectrum extended to a maximum of approximately 50-MeV, with a mean energy of about 20-MeV. Intercomparison results for currently used dosimeters, including Nuclear Type A (NTA) film, thermoluminescent dosimeter (TLD)-albedo, and track-etch dosimeters (TEDs), indicated a wide variation in response to identical doses of high-energy neutrons. Results of this study will be discussed along with a description of plans for future work.

  2. [Advance in studies on effect of Glycyrrhizae Radix et Rhizoma in relieving purgative activity of Rhei Radix et Rhizoma].

    PubMed

    Su, Bin; Li, Xiao-bo

    2015-02-01

    Rhei Radix et Rhizoma, as a commonly used traditional Chinese medicine, has been widely applied in clinic. Its major purgative constituent is anthraquinones, which are believed to be a toxic ingredient. Glycyrrhizae Radix et Rhizoma has been reputed as the best alexipharmic to moderate medicine natures. In this paper, the effect of Glycyrrhizae Radix et Rhizoma in relieving purgative activity of Rhei Radix et Rhizoma was studied in two aspects--the boiling process and intestinal metabolism; Studies on combined administration of Glycyrrhizae Radix et Rhizoma and Rhei Radix et Rhizoma in recent years were summarized according to chemical constituent, intestinal flora, I/II phase metabolism and drug transport. However, the material basis and mechanism for their compatibility remain unclear, further studies will be made in the future.

  3. Simultaneous analysis of seven marker compounds from Saposhnikoviae Radix, Glehniae Radix and Peucedani Japonici Radix by HPLC/PDA.

    PubMed

    Seo, U Min; Zhao, Bing Tian; Kim, Young Ho; Kang, Jong Seong; Son, Jong Keun; Woo, Mi-Hee

    2016-05-01

    A new combination of high performance liquid chromatography (HPLC) method coupled with photodiode array (PDA) analysis has been developed for the simultaneous quantitative determination of seven major components in Saposhnikoviae Radix (SR), Glehniae Radix (GR) and Peucedani Japonici Radix (PR), namely peucedanol 7-O-β-D-glucopyranoside (1), prim-O-glucosylcimifugin (2), cimifugin (3), 4'-O-β-D-glucosyl-5-O-methylvisamminol (4), bergapten (5), sec-O-glucosylhamaudol (6), and imperatorin (7). Clear separation of these seven components were achieved on a Phenomenex Kinetex C18 (250 × 4.6 mm, 5 μm) column by gradient elution of water (A) and methanol (B) as mobile phase. The flow rate was 1.0 mL/min and the UV detector wavelength was set at 254 nm. The method was successfully used in the analysis of SR, GR, and PR with relatively simple conditions and procedures, and the results were satisfactory for linearity, recovery, precision, accuracy, stability and robustness. The results indicate that the established HPLC/PDA method is suitable for the classification of SR, GR, and PR.

  4. Discrimination and Proper Use of Polygoni Multiflori Radix, Cynanchi Wilfordii Radix, and Cynanchi Auriculati Radix in Korea: A Descriptive Review

    PubMed Central

    Lee, Beom-Joon; Lee, Kyungjin

    2015-01-01

    Polygoni Multiflori Radix (PMR), Cynanchi Wilfordii Radix (CWR), and Cynanchi Auriculati Radix (CAR) are very popular herbal medicines in Traditional Korean Medicine, Traditional Chinese Medicine, and Kampo Medicine. However, the plant origins, efficacies, and traditional uses of these herbal medicines differ. In Korea, PMR is called Ha Su O (He Shou Wu in China), and CWR is called Baek Ha Su O or Baek Su O (Bai Shou Wu in China). Baek Su O refers to CWR in Korea and CAR in China. CAR has not been used as a traditional herbal medicine, and it cannot be legally used as a food or food ingredient in Korea. However, CAR is cultivated in Korea and imported from China. Because the morphology of CWR and CAR is very similar, they are often confused and misused in Korea. This review discusses the reasons for the confusion and misuse of these substances in Korea and provides the exact plant origins, efficacies, uses, components, and toxicities of PMR, CWR, and CAR so that they can be correctly understood and used. PMID:26539235

  5. Melanogenesis inhibitory compounds from Saussureae Radix.

    PubMed

    Choi, Ji Young; Choi, Eun Hyang; Jung, Hee Wook; Oh, Joon Seok; Lee, Won-Hee; Lee, Jong Gu; Son, Jong-Keun; Kim, Youngsoo; Lee, Seung Ho

    2008-03-01

    Ten compounds were isolated from the EtOAc soluble part of the MeOH extract of Saussureae Radix, with their effects on melanin production also evaluated in B-16 mouse melanoma cell lines stimulated with 3-isobutyl-1-methylxanthine (IBMX), an elevator of cellular cAMP. The compounds were identified as aplotaxene (1), 1 beta-hydroxy arbusculin A (2), costunolide (3), dehydrocostuslactone (4), 11 beta,13-dihydrocostunolide (5), reynosin (6), heptadec-(9Z)-enoic acid (7), beta-sitosterol (8), linoleic acid methyl ester (9) and betulinic acid methyl ester (10). Compounds 2, 9 and 10 were identified from Saussureae Radix for the first time. Furthermore, compounds 2, 3 and 6 showed potent inhibitory effects on the IBMX-induced melanogenesis, in dose-dependent manners, with IC50 values of 11, 3 and 2.5 microg/mL, respectively. As a positive control, arbutin exhibited an IC50 value of 29 microg/mL.

  6. Radix Representation of Triangular Discrete Grid System

    NASA Astrophysics Data System (ADS)

    Ben, J.; Li, Y. L.; Wang, R.

    2016-11-01

    Discrete Global Grid Systems (DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. It provides an organizational structure that permits fast integration between multiple sources of large and variable geospatial data. Although many endeavors have been done to describe certain discrete grid systems, there still lack of a uniform mathematical framework for them. This paper simplifies the planar class I aperture 4 triangular discrete grid system into a hierarchical lattice model which is proved to be a radix system in the complex number plane. Mathematical properties of the radix system reveal the discrete grid system is equivalent to the set of complex numbers with special form. The conclusion provides a potential way to build a uniform mathematical framework of DGGS and can be used to design efficient encoding and spatial operation scheme for DGGS.

  7. Complete or a partial sheet of deep temporal fascial graft as a radix graft for radix augmentation.

    PubMed

    Besharatizadeh, Rosina; Ozkan, Birkan Taha; Tabrizi, Reza

    2011-10-01

    Autogenous fascia, including the temporalis fascia, has a particular role in rhinoplasty as radix and dorsal onlay grafts. The main purpose of this study is to achieve desired appearance of facial harmony using either a complete or partial sheet of deep temporal fascia as a radix graft in the patients with required permanent radix augmentation. This is a prospective study of 15 patients who referred to Gandi Day Clinic, Tehran, Iran, between 2005 and 2006 and underwent rhinoplasty including nasal radix augmentation using deep temporalis fascia through external rhinoplasty approach. The patients with hump noses had low radix and required radix augmentation. Full sheet facial graft was used in 13 patients. Partial sheet facial graft was used in two patients. As a donor site problem, minor hematoma was observed in one patient. Temporary hair loss in incision line was another problem which were seen in five. As for the recipient site, no infection, persistent erythema of nasal skin extrusion, visibility, displacement of graft materials or irregularity of graft contour were observed postoperatively. Resorption rate was approximately 30% for grafted fascia. Using fascia grafts in radix point, the revision rate was minimal. In order to augment the radix, if 4 mm augmentation is needed, it should be considered that full sheet fascia graft alone would be insufficient. If more than 4 mm of augmentation is needed, 30% overcorrection would manage well the permanent radix augmentation without any problem.

  8. Pullout strength of fixation screws from polymethylmethacrylate bone cement.

    PubMed

    Flahiff, C M; Gober, G A; Nicholas, R W

    1995-05-01

    Polymethylmethacrylate bone cement is often used to fill voids and increase the strength of osteoporotic and pathological bone. However, it is unclear as to which method of cement augmentation provides optimal screw fixation. This study was conducted to determine which of the current cement augmentation techniques provides the strongest construct when used in association with orthopaedic fixation screws. Pullout strength was determined for screws placed in sawbones with no cement, soft cement, doughy cement and hard cement after drilling and tapping. All cement-screw constructs were significantly stronger than the no cement group. Screws placed in doughy cement had a significantly higher pullout force than those placed in hard cement. Pullout strength of screws placed in soft cement was intermediate between the other cement techniques but not significantly different from either group.

  9. Gold-implanted shallow conducting layers in polymethylmethacrylate

    SciTech Connect

    Teixeira, F. S.; Salvadori, M. C.; Cattani, M.; Brown, I. G.

    2009-03-15

    PMMA (polymethylmethacrylate) was ion implanted with gold at very low energy and over a range of different doses using a filtered cathodic arc metal plasma system. A nanometer scale conducting layer was formed, fully buried below the polymer surface at low implantation dose, and evolving to include a gold surface layer as the dose was increased. Depth profiles of the implanted material were calculated using the Dynamic TRIM computer simulation program. The electrical conductivity of the gold-implanted PMMA was measured in situ as a function of dose. Samples formed at a number of different doses were subsequently characterized by Rutherford backscattering spectrometry, and test patterns were formed on the polymer by electron beam lithography. Lithographic patterns were imaged by atomic force microscopy and demonstrated that the contrast properties of the lithography were well maintained in the surface-modified PMMA.

  10. Polymethylmethacrylate bone cements and additives: A review of the literature

    PubMed Central

    Arora, Manit; Chan, Edward KS; Gupta, Sunil; Diwan, Ashish D

    2013-01-01

    Polymethylmethacrylate (PMMA) bone cement technology has progressed from industrial Plexiglass administration in the 1950s to the recent advent of nanoparticle additives. Additives have been trialed to address problems with modern bone cements such as the loosening of prosthesis, high post-operative infection rates, and inflammatory reduction in interface integrity. This review aims to assess current additives used in PMMA bone cements and offer an insight regarding future directions for this biomaterial. Low index (< 15%) vitamin E and low index (< 5 g) antibiotic impregnated additives significantly address infection and inflammatory problems, with only modest reductions in mechanical strength. Chitosan (15% w/w PMMA) and silver (1% w/w PMMA) nanoparticles have strong antibacterial activity with no significant reduction in mechanical strength. Future work on PMMA bone cements should focus on trialing combinations of these additives as this may enhance favourable properties. PMID:23610754

  11. MR-safe personal radiation dosimeters.

    PubMed

    Tchistiakova, E; Kim, A; Song, W Y; Pang, G

    2017-07-01

    Magnetic resonance imaging (MRI) is being rapidly integrated for cancer treatments-such systems are referred to as MRI-guided radiation therapy (MRIgRT). As the magnet of an MRI scanner is always on, the presence of a strong static magnetic field from the MRI scanner during radiotherapy delivery presents new challenges. One of the challenges is that a personal radiation dosimeter used to estimate the radiation dose deposited in an individual wearing the device must be MR-safe. No such devices, however, are currently available. In this work we first modified an existing personal dosimeter (by removing a metal clip) to make it MR-safe and then investigated potential effects of magnetic field on dosimeter readings, i.e., optically stimulated luminescent dosimeter (OSLD) readings. We found that the effect of magnetic field on OSLD sensitivity was within radiation protection tolerance levels. OSLD personal dosimeters can be directly used in conjunction with MRIgRT radiation protection purposes. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  12. PNNL Results from 2009 Silene Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect

    Hill, Robin L.; Conrady, Matthew M.

    2010-06-30

    This document reports the results of testing of the Hanford Personnel Nuclear Accident Dosimeter (PNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on October 13, 14, and 15, 2009.

  13. Solid state neutron dosimeter for space applications

    SciTech Connect

    Nagarkar, V.; Entine, G.; Stoppel, P.; Cirignano, L. ); Swinehart, P. )

    1992-08-01

    One of the most important contributions to the radiation exposure of astronauts engaged in space flight is the significant flux of high energy neutrons arising from both primary and secondary sources of ionizing radiation. Under NASA sponsorship, the authors are developing a solid state neutron sensor capable of being incorporated into a very compact, flight instrument to provide high quality real time measurement of this important radiation flux. The dosimeter uses a special, high neutron sensitivity, PIN diode that is insensitive t the other forms of ionizing radiation. The dosimeter will have the ability to measure and record neutron dose over a range of 50 microgray to tens of milligrays (5 millirads to several rads) over a flight of up to 30 days. the performance characteristics of the PIN diode with a detailed description of the overall dosimeter is presented. in this paper.

  14. System for use with solid state dosimeter

    DOEpatents

    Miller, Steven D.; McDonald, Joseph C.; Eichner, Fred N.; Tomeraasen, Paul L.

    1990-01-01

    The present invention constitutes a system for determining the amounts of ionizing radiation to which dosimeters using thermoluminescent materials have been exposed. In accordance with this system, the thermoluminescent materials which comprise the dosimeters are first cooled by contact with a cryogenic substance such as liquified nitrogen. The thermoluminescent materials are then optically stimulated by exposure to ultraviolet light. Thereafter, the amounts of visible light emitted by the thermoluminescent materials are detected and counted as the materials are allowed to warm up to room temperature. The amounts of luminescence exhibited by the materials are related to radiation exposure and provide a sensitive measure of radiation dosage. It has been discovered that the above procedure is most effective when heavily doped thermoluminescent materials are used and that the procedure allows many useful plastic materials to now be employed in dosimeter constructions.

  15. System for use with solid state dosimeter

    DOEpatents

    Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Tomeraasen, P.L.

    1990-09-04

    The present invention constitutes a system for determining the amounts of ionizing radiation to which dosimeters using thermoluminescent materials have been exposed. In accordance with this system, the thermoluminescent materials which comprise the dosimeters are first cooled by contact with a cryogenic substance such as liquefied nitrogen. The thermoluminescent materials are then optically stimulated by exposure to ultraviolet light. Thereafter, the amounts of visible light emitted by the thermoluminescent materials are detected and counted as the materials are allowed to warm up to room temperature. The amounts of luminescence exhibited by the materials are related to radiation exposure and provide a sensitive measure of radiation dosage. It has been discovered that the above procedure is most effective when heavily doped thermoluminescent materials are used and that the procedure allows many useful plastic materials to now be employed in dosimeter constructions. 3 figs.

  16. Environmental dosimeter of the thermoluminescent type

    DOEpatents

    Eichner, F.N.; Kocher, L.F.

    1974-01-29

    A dosimeter for accurately monitoring normally low-energy radiation including a thermoluminescent CaF phosphor enclosed within a tantalum capsule is described. The tantalum acts as a filter to weaken the measured dose due to photons having energies below about 0.2 MeV. Tantalum end caps are maintained on the capsule body by a polyolefin sheath formed from heat-contractable tubing. After exposing the dosimeter to environmental radiation, it is placed in a shielded chamber for about 24 h and subsequently annealed at about 80 deg C to release radiation energy accumulated in low-temperature traps. The dosimeter is then disassembled and the phosphors photometrically read at temperatures about 50 deg C to determine the absorbed radiation dose. (Official Gazette)

  17. Radix mesiolingualis and radix distolingualis: a case report of a tooth with an unusual morphology

    PubMed Central

    Aeran, Himanshu; Singh, Inderpreet

    2016-01-01

    Variation in the root and canal morphology of the maxillary first molars is quite common. The most common configuration is 3 roots and 3 or 4 canals. Nonetheless, other possibilities still exist. The presence of an additional palatal root is rather uncommon and has been reported to have an incidence of 0.06 - 1.6% in varying populations studied. Whenever two palatal roots exist, one of them is the normal palatal root, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). This case report describes successful endodontic treatment of a maxillary first molar with radix mesiolingualis and radix distolingualis. Identification of this variation was done through clinical examination along with the aid of multiangled radiographs, and an accurate assessment of this morphology was made with the help of a cone-beam computed tomography imaging. In addition to the literature review, this article also discusses the epidemiology, classifications, morphometric features, guidelines for diagnosis, and endodontic management of a maxillary first molar with extra-palatal root. PMID:27847755

  18. New radiation dosimeter using a pyroelectric detector

    SciTech Connect

    de Paula, M.H.; Carvalho, A.A.; Mascarenhas, S.; Zimmerman, R.L.

    1984-11-01

    We describe a new type of radiation dosimeter, for the diagnostic x-ray region, using a pyroelectric detector. It consists of a PZT ceramic crystal thick enough to absorb all the incident radiation at 33 keV. This pyroelectric radiation dosimeter (PERD) produces an electrical signal when exposed to a chopped beam of x-ray photons. The PERD is basically a microcalorimeter. It has the following characteristics: (1) it responds linearly to the energy fluence rate of the radiation; (2) it responds linearly to the radiation inten

  19. New radiation dosimeter using a pyroelectric detector

    SciTech Connect

    de Paula, M.H.; Carvalho, A.A.; Mascarenhas, S.; Zimmerman, R.L.

    1984-11-01

    We describe a new type of radiation dosimeter, for the diagnostic x-ray region, using a pyroelectric detector. It consists of a PZT ceramic crystal thick enough to absorb all the incident radiation at 33 keV. This pyroelectric radiation dosimeter (PERD) produces an electrical signal when exposed to a chopped beam of x-ray photons. The PERD is basically a microcalorimeter. It has the following characteristics: (1) it responds linearly to the energy fluence rate of the radiation; (2) it responds linearly to the radiation intensity for a given radiation spectrum; (3) it has excellent stability; (4) it is simple to construct and inexpensive; and (5) it is rugged.

  20. Chemical Dosimeter Tube With Coaxial Sensing Rod

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E.

    1993-01-01

    Improved length-of-stain (LOS) chemical dosimeter indicates total dose of chemical vapor in air. Made with rods and tubes of various diameters to obtain various sensitivities and dynamic ranges. Sensitivity larger and dose range smaller when more room for diffusion in gap between tube and rod. Offers greater resistance to changing of color of exposed dye back to color of unexposed condition, greater sensitivity, and higher degree of repeatability. Developed to measure doses of gaseous HCI, dosimeter modified by use of other dyes to indicate doses of other chemical vapors.

  1. Fiber optic dosimeter with silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Moutinho, L. M.; Castro, I. F.; Peralta, L.; Abreu, M. C.; Veloso, J. F. C. A.

    2014-08-01

    A small dimension, real-time readout dosimeter is desirable for specific applications in medical physics as for example, dose measurement in prostate brachytherapy. This particular radiotherapy procedure consists in the permanent deposition of low energy, low-dose and low-dose rate small sized radioactive seeds. We developed a scintillating fiber optic based dosimeter suitable for in-vivo, real-time low dose and low dose rate measurements. Due to the low scintillation light produced in the scintillating fiber, a high sensitive and high gain light detector is required. The Silicon Photomultipliers are an interesting option that allowed us to obtain good results in our studies.

  2. DEPRON dosimeter for ``Lomonosov'' satellite

    NASA Astrophysics Data System (ADS)

    Brilkov, Ivan; Vedenkin, Nikolay; Panasyuk, Mikhail; Amelyushkin, Aleksandr; Petrov, Vasily; Nechayev, Oleg; Benghin, Victor

    appearance of the instrument DEPRON (Dosimeter of Electrons, PROtons and Neutrons) was determined. DEPRON is intended for registration of the absorbed doses and linear energy transfer spectra for high-energy electrons, protons and nuclei of space radiation, as well as registration of thermal and slow neutrons. The experiment based on DEPRON instrument is aimed at the studies of the distribution of space radiation dose rate at high latitude paths in order to study the flight paths of perspective manned spacecraft. Present work provides a brief description of the DEPRON instrument, its calibration results and the structure of the output data.

  3. Chemical constituents of radix Ranunculus ternati.

    PubMed

    Zhao, Yun; Ruan, Jin-Lan; Wang, Jin-Hui; Cong, Yue; Song, Shuang; Cai, Ya-Ling; Fang, Wei; Zhou, Dao-Nian

    2008-02-15

    3 Beta-acetoxy-(20S, 22E)-dammaran-22-en-25-ol, a new triterpene, was isolated along with five known triterpenes (ursolic acid, oleanolic acid, betulinic acid, 3-epiocotillol acetate, and dimmarenediol II acetate), and alpha-D-glc and sucrose from Radix Ranunculus ternati All of them, except oleanolic acid and alpha-D-glc, were isolated from the family of Ranunculaceae for the very first time, and the NMR data of sucrose was first described. In addition, the absolute configurations of alpha-D-glc and the glucose component of sucrose were determined.

  4. NOTE: Cell-phone interference with pocket dosimeters

    NASA Astrophysics Data System (ADS)

    Djajaputra, David; Nehru, Ramasamy; Bruch, Philip M.; Ayyangar, Komanduri M.; Raman, Natarajan V.; Enke, Charles A.

    2005-05-01

    Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag.

  5. Response characteristics of selected personnel neutron dosimeters

    SciTech Connect

    McDonald, J.C.; Fix, J.J.; Hadley, R.T.; Holbrook, K.L.; Yoder, R.C.; Roberson, P.L.; Endres, G.W.R.; Nichols, L.L.; Schwartz, R.B.

    1983-09-01

    Performance characteristics of selected personnel neutron dosimeters in current use at Department of Energy (DOE) facilities were determined from their evaluation of neutron dose equivalent received after irradiations with specific neutron sources at either the National Bureau of Standards (NBS) or the Pacific Northwest Laboratory (PNL). The characteristics assessed included: lower detection level, energy response, precision and accuracy. It was found that when all of the laboratories employed a common set of calibrations, the overall accuracy was approximately +-20%, which is within uncertainty expected for these dosimeters. For doses above 80 mrem, the accuracy improved to better than 10% when a common calibration was used. Individual differences found in this study may reflect differences in calibration technique rather than differences in the dose rates of actual calibration standards. Second, at dose rates above 100 mrem, the precision for the best participants was generally below +-10% which is also within expected limits for these types of dosimeters. The poorest results had a standard deviation of about +-25%. At the lowest doses, which were sometimes below the lower detection limit, the precision often approached or exceeded +-100%. Third, the lower level of detection for free field /sup 252/Cf neutrons generally ranged between 20 and 50 mrem. Fourth, the energy dependence study provided a characterization of the response of the dosimeters to neutron energies far from the calibration energy. 11 references, 22 figures, 26 tables.

  6. Analysis of nonstandard noise dosimeter microphone positions.

    PubMed

    Byrne, David C; Reeves, Efrem R

    2008-03-01

    This study was conducted as part of a project involving the evaluation of a new type of noise exposure monitoring paradigm. Laboratory tests were conducted to assess how "nonstandard" dosimeter microphones and microphone positions measured noise levels under different acoustical conditions (i.e., diffuse field and direct field). The data presented in this article reflect measurement differences due to microphone position and mounting/supporting structure only and are not an evaluation of any particular complete dosimeter system. To varying degrees, the results obtained with the dosimeter microphones used in this study differed from the reference results obtained in the unperturbed (subject absent) sound field with a precision (suitable for use in an ANSI Type 1 sound level meter) (1)/(2)-inch (12.7 mm) measurement microphone. Effects of dosimeter microphone placement in a diffuse field were found to be minor for most of the test microphones/locations, while direct field microphone placement effects were found to be quite large depending on the microphone position and supporting structure, sound source location, and noise spectrum.

  7. Underwater remote-reading dosimeter evaluation

    SciTech Connect

    Clow, H.E.; Emmons, G. )

    1985-01-01

    This paper reports on problems inherent in attempting to measure underwater dose rates and monitor and control diver exposures. At Connecticut Yankee, the authors had a specific procedure in effect to cover diving evolutions; however, the authors were not satisfied with the methods available to us for monitoring a diver's dose during a dive. The authors looked around and discovered that the ideal monitoring method was already at hand. In the past, the authors had successfully used the Xetex 503A Teledose system for high dose rate jobs under are variety of circumstances, but not underwater. The basic Teledose system consists of a base station and five individual electronic dosimeter/transmitters that can be worn by workers. The dosimeters are GM-tube types packaged in high-impact plastic or metal cases, each powered by a single 9-volt battery. The dosimeters do not have their own read-outs - instead, they transmit a coded pulse for each mR detected via a loop antenna to the base station, where the accumulated exposure for each of the five dosimeter units is displayed.

  8. Pen Ink as an Ultraviolet Dosimeter

    ERIC Educational Resources Information Center

    Downs, Nathan; Turner, Joanna; Parisi, Alfio; Spence, Jenny

    2008-01-01

    A technique for using highlighter ink as an ultraviolet dosimeter has been developed for use by secondary school students. The technique requires the students to measure the percentage of colour fading in ink drawn onto strips of paper that have been exposed to sunlight, which can be calibrated to measurements of the ultraviolet irradiance using…

  9. Pen Ink as an Ultraviolet Dosimeter

    ERIC Educational Resources Information Center

    Downs, Nathan; Turner, Joanna; Parisi, Alfio; Spence, Jenny

    2008-01-01

    A technique for using highlighter ink as an ultraviolet dosimeter has been developed for use by secondary school students. The technique requires the students to measure the percentage of colour fading in ink drawn onto strips of paper that have been exposed to sunlight, which can be calibrated to measurements of the ultraviolet irradiance using…

  10. Radiant energy dosimeter for field use

    Treesearch

    A. Broido; A.W. McMasters

    1967-01-01

    Thermal radiation measurements in Project Flambeau fires involved a limited number of conventional radiometers located outside the fire periphery. A simple, cheap, easily-fabricated, light-weight, self-contained, rugged dosimeter was desired to withstand a hot fire environment, including a specific energy input of 5,000 cal cm -2, and to record...

  11. Compton effect thermally activated depolarization dosimeter

    DOEpatents

    Moran, Paul R.

    1978-01-01

    A dosimetry technique for high-energy gamma radiation or X-radiation employs the Compton effect in conjunction with radiation-induced thermally activated depolarization phenomena. A dielectric material is disposed between two electrodes which are electrically short circuited to produce a dosimeter which is then exposed to the gamma or X radiation. The gamma or X-radiation impinging on the dosimeter interacts with the dielectric material directly or with the metal composing the electrode to produce Compton electrons which are emitted preferentially in the direction in which the radiation was traveling. A portion of these electrons becomes trapped in the dielectric material, consequently inducing a stable electrical polarization in the dielectric material. Subsequent heating of the exposed dosimeter to the point of onset of ionic conductivity with the electrodes still shorted through an ammeter causes the dielectric material to depolarize, and the depolarization signal so emitted can be measured and is proportional to the dose of radiation received by the dosimeter.

  12. Strategies for millirad sensitivity in PMOS dosimeters

    SciTech Connect

    Conneely, C.; O`Connell, B.; Hurley, P.; Lane, W.; Adams, L.

    1998-06-01

    Previous work at this center has shown enhanced sensitivity for PMOS dosimeters using a design approach. This is being extended presently to longer chains of devices. Prior to this extension, thermal effects have been investigated and a noise analysis has been undertaken. The need for a temperature compensation technique becomes imperative if the signal/noise ratio is to be improved.

  13. Investigating hydrogel dosimeter decomposition by chemical methods

    NASA Astrophysics Data System (ADS)

    Jordan, Kevin

    2015-01-01

    The chemical oxidative decomposition of leucocrystal violet micelle hydrogel dosimeters was investigated using the reaction of ferrous ions with hydrogen peroxide or sodium bicarbonate with hydrogen peroxide. The second reaction is more effective at dye decomposition in gelatin hydrogels. Additional chemical analysis is required to determine the decomposition products.

  14. Polymer gel dosimeter based on itaconic acid.

    PubMed

    Mattea, Facundo; Chacón, David; Vedelago, José; Valente, Mauro; Strumia, Miriam C

    2015-11-01

    A new polymeric dosimeter based on itaconic acid and N, N'-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158cGy/min, 226cGymin and 298cGy/min with doses up to 1000Gy. The dosimeters presented a linear response in the dose range 75-1000Gy, sensitivities of 0.037 1/Gyat 298cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Polymethylmethacrylate-induced release of bone-resorbing factors

    SciTech Connect

    Herman, J.H.; Sowder, W.G.; Anderson, D.; Appel, A.M.; Hopson, C.N. )

    1989-12-01

    A pseudomembranous structure that has the histological characteristics of a foreign-body-like reaction invariably develops at the bone-cement interface in the proximity of resorption of bone around aseptically loosened cemented prostheses. This study was an attempt to implicate polymethylmethacrylate in this resorptive process. Unfractionated peripheral-blood mononuclear cells (consisting of lymphocytes and monocytes) and surface-adherent cells (monocyte-enriched) were prepared from control subjects who did and did not have clinical evidence of osteoarthrosis and from patients who had osteoarthrosis and were having a revision for failure of a cemented hip or knee implant. Cells were cultured for varying periods in the presence and absence of nonpolymerized methacrylate (one to two-micrometer spherules), pulverized polymerized material, or culture chambers that were pre-coated with polymerized cement. Conditioned media that were derived from both methacrylate-stimulated cell populations were shown to contain specific bone-resorbing mediators (interleukin-1, tumor necrosis factor, or prostaglandin E2) and to directly affect bone resorption in 45Ca-labeled murine limb-bone assays.

  16. A poly-methylmethacrylate electrophoresis microchip with sample preconcentrator

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Cheng; Ho, Hsiao-Ching; Tseng, Chien-Kai; Hou, Shao-Qin

    2001-05-01

    A microstructure on poly-methylmethacrylate (PMMA) for sample concentration and electrophoresis was fabricated. This microfabricated structure was able to increase the detection signal and lower the amount of sample used in electrophoretic analysis. The thin-film electrode located at the T-intersection of the sample injection and separation channels provides the current path for the injection channel, but restrains the DNA molecules from passing through. This can accumulate DNA molecules and increase the concentration before performing the electrophoretic analysis. This microstructure was fabricated using krypton fluoride (KrF) excimer laser photo-ablation and fusion bonding techniques. The excimer laser photo-ablation performs rapid prototyping with great flexibility in design changes. The PMMA material is much cheaper than other materials, for example glass and silicon, used in capillary electrophoresis and concentration. The applied electrical field was 300 V cm-1 for the DNA concentration in this microstructure. Experiments show that the DNA concentration was saturated within 200 s after the DNA molecules first reached the injection tee. The DNA fragments can be concentrated up to five times greater than samples without a concentrator at the injection tee. The separation results also demonstrated that the detected signal intensities of the separated DNA fragments in the tee-type chip with a sample preconcentrator were five times greater than that obtained in a conventional cross-type capillary electrophoresis chip with an identical initial sample concentration.

  17. Surface engineering of poly(methylmethacrylate): Effects on fluorescence immunoassay.

    PubMed

    Akers, Peter W; Hoai Le, Nam Cao; Nelson, Andrew R J; McKenna, Milena; O'Mahony, Christy; McGillivray, Duncan J; Gubala, Vladimir; Williams, David E

    2017-06-06

    The authors present surface engineering modifications through chemistry of poly(methylmethacrylate) (PMMA) that have dramatic effects on the result of surface-bound fluorescence immunoassays, both for specific and nonspecific signals. The authors deduce the most important effect to be clustering of antibodies on the surface leading to significant self-quenching. Secondary effects are attributable to the formation of sparse multilayers of antibody. The authors compare PMMA as an antibody support surface with ultraviolet-ozone oxidized PMMA and also to substrates that were, after the oxidation, surface modified by a four-unit poly(ethyleneglycol) carboxylic acid (PEG4), a branched tricarboxylic acid, and a series of carboxylic acid-terminated dendrimers, from generation 1.5 to 5.5. Fluorescence immunoassay and neutron reflectometry were used to compare the apparent antibody surface loading, antigen binding and nonspecific binding on these various surfaces using anti-human IgG as a model antibody, chemically coupled to the surface by amide formation. Simple physical adsorption of the antibody on PMMA resulted in a thick antibody multilayer with small antigen binding capacity. On the carboxylated surfaces, with chemical coupling, a simple monolayer was formed. The authors deduce that antibody clustering was driven by conformational inflexibility and high carboxylate density. The PEG4-modified surface was the most conformationally flexible. The dendrimer-modified interfaces showed a collapse and densification. In fluorescence immunoassay, the optimal combination of high specific and low nonspecific fluorescence signal was found for the G3.5 dendrimer.

  18. Integrity of Polymethylmethacrylate (PMMA) Chemically Welded Joints Examined

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley A.; Thesken, John C.; Bunnell, Charles T.; Kurta, Carol E.; Sydenstricker, Mike

    2005-01-01

    NASA Glenn Research Center s Capillary Flow Experiments (CFE) program is developing experiment payloads to explore fluid interfaces in microgravity on the International Space Station. The information to be gained from the CFE is relevant to the design of fluid-bearing systems in which capillary forces predominate, for example in the passive positioning of liquids in spacecraft fuel tanks. To achieve the science goals of CFE, Glenn researchers constructed several types of experiment vessels. One type of vessel, known as the interior corner flow (ICF), will be used to determine important transients for low-gravity liquid management in a two-phase system. Each vessel has a cylindrical fluid reservoir connected to each end of the test chamber by internal transport tubes, each with a quarter-turn shutoff valve (see the following photograph). These multipiece vessels are made from polymethylmethacrylate (PMMA) because of its excellent optical properties (i.e., the fluids can be observed easily in the vessel). Because of the complexity of certain vessels, the test chamber had to be manufactured in pieces and welded chemically. Some past experience with adhesive bonded plastic showed that the experiment fluid degraded the adhesive to the point of failure. Therefore, it was necessary to see if the fluid also degraded the chemically welded PMMA joints.

  19. Polymethylmethacrylate dermal fillers: evaluation of the systemic toxicity in rats.

    PubMed

    Medeiros, C C G; Borghetti, R L; Nicoletti, N; da Silva, V D; Cherubini, K; Salum, F G; de Figueiredo, M A Z

    2014-01-01

    This study evaluated local and systemic reactions after an intravascular injection of polymethylmethacrylate (PMMA) at two concentrations in a murine model. Thirty rats were divided equally into three groups: 2% PMMA, 30% PMMA, and a control group (normal saline only injection). The filler was injected into the ranine vein. The rats were sedated at 7 and 90 days and a clinical evaluation performed. After euthanasia, the right lung, liver, and right kidney were removed, weighed, and microscopically analyzed. The submandibular lymph nodes and tongue were removed and examined microscopically. Serum was subjected to liver and kidney function tests. No groups showed clinical alterations. Microspheres were not observed at any distant organ. Two samples from the 2% PMMA group showed a local inflammatory response at day 7 and another two samples from the 30% PMMA group at day 90. The group injected with 30% PMMA presented higher levels of alanine aminotransferase (P = 0.047) after 90 days when compared with the other groups. The data obtained in this study demonstrate that intravascular injections of PMMA fillers show potential health risks such as chronic inflammation at the implantation site.

  20. Deficiencies of active electronic radiation protection dosimeters in pulsed fields.

    PubMed

    Ankerhold, U; Hupe, O; Ambrosi, P

    2009-07-01

    Nowadays nearly all radiation fields used for X-ray diagnostics are pulsed. These fields are characterised by a high dose rate during the pulse and a short pulse duration in the range of a few milliseconds. The use of active electronic dosimeters has increased in the past few years, but these types of dosimeters might possibly not measure reliably in pulsed radiation fields. Not only personal dosimeters but also area dosimeters that are used mainly for dose rate measurements are concerned. These cannot be substituted by using passive dosimeter types. The characteristics of active electronic dosimeters determined in a continuous radiation field cannot be transferred to those in pulsed fields. Some provisional measurements with typical electronic dosimeters in pulsed radiation fields are presented to reveal this basic problem.

  1. Efficient radix-r adders for nanoelectronics

    NASA Astrophysics Data System (ADS)

    Moaiyeri, Mohammad Hossein; Chavoshisani, Reza; Jalali, Ali; Navi, Keivan; Hashemipour, Omid

    2016-02-01

    In this study, a new design method and efficient designs for radix-r adders are proposed for carbon nanotube field effect transistor (CNFET) FET nanotechnology. This application also investigates the capability of the nanoscale device for designing high-performance analogue circuits. The proposed designs benefit from the unique electrical properties of CNFET, such as near-ideal current voltage characteristics, very high transconductance, high-performance switches and very high-performance and high-gain binary inverters, at nanoscale. Moreover, adjustable threshold voltage and the same mobility of electrons and holes in a CNFET facilitate the design and modification procedures. The proposed design can be considered as an instance of a general adder, capable of adding radix-r digits with high precision. It is noteworthy that a very limited number of carbon nanotube diameters for designing the proposed adder are needed, which enhance the manufacturability. The proposed circuits are designed based on arithmetic relations and are also verified at 32 nm feature size using HSPICE and the Stanford standard SPICE model.

  2. [Investigating mechanism of toxicity reduction by combination of Glycyrrhizae Radix et Rhizoma and Aconiti Lateralis Radix Preparata on terms of proteins self-assembly].

    PubMed

    Li, Bing-jie; Shen, Yong; Liao, Ri-tao; Gao, Guan-zhen; Ke, Li-jing; Zhou, Jian-wu; Rao, Ping-fan

    2015-02-01

    The combination of Glycyrrhizae Radix et Rhizoma and Aconiti Lateralis Radix Preparata can increase efficacy and decrease toxicity. This study started from the phenomena of protein self-assembly in the mixed decoction of Glycyrrhizae Radix et Rhizoma with Aconiti Lateralis Radix Preparata. The attenuated mechanism was explored between the combination of Glycyrrhizae Radix et Rhizoma and Aconiti Lateralis Radix Preparata by using the protein of Glycyrrhizae Radix et Rhizoma and aconitine which was the major toxic component of Aconiti Lateralis Radix Preparata. Glycyrrhizae Radix et Rhizoma protein with aconitine could form stable particles which particle mean diameter was (206.2 ± 2.02) nm and (238.20 ± 1.23) nm at pH 5.0 in normal temperature. Through the mouse acute toxicity experiment found that injection of aconitine monomer all mice were killed, and injection of Glycyrrhizae Radix et Rhizoma protein-aconitine particles with the same content of aconitine all mice survived. Survey the stability of Glycyrrhizae Radix et Rhizoma protein-aconitine shows that the colloid particles is stable at room temperature, and it has the possibility to candidate drug carrier. Glycyrrhizae Radix et Rhizoma protein can reduce the toxicity of aconitine through self-assembly.

  3. Diet and growth in juveniles of the garter snakes Thamnophis sirtalis infernalis and Thamnophis radix radix.

    PubMed

    Scudder-Davis, R M; Burghardt, G M

    1987-01-01

    The effects of diets consisting of different food types on the growth of juvenile garter snakes was tested using a litter each of Thamnophis sirtalis infernalis and T. radix radix. The snakes were fed diets consisting of earthworms, Lumbricus terrestris, and mosquitofish, Gambusia affinis. The results reveal differences in growth per unit of mass, calories, and protein consumed on the different diets with differences in length being more pronounced than differences in mass. The results indicate that the total mass, calories, or protein consumed are insufficient to reliably predict the amount of growth to be expected in these species. All results are given plus and minus one standard error with an analysis of variance for the production-ingestion ratios.

  4. Daptomycin-loaded polymethylmethacrylate bone cement for joint arthroplasty surgery.

    PubMed

    Hsu, Yuan-Ming; Liao, Chun-Hsing; Wei, Yu-Hong; Fang, Hsu-Wei; Hou, Hsiang-Huan; Chen, Chia-Chun; Chang, Chih-Hung

    2014-06-01

    Antibiotic-loaded acrylic bone cement has been frequently used as an infection prophylaxis or antibiotic-loaded spacer in infected arthroplasty. In addition, daptomycin has been used recently against broad spectrum Gram-positive organisms. The goal of this in vitro study is to investigate the bacteriacidal and mechanical properties of daptomycin-incorporated polymethylmethacrylate (PMMA) bone cement and evaluate its feasibility for clinical use. Daptomycin (0.5, 1, or 2 g) was premixed with 40 g of PMMA bone cement powder before curing. The mechanical properties of the daptomycin-loaded acrylic bone cement (DLABC) were estimated following standard guidance, and the release profile and kinetics of daptomycin from PMMA were analyzed. The antimicrobial efficacy of DLABC was determined with a zone of inhibition (ZOI) assay against Staphylococcus aureus, Staphylococcus epidermis, Enterococcus faecalis, and Enterococcus faecium, respectively. The results showed that the compressive strength, of PMMA bone cement, which was higher than 100 MPa in all groups, was sufficient according to ISO 5833 after incorporation of daptomycin. The encapsulated daptomycin was released for 2 weeks with a 9.59 ± 0.85%, 15.25 ± 0.69%, and 20.64 ± 20.33% released percentage on the first day in the low, mid, and high groups, respectively. According to the calculated release kinetics, incorporated daptomycin should be 3.3 times the original dose to double its release. Although all recipes of DLABC had a microbial inhibitory effect, the effect with a higher encapsulated amount of daptomycin was more significant. Therefore, we believe that daptomycin can be locally delivered from PMMA bone cement at the surgical site as a prophylactic or treatment for osteomyelitis against Gram-positive organisms with intact cement function.

  5. Penile Girth Enhancement With Polymethylmethacrylate-Based Soft Tissue Fillers.

    PubMed

    Casavantes, Luis; Lemperle, Gottfried; Morales, Palmira

    2016-09-01

    An unknown percentage of men will take every risk to develop a larger penis. Thus far, most injectables have caused serious problems. Polymethylmethacrylate (PMMA) microspheres have been injected as a wrinkle filler and volumizer with increasing safety since 1989. To report on a safe and permanently effective method to enhance penile girth and length with an approved dermal filler (ie, PMMA). Since 2007, the senior author has performed penile augmentation in 752 men mainly with Metacrill, a suspension of PMMA microspheres in carboxymethyl-cellulose. The data of 729 patients and 203 completed questionnaires were evaluated statistically. The overall satisfaction rate was 8.7 on a scale of 1 to 10. After one to three injection sessions, average girth increased by 3.5 cm, or 134% (10.2 to 13.7 cm = 134.31%). Penile length also increased by weight and stretching force of the implant from an average of 9.8 to 10.5 cm. Approximately half the patients perceived some irregularities of the implant, which caused no problems. Complications occurred in 0.4%, when PMMA nodules had to be surgically removed in three of the 24% of patients who had a non-circumcised penis. After 5 years of development, penile augmentation with PMMA microspheres appears to be a natural, safe, and permanently effective method. The only complication of nodule formation and other irregularities can be overcome by an improved injection technique and better postimplantation care. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  6. Characterization of MOSFET dosimeter angular dependence in three rotational axes measured free-in-air and in soft-tissue equivalent material.

    PubMed

    Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika

    2013-09-01

    When performing dose measurements on an X-ray device with multiple angles of irradiation, it is necessary to take the angular dependence of metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters into account. The objective of this study was to investigate the angular sensitivity dependence of MOSFET dosimeters in three rotational axes measured free-in-air and in soft-tissue equivalent material using dental photon energy. Free-in-air dose measurements were performed with three MOSFET dosimeters attached to a carbon fibre holder. Soft tissue measurements were performed with three MOSFET dosimeters placed in a polymethylmethacrylate (PMMA) phantom. All measurements were made in the isocenter of a dental cone-beam computed tomography (CBCT) scanner using 5º angular increments in the three rotational axes: axial, normal-to-axial and tangent-to-axial. The measurements were referenced to a RADCAL 1015 dosimeter. The angular sensitivity free-in-air (1 SD) was 3.7 ± 0.5 mV/mGy for axial, 3.8 ± 0.6 mV/mGy for normal-to-axial and 3.6 ± 0.6 mV/mGy for tangent-to-axial rotation. The angular sensitivity in the PMMA phantom was 3.1 ± 0.1 mV/mGy for axial, 3.3 ± 0.2 mV/mGy for normal-to-axial and 3.4 ± 0.2 mV/mGy for tangent-to-axial rotation. The angular sensitivity variations are considerably smaller in PMMA due to the smoothing effect of the scattered radiation. The largest decreases from the isotropic response were observed free-in-air at 90° (distal tip) and 270° (wire base) in the normal-to-axial and tangent-to-axial rotations, respectively. MOSFET dosimeters provide us with a versatile dosimetric method for dental radiology. However, due to the observed variation in angular sensitivity, MOSFET dosimeters should always be calibrated in the actual clinical settings for the beam geometry and angular range of the CBCT exposure.

  7. [Stud on quality standard for Aconiti Tatsienensis Radix].

    PubMed

    Zhou, Li-shi; Wang, Yu-jie; Du, Lei-lei; Tan, Er; Zeweng, Yong-zhong; Jiangyong, Si-lang; Zhang, Yi

    2014-06-01

    To establish the quality standard for Aconiti Tatsiehensis Radix. TLC was used to detect yunaconi- tine and talasamine in Aconiti Tatsiensis Radix. HPLC was adopted to determine the content of yunaconitine. Moisture,ash,acid insolu- ble ash and ethanol soluble extractive were determined according the procedures recorded in the Appendix of Chinese Pharmacopoeia (2010 edition). The microscopic identification was also carried out. Aconiti Tatsienensis Radix had obvious microscopic char- acteristics,and its TLC identification had a good resolution with clear spots. An average content of moisture was 11. 48%, ash was 4. 83% ,acid insoluble was 1. 81%, ethanol soluble extractive was 20. 46% and yunaconitine was 0. 23%. The established standard is acceptable for quality evaluation of Aconiti Tatsienensis Radix.

  8. [Effects of soil factor on active components of Radix Ophiopogonis].

    PubMed

    Zhang, Lianting; Ye, Zhengliang; Guo, Qiaosheng

    2010-06-01

    To study the effects of soil factors on the active components in Radix Ophiopogonis. The content of polysaccharide, flavonoids, saponins, water-soluble extract and inorganic elements in Radix Ophiopogonis gathered from 7 different places were compared, physical and chemical properties and inorganic elements of soil were analyzed. The path and grey connection analysis were applied for studying the effects on the active components of Radix Ophiopogonis. The concentrations of mineral elements in plant were mainly adjusted by active absorption. The active components in Radix Ophiopogonis was primarily effected by soil enzyme activity, the other important factors were potassium, pH, and organic matter. K, Fe, Mn, B, Ba, Zn of soil also had much influence on it then others inorganic elements.

  9. A new pregnane steroid from Poria cum radix pini.

    PubMed

    Tong, Xiao-Gang; Liu, Jin-Lei; Cheng, Yong-Xian

    2010-05-01

    A new pregnane steroid and eight known compounds were isolated from Poria cum radix pini. Their structures were identified by spectroscopic data. All the known compounds were isolated from this species for the first time.

  10. Cause and control of Radix Ophiopogonis browning during storage.

    PubMed

    Wang, Hui; Qi, Jin; Han, Dong-Qi; Xu, Tian; Liu, Ji-Hua; Qin, Min-Jian; Zhu, Dan-Ni; Bo-Yang, Yu

    2015-01-01

    In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatography (HPLC) and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron microscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural (5-HMF), total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were decreased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning (Y) could be described by following correlation equation: Y = - 0.625 4 + 0.020 84 × X3 + 0.001 514 × X1 × X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity (HR), temperature, and moisture content were under 25% RH, 12 °C and 18%, respectively. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  11. Exploring the dose response of radiochromic dosimeters

    NASA Astrophysics Data System (ADS)

    Skyt, P. S.; Wahlstedt, I.; Yates, E. S.; Muren, L. P.; Petersen, J. B. B.; Balling, P.

    2013-06-01

    The aim of this study was to explore the dose response of a newly developed radio-chromic hydrogel dosimeter based on leuco malachite green dye in a gelatine matrix. The original dosimeter composition was first investigated in terms of dose response and dose-rate dependence. In addition, the initiating compounds producing chlorine radicals were substituted with compounds producing fluorine radicals, oxygen-centered radicals, carbon-centered radicals and bromine radicals. Also the surfactant was substituted by other compounds of different molecular size and charge. The original composition gave a dose response of 3.5·10-3 Gy-1cm-1 at 6 Gy/min with a dose rate dependence giving a 27 % increase when decreasing the dose rate to 1 Gy/min. None of the substituted initiating components contributed to an increase in dose response while only one surfactant increased the dose response slightly.

  12. Radiological properties of normoxic polymer gel dosimeters

    SciTech Connect

    Venning, A.J.; Nitschke, K.N.; Keall, P.J.; Baldock, C.

    2005-04-01

    The radiological properties of the normoxic polymer gel dosimeters MAGIC, MAGAS, and MAGAT [methacrylic and ascorbic acid in gelatin initiated by copper; methacrylic acid gelatine gel with ascorbic acid; and methacrylic acid gelatine and tetrakis (hydroxymethyl) phosphonium chloride, respectively] have been investigated. The radiological water equivalence was determined by comparing the polymer gel macroscopic photon and electron interaction cross sections over the energy range from 10 keV to 20 MeV and by Monte Carlo modeling of depth doses. Normoxic polymer gel dosimeters have a high gelatine and monomer concentration and therefore mass density (kg m{sup -3}) up to 3.8% higher than water. This results in differences between the cross-section ratios of the normoxic polymer gels and water of up to 3% for the attenuation, energy absorption, and collision stopping power coefficient ratios through the Compton dominant energy range. The mass cross-section ratios were within 2% of water except for the mass attenuation and energy absorption coefficients ratios, which showed differences with water of up to 6% for energies less than 100 keV. Monte Carlo modeling was undertaken for the polymer gel dosimeters to model the electron and photon transport resulting from a 6 MV photon beam. The absolute percentage differences between gel and water were within 1% and the relative percentage differences were within 3.5%. The results show that the MAGAT gel formulation is the most radiological water equivalent of the normoxic polymer gel dosimeters investigated due to its lower mass density measurement compared with MAGAS and MAGIC gels.

  13. Performance Evaluation of a Colorimetric Hydrazine Dosimeter

    DTIC Science & Technology

    1994-06-16

    air has been developed. The passive badge consists of a dosimeter card containing a vanillin solution coated on a thin paper substrate. The active...patch consists of a thick cellulose substrate coated with a vanillin solution. When placed in a plastic sample holder attached to a personnel pump, up to...5 L/min can be drawn through the active badge substrate. Through a condensation reaction, vanillin reacts with hydrazine to form a colored product

  14. [NIR Fingerprints of Different Medicinal Parts of Angelicae Sinensis Radix].

    PubMed

    Zhang, Ya-ya; Gu, Zhi-rong; Ding, Jun-xia; Wang, Yao-peng; Sun, Yu-jing; Wang, Ya-li

    2015-07-01

    To investigate the spectrum characteristics of near-intrared dittuse retlectance spectroscopy (NIR) fingerprint of different medicinal parts of Angelicae Sinensis Radix. 96 batches of samples were collected from 14 counties of Gansu Province and Yunnan Province. The NIR fingerprints were collected by integrated sphere. Similarity analysis and partial least square discriminant analysis(PLS-DA) were used to analyze the fingerprint. The average spectrum of NIR fingerprint of different medicinal parts of Angelicae Sinensis Radix showed some differences; the absorbance in characteristic absorption was in a decreasing order of body > tail > head > whole. Most NIR fingerprint similarities of different medicinal parts of Angelicae Sinensis Radix exceeded 0. 95. The established model of PLS-DA could be used to accurately classify the medicinal parts of Angelicae Sinensis Radix. The differences of NIR fingerprints of different medicinal parts of Angelicae Sinensis Radix were mainly existing in the wave number ranges of 8,443 - 8,284 cm -1, 7,003 - 6,896 cm-1, 6,102 - 5,864 cm-1, 4,847 - 4,674 cm-1, and 4,386 - 4,208 cm-1. The different medicinal parts of Angelicae Sinensis Radix have some differences in chemical components.

  15. [Quality assessment of sulfur-fumigated paeoniae alba radix].

    PubMed

    Wang, Zhao; Chen, Yu-Wu; Wang, Qiong; Sun, Lei; Xu, Wei-Yi; Jin, Hong-Yu; Ma, Shuang-Cheng

    2014-08-01

    The samples of sulfur-fumigated Paeoniae Alba Radix acquired both by random spot check from domestic market and self-production by the research group in the laboratory were used to evaluate the effects of sulphur fumigation on the quality of Paeoniae Alba Radix by comparing sulfur-fumigated degree and character, the content of paeoniflorin and paeoniflorin sulfurous acid ester, and changes of the fingerprint. We used methods in Chinese Pharmacopeia to evaluate the character of sulfur-fumigated Paeoniae Alba Radix and determinate the content of aulfur-fumigated paeoniflorin. LC-MS method was used to analyze paeoniflorin-converted products. HPLC fingerprint methods were established to evaluate the differences on quality by similarity. Results showed that fumigated Paeoniae Alba Radix became white and its unique fragrance disappeared, along with the production of pungent sour gas. It also had a significant effect on paeoniflorin content. As sulfur smoked degree aggravated, paeoniflorin content decreased subsequently, some of which turned into paeoniflorin sulfurous acid ester, and this change was not reversible. Fingerprint also showed obvious changes. Obviously, sulfur fumigation had severe influence on the quality of Paeoniae Alba Radix, but we can control the quality of the Paeoniae Alba Radix by testing the paeoniflorin sulfurous acid ester content.

  16. Post-Irradiation Study of the Alanine Dosimeter

    PubMed Central

    Desrosiers, Marc F.

    2014-01-01

    Post-irradiation stability of high-dose dosimeters has traditionally been an important measurement influence quantity. Though the exceptional stability of the alanine dosimeter response with time has rendered this factor a non-issue for routine work, the archival quality of the alanine dosimeter has not been characterized. Here the alanine pellet dosimeter response is measured up to seven years post-irradiation for a range of absorbed doses. This long-term study is accompanied by an examination of the environmental influence quantities (e.g., ambient light) on the relatively short-term (3–4 month) stability of both pellet and film commercial dosimeters. Both dosimeter types demonstrated exceptional stability in the short term and proved to be relatively insensitive to common influence quantities. The long-term data revealed a complex dose-dependent response trend. PMID:26601033

  17. [Metabonomics on toxicity reduction of Glycyrrhizae Radix et Rhizoma for Aconiti Lateralis Radix Preparata in Sini Tang].

    PubMed

    Li, Ying; Fu, Chao-Mei; Peng, Wei; Li, Bo; Fu, Shu; Zhang, Hui-Min

    2016-04-01

    To analyze the endogenous metabolite changes in rat plasma after intervention by Sini Tang and Sini Tang without Glycyrrhizae Radix et Rhizoma based on GC-MS metabonomics technology, and study the toxicity reduction effect of Glycyrrhizae Radix et Rhizoma in Sini Tang on Aconiti Lateralis Radix Preparata. Eighteen SD rats were randomly divided into normal group, Sini Tang group and Sini Tang without Glycyrrhizae Radix et Rhizoma group on average. The rats in Sini Tang group and Sini Tang without Glycyrrhizae Radix et Rhizoma group were treated respectively with physic liquor by intragastric administration at the dose of 0.02 mL•g ⁻¹ (equivalent to 0.8 g•mL ⁻¹ crude drugs) once a day for 7 days. The rats in normal group were given with equal volume of saline solution. The plasma samples were collected from each rat 0.5 h after the last administration for GC-MS detection. The data was used for multivariate statistical analysis to obtain 14 potential metabolic markers(13 of them were identified). Then their relative content and metabolic pathways were analyzed. Compared with Sini Tang without Glycyrrhizae Radix et Rhizoma group, seven metabolic markers of were reduced in Sini Tang group. Analysis on physiological functions of these potential metabolic markers showed that the Glycyrrhizae Radix et Rhizoma in Sini Tang could reduce the toxicity of Aconiti Lateralis Radix Preparata by adjusting the glycolysis, lipid metabolism, citrate cycle and some amino acids metabolism. Copyright© by the Chinese Pharmaceutical Association.

  18. Hanford beta-gamma personnel dosimeter prototypes and evaluation

    SciTech Connect

    Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

    1983-04-01

    Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips.

  19. Standard Procedure for Calibrating an Areal Calorimetry Based Dosimeter

    DTIC Science & Technology

    2015-05-01

    provided to assist in calibrating other dosimeters. 15. SUBJECT TERMS Millimeter waves, dosimeter, calorimeter, CLT, Carbon-loaded Teflon 16. SECURITY...Bioeffects Branch CL Center Left CLT Carbon-loaded Teflon CR Center Right GPIB General Purpose Interface Bus IR Infrared LC Lower Center...used carbon-loaded Teflon ® (CLT) as the radio frequency (RF) absorber for the dosimeter. The methodology presented will use CLT for the calibration

  20. Application of quantitative 1H-NMR method to determination of gentiopicroside in Gentianae radix and Gentianae scabrae radix.

    PubMed

    Tanaka, Rie; Hasebe, Yuko; Nagatsu, Akito

    2014-07-01

    A quantitative (1)H-NMR method (qHNMR) was used to measure gentiopicroside content in Gentianae radix and Gentianae scabrae radix. Gentiopicroside is a major component of Gentianae radix and Gentianae scabrae radix. The purity of gentiopicroside was calculated from the ratio of the intensity of the H-3 signal at δ 7.44 ppm or the H-8 signal at δ 5.78 ppm in methanol-d 4 of gentiopicroside to that of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability by using potassium hydrogen phthalate of certified reference material (CRM) grade. As a result, the gentiopicroside content in two lots of Gentianae radix as determined by qHNMR was found to be 1.76 and 2.17 %, respectively. The gentiopicroside content in two lots of Gentianae scabrae radix was 2.73 and 3.99 %, respectively. We demonstrated that this method is useful for the quantitative analysis of crude drugs.

  1. Comparison of the fiber optic dosimeter and semiconductor dosimeter for use in diagnostic radiology

    NASA Astrophysics Data System (ADS)

    Yoo, W. J.; Shin, S. H.; Sim, H. I.; Hong, S.; Kim, S. G.; Jang, J. S.; Kim, J. S.; Jeon, H. S.; Kwon, G. W.; Jang, K. W.; Cho, S.; Lee, B.

    2014-05-01

    A fiber-optic dosimeter (FOD) was fabricated using a plstic scintillating fiber, a plastic optical fiber, and a multi-pixel photon counter to measure entrance surface dose (ESD) in diagnostic radiology. Under changing tube current and irradition time of the digital radiography (DR) system, we measured the scintillating light and the ESD simultaneously. As experiemtnal results, the total counts of the FOD were changed in a manner similar to the ESDs of the semiconductor dosimeter (SCD). In conclusion, we demonstrated that the proposed FOD minimally affected the diagnostic information of DR image while the SCD caused serious image artifacts.

  2. GAMMA AND X-RAY DOSIMETER AND DOSIMETRIC METHOD

    DOEpatents

    Taplin, G.V.; Douglas, C.H.; Sigoloff, S.C.

    1958-08-19

    An improvement in colorimetric gamma and x-ray dosimeter systems and a self-contained. hand carried dostmeter of the afore-mentioned type ts described. A novel point of the invention ltes in the addition of specific quantities of certain normalizing agents to the two phase chlorinated hydro-carbon-aqueous dyc colortmetric dosimeter to eliminate the after reaction and thereby extend the utility of such systein. The structure of the two phase colorimetric dosimeter tubes and the carrying case for the tubes of the portable dosimeter are unique features.

  3. Hepatoxicity of major constituents and extractions of Radix Polygoni Multiflori and Radix Polygoni Multiflori Praeparata.

    PubMed

    Yu, Jie; Xie, Jie; Mao, Xiao-jian; Wang, Min-jiang; Li, Na; Wang, Jing; Zhaori, Ge-tu; Zhao, Rong-hua

    2011-10-11

    Radix Polygoni Multiflori (RPM) and Radix Polygoni Multiflori Praeparata (RPMP) were traditionally widely used as Chinese herbal medicine. However, liver adverse reactions caused by RPM or RPMP were frequently reported all around the world recent years. The aim of this study was to study the cytotoxicities of RPM, RPMP and their major constituents on human liver cell L-02 simultaneously. Multi-assays, including MTT assay, neutral red uptake (NRU) assay, LDH leakage percentage and liver enzyme secretion (AST, ALT and ALP) were used. Cytotoxicities of major chemical constituents of RPM, 2, 3, 5, 4'-tetrahydroxy-stilbene-2-O-β-D-glucoside (TSG), physcion and emodin, were tested. The cytotoxicities of water, 50% ethanol and 95% ethanol extractions of RPM and RPMP were tested. HPLC-DAD analysis was carried to reveal the content change of TSG, physcion and emodin after the processing procedure. The TD(50) of TSG, physcion and emodin in MTT assay were >10,000 μM, 2853.61 μM and 520.37 μM. In the NRU assay, the TD(50) of TSG, physcion and emodin were much smaller (1401.53 μM, 1140.00 μM, and 3.80 μM). Emodin induced much severe liver enzyme secretion than TSG and physcion. Cell proliferation and LDH leakage rate showed no difference between RPM and RPMP extractions, but ALP, AST and ALT secretions in RPMP extractions were significant lower than that of PMR groups. Water extractions of RPM and RPMP were less toxic than any other solvent in most of the assays. Positive correlation was found between the TSG/emodin ratio and MTT survival rate. The emodin/physcion ratio also showed positive correlation with the LDH leakage percentage. In conclusion, Radix Polygonum multiflorum and Radix Polygonum multiflorum Praeparata were not liver injure inducing in our in vitro assays. However, the processing produce of RPM could reduce its effect on both cell proliferation and enzyme secretion of liver cell. Judging from cell proliferation, integrity of cell membrane and enzyme

  4. [Qualitative and quantitative analysis of major constituents of Paeoniae Radix Alba and Paeoniae Radix Rubra by HPLC-DAD-Q-TOF-MS/MS].

    PubMed

    Liu, Jie; Chen, Lin; Fan, Cai-rong; Li, Huang; Huang, Ming-qing; Xiang, Qing; Xu, Wen; Xu, Wei; Chu, Ke-dan; Lin, Yu

    2015-05-01

    In order to explore the differences of chemical constituents of Paeoniae Radix Alba and Paeoniae Radix Rubra, a qualitative analytical method of liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS) was developed for identification of multi-constituents and an HPLC-DAD analytical method was developed for simultaneously determining 14 major compounds (gallic acid, protocatechuic acid, paeoniflorin sulfonate, protocatechuic aldehyde, methyl gallate, oxypaeoniflorin, catechin, albiflorin, and paeoniflorin, ethyl gallate, benzoic acid, pentagaloylglucose, benzoyl-paeoniflorin, and paeonol) in Paeoniae Radix Alba and Paeoniae Radix Rubra. Q-TOF/MS qualitative analysis was performed under negative ion mode and inferred 38 components of Paeoniae Radix Alba and 30 components of Paeoniae Radix Rubra. HPLC-DAD quantitative method result showed the contents of 8 ingredients were different between Paeoniae Radix Alba and Paeoniae Radix Rubra. The results indicated that the new approach was applicable in qualitative and quantitative quality control of Paeoniae Radix Alba and Paeoniae Radix Rubra.

  5. Angular dependence of a simple accident dosimeter

    SciTech Connect

    Devine, R. T.; Romero, L. L.; Olsher, R. H.

    2004-01-01

    A simple dosimeter made of a sulfur tablet, bare and cadmium covered indium foils and a cadmium covered copper foil has been modeled using MCNP5. Studies of the model without phantom or other confounding factors have shown that the cross sections and fluence-to-dose factors generated by the Monte Carlo method agree with those generated by analytic expressions for the high energy component. The threshold cross sections for the detectors on a phantom were calculated. The resulting doses assigned agree well with exposures made to three critical assemblies. In this study the angular dependence on a phantom is studied and compared with measurements taken on the GODIVA reactor. The dosimeter positions on the phantom are facing the source, on the back and the side. In previous papers the modeling of a simple dosimeter made of a sulfur tablet, bare and cadmium covered indium foils and a cadmium covered copper foil has been modeled using MCNP5. The conclusion made was that most of the neutron dose from criticality assemblies results from the high energy neutron fluences determined by the sulfur and indium detectors. The results using doses measured from the GODIVA, SHEBA, and bare and lead shielded SILENE reactors confirmed this. The angular dependence of an accident dosemeter is of interest in evaluating the exposure of personnel. To investigate this effect accident dosemeters were placed on a phantom and exposed to the GODIVA reactor at phantom orientations of 0{sup o}, 45{sup o}, 90{sup o}, 135{sup o}, and 180{sup o} to the assembly center line.

  6. Real-time optical fiber dosimeter probe

    NASA Astrophysics Data System (ADS)

    Croteau, André; Caron, Serge; Rink, Alexandra; Jaffray, David; Mermut, Ozzy

    2011-03-01

    There is a pressing need for a passive optical fiber dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiation therapy patients. An optical fiber probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on a dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5 Gy were performed. Net optical densities increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20 μm, respectively.

  7. Use of mixed radix FFT in electric power systems studies

    SciTech Connect

    Lu, I.D.; Lee, P. )

    1994-07-01

    Radix-2 based Fast Fourier Transform (FFT) routines have been the main stream FFT that are commonly applied to the measurement and analysis of electric power system data. Because of the rigid sampling rates offered by most of the instrument manufacturers and the mathematical limitation imposed by the algorithm of radix-2 FFT, artificial post sampling data windows have been introduced to improve the utility of the radix-2 FFT. The 60 Hz and the 50 Hz based electrical power system frequencies are incompatible with the radix-2 FFT routine to the special requirements of electric power system. Recent advances in the personal computer hardware has opened a new approach to perform the FFT via mixed radix routines. It offers greatly improved flexibility in the selection of a practical data size. And this leads to the elimination of the need of the post sampling software windows. It also allows one to relax or eliminate the requirement of anti-aliasing measures for power system harmonic measurements.

  8. A novel structure optical fiber radiation dosimeter for radiotherapy applications

    NASA Astrophysics Data System (ADS)

    Sun, Weimin; Qin, Zhuang; Ma, Yu; Zhao, Wenhui; Hu, Yaosheng; Zhang, Daxin; Chen, Ziyin; Lewis, Elfed

    2016-04-01

    An investigation into a novel in-vivo PMMA (polymethyl methacrylate) fiber-optic dosimeter to monitor the dose of ionizing radiation, both for instantaneous and integrating measurements, for radiotherapy applications is proposed. This fiber sensor is designed as an intracorporal X-ray ionizing sensor to enhance the curative effect of radiotherapy. The fiber-optic dosimeter is made in a PMMA fiber, whose core is micromachined to create a small diameter (0.25 to 0.5 mm) hole at one fiber end. An inorganic scintillating material, terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) is chosen as the sensing material, because it can fluoresce on immediately under exposure of ionizing radiation (X-Rays or electron beam). This sensing material is filled and packaged in the small hole by epoxy resin adhesive. This kind of novel structure dosimeter shows high light coupling efficiency compared with other kind of inorganic scintillation dosimeter. This fiber-optic dosimeter shows good repeatability with a maximum deviation of 0.16%. The testing results of the fiber-optic dosimeter are perfectly proportional to the data of IC with R2 as 0.9999. In addition, the fiber sensor shows excellent isotropic in its radial angular dependence. All the experiments indicate that the fiber-optic dosimeter is properly used for patient in-vivo dosimeter such as brachytherapy applications or intraoperative radiation therapy.

  9. Evaluation of a Colorimetric Personal Dosimeter for Nitrogen Oxide.

    ERIC Educational Resources Information Center

    Diamond, Philip

    A personal colorimetric dosimeter for nitrogen dioxide was developed. Tests were performed to determine the response of these strips to various concentrations of NO2. The dosimeter strips were satisfactory for approximate determinations of total exposure (concentration + time) of nitrogen dioxide. The total exposure was calculated in terms of time…

  10. Evaluation of a Colorimetric Personal Dosimeter for Nitrogen Oxide.

    ERIC Educational Resources Information Center

    Diamond, Philip

    A personal colorimetric dosimeter for nitrogen dioxide was developed. Tests were performed to determine the response of these strips to various concentrations of NO2. The dosimeter strips were satisfactory for approximate determinations of total exposure (concentration + time) of nitrogen dioxide. The total exposure was calculated in terms of time…

  11. Application of electrets to passive Rn progeny dosimeters

    SciTech Connect

    Khan, A.; Phillips, C.R.

    1985-11-01

    The theoretical and experimental bases are presented for development of a passive electret dosimeter for Rn progeny. The mechanism of aerosol collection is described, and experiments to develop a suitable aerosol collecting element (electret) for a passive Rn progeny dosimeter are reported.

  12. Preliminary investigation and application of a novel deformable PRESAGE® dosimeter

    PubMed Central

    Juang, T; Newton, J; Das, S; Adamovics, J; Oldham, M

    2013-01-01

    Deformable 3D dosimeters have potential applications in validating deformable dose mapping algorithms. This study evaluates a novel deformable PRESAGE® dosimeter and its application toward validating the deformable algorithm employed by VelocityAI. The deformable PRESAGE® dosimeter exhibited a linear dose response with a sensitivity of 0.0032 ΔOD/(Gy/cm). Comparison of an experimental dosimeter irradiated with an MLC pencilbeam checkerboard pattern under lateral compression up to 27% to a non-deformed control dosimeter irradiated with the same pattern verified dose tracking under deformation. CTs of the experimental dosimeter prior to and during compression were exported into VelocityAI and used to map an Eclipse dose distribution calculated on the compressed dosimeter to its original shape. A comparison between the VelocityAI dose distribution and the distribution from the dosimeter showed field displacements up to 7.3 mm and up to a 175% difference in field dimensions. These results highlight the need for validating deformable dose mapping algorithms to ensure patient safety and quality of care. PMID:24454522

  13. Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

    DOEpatents

    Braunlich, Peter F.; Tetzlaff, Wolfgang

    1989-01-01

    Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phoshphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate.

  14. Investigation into the re-use of PMOS dosimeters

    SciTech Connect

    Kelleher, A.; McDonnell, N.; O'Neill, B.; Lane, W. ); Adams, L. )

    1994-06-01

    Radiation sensitive field effect transistors have applications integrating dosimetry in spacecraft, laboratories and medicine to measure the amount of radiation dose absorbed. However these dosimeters can measure only to a maximum dose which is determined by the type and sensitivity of the RADFET being used. On reaching the maximum radiation dose these dosimeters are usually replaced. The aim of this paper is to investigate the possibility of reusable dosimeters which to-date has not been addressed in the published literature. This study examines the response of dosimeters which were irradiated, annealed back to their original pre-irradiation threshold voltage and then irradiated for a second time. The results of the second irradiation suggest that re-using PMOS dosimeters is a feasible option.

  15. Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

    DOEpatents

    Braunlich, P.F.; Tetzlaff, W.

    1989-04-25

    Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters are disclosed. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phosphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate. 34 figs.

  16. Differentiating Puerariae Lobatae Radix and Puerariae Thomsonii Radix using HPTLC coupled with multivariate classification analyses.

    PubMed

    Wong, Ka H; Razmovski-Naumovski, Valentina; Li, Kong M; Li, George Q; Chan, Kelvin

    2014-07-01

    Puerariae Lobatae Radix (PLR), the root of Pueraria lobata, is a traditional Chinese medicine for treating diabetes and cardiovascular diseases. Puerariae Thomsonii Radix (PTR), the root of Pueraria thomsonii, is a closely related species to PLR and has been used as a PLR substitute in clinical practice. The aim of this study was to compare the classification accuracy of high performance thin-layer chromatography (HPTLC) with that of ultra-performance liquid chromatography (UPLC) in differentiating PLR from PTR. The Matlab functions were used to facilitate the digitalisation and pre-processing of the HPTLC plates. Seven multivariate classification methods were evaluated for the two chromatographic methods. The results demonstrated that the HPTLC classification models were comparable to the UPLC classification models. In particular, k-nearest neighbours, partial least square-discriminant analysis, principal component analysis-discriminant analysis and support vector machine-discriminant analysis showed the highest rate of correct species classification, whilst the lowest classification rate was obtained from soft independent modelling of class analogy. In conclusion, HPTLC combined with multivariate analysis is a promising technique for the quality control and differentiation of PLR and PTR. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Seasonal variations in the isoflavonoids of radix Puerariae.

    PubMed

    Sibao, Chen; Dajian, Yang; Shilin, Chen; Hongx, Xu; Chan, Albert S C

    2007-01-01

    The variations in isoflavonoid content in Radix Puerariae, the root of Pueraria lobata (Wild) Ohwi, have been examined in order to determine the optimum time to harvest the herb. Total isoflavonoid contents have been analysed by a UV spectrophotometric method whilst HPLC with photodiode array detection has been used to monitor the contents of seven major individual isoflavonoids, namely, 3'-hydroxypuerarin, puerarin, 3'-methoxypuerarin, daidzin, genistin, formononetin-7-glucoside and daidzein. Ninety-six samples of Radix Puerariae of different ages and harvested in different months were collected and analysed. The results clearly showed that 3-year-old roots harvested in January have the highest yields of isoflavonoid compounds. Moreover, the results obtained by both methods have a strong correlation. This suggested that the simple and fast UV spectrophotometric method could be used for monitoring the phytochemical quality of Radix Puerariae.

  18. [Molecular identification of astragali radix and its adulterants by ITS sequences].

    PubMed

    Cui, Zhan-Hu; Li, Yue; Yuan, Qing-Jun; Zhou, Li-She; Li, Min-Hui

    2012-12-01

    To explore a new method for identification Astragali Radix from its adulterants by using ITS sequence. Thirteen samples of the different Astragali Radix materials and 6 samples of the adulterants of the roots of Hedysarum polybotrys, Medicago sativa and Althaea rosea were collected. ITS sequence was amplified by PCR and sequenced unidirectionally. The interspecific K-2-P distances of Astragali Radix and its adulterants were calculated, and NJ tree and UPGMA tree were constructed by MEGA 4. ITS sequences were obtained from 19 samples respectively, there were Astragali Radix 646-650 bp, H. polybotrys 664 bp, Medicago sativa 659 bp, Althaea rosea 728 bp, which were registered in the GenBank. Phylogeny trees reconstruction using NJ and UPGMA analysis based on ITS nucleotide sequences can effectively distinguish Astragali Radix from adulterants. ITS sequence can be used to identify Astragali Radix from its adulterants successfully and is an efficient molecular marker for authentication of Astragali Radix and its adulterants.

  19. [Safety and risk factor analysis on Polygoni Multiflori Radix base on ancient traditional Chinese medicine literatures].

    PubMed

    Song, Hai-bo; Du, Xiao-xi; Guo, Xiao-xin; Ren, Jing-tian; Yang, Le; Pang, Yu

    2015-03-01

    Traditional Chinese medicine Polygoni Multiflori Radix is dried roots of Polygonaceae Polygortum multiflorum Thunb. Its clinical application records were first discovered in literatures of the Tang dynasty. The origins, efficacy, toxicity, processing and taboos of Polygoni Multiflori Radix have been discussed in many ancient herb literatures. In recent years, with the increase in the public awareness in health, Polygoni Multiflori Radix admits preparations have been more widely applied in the treatment and prevention of diseases. However, there have been more and more reports about Polygoni Multiflori Radix induced liver injury, the safety of Polygoni Multiflori Radix has increasingly attracted attention of the society. In this paper, the authors summarized and analyzed the toxicity and medication risk factors of Polygoni Multiflori Radix recorded in ancient herb literatures, and proposed that more attention shall be given to the effect of the planting and processing methods on the components and toxicity of Polygoni Multiflori Radix in safety studies, which provides clues for the further studies.

  20. [HPLC fingerprint of glycyrrhizea radix et rhizoma praeparata cum melle].

    PubMed

    Sun, Lei; Jin, Yong; Liu, Xiao-Qing; Qiao, Shan-Yi; Gao, Song; Che, Yan-Zhong

    2014-06-01

    The chromatographic fingerprint was established by eluting with the mobile phase consisted of acetonitrile and 0.2% formic acid water on an Agilent TC-C18 (2) column (4.6 mm x 250 mm, 5 microm). Six chromatographic peaks were identified by HPLC-MS/MS method. Ten batches of Glycyrrhizea Radix et Rhizoma Praeparata Cum Melle were determined, and the similarity was arranged from 0.72 to 0.99. Good precision, stability and repeatability were obtained, and this study provides a reference for the quality control of Glycyrrhizea Radix et Rhizoma Praeparata Cum Melle.

  1. [Effects of component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma on cell proliferation, apoptosis and skeleton in lung cancer A549 cells].

    PubMed

    Yan, Xiao-jing; Yang, Ye; Bi, Lei; Chen, Shan-shan; Zhu, Jing-jing; Chen, Wei-ping

    2014-11-01

    This study aims to optimize the most effective component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma on lung cancer A549 using the orthogonal design method, and to investigate its effects of the component formula on cell proliferation, apoptosis and cytoskeleton in lung cancer A549 cells. The orthogonal design method was introduced to optimize the most effective component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma on lung cancer A549 cells. CCK-8 assay and Real-time cell analysis were adapted to analyze the effect of component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma on A549 cells viability at different time and dose. Cell apoptosis was measured by Annexin V- FITC/PI double staining and flow cytometry. Cell skeleton protein F-actin was detected by high content screening (HCS). The optimizing component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma for total salvianolic acid, total saponins of panax ginseng and ginseng polysaccharide doses were 5, 10, 5 mg L(-1). CCK-8 assay and real-time cell analysis demonstrated that the component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma treatment could significantly decrease the A549 cell viability in both dose- and time-dependent manner compared with control group (P < 0.01). Moreover, the increase of cell apoptosis was detected by Annexin V-FITC/PI double staining and flow cytometry when cells treated with the component formula, which indicating that the component formula of Salviae Miltiorrhizae Radix et Rhizoma and Ginseng Radix et Rhizoma could induce A549 cell apoptosis in a time-dependent manner compared with control group (P < 0.01). Furthermore, compared with control group, a significant decrease in A549 cell skeleton area was found in the component formula-exposed cells in the dose-dependent manner (P < 0.01). In summary, the component formula

  2. Light scattering in optical CT scanning of Presage dosimeters

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Adamovics, J.; Cheeseborough, J. C.; Chao, K. S.; Wuu, C. S.

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS" optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  3. Limitations of using dosimeters in impulse noise environments.

    PubMed

    Kardous, Chucri A; Willson, Robert D

    2004-07-01

    The National Institute for Occupational Safety and Health (NIOSH) investigated the capabilities of noise dosimeters to measure personal exposure to impulse noise. The two leading types of commercially available dosimeters were evaluated in terms of their ability to measure and integrate impulses generated from gunfire during live-fire exercises at a law enforcement indoor firing range. Sound measurements were conducted throughout the firing range using dosimeters, sound level meters, and a measurement configuration that consisted of a quarter-inch microphone and a digital audiotape recorder to capture the impulse waveforms. Personal dosimetry was conducted on eight shooters, an observer, and the range master. Peak levels from gunfire reached 163 decibels (dB), exceeding the nominal input limit of the dosimeters. The dosimeters "clipped" the impulses by acting as if the gunfire had a maximum level of 146 dB. In other cases, however, peak levels (e.g., 108 dB) were below the dosimeter input limits, but the dosimeters still showed a peak level of 146 dB. Although NIOSH recommends that sound levels from 80 to 140 dB (A-weighted) be integrated in the calculation of dose and the time-weighted average, our present data suggest this criterion may be inadequate. These results showed that some instruments are incapable of providing accurate measures of impulse sounds because of their electroacoustic limitations.

  4. Radiation Measured during ISS-Expedition 13 with Different Dosimeters

    NASA Technical Reports Server (NTRS)

    Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Lee, K.; George, T.

    2008-01-01

    Radiation in low Earth orbit (LEO) is mainly composed of Galactic Cosmic Rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). The biological impact of space radiation to astronauts depends strongly on the particles linear energy transfer (LET) and is dominated by high LET radiation. It is important to measure the LET spectrum for the space radiation field and to investigate the influence of radiation on astronauts. At present, the preferred active dosimeters sensitive to all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors in various configurations; the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. The TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation exposure for the ISS mission Expedition 13 (ISS-12S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the space mission with different dosimeters. This paper introduces the operational principles for the dosimeters, describes the method to combine the results measured by TLDs/OSLDs and CR-39 PNTDs, and presents the LET spectra and the radiation quantities measured. Keywords: space radiation; cosmic rays; active and passive dosimeters; LET spectra

  5. SU-E-T-265: Presage Thin Sheet Dosimeter Characterization

    SciTech Connect

    Dumas, M; Rakowski, J

    2014-06-01

    Purpose: To quantify the sensitivity and stability of the Presage dosimeter in sheet form for different concentrations of chemicals and for a diverse range of clinical photon energies. Methods: Presage polymer dosimeters are formulated to investigate and optimize their sensitivity and stability. The dosimeter is composed of clear polyurethane base, leucomalachite green reporting dye, and bromoform radical initiator in 1mm thick sheets. The chemicals are well mixed together, cast in an aluminum mold, and left to cure at 60 psi for a minimum of 2 days. Dosimeter response will be characterized at multiple energies including Co-60, 6 MV, 15 MV, 50 kVp, and 250 kVp. The dosimeters are read by an Epson 10000 XL scanner at 800 dpi, 2{sup 16} bit depth. Red component images are analyzed with ImageJ. Results: Analysis of optical density verse dose for Co-60 energies indicates that the bromoform containing Presage was able to quantify dose from 0 to 300 Gy, with saturation beyond 300 Gy. Initial results show two regions of linear response, 0–100 Gy and 150–300 Gy. The 150–300 Gy region has a sensitivity of 0.0024 net OD/Gy. Further results on other energies are still in progress. Conclusions: This work shows the potential for use of thin sheets of Presage dosimeter as a dosimeter capable of being analyzed with a flatbed scanner.

  6. [Dissolution and differentiation of phytochemical components from mixture of Radix Paeoiae Alba and Radix Glycyrrhizae with different ratios].

    PubMed

    Zou, Hua-Bin; Du, Ai-Qin; Xia, Ying-Ying; Yuan, Jiu-Rong

    2006-11-01

    To investigate dissolution properties among different components with various polarities and to distinguish these groups from each other. Ultraviolet fingerprint spectra (UV FPS) of the components from Baishao (Radix Paeoiae Alba) and Gancao (Radix Glycyrrhizae) with various proportions, extracted with chloroform, ethanol and water successively, were obtained. The analysis was performed on the absolute and relative absorptions of peaks in UV FPS. Dissolutions in different rates and in synergy among chemical components were observed, by which different components can be distinguished. Dissolution kinetics and processes of the various chemical components from medicinal herbs are of great difference.

  7. SU-E-T-749: Thorough Calibration of MOSFET Dosimeters

    SciTech Connect

    Plenkovich, D; Thomas, J

    2015-06-15

    Purpose: To improve the accuracy of the MOSFET calibration procedure by performing the measurement several times and calculating the average value of the calibration factor for various photon and electron energies. Methods: The output of three photon and six electron beams of Varian Trilogy linear accelerator SN 5878 was calibrated. Five reinforced standard sensitivity MOSFET dosimeters were placed in the calibration jig and connected to the Reader Module. As the backscatter material was used 7 cm of Virtual Water. The MOSFET dosimeters were covered with 1.5 cm thick bolus for the regular and SRS 6 MV beams, 3 cm bolus for 15 MV beam, 1.5 cm bolus for 6 MeV electron beam, and 2 cm bolus for the electron energies of 9, 12, 15, 18, and 22 MeV. The dosimeters were exposed to 100 MU, and the calibration factor was determined using the mobileMOSFET software. To improve the accuracy of calibration, this procedure was repeated ten times and the calibration factors were averaged. Results: As the number of calibrations was increasing the variability of calibration factors of different dosimeters was decreasing. After ten calibrations, the calibration factors for all five dosimeters were within 1% of one another for all energies, except 6 MV SRS photons and 6 MeV electrons, for which the variability was 2%. Conclusions: The described process results in calibration factors which are almost independent of modality or energy. Once calibrated, the dosimeters may be used for in-vivo dosimetry or for daily verification of the beam output. Measurement of the radiation dose under bolus and scatter to the eye are examples of frequent use of calibrated MOSFET dosimeters. The calibration factor determined for full build-up is used under these circumstances. To the best of our knowledge, such thorough procedure for calibrating MOSFET dosimeters has not been reported previously. Best Medical Canada provided MOSFET dosimeters for this project.

  8. Calibration system for albedo neutron dosimeters

    SciTech Connect

    Rothermich, N.E.

    1981-01-01

    Albedo neutron dosimeters have proven to be effective as a method of measuring the dose from neutron exposures that other types of neutron detectors cannot measure. Results of research conducted to calibrate an albedo neutron dosemeter are presented. The calibration procedure consisted of exposing the TLD chips to a 46 curie /sup 238/PuBe source at known distances, dose rates and exposure periods. The response of the TLD's is related to the dose rate measured with a dose rate meter to obtain the calibration factor. This calibration factor is then related to the ratio of the counting rates determined by 9-inch and 3-inch Bonner spheres (also called remmeters) and a calibration curve was determined. 17 references, 10 figures, 3 tables.

  9. p-MOSFET total dose dosimeter

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor)

    1994-01-01

    A p-MOSFET total dose dosimeter where the gate voltage is proportional to the incident radiation dose. It is configured in an n-WELL of a p-BODY substrate. It is operated in the saturation region which is ensured by connecting the gate to the drain. The n-well is connected to zero bias. Current flow from source to drain, rather than from peripheral leakage, is ensured by configuring the device as an edgeless MOSFET where the source completely surrounds the drain. The drain junction is the only junction not connected to zero bias. The MOSFET is connected as part of the feedback loop of an operational amplifier. The operational amplifier holds the drain current fixed at a level which minimizes temperature dependence and also fixes the drain voltage. The sensitivity to radiation is made maximum by operating the MOSFET in the OFF state during radiation soak.

  10. Guidelines for the calibration of personnel dosimeters

    SciTech Connect

    Roberson, P.L.; Holbrook, K.L.

    1984-01-01

    This guide describes minimum acceptable performance levels for personnel dosimetry systems used at Department of Energy (DOE) facilities. The goal is to improve both the quality of radiological calibrations and the methods of comparing reported occupational doses between DOE facilities. Reference calibration techniques are defined. A standard for evaluation of personnel dosimetry systems and recommended design parameters for personnel dosimeters are also included. Approximate intervals for the radiation energies for which these guidelines are appropriate are 15 keV to 2 MeV for photons; above 0.3 MeV for beta particles; and 1 keV to 2 MeV for neutrons. An analysis of ANSI N13.11 was completed using performance evaluations of selected personnel dosimetry systems in use at DOE facilities. The results of this analysis are incorporated in the guidelines.

  11. Dosimeter for monitoring vapors and aerosols of organic compounds

    DOEpatents

    Vo-Dinh, T.

    1987-07-14

    A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique. 7 figs.

  12. Dosimeter for monitoring vapors and aerosols of organic compounds

    DOEpatents

    Vo-Dinh, Tuan

    1987-01-01

    A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique.

  13. A new dosimeter formulation for deformable 3D dose verification

    NASA Astrophysics Data System (ADS)

    Høye, E. M.; Skyt, P. S.; Yates, E. S.; Muren, L. P.; Petersen, J. B. B.; Balling, P.

    2015-01-01

    We present the characteristics of a new silicone-based radiochromic dosimeter containing the leuco-malachite green (LMG) dye. The dose response as well as the dose-rate and photon-energy dependence of the dosimeter were characterized. To optimise the dose response, different concentrations of the chemical components were investigated. The dose response was found to decrease exponentially as a function of time after irradiation. A cylindrical dosimeter was produced and irradiated with a volumetric modulated arc therapy plan; the standard deviation between measured and calculated dose was 5% of the total dose.

  14. Personal noise dosimeters: accuracy and reliability in varied settings.

    PubMed

    Cook-Cunningham, Sheri Lynn

    2014-01-01

    This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units) in both pink noise (PN) environments and natural environments (NEs) through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3) Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a) All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b) all dosimeters were within the recommended American National Standard Institute (ANSI) SI.25-1991 standard of ±2 dB (A) of a reference measurement; and (c) all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A) when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students). This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D) were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera) while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured during

  15. Semicustom integrated circuits and the standard transistor array radix (STAR)

    NASA Technical Reports Server (NTRS)

    Edge, T. M.

    1977-01-01

    The development, application, pros and cons of the semicustom and custom approach to the integration of circuits are described. Improvements in terms of cost, reliability, secrecy, power, and size reduction are examined. Also presented is the standard transistor array radix, a semicustom approach to digital integrated circuits that offers the advantages of both custom and semicustom approaches to integration.

  16. [Chemical studies on the constituents of radix Ophiopogonis].

    PubMed

    Zhu, Y X; Liu, L Z; Ling, D K; Wang, W

    1989-06-01

    In this paper four compounds isolated from Radix Ophiopogonis are described. Their structures have been identified as beta-sitosterol (I), 6-aldehydo-7-methoxy-isoophiopogonanone B (II), beta-sitosterol-beta-D-glucopyranoside (III) and 1-borneol-beta-D-apisyl-beta-D-glucopyranoside (IV) on the basis of spectral data and hydrolytic reaction.

  17. [Investigation on correlation between ratio of xylem to phloem of Radix Isatidis and efficacy, chemical composition].

    PubMed

    Yan, Dan; Han, Yu-mei; Luo, Jiao-yang; Yan, Yan; Zhang, Ping; Zhang, Shao-feng; Xiao, Xiao-he

    2011-01-01

    Explore contribution of ratio of xylem to phloem(RXP) to evaluate the quality of Radix Isatidis. Antivirus activity and chemical compositions of xylem, phloem and Radix Isatidis of different RXP were determined by RBC agglutination test and unique chromatogram. Meanwhile, correlation between RXP and bioactivity,components was investigated. the activity of medical material of Radix Isatidis whose RXP was 1:2 or 1:1 is equal to that of phloem sample, while is stronger than that of cylem sample. There was a good consistency among the chemical figureprints of three samples (Radix Isatidis, xylem and phloem). When the RXP was 2:1, the medical material of Radix Isatidi and its xylem had the same activity. But the activity of phloem was not obvious. Their consistency of chemical fingerprint was bad, and the activity of Radix Isatidis which had RXP of 1:2 or 1:1 was better than that formed by xylem and phloem of 2:1. The Radix Isatidis of RXP of 1:2 or 1:1 had less similarity of chemical figureprint with that having RXP of 2:1. The quality of Radix Isatidis made up by the various RXP had significant difference. Radix Isatidis whose RXP is less than 1:1 had good quality and better activity. As a characteristic parameter of biologic morpha, the RXP can be applied to identifying the quality of Radix Isatidis, and also provided a reference to evaluation of other medical material of roots.

  18. Use of a CD laser pickup head to fabricate microelectrodes in polymethylmethacrylate substrates for biosensing applications.

    PubMed

    López-Aparicio, Jehú; Hautefeuille, Mathieu; Herrera-Domínguez, Sara; Razo-de-León, Adriana; Cano-Jorge, Mariel; Rojas-Benito, Ixchetl; Centeno-Sierra, Mariana; Fiordelisio-Coll, Tatiana; Stern-Forgach, Catalina Elizabeth

    2017-03-01

    In this work, we report a simple fabrication method for microelectrodes on a polymethylmethacrylate substrate, using a low-cost laser platform based on a CD-DVD unit for direct rapid-prototyping. We used this laser microfabrication technique to etch any desired design on polymethylmethacrylate substrates to produce microchannels with controlled geometry, with a highly repeatable micron-scale resolution. Those shallow microchannels were then filled with a conductive paste of material of our choice that was converted into microelectrodes of desired shapes and geometries after drying. To validate our process, different geometries, sizes and materials were used as electrodes, and then tested for amperometry and impedance measurements. Development of these microelectrodes is motivated by their potential application in sensors and biosensors, such as glucose and cell counting, as demonstrated in this paper.

  19. [Ecology suitability study of Chinese materia medica Gentianae Macrophyllae Radix].

    PubMed

    Lu, You-Yuan; Yang, Yan-Mei; Ma, Xiao-Hui; Zhang, Xiao-Bo; Zhu, Shou-Dong; Jin, Ling

    2016-09-01

    This paper is aimed to predict ecology suitability distribution of Gentianae Macrophyllae Radix and search the main ecological factors affecting the suitability distribution. The 313 distribution information about G. macrophylla, 186 distribution information about G. straminea, 343 distribution information about G. dauricaand 131 distribution information about G. crasicaulis were collected though investigation and network sharing platform data . The ecology suitable distribution factors for production Gentianae Macrophyllae Radix was analyzed respectively by the software of ArcGIS and MaxEnt with 55 environmental factors. The result of MaxEnt prediction was very well (AUC was above 0.9). The results of predominant factors analysis showed that precipitation and altitude were all the major factors impacting the ecology suitable of Getiana Macrophylla Radix production. G. macrophylla ecology suitable region was mainly concentrated in south of Gansu, Shanxi, central of Shaanxi and east of Qinghai provinces. G. straminea ecology suitable region was mainly concentrated in southwest of Gansu, east of Qinghai, north and northwest of Sichuan, east of Xizang province. G. daurica ecology suitable region was mainly concentrated in south and southwest of Gansu, east of Qinghai, Shanxi and north of Shaanxi province. G. crasicaulis ecology suitable region was mainly concentrated in Sichuan and north of Yunnan, east of Xizang, south of Gansu and east of Qinghai province. The ecological suitability distribution result of Gentianae Macrophyllae Radix was consistent with each species actual distribution. The study could provide reference for the collection and protection of wild resources, meanwhile, provide the basis for the selection of cultivation area of Gentiana Macrophylla Radix. Copyright© by the Chinese Pharmaceutical Association.

  20. Preparation and characterization of Ag-cluster in poly(methylmethacrylate)

    SciTech Connect

    Yanagihara, Naohisa; Ishii, Yoshitaka; Kawase, Takanori; Kaneko, Toshimare; Horie, Hisashi; Hara, Toru

    1997-09-01

    Solid sols of silver in poly(methylmethacrylate), Ag/PMMA, were prepared by bulk polymerization of methyl methacrylate (MMA) with benzoyl peroxide (BPO) as an initiator in the presence of silver(I) trifluoroacetate. Ag/PMMAs were characterized by visible spectroscopy. Effects of the concentration of initiator, the concentration of silver(I) complex and the heat-treatment time on the formation of silver cluster were studied in detail.

  1. Antioxidant effect of green tea on polymer gel dosimeter

    NASA Astrophysics Data System (ADS)

    Samuel, E. J. J.; Sathiyaraj, P.; Deena, T.; Kumar, D. S.

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer.

  2. Method and apparatus for reading free falling dosimeter punchcodes

    DOEpatents

    Langsted, James M.

    1992-12-22

    A punchcode reader is provided for reading data encoded in a punchcode hole array on a dosimeter. The dosimeter falls through a passage in the reader containing photosensor detectors disposed along the passage which provide output signals to a microprocessor. The signals are processed to determine the orientation of the dosimeter in the reader, the location and state of punchcode holes in a two row array thereby decoding the encoded data. Multiple rate of fall calculations are made, and if appropriate matching of the punchcode array is not obtained in three tries, an error signal is outputted to the operator. The punchcode reader also provides for storage of data from multiple dosimeters passed through the reader, and for the output of decoded data to an external display or a computer for further processing.

  3. Method and apparatus for reading free falling dosimeter punchcodes

    DOEpatents

    Langsted, J.M.

    1992-12-22

    A punchcode reader is provided for reading data encoded in a punchcode hole array on a dosimeter. The dosimeter falls through a passage in the reader containing photosensor detectors disposed along the passage which provide output signals to a microprocessor. The signals are processed to determine the orientation of the dosimeter in the reader, the location and state of punchcode holes in a two row array thereby decoding the encoded data. Multiple rate of fall calculations are made, and if appropriate matching of the punchcode array is not obtained in three tries, an error signal is output to the operator. The punchcode reader also provides for storage of data from multiple dosimeters passed through the reader, and for the output of decoded data to an external display or a computer for further processing. 8 figs.

  4. Investigating potential physicochemical errors in polymer gel dosimeters

    NASA Astrophysics Data System (ADS)

    Sedaghat, Mahbod; Bujold, Rachel; Lepage, Martin

    2011-09-01

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  5. Efficacy of Antibiotic-Impregnated Polymethylmethacrylate Beads in a Rhesus Macaque (Macaca mulatta) with Osteomyelitis

    PubMed Central

    Kelly, Kristi R; Kapatkin, Amy R; Zwingenberger, Allison L; Christe, Kari L

    2012-01-01

    Here we describe the successful surgical implementation of antibiotic-impregnated polymethylmethacrylate beads in a rhesus macaque (Macaca mulatta) with marked osteomyelitis. The macaque presented to the veterinary clinic with grossly contaminated bite wounds in the left ankle secondary to conspecific trauma. Radiographic findings were highly suggestive of osteomyelitis. Additional differential diagnoses included bony infarct, fracture, and cellulitis. In light of the location of the lesion and extensive tissue trauma, the animal had a poor prognosis. Systemic, broad-spectrum antibiotics were instituted. After 2 wk of care, lesions did not respond to empirical therapies. On consultation, a veterinary orthopedic surgeon at another facility recommended placement of antibiotic-impregnated polymethylmethacrylate beads at the sites of osteomyelitis. The animal underwent minor surgery in which beads were introduced into the wound. The monkey had a positive response to therapy. The animal regained full function and was returned to outdoor social housing. Veterinarians are encouraged to consider using antibiotic-impregnated polymethylmethacrylate beads when treating osteomyelitis in other nonhuman primates and in other traditional laboratory animal species. PMID:23043785

  6. Efficacy of antibiotic-impregnated polymethylmethacrylate beads in a rhesus macaque (Macaca mulatta) with osteomyelitis.

    PubMed

    Kelly, Kristi R; Kapatkin, Amy R; Zwingenberger, Allison L; Christe, Kari L

    2012-08-01

    Here we describe the successful surgical implementation of antibiotic-impregnated polymethylmethacrylate beads in a rhesus macaque (Macaca mulatta) with marked osteomyelitis. The macaque presented to the veterinary clinic with grossly contaminated bite wounds in the left ankle secondary to conspecific trauma. Radiographic findings were highly suggestive of osteomyelitis. Additional differential diagnoses included bony infarct, fracture, and cellulitis. In light of the location of the lesion and extensive tissue trauma, the animal had a poor prognosis. Systemic, broad-spectrum antibiotics were instituted. After 2 wk of care, lesions did not respond to empirical therapies. On consultation, a veterinary orthopedic surgeon at another facility recommended placement of antibiotic-impregnated polymethylmethacrylate beads at the sites of osteomyelitis. The animal underwent minor surgery in which beads were introduced into the wound. The monkey had a positive response to therapy. The animal regained full function and was returned to outdoor social housing. Veterinarians are encouraged to consider using antibiotic-impregnated polymethylmethacrylate beads when treating osteomyelitis in other nonhuman primates and in other traditional laboratory animal species.

  7. Surface-enhanced Raman scattering (SERS) dosimeter and probe

    DOEpatents

    Vo-Dinh, Tuan

    1995-01-01

    A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devises, in probe array devices.

  8. Radiation measured during ISS-Expedition 13 with different dosimeters

    NASA Astrophysics Data System (ADS)

    Zhou, Dazhuang; Semones, Edward; Gaza, Ramona; Johnson, Steve; Zapp, Neal; Lee, Kerry; George, Tamra

    Radiation measured during ISS-Expedition 13 with different dosimeters D. Zhou1,2,*, E. Semones1, R. Gaza1,2, S. Johnson1, N. Zapp1, K. Lee1, T. George1 1Johnson Space Center - NASA, 2101 Nasa Parkway, Houston 77058, USA 2Universities Space Research Association, 3600 Bay Area Blvd, Houston 77058, USA *Corresponding author. E-mail address: dazhuang.zhou-1@nasa.gov (D. Zhou). Abstract Radiation in low Earth orbit (LEO) is mainly composed of Galactic Cosmic Rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). The biological impact of space radiation to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to measure the LET spectrum for the space radiation field and to investigate the influence of radiation on astronauts. At present, the preferred active dosimeters sensitive to all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors in various configurations; the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. The TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation exposure for the ISS mission Expedition 13 (ISS-12S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the space mission with different dosimeters. This paper introduces the operational principles for the dosimeters, describes the method to combine the results measured by TLDs/OSLDs and CR-39 PNTDs, and presents the LET spectra and the radiation quantities measured. Keywords: space radiation; cosmic rays; active and passive dosimeters; LET spectra

  9. Surface-enhanced Raman scattering (SERS) dosimeter and probe

    DOEpatents

    Vo-Dinh, T.

    1995-03-21

    A dosimeter and probe for measuring exposure to chemical and biological compounds is disclosed. The dosimeter or probe includes a collector which may be analyzed by surface-enhanced Raman spectroscopy. The collector comprises a surface-enhanced Raman scattering-active material having a coating applied thereto to improve the adsorption properties of the collector. The collector may also be used in automated sequential devices, in probe array devices. 10 figures.

  10. Methods and means of checking thermoluminescent and radiophotoluminescent dosimeters

    SciTech Connect

    Fominykh, V.I.; Oborin, A.V.; Sebekin, A.P.; Uryaev, I.A.

    1987-06-01

    The authors discuss methods of checking thermoluminescent and radiophotoluminescent dosimeters which are used often in monitoring radiation safety in various areas including nuclear power stations. When the dosimeters are checked in the fields of standard beta-ray sources, it is recommended that the standard absorbed-dose or equivalent-dose measures for beta radiation should be sources of /sup 90/Sr + /sup 90/Y, /sup 204/Tl, and /sup 147/Pm. Various safety guidelines are discussed.

  11. Applicability of the polysulphone horizontal calibration to differently inclined dosimeters.

    PubMed

    Casale, Giuseppe R; Siani, Anna Maria; Diémoz, Henri; Kimlin, Michael G; Colosimo, Alfredo

    2012-01-01

    Polysulphone (PS) dosimetry has been a widely used technique for more than 30 years to quantify the erythemally effective UV dose received by anatomic sites (personal exposure). The calibration of PS dosimeters is an important issue as their spectral response is different from the erythemal action spectrum. It is performed exposing a set of PS dosimeters on a horizontal plane and measuring the UV doses received by dosimeters using calibrated spectroradiometers or radiometers. In this study, data collected during PS field campaigns (from 2004 to 2006), using horizontal and differently inclined dosimeters, were analyzed to provide some considerations on the transfer of the horizontal calibration to differently inclined dosimeters, as anatomic sites usually are. The role of sky conditions, of the angle of incidence between the sun and the normal to the slope, and of the type of surrounding surface on the calibration were investigated. It was concluded that PS horizontal calibrations apply to differently inclined dosimeters for incidence angles up to approximately 70° and for surfaces excluding ones with high albedo. Caution should be used in the application of horizontal calibrations for cases of high-incidence angle and/or high albedo surfaces.

  12. Radiation measured for ISS-Expedition 12 with different dosimeters

    NASA Astrophysics Data System (ADS)

    Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Weyland, M.

    2007-10-01

    Radiation in low Earth orbit (LEO) is mainly from Galactic Cosmic Rays (GCR), solar energetic particles and particles in South Atlantic Anomaly (SAA). These particles' radiation impact to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to investigate the LET spectrum for the radiation field and the influence of radiation on astronauts. At present, the best active dosimeters used for all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors; the best passive dosimeters are thermoluminescence dosimeters (TLDs) or optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation for space mission Expedition 12 (ISS-11S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the mission with these different dosimeters. This paper introduces the operation principles for these dosimeters, describes the method to combine the results measured by CR-39 PNTDs and TLDs/OSLDs, presents the experimental LET spectra and the radiation quantities.

  13. Experimental evaluation of a MOSFET dosimeter for proton dose measurements.

    PubMed

    Kohno, Ryosuke; Nishio, Teiji; Miyagishi, Tomoko; Hirano, Eriko; Hotta, Kenji; Kawashima, Mitsuhiko; Ogino, Takashi

    2006-12-07

    The metal oxide semiconductor field-effect transistor (MOSFET) dosimeter has been widely studied for use as a dosimeter for patient dose verification. The major advantage of this detector is its size, which acts as a point dosimeter, and also its ease of use. The commercially available TN502RD MOSFET dosimeter manufactured by Thomson and Nielsen has never been used for proton dosimetry. Therefore we used the MOSFET dosimeter for the first time in proton dose measurements. In this study, the MOSFET dosimeter was irradiated with 190 MeV therapeutic proton beams. We experimentally evaluated dose reproducibility, linearity, fading effect, beam intensity dependence and angular dependence for the proton beam. Furthermore, the Bragg curve and spread-out Bragg peak were also measured and the linear-energy transfer (LET) dependence of the MOSFET response was investigated. Many characteristics of the MOSFET response for proton beams were the same as those for photon beams reported in previous papers. However, the angular MOSFET responses at 45, 90, 135, 225, 270 and 315 degrees for proton beams were over-responses of about 15%, and moreover the MOSFET response depended strongly on the LET of the proton beam. This study showed that the angular dependence and LET dependence of the MOSFET response must be considered very carefully for quantitative proton dose evaluations.

  14. Response of the Hanford Combination Neutron Dosimeter in plutonium environments

    SciTech Connect

    Endres, A.W.; Brackenbush, L.W.; Baumgartner, W.V.

    1996-02-01

    This report documents response characteristics and the development of dose algorithms for the Hanford Combination Neutron Dosimeter (HCNO) implemented on January 1, 1995. The HCND was accredited under the U.S. Department of Energy (DOE) Laboratory Accreditation Program (DOELAP) during 1994. The HCND employs two neutron dose components consisting of (1) an albedo thermoluminescent dosimeter (TLD), and (2) a track-etch dosimeter (TED). Response characteristics of these two dosimeter components were measured under the low-scatter conditions of the Hanford 318 Building Calibration Laboratory, and under the high-scatter conditions in the workplace at the Plutonium Finishing Plant (PFP). The majority of personnel neutron dose at Hanford (currently and historically) occurs at the PFP. National Institute of Standards and Technology (NIST) traceable sources were used to characterize dosimeter response in the laboratory. At the PFP, neutron spectra and dose-measuring instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters, were used to determine the neutron dose under several configurations from three different plutonium sources: (1) plutonium tetrafluoride, (2) plutonium metal, and (3) plutonium oxide. In addition, measurements were performed at many selected work locations. The HCNDs were included in all measurements. Comparison of dosimeter- and instrument-measured dose equivalents provided the data necessary to develop HCND dose algorithms and to assess the accuracy of estimated neutron dose under actual work conditions.

  15. Potential High Resolution Dosimeters For MRT

    SciTech Connect

    Braeuer-Krisch, E.; Brochard, T.; Prezado, Y.; Bravin, A.; Berkvens, P.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Kamlowski, A.; Cellere, G.

    2010-07-23

    /s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic registered films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al{sub 2}O{sub 3}:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1x1 cm{sup 5} field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

  16. Potential High Resolution Dosimeters For MRT

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

    2010-07-01

    resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic® films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al2O3:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1×1 cm5 field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

  17. Evaluation of a mucoactive herbal drug, Radix Ophiopogonis, in a pathogenic quail model.

    PubMed

    Tai, Shusheng; Sun, Feng; O'Brien, Darryl W; Lee, Megan S; Zayas, J Gustavo; King, Malcolm

    2002-01-01

    We investigated the effect of Radix Ophiopogonis on airway mucociliary clearance and mucus secretion in anesthetized quails. The oral administration of 10 g/kg of Radix Ophiopogonis significantly increased tracheal mucociliary transport velocity (MTV). Moreover, either 10 g/kg or 3 g/kg of Radix Ophiopogonis markedly attenuated the human neutrophil elastase (HNE)-induced decrease in MTV. Furthermore, we found that 10 g/kg of Radix Ophiopogonis significantly abolished the HNE-induced increases in fucose and protein contents of tracheal lavage, whereas Radix Ophiopogonis at the same dose only significantly decreased the protein content in the control group. These results suggest that Radix Ophiopogonis improves airway mucociliary clearance and that the improvement may, at least in part, be ascribed to the amelioration of airway mucus secretion.

  18. Chemical fingerprint of commercial Radix Echinopsis and quantitative analysis of alpha-terthienyl.

    PubMed

    Qiao, Xue; Han, Jian; He, Wen-ni; Wu, Tao; Wang, Bao-rong; Ye, Min; Guo, De-an

    2010-03-01

    New TLC, HPLC and LC/MS methods were developed for the rapid separation, characterization and quantitation of thiophenes in Radix Echinopsis, a herbal medicine, which has been used in China for long history. Nineteen commercial batches of this herb were analyzed by TLC and HPLC. Only five batches were derived from correct species. The other 14 batches were identified as its adulterating species, Radix Rhapontici, as they did not contain characteristic thiophenes of Echinopsis species. By LC/MS, 16 thiophenes were identified from the methanol extracts of Radix Echinopsis and Radix Rhapontici according to their fragmentation behaviors in MS/MS. In addition, a fully validated HPLC method was established to determine the contents of alpha-terthienyl in Radix Echinopsis. The contents ranged from 2.7 to 5.2 mg/g for five tested samples. The methods in this paper were simple and reliable, and could be used for the comprehensive quality control of Radix Echinopsis.

  19. Skin autofluorescence as a biological UVR dosimeter.

    PubMed

    Sandby-Møller, J; Thieden, E; Philipsen, P A; Heydenreich, J; Wulf, H C

    2004-02-01

    Collagen is one of the major endogenous skin fluorophores. Alteration in the structure of collagen due to chronic ultraviolet radiation (UVR) exposure may influence the intensity of the autofluorescence. The aim of this study was to investigate the relation between collagen-linked autofluorescence and sun exposure to clarify whether the skin can be used as a biological UVR dosimeter. We conducted an in vivo study with 131 healthy volunteers. Fluorescence was measured from sun-exposed (dorsal forearm, forehead and shoulder) and sun-protected (buttock) skin and corrected for the impact of pigmentation and redness. The excitation wavelengths (Ex) and emission wavelengths (Em) were: Ex330:Em370, Ex330:Em455 and Ex370:Em455 nm. Individual UVR exposure data were collected both retrospectively and prospectively using questionnaires and electronic personal UVR dosimeters for a summer period. Age, but not sex, skin type or smoking habits correlated significantly positively with skin autofluorescence at Ex370:Em455 at all body sites (P<0.001, r(2)=0.08-0.26), and at Ex330:Em455 only at the buttock (P=0.001, r(2)=0.08), whereas age was not correlated with Ex330:Em370. Sun-protected buttock skin had significantly higher autofluorescence than sun-exposed skin (P-values<0.0001). Because of great between-subject differences in autofluorescence at different body sites, and because the autofluorescence at the unexposed buttock represents the baseline value, individual correction of skin autofluorescence measurement with that of the buttock was performed. Different measures of individual chronic cumulative UVR doses correlated significantly negatively with the skin autofluorescence ratio (F(ratio)), but the correlations were poor (r(2)=0.03-0.10). The results indicate that the collagen-linked skin F(ratio) might be best to use as a measure of individual photodamage, a UVR dose effect, and that it is also a better marker of individual cumulative UVR dose than the used UVR exposure

  20. High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-Optical Applications

    DTIC Science & Technology

    2009-07-01

    High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-Optical Applications...High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-Optical Applications...January 2007–November 2008 4. title and subtitle High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for

  1. High-Voltage Poling of a Bulk Sample of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-optical Applications

    DTIC Science & Technology

    2008-12-01

    Poling Of A Bulk Sample Of Disperse Red 1 Polymethylmethacrylate Guest-Host Polymer For U.S. Army Electrooptical Applications 5a. CONTRACT NUMBER...explanations / continuatLons / OPSEC review comments Block A-2 ... Polymethylmethacrylate Guest-Host Polymer for U.S. Army Electro-Optical Applications Block...VOLTAGE POLING OF A BULK SAMPLE OF DISPERSE RED 1 POLYMETHYLMETHACRYLATE GUEST-HOST POLYMER FOR U.S. ARMY ELECTRO- OPTICAL APPLICATIONS Robert H

  2. A Case Report of Allergic Contact Dermatitis due to Mandragora Radix

    PubMed Central

    Baysak, Sevim; Gönül, Müzeyyen; Atacan, Damla; Ergin, Can

    2015-01-01

    An 82-year-old male presented with rash, burning, and itching on his knees that had started 4 days after the local application of Mandragora Radix sap for 3 consecutive days. A dermatological examination revealed erythematous, edematous, and scaly plaque lesions on the patient's knees. An open application test with M. Radix was performed, and the patient was diagnosed with allergic contact dermatitis due to M. Radix. Mandragora species, which belong to the Solanaceae family, have sedative, aphrodisiac, emetic, analgesic, and anesthetic properties. To the best of our knowledge, only one case of M. Radix-induced allergic contact dermatitis has been previously reported. PMID:26347280

  3. [Advance in research on chemical constituents from Notopterygii Rhizoma et Radix].

    PubMed

    Li, Shi-ping; Sha, Long; Zhao, Yi-wu; Xu, Zhi-liang; Huang, Wen-zhe; Wang, Zhen-zhong; Xiao, Wei

    2015-08-01

    This paper summarized the recent 30 years research progress of the chemical constituents from Notopterygii Rhizoma et Radix. The chemical constituents from Notopterygii Rhizoma et Radix mainly consist of coumarins, polyene-polyacetylenes, sesquiterpenes, phenolic acids, while steroids and flavonoids were less reported. All constituents were confirmed and corrected through SciFinder. We also checked the Chinese name and English name and listed the CAS number of each compound. It can provide some guidelines for the research, development and utilization of Notopterygii Rhizoma et Radix in the future. Whether there is columbianin in the Notopterygii Rhizoma et Radix need to be further researched.

  4. PDT dose dosimeter for pleural photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Kim, Michele M.; Darafsheh, Arash; Ahmad, Mahmoud; Finlay, Jarod C.; Zhu, Timothy C.

    2016-03-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in the target tissue. For improved dosimetry during plural photodynamic therapy (PDT), a PDT dose dosimeter was developed to measure both the light fluence and the photosensitizer concentration simultaneously in the same treatment location. Light fluence and spectral data were rigorously compared to other methods of measurement (e.g. photodiode, multi-fiber spectroscopy contact probe) to assess the accuracy of the measurements as well as their uncertainty. Photosensitizer concentration was obtained by measuring the fluorescence of the sensitizer excited by the treatment light. Fluence rate based on the intensity of the laser spectrum was compared to the data obtained by direct measurement of fluence rate by a fiber-coupled photodiode. Phantom studies were done to obtain an optical property correction for the fluorescence signal. Measurements were performed in patients treated Photofrin for different locations in the pleural cavity. Multiple sites were measured to investigate the heterogeneity of the cavity and to provide cross-validation via relative dosimetry. This novel method will allow for accurate real-time determination of delivered PDT dose and improved PDT dosimetry.

  5. A liquid fluorescence dosimeter for proton dosimetry

    NASA Astrophysics Data System (ADS)

    Nadrowitz, Roger; Coray, Adolf; Boehringer, Terence; Dunst, Jürgen; Rades, Dirk

    2012-03-01

    The pyromellitic acid (benzene-1,2,4,5-tetracrboxylic acid) dosimeter is a liquid, nearly tissue equivalent detector (the density of the solution is 1.000 56 g cm-3). This acid fluoresces after exposure to proton radiation, if excited with light. The detector was exposed to proton doses of 1.0-10.0 Gy (energies: 138 and 160 MeV). The correlation between fluorescence intensity and delivered energy dose is one to one and linear, whereby the deviation from the linear behavior for all measured values is less than 1%. Variations of the dose rate between 2.4 and 6.0 Gy s-1 had no influence on the correlation between dose and fluorescence. The quenching of the pyromellitic acid detector amounts to about 22% for 138 MeV protons in the Bragg peak. For the period of 1-26 days after exposure, an increase in fluorescence intensity of the exposed solutions (5.0 Gy) was noticed, which corresponds to a daily data drift averaging 0.91% if the solution is stored in the dark at 4 °C. Non-exposed solutions showed no change of the control value.

  6. A liquid fluorescence dosimeter for proton dosimetry.

    PubMed

    Nadrowitz, Roger; Coray, Adolf; Boehringer, Terence; Dunst, Jürgen; Rades, Dirk

    2012-03-07

    The pyromellitic acid (benzene-1,2,4,5-tetracrboxylic acid) dosimeter is a liquid, nearly tissue equivalent detector (the density of the solution is 1.000 56 g cm⁻³). This acid fluoresces after exposure to proton radiation, if excited with light. The detector was exposed to proton doses of 1.0-10.0 Gy (energies: 138 and 160 MeV). The correlation between fluorescence intensity and delivered energy dose is one to one and linear, whereby the deviation from the linear behavior for all measured values is less than 1%. Variations of the dose rate between 2.4 and 6.0 Gy s⁻¹ had no influence on the correlation between dose and fluorescence. The quenching of the pyromellitic acid detector amounts to about 22% for 138 MeV protons in the Bragg peak. For the period of 1-26 days after exposure, an increase in fluorescence intensity of the exposed solutions (5.0 Gy) was noticed, which corresponds to a daily data drift averaging 0.91% if the solution is stored in the dark at 4 °C. Non-exposed solutions showed no change of the control value.

  7. Mixed-radiation discrimination using thermoluminescent dosimeters

    NASA Astrophysics Data System (ADS)

    Skopec, Marlene

    This work has developed, analyzed, and tested methods to discriminate among different types of radiation exposures using the glow curves of thermoluminescent dosimeters (TLDs). Thermoluminescent materials, Harshaw LiF:Mg,Ti (TLD-100) and CaF2:Tm (TLD-300), were exposed to pure proton, pure photon (x-ray and gamma), and mixed fields to examine and use differences in the thermoluminescent (TL) glow curve shapes for the purpose of radiation type discrimination. The effect of radiation type exposure order on thermoluminescent glow curve shape and the principle of superposition of glow curves were evaluated. Using computerized glow curve deconvolution (CGCD), no significant differences in glow curve shape or magnitude were found. Results demonstrated that the superposition of pure field glow curves is a valid method of simulating mixed field glow curves (i.e., the principle of superposition holds). Two robust and novel techniques for radiation type discrimination were developed: vector representation (VR) and principal component analysis (PCA). In VR, vectors were constructed from glow curve points and classified based on the vector inner product with a unit vector and vector magnitude. In PCA, variations in the glow curves due to radiation type are classified according to one principal component. The two methods were tested for accuracy using leave-one-out validation (LOOV) with classification based on the Mahalanobis distance. Overall, both techniques performed equally well, with over 92% accurate three category classification using the high temperature peak of TLD-100 and nearly 100% correct classification in TLD-300.

  8. Preliminary evaluation of implantable MOSFET radiation dosimeters.

    PubMed

    Beddar, A S; Salehpour, M; Briere, T M; Hamidian, H; Gillin, M T

    2005-01-07

    In this paper, we report on measurements performed on a new prototype implantable radiation detector that uses metal-oxide semiconductor field effect transistors (MOSFETs) designed for in vivo dosimetry. The dosimeters, which are encapsulated in hermetically sealed glass cylinders, are used in an unbiased mode during irradiation, unlike other MOSFET detectors previously used in radiotherapy applications. They are powered by radio frequency telemetry for dose measurements, obviating the need for a power supply within each capsule. We have studied the dosimetric characteristics of these MOSFET detectors in vitro under irradiation from a 60Co source. The detectors show a dose reproducibility generally within 5% or better, with the main sources of error being temperature fluctuations occurring between the pre- and post-irradiation measurements as well as detector orientation. A better temperature-controlled environment leads to a reproducibility within 2%. Our preliminary in vitro results show clearly that true non-invasive in vivo dosimetry measurements are feasible and can be performed remotely using telemetric technology.

  9. Developing an integrating biological dosimeter for spaceflight

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Jones, Martin; Baillie, David; Rose, Ann

    2007-09-01

    Exposure to harmful radiation is one of the major threats to human beings in outer-space; however, the biological consequences of long term exposure are not well understood. It would be useful to have a means of measuring the effect of space radiation on a living organism during space flights. We conducted a pilot project as part of the International Caenorhabditis elegans Experiment First Flight (ICE-First) project on the International Space Station (ISS). Using a mutational capture system, the eT1 balancer, along with other mutation detection systems, we analyzed the mutational effects of the 11 day mission. Upon recovery, classical genetic approaches and comparative genomic hybridization (CGH) microarrays were used to isolate and characterize mutant strains. Although in this short period of time, as expected no increase in mutational background was observed, we were able to demonstrate the potential of this system for longer-term measurement of biological damage. A sixmonth exposure experiment using the same system is currently in progress on the ISS. The relative simplicity and robustness of this model system demonstrate its potential for use as a biological dosimeter.

  10. PDT Dose Dosimeter for Pleural Photodynamic Therapy

    PubMed Central

    Kim, Michele M.; Darafsheh, Arash; Ahmad, Mahmoud; Finlay, Jarod C.; Zhu, Timothy C.

    2016-01-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in the target tissue. For improved dosimetry during plural photodynamic therapy (PDT), a PDT dose dosimeter was developed to measure both the light fluence and the photosensitizer concentration simultaneously in the same treatment location. Light fluence and spectral data were rigorously compared to other methods of measurement (e.g. photodiode, multi-fiber spectroscopy contact probe) to assess the accuracy of the measurements as well as their uncertainty. Photosensitizer concentration was obtained by measuring the fluorescence of the sensitizer excited by the treatment light. Fluence rate based on the intensity of the laser spectrum was compared to the data obtained by direct measurement of fluence rate by a fiber-coupled photodiode. Phantom studies were done to obtain an optical property correction for the fluorescence signal. Measurements were performed in patients treated Photofrin for different locations in the pleural cavity. Multiple sites were measured to investigate the heterogeneity of the cavity and to provide cross-validation via relative dosimetry. This novel method will allow for accurate real-time determination of delivered PDT dose and improved PDT dosimetry. PMID:27053825

  11. Solid state neutron dosimeter for space applications

    NASA Technical Reports Server (NTRS)

    Entine, Gerald; Nagargar, Vivek; Sharif, Daud

    1990-01-01

    Personnel engaged in space flight are exposed to significant flux of high energy neutrons arising from both primary and secondary sources of ionizing radiation. Presently, there exist no compact neutron sensor capable of being integrated in a flight instrument to provide real time measurement of this radiation flux. A proposal was made to construct such an instrument using special PIN silicon diode which has the property of being insensitive to the other forms of ionizing radiation. Studies were performed to determine the design and construction of a better reading system to allow the PIN diode to be read with high precision. The physics of the device was studied, especially with respect to those factors which affect the sensitivity and reproducibility of the neutron response. This information was then used to develop methods to achieve high sensitivity at low neutron doses. The feasibility was shown of enhancing the PIN diode sensitivity to make possible the measurement of the low doses of neutrons encountered in space flights. The new PIN diode will make possible the development of a very compact, accurate, personal neutron dosimeter.

  12. Worms in space? A model biological dosimeter.

    PubMed

    Zhao, Yang; Johnsen, Robert; Baillie, David; Rose, Ann

    2005-06-01

    Although it is well known that radiation causes mutational damage, little is known about the biological effects of long-term exposure to radiation in space. Exposure to radiation can result in serious heritable defects in experimental animals, and in humans, susceptibility to cancer, radiation-sickness, and death at high dosages. It is possible to do ground controlled studies of different types of radiation on experimental animals and to physically measure radiation on the space station or on space probes. However, the actual biological affects of long-term exposure to the full range of space radiation have not been studied, and little information is available about the biological consequences of solar flares. Biological systems are not simply passive recording instruments. They respond differently under different conditions, and thus it is important to be able to collect data from a living animal. There are technical difficulties that restrict the placement of an experimental organism in a space environment for long periods of time, in a manner that allows for the recovery of genetic data. Use of the self-fertilizing hermaphroditic nematode, Caenorhabditis elegans offers potential for the design of a biological dosimeter. In this paper, we describe the advantages of this model system and review the literature of C. elegans in space.

  13. Description and evaluation of the Hanford personnel dosimeter program from 1944 through 1989. [Contain Glossary

    SciTech Connect

    Wilson, R.H.; Fix, J.J.; Baumgartner, W.V.; Nichols, L.L.

    1990-09-01

    This report describes the evolution of personnel dosimeter technology at Hanford since the inception of Hanford operations in 1944. Each of the personnel dosimeter systems used by people working or visiting Hanford is described. In addition, the procedures used to calibrate and calculate dose for each of the dosimeter systems are described. The accuracy of the recorded dose, primarily whole body deep dose, for the different dosimeter systems is evaluated. The evaluation is based on an extensive review of historical literature, as well as a 1989 intercomparison study of all film dosimeters and performance testing of the thermoluminescent dosimeter, also conducted during 1989. 73 refs., 40 figs., 41 tabs.

  14. [Study on modern processing technologies of aconiti kusnezoffii radix].

    PubMed

    Lin, Hua; Deng, Guang-hai; Gong, You-ming

    2014-07-01

    To compare different processing technologies of Aconiti Kusnezoffii Radix, and to optimize a kind of "low toxicity and high efficiency", simple and practical processing technology for Aconiti Kusnezoffii Radix. HPLC method was used to determine the content of six kinds of alkaloids, and titration method to determine the content of total alkaloids. These contents combined with production were used to evaluate the modern processing technologies of Aconiti Kusnezoffii Radix. There was serious drain of Aconitum alkaloids after treated by soaking, and the loss rates of the content of monoester alkaloids, diester alkaloids and total alkaloid were 20.97%, 31.13% and 14.57%, respectively. The content of alkaloids could maximize the retention using wetting method, the best methods for reducing poison were atmospheric pressure and high pressure steaming cooking methods, and its total diester alkaloids content was too low to be detected, the contents of alkaloids in samples of two kinds of high-temperature baking were 0.6903 mg/g and 0.5575 mg/g, which were higher than the requirement of Chinese Pharmacopoeia. The content of monoester alkaloids was 0.6336 - 2.2721 mg/g of 10 kinds of processing technologies, between which there were nine kinds of processing technologies beyong the Chinese Pharmacopoeia requirement of 0.7 mg/g, while the total alkaloids content was 7.8019 - 11.2078 mg/g. The best method for reducing poison is high-pressure steaming, whose content of diester alkaloids can reach the Chinese Pharmacopoeia requirement after treatment of wet autoclaved products, with higher content of total alkaloids. It is simple, controllable, and suitable for processing of Aconiti Kusnezoffii Radix.

  15. Highly polymorphic microsatellite markers for Radix balthica (Linnaeus 1758).

    PubMed

    Salinger, M; Pfenninger, M

    2009-07-01

    We present data for eight polymorphic microsatellite markers isolated from a microsatellite-enriched DNA library for the freshwater snail Radix balthica. Three of them were specific for R. balthica while five also amplified polymorphic products in two congeneric species. Test application on populations from all over the species range has shown that these loci are highly informative for analysing population structure and estimating migration rates. Observed deviations from Hardy-Weinberg equilibrium are attributed to a mixed mating system.

  16. Quantum Mechanics and the Principle of Least Radix Economy

    NASA Astrophysics Data System (ADS)

    Garcia-Morales, Vladimir

    2015-03-01

    A new variational method, the principle of least radix economy, is formulated. The mathematical and physical relevance of the radix economy, also called digit capacity, is established, showing how physical laws can be derived from this concept in a unified way. The principle reinterprets and generalizes the principle of least action yielding two classes of physical solutions: least action paths and quantum wavefunctions. A new physical foundation of the Hilbert space of quantum mechanics is then accomplished and it is used to derive the Schrödinger and Dirac equations and the breaking of the commutativity of spacetime geometry. The formulation provides an explanation of how determinism and random statistical behavior coexist in spacetime and a framework is developed that allows dynamical processes to be formulated in terms of chains of digits. These methods lead to a new (pre-geometrical) foundation for Lorentz transformations and special relativity. The Parker-Rhodes combinatorial hierarchy is encompassed within our approach and this leads to an estimate of the interaction strength of the electromagnetic and gravitational forces that agrees with the experimental values to an error of less than one thousandth. Finally, it is shown how the principle of least-radix economy naturally gives rise to Boltzmann's principle of classical statistical thermodynamics. A new expression for a general (path-dependent) nonequilibrium entropy is proposed satisfying the Second Law of Thermodynamics.

  17. A critical assessment of two types of personal UV dosimeters.

    PubMed

    Seckmeyer, Gunther; Klingebiel, Marcus; Riechelmann, Stefan; Lohse, Insa; McKenzie, Richard L; Liley, J Ben; Allen, Martin W; Siani, Anna-Maria; Casale, Giuseppe R

    2012-01-01

    Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut-off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over-estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

  18. Water-equivalent fiber radiation dosimeter with two scintillating materials

    PubMed Central

    Qin, Zhuang; Hu, Yaosheng; Ma, Yu; Lin, Wei; Luo, Xianping; Zhao, Wenhui; Sun, Weimin; Zhang, Daxin; Chen, Ziyin; Wang, Boran; Lewis, Elfed

    2016-01-01

    An inorganic scintillating material plastic optical fiber (POF) dosimeter for measuring ionizing radiation during radiotherapy applications is reported. It is necessary that an ideal dosimeter exhibits many desirable qualities, including water equivalence, energy independence, reproducibility, dose linearity. There has been much recent research concerning inorganic dosimeters. However, little reference has been made to date of the depth-dose characteristics of dosimeter materials. In the case of inorganic scintillating materials, they are predominantly non water-equivalent, with their effective atomic weight (Zeff) being typically much greater than that of water. This has been a barrier in preventing inorganic scintillating material dosimeter from being used in actual clinical applications. In this paper, we propose a parallel-paired fiber light guide structure to solve this problem. Two different inorganic scintillating materials are embedded separately in the parallel-paired fiber. It is shown that the information of water depth and absorbed dose at the point of measurement can be extracted by utilizing their different depth-dose properties. PMID:28018715

  19. An assessment of radiotherapy dosimeters based on CVD grown diamond

    NASA Astrophysics Data System (ADS)

    Ramkumar, S.; Buttar, C. M.; Conway, J.; Whitehead, A. J.; Sussman, R. S.; Hill, G.; Walker, S.

    2001-03-01

    Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after ≈6 Gy. The diamond devices of CVD2 type had a response at low fields (<1162.8 V/cm) that was linear with dose and dose rate. At high fields (>1162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied voltage. The sensitivity of CVD diamond devices was significantly higher than that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy applications.

  20. Portable magnetic field dosimeter with data acquisition capabilities

    NASA Astrophysics Data System (ADS)

    Fujita, T. Y.; Tenforde, T. S.

    1982-03-01

    Design concepts, engineering specifications, and performance test results are presented for a compact magnetic field dosimeter that is suitable for monitoring personnel exposures to steady-state and time-varying magnetic fields. The battery-operated dosimeter contains thin-film Hall sensors that record the magnetic induction (B) along three orthogonal axes. The Hall generators are operated in a pulsed mode, and the time rate of change of the magnetic induction (dB/dt) is determined for values of B recorded during consecutive sampling intervals (typically 75 ms). The pulsed mode operation also serves to reduce battery consumption. The dosimeter contains a programmable microprocessor-based logic circuit and 4096 12-bit words of permanent and random-access memory. Stored parameters include: (1) average values of B and dB/dt during a preset time interval (typically 5 min); (2) peak values of B and dB/dt during the preset interval; and (3) the number of times that specified threshold levels for these parameters are exceeded. An audible alarm is activated when B or dB/dt exceeds a specified threshold level. Sensitivity factors and threshold levels can be loaded into the dosimeter from a bench-mounted programmable calculator, which is also used at the end of each workday to record and process data stored in the dosimeter's random-access memory.

  1. PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect

    Hill, Robin L.; Conrady, Matthew M.

    2011-10-28

    This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

  2. Radiation measured with different dosimeters during STS-121 space mission

    NASA Astrophysics Data System (ADS)

    Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Weyland, M.; Rutledge, R.; Lin, T.

    2009-02-01

    Radiation impact to astronauts depends on the particles' linear energy transfer (LET) and is dominated by high LET radiation. Radiation risk experienced by astronauts can be determined with the radiation LET spectrum measured and the risk response function obtained from radiobiology. Systematical measurement of the space radiation is an important part for the research on the impact of radiation to astronauts and to make the radiation ALARA (as low as reasonably achievable). For NASA space missions at low Earth orbit (LEO), the active dosimeter used for all LET is the tissue equivalent proportional counter (TEPC) and the passive dosimeters used for the astronauts and for the monitored areas are the combination of CR-39 plastic nuclear track detectors (PNTDs) for high LET and thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeter (OSLDs) for low LET. TEPC, CR-39 PNTDs and TLDs/OSLDs were used to measure the radiation during STS-121 space mission. LET spectra and radiation quantities were obtained with active and passive dosimeters. This paper will introduce the physical principles for TEPC and CR-39 detectors, the LET spectrum method for radiation measurement using CR-39 detectors and TEPC, and will present and compare the radiation LET spectra and quantities measured with TEPC, CR-39 PNTDs and TLDs/OSLDs.

  3. Water-equivalent fiber radiation dosimeter with two scintillating materials.

    PubMed

    Qin, Zhuang; Hu, Yaosheng; Ma, Yu; Lin, Wei; Luo, Xianping; Zhao, Wenhui; Sun, Weimin; Zhang, Daxin; Chen, Ziyin; Wang, Boran; Lewis, Elfed

    2016-12-01

    An inorganic scintillating material plastic optical fiber (POF) dosimeter for measuring ionizing radiation during radiotherapy applications is reported. It is necessary that an ideal dosimeter exhibits many desirable qualities, including water equivalence, energy independence, reproducibility, dose linearity. There has been much recent research concerning inorganic dosimeters. However, little reference has been made to date of the depth-dose characteristics of dosimeter materials. In the case of inorganic scintillating materials, they are predominantly non water-equivalent, with their effective atomic weight (Zeff) being typically much greater than that of water. This has been a barrier in preventing inorganic scintillating material dosimeter from being used in actual clinical applications. In this paper, we propose a parallel-paired fiber light guide structure to solve this problem. Two different inorganic scintillating materials are embedded separately in the parallel-paired fiber. It is shown that the information of water depth and absorbed dose at the point of measurement can be extracted by utilizing their different depth-dose properties.

  4. Temperature measurements for shocked polymethylmethacrylate, epoxy resin, and polytetrafluoroethylene and their equations of state

    NASA Astrophysics Data System (ADS)

    Bordzilovskii, S. A.; Karakhanov, S. M.; Merzhievskii, L. A.; Voronin, M. S.

    2016-10-01

    This paper presents the results of computational and experimental studies of the temperature along the shock adiabat for three polymers. Measurements of the brightness temperatures of shock-compressed epoxy resin and polymethylmethacrylate and the brightness and color temperatures of shock-compressed polytetrafluoroethylene were carried out. The temperatures of the shock-compressed polymethylmethacrylate were determined in the range 1390-1900 K for shock pressures of 22-39 GPa. Similar measurements performed for epoxy resin in the pressure range of 18-40 GPa showed values of 940-1900 K, and the temperatures of polytetrafluoroethylene in the pressure range of 30-50 GPa were equal to 2000-3200 K. The equation of state for the three polymers with a nonspherical strain tensor was constructed to describe shock-wave and high-temperature processes in a wide range of thermodynamic parameters. In the proposed model, two Grüneisen parameters were used: the thermodynamic parameter corresponding to intrachain vibrations and the lattice parameter representing the contribution of interchain vibrations. The brightness temperatures of shocked-compressed polymethylmethacrylate and epoxy resin showed a good agreement with calculations using the proposed model and with the results of earlier calculation methods. Time dependences of the observed intensity of light were used to determine the absorption coefficients of the shocked polymers and estimate the effective thickness of the radiating layer. A typical feature of all the polymers is the width of the radiating layer of 0.8 to 2.5 mm, depending on the material and shock pressure.

  5. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray

    PubMed Central

    Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-01-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymerized Polymethylmethacrylate (PMMA) resin trays. PMID:28050525

  6. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray.

    PubMed

    Chidambaranathan, Ahila Singaravel; Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-11-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymerized Polymethylmethacrylate (PMMA) resin trays.

  7. Using rapid prototyping molds to create patient specific polymethylmethacrylate implants in cranioplasty.

    PubMed

    Gerber, N; Stieglitz, L; Peterhans, M; Nolte, L P; Raabe, A; Weber, S

    2010-01-01

    Cranioplasty is a commonly performed procedure. Outcomes can be improved by the use of patient specific implants, however, high costs limit their accessibility. This paper presents a low cost alternative technique to create patient specific polymethylmethacrylate (PMMA) implants using rapid prototyped mold template. We used available patient's CT-scans, one dataset without craniotomy and one with craniotomy, for computer-assisted design of a 3D mold template, which itself can be brought into the operating room and be used for fast and easy building of a PMMA implant. We applied our solution to three patients with positive outcomes and no complications.

  8. Reversible patterning of poly(methylmethacrylate) doped with disperse Red 1 by laser scanning

    SciTech Connect

    Tuma, J.; Lyutakov, O.; Huttel, I.; Slepicka, P.; Svorcik, V.

    2013-09-07

    Thin poly(methylmethacrylate) films doped by or covalently attached to disperse Red 1 acrylate (DR1) were patterned by laser scanning and simultaneous sample movement in confocal microscope. In both cases, periodical structure due to Marangoni effect is created. Modified polymers surfaces were analyzed by FTIR spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. After first stage of patterning, second stage with sample movement in perpendicular direction was applied. Depending on the method of DR1 dotation fishnet structure is obtained or pattern structure disappears. In the latter case, reversibility of pattern formation and erasure by laser scanning was studied.

  9. Influence of irradiation on the Heterogeneity of polymethylmethacrylate-polyvinylidene fluoride mixtures

    SciTech Connect

    Lipatov, Y.S.; Bliznyuk, V.N.; Boyarskii, G.Y.; Gomza, Y.P.; Shilov, V.V.

    1985-11-01

    Small- and wide-angle x-ray scattering was used to investigate the phase structure of mixtures of polymethylmethacrylate (PMMA) with polyvinylidene fluoride (PVDF) as function of the thermal treatment and the ..gamma..-radiation dose. Irradiation of 1/ 1 mixtures obtained by quenching from a homogeneous melt with doses of up to 1 Mrd leads to radiation breakdown of the components; on the other hand, irradiation with larger doses leads to radiation crosslinking of PVDF. ..gamma..-Irradiation accelerates phase separation in the system, as a result of which microregions of pure PVDF of colloidal size are formed.

  10. Occlusion of an Intraosseous Arteriovenous Malformation With Percutaneous Injection of Polymethylmethacrylate

    SciTech Connect

    Ierardi, Anna Maria; Mangini, Monica; Vaghi, Massimo; Cazzulani, Alberto; Mattassi, Raul; Carrafiello, Gianpaolo

    2011-02-15

    Primary intraosseous arteriovenous malformations are rare. Many minimally invasive procedures can be considered preoperative steps and/or definitive treatment. The case reported regards a young woman with a voluminous arteriovenous extratroncular infiltrating malformation of the humerus. She underwent several treatments, but none of them was completely occlusive. The last treatment consisted of direct percutaneous puncture of the intraosseous alteration and injection of polymethylmethacrylate (PMMA), which is normally used in percutaneous vertebroplasty. We obtained complete occlusion of the humerus lytic lesion. To the best of our knowledge, this represents the first case of intraosseous AVM treated by percutaneous injection of PMMA.

  11. Response of personal noise dosimeters to continuous and impulse-like signals

    NASA Astrophysics Data System (ADS)

    Evans, D. J.; Flynn, D. R.; Nedzelnitsky, V.; Burnett, E. D.

    1991-06-01

    A study of the capabilities of noise dosimeters to measure personal exposure to time varying and impulse-like noises was carried out. Ten commercial noise dosimeters were obtained. A laboratory reference noise dosimeter was constructed to provide a demonstrably accurate basis with which to compare the commercial noise dosimeters. Each commercial dosimeter, when ordered from the manufacturer, was specified to have a threshold A-weighted sound level of 80 dB, a criterion sound level of 90 dB, and an exchange rate of 5 dB and/or 3 dB. The performance of the commercial dosimeters was compared with theory and with results obtained from the reference dosimeter. Except in a few isolated cases, the commercial dosimeters were in general agreement with the performance specification of the appropriate American National Standard and with the Occupational Safety and Health Administration (OSHA) regulations.

  12. High-performance thin-layer chromatographic fingerprints of isoflavonoids for distinguishing between Radix Puerariae Lobate and Radix Puerariae Thomsonii.

    PubMed

    Chen, Si-Bao; Liu, He-Ping; Tian, Run-Tao; Yang, Da-Jian; Chen, Shi-Lin; Xu, Hong-Xi; Chan, Albert S C; Xie, Pei-Shan

    2006-07-14

    The roots of Pueraria lobata (Wild.) Ohwi and Pueraria thomsonii Benth have been officially recorded in all editions of Chinese Pharmacopoeia under the same monograph 'Gegen' (Radix Puerariae, RP). However, in its 2005 edition, the two species were separated into both individual monographs, namely 'Gegen' (Radix Puerariae Lobatae, RPL) and 'Fenge' (Radix Puerariae Thomsonii, RPT), respectively, due to their obvious content discrepancy of puerarin, the major active constituent. In present paper, the fingerprint of high-performance thin-layer chromatography (HPTLC) combining digital scanning profiling was developed to identify and distinguish the both species in detail. The unique properties of the HPTLC fingerprints were validated by analyzing ten batches of Pueraria lobata and P. thomsonii samples, respectively. The common pattern of the HPTLC images of the roots of Pueraria spp. and the respective different ratios of the chemical distribution can directly discern the two species. The corresponding digital scanning profiles provided an easy way for quantifiable comparison among the samples. Obvious difference in ingredient content and HPTLC patterns of the two species questioned their bio-equivalence and explained that recording both species separately in the current edition of Chinese Pharmacopoeia (2005 edition) is reasonable due to not only the content of major constituent, puerarin, but also the peak-to-peak distribution in the fingerprint and integration value of the total components. Furthermore, the HPTLC fingerprint is also suitable for rapid and simple authentication and comparison of the subtle difference among samples with identical plant resource but different geographic locations.

  13. Performance testing of extremity dosimeters against a draft standard

    SciTech Connect

    Harty, R.; Reece, W.D.; Hooker, C.D.; McDonald, J.C.

    1990-09-01

    The assurance of worker radiation safety is directly related to the performance of personnel dosimetry. The US Department of Energy (DOE) has long recognized this critical relationship and has addressed this issue by instituting the DOE Laboratory Accreditation Program (DOELAP) which strives to improve the quality of personnel dosimetry through performance testing, dosimetry calibration, intercomparisons, evaluations and accreditations. One area of personnel dosimetry that has not been specifically addressed by DOELAP is extremity dosimeter testing. This task was directed at assessing the problems of implementing extremity dosimeter performance testing. A series of performance tests were made based on a draft standard written by the Health Physics Society Standards Committee (HPSSC) using extremity dosimeters currently in use at DOE and DOE contractor facilities. The results of this study indicate the need to incorporate performance testing of extremity dosimetry systems into DOELAP. Based on the results of this study, recommendations are made for improvements to the draft standard. 20 refs., 6 figs., 3 tabs.

  14. Commissioning and implementation of an implantable dosimeter for radiation therapy.

    PubMed

    Buzurovic, Ivan; Showalter, Timothy N; Studenski, Matthew T; Den, Robert B; Dicker, Adam P; Cao, Junsheng; Xiao, Ying; Yu, Yan; Harrison, Amy

    2013-03-04

    In this article we describe commissioning and implementation procedures for the Dose Verification System (DVS) with permanently implanted in vivo wireless, telemetric radiation dosimeters for absolute dose measurements. The dosimeter uses a semiconductor device called a metal-oxide semiconductor field-effect transistor (MOSFET) to measure radiation dose. A MOSFET is a transistor that is generally used for amplifying or switching electronic signals. The implantable dosimeter was implemented with the goal of verifying the dose delivered to radiation therapy patients. For the purpose of acceptance testing, commissioning, and clinical implementation and to evaluate characteristics of the dosimeter, the following tests were performed: 1) temperature dependence, 2) reproducibility,3) field size dependence, 4) postirradiation signal drift, 5) dependence on average dose rate, 6) linearity test, 7) angular dependence (different gantry angle position), 8) angular dependence (different DVS angle position), 9) dose rate dependence,10) irradiation depth dependence, 11) effect of cone-beam exposure to the dosimeter, and 12) multiple reading effect. The dosimeter is not currently calibrated for use in the kV range; nonetheless, the effect of the cone-beam procedure on the MOSFET dosimeter was investigated. Phantom studies were performed in both air and water using an Elekta Synergy S Beam-Modulator linear accelerator. Commissioning and clinical implementation for prostate cancer patients receiving external-beam radiation therapy were performed in compliance with the general recommendations given for in vivo dosimetry devices. The reproducibility test in water at human body temperature (37°C) showed a 1.4% absolute difference, with a standard deviation of 5.72 cGy (i.e., SD = 2.9%). The constancy test shows that the average readings at room temperature were 3% lower compared to the readings at human body temperature, with a SD = 2%. Measurements were not dependent upon field size

  15. Monitoring of environmental UV radiation by biological dosimeters.

    PubMed

    Ronto, G; Berces, A; Grof, P; Fekete, A; Kerekgyarto, T; Gaspar, S; Stick, C

    2000-01-01

    As a consequence of the stratospheric ozone layer depletion biological systems can be damaged due to increased UV-B radiation. The aim of biological dosimetry is to establish a quantitative basis for the risk assessment of the biosphere. DNA is the most important target molecule of biological systems having special sensitivity against short wavelength components of the environmental radiation. Biological dosimeters are usually simple organisms, or components of them, modeling the cellular DNA. Phage T7 and polycrystalline uracil biological dosimeters have been developed and used in our laboratory for monitoring the environmental radiation in different radiation conditions (from the polar to equatorial regions). Comparisons with Robertson-Berger (RB) meter data, as well as with model calculation data weighted by the corresponding spectral sensitivities of the dosimeters are presented. Suggestion is given how to determine the trend of the increase in the biological risk due to ozone depletion. c2001 COSPAR Published by Elsevier Science Ltd. All rights reserved.

  16. Comparing morphological, chemical and anti-diabetic characteristics of Puerariae Lobatae Radix and Puerariae Thomsonii Radix.

    PubMed

    Wong, Ka H; Razmovski-Naumovski, Valentina; Li, Kong M; Li, George Q; Chan, Kelvin

    2015-04-22

    Puerariae Lobatae Radix (PLR) and Puerariae Thomsonii Radix (PTR) are traditional Chinese medicines used for the treatment of diabetes and cardiovascular diseases. These two herbs are used interchangeably in clinical practice, even though they possess significantly different chemical profiles. In the case of Pueraria species, the misidentification is related to the multiple Chinese common names in clinical practice and variable pharmaceutical Latin names in different versions of the Pharmacopoeia of the People's Republic of China. In addition, there is lack of evidence demonstrating how the differences in the chemical profile would impact on the pharmacological activity of the two herbs. Therefore, the aim of this study was to compare the microscopic, phytochemical profiles and anti-diabetic activity of PLR and PTR so that the two species can be differentiated. The microscopic characteristics of the PLR and PTR were observed and measured by an optical microscope. The major compounds were quantified by ultra-performance liquid chromatography (UPLC) and total flavonoid content (TFC) colorimetric assay. The free radical scavenging capacity was assessed by 2,2-diphenyl-2-picrylhydrazyl (DPPH) antioxidant assays. Anti-diabetic activity was determined by the inhibition of porcine pancreatic α-amylase and rat intestinal α-glucosidase activities. Microscopic results illustrated that the size of xylem vessels (PLR: 0.1390 ± 0.0184 mm; PTR: 0.0471 ± 0.0109 mm), number of fibre per bundle (PLR: 32.6800 ± 2.8780; PTR: 16.5900 ± 0.9982) and the size of fibre (PLR: 0.0075 ± 0.0003 mm(2); PTR: 0.0025 ± 0.0002 mm(2)) in PLR were significantly greater than that in PTR (p<0.01). PLR possessed a significantly lower total starch content (PLR: 0.5288 ± 1.2559 mg starch/g DM; PTR: 76.7954 ± 2.9905 mg starch/g DM) and total dietary fibre content (PLR: 4.2886 ± 0.3466 g/100g DM; PTR: 12.4148 ± 0.4541 g/100g DM) as compared to PTR. Isoflavonoids including puerarin, daidzin

  17. [Effect of Codonopsis Radix maintained with sulfur fumigation on immune function in mice].

    PubMed

    Liu, Cheng-song; Wang, Yu-ping; Shi, Yan-bin; Ma, Xing-ming; Li, Hui-li; Zhang, Xiao-yun; Li, Shou-tang

    2014-11-01

    To investigate the immune function of mice being given the extract of Codonopsis Radix maintained with sulfur fumigation. Mice were divided into five groups. Except the normal control group, the mice were fed with the extract of Codonopsis Radix maintained with sulfur fumigation at the high,medium and low doses, as well as medium dose of Codonopsis Radix maintained with low-temperature vacuum method, respectively. Mice were treated once a day for 10 continuous days. Weight change,organ indexes, blood cell indices, macrophage phagocytic function, and IL-2 and IFN-γ levels were measured. Compared with normal control group, Codonopsis Radix maintained with sulfur fumigation at medium and high doses inhibited body weight increase of mice; white blood cell count of high dose group was significantly increased; significant increase of macrophage phagocytosis were observed for all groups except the normal control group; and spleen index and IFN-γ level of Codonopsis Radix maintained with sulfur fumigation medium dose group were increased significantly. Codonopsis Radix maintained with sulfur fumigation can promote mouse immune function to a certain degree. There was no difference in immune effect between Codonopsis Radix maintained with sulfur fumigation and low-temperature vacuum method during experimental period. However,taking the extract of Codonopsis Radix maintained with sulfur fumigation can exert negative effect on appetite and body weight in mice.

  18. Elucidation of the Anti-Inflammatory Mechanisms of Bupleuri and Scutellariae Radix Using System Pharmacological Analyses

    PubMed Central

    Shen, Xia; Zhao, Zhenyu; Wang, Hao; Guo, Zihu; Hu, Benxiang

    2017-01-01

    Objective. This study was aimed at elucidating the molecular mechanisms underlying the anti-inflammatory effect of the combined application of Bupleuri Radix and Scutellariae Radix and explored the potential therapeutic efficacy of these two drugs on inflammation-related diseases. Methods. After searching the databases, we collected the active ingredients of Bupleuri Radix and Scutellariae Radix and calculated their oral bioavailability (OB) and drug-likeness (DL) based on the absorption-distribution-metabolism-elimination (ADME) model. In addition, we predicted the drug targets of the selected active components based on weighted ensemble similarity (WES) and used them to construct a drug-target network. Gene ontology (GO) analysis and KEGG mapper tools were performed on these predicted target genes. Results. We obtained 30 compounds from Bupleuri Radix and Scutellariae Radix of good quality as indicated by ADME assays, which possess potential pharmacological activity. These 30 ingredients have a total of 121 potential target genes, which are involved in 24 biological processes related to inflammation. Conclusions. Combined application of Bupleuri Radix and Scutellariae Radix was found not only to directly inhibit the synthesis and release of inflammatory cytokines, but also to have potential therapeutic effects against inflammation-induced pain. In addition, a combination therapy of these two drugs exhibited systemic treatment efficacy and provided a theoretical basis for the development of drugs against inflammatory diseases. PMID:28190938

  19. [Evolution and transition of source of Patrinia Herba and Patrinia Radix].

    PubMed

    Xiang, Ying-Long; Mei, Gui-Lin; Luo, Han; Fang, Wen-Tao; Peng, Hua-Sheng; Feng, Cheng-Wu; Yang, Qing-Shan; Li, Xiang-Yu; Zhang, Yan-Peng

    2017-07-01

    Both Patrinia Herba and Patrinia Radix are traditional Chinese herbal medicines. The herbal source and medicinal part of them are confusing in the herbal medicine market of China. To explore the evolution and transition of the herbal source and medicinal part of Patrinia Herba and Patrinia Radix, this paper systematically summarizes the record of the herbal source and medicinal part of them in ancient classics of herbal medicine in China. According to the findings, before Ming Dynasty, Patrinia Herba originated from the radix of the plants with yellow flowers of Patrinia. In Ming and Qing Dynasty, Patrinia Herba originates from the whole plant (including the radix)of the plant with white flowers of Patrinia. In Ming Dynasty, Patrinia Radix, stemming from the radix of the plants with yellow flowers of Patrinia, started to be used as a traditional Chinese herbal medicine, which had the same herbal source with that of Patrinia Herba before Ming Dynasty. Therefore, Patrinia Herba and Patrinia Radix can be seen as the same traditional Chinese herbal medicine, and the genuine of Patrinia Herba should be the radix and the whole herba of P. scabiosaefolia and P. heterophylla. Copyright© by the Chinese Pharmaceutical Association.

  20. Development and evaluation of polycrystalline cadmium telluride dosimeters for accurate quality assurance in radiation therapy

    NASA Astrophysics Data System (ADS)

    Oh, K.; Han, M.; Kim, K.; Heo, Y.; Moon, C.; Park, S.; Nam, S.

    2016-02-01

    For quality assurance in radiation therapy, several types of dosimeters are used such as ionization chambers, radiographic films, thermo-luminescent dosimeter (TLD), and semiconductor dosimeters. Among them, semiconductor dosimeters are particularly useful for in vivo dosimeters or high dose gradient area such as the penumbra region because they are more sensitive and smaller in size compared to typical dosimeters. In this study, we developed and evaluated Cadmium Telluride (CdTe) dosimeters, one of the most promising semiconductor dosimeters due to their high quantum efficiency and charge collection efficiency. Such CdTe dosimeters include single crystal form and polycrystalline form depending upon the fabrication process. Both types of CdTe dosimeters are commercially available, but only the polycrystalline form is suitable for radiation dosimeters, since it is less affected by volumetric effect and energy dependence. To develop and evaluate polycrystalline CdTe dosimeters, polycrystalline CdTe films were prepared by thermal evaporation. After that, CdTeO3 layer, thin oxide layer, was deposited on top of the CdTe film by RF sputtering to improve charge carrier transport properties and to reduce leakage current. Also, the CdTeO3 layer which acts as a passivation layer help the dosimeter to reduce their sensitivity changes with repeated use due to radiation damage. Finally, the top and bottom electrodes, In/Ti and Pt, were used to have Schottky contact. Subsequently, the electrical properties under high energy photon beams from linear accelerator (LINAC), such as response coincidence, dose linearity, dose rate dependence, reproducibility, and percentage depth dose, were measured to evaluate polycrystalline CdTe dosimeters. In addition, we compared the experimental data of the dosimeter fabricated in this study with those of the silicon diode dosimeter and Thimble ionization chamber which widely used in routine dosimetry system and dose measurements for radiation

  1. Imaging of Absorbed Dose in Radiotherapy by a Polymer Gel Dosimeter

    NASA Astrophysics Data System (ADS)

    Vanossi, E.; Gambarini, G.; Carrara, M.; Mariani, M.; Negri, A.

    2008-06-01

    Optical imaging of polymer gel dosimeters in form of layers was investigated to enquire their reliability for in-phantom dose measurements in photon or thermal neutron fields. The obtained dose measurements were compared with those achieved by means of Fricke gel dosimeters. Reliability of Fricke gel dosimeters was confirmed, whereas it has been shown that a conspicuous improvement of the adopted polymer gel dosimeters is necessary.

  2. Implanted Dosimeters Identify Radiation Overdoses During IMRT for Prostate Cancer

    SciTech Connect

    Den, Robert B.; Nowak, Kamila; Buzurovic, Ivan; Cao Junsheng; Harrison, Amy S.; Lawrence, Yaacov R.; Dicker, Adam P.; Showalter, Timothy N.

    2012-07-01

    Purpose: Image-guided dose-escalated radiotherapy is the standard of care for the treatment of prostate cancer. Although many published methods are available that account for prostate motion during delivery, evidence demonstrating that the planned dose is actually delivered on a daily basis is lacking. We report our initial clinical experience using implantable dosimeters to quantify and adjust the dose received during intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 20 patients undergoing IMRT with cone-beam computed tomography (CT) image guidance for prostate cancer had the dose verification system with radiopaque metal-oxide-semiconductor field effect transistor dosimeters implanted before treatment planning. All patients underwent planning with CT simulation in the supine position with custom immobilization, and the implanted dosimeters were located in the IMRT plans. The predicted dose for each dosimeter was defined and compared with the wireless readings before and after each treatment session. Investigations by physicians and medical physicists were initiated for two or more discrepancies >6% for any five consecutive fractions or for any discrepancy {>=}10%. Results: Using implanted in vivo dosimeters, dose measurements consistently >6% greater than the predicted values were observed during treatment for 3 of 20 prostate cancer patients who received IMRT with daily image guidance. A review of the daily cone-beam CT images revealed acceptable alignment of the prostate target volumes and implanted dosimeters but identified significant anatomic changes within the treated region. Repeat CT simulation and RT planning was performed, with resolution of the dose discrepancies in all 3 cases with the adoption of a new IMRT plan. Conclusions: Our report illustrates the potential effect of implanted in vivo dosimetry for prostate IMRT and emphasizes the importance of careful planning and delivery with attention to systematic shifts or anatomic

  3. A floating gate MOSFET dosimeter requiring no external bias supply

    SciTech Connect

    Tarr, N.G.; Mackay, G.F.; Thomson, I.; Shortt, K.

    1998-06-01

    MOSFET dosimeters incorporating an electrically floating polysilicon gate have been fabricated in a commercial CMOS technology. Charge is placed on the floating gate by tunneling from a small overlapping injector gate. Subsequent irradiation partially discharges the floating gate, producing a change in threshold voltage which can be used to infer the absorbed dose. No external power source is required during this sensing period. Sensitivities up to 70 mVGy{sup {minus}1} (0.7 mV/rad) have been obtained for temperature-compensated matched-pair dosimeters under {sup 60}Co gamma irradiation.

  4. Measurement of a PAGAT gel dosimeter by ultrasound computed tomography

    NASA Astrophysics Data System (ADS)

    Khoei, S.; Trapp, J. V.; Langton, C. M.

    2013-06-01

    In this work we used a 3D quantitative CT ultrasound imaging system to characterise polymer gel dosimeters. The system comprised of two identical 5 MHz 128 element phased-array ultrasound transducers co-axially aligned and submerged in water as a coupling agent. Rotational and translational movement of the gel dosimeter sample between the transducers were performed using a robotic arm. Ultrasound signals were generated and received using an Olympus Omniscan unit. Dose sensitivity of attenuation and time of flight ultrasonic parameters were assessed using this system.

  5. Basic radiological characteristics of a non-scattering gel dosimeter for 3D dosimetry

    NASA Astrophysics Data System (ADS)

    Chang, Kyung Hwan; Ji, Yunseo; Lee, Suk; Kim, Kwang Hyeon; Yang, Dae Sik; Lee, Jung Ae; Park, Young Je; Yoon, Won Sup; Kim, Chul Yong; Cao, Yuanjie; Cho, Samju

    2016-12-01

    We used a spectrophotometer to compare the dosimetric properties of two non-scattering (radiochromic) gel dosimeters: a non-scattering gel dosimeter developed in-house and a PRESAGE™ gel dosimeter. We evaluated the dosimetric characteristics, including spectral absorption, dose linearity, reproducibility, and dose rate dependency of the two gel dosimeters. The non-scattering gel and the PRESAGE™ gel dosimeters showed peak sensitivity at wavelengths of 600 nm and 630 nm, respectively. Over a range of doses the best dose linearities of the non-scattering and the PRESAGE™ gel dosimeters resulted in R2 values of 0.99 at wavelengths of 600 nm and 630 nm, respectively. The reproducibility and dose-rate dependence of each of the two gel dosimeters were within the range of ±3 %. Our results revealed that the peak sensitivities of the two radiochromic gel dosimeters were significantly different; the in-house non-scattering gel dosimeter demonstrated peak sensitivity at a wavelength of 600 nm while the PRESAGE™ gel dosimeter had peak sensitivity at a wavelength of 630 nm. We confirmed that for 3D gel dosimetry, the in-house non-scattering gel dosimeter had a more stable dose response compared with a commercial non-scattering gel dosimeter.

  6. A simple convenient biological dosimeter for monitoring solar UV-B radiation

    SciTech Connect

    Wang, T.C. )

    1991-05-31

    The use of dry Bacillus subtilis spores as a biological dosimeter for the monitoring of solar UV-B (290-330 nm) radiation was described. Our field tests had supported the utility of this dosimeter as a reproducible and reliable sunlight dosimeter.

  7. Radix Bupleuri: A Review of Traditional Uses, Botany, Phytochemistry, Pharmacology, and Toxicology.

    PubMed

    Yang, Fude; Dong, Xiaoxv; Yin, Xingbin; Wang, Wenping; You, Longtai; Ni, Jian

    2017-01-01

    Radix Bupleuri (Chaihu) has been used as a traditional medicine for more than 2000 years in China, Japan, Korea, and other Asian countries. Phytochemical studies demonstrated that this plant contains essential oils, triterpenoid saponins, polyacetylenes, flavonoids, lignans, fatty acids, and sterols. Crude extracts and pure compounds isolated from Radix Bupleuri exhibited various biological activities, such as anti-inflammatory, anticancer, antipyretic, antimicrobial, antiviral, hepatoprotective, neuroprotective, and immunomodulatory effects. However, Radix Bupleuri could also lead to hepatotoxicity, particularly in high doses and with long-term use. Pharmacokinetic studies have demonstrated that the major bioactive compounds (saikosaponins a, b2, c, and d) were absorbed rapidly in rats after oral administration of the extract of Radix Bupleuri. This review aims to comprehensively summarize the traditional uses, botany, phytochemistry, pharmacology, toxicology, and pharmacokinetics of Radix Bupleuri reported to date with an emphasis on its biological properties and mechanisms of action.

  8. [Study on quality standard of oil-processed Radix Angelica sinensis].

    PubMed

    Yang, Hong-Shen; Hua, Yong-Li; Guo, Yan-Sheng; Du, Tian-Xi; Yang, Xiao-Hu; Qinh, Liang; Qu, Ya-Ling; Wei, Yan-Ming

    2010-06-01

    To establish the quality standard of oil-processed Radix Angelica sinensis. Combined traditional identification, TLC and fingerprints of wine-processed Radix Angelica sinensis to control quality of oil-processed Radix Angelica sinensis. And referring to China Pharmacopoeia of 2005 edition, water, ash, and extract were also detected. The content of water, total ash, extract representatively was 7.30%, 8.70% and 50.9%. Eleven fingerprint peaks were defined, The eleven common peaks were appointed as fingerprint peaks by analyzing 14 representative samples, all the fingerprint peaks were quantified grounded on the peak of Ferulic acid. and quantified rested on the peak of ferulic acid. A multicomponent quantitative method for oil-processed Radix Angelica sinensis is established. The established method is feasible. The quality control standards of the oil-processed Radix Angelica sinensis is normative, systematic and accurate.

  9. [Researches on pyretic pulmonary syndrome model interfered by Scutellariae Radix based on variation of biomarker].

    PubMed

    Liu, Shumin; Liu, Changfeng; Zu, Jinxiang; Li, Junhang; Wang, Na; Lu, Fang

    2011-05-01

    Metabonomics researches of Scutellariae Radix interfering pyretic pulmonary syndrome had been done, to determine the specific biomarkers of pyretic pulmonary syndrome, and to approach the mechanism that Scutellariae Radix interfered the variation of these biomarkers. Metabonomics technique, UPLC-Q-TOF/MS analytical means and PCA statistical methods were utilized to investigate the trajectory change and inter-relationship of urinary metabolome of rats treated differently. Six specific biomarkers were determined which could represent Streptococcus pneumoniae-induced pyretic pulmonary syndrome in rats. Scutellariae Radix could significantly adjust the ascended biomarkers to the normal level. Meanwhile two of these biomarkers were identified as Delta-12-prostaglandin J2 and indoxyl sulfate. There was a good therapeutic function of Scutellariae Radix on pyretic pulmonary syndrome, which was elucidated on the metabolic aspects. There was also a correlationship between the mechanism of Scutellariae Radix curing pyretic pulmonary syndrome and the six specific biomarkers.

  10. Radix Bupleuri: A Review of Traditional Uses, Botany, Phytochemistry, Pharmacology, and Toxicology

    PubMed Central

    Yang, Fude; Dong, Xiaoxv; Yin, Xingbin; Wang, Wenping; You, Longtai

    2017-01-01

    Radix Bupleuri (Chaihu) has been used as a traditional medicine for more than 2000 years in China, Japan, Korea, and other Asian countries. Phytochemical studies demonstrated that this plant contains essential oils, triterpenoid saponins, polyacetylenes, flavonoids, lignans, fatty acids, and sterols. Crude extracts and pure compounds isolated from Radix Bupleuri exhibited various biological activities, such as anti-inflammatory, anticancer, antipyretic, antimicrobial, antiviral, hepatoprotective, neuroprotective, and immunomodulatory effects. However, Radix Bupleuri could also lead to hepatotoxicity, particularly in high doses and with long-term use. Pharmacokinetic studies have demonstrated that the major bioactive compounds (saikosaponins a, b2, c, and d) were absorbed rapidly in rats after oral administration of the extract of Radix Bupleuri. This review aims to comprehensively summarize the traditional uses, botany, phytochemistry, pharmacology, toxicology, and pharmacokinetics of Radix Bupleuri reported to date with an emphasis on its biological properties and mechanisms of action. PMID:28593176

  11. Two Traditional Chinese Medicines Curcumae Radix and Curcumae Rhizoma: An Ethnopharmacology, Phytochemistry, and Pharmacology Review

    PubMed Central

    Zhou, Yang; Xie, Meng; Song, Yan; Wang, Wenping; Zhao, Haoran; Tian, Yuxin; Wang, Yan; Bai, Shaojuan; Zhao, Yichen; Chen, Xiaoyi; She, Gaimei

    2016-01-01

    Curcumae Rhizoma, known as Ezhu (Chinese: 莪术), and Curcumae Radix, known as Yujin (Chinese: 郁金), are different plant parts coming from three same species according to China Pharmacopoeia. Actually, they are used in different ways in TCM clinical treatment. Curcumae Rhizoma is mainly used as antitumor drug, while Curcumae Radix has been used as antidepressant and cholagogue. Curcumae Rhizoma and Curcumae Radix are confused in variety and source, even in clinical trials by some nonprofessional workers. So it is important for us to make them clear. This review is aimed at summarizing the ethnopharmacology, phytochemical, and pharmacological differences between Curcumae Radix and Curcumae Rhizoma by SciFinder, CNKI, and so on, to use them exactly and clearly. Further studies on Curcumae Rhizoma and Curcumae Radix can lead to the development of new drugs and therapeutics for various diseases on the basis of the TCM theory. PMID:27057197

  12. [Discussion of price forecasting of Notoginseng Radix et Rhizoma based on ARIMA model].

    PubMed

    Wang, Nuo; Cheng, Meng; Zang, Chun-Xin; Yang, Guang

    2016-04-01

    Based on the analysis of price fluctuations on Notoginseng Radix et Rhizoma, this paper takes advantage of the price data of Notoginseng Radix et Rhizoma which specification is 120 from January 2004 to August 2015, using autoregressive integrated moving average model [ARIMA (p, d, q)] forecasting the price of Notoginseng Radix et Rhizoma from September 2015 to August 2016. In the process of determining the form of model, the stability test used to determine the model of p, and the autocorrelation function and particles autocorrelation functions to identify the p and q of model. According to test the model, the forecast minimum error model was identified. In this paper, ARIMA (2,1,3) model was used to predict next year's price of Notoginseng Radix et Rhizoma, for providing information for Notoginseng Radix et Rhizoma growers, pharmaceutical companies. Copyright© by the Chinese Pharmaceutical Association.

  13. [Determination of trace elements in radix ophiopogonis by HG-ICP-AES].

    PubMed

    Lou, Qi-Zheng; Xu, Run-Sheng

    2007-06-01

    In this paper, a method of microwave digestion technique for the contents determination of trace elements Ni, Zn, Mn, Cu, Mg, Fe, Ca and Pb in radix ophiopogonis by hydride generation inductively coupled plasma atomic emition spectrometry (HG-ICP-AES) was reported. Its recovery ratio obtained by standard addition method ranged between 97.8% and 102.5%, and its RSD was lower than 4.0%. The results of the determination show that radix ophiopogonis is rich in the inorganic elements such as Fe, and the content of Zn in radix ophiopogonis of Zhejiang is much higher in radix ophiopogonis of Sichun. The result will provide scientific data for the study on the elements in radix ophiopogonis and on their relativity of medicine efficacy.

  14. Two Traditional Chinese Medicines Curcumae Radix and Curcumae Rhizoma: An Ethnopharmacology, Phytochemistry, and Pharmacology Review.

    PubMed

    Zhou, Yang; Xie, Meng; Song, Yan; Wang, Wenping; Zhao, Haoran; Tian, Yuxin; Wang, Yan; Bai, Shaojuan; Zhao, Yichen; Chen, Xiaoyi; She, Gaimei

    2016-01-01

    Curcumae Rhizoma, known as Ezhu (Chinese: ), and Curcumae Radix, known as Yujin (Chinese: ), are different plant parts coming from three same species according to China Pharmacopoeia. Actually, they are used in different ways in TCM clinical treatment. Curcumae Rhizoma is mainly used as antitumor drug, while Curcumae Radix has been used as antidepressant and cholagogue. Curcumae Rhizoma and Curcumae Radix are confused in variety and source, even in clinical trials by some nonprofessional workers. So it is important for us to make them clear. This review is aimed at summarizing the ethnopharmacology, phytochemical, and pharmacological differences between Curcumae Radix and Curcumae Rhizoma by SciFinder, CNKI, and so on, to use them exactly and clearly. Further studies on Curcumae Rhizoma and Curcumae Radix can lead to the development of new drugs and therapeutics for various diseases on the basis of the TCM theory.

  15. Antibiotic-Releasing Porous Polymethylmethacrylate/Gelatin/Antibiotic Constructs for Craniofacial Tissue Engineering

    PubMed Central

    Shi, Meng; Kretlow, James D.; Spicer, Patrick P.; Tabata, Yasuhiko; Demian, Nagi; Wong, Mark E.; Kasper, F. Kurtis; Mikos, Antonios G.

    2011-01-01

    An antibiotic-releasing porous polymethylmethacrylate (PMMA) construct was developed to maintain the bony space and prime the wound site in the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite craniofacial tissue defects. Porous polymethylmethacrylate (PMMA) constructs incorporating gelatin microparticles (GMPs) were fabricated by the sequential assembly of GMPs, the antibiotic colistin, and a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid. PMMA/gelatin/antibiotic constructs with varying gelatin incorporation and drug content were investigated to elucidate the relationship between material composition and construct properties (porosity and drug release kinetics). The porosity of PMMA/gelatin/antibiotic constructs ranged between 7.6±1.8–38.4±1.4% depending on the amount of gelatin incorporated and the drug solution added for gelatin swelling. The constructs released colistin over 10 or 14 days with an average release rate per day above 10 µg/ml. The porosity and in vitro colistin release kinetics of PMMA/gelatin/antibiotic constructs were tuned by varying the material composition and fabrication parameters. This study demonstrates the potential of gelatin-incorporating PMMA constructs as a functional space maintainer for both promoting tissue healing/coverage and addressing local infections, enabling better long-term success of the definitive regenerated tissue construct. PMID:21295086

  16. Computer-aided design and manufacture and rapid prototyped polymethylmethacrylate reconstruction.

    PubMed

    Turgut, Gürsel; Özkaya, Özay; Kayali, Mahmut Ulvi

    2012-05-01

    This article discusses the application of computer-aided design and rapid prototyping techniques in polymethylmethacrylate reconstruction of craniofacial bone defects. This method avoids the probability of tissue damage due to exothermic reaction during the polymerization process and provides precise implants that exactly fit the defects. A total of 11 patients who have various-sized craniofacial defects underwent polymethylmethacrylate reconstruction. We performed three-dimensional reconstruction and operative design using computer software. According to the design, we determined the shape and size of the implants and made individualized implants for craniofacial bone defects with the rapid prototyping technique. With the application of computer-aided design and a rapid prototyping technique, we could accurately determine the shape, size, and embedding location. Prefabricating the individual implant models is useful in improving the accuracy of treatment. No cases of infection, seroma, extrusion, or contour irregularity occurred as a complication, and all patients were satisfied with the results. During the follow-up period, ranging from 1 to 6 years, all patients remained satisfied, and no complications were sustained. In cases of various-sized cranial defects and complex maxillofacial defects that have enough soft tissue coverage and that do not have contact with a third space, prefabricated methyl methacrylate implants can be used safely. Patients will feel more comfortable if the postoperative shape resembles the original appearance, so the proposed algorithm effectively creates a customized implant.

  17. [Classification study on commodity specification and grade standard of Pseudostellariae Radix].

    PubMed

    Kang, Chuan-Zhi; Zhou, Tao; Guo, Lan-Ping; Han, Bang-Xing; Huang, Lu-Qi; Xiao, Cheng-Hong; Xiong, Hou-Xi; Chen, Xue-Mei

    2014-08-01

    To study the commodity specification and grade standard of Pseudostellaria Radix, for standardizing market order and achieving industrialization, standardization and modernization of Pseudostellariae Radix. The different areas and grade medicinal materials of Pseudostellariae Radix were respectively measured in quantitative characteristics of appearance, and the present grade classification of Pseudostellaria Radix was scientifically verified by the content of polysaccharide. Then the determination data were evaluated by spss correlation analysis, principal component analysis and cluster analysis. So combining with the actual production, the commodity grade standard of Pseudostellariae Radix was formulated. Correlation analysis indicated that the present grade classification of Pseudostellaria Radix was reasonable, and the more the grade of Pseudostellariae Radix was high, the more the content of polysaccharide was high. Meanwhile, length as a classification index was not suitable for the commodity grade standard of Pseudostellariae Radix. Using principal component analysis and cluster analysis, combining actual production, the thickest diameter, weight of single root tuber and the number of 50 g root tuber were filtrated and the grade was divided into 5 ranks: big, mid- dle, small selected goods, big ungraded goods and small ungraded goods. the commodity specification and grade standard of Pseudostellariae Radix that mainly included the thickest diameter, weight of single root tuber and the number of 50 g root tuber was formulated, the standard was divided into 5 grade. Each grade was not only consistent with the present situation of medicinal materials market, it could also reflected the intrinsic quality of Pseudostellariae Radix. In conclusion, the standard could be used as a classifica- tion basis to the commodity specification and grade.

  18. [Ecological environment of cultivated Astragali radix and market specification of prepared slices].

    PubMed

    Yu, Kunzi; Liu, Jing; Hong, Hao; Guo, Baolin; Cai, Shaoqing; Chen, Hubiao

    2010-05-01

    Astragali Radix is derived from roots of Astragalus membranaceus var. mongholicus and A. membranaceus. The exhaustion of wild Astragali Radix has made cultivated Astragali Radix possess the commercial market of Astragali Radix. So the ecological environment of cultivated Astragali Radix should be investigated through field survey. Through investigation, we found that A. membranaceus var. mongholicus are cultivated in Hengshan mountain of Shanxi province, Longnan of Gansu province, south of Inner Mongolia and Qinghai provinces. A. membranaceus var. mongholicus is almost planted on the plain, except in Shanxi province it grows on the sunny side of the mountain. What is more, soil type, elevation, annual temperature and annual rainfall of these locations are different. So the ecological environments of cultivated location of Astragali Radix are different from each other. A. membranaceus is wild in Heilongjiang and northeast of Inner Mongolia, but the resource is drying up. It is also planted in few places of the provinces of Shanxi, Shandong, Hebei, Gansu, but cultivated scope of A. membranaceus is smaller than A. membranaceus var. mongholicus.. So A. membranaceus var. mongholicus possesses large part of Astragali Radix market. In market, there exists no unified specification fro slices of Astragali Radix, and specification of prepared slices will influence the contents of chemical components. Through investigation, different kind of prepared slices can be collected and compared, this provides evidences for quality control of prepared slices. Through investigation, five different specifications of prepared slices were found in market. The distributions of some specification of prepared slices are specified, like transverseprepared slices prepared from A. membranaceus only found in Heilongjiang province. Transverse prepared slices possess half part of prepared slice market, and can be used to identify original plant of Astragali Radix. So transverse prepared slices

  19. Radix Bupleuri ameliorates depression by increasing nerve growth factor and brain-derived neurotrophic factor

    PubMed Central

    Wang, Xia; Feng, Qing; Xiao, Yong; Li, Ping

    2015-01-01

    Background: Chinese herb Radix Bupleuri has been regarded effective to improve treatment of depression, but the molecular mechanism remains unknown. Low levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) increase the likelihood of developing the depression. Therefore, we want to know whether Radix Bupleuri affects the levels of these factors. Methods: A total 160 hemodialysis patients were diagnosed with depression and randomly assigned to two groups: Radix Bupleuri group (received 1 g root power of Radix Bupleuri in a capsule daily Radix Bupleuri) and control group (receive placebo). Results: After three-month follow-up, the patients who received Radix Bupleuri had greater improvement in depression symptoms, anxiety symptoms and general functioning via controls after three-month follow-up (P < 0.05). Serum NGF levels were significantly higher in subjects accepted Radix Bupleuris (178.64 ± 52.18 pg/mL) when compared to a control (103.54 ± 31.23 pg/ml) (P < 0.01). Similarly, serum BDNF levels were significantly higher in subjects accepted Radix Bupleuris (1635.26 ± 121.66 pg/ml) when compared to a control (516.38 ± 44.89 pg/ml) (P < 0.01). The serum levels of NGF and BDNF were negatively related with Montgomery-Asberg Depression Rating Scale (MADRS) and positively related with scores of RAND-36 item Health Survey (RAND-36) (P < 0.01). Conclusion: Thus, Radix Bupleuri ameliorates the patients with depression by increasing serum levels of NGF and BDNF. Radix Bupleuri should be developed a new drug for the therapy of depression. PMID:26309578

  20. Deconnable self-reading pocket dosimeter containment with self-contained light

    DOEpatents

    Stevens, Robyn L.; Arnold, Greg N.; McBride, Ryan G.

    1996-01-01

    A container for a self-reading pocket dosimeter includes a transparent tube for receiving the self-reading pocket dosimeter, a light source mounted at one end of the transparent tube, and an eyepiece mounted on an opposite end of the transparent tube for viewing a read-out of the self-reading pocket dosimeter. The container may further include an activation device for selectively supplying power to the light source. The container both protects the dosimeter from being contaminated and provides a light source for viewing the dosimeter.

  1. Two methods for examining angular response of personnel dosimeters

    SciTech Connect

    Plato, P.; Leib, R.; Miklos, J.

    1988-06-01

    The American National Standard ANSI N13.11-1983 is used to test the accuracy (bias plus precision) of dosimetry processors as part of the dosimetry accreditation program of the National Voluntary Laboratory Accreditation Program (NVLAP). Section 3.8 of the ANSI N13.11-1983 standard requires that a study of the angular response of a dosimeter be carried out once, although no pass/fail criterion is given for angular response. The NVLAP accreditation program excluded Section 3.8, and thus no angular response data have been generated in an organized fashion. The objective of this project is to examine the feasibility of two alternative methods to test the angular response of personnel dosimeters. The first alternative involves static irradiations with the dosimeters at fixed angles to a radiation source. The second alternative involves dynamic irradiations with the dosimeters mounted on a rotating phantom. A Panasonic UD-802 personnel dosimetry system** was used to generate data to examine both alternatives. The results lead to two major conclusions. Firstly, Section 3.8 of the ANSI N13.11-1983 standard should be amended to require a pass/fail test for angular response. Secondly, a comparison between angular response data generated with a fixed or a rotating phantom shows that the rotating phantom is the more cost-effective method.

  2. Thin thermoluminescent dosimeter and method of making same

    DOEpatents

    Simons, Gale G.; DeBey, Timothy M.

    1987-01-01

    An improved thermoluminescent ionizing radiation dosimeter of solid, extremely thin construction for more accurate low energy beta dosimetry is provided, along with a method of fabricating the dosimeter. In preferred forms, the dosimeter is a composite including a backing support (which may be tissue equivalent) and a self-sustaining body of solid thermoluminescent material such as LiF having a thickness of less than about 0.25 millimeters and a volume of at least about 0.0125 mm.sup.3. In preferred fabrication procedures, an initially thick (e.g., 0.89 millimeters) TLD body is wet sanded using 600 grit or less sandpaper to a thickness of less than about 0.25 millimeters, followed by adhesively attaching the sanded body to an appropriate backing. The sanding procedure permits routine production of extremely thin (about 0.05 millimeters) TLD bodies, and moreover serves to significantly reduce non-radiation-induced thermoluminescence. The composite dosimeters are rugged in use and can be subjected to annealing temperatures for increased accuracy.

  3. Activation of Dosimeters Used in qa of Medical Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Polaczek-Grelik, Kinga; Nowacka, Magdalena; Raczkowski, Maciej

    2017-09-01

    This paper presents the first results of a project intended to investigate γ-radiation activity induced in dosimeters used in clinical practice during routine quality assurance of high-energy photon beams emitted by electron linear accelerators. Two aspects of the activation via photonuclear reactions (X, n) of therapeutic beam and subsequent capture of secondary neutrons (n,γ) are under considerations: the influence of activation on intrinsic background of the dosimeters and exposure of dosimetrists who operate this equipment. The activation of several types of ionization chambers as well as the silicon diodes was studied after long-time exposure (10 000 MUs) of the 15 MV photon beam (Elekta Synergy). Photon fluxes obtained from spectra of γ-rays registered by HPGe spectrometer were subsequently converted to equivalent doses using appropriate coefficients. The main contribution to the induced activity comes from the neutron capture process on Al, Mn and Cu, therefore it decays quite fast with the half-lives of the order of 15 minutes. Nevertheless, the activation of chlorine was also observed. The estimated equivalent doses to skin and eye lens were in the range 0.19 - 0.62 μSv/min. However, no influence on intrinsic background signal of all studied dosimeters was observed. The preliminary results indicate that induced radioactivity of dosimeters is strongly influenced by therapeutic beam quality and neutron source strength of particular linac. This dependence will be studied deeper in order to quantify it more precisely.

  4. Improvements in opti-chromic dosimeters for radiation processing

    NASA Astrophysics Data System (ADS)

    Humpherys, K. C.; Kantz, A. D.

    "Opti-Chromic" dosimeters consisting of radiachromic dye in flourinated polymer tubing have been introduced as a dosimetry system in the range from 10 1 to 5 × 10 4 Gy. Batches of "Opti-Chromic" dosimeters have been produced to evaluate performance under large scale industrial conditions. A systematic study was undertaken to determine the effect of various dosimeter parameters on radiation sensitivity, shelf life, and response characteristics at the higher absorbed doses. These parameters were (A) Type of flourinated polymer tubing; (B) Organic solvent used to activate the radiachromic dye; (C) Concentration of radiachromic dye; (D) Additives to provide proper viscosity, color stability, and high-dose response. Prototype batches were produced and experimental dosimeters exposed to a range of absorbed doses and the response measured as a function of shelf life and dose. The results of the study are presented, and an improved formulation recommended for application to Food Processing. Other formulations may be of value in specific requirements of sensitivity or temperature.

  5. Thin thermoluminescent dosimeter and method of making same

    SciTech Connect

    Simons, G.G.; DeBey, T.M.

    1987-01-13

    An improved thermoluminescent ionizing radiation dosimeter of solid, extremely thin construction for more accurate low energy beta dosimetry is provided, along with a method of fabricating the dosimeter. In preferred forms, the dosimeter is a composite including a backing support (which may be tissue equivalent) and a self-sustaining body of solid thermoluminescent material such as LiF having a thickness of less than about 0.25 millimeters and a volume of at least about 0.0125 mm[sup 3]. In preferred fabrication procedures, an initially thick (e.g., 0.89 millimeters) TLD body is wet sanded using 600 grit or less sandpaper to a thickness of less than about 0.25 millimeters, followed by adhesively attaching the sanded body to an appropriate backing. The sanding procedure permits routine production of extremely thin (about 0.05 millimeters) TLD bodies, and moreover serves to significantly reduce non-radiation-induced thermoluminescence. The composite dosimeters are rugged in use and can be subjected to annealing temperatures for increased accuracy. 1 fig.

  6. Validation of an Innovative Satellite-Based UV Dosimeter

    NASA Astrophysics Data System (ADS)

    Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

    2016-08-01

    We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

  7. Hanford Personnel Dosimeter supporting studies FY-1980. [Lead abstract

    SciTech Connect

    Endres, G.W.R.; Cummings, F.M.; Aldrich, J.M.; Thorson, M.R.; Kathren, R.L.

    1981-02-01

    Separate abstracts were prepared for the 10 sections of this report which describe fundamental characteristics of the Hanford multipurpose personnel dosimeter (HMPD). Abstracts were not prepared for Appendix A and Appendix B which deal with calculated standard deviations for 100 mrem mixed field exposures and detailed calculations of standard deviations, respectively. (KRM)

  8. Field test of fiber optic hydrazine dosimeters at Cape Canaveral

    NASA Astrophysics Data System (ADS)

    Klimcak, Charles M.; Chan, Y.; Jaduszliwer, B.

    1999-02-01

    We tested seventy-two hydrazine fuel fiber optic dosimeters for periods up to three months or Cape Canaveral in order to determine the effect of the local environment on its lifetime and sensitivity. The dosimeters were deployed at a diverse group of sites including fuel, oxidizer, and hydrocarbon fuel storage and transfer locations, a salt spray corrosion test facility, a satellite processing area, an estuarine marsh, a paint storage locker, and several indoor locations including chemical laboratory fume hoods and bathrooms. In addition, a group were set aside in a sealed enclosure for control purposes. The dosimeters were retrieved at monthly intervals and exposed to measured doses of hydrazine vapor to determine the effects of the field exposure on their hydrazine response. Our analysis indicated that 90% of the exposed dosimeters were able to sense hydrazine at a dose detectivity of less than 15 ppb-hr, a value that meets the current hydrazine sensing requirement. Consequently, we are planning to deploy a full scale, continuously operating fiber optic system for detecting potential hydrazine leaks during launch operations at Cape Canaveral.

  9. Portable battery-free charger for radiation dosimeters

    DOEpatents

    Manning, Frank W.

    1984-01-01

    This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter.

  10. Case reports and clinical guidelines for managing radix entomolaris

    PubMed Central

    Thomas, Bejoy J.; Nishad, A.; Paulaian, Benin; Sam, Jonathan Emil

    2016-01-01

    Knowledge about the external and internal anatomy of the tooth is essential for successful dental practice. Anomalies in the tooth are often encountered which poses difficulties in dental treatments. As like any other tooth, mandibular first molars are also prone for anatomic malformations. One such anatomic variation is the presence of extra root distolingually. This distolingual root is called radix entomolaris (RE). The presence of an additional root can lead to difficulties during endodontic therapy. This article is a report of two cases describing the management of the first mandibular molars with an RE and clinical guidelines for its management. PMID:27829770

  11. Pharmacological effects of Radix Angelica Sinensis (Danggui) on cerebral infarction

    PubMed Central

    2011-01-01

    Radix Angelica Sinensis, the dried root of Angelica sinensis (Danggui), is a herb used in Chinese medicine to enrich blood, promote blood circulation and modulate the immune system. It is also used to treat chronic constipation of the elderly and debilitated as well as menstrual disorders. Research has demonstrated that Danggui and its active ingredients, as anti-arthrosclerotic, anti-hypertensive, antioxidant anti-inflammatory agents which would limit platelet aggregation, are effective in reducing the size of cerebral infarction and improving neurological deficit scores. PMID:21867503

  12. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification

    PubMed Central

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%. PMID:28046056

  13. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification.

    PubMed

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting; Huang, Yung-Hui; Huang, David Y C

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%.

  14. a Thermally Desorbable Miniature Passive Dosimeter for Organic Vapors

    NASA Astrophysics Data System (ADS)

    Gonzalez, Jesus Antonio

    A thermally desorbable miniature passive dosimeter (MPD) for organic vapors has been developed in conformity with theoretical and practical aspects of passive dosimeter design. The device was optimized for low sample loadings resulting from short-term and/or low concentration level exposure. This was accomplished by the use of thermal desorption rather than solvent elution, which provided the GC method with significantly higher sensitivity. Laboratory evaluation of this device for factors critical to the performance of passive dosimeters using benzene as the test vapor included: desorption efficiency (97.2%), capacity (1400 ppm-min), sensitivity (7ng/sample or 0.06 ppmv for 15 minutes sampling) accuracy and precision, concentration level, environmental conditions (i.e., air face velocity, relative humidity) and sample stability during short (15 minutes) and long periods of time (15 days). This device has demonstrated that its overall accuracy meets NIOSH and OSHA requirements for a sampling and analytical method for the exposure concentration range of 0.1 to 50 ppm (v/v) and 15 minutes exposures. It was demonstrated that the MPD operates in accordance with theoretically predicted performance and should be adequate for short-term and/or low concentration exposure monitoring of organic vapors in the workplace. In addition a dynamic vapor exposure evaluation system for passive dosimeters have been validated using benzene as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for ceiling exposure monitoring.

  15. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    SciTech Connect

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  16. Radix Achyranthis Bidentatae improves learning and memory capabilities in ovariectomized rats☆

    PubMed Central

    Wang, Yuefen; Xu, Ya; Pan, Yanshu; Li, Weihong; Zhang, Wei; Liu, Yang; Jia, Jing; Li, Pengtao

    2013-01-01

    Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extracts may dose-dependently inhibit non-enzymatic saccharification in vitro. This study aimed to examine the effect of Radix Achyranthis Bidentatae on advanced glycation end products and on learning and memory capabilities in ovariectomized rats. Ovariectomized rats were treated with Radix Achyranthis Bidentatae alcohol extracts (containing 1.5 g/kg crude drug) or 0.1% aminoguanidine for 12 weeks and behavioral testing was performed with the Y-electrical maze. This test revealed that Radix Achyranthis Bidentatae and aminoguanidine could improve the learning and memory capabilities of ovariectomized rats. Results of competitive enzyme-linked immunosorbent assay showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine reduced the accumulation of advanced glycation end products in the frontal cortex of ovariectomized rats, while increasing content in the blood and urine. Biochemical tests showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine decreased superoxide dismutase activity in the serum and frontal cortex, and increased serum levels of glutathione peroxidase in ovariectomized rats. In addition, there was no apparent effect on malondialdehyde levels. These experimental findings indicate that Radix Achyranthis Bidentatae inhibits production of advanced glycation end products and its accumulation in brain tissue, and improves learning and memory capabilities in ovariectomized rats. These effects may be associated with an anti-oxidative action of the extract. PMID:25206461

  17. Radix Achyranthis Bidentatae improves learning and memory capabilities in ovariectomized rats.

    PubMed

    Wang, Yuefen; Xu, Ya; Pan, Yanshu; Li, Weihong; Zhang, Wei; Liu, Yang; Jia, Jing; Li, Pengtao

    2013-06-25

    Kidney-tonifying recipe can reduce the accumulation of advanced glycation end products, prevent neuronal degeneration and improve cognitive functions in ovariectomized rats. Radix Achyranthis Bidentatae alcohol extracts may dose-dependently inhibit non-enzymatic saccharification in vitro. This study aimed to examine the effect of Radix Achyranthis Bidentatae on advanced glycation end products and on learning and memory capabilities in ovariectomized rats. Ovariectomized rats were treated with Radix Achyranthis Bidentatae alcohol extracts (containing 1.5 g/kg crude drug) or 0.1% aminoguanidine for 12 weeks and behavioral testing was performed with the Y-electrical maze. This test revealed that Radix Achyranthis Bidentatae and aminoguanidine could improve the learning and memory capabilities of ovariectomized rats. Results of competitive enzyme-linked immunosorbent assay showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine reduced the accumulation of advanced glycation end products in the frontal cortex of ovariectomized rats, while increasing content in the blood and urine. Biochemical tests showed that treatment with Radix Achyranthis Bidentatae or aminoguanidine decreased superoxide dismutase activity in the serum and frontal cortex, and increased serum levels of glutathione peroxidase in ovariectomized rats. In addition, there was no apparent effect on malondialdehyde levels. These experimental findings indicate that Radix Achyranthis Bidentatae inhibits production of advanced glycation end products and its accumulation in brain tissue, and improves learning and memory capabilities in ovariectomized rats. These effects may be associated with an anti-oxidative action of the extract.

  18. Preventing Elevated Radix Deformity in Asian Rhinoplasty with a Chimeric Dorsal-Glabellar Construct

    PubMed Central

    Zelken, Jonathan A.; Hong, Joon Pio; Broyles, Justin M.; Hsiao, Yen-Chang

    2016-01-01

    Background Asian facial aesthetic surgery should enhance, but not change, natural features. Augmentation rhinoplasty is a hallmark of Asian cosmetic surgery. In the authors' experience, I-shaped implants can elevate and efface the radix, leading to an unnatural appearance (elevated radix deformity). Objectives The Chimeric technique was developed to control final radix position and preserve the nasal profile. We aim to demonstrate that the Chimeric technique promotes forward projection, not elevation, of the radix. Methods Between 2013 and 2015, 49 patients underwent rhinoplasty with I-shaped implants. Nineteen patients had Chimeric dorsal-glabellar implants, 30 did not. Standardized photographs were obtained at every visit. Novel and established photogrammetric parameters were used to describe radix position and position change. A retrospective chart review provided additional procedural details and outcomes data. Results Patients were followed for 10.8 months (range, 2-36 months). Nasal height increase (113% vs 107%) and bridge length increase (118% vs 105%) were significantly greater when the Chimeric technique was not performed (P < .0001). The nasofrontal angle increased 6° in both groups; there was no difference between groups. The vector of radix position change was 26.1° in the Chimeric group and 63.4° in the traditional group (P < .0001). Conclusions The Chimeric technique preserves the nasal profile with a favorable (horizontal) radix transposition vector. There was not a significant difference in final radix position when Chimeric rhinoplasty was performed because that is controlled by implant thickness and position. The technique did not blunt the radix significantly. Level of Evidence: 4 Therapeutic PMID:26879296

  19. Pharmacokinetic Pilot Study of the Antiangiogenic Activity of Standardized Platycodi Radix

    PubMed Central

    Twiner, Emma M.; Liu, Zhijun; Gimble, Jeffrey; Yu, Ying

    2014-01-01

    Introduction Platycodi radix is a radish used in food, such as Korean kimchi, and has been shown to cause weight loss in rodents. Platycodin D is considered its active ingredient and has been shown to inhibit lipases. The authors hypothesized that platycodi radix and the platycodin D it contains inhibit angiogenesis; another mechanism for weight loss. Methods This study tested platycodi radix extract, platycodin D, and an extract of platycodi radix standardized to platycodin D for their ability to inhibit angiogenesis in a human adipose tissue assay. This study treated five healthy volunteers, orally, with platycodi radix extract standardized to 414 mg of platycodin D. Three volunteers were treated under fasting conditions, one volunteer with a 400 kcal meal, and one volunteer treated with a placebo. Blood was drawn over 5 hours to compare serum inhibition of the human adipose tissue angiogenesis. Results Platycodin radix extract, platycodin D, and platycodi radix extract standardized to platycodin D all inhibited angiogenesis. The three volunteers who consumed platycodi radix extract standardized to 414 mg of platycodin D had a 25.76% reduction in angiogenesis from baseline at 60 minutes (P<0.002), and had a statistically significant reduction in angiogenesis from 30 to 240 minutes (P<0.05 to P<0.002). The placebo decreased angiogenesis by 5.6% between 30 and 240 minutes, compared with 17.8% by the extract. The meal delayed absorption by approximately 3.5 hours. Conclusion Platycodi radix extract standardized to platycodin D inhibited angiogenesis in human volunteers, and paves the way for a dose-response study and a human clinical obesity trial. PMID:21975926

  20. Surface energy changes produced by ultraviolet-ozone irradiation of poly(methylmethacrylate), polycarbone and polytetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Ponter, A. B.; Jones, W. R., Jr.; Jansen, R. H.

    1994-01-01

    Contact angles of water and methylene iodide were measured as a function of UV/O3 treatment time for three polymers: poly(methylmethacrylate) (PMMA), polycarbonate, and polytetrafluoroethylene (PTFE). Surface roughnesses were also measured. Surface free energies were then calculated using relationships developed by Kaelble and Neumann. The surface energy of polycarbonate was found to increase (60 percent) during UV/O3 treatment. However, calculations on PMMA were hampered by the formation of a water soluble surface product. On PTFE surfaces, the UV/O3 treatment etched the surface causing large increases in surface roughness, rendering contact angle measurements impossible. It is concluded that care must be taken in interpreting contact angle measurements and surface energy calculations on UV/O3 treated polymer surfaces.

  1. Tissue biocompatibility of kevlar aramid fibers and polymethylmethacrylate, composites in rabbits.

    PubMed

    Henderson, J D; Mullarky, R H; Ryan, D E

    1987-01-01

    Two groups of female NZW rabbits were implanted in the paravertebral muscles with aramid (du Pont Kevlar aramid 49) fibers and aramid-polymethylmethacrylate (PMMA) composites for 14 and 28 days. Rabbits were killed at these times periods, necropsies performed, sites scored for gross tissue response, and tissue specimens containing the implants removed for histopathological evaluation. A mild fibrous tissue reaction was observed around all implants containing aramid fiber similar to that observed around the silicone control implant. Some foreign body giant cells were also present adjacent to the fibers. An intense necrotic inflammatory reaction was present around the positive control material (PVC Y-78). The tissue response to implantation of aramid fiber and fiber-PMMA composites indicates that aramid is a biocompatible material.

  2. Reconstruction of bony facial contour deficiencies with polymethylmethacrylate implants: case report

    PubMed Central

    ABDO FILHO, Ruy C. C.; OLIVEIRA, Thais M.; LOURENÇO, Natalino; GURGEL, Carla; ABDO, Ruy C.C.

    2011-01-01

    Facial trauma can be considered one of the most serious aggressions found in the medical centers due to the emotional consequences and the possibility of deformity. In craniofacial surgery, the use of autologous bone is still the first choice for reconstructing bony defects or irregularities. When there is a shortage of donor bone or a patient refuses an intracranial operation, alloplastic materials such as polymethylmethacrylate (PMMA) can be used. The PMMA prosthesis can be pre-fabricated, bringing advantages such as reduction of surgical time, easy technical handling and good esthetic results. This paper describes the procedures for rehabilitating a patient with PMMA implants in the region of the face, recovering the facial contours and esthetics of the patient. PMID:21952926

  3. The WS2 quantum dot: preparation, characterization and its optical limiting effect in polymethylmethacrylate

    NASA Astrophysics Data System (ADS)

    Long, Hui; Tao, Lili; Chiu, Chun Pang; Tang, Chun Yin; Fung, Kin Hung; Chai, Yang; Tsang, Yuen Hong

    2016-10-01

    Due to the matching surface energy, WS2 quantum dots (QDs) can be obtained through direct liquid exfoliation in N-methyl-2-pyrrolidone rather than an ethanol and water mixture. Ultra-small WS2 QDs with a diameter of 2.4 nm are fabricated by an ultrasound method followed by high speed centrifugation up to 10 000 rpm. An excellent nonlinear optical (NLO) property of the WS2 QD/ polymethylmethacrylate (PMMA) composite for the nanosecond pulsed laser at both 532 and 1064 nm has been measured. Results illustrate the lower onset thresholds (F ON ), lower optical limiting thresholds (F OL ), and higher two-photon absorption coefficient (β) with respect to a higher concentration of embedded WS2 QDs into the PMMA solid state matrix for both 532 and 1064 nm.

  4. Manufacturing of embedded multimode waveguides by reactive lamination of cyclic olefin polymer and polymethylmethacrylate

    NASA Astrophysics Data System (ADS)

    Kelb, Christian; Rother, Raimund; Schuler, Anne-Katrin; Hinkelmann, Moritz; Rahlves, Maik; Prucker, Oswald; Müller, Claas; Rühe, Jürgen; Reithmeier, Eduard; Roth, Bernhard

    2016-03-01

    We demonstrate the manufacturing of embedded multimode optical waveguides through linking of polymethylmethacrylate (PMMA) foils and cyclic olefin polymer (COP) filaments based on a lamination process. Since the two polymeric materials cannot be fused together through interdiffusion of polymer chains, we utilize a reactive lamination agent based on PMMA copolymers containing photoreactive 2-acryloyloxyanthraquinone units, which allows the creation of monolithic PMMA-COP substrates through C-H insertion reactions across the interface between the two materials. We elucidate the lamination process and evaluate the chemical link between filament and foils by carrying out extraction tests with a custom-built tensile testing machine. We also show attenuation measurements of the manufactured waveguides for different manufacturing parameters. The lamination process is in particular suited for large-scale and low-cost fabrication of board-level devices with optical waveguides or other micro-optical structures, e.g., optofluidic devices.

  5. In vitro and in vivo evaluation of antibiotic diffusion from antibiotic-impregnated polymethylmethacrylate beads.

    PubMed

    Adams, K; Couch, L; Cierny, G; Calhoun, J; Mader, J T

    1992-05-01

    The elution of antibiotics from antibiotic-impregnated polymethylmethacrylate (PMMA) beads was measured in mongrel dogs. The antibiotics, used in mixture with Simplex cement, included cefazolin (Ancef; 4.5 g/40 g cement powder), ciprofloxacin (Cipro; 6 g/40 g powder), clindamycin (Cleocin; 6 g/40 g powder), ticarcillin (Ticar; 12 g/40 g powder), tobramycin (Nebcin; 9.8 g/40 g powder), and vancomycin (Vancocin; 4 g/40 g powder). After a pneumatic drill was used to dredge a trough in the tibia, five beads were implanted. During the next 28 days, seroma samples and serum samples were taken for antibiotic measurements. On Day 28, the dogs were killed, beads removed, and the seroma, serum, bone, and granulation tissue sampled. The results of the study showed that clindamycin, vancomycin, and tobramycin exhibited good elution characteristics and had consistently high levels in bone and granulation tissue.

  6. A study of laser-based removal of polymethylmethacrylate bone cement.

    PubMed

    O'Neill, W; Kapadia, P; Thomas, T

    1996-06-01

    Complications are often produced with the removal of bone cement from the femoral cavity in the treatment of a failed hip prosthesis. Apart from being slow and difficult the conventional process runs the risk of producing damage to the femur. Ultrasonic techniques have been suggested to achieve these ends but removal of the cement by this approach is not entirely easy. The alternative laser-based approach would seem to have significant advantages over conventional techniques. The laser is capable of delivering energy to a specific region or surface under close control. The choice of laser is determined by its ability to ablate the cement and the ease with which it can be delivered to the base of the femur cavity. This paper examines several laser wavelengths: CO2 (10.6 microns), excimer (248 nm), Hol:YAG (2.12 microns), and presents polymethylmethacrylate (PMMA) vaporization thresholds for each laser.

  7. Communication: Effect of density on the physical aging of pressure-densified polymethylmethacrylate

    NASA Astrophysics Data System (ADS)

    Casalini, R.; Roland, C. M.

    2017-09-01

    The rate of physical aging of glassy polymethylmethacrylate (PMMA), followed from the change in the secondary relaxation with aging, is found to be independent of the density, the latter controlled by the pressure during glass formation. Thus, the aging behavior of the secondary relaxation is the same whether the glass is more compacted or less dense than the corresponding equilibrium liquid. This equivalence in aging of glasses formed under different pressures indicates that local packing is the dominant variable governing the glassy dynamics. The fact that pressure densification yields different glass structures is at odds with a model for non-associated materials having dynamic properties exhibited by PMMA, such as density scaling of the relaxation time and isochronal superposition of the relaxation dispersion.

  8. Towards disposable lab-on-a-chip: poly(methylmethacrylate) microchip electrophoresis device with electrochemical detection.

    PubMed

    Wang, Joseph; Pumera, Martin; Chatrathi, Madhu Prakash; Escarpa, Alberto; Konrad, Renate; Griebel, Anja; Dörner, Wolfgang; Löwe, Holger

    2002-02-01

    A fully disposable microanalytical device based on combination of poly(methylmethacrylate) (PMMA) capillary electrophoresis microchips and thick-film electrochemical detector strips is described. Variables influencing the separation efficiency and amperometric response, including separation voltage or detection potential are assessed and optimized. The versatility, simplicity and low-cost advantages of the new design are coupled to an attractive analytical performance, with good precision (relative standard deviation RSD = 1.68% for n = 10). Applicability for assays of mixtures of hydrazine, phenolic compounds, and catecholamines is demonstrated. Such coupling of low-cost PMMA-based microchips with thick-film electrochemical detectors holds great promise for mass production of single-use micrototal analytical systems.

  9. Communication: Effect of density on the physical aging of pressure-densified polymethylmethacrylate.

    PubMed

    Casalini, R; Roland, C M

    2017-09-07

    The rate of physical aging of glassy polymethylmethacrylate (PMMA), followed from the change in the secondary relaxation with aging, is found to be independent of the density, the latter controlled by the pressure during glass formation. Thus, the aging behavior of the secondary relaxation is the same whether the glass is more compacted or less dense than the corresponding equilibrium liquid. This equivalence in aging of glasses formed under different pressures indicates that local packing is the dominant variable governing the glassy dynamics. The fact that pressure densification yields different glass structures is at odds with a model for non-associated materials having dynamic properties exhibited by PMMA, such as density scaling of the relaxation time and isochronal superposition of the relaxation dispersion.

  10. Photoreactive phase conjugation strength in disperse red 1 doped poly(methylmethacrylate) thin films

    NASA Astrophysics Data System (ADS)

    Liu, Sean; Wang, Wei Lin; Fang, Chien Cheng; Huang, Tzer-Hsiang; Hsu, Chia Chen

    2005-01-01

    Near-resonant optical pumping was used to modulate third-order susceptibility χ(3) in disperse red 1 doped poly(methylmethacrylate) thin films. An optically pumped degenerate four-wave mixing (DFWM) experiment was conducted to examine the photoreactive phase conjugation (PC) signals. Experimental results indicated a large anisotropy in PC signals arising from ∣χ3333(3)∣2, and almost isotropic PC signals from ∣χ1331(3)∣2 under s-polarized and p-polarized pump fields. Additionally, a dynamic microscopic model, based on the theory developed by Sekkat et al.[Synth. Met. 54, 373 (1993); J. Phys. Chem. B 106, 12407 (2002); Opt. Commun. 229, 291 (2004)] was presented to describe the observed optical nonlinear responses. Results from the model were generally consistent with those of the optically pumped DFWM experiment.

  11. Residual gentamicin-release from antibiotic-loaded polymethylmethacrylate beads after 5 years of implantation.

    PubMed

    Neut, Daniëlle; van de Belt, Hilbrand; van Horn, Jim R; van der Mei, Henny C; Busscher, Henk J

    2003-05-01

    In infected joint arthroplasty, high local levels of antibiotics are achieved through temporary implantation of non-biodegradable gentamicin-loaded polymethylmethacrylate beads. Despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow and potentially develop antibiotic resistance. In routine clinical practice, these beads are removed after 14 days, but for a variety of reasons, we were confronted with a patient in which these beads were left in situ for 5 years. Retrieval of gentamicin-loaded beads from this patient constituted an exceptional case to study the effects of long-term implantation on potentially colonizing microflora and gentamicin release. Gentamicin-release test revealed residual antibiotic release after being 5 years in situ and extensive microbiological sampling resulted in recovery of a gentamicin-resistant staphylococcal strain from the bead surface. This case emphasizes the importance of developing biodegradable antibiotic-loaded beads as an antibiotic delivery system. Copyright 2003 Elsevier Science Ltd.

  12. [Effect on quality of Scrophulariae Radix with modern drying technology].

    PubMed

    Li, Hui-wei; Liu, Pei; Qian, Da-wei; Lu, Xue-jun; Guo, Sheng; Zhu, Zhen-hua; Duan, Jin-ao

    2015-11-01

    Modern drying technology was used to explore suitable drying process to provide scientific basis for improving drying processing methods of Scrophulariae Radix. Controlled temperature and humidity drying, vacuum drying apparatus, microwave vacuum drying apparatus, short infrared drying device were used to gain samples for analyzing. The character appearance, concentration of main components and power consumption indicators were chosen for preliminary judging. Six major components, including iridoids and phenylpropanoids were analyzed by UPLC-MS/MS method. The contents of polysaccharides were determined by UV-visible spectrophotometry. The character appearance with controlled temperature and humidity drying and short infrared drying meet the pharmacopoeia standard (Ch. p, edition 2015), while samples with vacuum and microwave vacuum drying apparatus didn't. Compared to fresh sample, concentrations of harpagide, harpagoside, aucubin and catalpol were lower in the dried samples. Angoroside-C showed no significant change before and after drying. Concentration of acteoside increased after drying. Samples with controlled temperature (70 degrees C) and humidity (15% - 10%) drying had high content and short drying time. The better drying process of Scrophulariae Radix was controlled temperature and humidity drying. The method will provide the reference for the drying technology standard of roots medicine.

  13. Importance of wine-treated Angelica Sinensis Radix in Si Wu Tang, a traditional herbal formula for treating women's ailments.

    PubMed

    Zhan, Janis Y X; Zheng, Ken Y Z; Zhu, Kevin Y; Zhang, Wendy L; Bi, Cathy W C; Chen, J P; Du, Crystal Y Q; Dong, Tina T X; Lau, David T W; Tsim, Karl W K

    2013-05-01

    Si Wu Tang (Four Agents Decoction), a traditional Chinese decoction composed of Angelica Sinensis Radix, Chuanxiong Rhizoma, Paeoniae Radix Alba, and Rehmanniae Radix Praeparata in a ratio of 1 : 1 : 1 : 1, has been used to treat women's diseases for more than a thousand years. According to the original description of Si Wu Tang, Angelica Sinensis Radix should be treated with wine. However, the importance of this wine-treated Angelica Sinensis Radix in Si Wu Tang's function has not been identified. In this article, the chemical and biological properties of two decoctions processed in different ways (Si Wu Tang with crude Angelica Sinensis Radix and Si Wu Tang with wine-treated Angelica Sinensis Radix) were compared for examination. The herbal decoction Si Wu Tang prepared from wine-treated Angelica Sinensis Radix contained much different amounts of its active compounds. Compared with Si Wu Tang using crude Angelica Sinensis Radix, Si Wu Tang prepared from wine-treated Angelica Sinensis Radix had better biological responses. Therefore, these findings accentuate the functional importance of herbs treated with wine in the Chinese decoction.

  14. Modified ferrous ammonium sulfate benzoic acid xyelenol orange (MFBX) and thermoluminescent dosimeters--a comparative study.

    PubMed

    Brindha, S; Rose, J V R; Sathyan, S; Singh I, Rabi Raja; Ravindran, B Paul

    2002-06-07

    Radiation dosimetry deals with the determination of absorbed dose to the medium exposed to ionizing radiation. Chemical dosimetry depends on oxidation or reduction of chemicals by ionizing radiation. A ferrous ammonium sulfate benzoic acid xyelenol orange (FBX) dosimeter based on this principle is being used as a clinical dosimeter at present. Certain modifications were carried out in the preparation and storage of the FBX dosimeter to increase its shelf life. The resulting dosimeter was called a modified FBX (MFBX) dosimeter and has been used in our department for the past few years. An extensive study of the dose, dose rate and energy response of the dosimeter was carried out and compared with a thermoluminescent (LiF7) dosimeter. The results obtained were found to be comparable to the thermoluminescent (LiF7) dosimeter. Hence it was concluded that the MFBX dosimeter could be used for phantom dosimetry, data collection and in vivo measurements. Easier preparation and availability of the reagents are added advantages of using MFBX as a clinical dosimeter in small radiotherapy departments.

  15. The high dose response and functional capability of the DT-702/Pd lithium fluoride thermoluminescent dosimeter.

    PubMed

    Lawlor, Tyler M; Talmadge, Molly D; Murray, Mark M; Nelson, Martin E; Mueller, Andrew C; Romanyukha, Alexander A; Fairchild, Gregory R; Grypp, Matthew D; Williams, Anthony S

    2015-05-01

    The United States Navy monitors the dose its radiation workers receive using the DT-702/PD thermoluminescent dosimeter, which consists of the Harshaw 8840 holder and the four-element Harshaw 8841 card. There were two main objectives of this research. In the first objective, the dosimeters were exposed to 100 Gy using electron and x-ray beams and found to respond approximately 30-40% lower than the delivered dose. No significant effect on the under-response was found when dose rate, radiation type, dosimeter position on the phantom, and dosimeter material were varied or when the card was irradiated while enclosed in its holder. Since the current naval policy is to remove from occupational use any thermoluminescent dosimeter with an accumulated deep dose equivalent of 0.05 Sv or greater, the functionality of the dosimeter was also investigated at deep dose equivalents of 0.05, 0.15, and 0.25 Sv using 60Co and 137Cs sources as the second main objective. All dosimeters were annealed following exposure and then exposed to 5.0 mSv from a 90Sr source. In all cases, the dosimeters responded within 3% of the delivered dose, indicating that the dosimeters remained functional as defined by naval dosimetry requirements. However, the anneal time required to clear the thermoluminescent dosimeter's reading was found to increase approximately as the cube root with the delivered dose.

  16. [Effects of Radix Ginseng and Radix Ophiopogonis extract (SMF) on protein S-nitrosylation in ischemic myocardial tissue].

    PubMed

    Feng, Jin-hong; Shi, Qiang; Wang, Yi; Cheng, Yi-yu

    2008-08-01

    To observe the effect of Radix Ginseng and Radix Ophiopogonis extract (SMF) on protein S-nitrosylation in rats myocardial with ischemia/reperfusion injury (MI/RI). Myocardial ischemia/reperfusion in rats were produced by occlusion of the left anterior descending coronary artery. To study the cardioprotective effects of SMF on the acute MI/RI rats, the serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), and nitric oxide (NO) were determined. The change of the expression of endothelial nitric oxide synthase (eNOS) was detected by Western blot. The content of related S-nitrosylation proteins in myocardial tissue was measured by Biotin-Switch method. SMF significantly decreased the serum levels of CK and LDH as well as increased the serum levels of NO and the expression of eNOS in myocardial tissue. The contents of S-nitrosylation proteins were significantly increased from (4.42 +/- 0.60) micromol x g(-1) to (8.78 +/- 1.37) micromol x g(-1). The molecular weight of the majority S-nitrosylation proteins were in the range of 90 x 10(3)-117 x 10(3). Increased expression of eNOS and NO induced by SMF may activate S-nitrosylation of many proteins in rat hearts. The change of the activities or functions of those proteins by S-nitrosylation may be an important mechanism for myocardial protective effects of SMF.

  17. Fricke Gel Dosimeter Tissue-Equivalence a Monte Carlo Study

    NASA Astrophysics Data System (ADS)

    Valente, M.; Bartesaghi, G.; Gambarini, G.; Brusa, D.; Castellano, G.; Carrara, M.

    2008-06-01

    Gel dosimetry has proved to be a valuable technique for absorbed dose distribution measurements in radiotherapy. FriXy-gel dosimeters consist of Fricke (ferrous sulphate) solution infused with xylenol orange. The solution is incorporated to a gel matrix in order to fix it to a solid structure allowing good spatial resolution and is imaged with a transportable optical system, measuring visible light transmittance before and after irradiation. This paper presents an evaluation of total photon mass attenuation coefficients at energies in the range of 50 keV-10MeV for the radiochromic FriXy gel dosimeter sensitive material. Mass attenuation coefficient estimations have been performed by means of Monte Carlo (PENELOPE) simulations. These calculations have been carried out for the FriXy gel sensitive material as well as for soft tissue (ICRU) and pure liquid water; a comparison of the obtained data shows good agreement between the different materials.

  18. A new electronic neutron dosimeter (END) for reliable personal dosimetry

    NASA Astrophysics Data System (ADS)

    Ing, H.; Cousins, T.; Andrews, H. R.; Machrafi, R.; Voevodskiy, A.; Kovaltchouk, V.; Clifford, E. T. H.; Robins, M.; Larsson, C.; Hugron, R.; Brown, J.

    2008-04-01

    Tests of existing electronic neutron dosimeters by military and civilian groups have revealed significant performance limitations. To meet the operational requirements of emergency response personnel to a radiological/nuclear incident as well as those in the nuclear industry, a new END has been developed. It is patterned after a unique commercial neutron spectral dosemeter known as the N-probe. It uses a pair of small special scintillators on tiny photomultiplier tubes. Special electronics were designed to minimize power consumption to allow for weeks of operation on a single charge. The size, performance, and data analysis for the END have been designed to meet/exceed international standards for electronic neutron dosimeters. Results obtained with the END prototype are presented.

  19. A genipin-gelatin gel dosimeter for radiation processing

    NASA Astrophysics Data System (ADS)

    Davies, J. B.; Bosi, S. G.; Baldock, C.

    2012-08-01

    Genipin, a fruit extract from Gardenia jasminoides Ellis, forms cross-links in solutions of gelatin, to form a blue hydrogel that bleaches quantitatively upon irradiation and the colour change can be measured with a spectrophotometer. With the addition of sulphuric acid this dosimeter is sufficiently sensitive for quality assurance of radiotherapy level dosimetry. Without sulphuric acid the gel has a reduced sensitivity and responds linearly with dose between 100 and 1000 Gy, making it potentially useful as a dosimeter for radiation processing applications such as the phytosanitary irradiation treatment of food. We investigated the dose response characteristics of this new formulation and found that the darker gels are more sensitive to dose and have a reduced uncertainty.

  20. [Residuals of organochlorine pesticides and heavy metals in Radix Ophiopogonis and Ophiopogon japonicus growing soil].

    PubMed

    Zhang, Lianting; Guo, Qiaosheng; Ye, Zhengliang

    2010-05-01

    To determine the residues of organochlorine pesticides and heavy metals in Radix Ophiopogonis and Ophiopogon japonicus. The residues of 4 isomers of benzene hexa chloride (BHC) and 4 isomers of dichloro dipheny trichloroethane (DDT) were determined by gas chromatography. The contents of Pb, Cd, Cu, Cr, Hg and As were determined by ICP. The residues of organochlorine pesticides in Radix Ophiopogonis were lower than the permissible maximum limits of the Chinese national standard except hexachloride (BHC) in Radix Ophiopogonis from Cixi as well as Cu in soil of Luojiang. The enrichment capacity of Radix Ophiopogonis for (BHC) and Hg is higher. It is suggested that we should try to select herbs-growing soil for O. japonicus with a particular emphasis on the pesticides residues in soil.

  1. [Effects of Radix Ophiopogonis decoction on embryo-fetal development in rats].

    PubMed

    Zhang, Min; Liu, Xiaomeng; Song, Jie; Hu, Yanping; Wang, Xiuwen; Li, Bo

    2010-09-01

    To investigate the potential developmental toxicity of Radix Ophiopogonis decoction in SD rats. Timed-pregnant SD rats were given Radix Ophiopogonis decoction (26.9 g x kg(-1)) or vehicle (distilled water) by gavage on gestation days 6-17. Maternal clinical sign, abortions, premature deliveries, and body weight were monitored throughout gestation. At termination (gestation days 20) pregnant females were evaluated for clinical status and gestational outcome; live fetuses were examined for gender, external, visceral and skeletal malformation and variations. No deaths, premature deliveries or dose-related clinical signs were attributed to Radix Ophiopogonis decoction. Maternal body weight and body weight gain were not affected. There were no effects on fetus weight and viability, incidences of fetal malformation and variation. These results demonstrated that Radix Ophiopogonis decoction had no detectable adverse effects in either the treated F0 female rats or the fetuses.

  2. [Analysis of vitamins and inorganic elements in the water extracts of Radix Changii].

    PubMed

    Chen, Jian-Wei; Li, Xiang; Zhao, Hou-Min

    2004-09-01

    To study the material basis of the tonifying effect of Radix Changii by observing its contents of nutrient elements. The contents of vitamins in Radix Changii and inorganic elements in the water extracts of it were tested by high performance liquid chromatography, fluorescence spectrophotography and scanning electron microanalysis. Radix Changii contains fat-soluble vitamins E and K 259.2 and 64.1 microg/kg respectively, and water-soluble vitamins C, B1 and B2 78.5, 0.6 and 0.7 mg/kg respectively. Its decoction contains abundant potassium and calcium ions. Radix Changii is rich in elements necessary for human body. It has the material basis for tonification.

  3. An optical dosimeter for monitoring heavy metal ions in water

    NASA Astrophysics Data System (ADS)

    Mignani, Anna G.; Regan, Fiona; Leamy, D.; Mencaglia, A. A.; Ciaccheri, L.

    2005-05-01

    This work presents an optochemical dosimeter for determining and discriminating nickel, copper, and cobalt ions in water that can be used as an early warning system for water pollution. An inexpensive fiber optic spectrophotometer monitors the sensor's spectral behavior under exposure to water solutions of heavy metal ions in the 1-10 mg/l concentration range. The Principal Component Analysis (PCA) method quantitatively determines the heavy metals and discriminates their type and combination.

  4. Fricke dosimeter gel measurements of the profiles of shielded fields.

    PubMed

    Pirani, Luis F; Moreira, Marcos V; Costa, Jhonatha J L; Oliveira, Lucas N; Caldas, Linda V E; de Almeida, Adelaide

    2013-12-01

    In radiation therapy, the shielding of normal tissue can be made using Cerrobend® blocks or a multileaf collimator. In this work, profiles of shielded fields collimated by Cerrobend blocks were obtained through the Fricke Xylenol Gel (FXG) dosimeter irradiated with 6 MV photon beams. The results show that the FXG system can be used in profile measurements of small fields in radiotherapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Thermal stability of kudzu root (Pueraria Radix) isoflavones as additives to beef patties.

    PubMed

    Kumari, S; Raines, J M; Martin, J M; Rodriguez, J M

    2015-03-01

    Kudzu root, Pueraria radix, extracts are a rich source of isoflavones. This study investigates the thermal stability of Pueraria radix extracts as a natural nutraceutical supplement in beef patties. The extract contained puerarin, diadzin, genistin, ononin, daidzein, glycitein, calycosin, genistein, formononetin and biochanin A; however, puerarin, daidzein and glycitein were the main components. The isoflavones concentrations in the spiked beef patties with kudzu root extracts were unaffected by cooking.

  6. A hyperglycemic silkworm model for evaluating hypoglycemic activity of Rehmanniae Radix, an herbal medicine.

    PubMed

    Matsumoto, Yasuhiko; Sekimizu, Kazuhisa

    2016-02-01

    Silkworm shows hyperglycemia after intake of diet containing large amount of glucose. The hyperglycemic silkworm model is useful for evaluation of anti-diabetic drugs. A hot water extract of Rehmanniae Radix, an herbal medicine, showed hypoglycemic effect against the hyperglycemic silkworms. This method is applicable for quick and simple evaluation of the hypoglycemic activities of different batches of Rehmanniae Radix. Our findings suggest that silkworms have a lot of merit as experimental animals for evaluation of various herbal medicines.

  7. Method for preparing dosimeter for measuring skin dose

    DOEpatents

    Jones, Donald E.; Parker, DeRay; Boren, Paul R.

    1982-01-01

    A personnel dosimeter includes a plurality of compartments containing thermoluminescent dosimeter phosphors for registering radiation dose absorbed in the wearer's sensitive skin layer and for registering more deeply penetrating radiation. Two of the phosphor compartments communicate with thin windows of different thicknesses to obtain a ratio of shallowly penetrating radiation, e.g. beta. A third phosphor is disposed within a compartment communicating with a window of substantially greater thickness than the windows of the first two compartments for estimating the more deeply penetrating radiation dose. By selecting certain phosphors that are insensitive to neutrons and by loading the holder material with neutron-absorbing elements, energetic neutron dose can be estimated separately from other radiation dose. This invention also involves a method of injection molding of dosimeter holders with thin windows of consistent thickness at the corresponding compartments of different holders. This is achieved through use of a die insert having the thin window of precision thickness in place prior to the injection molding step.

  8. Accelerator room photoneutron and photon background measurements using thermoluminescent dosimeters.

    PubMed

    Anderson, D W; Hwang, C C

    1983-02-01

    Photoneutron dose equivalents and photon doses in the treatment room of a clinical linear accelerator were measured with sets of isotopically enriched LiF thermoluminescent dosimeters and a moderating sphere. Dosimeter neutron calibrations with 252Cf sources were repeated many times during the extended series of measurements because the 6LiF dosimeter sensitivity increased with successive neutron irradiations. Expressed as a fraction of the primary bremsstrahlung beam dose at maximum, the photoneutron background was 2.04 +/- 0.05 mrem/rad (10(-3) Sv/Gy) at 1 m lateral to beam center in the patient midplane at 25 MV. The fraction of this result due to thermal neutrons was found to be only about 2%. The photon background dose was 2.98 +/- 0.04 mrad/rad (10(-3) Gy/Gy). The photoneutron dose equivalent per unit primary dose was found to be nearly independent of the collimator size used but increased by 40% when the bremsstrahlung endpoint energy was increased from 20 to 35 MeV with no change in flattening filters.

  9. Real-time dosimeter targeted to nuclear applications

    NASA Astrophysics Data System (ADS)

    Correia, Alexandre; Rosa, Carla C.; Santos, Pedro M. P.; Falcão, António N.; Lorentz, Katharina

    2014-08-01

    An intrinsic fiber optic dosimeter (FOD) targeted to nuclear applications is presented. The proposed real-time dosimeter provides dose information based on the historic record over time of the effects of ionizing radiation on single- and multimode pure silica fibers, and also on PMMA plastic fibers. The effect of 60Co gamma irradiation on optical links based on silica and plastic fibers were assessed, considering thermal environment effects over a wide range of variation of the operating parameters. Cerenkov radiation and radiation-induced absorption effects were in focus. The corresponding distortion and spectral transmission degradation were evaluated over wide range of the operating parameters. Radiation induced attenuation (RIA) has shown a spectral band dependent behaviour up to 840 Gy dose levels. The performance of different fibers was assessed against the performance of non-irradiated fibers. From the measurements of dose rate and total dose imparted by ionizing radiation in the fibers we verified that fibers with radiation resistance issues showed wavelength-dependent radiation sensitivity increasing with dose rate. Upon evaluation of correlations between the total dose, the induced loss at various dose rates and different wavelengths, it was concluded that intrinsic fiber dosimeters can be used for dose rates in the range 4 - 28 Gy/min., typical of severe radiation environments.

  10. Polymer gel dosimeters with PVA-GA matrix.

    PubMed

    Abtahi, Seyed Mohammad Mahdi; Sadeghi Abandansari, Hamid

    2017-07-27

    Properties of a new polymer gel with cross-linked polyvinyl alcohol as a gelatinous matrix were investigated. The new polymer gel dosimeter was named PVABAT. The irradiation was performed using a calibrated (60)Co beam. The dose responses of the PVABAT formulations were quantified with MRI transverse relaxation rate (R2) measurements. The results show that the PVABAT gel responds linearly to the absorbed dose for doses from 30 up to 45 Gy. The maximal amount of [Formula: see text] of PVABAT polymer gel dosimeter was about 0.19 Gy which was indicated on a better resolution in comparison with previously reported acrylamide-based polymer gel dosimeters formulations. Furthermore, the gel response remains stable in the investigated time (192 h) after the irradiation. The effective atomic number and electron density of the new gel showed a maximum difference of 3.2 and 2% with soft tissue respectively. The melting point also increased significantly for new formulation. Furthermore, the new gel formulation has an elemental tissue equivalency for dosimetry applications involving nuclear reactions.

  11. Dosimeter for measuring skin dose and more deeply penetrating radiation

    DOEpatents

    Jones, Donald E.; Parker, DeRay; Boren, Paul R.

    1981-01-01

    A personnel dosimeter includes a plurality of compartments containing thermoluminescent dosimeter phosphors for registering radiation dose absorbed in the wearer's sensitive skin layer and for registering more deeply penetrating radiation. Two of the phosphor compartments communicate with thin windows of different thicknesses to obtain a ratio of shallowly penetrating radiation, e.g. beta. A third phosphor is disposed within a compartment communicating with a window of substantially greater thickness than the windows of the first two compartments for estimating the more deeply penetrating radiation dose. By selecting certain phosphors that are insensitive to neutrons and by loading the holder material with netruon-absorbing elements, energetic neutron dose can be estimated separately from other radiation dose. This invention also involves a method of injection molding of dosimeter holders with thin windows of consistent thickness at the corresponding compartments of different holders. This is achieved through use of a die insert having the thin window of precision thickness in place prior to the injection molding step.

  12. [Study on industrialized production technology of fresh-cut for Paeonia radix alba].

    PubMed

    Jin, Chuanshan; Li, Suliang; Wu, Deling; Zhang, Wei

    2011-12-01

    To optimize the objective technical parameter for direct processing technology of fresh-cut for Paeonia Radix Alba. Peoniflorin and TGP were employed as the indexes of quality evaluation. Combining with the appearance of the slices, we investigated the influence of slice degree and thickness, drying temperature, drying time, drying method and other factors on the quality control of Paeonia Radix Alba slices. Furthermore, the key fresh-cut technology operating procedures parameter for Paeonia Radix Alba in Bozhou was established based on the semi-works production. It established tentatively the method for fresh-out and fresh-out after boiled of Paeonia Radix Alba as that selected fresh or beiled Paeonia Radix Alba, then divided them from different grades and put them into a roller to crash off the skin, cleaned and then dried them 9 h at 60 degrees C (water content 28% - 32%), and then moistened 2-3 h after spraying moderate water. Cut them into 1.5-2 mm decoction pieces and dried them at 60 degrees C, cooled, and sealed them in a package. The industrialization of processing decoction pieces with freshly cut Paeonia Radix Alba is stable shortens processing time, avoids effectively sulfur fumigation and infiltrating and soften, and keep high quality of production.

  13. Surface-enhanced Raman spectroscopy study of radix astragali based on soxhlet extractor

    NASA Astrophysics Data System (ADS)

    Lu, Peng; Lin, Juqiang; Liu, Nengrong; Shao, Yonghong; Wang, Jing; Shi, Wei; Lin, Jinyong; Chen, Rong

    2012-12-01

    Due to its high sensitivity, flexibility, and "fingerprints" sensing capability, Surface-enhanced Raman Spectroscopy (SERS) is a very powerful method for characterization of substances. In this paper, two kinds of Radix Astragali with different quality were firstly extracted through continuous circumfluence extraction method and then mixed with silver nanoparticles for SERS detection. Most Raman bands obtained in Radix Astragali extraction solution are found at 300-7000cm-1 and 900-1390 cm-1. Although, major peak positions at 470, 556, 949, 1178 and 1286 cm-1 found in these two kinds of Radix Astragali appear nearly the same, Raman bands of 556 and 1178 cm-1 are different in intensity, thus may be used as a characteristic marker of Radix Astragali quality. In detail, we can make full use of the different intensity of two different kinds but the same state at 556 cm-1 to describe the quality standard of Radix Astragali. Our preliminary results show that SERS combining with continuous circumfluence extraction method may provide a direct, accurate and rapid detection method of Radix Astragali.

  14. Mechanisms of improvement of intestinal transport of baicalin and puerarin by extracts of Radix Angelicae Dahuricae.

    PubMed

    Liang, Xin-Li; Zhang, Jing; Zhao, Guo-Wei; Li, Zhe; Luo, Yun; Liao, Zheng-Gen; Yan, Dong-Mei

    2015-02-01

    Radix Angelicae Dahuricae is the dried root of Angelicae Dahurica (Fisch.ex Hoffm.)Benth.et Hook.f. var.formosana (Boiss.) Shan et Yuan (Fam.Umbelliferae). The total coumarins (Cou) and volatile oil (VO) were main active components that drived from Radix Angelicae Dahuricae. Our previous studies have shown that Cou and VO could increase intestinal absorption for transmucosal drug delivery with unknown mechanism. The aim of this study was to investigate the molecular mechanism of Radix Angelicae Dahuricae for improving drug intestinal transport. Caco-2 cell model was used to study the effect of Radix Angelicae Dahurica on transepithelial electrical resistance. Western blot was used to study its effect on the expression of the actin and ZO-1, tight junction proteins. The effect of Radix Angelicae Dahurica on the expression of P-gp protein was investigated using flow cytometry. VO (0.036-2.88 μL/mL) and Cou (0.027-0.54 mg/mL) caused a reversible, time- and dose-dependent decrease in transepithelial electrical resistance. VO and/or Cou could inhibit the expression of the tight junction protein, ZO-1 and actin. VO and/or Cou also could inhibit the expression of P-gp. These data suggested that Radix Angelicae Dahurica increased cell permeability by affecting the expression of actin, ZO-1 or P-gp, opening the tight junction or inhibiting the efflux induced by P-gp.

  15. Research progress of Chinese herbal medicine Radix isatidis (banlangen).

    PubMed

    Zhou, Wei; Zhang, Xiao-Yan

    2013-01-01

    Radix isatidis (R. isatidis) (Banlangen) is a traditional Chinese medicine (TCM) famous for its broad antiviral activity. Its clinical medical history spans several thousands of years in China. Many scientists and scholars have conducted systematic research on this herb from its pharmacognosy to pharmaceuticals, especially in China. Through our research and literature reports, we inferred that the antiviral activity of R. isatidis mostly depended on the water-soluble part, including amino acids, IRPS, nucleosides, and sulfur-containing alkaloids. By playing a role in directly killing pathogenic viruses or regulating the immune system to enhance anti-virus ability, R. isatidis's biological activities mostly depend on the synergistic effect of its multiple components. This article aims to expand understanding of R. isatidis in the following aspects including medicinal resources, chemical constituents, pharmacological activities, clinical applications, and separation and analytical technologies.

  16. Investigation of radiological properties and water equivalency of PRESAGE dosimeters

    SciTech Connect

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Adamovics, John; Bosi, Stephen; Kim, Jung-Ha; Baldock, Clive

    2011-04-15

    Purpose: PRESAGE is a dosimeter made of polyurethane, which is suitable for 3D dosimetry in modern radiation treatment techniques. Since an ideal dosimeter is radiologically water equivalent, the authors investigated water equivalency and the radiological properties of three different PRESAGE formulations that differ primarily in their elemental compositions. Two of the formulations are new and have lower halogen content than the original formulation. Methods: The radiological water equivalence was assessed by comparing the densities, interaction probabilities, and radiation dosimetry properties of the three different PRESAGE formulations to the corresponding values for water. The relative depth doses were calculated using Monte Carlo methods for 50, 100, 200, and 350 kVp and 6 MV x-ray beams. Results: The mass densities of the three PRESAGE formulations varied from 5.3% higher than that of water to as much as 10% higher than that of water for the original formulation. The probability of photoelectric absorption in the three different PRESAGE formulations varied from 2.2 times greater than that of water for the new formulations to 3.5 times greater than that of water for the original formulation. The mass attenuation coefficient for the three formulations is 12%-50% higher than the value for water. These differences occur over an energy range (10-100 keV) in which the photoelectric effect is the dominant interaction. The collision mass stopping powers of the relatively lower halogen-containing PRESAGE formulations also exhibit marginally better water equivalency than the original higher halogen-containing PRESAGE formulation. Furthermore, the depth dose curves for the lower halogen-containing PRESAGE formulations are slightly closer to that of water for a 6 MV beam. In the kilovoltage energy range, the depth dose curves for the lower halogen-containing PRESAGE formulations are in better agreement with water than the original PRESAGE formulation. Conclusions: Based

  17. The Assessment of Effective Dose Equivalent Using Personnel Dosimeters

    NASA Astrophysics Data System (ADS)

    Xu, Xie

    From January 1994, U.S. nuclear plants must develop a technically rigorous approach for determining the effective dose equivalent for their work forces. This dissertation explains concepts associated with effective dose equivalent and describes how to assess effective dose equivalent by using conventional personnel dosimetry measurements. A Monte Carlo computer code, MCNP, was used to calculate photon transport through a model of the human body. Published mathematical phantoms of the human adult male and female were used to simulate irradiation from a variety of external radiation sources in order to calculate organ and tissue doses, as well as effective dose equivalent using weighting factors from ICRP Publication 26. The radiation sources considered were broad parallel photon beams incident on the body from 91 different angles and isotropic point sources located at 234 different locations in contact with or near the body. Monoenergetic photons of 0.08, 0.3, and 1.0 MeV were considered for both sources. Personnel dosimeters were simulated on the surface of the body and exposed to with the same sources. From these data, the influence of dosimeter position on dosimeter response was investigated. Different algorithms for assessing effective dose equivalent from personnel dosimeter responses were proposed and evaluated. The results indicate that the current single-badge approach is satisfactory for most common exposure situations encountered in nuclear plants, but additional conversion factors may be used when more accurate results become desirable. For uncommon exposures involving source situated at the back of the body or source located overhead, the current approach of using multi-badges and assigning the highest dose is overly conservative and unnecessarily expensive. For these uncommon exposures, a new algorithm, based on two dosimeters, one on the front of the body and another one on the back of the body, has been shown to yield conservative assessment of

  18. Highland cattle and Radix labiata, the hosts of Fascioloides magna

    PubMed Central

    2014-01-01

    Background Fascioloides magna is a pathogenic fluke introduced to Europe ca 140 years ago. As it is spreading over the continent, new intermediate and definitive hosts might be involved in transmission of the parasite. In Europe, several studies reported potential new intermediate snail hosts (Radix spp.) for F. magna, and also several cases of fascioloidosis of wild and domestic animals were published. However, the data based on molecular and histological analyses confirming these findings remained unreported. This study aims to refer to unique findings of F. magna in European snails and domestic animals (the first observation in the Czech Republic in the last 30 years) and demonstrate the use of molecular techniques in determination of F. magna. Results Two snails of R. labiata naturally infected with F. magna were found; mature cercariae and daughter rediae were observed. Maturity of cercariae was checked by histological methods, however, their ability to encyst was not confirmed. Co-infection of F. magna and Fasciola hepatica in the liver of two highland cattle bulls was proved. Adult fasciolid flukes producing eggs were found in the liver pseudocysts (F. magna) and the bile ducts (F. hepatica). Identification of intermediate hosts, intramolluscan stages, adult flukes and eggs was performed by sequencing the ITS2 region. Connection of F. magna pseudocysts with the gut (via the bile ducts) was not confirmed by means of histological and coprological examinations. Conclusions For the first time, Radix labiata was confirmed as the snail host for F. magna under natural conditions and, together with the finding of F. magna infection in cattle, we can expect further transmission of F. magna from wildlife to livestock in localities shared by these hosts. PMID:24517409

  19. Design of Interrogation Protocols for Radiation Dose Measurements Using Optically-Stimulated Luminescent Dosimeters.

    PubMed

    Abraham, Sara A; Kearfott, Kimberlee J; Jawad, Ali H; Boria, Andrew J; Buth, Tobias J; Dawson, Alexander S; Eng, Sheldon C; Frank, Samuel J; Green, Crystal A; Jacobs, Mitchell L; Liu, Kevin; Miklos, Joseph A; Nguyen, Hien; Rafique, Muhammad; Rucinski, Blake D; Smith, Travis; Tan, Yanliang

    2017-03-01

    Optically-stimulated luminescent dosimeters are capable of being interrogated multiple times post-irradiation. Each interrogation removes a fraction of the signal stored within the optically-stimulated luminescent dosimeter. This signal loss must be corrected to avoid systematic errors in estimating the average signal of a series of optically-stimulated luminescent dosimeter interrogations and requires a minimum number of consecutive readings to determine an average signal that is within a desired accuracy of the true signal with a desired statistical confidence. This paper establishes a technical basis for determining the required number of readings for a particular application of these dosimeters when using certain OSL dosimetry systems.

  20. Performance evaluation of diagnostic radiology dosimeters in clinical and calibration x-ray beams.

    PubMed

    Hourdakis, Costantine John; Boziari, Argyro; Manetou, Aggeliki

    2010-05-01

    Diagnostic radiology dosimeters should comply with International Electrotechnical Commission (IEC) 61674 standard in order to perform measurements with sufficient accuracy and reliability. The calibration of a dosimeter is performed under, and pertains to, reference conditions. However, in most cases, dosimeters are used for clinical measurements under non-reference conditions. The performance, in terms of accuracy of dose measurements, of six commercial diagnostic radiology dosimeters was tested at reference calibration and at clinical non-reference conditions. The results showed that all dosimeters being tested exhibited limits of variation within the +/-5% IEC limits. Depending on the detector's physical and operational properties, the dosimeters' energy dependence of response values varied from -4.7% to +4.2%. To address this variation of response, calibration at three radiation qualities (RQR 3, RQR 5, and RQR 9), at least, is recommended. Different irradiation conditions such as air kerma rate, x-ray tube design, x-ray system, and dosimeter operational modes affect the dosimeters' response by less than 3%. A dosimeter that complies with IEC standards and operates according to its specifications could be used at typical clinical irradiation conditions taking into account only corrections for the energy dependence of response. In this case, the error in dose accuracy is expected to be less than 3%.

  1. Cranioplasty by means of molded polymethylmethacrylate prosthetic reconstruction after radical excision of neoplasms of the skull in two dogs.

    PubMed

    Bryant, Karen J; Steinberg, Howard; McAnulty, Jonathan F

    2003-07-01

    Two dogs with osteoma or multilobulated tumor of bone of the skull were treated with large en bloc resections. The resections resulted in exposure of the brain above the horizon line of the remaining calvarium; in 1 dog, the removal of the dorsal orbital rims also exposed both orbits dorsally. Protection of the brain and exposed tissues and restoration of the cosmetic appearance of the skull were attempted by use of molded polymethylmethacrylate prosthetic reconstruction of the calvarium. The technique described involves cranioplasty by use of a preformed molded polymethylmethacrylate implant. Such prosthetic cranioplasty may benefit dogs undergoing radical excision of extensive tumors, and the usefulness and potential complications of its application are discussed.

  2. In vitro study of adhesive polymethylmethacrylate bone cement bonding to cortical bone in maxillofacial surgery.

    PubMed

    Smeets, Ralf; Marx, Rudolf; Kolk, Andreas; Said-Yekta, Sareh; Grosjean, Maurice B; Stoll, Christian; Tinschert, Joachim; Wirtz, Dieter C; Riediger, Dieter; Endres, Kira

    2010-12-01

    In the treatment of midface fractures, the fragments are immobilized using screws and plates for osteosynthesis until reunion has occurred. This method involves drilling holes for the insertion of the screws, which can be associated with additional fracturing of the corresponding bone owing to the complex architecture and thin layers of facial bone. To alleviate this problem, new adhesive techniques for fixing the plates for osteosynthesis have been investigated, mitigating the detrimental effects of screw hole drilling. In the present experimental study, the strength of this adhesive bond and its resistance to hydrolysis were investigated. To determine the adhesive bonding strength, a tension test was implemented. Osteosynthesis plates with screw holes 1.3 mm in diameter were fixed to cortical bone samples of bovine femur using ultraviolet (UV) light-curing polymethylmethacrylate bone cement. To facilitate bonding, the surface of the bone was conditioned with an amphiphilic bonding agent before cementing. UV light curing was implemented using either a conventional UV unit, such as is used in dentistry, or with a specialized UV unit with a limited emission spectrum but high luminosity. Reference control samples were prepared without application of the bone bonding agent. After this procedure, the samples were stored for 1 to 7 days at 37°C submerged in 0.9% saline solution before being subjected to the tension test. Without the bone bonding agent, the bonding strength was 0.2 MPa. The primary average bonding strength at day 0 was 8.5 MPa when cured with the conventional UV unit and 14 MPa for the samples cured with the specialized UV unit. An almost constant average bond strength of 8 and 16 MPa was noted for all samples stored up to 7 days after curing with the conventional and specialized UV unit, respectively. With the development of a new bone bonding agent, a method is now available to promote the bonding between the hydrophilic bone surface and the

  3. Neodymium: YAG laser damage threshold. A comparison of injection-molded and lathe-cut polymethylmethacrylate intraocular lenses.

    PubMed

    Wilson, S E; Brubaker, R F

    1987-01-01

    The possibility that injection-molded intraocular lenses (IOLs) with imperfections called iridescent clefts could have a decreased threshold to neodymium: YAG (Nd:YAG) laser-induced damage was investigated. Thresholds for Nd:YAG laser-induced damage were determined for injection-molded and lathe-cut polymethylmethacrylate lenses. When aimed at a membrane in contact with a posterior convex surface, the average thresholds were 0.96 +/- 0.18 mJ (Standard deviation [SD]) and 1.80 +/- 0.55 mJ, respectively. The difference was significant at P = 0.001. When injection-molding polymethylmethacrylate was used to make lathe-cut IOLs, very few iridescent clefts were present, and the threshold to Nd:YAG laser-induced damage was 0.94 +/- 0.25 mJ. Iridescent clefts are therefore produced during the injection-molding process but they do not lower the threshold to Nd:YAG laser-induced damage. Rather, the reduced threshold in injection-molded lenses is most probably a result of the polymethylmethacrylate used in their manufacture. Clinically, iridescent clefts in a lens suggest that it has been manufactured by an injection-molding process and that Nd:YAG laser posterior capsulotomy must be performed at the lowest possible energy level to avoid damage.

  4. Physicochemical properties and mineralization assessment of porous polymethylmethacrylate cement loaded with hydroxyapatite in simulated body fluid.

    PubMed

    Sa, Yue; Yang, Fang; de Wijn, Joost R; Wang, Yining; Wolke, Joop G C; Jansen, John A

    2016-04-01

    The aim of this study was to evaluate the effect of carboxymethylcellulose (CMC) as a pore generator and hydroxyapatite (HA) as an osteoconductive agent on the physicochemical properties and in-vitro mineralization ability of porous polymethylmethacrylate (PMMA) cement. To this end, various compositions of PMMA cements, which differed in amount of millimeter-sized hydroxyapatite (HA) particles and CMC hydrogel, were prepared and immersed into simulated body fluid (SBF) for 0, 7, 14, 21 and 28 days. It was demonstrated that the incorporation of CMC hydrogel decreased the maximum temperature of cement to the normal body temperature and prolonged the handling time during polymerization. Further, the amount of CMC was responsible for the creation of porosity and interconnectivity, which in turn determined the final mechanical properties of cements. The loaded HA particles enhanced the potential bioactivity of cement for bone ingrowth. Albeit different amount of HA particles influenced their final exposures on the surface of cured cement, all of the three amounts of HA did not weaken the final mechanical properties of cements. The data here suggests that the HA particle loaded porous PMMA cement can serve as the promising candidate for bone reconstruction. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Polymethylmethacrylate (PMMA) Material Test Results for the Capillary Flow Experiments (CFE)

    NASA Technical Reports Server (NTRS)

    Lerch, Bradley A.; Thesken, John C.; Bunnell, Charles T.

    2007-01-01

    In support of the Capillary Flow Experiments (CFE) program, several polymethylmethacrylate (PMMA) flight vessels were constructed. Some vessels used a multipiece design, which was chemically welded together. Due to questions regarding the effects of the experiment fluid (silicone oil) on the weld integrity, a series of tests were conducted to provide evidence of the adequacy of the current vessel design. Tensile tests were conducted on PMMA samples that were both in the as-received condition, and also aged in air or oil for up to 8 weeks. Both welded and unwelded samples were examined. Fracture of the joints was studied using notched tensile specimens and Brazilian disk tests. Results showed that aging had no effect on tensile properties. While the welded samples were weaker than the base parent material, the weld strength was found to be further degraded by bubbles in the weld zone. Finally a fracture analysis using the worst-case fracture conditions of the vessel was performed, and the vessel design was found to have a factor of three safety margin.

  6. Contact angle analysis on polymethylmethacrylate and commercial wax by using an environmental scanning electron microscope.

    PubMed

    Brugnara, Marco; Della Volpe, Claudio; Siboni, Stefano; Zeni, Dario

    2006-01-01

    The environmental scanning electron microscope (ESEM) represents one of the most exciting breakthroughs in electron microscopy since the invention of the electron microscope. Its ability to observe uncoated and hydrated samples enhances the possibility for investigating the wettability of surfaces at a microscopic level; by varying the relative vapour pressure or the temperature inside the chamber, it is possible to condense water drops on a micron scale. A large problem in measuring contact angles by ESEM is that the observation angle is not parallel or perpendicular to the surface; thus, the study of the droplets profile using the common algorithms such as spherical approximation or axisymmetric drop shape analysis (ADSA) is not possible, because only a spherical cap shape is commonly observed. In this paper we provide a useful mathematical model to calculate the real contact angle from the initial images. Initially, some simulated spherical caps with different contact and observation angles were created by an appropriate graphic package in order to test the mathematical model. Some real drops obtained by ESEM on wax and polymethylmethacrylate (PMMA) were then studied and the results compared with contact angles measured by common methods on the same materials.

  7. Ultrasonic Characterization of the Curing Process of Polymethylmethacrylate-based Bone Cement Modified with Hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Viano, Ann; Auwarter, Julie; Hoffmeister, Brent; Rho, Jae-Young

    2000-03-01

    The use of polymethylmethacrylate (PMMA)-based bone cement for implantation of metallic prostheses is becoming increasingly common. Failure of a cemented prosthesis often occurs when there is weak bonding at the bone/cement or cement/metal interface. The addition of hydroxyapatite (HA) particles, a synthetically produced version of the natural mineral in bone, may improve the adhesion by promoting bone growth into the cement itself. The curing time of PMMA bone cement determines the speed of implant insertion, which can affect the mechanical strength of the cement. Pure PMMA has a well-characterized curing time of 9-12 minutes, depending on environmental factors such as temperature and humidity. By measuring the propagation of ultrasonic pulses through a sample of bone cement, the curing process can be monitored. As the material hardens, the velocity of an ultrasonic pulse increases, and the attenuation decreases. These parameters were measured as a function of time for PMMA mixed with 0, 10 and 30investigation of the curing process as a function of hydroxyapatite concentration.

  8. The elution of colistimethate sodium from polymethylmethacrylate and calcium phosphate cement beads.

    PubMed

    Waterman, Paige; Barber, Melissa; Weintrob, Amy C; VanBrakle, Regina; Howard, Robin; Kozar, Michael P; Andersen, Romney; Wortmann, Glenn

    2012-06-01

    Gram-negative bacilli resistance to all antibiotics, except for colistimethate sodium (CMS), is an emerging healthcare concern. Incorporating CMS into orthopedic cement to treat bone and soft-tissue infections due to these bacteria is attractive, but the data regarding the elution of CMS from cement are conflicting. The in vitro analysis of the elution of CMS from polymethylmethacrylate (PMMA) and calcium phosphate (CP) cement beads is reported. PMMA and CP beads containing CMS were incubated in phosphate-buffered saline and the eluate sampled at sequential time points. The inhibition of the growth of a strain of Acinetobacter baumannii complex by the eluate was measured by disk diffusion and microbroth dilution assays, and the presence of CMS in the eluate was measured by mass spectroscopy. Bacterial growth was inhibited by the eluate from both PMMA and CP beads. Mass spectroscopy demonstrated greater elution of CMS from CP beads than PMMA beads. The dose of CMS in PMMA beads was limited by failure of bead integrity. CMS elutes from both CP and PMMA beads in amounts sufficient to inhibit bacterial growth in vitro. The clinical implications of these findings require further study.

  9. Characterization and performance of injection molded poly(methylmethacrylate) microchips for capillary electrophoresis.

    PubMed

    Nikcevic, Irena; Lee, Se Hwan; Piruska, Aigars; Ahn, Chong H; Ridgway, Thomas H; Limbach, Patrick A; Wehmeyer, K R; Heineman, William R; Seliskar, Carl J

    2007-06-22

    Injection molded poly(methylmethacrylate) (IM-PMMA), chips were evaluated as potential candidates for capillary electrophoresis disposable chip applications. Mass production and usage of plastic microchips depends on chip-to-chip reproducibility and on analysis accuracy. Several important properties of IM-PMMA chips were considered: fabrication quality evaluated by environmental scanning electron microscope imaging, surface quality measurements, selected thermal/electrical properties as indicated by measurement of the current versus applied voltage (I-V) characteristic and the influence of channel surface treatments. Electroosmotic flow was also evaluated for untreated and O2 reactive ion etching (RIE) treated surface microchips. The performance characteristics of single lane plastic microchip capillary electrophoresis (MCE) separations were evaluated using a mixture of two dyes-fluorescein (FL) and fluorescein isothiocyanate (FITC). To overcome non-wettability of the native IM-PMMA surface, a modifier, polyethylene oxide was added to the buffer as a dynamic coating. Chip performance reproducibility was studied for chips with and without surface modification via the process of RIE with O2 and by varying the hole position for the reservoir in the cover plate or on the pattern side of the chip. Additionally, the importance of reconditioning steps to achieve optimal performance reproducibility was also examined. It was found that more reproducible quantitative results were obtained when normalized values of migration time, peak area and peak height of FL and FITC were used instead of actual measured parameters.

  10. Possible migration and histopathological analysis of injections of polymethylmethacrylate in wistar rats.

    PubMed

    Neves, Rodrigo d'Eça; Herdt, Marcello Alberton; Wohlgemuth, Felipe Barbieri; Ely, Jorge Bins; de Vasconcellos, Zulmar Antonio Accioli; Bastos, José Caldeira Ferreira; d'Acampora, Armando José

    2012-01-01

    Objective. To evaluate the possible migration of polymethylmethacrylate after injections in various corporal compartments of Wistar rats. Methods. The experimental work consisted in the injection of PMMA in corporal compartments for later histopathological analysis of the locations of implants and of distant filtering organs. The dose applied in each implant was of 0.2 mL. The animals were divided into groups according to the location of the implant realized: group GB had intradermic injections in the glabella. Group SD had subdermal injections in dorsal subcutaneous tissue cells. Group IP had intraperitoneal injections in the abdomen. Group PD had intramuscular injections in the right rear leg. The rats were sacrificed 30 days after realization of the implants and tissue samples from the lung, liver, spleen, and kidney, and locations of implantation were removed for histopathological analysis. Results. Characteristic microspheres that were compatible with the presence of PMMA in any of the histological slides analyzed were not observed. One animal had an amorphous exogenous substance, with a histiocytic reaction. Twelve of the 16 lungs analyzed had locations of intraalveolar hemorrhaging. Two animals had nonspecific spleen alterations. Conclusion. The histopathological analysis of this study found no PMMA microspheres in any of the tissues analyzed.

  11. Patterning of ultrathin polymethylmethacrylate films by in-situ photodirecting of the Marangoni flow

    NASA Astrophysics Data System (ADS)

    Elashnikov, Roman; Fitl, Premysl; Svorcik, Vaclav; Lyutakov, Oleksiy

    2017-02-01

    Laser heating and Marangoni flow result in the formation of surface structures with different geometries and shape on thin polymer films. By laser beam irradiation combined with a sample movement the solid polymethylmethacrylate (PMMA) films are heated and undergo phase transition which leads to a material flow. Since the laser beam has a non-linear distribution of energy, the PMMA film is heated inhomogeneously and a surface tension gradient in a lateral direction is introduced. During this procedure additional phenomena such as "reversible" or cyclic polymer flow also take place. The careful choice of experimental conditions enables the preparation of patterns with sophisticated geometries and with hierarchical pattern organization. Depending on initial PMMA film thickness and speed of the sample movement line arrays are created, which can subsequently be transformed into the crimped lines or system of circular holes. In addition, the introduction of a constant acceleration in the sample movement or a laser beam distortion enables the preparation of regularly crimped lines, ordered hexagonal holes or overlapped plates.

  12. Near Surface Vapor Bubble Layers in Buoyant Low Stretch Burning of Polymethylmethacrylate

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L.; Tien, J. S.

    1999-01-01

    Large-scale buoyant low stretch stagnation point diffusion flames over solid fuel (polymethylmethacrylate) were studied for a range of aerodynamic stretch rates of 2-12/ sec which are of the same order as spacecraft ventilation-induced stretch in a microgravity environment. An extensive layer of polymer material above the glass transition temperature is observed. Unique phenomena associated with this extensive glass layer included substantial swelling of the burning surface, in-depth bubble formation, and migration and/or elongation of the bubbles normal to the hot surface. The bubble layer acted to insulate the polymer surface by reducing the effective conductivity of the solid. The reduced in-depth conduction stabilized the flame for longer than expected from theory neglecting the bubble layer. While buoyancy acts to move the bubbles deeper into the molten polymer, thermocapillary forces and surface regression both act to bring the bubbles to the burning surface. Bubble layers may thus be very important in low gravity (low stretch) burning of materials. As bubbles reached the burning surface, monomer fuel vapors jetted from the surface, enhancing burning by entraining ambient air flow. Popping of these bubbles at the surface can expel burning droplets of the molten material, which may increase the fire propagation hazards at low stretch rates.

  13. Deep proton writing with 12 MeV protons for rapid prototyping of microstructures in polymethylmethacrylate

    NASA Astrophysics Data System (ADS)

    Ebraert, Evert; Gökçe, Berkcan; Van Vlierberghe, Sandra; Vervaeke, Michael; Meyer, Pascal; Guttmann, Markus; Dubruel, Peter; Thienpont, Hugo; Van Erps, Jürgen

    2016-10-01

    Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer microstructures. We use polymethylmethacrylate (PMMA) substrates, which act as a positive resist, for irradiation with a collimated 12-MeV energy proton beam. Using 12 MeV enables the irradiation of increasingly thick PMMA substrates with less conicity of the sidewalls compared to the lower energies used in previous work. A microhole of 47.7 μm diameter over a depth of 1 mm is achieved, leading to a maximum aspect ratio of 21∶1. The sidewalls of the irradiated structures show a slightly conical shape and their root-mean-square surface roughness is lower than 50 nm averaged over 72 measured areas of 56 μm×44 μm. This means that DPW components have optical surface quality sidewalls for wavelengths larger than 400 nm. Based on the trade-off among the sidewall roughness, conicity, and the development time, we determine that the optimal proton fluence for 12-MeV DPW in PMMA is 7.75×106 μm-2. Finally, we discuss some high aspect ratio microstructures with optical surface quality that were created with DPW to be used for a myriad of applications, such as micromirrors, microlenses, optofluidic devices, and high-precision alignment structures for single-mode optical fiber connectors.

  14. Impregnation of glass fibres with polymethylmethacrylate using a powder-coating method

    NASA Astrophysics Data System (ADS)

    Vallittu, Pekka K.

    1995-01-01

    The aim of this study was to evaluate the usefulness of a powder-coating method to impregnate glass fibres with polymethylmethacrylate (PMMA) for dental purposes. The continuous unidirectional E-glass fibres, the surface of which had been treated with precured silane, were powder-coated with spherical PMMA particles. Before the powder-coated prepregs were used, the incorporated PMMA powder was dissolved with methylmethacrylate monomer. The degree of impregnation of the polymerized composite was determined with a scanning electron microscope. The results revealed that the mean degree of impregnation varied from 0.87 to 0.92, being lower in the heat-cured PMMA group (which simulated fabrication of a new denture), and higher in the autopolymerizing group (which simulated the repair of a fractured denture). The means between the two groups did not, however, differ significantly ( p=0.249). The results suggest that, even though the method has some shortcomings in terms of dental laboratory technology, the powder-coating method can be used to fabricate or repair acrylic resin-based dentures.

  15. A prospective study of non-surgical primary rhinoplasty using a polymethylmethacrylate injectable implant.

    PubMed

    Rivkin, Alexander

    2014-03-01

    Nonsurgical rhinoplasty involves the use of injectable fillers to improve the contours of the nose. It has become a widely practiced procedure since this author first popularized it in 2003. The use of permanent fillers in nonsurgical rhinoplasty has not been well documented, especially in this country. To demonstrate the safety and effectiveness of a polymethylmethacrylate (PMMA)-based filler for nonsurgical rhinoplasty. Eligible subjects underwent up to three injection sessions with a commercially available PMMA product and were followed for 1 year. Efficacy was assessed according to evaluator grading of subjects and digital image analysis of standardized photographs. Nineteen subjects were enrolled and followed to conclusion. Average improvement in global score was more than one point observed on day 90 and lasting through 1 year. Eight of 10 subjects showed improvement according to digital image analysis at 1 year. Subject satisfaction was high throughout the study. Adverse events were minimal and well tolerated. Filler rhinoplasty using a PMMA-based injectable filler is safe and effective. This is the first study documenting the use of PMMA for this indication. Longer-term follow-up is needed to demonstrate persistence of improvement. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  16. Synergistic toxicity of gentamicin- and nanosilver-doped polymethylmethacrylate bone cement on primary human osteoclasts.

    PubMed

    Pauksch, Linda; Franke, Jörg; Schnettler, Reinhard; Lips, Katrin S

    2014-01-01

    Bacterial colonization of implant surfaces is a feared complication in surgery and orthopedics. Due to the increasing number of periprosthetic infections caused by multidrug-resistant microorganisms, new antibacterial coatings for biomaterials must be developed. The excellent antibacterial properties of silver nanoparticles (AgNPs) against multidrug-resistant bacteria, for example, have been repeatedly described. For this reason, we tested a nanosilver-doped polymethylmethacrylate (PMMA) bone cement and a nanosilver-coated titanium alloy regarding their influence on osteoclastogenesis of primary human peripheral blood mononuclear cells. Both implant variants did not inhibit osteoclast differentiation. Excellent cell attachment and unaltered podosomal structures were confirmed. Additionally, no induction of oxidative or endoplasmic reticulum stress could be observed. However, PMMA loaded with gentamicin and nanosilver inhibited preosteoclast fusion and further osteoclastogenesis. The material also led to decreased clathrin-dependent endocytosis as well as decreased levels of endoplasmic reticulum stress. Therefore, biomaterial functionalization with AgNPs did not disturb osteoclastogenesis, while addition of gentamicin reduced the cytocompatibility of nanosilver-doped materials towards human osteoclasts.

  17. Specifications of nanosecond laser ablation with solid targets, aluminum, silicon rubber, and polymethylmethacrylate (PMMA)

    NASA Astrophysics Data System (ADS)

    Morshedian, Nader

    2017-09-01

    The ablation parameters such as threshold fluence, etch depth, ablation rate and the effect of material targets were investigated under the interaction of laser pulse with low intensity. The parameters of the laser system are: laser pulse energy in the range of 110-140 mJ, wavelength 1064 nm and pulse duration 20 ns. By macroscopic estimation of the outward images of the ablation and data obtained, we can conclude that the photothermal and photoionization processes have more influence for aluminum ablation. In contrast, for polymer samples, from the macroscopic observation of the border pattern at the irradiated spot, and also the data obtained from the experiment results, we deduce that both chemical change due to heating and photochemical dissociation were effective mechanisms of ablation. However, concerning the two polymer samples, apart from considering the same theoretical ablation model, it is conceived that the photomehanical specifications of PMMA are involved in the ablation parameters. The threshold fluence for an ablation rate of 30 laser shots were obtained as 12.4, 24.64, and 11.71 J cm-2, for aluminum, silicon rubber and polymethylmethacrylate (PMMA) respectively. The ablation rate is exponentially decreased by the laser-shot number, especially for aluminum. Furthermore, the etch depth after 30 laser shots was measured as 180, 630 and 870 μm, for aluminum, silicon rubber and PMMA, respectively.

  18. Enhanced osteointegration of poly(methylmethacrylate) bone cements by incorporating strontium-containing borate bioactive glass.

    PubMed

    Cui, Xu; Huang, Chengcheng; Zhang, Meng; Ruan, Changshun; Peng, Songlin; Li, Li; Liu, Wenlong; Wang, Ting; Li, Bing; Huang, Wenhai; Rahaman, Mohamed N; Lu, William W; Pan, Haobo

    2017-06-01

    Although poly(methylmethacrylate) (PMMA) cements are widely used in orthopaedics, they have numerous drawbacks. This study aimed to improve their bioactivity and osseointegration by incorporating strontium-containing borate bioactive glass (SrBG) as the reinforcement phase and bioactive filler of PMMA cement. The prepared SrBG/PMMA composite cements showed significantly decreased polymerization temperature when compared with PMMA and retained properties of appropriate setting time and high mechanical strength. The bioactivity of SrBG/PMMA composite cements was confirmed in vitro, evidenced by ion release (Ca, P, B and Sr) from SrBG particles. The cellular responses of MC3T3-E1 cells in vitro demonstrated that SrBG incorporation could promote adhesion, migration, proliferation and collagen secretion of cells. Furthermore, our in vivo investigation revealed that SrBG/PMMA composite cements presented better osseointegration than PMMA bone cement. SrBG in the composite cement could stimulate new-bone formation around the interface between the composite cement and host bone at eight and 12 weeks post-implantation, whereas PMMA bone cement only stimulated development of an intervening connective tissue layer. Consequently, the SrBG/PMMA composite cement may be a better alternative to PMMA cement in clinical applications and has promising orthopaedic applications by minimal invasive surgery. © 2017 The Author(s).

  19. Evaluation of antibiotic releasing porous polymethylmethacrylate space maintainers in an infected composite tissue defect model.

    PubMed

    Spicer, Patrick P; Shah, Sarita R; Henslee, Allan M; Watson, Brendan M; Kinard, Lucas A; Kretlow, James D; Bevil, Kristin; Kattchee, Lauren; Bennett, George N; Demian, Nagi; Mende, Katrin; Murray, Clinton K; Jansen, John A; Wong, Mark E; Mikos, Antonios G; Kasper, F Kurtis

    2013-11-01

    This study evaluated the in vitro and in vivo performance of antibiotic-releasing porous polymethylmethacrylate (PMMA)-based space maintainers comprising a gelatin hydrogel porogen and a poly(dl-lactic-co-glycolic acid) (PLGA) particulate carrier for antibiotic delivery. Colistin was released in vitro from either gelatin or PLGA microparticle loaded PMMA constructs, with gelatin-loaded constructs releasing colistin over approximately 7 days and PLGA microparticle-loaded constructs releasing colistin for up to 8 weeks. Three formulations with either burst release or extended release at different doses were tested in a rabbit mandibular defect inoculated with Acinetobacter baumannii (2×10(7) colony forming units ml(-1)). In addition, one material control that released antibiotic but was not inoculated with A. baumannii was tested. A. baumannii was not detectable in any animal after 12 weeks on culture of the defect, saliva, or blood. Defects with high dose extended release implants had greater soft tissue healing compared with defects with burst release implants, with 8 of 10 animals showing healed mucosae compared with 2 of 10 respectively. Extended release of locally delivered colistin via a PLGA microparticle carrier improved soft tissue healing compared with implants with burst release of colistin from a gelatin carrier. Copyright © 2013 Acta Materialia Inc. All rights reserved.

  20. Antibiotic-releasing porous polymethylmethacrylate/gelatin/antibiotic constructs for craniofacial tissue engineering.

    PubMed

    Shi, Meng; Kretlow, James D; Spicer, Patrick P; Tabata, Yasuhiko; Demian, Nagi; Wong, Mark E; Kasper, F Kurtis; Mikos, Antonios G

    2011-05-30

    An antibiotic-releasing porous polymethylmethacrylate (PMMA) construct was developed to maintain the bony space and prime the wound site in the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite craniofacial tissue defects. Porous PMMA constructs incorporating gelatin microparticles (GMPs) were fabricated by the sequential assembly of GMPs, the antibiotic colistin, and a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid. PMMA/gelatin/antibiotic constructs with varying gelatin incorporation and drug content were investigated to elucidate the relationship between material composition and construct properties (porosity and drug release kinetics). The porosity of PMMA/gelatin/antibiotic constructs ranged between 7.6±1.8% and 38.4±1.4% depending on the amount of gelatin incorporated and the drug solution added for gelatin swelling. The constructs released colistin over 10 or 14 days with an average release rate per day above 10 μg/ml. The porosity and in vitro colistin release kinetics of PMMA/gelatin/antibiotic constructs were tuned by varying the material composition and fabrication parameters. This study demonstrates the potential of gelatin-incorporating PMMA constructs as a functional space maintainer for both promoting tissue healing/coverage and addressing local infections, enabling better long-term success of the definitive regenerated tissue construct. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Polymethylmethacrylate imbedded with antibiotics cranioplasty: An infection solution for moderate and large defects reconstruction?

    PubMed Central

    Worm, Paulo Valdeci; do Nascimento, Tobias Ludwig; do Couto Nicola, Fabricio; Sanches, Eduardo Farias; dos Santos Moreira, Carlos Fernando; Rogério, Luiz Pedro Willimann; dos Reis, Marcelo Martins; Finger, Guilherme; Collares, Marcus Vinicius Martins

    2016-01-01

    Background: In cases where autologous bone graft reconstruction is not possible (such as comminuted fractures, bone graft reabsorption, or infection) and the use of synthetic material is required, polymethylmethacrylate (PMMA) use is a safe and efficient solution. Studies comparing the incidence of postoperative complications between autologous and synthetic cranioplasty are heterogeneous, not allowing a conclusion of which is the best material for skull defects reconstruction. Current medical literature lacks prospective well-delineated studies with long-term follow-up that analyze the impact of antibiotic use in PMMA cranial reconstruction of moderate and large defects. Methods: A prospective series of patients, who underwent cranioplasty reconstruction with PMMA impregnated with antibiotic, were followed for 2 years. Authors collected data regarding demographic status, clinical conditions, surgical information, and its complications. Results: A total of 58 patients completed full follow-up with a mean group age of 40 years and a male predominance (77%). Major complications that required surgical management were identified in 5 patients, and 10 patients evolved with minor complications. Postoperative surgical site infection incidence was 3.2%. Conclusion: The infection rate in patients submitted to PMMA flap cranioplasty impregnated with antibiotic is significantly inferior comparing to the data described in medical literature. A lower infection incidence impacts secondary endpoints such as minimizing surgical morbidity, mortality, hospitalization period, and, consequently, costs. PMID:27904754

  2. Fluoride release, recharge and flexural properties of polymethylmethacrylate containing fluoridated glass fillers.

    PubMed

    Al-Bakri, I A; Swain, M V; Naoum, S J; Al-Omari, W M; Martin, E; Ellakwa, A

    2014-06-01

    The purpose of this study was to investigate the effect of fluoridated glass fillers on fluoride release, recharge and the flexural properties of modified polymethylmethacrylate (PMMA). Specimens of PMMA denture base material with various loading of fluoridated glass fillers (0%, 1%, 2.5%, 5% and 10% by weight) were prepared. Flexural properties were evaluated on rectangular specimens (n = 10) aged in deionized water after 24 hours, 1 and 3 months. Disc specimens (n = 10) were aged for 43 days in deionized water and lactic acid (pH 4.0) and fluoride release was measured at numerous intervals. After ageing, specimens were recharged and fluoride re-release was recorded at 1, 3 and 7 days after recharge. Samples containing 2.5%, 5% and 10% glass fillers showed significantly (p < 0.05) greater levels of fluoride release compared with the control and 1% glass fillers specimens. All experimental specimens exhibited fluoride release in both media. The flexural strength of specimens decreased in proportion to the percentage filler inclusion with the modulus of elasticity values remaining within ISO Standard 1567. The modified PMMA with fluoridated glass fillers has the ability to release and re-release fluoride ion. Flexural strength decreased as glass filler uploading increased. © 2014 Australian Dental Association.

  3. Customized Cranioplasty Implants Using Three-Dimensional Printers and Polymethyl-Methacrylate Casting

    PubMed Central

    Kim, Bum-Joon; Hong, Ki-Sun; Park, Kyung-Jae; Park, Dong-Hyuk; Chung, Yong-Gu

    2012-01-01

    Objective The prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting. Methods A total of 16 patients with large skull defects (>100 cm2) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect. Results The median operation time was 184.36±26.07 minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously. Conclusion Customized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects. PMID:23346326

  4. The use of polymethyl-methacrylate (Artecoll) as an adjunct to facial reconstruction

    PubMed Central

    Mok, David; Schwarz, Jorge

    2004-01-01

    BACKGROUND: Injectable polymethyl-methacrylate (PMMA) microspheres, or Artecoll, has been used for the last few years in aesthetic surgery as long-term tissue filler for the correction of wrinkles and for lip augmentation. This paper presents three cases of the use of PMMA microsphere injection for reconstructive patients with defects of varying etiologies. These cases provide examples of a novel adjunct to the repertoire of the reconstructive surgeon. OBJECTIVES: To evaluate the effectiveness (short- and long-term) of PMMA injection for the correction of small soft tissue defects of the face. METHODS: Three case histories are presented. They include the origin of the defect; previous reconstructions of the defect; and area, volume, timing and technical particularities of PMMA administration. RESULTS: All three cases showed improvement of the defect with the PMMA injection with respect to both objective evidence and patient satisfaction. The improvements can still be seen after several years. CONCLUSIONS: PMMA microsphere injection can be effectively used to correct selected small facial defects in reconstructive cases and the results are long lasting. PMID:24115873

  5. Bone response to porous polymethylmethacrylate cement loaded with hydroxyapatite particles in a rabbit mandibular model.

    PubMed

    Sa, Yue; Yu, Na; Wolke, Joop G C; Chanchareonsook, Nattharee; Goh, Bee Tin; Wang, Yining; Yang, Fang; Jansen, John A

    2017-04-03

    The aim of the current study was to evaluate bone formation and tissue response to porous polymethylmethacrylate (PMMA) cement with or without hydroxyapatite (HA) in a rabbit mandibular model. Therefore, fourteen New Zealand white rabbits were randomly divided into two groups of seven according to the designed study end points of 4 and 12 weeks. For each rabbit, two decorticated defects (6 mm in height and 10 mm in width for each) were prepared at both sides of the mandible. Subsequently, the defects were filled with respectively porous PMMA and porous PMMA-HA cement. After reaching the designated implantation period, the rabbits were euthanized and the mandibles were retrieved for histological analysis. Results showed that both porous PMMA and porous PMMA-HA supported bone repair. Neither of the bone cements caused significant inflammation to nerve or other surrounding tissues. After implantation of 12 weeks, majority of the porosity was filled with newly formed bone for both cements, which supports the concept that a porous structure within PMMA can enhance bone ingrowth. Histomorphometrical evaluation, using histological grading scales, demonstrated that, at both implantation times, the presence of HA in the PMMA enhanced bone formation. Bone was always in direct contact with the HA particles, while intervening fibrous tissue was present at the PMMA-bone interface. On the basis of results, it was concluded that injectable porous PMMA-HA cement might be a good candidate for craniofacial bone repair, which should be further evaluated in a more clinically relevant large animal model.

  6. Sterilization by gamma radiation of antibiotic impregnated polymethylmethacrylate and plaster of Paris beads. A pilot study.

    PubMed

    Trencart, P; Elce, Y A; Rodriguez Batista, E; Michaud, G

    2014-01-01

    Ethylene oxide is currently recommended for sterilization of antibiotic impregnated beads; however this method carries health risks to personnel and is becoming less available. To perform a pilot study of the effect of radiation for sterilization of polymethylmethacrylate (PMMA) and plaster of Paris (POP) beads impregnated with amikacin, enrofloxacin, and ceftiofur. Radiation would effectively sterilize the beads without affecting the efficacy of the antibiotic. Beads of PMMA and POP were prepared in a clean but non-sterile manner with one of the three antibiotics (amikacin, enrofloxacin, ceftiofur) or no antibiotic. Beads were then exposed to radiation for a total dose of 0 kiloGray (kGy), 10 kGy and 25 kGy. Beads were incubated on Mueller-Hinton agar plates seeded with Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa for 24 hours or cultured in brain-heart infusion broth for 48 hours. Zones of inhibition were measured on the agar plates and statistics were performed on the diameters of the zones of inhibition using an analysis of variance. There were no differences in the diameters of inhibition for all levels of radiation for all PMMA beads. The same was true with POP beads with the exception of enrofloxacin which had a significantly decreased zone of inhibition with increased levels of radiation, though the clinical significance of this finding was not assessed. Only beads without antibiotics and not exposed to radiation had bacterial growth. Radiation may be an effective method of sterilization for antibiotic impregnated beads.

  7. Ablation of bone and polymethylmethacrylate by an XeCl (308 nm) excimer laser

    SciTech Connect

    Yow, L.; Nelson, J.S.; Berns, M.W.

    1989-01-01

    One of the main problems in orthopaedics is the surgical removal of hard substances, such as bone and polymethylmethacrylate (PMMA). Such materials are often very difficult to remove without mechanical trauma to the remaining tissue. This study investigated the feasibility of the ultraviolet 308 nm excimer laser in the ablation of these materials. The beam was delivered through a 1 mm-diameter fiber optic at 40 Hz with energy densities at the target surface of 20-80 J/cm2 per pulse. The goal of the study was to establish the ideal dosimetry for removing bone and PMMA with minimum trauma to the adjacent tissue. Histology revealed that the 308 nm laser effectively removed bone leaving a thermal damage zone of only 2-3 microns in the remaining tissue. Increasing the energy per pulse gave correspondingly larger and deeper cuts with increasing zones of thermal damage. The excimer laser was also effective in the ablation of PMMA, creating craters in the substrate with a thermal damage zone of 10-40 microns. The debris from both substrates was evaluated.

  8. Eurycoma longifolia in Radix for the treatment of ethanol-induced gastric lesion in rats.

    PubMed

    Qodriyah, H M S; Asmadi, A Y

    2013-12-01

    The effect of treatment with Radix on ethanol-induced gastric lesions was investigated. The main ingredient of Radix is Eurycoma longifolia. Twenty-four rats of the Sprague-Dawley species were randomly divided into four groups. Three groups were given 0.5 mL 100% ethanol orally. Another group was used as a control and was given only distilled water orally (control). After 6 h all the rats were fed with normal diet. One group that was administered with ethanol was only given distilled water orally (no treatment). Another two groups that were administered with ethanol were treated with oral Radix 0.128 mg g(-1) b.wt. (Radix) and oral ranitidine 21.4 mg kg(-1) b.wt. (Ranitidine), respectively. After one week, all the rats were fasted overnight and sacrificed. The stomach was isolated and examined for the presence and severity of gastric lesions. Measurements for malondialdehyde content and gastric acid concentration were also done. It is found that the ulcer index was lower in the Radix and ranitidine group compared to the no treatment group whereas in the control group there was no lesion. There was no difference in ulcer index between the Radix and ranitidine group. The gastric MDA content was significantly higher in all the groups that were induced with ethanol compared to the control group but no difference between all the ethanol-induced groups. There was no difference in the gastric acid concentration in all groups. Hence it is concluded that Eurycoma longifolia in Radix is as effective as ranitidine in the treatment of ethanol-induced gastric lesions in rats.

  9. Relationships between δ18O and δ13C of the of living Radix sp. shells and its ambient water

    NASA Astrophysics Data System (ADS)

    Hu, H. P.; Feng, J. L.; Chen, F.

    2016-12-01

    Radix sp. is widespread on the Tibetan Plateau. Living Radix sp. was collected from rivers, swamp, through-flow lakes and closed lakes. We measured the δ18Oshell and δ13Cshell values of living and fossil Radix sp. shells, and the δ18Owater and δ13CDIC values of the ambient water. The δ18Oshell values of living Radix sp. from different water bodies are significant related to the δ18Owater of the ambient water. The δ18Oshell values of living Radix sp. shells depend on the δ18Owater of the ambient water. Thus, δ18Oshell of fossil Radix sp. shells can be utilized to rebuild δ18Owater of the paleo-water body. Moreover, the δ18Oshell values of Radix sp. shells in the rivers are very low, the values from the swamp are bit higher, probably due to weak evaporation. The δ18Oshell values for the through-flow lakes ranging within a wide range, while values for the closed lakes are higher. It is possible that intensive evaporation may be the cause of the lake's isotopic characteristics. Therefore, the δ18Oshell values of living Radix sp. can be used to determine its hydrological status. In contrast, we do not observe a significant positive correlation between the δ13Cshell value of living Radix sp. and the δ13CDIC values of the ambient water. The δ13CDIC value of a water body is determined by many factors; in addition, δ13CDIC is more variable in the river, swamp and through-flow lake than in the closed lake. Consequently, the δ13CDIC values at the time of sampling cannot reflect the δ13CDIC values of the ambient water during the entire life span of Radix sp.. Moreover, the δ13Cshell values of living Radix sp. do not appear to have a close relationship with the hydrological status of the water body.

  10. Scintillating fiber optic dosimeters for breast and prostate brachytherapy

    NASA Astrophysics Data System (ADS)

    Moutinho, L. M.; Castro, I. F.; Freitas, H.; Melo, J.; Silva, P.; Gonçalves, A.; Peralta, L.; Rachinhas, P. J.; Simões, P. C. P. S.; Pinto, S.; Pereira, A.; Santos, J. A. M.; Costa, M.; Veloso, J. F. C. A.

    2017-02-01

    Brachytherapy is a radiotherapy modality where the radioactive material is placed close to the tumor, being a common treatment for skin, breast, gynecological and prostate cancers. These treatments can be of low-dose-rate, using isotopes with mean energy of 30 keV, or high-dose-rate, using isotopes such as 192Ir with a mean energy of 380 keV. Currently these treatments are performed in most cases without in-vivo dosimetry for quality control and quality assurance. We developed a dosimeter using small diameter probes that can be inserted into the patient's body using standard brachytherapy needles. By performing real-time dosimetry in breast and prostate brachytherapy it will be possible to perform real-time dose correction when deviations from the treatment plan are observed. The dosimeter presented in this work was evaluated in-vitro. The studies consisted in the characterization of the dosimeter with 500 μm diameter sensitive probes (with a BCF-12 scintillating optical fiber) using an inhouse made gelatin breast phantom with a volume of 566 cm3. A breast brachytherapy treatment was simulated considering a tumor volume of 27 cm3 and a prescribed absolute dose of 5 Gy. The dose distribution was determined by the Inverse Planning Simulated Annealing (IPSA) optimization algorithm (ELEKTA). The dwell times estimated from the experimental measurements are in agreement with the prescribed dwell times, with relative error below 3%. The measured signal-to-noise ratio (SNR) including the stem-effect contribution is below 3%.

  11. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect

    Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.; Edelstein, William A.

    2013-12-15

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on

  12. An RF dosimeter for independent SAR measurement in MRI scanners

    PubMed Central

    Qian, Di; El-Sharkawy, AbdEl-Monem M.; Bottomley, Paul A.; Edelstein, William A.

    2013-01-01

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B1) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average

  13. DNA as a solar dosimeter in the ocean.

    PubMed

    Regan, J D; Carrier, W L; Gucinski, H; Olla, B L; Yoshida, H; Fujimura, R K; Wicklund, R I

    1992-07-01

    Stratospheric ozone depletion may result in increased solar UV-B radiation to the ocean's upper layers and may cause deleterious effects on marine organisms. The primary UV-B damage induced in biological systems is to DNA. While physical measurements of solar UV-B penetration into the sea have been made, the effective depth and magnitude of actual DNA damage have not been determined. In the experiments reported here, UV-B-induced photoproducts (cyclobutane pyrimidine dimers) have been quantified in DNA molecules exposed to solar UV at the surface and at various depths in clear, tropical marine waters off Lee Stocking Island (23 degrees 45' N, 76 degrees 0.7' W), Exuma Cays, Bahamas. (14C)thymidine-labeled DNA or unlabeled bacteriophage phi X174 DNA was placed in specially designed quartz tubes at various depths for up to five days. Following exposure, DNA samples were removed to the laboratory where UV-B-induced pyrimidine dimers were quantified using a radiochromatographic assay, and bacteriophage DNA inactivation by solar UV-B was assayed by plaque formation in spheroplasts of Escherichia coli. Pyrimidine dimer induction was linear with time but the accumulation of dimers in DNA with time varied greatly with depth. Attenuation of dimer formation with depth of water was exponential. DNA at 3 m depth had only 17% of the pyrimidine dimers found at the surface. Bacteriophage phi X174 DNA, while reduced 96% in plaque-forming ability by a one day exposure to solar UV at the surface of the water, showed no effect on plaque formation after a similar exposure at 3 m. The data collected at the water's surface showed a "surface-enhanced dose" in that DNA damages at the real surface were greater than at the imaginary surface, which was obtained by extrapolating the data at depth to the surface. These results show the sensitivity of both the biochemical (dimers) and biological (phage plaques) DNA dosimeters. DNA dosimeters offer a sensitive, convenient and relatively

  14. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect

    Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.; Edelstein, William A.

    2013-12-15

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on

  15. FBX aqueous chemical dosimeter for measurement of dosimetric parameters.

    PubMed

    Moussous, O; Medjadj, T; Benguerba, M

    2011-02-01

    We investigated the ferrous sulphate-benzoic acid-xylenol orange (FBX) aqueous chemical dosimeter for measurement of dosimetric parameters such as the output factor, backscatter factor and lateral beam profiles for different square fields sizes for (60)Co γ-rays. A water phantom was employed to measure these parameters. An ionization chamber (IC) was used for calibration and comparison. A comparison of the resulting measurements with an ionization chamber's measured parameters showed good agreement. We thus believe that the tissue equivalent FBX dosimetry system can measure the dosimetric parameters for (60)Co with reasonable accuracy.

  16. An RF dosimeter for independent SAR measurement in MRI scanners.

    PubMed

    Qian, Di; El-Sharkawy, Abdel-Monem M; Bottomley, Paul A; Edelstein, William A

    2013-12-01

    The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B1) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole-body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging

  17. Ceric and ferrous dosimeters show precision for 50-5000 rad range

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Henry, V. D.

    1968-01-01

    Ammonium thiocyanate, added to the usual ferrous sulfate dosimeter solution, yielded a very stable, precise and temperature-independent system eight times as sensitive as the classical Fricke system in the 50 to 5000 rad range. The ceric dosimeters, promising for use in mixed radiation fields, respond nearly independently of LET.

  18. Longevity Tests of High-Sensitivity BD-PND Bubble Dosimeters

    SciTech Connect

    Radev, R; Carlberg, E

    2002-07-09

    Medium- and very-high-sensitivity neutron bubble dosimeters (BD-PNDs) made by Bubble Technology Industries (BTI) were used to study the life span of such dosimeters in a standard setup with a {sup 252}Cf source. Although data on the longevity of bubble dosimeters with low and medium sensitivity exist, such data for dosimeters with high and very high sensitivity are not readily available. The manufacturer guarantees optimum dosimeter performance for 3 months after receipt. However, it is important to know the change in the dosimeters' characteristics with time, especially after the first 3 months. The long-term performance of four sets of very high sensitivity and one set of medium-sensitivity bubble dosimeters was examined for periods of up to 13 months. During that time, the detectors were exposed and reset more than 20 times. Although departures from initial detection sensitivity were observed in several cases, the detectors indicated a significantly longer life span than stated in the manufacturer's warranty. In addition, the change in the number of bubbles and in evaluated neutron dose as a function of the time from the end of exposure until the dosimeters were read was investigated.

  19. Comparative study of three types of civil defense high-range pocket dosimeters

    SciTech Connect

    Siskel, R.L.; Sims, C.S.; Swaja, R.

    1987-01-01

    Civil defense shelters are stocked with high-range (0- to 200-R) CDV-742 pocket dosimeters. These dosimeters are intended for use by people that must leave the shelter when the environmental radiation level is either high or unknown. A total of 67 CDV-742 dosimeters were obtained and studied during the summer of 1986 at Oak Ridge National Lab. Health Physics Research Reactor (HPRR). Three different types of dosimeters (27 Bendix, 20 Landsverk-Gold, and 20 Landsverk-Yellow) in various combinations were exposed to 14 separate pulse operations of the HPRR. It can be concluded that the CDV-742 type dosimeters were not suitable for use in a neutron or mixed radiation field unless the spectra is known and correction factors determined in this study are properly applied. Further study is needed to determine the accuracy of these dosimeters in a pure gamma field and to determine their precision at the extreme ends of the dosimeter range. Furthermore, because of their failure rates, shelter occupants should consider exposure data from the Bendix and Landsverk-Yellow dosimeters to be highly unreliable unless sufficient evidence exists to support the exposure readings.

  20. Adaptation of a Pocket PC for Use as a Wearable Voice Dosimeter

    ERIC Educational Resources Information Center

    Popolo, Peter S.; Svec, Jan G.; Titze, Ingo R.

    2005-01-01

    This article deals with the adaptation of a commercially available Pocket PC for use as a voice dosimeter, a wearable device that measures the vocal dose of teachers or other individuals on the job, at home, and elsewhere during the course of an entire day. An engineering approach for designing a voice dosimeter is described, and design data are…

  1. [Estimation of personal dose based on the dependent calibration of personal dosimeters in interventional radiology].

    PubMed

    Mori, Hiroshige; Koshida, Kichiro; Ichikawa, Katsuhiro

    2007-08-20

    The purpose of present study is, in interventional radiology (IVR), to elucidate the differences between each personal dosimeter, and the dependences and calibrations of area or personal dose by measurement with electronic dosimeters in particular. We compare space dose rate distributions measured by an ionization survey meter with the value measured by personal dosimeter: an optically stimulated luminescence, two fluoroglass, and two electronic dosimeters. Furthermore, with electronic dosimeters, we first measured dose rate, energy, and directional dependences. Secondly, we calibrated the dose rate measured by electronic dosimeters with the results, and estimated these methods with coefficient of determination and Akaike's Information Criterion (AIC). The results, especially in electronic dosimeters, revealed that the dose rate measured fell by energy and directional dependences. In terms of methods of calibration, the method is sufficient for energy dependence, but not for directional dependence, because of the lack of stable calibration. This improvement poses a question for the future. The study suggested that these dependences of the personal dosimeter must be considered when area or personal dose is estimated in IVR.

  2. Adaptation of a Pocket PC for Use as a Wearable Voice Dosimeter

    ERIC Educational Resources Information Center

    Popolo, Peter S.; Svec, Jan G.; Titze, Ingo R.

    2005-01-01

    This article deals with the adaptation of a commercially available Pocket PC for use as a voice dosimeter, a wearable device that measures the vocal dose of teachers or other individuals on the job, at home, and elsewhere during the course of an entire day. An engineering approach for designing a voice dosimeter is described, and design data are…

  3. PRESAGETM - Development and optimization studies of a 3D radiochromic plastic dosimeter - Part 1

    NASA Astrophysics Data System (ADS)

    Adamovics, J.; Jordan, K.; Dietrich, J.

    2006-12-01

    This paper studies the polymerization of six different transparent plastics as potential 3D dosimeter matrices. In addition, six different leuco dyes and sixteen different free radical initiators were evaluated. Finally, the photoreactivity of the dosimeter was studied so that the effect of exposure to UV could be minimized.

  4. PRESAGETM - Development and optimization studies of a 3D radiochromic plastic dosimeter - Part 2

    NASA Astrophysics Data System (ADS)

    Adamovics, J.; Guo, P.; Burgess, D.; Manzoor, A.; Oldham, M.

    2006-12-01

    In a previous paper we described the evaluation of seven different transparent plastics as dosimeter matrices along with six different leuco dyes as the radiochromic agent. Here we present the evaluation of the dosimeter sensitivity and post irradiation stability of an additional plastic matrix and five different leuco dyes.

  5. Rehmanniae Radix in osteoporosis: A review of traditional Chinese medicinal uses, phytochemistry, pharmacokinetics and pharmacology.

    PubMed

    Liu, Chenyue; Ma, Rufeng; Wang, Lili; Zhu, Ruyuan; Liu, Haixia; Guo, Yubo; Zhao, Baosheng; Zhao, Shangang; Tang, Jinfa; Li, Yu; Niu, Jianzhao; Fu, Min; Zhang, Dongwei; Gao, Sihua

    2017-02-23

    Emerging clinical usage and pharmacological effects have been achieved in using Rehmanniae Radix either singly or in combination with other herbs to treat skeletal diseases in traditional Chinese medicine (TCM) in the recent years. This study is aimed to provide a comprehensive review about the historical TCM interpretation of the action of Rehmanniae Radix in osteoporosis, its usage in clinical trials and osteoporotic models, its main phytochemical constituents, and its pharmacokinetics. Several databases included PubMed, China Knowledge Resource Integrated Database, China Science and Technology Journal Database, National Science and Technology Library and the Web of Science Database were consulted to locate the publications pertaining to Rehmanniae Radix. The initial inquiry was conducted for the presence of the following terms combinations in the abstracts: Rehmanniae Radix, Dihuang, phytochemistry, pharmacokinetics, osteoporosis, bone, osteoclast and osteoblast. About 330 research papers and reviews were consulted. In TCM, Rehmanniae Radix exerts the anti-osteoporotic effect via regulating the functions of kidney and liver as well as improving blood circulation. 107 clinical trials are identified that used Rehmanniae Radix in combination with other herbs to treat post-menopausal, senile and secondary osteoporosis. Most of the clinical trials are characterized by high efficacy and no obvious adverse effects. However, the efficacies of these clinical trials are limited because of small patient sample size, short treatment duration and poor clinical design. In addition, TCM herbs under the clinical study are not clear because of a lack of standardization and authentication. The pharmacokinetics data demonstrate that the ingredients of Rehmanniae Radix are widely distributed after administration, and that catalpol and ajugol as well as acetoside are supposed to be the active constituents. More than 140 individual compounds have been currently isolated from this

  6. Effect of Ampelopsis Radix on wound healing in scalded rats.

    PubMed

    Lee, Kyungjin; Lee, Byonghee; Lee, Mi-Hwa; Kim, Bumjung; Chinannai, Khanita Suman; Ham, Inhye; Choi, Ho-Young

    2015-07-08

    Ampelopsis Radix has been used as a traditional Korean medicine for the treatment of burns and scalds. However, there has been no scientific research to date on the wound healing properties of Ampelopsis Radix for scald burns. This study aimed to evaluate the healing effect of Ampelopsis japonica root tuber ethanol extract (AJE) on induced cutaneous scald injury in Sprague Dawley (SD) rats. Hot water scalds were induced in SD rats, who were then divided into the following 5 groups; 1) control group without treatment, 2) positive control group with 1% Silver sulfadiazine (SSD), 3) Vaseline group, and groups 4) and 5) that used Vaseline containing 5% and 20% AJE, respectively. The ointment was applied topically to the experimental rats, once daily for 21 days, starting at 24 h post induction of the scald injury. Gross examination, measurement of wound size, and histopathological examination were performed. And quantitative measurement of cytokine levels of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), transforming growth factor beta 1 (TGF-β1), and vascular endothelial growth factor (VEGF) were performed by enzyme-linked immunosorbent assay. Clinical evaluation showed that the AJE and Vaseline groups, rapidly desquamated scab on day 12 post-scalding; in particular, the 20% AJE group achieved the greatest extent of skin recovery. Sizes of scald wound were significantly lower on days 12, 15, 18, and 21 in the AJE treated groups compared to the control groups. Histopathological evaluation showed a well-organized epithelial layer, angiogenesis, tissue granulation and collagen formation with the exception of inflammatory cells in the AJE-treated groups compared to the control groups on day 14, indicating that tissue regeneration had occurred. AJE treatment decreased TNF-α and increased IL-10 levels on days 2 and 14, indicating the anti-inflammatory action of AJE. The AJE groups also showed a decrease in TGF-β1 levels on day 7 and VEGF on day 14 in the

  7. Radix Ilicis Pubescentis total flavonoids ameliorates neuronal damage and reduces lesion extent in a mouse model of transient ischemic attack.

    PubMed

    Miao, Ming-San; Guo, Lin; Li, Rui-Qi; Zhang, Xiao-Lei

    2016-03-01

    Flavonoids are a major component in the traditional Chinese medicine Radix Ilicis Pubescentis. Previous studies have shown that the administration of Radix Ilicis Pubescentis total flavonoids is protective in cerebral ischemia. However, to our knowledge, no studies have examined whether the total flavonoids extracted from Radix Ilicis Pubescentis prevent or ameliorate neuronal damage following transient ischemic attacks. Therefore, Radix Ilicis Pubescentis total flavonoids question and the potential underlying mechanisms. Thus, beginning 3 days before the induction of a mouse model of transient ischemic attack using tert-butyl hydroperoxide injections, mice were intragastrically administered 0.3, 0.15, or 0.075 g/kg of Radix Ilicis Pubescentis total flavonoids daily for 10 days. The results of spectrophotometric analyses demonstrated that Radix Ilicis Pubescentis total flavonoids enhanced oxygen free radical scavenging and reduced pathological alterations in the brain. Hematoxylin-eosin staining results showed that Radix Ilicis Pubescentis total flavonoids reduced hippocampal neuronal damage and cerebral vascular injury in this mouse model of transient ischemic attack. These results suggest that the antioxidant effects of Radix Ilicis Pubescentis total flavonoids alleviate the damage to brain tissue caused by transient ischemic attack.

  8. [A model atlas of the crude drug Radix Ophiopogonis in tri-dimensional computer reconstraction from their serial transections].

    PubMed

    Xiao, X H; Shu, G M; Li, J L; Fang, Q M; Xia, W J; Yin, G P; Chen, Q; Li, S G

    1997-06-01

    In this paper, the tri-dimensional computer reconstruction and animated display from the serial transections of the crude drugs Radix Ophiopogonis and Radix Liriopes have been achieved. Accordingly, some tri-dimensional image techniques and information for the computer aided teaching and identification of pharmacognosy have been offered.

  9. [Identification of three-step IR spectra of radix Puerariae from different habitats].

    PubMed

    Han, Ming-Xia; Zhou, Qun; Li, Quan-Hong; Sun, Su-Qin

    2009-07-01

    The IR spectra method and 2D-IR correlation spectra method were used for the identification of radix puerariae from Baxian mountain in Tianjin, Huping mountain in Hunan and Jinfo mountain in Chongqing. The results show that the IR spectra (the first identification) and the second derivative spectra (the second identification) of kudzu roots from different habitats have some similarity. Compared with the spectra of amylum and puerarin, three samples are all rich in amylum, and have some puerarin. The primary difference is the 62 wave numbers between the strongest peak of Tianjin kudzu at 1 048 cm(-1) and amylum at 986 cm(-1), showing that the content of amylum is lower. Radix puerariae from Tianjin has characteristic peaks consistent with those of puerarin at 891, 835 and 797 cm(-1), which means that radix puerariae from Tianjin has more puerarin. In the 2D-IR correlation spectra (the third identification), the three kinds of radix puerariae have the difference in position and the intensity of the correlation peak cluster. Therefore, the three-step IR macro-fingerprint provides a rapid and effective method for the identification of radix puerariae from the different habitats.

  10. Mixed-radix Algorithm for the Computation of Forward and Inverse MDCT

    PubMed Central

    Wu, Jiasong; Shu, Huazhong; Senhadji, Lotfi; Luo, Limin

    2008-01-01

    The modified discrete cosine transform (MDCT) and inverse MDCT (IMDCT) are two of the most computational intensive operations in MPEG audio coding standards. A new mixed-radix algorithm for efficient computing the MDCT/IMDCT is presented. The proposed mixed-radix MDCT algorithm is composed of two recursive algorithms. The first algorithm, called the radix-2 decimation in frequency (DIF) algorithm, is obtained by decomposing an N-point MDCT into two MDCTs with the length N/2. The second algorithm, called the radix-3 decimation in time (DIT) algorithm, is obtained by decomposing an N-point MDCT into three MDCTs with the length N/3. Since the proposed MDCT algorithm is also expressed in the form of a simple sparse matrix factorization, the corresponding IMDCT algorithm can be easily derived by simply transposing the matrix factorization. Comparison of the proposed algorithm with some existing ones shows that our proposed algorithm is more suitable for parallel implementation and especially suitable for the layer III of MPEG-1 and MPEG-2 audio encoding and decoding. Moreover, the proposed algorithm can be easily extended to the multidimensional case by using the vector-radix method. PMID:21258639

  11. Photosynthetic physiological response of Radix Isatidis (Isatis indigotica Fort.) seedlings to nicosulfuron.

    PubMed

    Yuan, Xiangyang; Zhang, Liguang; Ning, Na; Wen, Yinyuan; Dong, Shuqi; Yin, Meiqiang; Guo, Meijun; Wang, Binqiang; Feng, Lei; Guo, Pingyi

    2014-01-01

    Radix Isatidis (Isatis indigotica Fort.) is one of the most important traditional Chinese medicine plants. However, there is no suitable herbicide used for weed control in Radix Isatidis field during postemergence stage. To explore the safety of sulfonylurea herbicide nicosulfuron on Radix Isatidis (Isatis indigotica Fort.) seedlings and the photosynthetic physiological response of the plant to the herbicide, biological mass, leaf area, photosynthetic pigment content, photosynthetic rate, chlorophyll fluorescence characteristics, and P700 parameters of Radix Isatidis seedlings were analyzed 10 d after nicosulfuron treatment at 5th leaf stage in this greenhouse research. The results showed that biological mass, total chlorophyll, chlorophyll a, and carotenoids content, photosynthetic rate, stomatal conductance, PS II maximum quantum yield, PS II effective quantum yield, PS II electron transport rate, photochemical quenching, maximal P700 change, photochemical quantum yield of PS I, and PS I electron transport rate decreased with increasing herbicide concentrations, whereas initial fluorescence, quantum yield of non-regulated energy dissipation in PS II and quantum yield of non-photochemical energy dissipation due to acceptor side limitation in PS I increased. It suggests that nicosulfuron ≥1 mg L-1 causes the damage of chloroplast, PS II and PS I structure. Electron transport limitations in PS I receptor side, and blocked dark reaction process may be the main cause of the significantly inhibited growth and decreased photosynthetic rate of Radix Isatidis seedlings.

  12. Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry

    PubMed Central

    Lee, Bongsoo; Kwon, Guwon; Shin, Sang Hun; Kim, Jaeseok; Yoo, Wook Jae; Ji, Young Hoon; Jang, Kyoung Won

    2015-01-01

    In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter. PMID:26593917

  13. An analysis of an implantable dosimeter system for external beam therapy

    SciTech Connect

    Black, Robert D. . E-mail: bblack@siceltech.com; Scarantino, Charles W.; Mann, Gregory G.; Anscher, Mitchell S.; Ornitz, Robert D.; Nelms, Benjamin E.

    2005-09-01

    Background and Purpose: To review the data from an implantable radiation dosimetry system used in a clinical setting and to examine correlations between dosimeter readings and potential causative error sources. Materials and Methods: MOSFET (metal oxide semiconductor field effect transistor) based encapsulated dosimeters were evaluated in a phantom (in vitro) and in a study with 18 patients. The dosimeters were placed in the gross tumor volume or in collateral normal tissue. Predicted dose values were established by imaging the dosimeters in the planning CTs. Results: The in vitro study confirmed that bounding cumulative errors due to setup, planning, and machine output within a {+-}5% level is achievable. In patients, it was found that deviations from the targeted dose often exceeded the 5% level. Conclusions: The use of an implantable dosimeter system could provide an effective empiric check on the dose delivered at depth. Such a tool may have value for institutional quality assurance, as well as for therapy delivered to individual patients.

  14. Characterization of a Fricke dosimeter at high energy photon and electron beams used in radiotherapy.

    PubMed

    Moussous, O; Khoudri, S; Benguerba, M

    2011-12-01

    The dosimetric features of the Fricke dosimeter in clinical linear accelerator beams are considered. Experimental data were obtained using various nominal energies 6 and 18 MV, 12 and 15 MeV, including the (60)Co γ-ray beam. The calibration of the dosimeters was performed using the ionization chamber as a reference dosimeter. Some general characteristics of Fricke dosimeter such as energy dependence, optical density (OD)-dose relationship, reproducibility, accuracy, dose rate dependence were analyzed. The Fricke solution shows linearity in OD-dose relationship, energy independence and a good reproducibility over the energy range investigated. The Fricke dosimeter was found to be suitable for carrying out absorbed dose to water measurements in the calibration of high energy electron and photon beams.

  15. Effects of temperature and humidity during irradiation on the response of a film dosimeter

    NASA Astrophysics Data System (ADS)

    Khan, Hasan M.; Wahid, Mian S.

    1995-09-01

    A commercially available leuco dye containing polyvinyl butyral based film (FWT-63-02) has been investigated ctrophotometrically for its dosimetric characteristic and for its use as routine dosimeter in radiation processing for the absorbed dose range 0.1 to 10 kGy. The present study was carried out to evaluate the performance of dosimeter under different environmental conditions (i.e. effects of temperature and relative humidity during irradiation). The response was measured at peak wavelength of 600 nm as well as at a number of other wavelengths (550, 625, 640 and 650 nm). The dosimeter was found to show quite stable response up to a radiation chamber temperature of 40°C. The dosimeter also showed stable behavior at low or moderate relative humidity conditions (<76%) in the radiation chamber. The characteristics of the dosimeter are suitable for its possible application in radiation processing, food irradiation and sterilization applications.

  16. Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry.

    PubMed

    Lee, Bongsoo; Kwon, Guwon; Shin, Sang Hun; Kim, Jaeseok; Yoo, Wook Jae; Ji, Young Hoon; Jang, Kyoung Won

    2015-11-17

    In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

  17. [Dynamic Changes of Nucleosides and Nucleobases in Different Harvest Periods of Polygoni Multiflori Radix by UPLC-QTRAP-MS/MS].

    PubMed

    Luo, Yi-Yuan; Liu, Juan-xiu; Liu, Xun-hong; Lan, Cai-wu; Hou, Ya; Ma, Yang; Xu, Li

    2015-05-01

    To analyze the dynamic changes of nucleosides and nucleobases in Polygoni Multiflori Radix harvested in different periods. UPLC-QTRAP-MS/MS method was applied for the analysis of nine kinds of nucleosides and nucleobases in Polygoni Multiflori Radix. The content of uridine, adenine, guanosine and cytidine was higher in Polygoni Multiflori Radix harvested in different periods and assumed some difference. The trends of nucleosides and nucleobases from Polygoni Multiflori Radix according to the peak valley shape changed. The highest contents of them were in December. The accumulation of nucleosides and nucleobases in Polygoni Multiflori Radix is closely related to its growth cycle. It is found to be basically the same as that obtained when the herb is collected during the conventional collecting time.

  18. A modified Fricke gel dosimeter for fast electron blood dosimetry

    NASA Astrophysics Data System (ADS)

    Del Lama, L. S.; de Góes, E. G.; Sampaio, F. G. A.; Petchevist, P. C. D.; de Almeida, A.

    2014-12-01

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXGp) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXGp dosimeter were also able to provide isodose curves and field profiles for the irradiated samples.

  19. Antibiotic-releasing porous polymethylmethacrylate constructs for osseous space maintenance and infection control.

    PubMed

    Shi, Meng; Kretlow, James D; Nguyen, Anson; Young, Simon; Scott Baggett, L; Wong, Mark E; Kasper, F Kurtis; Mikos, Antonios G

    2010-05-01

    The use of a strategy involving space maintenance as the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite tissue defects in the craniofacial area, preserves the void volume of bony defects and could promote soft tissue healing prior to the subsequent definitive repair. One of the complications with a biomaterial-based space maintenance approach is local infection, which requires early, effective eradication, ideally through local antibiotic delivery. The purpose of this study is to develop a dual function implant material for maintaining osseous space and releasing an antibiotic to eliminate local infection in bony defects. Colistin, a polymyxin antibiotic, was chosen specifically to address infections with Acinetobacter species, the most common pathogen associated with combat-related traumatic craniofacial injuries. Porous polymethylmethacrylate (PMMA) constructs incorporating poly(lactic-co-glycolic acid) (PLGA) microspheres were fabricated by mixing a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid with a carboxymethylcellulose (CMC) hydrogel (40 or 50 wt%) to impart porosity and PLGA microspheres (10 or 15 wt%) loaded with colistin to control drug release. The PMMA/CMC/PLGA construct featured mild setting temperature, controllable surface/bulk porosity by incorporation of the CMC hydrogel, reasonably strong compressive properties, and continuous drug release over a period of 5 weeks with total drug release of 68.1-88.3%, depending on the weight percentage of CMC and PLGA incorporation. The concentration of released colistin was well above its reported minimum inhibitory concentration against susceptible species for 5 weeks. This study provides information on the composition parameters that enable viable porosity characteristics/drug release kinetics of the PMMA/CMC/PLGA construct for the initial space maintenance as part of a two-stage regenerative medicine

  20. Filler-coupling agent-matrix interactions in silica/polymethylmethacrylate composites.

    PubMed

    Liu, Q; Ding, J; Chambers, D E; Debnath, S; Wunder, S L; Baran, G R

    2001-12-05

    The interactions of the silane coupling agent methacryloxypropyltrimethoxysilane (MPS) with both fumed silica and a polymethylmethacrylate (PMMA) resin matrix were investigated using thermogravimetric analysis and Fourier transform infrared spectroscopy. OX 50 fumed silica was silanated with MPS at concentrations of 1% and 5% in aqueous ethanol (95%), acetone, and anhydrous toluene. Methyl methacrylate was polymerized with the silanated fumed silica (5% wt/wt) to form composites. The amount of MPS adsorption on the fumed silica and the amount of PMMA attached to the silanated fumed silica were determined by thermogravimetric analysis. MPS could be removed from the fumed silica after washing with methanol, but not after it underwent a drying process at 25 degrees C under vacuum. After vacuum drying at 25 degrees C, two types of adsorbed silane were found, i.e., firmly adsorbed and loosely adsorbed silane. The loosely adsorbed silane could desorb from silica and be incorporated into the polymer matrix through copolymerization with monomeric methyl methacrylate, resulting in crosslinking of the matrix. When the silanated silica was dried at 110 degrees C for 2 h, the loosely adsorbed silane was removed and the amount of firmly adsorbed silane increased. There was a positive correlation between the amount of firmly adsorbed MPS and the amount of PMMA attachment. The highest efficiency for PMMA attachment was found when MPS was adsorbed as a monolayer, because the loosely adsorbed silane did not contribute to the bonding of PMMA, and this suggested that not all of the double bonds of the MPS were accessible for reaction with the methacrylate monomer. Drying at 110 degrees C may also decrease the number of unsaturated double bonds of MPS.

  1. Polymethylmethacrylate and radioisotopes in vertebral augmentation: an explanation of underlying principles.

    PubMed

    Hirsch, Ariel E; Rosenstein, Barry S; Medich, David C; Martel, Christopher B; Hirsch, Joshua A

    2009-01-01

    We recently reported a novel concept for combining radioactive isotope technology with polymethylmethacrylate (PMMA) cement used for vertebral augmentation and have advocated that pain physicians become aware of this new concept when treating malignant compression fractures. The use of vertebral augmentation for malignant compression fractures is steadily increasing, and the goal of this novel approach would be to stabilize the fractured vertebral body while also controlling proliferation of the tumor cells in the vertebral body that caused the vertebral fracture. This approach would therefore provide mechanical stabilization of the fractured vertebral body at the same time as direct targeting of the cancer cells causing the fracture. For our analysis, we investigated six specific radioisotopes with regard to physical and biologic properties as they would interact with PMMA and local bone metastatic disease, taking into consideration anatomical, biological and physical characteristics. The radioisotopes investigated include beta emitting (plus and minus) sources, as well as low energy and mid-energy photon sources and are: P-32, Ho-166, Y-90, I-125, F-18, and Tc-99m. We review the advantages and disadvantages of each radioisotope. In addition, this paper serves to provide pain physicians with a basic background of the biologic principles (Biologically Effective Dose) and statistical modeling (Monte Carlo method) used in that analysis. We also review the potential complications when using radioactive sources in a clinical setting. Understanding the methodologies employed in determining isotope selection empowers the practitioner by fostering understanding of this presently theoretical treatment option. We believe that embedding radioisotopes in PMMA is merely a first step in the road of local treatment for symptomatic local lesions in the setting of systemic disease.

  2. Energy deposition around swift proton tracks in polymethylmethacrylate: How much and how far

    NASA Astrophysics Data System (ADS)

    Dapor, Maurizio; Abril, Isabel; de Vera, Pablo; Garcia-Molina, Rafael

    2017-08-01

    The use of proton beams in several modern technologies to probe or modify the properties of materials, such as proton beam lithography or ion beam cancer therapy, requires us to accurately know the extent to which the energy lost by the swift projectiles in the medium is redistributed radially around their tracks, since this determines several endpoints, such as the resolution of imaging or manufacturing techniques, or even the biological outcomes of radiotherapy. In this paper, the radial distribution of the energy deposited around swift-proton tracks in polymethylmethacrylate (PMMA) by the transport of secondary electrons is obtained by means of a detailed Monte Carlo simulation. The initial energy and angular distributions of the secondary electrons generated by proton impact, as well as the electronic cross sections for the ejection of these electrons, are reliably calculated in the framework of the dielectric formalism, where a realistic electronic excitation spectrum of PMMA is accounted for. The cascade of all secondary electrons generated in PMMA is simulated taking into account the main interactions that occur between these electrons and the condensed phase target. After analyzing the influence that several angular distributions of the electrons generated by the proton beam have on the resulting radial profiles of deposited energy, we conclude that the widely used Rudd and Kim formula should be replaced by the simpler isotropic angular distribution, which leads to radial energy distributions comparable to the ones obtained from more realistic angular distributions. By studying the dependence of the radial dose on the proton energy we recommend lower proton energies than previously published for reducing proximity effects around a proton track. The obtained results are of relevance for assessing the resolution limits of proton beam based imaging and manufacturing techniques.

  3. Evaluation of Soft Tissue Coverage over Porous Polymethylmethacrylate Space Maintainers Within Nonhealing Alveolar Bone Defects

    PubMed Central

    Kretlow, James D.; Shi, Meng; Young, Simon; Spicer, Patrick P.; Demian, Nagi; Jansen, John A.; Wong, Mark E.; Kasper, F. Kurtis

    2010-01-01

    Current treatment of traumatic craniofacial injuries often involves early free tissue transfer, even if the recipient site is contaminated or lacks soft tissue coverage. There are no current tissue engineering strategies to definitively regenerate tissues in such an environment at an early time point. For a tissue engineering approach to be employed in the treatment of such injuries, a two-stage approach could potentially be used. The present study describes methods for fabrication, characterization, and processing of porous polymethylmethacrylate (PMMA) space maintainers for temporary retention of space in bony craniofacial defects. Carboxymethylcellulose hydrogels were used as a porogen. Implants with controlled porosity and pore interconnectivity were fabricated by varying the ratio of hydrogel:polymer and the amount of carboxymethylcellulose within the hydrogel. The in vivo tissue response to the implants was observed by implanting solid, low-porosity, and high-porosity implants (n = 6) within a nonhealing rabbit mandibular defect that included an oral mucosal defect to allow open communication between the oral cavity and the mandibular defect. Oral mucosal wound healing was observed after 12 weeks and was complete in 3/6 defects filled with solid PMMA implants and 5/6 defects filled with either a low- or high-porosity PMMA implant. The tissue response around and within the pores of the two formulations of porous implants tested in vivo was characterized, with the low-porosity implants surrounded by a minimal but well-formed fibrous capsule in contrast to the high-porosity implants, which were surrounded and invaded by almost exclusively inflammatory tissue. On the basis of these results, PMMA implants with limited porosity hold promise for temporary implantation and space maintenance within clean/contaminated bone defects. PMID:20524844

  4. Octenidine in combination with polymethylmethacrylate: a new option for preventing infection?

    PubMed

    Weckbach, Sebastian; Möricke, Angelika; Braunwarth, Horst; Goroncy-Bermes, Peter; Bischoff, Mark; Gebhard, Florian

    2012-01-01

    Orthopedic implant infections represent a serious complication for both patient and surgeon. In order to minimize this risk, it has become standard practice in surgery and orthopedics to add antimicrobial substances to the polymethylmethacrylate (PMMA) bone cement. The aim of this study is to find new options for preventing infection by using alternative adjuvants in combination with PMMA. We hypothesized, that Octenidine, after being combined with PMMA, can be released in vitro and an antimicrobial efficacy of discharged Octenidine can be shown. The release of Octenidine from PMMA was assessed in high pressure liquid chromatography of the supernatant. In order to assess the efficacy of Octenidine on Staphylococcus aureus and Pseudomonas aeruginosa in vitro, a nutrient solution for these bacteria was incubated with a defined number of these bacteria (10(6) colony forming units) and cement pellets containing the antiseptic Octenidine for 24 h. After the incubation the number of bacteria in the solution was determined by counting the colony forming units on blood agar plates. Octenidine was shown to be released in a concentration-dependent manner from PMMA in the elution experiment. The experimental procedure using S. aureus demonstrated a bactericidal effect for bone cement containing Octenidine. For P. aeruginosa, bone cement containing 5-8% Octenidine was associated with tenfold reduction in bacterial count. These results suggest that Octenidine is released after combining it with PMMA and reaches working concentrations in vitro. These findings suggest a new and effective alternative for prevention of infection in cemented implants. Further investigations on the biocompatibility of this combination is needed.

  5. Visualization of Tear Clearance Using Anterior Segment Optical Coherence Tomography and Polymethylmethacrylate Particles.

    PubMed

    Zheng, Xiaodong; Yamaguchi, Masahiko; Kamao, Tomoyuki; Sakane, Yuri; Goto, Tomoko; Shiraishi, Atsushi; Ohashi, Yuichi

    2016-11-01

    We previously reported 2 new methods, anterior segment optical coherence tomography (AS-OCT) and polymethylmethacrylate particles suspended in fluorescein solution (PPF), for the evaluation of tear clearance and rapid tear flow after blinking (tear Krehbiel flow). Here, we investigated age-related OCT tear clearance and tear film thickness (TFT) and the potential correlation of OCT tear clearance and PPF velocity indicative of tear Krehbiel flow. Normal subjects separated into young and older groups received 5 μL of saline solution into the lower conjunctival sac, and an image of the central lower eyelid tear meniscus was captured by AS-OCT immediately and 30 seconds after natural blinking. Tear meniscus height (TMH) and tear meniscus area (TMA) were measured, and their percentage decrease was defined as OCT clearance rate. A Spectralis OCT Anterior Segment Module captured the central corneal tear film layer for TFT measurements. OCT clearance rates were significantly higher in young versus older subjects (P = 0.0002). When all subjects were analyzed, age was significantly and negatively correlated with TMH clearance rate (r = -0.4928, P = 0.0003) and TMA clearance rate (r = -0.4596, P = 0.0008). TFT values were significantly and negatively correlated with age (r = -0.6662, P < 0.0001). A second experiment examined tear Krehbiel flow by measuring PPF velocity in frontal and medial gaze positions. The medial gaze position showed significantly increased PPF velocity compared with the frontal gaze position (P = 0.006). Significant and positive correlations were found between OCT clearance rates and PPF velocity (TMH rate: r = 0.2926, P = 0.0392; TMA rate: r = 0.3274, P = 0.0205). AS-OCT and PPF might be novel techniques for quantitative evaluation of tear clearance and Krehbiel flow.

  6. Evaluation of soft tissue coverage over porous polymethylmethacrylate space maintainers within nonhealing alveolar bone defects.

    PubMed

    Kretlow, James D; Shi, Meng; Young, Simon; Spicer, Patrick P; Demian, Nagi; Jansen, John A; Wong, Mark E; Kasper, F Kurtis; Mikos, Antonios G

    2010-12-01

    Current treatment of traumatic craniofacial injuries often involves early free tissue transfer, even if the recipient site is contaminated or lacks soft tissue coverage. There are no current tissue engineering strategies to definitively regenerate tissues in such an environment at an early time point. For a tissue engineering approach to be employed in the treatment of such injuries, a two-stage approach could potentially be used. The present study describes methods for fabrication, characterization, and processing of porous polymethylmethacrylate (PMMA) space maintainers for temporary retention of space in bony craniofacial defects. Carboxymethylcellulose hydrogels were used as a porogen. Implants with controlled porosity and pore interconnectivity were fabricated by varying the ratio of hydrogel:polymer and the amount of carboxymethylcellulose within the hydrogel. The in vivo tissue response to the implants was observed by implanting solid, low-porosity, and high-porosity implants (n = 6) within a nonhealing rabbit mandibular defect that included an oral mucosal defect to allow open communication between the oral cavity and the mandibular defect. Oral mucosal wound healing was observed after 12 weeks and was complete in 3/6 defects filled with solid PMMA implants and 5/6 defects filled with either a low- or high-porosity PMMA implant. The tissue response around and within the pores of the two formulations of porous implants tested in vivo was characterized, with the low-porosity implants surrounded by a minimal but well-formed fibrous capsule in contrast to the high-porosity implants, which were surrounded and invaded by almost exclusively inflammatory tissue. On the basis of these results, PMMA implants with limited porosity hold promise for temporary implantation and space maintenance within clean/contaminated bone defects.

  7. Clinical application of a pedicle nail system with polymethylmethacrylate for osteoporotic vertebral fracture

    PubMed Central

    Tanaka, Masato; Sugimoto, Yoshihisa; Takigawa, Tomoyuki; Ozaki, Toshifumi; Konishi, Hitoshi

    2010-01-01

    The instrumentation of the osteoporotic spine may sometimes result in failure due to the loosening or pullout of the conventional pedicle screw. Moreover, augmentation of screws with polymethylmethacrylate (PMMA) has risks of complications. We developed a new and original pedicle nail system with PMMA for osteoporotic vertebral fractures. A clinical evaluation of this novel pedicle nail system utilized in patients with an osteoporotic vertebral collapse was performed to determine the effectiveness and safety of this technique. Thirty-four elderly patients who suffered from osteoporotic compression fractures were treated by posterolateral fusion using the pedicle nail system. The mean follow-up period was 37 months. Of the 25 patients with neurological symptoms, two patients improved two stages at the Frankel level. Fifteen patients improved one stage at the Frankel level, and eight other patients improved, however, their improvement did not exceed a Frankel level. Nine cases with neuralgia symptoms improved from 4.4 to 2.2 points on average on the Denis pain scale (p < 0.01). The fusion rate was 94% as determined by X-rays of flexion and extension, and the correction of the compression fracture site was maintained well. A pedicle nail system stabilizes the spinal column with osteoporosis and reduces the instrumentation failure. The technique for the insertion of the pedicle nail reduces complication from cement augmentation. The authors speculate that the strategy using the pedicle nail system for osteoporotic spine may be effective and safe when the surgery is performed through a posterior approach. PMID:20414689

  8. Flame spread over thick polymethylmethacrylate samples in a simulated and actual microgravity environment

    NASA Astrophysics Data System (ADS)

    Shah, Tirthesh Jayesh

    The NASA Burning and Suppression of Solids-II (BASS II) experiment examines the combustion of different solid materials and material geometries in microgravity. While flames in microgravity are driven by diffusion and weak advection due to crew movements and ventilation, the current NASA spacecraft material selection test method (NASA-STD- 6001 Test 1) is driven by buoyant forces as gravity is present. The overall goal of this project is to understand the burning of intermediate and thick fuels in microgravity, and devise a normal gravity test to apply to future materials. Clear cast polymethylmethacrylate (PMMA) samples 10 cm long by 1 or 2 cm wide with thicknesses ranging from 1-5 mm were investigated. PMMA is the ideal choice since it is widely used and we know its stoichiometric chemistry. Tests included both one sided and two sided burns. Samples are ignited by heating a wire behind the sample. The samples are burned in a flow duct within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS) to ensure true microgravity conditions. The experiment takes place in opposed flow with varying Oxygen concentrations and flow velocities. Flames are recorded on two cameras and later tracked to determine spread rate. Currently we are modeling combustion of PMMA using Fire Dynamics Simulator (FDS 5.5.3) and Smokeview. The entire modelling for BASS-II is done in DNS mode because of the laminar conditions and small domain. In DNS mode the Navier Stokes equations are solved without the Turbulence model. The model employs the same test sample and MSG geometry as the experiment; but in 2D. The experimental data gave upstream velocity at several points using an anemometer. A flow profile for the inlet velocity is obtained using Matlab and input into the model. The flame spread rates obtained after tracking are then compared with the experimental data and the results follow the trends but the spread rates are higher.

  9. Antibiotic-releasing Porous Polymethylmethacrylate Constructs for Osseous Space Maintenance and Infection Control

    PubMed Central

    Shi, Meng; Kretlow, James D.; Nguyen, Anson; Young, Simon; Baggett, L. Scott; Wong, Mark E.; Kasper, F. Kurtis; Mikos, Antonios G.

    2010-01-01

    The use of a strategy involving space maintenance as the initial step of a two-stage regenerative medicine approach toward reconstructing significant bony or composite tissue defects in the craniofacial area, preserves the void volume of bony defects and could promote soft tissue healing prior to the subsequent definitive repair. One of the complications with a biomaterial-based space maintenance approach is local infection, which requires early, effective eradication, ideally through local antibiotic delivery. The purpose of this study is to develop a dual function implant material for maintaining osseous space and releasing an antibiotic to eliminate local infection in bony defects. Colistin, a polymyxin antibiotic, was chosen specifically to address infections with Acinetobacter species, the most common pathogen associated with combat-related traumatic craniofacial injuries. Porous polymethylmethacrylate (PMMA) constructs incorporating poly(lactic-co-glycolic acid) (PLGA) microspheres were fabricated by mixing a clinically used bone cement formulation of PMMA powder and methylmethacrylate liquid with a carboxymethylcellulose (CMC) hydrogel (40 or 50 wt%) to impart porosity and PLGA microspheres (10 or 15 wt%) loaded with colistin to control drug release. The PMMA/CMC/PLGA construct featured mild setting temperature, controllable surface/bulk porosity by incorporation of the CMC hydrogel, reasonably strong compressive properties, and continuous drug release over a period of 5 weeks with total drug release of 68.1-88.3%, depending on the weight percentage of CMC and PLGA incorporation. The concentration of released colistin was well above its reported minimum inhibitory concentration against susceptible species for 5 weeks. This study provides information on the composition parameters that enable viable porosity characteristics/drug release kinetics of the PMMA/CMC/PLGA construct for the initial space maintenance as part of a two-stage regenerative medicine

  10. Post-marketing safety monitoring of shenqifuzheng injection: a solution made of dangshen (Radix Codonopsis) and huangqi (Radix Astragali Mongolici).

    PubMed

    Ai, Qinghua; Zhang, Wen; Xie, Yanming; Huang, Wenhua; Liang, Hong; Cao, Hui

    2014-08-01

    To identify the potential risk factors associated with Shenqifuzheng injection (SFI), a solution made of Dangshen (Radix Codonopsis) and Huangqi (Radix Astragali Mongolici), for the timely provision of information to regulatory authorities. A comprehensive analysis of the production process, quality standards, pharmacology, post-marketing clinical studies, and safety evaluation using the primary literature of adverse reactions (ADR), case analyses, and systematic reviews, intensive hospital safety monitoring of post-marketing drugs, and data provided by the hospital information system (HIS). Sub-acute toxicity tests suggesting that a dose of 15 mL/kg (concentrated solution) had specific biological effects, whereas a smaller dose engendered no observable effects. Long-term toxicity testing in domestic rabbits showed that after SFI was administered for 90 days, the animals in each dosing group showed no chronic toxic reactions. Among 20 100 cases observed, the incidence of an ADR was 1.85 per thousand. From March to November 2013, of the leading institutions and 22 sub-centers involved in the post-marketing clinical safety intensive hospital monitoring, 21 units completed 8484 cases of monitoring, and reported 23 cases of adverse reactions. No damage to renal function was found using SFI at a dosage and a treatment course larger and longer than that recommended for the adjuvant treatment of tumors. This could reduce the mortality rate of admitted patients based on the analysis of the data provided by the HIS. A total of 16 clinical case reports of adverse reactions related to SFI in 1999-2012 were obtained through literature retrieval. These reports contained information concerning 17 cases, with adverse reaction symptoms including thrombocytopenia, rash, chills, feeling cold, palpitation, dyspnea, edema of a lower extremity, palpebral edema, and superficial vein inflammation, among others. This study introduces "get full access" to the flow of information on

  11. Synergistic interaction between Astragali Radix and Rehmanniae Radix in a Chinese herbal formula to promote diabetic wound healing.

    PubMed

    Lau, Kit-Man; Lai, Kwok-Kin; Liu, Cheuk-Lun; Tam, Jacqueline Chor-Wing; To, Ming-Ho; Kwok, Hin-Fai; Lau, Ching-Po; Ko, Chun-Hay; Leung, Ping-Chung; Fung, Kwok-Pui; Poon, Simon Kar-Sing; Lau, Clara Bik-San

    2012-05-07

    Astragali Radix (AR) and Rehmanniae Radix (RR) are two traditional Chinese medicines widely used in China for treating diabetes mellitus and its complications, such as diabetic foot ulcer. In our previous study, a herbal formula NF3 comprising AR and RR in the ratio of 2:1 was found effective in enhancing diabetic wound healing in rats through the actions of tissue regeneration, angiogenesis promotion and inflammation inhibition. The aims of the present study were to investigate the herb-herb interaction (or the possible synergistic effect) between AR and RR in NF3 to promote diabetic wound healing and to identify the principal herb in the formula by evaluating the potencies of individual AR and RR in different mechanistic studies. A chemically induced diabetic foot ulcer rat model was used to examine the wound healing effect of NF3 and its individual herbs AR and RR. For mechanistic studies, murine macrophage cell (RAW 264.7) inflammation, human fibroblast (Hs27) proliferation and human endothelial cell (HMEC-1) migration assays were adopted to investigate the anti-inflammatory, granulation formation and angiogenesis-promoting activities of the herbal extracts, respectively. In the foot ulcer animal model, neither AR nor RR at clinical relevant dose (0.98g/kg) promoted diabetic wound healing. However, when they were used in combination as NF3, synergistic interaction was demonstrated, of which NF3 could significantly reduce the wound area of rats when compared to water group (p<0.01). For anti-inflammation and granulation formation, AR was more effective than RR in inhibiting lipopolysaccharide (LPS)-induced nitric oxide production from RAW 264.7 cells and promoting Hs27 fibroblast proliferation. In the aspect of angiogenesis promotion, only NF3 promoted cell migration of HMEC-1 cells. AR plays a preeminent role in the anti-inflammatory and fibroblast-proliferating activities of NF3. The inclusion of RR, however, is crucial for NF3 to exert its overall wound

  12. [Pharmacokinetics of a long-circulating PEGylated Radix Ophiopogonis polysaccharide].

    PubMed

    Wang, Zhuo-jun; Lin, Xiao; Shen, Lan; Feng, Yi; Xu, De-sheng; Ruan, Ke-feng

    2011-10-01

    The pharmacokinetics of a long-circulating PEGylated Radix Ophiopogonis polysaccharide (ROP) was investigated in rats following i.v. or s.c. administration at three dose levels (9, 20, 50 mg x kg(-1)). A moderate coupling reaction between the hydroxyl-activated ROP and the amino-terminated mPEG was chosen to produce PEGylate ROP. The grafting degree of the prepared conjugate was 1.03, and the molecular mass of mPEG used was 20 kDa. High-performance gel permeation chromatorgraphy with fluorescein isothiocyanate prelabeling was established to determine levels of the conjugate in plasma. The results showed that the elimination half-life of the conjugate following s.c. administration was basically identical to that after iv administration. An accurate linear correlation was observed between administration doses and areas under the curve of plasma conjugate level vs. time profile, regardless of the administration route. The absolute bioavailability of the conjugate following sc administration was approximately 56%, and the mean in vivo residence time was 52.1 h, increased 2.4 times compared to those of iv administration. In general, linear pharmacokinetics was observed for the conjugate within the dose range studied, and sc should be a promising administration route for the conjugate.

  13. Effects of Lead Phytochemicals of Radix Scutellariae on Acanthamoeba.

    PubMed

    Cho, Pauline; Shi, Guangsen; Yap, Maurice; Boost, Maureen V

    2016-12-01

    Acanthamoeba keratitis (AK), which is associated with noncompliant use of contact lenses, remains difficult to treat due to delayed diagnosis and paucity of therapeutic agents. Although improvements in activity against Acanthamoeba infection have been achieved in disinfecting solutions for soft contact lenses, such modifications have not been extended to those for special rigid gas permeable (RGP) contact lenses, which are increasingly used for myopia control in children. Phytochemicals present in herbs used for traditional Chinese medicine may be effective as therapeutic or preventive agents. The purpose of this study was to investigate amoebicidal properties of lead phytochemicals of Radix scutellariae alone and in combination with multipurpose (disinfecting) solutions (MPS) for RGP lenses. Viability of Acanthamoeba castellani and A. polyphaga trophozoites was determined following exposure to four phytochemicals: baicalin, baicalein, wogonoside, and oroxylin A and both alone and in combination with four RGP MPS, using a modified stand-alone technique. As individual agents, wogonoside and oroxylin A showed highest activity against A. castellani and A. polyphaga trophozoites, respectively. For both organisms, the combination of baicalein and oroxylin A was superior. Effectiveness of MPS alone did not exceed 0.27 log reduction, but addition of combined baicalein and oroxylin A resulted in 0.92 and 0.64 log reductions of A. castellani and A. polyphaga, respectively. The combination of baicalein and oroxylin A enhanced the activity of MPS for RGP contact lenses against trophozoites of two pathogens, A. castellani, and A. polyphaga, and offers a potential therapeutic and/or preventative agent for AK.

  14. Rapid analysis of Radix puerariae by near-infrared spectroscopy.

    PubMed

    Lau, Ching-Ching; Chan, Chi-On; Chau, Foo-Tim; Mok, Daniel Kam-Wah

    2009-03-13

    A new, rapid analytical method using near-infrared spectroscopy (NIRS) was developed to differentiate two species of Radix puerariae (GG), Pueraria lobata (YG) and Pueraria thomsonii (FG), and to determine the contents of puerarin, daidzin and total isoflavonoid in the samples. Five isoflavonoids, puerarin, daidzin, daidzein, genistin and genistein were analyzed simultaneously by high-performance liquid chromatography-diode array detection (HPLC-DAD). The total isoflavonoid content was exploited as critical parameter for successful discrimination of the two species. Scattering effect and baseline shift in the NIR spectra were corrected and the spectral features were enhanced by several pre-processing methods. By using linear discriminant analysis (LDA) and soft independent modeling class analogy (SIMCA), samples were separated successfully into two different clusters corresponding to the two GG species. Furthermore, sensitivity and specificity of the classification models were determined to evaluate the performance. Finally, partial least squares (PLS) regression was used to build the correlation models. The results showed that the correlation coefficients of the prediction models are R=0.970 for the puerarin, R=0.939 for daidzin and R=0.969 for total isoflavonoid. The outcome showed that NIRS can serve as routine screening in the quality control of Chinese herbal medicine (CHM).

  15. Antithrombotic Effect and Mechanism of Radix Paeoniae Rubra

    PubMed Central

    Xie, Pingyao; Cui, Lili; Shan, Yuan

    2017-01-01

    The compounds of Radix Paeoniae Rubra (RPR) were isolated and identified by bioassay-guided method, and antithrombotic effects and mechanism were investigated by the acute blood stasis rat model. The RPR extract was evaluated by APTT, TT, PT, and FIB assays in vitro. Results indicated that RPR extract exhibited the anticoagulant activity. In order to find active compounds, six compounds were isolated and identified, and four compounds, paeoniflorin (Pae), pentagalloylglucose (Pen), albiflorin (Ali), and protocatechuic acid (Pro), exhibited the anticoagulant activity in vitro. Therefore, the antithrombosis effects of RPR extract and four active compounds were investigated in vivo by measuring whole blood viscosity (WBV), plasma viscosity (PV), APTT, PT, TT, and FIB. Meanwhile, the levels of TXB2, 6-Keto-PGF1α, eNOS, and ET-1 were detected. Results suggested that RPR extract and four active compounds had the inhibition effect on thrombus formation, and the antithrombotic effects were associated with the regulation of vascular endothelium active substance, activating blood flow and anticoagulation effect. PMID:28299338

  16. Structural Characterisation of a Polysaccharide from Radix Ranunculus Ternati

    PubMed Central

    Huang, Xuefeng; Zhao, Yun; Jin, Xin

    2014-01-01

    A water soluble polysaccharide, HB-1, with a molecular weight of 23,930, was isolated from radix Ranunculi ternati. by hot water extraction, ethanol precipitation, deproteination,ultrafiltration and gel-filtration column chromatography. Its sugar composition was determined by GLC as Glc, Ara, and Gal in a molar ration of 16.071: 2.722: 1. And the absolute configuration of Glc was identified as D. Smith degradation and methylation reaction showed the proportion of —1Glc (A) was about 16%, —1Glc4— (B) about 62%, (C) about 14%, and —1Gal6— (D) about 8%. The repetitive unit was likely composed of 3 As, 3 Cs, 13 Bs and 1 D. Together with the average molecular weight, it was predictable that HB-1 consisted of about seven of the repetitive unit. The inhibition activity of HB-1 on human glioma cell line SF188 was also measured, only to find it inactive. PMID:25587330

  17. Neuroprotective and Cytotoxic Phthalides from Angelicae Sinensis Radix.

    PubMed

    Gong, Wenxia; Zhou, Yuzhi; Li, Xiao; Gao, Xiaoxia; Tian, Junsheng; Qin, Xuemei; Du, Guanhua

    2016-04-26

    Seven phthalides, including a new dimeric one named tokinolide C (7), were isolated from Angelicae Sinensis Radix and characterized. The structures of these compounds were elucidated on the basis of comprehensive analysis of spectroscopic data and comparison with literature data. All of the compounds were evaluated for their cytotoxic activities against the A549, HCT-8, and HepG2 cancer cell lines. Riligustilide (4) showed cytotoxicity against three cancer cell lines, with IC50 values of 13.82, 6.79, and 7.92 μM, respectively. Tokinolide A (6) and tokinolide C (6) exerted low cytotoxicity in these cancer cell lines, while the remaining compounds were inactive. Flow cytometry analysis was employed to evaluate the possible mechanism of cytotoxic action of riligustilide (4). We observed that compound 4 was able to arrest the cell cycle in the G1, S phases and induce apoptosis in a time-dependent manner in HCT-8 cell lines. In addition, these compounds were evaluated for neuroprotective effect against SH-SY5Y cells injured by glutamate. The result showed that ligustilide (1), Z-butylidenephthalide (3) and tokinolide A (6) exhibited significant neuroprotective effects.

  18. [National physician master Jin Shiyuan's dispensing technology of Aconiti Lateralis Radix Praeparata based on Li Shizhen's pharmaceutical academic thought].

    PubMed

    Yuan, Yi-Ping; Zhai, Hua-Qiang; Guo, Zhao-Juan; Zhang, Tian; Kong, Li-Ting; Jia, Xiao-Yu; Tian, Wei-Lan; Li, Rui

    2016-05-01

    To collect Li Shizhen's experience in Aconiti Lateralis Radix Praeparata identification and clinical application, compare and analyze national physician master Jin Shiyuan's practical operation and theoretical knowledge, which is beneficial for the inheritance and improvement of Aconiti Lateralis Radix Praeparata clinical dispensing technology. In the analysis process, CNKI, Wanfang and other databases were searched with "Aconiti Lateralis Radix Praeparata", "Li Shizhen", "pharmacological method state theory" "Jin Shiyuan" and "Chinese medicine dispensing technology" as the key words. In addition, Treatise on Febrile Disease, Compendium of Materia Medica, Chinese Pharmacopoeia(2015 edition), Notes to Medical Professions(Yi Zong Shuo Yue), and other medicine books were accessed to summarize the processing methods and decoction dosage of Aconiti Lateralis Radix Praeparata in both ancient and modern medicine, and in consideration of technical research and practice operation, Li Shizhen's description of Aconiti Lateralis Radix Praeparata and Professor Jin Shiyuan's research on Aconiti Lateralis Radix Praeparata dispensing technology were analyzed and collected. Li Shizhen recorded the nature identification and clinical application of Aconiti Lateralis Radix Praeparata by using pharmacological method state theory in Compendium of Materia Medica. National physician master Jin Shiyuan carries forward the essence of Li Shizhen's pharmaceutical academic thought with his own proficient knowledge structure in medicine, providing scientific pharmaceutical service for clinical application of Aconiti Lateralis Radix Praeparata Professor. Jin Shiyuan put forward the dispensing technology for the first time, including nature identification technology, clinical processing technology, clinical decocting technology, prescription coping technology, and class specifications of Aconiti Lateralis Radix Praeparata. In this paper, Aconiti Lateralis Radix Praeparata was used as an example

  19. [Study on detoxication of euphorbia pekinensis radix processed with vinegar on rat small intestinal crypt epithelial cells IEC-6].

    PubMed

    Cao, Yu-Dan; Yan, Xiao-Jing; Zhang, Li; Ding, An-Wei

    2014-03-01

    To compare the difference of Euphorbia Pekinensis Radix before and after being processed with vinegar in the toxicity on rat small intestinal crypt epithelial cells IEC-6, and make a preliminary study on the mechanism of detoxication of Euphorbia Pekinensis Radix processed with vinegar. With rat small intestinal crypt epithelial cells IEC-6 as the study object, the MTT method was adopted to detect the effect of Euphorbia Pekinensis Radix before and after being processed with vinegar on IEC-6 cell activity. The morphology of cells were observed by the inverted microscope. The down-regulated mitochondrial apoptosis pathway of enterocytes caused by the vinegar processing was analyzed by using the high content screening. Compared with the negative control group, the proliferation inhibition experiment showed that Euphorbia Pekinensis Radix showed a relatively high intestinal cell toxicity (P < 0.01). The results of HCS analysis showed that Euphorbia Pekinensis Radix could significantly reduce the cell nucleus Hoechst fluorescence intensity and mitochondria membrane (P < 0.05, P < 0.01), and increase Annexin V-FITC and PI fluorescence intensity and membrane permeability (P < 0.01, P < 0.01, P < 0.01). After being processed with vinegar, compared with Euphorbia Pekinensis Radix groups with different doses, Euphorbia Pekinensis Radix processed with vinegar could significantly decrease the cell proliferation inhibition effect on enterocytes, increase the cell nuclear Hoechst fluorescence intensity and mitochondria membrane (P < 0.05, P < 0.05), and decrease Annexin V-FITC and PI fluorescence intensity and membrane permeability (P < 0.01, P < 0.01, P < 0.05), and showed a certain dose-effect relationship. The vinegar processing can further reduce the toxicity of Euphorbia Pekinensis Radix on enterocytes. Its possible mechanism can decrease the effect of Euphorbia Pekinensis Radix on the permeability of IEC-6 cell membrane, so as to provide a basis for further explanation of

  20. [Optimization of stir-baking with vinegar technology for Curcumae Radix by orthogonal test].

    PubMed

    Shi, Dianhua; Su, Benzheng; Sun, Lili; Zhang, Jun; Qu, Yongsheng

    2011-05-01

    To optimize the stir-baking with vinegar technology for Curcumae Radix. The intrinsic quality (the content of Curcumin) and traditional outward appearance were chosen as indexes. The best technology was determined by orthogonal test L9 (3(4)). The factors of the moistening time, stir-baking temperature and stir-baking time were investigated. The optimal technology was as follows: the quantity of vinegar was 10%, the moistening time was 10 min, the stir-baking temperature was 130 degrees C and the stir-baking time was 10 min. The optimal stir-baking with vinegar technology for Curcumae Radix is reasonable, which can be used to guide the standardized production of Curcumae Radix stir-baked with vinegar.

  1. [Determination of diosgenin and ruscogenin in Radix Ophiopogonis by nonaqueous capillary electrophoresis].

    PubMed

    Huang, Bao-mei; Yao, Cheng-wei; Bian, Qing-quan; Wang, Zhi-guo; Mo, Jin-yuan

    2011-04-01

    Nonaqueous capillary electrophoresis is used for the determination of the contents of diosgenin and ruscogenin in Radix Ophiopogonis. The operating buffer was composed of 20 mmol x L(-1) Na2B4O7-HCl (pH 7.61) in 70% methanol. The applied voltage was 25 kV and detection potential was at +0.70 V. With these conditions, the components were successfully separated. The content of diosgenin in Radix Ophiopogonis was 0.018 mg x g(-1) and ruscogenin was 0.008 mg x g(-1). The average recoveries of diosgenin and ruscogenin were 102% and 99.2%, respectively. A new method of the quality control of diosgenin and ruscogenin in Radix Ophiopogonis is provided.

  2. Promotion of hair growth by ginseng radix on cultured mouse vibrissal hair follicles.

    PubMed

    Matsuda, Hideaki; Yamazaki, Miho; Asanuma, Yusuke; Kubo, Michinori

    2003-08-01

    A 70% methanol extract from red ginseng (steamed and dried roots of Panax ginseng C. A. Meyer, a kind of Ginseng Radix) had superior activity to that of white ginseng (peeled and dried root of P. ginseng, another kind of Ginseng Radix) in a hair growth promoting assay using mouse vibrissal follicles in organ culture. Of the major constituents of P. ginseng, ginsenoside-Rb(1) (G-Rb(1)) exhibited activity, but ginsenoside-Rg(1) (G-Rg(1)) and -Ro (G-Ro) were ineffective. Additionally, 20(S)-ginsenoside-Rg(3) (20(S)-G-Rg(3)) formed by the processing of red ginseng from the crude root of P. ginseng also showed hair growth promoting activity. These results indicate that Ginseng Radix possesses hair growth promoting activity, and its bioactive components are partially attributable to the ginseng saponin components mentioned above.

  3. [Influence of drying method on content of epigoitrin and uridine in isatidis radix].

    PubMed

    Tan, Ming-Ming; Huang, Yong; Xu, Xiao-Fei; Zhang, Zhuo-Neng; Deng, Qiao-Hua

    2014-04-01

    To study the influence of different drying methods on the content of epigoitrin and uridine in Isatidis Radix. Fresh Isatidis Radix was processed by four drying methods including airing drying and drying in far infrared oven at different temperature,drying in the sun and drying in the shade. The contents of epigoitrin and uridine were determined by HPLC. The contents of epigoitrin as well as uridine in samples valued from 3.847 - 5.204 mg/g and 0.701 - 1.028 mg/g, respectively. The optimal drying method is airing drying at 55 degrees C, which will be serviced in the large-scale processing of Isatidis Radix.

  4. The decoction of radix Astragali inhibits the growth of Microcystis aeruginosa.

    PubMed

    Yan, Rong; Wu, Yonghong; Ji, Hongli; Fang, Yanming; Kerr, Philip G; Yang, Linzhang

    2011-05-01

    Many measures have been developed to control the harmful algal blooms that are potentially threatening potable waters. The pilot experiments showed that the unfiltered and the sterile-filtered decoctions of radix Astragali inhibited the growth of Microcystis aeruginosa. The inhibitory effect diminished in natural pond conditions after 68 days, due to photo-degradation of the flavonoids from radix Astragali that appear to be responsible for the action on M. aeruginosa. Four phases (assemblage, conglomeration, cell membrane destruction and decomposition) can be characterized in the process of cell death with increasing decoction dose. The quantum yields and electron transport rates of photosynthesis system II of M. aeruginosa cells markedly decreased during contact with the decoction, resulting in the disruption of M. aeruginosa photosynthesis. The results indicate that the application of radix Astragali decoction for the inhibition of M. aeruginosa growth is feasible when the dose is less than 20 ml L(-1). Copyright © 2011 Elsevier Inc. All rights reserved.

  5. On the design of a radix-10 online floating-point multiplier

    NASA Astrophysics Data System (ADS)

    McIlhenny, Robert D.; Ercegovac, Milos D.

    2009-08-01

    This paper describes an approach to design and implement a radix-10 online floating-point multiplier. An online approach is considered because it offers computational flexibility not available with conventional arithmetic. The design was coded in VHDL and compiled, synthesized, and mapped onto a Virtex 5 FPGA to measure cost in terms of LUTs (look-up-tables) as well as the cycle time and total latency. The routing delay which was not optimized is the major component in the cycle time. For a rough estimate of the cost/latency characteristics, our design was compared to a standard radix-2 floating-point multiplier of equivalent precision. The results demonstrate that even an unoptimized radix-10 online design is an attractive implementation alternative for FPGA floating-point multiplication.

  6. Development and characterization of a three-dimensional radiochromic film stack dosimeter for megavoltage photon beam dosimetry

    SciTech Connect

    McCaw, Travis J. Micka, John A.; DeWerd, Larry A.

    2014-05-15

    Purpose: Three-dimensional (3D) dosimeters are particularly useful for verifying the commissioning of treatment planning and delivery systems, especially with the ever-increasing implementation of complex and conformal radiotherapy techniques such as volumetric modulated arc therapy. However, currently available 3D dosimeters require extensive experience to prepare and analyze, and are subject to large measurement uncertainties. This work aims to provide a more readily implementable 3D dosimeter with the development and characterization of a radiochromic film stack dosimeter for megavoltage photon beam dosimetry. Methods: A film stack dosimeter was developed using Gafchromic{sup ®} EBT2 films. The dosimeter consists of 22 films separated by 1 mm-thick spacers. A Virtual Water™ phantom was created that maintains the radial film alignment within a maximum uncertainty of 0.3 mm. The film stack dosimeter was characterized using simulations and measurements of 6 MV fields. The absorbed-dose energy dependence and orientation dependence of the film stack dosimeter were investigated using Monte Carlo simulations. The water equivalence of the dosimeter was determined by comparing percentage-depth-dose (PDD) profiles measured with the film stack dosimeter and simulated using Monte Carlo methods. Film stack dosimeter measurements were verified with thermoluminescent dosimeter (TLD) microcube measurements. The film stack dosimeter was also used to verify the delivery of an intensity-modulated radiation therapy (IMRT) procedure. Results: The absorbed-dose energy response of EBT2 film differs less than 1.5% between the calibration and film stack dosimeter geometries for a 6 MV spectrum. Over a series of beam angles ranging from normal incidence to parallel incidence, the overall variation in the response of the film stack dosimeter is within a range of 2.5%. Relative to the response to a normally incident beam, the film stack dosimeter exhibits a 1% under-response when the

  7. [The extraction technology of epigoitri from isatidis radix by supercritical CO2 fluid].

    PubMed

    Nian, Si-Hui; Liu, Chun-Yun; Liu, Li-Min; Yang, Li-Fen

    2013-07-01

    To study the extraction technology of epigoitri from Isatidis Radix by supercritical CO2 fluid. The effects of pressure, temperature, time, concentration and dosage of alcohol were studied by single factor analysis and orthogonal test. The optimized conditions were as follows: The pressure was 20 MPs, the temperature was 50 degrees C, the time was 2 h, concentration of alcohol was 100%, dosage was 80 mL. The content of epigoitri in the extract could reach 38.63% under the above conditions. This method is simple, rapid and it is suitable for the extraction of epigoitri from Isatidis Radix.

  8. Green biosynthesis of silver nanoparticles using Althaea officinalis radix hydroalcoholic extract.

    PubMed

    Korbekandi, Hassan; Asghari, Gholamreza; Chitsazi, Mohammad Reza; Bahri Najafi, Rahim; Badii, Akbar; Iravani, Siavash

    2016-01-01

    The objectives were to study the potential of Althaea officinalis radix in production of silver NPs, and the effect of the extract ethanol concentration on the produced NPs. Seventy and ninety-six percent hydroalcoholic extracts were prepared by percolation of the plant powder. The extract was concentrated by rotary evaporator and then freeze-dried. Silver ions were determined using atomic absorption analysis. The NPs were characterized by Nano-Zeta Sizer and TEM. Both of 70% and 96% of hydroalcoholic extracts of A. officinalis radix successfully synthesized spherical and poly-dispersed silver NPs. The conversion was fast and almost completed in 5 h.

  9. [Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis].

    PubMed

    Sun, H L; Li, C D; Yang, Z C; Yi, X D; Liu, H; Lu, H L; Li, H; Wang, Y

    2016-12-18

    To describe the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis. Observation group included 14 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws from November 2014 to July 2015, control group included 12 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation with traditional pedicle screws.The operation time, blood loss, number of pedicle screws and number of augmented pedicle screws in the two groups were compared. The bone cement leakage and pulmonary bone cement embolism in the two groups were also compared. The fusion rate and pedicle screws loosening by lumbar X ray and dynamic X ray were evaluated. The clinical results were assessed by visual analog scale (VAS) of pain on lumbar and lower limbers, lumbar Japanese Orthopaedic Association scores (JOA), Prolo functional scores and Oswestry disability (ODI) scores. Differences of operation time and blood loss in the two groups were not statistically significant. The average number of pedicle screws was 9.9±4.7 and the average number of augmented pedicle screws was 5.9±2.6 in observation group while the average number of pedicle screws was 7.1±2.8 and the average number of augmented pedicle screws was 3.0±1.9 in control group. The ratio of augmented pedicle screws was higher in observation group than in control group (0.69±0.30 vs.0.47±0.30,P<0.05). The bone cement leakage rate was lower in observation group than in control group (5/83 vs. 12/42, P<0.01). All the cases in observation group were without leakage to the interspinal canal while one case in control group suffered from bone cement leakage to the interspinal canal with augmentation of 3 pedicle screws. The follow up period was (10.6±2.3) months in observation group and (36.5±7

  10. A high-quality narrow passband filter for elastic SV waves via aligned parallel separated thin polymethylmethacrylate plates

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Liu, Yaolu; Yan, Wensheng; Hu, Ning

    2017-08-01

    We designed a high-quality filter that consists of aligned parallel polymethylmethacrylate (PMMA) thin plates with small gaps for elastic SV waves propagate in metals. Both the theoretical model and the full numerical simulation show the transmission spectrum of the elastic SV waves through such a filter has several sharp peaks with flawless transmission within the investigated frequencies. These peaks can be readily tuned by manipulating the geometry parameters of the PMMA plates. Our investigation finds that the same filter performs well for different metals where the elastic SV waves propagated.

  11. Antispasmodic effect of shakuyakukanzoto extract on experimental muscle cramps in vivo: role of the active constituents of Glycyrrhizae radix.

    PubMed

    Lee, Keiko K; Omiya, Yuji; Yuzurihara, Mitsutoshi; Kase, Yoshio; Kobayashi, Hiroyuki

    2013-01-09

    Shakuyakukanzoto (SKT) composed of Glycyrrhizae radix (G. radix) and Paeoniae radix (P. radix) has been traditionally used in Japan, Korea and China as an antispasmodic drug for the treatment of skeletal muscle cramps and intestinal cramps. To evaluate the antispasmodic activity of SKT and its two components, as well as to identify the key constituents of the components which mediate this effect in skeletal muscles in vivo. An experimental cramp model was constructed to evaluate the effects of peripherally-acting muscle relaxants on electrically-induced cramps under physiological conditions. This was accomplished by surgically isolating the motor supply to the gastrocnemius muscle in an anesthetized rat and delivering electrical stimuli to an isolated tibial nerve to induce tetanic contractions. We first tested dantrolene, a well-known peripherally-acting relaxant, to determine the sensitivity and reliability of our experimental model. We then evaluated the effects of SKT, P. radix, G. radix, and the eight active constituents of G. radix against tetanic contractions. We found that dantrolene (10 and 30 mg/kg, i.d.) rapidly and significantly inhibited tetanic contractions (P<0.01) irrespective of dose. SKT (0.5, 1.0, and 2.0 g/kg, i.d.) and G. radix (0.5 and 1.0 g/kg, i.d.) also significantly inhibited tetanic contractions (P<0.01) but in a dose-dependent manner owing to the actions of six of the eight active constituents in G. radix (liquiritin apioside, liquiritigenin, isoliquiritin apioside, isoliquiritigenin, glycycoumarin, and glycyrrhetinic acid, 20 μmol/kg, i.v.). These constituents, which include flavonoids, a triterpenoid, and a courmarin derivative, demonstrated temporal variations in their inhibitory activity. In contrast, P. radix (0.5 and 1.0 g/kg, i.d.) did not show a statistically significant antispasmodic effect in our study; however, we previously found that it had a significant antinociceptive effect. Our findings show that SKT inhibits tetanic

  12. Radiological properties of the PRESAGE and PAGAT polymer dosimeters.

    PubMed

    Brown, S; Venning, A; De Deene, Y; Vial, P; Oliver, L; Adamovics, J; Baldock, C

    2008-12-01

    The radiological properties of the PRESAGE and PAGAT polymer dosimeters have been investigated and their water equivalence determined for use in radiotherapy dosimetry. The radiological water equivalence of each of the polymer dosimeters was determined by comparing the photon and electron interaction cross-sections over the 10 keV-20 MeV energy range and by Monte Carlo modelling the depth dose from a linear accelerator using the BEAMnrc software package. PRESAGE was found to have an effective Z-value and mass density (kgm(-3)) approximately 17% and 10% higher than water, respectively. A maximum difference of 85% was discovered in the photoelectric interaction probability curve of PRESAGE when compared to water over the energy range 10-100 keV, partially due to the Z(3) dependence of the photoelectric effect. The mass radiative stopping power ratios and mass scattering power ratios were both found to have less than 9% difference from water. The depth dose for PRESAGE from a 6MV photon beam had an absolute percentage difference to water of less than 2% and a relative percentage difference of less than 8%. The mass density of PAGAT was found to be 2.6% higher than water due to its high gelatine and monomer concentration. The cross-sectional attenuation and absorption coefficient ratios were found to be within 5% for energies between 10 and 100 keV and within 1% for energies between 100 keV and 20 MeV. The mass collisional stopping power, mass radiative stopping power and mass scattering power ratios were all less than 1% over the energy range studied. The depth dose had an absolute percentage difference to water of less than 1% and a relative percentage difference of less than 2.5%. These results indicate that the PAGAT polymer gel formulation is more radiological water equivalent than the PRESAGE formulation. However, the PRESAGE dosimeter offers some advantages in terms of ease of use and its lack of water equivalence may be overcome with dosimetric correction

  13. Characterization of the nanoDot OSLD dosimeter in CT

    SciTech Connect

    Scarboro, Sarah B.; Cody, Dianna; Followill, David; Court, Laurence; Stingo, Francesco C.; Kry, Stephen F.; Alvarez, Paola; Zhang, Di; McNitt-Gray, Michael

    2015-04-15

    Purpose: The extensive use of computed tomography (CT) in diagnostic procedures is accompanied by a growing need for more accurate and patient-specific dosimetry techniques. Optically stimulated luminescent dosimeters (OSLDs) offer a potential solution for patient-specific CT point-based surface dosimetry by measuring air kerma. The purpose of this work was to characterize the OSLD nanoDot for CT dosimetry, quantifying necessary correction factors, and evaluating the uncertainty of these factors. Methods: A characterization of the Landauer OSL nanoDot (Landauer, Inc., Greenwood, IL) was conducted using both measurements and theoretical approaches in a CT environment. The effects of signal depletion, signal fading, dose linearity, and angular dependence were characterized through direct measurement for CT energies (80–140 kV) and delivered doses ranging from ∼5 to >1000 mGy. Energy dependence as a function of scan parameters was evaluated using two independent approaches: direct measurement and a theoretical approach based on Burlin cavity theory and Monte Carlo simulated spectra. This beam-quality dependence was evaluated for a range of CT scanning parameters. Results: Correction factors for the dosimeter response in terms of signal fading, dose linearity, and angular dependence were found to be small for most measurement conditions (<3%). The relative uncertainty was determined for each factor and reported at the two-sigma level. Differences in irradiation geometry (rotational versus static) resulted in a difference in dosimeter signal of 3% on average. Beam quality varied with scan parameters and necessitated the largest correction factor, ranging from 0.80 to 1.15 relative to a calibration performed in air using a 120 kV beam. Good agreement was found between the theoretical and measurement approaches. Conclusions: Correction factors for the measurement of air kerma were generally small for CT dosimetry, although angular effects, and particularly effects due

  14. CCD imaging for optical tomography of gel radiation dosimeters.

    PubMed

    Wolodzko, J G; Marsden, C; Appleby, A

    1999-11-01

    Several investigations have been carried out by a number of researchers over the past few years to evaluate the utility of imaging gel dosimeters for the three-dimensional measurement of radiation fields. These have been proposed to be of particular value in mapping radiation dose distributions associated with emerging and complex approaches to cancer treatment such as conformal (CRT), intensity modulated (IMRT), "gamma knife," and pencil beam radiotherapies. Imaging of the gels has been successfully accomplished with clinical MRI units and via laser-based optical scanning. However, neither of these methods is generally accessible to all potential users, limiting the broader study and implementation of this valuable tool. We report here the design, methodology, and results of a preliminary study carried out to evaluate the utility of a new, inexpensive, and simplified approach to tomographic imaging of gel radiation dosimeters. For the purpose of this initial investigation, an array of liquid scintillation vials was prepared, containing a ferrous sulphate xylenol orange (FSX) gelatin formulation. The FSX formulation undergoes a change in optical absorption characteristics following irradiation, and the resulting color change can be observed visually. The vials were irradiated individually to different doses. Three-dimensional imaging was accomplished by tomographic reconstruction from two-dimensional optical images acquired using a diffuse, fluorescent light source, a digital charge-coupled device camera, single-photon-emission-computed tomography software, and other simple components designed by the authors. The resulting transverse images were evaluated through a region-of-interest (ROI) analysis to obtain the average change in image density in each vial as a function of radiation dose. These measured ROI values were subjected to a linear regression analysis to fit them to a straight line, and to determine the goodness of fit. Results from multiple imaging trials

  15. Characterization of the nanoDot OSLD dosimeter in CT

    PubMed Central

    Scarboro, Sarah B.; Cody, Dianna; Alvarez, Paola; Followill, David; Court, Laurence; Stingo, Francesco C.; Zhang, Di; Kry, Stephen F.

    2015-01-01

    Purpose: The extensive use of computed tomography (CT) in diagnostic procedures is accompanied by a growing need for more accurate and patient-specific dosimetry techniques. Optically stimulated luminescent dosimeters (OSLDs) offer a potential solution for patient-specific CT point-based surface dosimetry by measuring air kerma. The purpose of this work was to characterize the OSLD nanoDot for CT dosimetry, quantifying necessary correction factors, and evaluating the uncertainty of these factors. Methods: A characterization of the Landauer OSL nanoDot (Landauer, Inc., Greenwood, IL) was conducted using both measurements and theoretical approaches in a CT environment. The effects of signal depletion, signal fading, dose linearity, and angular dependence were characterized through direct measurement for CT energies (80–140 kV) and delivered doses ranging from ∼5 to >1000 mGy. Energy dependence as a function of scan parameters was evaluated using two independent approaches: direct measurement and a theoretical approach based on Burlin cavity theory and Monte Carlo simulated spectra. This beam-quality dependence was evaluated for a range of CT scanning parameters. Results: Correction factors for the dosimeter response in terms of signal fading, dose linearity, and angular dependence were found to be small for most measurement conditions (<3%). The relative uncertainty was determined for each factor and reported at the two-sigma level. Differences in irradiation geometry (rotational versus static) resulted in a difference in dosimeter signal of 3% on average. Beam quality varied with scan parameters and necessitated the largest correction factor, ranging from 0.80 to 1.15 relative to a calibration performed in air using a 120 kV beam. Good agreement was found between the theoretical and measurement approaches. Conclusions: Correction factors for the measurement of air kerma were generally small for CT dosimetry, although angular effects, and particularly effects due

  16. The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere.

    PubMed

    Yang, Zhen; Chen, Bo; Zhuo, Weihai; Fan, Dunhuang; Zhao, Chao; Zhang, Yu

    2015-12-01

    For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of (137)Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmic rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.

  17. The responses of three kinds of passive dosimeters to secondary cosmic rays in the lower atmosphere

    SciTech Connect

    Yang, Zhen; Chen, Bo Zhuo, Weihai; Fan, Dunhuang; Zhang, Yu; Zhao, Chao

    2015-12-15

    For accurate measurements of the secondary cosmic rays by using passive dosimeters, the relative responses of the thermoluminescence dosimeter (TLD), optically stimulated luminescence (OSL) dosimeter, and radiophotoluminescent glass dosimeter (RPLGD) were studied. The cosmic-ray shower generator was used to simulate the secondary cosmic rays at the sea level. Monte Carlo simulations were performed to calculate the air kerma and absorbed doses in each kind of dosimeter. The results showed that compared with their responses to gamma rays of {sup 137}Cs, the relative responses of the TLD, OSL, and RPLGD were 0.786, 0.707, and 0.735 to the hard component of cosmic rays, respectively, and the values were 0.904, 0.838, and 0.857 to the soft component of cosmic rays, respectively. To verify the simulations results, an in situ measurement with the three kinds of dosimeters was performed at the same place. The results indicated that the secondary cosmic rays monitored with the three kinds of dosimeters were well consistent with each other provided their relative responses were taken into account.

  18. Feasibility study of a lead monoxide-based dosimeter for quality assurance in radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, K. T.; Han, M. J.; Heo, Y. J.; Park, J. E.; Lee, Y. K.; Kim, J. N.; Oh, K. M.; Cho, H. L.; Choi, Y. S.; Kim, J. Y.; Nam, S. H.; Park, S. K.

    2016-11-01

    Lately, cancer has been treated using high-energy radiation, and this requires highly reliable treatment plans. Therefore, a dosimeter with excellent performance, which is capable of precise dose measurement, is critical. In current clinical practices, an ionization chamber and diode utilizing the ionization reaction mechanism are widely used. Several studies have been carried out to determine optimal materials for the detector in a dosimeter to enable diagnostic imaging. Recently, studies with lead monoxide, which was shown to have low drift current and high resolving power at a high bias, were reported with the dosimeter exhibiting a fast response time against incident photons. This research aims to investigate the feasibility of a lead monoxide-based dosimeter for QA (quality assurance) in radiotherapy. In this paper, we report that the manufactured dosimeter shows similar linearity to a silicon diode and demonstrates similar characteristics in terms of PDD (percent depth dose) results for the thimble ionization chamber. Based on these results, it is demonstrated that the lead monoxide-based dosimeter complies with radiotherapy QA requirements, namely rapid response time, dose linearity, dose rate independence. Thus, we expect the lead monoxide-based dosimeter to be used commercially in the future.

  19. Monte Carlo-based energy response studies of diode dosimeters in radiotherapy photon beams.

    PubMed

    Arun, C; Palani Selvam, T; Dinkar, Verma; Munshi, Prabhat; Kalra, Manjit Singh

    2013-01-01

    This study presents Monte Carlo-calculated absolute and normalized (relative to a (60)Co beam) sensitivity values of silicon diode dosimeters for a variety of commercially available silicon diode dosimeters for radiotherapy photon beams in the energy range of (60)Co-24 MV. These values were obtained at 5 cm depth along the central axis of a water-equivalent phantom of 10 cm × 10 cm field size. The Monte Carlo calculations were based on the EGSnrc code system. The diode dosimeters considered in the calculations have different buildup materials such as aluminum, brass, copper, and stainless steel + epoxy. The calculated normalized sensitivity values of the diode dosimeters were then compared to previously published measured values for photon beams at (60)Co-20 MV. The comparison showed reasonable agreement for some diode dosimeters and deviations of 5-17 % (17 % for the 3.4 mm brass buildup case for a 10 MV beam) for some diode dosimeters. Larger deviations of the measurements reflect that these models of the diode dosimeter were too simple. The effect of wall materials on the absorbed dose to the diode was studied and the results are presented. Spencer-Attix and Bragg-Gray stopping power ratios (SPRs) of water-to-diode were calculated at 5 cm depth in water. The Bragg-Gray SPRs of water-to-diode compare well with Spencer-Attix SPRs for ∆ = 100 keV and above at all beam qualities.

  20. [Is it really not possible to use electronic personal dosimeters in clinical exposure situations?].

    PubMed

    Borowski, M; Poppe, B; Looe, H K; von Boetticher, H

    2010-09-01

    Due to significant measuring inaccuracies that can occur under certain conditions, the use of electronic personal dosimeters in statutory measurements in X-ray diagnostics is currently legally restricted. The present study investigates the clinically relevant situations in which measurement errors of more then 20 % can be anticipated. Four series of experiments were made, comparing the results of the electronic personal dosimeter EPD Mk2.3 to those of reference dosimeters (TLDs and diagnostic dosimeters). On the one hand, personal doses have been determined in the routine operation of controlled areas in various departments. On the other hand, measurements on phantoms have been conducted in extreme but realistic situations under radiation protection. Experiments were conducted in unweakened scattered radiation as well as in unattenuated and attenuated direct radiation. The tested electronic personal dosimeter type meets the requirements regarding measurement accuracy for "official" personal dosimeters in all of the examined clinically relevant scattered radiation fields. Only if exposed to radiation directly, an underestimation of the dose can occur and can be greater than 90 %. In the range of scattered radiation of diagnostic X-ray equipment, even in pulsed fields, the use of electronic personal dosimeters is reasonable. Considerable measurement errors can only arise in radiation fields that are not realistic under regular conditions and even in connection with most accidents. Georg Thieme Verlag KG Stuttgart, New York.

  1. Feasibility study of a lead monoxide-based dosimeter for quality assurance in radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, K. T.; Han, M. J.; Heo, Y. J.; Park, J. E.; Lee, Y. K.; Kim, J. N.; Oh, K. M.; Cho, H. L.; Choi, Y. S.; Kim, J. Y.; Nam, S. H.; Park, S. K.

    2016-11-01

    Lately, cancer has been treated using high-energy radiation, and this requires highly reliable treatment plans. Therefore, a dosimeter with excellent performance, which is capable of precise dose measurement, is critical. In current clinical practices, an ionization chamber and diode utilizing the ionization reaction mechanism are widely used. Several studies have been carried out to determine optimal materials for the detector in a dosimeter to enable diagnostic imaging. Recently, studies with lead monoxide, which was shown to have low drift current and high resolving power at a high bias, were reported with the dosimeter exhibiting a fast response time against incident photons. This research aims to investigate the feasibility of a lead monoxide-based dosimeter for QA (quality assurance) in radiotherapy. In this paper, we report that the manufactured dosimeter shows similar linearity to a silicon diode and demonstrates similar characteristics in terms of PDD (percent depth dose) results for the thimble ionization chamber. Based on these results, it is demonstrated that the lead monoxide-based dosimeter complies with radiotherapy QA requirements, namely rapid response time, dose linearity, dose rate independence. Thus, we expect the lead monoxide-based dosimeter to be used commercially in the future.

  2. [Data mining analysis of regularity of formulas containing Salviae Miltiorrhizae Radix et Rhizoma-Carthami Flos medicin pair in Dictionary of Chinese Medicine Prescription].

    PubMed

    Cui, Yi-Ran; Liu, Xin; Shen, Dan; Yang, Hong-Jun; Tang, Shi-Huan

    2016-02-01

    In this study, formulas containing Salviae Miltiorrhizae Radix et Rhizoma-Carthami Flos in the database of Dictionary of Chinese Medicine Prescription (DCMP) were extracted by using traditional Chinese medicine inheritance support system (TCMISS). The drugs pairs and formula composition rules were analyzed with data mining methods, such as association rules, improved mutual information method and complex system entropy clustering. Totally 39 formulas were included in this study and involved 280 Chinese medicines. The top 5 Chinese medicines most frequently used were Danggui (Angelica sinensis), Chuanxiong (Ligusticum chuanxiong), Xiangfu (Cyperi Rhizoma), Baishao(Radix Paeoniae Alba), Taoren(Prunus persica) and Shengdihuang (Radix Rehmanniae Recens). Six core medicinal pairs were obtained through clustering analysis, namely Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Xiangfu (Cyperi Rhizoma)-Honghua (Carthami Flos), Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Baishao (Radix Paeoniae Alba)-Honghua (Carthami Flos), Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Danggui (A. sinensis)-Xiagnfu (Cyperi Rhizoma)-Honghua (Carthami Flos), Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Danggui (A. sinensis)-Baishao (Radix Paeoniae Alba)-Honghua (Carthami Flos), Honghua (Carthami Flos)-Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Baishao (Radix Paeoniae Alba)-Danggui (A. sinensis), Danshen (Salviae Miltiorrhizae Radix et Rhizoma)-Baishao (Radix Paeoniae Alba)-Honghua (Carthami Flos)-Danggui (A. sinensis). The support degree was set at 11 (38.46%), with a confidence coefficient of 80%, and then 38 associated pairs were screened. These results suggested that Salviae Miltiorrhizae Radix et Rhizoma, Carthami Flos is often combined with herbs for activating blood and promoting circulation of qi to treat gynecopathy, stasis blood pain syndrome, stroke and other syndromes. Copyright© by the Chinese Pharmaceutical Association.

  3. Ground-based evaluation of dosimeters for NASA high-altitude balloon flight

    NASA Astrophysics Data System (ADS)

    Straume, T.; Mertens, C. J.; Lusby, T. C.; Gersey, B.; Tobiska, W. K.; Norman, R. B.; Gronoff, G. P.; Hands, A.

    2016-11-01

    Results are presented from evaluations of radiation dosimeters prior to a NASA high-altitude balloon flight, the RaD-X mission. Four radiation dosimeters were on board RaD-X: a Far West Hawk (version 3), a Teledyne dosimeter (UDOS001), a Liulin dosimeter (MDU 6SA1), and a RaySure dosimeter (version 3b). The Hawk is a tissue-equivalent proportional counter (TEPC) and the others are solid-state Si sensors. The Hawk served as the "flight standard" and was calibrated for this mission. The Si-based dosimeters were tested to make sure they functioned properly prior to flight but were not calibrated for the radiation environment in the stratosphere. The dosimeters were exposed to 60Co gamma rays and 252Cf fission radiation (which includes both neutrons and gamma rays) at the Lawrence Livermore National Laboratory (LLNL). The measurement results were compared with results from standard "benchmark" measurements of the same sources and source-to-detector distances performed contemporaneously by LLNL calibration facility personnel. For 60Co gamma rays, the dosimeter-to-benchmark ratios were 0.84 ± 0.06, 1.07 ± 0.32, 1.31 ± 0.07, and 0.82 ± 0.24 for the TEPC, Teledyne, Liulin, and RaySure, respectively. For 252Cf radiation, the dosimeter-to-benchmark ratios were 0.94 ± 0.15, 0.55 ± 0.18, 0.58 ± 0.08, and 0.33 ± 0.12 for the TEPC, Teledyne, Liulin, and RaySure. Some examples of how the results were used to help interpret the flight data are also presented.

  4. An NMR relaxometry and gravimetric study of gelatin-free aqueous polyacrylamide dosimeters

    NASA Astrophysics Data System (ADS)

    Babic, Steven; Schreiner, L. John

    2006-09-01

    In conformal radiation therapy, a high dose of radiation is given to a target volume to increase the probability of cure, and care is taken to minimize the dose to surrounding healthy tissue. The techniques used to achieve this are very complicated and the precise verification of the resulting three-dimensional (3D) dose distribution is required. Polyacrylamide gelatin (PAG) dosimeters with magnetic resonance imaging and optical computed tomography scanning provide the required 3D dosimetry with high spatial resolution. Many basic studies have characterized these chemical dosimeters that polymerize under irradiation. However, the investigation of the fundamental properties of the radiation-induced polymerization in PAG dosimeters is complicated by the presence of the background gelatin matrix. In this work, a gelatin-free model system for the study of the basic radiation-induced polymerization in PAG dosimeters has been developed. Experiments were performed on gelatin-free dosimeters, named aqueous polyacrylamide (APA) dosimeters, containing equal amounts of acrylamide and N,N'-methylene-bisacrylamide. The APA dosimeters were prepared with four different total monomer concentrations (2, 4, 6 and 8% by weight). Nuclear magnetic resonance (NMR) spin-spin and spin-lattice proton relaxation measurements at 20 MHz, and gravimetric analyses performed on all four dosimeters, show a continuous degree of polymerization over the dose range of 0-25 Gy. The developed NMR model explains the relationship observed between the relaxation data and the amount of crosslinked polymer formed at each dose. This model can be extended with gelatin relaxation data to provide a fundamental understanding of radiation-induced polymerization in the conventional PAG dosimeters.

  5. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    SciTech Connect

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford`s mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  6. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    SciTech Connect

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  7. Applicability of the Sunna dosimeter for food irradiation control

    NASA Astrophysics Data System (ADS)

    Kovács, A.; Baranyai, M.; Wojnárovits, L.; Miller, S.; Murphy, M.; McLaughlin, W. L.; Slezsák, I.; Kovács, A. I.

    2002-03-01

    The quick development concerning the commercial application of food irradiation in the USA recently resulted in growing marketing of irradiated red meat as well as irradiated fresh and dried fruits. These gamma and electron irradiation technologies require specific dosimetry systems for process control. The new version of the Sunna dosimeter has been characterized in gamma, electron and bremsstrahlung radiation fields by measuring the optically stimulated luminescence (osl) at 530 nm both below and above 1 kGy, i.e. for disinfestation and for meat irradiation purposes. No humidity and no significant dose rate effect on the green osl signal was observed. The temperature coefficient was determined from 0°C up to about 40°C and to stabilize the osl signal after irradiation a heat treatment method was introduced. Based on these investigations the Sunna 'gamma' film is a suitable candidate for dose control below and above 1 kGy for food irradiation technologies.

  8. Solid state dosimeters used in medical physics 'A review'

    SciTech Connect

    Azorin-Nieto, Juan

    2012-10-23

    Many solid-state detectors have been successfully used to perform the quality control and in vivo dosimetry in medical physics, both in diagnostic radiology and radiotherapy, as they have high sensitivity in a small volume; most of them do not require electrical connection and have dosimetric characteristics of interest such as: good accuracy and reproducibility, as well as a response independent of the energy of radiation, some of them. For this reason, the selection of an appropriate detector for use in medical physics must take into account the energy mass absorption coefficient relative to water for photon sources and the mass stopping power relative to water for beta emitters and electron beams in the energy range of interest in medical physics, as well as the effective atomic number of materials that constitute them. This paper presents a review of the dosimetric characteristics of the solid state dosimeters most suitable for use in medical physics.

  9. Electron absorbed dose measurements in LINACs by thermoluminescent dosimeters.

    PubMed

    Cortés, J Rodríguez; Romero, R Alvarez; Nieto, J Azorín; Montalvo, T Rivera

    2014-01-01

    In this work, electron absorbed doses measurements in radiation therapy (RT) were obtained. Radiation measurements were made using thermoluminescent dosimeters of calcium sulfate doped with dysprosium (CaSO4:Dy) and zirconium oxide (ZrO2). TL response calibration was obtained by irradiating TLDs and a Farmer cylindrical ionization chamber PTW 30013 at the same time. Each TL material showed a typical glow curve according to each material. Both calcium sulfate doped with dysprosium and zirconium oxide exhibited better light intensity to high energy electron beam compared with lithium fluoride. TL response as a function of absorbed dose was analyzed. TL response as a function of high energy electron beam was also studied. © 2013 Published by Elsevier Ltd.

  10. A Radiation Dosimeter Concept for the Lunar Surface Environment

    NASA Technical Reports Server (NTRS)

    Adams, James H.; Christl, Mark J.; Watts, John; Kuznetsov, Eugeny N.; Parnell, Thomas A.; Pendleton, Geoff N.

    2007-01-01

    A novel silicon detector configuration for radiation dose measurements in an environment where solar energetic particles are of most concern is described. The dosimeter would also measure the dose from galactic cosmic rays. In the lunar environment a large range in particle flux and ionization density must be measured and converted to dose equivalent. This could be accomplished with a thick (e.g. 2mm) silicon detector segmented into cubic volume elements "voxels" followed by a second, thin monolithic silicon detector. The electronics needed to implement this detector concept include analog signal processors (ASIC) and a field programmable gate array (FPGA) for data accumulation and conversion to linear energy transfer (LET) spectra and to dose-equivalent (Sievert). Currently available commercial ASIC's and FPGA's are suitable for implementing the analog and digital systems.

  11. Turnbull Blue Gel (TBG) evaluation as optical dosimeter

    NASA Astrophysics Data System (ADS)

    Borguezan Neto, E.; Batistuti, M. R.; Pavoni, J. F.; Bachmann, L.

    2017-05-01

    The radiochromic Turnbull Blue Gel (TBG) is sensitive to X- and γ-rays. When exposed to high-energy radiation, TBG can simulate biological tissues, so this gel has potential use in ionizing radiation dosimetry. After irradiation, the yellow TBG changes to the blue Turnbull Blue dye. This work aims to evaluate how TBG responds to exposure to ultraviolet, visible, and infrared radiation from the sun. The gel was irradiated with a solar simulator, which sensitized TBG and transformed it into the Turnbull Blue dye; a change in the optical absorption ensued. The fluence values delivered by the source did not provide a linear response, but it was still possible to use TBG as an optical dosimeter. In conclusion, TBG can be applied to detect solar radiation because it is sensitive enough to measure sun exposure values at time intervals of few minutes.

  12. A BCCD-based dosimeter for mixed radiation fields

    NASA Astrophysics Data System (ADS)

    Pierschel, M.; Ehwald, K.-E.; Heinemann, B.; Januschewski, F.; Schmitz, T.; Schröder, O.

    1993-03-01

    The development of a personal dosimeter based on a BCCD-detector for mixed neutron and gamma radiation in the energy range from thermal energy to 20 MeV for neutrons respectively 30 keV to a few MeV for gammas will be presented. The detector has to give information on the total radiation dose, D, and on the radiation quality. Both peaces of information are required to determine the directional dose equivalent. The basic radiation physics requirements for the detector as well as a concept of a buried channel CCD-matrix for radiation applications including the technology process will be described. A two dimensional device simulation package was used for both optimization of the charge storage nodes including free charge transfer and the basic electronic processes depending on radiation interaction with silicon.

  13. Evaluation of commercial programmable floating gate devices as radiation dosimeters

    NASA Astrophysics Data System (ADS)

    Edgecock, R.; Matheson, J.; Weber, M.; Giulio Villani, E.; Bose, R.; Khan, A.; Smith, D. R.; Adil-Smith, I.; Gabrielli, A.

    2009-02-01

    Programmable floating gate MOSFET transistors were tested with gamma radiation with doses up to approximately 100Gy (air equivalent), to evaluate their suitability as dosimeters in radiotherapy. After characterization and programming at different threshold voltages, the devices were irradiated and their Vgs shift with dose monitored in real time. Post-irradiation analysis was carried out to evaluate sensitivity, linearity, reproducibility and voltage threshold annealing. A subsequent re-programming phase followed by characterization was performed to asses their post-irradiation charge restoring capabilities. It was found that up to 73% of the initial maximum threshold voltage could be recovered. A sensitivity of up to 9 mV/Gy with an uncertainty of less than 1%, an excellent linearity up to the maximum programmable threshold voltage and low noise suggest the use of this technology for in vivo dosimetry applications.

  14. Dental enamel as an in vivo radiation dosimeter

    SciTech Connect

    Pass, B.; Aldrich, J.E.

    1985-05-01

    The determination of the radiation exposure history of the population has become increasingly important in the study of the effects of low-level radiation. The present work was started to try to obtain an in vivo dosimeter that could give an indication of radiation exposure. Dental enamel is the only living tissue which retains indefinitely its radiation history, and electron spin resonance measurements have shown that the radiation signal can be resolved down to about 10 cGy. Measurements on samples from the general population give radiation exposure estimates that are reasonable, and one measurement on a patient who had radiotherapy to the mouth area showed a good correlation with tumor dose.We believe that this is an important new indicator of radiation dose and taken together with exposure histories should provide important data for epidemiological studies as well as accidental exposures.

  15. Energy dependence of metallic-encapsulated thermoluminescent dosimeters. Annual report

    SciTech Connect

    Simons, G.G.

    1980-06-01

    The gamma-ray energy responses of encapsulated /sup 7/LiF and CaF/sub 2/:Mn thermoluminescent dosimeters were measured and compred to calculated values. This study was performed in order to improve the accuracy of gamma-ray heating measurements made in polyenergetic gamma-ray fields such as Argonne National Laboratory's Zero Power Reactors. Equations used in the development of the TERC/III computer code and code input parameters are specified. A section on TLD precision is also included. Comparisons between calculations and experiments are reported for a gamma-ray energy range of 0.122 to 1.33 MeV and encasement media with a range of atomic numbers from 13 to 82.

  16. Non-diffusing radiochromic leuco-crystal violet hydrogel dosimeter

    NASA Astrophysics Data System (ADS)

    Jordan, K. J.; Lindenmaier, T.; Dekker, K. H.

    2017-05-01

    A systematic study to prepare mixed-micelle, radiochromic hydrogels found that non-diffusing dosimeters can be prepared. Subsequent experiments determined that sodium dodecyl sulfate (SDS) a negatively charged surfactant, binds positively charged crystal violet dye to gelatin below the critical micelle concentration. A typical formulation includes: 4% gelatin by mass, 1 mM hydrogen peroxide, 1 mM SDS, 1 mM leuco crystal violet (LCV) and 25 mM trichloroacetic acid (TCAA). This transparent material has an initial attenuation coefficient of 0.08 cm-1 and dose sensitivity of 0.015 cm-1 Gy-1. Which is a doubling of the dose sensitivity from the initial formulation with uncharged Triton X100 micelles. Reconstructed beam profiles from 3D optical CT scans performed 1, 14 and 85 hours post irradiation demonstrate no diffusion of the recorded dose distribution.

  17. [AOR characterization and zoning: a dosimeter for blue light].

    PubMed

    Dario, R; Uva, J; Di Lecce, V; Quarto, A

    2011-01-01

    The paper presents the results obtained thanks to an innovative experimental device for the assessment of artificial optical radiation (AOR) exposure in workplace. This . device was developed by 'Politecnico di Bari-DIASS'. The wearable personal dosimeter has three sensors: one is used for measuring head position/movement, therefore there is a color light sensor to determine the AOR and finally there is a video camera to localize sources. Our system is connected to a netbook via USB cable that allows one to obtain the real and extimated value of worker's exposure, also with "augmented reality". The aim of this paper is realizing work place safety zoning for the classifacation of not only specific dangerous areas through the analysis of overlapping information from the device.

  18. Review of four novel dosimeters developed for use in radiotherapy

    NASA Astrophysics Data System (ADS)

    Metcalfe, P.; Quinn, A.; Loo, K.; Lerch, M.; Petasecca, M.; Wong, J.; Hardcastle, N.; Carolan, M.; McNamara, J.; Cutajar, D.; Fuduli, I.; Espinoza, A.; Porumb, C.; Rosenfeld, A.

    2013-06-01

    Centre for Medical Radiation Physics (CMRP) is a research strength at the University of Wollongong, the main research theme of this centre is to develop prototype novel radiation dosimeters. Multiple detector systems have been developed by Prof Rosenfelds' group for various radiation detector applications. This paper focuses on four current detector systems being developed and studied at CMRP. Two silicon array detectors include the magic plate and dose magnifying glass (DMG), the primary focus of these two detectors is high spatial and temporal resolution dosimetry in intensity modulated radiation therapy (IMRT) beams. The third detector discussed is the MOSkinTM which is a high spatial resolution detector based on MOSFET technology, its primary role is in vivo dosimetry. The fourth detector system discussed is BrachyView, this is a high resolution dose viewing system based on Medipix detector technology.

  19. New technique to improve the accuracy of albedo neutron dosimeter evaluations

    NASA Astrophysics Data System (ADS)

    Hankins, D. E.

    The calibration factor for albedo neutron dosimeters varies greatly depending upon the energy of the neutrons in the exposure. Calibration results obtained over an eight-year period at each Lawrence Livermore National Laboratory facility where neutron exposure may occur were reviewed. A stronger relationship than expected was found between the ratio of the readings of the 9-in. to 3-in. spheres and the percent thermal. Readings from personnel and albedo badges were reviewed. The readings were consistent with the use of a calibration factor for the albedo dosimeter which varies with changes in the ratio of the personnel and albedo dosimeter TLD readings.

  20. Measurement of a 200 MeV proton beam using a polyurethane dosimeter

    NASA Astrophysics Data System (ADS)

    Heard, Malcolm; Adamovics, John; Ibbott, Geoffrey

    2006-12-01

    PRESAGETM (Heuris Pharma LLC, Skillman, NJ) is a three-dimensional polyurethane dosimeter containing a leuco dye that generates a color change when irradiated. The dosimeter is solid and does not require a container to maintain its shape. The dosimeter is transparent before irradiation and the maximum absorbance of the leuco dye occurs at 633 nm which is compatible with the OCT-OPUSTM laser CT scanner (MGS Research, Inc., Madison, CT). The purpose of this study was to investigate the response of PRESAGETM to proton beam radiotherapy.

  1. Characteristics of the DINA track dosimeter for monitoring chronic neutron exposure

    SciTech Connect

    Kraitor, S.N.; Kuz'mina, T.D.; Savinskii, A.K.

    1987-09-01

    The DINA personal dosimeter included in the GNEIS beta-, gamma-, and neutron-radiation safety kit uses fission-fragment track detectors and a target containing /sup 237/Np with a /sup 10/B filter. The purpose of this paper is to derive quantitative data on the characteristics of the DINA dosimeter in the measurement of the equivalent kerma during chronic personnel exposure in neutron fields, and to evaluate whether in that situation the dosimeter can be effectively used when only the track dose value varies.

  2. Investigation of on-chip high temperature annealing of PMOS dosimeters

    SciTech Connect

    Kelleher, A.; Lane, W.; Adams, L.K.

    1996-06-01

    Radiation sensitive pMOS dosimeters can measure only to a maximum dose which is determined by the type, sensitivity and irradiation conditions of the RADFET. On reaching the maximum dose, the dosimeters normally have to be replaced. The aim of this work is to study the feasibility of using on-chip poly-resistor heaters to anneal the dosimeters back to their pre-irradiation threshold voltage. This study shows that, on-chip heating is a viable option to achieve post-irradiation annealing, and that the fading characteristics obtained agree with those of oven annealing from a previous study which was carried out on the NMRC RADFETs.

  3. [Naringin reduced polymethylmethacrylate-induced osteolysis in the mouse air sacs model].

    PubMed

    Li, Nian-Hu; Xu, Zhan-wang

    2015-04-01

    To evaluate the influence of naringin on PMMA-induced osteoclastic bone resorption using the mouse air sacs model. Total 48 female Balb/c mices with the age of 8 to 10 weeks were chosen in the study. Air were injected into the back in 32 mices and formed the air sacs, 6 d later, the skulls (originated from other 16 mices) were implanted to the air sacs. Thirty-two animals were divided into naringin treatment group (with 2 concentrations of 150 mg/kg and 30 mg/ kg) , DMSO group and PBS blank group, 8 animals in each group. Polymethylmethacrylate (PMMA) particles were injected into the air sacs in naringin treatment groups and DMSO group so as to irritate inflammatory reaction. Naringin with 2 concentrations of 150 mg/kg and 30 mg/kg were dissolved in DMSO of 0.2 ml, and were injected into air sacs, respectively. In PBS black group, no stimulation with PMMA particles, only injected PBS, and in DMSO group, injected DMSO without naringin. Tartrate resistant acid phosphatase (TRAP), Ca2+ release, modified Masson stain and histological analysis were performed on the 7th day after stimulation. Compared with DMSO group, naringin treatment group's cellular infiltration decreased (P < 0.01); concentration of 150 mg/kg was better than that of concentrations of 30 mg/kg (8.90 ± 1.75 vs 15.23 ± 1.86). Naringin can decrease calcium release in the lavage of the air sacs bone resorption model, especially obvious in naringin with concentration of 150 mg/kg. Naringin can ameliorate the inflammatory reaction and the subsequent bone resorption (including bone collagen loss, TRAP positive cells amount and so on) in air sacs with bone implant and PMMA particles. Naringin with concentration of 150 mg/kg appeared to be an optimal dosage to deliver the therapeutic effects. Naringin inhibits PMMA-induced osteoclastogenesis and ameliorates the PMMA-associated inflammatory reaction and the subsequent bone resorption.

  4. Interbody distraction and vertebral body reconstruction with polymethylmethacrylate for the treatment of pathological fractures.

    PubMed

    Zuckerman, Scott L; Rao, Ganesh; Rhines, Laurence D; McCutcheon, Ian E; Everson, Richard G; Tatsui, Claudio E

    2017-10-06

    OBJECTIVE Treatment of epidural spinal cord compression (ESCC) caused by tumor includes surgical decompression and stabilization followed by postoperative radiation. In the case of severe axial loading impairment, anterior column reconstruction is indicated. The authors describe the use of interbody distraction to restore vertebral body height and correct kyphotic angulation prior to reconstruction with polymethylmethacrylate (PMMA), and report the long-term durability of such reconstruction. METHODS A single institution, prospective series of patients with ESCC undergoing single-stage decompression, anterior column reconstruction, and posterior instrumentation from 2013 to 2016 was retrospectively analyzed. Several demographic, perioperative, and radiographic measurements were collected. Descriptive statistics were compiled, in addition to postoperative changes in anterior height, posterior height, and kyphosis. Paired Student t-tests were performed for each variable. Overall survival was calculated using the techniques described by Kaplan and Meier. RESULTS Twenty-one patients underwent single-stage posterior decompression with interbody distraction and anterior column reconstruction using PMMA. The median age and Karnofsky Performance Scale score were 61 years and 70, respectively. Primary tumors included renal cell (n = 8), lung (n = 4), multiple myeloma (n = 2), prostate (n = 2), and other (n = 5). Eighteen patients underwent a single-level vertebral body reconstruction and 3 underwent multilevel transpedicular corpectomies. The median survival duration was 13.3 months. In the immediate postoperative setting, statistically significant improvement was noted in anterior body height (p = 0.0017, 95% confidence interval [CI] -4.15 to -1.11) and posterior body height (p = 0.0116, 95% CI -3.14 to -0.45) in all patients, and improved kyphosis was observed in those with oblique endplates (p = 0.0002, 95% CI 11.16-20.27). In the median follow-up duration of 13.9 months

  5. Antifungal, optical, and mechanical properties of polymethylmethacrylate material incorporated with silanized zinc oxide nanoparticles

    PubMed Central

    Kamonkhantikul, Krid; Arksornnukit, Mansuang; Takahashi, Hidekazu

    2017-01-01

    Background Fungal infected denture, which is typically composed of polymethylmethacrylate (PMMA), is a common problem for a denture wearer, especially an elderly patient with limited manual dexterity. Therefore, increasing the antifungal effect of denture by incorporating surface modification nanoparticles into the PMMA, while retaining its mechanical properties, is of interest. Aim of the study This study aimed to evaluate antifungal, optical, and mechanical properties of heat-cured PMMA incorporated with different amounts of zinc oxide nanoparticles (ZnOnps) with or without methacryloxypropyltrimethoxysilane modification. Materials and methods Specimens made from heat-cured PMMA containing 1.25, 2.5, and 5% (w/w) nonsilanized (Nosi) or silanized (Si) ZnOnps were evaluated. Specimens without filler served as control. The fungal assay was performed placing a Candida albicans suspension on the PMMA surface for 2 h, then Sabouraud Dextrose Broth was added, and growth after 24 h was determined by counting colony forming units on agar plates. A spectrophotometer was used to measure the color in L* (brightness), a* (red-green), b* (yellow-blue) and opacity of the experimental groups. Flexural strength and flexural modulus were determined using a three-point bending test on universal testing machine after 37°C water storage for 48 h and 1 month. Results The antifungal, optical, and mechanical properties of the PMMA incorporated with ZnOnps changed depending on the amount. With the same amount of ZnOnps, the silanized groups demonstrated a greater reduction in C. albicans compared with the Nosi groups. The color difference (ΔE) and opacity of the Nosi groups were greater compared with the Si groups. The flexural strength of the Si groups, except for the 1.25% group, was significantly greater compared with the Nosi groups. Conclusion PMMA incorporated with Si ZnOnps, particularly with 2.5% Si ZnOnps, had a greater antifungal effect, less color differences, and opacity

  6. Use of antibiotic-loaded polymethylmethacrylate beads for the treatment of extracavitary prosthetic vascular graft infections.

    PubMed

    Stone, Patrick A; Armstrong, Paul A; Bandyk, Dennis F; Brumberg, Robert S; Flaherty, Sarah K; Back, Martin R; Johnson, Brad L; Shames, Murray L

    2006-10-01

    This study was conducted to assess the efficacy of antibiotic-loaded polymethylmethacrylate (PMMA) beads in the management of lower extremity extracavitary prosthetic arterial graft infection. This was a retrospective review of 34 patients treated for vascular surgical site (VSS) infections involving 36 prosthetic lower extremity arterial bypasses using antibiotic-loaded PMMA beads and culture-specific parenteral antibiotics for 4 to 6 weeks. Sites of graft infection were explored, debrided, and cultured. As determined from the results of Gram's stains of VSS purulence, PMMA powder was polymerized with an antibiotic (vancomycin, daptomycin, or tobramycin/gentamicin, or a combination), molded into a chain of beads, and implanted adjacent to the infected graft after debridement and pulsed-spray antibacterial lavage. All wounds were closed primarily with planned exploration to verify sterilization before a graft preservation or in situ replacement procedure. Treatment outcomes, including wound sterilization, were analyzed based on tissue culture isolates, procedures for persistent infection, and freedom from graft infection. Cultures isolated 42 pathogens, (32 gram-positive, 9 gram-negative, 1 Candida albicans) with methicillin-resistant Staphylococcus aureus (MRSA) cultured from 16 (44%) of 36 surgical site infections. As determined from the initial operative Gram's stain or a prior culture result, vancomycin PMMA beads were implanted in 29 of 36 VSS infections at the first procedure; daptomycin (n = 4) or tobramycin (n = 3) beads were implanted in the rest. Repeat VSS exploration and culture results led to an average of 2.5 antibiotic bead replacements before definitive treatment. A sterile (no growth on tissue culture) VSS was achieved in 87% of cases before a graft preservation (n = 16) or in-situ replacement of an infected graft (n = 20) procedure. No patient deaths occurred. Early and late limb salvage was 100%. Infection recurred in 4 (11%) VSSs during a mean

  7. Calibration factors for the SNOOPY NP-100 neutron dosimeter

    NASA Astrophysics Data System (ADS)

    Moscu, D. F.; McNeill, F. E.; Chase, J.

    2007-10-01

    Within CANDU nuclear power facilities, only a small fraction of workers are exposed to neutron radiation. For these individuals, roughly 4.5% of the total radiation equivalent dose is the result of exposure to neutrons. When this figure is considered across all workers receiving external exposure of any kind, only 0.25% of the total radiation equivalent dose is the result of exposure to neutrons. At many facilities, the NP-100 neutron dosimeter, manufactured by Canberra Industries Incorporated, is employed in both direct and indirect dosimetry methods. Also known as "SNOOPY", these detectors undergo calibration, which results in a calibration factor relating the neutron count rate to the ambient dose equivalent rate, using a standard Am-Be neutron source. Using measurements presented in a technical note, readings from the dosimeter for six different neutron fields in six source-detector orientations were used, to determine a calibration factor for each of these sources. The calibration factor depends on the neutron energy spectrum and the radiation weighting factor to link neutron fluence to equivalent dose. Although the neutron energy spectra measured in the CANDU workplace are quite different than that of the Am-Be calibration source, the calibration factor remains constant - within acceptable limits - regardless of the neutron source used in the calibration; for the specified calibration orientation and current radiation weighting factors. However, changing the value of the radiation weighting factors would result in changes to the calibration factor. In the event of changes to the radiation weighting factors, it will be necessary to assess whether a change to the calibration process or resulting calibration factor is warranted.

  8. [Hemagglutination activity of radix isatidis detected by microcalorimetry].

    PubMed

    Ren, Yong-shen; Yan, Dan; Zhang, Ping; Li, Han-bing; Feng, Xue; Zhang, Ya-ming; Luo, Yun; Xiao, Xiao-he

    2010-08-01

    In this study, microcalorimetry was adopted to establish a novel method for detecting the hemagglutination process of Radix Isatidis (Banlangen in Chinese, BLG), and to evaluate the hemagglutination activity diversity of BLG from various habitats. The hemagglutination biothermokinetics curves of positive reagent (phytohemagglutinin, PHA) and 8 batches BLG from different regions of the hemagglutination with 20% rabbit erythrocyte were recorded by microcalorimetry, then biothermokinetics parameters were abstracted, the hemagglutination utility of samples were calculated and analyzed by principal component analysis (PCA) and cluster analysis (CA), meanwhile the results were authenticated by micro-plate agglutination. It showed that the hemagglutination was an exothermic reaction, the reaction rate constant (k: 0.039-73.6 min(-1)), maximum reaction power (Pmax: -1 140.2 - 988.2 microW) and reaction enthalpy (Hi: -529.9 - 717.9 microJ) had good linear correlation with BLG extraction concentration (0.2-1.0 g mL(-1), r > 0.97), and PCA showed Pmax (531-1 335 microW) and Ht (585.2-989.2 microJ) could represent the hemagglutination activity diversity of BLG samples, just confirming with the results of micro-plate agglutination (the agglutination dilution was 3-11 respectively). According to the hemagglutination utility, the BLG samples from Good Agriculture Practice (GAP) regions, main producing area and general regions could be clustered correctly; meanwhile, the biothermokinetics curves with perfect distinctive fingerprint and specificity could give out more information for the quality control and evaluation for BLG. In conclusion, the microcalorimetry method established for detecting the hemagglutination activity of BLG samples on rabbit erythrocyte is sensitive and reliable, and could be adopted as an effective technique in detection aggulatination precisely, quantitatively and consecutively; and provide a novel approach for examining and evaluating quality for Chinese

  9. Characterization of metal oxide semiconductor field effect transistor dosimeters for application in clinical mammography.

    PubMed

    Benevides, Luis A; Hintenlang, David E

    2006-02-01

    Five high-sensitivity metal oxide semiconductor field effect transistor dosimeters in the TN-502 and 1002 series (Thomson Nielsen Electronics Ltd., 25B, Northside Road, Ottawa, ON K2H8S1, Canada) were evaluated for use in the mammography x-ray energy range (22-50 kVp) as a tool to assist in the documentation of patient specific average glandular dose. The dosimeters were interfaced with the Patient Dose Verification System, model No. TN-RD 15, which consisted of a dosimeter reader and up to four dual bias power supplies. Two different dual bias power supplies were evaluated in this study, model No. TN-RD 22 in high-sensitivity mode and a very-high sensitivity prototype. Each bias supply accommodates up to five dosimeters for 20 dosimeters per system. Sensitivity of detectors, defined as the mV/C kg(-1), was measured free in air with the bubble side of the dosimeter facing the x-ray field with a constant exposure. All dosimeter models' angular response showed a marked decrease in response when oriented between 120 degrees and 150 degrees and between at 190 degrees and 220 degrees relative to the incident beam. Sensitivity was evaluated for Mo/Mo, Mo/Rh, and Rh/Rh target-filter combinations. The individual dosimeter model sensitiVity was 4.45 x 10(4) mV/C kg(-1) (11.47 mV R(-1)) for TN-502RDS(micro); 5.93 x 10(4) mV per C kg(-1) (15.31 mV R(-1)) for TN-1002RD; 6.06 x 10(4) mV/C kg(-1) (15.63 mV R(-1)) for TN-1002RDI; 9.49 x 10(4) mV per C kg(-1) (24.49 mV R(-1)) for TN-1002RDM (micro); and 11.20 x 10(4) mV/C kg(-1) (28.82 mV R(-1)) for TN-1002RDS (micro). The energy response is presented and is observed to vary with dosimeter model, generally increasing with tube potential through the mammography energy range. An intercomparison of the high-sensitivity mode of TN-RD-22 was made to the very-high sensitivity bias power supply using a Mo/Mo target-filter. The very-high sensitivity-bias power supply increased dosimeter response by 1.45 +/- 0.04 for dosimeter models TN

  10. [Prospective clinical study of radix astragali and its compound prescription for treatment of β-thalassemia in children].

    PubMed

    Lu, Zhuo-Ming; Qian, Xin-Hua; Chen, Zhi-Wen; Zhang, Chun-Hong; Guo, Li-Shan; Chen, Jia

    2012-05-01

    To evaluate the efficacy and safety of radix astragali and its compound prescription for treatment of β-thalassemia in children. This study was a randomized, controlled, double-blind clinical trial. Fifty-seven children with β-thalassemia were randomly assigned to radix astragali, compound prescription (radix astragali+ codonopsis pilosula + tortoise plastron) and placebo control groups after stratifying the patients according to disease type (intermedia and major). The parameters of hematology and safety were assessed after 12 weeks of treatment. After 12 weeks of treatment, the mean Hb elevation levels in children with β-thalassemia intermedia from the compound prescription and the radix astragali groups were 1.21±1.12 and 1.05±0.80 g/dL respectively compared with -(0.28±0.51) g/dL in the placebo control group (P<0.01). Mean Hb levels in the compound prescription and radix astragali groups were significantly higher than in the placebo control group (P<0.05). Therapy with both radix astragali and its compound prescription increased fetal hemoglobin, red blood cell, mean corpuscular hemoglobin and reticulocyte levels in children with β-thalassemia intermedia. The total effective rates were 64% and 62% in children with β-thalassemia intermedia from the compound prescription and radix astragali groups respectively, which was significantly higher than in the placebo control group (9%; P<0.01). Therapy with radix astragali or its compound prescription in children with β-thalassemia major had similar but less favourable effects than the same therapy in children with β-thalassemia intermedia. White blood cell, neutrophil, platelet and hepatic and renal functions were not adversely affected by the medicines. Therapy with radix astragali or its compound prescription is effective and safe in children with β-thalassemia.

  11. Effects of Asiasari radix on the morphology and viability of mesenchymal stem cells derived from the gingiva.

    PubMed

    Jeong, Su-Hyeon; Lee, Ji-Eun; Jin, Seong-Ho; Ko, Youngkyung; Park, Jun-Beom

    2014-12-01

    Medicinal herbs used in traditional Oriental medicine, which have been in use clinically for thousands of years, are attractive sources of novel therapeutics or preventatives. Asiasari radix (A. radix) has been suggested for use in the treatment of dental diseases, including toothache and aphthous stomatitis. The aim of this study was to evaluate the effects of A. radix extracts on the morphology and viability of human stem cells derived from the gingiva. An Asiasarum heterotropoides extract was centrifuged and freeze-dried in a lyophilizer. Stem cells derived from the gingiva were grown in the presence of A. radix at concentrations ranging between 0.1 µg/ml and 1 mg/ml (0, 0.1, 1, 10, 100 and 1,000 µg/ml). Cell morphology was evaluated with an optical microscope and the viability of the cells was quantitatively analyzed with a cell counting kit-8 (CCK-8) assay for up to seven days. The untreated control group exhibited normal fibroblast morphology. The shapes of the cells following 0.1, 1, 10 and 100 µg/ml A. radix treatments were similar to those of the control group. However, a significant change was noted in the 1,000 µg/ml group on day 1, when compared with the untreated group. Furthermore, on day 7, the shapes of the cells following 100 and 1,000 µg/ml A. radix treatments were rounder and fewer cells were present, when compared with those of the control group. The cultures that grew in the presence of A. radix did not exhibit any changes in the CCK‑8 assay on day 2; however, significant reductions in cell viability were noticed following 100 and 1,000 µg/ml A. radix treatment on days 5 and 7. Within the limits of this study, A. radix influenced the viability of the stem cells derived from the gingiva. Thus, the direct application of A. radix to oral tissues may produce adverse effects at high doses. Therefore, the concentration and application time of A. radix requires meticulous control to obtain optimal results. These effects require consideration

  12. [Influence of different original processing methods on quality of Salvia Miltiorrhizae Radix et Rhizoma from Shandong].

    PubMed

    Zhao, Zhi-Gang; Gao, Shu-Rui; Hou, Jun-Ling; Wang, Wen-Quan; Xu, Zhen-Guang; Song, Yan; Zhang, Xian-Ming; Li, Jun

    2014-04-01

    In this paper the contents of rosmarinic acid, salvianolic acid B, crytotanshinone, tanshinone II(A) in samples of different original processed Salvia Miltiorrhizae Radix et Rhizoma were determined by HPLC. Different processing methods have varied influences on four active ingredients in Salvia Miltiorrhizae Radix et Rhizoma. Sun-drying reduced the content of crytotanshinone, tanshi-none II(A) and rosmarinic acid, integralsamples were better than those cut into segments. Oven dry method had great influence on water--soluble ingredients, high temperature (80-100 degrees C) could easily cause big loss of rosmarinic acid and salvianolic acid B. The role of traditional processing method "fahan: was complicated, the content of rosmarinic acid decreased, crytotanshinone and tanshinone II(A) increased, and salvianolic acid B showed no difference after "fahan". Drying in the shade and oven dry under low temperatrure (40-60 degrees C) were all effective to keep active ingredients of Salvia Miltiorrhizae Radix et Rhizoma, and, there was no difference between integral samples and samples cut into segments. Therefore, considering comprehensively the content of active ingredients in Salvia Miltiorrhizae Radix et Rhizoma, and processing costing etc., shade-drying or oven dry underlow temperature (40-60 degrees C) should be the most suitable original processing method.

  13. [Study on simplification of extraction kinetics model and adaptability of total flavonoids model of Scutellariae radix].

    PubMed

    Chen, Yang; Zhang, Jin; Ni, Jian; Dong, Xiao-Xu; Xu, Meng-Jie; Dou, Hao-Ran; Shen, Ming-Rui; Yang, Bo-Di; Fu, Jing

    2014-01-01

    Because of irregular shapes of Chinese herbal pieces, we simplified the previously deduced general extraction kinetic model for TCMs, and integrated particle diameters of Chinese herbs that had been hard to be determined in the final parameter "a". The reduction of the direct determination of particle diameters of Chinese herbs was conducive to increase the accuracy of the model, expand the application scope of the model, and get closer to the actual production conditions. Finally, a simplified model was established, with its corresponding experimental methods and data processing methods determined. With total flavonoids in Scutellariae Radix as the determination index, we conducted a study on the adaptability of total flavonoids extracted from Scutellariae Radix with the water decoction method in the model. The results showed a good linear correlation among the natural logarithm value of the mass concentration of total flavonoids in Scutellariae Radix, the time and the changes in the natural logarithm of solvent multiple. Through calculating and fitting, efforts were made to establish the kinetic model of extracting total flavonoids from Scutellariae Radix with the water decoction method, and verify the model, with a good degree of fitting and deviation within the range of the industrial production requirements. This indicated that the model established by the method has a good adaptability.

  14. [Research model on commodity specification standard of radix Chinese materia medica].

    PubMed

    Kang, Chuan-Zhi; Zhou, Tao; Jiang, Wei-Ke; Huang, Lu-Qi; Guo, Lan-Ping

    2016-03-01

    As an important part of the market commodity circulation, the standard grade of Chinese traditional medicine commodity is very important to restrict the market order and guarantee the quality of the medicinal material. The State Council issuing the "protection and development of Chinese herbal medicine (2015-2020)" also make clear that the important task of improving the circulation of Chinese herbal medicine industry norms and the commodity specification standard of common traditional Chinese medicinal materials. However, as a large class of Chinese herbal medicines, the standard grade of the radix is more confused in the market circulation, and lack of a more reasonable study model in the development of the standard. Thus, this paper summarizes the research background, present situation and problems, and several key points of the commodity specification and grade standard in radix herbs. Then, the research model is introduced as an example of Pseudostellariae Radix, so as to provide technical support and reference for formulating commodity specifications and grades standard in other radix traditional Chinese medicinal materials. Copyright© by the Chinese Pharmaceutical Association.

  15. [A systematic study on comprehensive utilization of fibers of radix Ophiopogonis].

    PubMed

    Huang, K; Liu, Z; Yu, Z; Xu, Y

    1992-01-01

    The components, toxicology, bioactivity and application of fibers of Radix Ophiopogonis (RO) were studied. The components of its fibers and roots are similar. In a clinical study with 100 aged patients, the aging syndromes were markedly improved. No side-effect was found.

  16. [Development of full-quantified HPLC fingerprint for quality evaluation of ophiopogonis radix of sichuan].

    PubMed

    Wang, Jin; Liu, Han-Qing; Liu, Lin; Tang, Hai-Tao; Zhang, Ping; Tang, Yun

    2013-05-01

    To establish HPLC fingerprint of Ophiopogonis Radix of Sichuan and simultaneously determine two homoisoflavonoids (methylophiopogonanones A and B). Full-quantified HPLC fingerprint was used to establish the HPLC fingerprint and determine the active ingredients of the daodi medicinal material Ophiopogonis Radix of Sichuan in Shengmai injection. Chromatographic condition was as follows: The analytical column was Waters symmetry shield RP 18 (4.6 mm x 250 mm, 5 microm) with a pre-column of symmetry shield RP 18. The mobile phase was acetonitrile-water (containing 0.1% phosphoric acid) with gradient elution. The flow rate was 1.0 mL/min, the detection wavelength was set at 280 nm and the column temperature was maintained at 30 degrees C. The HPLC fingerprint of Ophiopogonis Radix of Sichuan was established with good separation and repeatability. 24 common peaks were defined in the HPLC fingerprint. The similarity among batches was more than 0.98. Compared with standard reference substances, No. 14 peak was methylophiopogonanone A and No. 15 peak was methylophiopogonanone B. Similarity determine system was applied to evaluate them. This analytical method is highly sensitive with strong specificity, which can be used efficiently in the quality control of Ophiopogonis Radix of Sichuan in Shengmai injection.

  17. Application of near-infrared spectroscopy for the rapid quality assessment of Radix Paeoniae Rubra

    NASA Astrophysics Data System (ADS)

    Zhan, Hao; Fang, Jing; Tang, Liying; Yang, Hongjun; Li, Hua; Wang, Zhuju; Yang, Bin; Wu, Hongwei; Fu, Meihong

    2017-08-01

    Near-infrared (NIR) spectroscopy with multivariate analysis was used to quantify gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra, and the feasibility to classify the samples originating from different areas was investigated. A new high-performance liquid chromatography method was developed and validated to analyze gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra as the reference. Partial least squares (PLS), principal component regression (PCR), and stepwise multivariate linear regression (SMLR) were performed to calibrate the regression model. Different data pretreatments such as derivatives (1st and 2nd), multiplicative scatter correction, standard normal variate, Savitzky-Golay filter, and Norris derivative filter were applied to remove the systematic errors. The performance of the model was evaluated according to the root mean square of calibration (RMSEC), root mean square error of prediction (RMSEP), root mean square error of cross-validation (RMSECV), and correlation coefficient (r). The results show that compared to PCR and SMLR, PLS had a lower RMSEC, RMSECV, and RMSEP and higher r for all the four analytes. PLS coupled with proper pretreatments showed good performance in both the fitting and predicting results. Furthermore, the original areas of Radix Paeoniae Rubra samples were partly distinguished by principal component analysis. This study shows that NIR with PLS is a reliable, inexpensive, and rapid tool for the quality assessment of Radix Paeoniae Rubra.

  18. Performance Testing Of Selected Types of Electronic Personal Dosimeters in X- and Gamma Radiation Fields.

    PubMed

    Kržanović, Nikola; Živanović, Miloš; Ciraj-Bjelac, Olivera; Lazarević, Đorđe; Ćeklić, Sandra; Stanković, Srboljub

    2017-10-01

    Electronic personal dosimeters (EPDs) are increasingly being used alongside conventional thermoluminescent dosimeters to measure the dose of legal record in terms of personal dose equivalent. Therefore, it is of great importance to execute performance tests of these dosimeters in photon fields of various energies and at various angles of incidence. This testing is done in order to simulate the behavior of these dosimeters in realistic multidirectional polyenergetic ionizing radiation fields. Tests of accuracy, linearity, energy response, and angular response have been performed on 10 EPDs from multiple manufacturers. Various radiation qualities have been used in the energy range from 33 keV to 1.33 MeV and for angles of incidence 0° to 80°. This research proves that many of the EPDs tested performed according to the manufacturer's specifications and the requirements of the international standards regarding personal dosimetry.

  19. An intercomparison of neutron dosimeters and detectors for in-containment dosimetry

    SciTech Connect

    Auman, L.E.; Miller, W.H.; Graham, C.C.; Stretch, C.D.; Welty, T.J.; West, L. Jr. )

    1992-02-01

    To improve the methodology for assessing neutron dose at Union Electric's Callaway Nuclear Power Plant, an intercomparison of neutron detectors and dosimeters was performed. Seven different neutron detectors and dosimeters were tested in four different neutron fields utilizing facilities at the Missouri University Research Reactor and at the Southwest Radiation Calibration Center at the University of Arkansas. In general, all results agree within a factor of 2 in predicting the neutron dose equivalent. It was concluded that measurements of dose in containment should utilize the Tissue-Equivalent Proportional Counter (TEPC), the Bonner-sphere system, and the proton recoil spectrometer to accurately assess the neutron dose. These data can then be used to provide correction factors for more traditionally used dosimeters in containment, such as thermoluminescent dosimeters and survey meters.

  20. Development and evaluation of a microprocessor-based ergonomic dosimeter for evaluating carpentry tasks.

    PubMed

    Bhattacharya, A; Warren, J; Teuschler, J; Dimov, M; Medvedovic, M; Lemasters, G

    1999-12-01

    This portable and self-contained lightweight microprocessor based Ergonomic Dosimeter is designed to collect continuously postural angles of the torso and the upper arm in the sagittal plane and the number of kneeling activities. Up to 4 h of task performance data can be stored in a non-volatile memory of the dosimeter, which can then be downloaded to a lap-top computer. The portable dosimeter was tested for test-retest reliability, compared with posture data obtained with a computer-based video analysis system and evaluated at a carpenter's apprentices school and at a construction site. The dosimeter was shown to be suitable for collecting posture and kneeling data for a prolonged period at construction sites.

  1. Radiation dose enhancement of gold nanoparticle on different polymer gel dosimeters

    NASA Astrophysics Data System (ADS)

    Jabaseelan Samuel, E. James; Srinivasan, K.; Poopathi, V.

    2017-05-01

    In this work, we evaluated the dose enhancement produced by gold nanoparticle on ten different polymer gel dosimeters with a concentration of 7mgAu /g over a wide photon energy range of 15KeV to 20MeV and the results were compared with Soft tissue ICRU-44 produced. Our result showed that maximum DEF was observed at 40KeV, while it was almost negligible at higher energy range. Dose enhancement produced by AuNP on the gel dosimeter medium was varied compared to the reference ICRU-44 tissue, it was ± <1% for PAGAT, NIPAM, nPAG and ± <5% for PABIG, VIPAR, HEAG, BANG1, nMAG & ± <10% for MAGIC, ABAGIC gel dosimeters. Hence, we conclude that choosing the proper gel dosimeter is essential in dose enhancement study.

  2. Novel radiochromic dosimeters based on Calcein dye for high dose applications

    NASA Astrophysics Data System (ADS)

    Aldweri, Feras M.; Rabaeh, Khalid A.; Al-Ahmad, Kefaia N.

    2017-10-01

    New compositions of radio-chromic solutions and polyvinyl alcohol (PVA) films containing different concentrations of Calcein dye have been introduced as high dose dosimeter. The dosimeters were irradiated with gamma rays from 60C o source at doses from 5 to 30 kGy for film and from 0.25 to 1 kGy for solution. UV/vis spectrophotometry was used to investigate the absorbance (optical density) of unirradiated and irradiated films and solutions in terms of absorbance at 493 nm for film and 496 nm for solution. The effects of scan temperature, relative humidity and stability of the response of films and solutions after irradiation were investigated. The results show that these films could be used as dosimeter in industrial radiation processing. The useful dose range of developed Calcein-PVA film and solution dosimeters is in the range of 5-20 kGy and 0.25-1 kGy respectively

  3. New polymer gel dosimeters consisting of less toxic monomers with radiation-crosslinked gel matrix

    NASA Astrophysics Data System (ADS)

    Hiroki, A.; Yamashita, S.; Sato, Y.; Nagasawa, N.; Taguchi, M.

    2013-06-01

    New polymer gel dosimeters consisting of less toxic methacrylate-type monomers such as 2-hydroxymethyl methacrylate (HEMA) and polyethylene glycol 400 dimethacrylate (9G) with hydroxypropyl cellulose (HPC) gel were prepared. The HPC gels were obtained by using a radiation-induced crosslinking technique to be applied in a matrix instead of a gelatin, which is conventionally used in earlier dosimeters, for the polymer gel dosimeters. The prepared polymer gel dosimeters showed cloudiness by exposing to 60Co γ-ray, in which the cloudiness increased with the dose up to 10 Gy. At the same dose, the increase in the cloudiness appeared with increasing concentration of 9G. As a result of the absorbance measurement, it was found that the dose response depended on the composition ratio between HEMA and 9G.

  4. NASA Crew Personal Active Dosimeters (CPADs): Leveraging Novel Terrestrial Personal Radiation Monitoring Capabilities for Space Exploration

    NASA Technical Reports Server (NTRS)

    Leitgab, Martin; Semones, Edward; Lee, Kerry

    2016-01-01

    The NASA Space Radiation Analysis Group (SRAG) is developing novel Crew Personal Active Dosimeters (CAPDs) for upcoming crewed space exploration missions and beyond. To reduce the resource footprint of the project a COTS dosimeter base is used for the development of CPADs. This base was identified from evaluations of existing COTS personal dosimeters against the concept of operations of future crewed missions and tests against detection requirements for radiation characteristic of the space environment. CPADs exploit operations efficiencies from novel features for space flight personal dosimeters such as real-time dose feedback, and autonomous measuring and data transmission capabilities. Preliminary CPAD design, results of radiation testing and aspects of operational integration will be presented.

  5. A design solution to increasing the sensitivity of pMOS dosimeters: The stacked RADFET approach

    SciTech Connect

    Kelleher, A.; Lane, W.; Adams, L.

    1995-02-01

    pMOS Radiation Sensitive Field Effect Transistors (RADFET`S) have applications as integrating dosimeters in laboratories and medicine to measure the amount of radiation dose absorbed. The suitability of these dosimeters to a certain application depends on the sensitivity of the RADFET being used. To date, this sensitivity is limited to the sensitivity of the gate oxide to radiation. The aim of this paper is to introduce a new design approach which will allow greater sensitivities to be achieved than is currently possible. An additional attractive feature of this design approach is that the sensitivity of the dosimeter may be changed depending on the total dose which is to be measured; essentially a dosimeter with auto-scaling may be achieved. This study introduces this autoscaling concept along with presenting the optimum RADFET device requirements which are necessary for this new design approach.

  6. Novel composition of polymer gel dosimeters based on N-(Hydroxymethyl)acrylamide for radiation therapy

    NASA Astrophysics Data System (ADS)

    Basfar, Ahmed A.; Moftah, Belal; Rabaeh, Khalid A.; Almousa, Akram A.

    2015-07-01

    A new composition of polymer gel dosimeters is developed based on radiation induced polymerization of N-(Hydroxymethyl)acrylamide (NHMA) for radiotherapy treatment planning. The dosimeters were irradiated by 10 MV photon beam of a medical linear accelerator at a constant dose rate of 600 cGy/min with doses up to 20 Gy. The polymerization occurs and increases with increasing absorbed dose. The dose response of polymer gel dosimeters was studied using nuclear magnetic imaging (NMR) for relaxation rate (R2) of water proton. Dose rate, energy of radiation and the stability of the polymerization after irradiation were investigated. No appreciable effects of these parameters on the performance of the novel gel dosimeters were observed.

  7. Neutron Fading Characteristics of Copper Doped Lithium Fluoride (LiF: MCP) Thermoluminescent Dosimeters (TLDs)

    DTIC Science & Technology

    2008-05-21

    Fading Characteristics of Copper-Doped Lithium Fluoride (LiF: MCP) Thermoluminescent Dosimeters (TLDs)" Name of Candidate: L T Jeffrey A. Delzer Master...Lithium Fluoride Thermoluminescent Dosimeters beyond brief excerpts is with the permission of the copyright owner, and will save and hold harmless...Thesis: Author: Thesis directed by: ABSTRACT "Neutron Fading Characteristics of Copper-Doped Lithium Fluoride (LiF: MCP) Thermoluminescent

  8. Performance of KCl:Eu2+ storage phosphor dosimeters for low-dose measurements

    NASA Astrophysics Data System (ADS)

    Li, H. Harold; Xiao, Zhiyan; Hansel, Rachael; Knutson, Nels; Yang, Deshan

    2013-06-01

    Recent research has demonstrated that europium doped potassium chloride (KCl:Eu2+) storage phosphor material has the potential to become the physical foundation of a novel and reusable dosimetry system using either film-like devices or devices similar to thermoluminescent dosimeter chips. The purposes of this work are to quantify the performance of KCl:Eu2+ prototype dosimeters for low-dose measurements and to demonstrate how it can be incorporated into clinical application for in vivo peripheral dose measurements. Pellet-style KCl:Eu2+ dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The dosimeters were read using a laboratory photostimulated luminescence detection system. KCl:Eu2+ prototype storage phosphor dosimeter was capable of measuring a dose-to-water as low as 0.01 cGy from a 6 MV photon beam with a signal-to-noise ratio greater than 6. A pre-readout thermal annealing procedure enabled the dosimeter to be read within an hour post-irradiation. After receiving large accumulated doses (˜10 kGy), the dosimeters retained linear response in the low-dose region with only a 20% loss of sensitivity comparing to a fresh sample (zero Gy history). The energy dependence encountered during low-dose peripheral measurements could be accounted for via a single point outside-field calibration per each beam quality. With further development the KCl:Eu2+--based dosimeter could become a versatile and durable dosimetry tool with large dynamic range (sub-cGy to 100 Gy).

  9. Impact of the Fukushima nuclear accident on background radiation doses measured by control dosimeters in Japan.

    PubMed

    Romanyukha, Alexander; King, David L; Kennemur, Lisa K

    2012-05-01

    After the 9.0 magnitude earthquake and subsequent massive tsunami on 11 March 2011 in Japan, several reactors at the Fukushima Daiichi Nuclear Power Plant suffered severe damage. There was immediate participation of U.S. Navy vessels and other United States Department of Defense (DoD) teams that were already in the area at the time of the disaster or arrived shortly thereafter. The correct determination of occupational dose equivalent requires estimation of the background dose component measured by control dosimeters, which is subsequently subtracted from the total dose equivalent measured by personal dosimeters. The purpose of the control dosimeters is to determine the amount of radiation dose equivalent that has accumulated on the dosimeter from background or other non-occupational sources while they are in transit or being stored. Given the release of radioactive material and potential exposure to radiation from the Fukushima Daiichi Nuclear Power Plant and the process by which the U.S. Navy calculates occupational exposure to ionizing radiation, analysis of pre- and post-event control dosimeters is warranted. Several hundred historical dose records from the Naval Dosimetry Center (NDC) database were analyzed and compared with the post-accident dose equivalent data of control dosimeters. As result, it was shown that the dose contribution of the radiation and released radiological materials from the Fukushima nuclear accident to background radiation doses is less than 0.375 μSv d for shallow and deep photon dose equivalent. There is no measurable effect on neutron background exposure. The latter has at least two important conclusions. First, the NDC can use doses measured by control dosimeters at issuing sites in Japan for determination of personnel dose equivalents; second, the dose data from control dosimeters prior to and after the Fukushima accident may be used to assist in dose reconstruction of non-radiological (non-badged) personnel at these locations.

  10. [Comparative study of Coptidis Rhizoma and Aconiti Kusnezoffii Radix on cell differentiation in lewis lung cancer].

    PubMed

    Zhao, Bei; Hou, Xi-Dong; Li, Hong; Qi, Xiao-Xiao; Li, Gang-Gang; Liu, Lin-Xin; Wang, Pei; Du, Gang-Jun

    2014-07-01

    Coptidis Rhizoma and Aconiti Kusnezoffii Radix represent hot Chinese medicine and cold Chinese medicine respectively. The purpose of this study is to observe the differentiation effect of Coptidis Rhizoma and Aconiti Kusnezoffii Radix on lewis lung cancer and compare effect of hot Chinese medicine and cold Chinese medicine on tumor progression. In this study, the rat serum containing Coptidis Rhizoma or Aconiti Kusnezoffii Radix was prepared to treat lewis lung cancer cells in vitro, and effects of the serum containing Coptidis Rhizoma or Aconiti Kusnezoffii Radix on cell differentiation, proliferation, adhesion, succinic dehydrogenase (SDH) activity and gap-junction intercellular communication (GJIC) were investigated. In vivo, the subcutaneous implant model and pulmonary metastasis model of lewis lung cancer were established. Tumor bearing mice were taken water decoction of coptis chinensis or aconite by intragastric administration bid for four weeks, and the influences of coptis chinensis and aconite on tumor progression were evaluated by body temperature, blood oxygen saturation, red cell ATPase, blood rheology, intratumor hypoxia, capillary permeability and GJIC. The results showed that the serum containing aconite could induce cell differentiation, inhibit cell proliferation and migration, promote SDH activity and GJIC in lewis lung cancer cells. The serum containing Coptidis Rhizoma increased cell adhesion and decreased SDH activity and GJIC without cell differentiation although it also suppressed cell proliferation. Aconiti Kusnezoffii Radix water decoction could keep body temperature, blood oxygen saturation, red cell ATPase and blood rheology, and improve intratumor hypoxia, capillary permeability and GJIC in tumor bearing mice, which led to slower tumor growth and less metastasis. Coptidis Rhizoma water decoction decreased body temperature, blood oxygen saturation, red cell ATPase, blood rheology and GJIC, and promoted intratumor hypoxia and capillary

  11. Characterization of a water-equivalent fiber-optic coupled dosimeter for use in diagnostic radiology

    SciTech Connect

    Hyer, Daniel E.; Fisher, Ryan F.; Hintenlang, David E.

    2009-05-15

    This work reports on the characterization of a new fiber-optic coupled (FOC) dosimeter for use in the diagnostic radiology energy range. The FOC dosimeter was constructed by coupling a small cylindrical plastic scintillator, 500 {mu}m in diameter and 2 mm in length, to a 2 m long optical fiber, which acts as a light guide to transmit scintillation photons from the sensitive element to a photomultiplier tube (PMT). A serial port interface on the PMT permits real-time monitoring of light output from the dosimeter via a custom computer program. The FOC dosimeter offered excellent sensitivity and reproducibility, allowing doses as low as 0.16 mGy to be measured with a coefficient of variation of only 3.64%. Dose linearity was also excellent with a correlation coefficient of 1.000 over exposures ranging from 0.16 to 57.29 mGy. The FOC dosimeter exhibited little angular dependence from axial irradiation, varying by less than 5% over an entire revolution. A positive energy dependence was observed and measurements performed within a scatter medium yielded a 10% variation in sensitivity as beam quality changed due to hardening and scatter across a 16 cm depth range. The current dosimetry system features an array of five PMTs to allow multiple FOC dosimeters to be monitored simultaneously. Overall, the system allows for rapid and accurate dose measurements relevant to a range of diagnostic imaging applications.

  12. Small-Field Measurements of 3D Polymer Gel Dosimeters through Optical Computed Tomography

    PubMed Central

    Shih, Cheng-Ting; Lee, Yao-Ting; Wu, Shin-Hua; Yao, Chun-Hsu; Hsieh, Bor-Tsung

    2016-01-01

    With advances in therapeutic instruments and techniques, three-dimensional dose delivery has been widely used in radiotherapy. The verification of dose distribution in a small field becomes critical because of the obvious dose gradient within the field. The study investigates the dose distributions of various field sizes by using NIPAM polymer gel dosimeter. The dosimeter consists of 5% gelatin, 5% monomers, 3% cross linkers, and 5 mM THPC. After irradiation, a 24 to 96 hour delay was applied, and the gel dosimeters were read by a cone beam optical computed tomography (optical CT) scanner. The dose distributions measured by the NIPAM gel dosimeter were compared to the outputs of the treatment planning system using gamma evaluation. For the criteria of 3%/3 mm, the pass rates for 5 × 5, 3 × 3, 2 × 2, 1 × 1, and 0.5 × 0.5 cm2 were as high as 91.7%, 90.7%, 88.2%, 74.8%, and 37.3%, respectively. For the criteria of 5%/5 mm, the gamma pass rates of the 5 × 5, 3 × 3, and 2 × 2 cm2 fields were over 99%. The NIPAM gel dosimeter provides high chemical stability. With cone-beam optical CT readouts, the NIPAM polymer gel dosimeter has potential for clinical dose verification of small-field irradiation. PMID:26974434

  13. An investigation into the sensitivity of various albedo neutron dosimeters aimed at correcting the readings

    NASA Astrophysics Data System (ADS)

    Alekseev, A. G.; Mokrov, Yu. V.; Morozova, S. V.

    2012-03-01

    The results of an experimental determination of the sensitivity of three types of individual neutron albedo dosimeters in neutron reference fields on the basis of radionuclide sources and at the top concrete shielding of the U-70 accelerator are presented. The results show that the ratios between the responses of the albedo dosimeters designed earlier at the Joint Institute for Nuclear Research (the albedo dosimeter (AD) and the multicomponent dosimeter (MD)) and the currently used DVGN-01 dosimeter are constant within 25% in a wide range of neutron energy. This fact makes it possible to use the results of measuring the AD and MD responses obtained earlier in neutron fields of nuclear-physical installations at the Joint Institute for Nuclear Research (JINR) for the correction of DVGN-01 dosimeter measurement results to apply it to personal radiation monitoring (PRM) at these installations. The correction factors for DVGN-01 measurement results are found and recommended to be used in PRM for most JINR installations.

  14. Characterization of a Tissue-Equivalent Dosimeter based on CMOS Solid-State Photomultipliers

    NASA Astrophysics Data System (ADS)

    Johnson, Erik; Benton, Eric; Stapels, Christopher; Chrsitian, James; Jie Chen, Xiao

    Available digital dosimeters are bulky and unable to provide real-time monitoring of dose from space radiation. The complexity of space-flight design requires reliable, fault-tolerant equip-ment capable of providing real-time dosimetry during a mission, which is not feasible with the existing thermoluminescent dosimeter (TLD) technology, especially during extravehicular activity (EVA). Real-time monitoring is important for low-Earth orbiting spacecraft and inter-planetary space flight to alert the crew when Solar Particle Events (SPE) increase the particle flux of the spacecraft environment. A dosimeter-on-a-chip for personal dosimetry is comprised of a tissue-equivalent scintillator coupled to a solid-state photomultiplier (SSPM) built using CMOS technology. The radiation sensitive component of the dosimeter is coupled to analog signal processing components and a microprocessor, which can maintain processing fidelity up to 5x105 events per second. The dynamic range of the dosimeter has been verified from 1-GeV protons (0.22 keV/µm in H20) to 420 MeV/n Fe (201.1 keV/µm in H20). The dosimeter confirmed doses to within 3

  15. Characterization of a water-equivalent fiber-optic coupled dosimeter for use in diagnostic radiology.

    PubMed

    Hyer, Daniel E; Fisher, Ryan F; Hintenlang, David E

    2009-05-01

    This work reports on the characterization of a new fiber-optic coupled (FOC) dosimeter for use in the diagnostic radiology energy range. The FOC dosimeter was constructed by coupling a small cylindrical plastic scintillator, 500 microm in diameter and 2 mm in length, to a 2 m long optical fiber, which acts as a light guide to transmit scintillation photons from the sensitive element to a photo-multiplier tube (PMT). A serial port interface on the PMT permits real-time monitoring of light output from the dosimeter via a custom computer program. The FOC dosimeter offered excellent sensitivity and reproducibility, allowing doses as low as 0.16 mGy to be measured with a coefficient of variation of only 3.64%. Dose linearity was also excellent with a correlation coefficient of 1.000 over exposures ranging from 0.16 to 57.29 mGy. The FOC dosimeter exhibited little angular dependence from axial irradiation, varying by less than 5% over an entire revolution. A positive energy dependence was observed and measurements performed within a scatter medium yielded a 10% variation in sensitivity as beam quality changed due to hardening and scatter across a 16 cm depth range. The current dosimetry system features an array of five PMTs to allow multiple FOC dosimeters to be monitored simultaneously. Overall, the system allows for rapid and accurate dose measurements relevant to a range of diagnostic imaging applications.

  16. N-isopropylacrylamide gel dosimeter to evaluate clinical photon beam characteristics.

    PubMed

    Chiu, Chung-Yu; Tsang, Yuk-Wah; Hsieh, Bor-Tsung

    2014-08-01

    The introduction of beam intensity control concept in current radiotherapy techniques has increased treatment planning complexity. Thus, small-field dose measurement has become increasingly vital. Polymer gel dosimetry method is widely studied. It is the only dose measurement tool that provides 3D dose distribution. This study aims to use an N-isopropylacrylamide (NIPAM) gel dosimeter to conduct beam performance measurements of percentage depth dose (PDD), beam flatness, and symmetry for photon beams with field sizes of 3×3 and 4×4 cm(2). Computed tomography scans were used to readout the gel dosimeters. In the PDD measurement, the NIPAM gel dosimeter and Gafchromic™ EBT3 radiochromic film displayed high consistency in the region deeper than the build-up region. The gel dosimeter dose profile had 3% lower flatness and symmetry measurement at 5 cm depth for different fields compared with that of the Gafchromic™ EBT3 film. During gamma evaluation under 3%/3 mm dose difference/distance-to-agreement standard, the pass rates of the polymer gel dosimeter to the TPS and EBT3 film were both higher than 96%. Given that the gel is tissue equivalent, it did not exhibit the energy dependence problems of radiochromic films. Therefore, the practical use of NIPAM polymer gel dosimeters is enhanced in clinical dose verification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Preparation of polymer gel dosimeters based on less toxic monomers and gellan gum

    NASA Astrophysics Data System (ADS)

    Hiroki, A.; Sato, Y.; Nagasawa, N.; Ohta, A.; Seito, H.; Yamabayashi, H.; Yamamoto, T.; Taguchi, M.; Tamada, M.; Kojima, T.

    2013-10-01

    New polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate (HEMA), triethylene glycol monoethyl ether monomethacrylate (TGMEMA), polyethylene glycol 400 dimethacrylate (9G), tetrakis (hydroxymethyl) phosphonium chloride as an antioxidant, and gellan gum as a gel matrix were prepared. They were optically analyzed by measuring absorbance to evaluate a dose response. The absorbance of the polymer gel dosimeters that were exposed to 60Co γ-rays increased with increasing dose. The dosimeters comprising HEMA and 9G showed a linear increase in absorbance in the dose range from 0 to 10 Gy. The dose response depended on the 9G concentration. For others comprising HEMA, 9G and TGMEMA, the absorbance of the polymer gel dosimeters drastically increased above a certain dose, and then leveled off up to 10 Gy. The optical variations in these polymer gel dosimeters were also induced by x-irradiation from Cyberknife radiotherapy equipment. Furthermore, the exposed region of the latter polymer gel dosimeter exhibited a thermo-responsive behavior.

  18. Polymethylmethacrylate combustion in a narrow channel apparatus simulating a microgravity environment

    NASA Astrophysics Data System (ADS)

    Bornand, Garrett Randall

    Fire safety is an important part of engineering when human lives are at stake. From everyday homes to spacecraft that can cost hundreds of millions of dollars. The research in this thesis attempts to provide scientific evidence that the apparatus in question successfully simulates microgravity and can possibly replace NASA's current test method for spacecraft fire safety. Flame spread tests were conducted with thermally thick and thermally thin polymethylmethacrylate (PMMA) samples to study flame spread behavior in response to environmental changes. The tests were conducted using the San Diego State University Narrow Channel Apparatus (SDSU NCA) as well as within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS). The SDSU NCA can suppress buoyant flow in horizontally spreading flames, and is currently being investigated as a possible replacement or complement to NASA's current material flammability test standard for non-metallic solids, NASA-STD-(I)-6001B Test 1. The buoyant suppression attained in the NCA allows tests to be conducted in a simulated microgravity environment-a characteristic that NASA's Test 1 lacks since flames present in Test 1 are driven by buoyant flows. The SDSU NCA allows for tests to be conducted at various opposed flow oxidizer velocities, oxygen percent by volume, and total pressure to mimic various spacecraft and habitat atmospheres. Tests were conducted at 1 atm pressure, thin fuel thickness of 50 and 75 microns, thick fuel thickness ranging from 3 mm to 5.6 mm, opposed oxidizer velocity ranging from 10 to 25 cm/s, and oxygen concentration by volume at 21, 30, and 50 percent. The simulated microgravity flame spread results were then compared to true microgravity experiments including; testing conducted on the International Space Station (ISS) under the Burning and Suppression of Solids (BASS) research, NASA's 5.2 second Drop Tower, and Micro-Gravity Laboratory's (MGLAB) 4.5 second Drop Tower. Data was also

  19. Single molecule detection of double-stranded DNA in poly(methylmethacrylate) and polycarbonate microfluidic devices.

    PubMed

    Wabuyele, M B; Ford, S M; Stryjewski, W; Barrow, J; Soper, S A

    2001-10-01

    Single photon burst techniques were used to detect double-stranded DNA molecules in poly(methylmethacrylate) (PM MA) and polycarbonate (PC) microfluidic devices. A confocal epi-illumination detection system was constructed to monitor the fluorescence signature from single DNA molecules that were multiply labeled with the mono-intercalating dye, TOPRO-5, which possessed an absorption maximum at 765 nm allowing excitation with a solid-state diode laser and fluorescence monitoring in the near-infrared (IR). Near-IR excitation minimized autofluorescence produced from the polymer substrate, which was found to be significantly greater when excitation was provided in the visible range (488 nm). A solution containing lambda-DNA (48.5 kbp) was electrokinetically transported through the microfluidic devices at different applied voltages and solution pH values to investigate the effects of polymer substrate on the transport rate and detection efficiency of single molecular events. By applying an autocorrelation analysis to the data, we were able to obtain the molecular transit time of the individual molecules as they passed through the 7 microm laser beam. It was observed that the applied voltage for both devices affected the transport rate. However, solution pH did not alter the transit time for PM MA-based devices since the electroosmotic flow of PMMA was independent of solution pH. In addition, efforts were directed toward optimizing the sampling efficiency (number of molecules passing through the probe volume) by using either hydrodynamically focused flows from a sheath generated by electrokinetic pumping from side channels or reducing the channel width of the microfluidic device. Due to the low electroosmotic flows generated by both PMMA and PC, tight focusing of the sample stream was not possible. However, in PMMA devices, flow gating was observed by applying field strengths > -120 V/cm to the sheath flow channels. By narrowing the microchannel width, the number of

  20. [QTRAP LC-MS/MS Analytical Study on Nucleosides and Nucleobases of Pseudostellariae Radix Cultivated in Different Idioplasm Resources].

    PubMed

    Ma, Yang; Hou, Ya; Zou, Li-si; Liu, Xun-hong; Xu, Li; Lan, Cai-wu; Yuan, Ji-duan

    2015-04-01

    To analyze nucleosides and nucleobases of Pseudostellariae Radix cultivated in different idibplasni resources and to compare the differences. QTRAP LC-MS/MS method was applied for the analysis of 13 kinds of nucleosides and nucleobases in Pseudostellariae Radix and the data obtained was analyzed by SPSS 16. 0 software. There were some differences between Pseudostellariae Radix cultivated in different idioplasm resources. The highest amount of nucleosides and nucleobases was ZS2 which came from Zherong in Fujian Province. The total content of nucleosides and nucleobases in the sample from Shibing in Guizhou Province was the lowest. There was little difference between ZS1 (Zherong in Fujian Province) and XC(Xuancheng in Anhui Province). This study provides evidence for the influence of eco-environment on the metabolites of Pseudostellariae Radix.

  1. Validation of an "Intelligent Mouthguard" Single Event Head Impact Dosimeter.

    PubMed

    Bartsch, Adam; Samorezov, Sergey; Benzel, Edward; Miele, Vincent; Brett, Daniel

    2014-11-01

    Dating to Colonel John Paul Stapp MD in 1975, scientists have desired to measure live human head impacts with accuracy and precision. But no instrument exists to accurately and precisely quantify single head impact events. Our goal is to develop a practical single event head impact dosimeter known as "Intelligent Mouthguard" and quantify its performance on the benchtop, in vitro and in vivo. In the Intelligent Mouthguard hardware, limited gyroscope bandwidth requires an algorithm-based correction as a function of impact duration. After we apply gyroscope correction algorithm, Intelligent Mouthguard results at time of CG linear acceleration peak correlate to the Reference Hybrid III within our tested range of pulse durations and impact acceleration profiles in American football and Boxing in vitro tests: American football, IMG=1.00REF-1.1g, R2=0.99; maximum time of peak XYZ component imprecision 3.6g and 370 rad/s2; maximum time of peak azimuth and elevation imprecision 4.8° and 2.9°; maximum average XYZ component temporal imprecision 3.3g and 390 rad/s2. Boxing, IMG=1.00REF-0.9 g, R2=0.99, R2=0.98; maximum time of peak XYZ component imprecision 3.9 g and 390 rad/s2, maximum time of peak azimuth and elevation imprecision 2.9° and 2.1°; average XYZ component temporal imprecision 4.0 g and 440 rad/s2. In vivo Intelligent Mouthguard true positive head impacts from American football players and amateur boxers have temporal characteristics (first harmonic frequency from 35 Hz to 79 Hz) within our tested benchtop (first harmonic frequency<180 Hz) and in vitro (first harmonic frequency<100 Hz) ranges. Our conclusions apply only to situations where the rigid body assumption is valid, sensor-skull coupling is maintained and the ranges of tested parameters and harmonics fall within the boundaries of harmonics validated in vitro. For these situations, Intelligent Mouthguard qualifies as a single event dosimeter in American football and Boxing.

  2. Characterization of a new radiochromic three-dimensional dosimeter

    SciTech Connect

    Guo, P.Y.; Adamovics, J.A.; Oldham, M.

    2006-05-15

    The development of intensity-modulated radiotherapy (IMRT) has created a clear need for a dosimeter that can accurately and conveniently measure dose distributions in three dimensions to assure treatment quality. PRESAGE{sup TM} is a new three dimensional (3D) dosimetry material consisting of an optically clear polyurethane matrix, containing a leuco dye that exhibits a radiochromic response when exposed to ionizing radiation. A number of potential advantages accrue over other gel dosimeters, including insensitivity to oxygen, radiation induced light absorption contrast rather than scattering contrast, and a solid texture amenable to machining to a variety of shapes and sizes without the requirement of an external container. In this paper, we introduce an efficient method to investigate the basic properties of a 3D dosimetry material that exhibits an optical dose response. The method is applied here to study the key aspects of the optical dose response of PRESAGE{sup TM}: linearity, dose rate dependency, reproducibility, stability, spectral changes in absorption, and temperature effects. PRESAGE{sup TM} was prepared in 1x1x4.5 cm{sup 3} optical cuvettes for convenience and was irradiated by both photon and electron beams to different doses, dose rates, and energies. Longer PRESAGE{sup TM} columns (2 x2x13 cm{sup 3}) were formed without an external container, for measurements of photon and high energy electron depth-dose curves. A linear optical scanning technique was used to detect the depth distribution of radiation induced optical density (OD) change along the PRESAGE{sup TM} columns and cuvettes. Measured depth-OD curves were compared with percent depth dose (PDD). Results indicate that PRESAGE{sup TM} has a linear optical response to radiation dose (with a root mean square error of {approx}1%), little dependency on dose rate ({approx}2%), high intrabatch reproducibility (<2%), and can be stable ({approx}2%) during 2 hours to 2 days post irradiation. Accurate

  3. Characterization of a new radiochromic three-dimensional dosimeter.

    PubMed

    Guo, P Y; Adamovics, J A; Oldham, M

    2006-05-01

    The development of intensity-modulated radiotherapy (IMRT) has created a clear need for a dosimeter that can accurately and conveniently measure dose distributions in three dimensions to assure treatment quality. PRESAGE is a new three dimensional (3D) dosimetry material consisting of an optically clear polyurethane matrix, containing a leuco dye that exhibits a radiochromic response when exposed to ionizing radiation. A number of potential advantages accrue over other gel dosimeters, including insensitivity to oxygen, radiation induced light absorption contrast rather than scattering contrast, and a solid texture amenable to machining to a variety of shapes and sizes without the requirement of an external container. In this paper, we introduce an efficient method to investigate the basic properties of a 3D dosimetry material that exhibits an optical dose response. The method is applied here to study the key aspects of the optical dose response of PRESAGE: linearity, dose rate dependency, reproducibility, stability, spectral changes in absorption, and temperature effects. PRESAGE was prepared in 1 x 1 x 4.5 cm3 optical cuvettes for convenience and was irradiated by both photon and electron beams to different doses, dose rates, and energies. Longer PRESAGE columns (2 x 2 x 13 cm3) were formed without an external container, for measurements of photon and high energy electron depth-dose curves. A linear optical scanning technique was used to detect the depth distribution of radiation induced optical density (OD) change along the PRESAGE columns and cuvettes. Measured depth-OD curves were compared with percent depth dose (PDD). Results indicate that PRESAGE has a linear optical response to radiation dose (with a root mean square error of -1%), little dependency on dose rate (-2%), high intrabatch reproducibility (< 2%), and can be stable (-2%) during 2 hours to 2 days post irradiation. Accurate PRESAGE dosimetry requires temperature control within 1 degrees C

  4. An investigation of a PRESAGE® in vivo dosimeter for brachytherapy

    NASA Astrophysics Data System (ADS)

    Vidovic, A. K.; Juang, T.; Meltsner, S.; Adamovics, J.; Chino, J.; Steffey, B.; Craciunescu, O.; Oldham, M.

    2014-07-01

    Determining accurate in vivo dosimetry in brachytherapy treatment with high dose gradients is challenging. Here we introduce, investigate, and characterize a novel in vivo dosimeter and readout technique with the potential to address this problem. A cylindrical (4 mm × 20 mm) tissue equivalent radiochromic dosimeter PRESAGE® in vivo (PRESAGE®-IV) is investigated. Two readout methods of the radiation induced change in optical density (OD) were investigated: (i) volume-averaged readout by spectrophotometer, and (ii) a line profile readout by 2D projection imaging utilizing a high-resolution (50 micron) telecentric optical system. Method (i) is considered the gold standard when applied to PRESAGE® in optical cuvettes. The feasibility of both methods was evaluated by comparison to standard measurements on PRESAGE® in optical cuvettes via spectrophotometer. An end-to-end feasibility study was performed by a side-by-side comparison with TLDs in an 192Ir HDR delivery. 7 and 8 Gy was delivered to PRESAGE®-IV and TLDs attached to the surface of a vaginal cylinder. Known geometry enabled direct comparison of measured dose with a commissioned treatment planning system. A high-resolution readout study under a steep dose gradient region showed 98.9% (5%/1 mm) agreement between PRESAGE®-IV and Gafchromic® EBT2 Film. Spectrometer measurements exhibited a linear dose response between 0-15 Gy with sensitivity of 0.0133 ± 0.0007 ΔOD/(Gy ṡ cm) at the 95% confidence interval. Method (ii) yielded a linear response with sensitivity of 0.0132 ± 0.0006 (ΔOD/Gy), within 2% of method (i). Method (i) has poor spatial resolution due to volume averaging. Method (ii) has higher resolution (˜1 mm) without loss of sensitivity or increased noise. Both readout methods are shown to be feasible. The end-to-end comparison revealed a 2.5% agreement between PRESAGE®-IV and treatment plan in regions of uniform high dose. PRESAGE®-IV shows promise for in vivo dose verification

  5. Chemosynthesis pathway and bioactivities comparison of saponins in radix and flower of Panax notoginseng (Burk.) F.H. Chen.

    PubMed

    Zhou, Xin; Chen, Lin-Lin; Xie, Rui Fang; Lam, Wing; Zhang, Zi-Jia; Jiang, Zao-Li; Cheng, Yung-Chi

    2017-04-06

    Panax notoginseng (Burk.) F.H. Chen is a well known medicinal plant. Its radix is used in the history while its flower is recently used for health care. In this study we compared chemical ingredients and bioactivities in cell culture for radix and flower of Panax notoginseng (Burk.) F.H. Chen. The liquid chromatography-mass spectrometry system was applied to determine the contents of saponins in flower and radix of Panax notoginseng (Burk.) F.H. Chen. Transcription specific luciferase reporter assay and qPCR method for selected RNA were carried out to assess the impacts of flower and radix extract on the transcription signal pathways. The results of chemical analysis showed that the contents of saponins in flower and radix are very different: the contents of Rg1, Rb1, Re, R1, Rg3-20R, Rh1 and Rf in radix are abundant; in contrast, the contents of Rb3, Fc, Ft1, Rb2 and Rh2-20s in flowers are plentiful. There are substantial variations of those saponin contents from one batch vs another. Based on relative content of saponins, the chemosynthesis pathway of ingredients in radix and flower are proposed: for radix, both PPT (Protopanaxatriol) and PPD (Protopanaxadiol) type triterpenoids are involved, the main pathway is PPT→Rb1→Rg1→R1 or PPD→Rh2 20s→Rg3(20s)→Rd→Rb1; for flowers, only PPD is main passage with PPD→Rh2 (20s)→Rg3(20s)→Rd→Rb2→Fc. The results of signal transcription assays demonstrated that herb water extract of radix and flower had no significant influences on most of transcription activities. However, total saponins of radix and flower which have highly content of saponins were able to inhibit the inflammatory related transcriptional activities and their related mRNA expression of IFNα, TNFα, il-6 and TGFβ as well as induce anti-oxygen NrF2 activities. In summary, although chemical ingredients and chemosynthesis pathway of flower and radix for Panax notoginseng (Burk.) F.H. Chen were different, these differences might not result in

  6. Comparative analysis of four terpenoids in root and cortex of Tripterygium wilfordii Radix by different drying methods.

    PubMed

    Wang, Tuanjie; Shen, Fei; Su, Shulan; Bai, Yongliang; Guo, Sheng; Yan, Hui; Ji, Tao; Wang, Yanyan; Qian, Dawei; Duan, Jin-Ao

    2016-11-23

    Tripterygium wilfordii Radix, a well-known traditional medicine in china which is used for treatment of inflammation, pain, tumor and immune regulation for centuries in china, accompany with the serious toxic side effects. This study was carried out for simultaneously analyzing the four main components (triptolide, triptophenolide, demethylzeylasteral and celastrol) in Tripterygium wilfordii Radix under different drying processes, which was important for reducing the toxicity and quality control of Tripterygium wilfordii Radix in future. The terpenes were extracted by using ultrasonic method with ethyl acetate from root or cortex of Tripterygium wilfordii Radix, and the sensitive and rapid HPLC-PDA method was developed for simultaneous quantification of triptolide, triptophenolide, demethylzeylasteral and celastrol in root and cortex of Tripterygium wilfordii Radix for evaluation of the impacts by different drying processes. The four compounds in their respective determined arrange had good linearity of 0.9998≦R(2)≦0.9999 and the average recoveries were range from 94.69 to 100.28%, RSDs were within 0.27 to 2.42%, respectively. The contents of triptolide, triptophenolide, demethylzeylasteral and celastrol in different Tripterygium wilfordii Radix individuals were varied greatly at different drying temperatures. Under different temperatures, the contents of triptolide, triptophenolide, demethylzeylasteral, and celastrol were 37.94-70.31 mg/g, 0-1.807 mg/g, 0.3513-9.205 mg/g, 3.202-15.31 mg/g, respectively. The suitable drying temperature of terpenoids in root of wild and cultivate are 80 °C and 60 °C, the suitable drying temperature of terpenoids in cortex is 40 °C. The method established is high sensitivity, accuracy, reliability and suitable for the simultaneous analysis of terpenoids in Tripterygium wilfordii Radix. The data provide a scientific basis and reference for the quality control of herb and preparations related to Tripterygium wilfordii

  7. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect

    PubMed Central

    Ishikawa, Masayori; Nagase, Naomi; Matsuura, Taeko; Hiratsuka, Junichi; Suzuki, Ryusuke; Miyamoto, Naoki; Sutherland, Kenneth Lee; Fujita, Katsuhisa; Shirato, Hiroki

    2015-01-01

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter. PMID:25618136

  8. Development of a wavelength-separated type scintillator with optical fiber (SOF) dosimeter to compensate for the Cerenkov radiation effect.

    PubMed

    Ishikawa, Masayori; Nagase, Naomi; Matsuura, Taeko; Hiratsuka, Junichi; Suzuki, Ryusuke; Miyamoto, Naoki; Sutherland, Kenneth Lee; Fujita, Katsuhisa; Shirato, Hiroki

    2015-03-01

    The scintillator with optical fiber (SOF) dosimeter consists of a miniature scintillator mounted on the tip of an optical fiber. The scintillator of the current SOF dosimeter is a 1-mm diameter hemisphere. For a scintillation dosimeter coupled with an optical fiber, measurement accuracy is influenced by signals due to Cerenkov radiation in the optical fiber. We have implemented a spectral filtering technique for compensating for the Cerenkov radiation effect specifically for our plastic scintillator-based dosimeter, using a wavelength-separated counting method. A dichroic mirror was used for separating input light signals. Individual signal counting was performed for high- and low-wavelength light signals. To confirm the accuracy, measurements with various amounts of Cerenkov radiation were performed by changing the incident direction while keeping the Ir-192 source-to-dosimeter distance constant, resulting in a fluctuation of <5%. Optical fiber bending was also addressed; no bending effect was observed for our wavelength-separated SOF dosimeter.

  9. Dissolution difference of ginsenosides from ultrafine granular powder and common powder traditional pieces of Panacis Quinquefolii Radix in vitro.

    PubMed

    Xu, Hao-qi; Chen, Sha; Zhang, Jun; Yang, Shi-lin; Cheng, Jin-le; Peng, Li-hua; Liu, An

    2015-07-01

    The dissolution of Panacis Quinquefolii Radix ultrafine granular powder and common powder, traditional pieces in water and simulated gastric juice in vitro was compared, and the effect of particles size of Panacis Quinquefolii Radix on the dissolution was studied. HPLC method was used for determination of five ginsenosides including Rg1, Re, Rb1, Rc and Rd from ultrafine granular powder and common powder, traditional pieces of Panacis Quinquefolii Radix at different points in time, furthermore, the dissolution curves of Panacis Quinquefolii Radix ultrafine granular powder and common powder, traditional pieces were obtained. The dissolution characteristics of the three Panacis Quinquefolii Radix forms were also compared in this study. According to the results, the dissolution rates of ginsenosides from ultrafine granular powder exceeded 90% of the total content with 5 min, significantly higher than that of the other two forms in water in vitro. At the same time, the dissolved amount of the ultrafine granular powder was fourteen percent higher than that of the traditional pieces and eight percent higher than that of the common powder. Under the condition of simulated gastric juice in vitro, the dissolution rates of ginsenosides from ultrafine granular powder were little lower than that of the other two, but the maximum dissolved amount of the former was fourteen percent higher than that of the common powder and five percent higher than that of the extracts. Therefore the conclusion is that micronization of Panacis Quinquefolii Radix contributed to dissolution of effective components.

  10. Feasibility Study of Glass Dosimeter for In Vivo Measurement: Dosimetric Characterization and Clinical Application in Proton Beams

    SciTech Connect

    Rah, Jeong-Eun; Oh, Do Hoon; Kim, Jong Won; Kim, Dae-Hyun; Suh, Tae-Suk; Ji, Young Hoon; Shin, Dongho; Lee, Se Byeong; Kim, Dae Yong; Park, Sung Yong

    2012-10-01

    Purpose: To evaluate the suitability of the GD-301 glass dosimeter for in vivo dose verification in proton therapy. Methods and Materials: The glass dosimeter was analyzed for its dosimetrics characteristic in proton beam. Dosimeters were calibrated in a water phantom using a stairlike holder specially designed for this study. To determine the accuracy of the glass dosimeter in proton dose measurements, we compared the glass dosimeter and thermoluminescent dosimeter (TLD) dose measurements using a cylindrical phantom. We investigated the feasibility of the glass dosimeter for the measurement of dose distributions near the superficial region for proton therapy plans with a varying separation between the target volume and the surface of 6 patients. Results and Discussion: Uniformity was within 1.5%. The dose-response has good linearity. Dose-rate, fading, and energy dependence were found to be within 3%. The beam profile measured using the glass dosimeter was in good agreement with the profile obtained from the ionization chamber. Depth-dose distributions in nonmodulated and modulated proton beams obtained with the glass dosimeter were estimated to be within 3%, which was lower than those with the ionization chamber. In the phantom study, the difference of isocenter dose between the delivery dose calculated by the treatment planning system and that measured by the glass dosimeter was within 5%. With in vivo dosimetry, the calculated surface doses overestimated measurements by 4%-16% using glass dosimeter and TLD. Conclusion: It is recommended that bolus be added for these clinical cases. We also believe that the glass dosimeter has considerable potential for use with in vivo patient proton dosimetry.

  11. Spectral discrimination of Cerenkov radiation in scintillating dosimeters.

    PubMed

    Frelin, A M; Fontbonne, J M; Ban, G; Colin, J; Labalme, M; Batalla, A; Isambert, A; Vela, A; Leroux, T

    2005-09-01

    Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.

  12. Production of element correction factors for thermoluminescent dosimeters

    SciTech Connect

    Plato, P.; Miklos, J.

    1985-11-01

    Approximately 80 processors of personal dosimetry in the United States use thermoluminescent dosimeters (TLDs). Recent demands that dosimetry processors be able to measure radiation doses to within +/- 50% of the correct value have focused attention on the reproducibility of the TL elements within each TLD. The phosphors for these TLDs are manufactured by three companies. A dosimetry processor faces three options concerning the quality of the TL elements purchased; trust the supplier's quality control program, screen new TL elements and discard those that are extremely bad, or use element correction factors (ECFs). The first option results in dosimetry processors failing the +/- 50% accuracy requirement due to excessive variability among the TL elements. The second option still permits large precision errors that come close to the +/- 50% accuracy requirement. This paper advocates the third option and presents a 10-step procedure to produce ECFs. The procedure ensures that the ECFs represent only variations among the TL elements and not variations caused by stability problems with the TLD reader. Following is an example of ECF production for 3000 TLDs.

  13. A small active dosimeter for applications in space

    NASA Astrophysics Data System (ADS)

    Ritter, Birgit; Maršálek, Karel; Berger, Thomas; Burmeister, Sönke; Reitz, Günther; Heber, Bernd

    2014-06-01

    The radiation field in low Earth orbits (LEO) differs significantly from the radiation environment on Earth's surface. Exposures are by far higher and pose an additional health risk for astronauts. Continuous monitoring is therefore a necessary task in the frame of radiation protection measures. A small battery-driven active dosimeter telescope based on silicon detectors meeting the requirements for LEO applications has been developed. The instrument, the Mobile Dosimetric Telescope (MDT), is designed to measure the absorbed dose rate and the linear energy transfer (LET) spectra. From the latter the mean quality factor of the radiation field can be derived and hence an estimate of the dose equivalent as a measure of the exposure. The calibration of the device is done using radioactive isotopes and heavy ions. Fragmentation products of heavy ions are used to show the ability of the MDT to reliably detect energy depositions from high energetic nuclei. Radiation measurements inside aircraft during long distance flights, serving as field tests of the instrument, prove the good performance of the instrument.

  14. Development and characterization of a DNA solar dosimeter.

    PubMed

    Ishigaki, Y; Takayama, A; Yamashita, S; Nikaido, O

    1999-06-01

    In this paper, we report the development and characterization of a solar ultraviolet (UV) dosimetry system that can be used as a film badge for radiation monitoring. DNA molecules are coated on a thin nylon membrane as a UV dosimeter. The membrane is sealed in a polyethylene filter envelope with silica gel to keep the humidity low. After exposure to UV or solar light, induced DNA damage is measured by an immunochemical reaction. The intensity of color developed during the immunological reaction can be correlated linearly with the irradiated UV dose delivered by an Oriel solar simulator within a limited dose range. We observe no effects of temperature on the level of damage induction. The membrane is proficient for measuring DNA damage for more than 21 days when stored at either 37 or 4 degrees C. The induced damage remains stable on the membrane for at least 22 days at both 37 and 4 degrees C. In addition to these indoor experiments, we report measurements of solar UV dose in outdoor experiments.

  15. Developments in production of silica-based thermoluminescence dosimeters

    NASA Astrophysics Data System (ADS)

    Bradley, D. A.; Siti Shafiqah, A. S.; Siti Rozaila, Z.; Sabtu, Siti Norbaini; Abdul Sani, S. F.; Alanazi, Abdulaziz H.; Jafari, S. M.; Amouzad Mahdiraji, G.; Mahamd Adikan, F. R.; Maah, M. J.; Nisbet, A. N.; Tamchek, N.; Abdul Rashid, H. A.; Alkhorayef, M.; Alzimami, K.

    2017-08-01

    This work addresses purpose-made thermoluminescence dosimeters (TLD) based on doped silica fibres and sol-gel nanoparticles, produced via Modified Chemical Vapour Deposition (MCVD) and wet chemistry techniques respectively. These seek to improve upon the versatility offered by conventional phosphor-based TLD forms such as that of doped LiF. Fabrication and irradiation-dependent factors are seen to produce defects of differing origin, influencing the luminescence of the media. In coming to a close, we illustrate the utility of Ge-doped silica media for ionizing radiation dosimetry, first showing results from gamma-irradiated Ag-decorated nanoparticles, in the particular instance pointing to an extended dynamic range of dose. For the fibres, at radiotherapy dose levels, we show high spatial resolution (0.1 mm) depth-dose results for proton irradiations. For novel microstructured fibres (photonic crystal fibres, PCFs) we show first results from a study of undisturbed and technologically modified naturally occurring radioactivity environments, measuring doses of some 10 s of μGy over a period of several months.

  16. Study of Fricke gel dosimeter response for different gel quality

    NASA Astrophysics Data System (ADS)

    Cavinato, C. C.; Campos, L. L.

    2010-11-01

    The Fricke xylenol gel (FXG) dosimeter has been studied for application in radiotherapy because it is capable of to measure the spatial distribution of radiation doses. The dosimetry is based on the oxidation of ferrous (Fe2+) to ferric (Fe3+) ions radiation induced, related to the radiation dose. The gel material usually employed is the 300 Bloom gelatin, which is imported and very expensive in Brazil. Aiming to analyze the viability of to use a locally produced and low cost gel material, in this work the spectrophotometric responses of FXG solutions prepared using 270 Bloom gelatin commercially available and 300 Bloom gelatin imported were compared. The absorption spectra of solutions prepared with 5% by weight 270 and 300 Bloom gelatins non-irradiated and irradiated with 60Co gamma radiation in the dose range between 0.5 and 100 Gy were analysed, the dose-response curves were evaluated and the useful dose range was established. The obtained results indicate that the FXG solution prepared with 270 Bloom gelatin presents good performance, similar to that presented by the FXG solution prepared with 300 Bloom gelatin and its use can be recommended owing to the low cost and the availability in local market.

  17. A CCD-based γ-ray dosimeter

    NASA Astrophysics Data System (ADS)

    Harris, E. J.; Royle, G. J.; Mooney, M. J.; Speller, R. D.

    2001-02-01

    This paper investigates the use of charged coupled devices (CCDs) for personal γ-ray dosimetry. Personal dosimeters require high sensitivity to the photon energies likely to be encountered and a sensitivity response across a wide dose rate range, particularly at low dose rates. The principal advantages of CCDs for this application are two-fold: sensitivity at low dose rates due to low-noise operation and a wide dynamic range. Preliminary experimental measurements have been performed on a standard buried channel CCD using a range of isotope sources. One half of the sensor was coated with a 100 μm thick layer of caesium iodide. It is proposed that the differing properties of the two halves of the sensor increases its range for personal dosimetry. Deposition of scintillator coatings of various thicknesses across the surface of the sensor should provide sensitivity to a wide energy range. The results demonstrated that the device has potential for this application. A linear dose rate response was observed over the dose rate range 0.08-35 μSv h -1. It was found that the uncoated side of the sensor demonstrated better response at low dose rates and a better energy response. Whereas the scintillator coated side would improve the detection efficiency at energies beyond 60 keV.

  18. DNA as a solar dosimeter in the ocean

    SciTech Connect

    Regan, J.D.; Carrier, W.L. ); Gucinski, H. ); Olla, B.L. ); Wicklund, R.I. )

    1990-01-09

    Increased solar UV[B] in the ocean may be one of the results of atmospheric ozone depletion and may cause deleterious effects on marine organisms. The primary lesion induced by UV(B) in biological systems in DNA damage. While physical measurements of solar UV(B) penetration into the sea have been made, depth and magnitude of actual DNA damage has yet to be demonstrated. We have quantitated UV(B)-induced photoproducts (cyclobutane pyrimidine dimers) in DNA molecules exposed to solar UV at the surface and at various depths in clear, tropical oceanic waters off Lee Stocking Island, Bahamas. [sup 14]C-thymidine-labeled DNA was placed in quartz cuvettes polished on all four sides and suspended horizontally in special holders at selected depths for exposures of up to five days. Simultaneous measurements of light were made with an underwater photometer. Following exposures, DNA samples were transported to the laboratory and the pyrimidine dimers induced were quantitated using a radiochromatographic assay. The attenuation of the yield of dimer was approximately linear between 0 and 1.0 m. However, at 3.0 m, the yield was considerably higher than predicted by the earlier portion of the curve. Preliminary laboratory experiments with DNA in seawater tanks using a solar simulating light source markedly underestimated the yield of dimers found under field conditions. Implications of these results and applications of this biomolecular dosimeter system will be discussed.

  19. Dose measurements in intraoral radiography using thermoluminescent dosimeters

    NASA Astrophysics Data System (ADS)

    Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

    2015-01-01

    The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

  20. Effects of polymethylmethacrylate-transfer residues on the growth of organic semiconductor molecules on chemical vapor deposited graphene

    SciTech Connect

    Kratzer, Markus Teichert, Christian; Bayer, Bernhard C.; Kidambi, Piran R.; Matković, Aleksandar; Gajić, Radoš; Cabrero-Vilatela, Andrea; Weatherup, Robert S.; Hofmann, Stephan

    2015-03-09

    Scalably grown and transferred graphene is a highly promising material for organic electronic applications, but controlled interfacing of graphene thereby remains a key challenge. Here, we study the growth characteristics of the important organic semiconductor molecule para-hexaphenyl (6P) on chemical vapor deposited graphene that has been transferred with polymethylmethacrylate (PMMA) onto oxidized Si wafer supports. A particular focus is on the influence of PMMA residual contamination, which we systematically reduce by H{sub 2} annealing prior to 6P deposition. We find that 6P grows in a flat-lying needle-type morphology, surprisingly independent of the level of PMMA residue and of graphene defects. Wrinkles in the graphene typically act as preferential nucleation centers. Residual PMMA does however limit the length of the resulting 6P needles by restricting molecular diffusion/attachment. We discuss the implications for organic device fabrication, with particular regard to contamination and defect tolerance.