Tracing reclaimed water in the Menifee, Winchester, and Perris-South ground-water subbasins, Riverside County, California

USGS Publications Warehouse

Kaehler, Charles A.; Belitz, Kenneth

2003-01-01

As a component in the management of water resources in the Menifee, Winchester, and Perris-South subbasins in Riverside County, California, ponds are operated by the Eastern Municipal Water District for the temporary storage of reclaimed water that is produced by several regional water-reclamation facilities. A primary goal of this study was to evaluate the potential for using various ground-water constituents or characteristics as tracers of reclaimed water that has infiltrated from the storage ponds into the ground water in the three subbasins. A secondary goal was to estimate the degree to which the infiltrated reclaimed water has mixed with the native ground water. The evaluation of potential tracers and the estimation of mixing focused on data from wells located relatively close to the ponds. The most useful constituents and characteristics for evaluation of the fate and mixing of reclaimed water in the Menifee, Winchester, and Perris-South subbasins are major-ion composition, stable isotopes of hydrogen and oxygen, ultraviolet absorbance (UV-A), chloride concentration, and boron/chloride ratio plotted against chloride concentration. Emphasis in this study was placed on evaluating the utility of UV-A as a tracer and boron/chloride ratios in estimating the fraction of reclaimed water in ground water. In the Menifee subbasin, major-ion data, stable isotopes, chloride, UV-A, and boron/chloride ratio are all useful in identifying reclaimed water, and the results based on these indicators are consistent with each other. The results suggest that values of UV-A greater than or equal to 0.007 indicate the presence of reclaimed water in the Menifee subbasin. Ground-water samples with UV-A greater than 0.007 are estimated to consist of about 75 to 100 percent reclaimed water, on the basis of chloride-mixing calculations and boron/chloride-versus-chloride mixing calculations. In the Winchester subbasin, results based on the same factors used in the Menifee subbasin are less conclusive; nevertheless, UV-A can be used as a tracer. The results suggest that values of UV-A greater than 0.01 indicate the presence of reclaimed water. Values from 0.006 to 0.01 may indicate the presence of reclaimed water; however, water from wells not likely to have reclaimed water may also have UV-A values in this range. Ground-water samples with UV-A greater than 0.01 seem to contain about 25 percent reclaimed water (range 6 to 32 percent), on the basis of the consistency of the results of three types of mixing calculations--chloride alone, boron/chloride versus chloride, and UV-A. In the Perris-South subbasin, the potential tracers are not as conclusive in identifying reclaimed water in the subsurface as in the Menifee and Winchester subbasins. The less-conclusive results are a consequence of the multiple, spatially distributed sources of reclaimed water; the relative absence of wells close to the reclaimed-water pond; and the short period of operation (about 1 year) of the pond at the time of sampling. Mixing calculations suggest that ground-water samples with elevated UV-A values (greater than 0.01) in the Perris-South subbasin could contain as much as 40 to 65 percent reclaimed water.

77 FR 37074 - License Amendment Request From the Alan J. Blotcky Reactor Facility

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-20

... the Alan J. Blotcky Reactor Facility AGENCY: Nuclear Regulatory Commission. ACTION: Notice of... section of this document. FOR FURTHER INFORMATION CONTACT: Theodore Smith, Project Manager, Reactor... provided the first time that a document is referenced. The Alan J. Blotcky Reactor Facility Decommissioning...

New semi-pilot-scale reactor to study the photocatalytic inactivation of phages contained in aerosol.

PubMed

Briggiler Marcó, Mariángeles; Negro, Antonio Carlos; Alfano, Orlando Mario; Quiberoni, Andrea Del Luján

2017-04-12

The aims of this work were to design and build a photocatalytic reactor (UV-A/TiO 2 ) to study the inactivation of phages contained in bioaerosols, which constitute the main dissemination via phages in industrial environments. The reactor is a close system with recirculation that consists of a stainless steel camera (cubic form, side of 60 cm) in which air containing the phage particles circulates and an acrylic compartment with six borosilicate plates covered with TiO 2 . The reactor is externally illuminated by 20 UV-A lamps. Both compartments are connected by a fan to facilitate the sample circulation. Samples are injected into the camera using two piston nebulizers working in series whereas several methodologies for sampling (impinger/syringe, sampling on photocatalytic plates, and impact of air on slide) were assayed. The reactor setup was carried out using phage B1 (Lactobacillus plantarum), and assays demonstrated a decrease of phage counts of 2.7 log orders after 1 h of photocatalytic treatment. Photonic efficiencies of inactivation were assessed by phage sampling on the photocatalytic plates or by impact of air on a glass slide at the photocatalytic reactor exit. Efficiencies of the same order of magnitude were observed using both sampling methods. This study demonstrated that the designed photocatalytic reactor is effective to inactivate phage B1 (Lb. plantarum) contained in bioaerosols.

Analysis of decommissioning costs for the AFRRI TRIGA reactor facility. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsbacka, M.; Moore, M.

1989-12-01

This report provides a cost analysis for decommissioning the Armed Forces Radiobiology Research Institute (AFRRI) TRIGA reactor facility. AFRRI is not suggesting that the AFRRI TRIGA reactor facility be decommissioned. This report was prepared in compliance with paragraph 50.33 of Title 10, Code of Federal Regulations, which requires that funding for the decommissioning of reactor facilities be available when licensed activities cease. The planned method of decommissioning is complete decontamination (DECON) of the AFRRI TRIGA reactor site to allow for restoration of the site to full public access. The cost of DECON in 1990 dollars is estimated to be $3,200,000.more » The anticipated ancillary costs of facility site demobilization and spent fuel shipment will be an additional $600,000. Thus, the total cost of terminating reactor operations at AFRRI will be about $3,800,000. The primary basis for developing this cost estimate was a study of the decommissioning costs of similar reactor facility performed by Battelle Pacific Northwest Laboratory, as provided in U.S. Nuclear Regulatory Commission publication NUREG/CR-1756. The data in this study were adapted to reflect the decommissioning requirements of the AFRRI TRIGA reactor facility.« less

Survival of Spacecraft-Associated Microorganisms under Simulated Martian UV Irradiation

PubMed Central

Newcombe, David A.; Schuerger, Andrew C.; Benardini, James N.; Dickinson, Danielle; Tanner, Roger; Venkateswaran, Kasthuri

2005-01-01

Spore-forming microbes recovered from spacecraft surfaces and assembly facilities were exposed to simulated Martian UV irradiation. The effects of UVA (315 to 400 nm), UVA+B (280 to 400 nm), and the full UV spectrum (200 to 400 nm) on the survival of microorganisms were studied at UV intensities expected to strike the surfaces of Mars. Microbial species isolated from the surfaces of several spacecraft, including Mars Odyssey, X-2000 (avionics), and the International Space Station, and their assembly facilities were identified using 16S rRNA gene sequencing. Forty-three Bacillus spore lines were screened, and 19 isolates showed resistance to UVC irradiation (200 to 280 nm) after exposure to 1,000 J m−2 of UVC irradiation at 254 nm using a low-pressure mercury lamp. Spores of Bacillus species isolated from spacecraft-associated surfaces were more resistant than a standard dosimetric strain, Bacillus subtilis 168. In addition, the exposure time required for UVA+B irradiation to reduce the viable spore numbers by 90% was 35-fold longer than the exposure time required for the full UV spectrum to do this, confirming that UVC is the primary biocidal bandwidth. Among the Bacillus species tested, spores of a Bacillus pumilus strain showed the greatest resistance to all three UV bandwidths, as well as the total spectrum. The resistance to simulated Mars UV irradiation was strain specific; B. pumilus SAFR-032 exhibited greater resistance than all other strains tested. The isolation of organisms like B. pumilus SAFR-032 and the greater survival of this organism (sixfold) than of the standard dosimetric strains should be considered when the sanitation capabilities of UV irradiation are determined. PMID:16332797

Survival of spacecraft-associated microorganisms under simulated martian UV irradiation.

PubMed

Newcombe, David A; Schuerger, Andrew C; Benardini, James N; Dickinson, Danielle; Tanner, Roger; Venkateswaran, Kasthuri

2005-12-01

Spore-forming microbes recovered from spacecraft surfaces and assembly facilities were exposed to simulated Martian UV irradiation. The effects of UVA (315 to 400 nm), UVA+B (280 to 400 nm), and the full UV spectrum (200 to 400 nm) on the survival of microorganisms were studied at UV intensities expected to strike the surfaces of Mars. Microbial species isolated from the surfaces of several spacecraft, including Mars Odyssey, X-2000 (avionics), and the International Space Station, and their assembly facilities were identified using 16S rRNA gene sequencing. Forty-three Bacillus spore lines were screened, and 19 isolates showed resistance to UVC irradiation (200 to 280 nm) after exposure to 1,000 J m(-2) of UVC irradiation at 254 nm using a low-pressure mercury lamp. Spores of Bacillus species isolated from spacecraft-associated surfaces were more resistant than a standard dosimetric strain, Bacillus subtilis 168. In addition, the exposure time required for UVA+B irradiation to reduce the viable spore numbers by 90% was 35-fold longer than the exposure time required for the full UV spectrum to do this, confirming that UVC is the primary biocidal bandwidth. Among the Bacillus species tested, spores of a Bacillus pumilus strain showed the greatest resistance to all three UV bandwidths, as well as the total spectrum. The resistance to simulated Mars UV irradiation was strain specific; B. pumilus SAFR-032 exhibited greater resistance than all other strains tested. The isolation of organisms like B. pumilus SAFR-032 and the greater survival of this organism (sixfold) than of the standard dosimetric strains should be considered when the sanitation capabilities of UV irradiation are determined.

Computational Tools and Facilities for the Next-Generation Analysis and Design Environment

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

1997-01-01

This document contains presentations from the joint UVA/NASA Workshop on Computational Tools and Facilities for the Next-Generation Analysis and Design Environment held at the Virginia Consortium of Engineering and Science Universities in Hampton, Virginia on September 17-18, 1996. The presentations focused on the computational tools and facilities for analysis and design of engineering systems, including, real-time simulations, immersive systems, collaborative engineering environment, Web-based tools and interactive media for technical training. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the level of maturity of a number of computational tools and facilities and their potential for application to the next-generation integrated design environment.

A facility for testing 10 to 100-kWe space power reactors

NASA Astrophysics Data System (ADS)

Carlson, William F.; Bitten, Ernest J.

1993-01-01

This paper describes an existing facility that could be used in a cost-effective manner to test space power reactors in the 10 to 100-kWe range before launch. The facility has been designed to conduct full power tests of 100-kWe SP-100 reactor systems and already has the structural features that would be required for lower power testing. The paper describes a reasonable scenario starting with the acceptance at the test site of the unfueled reactor assembly and the separately shipped nuclear fuel. After fueling the reactor and installing it in the facility, cold critical tests are performed, and the reactor is then shipped to the launch site. The availability of this facility represents a cost-effective means of performing the required prelaunch test program.

Mass-independent fractionation of mercury isotopes during photochemical reduction in freshwater systems

NASA Astrophysics Data System (ADS)

Rose, C. H.; Bergquist, B. A.; Blum, J. D.

2009-12-01

Mercury is a globally distributed environmental toxin. Both inorganic and methylated species have severe detrimental effects on humans and animals, but it is methyl mercury (MeHg) that bioaccumulates in food webs and results in significant human exposure via fish consumption. Photochemical reduction of aqueous Hg species to dissolved gaseous Hg(0) can result in a net transfer of Hg from aquatic systems to the atmosphere, making it unavailable for methylation. In addition, photo-reduction of MeHg is an alternative fate to bioaccumulation for this powerful neurotoxin. Both mass-dependent isotope fractionation (MDF) and mass-independent fractionation (MIF) are observed in natural samples. MIF is the deviation in isotope ratios from those predicted by MDF based on 202Hg/198Hg. Bergquist and Blum 2007 showed that aqueous photo-reduction of Hg2+ and MeHg in the presence of dissolved natural organic matter results not only in Rayleigh-type MDF but also significant MIF, with the odd isotopes 199Hg and 201Hg being preferentially retained in the reactant (soluble) phase. Berquist and Blum 2007 also observed that the ratio of the MIF for the odd isotopes was different for each of the photo-reduction pathways (MeHg versus Hg2+) and suggested this ratio could be unique to certain pathways, which might allow identification of photo-reduction among other pathways in natural samples. They also suggested that the magnitude of MIF might relate quantitatively to the amount of photo-reduction Hg undergoes in aqueous systems. To better understand the causes of MIF and its capacity along with MDF as a tool for tracing photo-reduction of Hg, further experiments mimicking the freshwater photo-reduction of Hg2+ and MeHg were carried out. Each species was photo-reduced in the presence of Suwannee River Fulvic Acid with different portions of the electromagnetic spectrum blocked by filters. Bergquist and Blum 2007 suggested the magnetic isotope effect (MIE) as the cause of the MIF they observed. The MIE should be expressed during reactions involving excited radical pair intermediates and therefore should be affected by the wavelengths of light available for radical production. Experiments were performed (1) under full spectrum, (2) with over 90 percent of UVB rays blocked and (3) with over 95 percent of both UVA and UVB rays blocked. These experiments were run simultaneously under natural sunlight. The Hg2+ full spectrum experiments showed an 84 percent loss of Hg2+ to Hg vapor, which was larger than the 77 percent loss of the UVB blocked reactor and the 14 percent loss of the UVA and UVB blocked reactor. Significant differences in isotope ratios were also observed, and initial results suggest that MIF may be most sensitive to UVA. Since radical production is key to the MIE, this suggests that the UVA region may be most important to producing Hg radicals. In contrast, the losses in all three MeHg reservoirs were similar suggesting that the UVA and UVB portions of the spectrum are not critical in MeHg photo-reduction.

CFD modeling of a UV-A LED baffled flat-plate photoreactor for environment applications: a mining wastewater case.

PubMed

Devia-Orjuela, John Steven; Betancourt-Buitrago, Luis Andrés; Machuca-Martinez, Fiderman

2018-06-02

The use of ultraviolet light in photoreactors for wastewater treatment has become popular as an alternative of known chemical oxidative substances. UV LED light represents cheaper, robust, and versatile alternative to traditional UV lamps. In this study, it was designed and evaluated a photoreactor with an approach of chemical fluid dynamics (CFD) and experimental validation. The evaluation consisted of (1) CFD velocity profile analysis, (2) characterization of the average light distribution with potassium ferrioxalate actinometry, (3) degradation of a typical recalcitrant metallic cyanocomplex Fe(CN) 6 3- , and (4) scavenger effect analysis in the photodegradation using potassium persulfate. Actinometrical essay concluded that the system was able to receive 1.93 μE/s. The reactor operated under turbulent regime and best result for Fe(CN) 6 3- degradation was obtained at 4 h of operation, using 5-W UV-A LEDs, with pH ~ 7 and 10 mM de S 2 O 8 2- . Baffled photoreactor demonstrated to be useful for this type of illumination and wastewater treatment.

10 CFR 50.83 - Release of part of a power reactor facility or site for unrestricted use.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Release of part of a power reactor facility or site for... of a power reactor facility or site for unrestricted use. (a) Prior written NRC approval is required... release. Nuclear power reactor licensees seeking NRC approval shall— (1) Evaluate the effect of releasing...

10 CFR 50.83 - Release of part of a power reactor facility or site for unrestricted use.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Release of part of a power reactor facility or site for... of a power reactor facility or site for unrestricted use. (a) Prior written NRC approval is required... release. Nuclear power reactor licensees seeking NRC approval shall— (1) Evaluate the effect of releasing...

Robust evaluation of performance monitoring options for ozone disinfection in water recycling using Bayesian analysis.

PubMed

Carvajal, Guido; Branch, Amos; Michel, Philipp; Sisson, Scott A; Roser, David J; Drewes, Jörg E; Khan, Stuart J

2017-11-01

Ozonation of wastewater has gained popularity because of its effectiveness in removing colour, UV absorbance, trace organic chemicals, and pathogens. Due to the rapid reaction of ozone with organic compounds, dissolved ozone is often not measurable and therefore, the common disinfection controlling parameter, concentration integrated over contact time (CT) cannot be obtained. In such cases, alternative parameters have been shown to be useful as surrogate measures for microbial removal including change in UV 254 absorbance (ΔUVA), change in total fluorescence (ΔTF), or O 3 :TOC (or O 3 :DOC). Although these measures have shown promise, a number of caveats remain. These include uncertainties in the associations between these measurements and microbial inactivation. Furthermore, previous use of seeded microorganisms with higher disinfection sensitivity compared to autochthonous microorganisms could lead to overestimation of appropriate log credits. In our study, secondary treated wastewater from a full-scale plant was ozonated in a bench-scale reactor using five increasing ozone doses. During the experiments, removal of four indigenous microbial indicators representing viruses, bacteria and protozoa were monitored concurrent with ΔUVA, ΔTF, O 3 :DOC and PARAFAC derived components. Bayesian methods were used to fit linear regression models, and the uncertainty in the posterior predictive distributions and slopes provided a comparison between previously reported results and those reported here. Combined results indicated that all surrogate parameters were useful in predicting the removal of microorganisms, with a better fit to the models using ΔUVA, ΔTF in most cases. Average adjusted determination coefficients for fitted models were high (R 2 adjusted >0.47). With ΔUVA, one unit decrease in LRV corresponded with a UVA mean reduction of 15-20% for coliforms, 59% for C. perfringens spores, and 11% for somatic coliphages. With ΔTF, a one unit decrease in LRV corresponded with a TF mean reduction of 18-23% for coliforms, 71% for C. perfringens spores, and 14% for somatic coliphages. Compared to previous studies also analysed, our results suggest that microbial reductions were more conservative for autochthonous than for seeded microorganisms. The findings of our study suggested that site-specific analyses should be conducted to generate models with lower uncertainty and that indigenous microorganisms are useful for the measurement of system performance even when censored observations are obtained. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoprotective efficacy and photostability of fifteen sunscreen products having the same label SPF subjected to natural sunlight.

PubMed

Hojerová, J; Medovcíková, A; Mikula, M

2011-04-15

The first objective of this study is to show how different can be photoprotection by sunscreens with an identical SPF given on the packaging, when subjected to sunlight radiation. The second objective is to highlight the need for global harmonization of photostability testing and UVA protection labelling. Fifteen products with various combinations of UV filters marketed in Europe were assessed based on transmission measurements of 0.75 mg cm⁻² layer covered onto polymethylmethacrylate plate roughness 2 μm. Two absolute UV spectroscopic indices (in vitro SPF, UVA-PF), four well-known relative UVA indices: the UVA-PF/SPF ratio and critical wavelength by European Commission (EC); UVA/UVB ratio by Boots Star Rating system; UVA1/UV ratio by FDA Proposed Ruling and one new relative indices the Spectral Uniformity Index (SUI) by Diffey, were compared before and after sunlight exposure with dose about 42 SEDs. The UVA-PF values before exposure proved a high degree of variation among samples. After exposure only five sunscreens observed UVA protection standard by EC and the same products showed compliance with the first UVA rating by Boots system (three stars). According to the UVA1/UV ratio, except for one product, all sunscreens manifested certain UVA protection level (low, medium or high). In compliance with criteria of new rating proposed by Diffey, exactly all fifteen sunscreens gave some UVA rating exhibited as SUI (low, medium or high). These results mean that the different UVA protection indices can exhibit various data and be confusing for consumer. Photostability of each product was assessed with three indices: the area under curve (Auc) Index for the total UV range, and UVB, UVA, UVA2, UVA1 range separately; the residual effectiveness of in vitro SPF and UVA-PF. All fifteen sunscreens were photostable in the UVB region. Seven products exhibited photoinstability in the total UV range (290-400 nm); all of them contained a combination of the ethylhexyl methoxycinnamate (EHMC) and butyl methoxydibenzoylmethane (BMBM) together with other UV filters. Eight products lacked their stability in the UVA1 range (340-400 nm) thus confirmed that photodegradation of some current sunscreens is primarily problem of this region. The most photoinstability showed sunscreens S1 (EHMC, BMBM and phenylbenzimidazole sulphonic acid) and S6 (EHMC, BMBM, phenylbenzimidazole sulphonic acid and ethylhexyl triazone); Auc-UVA1 Index was 0.15 only. Excellent UVA1 photostability showed sunscreen S8 (EHMC, EHT and methylene bis-benzotriazolyl tetramethylbutylphenol); Auc-UVA1 Index was of 1.00. Three sunscreens showed very good UVA1 photostability (Auc-UVA1 Index ranged from 0.98 to 0.93). The fact that these products applied only in the layer of 0.75 mg cm⁻² were photostable under the sunlight dose, which corresponds to layer of 2 mg cm⁻², is proof of their quality. Comparison of the residual effectiveness of in vitro SPF and UVA-PF values with the Auc-Index showed that methods give a similar ranking of the sunscreens' photostability. Copyright © 2011 Elsevier B.V. All rights reserved.

ADVANCED REACTIVITY MEASUREMENT FACILITY, TRA660, INTERIOR. REACTOR INSIDE TANK. METAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ADVANCED REACTIVITY MEASUREMENT FACILITY, TRA-660, INTERIOR. REACTOR INSIDE TANK. METAL WORK PLATFORM ABOVE. THE REACTOR WAS IN A SMALL WATER-FILLED POOL. INL NEGATIVE NO. 66-6373. Unknown Photographer, ca. 1966 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

NACA Zero Power Reactor Facility Hazards Summary

NASA Technical Reports Server (NTRS)

1957-01-01

The Lewis Flight Propulsion Laboratory of the National Advisory Committee for Aeronautics proposes to build a zero power research reactor facility which will be located in the laboratory grounds near Clevelaurd, Ohio. The purpose of this report is to inform the Advisory Commit tee on Reactor Safeguards of the U. S. Atomic Energy Commission in re gard to the design of the reactor facility, the cha,acteristics of th e site, and the hazards of operation at this location, The purpose o f this reactor is to perform critical experiments, to measure reactiv ity effects, to serve as a neutron source, and to serve as a training tool. The reactor facility is described. This is followed by a discu ssion of the nuclear characteristics and the control system. Site cha racteristics are then discussed followed by a discussion of the exper iments which may be conducted in the facility. The potential hazards of the facility are then considered, particularly, the maximum credib le accident. Finally, the administrative procedure is discussed.

Laboratory instrumentation modernization at the WPI Nuclear Reactor Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1995-01-01

With partial funding from the Department of Energy (DOE) University Reactor Instrumentation Program several laboratory instruments utilized by students and researchers at the WPI Nuclear Reactor Facility have been upgraded or replaced. Designed and built by General Electric in 1959, the open pool nuclear training reactor at WPI was one of the first such facilities in the nation located on a university campus. Devoted to undergraduate use, the reactor and its related facilities have been since used to train two generations of nuclear engineers and scientists for the nuclear industry. The low power output of the reactor and an ergonomicmore » facility design make it an ideal tool for undergraduate nuclear engineering education and other training. The reactor, its control system, and the associate laboratory equipment are all located in the same room. Over the years, several important milestones have taken place at the WPI reactor. In 1969, the reactor power level was upgraded from 1 kW to 10 kW. The reactor`s Nuclear Regulatory Commission operating license was renewed for 20 years in 1983. In 1988, under DOE Grant No. DE-FG07-86ER75271, the reactor was converted to low-enriched uranium fuel. In 1992, again with partial funding from DOE (Grant No. DE-FG02-90ER12982), the original control console was replaced.« less

U.S. Nuclear Cooperation with India: Issues for Congress

DTIC Science & Technology

2008-10-17

safeguards-irrelevant.” The following facilities and activities were not on the separation list: ! 8 indigenous Indian power reactors ! Fast Breeder ...test Reactor (FTBR) and Prototype Fast Breeder Reactors (PFBR) under construction ! Enrichment facilities ! Spent fuel reprocessing facilities (except...potential use in a bomb. In addition, safeguards on enrichment, reprocessing plants, and breeder reactors would support the 2002 U.S. National Strategy to

UVA-induced protection of skin through the induction of heme oxygenase-1.

PubMed

Xiang, Yuancai; Liu, Gang; Yang, Li; Zhong, Julia Li

2011-12-01

UVA (320-400 nm) and UVB (290-320 nm) are the major components of solar UV irradiation, which is associated with various pathological conditions. UVB causes direct damage to DNA of epidermal cells and is mainly responsible for erythema, immunosuppression, photoaging, and skin cancer. UVA has oxidizing properties that can cause damage or enhance UVB damaging effects on skin. On the other hand, UVA can also lead to high levels of heme oxygenase-1 (HO-1) expression of cells that can provide an antioxidant effect on skin as well as anti-inflammatory properties in mammals and rodents. Therefore, this review focuses on the potential protection of UVA wavebands for the skin immune response, instead of mechanisms that underlie UVA-induced damage. Also, the role of HO-1 in UVA-mediated protection against UVB-induced immunosuppression in skin will be summarized. Thus, this review facilitates further understanding of potential beneficial mechanisms of UVA irradiation, and using the longer UVA (UVA1, 340-400 nm) in combination with HO-1 for phototherapy and skin protection against sunlight exposure.

An analysis of decommissioning costs for the AFRRI TRIGA reactor facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsbacka, Matt

1990-07-01

A decommissioning cost analysis for the AFRRI TRIGA Reactor Facility was made. AFRRI is not at this time suggesting that the AFRRI TRIGA Reactor Facility be decommissioned. This report was prepared to be in compliance with paragraph 50.33 of Title 10, Code of Federal Regulations which requires the assurance of availability of future decommissioning funding. The planned method of decommissioning is the immediate decontamination of the AFRRI TRIGA Reactor site to allow for restoration of the site to full public access - this is called DECON. The cost of DECON for the AFRRI TRIGA Reactor Facility in 1990 dollars ismore » estimated to be $3,200,000. The anticipated ancillary costs of facility site demobilization and spent fuel shipment is an additional $600,000. Thus the total cost of terminating reactor operations at AFRRI will be about $3,800,000. The primary basis for this cost estimate is a study of the decommissioning costs of a similar reactor facility that was performed by Battelle Pacific Northwest Laboratory (PNL) as provided in USNRC publication NUREG/CR-1756. The data in this study were adapted to reflect the decommissioning requirements of the AFRRI TRIGA. (author)« less

Plum Brook Reactor Facility Control Room during Facility Startup

NASA Image and Video Library

1961-02-21

Operators test the National Aeronautics and Space Administration’s (NASA) Plum Brook Reactor Facility systems in the months leading up to its actual operation. The “Reactor On” signs are illuminated but the reactor core was not yet ready for chain reactions. Just a couple weeks after this photograph, Plum Brook Station held a media open house to unveil the 60-megawatt test reactor near Sandusky, Ohio. More than 60 members of the print media and radio and television news services met at the site to talk with community leaders and representatives from NASA and Atomic Energy Commission. The Plum Brook reactor went critical for the first time on the evening of June 14, 1961. It was not until April 1963 that the reactor reached its full potential of 60 megawatts. The reactor control room, located on the second floor of the facility, was run by licensed operators. The operators manually operated the shim rods which adjusted the chain reaction in the reactor core. The regulating rods could partially or completely shut down the reactor. The control room also housed remote area monitoring panels and other monitoring equipment that allowed operators to monitor radiation sensors located throughout the facility and to scram the reactor instantly if necessary. The color of the indicator lights corresponded with the elevation of the detectors in the various buildings. The reactor could also shut itself down automatically if the monitors detected any sudden irregularities.

New Water Disinfection Technology for Earth and Space Applications as Part of the NPP Fellowship Research

NASA Technical Reports Server (NTRS)

SilvestryRodriquez, Nadia

2010-01-01

There is the need for a safe, low energy consuming and compact water disinfection technology to maintain water quality for human consumption. The design of the reactor should present no overheating and a constant temperature, with good electrical and optical performance for a UV water treatment system. The study assessed the use of UVA-LEDs to disinfectant water for MS2 Bacteriophage. The log reduction was sufficient to meet US EPA standards as a secondary disinfectant for maintaining water quality control. The study also explored possible inactivation of Pseudomonas aeruginosa and E. coli.

5 CFR 5801.102 - Prohibited securities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... licenses for facilities which generate electric energy by means of a nuclear reactor; (2) State or local... reactor or a low-level waste facility; (3) Entities manufacturing or selling nuclear power or test reactors; (4) Architectural-engineering companies providing services relating to a nuclear power reactor...

5 CFR 5801.102 - Prohibited securities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... licenses for facilities which generate electric energy by means of a nuclear reactor; (2) State or local... reactor or a low-level waste facility; (3) Entities manufacturing or selling nuclear power or test reactors; (4) Architectural-engineering companies providing services relating to a nuclear power reactor...

The U.S. Geological Survey's TRIGA® reactor

USGS Publications Warehouse

DeBey, Timothy M.; Roy, Brycen R.; Brady, Sally R.

2012-01-01

The U.S. Geological Survey (USGS) operates a low-enriched uranium-fueled, pool-type reactor located at the Federal Center in Denver, Colorado. The mission of the Geological Survey TRIGA® Reactor (GSTR) is to support USGS science by providing information on geologic, plant, and animal specimens to advance methods and techniques unique to nuclear reactors. The reactor facility is supported by programs across the USGS and is organizationally under the Associate Director for Energy and Minerals, and Environmental Health. The GSTR is the only facility in the United States capable of performing automated delayed neutron analyses for detecting fissile and fissionable isotopes. Samples from around the world are submitted to the USGS for analysis using the reactor facility. Qualitative and quantitative elemental analyses, spatial elemental analyses, and geochronology are performed. Few research reactor facilities in the United States are equipped to handle the large number of samples processed at the GSTR. Historically, more than 450,000 sample irradiations have been performed at the USGS facility. Providing impartial scientific information to resource managers, planners, and other interested parties throughout the world is an integral part of the research effort of the USGS.

L-carnitine mitigates UVA-induced skin tissue injury in rats through downregulation of oxidative stress, p38/c-Fos signaling, and the proinflammatory cytokines.

PubMed

Salama, Samir A; Arab, Hany H; Omar, Hany A; Gad, Hesham S; Abd-Allah, Gamil M; Maghrabi, Ibrahim A; Al Robaian, Majed M

2018-04-01

UVA comprises more than 90% of the solar UV radiation reaching the Earth. Artificial lightening lamps have also been reported to emit significant amounts of UVA. Exposure to UVA has been associated with dermatological disorders including skin cancer. At the molecular level, UVA damages different cellular biomolecules and triggers inflammatory responses. The current study was devoted to investigate the potential protective effect of L-carnitine against UVA-induced skin tissue injury using rats as a mammalian model. Rats were distributed into normal control group (NC), L-carnitine control group (LC), UVA-Exposed group (UVA), and UVA-Exposed and L-carnitine-treated group (UVA-LC). L-carnitine significantly attenuated UVA-induced elevation of the DNA damage markers 8-oxo-2'-deoxyguanosine (8-oxo-dG) and cyclobutane pyrimidine dimers (CPDs) as well as decreased DNA fragmentation and the activity of the apoptotic marker caspase-3. In addition, L-carnitine substantially reduced the levels of lipid peroxidation marker (TBARS) and protein oxidation marker (PCC) and significantly elevated the levels of the total antioxidant capacity (TAC) and the antioxidant reduced glutathione (GSH) in the skin tissues. Interestingly, L-carnitine upregulated the level of the DNA repair protein proliferating cell nuclear antigen (PCNA). Besides it mitigated the UVA-induced activation of the oxidative stress-sensitive signaling protein p38 and its downstream target c-Fos. Moreover, L-carnitine significantly downregulated the levels of the early response proinflammatory cytokines TNF-α, IL-6, and IL-1β. Collectively, our results highlight, for the first time, the potential attenuating effects of L-carnitine on UVA-induced skin tissue injury in rats that is potentially mediated through suppression of UVA-induced oxidative stress and inflammatory responses. Copyright © 2018 Elsevier B.V. All rights reserved.

Intensities of Incident and Transmitted Ultraviolet-A Rays through Gafchromic Films

PubMed Central

Katsuda, Toshizo; Gotanda, Rumi; Gotanda, Tatsuhiro; Akagawa, Takuya; Tanki, Nobuyoshi; Kuwano, Tadao; Noguchi, Atsushi; Yabunaka, Kouichi

2017-01-01

Gafchromic films have been applied to X-ray dosimetry in diagnostic radiology. To correct nonuniformity errors in Gafchromic films, X-rays in the double-exposure technique can be replaced with ultraviolet (UV)-A rays. Intensities of the incident and transmitted UV-A rays were measured. However, it is unclear whether the chemical color change of Gafchromic films affects the UV-A transmission intensity. Gafchromic EBT3 films were suitable to be used in this study because non-UV protection layers are present on both sides of the film. The film is placed between UV-A ray light-emitting diodes and a probe of a UV meter. Gafchromic EBT3 films were irradiated by UV-A rays for up to 60 min. Data for analysis were obtained in the subsequent 60 min. Images from before and after UV-A irradiation were subtracted. When using 375 nm UV-A, the mean ± standard deviation (SD) of the pixel values in the subtracted image was remarkably high (11,194.15 ± 586.63). However, the UV-A transmissivity remained constant throughout the 60 min irradiation period. The mean ± SD UV-A transmission intensity was 184.48 ± 0.50 μm/cm2. Our findings demonstrate that color density changes in Gafchromic EBT3 films do not affect their UV-A transmission. Therefore, Gafchromic films were irradiated by UV-A rays as a preexposure. PMID:28706354

Photoprotection by dietary phenolics against melanogenesis induced by UVA through Nrf2-dependent antioxidant responses

PubMed Central

Chaiprasongsuk, Anyamanee; Onkoksoong, Tasanee; Pluemsamran, Thanyawan; Limsaengurai, Saowalak; Panich, Uraiwan

2015-01-01

Dietary phenolics may play a protective role in UV-mediated skin pigmentation through their antioxidant and UV-absorbing actions. In this study, we investigated whether genetic silencing of Nrf2, regulating the transcription of antioxidant genes, affected melanogenesis in primary human epidermal melanocytes (HEMn) and B16F10 melanoma cells subjected to UVA (8 J/cm2) exposure. Then, we explored the antimelanogenic actions of phenolics; caffeic acid (CA) and ferulic acid (FA) providing partial UVA protection; quercetin (QU) and rutin (RU) providing strong UVA protection and; avobenzone (AV), an efficient UVA filter, in association with modulation of Nrf2-mediated antioxidant defenses in response to UVA insults in B16F10 cells. Upon oxidative insults, Nrf2 silencing promoted melanogenesis in both HEMn and B16F10 cells irradiated with UVA. Stimulation of melanogenesis by UVA correlated with increased ROS and oxidative DNA damage (8-OHdG), GSH depletion as well as a transient downregulation of Nrf2 nuclear translocation and of Nrf2-ARE signaling in B16F10 cells. All test compounds exerted antimelanogenic effects with respect to their abilities to reverse UVA-mediated oxidative damage as well as downregulation of Nrf2 activity and its target antioxidants (GCLC, GST and NQO1) in B16F10 cells. In conclusion, defective Nrf2 may promote melanogenesis under UVA irradiation through oxidative stress mechanisms. Compounds with antioxidant and/or UVA absorption properties could protect against UVA-induced melanogenesis through indirect regulatory effect on Nrf2-ARE pathway. PMID:26765101

UVA Causes Dual Inactivation of Cathepsin B and L Underlying Lysosomal Dysfunction in Human Dermal Fibroblasts

PubMed Central

Lamore, Sarah D.; Wondrak, Georg T.

2013-01-01

Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display ‘UVA-mimetic’ effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts. PMID:23603447

NASA Reactor Facility Hazards Summary. Volume 1

NASA Technical Reports Server (NTRS)

1959-01-01

The Lewis Research Center of the National Aeronautics and Space Administration proposes to build a nuclear research reactor which will be located in the Plum Brook Ordnance Works near Sandusky, Ohio. The purpose of this report is to inform the Advisory Committee on Reactor Safeguards of the U. S. Atomic Energy Commission in regard to the design Lq of the reactor facility, the characteristics of the site, and the hazards of operation at this location. The purpose of this research reactor is to make pumped loop studies of aircraft reactor fuel elements and other reactor components, radiation effects studies on aircraft reactor materials and equipment, shielding studies, and nuclear and solid state physics experiments. The reactor is light water cooled and moderated of the MTR-type with a primary beryllium reflector and a secondary water reflector. The core initially will be a 3 by 9 array of MTR-type fuel elements and is designed for operation up to a power of 60 megawatts. The reactor facility is described in general terms. This is followed by a discussion of the nuclear characteristics and performance of the reactor. Then details of the reactor control system are discussed. A summary of the site characteristics is then presented followed by a discussion of the larger type of experiments which may eventually be operated in this facility. The considerations for normal operation are concluded with a proposed method of handling fuel elements and radioactive wastes. The potential hazards involved with failures or malfunctions of this facility are considered in some detail. These are examined first from the standpoint of preventing them or minimizing their effects and second from the standpoint of what effect they might have on the reactor facility staff and the surrounding population. The most essential feature of the design for location at the proposed site is containment of the maximum credible accident.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulder, R. U.; Benneche, P. E.; Hosticka, B.

The objective of the DOE supported Reactor Sharing Program is to increase the availability of university nuclear reactor facilities to non-reactor-owning educational institutions. The educational and research programs of these users institutions is enhanced by the use of the nuclear facilities.

Upregulation of MMP12 and its activity by UVA1 in human skin: potential implications for photoaging.

PubMed

Tewari, Angela; Grys, Katarzyna; Kollet, Jutta; Sarkany, Robert; Young, Antony R

2014-10-01

UVA1 constitutes around 75% of the terrestrial UV radiation, and most of the output of artificial tanning sources. However, the molecular effects of UVA1 in human skin in vivo are surprisingly poorly understood. We have examined time-dependent whole-genome expression, along with mRNA and protein changes in the skin after one minimal erythema dose of spectrally pure UVA1 (50 J cm(-2)) and 300 nm UVB (30 mJ cm(-2)). After 24 hours, the genes induced to the greatest extent were those involved in extracellular matrix remodeling with both UVA1 (P=5.5e-7) and UVB (P=2.9e-22). UVA1 and UVB caused different effects on matrix metalloproteinase (MMP) expression: UVB induced MMP1, MMP3, and MMP10 mRNA at 24 hours to a much greater extent than UVA1. MMP12 induction by UVA1 at 6 hours is marked and much greater than that by UVB. We have found that MMP12 mRNA induction by UVA1 resulted in expression of MMP12 protein, which is functional as an elastase. This induction of elastase activity did not occur with UVB. We hypothesize that the UVA1 induction of MMP12 mediates some of its photoaging effects, particularly by contributing to elastin degeneration in late solar elastosis. MMP12 is a good marker of UVA1 exposure.

RADIATION FACILITY FOR NUCLEAR REACTORS

DOEpatents

Currier, E.L. Jr.; Nicklas, J.H.

1961-12-12

A radiation facility is designed for irradiating samples in close proximity to the core of a nuclear reactor. The facility comprises essentially a tubular member extending through the biological shield of the reactor and containing a manipulatable rod having the sample carrier at its inner end, the carrier being longitudinally movable from a position in close proximity to the reactor core to a position between the inner and outer faces of the shield. Shield plugs are provided within the tubular member to prevent direct radiation from the core emanating therethrough. In this device, samples may be inserted or removed during normal operation of the reactor without exposing personnel to direct radiation from the reactor core. A storage chamber is also provided within the radiation facility to contain an irradiated sample during the period of time required to reduce the radioactivity enough to permit removal of the sample for external handling. (AEC)

Exposure to low UVA doses increases KatA and KatB catalase activities, and confers cross-protection against subsequent oxidative injuries in Pseudomonas aeruginosa.

PubMed

Pezzoni, Magdalena; Tribelli, Paula M; Pizarro, Ramón A; López, Nancy I; Costa, Cristina S

2016-05-01

Solar UVA radiation is one of the main environmental stress factors for Pseudomonas aeruginosa. Exposure to high UVA doses produces lethal effects by the action of the reactive oxygen species (ROS) it generates. P. aeruginosa has several enzymes, including KatA and KatB catalases, which provide detoxification of ROS. We have previously demonstrated that KatA is essential in defending P. aeruginosa against high UVA doses. In order to analyse the mechanisms involved in the adaptation of this micro-organism to UVA, we investigated the effect of exposure to low UVA doses on KatA and KatB activities, and the physiological consequences. Exposure to UVA induced total catalase activity; assays with non-denaturing polyacrylamide gels showed that both KatA and KatB activities were increased by radiation. This regulation occurred at the transcriptional level and depended, at least partly, on the increase in H2O2 levels. We demonstrated that exposure to low UVA produced a protective effect against subsequent lethal doses of UVA, sodium hypochlorite and H2O2. Protection against lethal UVA depends on katA, whilst protection against sodium hypochlorite depends on katB, demonstrating that different mechanisms are involved in the defence against these oxidative agents, although both genes can be involved in the global cellular response. Conversely, protection against lethal doses of H2O2 could depend on induction of both genes and/or (an)other defensive factor(s). A better understanding of the adaptive response of P. aeruginosa to UVA is relevant from an ecological standpoint and for improving disinfection strategies that employ UVA or solar irradiation.

The impact of natural sunlight exposure on the UVB-sun protection factor (UVB-SPF) and UVA protection factor (UVA-PF) of a UVA/UVB SPF 50 sunscreen.

PubMed

Stephens, Thomas J; Herndon, James H; Colón, Luz E; Gottschalk, Ronald W

2011-02-01

To compare the functional stability of Cetaphil UVA/UVB Defense SPF 50 as measured by its ultraviolet B sun protection factor (UVB-SPF) and ultraviolet A protection factor (UVA-PF) values following exposure to natural sunlight versus the UVB-SPF and UVA-PF values of unexposed product. These two randomized, controlled, evaluator-blinded, single-center trials were conducted according to the methods outlined in the 2007 Proposed Amendment to the Final Monograph, “Sunscreen Drug Products for Over-the-Counter Human Use.” Sunscreen samples were applied to glass plates and exposed to ultraviolet radiation in the form of natural sunlight in four minimal erythemal doses (MED) ranging from 2–6 MED (42–36 mJ/cm2). Three test sites were identified on the back of each study subject. Exposed sunscreen (one of four doses), unexposed sunscreen, and a UVB-SPF 15 control sunscreen were applied to the three test sites in a randomized fashion, followed by UV irradiation of incremental doses. Erythema and pigment darkening responses were assessed immediately following UV exposure and again 16–24 hours (erythema) or three to 24 hours (pigment darkening) after exposure. UVB-SPF and UVA-PF values were calculated for the exposed and unexposed samples. The calculated UVB-SPF and UVA-PF values for all test samples (exposed and unexposed) were >50 and >9, respectively, which were greater than the stated UVB-SPF and UVA-PF values on the product label. No differences were observed between the exposed and unexposed samples in UVB-SPF or UVA-PF. The UVA and UVB protection using standard evaluation techniques of Cetaphil UVA/UVB Defense SPF 50 remains stable despite exposure of the sunscreen to natural sunlight containing UVB ranging from 2–16 MED (41–336 mJ/cm2) and coexistent UVA.

Effect of supplemental UV-A irradiation in solid-state lighting on the growth and phytochemical content of microgreens

NASA Astrophysics Data System (ADS)

Brazaitytė, A.; Viršilė, A.; Jankauskienė, J.; Sakalauskienė, S.; Samuolienė, G.; Sirtautas, R.; Novičkovas, A.; Dabašinskas, L.; Miliauskienė, J.; Vaštakaitė, V.; Bagdonavičienė, A.; Duchovskis, P.

2015-01-01

In this study, we sought to find and employ positive effects of UV-A irradiation on cultivation and quality of microgreens. Therefore, the goal of our study was to investigate the influence of 366, 390, and 402 nm UV-A LED wavelengths, supplemental for the basal solid-state lighting system at two UV-A irradiation levels on the growth and phytochemical contents of different microgreen plants. Depending on the species, supplemental UV-A irradiation can improve antioxidant properties of microgreens. In many cases, a significant increase in the investigated phytochemicals was found under 366 and 390 nm UV-A wavelengths at the photon flux density (12.4 μmol m-2 s-1). The most pronounced effect of supplemental UV-A irradiation was detected in pak choi microgreens. Almost all supplemental UV-A irradiation treatments resulted in increased leaf area and fresh weight, in higher 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging activity, total phenols, anthocyanins, ascorbic acid, and α-tocopherol.

In vivo UVA irradiation of mouse is more efficient in promoting pulmonary melanoma metastasis than in vitro

PubMed Central

2011-01-01

Background We have previously shown in vitro that UVA increases the adhesiveness of mouse B16-F1 melanoma cells to endothelium. We have also shown in vivo that UVA exposure of C57BL/6 mice, i.v. injected with B16-F1 cells, increases formation of pulmonary colonies of melanoma. The aim of the present animal study was to confirm the previously observed in vivo UVA effect and to determine whether in vitro UVA-exposure of melanoma cells, prior the i.v. injection, will have an enhancing effect on the pulmonary colonization capacity of melanoma cells. As a second aim, UVA-derived immunosuppression was determined. Methods Mice were i.v. injected with B16-F1 cells into the tail vein and then immediately exposed to UVA. Alternatively, to study the effect of UVA-induced adhesiveness on the colonization capacity of B16-F1 melanoma, cells were in vitro exposed prior to i.v. injection. Fourteen days after injection, lungs were collected and the number of pulmonary nodules was determined under dissecting microscope. The UVA-derived immunosuppression was measured by standard contact hypersensitivity assay. Results and Discussion Obtained results have confirmed that mice, i.v. injected with B16-F1 cells and thereafter exposed to UVA, developed 4-times more of melanoma colonies in lungs as compared with the UVA non-exposed group (p < 0.01). The in vitro exposure of melanoma cells prior to their injection into mice, led only to induction of 1.5-times more of pulmonary tumor nodules, being however a statistically non-significant change. The obtained results postulate that the UVA-induced changes in the adhesive properties of melanoma cells do not alone account for the 4-fold increase in the pulmonary tumor formation. Instead, it suggests that some systemic effect in a mouse might be responsible for the increased metastasis formation. Indeed, UVA was found to induce moderate systemic immunosuppression, which effect might contribute to the UVA-induced melanoma metastasis in mice lungs. PMID:21645404

TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

PubMed

Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

2015-01-01

A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

The WPI reactor-readying for the next generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bobek, L.M.

1993-01-01

Built in 1959, the 10-kW open-pool nuclear training reactor at Worcester Polytechnic Institute (WPI) was one of the first such facilities in the nation located on a university campus. Since then, the reactor and its related facilities have been used to train two generations of nuclear engineers and scientists for the nuclear industry. With the use of nuclear technology playing an increasing role in many segments of the economy, WPI with its nuclear reactor facility is committed to continuing its mission of training future nuclear engineers and scientists. The WPI reactor includes a 6-in. beam port, graphite thermal column, andmore » in-core sample facility. The reactor, housed in an open 8000-gal tank of water, is designed so that the core is readily accessible. Both the control console and the peripheral counting equipment used for student projects and laboratory exercises are located in the reactor room. This arrangement provides convenience and flexibility in using the reactor for foil activations in neutron flux measurements, diffusion measurements, radioactive decay measurements, and the neutron activation of samples for analysis. In 1988, the reactor was successfully converted to low-enriched uranium fuel.« less

Background radiation measurements at high power research reactors

NASA Astrophysics Data System (ADS)

Ashenfelter, J.; Balantekin, B.; Baldenegro, C. X.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bryan, C. D.; Cherwinka, J. J.; Chu, R.; Classen, T.; Davee, D.; Dean, D.; Deichert, G.; Dolinski, M. J.; Dolph, J.; Dwyer, D. A.; Fan, S.; Gaison, J. K.; Galindo-Uribarri, A.; Gilje, K.; Glenn, A.; Green, M.; Han, K.; Hans, S.; Heeger, K. M.; Heffron, B.; Jaffe, D. E.; Kettell, S.; Langford, T. J.; Littlejohn, B. R.; Martinez, D.; McKeown, R. D.; Morrell, S.; Mueller, P. E.; Mumm, H. P.; Napolitano, J.; Norcini, D.; Pushin, D.; Romero, E.; Rosero, R.; Saldana, L.; Seilhan, B. S.; Sharma, R.; Stemen, N. T.; Surukuchi, P. T.; Thompson, S. J.; Varner, R. L.; Wang, W.; Watson, S. M.; White, B.; White, C.; Wilhelmi, J.; Williams, C.; Wise, T.; Yao, H.; Yeh, M.; Yen, Y.-R.; Zhang, C.; Zhang, X.; Prospect Collaboration

2016-01-01

Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

Extracellular Polysaccharide Production in a Scytonemin-Deficient Mutant of Nostoc punctiforme Under UVA and Oxidative Stress.

PubMed

Soule, Tanya; Shipe, Dexter; Lothamer, Justin

2016-10-01

Some cyanobacteria can protect themselves from ultraviolet radiation by producing sunscreen pigments. In particular, the sheath pigment scytonemin protects cells against long-wavelength UVA radiation and is only found in cyanobacteria which are capable of extracellular polysaccharide (EPS) production. The presence of a putative glycosyltransferase encoded within the scytonemin gene cluster, along with the localization of scytonemin and EPS to the extracellular sheath, prompted us to investigate the relationship between scytonemin and EPS production under UVA stress. In this study, it was hypothesized that there would be a relationship between the biosynthesis of scytonemin and EPS under both UVA and oxidative stress, since the latter is a by-product of UVA radiation. EPS production was measured following exposure of wild-type Nostoc punctiforme and the non-scytonemin-producing strain SCY59 to UVA and oxidative stress. Under UVA, SCY59 produced significantly more EPS than the unstressed controls and the wild type, while both strains produced more EPS under oxidative stress compared to the controls. The results suggest that EPS secretion occurs in response to the oxidative stress by-product of UVA rather than as a direct response to UVA radiation.

UVA/UVA1 phototherapy and PUVA photochemotherapy in connective tissue diseases and related disorders: a research based review

PubMed Central

Breuckmann, Frank; Gambichler, Thilo; Altmeyer, Peter; Kreuter, Alexander

2004-01-01

Background Broad-band UVA, long-wave UVA1 and PUVA treatment have been described as an alternative/adjunct therapeutic option in a number of inflammatory and malignant skin diseases. Nevertheless, controlled studies investigating the efficacy of UVA irradiation in connective tissue diseases and related disorders are rare. Methods Searching the PubMed database the current article systematically reviews established and innovative therapeutic approaches of broad-band UVA irradiation, UVA1 phototherapy and PUVA photochemotherapy in a variety of different connective tissue disorders. Results Potential pathways include immunomodulation of inflammation, induction of collagenases and initiation of apoptosis. Even though holding the risk of carcinogenesis, photoaging or UV-induced exacerbation, UVA phototherapy seems to exhibit a tolerable risk/benefit ratio at least in systemic sclerosis, localized scleroderma, extragenital lichen sclerosus et atrophicus, sclerodermoid graft-versus-host disease, lupus erythematosus and a number of sclerotic rarities. Conclusions Based on the data retrieved from the literature, therapeutic UVA exposure seems to be effective in connective tissue diseases and related disorders. However, more controlled investigations are needed in order to establish a clear-cut catalogue of indications. PMID:15380024

Dermal damage promoted by repeated low-level UV-A1 exposure despite tanning response in human skin.

PubMed

Wang, Frank; Smith, Noah R; Tran, Bao Anh Patrick; Kang, Sewon; Voorhees, John J; Fisher, Gary J

2014-04-01

Solar UV irradiation causes photoaging, characterized by fragmentation and reduced production of type I collagen fibrils that provide strength to skin. Exposure to UV-B irradiation (280-320 nm) causes these changes by inducing matrix metalloproteinase 1 and suppressing type I collagen synthesis. The role of UV-A irradiation (320-400 nm) in promoting similar molecular alterations is less clear yet important to consider because it is 10 to 100 times more abundant in natural sunlight than UV-B irradiation and penetrates deeper into the dermis than UV-B irradiation. Most (approximately 75%) of solar UV-A irradiation is composed of UV-A1 irradiation (340-400 nm), which is also the primary component of tanning beds. To evaluate the effects of low levels of UV-A1 irradiation, as might be encountered in daily life, on expression of matrix metalloproteinase 1 and type I procollagen (the precursor of type I collagen). In vivo biochemical analyses were conducted after UV-A1 irradiation of normal human skin at an academic referral center. Participants included 22 healthy individuals without skin disease. Skin pigmentation was measured by a color meter (chromometer) under the L* variable (luminescence), which ranges from 0 (black) to 100 (white). Gene expression in skin samples was assessed by real-time polymerase chain reaction. Lightly pigmented human skin (L* >65) was exposed up to 4 times (1 exposure/d) to UV-A1 irradiation at a low dose (20 J/cm2), mimicking UV-A levels from strong sun exposure lasting approximately 2 hours. A single exposure to low-dose UV-A1 irradiation darkened skin slightly and did not alter matrix metalloproteinase 1 or type I procollagen gene expression. With repeated low-dose UV-A1 irradiation, skin darkened incrementally with each exposure. Despite this darkening, 2 or more exposures to low-dose UV-A1 irradiation significantly induced matrix metalloproteinase 1 gene expression, which increased progressively with successive exposures. Repeated UV-A1 exposures did not suppress type I procollagen expression. A limited number of low-dose UV-A1 exposures, as commonly experienced in daily life, potentially promotes photoaging by affecting breakdown, rather than synthesis, of collagen. Progressive skin darkening in response to repeated low-dose UV-A1 exposures in lightly pigmented individuals does not prevent UV-A1-induced collagenolytic changes. Therefore, for optimal protection against skin damage, sunscreen formulations should filter all UV wavelengths, including UV-A1 irradiation.

Skin cell protection against UVA by Sideroxyl, a new antioxidant complementary to sunscreens.

PubMed

Pygmalion, Marie-Jocelyne; Ruiz, Laetitia; Popovic, Evelyne; Gizard, Julie; Portes, Pascal; Marat, Xavier; Lucet-Levannier, Karine; Muller, Benoit; Galey, Jean-Baptiste

2010-12-01

Oxidative stress resulting from photosensitized ROS production in skin is widely accepted as the main contributor to the deleterious effects of UVA exposure. Among the mechanisms known to be involved in UVA-induced oxidative damage, iron plays a central role. UVA radiation of skin cells induces an immediate release of iron, which can then act as a catalyst for uncontrolled oxidation reactions of cell components. Such site-specific damage can scarcely be counteracted by classical antioxidants. In contrast, iron chelators potentially offer an effective way to protect skin against UVA insults. However, iron chelation is very difficult to achieve without disturbing iron homeostasis or inducing iron depletion. A novel compound was developed to avoid these potentially harmful side effects. Sideroxyl was designed to acquire its strong chelating capability only during oxidative stress according to an original process of intramolecular hydroxylation. Herein, we describe in vitro results demonstrating the protective efficiency of Sideroxyl against deleterious effects of UVA at the molecular, cellular, and tissular levels. First, the Sideroxyl diacid form protects a model protein against UVA-induced photosensitized carbonylation. Second, intracellular ROS are dose-dependently decreased in the presence of Sideroxyl in both human cultured fibroblasts and human keratinocytes. Third, Sideroxyl protects normal human fibroblasts against UVA-induced DNA damage as measured by the comet assay and MMP-1 production. Finally, Sideroxyl provides protection against UVA-induced alterations in human reconstructed skin. These results suggest that Sideroxyl may prevent UVA-induced damage in human skin as a complement to sunscreens, especially in the long-wavelength UVA range. Copyright © 2010 Elsevier Inc. All rights reserved.

Graphene Oxide Transparent Hybrid Film and Its Ultraviolet Shielding Property.

PubMed

Xie, Siyuan; Zhao, Jianfeng; Zhang, Bowu; Wang, Ziqiang; Ma, Hongjuan; Yu, Chuhong; Yu, Ming; Li, Linfan; Li, Jingye

2015-08-19

Herein, we first reported a facile strategy to prepare functional Poly(vinyl alcohol) (PVA) hybrid film with well ultraviolet (UV) shielding property and visible light transmittance using graphene oxide nanosheets as UV-absorber. The absorbance of ultraviolet light at 300 nm can be up to 97.5%, while the transmittance of visible light at 500 nm keeps 40% plus. This hybrid film can protect protein from UVA light induced photosensitive damage, remarkably.

The role of commercial tanning beds and ultraviolet A light in the treatment of psoriasis.

PubMed

Su, Johanna; Pearce, Daniel J; Feldman, Steven R

2005-01-01

Phototherapy is an effective, safe psoriasis treatment administered via office-based units or home devices. There is controversy over the use of commercial tanning beds; ultraviolet B (UVB) has documented efficacy although commercial beds emit largely UVA. To determine the efficacy of UVA and the role of commercial tanning beds in treating psoriasis. A literature search of UVA and commercial tanning was performed. UVA can be effective for psoriasis, but achieving the high doses required may not be practical. Tanning beds do emit UVB although amounts are variable. Because of variability in UVA and UVB output in different tanning bulbs, it is difficult to predict response rates using commercial tanning beds. UVA can be used to treat psoriasis but may not be practical. Commercial tanning beds, emitting both UVA and UVB, have a role in treating psoriasis as an alternative to office-based therapy.

New apparatus with high radiation energy between 320 to 460 nm: physical description and dermatological applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high radiation energy between 320 to 460 nm. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. The uv-A energy in the range of 320 to 400 nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-A applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. Repeated exposure to this uv-A delivering system yields longmore » lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne.« less

Suppression of PTEN transcription by UVA

PubMed Central

Zhao, Baozhong; Ming, Mei; He, Yu-Ying

2012-01-01

Although UVA has different physical and biological targets than UVB, the contribution of UVA to skin cancer susceptibility and its molecular basis remain largely unknown. Here we show that chronic UVA radiation suppresses PTEN expression at the mRNA level. Subchronic and acute UVA radiation also down-regulated PTEN in normal human epidermal keratinocytes, skin culture and mouse skin. At the molecular level, chronic UVA radiation decreased the transcriptional activity of the PTEN promoter in a methylation-independent manner, while it had no effect on the protein stability or mRNA stability of PTEN. In contrast, we found that UVA-induced activation of the Ras/ERK/AKT and NF-κB pathways plays an important role in UV-induced PTEN down-regulation. Inhibiting ERK or AKT increases PTEN expression. Our findings may provide unique insights into PTEN down-regulation as a critical component of UVA’s molecular impact during keratinocyte transformation. PMID:23129115

10 CFR 55.5 - Communications.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Nuclear Regulatory Commission, Washington, DC 20555-0001. The guidance discusses, among other topics, the.... (b)(1) Except for test and research reactor facilities, the Director, Office of Nuclear Reactor... involving a test and research reactor facility licensed under 10 CFR part 50 and any related inquiry...

10 CFR 55.5 - Communications.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Nuclear Regulatory Commission, Washington, DC 20555-0001. The guidance discusses, among other topics, the.... (b)(1) Except for test and research reactor facilities, the Director, Office of Nuclear Reactor... involving a test and research reactor facility licensed under 10 CFR part 50 and any related inquiry...

Background radiation measurements at high power research reactors

DOE PAGES

Ashenfelter, J.; Yeh, M.; Balantekin, B.; ...

2015-10-23

Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the backgroundmore » fields encountered. Furthermore, the general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.« less

Phyllosphere Methylobacterium bacteria contain UVA-absorbing compounds.

PubMed

Yoshida, Shigenobu; Hiradate, Syuntaro; Koitabashi, Motoo; Kamo, Tsunashi; Tsushima, Seiya

2017-02-01

Microbes inhabiting the phyllosphere encounter harmful ultraviolet rays, and must develop adaptive strategies against this irradiation. In this study, we screened bacterial isolates originating from the phyllosphere of various plants which harbored absorbers of ultraviolet A (UVA), a wavelength range which is recognized as harmful to human skin. Of the 200 phyllosphere bacterial isolates we screened, methanol extracts from bacterial cells of seventeen isolates absorbed wavelengths in the range of 315-400nm. All of the UVA-absorbing strains belonged to Methylobacterium species based on 16S ribosomal RNA gene sequences, suggesting that cells of this bacterial genus contain specific UVA-absorbing compounds. When cells of a representative Methylobacterium strain were extracted using various solvents, UVA absorption was observed in the extracts obtained using several aqueous solvents, indicating that the UVA-absorbing compounds were highly polar. A compound was purified using solid columns and HPLC separation, and comparative analysis revealed that the absorption strength and spectrum of the compound were similar to those of the known UVA filter, avobenzone. The compound was also verified to be stable under UVA exposure for at least 480min. Based on these results, the UVA-absorbing compound harbored by Methylobacterium has potential to be used as a novel sunscreen ingredient. Copyright © 2016 Elsevier B.V. All rights reserved.

Photosensitized UVA-Induced Cross-Linking between Human DNA Repair and Replication Proteins and DNA Revealed by Proteomic Analysis

PubMed Central

2016-01-01

Long wavelength ultraviolet radiation (UVA, 320–400 nm) interacts with chromophores present in human cells to induce reactive oxygen species (ROS) that damage both DNA and proteins. ROS levels are amplified, and the damaging effects of UVA are exacerbated if the cells are irradiated in the presence of UVA photosensitizers such as 6-thioguanine (6-TG), a strong UVA chromophore that is extensively incorporated into the DNA of dividing cells, or the fluoroquinolone antibiotic ciprofloxacin. Both DNA-embedded 6-TG and ciprofloxacin combine synergistically with UVA to generate high levels of ROS. Importantly, the extensive protein damage induced by these photosensitizer+UVA combinations inhibits DNA repair. DNA is maintained in intimate contact with the proteins that effect its replication, transcription, and repair, and DNA–protein cross-links (DPCs) are a recognized reaction product of ROS. Cross-linking of DNA metabolizing proteins would compromise these processes by introducing physical blocks and by depleting active proteins. We describe a sensitive and statistically rigorous method to analyze DPCs in cultured human cells. Application of this proteomics-based analysis to cells treated with 6-TG+UVA and ciprofloxacin+UVA identified proteins involved in DNA repair, replication, and gene expression among those most vulnerable to cross-linking under oxidative conditions. PMID:27654267

Ultraviolet A Eye Irradiation Ameliorates Atopic Dermatitis via p53 and Clock Gene Proteins in NC/Nga Mice.

PubMed

Hiramoto, Keiichi; Yamate, Yurika; Yokoyama, Satoshi

2018-03-01

Atopic dermatitis (AD) is a widespread chronic skin condition that severely affects quality of life and can lead to more serious complications. Although ultraviolet (UV)A eye irradiation can exert various effects on the skin, it is unknown whether UVA can affect AD. To investigate potential associations, we used an NC/Nga mouse model of AD to study the effects of UVA eye irradiation. The eyes of mice were irradiated with a UVA dose of 100 kJ m -2 using a FL20SBLB-A lamp. Our histological data demonstrated that AD symptoms could be ameliorated by UVA eye irradiation. We also observed an increase in the levels of adrenocorticotropic hormone (ACTH), p53 and retinoid X receptor α (RXRα) in mice with UVA-irradiated eyes. In contrast, the levels of thymic stromal lymphopoietin (TSLP), period 2 (PER2) and differentiated embryo chondrocytes 1 (DEC1) protein were decreased in mice treated with UVA irradiation. Furthermore, UVA eye-irradiated mice exhibited reduced DEC1 and RXRα colocalization compared with nonirradiated mice. These results suggested that p53 and various clock gene proteins played important roles in the amelioration of AD symptoms observed after UVA eye irradiation; this technique may have therapeutic applications in AD. © 2017 The American Society of Photobiology.

UV-A radiation effects on higher plants: Exploring the known unknown.

PubMed

Verdaguer, Dolors; Jansen, Marcel A K; Llorens, Laura; Morales, Luis O; Neugart, Susanne

2017-02-01

Ultraviolet-A radiation (UV-A: 315-400nm) is a component of solar radiation that exerts a wide range of physiological responses in plants. Currently, field attenuation experiments are the most reliable source of information on the effects of UV-A. Common plant responses to UV-A include both inhibitory and stimulatory effects on biomass accumulation and morphology. UV-A effects on biomass accumulation can differ from those on root: shoot ratio, and distinct responses are described for different leaf tissues. Inhibitory and enhancing effects of UV-A on photosynthesis are also analysed, as well as activation of photoprotective responses, including UV-absorbing pigments. UV-A-induced leaf flavonoids are highly compound-specific and species-dependent. Many of the effects on growth and development exerted by UV-A are distinct to those triggered by UV-B and vary considerably in terms of the direction the response takes. Such differences may reflect diverse UV-perception mechanisms with multiple photoreceptors operating in the UV-A range and/or variations in the experimental approaches used. This review highlights a role that various photoreceptors (UVR8, phototropins, phytochromes and cryptochromes) may play in plant responses to UV-A when dose, wavelength and other conditions are taken into account. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Assessment of Levels of Ultraviolet A Light Protection in Automobile Windshields and Side Windows.

PubMed

Boxer Wachler, Brian S

2016-07-01

Ultraviolet A (UV-A) light is associated with the risks of cataract and skin cancer. To assess the level of UV-A light protection in the front windshields and side windows of automobiles. In this cross-sectional study, 29 automobiles from 15 automobile manufacturers were analyzed. The outside ambient UV-A radiation, along with UV-A radiation behind the front windshield and behind the driver's side window of all automobiles, was measured. The years of the automobiles ranged from 1990 to 2014, with an average year of 2010. The automobile dealerships were located in Los Angeles, California. Amount of UV-A blockage from windshields and side windows. The average percentage of front-windshield UV-A blockage was 96% (range, 95%-98% [95% CI, 95.7%-96.3%]) and was higher than the average percentage of side-window blockage, which was 71% (range, 44%-96% [95% CI, 66.4%-75.6%]). The difference between these average percentages is 25% (95% CI, 21%-30% [P < .001]). A high level of side-window UV-A blockage (>90%) was found in 4 of 29 automobiles (13.8%). The level of front-windshield UV-A protection was consistently high among automobiles. The level of side-window UV-A protection was lower and highly variable. These results may in part explain the reported increased rates of cataract in left eyes and left-sided facial skin cancer. Automakers may wish to consider increasing the degree of UV-A protection in the side windows of automobiles.

Impact of UVA exposure on psychological parameters and circulating serotonin and melatonin

PubMed Central

Gambichler, Thilo; Bader, Armin; Vojvodic, Mirjana; Bechara, Falk G; Sauermann, Kirsten; Altmeyer, Peter; Hoffmann, Klaus

2002-01-01

Background People tend to feel better after exposure to ultraviolet (UV) radiation. This study was performed to investigate the impact of UVA exposure on psychological and neuroendocrine parameters. Methods Fifty-three volunteers were separated into 42 individuals who had UVA exposure and 11 individuals who had no UVA exposure. The UVA-exposed volunteers had irradiation sessions six times in a three-week period. All volunteers completed two questionnaires at baseline (T1) and at the end of the study (T3). For the determination of serotonin and melatonin serum levels of all volunteers blood samples were collected at baseline (T1), after the first UVA exposure (T2), and at the end of the study after the sixth exposure (T3). Results UVA-exposed volunteers felt significantly more balanced, less nervous, more strengthened, and more satisfied with their appearance at T3. By contrast, the controls did not show significant changes of psychological parameters. In comparison to T1 and T3, serum serotonin was significantly higher and the serum melatonin was significantly lower for the volunteers exposed to UVA at T2. Both, for exposed and non-exposed volunteers serotonin and melatonin levels did not significantly differ at T1 and T3. Conclusions It remains obscure, whether the exposure to UVA or other components of the treatment were responsible for the psychological benefits observed. The changes of circulating neuroendocrine mediators found after UVA exposure at T2 may be due to an UVA-induced effect via a cutaneous pathway. Nevertheless, the positive psychological effects observed in our study cannot be attributed to circulating serotonin or melatonin. PMID:11952999

REACTIVITY MEASUREMENT FACILITY. CAMERA LOOKS DOWN INTO MTR CANAL. REACTOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REACTIVITY MEASUREMENT FACILITY. CAMERA LOOKS DOWN INTO MTR CANAL. REACTOR IS FUELED AS AN ETR MOCK-UP. LIGHTS DANGLE BELOW WATER LEVEL. CONTROL RODS AND OTHER APPARATUS DESCEND FROM ABOVE WATER LEVEL. INL NEGATIVE NO. 56-900. Jack L. Anderson, Photographer, 3/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Influence of repetitive UVA stimulation on skin protection capacity and antioxidant efficacy.

PubMed

Rohr, Mathias; Rieger, Ingrid; Jain, Anil; Schrader, Andreas

2011-01-01

Topically applied antioxidants (AOs) are widely used in cosmetic products - especially in day and sun care - to help reduce oxidative stress caused by exogenous influences such as ultraviolet (UV) radiation. Despite several advances in recent years, little is known about the duration of protective effects by application of topical AOs, AO protection capacity (APC) or the activation of an endogenous protection capacity (EPC). By measuring oxidative-stress-induced photon emission of human skin in vivo with the ICL-S method (induced chemiluminescence of human skin), the protective effect of daily AO treatment for 2 weeks was examined on 4 consecutive days after treatment. UVA-dose-independent effects were investigated by decay curve intersection point analysis. In addition, chemiluminescence signal integration was used to investigate the influence of different UVA doses for stimulation on the determined APC as well as the modulation of the EPC by repetitive UVA stimulation both forming the skin protection capacity (SPC). The SPC showed a strong dependency on the UVA dose used for stimulation. AO pretreatment was more effective against lower UVA doses. Over the course of 4 days, the AO-induced SPC did not change significantly for a given UVA dose. Analyzing the decay curve intersection point for 2 different UVA doses, however, revealed a decrease in SPC with time. In addition, we found that a repetitive UVA irradiation of 1 J/cm(2) caused a statistically significant protective effect against UVA irradiation by stimulation of endogenous mechanisms. Topically supplemented AOs provide a protective effect against oxidative stress for at least 3 days, supporting their widespread use in cosmetic products. Especially their interaction with cutaneous protective mechanisms should be investigated in more detail for maximal protection, as endogenous defense mechanisms are already triggered by 2 low-dose UVA irradiations within 24 h. In summary, the in vivo measurement of UVA-induced cutaneous chemiluminescence permits the UVA-dose-independent determination of the AO efficacy for better comparability of the results while also taking endogenous defense mechanisms into account. Copyright © 2011 S. Karger AG, Basel.

Preliminary plan for testing a thermionic reactor in the Plum Brook Space Power Facility

NASA Technical Reports Server (NTRS)

Haley, F. A.

1972-01-01

A preliminary plan is presented for testing a thermionic reactor in the Plum Brook Space Power Facility (SPF). A technical approach, cost estimate, manpower estimate, and schedule are presented to cover a 2 year full power reactor test.

10 CFR 55.5 - Communications.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... Nuclear Regulatory Commission, Washington, DC 20555-0001. The guidance discusses, among other topics, the.... (b)(1) Except for test and research reactor facilities, the Director, Office of Nuclear Reactor... this part involving a test and research reactor facility licensed under 10 CFR part 50 and any related...

Long-term storage facility for reactor compartments in Sayda Bay - German support for utilization of nuclear submarines in Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolff, Dietmar; Voelzke, Holger; Weber, Wolfgang

2007-07-01

The German-Russian project that is part of the G8 initiative on Global Partnership Against the Spread of Weapons and Materials of Mass Destruction focuses on the speedy construction of a land-based interim storage facility for nuclear submarine reactor compartments at Sayda Bay near Murmansk. This project includes the required infrastructure facilities for long-term storage of about 150 reactor compartments for a period of about 70 years. The interim storage facility is a precondition for effective activities of decommissioning and dismantlement of almost all nuclear-powered submarines of the Russian Northern Fleet. The project also includes the establishment of a computer-assisted wastemore » monitoring system. In addition, the project involves clearing Sayda Bay of other shipwrecks of the Russian navy. On the German side the project is carried out by the Energiewerke Nord GmbH (EWN) on behalf of the Federal Ministry of Economics and Labour (BMWi). On the Russian side the Kurchatov Institute holds the project management of the long-term interim storage facility in Sayda Bay, whilst the Nerpa Shipyard, which is about 25 km away from the storage facility, is dismantling the submarines and preparing the reactor compartments for long-term interim storage. The technical monitoring of the German part of this project, being implemented by BMWi, is the responsibility of the Federal Institute for Materials Research and Testing (BAM). This paper gives an overview of the German-Russian project and a brief description of solutions for nuclear submarine disposal in other countries. At Nerpa shipyard, being refurbished with logistic and technical support from Germany, the reactor compartments are sealed by welding, provided with biological shielding, subjected to surface treatment and conservation measures. Using floating docks, a tugboat tows the reactor compartments from Nerpa shipyard to the interim storage facility at Sayda Bay where they will be left on the on-shore concrete storage space to allow the radioactivity to decay. For transport of reactor compartments at the shipyard, at the dock and at the storage facility, hydraulic keel blocks, developed and supplied by German subcontractors, are used. In July 2006 the first stage of the reactor compartment storage facility was commissioned and the first seven reactor compartments have been delivered from Nerpa shipyard. Following transports of reactor compartments to the storage facility are expected in 2007. (authors)« less

TREAT neutron-radiography facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrison, L.J.

1981-01-01

The TREAT reactor was built as a transient irradiation test reactor. By taking advantage of built-in system features, it was possible to add a neutron-radiography facility. This facility has been used over the years to radiograph a wide variety and large number of preirradiated fuel pins in many different configurations. Eight different specimen handling casks weighing up to 54.4 t (60 T) can be accommodated. Thermal, epithermal, and track-etch radiographs have been taken. Neutron-radiography service can be provided for specimens from other reactor facilities, and the capacity for storing preirradiated specimens also exists.

Tower Shielding Reactor II design and operation report: Vol. 2. Safety Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, L. B.; Kolb, J. O.

1970-01-01

Information on the Tower Shielding Reactor II is contained in the TSR-II Design and Operation Report and in the Tower Shielding Facility Manual. The TSR-II Design and Operating Report consists of three volumes. Volume 1 is Descriptions of the Tower Shielding Reactor II and Facility; Volume 2 is Safety analysis of the Tower Shielding Reactor II; and Volume 3 is the Assembly and Testing of the Tower Shielding Reactor II Control Mechanism Housing.

Earthquake effects at nuclear reactor facilities: San Fernando earthquake of February 9th, 1971

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howard, G.; Ibanez, P.; Matthiesen, F.

1972-02-01

The effects of the San Fernando earthquake of February 9, 1971 on 26 reactor facilities located in California, Arizona, and Nevada are reported. The safety performance of the facilities during the earthquake is discussed. (JWR)

MYRRHA: A multipurpose nuclear research facility

NASA Astrophysics Data System (ADS)

Baeten, P.; Schyns, M.; Fernandez, Rafaël; De Bruyn, Didier; Van den Eynde, Gert

2014-12-01

MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a multipurpose research facility currently being developed at SCK•CEN. MYRRHA is based on the ADS (Accelerator Driven System) concept where a proton accelerator, a spallation target and a subcritical reactor are coupled. MYRRHA will demonstrate the ADS full concept by coupling these three components at a reasonable power level to allow operation feedback. As a flexible irradiation facility, the MYRRHA research facility will be able to work in both critical as subcritical modes. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material developments for GEN IV and fusion reactors, and radioisotope production for medical and industrial applications. MYRRHA will be cooled by lead-bismuth eutectic and will play an important role in the development of the Pb-alloys technology needed for the LFR (Lead Fast Reactor) GEN IV concept. MYRRHA will also contribute to the study of partitioning and transmutation of high-level waste. Transmutation of minor actinides (MA) can be completed in an efficient way in fast neutron spectrum facilities, so both critical reactors and subcritical ADS are potential candidates as dedicated transmutation systems. However critical reactors heavily loaded with fuel containing large amounts of MA pose reactivity control problems, and thus safety problems. A subcritical ADS operates in a flexible and safe manner, even with a core loading containing a high amount of MA leading to a high transmutation rate. In this paper, the most recent developments in the design of the MYRRHA facility are presented.

Multi-Purpose Thermal Hydraulic Loop: Advanced Reactor Technology Integral System Test (ARTIST) Facility for Support of Advanced Reactor Technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

James E. O'Brien; Piyush Sabharwall; SuJong Yoon

2001-11-01

Effective and robust high temperature heat transfer systems are fundamental to the successful deployment of advanced reactors for both power generation and non-electric applications. Plant designs often include an intermediate heat transfer loop (IHTL) with heat exchangers at either end to deliver thermal energy to the application while providing isolation of the primary reactor system. In order to address technical feasibility concerns and challenges a new high-temperature multi-fluid, multi-loop test facility “Advanced Reactor Technology Integral System Test facility” (ARTIST) is under development at the Idaho National Laboratory. The facility will include three flow loops: high-temperature helium, molten salt, and steam/water.more » Details of some of the design aspects and challenges of this facility, which is currently in the conceptual design phase, are discussed« less

The TRIGA Reactor Facility at the Armed Forces Radiobiology Research Institute: A Simplified Technical Description.

DTIC Science & Technology

1986-05-01

COUNT Technical FROM_ TO May 1986 20 16. SUPPLEMENTARY NOTATION 17. COSATI CODES 18. SUBJECT TERMS iConitinue on reverse if neceasary and identify by...Reactor, Modes of Operation, The AFRRI Reactor, Exposure Facilities, and Cerenkov Radiation. I- 20 DISTRISUTIONIAVAILABILITY OF ABSTRACT 21. ABSTRACT...6 Exposure Facilities 12 Cerenkov Radiation 17 Acoessiofl For NTIS GRA&I DT.C TABUnamnnounced [] UusnriOfltond -. By IZ Distribution/ Availability

Overview of Fuel Rod Simulator Usage at ORNL

NASA Astrophysics Data System (ADS)

Ott, Larry J.; McCulloch, Reg

2004-02-01

During the 1970s and early 1980s, the Oak Ridge National Laboratory (ORNL) operated large out-of-reactor experimental facilities to resolve thermal-hydraulic safety issues in nuclear reactors. The fundamental research ranged from material mechanical behavior of fuel cladding during the depressurization phase of a loss-of-coolant accident (LOCA) to basic heat transfer research in gas- or sodium-cooled cores. The largest facility simulated the initial phase (less than 1 min. of transient time) of a LOCA in a commercial pressurized-water reactor. The nonnuclear reactor cores of these facilities were mimicked via advanced, highly instrumented electric fuel rod simulators locally manufactured at ORNL. This paper provides an overview of these experimental facilities with an emphasis on the fuel rod simulators.

Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul

2011-06-24

Highlights: {yields} Pin1 expression is enhanced by low energy UVA irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. {yields} UVA irradiation increases activator protein-1 activity and cyclin D1 in a Pin1-dependent manner. {yields} UVA potentiates EGF-inducible, anchorage-independent growth of epidermal cells, and this is suppressed by Pin1 inhibition or by anti-oxidant. -- Abstract: Ultraviolet A (UVA) radiation ({lambda} = 320-400 nm) is considered a major cause of human skin cancer. Pin1, a peptidyl prolyl isomerase, is overexpressed in most types of cancer tissues and plays an important role in cell proliferation and transformation. Here, wemore » demonstrated that Pin1 expression was enhanced by low energy UVA (300-900 mJ/cm{sup 2}) irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. Exposure of epidermal cells to UVA radiation increased cell proliferation and cyclin D1 expression, and these changes were blocked by Pin1 inhibition. UVA irradiation also increased activator protein-1 (AP-1) minimal reporter activity and nuclear levels of c-Jun, but not c-Fos, in a Pin1-dependent manner. The increases in Pin1 expression and in AP-1 reporter activity in response to UVA were abolished by N-acetylcysteine (NAC) treatment. Finally, we found that pre-exposure of JB6 C141 cells to UVA potentiated EGF-inducible, anchorage-independent growth, and this effect was significantly suppressed by Pin1inhibition or by NAC.« less

The comparative safety of genipin versus UVA-riboflavin crosslinking of rabbit corneas

PubMed Central

Song, Wenjing; Tang, Yun; Qiao, Jing; Li, Haili; Rong, Bei; Yang, Songlin; Wu, Yuan

2017-01-01

Purpose To investigate, after 24 h, the safety of genipin or ultraviolet A (UVA)-riboflavin crosslinking of keratocytes and endothelial cells. Methods Fifteen New Zealand white rabbits were selected and divided into a PBS group (five rabbits), a 0.2% genipin crosslinking (GP-CXL) group (five rabbits), and a UVA-riboflavin crosslinking (UVA-CXL) group (five rabbits). In the GP-CXL and PBS groups, 0.2% genipin or PBS was applied to the corneal surface of the right eyes. In the UVA-CXL group, a clinical crosslinking procedure was used. Before and after surgery, the operated eyes of each group were characterized with confocal microscopy, and the corneal buttons were excised for endothelium staining and electron microscopy. Results The corneal endothelial cell density of the GP-CXL, UVA-CLX, and PBS groups changed. There was a statistically significant difference in thickness and changes in corneal endothelial cell density between the UVA-CXL group and the PBS group (p<0.05), and between the UVA-CXL group and the GP-CXL group (p<0.05), but no statistically significant difference between the GP-CXL group and the PBS group. Confocal microscopy, transmission electron microscopy, and hematoxylin and eosin staining showed that there was keratocyte apoptosis in the anterior and middle stroma and endothelial cell damage in the UVA-CXL group. In the GP-CXL group, only active keratocytes were found and minimal endothelial cell damage. Conclusions Treatment of rabbit corneas with 0.2% genipin showed minimal toxicity toward keratocytes and endothelial cells. Genipin is safer than UVA-CXL for crosslinking of thin corneas. PMID:28761323

Autophagic-lysosomal dysregulation downstream of cathepsin B inactivation in human skin fibroblasts exposed to UVA

PubMed Central

Lamore, Sarah D.; Wondrak, Georg T.

2014-01-01

Recently, using 2D-DIGE proteomics we have identified cathepsin B as a novel target of UVA in human Hs27 skin fibroblasts. In response to chronic exposure to noncytotoxic doses of UVA (9.9 J/cm2, twice a week, 3 weeks), photooxidative impairment of cathepsin B enzymatic activity occurred with accumulation of autofluorescent aggregates colocalizing with lysosomes, an effect mimicked by pharmacological antagonism of cathepsin B using the selective inhibitor CA074Me. Here, we have further explored the mechanistic involvement of cathepsin B inactivation in UVA-induced autophagic-lysosomal alterations using autophagy-directed PCR expression array analysis as a discovery tool. Consistent with lysosomal expansion, UVA upregulated cellular protein levels of the lysosomal marker glycoprotein Lamp-1, and increased levels of the lipidated autophagosomal membrane constituent LC3-II were detected. UVA did not alter expression of beclin 1 (BECN1), an essential factor for initiation of autophagy, but upregulation of p62 (sequestosome 1, SQSTM1), a selective autophagy substrate, and α-synuclein (SNCA), an autophagic protein substrate and aggresome component, was observed at the mRNA and protein level. Moreover, UVA downregulated transglutaminase-2 (TGM2), an essential enzyme involved in autophagolysosome maturation. Strikingly, UVA effects on Lamp-1, LC3-II, beclin 1, p62, α-synuclein, and transglutaminase-2 were mimicked by CA074Me treatment. Taken together, our data suggest that UVA-induced autophagic-lysosomal alterations occur as a consequence of impaired autophagic flux downstream of cathepsin B inactivation, a novel molecular mechanism potentially involved in UVA-induced skin photodamage. PMID:21773629

MUTYH mediates the toxicity of combined DNA 6-thioguanine and UVA radiation.

PubMed

Grasso, Francesca; Ruggieri, Vitalba; De Luca, Gabriele; Leopardi, Paola; Mancuso, Maria Teresa; Casorelli, Ida; Pichierri, Pietro; Karran, Peter; Bignami, Margherita

2015-04-10

The therapeutic thiopurines, including the immunosuppressant azathioprine (Aza) cause the accumulation of the UVA photosensitizer 6-thioguanine (6-TG) in the DNA of the patients' cells. DNA 6-TG and UVA are synergistically cytotoxic and their interaction causes oxidative damage. The MUTYH DNA glycosylase participates in the base excision repair of oxidized DNA bases. Using Mutyh-nullmouse fibroblasts (MEFs) we examined whether MUTYH provides protection against the lethal effects of combined DNA 6-TG/UVA. Surprisingly, Mutyh-null MEFs were more resistant than wild-type MEFs, despite accumulating higher levels of DNA 8-oxo-7,8-dihydroguanine (8-oxoG).Their enhanced 6-TG/UVA resistance reflected the absence of the MUTYH protein and MEFs expressing enzymatically-dead human variants were as sensitive as wild-type cells. Consistent with their enhanced resistance, Mutyh-null cells sustained fewer DNA strand breaks and lower levels of chromosomal damage after 6-TG/UVA. Although 6-TG/UVA treatment caused early checkpoint activation irrespective of the MUTYH status, Mutyh-null cells failed to arrest in S-phase at late time points. MUTYH-dependent toxicity was also apparent in vivo. Mutyh-/- mice survived better than wild-type during a 12-month chronicexposure to Aza/UVA treatments that significantly increased levels of skin DNA 8-oxoG. Two squamous cell skin carcinomas arose in Aza/UVA treated Mutyh-/- mice whereas similarly treated wild-type animals remained tumor-free.

Thioredoxin reductase activity may be more important than GSH level in protecting human lens epithelial cells against UVA light.

PubMed

Padgaonkar, Vanita A; Leverenz, Victor R; Bhat, Aparna V; Pelliccia, Sara E; Giblin, Frank J

2015-01-01

This study compares the abilities of the glutathione (GSH) and thioredoxin (Trx) antioxidant systems in defending cultured human lens epithelial cells (LECs) against UVA light. Levels of GSH were depleted with either L-buthionine-(S,R)-sulfoximine (BSO) or 1-chloro-2,4-dinitrobenzene (CDNB). CDNB treatment also inhibited the activity of thioredoxin reductase (TrxR). Two levels of O2 , 3% and 20%, were employed during a 1 h exposure of the cells to 25 J cm(-2) of UVA radiation (338-400 nm wavelength, peak at 365 nm). Inhibition of TrxR activity by CDNB, combined with exposure to UVA light, produced a substantial loss of LECs and cell damage, with the effects being considerably more severe at 20% O2 compared to 3%. In contrast, depletion of GSH by BSO, combined with exposure to UVA light, produced only a slight cell loss, with no apparent morphological effects. Catalase was highly sensitive to UVA-induced inactivation, but was not essential for protection. Although UVA light presented a challenge for the lens epithelium, it was well tolerated under normal conditions. The results demonstrate an important role for TrxR activity in defending the lens epithelium against UVA light, possibly related to the ability of the Trx system to assist DNA synthesis following UVA-induced cell damage. © 2014 The American Society of Photobiology.

Chronic Exposure to Rhodobacter Sphaeroides Extract Lycogen™ Prevents UVA-Induced Malondialdehyde Accumulation and Procollagen I Down-Regulation in Human Dermal Fibroblasts

PubMed Central

Yang, Tsai-Hsiu; Lai, Ying-Hsiu; Lin, Tsuey-Pin; Liu, Wen-Sheng; Kuan, Li-Chun; Liu, Chia-Chyuan

2014-01-01

UVA contributes to the pathogenesis of skin aging by downregulation of procollagen I content and induction of matrix metalloproteinase (MMP)-associated responses. Application of antioxidants such as lycopene has been demonstrated as a convenient way to achieve protection against skin aging. Lycogen™, derived from the extracts of Rhodobacter sphaeroides, exerts several biological effects similar to that of lycopene whereas most of its anti-aging efficacy remains uncertain. In this study, we attempted to examine whether Lycogen™ could suppress malondialdehyde (MDA) accumulation and restore downregulated procollagen I expression induced by UVA exposure. In human dermal fibroblasts Hs68 cells, UVA repressed cell viability and decreased procollagen I protein content accompanied with the induction of MMP-1 and MDA accumulation. Remarkably, incubation with 50 μM Lycogen™ for 24 h ameliorated UVA-induced cell death and restored UVA-induced downregulation of procollagen in a dose-related manner. Lycogen™ treatment also prevented the UVA-induced MMP-1 upregulation and intracellular MDA generation in Hs68 cells. Activation of NFκB levels, one of the downstream events induced by UVA irradiation and MMP-1 induction, were also prevented by Lycogen™ administration. Taken together, our findings demonstrate that Lycogen™ may be an alternative agent that prevents UVA-induced skin aging and could be used in cosmetic and pharmaceutical applications. PMID:24463291

The tryptophan-derived endogenous arylhydrocarbon receptor ligand 6-formylindolo[3,2-b]carbazole (FICZ) is a nanomolar UVA-photosensitizer in epidermal keratinocytes

PubMed Central

Williams, Joshua D.; Cabello, Christopher M.; Qiao, Shuxi; Wondrak, Georg T.

2014-01-01

Endogenous UVA-chromophores may act as sensitizers of oxidative stress underlying cutaneous photoaging and photocarcinogenesis, but the molecular identity of non-DNA key chromophores displaying UVA-driven photodyamic activity in human skin remains largely undefined. Here we report that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct and endogenous high affinity aryl hydrocarbon receptor (AhR) agonist, acts as a nanomolar photosensitizer potentiating UVA-induced oxidative stress irrespective of AhR ligand activity. In human HaCaT and primary epidermal keratinocytes, photodynamic induction of apoptosis was elicited by the combined action of solar simulated UVA and FICZ, whereas exposure to the isolated action of UVA or FICZ did not impair viability. In a human epidermal tissue reconstruct, FICZ/UVA-cotreatment caused pronounced phototoxicity inducing keratinocyte cell death, and FICZ photodynamic activity was also substantiated in a murine skin exposure model. Array analysis revealed pronounced potentiation of cellular heat shock, ER stress, and oxidative stress response gene expression observed only upon FICZ/UVA-cotreatment. FICZ photosensitization caused intracellular oxidative stress, and comet analysis revealed introduction of formamidopyrimidine-DNA glycosylase (FPG)-sensitive oxidative DNA lesions suppressible by antioxidant cotreatment. Taken together, our data demonstrate that the endogenous AhR ligand FICZ displays nanomolar photodynamic activity representing a molecular mechanism of UVA-induced photooxidative stress potentially operative in human skin. PMID:25431849

Thioredoxin Reductase Activity may be More Important than GSH Level in Protecting Human Lens Epithelial Cells Against UVA Light

PubMed Central

Padgaonkar, Vanita A.; Leverenz, Victor R.; Bhat, Aparna V.; Pelliccia, Sara E.; Giblin, Frank J.

2014-01-01

This study compares the abilities of the glutathione (GSH) and thioredoxin (Trx) antioxidant systems in defending cultured human lens epithelial cells (LECs) against UVA light. Levels of GSH were depleted with either L-buthionine-(S,R)-sulfoximine (BSO) or 1-chloro-2,4-dinitrobenzene (CDNB). CDNB treatment also inhibited the activity of thioredoxin reductase (TrxR). Two levels of O2, 3% and 20%, were employed during a 1 hr exposure of the cells to 25 J/cm2 of UVA radiation (338-400nm wavelength, peak at 365nm). Inhibition of TrxR activity by CDNB, combined with exposure to UVA light, produced a substantial loss of LECs and cell damage, with the effects being considerably more severe at 20% O2 compared to 3%. In contrast, depletion of GSH by BSO, combined with exposure to UVA light, produced only a slight cell loss, with no apparent morphological effects. Catalase was highly sensitive to UVA-induced inactivation, but was not essential for protection. Although UVA light presented a challenge for the lens epithelium, it was well-tolerated under normal conditions. The results demonstrate an important role for TrxR activity in defending the lens epithelium against UVA light, possibly related to the ability of the Trx system to assist DNA synthesis following UVA-induced cell damage. PMID:25495870

Modifications to the NRAD Reactor, 1977 to present

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weeks, A.A.; Pruett, D.P.; Heidel, C.C.

1986-01-01

Argonne National Laboratory-West, operated by the University of Chicago, is located near Idaho Falls, ID, on the Idaho National Engineering laboratory Site. ANL-West performs work in support of the Liquid Metal Fast Breeder Reactor Program (LMFBR) sponsored by the United States Department of Energy. The NRAD reactor is located at the Argonne Site within the Hot Fuel Examination Facility/North, a large hot cell facility where both non-destructive and destructive examinations are performed on highly irradiated reactor fuels and materials in support of the LMFBR program. The NRAD facility utilizes a 250-kW TRIGA reactor and is completely dedicated to neutron radiographymore » and the development of radiography techniques. Criticality was first achieved at the NRAD reactor in October of 1977. Since that time, a number of modifications have been implemented to improve operational efficiency and radiography production. This paper describes the modifications and changes that significantly improved operational efficiency and reliability of the reactor and the essential auxiliary reactor systems.« less

Inactivation and injury assessment of Escherichia coli during solar and photocatalytic disinfection in LDPE bags.

PubMed

Dunlop, P S M; Ciavola, M; Rizzo, L; Byrne, J A

2011-11-01

Solar disinfection (SODIS) of Escherichia coli suspensions in low-density polyethylene bag reactors was investigated as a low-cost disinfection method suitable for application in developing countries. The efficiency of a range of SODIS reactor configurations was examined (single skin (SS), double skin, black-backed single skin, silver-backed single skin (SBSS) and composite-backed single skin) using E. coli suspended in model and real surface water. Titanium dioxide was added to the reactors to improve the efficiency of the SODIS process. The effect of turbidity was also assessed. In addition to viable counts, E. coli injury was characterised through spread-plate analysis using selective and non-selective media. The optimal reactor configuration was determined to be the SBSS bag (t(50)=9.0min) demonstrating the importance of UVA photons, as opposed to infrared in the SODIS disinfection mechanism. Complete inactivation (6.5-log) was achieved in the presence of turbidity (50NTU) using the SBSS bag within 180min simulated solar exposure. The addition of titanium dioxide (0.025gL(-1)) significantly enhanced E. coli inactivation in the SS reactor, with 6-log inactivation observed within 90min simulated solar exposure. During the early stages of both SODIS and photocatalytic disinfection, injured E. coli were detected; however, irreversible injury was caused and re-growth was not observed. Experiments under solar conditions were undertaken with total inactivation (6.5-log) observed in the SS reactor within 240min, incomplete inactivation (4-log) was observed in SODIS bottles exposed to the same solar conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

PubMed

Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

2016-09-01

To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

Ultraviolet A within Sunlight Induces Mutations in the Epidermal Basal Layer of Engineered Human Skin

PubMed Central

Huang, Xiao Xuan; Bernerd, Françoise; Halliday, Gary Mark

2009-01-01

The ultraviolet B (UVB) waveband within sunlight is an important carcinogen; however, UVA is also likely to be involved. By ascribing mutations to being either UVB or UVA induced, we have previously shown that human skin cancers contain similar numbers of UVB- and UVA-induced mutations, and, importantly, the UVA mutations were at the base of the epidermis of the tumors. To determine whether these mutations occurred in response to UV, we exposed engineered human skin (EHS) to UVA, UVB, or a mixture that resembled sunlight, and then detected mutations by both denaturing high-performance liquid chromatography and DNA sequencing. EHS resembles human skin, modeling differential waveband penetration to the basal, dividing keratinocytes. We administered only four low doses of UV exposure. Both UVA and UVB induced p53 mutations in irradiated EHS, suggesting that sunlight doses that are achievable during normal daily activities are mutagenic. UVA- but not UVB-induced mutations predominated in the basal epidermis that contains dividing keratinocytes and are thought to give rise to skin tumors. These studies indicate that both UVA and UVB at physiological doses are mutagenic to keratinocytes in EHS. PMID:19264911

Operating manual for the High Flux Isotope Reactor. Volume I. Description of the facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-09-01

This volume contains a comprehensive description of the High Flux Isotope Reactor Facility. Its primary purpose is to supplement the detailed operating procedures, providing the reactor operators with background information on the various HFIR systems. The detailed operating procdures are presented in another report.

Identification of differentially expressed proteins in Ostrinia furnacalis adults after exposure to ultraviolet A.

PubMed

Zhang, Changyu; Meng, Jianyu

2018-06-23

Ultraviolet A (UVA), the major component of solar UV irradiation, is an important environmental factor inducing damage to insects including cell death, photoreceptor damage, and oxidative stress. In order to improve understanding of the adaptation mechanisms of insect after UVA exposure, a comparative proteomic analysis was carried out to reveal differential protein expression in Ostrinia furnacalis. Three-day-old adults were treated with UVA for 1 h. Total proteins of control and UVA-treated insects were examined using two-dimensional electrophoresis (2-DE). 2-DE analysis demonstrated that 19 proteins were increased and 18 proteins were decreased significantly in O. furnacalis after UVA exposure, respectively. Thirty differentially expressed proteins were successfully identified by mass spectrometry. The identified proteins were involved in diverse biological processes, such as signal transduction, transport processing, cellular stress, metabolisms, and cytoskeleton organization. Our results reveal that the response patterns of O. furnacalis to UVA irradiation are complex and provide novel insights into the adaptation response to UVA irradiation stress.

A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

PubMed Central

Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

2012-01-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear λ-crystallin after the in vivo UVA exposure. It is concluded that UVA-induced loss of free NADH (which fluoresces blue) may have allowed the natural yellow fluorescence of λ-crystallin and other proteins in the lens nucleus to become visible. Increased fluorescence exhibited by UVA-exposed λ-crystallin may have been the result of a UVA-induced change in the conformation of the protein occurring during the initial UVA-exposure in vivo. The results demonstrate the greater susceptibility of the lens nucleus to UVA-induced stress, and may relate to the formation of human nuclear cataract. The senofilcon A contact lens was shown to be beneficial in protecting the rabbit lens against effects of UVA light, including changes in fluorescence, increased yellowing and loss of pyridine nucleotides. PMID:22766154

A Class I UV-blocking (senofilcon A) soft contact lens prevents UVA-induced yellow fluorescence and NADH loss in the rabbit lens nucleus in vivo.

PubMed

Giblin, Frank J; Lin, Li-Ren; Simpanya, Mukoma F; Leverenz, Victor R; Fick, Catherine E

2012-09-01

It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm(2) on the cornea) for 1 h using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 h. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear λ-crystallin after the in vivo UVA exposure. It is concluded that UVA-induced loss of free NADH (which fluoresces blue) may have allowed the natural yellow fluorescence of λ-crystallin and other proteins in the lens nucleus to become visible. Increased fluorescence exhibited by UVA-exposed λ-crystallin may have been the result of a UVA-induced change in the conformation of the protein occurring during the initial UVA-exposure in vivo. The results demonstrate the greater susceptibility of the lens nucleus to UVA-induced stress, and may relate to the formation of human nuclear cataract. The senofilcon A contact lens was shown to be beneficial in protecting the rabbit lens against effects of UVA light, including changes in fluorescence, increased yellowing and loss of pyridine nucleotides. Copyright © 2012 Elsevier Ltd. All rights reserved.

Review of Transient Testing of Fast Reactor Fuels in the Transient REActor Test Facility (TREAT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, C.; Wachs, D.; Carmack, J.

The restart of the Transient REActor Test (TREAT) facility provides a unique opportunity to engage the fast reactor fuels community to reinitiate in-pile experimental safety studies. Historically, the TREAT facility played a critical role in characterizing the behavior of both metal and oxide fast reactor fuels under off-normal conditions, irradiating hundreds of fuel pins to support fast reactor fuel development programs. The resulting test data has provided validation for a multitude of fuel performance and severe accident analysis computer codes. This paper will provide a review of the historical database of TREAT experiments including experiment design, instrumentation, test objectives, andmore » salient findings. Additionally, the paper will provide an introduction to the current and future experiment plans of the U.S. transient testing program at TREAT.« less

77 FR 26321 - Reed College, Reed Research Nuclear Reactor, Renewed Facility Operating License No. R-112

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... Nuclear Reactor, Renewed Facility Operating License No. R-112 AGENCY: Nuclear Regulatory Commission... Commission (NRC or the Commission) has issued renewed Facility Operating License No. R- 112, held by Reed... License No. R-112 will expire 20 years from its date of issuance. The renewed facility operating license...

Using Teleducation and Field Experiences to further the Understanding of Coastal Environments

NASA Astrophysics Data System (ADS)

Macko, S. A.; Szuba, T. A.; Shugart, H.

2007-05-01

This project is an outreach and education program with a partner in the K-12 schools at Accomack County on the Eastern Shore of Virginia. It endeavors to build a community knowledgeable of the importance the ocean plays daily in our lives, and our own impact on the ocean. It is an program built in stages that: 1) Establish high speed live interactive classes (teleducation) linkages with the Eastern Shore High Schools with earth science teachers enabling them to remotely participate in University of Virginia classes in Oceanography (designed on a faculty development basis or acquire NSTA certification in Earth Science Education, as well as participation by seniors in the Accomack Schools; 2) Establish field experiences for teachers and selected students that involve travel to both the Virginia Coast Reserve Long Term Ecological Research (VCR/LTER) Center, UVA to observe first- hand the science programs at those locations and participate in cutting edge coastal marine research efforts. These experiences improve student understanding of the ocean-atmosphere biogeophysical system and encourage students to explore the sciences as a field of study and possible vocation. Advanced high school students and science teachers from Accomack County Public Schools participated in an experience involving field and laboratory methods employed in a NSF-sponsored study of the coupled natural-human dynamics on the Eastern Shore of Virginia over the past 500 years (NSF-Biocomplexity). Students and teachers worked with researchers of the VCR facility in Oyster, VA, collected sediment cores from Chesapeake Bay tributaries, and traveled to the Organic Geochemistry Laboratory at UVA, in Charlottesville, VA to prepare and analyze samples for isotopic and palynological information. In a first of its kind connectivity, in June/July, 2006, using high speed internet connections, a summer class in Oceanography was live, interactively broadcast (teleducation) from UVA to Arcadia High School on the Eastern Shore, allowing teachers in the Accomack School district to receive university credit without leaving their home classrooms 250 miles from UVA.

The preparation of TiO2@rGO nanocomposite efficiently activated with UVA/LED and H2O2 for high rate oxidation of acetaminophen: Catalyst characterization and acetaminophen degradation and mineralization

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Moussavi, Gholamreza; Mahjoub, Ali Reza

2018-05-01

The present work was focused on the preparation of TiO2@rGO nanocomposite using an innovative facile synthesis method and the investigation of its photocatalytic activity in a UVA/LED photoreactor. The XRD patterns indicated anatase structure for all samples. Presence of rGO in nanocomposites was confirmed by FT-IR and Raman spectra. Also, mono-dispersed TiO2 nanoparticles on rGO sheet were shown in the SEM and HRTEM images. The prepared TiO2@rGO nanocomposite was used as the photocatalyst for degradation of acetaminophen (ACT) in the photoreactor illuminated with UVA/LEDs having the intensity of 95 μW/cm2. The complete degradation of 50 mg/L ACT was attained within 50 min in the LED/TiO2@rGO process while P25/LED process only showed 17% ACT degradation under similar experimental conditions. The photocatalytic activity was strongly affected by the rGO to TiO2 ratio in the nanocomposites and the highest photocatalytic activity was observed at 3.0 wt.% of rGO. Reaction with free radOH was the main mechanism involved in the ACT photodegradation in the TiO2@rGO/LED process under the selected conditions. The performance of LED/TiO2@rGO process improved by four and three times in ACT degradation and mineralization, respectively, at the presence of H2O2. As made TiO2@rGO nanocompsite could preserve its catalytic activity during five consecutive recycles in the process. Accordingly, TiO2@rGO nanocomposite is an active and stable catalyst in the UVA/LED photoreactor for high rate degradation of pharmaceuticals in the contaminated water.

Control console replacement at the WPI Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-01-01

With partial funding from the Department of Energy (DOE) University Reactor Instrumentation Upgrade Program (DOE Grant No. DE-FG02-90ER12982), the original control console at the Worcester Polytechnic Institute (WPI) Reactor has been replaced with a modern system. The new console maintains the original design bases and functionality while utilizing current technology. An advanced remote monitoring system has been added to augment the educational capabilities of the reactor. Designed and built by General Electric in 1959, the open pool nuclear training reactor at WPI was one of the first such facilities in the nation located on a university campus. Devoted to undergraduatemore » use, the reactor and its related facilities have been since used to train two generations of nuclear engineers and scientists for the nuclear industry. The reactor power level was upgraded from 1 to 10 kill in 1969, and its operating license was renewed for 20 years in 1983. In 1988, the reactor was converted to low enriched uranium. The low power output of the reactor and ergonomic facility design make it an ideal tool for undergraduate nuclear engineering education and other training.« less

The Possible Pre- and Post-UVA Radiation Protective Effect of Amaranth Oil on Human Skin Fibroblast Cells.

PubMed

Wolosik, Katarzyna; Zareba, Ilona; Surazynski, Arkadiusz; Markowska, Agnieszka

2017-07-01

The health effects of Amaranth Oil (AO) are attributed to its specific chemical composition. That makes it an outstanding natural product for the prevention and treatment of ultraviolet (UV) irradiation-related pathologies such as sunburn, photoaging, photoimmunosuppression, and photocarcinogenesis. Most of the studies are taken on animal model, and there is a lack of research on the endogenous effect of AO on fibroblast level, where UVA takes it harmful place. The aim of this study was evaluation if AO can protect or abolish UVA exposure effect on human skin fibroblast. The 0.1% AO, 0.25% AO, and 0.5% AO concentration and irradiation for 15 min under UVA-emitting lamp were studied in various condition. In all experiments, the mean values for six assays ± standard deviations were calculated. Pretreatment with various concentrations of AO was tested. The highest concentration of AO where cell survival was observed was 0.5%. Cytotoxicity assays provided evidence for pre- and post-UVA protective effect of 0.1% AO among three tested concentrations. The results also provide evidence that UVA has inhibitory effect on collagen biosynthesis in confluent skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect comparing to other used AO concentration. The assessment results on DNA biosynthesis show the significant abolished post-UVA effect when 0.1% and 0.5% of AO were added. AO gives pre- and post-UVA protection in low concentration. This provides the evidence for using it not as a main protective factor against UV but as one of the combined components in cosmetic formulation. The recommended Amaranth Oil (AO) concentration in cosmetic formulation is between 0.1 and 5%Pretreatment with various concentrations of AO suggests to use the highest 0.5% concentration of AO in human skin fibroblast culturesThe 0.1% of AO in fibroblast cultures, protects and abolishes effect of ultraviolet A (UVA) exposureUVA has inhibitory effect on collagen biosynthesis in skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effectThe abolished post-UVA effect occurs when 0.1% and 0.5% of AO were added on DNA biosynthesis. Abbreviations used: AO: Amaranth Oil.

UV reflection properties of plumage and skin of domesticated turkeys (Meleagris gallopavo f. dom.) as revealed by UV photography.

PubMed

Bartels, T; Lütgeharm, J-H; Wähner, M; Berk, J

2017-12-01

Reflection and fluorescence properties of feathered and non-feathered body regions of white- and bronze-colored fattening turkeys of various ages were examined by ultraviolet (UV) photography. The examinations were carried out on 20 white-feathered fattening turkeys (B.U.T. 6; 10 males, 10 females) and 20 bronze-feathered fattening turkeys (Grelier 708; 10 males, 10 females) over a period of 21 weeks. The turkeys were photographed once a wk under long-wave UV (UVA) radiation illumination (λ = 344-407 nm) using a digital camera. A bandpass filter was used for UV reflectography to filter out the visible components of the used light source. A longpass filter was used for UV fluorescence photography to avoid blurring in the image due to chromatic aberration as a result of UV illumination. We found that natal down feathers of white-feathered turkeys showed an intense yellowish-green fluorescence under UVA light. UVA fluorescence also was shown by the natal downs of the slightly melanized plumage areas of bronze turkeys. Vaned feathers of white fattening turkeys reflected UVA radiation. Freshly molted feathers were optically distinguishable from the previous feather generation due to their more intense UVA reflection. In bronze turkeys, both the bright end seams of the dark pennaceous feathers and rectrices and the bright banding of primary and secondary remiges reflected UVA radiation. Intense UVA fluorescence was recognizable in day-old chicks of both color variants on the scutellate scales of the legs and toes. In male turkeys of both color variants, UVA-reflecting parts were recognizable with increasing age on the featherless head region. The UVA-fluorescent and UVA-reflective characteristics of the plumage of fattening turkeys were closely related to the plumage color, the feather type, the molting state, and the age of the birds. Further research is needed regarding the UVA-reflecting properties of the turkey plumage and the effects of full-spectrum illumination, including the UVA spectrum, on the behavior and health of fattening turkeys. © 2017 Poultry Science Association Inc.

Impact of UVA pre-radiation on UVC disinfection performance: Inactivation, repair and mechanism study.

PubMed

Xiao, Y; Chu, X N; He, M; Liu, X C; Hu, J Y

2018-05-15

Ultraviolet (UV) light emission diode (LED), which is mercury free and theoretically more energy efficient, has now become an alternative to conventional UV lamps in water disinfection industry. In this research, the disinfection performance of a novel sequential process, UVA 365nm LED followed by UVC 265nm LED (UVA-UVC), was evaluated. The results revealed that the responses of different bacterial strains to UVA-UVC varied. Coupled with appropriate dosages of UVC, a 20 min UVA pre-radiation provided higher inactivations (log inactivation) of E. coli ATCC 11229, 15597 and 700891 by 1.2, 1.4 and 1.2 times, respectively than the sum of inactivations by UVA alone and UVC alone. On the contrary, the inactivation of E. coli ATCC 25922, the most UVC sensitive strain, decreased from 3 log to 1.8 log after UVA pre-radiation. A 30 min UVA pre-radiation did not affect the photo repair capacity of the four strains (n = 23, p > 0.1), but their dark repair ability was significantly inhibited (n = 14, p < 0.05). Mechanism study was conducted for two representative strains, E. coli ATCC 15597 and 25922 to understand the observed effect. The hypothesis that UVA pre-radiation promoted the yield of reactive oxygen species (ROS) was rejected. ELISA results indicated that 18% more cyclobutane pyrimidine dimers (CPD) were formed in E. coli ATCC 15597 with UVA pre-radiation (n = 3, p < 0.01), however, the CPD levels of E. coli ATCC 25922 was the same with or without UVA pre-radiation (n = 3, p > 0.01). Considering the results of both dark repair and CPD formation, it was concluded that the increased UV sensitivity of E. coli 15597 was originated from the increased CPD. For E. coli ATCC 25922, the enhanced UV resistance was attributed to the strain's adoption of a survival strategy, translesion DNA synthesis (TLS), when triggered by UVA pre-radiation. The study on UmuD protein, which is a key protein during TLS, confirmed this hypothesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Travel Time Influences Readmission Risk: Geospatial Mapping of Surgical Readmissions.

PubMed

Turrentine, Florence E; Buckley, Patrick J; Sohn, Min-Woong; Williams, Michael D

2017-06-01

The University of Virginia (UVA) has recently become an Accountable Care Organization (ACO), intensifying efforts to provide better care for individuals. UVA's ACO population resides across the entire Commonwealth, with a large percentage of patients living in rural areas. To provide better health for this population, the central tenet of the ACO mission, we identified geographic risk factors influencing hospital readmission. We analyzed the relationship between the distance of patients' residence to the nearest hospital and 30-day readmission in general surgery patients. A retrospective chart review using January 1, 2011 through October 31, 2013 American College of Surgeons National Surgical Quality Improvement Program data for general surgery procedures was conducted. ArcGIS mapped street addresses provided graphical representation of distance between surgical population and the nearest hospital. We analyzed the impact on readmission, of time traveled, insurance status, and median household income. Each increase of 10 minutes in travel time from the patient's residence to the nearest hospital, not just UVA, was associated with a 9 per cent increase in the probability of readmission after adjusting for patient characteristics, preoperative comorbidities, laboratory values, and postoperative complications before or after discharge (odds ratio = 1.09; 95% confidence interval = 1.01-1.17; P = 0.019). Unlike urban hospitals, those serving rural populations may be at particular risk of postsurgical readmissions. Patients living furthest from a hospital facility are most at risk for readmission after a general surgery procedure. This vulnerable population may benefit most from comprehensive discharge planning.

UV-A Irradiation Activates Nrf2-Regulated Antioxidant Defense and Induces p53/Caspase3-Dependent Apoptosis in Corneal Endothelial Cells.

PubMed

Liu, Cailing; Vojnovic, Dijana; Kochevar, Irene E; Jurkunas, Ula V

2016-04-01

To examine whether Nrf2-regulated antioxidant defense and p53 are activated in human corneal endothelial cells (CEnCs) by environmental levels of ultraviolet A (UV-A), a known stimulator of oxidative stress. Immortalized human CEnCs (HCEnCi) were exposed to UV-A fluences of 2.5, 5, 10, or 25 J/cm2, then allowed to recover for 3 to 24 hours. Control HCEnCi did not receive UV-A. Reactive oxygen species (ROS) were measured using H2DCFDA. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. Levels of Nrf2, HO-1, NQO-1, p53, and caspase3 were detected by immunnoblotting or real-time PCR. Activated caspase3 was measured by immunoblotting and a fluorescence assay. Exposure of HCEnCi to 5, 10, and 25 J/cm2 UV-A increased ROS levels compared with controls. Nrf2, HO-1, and NQO-1 mRNA increased 1.7- to 3.2-fold at 3 and 6 hours after irradiation with 2.5 and 5 J/cm2 UV-A. At 6 hours post irradiation, UV-A (5 J/cm2) enhanced nuclear Nrf2 translocation. At 24 hours post treatment, UV-A (5, 10, and 25 J/cm2) produced a 1.8- to 2.8-fold increase in phospho-p53 and a 2.6- to 6.0-fold increase in activated caspase3 compared with controls, resulting in 20% to 42% cell death. Lower fluences of UV-A induce Nrf2-regulated antioxidant defense and higher fluences activate p53 and caspase3, indicating that even near-environmental levels of UV-A may affect normal CEnCs. This data suggest that UV-A may especially damage cells deficient in antioxidant defense, and thus may be involved in the etiology of Fuchs' endothelial corneal dystrophy (FECD).

UV-A Irradiation Activates Nrf2-Regulated Antioxidant Defense and Induces p53/Caspase3-Dependent Apoptosis in Corneal Endothelial Cells

PubMed Central

Liu, Cailing; Vojnovic, Dijana; Kochevar, Irene E.; Jurkunas, Ula V.

2016-01-01

Purpose To examine whether Nrf2-regulated antioxidant defense and p53 are activated in human corneal endothelial cells (CEnCs) by environmental levels of ultraviolet A (UV-A), a known stimulator of oxidative stress. Methods Immortalized human CEnCs (HCEnCi) were exposed to UV-A fluences of 2.5, 5, 10, or 25 J/cm2, then allowed to recover for 3 to 24 hours. Control HCEnCi did not receive UV-A. Reactive oxygen species (ROS) were measured using H2DCFDA. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. Levels of Nrf2, HO-1, NQO-1, p53, and caspase3 were detected by immunnoblotting or real-time PCR. Activated caspase3 was measured by immunoblotting and a fluorescence assay. Results Exposure of HCEnCi to 5, 10, and 25 J/cm2 UV-A increased ROS levels compared with controls. Nrf2, HO-1, and NQO-1 mRNA increased 1.7- to 3.2-fold at 3 and 6 hours after irradiation with 2.5 and 5 J/cm2 UV-A. At 6 hours post irradiation, UV-A (5 J/cm2) enhanced nuclear Nrf2 translocation. At 24 hours post treatment, UV-A (5, 10, and 25 J/cm2) produced a 1.8- to 2.8-fold increase in phospho-p53 and a 2.6- to 6.0-fold increase in activated caspase3 compared with controls, resulting in 20% to 42% cell death. Conclusions Lower fluences of UV-A induce Nrf2-regulated antioxidant defense and higher fluences activate p53 and caspase3, indicating that even near-environmental levels of UV-A may affect normal CEnCs. This data suggest that UV-A may especially damage cells deficient in antioxidant defense, and thus may be involved in the etiology of Fuchs' endothelial corneal dystrophy (FECD). PMID:27127932

The effects of two different doses of ultraviolet-A light exposure on nitric oxide metabolites and cardiorespiratory outcomes.

PubMed

Monaghan, Chris; McIlvenna, Luke C; Liddle, Luke; Burleigh, Mia; Weller, Richard B; Fernandez, Bernadette O; Feelisch, Martin; Muggeridge, David J; Easton, Chris

2018-05-01

The present study investigated different doses of ultraviolet-A (UV-A) light on plasma nitric oxide metabolites and cardiorespiratory variables. Ten healthy male participants completed three experimental conditions, 7 days apart. Participants were exposed to no light (CON); 10 J cm 2 (15 min) of UV-A light (UVA10) and 20 J cm 2 (30 min) of UV-A light (UVA20) in a randomized order. Plasma nitrite [NO 2 - ] and nitrate [NO 3 - ] concentrations, blood pressure (BP), and heart rate (HR) were recorded before, immediately after exposure and 30 min post-exposure. Whole body oxygen utilization ([Formula: see text]), resting metabolic rate (RMR) and skin temperature were recorded continuously. None of the measured parameters changed significantly during CON (all P > 0.05). [Formula: see text] and RMR were significantly reduced immediately after UVA10 (P < 0.05) despite no change in plasma [NO 2 - ] (P > 0.05). Immediately after exposure to UVA20, plasma [NO 2 - ] was higher (P = 0.014) and [Formula: see text] and RMR tended to be lower compared to baseline (P = 0.06). There were no differences in [NO 2 - ] or [Formula: see text] at the 30 min time point in any condition. UV-A exposure did not alter systolic BP, diastolic BP or MAP (all P > 0.05). UV-A light did not alter plasma [NO 3 - ] at any time point (all P > 0.05). This study demonstrates that a UV-A dose of 20 J cm 2 is necessary to increase plasma [NO 2 - ] although a smaller dose is capable of reducing [Formula: see text] and RMR at rest. Exposure to UV-A did not significantly reduce BP in this cohort of healthy adults. These data suggest that exposure to sunlight has a meaningful acute impact on metabolic function.

Can possible toxic effect of ultraviolet-A after corneal cross-linking be prevented? In vitro transmittance study of contact lenses at 370 nm wavelength.

PubMed

Bilgihan, Kamil; Yuksel, Erdem; Deniz, Nuriye Gokcen; Yuksel, Nilay

2015-01-01

Corneal collagen cross linking (CCL) with ultraviolet A (UVA) has been proposed as a treatment for the progression of corneal ectasia associated with keratoconus and post-laser-assisted in situ keratomileusis (LASIK) ectasia. Despite the reports about safety of procedure, we consider that UVA of sunlight can effect riboflavin saturated and de-epitelizated cornea early after CCL. To evaluate the UVA blockage capability of 11 different silicone hydrogel contact lenses which are widely used after CCL treatment. Eleven different silicone hydrogel and daily disposable contact lenses were evaluated. The UVA light at 365 nm wavelength for UVA source and UV light meter to measure UVA radiation were used. 3, 9 and 18 mW/cm(2) power of UV radiance was applied centrally to the each type of contact lenses. The power of UVA transmittance for each radiance and percentage of blockage were evaluated for each brand. Also, protection factor (PF) was calculated. The senofilcon A and narafilcon A had the highest blockage and lowest transmittance (p = 0.02). PF was significantly higher in the senofilcon A and narafilcon A at 3, 9 and 18 mW/cm(2) (p = 0.0001). And also, the hilafilcon B, filcon IV, nelfilcon A, enfilcon A, lotrafilcon A and lotrafilcon B had the highest UVA transmittance. The narafilcon A and the senofilcon A may be a good options for epithelial healing after CCL procedure to protect the cornea from UVA of sunlight. And also, the hilafilcon B, filcon IV, nelfilcon A, enfilcon A, lotrafilcon A and lotrafilcon B contact lenses that have high-UVA transmittance feature can be a treatment choice for contact lens-assisted CCL technique in thin corneas.

Phototoxicity of B-RAF inhibitors: Exclusively due to UVA radiation and rapidly regressive.

PubMed

Gabeff, Romain; Dutartre, Hervé; Khammari, Amir; Boisrobert, Aurélie; Nguyen, Jean-Michel; Quereux, Gaëlle; Brocard, Anabelle; Saint-Jean, Mélanie; Peuvrel, Lucie; Dreno, Brigitte

2015-01-01

New targeted melanoma therapies such as B-RAF inhibitors have shown high and promising clinical benefit but have cutaneous side-effects, including photosensitivity, which is triggered in the UVA radiation spectrum. However, visible spectrum implication has not yet been investigated. We conducted a study to determine whether visible light also contributes to the phototoxicity action spectrum of vemurafenib. The secondary end points were to determine the time to complete regression of the phototoxicity post-vemurafenib discontinuation and whether there was a significant difference between the UVA radiation immediate reactivity cut-offs, in patients treated with vemurafenib vs. those treated with dabrafenib. This prospective, observational study included patients with B-RAF mutant metastatic melanoma: 34 patients treated with vemurafenib and 9 with dabrafenib. The visible-light phototest results in patients treated with vemurafenib were all negative before and after 2 months of treatment. The UVA radiation phototests conducted 1 or 2 weeks post-vemurafenib discontinuation in 4 patients showed a normalised UVA-radiation reactivity cut-off. UVA radiation phototests after 2 months of treatment were conducted for all patients. The UVA radiation reactivity cut-off had been lowered for 30 patients (88%) on vemurafenib and 3 patients (33%) on dabrafenib. The median UVA radiation reactivity cut-off was 12 J/cm(2) for the patients on vemurafenib and 20 J/cm(2) for the patients on dabrafenib. B-RAF inhibitor phototoxicity is exclusively triggered by UVA radiation and resolves rapidly post-treatment discontinuation. A significant difference between the UVA immediate reactivity cut-offs, vemurafenib vs. dabrafenib, explains the difference in the clinical photosensitivity rates reported in the clinical trials.

Response and Defense Mechanisms of Taxus chinensis Leaves Under UV-A Radiation are Revealed Using Comparative Proteomics and Metabolomics Analyses.

PubMed

Zheng, Wen; Komatsu, Setsuko; Zhu, Wei; Zhang, Lin; Li, Ximin; Cui, Lei; Tian, Jingkui

2016-09-01

Taxus chinensis var. mairei is a species endemic to south-eastern China and one of the natural sources for the anticancer medicine paclitaxel. To investigate the molecular response and defense mechanisms of T. chinensis leaves to enhanced ultraviolet-A (UV-A) radiation, gel-free/label-free and gel-based proteomics and gas chromatography-mass spectrometry (GC-MS) analyses were performed. The transmission electron microscopy results indicated damage to the chloroplast under UV-A radiation. Proteomics analyses in leaves and chloroplasts showed that photosynthesis-, glycolysis-, secondary metabolism-, stress-, and protein synthesis-, degradation- and activation-related systems were mainly changed under UV-A radiation. Forty-seven PSII proteins and six PSI proteins were identified as being changed in leaves and chloroplasts under UV-A treatment. This indicated that PSII was more sensitive to UV-A than PSI as the target of UV-A light. Enhanced glycolysis, with four glycolysis-related key enzymes increased, provided precursors for secondary metabolism. The 1-deoxy-d-xylulose-5-phosphate reductoisomerase and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase were identified as being significantly increased during UV-A radiation, which resulted in paclitaxel enhancement. Additionally, mRNA expression levels of genes involved in the paclitaxel biosynthetic pathway indicated a down-regulation under UV-A irradiation and up-regulation in dark incubation. These results reveal that a short-term high dose of UV-A radiation could stimulate the plant stress defense system and paclitaxel production. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Removal of pharmaceutically active compounds from synthetic and real aqueous mixtures and simultaneous disinfection by supported TiO2/UV-A, H2O2/UV-A, and TiO2/H2O2/UV-A processes.

PubMed

Bosio, Morgana; Satyro, Suéllen; Bassin, João Paulo; Saggioro, Enrico; Dezotti, Márcia

2018-05-01

Pharmaceutically active compounds are carried into aquatic bodies along with domestic sewage, industrial and agricultural wastewater discharges. Psychotropic drugs, which can be toxic to the biota, have been detected in natural waters in different parts of the world. Conventional water treatments, such as activated sludge, do not properly remove these recalcitrant substances, so the development of processes able to eliminate these compounds becomes very important. Advanced oxidation processes are considered clean technologies, capable of achieving high rates of organic compounds degradation, and can be an efficient alternative to conventional treatments. In this study, the degradation of alprazolam, clonazepam, diazepam, lorazepam, and carbamazepine was evaluated through TiO 2 /UV-A, H 2 O 2 /UV-A, and TiO 2 /H 2 O 2 /UV-A, using sunlight and artificial irradiation. While using TiO 2 in suspension, best results were found at [TiO 2 ] = 0.1 g L -1 . H 2 O 2 /UV-A displayed better results under acidic conditions, achieving from 60 to 80% of removal. When WWTP was used, degradation decreased around 50% for both processes, TiO 2 /UV-A and H 2 O 2 /UV-A, indicating a strong matrix effect. The combination of both processes was shown to be an adequate approach, since removal increased up to 90%. H 2 O 2 /UV-A was used for disinfecting the aqueous matrices, while mineralization was obtained by TiO 2 -photocatalysis.

10 CFR 2.103 - Action on applications for byproduct, source, special nuclear material, facility and operator...

Code of Federal Regulations, 2013 CFR

2013-01-01

... nuclear material, facility and operator licenses. (a) If the Director, Office of Nuclear Reactor... repository operations area under parts 60 or 63 of this chapter, the Director, Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Nuclear Material Safety and Safeguards, or...

10 CFR 2.103 - Action on applications for byproduct, source, special nuclear material, facility and operator...

Code of Federal Regulations, 2014 CFR

2014-01-01

... nuclear material, facility and operator licenses. (a) If the Director, Office of Nuclear Reactor... repository operations area under parts 60 or 63 of this chapter, the Director, Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Nuclear Material Safety and Safeguards, or...

A novel research model for evaluating sunscreen protection in the UV-A1.

PubMed

Figueiredo, Sônia Aparecida; de Moraes, Dayane Cristina; Vilela, Fernanda Maria Pinto; de Faria, Amanda Natalina; Dos Santos, Marcelo Henrique; Fonseca, Maria José Vieira

2018-01-01

The use of a broad spectrum sunscreen is considered one of the main and most popular measures for preventing the damaging effects of ultraviolet radiation (UVR) on the skin. In this study we have developed a novel in vitro method to assess sunscreens efficacy to protect calcineurin enzyme activity, a skin cell marker. The photoprotective efficacy of sunscreen products was assessed by measuring the UV-A1 radiation-induced depletion of calcineurin (Cn) enzyme activity in primary neonatal human dermal fibroblast (HDFn) cell lysates. After exposure to 24J/cm 2 UV-A1 radiation, the sunscreens containing larger amounts of UV-A1 filters (brand B), the astaxanthin (UV-A1 absorber) and the Tinosorb® M (UV-A1 absorber) were capable of preventing loss of Cn activity when compared to the sunscreens formulations of brand A (low concentration of UV-A1 filters), with the Garcinia brasiliensis extract (UV-B absorber) and with the unprotected cell lysate and exposed to irradiation (Irradiated Control - IC). The Cn activity assay is a reproducible, accurate and selective technique for evaluating the effectiveness of sunscreens against the effects of UV-A1 radiation. The developed method showed that calcineurin activity have the potential to act as a biological indicator of UV-A1 radiation-induced damages in skin and the assay might be used to assess the efficacy of sunscreens agents and plant extracts prior to in vivo tests. Copyright © 2017 Elsevier B.V. All rights reserved.

MUTYH mediates the toxicity of combined DNA 6-thioguanine and UVA radiation

PubMed Central

De Luca, Gabriele; Leopardi, Paola; Mancuso, Maria Teresa; Casorelli, Ida; Pichierri, Pietro; Karran, Peter; Bignami, Margherita

2015-01-01

The therapeutic thiopurines, including the immunosuppressant azathioprine (Aza) cause the accumulation of the UVA photosensitizer 6-thioguanine (6-TG) in the DNA of the patients' cells. DNA 6-TG and UVA are synergistically cytotoxic and their interaction causes oxidative damage. The MUTYH DNA glycosylase participates in the base excision repair of oxidized DNA bases. Using Mutyh-nullmouse fibroblasts (MEFs) we examined whether MUTYH provides protection against the lethal effects of combined DNA 6-TG/UVA. Surprisingly, Mutyh-null MEFs were more resistant than wild-type MEFs, despite accumulating higher levels of DNA 8-oxo-7,8-dihydroguanine (8-oxoG). Their enhanced 6-TG/UVA resistance reflected the absence of the MUTYH protein and MEFs expressing enzymatically-dead human variants were as sensitive as wild-type cells. Consistent with their enhanced resistance, Mutyh-null cells sustained fewer DNA strand breaks and lower levels of chromosomal damage after 6-TG/UVA. Although 6-TG/UVA treatment caused early checkpoint activation irrespective of the MUTYH status, Mutyh-null cells failed to arrest in S-phase at late time points. MUTYH-dependent toxicity was also apparent in vivo. Mutyh−/−mice survived better than wild-type during a 12-month chronicexposure to Aza/UVA treatments that significantly increased levels of skin DNA 8-oxoG. Two squamous cell skin carcinomas arose in Aza/UVA treated Mutyh−/− mice whereas similarly treated wild-type animals remained tumor-free. PMID:25638157

Exposure of vitamins to UVB and UVA radiation generates singlet oxygen.

PubMed

Knak, Alena; Regensburger, Johannes; Maisch, Tim; Bäumler, Wolfgang

2014-05-01

Deleterious effects of UV radiation in tissue are usually attributed to different mechanisms. Absorption of UVB radiation in cell constituents like DNA causes photochemical reactions. Absorption of UVA radiation in endogenous photosensitizers like vitamins generates singlet oxygen via photosensitized reactions. We investigated two further mechanisms that might be involved in UV mediated cell tissue damage. Firstly, UVB radiation and vitamins also generate singlet oxygen. Secondly, UVB radiation may change the chemical structure of vitamins that may change the role of such endogenous photosensitizers in UVA mediated mechanisms. Vitamins were irradiated in solution using monochromatic UVB (308 nm) or UVA (330, 355, or 370 nm) radiation. Singlet oxygen was directly detected and quantified by its luminescence at 1270 nm. All investigated molecules generated singlet oxygen with a quantum yield ranging from 0.007 (vitamin D3) to 0.64 (nicotinamide) independent of the excitation wavelength. Moreover, pre-irradiation of vitamins with UVB changed their absorption in the UVB and UVA spectral range. Subsequently, molecules such as vitamin E and vitamin K1, which normally exhibit no singlet oxygen generation in the UVA, now produce singlet oxygen when exposed to UVA at 355 nm. This interplay of different UV sources is inevitable when applying serial or parallel irradiation with UVA and UVB in experiments in vitro. These results should be of particular importance for parallel irradiation with UVA and UVB in vivo, e.g. when exposing the skin to solar radiation.

Micronucleated erythrocytes in newborns rats exposed to three different types of ultraviolet-A (UVA) lamps from commonly uses devices.

PubMed

Zúñiga-González, Guillermo M; Gómez-Meda, Belinda C; Zamora-Perez, Ana L; Martínez-González, María A; Bautista-Bejarano, Miguel A; Patiño-Valenzuela, Sebastián; Armendáriz-Borunda, Juan; Lazalde-Ramos, Blanca P; Sánchez-Parada, María G; Gallegos-Arreola, Martha P

2016-12-01

Exposure to ultraviolet-A (UVA) light can accidentally cause adverse effects in the skin and eyes. UVA induces DNA damage directly by creating pyrimidine dimers or by the formation of reactive oxygen species that can indirectly affect DNA integrity. UVA radiation is emitted by lamps from everyday devices. In adult rats, micronucleated erythrocytes (MNE) are removed from the circulation by the spleen. However, in newborn rats, MNE have been observed in peripheral blood erythrocytes. The objective of this study was to use micronucleus tests to evaluate the DNA damage caused in newborn rats exposed to UVA light from three different types of UVA lamps obtained from commonly used devices: counterfeit detectors, insecticide devices, and equipment used to harden resins for artificial nails. Rat neonates were exposed to UVA lamps for 20min daily for 6days. The neonates were sampled every third day, and the numbers of MNE and micronucleated polychromatic erythrocytes (MNPCE) in the peripheral blood were determined. The rat neonates exposed to the three types of UVA lamps showed increased numbers of MNE and MNPCE from 48h to 144h (P<0.05 and P<0.001 respectively). However, no relationship was observed between the number of MNE and the wattage of the lamps. In conclusion, under these conditions, UVA light exposure induced an increase in MNE without causing any apparent damage to the skin. Copyright © 2016 Elsevier B.V. All rights reserved.

Changes of MMP-1 and collagen type Ialpha1 by UVA, UVB and IRA are differentially regulated by Trx-1.

PubMed

Buechner, Nicole; Schroeder, Peter; Jakob, Sascha; Kunze, Kerstin; Maresch, Tanja; Calles, Christian; Krutmann, Jean; Haendeler, Judith

2008-07-01

Exposure of human skin to solar radiation, which includes ultraviolet (UV) radiation (UVA and UVB) visible light and infrared radiation, induces skin aging. The effects of light have been attributed to irradiation-induced reactive oxygen species (ROS) formation, but the specific signaling pathways are not well understood. Detrimental effects of solar radiation are dermal diseases and photoaging. Exposure of cultured human dermal fibroblasts to UVA, UVB or IRA increased ROS formation in vitro. One important redox regulator is the oxidoreductase thioredoxin-1 (Trx). Trx is ubiquitously expressed and has anti-oxidative and anti-apoptotic properties. Besides its function to reduce H(2)O(2), Trx binds to and regulates transcription factors. The aim of this study was to investigate whether Trx influences the regulation of MMP-1 and collagen Ialpha1 by UVA, UVB and IRA. We irradiated human dermal fibroblasts with UVA, UVB and IRA. UVA, UVB and IRA upregulated MMP-1 expression. Trx inhibited UVA-induced MMP-1 upregulation in a NFkappaB dependent manner. UVA, UVB and IRA reduced collagen Ialpha1 expression. Incubation with Trx inhibited the effects of UVB and IRA on collagen Ialpha1 expression. In conclusion, MMP-1 and collagen Ialpha1, which play important roles in aging processes, seems to be regulated by different transcriptional mechanisms and Trx can only influence distinct signaling pathways induced by UVA, UVB and probably IRA. Thus, Trx may serve as an important contributor to an "anti-aging therapeutic cocktail".

Large-scale testing of in-vessel debris cooling through external flooding of the reactor pressure vessel in the CYBL facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, T.Y.; Bentz, J.H.; Bergeron, K.D.

1994-04-01

The possibility of achieving in-vessel core retention by flooding the reactor cavity, or the ``flooded cavity``, is an accident management concept currently under consideration for advanced light water reactors (ALWR), as well as for existing light water reactors (LWR). The CYBL (CYlindrical BoiLing) facility is a facility specifically designed to perform large-scale confirmatory testing of the flooded cavity concept. CYBL has a tank-within-a-tank design; the inner 3.7 m diameter tank simulates the reactor vessel, and the outer tank simulates the reactor cavity. The energy deposition on the bottom head is simulated with an array of radiant heaters. The array canmore » deliver a tailored heat flux distribution corresponding to that resulting from core melt convection. The present paper provides a detailed description of the capabilities of the facility, as well as results of recent experiments with heat flux in the range of interest to those required for in-vessel retention in typical ALWRs. The paper concludes with a discussion of other experiments for the flooded cavity applications.« less

Photodegradation applied to the treatment of phenol and derived substances catalyzed by TiO2/BiPO4 and biological toxicity analysis.

PubMed

Zaidan, Léa Elias Mendes Carneiro; de Lima Sales, Renata Vitória; de Almeida Salgado, Júlia Barbosa; da Silva, Ana Maria Ribeiro Bastos; Napoleão, Daniella Carla; Rodríguez-Díaz, Joan Manuel; Marques, Olga Martins; Benachour, Mohand; da Silva, Valdinete Lins

2017-03-01

For this work, a phenol solution model was treated by an advanced oxidation process (AOPs), using the heterogeneous catalyst TiO 2 /BiPO 4 and hydrogen peroxide combined with UVA for 240 min. An annular reactor containing a UVA lamp (80 W) was employed. A central composite rotacional design was developed employing a TiO 2 /BiPO 4 concentration of 87 mg L -1 and a hydrogen peroxide concentration of 1800 mg L -1 , being evaluated by the degradation percentage and phenol mineralization percentage as responses; 94.30 and 67.00 % were obtained for the phenol degradation and total organic carbon (TOC) conversion, respectively. The lumped kinetic model (LKM) was applied and a satisfactory profile of the residual fractions of the organic compounds present in the liquid phase as a time function with a determination coefficient (R 2  = 0.9945). The toxicity tests employing microbiological species indicated that the organisms tested for the evaluation of the toxic compounds present in the contaminated samples presented a practical low cost test, rapid execution, and high sensibility as an indicator of the presence of toxic substances in liquid effluents.

Arctigenin protects against ultraviolet-A-induced damage to stemness through inhibition of the NF-κB/MAPK pathway.

PubMed

Park, See-Hyoung; Cho, Jae Youl; Oh, Sae Woong; Kang, Mingyeong; Lee, Seung Eun; Yoo, Ju Ah; Jung, Kwangseon; Lee, Jienny; Lee, Sang Yeol; Lee, Jongsung

2018-02-25

The stemness of stem cells is negatively affected by ultraviolet A (UVA) irradiation. This study was performed to examine the effects of arctigenin on UVA-irradiation-induced damage to the stemness of human mesenchymal stem cells (hMSCs) derived from adipose tissue. The mechanisms of action of arctigenin were also investigated. A BrdU-incorporation assay demonstrated that arctigenin attenuated the UVA-induced reduction of the cellular proliferative potential. Arctigenin also increased the UVA-induced reduction in stemness of hMSCs by upregulating stemness-related genes such as SOX2, OCT4, and NANOG. In addition, the UVA-induced reduction in the mRNA expression level of hypoxia-inducible factor (HIF)-1α was significantly recovered by arctigenin. The antagonizing effect of arctigenin on UVA irradiation was mediated by reduced PGE 2 production through the inhibition of MAPKs (p42/44 MAPK, p38 MAPK, and JNK) and NF-κB. Overall, these findings suggest that arctigenin can ameliorate the reduced stemness of hMSCs induced by UVA irradiation. The effects of arctigenin are mediated by PGE 2 -cAMP signaling-dependent upregulation of HIF-1α. Therefore, arctigenin could be used as an antagonist to attenuate the effects of UVA irradiation. Copyright © 2018 Elsevier B.V. All rights reserved.

Gene expression of Escherichia coli in continuous culture during adaptation to artificial sunlight.

PubMed

Berney, Michael; Weilenmann, Hans-Ulrich; Egli, Thomas

2006-09-01

Escherichia coli growing in continuous culture under continuous UVA irradiation exhibits growth inhibition with a subsequent adaptation to the stress. Transcriptome analysis was performed during transient growth inhibition and in the UVA light-adapted growth state. The results indicate that UVA light induces stringent response and an additional response that includes the upregulation of the synthesis of valine, isoleucine, leucine, phenylalanine, histidine and glutamate. The induction of several SOS response-genes strongly points to DNA damage as a result of UVA exposure. The involvement of oxidative stress was observed with the induction of ahpCF. Taken together it supports the hypothesis of the production of reactive oxygen species by UVA light. In the UVA-adapted cell population strong repression of the acid tolerance response was found. We identified the enzyme chorismate mutase as a possible chromophore for UVA light-inactivation and found strong repression of the pyrBI operon and the gene mgtA encoding for an ATP-dependent Mg2+ transporter. Furthermore, our results indicate that the role of RpoS may not be as important in the adaptation of E. coli to UVA light as it was implicated by previous results with starved cells, but that RpoS might be of crucial importance for the resistance under transient light exposure.

Role of the Pseudomonas quinolone signal (PQS) in sensitising Pseudomonas aeruginosa to UVA radiation.

PubMed

Pezzoni, Magdalena; Meichtry, Martín; Pizarro, Ramón A; Costa, Cristina S

2015-01-01

One of the main stress factors that bacteria face in the environment is solar ultraviolet-A (UVA) radiation, which leads to lethal effects through oxidative damage. The aim of this work was to investigate the role of 2-heptyl-3-hydroxi-4-quinolone (the Pseudomonas quinolone signal or PQS) in the response of Pseudomonas aeruginosa to UVA radiation. PQS is an intercellular quorum sensing signal associated to membrane vesicles which, among other functions, regulates genes related to iron acquisition, forms stable complexes with iron and participates in oxidative phenomena. UVA exposure of the wild-type PAO1 strain and a pqsA mutant unable to produce PQS revealed a sensitising role for this signal. Research into the mechanism involved in this phenomenon revealed that catalase, an essential factor in the UVA defence, is not related to PQS-mediated UVA sensitivity. Absorption of UVA by PQS produced its own photo-degradation, oxidation of the probe 2',7'- dichlorodihydrofluorescein and generation of singlet oxygen and superoxide anion, suggesting that this signal could be acting as an endogenous photosensitiser. The results presented in this study could explain the high sensitivity to UVA of P. aeruginosa when compared to enteric bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

Policies and practices pertaining to the selection, qualification requirements, and training programs for nuclear-reactor operating personnel at the Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Culbert, W.H.

1985-10-01

This document describes the policies and practices of the Oak Ridge National Laboratory (ORNL) regarding the selection of and training requirements for reactor operating personnel at the Laboratory's nuclear-reactor facilities. The training programs, both for initial certification and for requalification, are described and provide the guidelines for ensuring that ORNL's research reactors are operated in a safe and reliable manner by qualified personnel. This document gives an overview of the reactor facilities and addresses the various qualifications, training, testing, and requalification requirements stipulated in DOE Order 5480.1A, Chapter VI (Safety of DOE-Owned Reactors); it is intended to be in compliancemore » with this DOE Order, as applicable to ORNL facilities. Included also are examples of the documentation maintained amenable for audit.« less

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77 FR 7613 - Dow Chemical Company; Dow Chemical TRIGA Research Reactor; Facility Operating License No. R-108

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-264; NRC-2012-0026] Dow Chemical Company; Dow Chemical TRIGA Research Reactor; Facility Operating License No. R-108 AGENCY: Nuclear Regulatory Commission... Facility Operating License No. R-108 (``Application''), which currently authorizes the Dow Chemical Company...

78 FR 24438 - Evaluations of Explosions Postulated To Occur at Nearby Facilities and on Transportation Routes...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-25

... Nearby Facilities and on Transportation Routes Near Nuclear Power Plants AGENCY: Nuclear Regulatory... Nearby Facilities and on Transportation Routes Near Nuclear Power Plants.'' This regulatory guide describes for applicants seeking nuclear power reactor licenses and licensees of nuclear power reactors...

Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamarudin, S. U.; Gopir, G.; Yatim, B.

The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2 degree sign 55' N, 101 degree sign 46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3 degree sign 06' N, 101 degree sign 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298{+-}105) kJm{sup -2} while the total daily maximummore » is (600{+-}56) kJm{sup -2}. From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.« less

Operators in the Plum Brook Reactor Facility Control Room

NASA Image and Video Library

1970-03-21

Donald Rhodes, left, and Clyde Greer, right, monitor the operation of the National Aeronautics and Space Administration’s (NASA) Plum Brook Reactor Facility from the control room. The 60-megawatt test reactor, NASA’s only reactor, was the eighth largest test reactor in the world. The facility was built by the Lewis Research Center in the late 1950s to study the effects of radiation on different materials that could be used to construct nuclear propulsion systems for aircraft or rockets. The reactor went critical for the first time in 1961. For the next two years, two operators were on duty 24 hours per day working on the fission process until the reactor reached its full-power level in 1963. Reactor Operators were responsible for monitoring and controlling the reactor systems. Once the reactor was running under normal operating conditions, the work was relatively uneventful. Normally the reactor was kept at a designated power level within certain limits. Occasionally the operators had to increase the power for a certain test. The shift supervisor and several different people would get together and discuss the change before boosting the power. All operators were required to maintain a Reactor Operator License from the Atomic Energy Commission. The license included six months of training, an eight-hour written exam, a four-hour walkaround, and testing on the reactor controls.

Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.

PubMed

Coelho, Sergio G; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Hearing, Vincent J

2015-03-01

Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive. Published 2014. This article is a US Government work and is in the public domain in the USA.

Opportunities for Materials Science and Biological Research at the OPAL Research Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, S. J.

Neutron scattering techniques have evolved over more than 1/2 century into a powerful set of tools for determination of atomic and molecular structures. Modern facilities offer the possibility to determine complex structures over length scales from {approx}0.1 nm to {approx}500 nm. They can also provide information on atomic and molecular dynamics, on magnetic interactions and on the location and behaviour of hydrogen in a variety of materials. The OPAL Research Reactor is a 20 megawatt pool type reactor using low enriched uranium fuel, and cooled by water. OPAL is a multipurpose neutron factory with modern facilities for neutron beam research,more » radioisotope production and irradiation services. The neutron beam facility has been designed to compete with the best beam facilities in the world. After six years in construction, the reactor and neutron beam facilities are now being commissioned, and we will commence scientific experiments later this year. The presentation will include an outline of the strengths of neutron scattering and a description of the OPAL research reactor, with particular emphasis on it's scientific infrastructure. It will also provide an overview of the opportunities for research in materials science and biology that will be possible at OPAL, and mechanisms for accessing the facilities. The discussion will emphasize how researchers from around the world can utilize these exciting new facilities.« less

Nuclear energy center site survey reactor plant considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harty, H.

The Energy Reorganization Act of 1974 required the Nuclear Regulatory Commission (NRC) to make a nuclear energy center site survey (NECSS). Background information for the NECSS report was developed in a series of tasks which include: socioeconomic inpacts; environmental impact (reactor facilities); emergency response capability (reactor facilities); aging of nuclear energy centers; and dry cooled nuclear energy centers.

ACHP | News | President Appoints Clement A. Price Vice Chairman of ACHP

Science.gov Websites

Project Honored For Federal Leadership, Commitment to Historic Hanford Facility Department of Energy’s B Reactor Preservation Project Honored For Federal Leadership, Commitment to Historic Hanford Facility Reactor Preservation Project at DOE’s Hanford Site in southeastern Washington state. “The B Reactor

Fibrinogen, Riboflavin, and UVA to Immobilize a Corneal Flap—Conditions for Tissue Adhesion

PubMed Central

Littlechild, Stacy L.; Brummer, Gage; Zhang, Yuntao; Conrad, Gary W.

2012-01-01

Purpose. Laser-assisted in situ keratomileus (LASIK) creates a permanent flap that remains non-attached to the underlying laser-modified stroma. This lack of permanent adhesion is a liability. To immobilize a corneal flap, a protocol using fibrinogen (FIB), riboflavin (RF), and ultraviolet (UVA) light (FIB+RF+UVA) was devised to re-adhere the flap to the stroma. Methods. A model flap was created using rabbit (Oryctolagus cuniculus) and shark (Squalus acanthias) corneas. Solutions containing FIB and RF were applied between corneal strips as glue. Experimental corneas were irradiated with long wavelength (365 nm) UVA. To quantify adhesive strength between corneal strips, the glue-tissue interface was subjected to a constant force while a digital force gauge recorded peak tension. Results. In the presence of FIB, substantive non-covalent interactions occurred between rabbit corneal strips. Adhesiveness was augmented if RF and UVA also were applied, suggesting formation of covalent bonds. Additionally, exposing both sides of rabbit corneas to UVA generated more adhesion than exposure from one side, suggesting that RF in the FIB solution catalyzes formation of covalent bonds at only the interface between stromal molecules and FIB closest to the UVA. In contrast, in the presence of FIB, shark corneal strips interacted non-covalently more substantively than those of rabbits, and adhesion was not augmented by applying RF+UVA, from either or both sides. Residual RF could be rinsed away within 1 hour. Conclusions. Glue solution containing FIB and RF, together with UVA treatment, may aid immobilization of a corneal flap, potentially reducing risk of flap dislodgement. PMID:22589434

Identification of potentially cytotoxic lesions induced by UVA photoactivation of DNA 4-thiothymidine in human cells

PubMed Central

Reelfs, Olivier; Macpherson, Peter; Ren, Xiaolin; Xu, Yao-Zhong; Karran, Peter; Young, Antony R.

2011-01-01

Photochemotherapy—in which a photosensitizing drug is combined with ultraviolet or visible radiation—has proven therapeutic effectiveness. Existing approaches have drawbacks, however, and there is a clinical need to develop alternatives offering improved target cell selectivity. DNA substitution by 4-thiothymidine (S4TdR) sensitizes cells to killing by ultraviolet A (UVA) radiation. Here, we demonstrate that UVA photoactivation of DNA S4TdR does not generate reactive oxygen or cause direct DNA breakage and is only minimally mutagenic. In an organotypic human skin model, UVA penetration is sufficiently robust to kill S4TdR-photosensitized epidermal cells. We have investigated the DNA lesions responsible for toxicity. Although thymidine is the predominant UVA photoproduct of S4TdR in dilute solution, more complex lesions are formed when S4TdR-containing oligonucleotides are irradiated. One of these, a thietane/S5-(6-4)T:T, is structurally related to the (6-4) pyrimidine:pyrimidone [(6-4) Py:Py] photoproducts induced by UVB/C radiation. These lesions are detectable in DNA from S4TdR/UVA-treated cells and are excised from DNA more efficiently by keratinocytes than by leukaemia cells. UVA irradiation also induces DNA interstrand crosslinking of S4TdR-containing duplex oligonucleotides. Cells defective in repairing (6-4) Py:Py DNA adducts or processing DNA crosslinks are extremely sensitive to S4TdR/UVA indicating that these lesions contribute significantly to S4TdR/UVA cytotoxicity. PMID:21890905

Characteristics of potential repository wastes: Volume 4, Appendix 4A, Nuclear reactors at educational institutions of the United States; Appendix 4B, Data sheets for nuclear reactors at educational institutions; Appendix 4C, Supplemental data for Fort St. Vrain spent fuel; Appendix 4D, Supplemental data for Peach Bottom 1 spent fuel; Appendix 4E, Supplemental data for Fast Flux Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-07-01

Volume 4 contains the following appendices: nuclear reactors at educational institutions in the United States; data sheets for nuclear reactors at educational institutions in the United States(operational reactors and shut-down reactors); supplemental data for Fort St. Vrain spent fuel; supplemental data for Peach Bottom 1 spent fuel; and supplemental data for Fast Flux Test Facility.

Control console replacement at the WPI Reactor. [Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-12-31

With partial funding from the Department of Energy (DOE) University Reactor Instrumentation Upgrade Program (DOE Grant No. DE-FG02-90ER12982), the original control console at the Worcester Polytechnic Institute (WPI) Reactor has been replaced with a modern system. The new console maintains the original design bases and functionality while utilizing current technology. An advanced remote monitoring system has been added to augment the educational capabilities of the reactor. Designed and built by General Electric in 1959, the open pool nuclear training reactor at WPI was one of the first such facilities in the nation located on a university campus. Devoted to undergraduatemore » use, the reactor and its related facilities have been since used to train two generations of nuclear engineers and scientists for the nuclear industry. The reactor power level was upgraded from 1 to 10 kill in 1969, and its operating license was renewed for 20 years in 1983. In 1988, the reactor was converted to low enriched uranium. The low power output of the reactor and ergonomic facility design make it an ideal tool for undergraduate nuclear engineering education and other training.« less

Effects of light on the cytotoxicity and genotoxicity of benzo(a)pyrene and an oil refinery effluent in the newt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, M.; l`Haridon, J.

1994-12-31

The genotoxicity and/or toxicity of benzo(a)pyrene (BaP) were evaluated under different lighting conditions in larvae and embryos of the newt Pleurodeles waltl. Visible light alone, UVA alone, or BaP alone had no toxic effects on the larvae. Conversely, toxic effects were observed in animals exposed to BaP + daylight, or BaP + UVA. The genotoxicity of BaP (50 ppb) was halved by its previous exposure to UVA, and was abolished at the lowest concentration (12.5 ppb). In other experiments, the larvae were exposed alternatively to BaP or Irr BaP (18 hours in dark) and UVA (6 hr in water), everymore » day for 8 days. All animals that had accumulated non-irradiated BaP (50 ppb) showed signs of severe toxicity, and 90% died before the end of the test. On the other hand, irradiated BaP (50 ppb) was a 4-fold less toxic and half as genotoxic as non-irradiated BaP. In addition, exposure of the animals to UVA alone for 4 days prior to treatment with BaP did not affect the genotoxicity or toxicity of this hydrocarbon. In the dark, the embryotoxicity of BaP was markedly attenuated by the presence of the jelly coats. Although UVA alone did not affect growth of the embryos, the toxicity of BaP was enhanced by the combined action of the two agents together or in succession (BaP + UVA or BaP then UVA). Larvae were treated with an oil refinery effluent (EF). At 125 ml/l, EF was not found to be genotoxic in the dark. However, in animals exposed to both EF and UVA, there was a progressive increase in level of micronucleated erythrocytes with increasing duration of daily exposure to UVA. Moreover, the genotoxic potential of irradiated EF + UVA was systematically below that of non-irradiated EF + UVA for all durations of exposure to ultraviolet light. Irradiation of this type of effluent might help reduce its harmful effects on aquatic species. Our results also suggest that metabolic activation is not necessary for hydrocarbons to induce toxic effects. 51 refs., 5 tabs., 3 figs.« less

Combined treatment of UVA irradiation and antibiotics induces greater bactericidal effects on Vibrio parahaemolyticus.

PubMed

Hou, Yanfei; Nakahashi, Mutsumi; Mawatari, Kazuaki; Shimohata, Takaaki; Uebanso, Takashi; Harada, Yumi; Tsunedomi, Akari; Emoto, Takahiro; Akutagawa, Masatake; Kinouchi, Yohsuke; Takahashi, Akira

2016-01-01

The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and UVA irradiation was more bactericidal than UVA irradiation or antibacterial drugs alone. The bactericidal synergy was observed at low concentrations of each drug that are normally unable to kill the bacteria. This combination has the potential to become a sterilization technology.

Influence of uvA on the erythematogenic and therapeutic effects of uvB irradiation in psoriasis; photoaugmentation effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boer, J.; Schothorst, A.A.; Suurmond, D.

1981-01-01

The effect of repeated exposure to an additive dose of long ultraviolet (uvA) radiation on the erythemogenic and therapeutic effects of middle ultraviolet (uvB) irradiation was investigated in 8 patients with psoriasis. The surface of the backs of these patients was divided into 2 parts, 1 of which received only uvB irradiation 4 times a week and the other uvA + uvB. uvB was provided by Philips TL-12 lamps and uvA by glass-filtered Philips TL-09 lamps. uvA was held constantly at 10 J/cm2, whereas uvB alone were evaluated by 4 tests during the treatment to determine the minimal erythema dosemore » (MED). Test I (at the start of the therapy) showed a photoaugmentative effect which was no longer apparent in Test III (third week). Test III showed a reversal of the ratios of the MEDs of the sites irradiated with the uvA + uvB and uvB (MED A + B/MED B). This is ascribed to the marked pigmentation which appeared after repeated irradiation with the uvA + uvB combination. Comparison showed for the improvement of the psoriasis no distinct differences between uvA + uvB irradiation and uvB alone, but the former had the cosmetic advantage of giving pleasing tan.« less

Antagonizing Effects of Aspartic Acid against Ultraviolet A-Induced Downregulation of the Stemness of Human Adipose Tissue-Derived Mesenchymal Stem Cells.

PubMed

Jung, Kwangseon; Cho, Jae Youl; Soh, Young-Jin; Lee, Jienny; Shin, Seoung Woo; Jang, Sunghee; Jung, Eunsun; Kim, Min Hee; Lee, Jongsung

2015-01-01

Ultraviolet A (UVA) irradiation is responsible for a variety of changes in cell biology. The purpose of this study was to investigate effects of aspartic acid on UVA irradiation-induced damages in the stemness properties of human adipose tissue-derived mesenchymal stem cells (hAMSCs). Furthermore, we elucidated the UVA-antagonizing mechanisms of aspartic acid. The results of this study showed that aspartic acid attenuated the UVA-induced reduction of the proliferative potential and stemness of hAMSCs, as evidenced by increased proliferative activity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and upregulation of stemness-related genes OCT4, NANOG, and SOX2 in response to the aspartic acid treatment. UVA-induced reduction in the mRNA level of hypoxia-inducible factor (HIF)-1α was also significantly recovered by aspartic acid. In addition, the antagonizing effects of aspartic acid against the UVA effects were found to be mediated by reduced production of PGE2 through the inhibition of JNK and p42/44 MAPK. Taken together, these findings show that aspartic acid improves reduced stemness of hAMSCs induced by UVA and its effects are mediated by upregulation of HIF-1α via the inhibition of PGE2-cAMP signaling. In addition, aspartic acid may be used as an antagonizing agent to mitigate the effects of UVA.

UVA-induced DNA double-strand breaks result from the repair of clustered oxidative DNA damages

PubMed Central

Greinert, R.; Volkmer, B.; Henning, S.; Breitbart, E. W.; Greulich, K. O.; Cardoso, M. C.; Rapp, Alexander

2012-01-01

UVA (320–400 nm) represents the main spectral component of solar UV radiation, induces pre-mutagenic DNA lesions and is classified as Class I carcinogen. Recently, discussion arose whether UVA induces DNA double-strand breaks (dsbs). Only few reports link the induction of dsbs to UVA exposure and the underlying mechanisms are poorly understood. Using the Comet-assay and γH2AX as markers for dsb formation, we demonstrate the dose-dependent dsb induction by UVA in G1-synchronized human keratinocytes (HaCaT) and primary human skin fibroblasts. The number of γH2AX foci increases when a UVA dose is applied in fractions (split dose), with a 2-h recovery period between fractions. The presence of the anti-oxidant Naringin reduces dsb formation significantly. Using an FPG-modified Comet-assay as well as warm and cold repair incubation, we show that dsbs arise partially during repair of bi-stranded, oxidative, clustered DNA lesions. We also demonstrate that on stretched chromatin fibres, 8-oxo-G and abasic sites occur in clusters. This suggests a replication-independent formation of UVA-induced dsbs through clustered single-strand breaks via locally generated reactive oxygen species. Since UVA is the main component of solar UV exposure and is used for artificial UV exposure, our results shine new light on the aetiology of skin cancer. PMID:22941639

Autophagy mediates cell cycle response by regulating nucleocytoplasmic transport of PAX6 in limbal stem cells under ultraviolet-A stress

PubMed Central

Laggner, Maria; Pollreisz, Andreas; Schmidinger, Gerald; Schmidt-Erfurth, Ursula; Chen, Ying-Ting

2017-01-01

Limbal stem cells (LSC) account for homeostasis and regeneration of corneal epithelium. Solar ultraviolet A (UVA) is the major source causing oxidative damage in the ocular surface. Autophagy, a lysosomal degradation mechanism, is essential for physiologic function and stress defense of stem cells. PAX6, a master transcription factor governing corneal homeostasis by regulating cell cycle and cell fate of LSC, responds to oxidative stress by nucleocytoplasmic shuttling. Impaired autophagy and deregulated PAX6 have been reported in oxidative stress-related ocular surface disorders. We hypothesize a functional role for autophagy and PAX6 in LSC’s stress response to UVA. Therefore, human LSC colonies were irradiated with a sub-lethal dose of UVA and autophagic activity and intracellular reactive oxygen species (ROS) were measured by CYTO-ID assay and CM-H2DCFDA live staining, respectively. Following UVA irradiation, the percentage of autophagic cells significantly increased in LSC colonies while intracellular ROS levels remained unaffected. siRNA-mediated knockdown (KD) of ATG7 abolished UVA-induced autophagy and led to an excessive accumulation of ROS. Upon UVA exposure, LSCs displayed nuclear-to-cytoplasmic translocation of PAX6, while ATG7KD or antioxidant pretreatment largely attenuated the intracellular trafficking event. Immunofluorescence showing downregulation of proliferative marker PCNA and induction of cell cycle regulator p21 indicates cell cycle arrest in UVA-irradiated LSC. Abolishing autophagy, adenoviral-assisted restoration of nuclear PAX6 or antioxidant pretreatment abrogated the UVA-induced cell cycle arrest. Adenoviral expression of an ectopic PAX gene, PAX7, did not affect UVA cell cycle response. Furthermore, knocking down PAX6 attenuated the cell cycle progression of irradiated ATG7KD LSC by de-repressing p21 expression. Collectively, our data suggest a crosstalk between autophagy and PAX6 in regulating cell cycle response of ocular progenitors under UVA stress. Autophagy deficiency leads to impaired intracellular trafficking of PAX6, perturbed redox balance and uncurbed cell cycle progression in UVA-stressed LSCs. The coupling of autophagic machinery and PAX6 in cell cycle regulation represents an attractive therapeutic target for hyperproliferative ocular surface disorders associated with solar radiation. PMID:28700649

Advanced reactors and associated fuel cycle facilities: safety and environmental impacts.

PubMed

Hill, R N; Nutt, W M; Laidler, J J

2011-01-01

The safety and environmental impacts of new technology and fuel cycle approaches being considered in current U.S. nuclear research programs are contrasted to conventional technology options in this paper. Two advanced reactor technologies, the sodium-cooled fast reactor (SFR) and the very high temperature gas-cooled reactor (VHTR), are being developed. In general, the new reactor technologies exploit inherent features for enhanced safety performance. A key distinction of advanced fuel cycles is spent fuel recycle facilities and new waste forms. In this paper, the performance of existing fuel cycle facilities and applicable regulatory limits are reviewed. Technology options to improve recycle efficiency, restrict emissions, and/or improve safety are identified. For a closed fuel cycle, potential benefits in waste management are significant, and key waste form technology alternatives are described. Copyright © 2010 Health Physics Society

Inactivation of foodborne pathogenic and spoilage micro-organisms using ultraviolet-A light in combination with ferulic acid.

PubMed

Shirai, A; Watanabe, T; Matsuki, H

2017-02-01

The low energy of UV-A (315-400 nm) is insufficient for disinfection. To improve UV-A disinfection technology, we evaluated the effect of ferulic acid (FA) addition on disinfection by UV-A light-emitting diode (LED) (350-385 nm) against various food spoilers and pathogens (seven bacteria and four fungi species). Photoantimicrobial assays were performed at FA concentrations below the MIC. The MIC of the isomerized FA, consisting of 93% cis-form and 7% trans-form, was very similar to that of the commercially available FA (trans-form). Irradiation with UV-A (1·0 J cm -2 ) in the presence of 100 mg l -1 FA resulted in enhanced reducing of all of the tested bacterial strains. A combination of UV-A (10 J cm -2 ) and 1000 mg l -1 FA resulted in enhanced reducing of Saccharomyces cerevisiae and one of the tested filamentous fungi. These results demonstrated that the combination of a short-term application of UV-A and FA at a low concentration yielded synergistic enhancement of antimicrobial activity, especially against bacteria. Microbial contamination is one of the most serious problems for foods, fruit and sugar thick juices. UV light is suitable for the nonthermal decontamination of food products by inactivating the contaminating micro-organisms. However, UV-A exposure is insufficient for disinfection. This study demonstrates that the combination of UV-A LED light (350-385 nm), which is not hazardous to human eyes and skin, and ferulic acid (FA), a known phytochemical and food additive, provides synergistic antimicrobial activity against foodborne pathogenic and spoilage micro-organisms. Therefore, FA addition to UV-A light treatment may be useful for improvement of UV-A disinfection technology to prevent food deterioration. © 2016 The Society for Applied Microbiology.

Lipid nanoparticles based on butyl-methoxydibenzoylmethane: in vitro UVA blocking effect

NASA Astrophysics Data System (ADS)

Niculae, G.; Lacatusu, I.; Badea, N.; Meghea, A.

2012-08-01

The aim of the present study was to obtain efficient lipid nanoparticles loaded with butyl-methoxydibenzoylmethane (BMDBM) in order to develop cosmetic formulations with enhanced UVA blocking effect. For this purpose, two adequate liquid lipids (medium chain triglycerides and squalene) have been used in combination with two solid lipids (cetyl palmitate and glyceryl stearate) in order to create appropriate nanostructured carriers with a disordered lipid network able to accommodate up to 1.5% BMDBM. The lipid nanoparticles (LNs) were characterized in terms of particle size, zeta potential, entrapment efficiency, loading capacity and in vitro UVA blocking effect. The efficiency of lipid nanoparticles in developing some cosmetic formulations has been evaluated by determining the in vitro erythemal UVA protection factor. In order to quantify the photoprotective effect, some selected cream formulations based on BMDBM-LNs and a conventional emulsion were exposed to photochemical UV irradiation at a low energy to simulate the solar energy during the midday. The results obtained demonstrated the high ability of cream formulations based on BMDBM-LNs to absorb more than 96% of UVA radiation. Moreover, the developed cosmetic formulations manifest an enhanced UVA blocking effect, the erythemal UVA protection factor being four times higher than those specific to conventional emulsions.

Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice.

PubMed

Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi; Sugawara, Tatsuya

2017-01-01

Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis.

Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice

PubMed Central

Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi

2017-01-01

Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis. PMID:28170435

Customized Corneal Cross-Linking-A Mathematical Model.

PubMed

Caruso, Ciro; Epstein, Robert L; Ostacolo, Carmine; Pacente, Luigi; Troisi, Salvatore; Barbaro, Gaetano

2017-05-01

To improve the safety, reproducibility, and depth of effect of corneal cross-linking with the ultraviolet A (UV-A) exposure time and fluence customized according to the corneal thickness. Twelve human corneas were used for the experimental protocol. They were soaked using a transepithelial (EPI-ON) technique using riboflavin with the permeation enhancer vitamin E-tocopheryl polyethylene glycol succinate. The corneas were then placed on microscope slides and irradiated at 3 mW/cm for 30 minutes. The UV-A output parameters were measured to build a new equation describing the time-dependent loss of endothelial protection induced by riboflavin during cross-linking, as well as a pachymetry-dependent and exposure time-dependent prescription for input UV-A fluence. The proposed equation was used to establish graphs prescribing the maximum UV-A fluence input versus exposure time that always maintains corneal endothelium exposure below toxicity limits. Analysis modifying the Lambert-Beer law for riboflavin oxidation leads to graphs of the maximum safe level of UV-A radiation fluence versus the time applied and thickness of the treated cornea. These graphs prescribe UV-A fluence levels below 1.8 mW/cm for corneas of thickness 540 μm down to 1.2 mW/cm for corneas of thickness 350 μm. Irradiation times are typically below 15 minutes. The experimental and mathematical analyses establish the basis for graphs that prescribe maximum safe fluence and UV-A exposure time for corneas of different thicknesses. Because this clinically tested protocol specifies a corneal surface clear of shielding riboflavin on the corneal surface during UV-A irradiation, it allows for shorter UV-A irradiation time and lower fluence than in the Dresden protocol.

Examination of tetrachlorosalicylanilide (TCSA) photoallergy using in vitro photohapten-modified Langerhans cell-enriched epidermal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerberick, G.F.; Ryan, C.A.; Von Bargen, E.C.

Lymphocytes from BALB/c mice photosensitized in vivo to tetrachlorosalicylanilide (TCSA) were investigated to determine whether they could be stimulated to proliferate when cultured with Langerhans cell-enriched cultured epidermal cells (LC-EC) photohapten-modified in vitro with TCSA + UVA radiation. Cultured LC-EC were photohapten-modified in vitro by irradiation in TCSA-containing medium using a 1000-watt solar simulator equipped with filters to deliver primarily UVA radiation (320-400 nm). Lymphocytes from TCSA-photosensitized mice were incubated with LC-EC that had been treated in vitro with 0.1 mM TCSA and 2 J/cm2 UVA radiation (TCSA + UVA). Responder lymphocytes demonstrated a significant increase in their blastogenesis responsemore » compared to lymphocytes that were incubated with LC-EC irradiated with UVA prior to treatment with TCSA (UVA/TCSA) or with LC-EC that had received no treatment. Lymphocytes from naive mice or mice photosensitized with musk ambrette (MA) demonstrated a significantly lower response to LC-EC modified with TCSA + UVA, indicating the specificity of the response. Maximum blastogenesis response was achieved when LC-EC were treated with 0.1 mM TCSA and a UVA radiation dose of at least 0.5 J/cm2. Epidermal cells depleted of LC by treatment with anti-Ia antibody plus complement or by an adherence procedure were unable to stimulate this blastogenesis response. Epidermal cells treated in vitro with TCSA + UVA demonstrated enhanced fluorescence compared to control cells. The fluorescence observed was not restricted to any specific epidermal cell type; however, fluorescence microscopy studies revealed that dendritic Ia-positive cells, presumably LC, were also TCSA fluorescent.« less

Photosynthetic benefits of ultraviolet-A to Pimelea ligustrina, a woody shrub of sub-alpine Australia.

PubMed

Turnbull, Tarryn L; Barlow, Alexandra M; Adams, Mark A

2013-10-01

The definition of photosynthetically active radiation (Q) as the visible waveband (λ 400-700 nm) is a core assumption of much of modern plant biology and global models of carbon and water fluxes. On the other hand, much research has focused on potential mutation and damage to leaves caused by ultraviolet (UV) radiation (280-400 nm), and anatomical and physiological adaptations that help avoid such damage. Even so, plant responses to UV-A are poorly described and, until now, photosynthetic utilization of UV-A has not been elucidated under full light conditions in the field. We found that the UV-A content of sunlight increased photosynthetic rates in situ by 12% in Pimelea ligustrina Labill., a common and indigenous woody shrub of alpine ecosystems of the Southern Hemisphere. Compared to companion shrubs, UV-A-induced photosynthesis in P. ligustrina resulted from reduced physical and chemical capacities to screen UV-A at the leaf surface (illustrated by a lack of cuticle and reduced phenol index) and the resulting ability of UV-A to excite chlorophyll (Chl) a directly, and via energy provided by the carotenoid lutein. A screening of 55 additional sub-alpine species showed that 47% of the plant taxa also display Chl a fluorescence under UV-A. If Chl a fluorescence indicates potential for photosynthetic gain, continued exclusion of UV-A from definitions of Q in this ecosystem could result in underestimates of measured and modeled rates of photosynthesis and miscalculation of potential for carbon sequestration. We suggest that carbon gain for alpine environs across the globe could be similarly underestimated given that UV-A radiation increases with altitude and that the frequently dominant herb and grass life-forms often transmit UV-A through the epidermis.

Simulation of the neutron flux in the irradiation facility at RA-3 reactor.

PubMed

Bortolussi, S; Pinto, J M; Thorp, S I; Farias, R O; Soto, M S; Sztejnberg, M; Pozzi, E C C; Gonzalez, S J; Gadan, M A; Bellino, A N; Quintana, J; Altieri, S; Miller, M

2011-12-01

A facility for the irradiation of a section of patients' explanted liver and lung was constructed at RA-3 reactor, Comisión Nacional de Energía Atómica, Argentina. The facility, located in the thermal column, is characterized by the possibility to insert and extract samples without the need to shutdown the reactor. In order to reach the best levels of security and efficacy of the treatment, it is necessary to perform an accurate dosimetry. The possibility to simulate neutron flux and absorbed dose in the explanted organs, together with the experimental dosimetry, allows setting more precise and effective treatment plans. To this end, a computational model of the entire reactor was set-up, and the simulations were validated with the experimental measurements performed in the facility. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of fast neutron spectrum in the TRIGA for hardness testing of electronic components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, George W.

1986-07-01

Argonne National Laboratory-West, operated by the University of Chicago, is located near Idaho Falls, ID, on the Idaho National Engineering Laboratory Site. ANL-West performs work in support of the Liquid Metal Fast Breeder Reactor Program (LMFBR) sponsored by the United States Department of Energy. The NRAD reactor is located at the Argonne Site within the Hot Fuel Examination Facility/North, a large hot cell facility where both non-destructive and destructive examinations are performed on highly irradiated reactor fuels and materials in support of the LMFBR program. The NRAD facility utilizes a 250-kW TRIGA reactor and is completely dedicated to neutron radiographymore » and the development of radiography techniques. Criticality was first achieved at the NRAD reactor in October of 1977. Since that time, a number of modifications have been implemented to improve operational efficiency and radiography production. This paper describes the modifications and changes that significantly improved operational efficiency and reliability of the reactor and the essential auxiliary reactor systems. (author)« less

Characterization of a smartphone camera's response to ultraviolet A radiation.

PubMed

Igoe, Damien; Parisi, Alfio; Carter, Brad

2013-01-01

As part of a wider study into the use of smartphones as solar ultraviolet radiation monitors, this article characterizes the ultraviolet A (UVA; 320-400 nm) response of a consumer complementary metal oxide semiconductor (CMOS)-based smartphone image sensor in a controlled laboratory environment. The CMOS image sensor in the camera possesses inherent sensitivity to UVA, and despite the attenuation due to the lens and neutral density and wavelength-specific bandpass filters, the measured relative UVA irradiances relative to the incident irradiances range from 0.0065% at 380 nm to 0.0051% at 340 nm. In addition, the sensor demonstrates a predictable response to low-intensity discrete UVA stimuli that can be modelled using the ratio of recorded digital values to the incident UVA irradiance for a given automatic exposure time, and resulting in measurement errors that are typically less than 5%. Our results support the idea that smartphones can be used for scientific monitoring of UVA radiation. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Skin protection against UVA-induced iron damage by multiantioxidants and iron chelating drugs/prodrugs.

PubMed

Reelfs, Olivier; Eggleston, Ian M; Pourzand, Charareh

2010-03-01

In humans, prolonged sunlight exposure is associated with various pathological states. The continuing drive to develop improved skin protection involves not only approaches to reduce DNA damage by solar ultraviolet B (UVB) but also the development of methodologies to provide protection against ultraviolet A (UVA), the oxidising component of sunlight. Furthermore identification of specific cellular events following ultraviolet (UV) irradiation is likely to provide clues as to the mechanism of the development of resulting pathologies and therefore strategies for protection. Our discovery that UVA radiation, leads to an immediate measurable increase in 'labile' iron in human skin fibroblasts and keratinocytes provides a new insight into UVA-induced skin damage, since iron is a catalyst of biological oxidations. The main purpose of this overview is to bring together some of the new findings related to mechanisms underlying UVA-induced iron release and to discuss novel approaches based on the use of multiantioxidants and light-activated caged-iron chelators for efficient protection of skin cells against UVA-induced iron damage.

Investigation of materials for fusion power reactors

NASA Astrophysics Data System (ADS)

Bouhaddane, A.; Slugeň, V.; Sojak, S.; Veterníková, J.; Petriska, M.; Bartošová, I.

2014-06-01

The possibility of application of nuclear-physical methods to observe radiation damage to structural materials of nuclear facilities is nowadays a very actual topic. The radiation damage to materials of advanced nuclear facilities, caused by extreme radiation stress, is a process, which significantly limits their operational life as well as their safety. In the centre of our interest is the study of the radiation degradation and activation of the metals and alloys for the new nuclear facilities (Generation IV fission reactors, fusion reactors ITER and DEMO). The observation of the microstructure changes in the reactor steels is based on experimental investigation using the method of positron annihilation spectroscopy (PAS). The experimental part of the work contains measurements focused on model reactor alloys and ODS steels. There were 12 model reactor steels and 3 ODS steels. We were investigating the influence of chemical composition on the production of defects in crystal lattice. With application of the LT 9 program, the spectra of specimen have been evaluated and the most convenient samples have been determined.

Protective Effects of Resveratrol against UVA-Induced Damage in ARPE19 Cells

PubMed Central

Chan, Chi-Ming; Huang, Cheng-Hua; Li, Hsin-Ju; Hsiao, Chien-Yu; Su, Ching-Chieh; Lee, Pei-Lan; Hung, Chi-Feng

2015-01-01

Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE) cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS) and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD). Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H2O2 induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH2 terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2) expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD. PMID:25775159

Protective effects of resveratrol against UVA-induced damage in ARPE19 cells.

PubMed

Chan, Chi-Ming; Huang, Cheng-Hua; Li, Hsin-Ju; Hsiao, Chien-Yu; Su, Ching-Chieh; Lee, Pei-Lan; Hung, Chi-Feng

2015-03-12

Ultraviolet radiation, especially UVA, can penetrate the lens, reach the retina, and induce oxidative stress to retinal pigment epithelial (RPE) cells. Even though it is weakly absorbed by protein and DNA, it may trigger the production of reactive oxygen species (ROS) and generate oxidative injury; oxidative injury to the retinal pigment epithelium has been implicated to play a contributory role in age-related macular degeneration (AMD). Studies showed that resveratrol, an abundant and active component of red grapes, can protect several cell types from oxidative stress. In this study, adult RPE cells being treated with different concentrations of resveratrol were used to evaluate the protective effect of resveratrol on RPE cells against UVA-induced damage. Cell viability assay showed that resveratrol reduced the UVA-induced decrease in RPE cell viability. Through flow cytometry analysis, we found that the generation of intracellular H2O2 induced by UVA irradiation in RPE cells could be suppressed by resveratrol in a concentration-dependent manner. Results of Western blot analysis demonstrated that resveratrol lowered the activation of UVA-induced extracellular signal-regulated kinase, c-jun-NH2 terminal kinase and p38 kinase in RPE cells. In addition, there was also a reduction in UVA-induced cyclooxygenase-2 (COX-2) expression in RPE cells pretreated with resveratrol. Our observations suggest that resveratrol is effective in preventing RPE cells from being damaged by UVA radiation, and is worth considering for further development as a chemoprotective agent for the prevention of early AMD.

New apparatus with high radiation energy between 320-460 nm: physical description and dermatological applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mutzhas, M.F.; Holzle, E.; Hofmann, C.

1981-01-01

A new apparatus (UVASUN 5000) is presented with high-radiation energy between 320 to 460 nm. The measureable energy below 320 nm was shown to be many orders of magnitude too low to produce erythema. The radiator is a specially developed source for high uv-A intensity, housing a quartz bulb with a mixture of argon, mercury and metal-halides. At a skin-target distance of 0.2 m the size of the irradiated area is 0.35 x 0.35 m, and the measured mean uv-A intensity is about 1400 W. m-2 (140 mW . cm-2). The uv-A energy in the range of 320 to 400more » nm is about 84% of the total radiation energy. Effects of very high doses of uv-A on human skin were studied. Following single uv-a applications the minimal tanning dose uv-A (MTD) and the immediate pigment darkening (IPD) dose of uv-A were established. The calculated IPD threshold time was 1.8 min at 0.2 m. Repeated exposure to this uv-A delivering system yields long lasting dark brown skin pigmentation without any clinical or histological signs of sunburn (uv-B) damage, epidermal hyperplasia or thickening of the stratum corneum. The instrument was also successfully used for photo-patch testing and reproduction of skin lesions of polymorphous light eruption. Minimal therapeutic results were seen in the phototherapy of vitiligo and inflammatory acne.« less

Antagonizing Effects of Aspartic Acid against Ultraviolet A-Induced Downregulation of the Stemness of Human Adipose Tissue-Derived Mesenchymal Stem Cells

PubMed Central

Lee, Jienny; Shin, Seoung Woo; Jang, Sunghee; Jung, Eunsun; Kim, Min Hee; Lee, Jongsung

2015-01-01

Ultraviolet A (UVA) irradiation is responsible for a variety of changes in cell biology. The purpose of this study was to investigate effects of aspartic acid on UVA irradiation-induced damages in the stemness properties of human adipose tissue-derived mesenchymal stem cells (hAMSCs). Furthermore, we elucidated the UVA-antagonizing mechanisms of aspartic acid. The results of this study showed that aspartic acid attenuated the UVA-induced reduction of the proliferative potential and stemness of hAMSCs, as evidenced by increased proliferative activity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and upregulation of stemness-related genes OCT4, NANOG, and SOX2 in response to the aspartic acid treatment. UVA-induced reduction in the mRNA level of hypoxia-inducible factor (HIF)-1α was also significantly recovered by aspartic acid. In addition, the antagonizing effects of aspartic acid against the UVA effects were found to be mediated by reduced production of PGE2 through the inhibition of JNK and p42/44 MAPK. Taken together, these findings show that aspartic acid improves reduced stemness of hAMSCs induced by UVA and its effects are mediated by upregulation of HIF-1α via the inhibition of PGE2-cAMP signaling. In addition, aspartic acid may be used as an antagonizing agent to mitigate the effects of UVA. PMID:25909857

Apoptosis induction is involved in UVA-induced autolysis in sea cucumber Stichopus japonicus.

PubMed

Qi, Hang; Fu, Hui; Dong, Xiufang; Feng, Dingding; Li, Nan; Wen, Chengrong; Nakamura, Yoshimasa; Zhu, Beiwei

2016-05-01

Autolysis easily happens to sea cucumber (Stichopus japonicus, S. japonicus) for external stimulus like UV exposure causing heavy economic losses. Therefore, it is meaningful to reveal the mechanism of S. japonicas autolysis. In the present study, to examine the involvement of apoptosis induction in UVA-induced autolysis of S. japonicas, we investigated the biochemical events including the DNA fragmentation, caspase-3 activation, mitogen-activated protein kinases (MAPKs) phosphorylation and free radical formation. Substantial morphological changes such as intestine vomiting and dermatolysis were observed in S. japonicus during the incubation after 1-h UVA irradiation (10W/m(2)). The degradation of the structural proteins and enhancement of cathepsin L activity were also detected, suggesting the profound impact of proteolysis caused by the UVA irradiation even for 1h. Furthermore, the DNA fragmentation and specific activity of caspase-3 was increased up to 12h after UVA irradiation. The levels of phosphorylated p38 mitogen activated protein kinase (MAPK) and phosphorylated c-Jun.-N-terminal kinase (JNK) were significantly increased by the UVA irradiation for 1h. An electron spin resonance (ESR) analysis revealed that UVA enhanced the free radical formation in S. japonicas, even through we could not identify the attributed species. These results suggest that UVA-induced autolysis in S. japonicas at least partially involves the oxidative stress-sensitive apoptosis induction pathway. These data present a novel insight into the mechanisms of sea cucumber autolysis induced by external stress. Copyright © 2016 Elsevier B.V. All rights reserved.

10 CFR 52.167 - Issuance of manufacturing license.

Code of Federal Regulations, 2010 CFR

2010-01-01

... proposed reactor(s) can be incorporated into a nuclear power plant and operated at sites having... design and manufacture the proposed nuclear power reactor(s); (5) The proposed inspections, tests... the construction of a nuclear power facility using the manufactured reactor(s). (2) A holder of a...

Interior of the Plum Brook Reactor Facility

NASA Image and Video Library

1961-02-21

A view inside the 55-foot high containment vessel of the National Aeronautics and Space Administration (NASA) Plum Brook Reactor Facility in Sandusky, Ohio. The 60-megawatt test reactor went critical for the first time in 1961 and began its full-power research operations in 1963. From 1961 to 1973, this reactor performed some of the nation’s most advanced nuclear research. The reactor was designed to determine the behavior of metals and other materials after long durations of irradiation. The materials would be used to construct a nuclear-powered rocket. The reactor core, where the chain reaction occurred, sat at the bottom of the tubular pressure vessel, seen here at the center of the shielding pool. The core contained fuel rods with uranium isotopes. A cooling system was needed to reduce the heat levels during the reaction. A neutron-impervious reflector was also employed to send many of the neutrons back to the core. The Plum Brook Reactor Facility was constructed from high-density concrete and steel to prevent the excess neutrons from escaping the facility, but the water in the pool shielded most of the radiation. The water, found in three of the four quadrants served as a reflector, moderator, and coolant. In this photograph, the three 20-ton protective shrapnel shields and hatch have been removed from the top of the pressure tank revealing the reactor tank. An overhead crane could be manipulated to reach any section of this room. It was used to remove the shrapnel shields and transfer equipment.

BIOLOGICAL IRRADIATION FACILITY

DOEpatents

McCorkle, W.H.; Cern, H.S.

1962-04-24

A facility for irradiating biological specimens with neutrons is described. It includes a reactor wherein the core is off center in a reflector. A high-exposure room is located outside the reactor on the side nearest the core while a low-exposure room is located on the opposite side. Means for converting thermal neutrons to fast neutrons are movably disposed between the reactor core and the high and low-exposure rooms. (AEC)

Looking Southwest at Reactor Box Furnaces With Reactor Boxes and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking Southwest at Reactor Box Furnaces With Reactor Boxes and Repossessed Uranium in Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

N Reactor Deactivation Program Plan. Revision 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, J.L.

1993-12-01

This N Reactor Deactivation Program Plan is structured to provide the basic methodology required to place N Reactor and supporting facilities {center_dot} in a radiologically and environmentally safe condition such that they can be decommissioned at a later date. Deactivation will be in accordance with facility transfer criteria specified in Department of Energy (DOE) and Westinghouse Hanford Company (WHC) guidance. Transition activities primarily involve shutdown and isolation of operational systems and buildings, radiological/hazardous waste cleanup, N Fuel Basin stabilization and environmental stabilization of the facilities. The N Reactor Deactivation Program covers the period FY 1992 through FY 1997. The directivemore » to cease N Reactor preservation and prepare for decommissioning was issued by DOE to WHC on September 20, 1991. The work year and budget data supporting the Work Breakdown Structure in this document are found in the Activity Data Sheets (ADS) and the Environmental Restoration Program Baseline, that are prepared annually.« less

Characterisation of optical filters for broadband UVA radiometer

NASA Astrophysics Data System (ADS)

Alves, Luciana C.; Coelho, Carla T.; Corrêa, Jaqueline S. P. M.; Menegotto, Thiago; Ferreira da Silva, Thiago; Aparecida de Souza, Muriel; Melo da Silva, Elisama; Simões de Lima, Maurício; Dornelles de Alvarenga, Ana Paula

2016-07-01

Optical filters were characterized in order to know its suitability for use in broadband UVA radiometer head for spectral irradiance measurements. The spectral transmittance, the angular dependence and the spatial uniformity of the spectral transmittance of the UVA optical filters were investigated. The temperature dependence of the transmittance was also studied.

Bioaccumulation and biomagnification of ultraviolet absorbents in marine wildlife of the Pearl River Estuarine, South China Sea.

PubMed

Peng, Xianzhi; Fan, Yujuan; Jin, Jiabin; Xiong, Songsong; Liu, Jun; Tang, Caiming

2017-06-01

Bioaccumulation and trophic transfer in ecosystems is an important criterion for assessing environmental risks of contaminants. This study investigated bioaccumulation and biomagnification of 13 organic ultraviolet absorbents (UVAs) in marine wildlife organisms in the Pearl River Estuary, South China Sea. The UVAs could accumulate in the organisms with biota - sediment accumulation factors (BSAF) of 0.003-2.152. UV531 was the most abundant and showed the highest tendency to accumulate in the organisms with a median BSAF of 1.105. The UVAs demonstrated species - and compound-specific accumulation in the marine organism. Fishes showed significantly higher capability than the cephalopods and crustaceans in accumulation of the UVAs. Habitat did not demonstrate obvious impact on accumulation of the UVA. On the other hand, benzophenone-3, UV328, and UV234 showed significantly higher concentration in the detritus feeding fishes than carnivorous and planktivorous fishes, suggesting governing effect of dietary habits of the organisms on bioaccumulation of these UVAs. Direct uptake from growth media was a significant exposure pathway of the organisms to the UVAs. The estimated trophic magnification factors and biomagnification factors revealed that UV329, UV531, and octocrylene could potentially biomagnify in the marine food web. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultraviolet A irradiation of the eye activates a nitric oxide-dependent hypothalamo-pituitary pro-opiomelanocortin pathway and modulates the functions of Langerhans cells.

PubMed

Hiramoto, Keiichi

2009-06-01

Ultraviolet A (UV-A) radiation decreases Langerhans cells (LC) in the skin specifically at the site of exposure. Unexpectedly, UV-A irradiation of the eye has been found systemically downregulating epidermal LC in mice. Male C57BL/6j mice and an inducible type of nitric oxide synthase knockout mice (iNOS(-/-)) were used in this study. The eye or ear was locally exposed to UV-A after covering the remaining body surface with aluminum foil at a dose of 110 kJ/m(2) using a sunlamp. Localized UV-A irradiation of the eye downregulated epidermal LC. The hypophysectomy strongly inhibited the UV-A-induced downregulation of LC. To elucidate the pathway by UV-A irradiation of the eye, the effect of a bilateral ciliary ganglionectomy and denervation of the optic nerves was examined. Optic nerve denervation strongly inhibited LC downregulation in response to localized irradiation of the eye. Furthermore, no LC downregulation in response to localized UV-A irradiation of the eye was observed in iNOS(-/-) mice. These results clearly indicate that a signal evoked by UV-A irradiation of the eye is transmitted in a nitric oxide-dependent manner through the optic nerves to the hypothalamo-pituitary pro-opiomelanocortin system.

Epidemiologic evidence for different roles of ultraviolet A and B radiation in melanoma mortality rates.

PubMed

Garland, Cedric F; Garland, Frank C; Gorham, Edward D

2003-07-01

The action spectrum of ultraviolet radiation mainly responsible for melanoma induction is unknown, but evidence suggests it could be ultraviolet A (UVA), which has a different geographic distribution than ultraviolet B (UVB). This study assessed whether melanoma mortality rates are more closely related to the global distribution of UVA or UVB. UVA and UVB radiation and age-adjusted melanoma mortality rates were obtained for all 45 countries reporting cancer data to the World Health Organization. Stratospheric ozone data were obtained from NASA satellites. Average population skin pigmentation was obtained from skin reflectometry measurements. Paradoxically, melanoma mortality rates decreased with increasing UVB in men (r = -0.48, p < 0.001), and women (r = -0.57, p < 0.001), and with increasing UVA in both sexes. By contrast, rates were positively associated with increasing UVA/UVB ratio in men (r = + 0.49, p < 0.001) and women (r = + 0.55, p < 0.001). After multiple adjustment that included controlling for skin pigmentation, only UVA was associated with melanoma mortality rates in men (p < 0.02) with a suggestive but non-significant trend present in women (p = 0.12). UVA radiation was associated with melanoma mortality rates after controlling for UVB and average pigmentation. The results require confirmation in observational studies.

Photogenotoxicity of hypericin in HaCaT keratinocytes: implications for St. John's Wort supplements and high dose UVA-1 therapy.

PubMed

Traynor, N J; Beattie, P E; Ibbotson, S H; Moseley, H; Ferguson, J; Woods, J A

2005-09-15

Extract of St. John's Wort (Hypericum perforatum) is commonly used as natural remedy for treatment of mild to moderate depression. However, it contains a powerful photoactive component, hypericin, which can cause a severe photodermatitis when eaten by grazing animals (hypericism). In humans, there is evidence that supplementation with St. John's Wort can reduce the minimal erythemal dose (MED) in patients undergoing high dose UVA-1 phototherapy. This is a recent development in phototherapy where the most erythemogenic parts of the UVA spectrum are filtered out, allowing delivery of higher doses of the longer wavelengths of UVA. Although current published evidence suggests that the plasma levels of hypericin are unlikely to cause clinical phototoxicity, it has been established that photoactive compounds can cause DNA damage at sub-toxic and sub-erythemal doses, the effects of which might not be apparent for many years after the event. The present study used HaCaT keratinocytes to investigate the photoclastogenic ability of hypericin on irradiation with UVA. The results show that although the combination of hypericin and UVA light increased the genotoxic burden, when all factors are taken into account, the risk of significant photogenotoxic damage incurred by the combination of Hypericum extracts and UVA phototherapy may be low in the majority of individuals.

UVA radiation impairs phenotypic and functional maturation of human dermal dendritic cells.

PubMed

Furio, Laetitia; Berthier-Vergnes, Odile; Ducarre, Blandine; Schmitt, Daniel; Peguet-Navarro, Josette

2005-11-01

There is now strong evidence that the ultraviolet A (UVA) part of the solar spectrum contributes to the development of skin cancers. Its effect on the skin immune system, however, has not been fully investigated. Here, we analyzed the effects of UVA radiation on dermal dendritic cells (DDC), which, in addition, provided further characterization of these cells. Dermal sheets were obtained from normal human skin and irradiated, or not, with UVA at 2 or 12 J per cm2. After a 2 d incubation, the phenotype of emigrant cells was analyzed by double immunostaining and flow cytometry. Results showed that migratory DDC were best characterized by CD1c expression and that only few cells co-expressed the Langerhans cell marker Langerin. Whereas the DC extracted from the dermis displayed an immature phenotype, emigrant DDC showed increased expression of HLA-DR and acquired co-stimulation and maturation markers. We showed here that UVA significantly decreased the number of viable emigrant DDC, a process related to increased apoptosis. Furthermore, UVA irradiation impaired the phenotypic and functional maturation of migrating DDC into potent antigen-presenting cells, in a concentration-dependent manner. The results provide further evidence that UVA are immunosuppressive and suggest an additional mechanism by which solar radiation impairs immune response.

The notochord curvature in medaka (Oryzias latipes) embryos as a response to ultraviolet A irradiation.

PubMed

Sayed, Alaa El-Din Hamid; Mitani, Hiroshi

2016-11-01

In the present work, the destructive effects of ultraviolet A (UVA; 366nm) irradiation on the developmental stages of Japanese medaka (Oryzias latipes) are revealed in terms of hatching success, mortality rate, and morphological malformations (yolk sac edema, body curvature, fin blistering, and dwarfism). Fertilized eggs in stage 4 were exposed to 15, 30, and 60min/day UVA for 3days in replicates. Fish were staged and aged following the stages established by Iwamatsu [1]. We observed and recorded the hatching time and deformed and dead embryos continuously. The hatching time was prolonged and the deformed and dead embryos numbers were increased by UVA dose increase. At stage 40, samples from each group were fixed to investigate their morphology and histopathology. Some morphological malformations were recorded after UVA exposure in both strains. Histopathological changes were represented as different shapes of curvature in notochord with collapse. The degree of collapsation was depended on the dose and time of UVA exposure. Our findings show that exposure to UVA irradiation caused less vertebral column curvature in medaka fry. Moreover, p53-deficient embryos were more tolerant than those of wild-type (Hd-rR) Japanese medaka. This study indicated the dangerous effects of the UVA on medaka. Copyright © 2016 Elsevier B.V. All rights reserved.

Keratinocyte Motility Is Affected by UVA Radiation-A Comparison between Normal and Dysplastic Cells.

PubMed

Niculiţe, Cristina M; Nechifor, Marina T; Urs, Andreea O; Olariu, Laura; Ceafalan, Laura C; Leabu, Mircea

2018-06-07

UVA radiation induces multiple and complex changes in the skin, affecting epidermal cell behavior. This study reports the effects of UVA exposure on normal (HaCaT) and dysplastic (DOK) keratinocytes. The adherence, spreading and proliferation were investigated by time-lapse measurement of cell layer impedance on different matrix proteins. Prior to UVA exposure, the time required for adherence and spreading did not differ significantly for HaCaT and DOK cells, while spreading areas were larger for HaCaT cells. Under UVA exposure, HaCaT and DOK cells behavior differed in terms of movement and proliferation. The cells' ability to cover the denuded surface and individual cell trajectories were recorded by time-lapse videomicroscopy, during wound healing experiments. Dysplastic keratinocytes showed more sensitivity to UVA, exhibiting transient deficiencies in directionality of movement and a delay in re-coating the denuded area. The actin cytoskeleton displayed a cortical organization immediately after irradiation, in both cell lines, similar to mock-irradiated cells. Post-irradiation, DOK cells displayed a better organization of stress fibers, persistent filopodia, and new, stronger focal contacts. In conclusion, after UVA exposure HaCaT and DOK cells showed a different behavior in terms of adherence, spreading, motility, proliferation, and actin cytoskeleton dynamics, with the dyplastic keratinocytes being more sensitive.

Phototoxic effects of PAH and UVA exposure on molecular responses and developmental success in coral larvae.

PubMed

Overmans, Sebastian; Nordborg, Mikaela; Díaz-Rúa, Rubén; Brinkman, Diane L; Negri, Andrew P; Agustí, Susana

2018-05-01

Exposure to polycyclic aromatic carbons (PAHs) poses a growing risk to coral reefs due to increasing shipping and petroleum extraction in tropical waters. Damaging effects of specific PAHs can be further enhanced by the presence of ultraviolet radiation, known as phototoxicity. We tested phototoxic effects of the PAHs anthracene and phenanthrene on larvae of the scleractinian coral Acropora tenuis in the presence and absence of UVA (320-400 nm). Activity of superoxide dismutase (SOD) enzyme was reduced by anthracene while phenanthrene and UVA exposure did not have any effect. Gene expression of MnSod remained constant across all treatments. The genes Catalase, Hsp70 and Hsp90 showed increased expression levels in larvae exposed to anthracene, but not phenanthrene. Gene expression of p53 was upregulated in the presence of UVA, but downregulated when exposed to PAHs. The influence on stress-related biochemical pathways and gene expresson in A. tenuis larvae was considerably greater for anthracene than phenanthrene, and UVA-induced phototoxicity was only evident for anthracene. The combined effects of UVA and PAH exposure on larval survival and metamorphosis paralleled the sub-lethal stress responses, clearly highlighting the interaction of UVA on anthracene toxicity and ultimately the coral's development. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

ETR CRITICAL FACILITY, TRA654. SCIENTISTS STAND AT EDGE OF TANK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR CRITICAL FACILITY, TRA-654. SCIENTISTS STAND AT EDGE OF TANK AND LIFT REMOVABLE BRIDGE ABOVE THE REACTOR. CONTROL RODS AND FUEL RODS ARE BELOW ENOUGH WATER TO SHIELD WORKERS ABOVE. NOTE CRANE RAILS ALONG WALLS, PUMICE BLOCK WALLS. INL NEGATIVE NO. 57-3690. R.G. Larsen, Photographer, 7/29/1957 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Responses of Crepis japonica induced by supplemental blue light and UV-A radiation.

PubMed

Constantino, L F da S; Nascimento, L B Dos S; Casanova, L M; Moreira, N Dos S; Menezes, E A; Esteves, R L; Costa, S S; Tavares, E S

2017-02-15

Crepis japonica (L.) D.C. (Asteraceae), a weed with antioxidant, antiallergenic, antiviral and antitumor properties displays both medicinal properties and nutritional value. This study aims to assess the effects of a supplementation of blue light and UV-A radiation on the growth, leaf anatomical structure and phenolic profile of the aerial parts of Crepis japonica. Plants were grown under two light treatments: W (control - white light), W + B (white light supplemented with blue light) and W + UV-A (white light supplemented with UV-A radiation). We recorded the length, width, and weight of fresh and dry leaves, the thickness of the epidermis and mesophyll, and stomata density. The phenolic profiles of the aqueous extracts of the aerial parts were analyzed by HPLC-DAD. There was an increase in the leaf size, stomatal density, and phenolic production, and a thickening of the mesophyll and epidermis. UV-A radiation increased the phenolic production more than blue light. Blue light and UV-A radiation both improved the production of caffeic acid by about 6 and 3 times, respectively, in comparison to control. This compound was first reported as a constituent of the extract from the aerial parts together with caftaric acid. UV-A also promoted the production of chlorogenic acid (about 1.5 times in comparison to the control). We observed that the morphological and chemical parameters of C. japonica are modified in response to blue light and UV-A radiation, which can be used as tools in the cultivation of this species in order to improve its medicinal properties and nutritional value.

Autocrine Regulation of UVA-Induced IL-6 Production via Release of ATP and Activation of P2Y Receptors

PubMed Central

Kawano, Ayumi; Kadomatsu, Remi; Ono, Miyu; Kojima, Shuji; Tsukimoto, Mitsutoshi; Sakamoto, Hikaru

2015-01-01

Extracellular nucleotides, such as ATP, are released from cells in response to various stimuli and act as intercellular signaling molecules through activation of P2 receptors. Exposure to the ultraviolet radiation A (UVA) component of sunlight causes molecular and cellular damage, and in this study, we investigated the involvement of extracellular nucleotides and P2 receptors in the UVA-induced cellular response. Human keratinocyte-derived HaCaT cells were irradiated with a single dose of UVA (2.5 J/cm2), and ATP release and interleukin (IL)-6 production were measured. ATP was released from cells in response to UVA irradiation, and the release was blocked by pretreatment with inhibitors of gap junction hemichannels or P2X7 receptor antagonist. IL-6 production was increased after UVA irradiation, and this increase was inhibited by ecto-nucleotidase or by antagonists of P2Y11 or P2Y13 receptor. These results suggest that UVA-induced IL-6 production is mediated by release of ATP through hemichannels and P2X7 receptor, followed by activation of P2Y11 and P2Y13 receptors. Interestingly, P2Y11 and P2Y13 were associated with the same pattern of IL-6 production, though they trigger different intracellular signaling cascades: Ca2+-dependent and PI3K-dependent, respectively. Thus, IL-6 production in response to UVA-induced ATP release involves at least two distinct pathways, mediated by activation of P2Y11 and P2Y13 receptors. PMID:26030257

The chromene sargachromanol E inhibits ultraviolet A-induced ageing of skin in human dermal fibroblasts.

PubMed

Kim, J-A; Ahn, B-N; Kong, C-S; Kim, S-K

2013-05-01

Skin ageing is influenced by environmental factors such as ultraviolet (UV) radiation. The effects of UV radiation on skin functions should be investigated using human in vitro models to understand the mechanisms of skin ageing. Additionally, marine algae provide a valuable source for identifying and extracting biologically active substances. In this study, sargachromanol E was isolated from a marine brown alga, Sargassum horneri, and its inhibitory effect on skin ageing was investigated using UVA-irradiated dermal fibroblasts. Formation of intracellular reactive oxygen species (ROS), lipid peroxidation and protein oxidation induced by UVA irradiation were investigated in UVA-irradiated human dermal fibroblasts. The levels of matrix metalloproteinases (MMPs) were determined by reverse-transcriptase polymerase chain reaction and Western blot analysis. Sargachromanol E did not exhibit any significant cytotoxicity or phototoxicity in UVA-exposed dermal fibroblasts. Additionally, sargachromanol E suppressed intracellular formation of ROS, membrane protein oxidation, lipid peroxidation and expression of collagenases such as MMP-1, MMP-2 and MMP-9, all of which are caused by UVA exposure. It was further found that these inhibitions were related to an increase in the expression of the tissue inhibitor of metalloproteinase (TIMP) genes, TIMP1 and TIMP2. Moreover, we have shown that the transcriptional activation of activator protein 1 (AP-1) signalling caused by UVA irradiation was inhibited by treatment with sargachromanol E. This study suggests that UVA irradiation modulates MMP expression via the transcriptional activation of AP-1 signalling, whereas treatment with sargachromanol E protected cell damage caused by UVA irradiation. © 2013 The Authors. BJD © 2013 British Association of Dermatologists.

Total Dose Effects of Ionizing and Non-Ionizing Radiation on Piezoresistive Pressure Transducer Chips

DTIC Science & Technology

2003-03-01

facility and Mr. Joseph Talnagi of the Ohio State Research Reactor facility for their personal guidance and insight into reactor dosimetry and neutron...62 Test C1: Dosimetry ..................................................................................................... 63 Special...66 Annex A-3. Preliminary Dosimetry Calculations

Looking Northeast in Oxide Building at Reactors on Second Floor ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking Northeast in Oxide Building at Reactors on Second Floor Including Reactor One (Left) and Reactor Two (Right) - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

Neutron scattering facilities at Chalk River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holden, T.M.; Powell, B.M.; Dolling, G.

1995-12-31

The Chalk River Laboratories of AECL Research provides neutron beams for research with the NRU reactor. The NRU reactor has eight reactor loops for engineering test experiments, 30 isotope irradiation sites and beam tubes, six of which feed the neutron scattering instruments. The peak thermal flux is 3 {times} 10{sup 14}n cm{sup {minus}2} s{sup {minus}1}. The neutron spectrometers are operated as national facilities for Canadian neutron scattering research. Since the research requirements for the Canadian nuclear industry are changing, and since the NRU reactor is unlikely to operate much beyond the year 2000, a new Irradiation Research Facility (IRF) ismore » being considered for start-up in the first decade of the next century. An outline is given of this proposed new neutron source.« less

Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quesada, A.; Mouget, J.L.; Vincent, W.F.

A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect wasmore » dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs.« less

A new photocatalytic reactor for trace contaminant control: a water polishing system.

PubMed

Gonzalez-Martin, A; Kim, J; Van Hyfte, J; Rutherford, L A; Andrews, C

2001-01-01

In spacecraft water recovery systems there is a need to develop a postprocessor water polishing system to remove organic impurities to levels below 250 micrograms/L (ppb) with a minimum use of expendables. This article addresses the development of a photocatalytic process as a postprocessor water polishing system that is microgravity compatible, operates at room temperature, and requires only a minimal use of both oxygen gas (or air) and electrical power for low energy UV-A (315-400 nm) lamps. In the photocatalytic process, organic contaminants are degraded to benign end products on semiconductor surfaces, usually TiO2. Some challenging issues related to the use of TiO2 for the degradation of organic contaminants have been addressed. These include: i) efficient and stable catalytic material; ii) immobilization of the catalyst to produce a high surface area material that can be used in packed-bed reactors, iii) effective light penetration, iv) effective, microgravity-compatible, oxidant delivery; v) reduced pressure drop, and vi) minimum retention time. The research and development performed on this photocatalytic process is presented in detail. Grant numbers: NAS9-97182.

Enhancing the Understanding of Marine Ecosystems through Teleducation and Field Experiences

NASA Astrophysics Data System (ADS)

Macko, S.

2006-12-01

This project is an outreach and education program with a partner in the K-12 schools at Accomack County on the Eastern Shore of Virginia. It endeavors to build a community more knowledgeable of the importance the ocean plays daily in our lives, and our own impact on the ocean. It is an program built in stages that: 1) Establish high speed teleducation linkages with Eastern Shore of Virginia High Schools, for live interactive, classes (teleducation) for earth science teachers enabling them to remotely participate in University of Virginia classes in Oceanography (designed on a faculty development basis or acquire NSTA certification in Earth Science Education, as well as participation by seniors in the Accomack Schools; 2) Establish field experiences for teachers and selected students that involve travel to both the Virginia Coast Reserve Long Term Ecological Research (VCR/LTER) Center, UVA and the NOAA Beaufort, NC Laboratory to observe first- hand the science programs at those locations and participate in cutting edge coastal marine research efforts. These experiences will not only improve student understanding of the ocean-atmosphere biogeophysical system, but also encourage students to explore the sciences as a field of study and possible vocation. Advanced high school students and science teachers from Accomack County Public Schools participated in an experience involving field and laboratory methods employed in a NSF-sponsored study of the coupled natural-human dynamics on the Eastern Shore of Virginia over the past 500 years (NSF-Biocomplexity). Students and teachers worked with researchers of the VCR facility in Oyster, VA, collected sediment cores from Chesapeake Bay tributaries, and traveled to the Organic Geochemistry Laboratory at UVA, in Charlottesville, VA to prepare and analyze samples for isotopic and palynological information. In a first of its kind connectivity, in June/July, 2006, using high speed internet connections, a summer class in Oceanography was live, interactively broadcast (teleducation) from UVA to Arcadia High School on the Eastern Shore, allowing teachers in the Accomack School district to receive university credit without leaving their home classrooms 250 miles from UVA.

A Blueprint for GNEP Advanced Burner Reactor Startup Fuel Fabrication Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. Khericha

2010-12-01

The purpose of this article is to identify the requirements and issues associated with design of GNEP Advanced Burner Reactor Fuel Facility. The report was prepared in support of providing data for preparation of a NEPA Environmental Impact Statement in support the U. S. Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP). One of the GNEP objectives was to reduce the inventory of long lived actinide from the light water reactor (LWR) spent fuel. The LWR spent fuel contains Plutonium (Pu) -239 and other transuranics (TRU) such as Americium-241. One of the options is to transmute or burn thesemore » actinides in fast neutron spectra as well as generate the electricity. A sodium-cooled Advanced Recycling Reactor (ARR) concept was proposed to achieve this goal. However, fuel with relatively high TRU content has not been used in the fast reactor. To demonstrate the utilization of TRU fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype of ARR was proposed, which would necessarily be started up using weapons grade (WG) Pu fuel. The WG Pu is distinguished by relatively highest proportions of Pu-239 and lesser amount of other actinides. The WG Pu was assumed to be used as the startup fuel along with TRU fuel in lead test assemblies. Because such fuel is not currently being produced in the US, a new facility (or new capability in an existing facility) was being considered for fabrication of WG Pu fuel for the ABR. It was estimated that the facility will provide the startup fuel for 10-15 years and would take 3 to 5 years to construct.« less

UVA-potentiated damage to calf thymus DNA by Fenton reaction system and protection by para-aminobenzoic acid.

PubMed

Shih, M K; Hu, M L

1996-03-01

Calf thymus DNA was irradiated with low-intensity UVA (main output at 365 nm, 2 mW cm-2 or 36 kJ m-2 for 30 min), and the role of metal ions, hydrogen peroxide and reactive oxygen species (ROS) was examined. DNA damage was measured as thiobarbituric acid-reactive substances (possibly from degradation of deoxyribose) and as changes in ethidium bromide-DNA fluorescence due to unwinding from strand breaks. Under the present experimental conditions, UVA alone or in the presence of H2O2 had no effect on DNA but slightly enhanced the damage by iron/EDTA. Ultraviolet A strongly enhanced DNA damage (ca four- to five-fold) by the Fenton reaction system (50 microM Fe2+/100 microM EDTA + 0.5 mM H2O2). The results suggest that the Fenton reaction system was "photosensitized" to damage DNA by low-intensity UVA radiation. The enhanced damage by UVA was attributed in part to the reduction of Fe3+ to Fe2+. Ultraviolet A had no effect when iron (ferric or ferrous) ions were replaced by Cu2+, Zn2+, Mn2+ or Cd2+. The ROS involved in the UVA-enhanced damage to DNA by the Fenton reagents were OH and, to a lesser extent, superoxide anions. The UVA-potentiated DNA damage by the Fenton reaction system was then used to examine the protective effect of para-aminobenzoate (PABA), a UVB-absorbing sunscreen that protects against photocarcinogenesis in hairless mice. The results show that PABA and mannitol dose-dependently inhibited the damage with concentrations required for 50% inhibition at 0.1 mM and 3 mM, respectively. The protection by PABA was attributed to its radical-scavenging ability because PABA does not absorb light in the UVA region. These findings may be relevant to the biological damage by UVA and suggest that PABA is useful in protection against photocarcinogenesis by wide-range UV radiation.

The risk of hydroquinone and sunscreen over-absorption via photodamaged skin is not greater in senescent skin as compared to young skin: nude mouse as an animal model.

PubMed

Hung, Chi-Feng; Chen, Wei-Yu; Aljuffali, Ibrahim A; Shih, Hui-Chi; Fang, Jia-You

2014-08-25

Intrinsic aging and photoaging modify skin structure and components, which subsequently change percutaneous absorption of topically applied permeants. The purpose of this study was to systematically evaluate drug/sunscreen permeation via young and senescent skin irradiated by ultraviolet (UV) light. Both young and senescent nude mice were subjected to UVA (10 J/cm(2)) and/or UVB radiation (175 mJ/cm(2)). Physiological parameters, immunohistology, and immunoblotting were employed to examine the aged skin. Hydroquinone and sunscreen permeation was determined by in vitro Franz cell. In vivo skin absorption was documented using a hydrophilic dye, rhodamine 123 (log P=-0.4), as a permeant. UVA exposure induced cyclooxygenase (COX)-2 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) upregulation. Epidermal tight junction (TJ) were degraded by UVA. UVB increased transepidermal water loss (TEWL) from 13 to 24 g/m(2)/h. Hyperplasia and inflammation, but not loss of TJ, were also observed in UVB-treated skin. UVA+UVB- and UVA-irradiated skin demonstrated similar changes in histology and biomarkers. UVA+UVB or UVA exposure increased hydroquinone flux five-fold. A negligible alteration of hydroquinone permeation was shown with UVB exposure. Hydroquinone exhibited a lower penetration through senescent skin than young skin. Both UVA and UVB produced enhancement of oxybenzone flux and skin uptake. However, the amount of increase was less than that of hydroquinone delivery. Photoaging did not augment skin absorption of sunscreens with higher lipophilicity, including avobenzone and ZnO. Exposure to UVA generally increased follicular entrance of these permeants, which showed two- to three-fold greater follicular uptake compared to the untreated group. Photoaging had less impact on drug/sunscreen absorption with more lipophilic permeants. Percutaneous absorption did not increase in skin subjected to both intrinsic and extrinsic aging. Copyright © 2014 Elsevier B.V. All rights reserved.

Space Nuclear Facility test capability at the Baikal-1 and IGR sites Semipalatinsk-21, Kazakhstan

NASA Astrophysics Data System (ADS)

Hill, T. J.; Stanley, M. L.; Martinell, J. S.

1993-01-01

The International Space Technology Assessment Program was established 1/19/92 to take advantage of the availability of Russian space technology and hardware. DOE had two delegations visit CIS and assess its space nuclear power and propulsion technologies. The visit coincided with the Conference on Nuclear Power Engineering in Space Nuclear Rocket Engines at Semipalatinsk-21 (Kurchatov, Kazakhstan) on Sept. 22-25, 1992. Reactor facilities assessed in Semipalatinski-21 included the IVG-1 reactor (a nuclear furnace, which has been modified and now called IVG-1M), the RA reactor, and the Impulse Graphite Reactor (IGR), the CIS version of TREAT. Although the reactor facilities are being maintained satisfactorily, the support infrastructure appears to be degrading. The group assessment is based on two half-day tours of the Baikals-1 test facility and a brief (2 hr) tour of IGR; because of limited time and the large size of the tour group, it was impossible to obtain answers to all prepared questions. Potential benefit is that CIS fuels and facilities may permit USA to conduct a lower priced space nuclear propulsion program while achieving higher performance capability faster, and immediate access to test facilities that cannot be available in this country for 5 years. Information needs to be obtained about available data acquisition capability, accuracy, frequency response, and number of channels. Potential areas of interest with broad application in the U.S. nuclear industry are listed.

NNSA B-Roll: MOX Facility

ScienceCinema

None

2017-12-09

In 1999, the National Nuclear Security Administration (NNSA) signed a contract with a consortium, now called Shaw AREVA MOX Services, LLC to design, build, and operate a Mixed Oxide (MOX) Fuel Fabrication Facility. This facility will be a major component in the United States program to dispose of surplus weapon-grade plutonium. The facility will take surplus weapon-grade plutonium, remove impurities, and mix it with uranium oxide to form MOX fuel pellets for reactor fuel assemblies. These assemblies will be irradiated in commercial nuclear power reactors.

NNSA B-Roll: MOX Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-05-21

In 1999, the National Nuclear Security Administration (NNSA) signed a contract with a consortium, now called Shaw AREVA MOX Services, LLC to design, build, and operate a Mixed Oxide (MOX) Fuel Fabrication Facility. This facility will be a major component in the United States program to dispose of surplus weapon-grade plutonium. The facility will take surplus weapon-grade plutonium, remove impurities, and mix it with uranium oxide to form MOX fuel pellets for reactor fuel assemblies. These assemblies will be irradiated in commercial nuclear power reactors.

DESIGN CRITERIA FOR HIGH TEMPERATURE LATTICE TEST REACTOR PROJECT CAH-100

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballard, D.L.; Brown, W.W.; Harrison, C.W.

Design and construction specifications to be followed in the development of the reactor, its associated systems and experimental facilities, and the housing and required services for the facility are presented. The testing procedures to be used are outlined. (D.C.W.)

Classification of Reactor Facility Operational State Using SPRT Methods with Radiation Sensor Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramirez Aviles, Camila A.; Rao, Nageswara S.

We consider the problem of inferring the operational state of a reactor facility by using measurements from a radiation sensor network, which is deployed around the facility’s ventilation stack. The radiation emissions from the stack decay with distance, and the corresponding measurements are inherently random with parameters determined by radiation intensity levels at the sensor locations. We fuse measurements from network sensors to estimate the intensity at the stack, and use this estimate in a one-sided Sequential Probability Ratio Test (SPRT) to infer the on/off state of the reactor facility. We demonstrate the superior performance of this method over conventionalmore » majority vote fusers and individual sensors using (i) test measurements from a network of NaI sensors, and (ii) emulated measurements using radioactive effluents collected at a reactor facility stack. We analytically quantify the performance improvements of individual sensors and their networks with adaptive thresholds over those with fixed ones, by using the packing number of the radiation intensity space.« less

Mass tracking and material accounting in the integral fast reactor (IFR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orechwa, Y.; Adams, C.H.; White, A.M.

1991-01-01

This paper reports on the Integral Fast Reactor (IFR) which is a generic advanced liquid metal cooled reactor concept being developed at Argonne National Laboratory. There are a number of technical features of the IFR which contribute to its potential as a next-generation reactor. These are associated with large safety margins with regard to off-normal events involving the heat transport system, and the use of metallic fuel which makes possible the utilization of innovative fuel cycle processes. The latter feature permits fuel cycle closure with compact, low-cost reprocessing facilities, collocated with the reactor plant. These primary features are being demonstratedmore » in the facilities at ANL-West, utilizing Experimental Breeder Reactor II and the associated Fuel Cycle Facility (FCF) as an IFR prototype. The demonstration of this IFR prototype includes the design and implementation of the Mass-tracking System (MTG). In this system, data from the operations of the FCF, including weights and batch-process parameters, are collected and maintained by the MTG running on distributed workstations.« less

POWER-BURST FACILITY (PBF) CONCEPTUAL DESIGN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wasserman, A.A.; Johnson, S.O.; Heffner, R.E.

1963-06-21

A description is presented of the conceptual design of a high- performance, pulsed reactor called the Power Burst Facility (PBF). This reactor is designed to generate power bursts with initial asymptotic periods as short as 1 msec, producing energy releases large enough to destroy entire fuel subassemblies placed in a capsule or flow loop mounted in the reactor, all without damage to the reactor itself. It will be used primarily to evaluate the consequences and hazards of very rapid destructive accidents in reactors representing the entire range of current nuclear technology as applied to power generation, propulsion, and testing. Itmore » will also be used to carry out detailed studies of nondestructive reactivity feedback mechanisms in the shortperiod domain. The facility was designed to be sufficiently flexible to accommodate future cores of even more advanced design. The design for the first reactor core is based upon proven technology; hence, completion of the final design of this core will involve no significant development delays. Construction of the PBF is proposed to begin in September 1984, and is expected to take approximately 20 months to complete. (auth)« less

The global response of Nostoc punctiforme ATCC 29133 to UVA stress, assessed in a temporal DNA microarray study.

PubMed

Soule, Tanya; Gao, Qunjie; Stout, Valerie; Garcia-Pichel, Ferran

2013-01-01

Cyanobacteria in nature are exposed not only to the visible spectrum of sunlight but also to its harmful ultraviolet components (UVA and UVB). We used Nostoc punctiforme ATCC 29133 as a model to study the UVA response by analyzing global gene expression patterns using genomic microarrays. UVA exposure resulted in the statistically detectable differential expression of 573 genes of the 6903 that were probed, compared with that of the control cultures. Of those genes, 473 were up-regulated, while only 100 were down-regulated. Many of the down-regulated genes were involved in photosynthetic pigment biosynthesis, indicating a significant shift in this metabolism. As expected, we detected the up-regulation of genes encoding antioxidant enzymes and the sunscreen, scytonemin. However, a majority of the up-regulated genes, 47%, were unassignable bioinformatically to known functional categories, suggesting that the UVA stress response is not well understood. Interestingly, the most dramatic up-regulation involved several contiguous genes of unassigned metabolism on plasmid A. This is the first global UVA stress response analysis of any phototrophic microorganism and the differential expression of 8% of the genes of the Nostoc genome indicates that adaptation to UVA in Nostoc has been an evolutionary force of significance. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Ultraviolet A eye irradiation ameliorates colon carcinoma induced by azoxymethane and dextran sodium sulfate through β-endorphin and methionine-enkephalin.

PubMed

Hiramoto, Keiichi; Yokoyama, Satoshi; Yamate, Yurika

2017-03-01

We previously reported that ultraviolet (UV) A eye irradiation reduces the ulcerative colitis induced by dextran sodium sulfate (DSS). This study examined the effects of UVA on colon carcinoma induced by azoxymethane (AOM) and DSS. We irradiated the eyes of ICR mice with UVA at a dose of 110 kJ/m 2 using an FL20SBLB-A lamp for the experimental period. In mice treated with these drugs, the symptom of colon carcinoma was reduced by UVA eye irradiation. The levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in the blood were increased in AOM + DSS-treated mice; however, those levels were reduced by UVA eye irradiation. The expression of β-endorphin, methionine-enkephalin (OGF), μ-opioid receptor, and opioid growth factor receptor (OGFR) of the colon was increased in the AOM + DSS-treated mice, and these levels were increased further following UVA eye irradiation. When β-endorphin inhibitor was administered, the ameliorative effect of UVA eye irradiation was reduced, and the effect of eye irradiation disappeared entirely following the administration of naltrexone (inhibitor of both opioid receptor and OGFR). These results suggested that UVA eye irradiation exerts major effects on AOM + DSS-induced colon carcinoma. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

UVA, UVB Light, and Methyl Jasmonate, Alone or Combined, Redirect the Biosynthesis of Glucosinolates, Phenolics, Carotenoids, and Chlorophylls in Broccoli Sprouts

PubMed Central

Moreira-Rodríguez, Melissa; Benavides, Jorge

2017-01-01

Broccoli sprouts contain health-promoting phytochemicals that can be enhanced by applying ultraviolet light (UV) or phytohormones. The separate and combined effects of methyl jasmonate (MJ), UVA, or UVB lights on glucosinolate, phenolic, carotenoid, and chlorophyll profiles were assessed in broccoli sprouts. Seven-day-old broccoli sprouts were exposed to UVA (9.47 W/m2) or UVB (7.16 W/m2) radiation for 120 min alone or in combination with a 25 µM MJ solution, also applied to sprouts without UV supplementation. UVA + MJ and UVB + MJ treatments increased the total glucosinolate content by ~154% and ~148%, respectively. MJ induced the biosynthesis of indole glucosinolates, especially neoglucobrassicin (~538%), showing a synergistic effect with UVA stress. UVB increased the content of aliphatic and indole glucosinolates, such as glucoraphanin (~78%) and 4-methoxy-glucobrassicin (~177%). UVA increased several phenolics such as gallic acid (~57%) and a kaempferol glucoside (~25.4%). MJ treatment decreased most phenolic levels but greatly induced accumulation of 5-sinapoylquinic acid (~239%). MJ treatments also reduced carotenoid and chlorophyll content, while UVA increased lutein (~23%), chlorophyll b (~31%), neoxanthin (~34%), and chlorophyll a (~67%). Results indicated that UV- and/or MJ-treated broccoli sprouts redirect the carbon flux to the biosynthesis of specific glucosinolates, phenolics, carotenoids, and chlorophylls depending on the type of stress applied. PMID:29113068

UVA, UVB Light, and Methyl Jasmonate, Alone or Combined, Redirect the Biosynthesis of Glucosinolates, Phenolics, Carotenoids, and Chlorophylls in Broccoli Sprouts.

PubMed

Moreira-Rodríguez, Melissa; Nair, Vimal; Benavides, Jorge; Cisneros-Zevallos, Luis; Jacobo-Velázquez, Daniel A

2017-11-04

Broccoli sprouts contain health-promoting phytochemicals that can be enhanced by applying ultraviolet light (UV) or phytohormones. The separate and combined effects of methyl jasmonate (MJ), UVA, or UVB lights on glucosinolate, phenolic, carotenoid, and chlorophyll profiles were assessed in broccoli sprouts. Seven-day-old broccoli sprouts were exposed to UVA (9.47 W/m²) or UVB (7.16 W/m²) radiation for 120 min alone or in combination with a 25 µM MJ solution, also applied to sprouts without UV supplementation. UVA + MJ and UVB + MJ treatments increased the total glucosinolate content by ~154% and ~148%, respectively. MJ induced the biosynthesis of indole glucosinolates, especially neoglucobrassicin (~538%), showing a synergistic effect with UVA stress. UVB increased the content of aliphatic and indole glucosinolates, such as glucoraphanin (~78%) and 4-methoxy-glucobrassicin (~177%). UVA increased several phenolics such as gallic acid (~57%) and a kaempferol glucoside (~25.4%). MJ treatment decreased most phenolic levels but greatly induced accumulation of 5-sinapoylquinic acid (~239%). MJ treatments also reduced carotenoid and chlorophyll content, while UVA increased lutein (~23%), chlorophyll b (~31%), neoxanthin (~34%), and chlorophyll a (~67%). Results indicated that UV- and/or MJ-treated broccoli sprouts redirect the carbon flux to the biosynthesis of specific glucosinolates, phenolics, carotenoids, and chlorophylls depending on the type of stress applied.

Effects of cloudiness on global and diffuse UV irradiance in a high-mountain area

NASA Astrophysics Data System (ADS)

Blumthaler, M.; Ambach, W.; Salzgeber, M.

1994-03-01

At the high-mountain station Jungfraujoch (3576 m a.s.l., Switzerland), measurements of the radiation fluxes were made during 16 periods of six to eight weeks by means of a Robertson—Berger sunburn meter (UVB data), an Eppley UVA radiometer and an Eppley pyranometer. Cloudiness, opacity and altitude of clouds were recorded at 30-minute intervals. A second set of instruments was employed for separate measurement of the diffuse radiation fluxes using shadow bands. The global and diffuse UVA- and UVB radiation fluxes change less with cloudiness than the corresponding total radiation fluxes. When the sun is covered by clouds, the global UVA- and UVB radiation fluxes are also affected less than the global total radiation flux. The roughly equal influence of cloudiness on the UVA- and UVB radiation fluxes suggests that the reduction is influenced more by scattering than by ozone. Also, the share of diffuse irradiance in global irradiance is considerably higher for UVA- and UVB irradiance than for total irradiance. At 50° solar elevation and 0/10 cloudiness, the share is 39% for UVB irradiance, 34% for UVA irradiance and 11% for total irradiance. The increased aerosol turbidity after the eruptions of El Chichon and Pinatubo has caused a significant increase in diffuse total irradiance but has not produced any significant changes in diffuse UVA- and UVB irradiances.

UV254 absorbance as real-time monitoring and control parameter for micropollutant removal in advanced wastewater treatment with powdered activated carbon.

PubMed

Altmann, Johannes; Massa, Lukas; Sperlich, Alexander; Gnirss, Regina; Jekel, Martin

2016-05-01

This study investigates the applicability of UV absorbance measurements at 254 nm (UVA254) to serve as a simple and reliable surrogate parameter to monitor and control the removal of organic micropollutants (OMPs) in advanced wastewater treatment applying powdered activated carbon (PAC). Correlations between OMP removal and corresponding UVA254 reduction were determined in lab-scale adsorption batch tests and successfully applied to a pilot-scale PAC treatment stage to predict OMP removals in aggregate samples with good accuracy. Real-time UVA254 measurements were utilized to evaluate adapted PAC dosing strategies and proved to be effective for online monitoring of OMP removal. Furthermore, active PAC dosing control according to differential UVA254 measurements was implemented and tested. While precise removal predictions based on real-time measurements were not accurate for all OMPs, UVA254-controlled dynamic PAC dosing was capable of achieving stable OMP removals. UVA254 can serve as an effective surrogate parameter for OMP removal in technical PAC applications. Even though the applicability as control parameter to adjust PAC dosing to water quality changes might be limited to applications with fast response between PAC adjustment and adsorptive removal (e.g. direct filtration), UVA254 measurements can also be used to monitor the adsorption efficiency in more complex PAC applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

PBF (PER620) interior of Reactor Room. Camera facing south from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF (PER-620) interior of Reactor Room. Camera facing south from stairway platform in southwest corner (similar to platform in view at left). Reactor was beneath water in circular tank. Fuel was stored in the canal north of it. Platform and apparatus at right is reactor bridge with control rod mechanisms and actuators. The entire apparatus swung over the reactor and pool during operations. Personnel in view are involved with decontamination and preparation of facility for demolition. Note rails near ceiling for crane; motor for rollup door at upper center of view. Date: March 2004. INEEL negative no. HD-41-3-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Removal design report for the 108-F Biological Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-09-01

Most of the 100-F facilities were deactivated with the reactor and have since been demolished. Of the dozen or so reactor-related structures, only the 105-F Reactor Building and the 108-F Biology Laboratory remain standing today. The 108-F Biology Laboratory was intended to be used as a facility for the mixing and addition of chemicals used in the treatment of the reactor cooling water. Shortly after F Reactor began operation, it was determined that the facility was not needed for this purpose. In 1949, the building was converted for use as a biological laboratory. In 1962, the lab was expanded bymore » adding a three-story annex to the original four-story structure. The resulting lab had a floor area of approximately 2,883 m{sup 2} (main building and annex) that operated until 1973. The building contained 47 laboratories, a number of small offices, a conference room, administrative section, lunch and locker rooms, and a heavily shielded, high-energy exposure cell. The purpose of this removal design report is to establish the methods of decontamination and decommissioning and the supporting functions associated with facility removal and disposal.« less

Human amnion-derived mesenchymal stem cells protect against UVA irradiation-induced human dermal fibroblast senescence, in vitro

PubMed Central

Zhang, Chunli; Yuchi, Haishen; Sun, Lu; Zhou, Xiaoli; Lin, Jinde

2017-01-01

The aim of the present study was to determine if human amnion-derived mesenchymal stem cells (HAMSCs) exert a protective effect on ultraviolet A (UVA) irradiation-induced human dermal fibroblast (HDF) senescence. A senescence model was constructed as follows: HDFs (104–106 cells/well) were cultured in a six-well plate in vitro and then exposed to UVA irradiation at 9 J/cm2 for 30 min. Following the irradiation period, HDFs were co-cultured with HAMSCs, which were seeded on transwells. A total of 72 h following the co-culturing, senescence-associated β-galactosidase staining was performed and reactive oxygen species (ROS) content and mitochondrial membrane potential (Δψm) were detected in the HDFs via flow cytometric analysis. The results demonstrated that the percentage of HDFs, detected via staining with X-gal, were markedly decreased when co-cultured with human HAMSCs, compared with the group that were not co-cultured. The ROS content was decreased and the mitochondrial membrane potential (Δψm) recovered in cells treated with UVA and HAMSCs, compared with that of cells treated with UVA alone. Reverse transcription-quantitative polymerase chain reaction revealed the significant effects of HAMSCs on the HDF senescence marker genes p53 and matrix metalloproteinase-1 mRNA expression. In addition to this, western blot analysis verified the effects of HAMSCs on UVA induced senescence, providing a foundation for novel regenerative therapeutic methods. Furthermore, the results suggested that activation of the extracellular-signal regulated kinase 1/2 mitogen activated protein kinase signal transduction pathway, is essential for the HAMSC-mediated UVA protective effects. The decrease in ROS content additionally indicated that HAMSCs may exhibit the potential to treat oxidative stress-mediated UVA skin senescence in the future. PMID:28627622

Activation of Nrf2 Reduces UVA-Mediated MMP-1 Upregulation via MAPK/AP-1 Signaling Cascades: The Photoprotective Effects of Sulforaphane and Hispidulin

PubMed Central

Chaiprasongsuk, Anyamanee; Lohakul, Jinaphat; Soontrapa, Kitipong; Sampattavanich, Somponnat; Akarasereenont, Pravit

2017-01-01

UVA irradiation plays a role in premature aging of the skin through triggering oxidative stress-associated stimulation of matrix metalloproteinase-1 (MMP-1) responsible for collagen degradation, a hallmark of photoaged skin. Compounds that can activate nuclear factor E2-related factor 2 (Nrf2), a transcription factor regulating antioxidant gene expression, should therefore serve as effective antiphotoaging agents. We investigated whether genetic silencing of Nrf2 could relieve UVA-mediated MMP-1 upregulation via activation of mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) signaling using human keratinocyte cell line (HaCaT). Antiphotoaging effects of hispidulin (HPD) and sulforaphane (SFN) were assessed on their abilities to activate Nrf2 in controlling MMP-1 and collagen expressions in association with phosphorylation of MAPKs (extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38), c-Jun, and c-Fos, using the skin of BALB/c mice subjected to repetitive UVA irradiation. Our findings suggested that depletion of Nrf2 promoted both mRNA expression and activity of MMP-1 in the UVA-irradiated HaCaT cells. Treatment of Nrf2 knocked-down HaCaT cells with MAPK inhibitors significantly suppressed UVA-induced MMP-1 and AP-1 activities. Moreover, pretreatment of the mouse skin with HPD and SFN, which could activate Nrf2, provided protective effects against UVA-mediated MMP-1 induction and collagen depletion in correlation with the decreased levels of phosphorylated MAPKs, c-Jun, and c-Fos in the mouse skin. In conclusion, Nrf2 could influence UVA-mediated MMP-1 upregulation through the MAPK/AP-1 signaling cascades. HPD and SFN may therefore represent promising antiphotoaging candidates. PMID:28011874

Disposition of fuel elements from the Aberdeen and Sandia pulse reactor (SPR-II) assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mckerley, Bill; Bustamante, Jacqueline M; Costa, David A

2010-01-01

We describe the disposition of fuel from the Aberdeen (APR) and the Sandia Pulse Reactors (SPR-II) which were used to provide intense neutron bursts for radiation effects testing. The enriched Uranium - 10% Molybdenum fuel from these reactors was shipped to the Los Alamos National Laboratory (LANL) for size reduction prior to shipment to the Savannah River Site (SRS) for final disposition in the H Canyon facility. The Shipper/Receiver Agreements (SRA), intra-DOE interfaces, criticality safety evaluations, safety and quality requirements and key materials management issues required for the successful completion of this project will be presented. This work is inmore » support of the DOE Consolidation and Disposition program. Sandia National Laboratories (SNL) has operated pulse nuclear reactor research facilities for the Department of Energy since 1961. The Sandia Pulse Reactor (SPR-II) was a bare metal Godiva-type reactor. The reactor facilities have been used for research and development of nuclear and non-nuclear weapon systems, advanced nuclear reactors, reactor safety, simulation sources and energy related programs. The SPR-II was a fast burst reactor, designed and constructed by SNL that became operational in 1967. The SPR-ll core was a solid-metal fuel enriched to 93% {sup 235}U. The uranium was alloyed with 10 weight percent molybdenum to ensure the phase stabilization of the fuel. The core consisted of six fuel plates divided into two assemblies of three plates each. Figure 1 shows a cutaway diagram of the SPR-II Reactor with its decoupling shroud. NNSA charged Sandia with removing its category 1 and 2 special nuclear material by the end of 2008. The main impetus for this activity was based on NNSA Administrator Tom D'Agostino's six focus areas to reenergize NNSA's nuclear material consolidation and disposition efforts. For example, the removal of SPR-II from SNL to DAF was part of this undertaking. This project was in support of NNSA's efforts to consolidate the locations of special nuclear material (SNM) to reduce the cost of securing many SNM facilities. The removal of SPR-II from SNL was a significant accomplishment in SNL's de-inventory efforts and played a key role in reducing the number of locations requiring the expensive security measures required for category 1 and 2 SNM facilities. A similar pulse reactor was fabricated at the Y-12 National Security Complex beginning in the late 1960's. This Aberdeen Pulse Reactor (APR) was operated at the Army Pulse Radiation Facility (APRF) located at the Aberdeen Test Center (ATC) in Maryland. When the APRF was shut down in 2003, a portion of the DOE-owned Special Nuclear Material (SNM) was shipped to an interim facility for storage. Subsequently, the DOE determined that the material from both the SPR-II and the APR would be processed in the H-Canyon at the Savannah River Site (SRS). Because of the SRS receipt requirements some of the material was sent to the Los Alamos National Laboratory (LANL) for size-reduction prior to shipment to the SRS for final disposition.« less

Development of photo-modified starch/kefiran/TiO2 bio-nanocomposite as an environmentally-friendly food packaging material.

PubMed

Goudarzi, Vahid; Shahabi-Ghahfarrokhi, Iman

2018-05-21

This paper reports on an experiment in which starch/kefiran/TiO 2 (SKT)-based bio-nanocomposite films were developed and modified by photo-chemical reaction. In so doing, film-forming solutions were exposed to ultraviolet A (UV-A) for different times (1, 6, and 12 h). The obtained results indicated that increasing UV-A exposure time brought about an increase (≈14.9%) in the tensile strength of bio-nanocomposites. However, elongation at break and Young's modulus of irradiated film specimen decreased (≈32%, ≈12%, respectively) by increasing UV-A exposure time, and the moisture-sensitive parameters of specimen decreased using UV-A irradiation. According to the results, the functional properties of irradiated bio-nanocomposite are depended on the ratio of cross-linkages between polymer chains and the potentially produced mono and disaccharide by UV-A. Copyright © 2018. Published by Elsevier B.V.

Decontamination and decommissioning of the Mayaguez (Puerto Rico) facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, P.K.; Freemerman, R.L.

1989-11-01

On February 6, 1987 the US Department of Energy (DOE) awarded the final phase of the decontamination and decommissioning of the nuclear and reactor facilities at the Center for Energy and Environmental Research (CEER), in Mayaguez, Puerto Rico. Bechtel National, Inc., was made the decontamination and decommissioning (D and D) contractor. The goal of the project was to enable DOE to proceed with release of the CEER facility for use by the University of Puerto Rico, who was the operator. This presentation describes that project and lesson learned during its progress. The CEER facility was established in 1957 as themore » Puerto Rico Nuclear Center, a part of the Atoms for Peace Program. It was a nuclear training and research institution with emphasis on the needs of Latin America. It originally consisted of a 1-megawatt Materials Testing Reactor (MTR), support facilities and research laboratories. After eleven years of operation the MTR was shutdown and defueled. A 2-megawatt TRIGA reactor was installed in 1972 and operated until 1976, when it woo was shutdown. Other radioactive facilities at the center included a 10-watt homogeneous L-77 training reactor, a natural uranium graphite-moderated subcritical assembly, a 200KV particle accelerator, and a 15,000 Ci Co-60 irradiation facility. Support facilities included radiochemistry laboratories, counting rooms and two hot cells. As the emphasis shifted to non-nuclear energy technology a name change resulted in the CEER designation, and plans were started for the decontamination and decommissioning effort.« less

Scaling Studies for Advanced High Temperature Reactor Concepts, Final Technical Report: October 2014—December 2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woods, Brian; Gutowska, Izabela; Chiger, Howard

Computer simulations of nuclear reactor thermal-hydraulic phenomena are often used in the design and licensing of nuclear reactor systems. In order to assess the accuracy of these computer simulations, computer codes and methods are often validated against experimental data. This experimental data must be of sufficiently high quality in order to conduct a robust validation exercise. In addition, this experimental data is generally collected at experimental facilities that are of a smaller scale than the reactor systems that are being simulated due to cost considerations. Therefore, smaller scale test facilities must be designed and constructed in such a fashion tomore » ensure that the prototypical behavior of a particular nuclear reactor system is preserved. The work completed through this project has resulted in scaling analyses and conceptual design development for a test facility capable of collecting code validation data for the following high temperature gas reactor systems and events— 1. Passive natural circulation core cooling system, 2. pebble bed gas reactor concept, 3. General Atomics Energy Multiplier Module reactor, and 4. prismatic block design steam-water ingress event. In the event that code validation data for these systems or events is needed in the future, significant progress in the design of an appropriate integral-type test facility has already been completed as a result of this project. Where applicable, the next step would be to begin the detailed design development and material procurement. As part of this project applicable scaling analyses were completed and test facility design requirements developed. Conceptual designs were developed for the implementation of these design requirements at the Oregon State University (OSU) High Temperature Test Facility (HTTF). The original HTTF is based on a ¼-scale model of a high temperature gas reactor concept with the capability for both forced and natural circulation flow through a prismatic core with an electrical heat source. The peak core region temperature capability is 1400°C. As part of this project, an inventory of test facilities that could be used for these experimental programs was completed. Several of these facilities showed some promise, however, upon further investigation it became clear that only the OSU HTTF had the power and/or peak temperature limits that would allow for the experimental programs envisioned herein. Thus the conceptual design and feasibility study development focused on examining the feasibility of configuring the current HTTF to collect validation data for these experimental programs. In addition to the scaling analyses and conceptual design development, a test plan was developed for the envisioned modified test facility. This test plan included a discussion on an appropriate shakedown test program as well as the specific matrix tests. Finally, a feasibility study was completed to determine the cost and schedule considerations that would be important to any test program developed to investigate these designs and events.« less

The Fast-spectrum Transmutation Experimental Facility FASTEF: Main design achievements (part 2: Reactor building design and plant layout) within the FP7-CDT collaborative project of the European Commission

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Bruyn, D.; Engelen, J.; Ortega, A.

MYRRHA (Multi-purpose hybrid Research Reactor for High-tech Applications) is the flexible experimental accelerator-driven system (ADS) in development at SCK-CEN in replacement of its material testing reactor BR2. SCK-CEN in association with 17 European partners from industry, research centres and academia, responded to the FP7 (Seventh Framework Programme) call from the European Commission to establish a Central Design Team (CDT) for the design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. The project has started on April 01, 2009 for a period of threemore » years. In this paper, we present the latest concept of the reactor building and the plant layout. The FASTEF facility has evolved quite a lot since the intermediate reporting done at the ICAPP'10 and ICAPP'11 conferences 1,2. Many iterations have been performed to take into account the safety requirements. The present configuration enables an easy operation and maintenance of the facility, including the possibility to change large components of the reactor. In a companion paper 3, we present the latest configuration of the reactor core and primary system. (authors)« less

UVA is the major contributor to the photodegradation of tretinoin and isotretinoin: implications for development of improved pharmaceutical formulations

PubMed Central

Tashtoush, Bassam M.; Jacobson, Elaine L.; Jacobson, Myron K.

2008-01-01

The chemical stability of tretinoin (RA) and isotretinoin (13RA) in ethanol and dermatological cream preparations exposed to solar simulated light (SSL), UVA, and visible light has been studied. Photostability was monitored by an HPLC method that allowed simultaneous analysis of RA and 13RA, thus allowing photodegradation due to isomerization to other retinoids and photolysis to non-retinoid products to be monitored. Both retinoids undergo both isomerization and photolysis following SSL, UVA and visible light exposure but RA is more sensitive to photodegradation than 13RA. Degradation of both retinoids by photolysis is considerably greater in cream formulations than in ethanol and the photodegradation follows second order kinetics. Rate constants and half-lives for degradation of RA and 13RA in ethanol solution and cream preparations subjected to different light sources are reported. The UVA component of SSL is the major contributor to photodegradation. Since UVA penetrates deeply into skin, our results suggest that photodegradation of RA may contribute to the photosensitivity associated with RA therapy. Our studies suggest that development of improved formulations and the use of effective UVA sunscreens may reduce the side effects of RA therapy. PMID:18093761

Measuring sunscreen protection against solar-simulated radiation-induced structural radical damage to skin using ESR/spin trapping: development of an ex vivo test method.

PubMed

Haywood, Rachel; Volkov, Arsen; Andrady, Carima; Sayer, Robert

2012-03-01

The in vitro star system used for sunscreen UVA-testing is not an absolute measure of skin protection being a ratio of the total integrated UVA/UVB absorption. The in vivo persistent-pigment-darkening method requires human volunteers. We investigated the use of the ESR-detectable DMPO protein radical-adduct in solar-simulator-irradiated skin substitutes for sunscreen testing. Sunscreens SPF rated 20+ with UVA protection, reduced this adduct by 40-65% when applied at 2 mg/cm(2). SPF 15 Organic UVA-UVB (BMDBM-OMC) and TiO(2)-UVB filters and a novel UVA-TiO(2) filter reduced it by 21, 31 and 70% respectively. Conventional broad-spectrum sunscreens do not fully protect against protein radical-damage in skin due to possible visible-light contributions to damage or UVA-filter degradation. Anisotropic spectra of DMPO-trapped oxygen-centred radicals, proposed intermediates of lipid-oxidation, were detected in irradiated sunscreen and DMPO. Sunscreen protection might be improved by the consideration of visible-light protection and the design of filters to minimise radical leakage and lipid-oxidation.

UVA is the major contributor to the photodegradation of tretinoin and isotretinoin: Implications for development of improved pharmaceutical formulations.

PubMed

Tashtoush, Bassam M; Jacobson, Elaine L; Jacobson, Myron K

2008-03-20

The chemical stability of tretinoin (RA) and isotretinoin (13RA) in ethanol and dermatological cream preparations exposed to solar simulated light (SSL), UVA, and visible light has been studied. Photostability was monitored by an HPLC method that allowed simultaneous analysis of RA and 13RA, thus allowing photodegradation due to isomerization to other retinoids and photolysis to non-retinoid products to be monitored. Both retinoids undergo both isomerization and photolysis following SSL, UVA and visible light exposure but RA is more sensitive to photodegradation than 13RA. Degradation of both retinoids by photolysis is considerably greater in cream formulations than in ethanol and the photodegradation follows second order kinetics. Rate constants and half-lives for degradation of RA and 13RA in ethanol solution and cream preparations subjected to different light sources are reported. The UVA component of SSL is the major contributor to photodegradation. Since UVA penetrates deeply into skin, our results suggest that photodegradation of RA may contribute to the photosensitivity associated with RA therapy. Our studies suggest that development of improved formulations and the use of effective UVA sunscreens may reduce the side effects of RA therapy.

Impact of long-wavelength UVA and visible light on melanocompetent skin.

PubMed

Mahmoud, Bassel H; Ruvolo, Eduardo; Hexsel, Camile L; Liu, Yang; Owen, Michael R; Kollias, Nikiforos; Lim, Henry W; Hamzavi, Iltefat H

2010-08-01

The purpose of this study was to determine the effect of visible light on the immediate pigmentation and delayed tanning of melanocompetent skin; the results were compared with those induced by long-wavelength UVA (UVA1). Two electromagnetic radiation sources were used to irradiate the lower back of 20 volunteers with skin types IV-VI: UVA1 (340-400 nm) and visible light (400-700 nm). Pigmentation was assessed by visual examination, digital photography with a cross-polarized filter, and diffused reflectance spectroscopy at 7 time points over a 2-week period. Confocal microscopy and skin biopsies for histopathological examination using different stains were carried out. Irradiation was also carried out on skin type II. Results showed that although both UVA1 and visible light can induce pigmentation in skin types IV-VI, pigmentation induced by visible light was darker and more sustained. No pigmentation was observed in skin type II. The quality and quantity of pigment induced by visible light and UVA1 were different. These findings have potential implications on the management of photoaggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.

75 FR 68629 - Massachusetts Institute of Technology Reactor Notice of Issuance of Renewed Facility Operating...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-020; NRC-2010-0313] Massachusetts Institute of Technology Reactor Notice of Issuance of Renewed Facility Operating; License No. R-37 The U.S. Nuclear... Institute of Technology (the licensee), which authorizes continued operation of the Massachusetts Institute...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramalho, Antonio G.

The Portuguese Research Reactor (RPI) is the main research facility in the Laboratorio de Fisica e Engenharia Nucleares. This laboratory is one of the departments of Junta de Energia Nuclear, the coordinating body of the nuclear activity in Portugal. A description of the facility, reactor utilization, positioning within Portugal, and areas of cooperation with other institutions are summarized.

REACTIVITY MEASUREMENT FACILITY, UNDER CONSTRUCTION OVER MTR CANAL IN BASEMENT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

REACTIVITY MEASUREMENT FACILITY, UNDER CONSTRUCTION OVER MTR CANAL IN BASEMENT OF MTR BUILDING, TRA-603. WOOD PLANKS REST ON CANAL WALL OBSERVABLE IN FOREGROUND. INL NEGATIVE NO. 11745. Unknown Photographer, 8/20/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

78 FR 26812 - University of California, Irvine; License Renewal for University of California, Irvine Nuclear...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-326; NRC-2010-0217] University of California, Irvine; License Renewal for University of California, Irvine Nuclear Reactor Facility; Supplemental Information... Renewal for University of California, Irvine Nuclear Reactor Facility,'' to inform the public that the NRC...

Impact of UV-A radiation on the performance of aphids and whiteflies and on the leaf chemistry of their host plants.

PubMed

Dáder, Beatriz; Gwynn-Jones, Dylan; Moreno, Aránzazu; Winters, Ana; Fereres, Alberto

2014-09-05

Ultraviolet (UV) radiation directly regulates a multitude of herbivore life processes, in addition to indirectly affecting insect success via changes in plant chemistry and morphogenesis. Here we looked at plant and insect (aphid and whitefly) exposure to supplemental UV-A radiation in the glasshouse environment and investigated effects on insect population growth. Glasshouse grown peppers and eggplants were grown from seed inside cages covered by novel plastic filters, one transparent and the other opaque to UV-A radiation. At a 10-true leaf stage for peppers (53 days) and 4-true leaf stage for eggplants (34 days), plants were harvested for chemical analysis and infested by aphids and whiteflies, respectively. Clip-cages were used to introduce and monitor the insect fitness and populations of the pests studied. Insect pre-reproductive period, fecundity, fertility and intrinsic rate of natural increase were assessed. Crop growth was monitored weekly for 7 and 12 weeks throughout the crop cycle of peppers and eggplants, respectively. At the end of the insect fitness experiment, plants were harvested (68 days and 18-true leaf stage for peppers, and 104 days and 12-true leaf stage for eggplants) and leaves analysed for secondary metabolites, soluble carbohydrates, amino acids, total proteins and photosynthetic pigments. Our results demonstrate for the first time, that UV-A modulates plant chemistry with implications for insect pests. Both plant species responded directly to UV-A by producing shorter stems but this effect was only significant in pepper whilst UV-A did not affect the leaf area of either species. Importantly, in pepper, the UV-A treated plants contained higher contents of secondary metabolites, leaf soluble carbohydrates, free amino acids and total content of protein. Such changes in tissue chemistry may have indirectly promoted aphid performance. For eggplants, chlorophylls a and b, and carotenoid levels decreased with supplemental UV-A over the entire crop cycle but UV-A exposure did not affect leaf secondary metabolites. However, exposure to supplemental UV-A had a detrimental effect on whitefly development, fecundity and fertility presumably not mediated by plant cues as compounds implied in pest nutrition - proteins and sugars - were unaltered. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisowski, Darius D.; Kraus, Adam R.; Bucknor, Matthew D.

A 1/2 scale test facility has been constructed at Argonne National Laboratory to study the heat removal performance and natural circulation flow patterns in a Reactor Cavity Cooling System (RCCS). Our test facility, the Natural convection Shutdown heat removal Test Facility (NSTF), supports the broader goal of developing an inherently safe and fully passive ex-vessel decay heat removal for advanced reactor designs. The project, initiated in 2010 to support the Advanced Reactor Technologies (ART), Small Modular Reactor (SMR), and Next Generation Nuclear Plant (NGNP) programs, has been conducting experimental operations since early 2014. The following paper provides a summary ofmore » some primary design features of the 26-m tall test facility along with a description of the data acquisition suite that guides our experimental practices. Specifics of the distributed fiber optic temperature measurements will be discussed, which introduces an unparalleled level of data density that has never before been implemented in a large scale natural circulation test facility. Results from our test series will then be presented, which provide insight into the thermal hydraulic behavior at steady-state and transient conditions for varying heat flux levels and exhaust chimney configuration states. (C) 2016 Elsevier B.V. All rights reserved.« less

10 CFR 50.60 - Acceptance criteria for fracture prevention measures for lightwater nuclear power reactors for...

Code of Federal Regulations, 2010 CFR

2010-01-01

... lightwater nuclear power reactors for normal operation. 50.60 Section 50.60 Energy NUCLEAR REGULATORY... lightwater nuclear power reactors for normal operation. (a) Except as provided in paragraph (b) of this section, all light-water nuclear power reactors, other than reactor facilities for which the...

10 CFR 50.60 - Acceptance criteria for fracture prevention measures for lightwater nuclear power reactors for...

Code of Federal Regulations, 2011 CFR

2011-01-01

... lightwater nuclear power reactors for normal operation. 50.60 Section 50.60 Energy NUCLEAR REGULATORY... lightwater nuclear power reactors for normal operation. (a) Except as provided in paragraph (b) of this section, all light-water nuclear power reactors, other than reactor facilities for which the...

PBF Reactor Building (PER620). Camera faces north into highbay/reactor pit ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera faces north into high-bay/reactor pit area. Inside from for reactor enclosure is in place. Photographer: John Capek. Date: March 15, 1967. INEEL negative no. 67-1769 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

10 CFR 2.103 - Action on applications for byproduct, source, special nuclear material, facility and operator...

Code of Federal Regulations, 2011 CFR

2011-01-01

..., Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Federal and..., Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Nuclear... of this chapter, see § 2.106(d). (b) If the Director, Office of Nuclear Reactor Regulation, Director...

10 CFR 2.103 - Action on applications for byproduct, source, special nuclear material, facility and operator...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Federal and..., Office of Nuclear Reactor Regulation, Director, Office of New Reactors, Director, Office of Nuclear... of this chapter, see § 2.106(d). (b) If the Director, Office of Nuclear Reactor Regulation, Director...

Impact of an ultraviolet air sterilizer on cardiac surgery patients, a randomized clinical trial.

PubMed

Heredia-Rodríguez, María; Álvarez-Fuente, Elisa; Bustamante-Munguira, Juan; Poves-Alvarez, Rodrigo; Fierro, Inmaculada; Gómez-Sánchez, Esther; Gómez-Pesquera, Estefanía; Lorenzo-López, Mario; Eiros, José María; Álvarez, Francisco Javier; Tamayo, Eduardo

2018-05-25

Numerous studies have evaluated the use of ultraviolet-C devices for terminal disinfection in hospitals, however, to date there is little information about the device's final impact on patients. We investigated the effect of an ultraviolet air sterilizer (UVAS) on the clinical outcomes of cardiac surgery patients. This random, prospective and non-interventional study included 1097 adult patients undergoing elective cardiac surgery: 522 stayed in an ICU room with UVAS (Medixair ® ) and 575 patients ICU room without UVAS and were used as a control. The primary outcome measure was to evaluate the effect of a UVAS on the overall prevalence of nosocomial infections in postoperative cardiac patients in ICUs. No significant differences in ventilator-associated pneumonia (4.6% vs. 5.0%, p=0.77) and total infection (14.0% vs. 15.5%, p=0.45) rates were detected in patients with and without the UVAS. The length of stay in the intensive care unit and at the hospital was similar in both groups, UVAS (4.6 (8.2) days and 18.3 (5.5) days) and without UVAS (4.6 (7.3) days and 19.2 (18.6) days). The 30-day in-hospital mortality rate was 5.3%, no significant differences between groups were observed (p=0.053). Novel ultraviolet-C technology has not been shown to significantly reduce nosocomial infections or mortality rates in cardiac surgery patients. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

Modulation of cathepsin G expression in severe atopic dermatitis following medium-dose UVA1 phototherapy

PubMed Central

Breuckmann, Frank; von Kobyletzki, Gregor; Avermaete, Annelies; Kreuter, Alexander; Altmeyer, Peter; Gambichler, Thilo

2002-01-01

Background During the last decade, medium-dose UVA1 phototherapy (50 J/cm2) has achieved great value within the treatment of severe atopic dermatitis (AD). The purpose of our study was to investigate to what extent UVA1 irradiation is able to modulate the status of protease activity by the use of a monoclonal antibody labeling cathepsin G. Methods In order to further elucidate the mechanisms by which medium-dose UVA1 irradiation leads to an improvement of skin status in patients with AD, biopsy specimens from 15 patients before and after treatment were analyzed immunohistochemically for proteolytic activation. Results Compared to lesional skin of patients with AD before UVA1 irradiation, the number of cells positive for cathepsin G within the dermal infiltrate decreased significantly after treatment. The decrease of cathepsin G+ cells was closely linked to a substantial clinical improvement in skin condition. Conclusions In summary, our findings demonstrated that medium-dose UVA1 irradiation leads to a modulation of the expression of cathepsin G in the dermal inflammatory infiltrate in patients with severe AD. Cathepsin G may attack laminin, proteoglycans, collagen I and insoluble fibronectin, to provoke proinflammatory events, to degrade the basement membrane, to destroy the tissue inhibitor of metalloproteinases and to increase the endothelial permeability. Therefore, its down-regulation by UVA1 phototherapy may induce the reduction of skin inflammation as well as improvement of the skin condition. PMID:12204095

Photo-producible and photo-degradable starch/TiO2 bionanocomposite as a food packaging material: Development and characterization.

PubMed

Goudarzi, Vahid; Shahabi-Ghahfarrokhi, Iman

2018-01-01

In current study, starch/TiO 2 bionanocomposites were produced by photochemical reactions as a biodegradable food packaging material. Physical, mechanical, thermal and water-vapor permeability properties were investigated. Then, the photo-degradation properties of nanocomposite films were studied. This is the first report of the photo-producible and photo-degradable bionanocomposite as a food packaging material. Film-forming solutions were exposed to ultraviolet A (UV-A) for different times. Our results showed that UV-A irradiation increased the hydrophobicity of starch films. With increasing UV-A exposure time, tensile strength and Young's modulus of the specimens were decreased. On the other hand, elongation at break of the films was increased with increasing UV-A irradiation. The glass transition temperature and melting point of the films were increased by increasing UV-A exposure time. Nevertheless, the results showed that photo-degradation properties of photo-produced starch/TiO 2 nanocomposite were significantly higher than virgin starch and virgin starch/TiO 2 films. According to obtain results and bibliography a schema was developed to describe the mechanism of photo-production and photo-degradation of starch/TiO 2 by UV-A ray. It can be concluded, the modification of starch based biopolymer by UV-A and nano-TiO 2 , is an easy and accessible process to improve the packaging properties and photo-degradability of biopolymer based films. Copyright © 2017 Elsevier B.V. All rights reserved.

Nitric oxide-dependent pigment migration induced by ultraviolet radiation in retinal pigment cells of the crab Neohelice granulata.

PubMed

Filgueira, Daza de Moraes Vaz Batista; Guterres, Laís Pereira; Votto, Ana Paula de Souza; Vargas, Marcelo Alves; Boyle, Robert Tew; Trindade, Gilma Santos; Nery, Luiz Eduardo Maia

2010-01-01

The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm(-2) UVA, 0.07 and 0.9 J cm(-2) UVB, 20 nmβ-PDH (pigment dispersing hormone) or 10 μm SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo. Cultured cells were exposed to 250 μm L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or β-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and β-PDH. The same responses to UVA and UVB were observed in vivo. SIN-1 did not induce pigment dispersion in the cell cultures. L-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by β-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

Comparison of ultraviolet A light protection standards in the United States and European Union through in vitro measurements of commercially available sunscreens.

PubMed

Wang, Steven Q; Xu, Haoming; Stanfield, Joseph W; Osterwalder, Uli; Herzog, Bernd

2017-07-01

The importance of adequate ultraviolet A light (UVA) protection has become apparent in recent years. The United States and Europe have different standards for assessing UVA protection in sunscreen products. We sought to measure the in vitro critical wavelength (CW) and UVA protection factor (PF) of commercially available US sunscreen products and see if they meet standards set by the United States and the European Union. Twenty sunscreen products with sun protection factors ranging from 15 to 100+ were analyzed. Two in vitro UVA protection tests were conducted in accordance with the 2011 US Food and Drug Administration final rule and the 2012 International Organization for Standardization method for sunscreen effectiveness testing. The CW of the tested sunscreens ranged from 367 to 382 nm, and the UVA PF of the products ranged from 6.1 to 32. Nineteen of 20 sunscreens (95%) met the US requirement of CW >370 nm. Eleven of 20 sunscreens (55%) met the EU desired ratio of UVA PF/SPF > 1:3. The study only evaluated a small number of sunscreen products. The majority of tested sunscreens offered adequate UVA protection according to US Food and Drug Administration guidelines for broad-spectrum status, but almost half of the sunscreens tested did not pass standards set in the European Union. Copyright © 2017. Published by Elsevier Inc.

UV exposure in artificial and natural weathering: A comparative study

NASA Astrophysics Data System (ADS)

Heikkilä, A.; Kazadzis, S.; Meinander, O.; Vaskuri, A.; Kärhä, P.; Mylläri, V.; Syrjälä, S.; Koskela, T.

2017-02-01

We report on a study focusing on UV exposure conditions in three different types of chambers used for accelerated ageing of materials. The first chamber is equipped with four 300-W UVA/UVB mercury vapour lamps (Ultra-Vitalux/Osram). The second chamber uses four 40-W UVA fluorescent lamps (QUV-340/Q-Lab). The third chamber is Weather-Ometer Ci3000+ from Atlas with a 4500-W xenon arc lamp. UV irradiance prevailing in each chamber was measured using Bentham DM150 double monochromator spectroradiometer. The results were compared to measurements of solar spectral UV irradiance at Jokioinen, Finland, with a Brewer MkIII double monochromator spectrophotometer. The spectral shapes of the exposing UV radiation in the different chambers were found to notably differ from each other and from the solar UV spectrum. Both spatial inhomogeneities and temporal variability caused by various factors, like the ageing of the lamps, were detected. The effects were found to strongly depend on wavelength of the exposing UV radiation. The findings of this study underline the necessity of careful characterization of the UV exposure conditions provided by the facilities used in accelerated testing of materials.

10 CFR 100.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... COMMISSION (CONTINUED) REACTOR SITE CRITERIA § 100.3 Definitions. As used in this part: Combined license... power facilities. Exclusion area means that area surrounding the reactor, in which the reactor licensee.... Activities unrelated to operation of the reactor may be permitted in an exclusion area under appropriate...

10 CFR 100.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... COMMISSION (CONTINUED) REACTOR SITE CRITERIA § 100.3 Definitions. As used in this part: Combined license... power facilities. Exclusion area means that area surrounding the reactor, in which the reactor licensee.... Activities unrelated to operation of the reactor may be permitted in an exclusion area under appropriate...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Little, G.A.

For better than ten years there was little public notice of the TRIGA reactor at UC-Berkeley. Then: a) A non-student persuaded the Student and Senate to pass a resolution to request Campus Administration to stop operation of the reactor and remove it from campus. b) Presence of the reactor became a campaign-issue in a City Mayoral election. c) Two local residents reported adverse physical reactions before, during, and after a routine tour of the reactor facility. d) The Berkeley City Council began a study of problems associated with radioactive material within the city. e) Friends Of The Earth formally petitionedmore » the NRC to terminate the reactor's license. Campus personnel have expended many man-hours and many pounds of paper in responding to these happenings. Some of the details are of interest, and may be of use to other reactor facilities. (author)« less

Final report of the decontamination and decommissioning of the BORAX-V facility turbine building

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arave, A.E.; Rodman, G.R.

1992-12-01

The Boiling Water Reactor Experiment (BORAX)-V Facility Turbine Building Decontamination and Decommissioning (D&D) Project is described in this report. The BORAX series of five National Reactor Testing Station (NRTS) reactors pioneered intensive work on boiling water reactor (BWR) experiments conducted between 1953 and 1964. Facility characterization, decision analyses, and D&D plans for the turbine building were prepared from 1979 through 1990. D&D activities of the turbine building systems were initiated in November of 1988 and completed with the demolition and backfill of the concrete foundation in March 1992. Due to the low levels of radioactivity and the absence of loosemore » contamination, the D&D activities were completed with no radiation exposure to the workers. The D&D activities were performed in a manner that no radiological health or safety hazard to the public or to personnel at the Idaho National Engineering Laboratory (INEL) remain.« less

Final report of the decontamination and decommissioning of the BORAX-V facility turbine building

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arave, A.E.; Rodman, G.R.

1992-12-01

The Boiling Water Reactor Experiment (BORAX)-V Facility Turbine Building Decontamination and Decommissioning (D D) Project is described in this report. The BORAX series of five National Reactor Testing Station (NRTS) reactors pioneered intensive work on boiling water reactor (BWR) experiments conducted between 1953 and 1964. Facility characterization, decision analyses, and D D plans for the turbine building were prepared from 1979 through 1990. D D activities of the turbine building systems were initiated in November of 1988 and completed with the demolition and backfill of the concrete foundation in March 1992. Due to the low levels of radioactivity and themore » absence of loose contamination, the D D activities were completed with no radiation exposure to the workers. The D D activities were performed in a manner that no radiological health or safety hazard to the public or to personnel at the Idaho National Engineering Laboratory (INEL) remain.« less

INDEPENDENT CONFIRMATORY SURVEY REPORT FOR THE REACTOR BUILDING, HOT LABORATORY, PRIMARY PUMP HOUSE, AND LAND AREAS AT THE PLUM BROOK REACTOR FACILITY, SANDUSKY, OHIO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erika N. Bailey

2011-10-10

In 1941, the War Department acquired approximately 9,000 acres of land near Sandusky, Ohio and constructed a munitions plant. The Plum Brook Ordnance Works Plant produced munitions, such as TNT, until the end of World War II. Following the war, the land remained idle until the National Advisory Committee for Aeronautics later called the National Aeronautics and Space Administration (NASA) obtained 500 acres to construct a nuclear research reactor designed to study the effects of radiation on materials used in space flight. The research reactor was put into operation in 1961 and was the first of fifteen test facilities eventuallymore » built by NASA at the Plum Brook Station. By 1963, NASA had acquired the remaining land at Plum Brook for these additional test facilities« less

Dual-Mode Scramjet Flameholding Operability Measurements

NASA Technical Reports Server (NTRS)

Donohue, James M.

2012-01-01

Flameholding measurements were made in two different direct connect combustor facilities that were designed to simulate a cavity flameholder in the flowfield of a hydrocarbon fueled dual-mode scramjet combustor. The presence of a shocktrain upstream of the flameholder has a significant impact on the inlet flow to the combustor and on the flameholding limits. A throttle was installed in the downstream end of the test rigs to provide the needed back-pressurization and decouple the operation of the flameholder from the backpressure formed by heat release and thermal choking, as in a flight engine. Measurements were made primarily with ethylene fuel but a limited number of tests were also performed with heated gaseous JP-7 fuel injection. The flameholding limits were measured by ramping inlet air temperature down until blowout was observed. The tests performed in the United Technologies Research Center (UTRC) facility used a hydrogen fueled vitiated air heater, Mach 2.2 and 3.3 inlet nozzles, a scramjet combustor rig with a 1.666 by 6 inch inlet and a 0.65 inch deep cavity. Mean blowout temperature measured at the baseline condition with ethylene fuel, the Mach 2.2 inlet and a cavity pressure of 21 psia was 1502 oR. Flameholding sensitivity to a variety of parameters was assessed. Blowout temperature was found to be most sensitive to fuel injection location and fuel flowrates and surprisingly insensitive to operating pressure (by varying both back-pressurization and inlet flowrate) and inlet Mach number. Video imaging through both the bottom and side wall windows was collected simultaneously and showed that the flame structure was quite unsteady with significant lateral movements as well as movement upstream of the flameholder. Experiments in the University of Virginia (UVa) test facility used a Mach 2 inlet nozzle with a 1 inch by 1.5 inch exit cross section, an aspect ratio of 1.5 versus 3.6 in the UTRC facility. The UVa facility tests were designed to measure the sensitivity of flameholding limits to inlet air vitiation by using electrically heated air and adding steam at levels to simulate vitiated air heaters. The measurements showed no significant difference in blowout temperature with inlet air mole fractions of steam from 0 to 6.7%.

10 CFR 170.21 - Schedule of fees for production and utilization facilities, review of standard referenced design...

Code of Federal Regulations, 2012 CFR

2012-01-01

..., Certification Full cost. Amendment, Renewal, Other Approvals Full cost. C. Test Facility/Research Reactor... of components requiring Commission and Executive Branch review, for example, actions under 10 CFR 110... export of reactor and other components requiring Executive Branch review, for example, those actions...

ETR CRITICAL FACILITY (ETRCF), TRA654. SOUTH SIDE. CAMERA FACING NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR CRITICAL FACILITY (ETR-CF), TRA-654. SOUTH SIDE. CAMERA FACING NORTH AND ROLL-UP DOOR. ORIGINAL SIDING HAS BEEN REPLACED WITH STUCCO-LIKE MATERIAL. INL NEGATIVE NO. HD46-40-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

SPERTI Reactor Pit Building (PER605) from contrasting direction as photo ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

SPERT-I Reactor Pit Building (PER-605) from contrasting direction as photo above (ID-33-F-32). Note Guard House door, security fencing around facility. Photographer: R.G. Larsen. Date: July 22, 1955. INEEL negative no. 55-1702. - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.

Code of Federal Regulations, 2014 CFR

2014-01-01

... light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... reactors. (a)(1)(i) Each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide... evaluation model. This section does not apply to a nuclear power reactor facility for which the...

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.

Code of Federal Regulations, 2013 CFR

2013-01-01

... light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... reactors. (a)(1)(i) Each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide... evaluation model. This section does not apply to a nuclear power reactor facility for which the...

10 CFR 50.46 - Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... light-water nuclear power reactors. 50.46 Section 50.46 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC... reactors. (a)(1)(i) Each boiling or pressurized light-water nuclear power reactor fueled with uranium oxide... evaluation model. This section does not apply to a nuclear power reactor facility for which the...

Microvascular leakage of plasma proteins after PUVA and UVA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Staberg, B.; Worm, A.M.; Rossing, N.

1982-04-01

The transcapillary escape rate of albumin (TERalb), is a parameter of the leakage of macromolecules from the total microvasculature. In patients with psoriasis short-term PUVA treatment induces an increase in TERalb. In this study TERalb was measured in 3 groups of normal humans treated with PUVA, UVA and 8-methoxypsoralen. Treatment with PUVA and UVA caused a statistically significant increase in TERalb, whereas treatment with 8-methoxypsoralen did not induce any measurable changes. It is concluded that the UVA irradiation causes the abnormal leakage of macromolecules, whereas psoralen is not the responsible component. Furthermore the phenomenon can be elicited in normals andmore » is not based on a preexisting psoriasis.« less

Research on the measurement of the ultraviolet irradiance in the xenon lamp aging test chamber

NASA Astrophysics Data System (ADS)

Ji, Muyao; Li, Tiecheng; Lin, Fangsheng; Yin, Dejin; Cheng, Weihai; Huang, Biyong; Lai, Lei; Xia, Ming

2018-01-01

This paper briefly introduces the methods of calibrating the irradiance in the Xenon lamp aging test chamber. And the irradiance under ultraviolet region is mainly researched. Three different detectors whose response wave range are respectively UVA (320 400nm), UVB (275 330nm) and UVA+B (280 400nm) are used in the experiment. Through comparing the measuring results with different detectors under the same xenon lamp source, we discuss the difference between UVA, UVB and UVA+B on the basis of the spectrum of the xenon lamp and the response curve of the detectors. We also point out the possible error source, when use these detectors to calibrate the chamber.

The Advanced Test Reactor National Scientific User Facility Advancing Nuclear Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

T. R. Allen; J. B. Benson; J. A. Foster

2009-05-01

To help ensure the long-term viability of nuclear energy through a robust and sustained research and development effort, the U.S. Department of Energy (DOE) designated the Advanced Test Reactor and associated post-irradiation examination facilities a National Scientific User Facility (ATR NSUF), allowing broader access to nuclear energy researchers. The mission of the ATR NSUF is to provide access to world-class nuclear research facilities, thereby facilitating the advancement of nuclear science and technology. The ATR NSUF seeks to create an engaged academic and industrial user community that routinely conducts reactor-based research. Cost free access to the ATR and PIE facilities ismore » granted based on technical merit to U.S. university-led experiment teams conducting non-proprietary research. Proposals are selected via independent technical peer review and relevance to DOE mission. Extensive publication of research results is expected as a condition for access. During FY 2008, the first full year of ATR NSUF operation, five university-led experiments were awarded access to the ATR and associated post-irradiation examination facilities. The ATR NSUF has awarded four new experiments in early FY 2009, and anticipates awarding additional experiments in the fall of 2009 as the results of the second 2009 proposal call. As the ATR NSUF program mature over the next two years, the capability to perform irradiation research of increasing complexity will become available. These capabilities include instrumented irradiation experiments and post-irradiation examinations on materials previously irradiated in U.S. reactor material test programs. The ATR critical facility will also be made available to researchers. An important component of the ATR NSUF an education program focused on the reactor-based tools available for resolving nuclear science and technology issues. The ATR NSUF provides education programs including a summer short course, internships, faculty-student team projects and faculty/staff exchanges. In June of 2008, the first week-long ATR NSUF Summer Session was attended by 68 students, university faculty and industry representatives. The Summer Session featured presentations by 19 technical experts from across the country and covered topics including irradiation damage mechanisms, degradation of reactor materials, LWR and gas reactor fuels, and non-destructive evaluation. High impact research results from leveraging the entire research infrastructure, including universities, industry, small business, and the national laboratories. To increase overall research capability, ATR NSUF seeks to form strategic partnerships with university facilities that add significant nuclear research capability to the ATR NSUF and are accessible to all ATR NSUF users. Current partner facilities include the MIT Reactor, the University of Michigan Irradiated Materials Testing Laboratory, the University of Wisconsin Characterization Laboratory, and the University of Nevada, Las Vegas transmission Electron Microscope User Facility. Needs for irradiation of material specimens at tightly controlled temperatures are being met by dedication of a large in-pile pressurized water loop facility for use by ATR NSUF users. Several environmental mechanical testing systems are under construction to determine crack growth rates and fracture toughness on irradiated test systems.« less

PRELIMINARY DATA CALL REPORT ADVANCED BURNER REACTOR START UP FUEL FABRICATION FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. T. Khericha

2007-04-01

The purpose of this report is to provide data for preparation of a NEPA Environmental Impact Statement in support the U. S. Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP). One of the GNEP objectives is to reduce the inventory of long lived actinide from the light water reactor (LWR) spent fuel. The LWR spent fuel contains Plutonium (Pu) -239 and other transuranics (TRU) such as Americium-241. One of the options is to transmute or burn these actinides in fast neutron spectra as well as generate the electricity. A sodium-cooled Advanced Recycling Reactor (ARR) concept has been proposed tomore » achieve this goal. However, fuel with relatively high TRU content has not been used in the fast reactor. To demonstrate the utilization of TRU fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype of ARR is proposed, which would necessarily be started up using weapons grade (WG) Pu fuel. The WG Pu is distinguished by relatively highest proportions of Pu-239 and lesser amount of other actinides. The WG Pu will be used as the startup fuel along with TRU fuel in lead test assemblies. Because such fuel is not currently being produced in the US, a new facility (or new capability in an existing facility) is being considered for fabrication of WG Pu fuel for the ABR. This report is provided in response to ‘Data Call’ for the construction of startup fuel fabrication facility. It is anticipated that the facility will provide the startup fuel for 10-15 years and will take to 3 to 5 years to construct.« less

Are the surgeons safe during UV-A radiation exposure in collagen cross-linking procedure?

PubMed

Shetty, Rashmi; Shetty, Rohit; Mahendradas, Padmamalini; Shetty, Bhujang K

2012-02-01

To quantify the effect of scattered UV-A radiation used in the collagen cross-linking (CXL) procedure and the amount of radiation reaching the surgeon and the surrounding area and to estimate the dampening effect by various protective devices. In this case series, 3 patients [aged 25-30 (±2.5) years] with keratoconus underwent a CXL procedure with UV-A light and riboflavin. Irradiance was measured using a spectrometer (Model USB2000; Ocean Optics, Inc) for various distances from the source, at various angles, and for different durations of radiation. The spectrometer was also used to measure the dampening effect produced by gown, latex gloves, and UV-protective glasses. Maximum UV-A radiation (1.4 × 10(-9) mW/cm(2)) was measured at 2 cm from the limbus, when the probe was held at a 45-degree angle to the floor. UV-A radiation reaching the surgeon's eye and the abdomen was 3.403 × 10(-11) and 2.36 × 10(-11) mW/cm(2), respectively. Gown, latex gloves, and UV-protective glasses showed dampening effects of 99.58%, 95.01%, and 99.73%, respectively. CXL appears to be a safe procedure with respect to UV-A radiation exposure to the surgeon. Further safety can be ensured by UV-protective devices.

Photo-oxidation of 6-thioguanine by UVA: the formation of addition products with low molecular weight thiol compounds.

PubMed

Ren, Xiaolin; Xu, Yao-Zhong; Karran, Peter

2010-01-01

The thiopurine, 6-thioguanine (6-TG) is present in the DNA of patients treated with the immunosuppressant and anticancer drugs azathioprine or mercaptopurine. The skin of these patients is selectively sensitive to UVA radiation-which comprises >90% of the UV light in incident sunlight-and they suffer high rates of skin cancer. UVA irradiation of DNA 6-TG produces DNA lesions that may contribute to the development of cancer. Antioxidants can protect 6-TG against UVA but 6-TG oxidation products may undergo further reactions. We characterize some of these reactions and show that addition products are formed between UVA-irradiated 6-TG and N-acetylcysteine and other low molecular weight thiol compounds including β-mercaptoethanol, cysteine and the cysteine-containing tripeptide glutathione (GSH). GSH is also adducted to 6-TG-containing oligodeoxynucleotides in an oxygen- and UVA-dependent nucleophilic displacement reaction that involves an intermediate oxidized 6-TG, guanine sulfonate (G(SO3) ). These photochemical reactions of 6-TG, particularly the formation of a covalent oligodeoxynucleotide-GSH complex, suggest that crosslinking of proteins or low molecular weight thiol compounds to DNA may be a previously unrecognized hazard in sunlight-exposed cells of thiopurine-treated patients. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

UVA Irradiation of Dysplastic Keratinocytes: Oxidative Damage versus Antioxidant Defense

PubMed Central

Nechifor, Marina T.; Niculiţe, Cristina M.; Urs, Andreea O.; Regalia, Teodor; Mocanu, Mihaela; Popescu, Alexandra; Manda, Gina; Dinu, Diana; Leabu, Mircea

2012-01-01

UVA affects epidermal cell physiology in a complex manner, but the harmful effects have been studied mainly in terms of DNA damage, mutagenesis and carcinogenesis. We investigated UVA effects on membrane integrity and antioxidant defense of dysplastic keratinocytes after one and two hours of irradiation, both immediately after exposure, and 24 h post-irradiation. To determine the UVA oxidative stress on cell membrane, lipid peroxidation was correlated with changes in fatty acid levels. Membrane permeability and integrity were assessed by propidium iodide staining and lactate dehydrogenase release. The effects on keratinocyte antioxidant protection were investigated in terms of catalase activity and expression. Lipid peroxidation increased in an exposure time-dependent manner. UVA exposure decreased the level of polyunsaturated fatty acids, which gradually returned to its initial value. Lactate dehydrogenase release showed a dramatic loss in membrane integrity after 2 h minimum of exposure. The cell ability to restore membrane permeability was noted at 24 h post-irradiation (for one hour exposure). Catalase activity decreased in an exposure time-dependent manner. UVA-irradiated dysplastic keratinocytes developed mechanisms leading to cell protection and survival, following a non-lethal exposure. The surviving cells gained an increased resistance to apoptosis, suggesting that their pre-malignant status harbors an abnormal ability to control their fate. PMID:23222638

UVA1 a promising approach for scleroderma

PubMed Central

Keyal, Uma; Bhatta, Anil Kumar; Wang, Xiu Li

2017-01-01

Scleroderma is a complex connective tissue disease characterized by fibrosis, vasculopathy, and immune system dysfunction. The heterogeneity of disease presentation and poorly understood etiology has made the management of scleroderma difficult. The available treatment options like immunosuppressive agents are associated with potentially hazardous side effects and physiotherapy, which to a certain degree helps to minimize the loss of function in digits and limbs, has only limited success. Also, studies investigating antifibrotic therapies have failed to report any significant improvement. Hence, there is currently no effective therapy for scleroderma. Recently, phototherapy has been extensively studied and found to be effective in treating scleroderma. Initially psoralen + ultraviolet A (PUVA) significantly enriched the therapeutic panel, but more recently ultraviolet A1 (UVA1) is seen to replace PUVA therapy. This might be because of UVA1 therapy being free of side effects seen with psoralens such as nausea, vomiting or photokeratitis. In addition, UVA1 is seen to lower risk of phototoxic reactions with deeper penetration of radiation. The present review will put some light on the use of UVA1 for treating cutaneous lesion in scleroderma and we aim to find the most benefitted group of patients and most effective dose of UVA1 for different types of scleroderma. PMID:28979701

Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

PubMed

Abukassem, I; Bero, M A

2015-04-01

Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Protective role of extracellular catalase (KatA) against UVA radiation in Pseudomonas aeruginosa biofilms.

PubMed

Pezzoni, Magdalena; Pizarro, Ramón A; Costa, Cristina S

2014-02-05

One of the more stressful factors that Pseudomonas aeruginosa must face in nature is solar UVA radiation. In this study, the protective role of KatA catalase in both planktonic cells and biofilms of P. aeruginosa against UVA radiation was determined by using the wild-type (PAO1) and an isogenic catalase deficient strain (katA). The katA strain was more sensitive than the wild-type, especially in the case of biofilms. Moreover, the wild-type biofilm was more resistant than its planktonic counterpart, but this was not observed in the katA strain. Striking KatA activity was detected in the matrix of katA(+) strains, and to our knowledge, this is the first report of this activity in the matrix of P. aeruginosa biofilms. Provision of bovine catalase or KatA to the matrix of a katA biofilm significantly increased its UVA tolerance, demonstrating that extracellular KatA is essential to optimal defense against UVA in P. aeruginosa biofilms. Efficiency of photocatalytic treatments using TiO2 and UVA was lower in biofilms than in planktonic cells, but KatA and KatB catalases seem not to be responsible for the higher resistance of the sessile cells to this treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Of Ashes and Atoms

NASA Technical Reports Server (NTRS)

2005-01-01

This feature length DVD documentary, reviews the history of the Plum Brook Nuclear Reactor from the initial settlers of the area, through its use as a munitions facility during the second World War to the development of the nuclear facility and its use as one of the first nuclear test reactors built in the United States, and the only one built by NASA. It concludes with the beginning of the decommissioning of the facility. There is a brief review of the reactor design, and its workings. Through discussions with the NASA engineers and operators of the facility, the film reviews the work done to advance the knowledge of the effects of radiation, the properties of radiated materials, and the work to advance the state of the art in nuclear propulsion. The film shows footage of public tours, and shows actual footage of the facility in operation, and after its shutdown in 1973. The DVD was narrated by Kate Mulgrew, who leads the viewer through the history of the facility to its eventual ongoing decommissioning, and return to the state of pastoral uses.

Evaluation of drug and sunscreen permeation via skin irradiated with UVA and UVB: comparisons of normal skin and chronologically aged skin.

PubMed

Hung, Chi-Feng; Fang, Chia-Lang; Al-Suwayeh, Saleh A; Yang, Shih-Yung; Fang, Jia-You

2012-12-01

Ultraviolet (UV) exposure is the predominant cause of skin aging. A systematic evaluation of drug skin permeation via photoaged skin is lacking. The aim of this work was to investigate whether UVA and UVB affect absorption by the skin of drugs and sunscreens, including tetracycline, quercetin, and oxybenzone. The dorsal skin of nude mice was subjected to UVA (24 and 39 J/cm(2)) or UVB (150, 200, and 250 mJ/cm(2)) irradiation. Levels of skin water loss, erythema, and sebum were evaluated, and histological examinations of COX-2 and claudin-1 expressions were carried out. Permeation of the permeants into and through the skin was determined in vitro using a Franz cell. In vivo skin uptake was also evaluated. Senescent skin (24 weeks old) was used for comparison. Wrinkling and scaling were significant signs of skin treated with UVA and UVB, respectively. The level of claudin-1, an indicator of tight junctions (TJs), was reduced by UVA and UVB irradiation. UVA enhanced tetracycline and quercetin skin deposition by 11- and 2-fold, respectively. A similar enhancement was shown for flux profiles. Surprisingly, a lower UVA dose revealed greater enhancement compared to the higher dose. The skin deposition and flux of tetracycline both decreased with UVB exposure. UVB also significantly reduced quercetin flux. The skin absorption behavior of chronologically aged skin approximated that of the UVA group, with photoaged skin showing higher enhancement. UV generally exhibited a negligible effect on modulating oxybenzone permeation. Skin disruption produced by UV does not necessarily result in enhanced skin absorption. It depends on the UV wavelength, irradiated energy, and physicochemical properties of the permeant. To the best of our knowledge, this is the first report establishing drug permeation profiles for UV-irradiated skin. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Combined effects of constant sublethal UVA irradiation and elevated temperature on the survival and general metabolism of the convict-cichlid fish, Cichlasoma nigrofasciatum.

PubMed

Winckler, K; Fidhiany, L

1996-04-01

In a previous study we observed that a constant sublethal UVA (320-400 nm) irradiation had a significant effect on the general metabolism in the Convict-cichlid fish (Cichlasoma nigrofasciatum) [Winckler, K. and Fidhiany, L. (1996) J. Photochem. Photobiol. B. Biol. (In press)]. In the present study we show that sublethal UVA irradiation in combination with elevated environmental temperature has a deleterious effect on the same population. The threshold temperature for a sudden increase in mortality of fish receiving an additional sublethal UVA irradiation was 32 degrees C. Prior to the increased mortality, the fish started to avoid the UV light source when the water temperature increased to 31.5 degrees C. Mortality decreased when the temperature declined below 31.5 degrees C. As soon as the temperature changed to normal (adapted) condition (27-29 degrees C) mortality returned to normal levels. In contrast, no changes of fish behavior or mortality were observed at elevated temperature in the nonirradiated reference population. The percentages of fish surviving the high temperature stress were 21.9% for the UVA population and 96.8% for the reference population. The specific oxygen consumption (SOC, average +/- SD) of the survivors from the UVA population during temperature stress was 0.21 +/- 0.05 mg O2 h-1 g body weight (BW)-1, while it was 0.54 +/- 0.11 mg O2 h-1 g BW-1 in the reference population. After the environmental temperature returned below the apparent upper temperature tolerance limit, the oxygen consumption of the UVA population gradually normalized. The SOC measured at different temperature levels--after after the fish passed the temperature stress--showed no significant differences between the UVA population and its reference at 23, 25, 27 and 29 degrees C. However, the SOC at 31 degrees C was significantly (P < 0.05) lower than reference, while at 33 degrees C it was higher (P < 0.10).

Photostability of commercial sunscreens upon sun exposure and irradiation by ultraviolet lamps

PubMed Central

Gonzalez, Helena; Tarras-Wahlberg, Nils; Strömdahl, Birgitta; Juzeniene, Asta; Moan, Johan; Larkö, Olle; Rosén, Arne; Wennberg, Ann-Marie

2007-01-01

Background Sunscreens are being widely used to reduce exposure to harmful ultraviolet (UV) radiation. The fact that some sunscreens are photounstable has been known for many years. Since the UV-absorbing ingredients of sunscreens may be photounstable, especially in the long wavelength region, it is of great interest to determine their degradation during exposure to UV radiation. Our aim was to investigate the photostability of seven commercial sunscreen products after natural UV exposure (UVnat) and artificial UV exposure (UVart). Methods Seven commercial sunscreens were studied with absorption spectroscopy. Sunscreen product, 0.5 mg/cm2, was placed between plates of silica. The area under the curve (AUC) in the spectrum was calculated for UVA (320–400 nm), UVA1 (340–400 nm), UVA2 (320–340 nm) and UVB (290–320 nm) before (AUCbefore) and after (AUCafter) UVart (980 kJ/m2 UVA and 12 kJ/m2 of UVB) and before and after UVnat. If theAUC Index (AUCI), defined as AUCI = AUCafter/AUCbefore, was > 0.80, the sunscreen was considered photostable. Results Three sunscreens were unstable after 90 min of UVnat; in the UVA range the AUCI was between 0.41 and 0.76. In the UVB range one of these sunscreens was unstable with an AUCI of 0.75 after 90 min. Three sunscreens were photostable after 120 min of UVnat; in the UVA range the AUCI was between 0.85 and 0.99 and in the UVB range between 0.92 and 1.0. One sunscreen showed in the UVA range an AUCI of 0.87 after UVnat but an AUCI of 0.72 after UVart. Five of the sunscreens were stable in the UVB region. Conclusion The present study shows that several sunscreens are photounstable in the UVA range after UVnat and UVart. There is a need for a standardized method to measure photostability, and the photostability should be marked on the sunscreen product. PMID:17324264

The advantages and disadvantages of using the TREAT reactor for nuclear laser experiments

NASA Astrophysics Data System (ADS)

Dickson, P. W.; Snyder, A. M.; Imel, G. R.; McConnell, R. J.

The Transient Reactor Test Facility (TREAT) is a large air-cooled test facility located at the Idaho National Engineering Laboratory. Two of the major design features of TREAT, its large size and its being an air-cooled reactor, provide clues to both its advantages and disadvantages for supporting nuclear laser experiments. Its large size, which is dictated by the dilute uranium/graphite fuel, permits accommodation of geometrically large experiments. However, TREAT's large size also results in relatively long transients so that the energy deposited in an experiment is large relative to the peak power available from the reactor. TREAT's air-cooling mode of operation allows its configuration to be changed fairly readily. Due to air cooling, the reactor cools down slowly, permitting only one full power transient a day, which can be a disadvantage in some experimental programs. The reactor is capable of both steady-state or transient operation.

Recent upgrades and new scientific infrastructure of MARIA research reactor, Otwock-Swierk, Poland

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The MARIA reactor is open-pool type, water and beryllium moderated. It has two independent primary cooling systems: fuel and pool cooling system. Each fuel assembly is cooled down separately in pressurized channels with individual performances characterization. The fuel assemblies consist of five layers of bent plates or six concentric tubes. Currently it is one of the most powerful research reactors in Europe with operation availability at least up to 2030. Its nominal thermal power is 30 MW. It is characterized by high neutron flux density: up to 3x10{sup 14} n cm{sup -2} s{sup -1} in case of thermal neutrons, andmore » up to 2x10{sup 13} n cm{sup -2} s{sup -1} in case of fast neutrons. The reactor is operated for ca. 4000 h per year. The reactor facility is equipped with fully equipped three hot cells with shielding up to 10{sup 15} Bq. Adjacent to the reactor facility, the radio-pharmaceutics plant (POLATOM) and Material Research Laboratory are located. They are equipped with a number of hot cells with instrumentation. The transport system of radioactive materials from reactor facility to Material Research Laboratory is available. During 2014 the MARIA reactor has been operated with three different types of fuel the same time: previous 36% enriched fuel, and two types of new LEU fuels. In the meantime, molybdenum irradiation programme has been developed. Maria is a multifunctional research tool, with a notable application in production of radioisotopes, radio-pharmaceutics manufacturing (ca. 600 TBq/y), {sup 99}Mo for medical scintigraphy (ca. 6000 TBq/y), neutron transmutation doping of silicon single crystals, wide scientific research based on neutron beams utilization. From the beginning MARIA reactor was intended for loop and fuel testing research activities. Currently it is used mostly as material testing and irradiation facility and for that reason it has wide experimental capabilities. There are eight horizontal irradiation channels from among whom six of them are equipped with instrumentation for condensed matter physics research: - H3 - spectrometer and diffractometer with double monochromator; - H4 - small angle scattering spectrometer; - H5 - polarized neutrons spectrometer; - H6, H7 - two 3-axial crystal neutron spectrometers; - H8 - neutron radiography stand. For two horizontal channels are ongoing exploitation programs: - H2 - station with epithermal neutron beam produced in uranium converter is being developed. Intelligent converter will be installed on the periphery of reactor core. The intensity of the beam will be at the level 2x10{sup 9} n cm{sup -2}s{sup -1} what makes the beam unique in the Europe. - H1 - special pneumatic horizontal mail is being developed for irradiation material samples in the vicinity of the core i.e. in the distal part of the H1 channel. The number of neutron irradiation facilities in MARIA reactor is increasing every year. Numerous of thermal neutron irradiation channels including fast hydraulic rabbit system and large size channels for fast neutron irradiation are used routinely. Recently new in-pile facility with ITER-like neutron energy spectrum for 14 MeV neutron irradiation has been constructed. Taking into account its performance and ability of almost incessant operation the facility appears as one of the most powerful 14 MeV neutron sources. The facility shall be used for material research connected with thermonuclear devices (ITER) and 4. generation nuclear reactors. The system of independent fuels channels used in MARIA reactor appear to be very flexible and very convenient to be used as irradiation channels for uranium targets for {sup 99}Mo production. Currently, MARIA reactor supplies ca. 18% world production of {sup 99}Mo. The MARIA reactor research activities are still extended. The current scientific projects are connected e.g. with silicon neutron transmutation doping, in-pile gamma heating measurements, French calculation codes implementation (TRIPOLI4, APOLLO2). The horizontal neutron beams utilization is also developed. The MARIA reactor, due to its primary application connected with loop and fuel testing, is very convenient for testing the nuclear instrumentation, control and measurement systems.« less

Studies of neutron-rich nuclei far from stability at TRISTAN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gill, R.L.

The ISOL facility, TRISTAN, is a user facility located at Brookhaven National Laboratory's High Flux Beam Reactor. Short-lived, neutron-rich nuclei, far from stability, are produced by thermal neutron fission of /sup 235/U. An extensive array of experimental end stations are available for nuclear structure studies. These studies are augmented by a variety of long-lived ion sources suitable for use at a reactor facility. Some recent results at TRISTAN are presented as examples of using an ISOL facility to study series of nuclei, whereby an effective means of conducting nuclear structure investigations is available.

General layout of reactor and control areas upon advent of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General layout of reactor and control areas upon advent of power burst facility (PBF). Shows relationship of PBF to SPERT-I, -II, -III, and -IV. Ebasco Services 1205-PER/PBF-U-102. Date: July 1965. INEEL index no. 761-0100-00-205-123006 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

10. Photocopy of drawing, February 1958, NUCLEAR REACTOR FACILITY, STRUCTURAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Photocopy of drawing, February 1958, NUCLEAR REACTOR FACILITY, STRUCTURAL CROSS SECTION. Giffals & Vallet, Inc., L. Rosetti, Associated Architects and Engineers, Detroit, Michigan; and U.S. Army Engineer Division, New England Corps of Engineers, Boston, Massachusetts. Drawing Number 35-84-04. (Original: AMTL Engineering Division, Watertown). - Watertown Arsenal, Building No. 100, Wooley Avenue, Watertown, Middlesex County, MA

Photosynthetic carbon reduction by seagrasses exposed to ultraviolet A radiation

NASA Technical Reports Server (NTRS)

1979-01-01

The seagrasses Halophila engelmannii, Halodule wrightii, and Syringodium filiforme were examined for their intrinsic sensitivity to ultraviolet-A-UV-A and ultraviolet-B-UV-B radiation. The effect of UV-A on photosynthetically active radiation (PAR) was also determined. Ultraviolet-A and ultraviolet-B were studied with emphasis on the greater respective environmental consequence in terms of seagrass distribution and abundance. Results indicate that an intrinsic sensitivity to UV-A alone is apparent only in Halophila, while net photosynthesis in Halodule and Syringodium seems unaffected by the level of UV-A provided. The sensitivity of Halophila to UV-A in the absense of (PAR) indicates that the photosynthetic reaction does not need to be in operation for damage to occur. Other significant results are reported.

DESIGN CRITERIA FOR FUEL DISSOLUTION SYSTEMS AND ASSOCIATED SERVICE FACILITIES. PLANT MODIFICATIONS FOR REPROCESSING NON-PRODUCTION REACTOR FUELS. PROJECT CGC-830

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bierman, S.R.; Graf, W.A.; Kass, M.

1960-07-29

Design panameters are presented for phases of the facility to reprocess low-enrichment fuels from nonproduction reactors. Included are plant flowsheets and equipment layouts for fuel element dissolution, centrifugation, solution adjustment, and waste handling. Also included are the basic design criteria for the supporting facilities which service these phases and all other facilites located in the vicinity of the selected building (Bldg. 221-U). (J.R.D.)

All About MOX

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-07-29

In 1999, the Nuclear Nuclear Security Administration (NNSA) signed a contract with a consortium, now called Shaw AREVA MOX Services, LLC to design, build, and operate a Mixed Oxide (MOX) Fuel Fabrication Facility. This facility will be a major component in the United States program to dispose of surplus weapon-grade plutonium. The facility will take surplus weapon-grade plutonium, remove impurities, and mix it with uranium oxide to form MOX fuel pellets for reactor fuel assemblies. These assemblies will be irradiated in commercial nuclear power reactors.

All About MOX

ScienceCinema

None

2018-01-16

In 1999, the Nuclear Nuclear Security Administration (NNSA) signed a contract with a consortium, now called Shaw AREVA MOX Services, LLC to design, build, and operate a Mixed Oxide (MOX) Fuel Fabrication Facility. This facility will be a major component in the United States program to dispose of surplus weapon-grade plutonium. The facility will take surplus weapon-grade plutonium, remove impurities, and mix it with uranium oxide to form MOX fuel pellets for reactor fuel assemblies. These assemblies will be irradiated in commercial nuclear power reactors.

The CABRI fast neutron Hodoscope: Renovation, qualification program and first results following the experimental reactor restart

NASA Astrophysics Data System (ADS)

Chevalier, V.; Mirotta, S.; Guillot, J.; Biard, B.

2018-01-01

The CABRI experimental pulse reactor, located at the Cadarache nuclear research center, southern France, is devoted to the study of Reactivity Initiated Accidents (RIA). For the purpose of the CABRI International Program (CIP), managed and funded by IRSN, in the framework of an OECD/NEA agreement, a huge renovation of the facility has been conducted since 2003. The Cabri Water Loop was then installed to ensure prototypical Pressurized Water Reactor (PWR) conditions for testing irradiated fuel rods. The hodoscope installed in the CABRI reactor is a unique online fuel motion monitoring system, operated by IRSN and dedicated to the measurement of the fast neutrons emitted by the tested rod during the power pulse. It is one of the distinctive features of the CABRI reactor facility, which is operated by CEA. The system is able to determine the fuel motion, if any, with a time resolution of 1 ms and a spatial resolution of 3 mm. The hodoscope equipment has been upgraded as well during the CABRI facility renovation. This paper presents the main outcomes achieved with the hodoscope since October 2015, date of the first criticality of the CABRI reactor in its new Cabri Water Loop configuration. Results obtained during reactor commissioning phase functioning, either in steady-state mode (at low and high power, up to 23 MW) or in transient mode (start-up, possibly beyond 20 GW), are discussed.

Utilization of the Philippine Research Reactor as a training facility for nuclear power plant operators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palabrica, R.J.

1981-01-01

The Philippines has a 1-MW swimming-pool reactor facility operated by the Philippine Atomic Energy Commission (PAEC). The reactor is light-water moderated and cooled, graphite reflected, and fueled with 90% enriched uranium. Since it became critical in 1963 it has been utilized for research, radioisotope production, and training. It was used initially in the training of PAEC personnel and other research institutions and universities. During the last few years, however, it has played a key role in training personnel for the Philippine Nuclear Power Project (PNPP).

ETR CRITICAL FACILITY, TRA654. CONTEXTUAL VIEW. CAMERA ON ROOF OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR CRITICAL FACILITY, TRA-654. CONTEXTUAL VIEW. CAMERA ON ROOF OF MTR BUILDING AND FACING SOUTH. ETR AND ITS COOLANT BUILDING AT UPPER PART OF VIEW. ETR COOLING TOWER NEAR TOP EDGE OF VIEW. EXCAVATION AT CENTER IS FOR ETR CF. CENTER OF WHICH WILL CONTAIN POOL FOR REACTOR. NOTE CHOPPER TUBE PROCEEDING FROM MTR IN LOWER LEFT OF VIEW, DIAGONAL TOWARD LEFT. INL NEGATIVE NO. 56-4227. Jack L. Anderson, Photographer, 12/18/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

10 CFR 1.44 - Office of New Reactors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Office of New Reactors. 1.44 Section 1.44 Energy NUCLEAR... Office of New Reactors. The Office of New Reactors— (a) Develops, promulgates and implements regulations... safeguarding of nuclear reactor facilities licensed under part 52 of this chapter prior to initial commencement...

10 CFR 1.44 - Office of New Reactors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Office of New Reactors. 1.44 Section 1.44 Energy NUCLEAR... Office of New Reactors. The Office of New Reactors— (a) Develops, promulgates and implements regulations... safeguarding of nuclear reactor facilities licensed under part 52 of this chapter prior to initial commencement...

CRITICAL EXPERIMENT TANK (CET) REACTOR HAZARDS SUMMARY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becar, N.J.; Kunze, J.F.; Pincock, G..D.

1961-03-31

The Critical Experiment Tank (CET) reactor assembly, the associated systems, and the Low Power Test Facility in which the reactor is to be operated are described. An evaluation and summary of the hazards associated with the operation of the CET reactor in the LPTF at the ldsho Test Station are also presented. (auth)

PBF Reactor Building (PER620). Reactor vessel arrives from gate city ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Reactor vessel arrives from gate city steel at door of PBF. On flatbed, it is too high to fit under door. Photographer: Larry Page. Date: February 13, 1970. INEEL negative no. 70-737 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

10 CFR 1.44 - Office of New Reactors.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Office of New Reactors. 1.44 Section 1.44 Energy NUCLEAR... safeguarding of nuclear reactor facilities licensed under part 52 of this chapter prior to initial commencement... Office of New Reactors. The Office of New Reactors— (a) Develops, promulgates and implements regulations...

10 CFR 1.44 - Office of New Reactors.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Office of New Reactors. 1.44 Section 1.44 Energy NUCLEAR... safeguarding of nuclear reactor facilities licensed under part 52 of this chapter prior to initial commencement... Office of New Reactors. The Office of New Reactors— (a) Develops, promulgates and implements regulations...

10 CFR 1.44 - Office of New Reactors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Office of New Reactors. 1.44 Section 1.44 Energy NUCLEAR... safeguarding of nuclear reactor facilities licensed under part 52 of this chapter prior to initial commencement... Office of New Reactors. The Office of New Reactors— (a) Develops, promulgates and implements regulations...

Test facility for investigation of heat transfer of promising coolants for the nuclear power industry

NASA Astrophysics Data System (ADS)

Belyaev, I. A.; Sviridov, V. G.; Batenin, V. M.; Biryukov, D. A.; Nikitina, I. S.; Manchkha, S. P.; Pyatnitskaya, N. Yu.; Razuvanov, N. G.; Sviridov, E. V.

2017-11-01

The results are presented of experimental investigations into liquid metal heat transfer performed by the joint research group consisting of specialist in heat transfer and hydrodynamics from NIU MPEI and JIHT RAS. The program of experiments has been prepared considering the concept of development of the nuclear power industry in Russia. This concept calls for, in addition to extensive application of water-cooled, water-moderated (VVER-type) power reactors and BN-type sodium cooled fast reactors, development of the new generation of BREST-type reactors, fusion power reactors, and thermonuclear neutron sources. The basic coolants for these nuclear power installations will be heavy liquid metals, such as lead and lithium-lead alloy. The team of specialists from NRU MPEI and JIHT RAS commissioned a new RK-3 mercury MHD-test facility. The major components of this test facility are a unique electrical magnet constructed at Budker Nuclear Physics Institute and a pressurized liquid metal circuit. The test facility is designed for investigating upward and downward liquid metal flows in channels of various cross-sections in a transverse magnetic field. A probe procedure will be used for experimental investigation into heat transfer and hydrodynamics as well as for measuring temperature, velocity, and flow parameter fluctuations. It is generally adopted that liquid metals are the best coolants for the Tokamak reactors. However, alternative coolants should be sought for. As an alternative to liquid metal coolants, molten salts, such as fluorides of lithium and beryllium (so-called FLiBes) or fluorides of alkali metals (so-called FLiNaK) doped with uranium fluoride, can be used. That is why the team of specialists from NRU MPEI and JIHT RAS, in parallel with development of a mercury MHD test facility, is designing a test facility for simulating molten salt heat transfer and hydrodynamics. Since development of this test facility requires numerical predictions and verification of numerical codes, all examined configurations of the MHD flow are also investigated numerically.

Developing a concept for a national used fuel interim storage facility in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Donald Wayne

2013-07-01

In the United States (U.S.) the nuclear waste issue has plagued the nuclear industry for decades. Originally, spent fuel was to be reprocessed but with the threat of nuclear proliferation, spent fuel reprocessing has been eliminated, at least for now. In 1983, the Nuclear Waste Policy Act of 1982 [1] was established, authorizing development of one or more spent fuel and high-level nuclear waste geological repositories and a consolidated national storage facility, called a 'Monitored Retrievable Storage' facility, that could store the spent nuclear fuel until it could be placed into the geological repository. Plans were under way to buildmore » a geological repository, Yucca Mountain, but with the decision by President Obama to terminate the development of Yucca Mountain, a consolidated national storage facility that can store spent fuel for an interim period until a new repository is established has become very important. Since reactor sites have not been able to wait for the government to come up with a storage or disposal location, spent fuel remains in wet or dry storage at each nuclear plant. The purpose of this paper is to present a concept developed to address the DOE's goals stated above. This concept was developed over the past few months by collaboration between the DOE and industry experts that have experience in designing spent nuclear fuel facilities. The paper examines the current spent fuel storage conditions at shutdown reactor sites, operating reactor sites, and the type of storage systems (transportable versus non-transportable, welded or bolted). The concept lays out the basis for a pilot storage facility to house spent fuel from shutdown reactor sites and then how the pilot facility can be enlarged to a larger full scale consolidated interim storage facility. (authors)« less

Tolerance of the eriophyid mite Aceria salsolae to UV-A light and implications for biological control of Russian thistle.

PubMed

Moran, Patrick J; Wibawa, M Irene; Smith, Lincoln

2017-12-01

Aceria salsolae (Acari: Eriophyidae) is being evaluated as a candidate biological control agent of Russian thistle (Salsola tragus, Chenopodiaceae), a major invasive weed of rangelands and dryland crops in the western USA. Prior laboratory host range testing under artificial lighting indicated reproduction on non-native Bassia hyssopifolia and on a native plant, Suaeda calceoliformis. However, in field tests in the native range, mite populations released on these 'nontarget' plants remained low. We hypothesized that UV-A light, which can affect behavior of tetranychid mites, would affect populations of the eriophyid A. salsolae differently on the target and nontarget plant species, decreasing the mite's realized host range. Plants were infested with A. salsolae under lamps that emitted UV-A, along with broad-spectrum lighting, and the size of mite populations and plant growth was compared to infested plants exposed only to broad-spectrum light. Russian thistle supported 3- to 55-fold larger mite populations than nontarget plants regardless of UV-A treatment. UV-A exposure did not affect mite populations on Russian thistle or S. calceoliformis, whereas it increased populations 7-fold on B. hyssopifolia. Main stems on nontarget plants grew 2- to 6-fold faster than did Russian thistle under either light treatment. The two nontarget plants attained greater volume under the control light regime than UV-A, but Russian thistle was unaffected. Although Russian thistle was always the superior host, addition of UV-A light to the artificial lighting regime did not reduce the ability of A. salsolae to reproduce on the two nontarget species, suggesting that UV-B or other environmental factors may be more important in limiting mite populations in the field.

The deceptive nature of UVA tanning versus the modest protective effects of UVB tanning on human skin.

PubMed

Miyamura, Yoshinori; Coelho, Sergio G; Schlenz, Kathrin; Batzer, Jan; Smuda, Christoph; Choi, Wonseon; Brenner, Michaela; Passeron, Thierry; Zhang, Guofeng; Kolbe, Ludger; Wolber, Rainer; Hearing, Vincent J

2011-02-01

The relationship between human skin pigmentation and protection from ultraviolet (UV) radiation is an important element underlying differences in skin carcinogenesis rates. The association between UV damage and the risk of skin cancer is clear, yet a strategic balance in exposure to UV needs to be met. Dark skin is protected from UV-induced DNA damage significantly more than light skin owing to the constitutively higher pigmentation, but an as yet unresolved and important question is what photoprotective benefit, if any, is afforded by facultative pigmentation (i.e. a tan induced by UV exposure). To address that and to compare the effects of various wavelengths of UV, we repetitively exposed human skin to suberythemal doses of UVA and/or UVB over 2 weeks after which a challenge dose of UVA and UVB was given. Although visual skin pigmentation (tanning) elicited by different UV exposure protocols was similar, the melanin content and UV-protective effects against DNA damage in UVB-tanned skin (but not in UVA-tanned skin) were significantly higher. UVA-induced tans seem to result from the photooxidation of existing melanin and its precursors with some redistribution of pigment granules, while UVB stimulates melanocytes to up-regulate melanin synthesis and increases pigmentation coverage, effects that are synergistically stimulated in UVA and UVB-exposed skin. Thus, UVA tanning contributes essentially no photoprotection, although all types of UV-induced tanning result in DNA and cellular damage, which can eventually lead to photocarcinogenesis. 2010 John Wiley & Sons A/S. This article is a US Government work and is in the public domain in the USA.

Broad-spectrum photoprotection: the roles of tinted auto windows, sunscreens and browning agents in the diagnosis and treatment of photosensitivity.

PubMed

Johnson, J A; Fusaro, R M

1992-01-01

Since window glass absorbs sunlight below 320 nm, it provides a means of assessing sensitivity to longer wavelengths, i.e. UVA and visible radiation. Positive responses to the query of whether symptoms develop in the auto with the windows up must now be interpreted with regard to the possible presence of tinted plastic film on side and rear windows. These films block nearly all UVA radiation, as does the plastic interleaf of windshields. Thus, occupants of an auto equipped with plastic film receive photoprotection from UVB radiation and well into the UVA region. We define three classes of topical sunscreens: (1) conventional UVB screens, (2) broad-spectrum preparations containing a UVB screen and a UVA absorber and (3) browning agents such as dihydroxyacetone (DHA) that produce a skin coloration that absorbs in the low end of the visible region, with overlap into long-wavelength UVA. By considering responses of photosensitive persons in autos with tinted or untinted windows, coupled with efficacy of appropriate sunscreens, we produced an algorithm defining three photosensitivity subsets. Persons sensitive to long-wavelength UVA and/or visible radiation will benefit from tinted auto windows. In particular, patients with lupus erythematosus (LE) have actively promoted legislation allowing tinted windows. Support for their position is documented by recent reports of induction of lesions in LE patients by exposure to UVA and visible radiation. The brown color produced by DHA is a useful adjunct to the screening action of broad-spectrum sunscreens. Development of a durable color overnight allows application of the DHA preparation in the evening, thus eliminating possible interference with sunscreen use during the day.

Cyclobutane pyrimidine dimers are photosensitised by carprofen plus UVA in human HaCaT cells.

PubMed

Robinson, K S; Traynor, N J; Moseley, H; Ferguson, J; Woods, J A

2010-06-01

Every year in the UK about 75,000 cases of non-melanoma skin cancer (NMSC) are registered, and about 9500 people are diagnosed with cutaneous melanoma (CM). The main risk factor for these cancers is exposure to sunlight. The effects of light on skin are wavelength dependent, with wavelengths in the UVB waveband (280-315 nm) being the most carcinogenic. UVB is directly absorbed by DNA, producing dimeric pyrimidine photoproducts including cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimodone photoproducts (6-4PP). However UVA (315-400 nm) can also produce CPD, induce skin tumours in mice, and has been shown to be mutagenic in cell culture. Although the precise role of UVA in human skin cancer remains to be elucidated, it comprises the major portion of solar UV radiation, transmits through window glass and can be delivered in high doses from tanning lamps. Non-steroidal anti-inflammatory drugs (NSAIDs), in particular the 2-aryl propionic acid derivatives, are a well-documented group of photosensitising chemicals producing clinical phototoxic and photoallergic reactions. We have used carprofen, a model compound from this group to see if it could amplify the effects of UVA and contribute to the formation of CPD by UVA. Preliminary work has shown that carprofen combined with low doses of UVA (lambda(max): 365 nm; 5 J/cm(2)) can produce both strand breaks (SB) and CPD in human skin or blood cells. CPD were detected indirectly by both an immunofluorescence method and as T4 endonuclease V sensitive sites in the comet assay. These findings show that compounds other than fluoroquinolones and psoralen derivatives may contribute to CPD formation in skin cells in combination with UVA. Copyright 2010 Elsevier Ltd. All rights reserved.

The effects of ultraviolet radiation on photosynthetic performance, growth and sunscreen compounds in aeroterrestrial biofilm algae isolated from building facades.

PubMed

Karsten, U; Lembcke, S; Schumann, R

2007-03-01

The effects of artificial ultraviolet radiation [UVR; 8 W m(-2) ultraviolet-A (UVA), 0.4 W m(-2) ultraviolet-B (UVB)] on photosynthetic performance, growth and the capability to synthesise mycosporine-like amino acids (MAAs) was investigated in the aeroterrestrial green algae Stichococcus sp. and Chlorella luteoviridis forming biofilms on building facades, and compared with the responses of two green algae, from soil (Myrmecia incisa) and brackish water (Desmodesmus subspicatus). All species exhibited decreasing quantum efficiency (Fv/Fm) after 1-3 days exposure to UVR. After 8-12 days treatment, however, all aeroterrestrial isolates exhibited full recovery under UVA and UVA/B. In contrast, D. subspicatus showed only 80% recovery after treatment with UVB. While Stichococcus sp. and C. luteoviridis exhibited a broad tolerance in growth under all radiation conditions tested, M. incisa showed a significant decrease in growth rate after exposure to UVA and UVA/B. Similarly D. subspicatus grew with a reduced rate under UVA, but UVA/B led to full inhibition. Using HPLC, an UV-absorbing MAA (324 nm-MAA) was identified in Stichococcus sp. and C. luteoviridis. While M. incisa contained a specific 322 nm-MAA, D. subspicatus lacked any trace of such compounds. UV-exposure experiments indicated that all MAA-containing species are capable of synthesizing and accumulating these compounds, thus supporting their function as an UV-sunscreen. All data well explain the conspicuous ecological success of aeroterrestrial green algae in biofilms on facades. Biosynthesis and accumulation of MAAs under UVR seem to result in a reduced UV-sensitivity of growth and photosynthesis, which consequently may enhance survival in the environmentally harsh habitat.

Pigmentation after single and multiple UV-exposures depending on UV-spectrum.

PubMed

Ravnbak, M H; Wulf, H C

2007-04-01

Minimal pigmentation dose (MMD) after a single UV-exposure is well investigated. Whereas only few studies have established MMD after multiple UV-exposures and mainly in fair-skinned persons. The purpose of this study was to establish MMD 1 week after, respectively, one and five UV-exposures in volunteers with a large variation in constitutive pigmentation. A total of 52 volunteers (skin Types II-V) had skin pigmentation quantified by reflectance spectroscopy. They were UV-exposed on the back for 1 and 5 days using a Solar Simulator, narrowband UVB, broadband UVA and UVA1. For all sources a higher dose was needed the more pigmented the skin, except for UVA1. After one UV-exposure, we found a significant positive linear correlation between UV-dose to one MMD, skin type and pre-exposure skin pigmentation. After five UV-exposures the positive linear correlation between UV-dose and MMD and skin type was only significant for narrow band UVB, pre-exposure skin pigmentation was significant also for Solar Simulator. For UVA and particularly UVA1 the MMD was independent of pre-exposure pigmentation. The number of SED to MMD is therefore almost the same for very fair-skinned and dark-skinned persons. Pre-exposure pigmentation was clearly more predictive of MMD than skin type. 50% of MMD equals a pigmentation increase of 1%. The shorter the wavelengths the higher the SED to produce MMD. Solar was the least melanogenic and UVA1 the most melanogenic. For the UVB-sources a higher dose was needed the more pigmented the skin. For UVA the MMD was independent of pre-exposure pigmentation.

Transmutation of actinides in power reactors.

PubMed

Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

2005-01-01

Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides.

U.S. Nuclear Cooperation with India: Issues for Congress

DTIC Science & Technology

2008-11-03

separation list: ! 8 indigenous Indian power reactors ! Fast Breeder test Reactor (FTBR) and Prototype Fast Breeder Reactors (PFBR) under construction...facilities like reprocessing and enrichment plants and breeder reactors could be viewed as providing a significant nonproliferation benefit because the... breeder reactors would support the 2002 U.S. National Strategy to Combat Weapons of Mass Destruction, in which the United States pledged to “continue to

Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals

PubMed Central

de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

2010-01-01

This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals. PMID:22163515

Man-machine interface system for neuromuscular training and evaluation based on EMG and MMG signals.

PubMed

de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

2010-01-01

This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

High-Si content BARC for dual-BARC systems such as trilayer patterning

NASA Astrophysics Data System (ADS)

Kennedy, Joseph; Xie, Song-Yuan; Wu, Ze-Yu; Katsanes, Ron; Flanigan, Kyle; Lee, Kevin; Slezak, Mark; Liu, Zhi; Lin, Shang-Ho

2009-03-01

This work discusses the requirements and performance of Honeywell's middle layer material, UVAS, for tri-layer patterning. UVAS is a high Si content polymer synthesized directly from Si containing starting monomer components. The monomers are selected to produce a film that meets the requirements as a middle layer for tri-layer patterning (TLP) and gives us a level of flexibility to adjust the properties of the film to meet the customer's specific photoresist and patterning requirements. Results of simulations of the substrate reflectance versus numerical aperture, UVAS thickness, and under layer film are presented. ArF photoresist line profiles and process latitude versus UVAS bake at temperatures as low as 150ºC are presented and discussed. Immersion lithographic patterning of ArF photoresist line space and contact hole features will be presented. A sequence of SEM images detailing the plasma etch transfer of line space photoresist features through the middle and under layer films comprising the TLP film stack will be presented. Excellent etch selectivity between the UVAS and the organic under layer film exists as no edge erosion or faceting is observed as a result of the etch process. A detailed study of the impact of a PGMEA solvent photoresist rework process on the lithographic process window of a TLP film stack was performed with the results indicating that no degradation to the UVAS film occurs.

Rapid repair of UVA-induced oxidized purines and persistence of UVB-induced dipyrimidine lesions determine the mutagenicity of sunlight in mouse cells

PubMed Central

Besaratinia, Ahmad; Kim, Sang-in; Pfeifer, Gerd P.

2009-01-01

Despite the predominance of UVA relative to UVB in terrestrial sunlight, solar mutagenesis in humans and rodents is characterized by mutations specific for UVB. We have investigated the kinetics of repair of UVA- and UVB-induced DNA lesions in relation to mutagenicity in transgenic mouse fibroblasts irradiated with equilethal doses of UVA and UVB in comparison to SSL. We have also analyzed mutagenesis-derived carcinogenesis in sunlight-associated human skin cancers by compiling the published data on mutation types found in crucial genes in non-melanoma and melanoma skin cancers. Here, we demonstrate a resistance to repair of UVB-induced CPDs together with rapid removal of UVA-induced oxidized purines in the genome overall and in the cII transgene of SSL-irradiated cells. The spectra of mutation induced by both UVB- and SSL-irradiation in this experimental system are characterized by significant increases in relative frequency of C to T transitions at dipyrimidines, which are the established signature mutation of CPDs. This type of mutation is also the predominant mutation found in human non-melanoma and melanoma tumor samples in the TP53, CDKN2, PTCH, and protein kinase genes. The prevailing role of UVB over UVA in solar mutagenesis in our test system can be ascribed to different kinetics of repair for lesions induced by the respective UV-irradiation. PMID:18326785

UVA photoactivation of DNA containing halogenated thiopyrimidines induces cytotoxic DNA lesions

PubMed Central

Brem, Reto; Zhang, Xiaohui; Xu, Yao-Zhong; Karran, Peter

2015-01-01

Photochemotherapy, the combination of a photosensitiser and ultraviolet (UV) or visible light, is an effective treatment for skin conditions including cancer. The high mutagenicity and non-selectivity of photochemotherapy regimes warrants the development of alternative approaches. We demonstrate that the thiopyrimidine nucleosides 5-bromo-4-thiodeoxyuridine (SBrdU) and 5-iodo-4-thiodeoxyuridine (SIdU) are incorporated into the DNA of cultured human and mouse cells where they synergistically sensitise killing by low doses of UVA radiation. The DNA halothiopyrimidine/UVA combinations induce DNA interstrand crosslinks, DNA-protein crosslinks, DNA strand breaks, nucleobase damage and lesions that resemble UV-induced pyrimidine(6-4)pyrimidone photoproducts. These are potentially lethal DNA lesions and cells defective in their repair are hypersensitive to killing by SBrdU/UVA and SIdU/UVA. DNA SIdU and SBrdU generate lethal DNA photodamage by partially distinct mechanisms that reflect the different photolabilities of their C–I and C–Br bonds. Although singlet oxygen is involved in photolesion formation, DNA SBrdU and SIdU photoactivation does not detectably increase DNA 8-oxoguanine levels. The absence of significant collateral damage to normal guanine suggests that UVA activation of DNA SIdU or SBrdU might offer a strategy to target hyperproliferative skin conditions that avoids the extensive formation of a known mutagenic DNA lesion. PMID:25747491

UVA, UVB Light Doses and Harvesting Time Differentially Tailor Glucosinolate and Phenolic Profiles in Broccoli Sprouts.

PubMed

Moreira-Rodríguez, Melissa; Nair, Vimal; Benavides, Jorge; Cisneros-Zevallos, Luis; Jacobo-Velázquez, Daniel A

2017-06-26

Broccoli sprouts contain health-promoting glucosinolate and phenolic compounds that can be enhanced by applying ultraviolet light (UV). Here, the effect of UVA or UVB radiation on glucosinolate and phenolic profiles was assessed in broccoli sprouts. Sprouts were exposed for 120 min to low intensity and high intensity UVA (UVA L , UVA H ) or UVB (UVB L , UVB H ) with UV intensity values of 3.16, 4.05, 2.28 and 3.34 W/m², respectively. Harvest occurred 2 or 24 h post-treatment; and methanol/water or ethanol/water (70%, v / v ) extracts were prepared. Seven glucosinolates and 22 phenolics were identified. Ethanol extracts showed higher levels of certain glucosinolates such as glucoraphanin, whereas methanol extracts showed slight higher levels of phenolics. The highest glucosinolate accumulation occurred 24 h after UVB H treatment, increasing 4-methoxy-glucobrassicin, glucobrassicin and glucoraphanin by ~170, 78 and 73%, respectively. Furthermore, UVA L radiation and harvest 2 h afterwards accumulated gallic acid hexoside I (~14%), 4- O -caffeoylquinic acid (~42%), gallic acid derivative (~48%) and 1-sinapoyl-2,2-diferulolyl-gentiobiose (~61%). Increases in sinapoyl malate (~12%), gallotannic acid (~48%) and 5-sinapoyl-quinic acid (~121%) were observed with UVB H Results indicate that UV-irradiated broccoli sprouts could be exploited as a functional food for fresh consumption or as a source of bioactive phytochemicals with potential industrial applications.

The protective effects of bilberry and lingonberry extracts against UV light-induced retinal photoreceptor cell damage in vitro.

PubMed

Ogawa, Kenjirou; Tsuruma, Kazuhiro; Tanaka, Junji; Kakino, Mamoru; Kobayashi, Saori; Shimazawa, Masamitsu; Hara, Hideaki

2013-10-30

Bilberry extract (B-ext) and lingonberry extract (L-ext) are currently used as health supplements. We investigated the protective mechanisms of the B-ext and L-ext against ultraviolet A (UVA)-induced retinal photoreceptor cell damage. Cultured murine photoreceptor (661W) cells were exposed to UVA following treatment with B-ext and L-ext and their main constituents (cyanidin, delphinidin, malvidin, trans-resveratrol, and procyanidin). B-ext, L-ext, and constituents improved cell viability and suppressed ROS generation. Phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), and protein kinase B (Akt) were analyzed by Western blotting. B-ext and cyanidin inhibited phosphorylation of p38 MAPK, and B-ext also inhibited phosphorylation of JNK by UVA. L-ext, trans-resveratrol, and procyanidin alleviated the reduction of phosphorylated Akt levels by UVA. Finally, a cotreatment with B-ext and L-ext showed an additive effect on cell viability. Our findings suggest that both B-ext and L-ext endow protective effects against UVA-induced retinal damage.

UVA irradiation of BrU-substituted DNA in the presence of Hoechst 33258.

PubMed

Saha, Abhijit; Kizaki, Seiichiro; Han, Ji Hoon; Yu, Zutao; Sugiyama, Hiroshi

2018-01-01

Given that our knowledge of DNA repair is limited because of the complexity of the DNA system, a technique called UVA micro-irradiation has been developed that can be used to visualize the recruitment of DNA repair proteins at double-strand break (DSB) sites. Interestingly, Hoechst 33258 was used under micro-irradiation to sensitize 5-bromouracil ( Br U)-labelled DNA, causing efficient DSBs. However, the molecular basis of DSB formation under UVA micro-irradiation remains unknown. Herein, we investigated the mechanism of DSB formation under UVA micro-irradiation conditions. Our results suggest that the generation of a uracil-5-yl radical through electron transfer from Hoechst 33258 to Br U caused DNA cleavage preferentially at self-complementary 5'-AA Br U Br U-3' sequences to induce DSB. We also investigated the DNA cleavage in the context of the nucleosome to gain a better understanding of UVA micro-irradiation in a cell-like model. We found that DNA cleavage occurred in both core and linker DNA regions although its efficiency reduced in core DNA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Nuclear Facility Decommissioning Projects program: a reference research reactor. Project summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumann, B.L.; Miller, R.L.

1983-10-01

This document presents, in summary form, generic conceptual information relevant to the decommissioning of a reference research reactor (RRR). All of the data presented were extracted from NUREG/CR-1756 and arranged in a form that will provide a basis for future comparison studies for the Evaluation of Nuclear Facility Decommissioning Projects (ENFDP) program.

ELECTRICAL LINES ARRIVE FROM CENTRAL FACILITIES AREA, SOUTH OF MTR. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ELECTRICAL LINES ARRIVE FROM CENTRAL FACILITIES AREA, SOUTH OF MTR. EXCAVATION RUBBLE IN FOREGROUND. CONTRACTOR CRAFT SHOPS, CRANES, AND OTHER MATERIALS ON SITE. CAMERA FACES EAST, WITH LITTLE BUTTE AND MIDDLE BUTTE IN DISTANCE. INL NEGATIVE NO. 335. Unknown Photographer, 7/1/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Stability Estimation of ABWR on the Basis of Noise Analysis

NASA Astrophysics Data System (ADS)

Furuya, Masahiro; Fukahori, Takanori; Mizokami, Shinya; Yokoya, Jun

In order to investigate the stability of a nuclear reactor core with an oxide mixture of uranium and plutonium (MOX) fuel installed, channel stability and regional stability tests were conducted with the SIRIUS-F facility. The SIRIUS-F facility was designed and constructed to provide a highly accurate simulation of thermal-hydraulic (channel) instabilities and coupled thermalhydraulics-neutronics instabilities of the Advanced Boiling Water Reactors (ABWRs). A real-time simulation was performed by modal point kinetics of reactor neutronics and fuel-rod thermal conduction on the basis of a measured void fraction in a reactor core section of the facility. A time series analysis was performed to calculate decay ratio and resonance frequency from a dominant pole of a transfer function by applying auto regressive (AR) methods to the time-series of the core inlet flow rate. Experiments were conducted with the SIRIUS-F facility, which simulates ABWR with MOX fuel installed. The variations in the decay ratio and resonance frequency among the five common AR methods are within 0.03 and 0.01 Hz, respectively. In this system, the appropriate decay ratio and resonance frequency can be estimated on the basis of the Yule-Walker method with the model order of 30.

Dermatology Procedures

MedlinePlus

... of psoralen (P) and long-wave ultraviolet radiation (UVA) that is used to treat several severe skin ... to ultraviolet light. This allows the deeply penetrating UVA band of light to work on the skin. ...

PBF Reactor Building (PER620). PBF crane holds fuel test assembly ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). PBF crane holds fuel test assembly aloft prior to lowering into reactor for test. Date: 1982. INEEL negative no. 82-4909 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 2: Power from nuclear fission

NASA Technical Reports Server (NTRS)

Clement, J. D.

1973-01-01

Different types of nuclear fission reactors and fissionable materials are compared. Special emphasis is placed upon the environmental impact of such reactors. Graphs and charts comparing reactor facilities in the U. S. are presented.

Environmental Assessment for Authorizing the Puerto Rico Electric Power Authority (PREPA) to allow Public Access to the Boiling Nuclear Superheat (BONUS) Reactor Building, Rincon, Puerto Rico

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

The U.S. Department of Energy (DOE) proposes to consent to a proposal by the Puerto Rico Electric Power Authority (PREPA) to allow public access to the Boiling Nuclear Superheat (BONUS) reactor building located near Rincon, Puerto Rico for use as a museum. PREPA, the owner of the BONUS facility, has determined that the historical significance of this facility, as one of only two reactors of this design ever constructed in the world, warrants preservation in a museum, and that this museum would provide economic benefits to the local community through increased tourism. Therefore, PREPA is proposing development of the BONUSmore » facility as a museum.« less

10 CFR 50.58 - Hearings and report of the Advisory Committee on Reactor Safeguards.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Hearings and report of the Advisory Committee on Reactor... Hearings and report of the Advisory Committee on Reactor Safeguards. (a) Each application for a....22, or for a testing facility, shall be referred to the Advisory Committee on Reactor Safeguards for...

10 CFR 50.58 - Hearings and report of the Advisory Committee on Reactor Safeguards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Hearings and report of the Advisory Committee on Reactor... Hearings and report of the Advisory Committee on Reactor Safeguards. (a) Each application for a....22, or for a testing facility, shall be referred to the Advisory Committee on Reactor Safeguards for...

Combination of UV absorbance and electron donating capacity to assess degradation of micropollutants and formation of bromate during ozonation of wastewater effluents.

PubMed

Chon, Kangmin; Salhi, Elisabeth; von Gunten, Urs

2015-09-15

In this study, the changes in UV absorbance at 254 nm (UVA254) and electron donating capacity (EDC) were investigated as surrogate indicators for assessing removal of micropollutants and bromate formation during ozonation of wastewater effluents. To measure the EDC, a novel method based on size exclusion chromatography followed by a post-column reaction was developed and calibrated against an existing electrochemical method. Low specific ozone doses led to a more efficient abatement of EDC than of UVA254. This was attributed to the abatement of phenolic moieties in the dissolved organic matter (DOM), which lose their EDC upon oxidation, but are partially transformed into quinones, which still absorb in the measured UV range. For higher specific ozone doses, the relative EDC abatement was lower than the relative UVA abatement, which can be explained by the oxidation of UV absorbing moieties (e.g. non-activated aromatic compounds), which contribute less to EDC. The abatement of the selected micropollutants (i.e., 17α-ethinylestradiol (EE2), carbamazepine (CBZ), atenolol (ATE), bezafibrate (BZF), ibuprofen (IBU), and p-chlorobenzoic acid (pCBA)) varied significantly depending on their reactivity with ozone in the examined specific ozone dose range of 0-1.45 mgO3/mgDOC. The decrease of EE2 and CBZ with high ozone reactivity was linearly proportional to the reduction of the relative residuals of UVA254 and EDC. The abatement of ATE, BZF, IBU, and pCBA with intermediate to low ozone reactivities was not significant in a first phase (UVA254/UVA254,0 = 1.00-0.70; EDC/EDC0 = 1.00-0.56) while their abatement was more efficient than the degradation of the relative residual UVA254 and much more noticeable than the degradation of the relative residual EDC in a second phase (UVA254/UVA254,0 = 0.70-0.25; EDC/EDC0 = 0.56-0.25) because the partially destroyed UV absorbing and electron donating DOM moieties become recalcitrant to ozone attack. Bromate formation was pronounced for specific ozone doses >0.25 mgO3/mgDOC. At these ozone doses, the residual DOM competes less with bromide for ozone as the electron-rich DOM moieties are almost completely degraded. Overall, these results imply that a combination of the relative residual UVA254 and EDC more truly reflects the intrinsic reactivity of DOM associated with the removal of micropollutants and bromate formation than the single use of the UV absorbance-based surrogate indicators. Copyright © 2015 Elsevier Ltd. All rights reserved.

SP-100 ground engineering system test site description and progress update

NASA Astrophysics Data System (ADS)

Baxter, William F.; Burchell, Gail P.; Fitzgibbon, Davis G.; Swita, Walter R.

1991-01-01

The SP-100 Ground Engineering System Test Site will provide the facilities for the testing of an SP-100 reactor, which is technically prototypic of the generic design for producing 100 kilowatts of electricity. This effort is part of the program to develop a compact, space-based power system capable of producing several hundred kilowatts of electrical power. The test site is located on the U.S. Department of Energy's Hanford Site near Richland, Washington. The site is minimizing capital equipment costs by utilizing existing facilities and equipment to the maximum extent possible. The test cell is located in a decommissioned reactor containment building, and the secondary sodium cooling loop will use equipment from the Fast Flux Test Facility plant which has never been put into service. Modifications to the facility and special equipment are needed to accommodate the testing of the SP-100 reactor. Definitive design of the Ground Engineering System Test Site facility modifications and systems is in progress. The design of the test facility and the testing equipment will comply with the regulations and specifications of the U.S. Department of Energy and the State of Washington.

Draft environmental impact statement siting, construction, and operation of New Production Reactor capacity. Volume 4, Appendices D-R

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1991-04-01

This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build newmore » production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public. This volume contains 15 appendices.« less

The New Facilities for Neutron Radiography at the LVR-15 Reactor

NASA Astrophysics Data System (ADS)

Soltes, J.; Viererbl, L.; Vacik, J.; Tomandl, I.; Krejci, F.; Jakubek, J.

2016-09-01

Neutron radiography is an imaging method often used at research reactor sites. Back in 2011 a project was started with the goal to build a neutron radiography facility at the site of the LVR-15 research reactor in Rez, Czech Republic. In the scope of the project two horizontal channels were adapted for the needs of neutron radiography. This comprises the HC1 channel which offers an intense thermal neutron beam with a diameter of 10 cm, which can be used for imaging of larger samples, and the HC3 channel which beam is restricted just to 4x80 mm2, but is highly thermalized, collimated and reduced from gamma background, thus capable of providing better radiograph resolution. Both facilities are equipped with newest Timepix based detectors, with thin 6LiF converters for neutron detection capable of delivering high resolution. Both facilities offer a unique opportunity for non-destructive testing in the Czech region. In 2015 both facilities were put into test operation and several radiographs were acquired, which are presented in the following text.

The Australian Replacement Research Reactor

NASA Astrophysics Data System (ADS)

Kennedy, Shane; Robinson, Robert

2004-03-01

The 20-MW Australian Replacement Research Reactor represents possibly the greatest single research infrastructure investment in Australia's history. Construction of the facility has commenced, following award of the construction contract in July 2000, and the construction licence in April 2002. The project includes a large state-of-the-art liquid deuterium cold-neutron source and supermirror guides feeding a large modern guide hall, in which most of the instruments are placed. Alongside the guide hall, there is good provision of laboratory, office and space for support activities. While the facility has "space" for up to 18 instruments, the project has funding for an initial set of 8 instruments, which will be ready when the reactor is fully operational in July 2006. Instrument performance will be competitive with the best research-reactor facilities anywhere, and our goal is to be in the top 3 such facilities worldwide. Staff to lead the design effort and man these instruments have been hired on the international market from leading overseas facilities, and from within Australia, and 7 out of 8 instruments have been specified and costed. At present the instrumentation project carries 10contingency. An extensive dialogue has taken place with the domestic user community and our international peers, via various means including a series of workshops over the last 2 years covering all 8 instruments, emerging areas of application like biology and the earth sciences, and computing infrastructure for the instruments.

Synergistic Effects Induced by a Low Dose of Diesel Particulate Extract and Ultraviolet-A in Caenorhabditis elegans: DNA Damage-Triggered Germ Cell Apoptosis

PubMed Central

2015-01-01

Diesel exhaust has been classified as a potential carcinogen and is associated with various health effects. A previous study showed that the doses for manifesting the mutagenetic effects of diesel exhaust could be reduced when coexposed with ultraviolet-A (UVA) in a cellular system. However, the mechanisms underlying synergistic effects remain to be clarified, especially in an in vivo system. In the present study, using Caenorhabditis elegans (C. elegans) as an in vivo system we studied the synergistic effects of diesel particulate extract (DPE) plus UVA, and the underlying mechanisms were dissected genetically using related mutants. Our results demonstrated that though coexposure of wild type worms at young adult stage to low doses of DPE (20 μg/mL) plus UVA (0.2, 0.5, and 1.0 J/cm2) did not affect worm development (mitotic germ cells and brood size), it resulted in a significant induction of germ cell death. Using the strain of hus-1::gfp, distinct foci of HUS-1::GFP was observed in proliferating germ cells, indicating the DNA damage after worms were treated with DPE plus UVA. Moreover, the induction of germ cell death by DPE plus UVA was alleviated in single-gene loss-of-function mutations of core apoptotic, checkpoint HUS-1, CEP-1/p53, and MAPK dependent signaling pathways. Using a reactive oxygen species (ROS) probe, it was found that the production of ROS in worms coexposed to DPE plus UVA increased in a time-dependent manner. In addition, employing a singlet oxygen (1O2) trapping probe, 2,2,6,6-tetramethyl-4-piperidone, coupled with electron spin resonance analysis, we demonstrated the increased 1O2 production in worms coexposed to DPE plus UVA. These results indicated that UVA could enhance the apoptotic induction of DPE at low doses through a DNA damage-triggered pathway and that the production of ROS, especially 1O2, played a pivotal role in initiating the synergistic process. PMID:24841043

Primary fibroblasts from BRCA1 heterozygotes display an abnormal G1/S cell cycle checkpoint following UVA irradiation but show normal levels of micronuclei following oxidative stress or mitomycin C treatment.

PubMed

Shorrocks, Julie; Tobi, Simon E; Latham, Harry; Peacock, John H; Eeles, Ros; Eccles, Diana; McMillan, Trevor J

2004-02-01

There is evidence to suggest that the breast cancer predisposing gene, BRCA1, is involved in cell cycle control and the response to damage but mouse brca1+/- heterozygotes have no distinctive phenotype. Here the response to the three forms of cellular stress was examined in primary human fibroblasts from individuals with a +/+ or +/- genotype for BRCA1. Fibroblasts from individuals carrying mutations in the BRCA1 gene were compared with those from those wild-type for BRCA1 in their response to long wavelength uv (UVA), hydrogen peroxide, and mitomycin C (MMC). Cell cycle progression and micronucleus formation (MN) were used as end points. After UVA treatment there was no difference between +/- and +/+ cells in the initial fall in DNA synthetic activity (G(1) arrest) but the reentry into S-phase was restored at a faster rate in the BRCA1+/- cells after UVA exposure. Thus, for three normal (+/+) cell lines irradiated in monolayer, S-phase values averaged 15 +/- 3.7% 14 h post-UVA (1 x 10(5) J/m(2)), as compared with 35.7 +/- 1.9 (range) for two BRCA1(+/-) strains. Because a defective G(1)/S checkpoint in BRCA1 heterozygotes could lead to a greater proportion of S-phase cells with unrepaired DNA damage (strand breaks) and a resultant increase in chromosomal instability, the frequency of micronuclei induced by UVA was examined. Three normal (+/+) and three mutant (+/-) strains (two of which were used in the cell cycle experiments) produced mean micronuclei frequencies of 0.077 +/- 0.016 and 0.094 +/- 0.04/binucleate cell respectively (not statistically significant), 48 h after UVA exposure. No differences were found between BRCA1+/+ and +/- cells in MN formation after treatment with MMC or hydrogen peroxide. Our data suggest a defective G(1)/S checkpoint in cells from BRCA1 heterozygotes in response to UVA although this is not reflected in genomic instability as measured by micronuclei induction after oxidative stress or MMC treatment.

Final Report for the “WSU Neutron Capture Therapy Facility Support”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerald E. Tripard; Keith G. Fox

2006-08-24

The objective for the cooperative research program for which this report has been written was to provide separate NCT facility user support for the students, faculty and scientists who would be doing the U.S. Department of Energy Office (DOE) of Science supported advanced radiotargeted research at the WSU 1 megawatt TRIGA reactor. The participants were the Idaho National laboratory (INL, P.I., Dave Nigg), the Veterinary Medical Research Center of Washington State University (WSU, Janean Fidel and Patrick Gavin), and the Washington State University Nuclear Radiation Center (WSU, P.I., Gerald Tripard). A significant number of DOE supported modifications were made tomore » the WSU reactor in order to create an epithermal neutron beam while at the same time maintaining the other activities of the 1 MW reactor. These modifications were: (1) Removal of the old thermal column. (2) Construction and insertion of a new epithermal filter, collimator and shield. (3) Construction of a shielded room that could accommodate the very high radiation field created by an intense neutron beam. (4) Removal of the previous reactor core fuel cluster arrangement. (5) Design and loading of the new reactor core fuel cluster arrangement in order to optimize the neutron flux entering the epithermal neutron filter. (6) The integration of the shielded rooms interlocks and radiological controls into the SCRAM chain and operating electronics of the reactor. (7) Construction of a motorized mechanism for moving and remotely controlling the position of the entire reactor bridge. (8) The integration of the reactor bridge control electronics into the SCRAM chain and operating electronics of the reactor. (9) The design, construction and attachment to the support structure of the reactor of an irradiation box that could be inserted into position next to the face of the reactor. (Necessitated by the previously mentioned core rearrangement). All of the above modifications were successfully completed and tested. The resulting epithermal beam of 1 x 10{sup 9} n/sec-cm{sup 2} was measured by Idaho National Laboratory with assistance from WSU's Neutron Activation Analysis Group. The beam is as good as our initial proposals for the project had predicted. In addition to all of the design, construction and insertion of the hardware, shielding, electronics and radiation monitoring systems there was considerable manpower and effort put into changes in the Technical Specifications of the reactor and implementing procedures for use of the new facility. This staff involvement is one of the reasons we requested special facility support from the DOE. Once the facility was competed and all of the recalibrations and measurements made to characterize the differences between this reactor core and the previous core we began to assist INL in making their beam measurements with foils and phantoms. Although we proposed support for only one additional staff position to support this new NCT facility the staff support provided by the WSU Nuclear Radiation Center was greater than had been anticipated by our initial proposal. INL was also assisted in the testing of a heavy water (deuterated water) bladder that can be inserted into the collimator in order to produce an intense, external thermal neutron beam. The external epithermal and/or thermal neutron beam capability remains available for use, if funding becomes available for future research projects.« less

Conceptual design of BNCT facility based on the TRR medical room

NASA Astrophysics Data System (ADS)

Golshanian, M.; Rajabi, A. A.; Kasesaz, Y.

2017-10-01

This paper presents a conceptual design of the Boron Neutron Capture Therapy (BNCT) facility based on the medical room of Tehran Research Reactor (TRR). The medical room is located behind the east wall of the reactor pool. The designed beam line is an in-pool Beam Shaping Assembly (BSA) which is considered between the reactor core and the medical room wall. The final designed BSA can provide 2.96× 109 n/cm2ṡs epithermal neutron flux at the irradiation position with acceptable beam contamination to use as a clinical BNCT.

Cyber Mutual Assistance Workshop Report

DTIC Science & Technology

2018-02-01

Information Technology, Nuclear Reactors, Materials/Waste, Defense Industrial Base, Critical Manufacturing, Food/ Agriculture Government Facilities and...Manufacturing, Food/ Agriculture Government Facilities and Chemical, Commercial Facilities [DHS 2017c]. Distributed Energy Resources (DER) are

ADVANCED HEAT TRANSFER TEST FACILITY, TRA666A. ELEVATIONS. ROOF FRAMING PLAN. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ADVANCED HEAT TRANSFER TEST FACILITY, TRA-666A. ELEVATIONS. ROOF FRAMING PLAN. CONCRETE BLOCK SIDING. SLOPED ROOF. ROLL-UP DOOR. AIR INTAKE ENCLOSURE ON NORTH SIDE. F.C. TORKELSON 842-MTR-666-A5, 8/1966. INL INDEX NO. 531-0666-00-851-152258, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Heat barrier for use in a nuclear reactor facility

DOEpatents

Keegan, Charles P.

1988-01-01

A thermal barrier for use in a nuclear reactor facility is disclosed herein. Generally, the thermal barrier comprises a flexible, heat-resistant web mounted over the annular space between the reactor vessel and the guard vessel in order to prevent convection currents generated in the nitrogen atmosphere in this space from entering the relatively cooler atmosphere of the reactor cavity which surrounds these vessels. Preferably, the flexible web includes a blanket of heat-insulating material formed from fibers of a refractory material, such as alumina and silica, sandwiched between a heat-resistant, metallic cloth made from stainless steel wire. In use, the web is mounted between the upper edges of the guard vessel and the flange of a sealing ring which surrounds the reactor vessel with a sufficient enough slack to avoid being pulled taut as a result of thermal differential expansion between the two vessels. The flexible web replaces the rigid and relatively complicated structures employed in the prior art for insulating the reactor cavity from the convection currents generated between the reactor vessel and the guard vessel.

The University of Virginia

Science.gov Websites

Community Your Support Matters Audiences Prospective Students Current Students Faculty & Staff Alumni four young UVA alumni made the transition from classroom to career. Read More This is UVA An

Solar UV-A and UV-B radiation fluxes at two Alpine stations at different altitudes

NASA Astrophysics Data System (ADS)

Blumthaler, M.; Ambach, W.; Rehwald, W.

1992-03-01

Daily totals of UV-A and UV-B radiation fluxes and global radiation were measured since 1981 at Jungfraujoch (3576 m) a.s.l.) and in Innsbruck (577 m a.s.l.) in their seasonal course. The altitude effect of annual totals yields 19%/1000 m (UV-B), 11%/1000 m (UV-A) and 9%/1000 m (global radiation) with reference to Innsbruck station. The ratio of the daily totals of UV-B/global radiation shows a significant seasonal course with the maximum in summer, whereas the ratio of the daily totals of UV-A/global radiation shows no significant seasonal variation. The biological effective doses of erythema reaction, delayed tanning and immediate tanning by UV-A and UV-B radiant exposure are reported in the seasonal course at Jungfraujoch and in Innsbruck.

UVA Light-excited Kynurenines Oxidize Ascorbate and Modify Lens Proteins through the Formation of Advanced Glycation End Products

PubMed Central

Linetsky, Mikhail; Raghavan, Cibin T.; Johar, Kaid; Fan, Xingjun; Monnier, Vincent M.; Vasavada, Abhay R.; Nagaraj, Ram H.

2014-01-01

Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood. Kynurenines are tryptophan oxidation products produced from the indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway and are present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins. UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ASC, and such oxidation occurred even in the absence of oxygen. High levels of GSH inhibited but did not completely block ASC oxidation. Upon UVA irradiation, pigmented proteins from human cataractous lenses also oxidized ASC. When exposed to UVA light (320–400 nm, 100 milliwatts/cm2, 45 min to 2 h), young human lenses (20–36 years), which contain high levels of free kynurenines, lost a significant portion of their ASC content and accumulated AGEs. A similar formation of AGEs was observed in UVA-irradiated lenses from human IDO/human sodium-dependent vitamin C transporter-2 mice, which contain high levels of kynurenines and ASC. Our data suggest that kynurenine-mediated ASC oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans. PMID:24798334

Singlet Oxygen-Mediated Oxidation during UVA Radiation Alters the Dynamic of Genomic DNA Replication

PubMed Central

Graindorge, Dany; Martineau, Sylvain; Machon, Christelle; Arnoux, Philippe; Guitton, Jérôme; Francesconi, Stefania; Frochot, Céline; Sage, Evelyne; Girard, Pierre-Marie

2015-01-01

UVA radiation (320–400 nm) is a major environmental agent that can exert its deleterious action on living organisms through absorption of the UVA photons by endogenous or exogenous photosensitizers. This leads to the production of reactive oxygen species (ROS), such as singlet oxygen (1O2) and hydrogen peroxide (H2O2), which in turn can modify reversibly or irreversibly biomolecules, such as lipids, proteins and nucleic acids. We have previously reported that UVA-induced ROS strongly inhibit DNA replication in a dose-dependent manner, but independently of the cell cycle checkpoints activation. Here, we report that the production of 1O2 by UVA radiation leads to a transient inhibition of replication fork velocity, a transient decrease in the dNTP pool, a quickly reversible GSH-dependent oxidation of the RRM1 subunit of ribonucleotide reductase and sustained inhibition of origin firing. The time of recovery post irradiation for each of these events can last from few minutes (reduction of oxidized RRM1) to several hours (replication fork velocity and origin firing). The quenching of 1O2 by sodium azide prevents the delay of DNA replication, the decrease in the dNTP pool and the oxidation of RRM1, while inhibition of Chk1 does not prevent the inhibition of origin firing. Although the molecular mechanism remains elusive, our data demonstrate that the dynamic of replication is altered by UVA photosensitization of vitamins via the production of singlet oxygen. PMID:26485711

Protection against ultraviolet A-induced oxidative damage in normal human epidermal keratinocytes under post-menopausal conditions by an ultraviolet A-activated caged-iron chelator: a pilot study.

PubMed

Pelle, Edward; Jian, Jinlong; Declercq, Lieve; Dong, Kelly; Yang, Qing; Pourzand, Charareh; Maes, Daniel; Pernodet, Nadine; Yarosh, Daniel B; Huang, Xi

2011-10-01

Human skin is constantly exposed to ultraviolet A (UVA), which can generate reactive oxygen species and cause iron release from ferritin, leading to oxidative damage in biomolecules. This is particularly true in post-menopausal skin due to an increase in iron as a result of menopause. As iron is generally released through desquamation, the skin becomes a main portal for the release of excess iron in this age group. In the present study, we examined a strategy for controlling UVA- and iron-induced oxidative stress in skin using a keratinocyte post-menopausal cellular model system. Keratinocytes that had been cultured under normal or high-iron, low-estrogen conditions were treated with (2-nitrophenyl) ethyl pyridoxal isonicotinoyl hydrazone (2-PNE-PIH). 2-PNE-PIH is a caged-iron chelator that does not normally bind iron but can be activated by UVA radiation to bind iron. Following incubation with 2-PNE-PIH, the cells were exposed to 5 J/cm² UVA and then measured for changes in lipid peroxidation and ferritin levels. 2-PNE-PIH protected keratinocytes against UVA-induced lipid peroxidation and ferritin depletion. Further, 2-PNE-PIH was neither cytotoxic nor did it alter iron metabolism. 2-PNE-PIH may be a useful deterrent against UVA-induced oxidative stress in post-menopausal women. © 2011 John Wiley & Sons A/S.

Investigating the role of melanin in UVA/UVB- and hydrogen peroxide-induced cellular and mitochondrial ROS production and mitochondrial DNA damage in human melanoma cells.

PubMed

Swalwell, Helen; Latimer, Jennifer; Haywood, Rachel M; Birch-Machin, Mark A

2012-02-01

Skin cancer incidence is dramatically increasing worldwide, with exposure to ultraviolet radiation (UVR) a predominant factor. The UVA component initiates oxidative stress in human skin, although its exact role in the initiation of skin cancer, particularly malignant melanoma, remains unclear and is controversial because there is evidence for a melanin-dependent mechanism in UVA-linked melanoma studies. Nonpigmented (CHL-1, A375), moderately pigmented (FM55, SKmel23), and highly pigmented (FM94, hyperpigmented FM55) human melanoma cell lines have been used to investigate UVA-induced production of reactive oxygen species using FACS analysis, at both the cellular (dihydrorhodamine-123) and the mitochondrial (MitoSOX) level, where most cellular stress is generated. For the first time, downstream mtDNA damage (utilizing a quantitative long-PCR assay) has been investigated. Using UVA, UVB, and H(2)O(2) as cellular stressors, we have explored the dual roles of melanin as a photoprotector and photosensitizer. The presence of melanin has no influence over cellular oxidative stress generation, whereas, in contrast, melanin protects against mitochondrial superoxide generation and mtDNA damage (one-way ANOVA with post hoc Tukey's analysis, P<0.001). We show that if melanin binds directly to DNA, it acts as a direct photosensitizer of mtDNA damage during UVA irradiation (P<0.001), providing evidence for the dual roles of melanin. Copyright © 2011 Elsevier Inc. All rights reserved.

Operational Philosophy for the Advanced Test Reactor National Scientific User Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Benson; J. Cole; J. Jackson

2013-02-01

In 2007, the Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF). At its core, the ATR NSUF Program combines access to a portion of the available ATR radiation capability, the associated required examination and analysis facilities at the Idaho National Laboratory (INL), and INL staff expertise with novel ideas provided by external contributors (universities, laboratories, and industry). These collaborations define the cutting edge of nuclear technology research in high-temperature and radiation environments, contribute to improved industry performance of current and future light-water reactors (LWRs), and stimulate cooperative research between user groupsmore » conducting basic and applied research. To make possible the broadest access to key national capability, the ATR NSUF formed a partnership program that also makes available access to critical facilities outside of the INL. Finally, the ATR NSUF has established a sample library that allows access to pre-irradiated samples as needed by national research teams.« less

An Experimental Test Facility to Support Development of the Fluoride Salt Cooled High Temperature Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoder Jr, Graydon L; Aaron, Adam M; Cunningham, Richard Burns

2014-01-01

The need for high-temperature (greater than 600 C) energy exchange and delivery systems is significantly increasing as the world strives to improve energy efficiency and develop alternatives to petroleum-based fuels. Liquid fluoride salts are one of the few energy transport fluids that have the capability of operating at high temperatures in combination with low system pressures. The Fluoride Salt-Cooled High-Temperature Reactor design uses fluoride salt to remove core heat and interface with a power conversion system. Although a significant amount of experimentation has been performed with these salts, specific aspects of this reactor concept will require experimental confirmation during themore » development process. The experimental facility described here has been constructed to support the development of the Fluoride Salt Cooled High Temperature Reactor concept. The facility is capable of operating at up to 700 C and incorporates a centrifugal pump to circulate FLiNaK salt through a removable test section. A unique inductive heating technique is used to apply heat to the test section, allowing heat transfer testing to be performed. An air-cooled heat exchanger removes added heat. Supporting loop infrastructure includes a pressure control system; trace heating system; and a complement of instrumentation to measure salt flow, temperatures, and pressures around the loop. The initial experiment is aimed at measuring fluoride salt heat transfer inside a heated pebble bed similar to that used for the core of the pebble bed advanced high-temperature reactor. This document describes the details of the loop design, auxiliary systems used to support the facility, the inductive heating system, and facility capabilities.« less

10 CFR Appendix A to Part 725 - Categories of Restricted Data Available

Code of Federal Regulations, 2011 CFR

2011-01-01

... centrifuge or gaseous diffusion processes. b. Design, construction, and operation of any plant, facility or..., design, criticality studies and operation of reactors, reactor systems and reactor components. d... aqueous lithium hydroxide solution in packed columns. Not included is information regarding plant design...

10 CFR Appendix A to Part 725 - Categories of Restricted Data Available

Code of Federal Regulations, 2012 CFR

2012-01-01

... centrifuge or gaseous diffusion processes. b. Design, construction, and operation of any plant, facility or..., design, criticality studies and operation of reactors, reactor systems and reactor components. d... aqueous lithium hydroxide solution in packed columns. Not included is information regarding plant design...

10 CFR Appendix A to Part 725 - Categories of Restricted Data Available

Code of Federal Regulations, 2010 CFR

2010-01-01

... centrifuge or gaseous diffusion processes. b. Design, construction, and operation of any plant, facility or..., design, criticality studies and operation of reactors, reactor systems and reactor components. d... aqueous lithium hydroxide solution in packed columns. Not included is information regarding plant design...

10 CFR Appendix A to Part 725 - Categories of Restricted Data Available

Code of Federal Regulations, 2014 CFR

2014-01-01

... centrifuge or gaseous diffusion processes. b. Design, construction, and operation of any plant, facility or..., design, criticality studies and operation of reactors, reactor systems and reactor components. d... aqueous lithium hydroxide solution in packed columns. Not included is information regarding plant design...

Looking East at BottomHalf of Reactor Number One and TopHalf ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking East at Bottom-Half of Reactor Number One and Top-Half of Reactor Number 2 Including Weigh Hopper on Third Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

PBF Reactor Building (PER620). After lowering reactor vessel onto blocks, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). After lowering reactor vessel onto blocks, it is rolled on logs into PBF. Metal framework under vessel is handling device. Various penetrations in reactor bottom were for instrumentation, poison injection, drains. Large one, below center "manhole" was for primary coolant. Photographer: Larry Page. Date: February 13, 1970. INEEL negative no. 70-736 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Development of a regenerable system employing silica-titania composites for the recovery of mercury from end-box exhaust at a chlor-alkali facility.

PubMed

Stokke, Jennifer M; Mazyck, David W

2008-04-01

The release of mercury to the environment is of particular concern because of its volatility, persistence, and tendency to bioaccumulate. The recovery of mercury from end-box exhaust at chlor-alkali facilities is important to prevent release into the environment and reduce emissions as required by NESHAP (National Emission Standards for Hazardous Air Pollutants). A pilot-scale photocatalytic reactor packed with silica-titania composite (STC) pellets was tested at a chloralkali facility over a 3-month period. This pilot reactor treated up to 10 ft3/min (ACFM) of end-box exhaust and achieved 95% removal. The pilot reactor was able to maintain excellent removal efficiency even with large fluctuations in influent mercury concentration (400-1600 microg/ft3). The STC pellets were regenerated ex situ by regeneration with hydrochloric acid and performed similarly to virgin STC pellets when returned to service. On the basis of these promising results, two full-scale reactors with in situ regeneration capabilities were installed and operated. After optimization, these reactors performed similarly to the pilot reactor. A cost analysis was performed comparing the treatment costs (i.e., cost per pound of mercury removed) for sulfur-impregnated activated carbon and the STC system. The STC proved to be both technologically and economically feasible for this installation.

Liquid Metal Fast Breeder Reactor Program: Argonne facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephens, S. V.

1976-09-01

The objective of the document is to present in one volume an overview of the Argonne National Laboratory test facilities involved in the conduct of the national LMFBR research and development program. Existing facilities and those under construction or authorized as of September 1976 are described. Each profile presents brief descriptions of the overall facility and its test area and data relating to its experimental and testing capability. The volume is divided into two sections: Argonne-East and Argonne-West. Introductory material for each section includes site and facility maps. The profiles are arranged alphabetically by title according to their respective locationsmore » at Argonne-East or Argonne-West. A glossary of acronyms and letter designations in common usage to describe organizations, reactor and test facilities, components, etc., involved in the LMFBR program is appended.« less

75 FR 76923 - Domestic Licensing of Production and Utilization Facilities; Updates to Incorporation by...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-10

..., Classified information, Criminal penalties, Fire protection, Intergovernmental relations, Nuclear power plants and reactors, Radiation protection, Reactor siting criteria, Reporting and recordkeeping...

Novel DNA lesions generated by the interaction between therapeutic thiopurines and UVA light.

PubMed

Zhang, Xiaohong; Jeffs, Graham; Ren, Xiaolin; O'Donovan, Peter; Montaner, Beatriz; Perrett, Conal M; Karran, Peter; Xu, Yao-Zhong

2007-03-01

The therapeutic effect of the thiopurines, 6-thioguanine (6-TG), 6-mercaptopurine, and its prodrug azathioprine, depends on the incorporation of 6-TG into cellular DNA. Unlike normal DNA bases, 6-TG absorbs UVA radiation, and UVA-mediated photochemical damage of DNA 6-TG has potentially harmful side effects. When free 6-TG is UVA irradiated in solution in the presence of molecular oxygen, reactive oxygen species are generated and 6-TG is oxidized to guanine-6-sulfonate (G(SO3)) and guanine-6-thioguanine in reactions involving singlet oxygen. This conversion is prevented by antioxidants, including the dietary vitamin ascorbate. DNA G(SO3) is also the major photoproduct of 6-TG in DNA and it can be selectively introduced into DNA or oligonucleotides in vitro by mild chemical oxidation. Thermal stability measurements indicate that G(SO3) does not form stable base pairs with any of the normal DNA bases in duplex oligonucleotides and is a powerful block for elongation by Klenow DNA polymerase in primer extension experiments. In cultured human cells, DNA damage produced by 6-TG and UVA treatment is associated with replication inhibition and provokes a p53-dependent DNA damage response.

Development of a new water sterilization device with a 365 nm UV-LED.

PubMed

Mori, Mirei; Hamamoto, Akiko; Takahashi, Akira; Nakano, Masayuki; Wakikawa, Noriko; Tachibana, Satoko; Ikehara, Toshitaka; Nakaya, Yutaka; Akutagawa, Masatake; Kinouchi, Yohsuke

2007-12-01

Ultraviolet (UV) irradiation is an effective disinfection method. In sterilization equipment, a low-pressure mercury lamp emitting an effective germicidal UVC (254 nm) is used as the light source. However, the lamp, which contains mercury, must be disposed of at the end of its lifetime or following damage due to physical shock or vibration. We investigated the suitability of an ultraviolet light-emitting diode at an output wavelength of 365 nm (UVA-LED) as a sterilization device, comparing with the other wavelength irradiation such as 254 nm (a low-pressure mercury lam) and 405 nm (LED). We used a commercially available UVA-LED that emitted light at the shortest wavelength and at the highest output energy. The new sterilization system using the UVA-LED was able to inactivate bacteria, such as Escherichia coli DH5 alpha, Enteropathogenic E. coli, Vibrio parahaemolyticus, Staphylococcus aureus, and Salmonella enterica serovar Enteritidis. The inactivations of the bacteria were dependent on the accumulation of UVA irradiation. Taking advantage of the safety and compact size of LED devices, we expect that the UVA-LED sterilization device can be developed as a new type of water sterilization device.

Comparison of methods for assessing photoprotection against ultraviolet A in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaidbey, K.; Gange, R.W.

Photoprotection against ultraviolet A (UVA) by three sunscreens was evaluated in humans, with erythema and pigmentation used as end points in normal skin and in skin sensitized with 8-methoxypsoralen and anthracene. The test sunscreens were Parsol 1789 (2%), Eusolex 8020 (2%), and oxybenzone (3%). UVA was obtained from two filtered xenon-arc sources. UVA protection factors were found to be significantly higher in sensitized skin compared with normal skin. Both Parsol and Eusolex provided better and comparable photoprotection (approximately 3.0) than oxybenzone (approximately 2.0) in sensitized skin, regardless of whether 8-methoxypsoralen or anthracene was used. In normal unsensitized skin, Parsol 1789more » and Eusolex 8020 were also comparable and provided slightly better photoprotection (approximately 1.8) than oxybenzone (approximately 1.4) when pigmentation was used as an end point. The three sunscreens, however, were similar in providing photoprotection against UVA-induced erythema. Protection factors obtained in artificially sensitized skin are probably not relevant to normal skin. It is concluded that pigmentation, either immediate or delayed, is a reproducible and useful end point for the routine assessment of photoprotection of normal skin against UVA.« less

UVA-induced ROS generation inhibition by Oenothera paradoxa defatted seeds extract and subsequent cell death in human dermal fibroblasts.

PubMed

Jaszewska, Edyta; Soin, Magdalena; Filipek, Agnieszka; Naruszewicz, Marek

2013-09-05

UVA radiation stimulates the production of reactive oxygen species (ROS), which react with lipids, proteins and other intracellular molecules leading to oxidative stress, cellular damage and ultimately cell death. There is, therefore, a growing need for substances exhibiting antioxidant activity, which may support repair mechanisms of the skin. This study evaluates the protective effect of the aqueous Oenothera paradoxa Hudziok defatted seeds extract, rich in polyphenolic compounds, against UVA (25 and 50J/cm(2))-induced changes in normal human dermal fibroblasts (NHDFs). The tested extract (0.1-10μg/ml) has decreased, in a concentration-dependent fashion, the UVA-induced release of lactate dehydrogenase (LDH) into the culture medium, the ROS production (with the use of 2',7'-dichlorodihydrofluorescein diacetate) and lipid peroxidation (utilizing redox reactions with ferrous ions) as compared to the control cells (incubated without the extract). Moreover, the extract increased the number of viable (calcein positive) cells decreasing the number of cells in late apoptosis (annexin V-FITC and propidium iodide positive). Thus our results show that O. paradoxa defatted seeds extract may be beneficial for the prevention of UVA skin damage. Copyright © 2013 Elsevier B.V. All rights reserved.

Why soft UV-A damages DNA: An optical micromanipulation study

NASA Astrophysics Data System (ADS)

Rapp, A.; Greulich, K. O.

2013-09-01

Optical micromanipulation studies have solved a puzzle on DNA damage and repair. Such knowledge is crucial for understanding cancer and ageing. So far it was not understood, why the soft UV component of sunlight, UV-A, causes the dangerous DNA double strand breaks. The energy of UV-A photons is below 4 eV per photon, too low to directly cleave the corresponding chemical bonds in DNA. This is occasionally used to claim that artificial sunbeds, which mainly use UV-A, would not impose a risk on health. UV-A is only sufficient for induction of single strand breaks. The essential new observation is that, when on the opposite strand there is another single strand break at a distance of up to 20 base pairs. These two breaks will be converted into a break of the whole double strand with all its known consequences for cancer and ageing. However, in natural sun the effect is counteracted. Simultaneous red light illumination reduces UV induced DNA damages to 1/3. Since sunlight has a red component, skin tanning with natural sun is not as risky as might appear at a first glance.

Photodynamic therapy does not induce cyclobutane pyrimidine dimers in the presence of melanin.

PubMed

Mudambi, Shaila; Pera, Paula; Washington, Deschana; Remenyik, Eva; Fidrus, Eszter; Shafirstein, Gal; Bellnier, David; Paragh, Gyorgy

2018-04-24

Photodynamic therapy (PDT) is an office-based treatment for precancerous and early cancerous skin changes. PDT induces cell death through the production of reactive oxygen species (ROS). Cyclobutane pyrimidine dimers (CPDs) are the most important DNA changes responsible for ultraviolet (UV) carcinogenesis. Recently ROS induced by UVA were shown to generate CPDs via activating melanin. This raised the possibility that PDT induced ROS may also induce CPDs and mutagenesis in melanin containing cells. Previously the effect of PDT on CPDs in melanin containing cells has not been assessed. Our current work aimed to compare the generation of CPDs in melanin containing cells subjected to UVA treatment and porfimer sodium red light PDT. We used ELISA to detect CPDs. After UVA we found a dose dependent increase in CPDs in melanoma cells (B16-F10, MNT-1) with CPD levels peaking hours after discontinuation of UVA treatment. This indicated the generation of UVA induced dark-CPDs in the model. Nevertheless, PDT in biologically relevant doses was unable to induce CPDs. Our work provides evidence for the lack of CPD generation by PDT in melanin containing cells. Copyright © 2018 Elsevier B.V. All rights reserved.

DNA repair inhibition by UVA photoactivated fluoroquinolones and vemurafenib

PubMed Central

Peacock, Matthew; Brem, Reto; Macpherson, Peter; Karran, Peter

2014-01-01

Cutaneous photosensitization is a common side effect of drug treatment and can be associated with an increased skin cancer risk. The immunosuppressant azathioprine, the fluoroquinolone antibiotics and vemurafenib—a BRAF inhibitor used to treat metastatic melanoma—are all recognized clinical photosensitizers. We have compared the effects of UVA radiation on cultured human cells treated with 6-thioguanine (6-TG, a DNA-embedded azathioprine surrogate), the fluoroquinolones ciprofloxacin and ofloxacin and vemurafenib. Despite widely different structures and modes of action, each of these drugs potentiated UVA cytotoxicity. UVA photoactivation of 6-TG, ciprofloxacin and ofloxacin was associated with the generation of singlet oxygen that caused extensive protein oxidation. In particular, these treatments were associated with damage to DNA repair proteins that reduced the efficiency of nucleotide excision repair. Although vemurafenib was also highly phototoxic to cultured cells, its effects were less dependent on singlet oxygen. Highly toxic combinations of vemurafenib and UVA caused little protein carbonylation but were nevertheless inhibitory to nucleotide excision repair. Thus, for three different classes of drugs, photosensitization by at least two distinct mechanisms is associated with reduced protection against potentially mutagenic and carcinogenic DNA damage. PMID:25414333

UVA Irradiation Enhances Brusatol-Mediated Inhibition of Melanoma Growth by Downregulation of the Nrf2-Mediated Antioxidant Response

PubMed Central

Wang, Mei; Shi, Guangwei; Bian, Chunxiang; Nisar, Muhammad Farrukh; Guo, Yingying; Wu, Yan; Li, Wei; Huang, Xiao; Jiang, Xuemei; Bartsch, Jörg W.

2018-01-01

Brusatol (BR) is a potent inhibitor of Nrf2, a transcription factor that is highly expressed in cancer tissues and confers chemoresistance. UVA-generated reactive oxygen species (ROS) can damage both normal and cancer cells and may be of potential use in phototherapy. In order to provide an alternative method to treat the aggressive melanoma, we sought to investigate whether low-dose UVA with BR is more effective in eliminating melanoma cells than the respective single treatments. We found that BR combined with UVA led to inhibition of A375 melanoma cell proliferation by cell cycle arrest in the G1 phase and triggers cell apoptosis. Furthermore, inhibition of Nrf2 expression attenuated colony formation and tumor development from A375 cells in heterotopic mouse models. In addition, cotreatment of UVA and BR partially suppressed Nrf2 and its downstream target genes such as HO-1 along with the PI3K/AKT pathway. We propose that cotreatment increased ROS-induced cell cycle arrest and cellular apoptosis and inhibits melanoma growth by regulating the AKT-Nrf2 pathway in A375 cells which offers a possible therapeutic intervention strategy for the treatment of human melanoma. PMID:29670684

Rhythmic syllable-related activity in a songbird motor thalamic nucleus necessary for learned vocalizations

PubMed Central

Danish, Husain H.; Aronov, Dmitriy; Fee, Michale S.

2017-01-01

Birdsong is a complex behavior that exhibits hierarchical organization. While the representation of singing behavior and its hierarchical organization has been studied in some detail in avian cortical premotor circuits, our understanding of the role of the thalamus in adult birdsong is incomplete. Using a combination of behavioral and electrophysiological studies, we seek to expand on earlier work showing that the thalamic nucleus Uvaeformis (Uva) is necessary for the production of stereotyped, adult song in zebra finch (Taeniopygia guttata). We confirm that complete bilateral lesions of Uva abolish singing in the ‘directed’ social context, but find that in the ‘undirected’ social context, such lesions result in highly variable vocalizations similar to early babbling song in juvenile birds. Recordings of neural activity in Uva reveal strong syllable-related modulation, maximally active prior to syllable onsets and minimally active prior to syllable offsets. Furthermore, both song and Uva activity exhibit a pronounced coherent modulation at 10Hz—a pattern observed in downstream premotor areas in adult and, even more prominently, in juvenile birds. These findings are broadly consistent with the idea that Uva is critical in the sequential activation of behavioral modules in HVC. PMID:28617829

Roles of reactive oxygen species in UVA-induced oxidation of 5,6-dihydroxyindole-2-carboxylic acid-melanin as studied by differential spectrophotometric method.

PubMed

Ito, Shosuke; Kikuta, Marina; Koike, Shota; Szewczyk, Grzegorz; Sarna, Michal; Zadlo, Andrzej; Sarna, Tadeusz; Wakamatsu, Kazumasa

2016-05-01

Eumelanin photoprotects pigmented tissues from ultraviolet (UV) damage. However, UVA-induced tanning seems to result from the photooxidation of preexisting melanin and does not contribute to photoprotection. We investigated the mechanism of UVA-induced degradation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-melanin taking advantage of its solubility in a neutral buffer and using a differential spectrophotometric method to detect subtle changes in its structure. Our methodology is suitable for examining the effects of various agents that interact with reactive oxygen species (ROS) to determine how ROS is involved in the UVA-induced oxidative modifications. The results show that UVA radiation induces the oxidation of DHICA to indole-5,6-quinone-2-carboxylic acid in eumelanin, which is then cleaved to form a photodegraded, pyrrolic moiety and finally to form free pyrrole-2,3,5-tricarboxylic acid. The possible involvement of superoxide radical and singlet oxygen in the oxidation was suggested. The generation and quenching of singlet oxygen by DHICA-melanin was confirmed by direct measurements of singlet oxygen phosphorescence. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Validity of Teacher-Based Vision Screening and Factors Associated with the Accuracy of Vision Screening in Vietnamese Children.

PubMed

Paudel, Prakash; Kovai, Vilas; Naduvilath, Thomas; Phuong, Ha Thanh; Ho, Suit May; Giap, Nguyen Viet

2016-01-01

To assess validity of teacher-based vision screening and elicit factors associated with accuracy of vision screening in Vietnam. After brief training, teachers independently measured visual acuity (VA) in 555 children aged 12-15 years in Ba Ria - Vung Tau Province. Teacher VA measurements were compared to those of refractionists. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for uncorrected VA (UVA) and presenting VA (PVA) 20/40 or worse in either eye. Chi-square, Fisher's exact test and multivariate logistic regression were used to assess factors associated with accuracy of vision screening. Level of significance was set at 5%. Trained teachers in Vietnam demonstrated 86.7% sensitivity, 95.7% specificity, 86.7% positive predictive value and 95.7% negative predictive value in identifying children with visual impairment using the UVA measurement. PVA measurement revealed low accuracy for teachers, which was significantly associated with child's age, sex, spectacle wear and myopic status, but UVA measurement showed no such associations. Better accuracy was achieved in measurement of VA and identification of children with visual impairment using UVA measurement compared to PVA. UVA measurement is recommended for teacher-based vision screening programs.

ROS production in homogenate from the body wall of sea cucumber Stichopus japonicus under UVA irradiation: ESR spin-trapping study.

PubMed

Qi, Hang; Dong, Xiu-fang; Zhao, Ya-ping; Li, Nan; Fu, Hui; Feng, Ding-ding; Liu, Li; Yu, Chen-xu

2016-02-01

Sea cucumber Stichopus japonicus (S. japonicus) shows a strong ability of autolysis, which leads to severe deterioration in sea cucumber quality during processing and storage. In this study, to further characterize the mechanism of sea cucumber autolysis, hydroxyl radical production induced by ultraviolet A (UVA) irradiation was investigated. Homogenate from the body wall of S. japonicas was prepared and subjected to UVA irradiation at room temperature. Electron Spin Resonance (ESR) spectra of the treated samples were subsequently recorded. The results showed that hydroxyl radicals (OH) became more abundant while the time of UVA treatment and the homogenate concentration were increased. Addition of superoxide dismutase (SOD), catalase, EDTA, desferal, NaN3 and D2O to the homogenate samples led to different degrees of inhibition on OH production. Metal cations and pH also showed different effects on OH production. These results indicated that OH was produced in the homogenate with a possible pathway as follows: O2(-) → H2O2 → OH, suggesting that OH might be a critical factor in UVA-induced S. japonicus autolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

First record of Tenuipalpus uvae De Leon, 1962 (Acari: Tenuipalpidae) in Brazil

USDA-ARS?s Scientific Manuscript database

This is the first record of Tenuipalpus uvae De Leon (Tenuipalpidae) in Brazil. Specimens were collected from Spondias mombin L. (Anacardiaceae) in the states of Amapa (Northern Brazil) and Pernambuco (northeast)....

Strategic need for a multi-purpose thermal hydraulic loop for support of advanced reactor technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Brien, James E.; Sabharwall, Piyush; Yoon, Su -Jong

2014-09-01

This report presents a conceptual design for a new high-temperature multi fluid, multi loop test facility for the INL to support thermal hydraulic, materials, and thermal energy storage research for nuclear and nuclear-hybrid applications. In its initial configuration, the facility will include a high-temperature helium loop, a liquid salt loop, and a hot water/steam loop. The three loops will be thermally coupled through an intermediate heat exchanger (IHX) and a secondary heat exchanger (SHX). Research topics to be addressed with this facility include the characterization and performance evaluation of candidate compact heat exchangers such as printed circuit heat exchangers (PCHEs)more » at prototypical operating conditions, flow and heat transfer issues related to core thermal hydraulics in advanced helium-cooled and salt-cooled reactors, and evaluation of corrosion behavior of new cladding materials and accident-tolerant fuels for LWRs at prototypical conditions. Based on its relevance to advanced reactor systems, the new facility has been named the Advanced Reactor Technology Integral System Test (ARTIST) facility. Research performed in this facility will advance the state of the art and technology readiness level of high temperature intermediate heat exchangers (IHXs) for nuclear applications while establishing the INL as a center of excellence for the development and certification of this technology. The thermal energy storage capability will support research and demonstration activities related to process heat delivery for a variety of hybrid energy systems and grid stabilization strategies. Experimental results obtained from this research will assist in development of reliable predictive models for thermal hydraulic design and safety codes over the range of expected advanced reactor operating conditions. Proposed/existing IHX heat transfer and friction correlations and criteria will be assessed with information on materials compatibility and instrumentation needs. The experimental database will guide development of appropriate predictive methods and be available for code verification and validation (V&V) related to these systems.« less

Dual Band Deep Ultraviolet AlGaN Photodetectors

NASA Technical Reports Server (NTRS)

Aslam, S.; Miko, L.; Stahle, C.; Franz, D.; Pugel, D.; Guan, B.; Zhang, J. P.; Gaska, R.

2007-01-01

We report on the design, fabrication and characterization of a back-illuminated voltage bias selectable dual-band AlGaN UV photodetector. The photodetector can separate UVA and W-B band radiation by bias switching a two terminal n-p-n homojunction structure that is fabricated in the same pixel. When a forward bias is applied between the top and bottom electrodes, the detector can sense UV-A and reject W-B band radiation. Alternatively, under reverse bias, the photodetector can sense UV-B and reject UV-A band radiation.

WET OXIDATION OF MUNICIPAL SLUDGE BY THE VERTICAL TUBE REACTOR

EPA Science Inventory

A study was undertaken to assess the feasibility of carrying out oxidation of dilute sewage sludge by means of the vertical tube reactor (VTR) system. A pilot scale facility along with a laboratory reactor were used for this study. Dilute sewage sludge was oxidized in the laborat...

Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arcilesi, David J.; Ham, Tae Kyu; Kim, In Hun

2015-07-01

A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air–helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to dependmore » largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.« less

Quantitative analysis of UV-A shock and short term stress using iTRAQ, pseudo selective reaction monitoring (pSRM) and GC-MS based metabolite analysis of the cyanobacterium Nostoc punctiforme ATCC 29133.

PubMed

Wase, Nishikant; Pham, Trong Khoa; Ow, Saw Yen; Wright, Phillip C

2014-09-23

A quantitative proteomics and metabolomics analysis was performed using iTRAQ, HPLC and GC-MS in the filamentous cyanobacterium Nostoc punctiforme ATCC 29133 to understand the effect of short and long term UV-A exposure. Changes in the proteome were measured for short-term stress (4-24h) using iTRAQ. Changes in the photosynthetic pigments and intracellular metabolites were observed at exposures of up to 7days (pigments) and up to 11days (intracellular metabolites). To assess iTRAQ measurement quality, pseudo selected reaction monitoring (pSRM) was used, with this confirming underestimation of protein abundance levels by iTRAQ. Our results suggest that short term UV-A radiation lowers the abundance of PS-I and PS-II proteins. We also observed an increase in abundance of intracellular redox homeostasis proteins and plastocyanin. Additionally, we observed statistically significant changes in scytonemin, Chlorophyll A, astaxanthin, zeaxanthin, and β-carotene. Assessment of intracellular metabolites showed significant changes in several, suggesting their potential role in the Nostoc's stress mitigation strategy. Cyanobacteria under UV-A radiation have reduced growth due to intensive damage to essential functions, but the organism shows a defense response by remodeling bioenergetics pathway, induction of the UV protection compound scytonemin and increased levels of proline and tyrosine as a mitigation response. The effect of UV-A radiation on the proteome and intracellular metabolites of N. punctiforme ATCC 29133 including photosynthetic pigments has been described. We also verify the expression of 13 iTRAQ quantified protein using LC-pSRM. Overall we observed that UV-A radiation has a drastic effect on the photosynthetic machinery, photosynthetic pigments and intracellular amino acids. As a mitigation strategy against UV-A radiation, proline, glycine, and tyrosine were accumulated. Copyright © 2014. Published by Elsevier B.V.

PBF Reactor Building (PER620). Camera faces south toward verticallift door, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera faces south toward vertical-lift door, which is closed. Note crane and its trolley positioned near door; its rails along side walls. Reactor vessel and lifting beams are positioned above reactor pit. Photographer: John Capek. Date: January 9, 1970. INEEL negative no. 70-132 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

SPERTI. Detail view of Reactor Pit Building (PER605) and Instrument ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

SPERT-I. Detail view of Reactor Pit Building (PER-605) and Instrument Cell (PER-606). Earth shielding covers side of Cell Building next to reactor. Instrumentation required protection from radiation emitted during reactor operation. Photographer: R.G. Larsen. Date: May 20, 1955. INEEL negative no. 55-1290 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Proposed Design and Operation of a Heat Pipe Reactor using the Sandia National Laboratories Annular Core Test Facility and Existing UZrH Fuel Pins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wright, Steven A.; Lipinski, Ronald J.; Pandya, Tara

2005-02-06

Heat Pipe Reactors (HPR) for space power conversion systems offer a number of advantages not easily provided by other systems. They require no pumping, their design easily deals with freezing and thawing of the liquid metal, and they can provide substantial levels of redundancy. Nevertheless, no reactor has ever been operated and cooled with heat pipes, and the startup and other operational characteristics of these systems remain largely unknown. Signification deviations from normal reactor heat removal mechanisms exist, because the heat pipes have fundamental heat removal limits due to sonic flow issues at low temperatures. This paper proposes an earlymore » prototypic test of a Heat Pipe Reactor (using existing 20% enriched nuclear fuel pins) to determine the operational characteristics of the HPR. The proposed design is similar in design to the HOMER and SAFE-300 HPR designs (Elliot, Lipinski, and Poston, 2003; Houts, et. al, 2003). However, this reactor uses existing UZrH fuel pins that are coupled to potassium heat pipes modules. The prototype reactor would be located in the Sandia Annular Core Research Reactor Facility where the fuel pins currently reside. The proposed reactor would use the heat pipes to transport the heat from the UZrH fuel pins to a water pool above the core, and the heat transport to the water pool would be controlled by adjusting the pressure and gas type within a small annulus around each heat pipe. The reactor would operate as a self-critical assembly at power levels up to 200 kWth. Because the nuclear heated HPR test uses existing fuel and because it would be performed in an existing facility with the appropriate safety authorization basis, the test could be performed rapidly and inexpensively. This approach makes it possible to validate the operation of a HPR and also measure the feedback mechanisms for a typical HPR design. A test of this nature would be the world's first operating Heat Pipe Reactor. This reactor is therefore called 'HPR-1'.« less

Assessment of extracts of Helichrysum arenarium, Crataegus monogyna, Sambucus nigra in photoprotective UVA and UVB; photostability in cosmetic emulsions.

PubMed

Jarzycka, Anna; Lewińska, Agnieszka; Gancarz, Roman; Wilk, Kazimiera A

2013-11-05

The aim of our study was to investigate the photoprotective activity and photostability efficacy of sunscreen formulations containing Helichrysum arenarium, Sambucus nigra, Crataegus monogyna extracts and their combination. UV transmission of the emulsion films was performed by using diffuse transmittance measurements coupling to an integrating sphere. In vitro photoprotection and photostability efficacy were evaluated according to the following parameters: sun protection factor (SPF), UVA protection factor (PF-UVA), UVA/UVB ratio and critical wavelength (λc) before and after UV irradiation. The results obtained show that the formulations containing polyphenols fulfill the official requirements for sunscreen products due to their broad spectrum of UV protection combined with their high photostability and remarkable antioxidant properties. Therefore H. arenarium, S. nigra, C. monogyna extracts represent useful additives for cosmetic formulation. Copyright © 2013 Elsevier B.V. All rights reserved.

Changes in UV absorption of sunscreens after UV irradiation

NASA Astrophysics Data System (ADS)

Tarras-Wahlberg, N.; Stenhagen, G.; Larkö, O.; Rosén, A.; Wennberg, A.-M.; Wennerström, O.

2000-03-01

In the present investigation we have studied the change in the absorption spectrum of some photoactive organic species in sunscreens after UVA and UVB irradiation in a dose normally encountered during a full day in the sun. The absorbance of 2-ethylhexyl 4-methoxycinnamate was reduced significantly, while 3-(4-methylbenzyliden)camphor seemed to be rather stable. The benzophenones studied seemed to be relatively stable. In the case of 4-tert.butyl-4´-methoxy-dibenzoylmethane there was a rapid decrease in the UVA absorption leading to unsatisfactory protection in the UVA region. 4-Isopropyl-dibenzoylmethane also lost most of its UV protective capacity after irradiation with UVA. UVB seemed to have a minor effect on all the samples. The present study including gas chromatography and mass spectrometry analysis indicates that some of the photoactive organic species commonly used today in sunscreens are unstable following UV irradiation.

Kinetic study on UV-absorber photodegradation under different conditions

NASA Astrophysics Data System (ADS)

Bubev, Emil; Georgiev, Anton; Machkova, Maria

2016-09-01

The photodegradation kinetics of two benzophenone derivative UV-absorbers (UVAs)-BP-4 (benzophenone-4) and 4-HBP (4-hydroxybenzophenone), as additives in polyvinyl acetate (PVAc) films, were studied. Solution-processed PVAc films were irradiated in different environments in order to study oxygen and atmospheric humidity influence on UVA photodegradation. Photodegradation was traced by absorption intensity loss via UV-vis spectroscopy. Both UVAs exhibited excellent photostability in an inert atmosphere. Rate constants showed that BP-4 has better permanence in absence of oxygen. Both film types experienced rapid absorption loss, when irradiated in an oxygen containing atmosphere. UVA degradation was treated as a two-stage process. The photodegradation kinetics in the first stage agreed with the adopted complex rate law, but the second stage was best described by pseudo-first order kinetics. BP-4 exhibited better stability. Oxygen was established as the main accelerating factor for photodegradation of benzophenone derivatives UV-absorbers in thin PVAc films.

Hyperthermal Environments Simulator for Nuclear Rocket Engine Development

NASA Technical Reports Server (NTRS)

Litchford, Ron J.; Foote, John P.; Clifton, W. B.; Hickman, Robert R.; Wang, Ten-See; Dobson, Christopher C.

2011-01-01

An arc-heater driven hyperthermal convective environments simulator was recently developed and commissioned for long duration hot hydrogen exposure of nuclear thermal rocket materials. This newly established non-nuclear testing capability uses a high-power, multi-gas, wall-stabilized constricted arc-heater to produce hightemperature pressurized hydrogen flows representative of nuclear reactor core environments, excepting radiation effects, and is intended to serve as a low-cost facility for supporting non-nuclear developmental testing of hightemperature fissile fuels and structural materials. The resulting reactor environments simulator represents a valuable addition to the available inventory of non-nuclear test facilities and is uniquely capable of investigating and characterizing candidate fuel/structural materials, improving associated processing/fabrication techniques, and simulating reactor thermal hydraulics. This paper summarizes facility design and engineering development efforts and reports baseline operational characteristics as determined from a series of performance mapping and long duration capability demonstration tests. Potential follow-on developmental strategies are also suggested in view of the technical and policy challenges ahead. Keywords: Nuclear Rocket Engine, Reactor Environments, Non-Nuclear Testing, Fissile Fuel Development.

Proposed Guidance for Preparing and Reviewing Molten Salt Nonpower Reactor Licence Applications (NUREG-1537)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belles, Randy; Flanagan, George F.; Voth, Marcus

Development of non-power molten salt reactor (MSR) test facilities is under consideration to support the analyses needed for development of a full-scale MSR. These non-power MSR test facilities will require review by the US Nuclear Regulatory Commission (NRC) staff. This report proposes chapter adaptations for NUREG-1537 in the form of interim staff guidance to address preparation and review of molten salt non-power reactor license applications. The proposed adaptations are based on a previous regulatory gap analysis of select chapters from NUREG-1537 for their applicability to non-power MSRs operating with a homogeneous fuel salt mixture.

Radioactive Waste Management and Nuclear Facility Decommissioning Progress in Iraq - 13216

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Musawi, Fouad; Shamsaldin, Emad S.; Jasim, Hadi

2013-07-01

Management of Iraq's radioactive wastes and decommissioning of Iraq's former nuclear facilities are the responsibility of Iraq's Ministry of Science and Technology (MoST). The majority of Iraq's former nuclear facilities are in the Al-Tuwaitha Nuclear Research Center located a few kilometers from the edge of Baghdad. These facilities include bombed and partially destroyed research reactors, a fuel fabrication facility and radioisotope production facilities. Within these facilities are large numbers of silos, approximately 30 process or waste storage tanks and thousands of drums of uncharacterised radioactive waste. There are also former nuclear facilities/sites that are outside of Al-Tuwaitha and these includemore » the former uranium processing and waste storage facility at Jesira, the dump site near Adaya, the former centrifuge facility at Rashdiya and the former enrichment plant at Tarmiya. In 2005, Iraq lacked the infrastructure needed to decommission its nuclear facilities and manage its radioactive wastes. The lack of infrastructure included: (1) the lack of an organization responsible for decommissioning and radioactive waste management, (2) the lack of a storage facility for radioactive wastes, (3) the lack of professionals with experience in decommissioning and modern waste management practices, (4) the lack of laws and regulations governing decommissioning or radioactive waste management, (5) ongoing security concerns, and (6) limited availability of electricity and internet. Since its creation eight years ago, the MoST has worked with the international community and developed an organizational structure, trained staff, and made great progress in managing radioactive wastes and decommissioning Iraq's former nuclear facilities. This progress has been made, despite the very difficult implementing conditions in Iraq. Within MoST, the Radioactive Waste Treatment and Management Directorate (RWTMD) is responsible for waste management and the Iraqi Decommissioning Directorate (IDD) is responsible for decommissioning activities. The IDD and the RWTMD work together on decommissioning projects. The IDD has developed plans and has completed decommissioning of the GeoPilot Facility in Baghdad and the Active Metallurgical Testing Laboratory (LAMA) in Al-Tuwaitha. Given this experience, the IDD has initiated work on more dangerous facilities. Plans are being developed to characterize, decontaminate and decommission the Tamuz II Research Reactor. The Tammuz Reactor was destroyed by an Israeli air-strike in 1981 and the Tammuz II Reactor was destroyed during the First Gulf War in 1991. In addition to being responsible for managing the decommissioning wastes, the RWTMD is responsible for more than 950 disused sealed radioactive sources, contaminated debris from the first Gulf War and (approximately 900 tons) of naturally-occurring radioactive materials wastes from oil production in Iraq. The RWTMD has trained staff, rehabilitated the Building 39 Radioactive Waste Storage building, rehabilitated portions of the French-built Radioactive Waste Treatment Station, organized and secured thousands of drums of radioactive waste organized and secured the stores of disused sealed radioactive sources. Currently, the IDD and the RWTMD are finalizing plans for the decommissioning of the Tammuz II Research Reactor. (authors)« less

Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

PubMed

Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

2015-01-01

This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

Daily, seasonal, and latitudinal variations in solar ultraviolet A and B radiation in relation to vitamin D production and risk for skin cancer.

PubMed

Grigalavicius, Mantas; Moan, Johan; Dahlback, Arne; Juzeniene, Asta

2016-01-01

Solar ultraviolet (UV) radiation varies with latitude, time of day, and season. Both spectral UV composition and ambient UV dose lead to different health outcomes at different latitudes. Finding the optimal time for sun exposure, whereby the positive effects of UV exposure (vitamin D) are facilitated and the negative effects (skin cancer, photoimmunosuppression) avoided are the most important consideration in modern skin cancer prevention programs. This paper focuses on the latitude dependency of UVB, UVA, vitamin D production, and skin cancer risk in Caucasians. Biologically effective UVB (280-315 nm) and UVA (315-400 nm) doses were calculated using radiative transfer models with appropriate climatologic data for selected locations. Incidences of squamous cell carcinoma (SCC) and cutaneous melanoma (CM) were retrieved from cancer registries and published articles. Annual doses of UVA radiation decrease much less with increasing latitude than annual doses of UVB. Incidences of CM also decrease less steeply with increasing latitude than incidences of SCC. As SCC is caused mainly by UVB, these observations support the assumption that UVA plays an important role in the development of CM. The variations in UVA (relevant to CM) and UVB (relevant to vitamin D production) over 1 day differ: the UVB : UVA ratio is maximal at noon. The best way to obtain a given dose of vitamin D with minimal carcinogenic risk is through a non-burning exposure in the middle of the day, rather than in the afternoon or morning. © 2015 The International Society of Dermatology.

Different susceptibility of cells of porcine skin and internal organs to ultraviolet A-induced breaking of nuclear DNA.

PubMed

Brozyna, Anna; Chwirot, Barbara W

2005-01-01

There is a continuously growing interest in medical applications of ultraviolet radiation (UV-A and long-wavelength UV-B) especially for laser surgery, phototherapy and photodiagnostics of human internal organs. UV-B and UV-A radiation is potentially mutagenic, however, there has been very little information published to date concerning the significance of possible deleterious action of such photons on cells of internal tissues. The aim of this study is to compare the sensitivities of skin cells to those of internal organs upon exposure to UV-A. To assess this sensitivity we have determined the UV-A dose-dependent frequency of nuclear DNA breaks detected with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) technique. The materials for the study were macroscopic samples of porcine skin, colon and esophagus. The UV-A dose ranged from 0.1 to 1000 mJ/cm2, which is similar to doses received by cells in regions examined with laser-induced fluorescence or by cells surrounding areas subject to a laser ablation. To reduce the influence of DNA repair processes the tissue samples were kept at a low temperature during the irradiation and were deep frozen immediately after completing the irradiation procedure. The cells of the internal organs are much more susceptible to UV-A-induced breaking of DNA than the skin cells. The percentage fractions and the spatial distributions of the damaged cells and the characteristics of the UV-A dose dependence seem to vary by type of internal organ.

Pretreatment of Ferulic Acid Protects Human Dermal Fibroblasts against Ultraviolet A Irradiation

PubMed Central

Hahn, Hyung Jin; Kim, Ki Bbeum; Bae, Seunghee; Choi, Byung Gon; An, Sungkwan

2016-01-01

Background Approximately 90%~99% of ultraviolet A (UVA) ray reaches the Earth's surface. The deeply penetrating UVA rays induce the formation of reactive oxygen species (ROS), which results in oxidative stress such as photoproducts, senescence, and cell death. Thus, UVA is considered a primary factor that promotes skin aging. Objective Researchers investigated whether pretreatment with ferulic acid protects human dermal fibroblasts (HDFs) against UVA-induced cell damages. Methods HDF proliferation was analyzed using the water-soluble tetrazolium salt assay. Cell cycle distribution and intracellular ROS levels were assessed by flow cytometric analysis. Senescence was evaluated using a senescence-associated β-galactosidase assay, while Gadd45α promoter activity was analyzed through a luciferase assay. The expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), xeroderma pigmentosum complementation group A and C, matrix metalloproteinase 1 and 3, as well as p21 and p16 were measured using quantitative real-time polymerase chain reaction. Results Inhibition of proliferation and cell cycle arrest were detected in cells that were irradiated with UVA only. Pretreatment with ferulic acid significantly increased the proliferation and cell cycle progression in HDFs. Moreover, ferulic acid pretreatment produced antioxidant effects such as reduced DCF intensity, and affected SOD1 and CAT mRNA expression. These effects were also demonstrated in the analysis of cell senescence, promoter activity, expression of senescent markers, and DNA repair. Conclusion These results demonstrate that ferulic acid exerts protective effects on UVA-induced cell damages via anti-oxidant and stress-inducible cellular mechanisms in HDFs. PMID:27904274

Comparing ultraviolet light A photo(chemo)therapy with Methotrexate protocol in childhood localized scleroderma: Evidence from systematic review and meta-analysis approach.

PubMed

Marrani, Edoardo; Foeldvari, Ivan; Lopez, Jordi Anton; Cimaz, Rolando; Simonini, Gabriele

2018-03-14

Localized scleroderma is a skin fibrosing disorder that, if untreated, may result in severe disability. The purpose of this systematic review is to compare the present evidence concerning the effectiveness of Methotrexate versus phototherapy, alone or associated with Psoralen, in childhood localized scleroderma. A systematic search between January 1996 and May 2017 was performed to identify studies investigating the efficacy of Methotrexate (MTX) or phototherapy (UVA) for treating localized scleroderma with onset ≤18 years. Due to a lack of validated clinical criteria, four clinical response criteria were used to assess the treatment efficacy as primary outcome. We determined a combined estimate of the proportion of children responding to MTX and UVA. A total of 19 studies was included (8 MTX; 11 UVA). In the methotrexate group, 193 children were included in the analysis; in the phototherapy group, a total of 48 treated children. For both groups age, disease subtype, glucocorticoids (GCs) use, and side effects of treatment were also analyzed. The meta-analysis suggested that UVA and MTX protocols have both a favorable effect in active lesions of childhood localized scleroderma. However, MTX resulted significantly superior to UVA, with or without Psoralen. Our study supports the combination of MTX and GCs in patients with a high risk of complication. Phototherapy with UVA1 could represent a therapeutic option in patients with limited scleroderma, where lesions do not cross joints and they do not lead to potential cosmetic changes. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of UVC, UVB, UVA and a solar simulator on the survival of mouse melanoma cell lines differing in melanin content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, H.Z.; Hill, G.J.; Cieszka, K.

These studies were designed to determine the survival of cells that vary in constitutive pigment levels after exposure to different UV wave lengths. The lamps employed emitted UVC (near monochromatic 254 nm), UVB (Philips TL01-88.7% of UV output is UVB), UVA (Philips HPW125-89% of output is at 365 nm) and Westinghouse FS20 (broad band UVB and UVA). Dish lids were used to cut off UVC in the UVB and FS20 experiments and 0.25 inch plate glass was used to cut off UVB in the UVA experiments. UVC photons interact with putative intracellular photosensitizers which in turn convert O{sub 2} tomore » active oxygen species which damage DNA to produce strand breaks, cross links and base damage. UVB acts by both mechanisms. The two cell lines studied were Cloudman S91/I3 (3.6 pg melanin/cell) and the closely related S91/amel (1.2 pg melanin/cell). Attached cells were covered with Ca{sup ++} and Mg{sup ++} free PBS and irradiated in the cold. Colonies were scored after 2 weeks. The two cell lines exhibit similar survival kinetics after UVC. S91/IE is more sensitive to killing by either UVB (TL01) or UVA. However, S91/amel cells are more sensitive to killing by UVB plus UVA (FS20). It is clear that UV of different qualities can interact to produce effects that would not be predicted based on responses to monochromatic wave lengths.« less

Fibrinogen, Riboflavin, and UVA to Immobilize a Corneal Flap – Molecular Mechanisms

PubMed Central

Littlechild, Stacy L.; Zhang, Yuntao; Tomich, John M.; Conrad, Gary W.

2012-01-01

Purpose. Tissue glue containing fibrinogen (FIB) and riboflavin (RF), upon exposure to long wavelength ultraviolet light (UVA, 365 nM) has been proposed potentially to solve long-standing problems presented by corneal wound and epithelial ingrowth side-effects from laser-assisted in situ keratomileuis (LASIK). Data presented in a previous study demonstrated an ability of FIB + RF + UVA to adhere two stromal surfaces; however, to our knowledge no molecular mechanisms have been proposed to account for interactions occurring between corneal extracellular matrix (ECM) and tissue glue molecules. Here, we document several covalent and noncovalent interactions between these classes of macromolecules. Methods. SDS-PAGE and Western blot techniques were used to identify covalent interactions between tissue glue molecules and corneal ECM molecules in either the presence or absence of RF and UVA, in vitro and ex vivo. Surface plasmon resonance (SPR) was used to characterize noncovalent interactions, and obtain ka, kd, and KD binding affinity values. Results. SDS-PAGE and Western blot analyses indicated that covalent interactions occurred between neighboring FIB molecules, as well as between FIB and collagen type I (Coll-I) proteins (in vitro and ex vivo). These interactions occurred only in the presence of RF and UVA. SPR data demonstrated the ability of FIB to bind noncovalently to corneal stroma molecules, Coll-I, decorin, dermatan sulfate, and corneal basement membrane molecules, laminin and heparan sulfate – only in the presence of Zn2+. Conclusions. Covalent and (zinc-mediated) noncovalent mechanisms involving FIB and stromal ECM molecules contribute to the adhesion created by FIB + RF + UVA. PMID:22879413

Comparative studies on the lethal, mutagenic, and recombinogenic effects of ultraviolet -A, -B, -C, and visible light with and without 8-methoxypsoralen in Saccharomyces cerevisiae.

PubMed

Mondon, P; Shahin, M M

1992-05-01

Genetic effects of UV-A, UV-B, UV-C, and the combination of 8-methoxypsoralen (8-MOP) with UV-A or visible light were studied in the haploid strain XV185-14C and diploid strain D5 of Saccharomyces cerevisiae. The induction of his+, lys+, and hom+ reverse mutations was measured in strain XV185-14C. In strain D5 we measured the induction of genetically altered colonies, particularly twin spot colonies arising from a mitotic crossing-over. UV-C and UV-B induced point mutations at the three loci in the haploid strain and mitotic crossing-over and other genetic alterations in the diploid strain. UV-C was more mutagenic and recombinogenic than UV-B. UV-A or visible light alone did not induce genotoxic effects at the doses tested. However, UV-A plus 8-MOP produced lethal and mutagenic effects in the haploid strain XV185-14C, although mutagenic activity was less than that of UV-B. Visible light plus 8-MOP also induced genotoxic effects in strain XV185-14C. In the diploid strain D5, UV-A plus 8-MOP induced a higher frequency of genetic alterations than UV-B at comparative doses. Visible light plus 8-MOP was also genetically active in strain D5. The haploid strain was more sensitive to the lethal effects of UV-C, UV-B, UV-A, and impure visible light plus 8-MOP than the diploid strain.

Sun protection

MedlinePlus

... age spots are caused by exposure to the sun. This is because the damage caused by the sun is permanent. ... The two types of sun rays that can injure the skin are ultraviolet A (UVA) and ultraviolet B (UVB). UVA affects the deep layers of ...

Mechanistic considerations on the wavelength-dependent variations of UVR genotoxicity and mutagenesis in skin: the discrimination of UVA-signature from UV-signature mutation.

PubMed

Ikehata, Hironobu

2018-05-31

Ultraviolet radiation (UVR) predominantly induces UV-signature mutations, C → T and CC → TT base substitutions at dipyrimidine sites, in the cellular and skin genome. I observed in our in vivo mutation studies of mouse skin that these UVR-specific mutations show a wavelength-dependent variation in their sequence-context preference. The C → T mutation occurs most frequently in the 5'-TCG-3' sequence regardless of the UVR wavelength, but is recovered more preferentially there as the wavelength increases, resulting in prominent occurrences exclusively in the TCG sequence in the UVA wavelength range, which I will designate as a "UVA signature" in this review. The preference of the UVB-induced C → T mutation for the sequence contexts shows a mixed pattern of UVC- and UVA-induced mutations, and a similar pattern is also observed for natural sunlight, in which UVB is the most genotoxic component. In addition, the CC → TT mutation hardly occurs at UVA1 wavelengths, although it is detected rarely but constantly in the UVC and UVB ranges. This wavelength-dependent variation in the sequence-context preference of the UVR-specific mutations could be explained by two different photochemical mechanisms of cyclobutane pyrimidine dimer (CPD) formation. The UV-signature mutations observed in the UVC and UVB ranges are known to be caused mainly by CPDs produced through the conventional singlet/triplet excitation of pyrimidine bases after the direct absorption of the UVC/UVB photon energy in those bases. On the other hand, a novel photochemical mechanism through the direct absorption of the UVR energy to double-stranded DNA, which is called "collective excitation", has been proposed for the UVA-induced CPD formation. The UVA photons directly absorbed by DNA produce CPDs with a sequence context preference different from that observed for CPDs caused by the UVC/UVB-mediated singlet/triplet excitation, causing CPD formation preferentially at thymine-containing dipyrimidine sites and probably also preferably at methyl CpG-associated dipyrimidine sites, which include the TCG sequence. In this review, I present a mechanistic consideration on the wavelength-dependent variation of the sequence context preference of the UVR-specific mutations and rationalize the proposition of the UVA-signature mutation, in addition to the UV-signature mutation.

Management of atopic dermatitis: safety and efficacy of phototherapy

PubMed Central

Patrizi, Annalisa; Raone, Beatrice; Ravaioli, Giulia Maria

2015-01-01

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that can affect all age groups. It is characterized by a relapsing course and a dramatic impact on quality of life for patients. Environmental interventions together with topical devices represent the mainstay of treatment for AD, in particular emollients, corticosteroids, and calcineurin inhibitors. Systemic treatments are reserved for severe cases. Phototherapy represents a valid second-line intervention in those cases where non-pharmacological and topical measures have failed. Different forms of light therapy are available, and have showed varying degrees of beneficial effect against AD: natural sunlight, narrowband (NB)-UVB, broadband (BB)-UVB, UVA, UVA1, cold-light UVA1, UVA and UVB (UVAB), full-spectrum light (including UVA, infrared and visible light), saltwater bath plus UVB (balneophototherapy), Goeckerman therapy (coal tar plus UVB radiation), psoralen plus UVA (PUVA), and other forms of phototherapy. In particular, UVA1 and NB-UVB have gained importance in recent years. This review illustrates the main trials comparing the efficacy and safety of the different forms of phototherapy. No sufficiently large randomized controlled studies have been performed as yet, and no light modality has been defined as superior to all. Parameters and dosing protocols may vary, although clinicians mainly refer to the indications included in the American Academy of Dermatology psoriasis guidelines devised by Menter et al in 2010. The efficacy of phototherapy (considering all forms) in AD has been established in adults and children, as well as for acute (UVA1) and chronic (NB-UVB) cases. Its use is suggested with strength of recommendation B and level of evidence II. Home phototherapy can also be performed; this technique is recommended with strength C and level of evidence III. Phototherapy is generally considered to be safe and well tolerated, with a low but established percentage of short-term and long-term adverse effects, with the most common being photodamage, xerosis, erythema, actinic keratosis, sunburn, and tenderness. A carcinogenic risk related to UV radiation has not been excluded. Phototherapy also has some limitations related to costs, availability, and patient compliance. In conclusion, phototherapy is an optimal second-line treatment for AD. It can be used as monotherapy or in combination with systemic drugs, in particular corticosteroids. It must be performed conscientiously, especially in children, and must take into account the patient’s features and overall condition. PMID:26491366

Analysis of ORNL site temperature and humidity data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willis, B.E.

1989-08-01

The Advanced Neutron Source (ANS) is planned as a new state-of-the-art facility for neutron research and is currently undergoing conceptual design at the Oak Ridge National Laboratory (ORNL). The current concept calls for a nuclear research reactor with an operating power near 350 MW and extensive experiment and user support facilities. Analyses have been undertaken to determine an acceptable design basis wet-bulb temperature range for the facility. Comparisons are drawn with the design wet-bulb temperature previously used for the High Flux Isotope Reactor (HFIR), which is located on an adjacent site a Oak Ridge. This report explains the importance ofmore » wet-bulb temperature to the reactor cooling system performance, and describes the analysis of available meteorological data, and presents the results and the recommendations for a wet-bulb temperature range for use as a part of the plant design basis conditions. 1 ref., 6 figs.« less

Methods and systems for the production of hydrogen

DOEpatents

Oh, Chang H [Idaho Falls, ID; Kim, Eung S [Ammon, ID; Sherman, Steven R [Augusta, GA

2012-03-13

Methods and systems are disclosed for the production of hydrogen and the use of high-temperature heat sources in energy conversion. In one embodiment, a primary loop may include a nuclear reactor utilizing a molten salt or helium as a coolant. The nuclear reactor may provide heat energy to a power generation loop for production of electrical energy. For example, a supercritical carbon dioxide fluid may be heated by the nuclear reactor via the molten salt and then expanded in a turbine to drive a generator. An intermediate heat exchange loop may also be thermally coupled with the primary loop and provide heat energy to one or more hydrogen production facilities. A portion of the hydrogen produced by the hydrogen production facility may be diverted to a combustor to elevate the temperature of water being split into hydrogen and oxygen by the hydrogen production facility.

Evaluation of Municipal Wastewater Treatment Plant Activated Sludge for Biodegradation of Propylene Glycol as an Aircraft Deicing Fluid

DTIC Science & Technology

2012-03-01

Propylene Glycol Deicer Biodegredation Kinetics: Complete-Mix Stirred Tank Reactors , Filter, and Fluidized Bed . Journal of Environmental...scale sequencing batch reactor containing municipal waste water treatment facility activated sludge (AS) performing simultaneous organic carbon...Sequencing Batch Reactor Operation ..................................................................... 13 PG extraction from AS

PBF Reactor Building (PER620). Camera in second basement near subpile ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera in second basement near sub-pile room (directly below reactor vessel). Door and penetrations lead to sub-pile room. Date: August 15, 1969. Photographer: Larry Page. INEEL negative no. 69-4310 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

76 FR 63668 - Guidelines for Preparing and Reviewing Licensing Applications for the Production of Radioisotopes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-13

... Licensing of Non-Power Reactors: Format and Content,'' for the Production of Radioisotopes and NUREG-1537, part 2, ``Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors... production facility and the Research and Test Reactor Licensing Branch (PRLB) of the Division of Policy and...

10 CFR 50.44 - Combustible gas control for nuclear power reactors.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Combustible gas control for nuclear power reactors. 50.44... FACILITIES Standards for Licenses, Certifications, and Regulatory Approvals § 50.44 Combustible gas control... capability for ensuring a mixed atmosphere. (2) Combustible gas control. (i) All boiling water reactors with...

10 CFR 50.44 - Combustible gas control for nuclear power reactors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Combustible gas control for nuclear power reactors. 50.44... FACILITIES Standards for Licenses, Certifications, and Regulatory Approvals § 50.44 Combustible gas control... capability for ensuring a mixed atmosphere. (2) Combustible gas control. (i) All boiling water reactors with...

10 CFR 50.44 - Combustible gas control for nuclear power reactors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Combustible gas control for nuclear power reactors. 50.44... FACILITIES Standards for Licenses, Certifications, and Regulatory Approvals § 50.44 Combustible gas control... capability for ensuring a mixed atmosphere. (2) Combustible gas control. (i) All boiling water reactors with...

PBF Reactor Building (PER620). Camera on main floor faces south ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera on main floor faces south (open) doorway. In foreground is canal gate, lined with stainless steel and painted with protective coatings. Reactor pit is round with protective coatings. Reactor put is round form discernible beyond. Lifting beams and rigging are in place for a load test before reactor vessel arrives. Photographer: John Capek. Date: January 26, 1970. INEEL negative no. 70-347 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

PBF Reactor Building (PER620). Camera is in cab of electricpowered ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera is in cab of electric-powered rail crane and facing east. Reactor pit and storage canal have been shaped. Floors for wings on east and west side are above and below reactor in view. Photographer: Larry Page. Date: August 23, 1967. INEEL negative no. 67-4403 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Small Reactor for Deep Space Exploration

ScienceCinema

none,

2018-06-06

This is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and an experiment demonstrated the first use of a heat pipe to cool a small nuclear reactor and then harvest the heat to power a Stirling engine at the Nevada National Security Site's Device Assembly Facility confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venkataraman, M.; Natarajan, R.; Raj, Baldev

The reprocessing of spent fuel from Fast Breeder Test Reactor (FBTR) has been successfully demonstrated in the pilot plant, CORAL (COmpact Reprocessing facility for Advanced fuels in Lead shielded cell). Since commissioning in 2003, spent mixed carbide fuel from FBTR of different burnups and varying cooling period, have been reprocessed in this facility. Reprocessing of the spent fuel with a maximum burnup of 100 GWd/t has been successfully carried out so far. The feed backs from these campaigns with progressively increasing specific activities, have been useful in establishing a viable process flowsheet for reprocessing the Prototype Fast Breeder Reactor (PFBR)more » spent fuel. Also, the design of various equipments and processes for the future plants, which are either under design for construction, namely, the Demonstration Fast Reactor Fuel Reprocessing Plant (DFRP) and the Fast reactor fuel Reprocessing Plant (FRP) could be finalized. (authors)« less

Mass tracking and material accounting in the Integral Fast Reactor (IFR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orechwa, Y.; Adams, C.H.; White, A.M.

1991-01-01

The Integral Fast Reactor (IFR) is a generic advanced liquid metal cooled reactor concept being developed at Argonne National Laboratory (ANL). There are a number of technical features of the IFR which contribute to its potential as a next-generation reactor. These are associated with large safety margins with regard to off-normal events involving the heat transport system, and the use of metallic fuel which makes possible the utilization of innovative fuel cycle processes. The latter feature permits fuel cycle closure the compact, low-cost reprocessing facilities, collocated with the reactor plant. These primary features are being demonstrated in the facilities atmore » ANL-West, utilizing Experimental Breeder Reactor 2 and the associated Fuel Cycle Facility (FCF) as an IFR prototype. The demonstration of this IFR prototype includes the design and implementation of the Mass-Tracking System (MTG). In this system, data from the operations of the FCF, including weights and batch-process parameters, are collected and maintained by the MTG running on distributed workstations. The components of the MTG System include: (1) an Oracle database manager with a Fortran interface, (2) a set of MTG Tasks'' which collect, manipulate and report data, (3) a set of MTG Terminal Sessions'' which provide some interactive control of the Tasks, and (4) a set of servers which manage the Tasks and which provide the communications link between the MTG System and Operator Control Stations, which control process equipment and monitoring devices within the FCF.« less

Measurements of UV-A radiation and hazard limits from some types of outdoor lamps

NASA Astrophysics Data System (ADS)

El-Moghazy, Essam; Abd-Elmageed, Alaa-Eldin; Reda, Sameh

2015-05-01

Illumination using artificial light sources is common in these days. Many manufactures are paying for the design of lamps depending on high efficacy and low UV hazards. This research is focusing on the most useable lamps in the Egyptian markets; High Pressure Mercury (HPM), Metal Halide (MH), and High Pressure Sodium (HPS). A set up for relative spectral power distribution based on single monochromator and UVA silicon detector for absolute irradiance measurements are used. The absolute irradiance in (W/m2) in UVA region of the lamps and their accompanied standard uncertainty are evaluated.

UVA irradiation of human skin vasodilates arterial vasculature and lowers blood pressure independently of nitric oxide synthase.

PubMed

Liu, Donald; Fernandez, Bernadette O; Hamilton, Alistair; Lang, Ninian N; Gallagher, Julie M C; Newby, David E; Feelisch, Martin; Weller, Richard B

2014-07-01

The incidence of hypertension and cardiovascular disease (CVD) correlates with latitude and rises in winter. The molecular basis for this remains obscure. As nitric oxide (NO) metabolites are abundant in human skin, we hypothesized that exposure to UVA may mobilize NO bioactivity into the circulation to exert beneficial cardiovascular effects independently of vitamin D. In 24 healthy volunteers, irradiation of the skin with two standard erythemal doses of UVA lowered blood pressure (BP), with concomitant decreases in circulating nitrate and rises in nitrite concentrations. Unexpectedly, acute dietary intervention aimed at modulating systemic nitrate availability had no effect on UV-induced hemodynamic changes, indicating that cardiovascular effects were not mediated via direct utilization of circulating nitrate. UVA irradiation of the forearm caused increased blood flow independently of NO synthase (NOS) activity, suggesting involvement of pre-formed cutaneous NO stores. Confocal fluorescence microscopy studies of human skin pre-labeled with the NO-imaging probe diaminofluorescein 2 diacetate revealed that UVA-induced NO release occurs in a NOS-independent, dose-dependent manner, with the majority of the light-sensitive NO pool in the upper epidermis. Collectively, our data provide mechanistic insights into an important function of the skin in modulating systemic NO bioavailability, which may account for the latitudinal and seasonal variations of BP and CVD.

[Deceleration of cataract development in rats under the action of N-acetylcarnosine and D-pantethine mixture].

PubMed

Avetisov, S É; Sheremet, N L; Muranov, K O; Polianskiĭ, N B; Polunin, G S; Ostrovskiĭ, M A

2014-01-01

The effect of a mixture of N-acetylcarnosine and D-pantethine (1 : 1, m/m) on UV-A induced cataract in rats was studied. It is shown that instillation of a 5% mixture into the eyes or intraperitoneal injections (25 or 150 mg/kg) inhibit the formation of cataracts, starting from 82nd day of the experiment (p < 0.03), after which the protective effect of the mixture significantly increases (p = 0.0003). UV-A irradiation significantly (p < 0.01) increased the content of water-insoluble proteins in the lens. The use of the mixture of N-Acetylcarnosine and D-pantethine prevented (p < 0.001) an increase in the content of water-insoluble proteins caused by UV-A irradiation. Gel permeation chromatography data showed that, in the control group, water insoluble proteins consist of 3 fractions (40 kDa, 100 - 200 kDa, and1000 kDa). UV-A irradiation reduced the amount of protein in fraction 1 and increases the amount of protein in the fractions 2 and 3. The use of the mixture of N-acetylcarnosine and D-pantethine reduced the effects of UV-A light. The authors attribute the effect of the N-acetylcarnosine and D-pantethine mixture to their chaperone-like properties.

Potential apoptotic effect of ultraviolet-A irradiation during cross-linking: a study on ex vivo cultivated limbal epithelial cells.

PubMed

Matalia, Himanshu; Shetty, Rohit; Dhamodaran, Kamesh; Subramani, Murali; Arokiaraj, Vincent; Das, Debashish

2012-10-01

To study the effects of ultraviolet-A (UV-A) irradiation, in the presence or absence of riboflavin, on ex vivo cultured limbal epithelial cells (LECs). The study was carried out in a super specialty ophthalmic hospital. Ex vivo cultured LECs were grown on denuded amniotic membranes and exposed to similar levels of UV-A radiation used during corneal cross-linking (CXL), in the presence or absence of the photosensitiser, riboflavin. These cells were then used for extraction of RNA, cDNA conversion, and antibody staining. Quantitative PCR and immunofluorescence staining were performed to evaluate the apoptotic state of treated and non-treated LECs. Statistical analyses were evaluated using a Student's t test. We found that bcl-2, an antiapoptotic gene, was downregulated, whereas, bax, a proapoptotic gene, was upregulated. After LECs were exposed to UV-A radiation, a significant upregulation of both caspase 3 and caspase 9 was observed in treated cells when compared with untreated LECs. These results indicate that exposure of LECs to UV-A dosages similar to those used in the CXL procedure promotes the expression of genes known to promote apoptosis. In the presence of riboflavin, the damage caused by UV-A treatment was marginalised, but not totally blocked.

Effect of UV-A radiation as an environmental stress on the development, longevity, and reproduction of the oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae).

PubMed

Ali, Arif; Rashid, Muhammad Adnan; Huang, Qiu Ying; Lei, Chao-Liang

2016-09-01

The ultraviolet light (UV-A) range of 320-400 nm is widely used as light trap for insect pests. Present investigation was aimed to determine the effect of UV light-A radiation on development, adult longevity, reproduction, and development of F1 generation of Mythimna separata. Our results revealed that the mortality of the second instar larvae was higher than the third and fourth instar larvae after UV-A radiation. As the time of UV-A irradiation for pupae prolonged, the rate of adult emergence reduced. Along with the extension of radiation time decreased the longevity of adult females and males. However, the radiation exposure of 1 and 4 h/day increased fecundity of female adults, and a significant difference was observed in a 1 h/day group. The oviposition rates of female adults in all the treatments were significantly higher than the control. In addition, UV-A radiation treatments resulted in declined cumulative survival of F1 immature stages (eggs, larvae, and pupae). After exposure time of 4 and 7 h/day, the developmental periods of F1 larvae increased significantly, but no significant effects on F1 pupal period were recorded.

Local suppression of contact hypersensitivity in mice by a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen, and UVA radiation.

PubMed

Aubin, F; Dall'Acqua, F; Kripke, M L

1991-07-01

Although psoralens plus UVA radiation (320-400 nm) have been widely used for the treatment of dermatologic diseases, the toxic effects of these agents have led investigators to develop new photochemotherapeutic compounds. One such compound is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional molecule. The purpose of this study was to examine the immunologic side effects of repeated treatment of C3H mice with TMAP plus UVA radiation. During this treatment, the number of ATPase+, la+, and Thy-1+ dendritic epidermal cells greatly decreased in the treated site, despite the lack of phototoxicity. The reduction in the number of detectable cutaneous immune cells was accompanied by a decrease in the induction of contact hypersensitivity to dinitrofluorobenzene applied to the treated skin, an impairment in the antigen-presenting activity of draining lymph node cells, and the presence of suppressor lymphoid cells in the spleen of unresponsive mice. Treatment with UVA radiation alone also reduced the number of ATPase+, Ia+, and Thy-1+ cells in the skin, but did not cause any detectable alterations in immune function. This implies that morphologic alterations in these cells do not necessarily indicate loss of function. Thus, although TMAP in combination with UVA radiation is not overtly phototoxic, it is highly immunosuppressive in mice.

Ultraviolet radiation induces dose-dependent pigment dispersion in crustacean chromatophores.

PubMed

Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

2004-10-01

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm(2) for UVA and 2.15 J/cm(2) for UVB. Maximal response was achieved with 10.0 J/cm(2) UVA and 8.6 J/cm(2) UVB. UVA was more effective than UVB in inducing pigment dispersion. Soon after UV exposure, melanophores once again reached the initial stage of pigment aggregation after 45 min. Aggregated erythrophores of shrimps adapted to a white background showed significant pigment dispersion with 2.5 J/cm(2) UVA and 0.29 J/cm(2) UVC. Dispersed erythrophores of shrimps adapted to a black background did not show any significant response to UVA, UVB or UVC radiation. UVB did not induce any significant pigment dispersion in shrimps adapted to either a white or a black background. As opposed to the tanning response, which only protects against future UV exposure, the pigment dispersion response could be an important agent protecting against the harmful effects of UV radiation exposure.

A novel genotoxic aspect of thiabendazole as a photomutagen in bacteria and cultured human cells.

PubMed

Watanabe-Akanuma, Mie; Ohta, Toshihiro; Sasaki, Yu F

2005-09-15

Thiabendazole (TBZ) is a post-harvest fungicide commonly used on imported citrus fruits. We recently found that TBZ showed photomutagenicity with UVA-irradiation in the Ames test using plate incorporation method. In the present study, potential of DNA-damaging activity, mutagenicity, and clastogenicity were investigated by short pulse treatment for 10 min with TBZ (50-400 microg/ml) and UVA-irradiation (320-400 nm, 250 microW/cm2) in bacterial and human cells. UVA-irradiated TBZ caused DNA damage in Escherichia coli and human lymphoblastoid WTK1 cells assayed, respectively, by the umu-test and the single cell gel electrophoresis (comet) assay. In a modified Ames test using Salmonella typhimurium and E. coli, strong induction of -1 frameshift mutations as well as base-substitution mutations were detected. TBZ at 50-100 microg/ml with UVA-irradiation significantly induced micronuclei in WTK1 cells in the in vitro cytochalasin-B micronucleus assay. Pulse treatment for 10 min with TBZ alone did not show any genotoxicity. Although TBZ is a spindle poison that induces aneuploidy, we hypothesize that the photogenotoxicity of TBZ in the present study was produced by a different mechanism, probably by DNA adduct formation. We concluded that UVA-activated TBZ is genotoxic in bacterial and human cells in vitro.

Nitroxides are more efficient inhibitors of oxidative damage to calf skin collagen than antioxidant vitamins.

PubMed

Venditti, Elisabetta; Scirè, Andrea; Tanfani, Fabio; Greci, Lucedio; Damiani, Elisabetta

2008-01-01

Reactive oxygen species generated upon UV-A exposure appear to play a major role in dermal connective tissue transformations including degradation of skin collagen. Here we investigate on oxidative damage to collagen achieved by exposure to (i) UV-A irradiation and to (ii) AAPH-derived radicals and on its possible prevention using synthetic and natural antioxidants. Oxidative damage was identified through SDS-PAGE, circular dichroism spectroscopy and quantification of protein carbonyl residues. Collagen (2 mg/ml) exposed to UV-A and to AAPH-derived radicals was degraded in a time- and dose-dependent manner. Upon UV-A exposure, maximum damage was observable at 730 kJ/m2 UV-A, found to be equivalent to roughly 2 h of sunshine, while exposure to 5 mM AAPH for 2 h at 50 degrees C lead to maximum collagen degradation. In both cases, dose-dependent protection was achieved by incubation with muM concentrations of nitroxide radicals, where the extent of protection was shown to be dictated by their structural differences whereas the vitamins E and C proved less efficient inhibitors of collagen damage. These results suggest that nitroxide radicals may be able to prevent oxidative injury to dermal tissues in vivo alternatively to commonly used natural antioxidants.

ENGINEERING AND CONSTRUCTING THE HALLAM NUCLEAR POWER FACILITY REACTOR STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahlmeister, J E; Haberer, W V; Casey, D F

1960-12-15

The Hallam Nuclear Power Facility reactor structure, including the cavity liner, is described, and the design philosophy and special design requirements which were developed during the preliminary and final engineering phases of the project are explained. The structure was designed for 600 deg F inlet and 1000 deg F outlet operating sodium temperatures and fabricated of austenitic and ferritic stainless steels. Support for the reactor core components and adequate containment for biological safeguards were readily provided even though quite conservative design philosophy was used. The calculated operating characteristics, including heat generation, temperature distributions and stress levels for full-power operation, aremore » summarized. Ship fabrication and field installation experiences are also briefly related. Results of this project have established that the sodium graphite reactor permits practical and economical fabrication and field erection procedures; considerably higher operating design temperatures are believed possible without radical design changes. Also, larger reactor structures can be similarly constructed for higher capacity (300 to 1000 Mwe) nuclear power plants. (auth)« less

9 CFR 71.20 - Approval of livestock facilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... shall signify the class or classes of livestock that the facility will handle.) (14) Cattle and bison: —This facility will handle cattle and bison: [Initials of operator, date] —This facility will handle cattle and bison known to be brucellosis reactors, suspects, or exposed: [Initials of operator, date...

3718-F Alkali Metal Treatment and Storage Facility Closure Plan. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

The Hanford Site, located northwest of the city of Richland, Washington, houses reactors, chemical-separation systems, and related facilities used for the production of special nuclear materials, as well as for activities associated with nuclear energy development. The 300 Area of the Hanford Site contains reactor fuel manufacturing facilities and several research and development laboratories. The 3718-F Alkali Metal Treatment and Storage Facility (3718-F Facility), located in the 300 Area, was used to store and treat alkali metal wastes. Therefore, it is subject to the regulatory requirements for the storage and treatment of dangerous wastes. Closure will be conducted pursuant tomore » the requirements of the Washington Administrative Code (WAC) 173-303-610 (Ecology 1989) and 40 CFR 270.1. Closure also will satisfy the thermal treatment facility closure requirements of 40 CFR 265.381. This closure plan presents a description of the 3718-F Facility, the history of wastes managed, and the approach that will be followed to close the facility. Only hazardous constituents derived from 3718-F Facility operations will be addressed.« less

Efficiency of clay--TiO2 nanocomposites on the photocatalytic elimination of a model hydrophobic air pollutant.

PubMed

Kibanova, Daria; Cervini-Silva, Javiera; Destaillats, Hugo

2009-03-01

Clay-supported TiO2 photocatalysts can potentially improve the performance of air treatment technologies via enhanced adsorption and reactivity of target volatile organic compounds (VOCs). In this study, a benchtop photocatalytic flow reactor was used to evaluate the efficiency of hectorite-TiO2 and kaolinite-TiO2, two novel composite materials synthesized in our laboratory. Toluene, a model hydrophobic VOC and a common indoor air pollutant, was introduced in the air stream at realistic concentrations, and reacted under UVA (lamda(max) = 365 nm) or UVC (lamda(max) = 254 nm) irradiation. The UVC lamp generated secondary emission at 185 nm, leading to the formation of ozone and other short-lived reactive species. Performance of clay-Ti02 composites was compared with that of pure TiO2 (Degussa P25), and with UV irradiation in the absence of photocatalyst under identical conditions. Films of clay-TiO2 composites and of P25 were prepared by a dip-coating method on the surface of Raschig rings, which were placed inside the flow reactor. An upstream toluene concentration of approximately 170 ppbv was generated by diluting a constant flow of toluene vapor from a diffusion source with dry air, or with humid air at 10, 33, and 66% relative humidity (RH). Toluene concentrations were determined by collecting Tenax-TA sorbent tubes downstream of the reactor, with subsequent thermal desorption--GC/MS analysis. The fraction of toluene removed, %R, and the reaction rate, Tr, were calculated for each experimental condition from the concentrations measured with and without UV irradiation. Use of UVC light (UV/TiO2/O3) led to overall higher reactivity, which can be partially attributed to the contribution of gas phase reactions by short-lived radical species. When the reaction rate was normalized to the light irradiance, Tr/Ilamda,the UV/TiO2 reaction under UVA irradiation was more efficient for samples with a higher content of TiO2 (P25 and Hecto-TiO2), but notfor Kao-TiO2. In all cases, reaction rates peaked at 10% RH, with Tr values between 10 and 50% higherthan those measured under dry air. However, a net inhibition was observed as RH increased to 33% and 66%, indicating that water molecules competed effectively with toluene for reactive surface sites and limited the overall photocatalytic conversion. Compared to P25, inhibition by coadsorbed water was less significant for Kao-TiO2 samples, but was more dramatic for Hecto-TiO2 due to the high water uptake capacity of hectorite.

Efficiency of clay-TiO2 nanocomposites on the photocatalytic eliminationof a model hydrophobic air pollutant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kibanova, Daria; Cervini-Silva, Javiera; Destaillats, Hugo

2009-01-01

Clay-supported TiO2 photocatalysts can potentially improve the performance of air treatment technologies via enhanced adsorption and reactivity of target volatile organic compounds (VOCs). In this study, a bench-top photocatalytic flow reactor was used to evaluate the efficiency of hectorite-TiO2 and kaolinite-TiO2, two novel composite materials synthesized in our laboratory. Toluene, a model hydrophobic VOC and a common indoor air pollutant, was introduced in the air stream at realistic concentrations, and reacted under UVA (gamma max = 365 nm) or UVC (gamma max = 254 nm) irradiation. The UVC lamp generated secondary emission at 185 nm, leading to the formation ofmore » ozone and other short-lived reactive species. Performance of clay-TiO2 composites was compared with that of pure TiO2 (Degussa P25), and with UV irradiation in the absence of photocatalyst under identical conditions. Films of clay-TiO2 composites and of P25 were prepared by a dip-coating method on the surface of Raschig rings, which were placed inside the flow reactor. An upstream toluene concentration of ~;;170 ppbv was generated by diluting a constant flow of toluene vapor from a diffusion source with dry air, or with humid air at 10, 33 and 66percent relative humidity (RH). Toluene concentrations were determined by collecting Tenax-TA (R) sorbent tubes downstream of the reactor, with subsequent thermal desorption -- GC/MS analysis. The fraction of toluene removed, percentR, and the reaction rate, Tr, were calculated for each experimental condition from the concentration changes measured with and without UV irradiation. Use of UVC light (UV/TiO2/O3) led to overall higher reactivity, which can be partially attributed to the contribution of gas phase reactions by short-lived radical species. When the reaction rate was normalized to the light irradiance, Tr/I gamma, the UV/TiO2 reaction under UVA irradiation was more efficient for samples with a higher content of TiO2 (P25 and Hecto-TiO2), but not for Kao-TiO2. In all cases, reaction rates peaked at 10percent RH, with Tr values between 10 and 50percent higher than those measured under dry air. However, a net inhibition was observed as RH increased to 33percent and 66percent, indicating that water molecules competed effectively with toluene for reactive surface sites and limited the overall photocatalytic conversion. Compared to P25, inhibition by co-adsorbed water was less significant for Kao-TiO2 samples, but was more dramatic for Hecto-TiO2 due to the high water uptake capacity of hectorite.« less

Advanced Test Reactor Safety Basis Upgrade Lessons Learned Relative to Design Basis Verification and Safety Basis Management

DOE Office of Scientific and Technical Information (OSTI.GOV)

G. L. Sharp; R. T. McCracken

The Advanced Test Reactor (ATR) is a pressurized light-water reactor with a design thermal power of 250 MW. The principal function of the ATR is to provide a high neutron flux for testing reactor fuels and other materials. The reactor also provides other irradiation services such as radioisotope production. The ATR and its support facilities are located at the Test Reactor Area of the Idaho National Engineering and Environmental Laboratory (INEEL). An audit conducted by the Department of Energy's Office of Independent Oversight and Performance Assurance (DOE OA) raised concerns that design conditions at the ATR were not adequately analyzedmore » in the safety analysis and that legacy design basis management practices had the potential to further impact safe operation of the facility.1 The concerns identified by the audit team, and issues raised during additional reviews performed by ATR safety analysts, were evaluated through the unreviewed safety question process resulting in shutdown of the ATR for more than three months while these concerns were resolved. Past management of the ATR safety basis, relative to facility design basis management and change control, led to concerns that discrepancies in the safety basis may have developed. Although not required by DOE orders or regulations, not performing design basis verification in conjunction with development of the 10 CFR 830 Subpart B upgraded safety basis allowed these potential weaknesses to be carried forward. Configuration management and a clear definition of the existing facility design basis have a direct relation to developing and maintaining a high quality safety basis which properly identifies and mitigates all hazards and postulated accident conditions. These relations and the impact of past safety basis management practices have been reviewed in order to identify lessons learned from the safety basis upgrade process and appropriate actions to resolve possible concerns with respect to the current ATR safety basis. The need for a design basis reconstitution program for the ATR has been identified along with the use of sound configuration management principles in order to support safe and efficient facility operation.« less

GAMMA FACILITY, TRA611, INTERIOR. WITH HELP OF OVERHEAD CHAIN AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GAMMA FACILITY, TRA-611, INTERIOR. WITH HELP OF OVERHEAD CHAIN AND HOOK, SCIENTIST GUIDES METAL CONTAINER (HOLDING POTATOES, IN THIS CASE) INTO RECEIVING "COLUMN" IN THE GAMMA CANAL. NOTE OTHER COLUMNS AT RIGHT AND LEFT WALLS OF CANAL. NEAR BOTTOM OF CANAL, SPENT MTR FUEL WILL IRRADIATE POTATOES. INL NEGATIVE NO. 56-439. R.G. Larsen, Photographer, 2/8/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Looking North at Reactor Number One and Air Vent on ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking North at Reactor Number One and Air Vent on Fourth Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

Multifunctional transparent ZnO nanorod films.

PubMed

Kwak, Geunjae; Jung, Sungmook; Yong, Kijung

2011-03-18

Transparent ZnO nanorod (NR) films that exhibit extreme wetting states (either superhydrophilicity or superhydrophobicity through surface chemical modification), high transmittance, UV protection and antireflection have been prepared via the facile ammonia hydrothermal method. The periodic 1D ZnO NR arrays showed extreme wetting states as well as antireflection properties due to their unique surface structure and prevented the UVA region from penetrating the substrate due to the unique material property of ZnO. Because of the simple, time-efficient and low temperature preparation process, ZnO NR films with useful functionalities are promising for fabrication of highly light transmissive, antireflective, UV protective, antifogging and self-cleaning optical materials to be used for optical devices and photovoltaic energy devices.

The effects of phototherapy and melanocytes on keratinocytes

PubMed Central

Tang, Luyan; Wu, Wenyu; Fu, Wenwen; Hu, Yao

2018-01-01

Phototherapy is widely used in the treatment of vitiligo. Previous studies have focused on the effects of ultraviolet (UV) radiation on melanocytes; however, the biological effects of phototherapy and melanocytes on keratinocytes remain to be elucidated. To investigate and assess the effects of clinically doses of broad band (BB)-UVA, narrow band (NB)-UVB and melanocytes on human keratinocytes in vitro, clinical doses of BB-UVA or NB-UVB radiation and human melanoma cell A375 co-culture were performed as stress divisors to HaCaT cells. Cell proliferation, expression of protease-activated receptor-2 (PAR-2) and nuclear factor E2-related factor 2 mRNA, lipid peroxidation and intracellular antioxidant level of keratinocytes were analyzed. It was demonstrated that UV radiation inhibited the proliferation of cells apart from following exposure to low dose (1 J/cm2) UVA. Medium dose (5 J/cm2) UVA radiation had no adverse effects on lipid peroxidation and increased antioxidant levels in HaCaT cells. Medium (200 mJ/cm2) and high (400 mJ/cm2) doses of UVB radiation induced cellular damage due to increased lipid peroxidation as indicated by levels of malondialdehyde. Furthermore, A375 co-culture treatment induced a similar effect on the lipid peroxidation of HaCaT as with low dose UVB radiation. Therefore, the results of the present study determined that clinical doses of BB-UVA and NB-UVB radiation had varying effects on proliferation and related protein levels in HaCaT cells. Co-culture with A375 had similar effects as those of low dose UVA and UVB radiation, in which the PAR-2 expression was significantly upregulated. PMID:29545869

Effect of surface modification and UVA photoactivation on antibacterial bioactivity of zinc oxide powder

NASA Astrophysics Data System (ADS)

Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd; Sirelkhatim, Amna; Mohamad, Dasmawati; Hasan, Habsah; Seeni, Azman; Rahman, Rosliza Abdul

2014-02-01

The effects of surface modification of zinc oxide (ZnO) powder and UVA illumination on the powder towards Escherichia coli and Staphylococcus aureus were investigated. FESEM-EDS results showed that oxygen annealing increased the O:Zn ratio on the surface of ZnO-rod and ZnO-plate samples. Surface conductances of ZnO-rod and ZnO-plate pellets were reduced from 1.05 nS to 0.15 nS and 1.34 nS to 0.23 nS, respectively. Meanwhile, UVA illumination on the surface of the ZnO-rod and ZnO-plate samples was found to improve surface conductance to 7.08 nS and 6.51 nS, respectively, due to the release of charge carrier. Photoluminescence results revealed that oxygen annealing halved the UV emission intensity and green emission intensity, presumably caused by oxygen absorption in the ZnO lattice. The antibacterial results showed that oxygen-treated ZnO exhibited slightly higher growth inhibition on E. coli and S. aureus compared with unannealed ZnO. UVA illumination on ZnO causes the greatest inhibition toward E. coli and S. aureus. Under the UVA excitation, the inhibition of E. coli increased by 18% (ZnO-rod) and 13% (ZnO-plate) while the inhibition of S. aureus increased by 22% (ZnO-rod) and 21% (ZnO-plate). Release of reactive oxygen species were proposed in antibacterial mechanisms, which were aided by surface modification and UVA photoactivation. The reactive oxygen species disrupted the DNA and protein synthesis of the bacterial cell, causing bacteriostatic effects toward E. coli and S. aureus.

Direct participation of DNA in the formation of singlet oxygen and base damage under UVA irradiation.

PubMed

Yagura, Teiti; Schuch, André Passaglia; Garcia, Camila Carrião Machado; Rocha, Clarissa Ribeiro Reily; Moreno, Natália Cestari; Angeli, José Pedro Friedmann; Mendes, Davi; Severino, Divinomar; Bianchini Sanchez, Angelica; Di Mascio, Paolo; de Medeiros, Marisa Helena Gennari; Menck, Carlos Frederico Martins

2017-07-01

UVA light is hardly absorbed by the DNA molecule, but recent works point to a direct mechanism of DNA lesion by these wavelengths. UVA light also excite endogenous chromophores, which causes DNA damage through ROS. In this study, DNA samples were irradiated with UVA light in different conditions to investigate possible mechanisms involved in the induction of DNA damage. The different types of DNA lesions formed after irradiation were determined through the use of endonucleases, which recognize and cleave sites containing oxidized bases and cyclobutane pyrimidine dimers (CPDs), as well as through antibody recognition. The formation of 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxodG) was also studied in more detail using electrochemical detection. The results show that high NaCl concentration and concentrated DNA are capable of reducing the induction of CPDs. Moreover, concerning damage caused by oxidative stress, the presence of sodium azide and metal chelators reduce their induction, while deuterated water increases the amounts of oxidized bases, confirming the involvement of singlet oxygen in the generation of these lesions. Curiously, however, high concentrations of DNA also enhanced the formation of oxidized bases, in a reaction that paralleled the increase in the formation of singlet oxygen in the solution. This was interpreted as being due to an intrinsic photosensitization mechanism, depending directly on the DNA molecule to absorb UVA and generate singlet oxygen. Therefore, the DNA molecule itself may act as a chromophore for UVA light, locally producing a damaging agent, which may lead to even greater concerns about the deleterious impact of sunlight. Copyright © 2017 Elsevier Inc. All rights reserved.

Towards a high performing UV-A sensor based on Silicon Carbide and hydrogenated Silicon Nitride absorbing layers

NASA Astrophysics Data System (ADS)

Mazzillo, M.; Sciuto, A.; Mannino, G.; Renna, L.; Costa, N.; Badalà, P.

2016-10-01

Exposure to ultraviolet (UV) radiation is a major risk factor for most skin cancers. The sun is our primary natural source of UV radiation. The strength of the sun's ultraviolet radiation is expressed as Solar UV Index (UVI). UV-A (320-400 nm) and UV-B (290-320 nm) rays mostly contribute to UVI. UV-B is typically the most destructive form of UV radiation because it has enough energy to cause photochemical damage to cellular DNA. Also overexposure to UV-A rays, although these are less energetic than UV-B photons, has been associated with toughening of the skin, suppression of the immune system, and cataract formation. The use of preventive measures to decrease sunlight UV radiation absorption is fundamental to reduce acute and irreversible health diseases to skin, eyes and immune system. In this perspective UV sensors able to monitor in a monolithic and compact chip the UV Index and relative UV-A and UV-B components of solar spectrum can play a relevant role for prevention, especially in view of the integration of these detectors in close at hand portable devices. Here we present the preliminary results obtained on our UV-A sensor technology based on the use of hydrogenated Silicon Nitride (SiN:H) thin passivating layers deposited on the surface of thin continuous metal film Ni2Si/4H-SiC Schottky detectors, already used for UV-Index monitoring. The first UV-A detector prototypes exhibit a very low leakage current density of about 0.2 pA/mm2 and a peak responsivity value of 0.027 A/W at 330 nm, both measured at 0V bias.

23-Hydroxytormentic acid protects human dermal fibroblasts by attenuating UVA-induced oxidative stress.

PubMed

Youn, Hae Jeong; Kim, Ki Bbeum; Han, Hyo-Sun; An, In-Sook; Ahn, Kyu Joong

2017-03-01

Ultraviolet A (UVA), one of the major components of sunlight, can penetrate the dermal layer of the skin and generate reactive oxygen species (ROS). It causes alterations in the dermal connective tissue and gene expression, inflammation, photoaging, and DNA damage. Therefore, the harmful effects of UVA and strategies to reduce it have been consistently investigated. 23-Hydroxytormentic acid (23-HTA) has been demonstrated to improve drug-induced nephrotoxicity and exhibit several free radical scavenging effects with other molecules. Therefore, the aim of this study was to investigate the anti-inflammatory effects and extracellular matrix (ECM) reconstructive activity of 23-HTA in UVA-irradiated normal human dermal fibroblasts (NHDFs). The antioxidant capacity of 23-HTA was determined by examining its scavenging activities against hydrogen peroxide, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and diphenylpicrylhydrazyl in vitro. Its effect on cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide, and 2,7-dichlorofluorescin diacetate was used to investigate intracellular ROS scavenging activity. The mRNA levels of antioxidant enzymes and pro-inflammatory cytokines were detected using quantitative real-time polymerase chain reaction. A senescence-associated β-galactosidase (SA-β-gal) staining kit was used to assess senescent cells. 23-HTA showed antioxidant capacity mediated by ROS scavenging and regulation of antioxidant-related gene expression. Further, the SA-β-gal analysis and mRNA expression of matrix metalloproteinases and type I procollagen suggested that 23-HTA regulates the gene expression of ECM proteins and cellular senescence under UVA-irradiated conditions. In conclusion, 23-HTA protects against and attenuates UVA-induced oxidative stress in NHDFs likely via the nuclear factor erythroid-derived 2-like 2 signaling pathway. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

New insight into the disinfection mechanism of Fusarium monoliforme and Aspergillus niger by TiO2 photocatalyst under low intensity UVA light.

PubMed

Pokhum, Chonlada; Viboonratanasri, Duangamon; Chawengkijwanich, Chamorn

2017-11-01

Titanium dioxide (TiO 2) photocatalytic reaction has great potential for the disinfection of harmful pathogens. However, the disinfection mechanisms of TiO 2 photocatalysis are not yet well-known for fungi and protozoa. In this work, the photocatalytic disinfection mechanism of Fusarium monoliforme and Aspergillus niger under low intensity UVA light (365nm, <10W/m 2 ) was studied at the ultrastructural level. Photocatalytic treatments showed that the photocatalytic oxidation of 10% TiO 2 based paint was efficacious in the complete disinfection of F. monoliforme under low intensity UVA light. No growth of F. monoliforme was observed on agar plate in the subsequent dark. Transmission electron microscopy (TEM) of F. monoliforme exposed to TiO 2 photocatalysis treatment showed a distinct damage to electron-dense outer cell wall, but not to an underlying electron-transparent layer cell wall. The TEM image revealed that the UVA-light only did not damage cell wall, cell membrane and cellular organelles. Unlike, A. niger was more sensitive to UVA-light. Serious destructions of cell membrane and cellular organelles were shown in A. niger exposed to UVA-light only and photocatalytic treatments. However, morphological change in A. niger cell wall was only observed in photocatalytic treatment. Changes to the outermost melanin like layer and cell wall of A. niger spore due to photocatalytic treatment were greatly apparent while the intracellular organelles of A. niger spore were not affected. Therefore, regrowth of A. niger on agar plate was expected from the germination of A. niger spore in the subsequent dark. These observations give a better understanding of the photocatalytic disinfection mechanism toward fungi. Copyright © 2017 Elsevier B.V. All rights reserved.

The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism.

PubMed

Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E; Szabó, Éva; Virág, László

2016-08-01

A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5J/cm(2)) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ-34+UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and -8. In conclusion, PJ-34 is a photosensitizer and PJ-34+UVA causes DNA damage and caspase-mediated cell death independently of PARP-1 inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

Transformation products formation of ciprofloxacin in UVA/LED and UVA/LED/TiO2 systems: Impact of natural organic matter characteristics.

PubMed

Li, Si; Hu, Jiangyong

2018-04-01

The role of natural organic matter (NOM) in contaminants removal by photolysis and photocatalysis has aroused increasing interest. However, evaluation of the influence of NOM characteristics on the transformation products (TPs) formation and transformation pathways of contaminants has rarely been performed. This study investigated the decomposition kinetics, mineralization, TPs formation and transformation pathways of antibiotic ciprofloxacin (CIP) during photolysis and photocatalysis in the presence of three commercial NOM isolates (Sigma-Aldrich humic acid (SAHA), Suwannee River humic acid (SRHA) and Suwannee River NOM (SRNOM)) by using UVA light emitting diode (UVA/LED) as an alternative light source. NOM isolates insignificantly affected CIP photolysis but strongly inhibited CIP photocatalysis due to competitive radical quenching. The inhibitory effect followed the order of SAHA (49.6%) > SRHA (29.9%) > SRNOM (21.2%), consistent with their •OH quenching abilities, SUVA 254 values and orders of aromaticity. Mineralization rates as revealed by F - release were negatively affected by NOM during CIP photocatalysis. TPs arising from hydroxylation and defluorination were generally suppressed by NOM isolates in UVA/LED and UVA/LED/TiO 2 systems. In contrast, dealkylation and oxidation of piperazine ring were promoted by NOM. The enhancement in the apparent formation kinetics (k app ) of TP245, TP291, TP334a, TP334b and TP362 followed the order of SRNOM > SRHA > SAHA. k app values were positively correlated with O/C ratio, carboxyl content, E2/E3 and fluorescence index (FI) of NOM and negatively related with SUVA 254 values. The observed correlations indicate that NOM properties are important in determining the fate and transformation of organic contaminants during photolysis and photocatalysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Do UV-A radiation and blue light during growth prime leaves to cope with acute high-light in photoreceptor mutants of Arabidopsis thaliana?

PubMed

Brelsford, Craig C; Morales, Luis O; Nezval, Jakub; Kotilainen, Titta K; Hartikainen, Saara M; Aphalo, Pedro J; Robson, T Matthew

2018-04-28

We studied how plants acclimated to growing conditions that included combinations of blue light and ultraviolet-A (UV-A) radiation, and whether their growing environment affected their photosynthetic capacity during and after a brief period of acute high light (as might happen during an under-canopy sunfleck). Arabidopsis thaliana Landsberg erecta wild-type were compared with mutants lacking functional blue-light-and-UV photoreceptors: phototropin 1PHOT1, cryptochromes (CRY1 and CRY2) and UV RESISTANT LOCUS 8 (uvr8). This was achieved using LED lamps in a controlled environment to create treatments with or without blue light, in a split-plot design with or without UV-A radiation. We compared the accumulation of phenolic compounds under growth conditions and after exposure to 30 minutes of high light at the end of the experiment (46 days), and likewise measured the operational efficiency of photosystem II (φPSII a proxy for photosynthetic performance) and dark-adapted maximum quantum yield (F v /F m to assess PSII damage). Our results indicate that cryptochromes are the main photoreceptors regulating phenolic-compound accumulation in response to blue light and UV-A radiation, and a lack of functional cryptochromes impairs photosynthetic performance under high light. Our findings also reveal a role for UVR8 in accumulating flavonoids in response to a low UV-A dose. Interestingly, phototropin 1 partially-mediated constitutive accumulation of phenolic compounds in the absence of blue light. Low irradiance blue light and UV-A did not improve φPSII and F v /F m upon our acute high light treatment, however CRYs played an important role in ameliorating high-light stress. This article is protected by copyright. All rights reserved.

75 FR 34219 - Revision of Fee Schedules; Fee Recovery for FY 2010

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

....8 $6.3 $7.5 Spent Fuel Storage/Reactor Decommissioning..... -- -- 2.7 0.2 0.2 Test and Research... 2009 fee is also shown for comparative purposes. Table V--Rebaselined Annual Fees FY2009 Annual FY 2010... Decommissioning Test and Research Reactors (Non-power 87,600 81,700 Reactors) High Enriched Uranium Fuel Facility...

PBF (PER620) interior. Detail view across top of reactor tank. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF (PER-620) interior. Detail view across top of reactor tank. Camera facing northeast. Ait tubing is cleanup equipment. Note projections from reactor structure above water level in tank. Date: May 2004. INEEL negative no. HD-41-5-1 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

76 FR 69296 - University of Utah, University of Utah TRIGA Nuclear Reactor, Notice of Issuance of Renewed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-08

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-407, NRC-2011-0153] University of Utah, University of Utah TRIGA Nuclear Reactor, Notice of Issuance of Renewed Facility Operating License No. R-126 AGENCY... University of Utah (UU, the licensee), which authorizes continued operation of the UU TRIGA Nuclear Reactor...

Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheryl Morton; Carl Baily; Tom Hill

Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. Itmore » provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a lowtemperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform posttest examination. Capability for waste disposal is also available at the INL.« less

Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morton, Sheryl L.; Baily, Carl E.; Hill, Thomas J.

Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. Itmore » provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a low-temperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform posttest examination. Capability for waste disposal is also available at the INL.« less

Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II

NASA Astrophysics Data System (ADS)

Morton, Sheryl L.; Baily, Carl E.; Hill, Thomas J.; Werner, James E.

2006-01-01

Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. It provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a low-temperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform posttest examination. Capability for waste disposal is also available at the INL.

Coupled reactor kinetics and heat transfer model for heat pipe cooled reactors

NASA Astrophysics Data System (ADS)

Wright, Steven A.; Houts, Michael

2001-02-01

Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). This paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities. .

Reactive oxygen-mediated damage to a human DNA replication and repair protein.

PubMed

Montaner, Beatriz; O'Donovan, Peter; Reelfs, Olivier; Perrett, Conal M; Zhang, Xiaohong; Xu, Yao-Zhong; Ren, Xiaolin; Macpherson, Peter; Frith, David; Karran, Peter

2007-11-01

Ultraviolet A (UVA) makes up more than 90% of incident terrestrial ultraviolet radiation. Unlike shorter wavelength UVB, which damages DNA directly, UVA is absorbed poorly by DNA and is therefore considered to be less hazardous. Organ transplant patients treated with the immunosuppressant azathioprine frequently develop skin cancer. Their DNA contains 6-thioguanine-a base analogue that generates DNA-damaging singlet oxygen ((1)O(2)) when exposed to UVA. Here, we show that this (1)O(2) damages proliferating cell nuclear antigen (PCNA), the homotrimeric DNA polymerase sliding clamp. It causes covalent oxidative crosslinking between the PCNA subunits through a histidine residue in the intersubunit domain. Crosslinking also occurs after treatment with higher-although still moderate-doses of UVA alone or with chemical oxidants. Chronic accumulation of oxidized proteins is linked to neurodegenerative disorders and ageing. Our findings identify oxidative damage to an important DNA replication and repair protein as a previously unrecognized hazard of acute oxidative stress.

Ultraviolet A irradiation increases the permeation of fullerenes into human and porcine skin from C₆₀-poly(vinylpyrrolidone) aggregate dispersions.

PubMed

Souto, Gabriele Dadalt; Pohlmann, Adriana Raffin; Guterres, Sílvia Stanisçuaski

2015-01-01

The purpose of this study was to characterise C₆₀-poly(vinylpyrrolidone) (PVP) dispersions, to analyse the cutaneous absorption of fullerenes as well as to evaluate whether UVA radiation (UVA-R) could modify its permeation profile. Dispersions were characterised according to their pH, particle size, zeta potential, and morphology. Skin absorption studies were performed using porcine or human skin under UVA or sham irradiation. The C₆₀ aggregate size was 129 ± 54 nm (as determined by nanoparticle tracking analysis) and the zeta potential was -4.93 ± 1.72 mV. The C₆₀ aggregates presented an irregular shape (as measured by transmission electron microscopy) and permeated through human and porcine skin. C₆₀-PVP aggregates were adequately characterised. Human skin was less permeable than porcine skin, and the presence of UVA-R increased the C₆₀ content up to the dermis. © 2014 S. Karger AG, Basel.

Inactivation of bacteria via photosensitization of vitamin K3 by UV-A light.

PubMed

Xu, Fei; Vostal, Jaroslav G

2014-09-01

This study investigated inactivation of bacteria with ultraviolet light A irradiation in combination with vitamin K3 as a photosensitizer. Six bacteria including Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and Escherichia coli suspended in vitamin K3 aqueous solution were exposed to ultraviolet light A. Five of six bacteria, with the exception of Pseudomonas aeruginosa, were reduced by eight logs with 1600 μM of vitamin K3 and 5.8 J cm(-2) UV-A irradiation. Pseudomonas aeruginosa was reduced by four logs under these conditions. Reactive oxygen species including singlet oxygen, hydroxyl radical and superoxide anion radical were generated in vitamin K3 aqueous solution under UV-A irradiation. These results suggest that vitamin K3 and UV-A irradiation may be effective for bacterial inactivation in environmental and medical applications. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Evaluation of window-tinting films for sunlight phototherapy.

PubMed

Vreman, Hendrik J; Slusher, Tina M; Wong, Ronald J; Schulz, Stephanie; Olusanya, Bolajoko O; Stevenson, David K

2013-12-01

We evaluated nine semi-transparent plastic window-tinting films for their ability to block ultraviolet A (UVA) and infrared (IR) radiation and transmit therapeutic blue light (400-520 nm) for treating jaundiced newborns. For indoor testing, three light sources (TL/52 special blue fluorescent, Black Light UVA and IR heat lamps) were positioned above each film and measured successively using a thermocouple thermometer, UVA radiometer and blue light irradiance meter, placed below each film. For outdoor testing, the same setup was used with the sun at zenith and a cloudless sky. Compared with unfiltered radiation, blue light transmission through films ranged from 24 to 83%, UVA transmission was 0.1-7.1% and reductions in IR heat were 6-12°C and 5-10°C for heat lamp and sun, respectively. The data suggest that most of the relatively low-cost window-tinting films tested can effectively reduce sunlight UV and IR and offer a range of significant attenuations of therapeutic blue light.

Coexistence effect of UVA absorbers to increase their solubility and stability of supersaturation.

PubMed

Endo, M; Mukawa, T; Sato, N; Maezawa, D; Ohtsu, Y; Kuroda, A; Wakabayashi, M; Asakura, K

2014-12-01

Sunscreens containing UVA absorbers in high concentrations are expected to be developed, since recent studies have suggested the possibility of involvement of UVA ray in skin cancer and early skin aging. Solubility and stability of supersaturation of UVA absorbers in UVB absorber were determined in the absence and the presence of cosmetic oil. Coexistence effect of UVA absorbers was analyzed to dissolve them in high concentrations. Two UVA absorbers, diethylamino hydroxybenzoyl hexyl benzoate (DHHB) and butyl methoxydibenzoylmethane (BMDM), a UVB absorber, 2-ethylhexyl methoxycinnamate (EHMC), and a cosmetic oil, 2-ethylhexyl ester of oligomer of hydroxystearic acid (EH-O-HSA), were used. Their solutions were prepared at 80°C and cooled to 5°C. The solid DHHB and/or BMDM were added to it, and the time evolution of concentrations of the UVA absorbers in the solution phase was monitored. At the saturation in the absence of EH-O-HSA at 5°C, weight ratio of DHHB and BMDM to EHMC was 0.39/1.00 and 0.22/1.00, respectively. Addition of EH-O-HSA slightly changed the solubility of DHHB and BMDM. When the weight ratio of EH-O-HSA to EHMC was 0.20/1.00, weight ratio of DHHB and BMDM to EHMC was 0.35/1.00 and 0.25/1.00, respectively at the saturation at 5°C. In the presence of EH-O-HSA, a strong coexistence effect of DHHB and BMDM was found on their solubility. A thermodynamically stable saturated solution at 5°C having the composition that DHHB: BMDM: EHMC: EH-O-HSA = 0.47: 0.46: 1.00: 0.20 was obtained by the simultaneous addition of solid DHHB and BMDM into the initial solution. The solution type composite having the highest concentrations of DHHB and BMDM prepared in this study exhibited critical wavelength at 368 nm that was just below the border for sunscreens being qualified as 'Broad Spectrum' protection under the new rule launched by US FDA. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Protective effect of curcumin against ultraviolet A irradiation-induced photoaging in human dermal fibroblasts

PubMed Central

Liu, Xiaoming; Zhang, Ruizhi; Shi, Haixia; Li, Xiaobo; Li, Yanhong; Taha, Ahmad; Xu, Chunxing

2018-01-01

Ultraviolet (UV) radiation induces DNA damage, oxidative stress, and inflammatory processes in skin, resulting in photoaging. Natural botanicals have gained considerable attention due to their beneficial protection against the harmful effects of UV irradiation. The present study aimed to evaluate the ability of curcumin (Cur) to protect human dermal fibroblasts (HDFs) against ultraviolet A (UVA)-induced photoaging. HDFs were treated with 0–10 µM Cur for 2 h and subsequently exposed to various intensities of UVA irradiation. The cell viability and apoptotic rate of HDFs were investigated by MTT and flow cytometry assays, respectively. The effect of UVA and Cur on the formation of reactive oxygen species (ROS), malondialdehyde levels, which are an indicator of ROS, and the levels/activity of antioxidative defense proteins, including glutathione, superoxide dismutase and catalase, were evaluated using 2′,7′-dichlorofluorescin diacetate and commercial assay kits. Furthermore, western blotting was performed to determine the levels of proteins associated with endoplasmic reticulum (ER) stress, the apoptotic pathway, inflammation and the collagen synthesis pathway. The results demonstrated that Cur reduced the accumulation of ROS and restored the activity of antioxidant defense enzymes, indicating that Cur minimized the damage induced by UVA irradiation in HDFs. Furthermore, western blot analysis demonstrated that Cur may attenuate UVA-induced ER stress, inflammation and apoptotic signaling by downregulating the protein expression of glucose-regulated protein 78, C/EBP-homologous protein, nuclear factor-κB and cleaved caspase-3, while upregulating the expression of Bcl-2. Additionally, it was demonstrated that Cur may regulate collagen metabolism by decreasing the protein expression of matrix metalloproteinase (MMP)-1 and MMP-3, and may promote the repair of cells damaged as a result of UVA irradiation through increasing the protein expression of transforming growth factor-β (TGF-β) and Smad2/3, and decreasing the expression of the TGF-β inhibitor, Smad7. In conclusion, the results of the present study indicate the potential benefits of Cur for the protection of HDFs against UVA-induced photoaging and highlight the potential for the application of Cur in skin photoprotection. PMID:29568864

Design Report for the ½ Scale Air-Cooled RCCS Tests in the Natural convection Shutdown heat removal Test Facility (NSTF)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisowski, D. D.; Farmer, M. T.; Lomperski, S.

The Natural convection Shutdown heat removal Test Facility (NSTF) is a large scale thermal hydraulics test facility that has been built at Argonne National Laboratory (ANL). The facility was constructed in order to carry out highly instrumented experiments that can be used to validate the performance of passive safety systems for advanced reactor designs. The facility has principally been designed for testing of Reactor Cavity Cooling System (RCCS) concepts that rely on natural convection cooling for either air or water-based systems. Standing 25-m in height, the facility is able to supply up to 220 kW at 21 kW/m 2 tomore » accurately simulate the heat fluxes at the walls of a reactor pressure vessel. A suite of nearly 400 data acquisition channels, including a sophisticated fiber optic system for high density temperature measurements, guides test operations and provides data to support scaling analysis and modeling efforts. Measurements of system mass flow rate, air and surface temperatures, heat flux, humidity, and pressure differentials, among others; are part of this total generated data set. The following report provides an introduction to the top level-objectives of the program related to passively safe decay heat removal, a detailed description of the engineering specifications, design features, and dimensions of the test facility at Argonne. Specifications of the sensors and their placement on the test facility will be provided, along with a complete channel listing of the data acquisition system.« less

Decontamination and deactivation of the power burst facility at the Idaho National Laboratory.

PubMed

Greene, Christy Jo

2007-05-01

Successful decontamination and deactivation of the Power Burst Facility located at the Idaho National Laboratory was accomplished through the use of extensive planning, job sequencing, engineering controls, continuous radiological support, and the use of a dedicated group of experienced workers. Activities included the removal and disposal of irradiated fuel, miscellaneous reactor components and debris stored in the canal, removal and disposition of a 15.6 curie Pu:Be start-up source, removal of an irradiated in-pile tube, and the removal of approximately 220,000 pounds of lead that was used as shielding primarily in Cubicle 13. The canal and reactor vessel were drained and water was transferred to an evaporation tank adjacent to the facility. The canal was decontaminated using underwater divers, and epoxy was affixed to the interior surfaces of the canal to contain loose contamination. The support structures and concrete or steel frame walls that form the confinement were left in place. The reactor core was left in place and a carbon steel shielding plate was placed over the reactor core to reduce radiation levels. All low-level waste and mixed low level waste generated as a result of the work activities was characterized and disposed.

As Universities Close Their Reactors, Energy Dept. Considers a Policy Shift.

ERIC Educational Resources Information Center

Southwick, Ron

2001-01-01

Discusses how, as many universities shut down their nuclear reactors used for research and training, the Energy Department considers moving its support to regional facilities, a change that might lead to more shutdowns. (EV)

Features of postfailure fuel behavior in transient overpower and transient undercooled/overpower tests in the transient reactor test facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doerner, R.C.; Bauer, T.H.; Morman, J.A.

Prototypic oxide fuel was subjected to simulated, fast reactor severe accident conditions in a series of in-pile tests in the Transient Reactor Test Facility reactor. Seven experiments were performed on fresh and previously irradiated oxide fuel pins under transient overpower and transient undercooled. overpower accident conditions. For each of the tests, fuel motions were observed by the hodoscope. Hodoscope data are correlated with coolant flow, pressure, and temperature data recorded by the loop instrumentation. Data were analyzed from the onset of initial failure to a final mass distribution at the end of the test. In this paper results of thesemore » analyses are compared to pre- and posttest accident calculations and to posttest metallographic accident calculations and to posttest metallographic examinations and computed tomographic reconstructions from neutron radiographs.« less

RADON LEVELS AND ЕQUIVALENT DOSE RATES AT THE IRT-SOFIA RESEARCH REACTOR SITE.

PubMed

Krezhov, Kiril; Mladenov, Aleksander; Dimitrov, Dobromir

2018-06-11

Results from radon measurements by active sampling of indoor air in the buildings within the Nuclear Scientific Experimental and Educational Centre (NSEEC) protected site at the Institute for Nuclear Research and Nuclear Energy (INRNE) are presented. The inspected buildings included in this report are the IRT research reactor structure and several auxiliary formations wherein the laundry facilities and the gamma irradiator GOU-1 (60Co source) are installed as well as the Central Alarm Station (CAS) premises. Besides the reactor hall and the primary cooling loop area, special attention was given to the premises of the First Class Radiochemical Laboratory in the IRT reactor basement. Determination of radon concentration distribution in the premises of the constructions within the site is an important part of radiation surveillance during the operation and maintenance of the NSEEC facilities as well as for their involvement in the educational activities at INRNE.

UAV using the open-source flight-control-system in the application of aerial survey

NASA Astrophysics Data System (ADS)

Huang, Ji-chen; Ru, Chen

2015-12-01

The aerial survey as one of the branches of the Space Information Technology system, has an important application in data acquisition of the earth's surface. In recent years, the trend of UVA (unmanned aerial vehicle) to replace traditional survey aircraft has become increasingly obvious with the progress of science and technology. At present, the price of the commercial UAV Flight Control System is higher, limiting the application of UVA. This paper mainly discusses the possibility that the open-source's flight-control-system take the place of the commercial one. Result is that the costs of UVA are reduced, and make the application more widely.

TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR AREAS SOUTH OF PERCH AVENUE. "COLD" SERVICES NORTH OF PERCH. ADVANCED TEST REACTOR IN NEW SECTION WEST OF COLD SERVICES SECTION. NEW PERIMETER FENCE ENCLOSES BETA RAY SPECTROMETER, TRA-669, AN ATR SUPPORT FACILITY, AND ATR STACK. UTM LOCATORS HAVE BEEN DELETED. IDAHO NUCLEAR CORPORATION, FROM A BLAW-KNOX DRAWING, 3/1968. INL INDEX NO. 530-0100-00-400-011646, REV. 0. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Space Nuclear Thermal Propulsion (SNTP) Air Force facility

NASA Technical Reports Server (NTRS)

Beck, David F.

1993-01-01

The Space Nuclear Thermal Propulsion (SNTP) Program is an initiative within the US Air Force to acquire and validate advanced technologies that could be used to sustain superior capabilities in the area or space nuclear propulsion. The SNTP Program has a specific objective of demonstrating the feasibility of the particle bed reactor (PBR) concept. The term PIPET refers to a project within the SNTP Program responsible for the design, development, construction, and operation of a test reactor facility, including all support systems, that is intended to resolve program technology issues and test goals. A nuclear test facility has been designed that meets SNTP Facility requirements. The design approach taken to meet SNTP requirements has resulted in a nuclear test facility that should encompass a wide range of nuclear thermal propulsion (NTP) test requirements that may be generated within other programs. The SNTP PIPET project is actively working with DOE and NASA to assess this possibility.

The SANS facility at the Pitesti 14MW TRIGA reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ionita, I.; Grabcev, B.; Todireanu, S.

2006-12-15

The SANS facility existing at the Pitesti 14MW TRIGA reactor is presented. The main characteristics and the preliminary evaluation of the installation performances are given. A monochromatic neutron beam with 1.5 A {<=} {lambda} {<=} 5 A is produced by a mechanical velocity selector with helical slots. A fruitful partnership was established between INR Pitesti (Romania) and JINR Dubna (Russia). The first step in this cooperation consists in the manufacturing in Dubna of a battery of gas-filled positional detectors devoted to the SANS instrument.

Gene expression of a two-component regulatory system associated with sunscreen biosynthesis in the cyanobacterium Nostoc punctiforme ATCC 29133.

PubMed

Janssen, Jacob; Soule, Tanya

2016-01-01

Long-wavelength ultraviolet radiation (UVA) can damage cells through photooxidative stress, leading to harmful photosensitized proteins and pigments in cyanobacteria. To mitigate damage, some cyanobacteria secrete the UVA-absorbing pigment scytonemin into their extracellular sheath. Comparative genomic analyses suggest that scytonemin biosynthesis is regulated by the two-component regulatory system (TCRS) proteins encoded by Npun_F1277 and Npun_F1278 in the cyanobacterium Nostoc punctiforme ATCC 29133. To understand the dynamics of these genes, their expression was measured following exposure to UVA, UVB, high visible (VIS) irradiance and oxidative stress for 20, 40 and 60 min. Overall, both genes had statistically similar patterns of expression for all four conditions and were generally upregulated, except for those exposed to UVB by 60 min and for the cells under oxidative stress. The greatest UVA response was an upregulation by 20 min, while the response to UVB was the most dramatic and persisted through 40 min. High VIS irradiance resulted in a modest upregulation, while oxidative stress caused a slight downregulation. Both genes were also found to occur on the same transcript. These results demonstrate that these genes are positively responding to several light-associated conditions, which suggests that this TCRS may regulate more than just scytonemin biosynthesis under UVA stress. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Epidermal UV-A absorbance and whole-leaf flavonoid composition in pea respond more to solar blue light than to solar UV radiation.

PubMed

Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J

2015-05-01

Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A < 370 nm; (3) attenuate UV-B and UV-A; (4) attenuate UV-B, UV-A and blue light; and (5) as a control not attenuating these wavebands. Attenuation of blue light significantly reduced the flavonoid content in leaf adaxial epidermis and reduced the whole-leaf concentrations of quercetin derivatives relative to kaempferol derivatives. In contrast, UV-B responses were not significant. These results show that pea plants regulate epidermal UV-A absorbance and accumulation of individual flavonoids by perceiving complex radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors. © 2014 John Wiley & Sons Ltd.

Strawberry-Based Cosmetic Formulations Protect Human Dermal Fibroblasts against UVA-Induced Damage

PubMed Central

Gasparrini, Massimiliano; Forbes-Hernandez, Tamara Y.; Afrin, Sadia; Reboredo-Rodriguez, Patricia; Cianciosi, Danila; Mezzetti, Bruno; Quiles, Josè L.; Bompadre, Stefano; Battino, Maurizio; Giampieri, Francesca

2017-01-01

Extreme exposure of skin to Ultraviolet A (UVA)-radiation may induce a dysregulated production of reactive oxygen species (ROS) which can interact with cellular biomolecules leading to oxidative stress, inflammation, DNA damage, and alteration of cellular molecular pathways, responsible for skin photoaging, hyperplasia, erythema, and cancer. For these reasons, the use of dietary natural bioactive compounds with remarkable antioxidant activity could be a strategic tool to counteract these UVA-radiation-caused deleterious effects. Thus, the purpose of the present work was to test the efficacy of strawberry (50 μg/mL)-based formulations supplemented with Coenzyme Q10 (100 μg/mL) and sun protection factor 10 in human dermal fibroblasts irradiated with UVA-radiation. The apoptosis rate, the amount of intracellular reactive oxygen species (ROS) production, the expression of proteins involved in antioxidant and inflammatory response, and mitochondrial functionality were evaluated. The results showed that the synergic topical use of strawberry and Coenzyme Q10 provided a significant (p < 0.05) photoprotective effect, reducing cell death and ROS, increasing antioxidant defense, lowering inflammatory markers, and improving mitochondrial functionality. The obtained results suggest the use of strawberry-based formulations as an innovative, natural, and useful tool for the prevention of UVA exposure-induced skin diseases in order to decrease or substitute the amount of synthetic sunscreen agents. PMID:28613256

Effect of photoactivated riboflavin on the biodegradation-resistance of root-dentin collagen.

PubMed

Priyadarshini, Balasankar Meera; Lu, Thong Beng; Fawzy, Amr S

2017-12-01

This study was conducted to evaluate the effect of UVA-activated 1% riboflavin solution on structural integrity; mechanical properties and stability; and collagenase-mediated collagen solubilisation resistance of demineralized root dentin collagen matrix. Root dentin specimens demineralized with 17% EDTA for 7days were treated with 1% RF for 1min followed by UVA photo-activation at intensity 7mW/cm 2 for 1min. Control specimens were completely devoid of riboflavin and/or UVA treatments. Specimens were challenged with bacterial collagenase type-I solution for different time-periods at 37°C. Collagen solubilisation resistance was evaluated in terms of hydroxyproline (HYP) liberation. Mechanical characterization of dentin specimens before and after 24h of exposure to collagenase solution was done in terms of apparent-elastic modulus (E appr ) and ultimate tensile strength (UTS). Variations in dentin collagen-network structure with exposure time in collagenase were visualized by TEM. Crosslinking dentin with UVA-activated riboflavin significantly decreased HYP release and increased E appr and UTS compared to control specimens with storage time in collagenase. Moreover, crosslinked specimens showed higher structural resistance to collagenase effect reflected from dense, well-formed collagen fibrils-network with characteristic collagen cross-banding. UVA-activated riboflavin treatment increased collagenase-mediated collagen degradation resistance and enhanced mechanical stability against collagenase challenges of root dentin after EDTA demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Smartphone-Based Android app for Determining UVA Aerosol Optical Depth and Direct Solar Irradiances.

PubMed

Igoe, Damien P; Parisi, Alfio; Carter, Brad

2014-01-01

This research describes the development and evaluation of the accuracy and precision of an Android app specifically designed, written and installed on a smartphone for detecting and quantifying incident solar UVA radiation and subsequently, aerosol optical depth at 340 and 380 nm. Earlier studies demonstrated that a smartphone image sensor can detect UVA radiation and the responsivity can be calibrated to measured direct solar irradiance. This current research provides the data collection, calibration, processing, calculations and display all on a smartphone. A very strong coefficient of determination of 0.98 was achieved when the digital response was recalibrated and compared to the Microtops sun photometer direct UVA irradiance observations. The mean percentage discrepancy for derived direct solar irradiance was only 4% and 6% for observations at 380 and 340 nm, respectively, lessening with decreasing solar zenith angle. An 8% mean percent difference discrepancy was observed when comparing aerosol optical depth, also decreasing as solar zenith angle decreases. The results indicate that a specifically designed Android app linking and using a smartphone image sensor, calendar and clock, with additional external narrow bandpass and neutral density filters can be used as a field sensor to evaluate both direct solar UVA irradiance and low aerosol optical depths for areas with low aerosol loads. © 2013 The American Society of Photobiology.

Photostabilization of butyl methoxydibenzoylmethane (Avobenzone) and ethylhexyl methoxycinnamate by bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a new UV broadband filter.

PubMed

Chatelain, E; Gabard, B

2001-09-01

It is now well documented that chronic UVA exposure induces damage to human skin. Therefore, modern sunscreens should not only provide protection from both UVB and UVA radiation but also maintain this protection during the entire period of exposure to the sun. UVA filters, however, are rare and not sufficiently photostable. We investigated the effect of the introduction of a new UV filter, bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), in oil in water sunscreen formulations on the photostability of butyl methoxydibenzoylmethane (Avobenzone [AVB]) after irradiation with an optically filtered Xenon arc source (UV irradiance adjusted at 1 mean effective dose [MED]/min). With spectrophotometrical methods to assess the sun protection factor (SPF) and UVA ratio and chromatographical methods to determine the amount of UV filters recovered after irradiation we showed that Tinosorb S prevented the photodegradation of AVB in a concentration-dependent way, leading to a sustained SPF and UVA ratio even after irradiation with doses of up to 30 MED. Since AVB was shown to destabilize ethylhexyl methoxycinnamate (EHM) we tested the effect of Tinosorb S in sunscreens containing this UV filter combination. Here too Tinosorb S showed photoprotective properties toward both UV filters. Thus, Tinosorb S can be used successfully to improve the photostability and efficiency of sunscreens containing AVB and EHM.

Ozone and photocatalytic processes to remove the antibiotic sulfamethoxazole from water.

PubMed

Beltrán, Fernando J; Aguinaco, Almudena; García-Araya, Juan F; Oropesa, Ana

2008-08-01

In this study, water containing the pharmaceutical compound sulfamethoxazole (SMT) was subjected to the various treatments of different oxidation processes involving ozonation, and photolysis and catalysis under different experimental conditions. Removal rates of SMT and total organic carbon (TOC), from experiments of simple UVA radiation, ozonation (O(3)), catalytic ozonation (O(3)/TiO(2)), ozone photolysis (O(3)/UVA), photocatalytic oxidation (O(2)/TiO(2)/UVA) and photocatalytic ozonation (O(3)/UVA/TiO(2)), have been compared. Photocatalytic ozonation leads to the highest SMT removal rate (pH 7 in buffered systems, complete removal is achieved in less than 5min) and total organic carbon (in unbuffered systems, with initial pH=4, 93% TOC removal is reached). Also, lowest ozone consumption per TOC removed and toxicity was achieved with the O(3)/UVA/TiO(2) process. Direct ozone and free radical reactions were found to be the principal mechanisms for SMT and TOC removal, respectively. In photocatalytic ozonation, with buffered (pH 7) aqueous solutions phosphates (buffering salts) and accumulation of bicarbonate scavengers inhibit the reactions completely on the TiO(2) surface. As a consequence, TOC removal diminishes. In all cases, hydrogen peroxide plays a key role in TOC mineralization. According to the results obtained in this work the use of photocatalytic ozonation is recommended to achieve a high mineralization degree of water containing SMT type compounds.

DNA repair kinetic of hydrogen peroxide and UVA/B induced lesions in peripheral blood leucocytes from xeroderma pigmentosum patients and healthy subjects.

PubMed

Gonzalez, Elio A Prieto; Mudry, Marta D; Palermo, Ana Maria

2014-01-01

The objective of the present work was to study the fine kinetics of DNA repair in xeroderma pigmentosum (XP) syndrome, a complex disorder linked to a deficiency in repair that increases cancer susceptibility. The repair process was evaluated by the comet assay (CA) in cells from 2 XP patients and 9 controls exposed to UVA/B (UVA 366/UVB 280 nm) and H2O2 (150 μM) at temperatures of 4, 15, and 37°C. Samples were taken at 2-min intervals during the first 10 min to analyze the "fine kinetics" repair during the initial phase of the curve, and then at 15, 20, 25, 30, 45, 60, and 120 min. CA evaluation of DNA repair activity points to BER/NER initiation in the first 30 min with both inductors at 37°C and 15°C, but final comet length showed differences according to treatment. Repair kinetics during 120 min showed a good correlation with clinical features in both XP patients. Differences in final comet length were less pronounced in XP cells treated with H2O2 than with UVA/B, probably because the peroxide produces mainly base oxidation but less bulky lesions; UVA/B generates a mixture of both. These findings reinforce the value of CA in testing in DNA repair ability or exposure monitoring.

UVA phototransduction drives early melanin synthesis in human melanocytes.

PubMed

Wicks, Nadine L; Chan, Jason W; Najera, Julia A; Ciriello, Jonathan M; Oancea, Elena

2011-11-22

Exposure of human skin to solar ultraviolet radiation (UVR), a powerful carcinogen [1] comprising ~95% ultraviolet A (UVA) and ~5% ultraviolet B (UVB) at the Earth's surface, promotes melanin synthesis in epidermal melanocytes [2, 3], which protects skin from DNA damage [4, 5]. UVB causes DNA lesions [6] that lead to transcriptional activation of melanin-producing enzymes, resulting in delayed skin pigmentation within days [7]. In contrast, UVA causes primarily oxidative damage [8] and leads to immediate pigment darkening (IPD) within minutes, via an unknown mechanism [9, 10]. No receptor protein directly mediating phototransduction in skin has been identified. Here we demonstrate that exposure of primary human epidermal melanocytes (HEMs) to UVA causes calcium mobilization and early melanin synthesis. Calcium responses were abolished by treatment with G protein or phospholipase C (PLC) inhibitors or by depletion of intracellular calcium stores. We show that the visual photopigment rhodopsin [11] is expressed in HEMs and contributes to UVR phototransduction. Upon UVR exposure, significant melanin production was measured within one hour; cellular melanin continued to increase in a retinal- and calcium-dependent manner up to 5-fold after 24 hr. Our findings identify a novel UVA-sensitive signaling pathway in melanocytes that leads to calcium mobilization and melanin synthesis and may underlie the mechanism of IPD in human skin. Copyright © 2011 Elsevier Ltd. All rights reserved.

The influence of ambient ultraviolet light on sperm quality and sexual ornamentation in three-spined sticklebacks (Gasterosteus aculeatus).

PubMed

Rick, Ingolf P; Mehlis, Marion; Eßer, Elisabeth; Bakker, Theo C M

2014-02-01

Exposure to enhanced levels of ambient ultraviolet (UV) radiation (UVR) can have adverse effects on aquatic organisms including damage at the cellular and molecular level and impairment of development, fecundity and survival. Much research has been conducted on the role of the harmful UVB radiation. However, due to its greater penetration in water the more abundant UVA radiation can also act as an environmental stressor. Little is known about UVR effects on sperm characteristics although sperm cells should be especially prone to UV-induced oxidative stress. Moreover, UV-related changes in oxidative status may affect the phenotypic expression of energetically costly sexual ornaments. We investigated the effects of long-term exposure to ecologically relevant levels of simulated UVA radiation on sperm quality and sexual ornamentation in three-spined sticklebacks (Gasterosteus aculeatus). Males were assigned to three spectral exposure treatments differing in the UV spectral part so that they received either enhanced, moderate or no UVA radiation. The results reveal that exposure to enhanced ambient UVA levels had detrimental effects on both male breeding coloration and sperm velocity providing evidence that UVR affects traits targeted by pre- and post-copulatory sexual selection. By highlighting the role of UVA as a factor influencing fitness-relevant traits, our findings may contribute to a better understanding of the consequences of current and future levels of solar UVR for mating systems and life history.

Experimental study of radiation dose rate at different strategic points of the BAEC TRIGA Research Reactor.

PubMed

Ajijul Hoq, M; Malek Soner, M A; Salam, M A; Haque, M M; Khanom, Salma; Fahad, S M

2017-12-01

The 3MW TRIGA Mark-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) has been under operation for about thirty years since its commissioning at 1986. In accordance with the demand of fundamental nuclear research works, the reactor has to operate at different power levels by utilizing a number of experimental facilities. Regarding the enquiry for safety of reactor operating personnel and radiation workers, it is necessary to know the radiation level at different strategic points of the reactor where they are often worked. In the present study, neutron, beta and gamma radiation dose rate at different strategic points of the reactor facility with reactor power level of 2.4MW was measured to estimate the rising level of radiation due to its operational activities. From the obtained results high radiation dose is observed at the measurement position of the piercing beam port which is caused by neutron leakage and accordingly, dose rate at the stated position with different reactor power levels was measured. This study also deals with the gamma dose rate measurements at a fixed position of the reactor pool top surface for different reactor power levels under both Natural Convection Cooling Mode (NCCM) and Forced Convection Cooling Mode (FCCM). Results show that, radiation dose rate is higher for NCCM in compared with FCCM and increasing with the increase of reactor power. Thus, concerning the radiological safety issues for working personnel and the general public, the radiation dose level monitoring and the experimental analysis performed within this paper is so much effective and the result of this work can be utilized for base line data and code verification of the nuclear reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

HEDL FACILITIES CATALOG 400 AREA

DOE Office of Scientific and Technical Information (OSTI.GOV)

MAYANCSIK BA

1987-03-01

The purpose of this project is to provide a sodium-cooled fast flux test reactor designed specifically for irradiation testing of fuels and materials and for long-term testing and evaluation of plant components and systems for the Liquid Metal Reactor (LMR) Program. The FFTF includes the reactor, heat removal equipment and structures, containment, core component handling and examination, instrumentation and control, and utilities and other essential services. The complex array of buildings and equipment are arranged around the Reactor Containment Building.

THE COOLING REQUIREMENTS AND PROCESS SYSTEMS OF THE SOUTH AFRICAN RESEARCH REACTOR, SAFARI 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colley, J.R.

1962-12-01

The SAFARI 1 research reactor is cooled and moderated by light water. There are three process systems, a primary water system which cools the reactor core and surroundings, a pool water system, and a secondary water system which removes the heat from the primary and pool systems. The cooling requirements for the reactor core and experimental facilities are outlined, and the cooling and purification functions of the three process systems are described. (auth)

The Birth of Nuclear-Generated Electricity

DOE R&D Accomplishments Database

1999-09-01

The Experimental Breeder Reactor-I (EBR-I), built in Idaho in 1949, generated the first usable electricity from nuclear power on December 20, 1951. More importantly, the reactor was used to prove that it was possible to create more nuclear fuel in the reactor than it consumed during operation -- fuel breeding. The EBR-I facility is now a National Historic Landmark open to the public.

Large-scale boiling experiments of the flooded cavity concept for in-vessel core retention

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, T.Y.; Slezak, S.E.; Bentz, J.H.

1994-03-01

This paper presents results of ex-vessel boiling experiments performed in the CYBL (CYlindrical BoiLing) facility. CYBL is a reactor-scale facility for confirmatory research of the flooded cavity concept for accident management. CYBL has a tank-within-a-tank design; the inner tank simulates the reactor vessel and the outer tank simulates the reactor cavity. Experiments with uniform and edge-peaked heat flux distributions up to 20 W/cm{sup 2} across the vessel bottom were performed. Boiling outside the reactor vessel was found to be subcooled nucleate boiling. The subcooling is mainly due to the gravity head which results from flooding the sides of the reactormore » vessel. The boiling process exhibits a cyclic pattern with four distinct phases: direct liquid/solid contact, bubble nucleation and growth, coalescence, and vapor mass dispersion (ejection). The results suggest that under prototypic heat load and heat flux distributions, the flooded cavity in a passive pressurized water reactor like the AP-600 should be capable of cooling the reactor pressure vessel in the central region of the lower head that is addressed by these tests.« less

SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2013-09-25

U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in amore » remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.« less

SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

ScienceCinema

None

2018-01-16

U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

PBF Reactor Building (PER620). Fuel rod test assembly is on ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Fuel rod test assembly is on display at PBF. Date: 1982. INEEL negative no. 82-4893 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

An Overview of INEL Fusion Safety R&D Facilities

NASA Astrophysics Data System (ADS)

McCarthy, K. A.; Smolik, G. R.; Anderl, R. A.; Carmack, W. J.; Longhurst, G. R.

1997-06-01

The Fusion Safety Program at the Idaho National Engineering Laboratory has the lead for fusion safety work in the United States. Over the years, we have developed several experimental facilities to provide data for fusion reactor safety analyses. We now have four major experimental facilities that provide data for use in safety assessments. The Steam-Reactivity Measurement System measures hydrogen generation rates and tritium mobilization rates in high-temperature (up to 1200°C) fusion relevant materials exposed to steam. The Volatilization of Activation Product Oxides Reactor Facility provides information on mobilization and transport and chemical reactivity of fusion relevant materials at high temperature (up to 1200°C) in an oxidizing environment (air or steam). The Fusion Aerosol Source Test Facility is a scaled-up version of VAPOR. The ion-implanta-tion/thermal-desorption system is dedicated to research into processes and phenomena associated with the interaction of hydrogen isotopes with fusion materials. In this paper we describe the capabilities of these facilities.

Timber management and use-value assessment

Treesearch

Paul E. Sendak; Neil K. Huyler

1994-01-01

Describes timber management activity and estimates timber harvest from forest land enrolled in Vermont's Use Value Appraisal (UVA) Forest Land property tax program. Data were compiled from the mandatory management plans and annual conformance reports filed for each property enrolled in the Program. Overall, 31 percent of the UVA properties reported a commercial...

Silica-Titania Composite (STC)'s Performance in the Photocatalytic Oxidation of Polar VOCs

NASA Technical Reports Server (NTRS)

Levine, Lanfang H.; Coutts, Janelle; Richards, Jeffrey; Mazyck, David; Mazyck, David

2011-01-01

The objective of this paper is to determine the performance of a Silica-Titania Composite (STC) in the photocatalytic oxidation (PCO) of polar VOCs for potential applications in trace contaminant control within space habitats such as the ISS and CEV Orion. Tests were carried out in a bench scale STC-packed annular reactor under continuous illumination by either a UV-C germicidal lamp(lambda (sub max) = 254 nm) or UV-A fluorescent BLB (lambda(sub max) = 365 nm) for the removal of ethanol (a predominant polar VOC in the ISS cabin). The STC's performance was evaluated in terms of the ethanol mineralization rate, mineralization efficiency, and the extent of its oxidation intermediate (acetaldehyde) formation in response to the type of light source (photon energy and photon flux) and relative humidity (RH) implemented. Results demonstrated that acetaldehyde was the only quantifiable intermediate in the effluent under UV illumination, but was not found in the dark adsorption experiments. The mineralization rate increased with an increase in photon energy (UV-C greater than UV-A), even though both lamps were adjusted to emit the same incident photon flux, and also increased with increasing photon flux. However, photonic efficiency decreased as the photon flux increased. More importantly, a higher photon flux gave rise to a lower effluent acetaldehyde concentration. The effect of RH on PCO was complex and intriguing because it affected both physical adsorption and photocatalytic oxidation. In general, increasing RH caused a decrease in adsorption capacity for ethanol and reduced the mineralization efficiency with a concomitant higher acetaldehyde evolution rate. The effect of RH was less profound than that of photon flux.

Initial Back-to-Back Fission Chamber Testing in ATRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benjamin Chase; Troy Unruh; Joy Rempe

2014-06-01

Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to providemore » calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.« less

Neutron measurement at the thermal column of the Malaysian Triga Mark II reactor using gold foil activation method and TLD

NASA Astrophysics Data System (ADS)

Shalbi, Safwan; Salleh, Wan Norhayati Wan; Mohamad Idris, Faridah; Aliff Ashraff Rosdi, Muhammad; Syahir Sarkawi, Muhammad; Liyana Jamsari, Nur; Nasir, Nur Aishah Mohd

2018-01-01

In order to design facilities for boron neutron capture therapy (BNCT), the neutron measurement must be considered to obtain the optimal design of BNCT facility such as collimator and shielding. The previous feasibility study showed that the thermal column could generate higher thermal neutrons yield for BNCT application at the TRIGA MARK II reactor. Currently, the facility for BNCT are planned to be developed at thermal column. Thus, the main objective was focused on the thermal neutron and epithermal neutron flux measurement at the thermal column. In this measurement, pure gold and cadmium were used as a filter to obtain the thermal and epithermal neutron fluxes from inside and outside of the thermal column door of the 200kW reactor power using a gold foil activation method. The results were compared with neutron fluxes using TLD 600 and TLD 700. The outcome of this work will become the benchmark for the design of BNCT collimator and the shielding

Postirradiation thermocyclic loading of ferritic-martensitic structural materials

NASA Astrophysics Data System (ADS)

Belyaeva, L.; Orychtchenko, A.; Petersen, C.; Rybin, V.

Thermonuclear fusion reactors of the Tokamak-type will be unique power engineering plants to operate in thermocyclic mode only. Ferritic-martensitic stainless steels are prime candidate structural materials for test blankets of the ITER fusion reactor. Beyond the radiation damage, thermomechanical cyclic loading is considered as the most detrimental lifetime limiting phenomenon for the above structure. With a Russian and a German facility for thermal fatigue testing of neutron irradiated materials a cooperation has been undertaken. Ampule devices to irradiate specimens for postirradiation thermal fatigue tests have been developed by the Russian partner. The irradiation of these ampule devices loaded with specimens of ferritic-martensitic steels, like the European MANET-II, the Russian 05K12N2M and the Japanese Low Activation Material F82H-mod, in a WWR-M-type reactor just started. A description of the irradiation facility, the qualification of the ampule device and the modification of the German thermal fatigue facility will be presented.

The new postirradiation examination facility of the Atomic Energy Corporation of South Africa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walt, P.L. van der; Aspeling, J.C.; Jonker, W.D.

1992-01-01

The Pelindaba Hot Cell Complex (HCC) forms an important part of the infrastructure and support services of the Atomic Energy Corporation (AEC) of South Africa. It is a comprehensive, one-stop facility designed to make South Africa self-sufficient in the fields of spent-fuel qualification and verification, reactor pressure vessel surveillance program testing, ad hoc failure analyses for the nuclear power industry, and research and development studies in conjunction with the Safari I material test reactor (MTR) and irradiation rigs. Local technology and expertise was used for the design and construction of the HCC, which start up in 1980. The facility wasmore » commissioned in 1990.« less

Trace-element characterization of evidential cannabis sative samples using k{sub 0}-standardization methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, D.P. Jr.; Vernetson, W.G.; Ratner, R.T.

The University of Florida Training Reactor (UFTR) facilities including the analytical laboratory are used for a wide range of educational, research, training, and service functions. The UFTR is a 100-kW light-water-cooled, graphite-and-water-moderated modified Argonaut-type reactor. The UFTR utilizes high enriched plate-type fuel in a two-slab arrangement and operates at a 100-kW power level. Since first licensed to operate at 10 kW in 1959, this nonpower reactor facility has had an active but evolving record of continuous service to a wide range of academic, utility, and community users. The services of the UFTR have also been used by various state authoritiesmore » in criminal investigations. Because of its relatively low power and careful laboratory analyses, the UFTR neutron flux characteristics in several ports are not only well characterized but they are also quite invariant with time. As a result, such a facility is well-suited to the application of the multielement analysis using the k{sub o}-standardization method of neutron activation analysis. The analysis of untreated evidential botanical samples presented a unique opportunity to demonstrate implementation of this method at the UFTR facilities.« less

Review of the TREAT Conversion Conceptual Design and Fuel Qualification Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diamond, David

The U.S. Department of Energy (DOE) is preparing to re establish the capability to conduct transient testing of nuclear fuels at the Idaho National Laboratory (INL) Transient Reactor Test (TREAT) facility. The original TREAT core went critical in February 1959 and operated for more than 6,000 reactor startups before plant operations were suspended in 1994. DOE is now planning to restart the reactor using the plant's original high-enriched uranium (HEU) fuel. At the same time, the National Nuclear Security Administration (NNSA) Office of Material Management and Minimization Reactor Conversion Program is supporting analyses and fuel fabrication studies that will allowmore » for reactor conversion to low-enriched uranium (LEU) fuel (i.e., fuel with less than 20% by weight 235U content) after plant restart. The TREAT Conversion Program's objectives are to perform the design work necessary to generate an LEU replacement core, to restore the capability to fabricate TREAT fuel element assemblies, and to implement the physical and operational changes required to convert the TREAT facility to use LEU fuel.« less

Toward a Mechanistic Source Term in Advanced Reactors: A Review of Past U.S. SFR Incidents, Experiments, and Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bucknor, Matthew; Brunett, Acacia J.; Grabaskas, David

In 2015, as part of a Regulatory Technology Development Plan (RTDP) effort for sodium-cooled fast reactors (SFRs), Argonne National Laboratory investigated the current state of knowledge of source term development for a metal-fueled, pool-type SFR. This paper provides a summary of past domestic metal-fueled SFR incidents and experiments and highlights information relevant to source term estimations that were gathered as part of the RTDP effort. The incidents described in this paper include fuel pin failures at the Sodium Reactor Experiment (SRE) facility in July of 1959, the Fermi I meltdown that occurred in October of 1966, and the repeated meltingmore » of a fuel element within an experimental capsule at the Experimental Breeder Reactor II (EBR-II) from November 1967 to May 1968. The experiments described in this paper include the Run-Beyond-Cladding-Breach tests that were performed at EBR-II in 1985 and a series of severe transient overpower tests conducted at the Transient Reactor Test Facility (TREAT) in the mid-1980s.« less

An Overview of Facilities and Capabilities to Support the Development of Nuclear Thermal Propulsion

DOE Office of Scientific and Technical Information (OSTI.GOV)

James Werner; Sam Bhattacharyya; Mike Houts

Abstract. The future of American space exploration depends on the ability to rapidly and economically access locations of interest throughout the solar system. There is a large body of work (both in the US and the Former Soviet Union) that show that Nuclear Thermal Propulsion (NTP) is the most technically mature, advanced propulsion system that can enable this rapid and economical access by its ability to provide a step increase above what is a feasible using a traditional chemical rocket system. For an NTP system to be deployed, the earlier measurements and recent predictions of the performance of the fuelmore » and the reactor system need to be confirmed experimentally prior to launch. Major fuel and reactor system issues to be addressed include fuel performance at temperature, hydrogen compatibility, fission product retention, and restart capability. The prime issue to be addressed for reactor system performance testing involves finding an affordable and environmentally acceptable method to test a range of engine sizes using a combination of nuclear and non-nuclear test facilities. This paper provides an assessment of some of the capabilities and facilities that are available or will be needed to develop and test the nuclear fuel, and reactor components. It will also address briefly options to take advantage of the greatly improvement in computation/simulation and materials processing capabilities that would contribute to making the development of an NTP system more affordable. Keywords: Nuclear Thermal Propulsion (NTP), Fuel fabrication, nuclear testing, test facilities.« less

77 FR 34367 - Proposed Subsequent Arrangement

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... reactors, and a research reactor, at the Post Irradiation Examination Facility (PIEF), the Irradiated.../2011, ``Post-Irradiation Examination and R&D Programs Using Irradiated Fuels at KAERI,'' dated June... fuel elements for post-irradiation examination and for research, development and manufacture of DUPIC...

10 CFR 51.121 - Status of NEPA actions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... address inquiries to: (a) Utilization facilities: ATTN: Document Control Desk, Director, Office of Nuclear Reactor Regulation or Director, Office of New Reactors, as appropriate, U.S. Nuclear Regulatory Commission... NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND...

10 CFR 51.121 - Status of NEPA actions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... address inquiries to: (a) Utilization facilities: ATTN: Document Control Desk, Director, Office of Nuclear Reactor Regulation or Director, Office of New Reactors, as appropriate, U.S. Nuclear Regulatory Commission... NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND...

10 CFR 51.121 - Status of NEPA actions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... address inquiries to: (a) Utilization facilities: ATTN: Document Control Desk, Director, Office of Nuclear Reactor Regulation or Director, Office of New Reactors, as appropriate, U.S. Nuclear Regulatory Commission... NUCLEAR REGULATORY COMMISSION (CONTINUED) ENVIRONMENTAL PROTECTION REGULATIONS FOR DOMESTIC LICENSING AND...

The procedure and results of calculations of the equilibrium isotopic composition of a demonstration subcritical molten salt reactor

NASA Astrophysics Data System (ADS)

Nevinitsa, V. A.; Dudnikov, A. A.; Blandinskiy, V. Yu.; Balanin, A. L.; Alekseev, P. N.; Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.

2015-12-01

A subcritical molten salt reactor with an external neutron source is studied computationally as a facility for incineration and transmutation of minor actinides from spent nuclear fuel of reactors of VVER-1000 type and for producing 233U from 232Th. The reactor configuration is chosen, the requirements to be imposed on the external neutron source are formulated, and the equilibrium isotopic composition of heavy nuclides and the key parameters of the fuel cycle are calculated.

Posttest examination of Sodium Loop Safety Facility experiments. [LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holland, J.W.

In-reactor, safety experiments performed in the Sodium Loop Safety Facility (SLSF) rely on comprehensive posttest examinations (PTE) to characterize the postirradiation condition of the cladding, fuel, and other test-subassembly components. PTE information and on-line instrumentation data, are analyzed to identify the sequence of events and the severity of the accident for each experiment. Following in-reactor experimentation, the SLSF loop and test assembly are transported to the Hot Fuel Examination Facility (HFEF) for initial disassembly. Goals of the HFEF-phase of the PTE are to retrieve the fuel bundle by dismantling the loop and withdrawing the test assembly, to assess the macro-conditionmore » of the fuel bundle by nondestructive examination techniques, and to prepare the fuel bundle for shipment to the Alpha-Gamma Hot Cell Facility (AGHCF) at Argonne National Laboratory.« less

Decommissioning ALARA programs Cintichem decommissioning experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adler, J.J.; LaGuardia, T.S.

1995-03-01

The Cintichem facility, originally the Union Carbide Nuclear Company (UCNC) Research Center, consisted primarily of a 5MW pool type reactor linked via a four-foot-wide by twelve-foot-deep water-filled canal to a bank of five adjacent hot cells. Shortly after going into operations in the early 1960s, the facility`s operations expanded to provide various reactor-based products and services to a multitude of research, production, medical, and education groups. From 1968 through 1972, the facility developed a process of separating isotopes from mixed fission products generated by irradiating enriched Uranium target capsules. By the late 1970s, 20 to 30 capsules were being processedmore » weekly, with about 200,000 curies being produced per week. Several isotopes such as Mo{sup 99}, I{sup 131}, and Xe{sup 133} were being extracted for medical use.« less

Dynamic characterization and microprocessor control of the NASA/UVA proof mass actuator

NASA Technical Reports Server (NTRS)

Zimmerman, D. C.; Inman, D. J.; Horner, G. C.

1984-01-01

The self-contained electromagnetic-reaction-type force-actuator system developed by NASA/UVA for the verification of spacecraft-structure vibration-control laws is characterized and demonstrated. The device is controlled by a dedicated microprocessor and has dynamic characteristics determined by Fourier analysis. Test data on a cantilevered beam are shown.

Treatment of crystallized-fruit wastewater by UV-A LED photo-Fenton and coagulation-flocculation.

PubMed

Rodríguez-Chueca, Jorge; Amor, Carlos; Fernandes, José R; Tavares, Pedro B; Lucas, Marco S; Peres, José A

2016-02-01

This work reports the treatment of crystallized-fruit effluents, characterized by a very low biodegradability (BOD5/COD <0.19), through the application of a UV-A LED photo-Fenton process. Firstly, a Box-Behnken design of Response Surface Methodology was applied to achieve the optimal conditions for the UV-A LED photo-Fenton process, trying to maximize the efficiency by saving chemicals and time. Under the optimal conditions ([H2O2] = 5459 mg/L; [Fe(3+)] = 286 mg/L; time >180 min), a COD removal of 45, 64 and 74% was achieved after 360 min, using an irradiance of 23, 70 and 85 W/m(2) respectively. Then a combination of UV-A LED photo-Fenton with coagulation-flocculation-decantation attained a higher COD removal (80%), as well as almost total removal of turbidity (99%) and total suspended solids (95%). Subsequent biodegradability of treated effluents increased, allowing the application of a biological treatment step after the photochemical/CFD with 85 W/m(2). Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen and ultraviolet-A radiation on murine dendritic epidermal cells.

PubMed

Aubin, F; Alcalay, J; Dall'Acqua, F; Kripke, M L

1990-06-01

Although some psoralens are therapeutically active in the treatment of cutaneous hyperproliferative diseases when combined with UVA (320-400 nm) radiation, the toxic effects of these compounds have led physicians to seek new photochemotherapeutic agents. One such agent is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional psoralen compound. We investigated the effects of repetitive treatments with TMAP plus UVA radiation on the number of dendritic immune cells in murine epidermis and on the induction of phototoxicity. Mice treated 3 times per week for 4 weeks with 129 microgram TMAP plus 10 kJ/m2 UVA radiation exhibited no gross or microscopic evidence of phototoxicity. During this treatment, the numbers of ATPase+, Ia+, and Thy-l+ dendritic epidermal cells were greatly reduced, and by the end of the treatment period, few dendritic immune cells could be detected. We conclude that morphological alterations of cutaneous immune cells can occur in the absence of overt phototoxicity, and that TMAP plus low-dose UVA radiation decreases the numbers of detectable Langerhans cells and Thy-1+ cells in murine skin.

75 FR 54961 - Final Supplemental Environmental Impact Statement, Single Nuclear Unit at the Bellefonte Plant...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... facility, a wind farm, a methane- gas cofiring facility, and several small solar photovoltaic facilities... maintenance of select plant systems and other regulatory compliance activities. Major buildings and plant... the plant cooling towers and the reactor, auxiliary, control, turbine, office, and service buildings...

Pebble Fuel Handling and Reactivity Control for Salt-Cooled High Temperature Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Per; Greenspan, Ehud

2015-02-09

This report documents the work completed on the X-PREX facility under NEUP Project 11- 3172. This project seeks to demonstrate the viability of pebble fuel handling and reactivity control for fluoride salt-cooled high-temperature reactors (FHRs). The research results also improve the understanding of pebble motion in helium-cooled reactors, as well as the general, fundamental understanding of low-velocity granular flows. Successful use of pebble fuels in with salt coolants would bring major benefits for high-temperature reactor technology. Pebble fuels enable on-line refueling and operation with low excess reactivity, and thus simpler reactivity control and improved fuel utilization. If fixed fuel designsmore » are used, the power density of salt- cooled reactors is limited to 10 MW/m 3 to obtain adequate duration between refueling, but pebble fuels allow power densities in the range of 20 to 30 MW/m 3. This can be compared to the typical modular helium reactor power density of 5 MW/m3. Pebble fuels also permit radial zoning in annular cores and use of thorium or graphite pebble blankets to reduce neutron fluences to outer radial reflectors and increase total power production. Combined with high power conversion efficiency, compact low-pressure primary and containment systems, and unique safety characteristics including very large thermal margins (>500°C) to fuel damage during transients and accidents, salt-cooled pebble fuel cores offer the potential to meet the major goals of the Advanced Reactor Concepts Development program to provide electricity at lower cost than light water reactors with improved safety and system performance.This report presents the facility description, experimental results, and supporting simulation methods of the new X-Ray Pebble Recirculation Experiment (X-PREX), which is now operational and being used to collect data on the behavior of slow dense granular flows relevant to pebble bed reactor core designs. The X-PREX facility uses novel digital x-ray tomography methods to track both the translational and rotational motion of spherical pebbles, which provides unique experimental results that can be used to validate discrete element method (DEM) simulations of pebble motion. The validation effort supported by the X-PREX facility provides a means to build confidence in analysis of pebble bed configuration and residence time distributions that impact the neutronics, thermal hydraulics, and safety analysis of pebble bed reactor cores. Experimental and DEM simulation results are reported for silo drainage, a classical problem in the granular flow literature, at several hopper angles. These studies include conventional converging and novel diverging geometries that provide additional flexibility in the design of pebble bed reactor cores. Excellent agreement is found between the X-PREX experimental and DEM simulation results. This report also includes results for additional studies relevant to the design and analysis of pebble bed reactor cores including the study of forces on shut down blades inserted directly into a packed bed and pebble flow in a cylindrical hopper that is representative of a small test reactor.« less

16. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 137, A ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 137, A REACTOR CONTROL LAB ADJACENT TO ASSEMBLY BAY NO. 2. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV

PBF Reactor Building (PER620). Canal takes shape, with rebar and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Canal takes shape, with rebar and concrete placement underway. Photographer: John Capek. Date: August 16, 1967. INEEL negative no. 67-4370 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Understanding sunscreen SPF performance using cross-polarized UVA reflectance photography.

PubMed

Crowther, J M

2018-04-01

Objective methods for understanding sunscreen behaviour in vitro before they are applied to the skin have failed to keep pace with the ever-increasing demands for higher SPF scores where the products are absorbing more and more similar levels of UV. A novel method for visualizing the spreading and location of SPF ingredients based on cross-polarized UVA reflectance photography is described here which gives new insights into the formation of final film morphology and how it correlates with in vivo SPF efficacy for a set of test products. High-resolution UVA-based images of sunscreen films spread onto PMMA plates were captured using a modified commercial SLR camera in a custom imaging system. Visual grading and image analysis were used to describe the overall UVA absorbance and streakiness of the resultant films, and the data compared with both in vivo and calculated in vitro SPF scores for the products. Differences were observed between the products in terms of how they spread during application. A strong correlation was observed between the evenness of the resultant film as determined from the photographs and final in vivo SPF scores. Cross-polarized UVA reflectance photography has been demonstrated to be a valuable new method for assessing sunscreen distribution after spreading and to differentiate product based on film morphology, as well as strongly correlating with final in vivo behaviour. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

A novel mechanism of UV-A and riboflavin-mediated corneal cross-linking through induction of tissue transglutaminases.

PubMed

Kopsachilis, Nikolaos; Tsaousis, Konstantinos T; Tsinopoulos, Ioannis T; Kruse, Friedrich E; Welge-Luessen, Ulrich

2013-07-01

Collagen cross-linking using UV-A irradiation combined with the photosensitizer riboflavin is a new technique for treating progressive keratoconus. The purposes of this study were to examine whether primary human corneal keratocytes (HCKs) are capable of expressing and secreting fibronectin and tissue transglutaminase (tTgase), an enzyme cross-linking extracellular matrix protein, and to examine whether fibronectin and tTgase are increased after the treatment of HCK cells with UV-A irradiation combined with riboflavin (RFUV-A), thus providing another possible physiological mechanism of the cross-linking pathway. Cell cultures established from HCKs were treated with 0.025% riboflavin solution and UV-A (370 nm) irradiance 3 mW/cm2 for 30 minutes. Induction of fibronectin and tTgase was investigated by immunohistochemistry, real-time polymerase chain reaction, and Western blot analysis. Cell viability was quantified by a microscopic live-dead assay. External tTgase activity was measured by the ability to form polymerized fibronectin and the incorporation of biotinylated cadaverine into fibronectin. Treatment of cultured HCK cells with RFUV-A increased the fibronectin and tTgase messenger RNA and protein levels. This effect was not observed in cells treated with riboflavin or UV-A radiation alone. Incorporation of biotinylated cadaverine was significantly increased when HCK cells were treated with RFUV-A. The enzymes tTgase and fibronectin are expressed by RFUV-A treatment in cultured HCK cells. This mechanism provides more information about the physiology of corneal cross-linking.

Effects of ultraviolet radiation (UVA+UVB) on young gametophytes of Gelidium floridanum: growth rate, photosynthetic pigments, carotenoids, photosynthetic performance, and ultrastructure.

PubMed

Simioni, Carmen; Schmidt, Eder C; Felix, Marthiellen R de L; Polo, Luz Karime; Rover, Ticiane; Kreusch, Marianne; Pereira, Debora T; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

2014-01-01

This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1) and PAR+UVA (0.70 W m(-2))+UVB (0.35 W m(-2)) for 3 h per day. The samples were processed for light and electron microscopy to analyze the ultrastructure features, as well as carry out metabolic studies of GRs, quantify the content of photosynthetic pigments, identify carotenoids and assess photosynthetic performance. PAR+UVA+UVB promoted increase in cell wall thickness, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Algae exposed to PAR+UVA+UVB also showed a reduction in GR of 97%. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin contents, decreased significantly from UV radiation exposure. This result agrees with the decrease in photosynthetic performance observed after exposure to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR), where values of ETRmax declined approximately 44.71%. It can be concluded that radiation is a factor that affects the young gametophytes of G. floridanum at this stage of development. © 2014 The American Society of Photobiology.

Biological Mechanisms Underlying the Ultraviolet Radiation-Induced Formation of Skin Wrinkling and Sagging II: Over-Expression of Neprilysin Plays an Essential Role

PubMed Central

Imokawa, Genji; Nakajima, Hiroaki; Ishida, Koichi

2015-01-01

Our previous studies strongly indicated that the up-regulated activity of skin fibroblast-derived elastase plays a pivotal role in wrinkling and/or sagging of the skin via the impairment of elastic fiber configuration and the subsequent loss of skin elasticity. Fortunately, we succeeded in identifying human skin fibroblast-derived elastase as a previously known enzyme, neprilysin or neutral endopeptidase (NEP). We have also characterized epithelial-mesenchymal paracrine cytokine interactions between UVB-exposed-keratinocytes and dermal fibroblasts and found that interleukin-1α and granulocyte macrophage colony stimulatory factor (GM-CSF) are intrinsic cytokines secreted by UVB-exposed keratinocytes that stimulate the expression of neprilysin by fibroblasts. On the other hand, direct UVA exposure of human fibroblasts significantly stimulates the secretion of IL-6 and also elicits a significant increase in the gene expression of matrix metallo-protease(MMP)-1 as well as neprilysin (to a lesser extent), which is followed by distinct increases in their protein and enzymatic activity levels. Direct UVA exposure of human keratinocytes also stimulates the secretion of IL-6, IL-8 and GM-CSF but not of IL-1 and endothelin-1. These findings suggest that GM-CSF secreted by UVA-exposed keratinocytes as well as IL-6 secreted by UVA-exposed dermal fibroblasts play important and additional roles in UVA-induced sagging and wrinkling by up-regulation of neprilysin and MMP-1, respectively, in dermal fibroblasts. PMID:25856676

Regulation of Human Skin Pigmentation in situ by Repetitive UV Exposure – Molecular Characterization of Responses to UVA and/or UVB

PubMed Central

Choi, Wonseon; Miyamura, Yoshinori; Wolber, Rainer; Smuda, Christoph; Reinhold, William; Liu, Hongfang; Kolbe, Ludger; Hearing, Vincent J.

2012-01-01

Ultraviolet (UV) radiation is a major environmental factor that affects pigmentation in human skin and can eventually result in various types of UV-induced skin cancers. The effects of various wavelengths of UV on melanocytes and other types of skin cells in culture have been studied but little is known about gene expression patterns in situ following in situe exposure of human skin to different types of UV (UVA and/or UVB). Paracrine factors expressed by keratinocytes and/or fibroblasts that affect skin pigmentation might be regulated differently by UV, as might their corresponding receptors expressed on melanocytes. To test the hypothesis that different mechanisms are involved in the pigmentary responses of the skin to different types of UV, we used immunohistochemical and whole human genome microarray analyses to characterize human skin in situ to examine how melanocyte-specific proteins and paracrine melanogenic factors are regulated by repetitive exposure to different types of UV compared with unexposed skin as a control. The results show that gene expression patterns induced by UVA or UVB are distinct, UVB eliciting dramatic increases in a large number of genes involved in pigmentation as well as in other cellular functions, while UVA had little or no effect on those. The expression patterns characterize the distinct responses of the skin to UVA or UVB, and identify several potential previously unidentified factors involved in UV-induced responses of human skin. PMID:20147966

In vitro photostability and photoprotection studies of a novel 'multi-active' UV-absorber.

PubMed

Venditti, E; Spadoni, T; Tiano, L; Astolfi, P; Greci, L; Littarru, G P; Damiani, E

2008-08-01

This paper reports on the synthesis and properties of a new UV-absorber (OC-NO) based on the most popular UV filter worldwide, ethylhexyl methoxycinnamate (OMC) in which the methoxy group has been replaced with a pyrrolidine nitroxide bearing antioxidant activity. This sunscreen active has therefore both UV-absorbing and antioxidant properties which could ideally address both the UV-B and UV-A skin photo-damage. For broad-spectrum coverage, the combinations of OC-NO with two commonly used UV-A absorbers (BMDBM and DHHB) were also studied. The results obtained reveal that OC-NO: (a) is as photostable as OMC after UV-A exposure; (b) acts as free radical scavenger as demonstrated by EPR and chemical studies; (c) reduces UV-A and UV-A+BMDBM induced lipid peroxidation in liposomes and cells, measured as reduced TBARS levels and increased C11-BODIPY red fluorescence, respectively; (d) has comparable antioxidant activity to that of vitamin E and BHT commonly used in skin care formulations; (e) is non-cytotoxic to human skin fibroblasts as assessed with the MTT assay when exposed to increasing doses of UV-A; and (f) OC-NO+DHHB is a promising, photostable broad spectrum UV-filter combination that concomitantly reduces UV-induced free radical damage. These results suggest that nitroxide/antioxidant-based UV-absorbers may pave the way for the utilization of 'multi-active' ingredients in sunscreens thereby reducing the number of ingredients in these formulations.

Vemurafenib skin phototoxicity is indirectly linked to ultraviolet A minimal erythema dose decrease.

PubMed

Brugière, C; Stefan, A; Morice, C; Cornet, E; Moreau, A; Allouche, S; Verneuil, L

2014-12-01

Vemurafenib, an anti-rapidly accelerated fibrosarcoma kinase B (BRAF) molecule, improves survival among patients with metastatic BRAF-mutated melanoma. Photosensitivity, a frequent cutaneous adverse effect induced by vemurafenib, can lead to cessation of treatment. To investigate photosensitivity mechanisms in patients treated with vemurafenib for metastatic melanoma. In a prospective study of 12 patients, photobiological explorations with measurements of ultraviolet A (UVA) minimal erythema dose (MED) and polychromatic MED were performed over 3 days in all 12 patients. UVA MED and polychromatic MED were also assessed for four patients before treatment. We then performed spectrophotometric analyses of (i) serum and faeces in these four patients, before and after introduction of vemurafenib; (ii) the lyophilized form of vemurafenib without excipient added; and (iii) the lyophilized form of vemurafenib added to serum and faeces before treatment. Photosensitivity was present in 92% of the patients. UVA MED was normal before treatment and decreased after treatment, while polychromatic MED remained normal. The same three peaks (210, 260 and 310 nm) were identified in the spectrum for UVB and UVC but not for UVA on spectrophotometric analyses for each condition (lyophilized vemurafenib; serum and faeces after introduction of vemurafenib; and lyophilized vemurafenib added to serum and faeces before treatment). The peaks were different before treatment. Our study confirms that photosensitivity under vemurafenib treatment was a UVA phototoxicity reaction, and our results suggest that a metabolite of vemurafenib rather than the parent molecule is involved in this phototoxicity. © 2014 British Association of Dermatologists.

Molecular evidence that oral supplementation with lycopene or lutein protects human skin against ultraviolet radiation: results from a double-blinded, placebo-controlled, crossover study.

PubMed

Grether-Beck, S; Marini, A; Jaenicke, T; Stahl, W; Krutmann, J

2017-05-01

Increasing evidence suggests photoprotection by oral supplementation with β-carotene and lycopene. To examine the capacity of lycopene-rich tomato nutrient complex (TNC) and lutein, to protect against ultraviolet (UV)A/B and UVA1 radiation at a molecular level. In a placebo-controlled, double-blinded, randomized, crossover study two active treatments containing either TNC or lutein were assessed for their capacity to decrease the expression of UVA1 the radiation-inducible genes HO1, ICAM1 and MMP1. Sixty-five healthy volunteers were allocated to four treatment groups and subjected to a 2-week washout phase, followed by two 12-week treatment phases separated by another 2 weeks of washout. Volunteers started either with active treatment and were then switched to placebo, or vice versa. At the beginning and at the end of each treatment phase skin was irradiated and 24 h later biopsies were taken from untreated, UVA/B- and UVA1-irradiated skin for subsequent reverse transcriptase polymerase chain reaction analysis of gene expression. Moreover, blood samples were taken after the washout and the treatment phases for assessment of carotenoids. TNC completely inhibited UVA1- and UVA/B-induced upregulation of heme-oxygenase 1, intercellular adhesion molecule 1 and matrix metallopeptidase 1 mRNA, no matter the sequence (anova, P < 0·05). In contrast, lutein provided complete protection if it was taken in the first period but showed significantly smaller effects in the second sequence compared with TNC. Assuming the role of these genes as indicators of oxidative stress, photodermatoses and photoageing, these results might indicate that TNC and lutein could protect against solar radiation-induced health damage. © 2016 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

UVA Photoirradiation of Oxygenated Benz[a]anthracene and 3-Methylcholanthene - Generation of Singlet Oxygen and Induction of Lipid Peroxidation

PubMed Central

Yin, Jun-Jie; Xia, Qingsu; Cherng, Shu-Hui; Tang, I-Wah; Fu, Peter P.; Lin, Ge; Yu, Hongtao; Herreño Sáenz, Diógenes

2008-01-01

Polycyclic aromatic hydrocarbons (PAHs) are widespread genotoxic environmental pollutants and potentially pose a health risk to humans. Although the biological and toxicological activities, including metabolism, mutagenicity, and carcinogenicity, of PAHs have been thoroughly studied, their phototoxicity and photo-induced biological activity have not been well examined. We have long been interested in phototoxicity of PAHs and their derivatives induced by irradiation with UV light. In this paper we report the photoirradiation of a series of oxygenated benz[a]anthracene (BA) and 3-methylcholanthene (3-MC) by UVA light in the presence of a lipid, methyl linoleate. The studied PAHs include 2-hydroxy-BA (2-OH-BA), 3-hydroxy-BA (3-OH-BA), 5-hydroxymethyl-BA (5-CH2OH-BA), 7-hydroxymethyl-BA (7-CH2OH-BA), 12-hydroxymethyl-BA (12-CH2OH-BA), 7-hydroxymethyl-12-methyl-BA (7-CH2OH-12-MBA), 5-formyl-BA (5-CHO-BA), BA 5,6-cis-dihydrodiol (BA 5,6-cis-diol), 1-hydroxy-3-methylcholanthene (1-OH-3-MC), 1-keto-3-methylcholanthene (1-keto-3-MC), and 3-MC 1,2-diol. The results indicate that upon photoirradiation by UVA at 7 and 21 J/cm2, respectively all these compounds induced lipid peroxidation and exhibited a relationship between the dose of the light and the level of lipid peroxidation induced. To determine whether or not photoirradiation of these compounds by UVA light produces ROS, an ESR spin-trap technique was employed to provide direct evidence. Photoirradiation of 3-keto-3-MC by UVA (at 389 nm) in the presence of 2,2,6,6-tetramethylpiperidine (TEMP), a specific probe for singlet oxygen, resulted in the formation of TEMPO, indicating that singlet oxygen was generated. These overall results suggest that UVA photoirradiation of oxygenated BA and 3-methylcholanthrene generates singlet oxygen, one of the reactive oxygen species (ROS), which induce lipid peroxidation. PMID:18441402

Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

NASA Technical Reports Server (NTRS)

Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

2011-01-01

Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in <180 minutes of contact time. With continued advances in the design and manufacture of UV-A LEDs and semi-conducting photocatalysts, LED activated photochemical process technology promises to extend its application to spacecraft environmental systems.

Inhibitions by hydrogen-occluding silica microcluster to melanogenesis in human pigment cells and tyrosinase reaction.

PubMed

Kato, Shinya; Saitoh, Yasukazu; Miwa, Nobuhiko

2013-01-01

We investigated the anti-melanogenetic efficacy of hydrogen-occluding silica microcluster (H2-Silica), which is a silsesquioxane-based compound with hydrogen interstitially embedded in a matrix of caged silica, against melanogenesis in HMV-II human melanoma cells and L-DOPA-tyrosinase reaction [EC1.14.18.1]. HMV-II cells were subjected to oxidative stress by ultraviolet ray-A (UVA) exposure of 3-times of 0.65 J/cm2 summed up to 1.95 J/cm2. After UVA irradiation, HMV-II cells were stimulated to produce melanin by 2.72-fold more abundantly than unirradiated control. When HMV-II cells were treated with H2-Silica of 20 ppm or kojic acid of 28.4 ppm before and after UVA-irradiation, the amount of melanin was repressed to 12.2% or 14.5% as compared to that of UVA-irradiated control, respectively. That is, H2-Silica exhibited a comparable efficacy to the whitening agent kojic acid. The H2-Silica could prevent melanogenesis in HMV-II cells by low-level doses at 1-10 ppm, and cell viability and apoptosis event did not change even by high-level doses at 100-1000 ppm. On the contrary, kojic acid was cytotoxic at the concentration of 14-28 ppm or more. By microscopic observation, H2-Silica suppressed such properties indicative of melanin-rich cells as cellular hypertrophy, cell process formation, and melanogenesis around the outside of nuclei. The enzymatic assay using L-DOPA and mushroom tyrosinase demonstrated that H2-Silica restrained UVA-mediated melanin formation owing to down-regulation of tyrosinase activity, which could be attributed to scavenging of free radicals and inhibition of L-DOPA-to-dopachrome oxidation by hydrogen released from H2-Silica. Thus H2-Silica has a potential to prevent melanin production against UVA and serves as a skin-lightening ingredient for supplements or cosmetics.

The effect of riboflavin/UVA collagen cross-linking therapy on the structure and hydrodynamic behaviour of the ungulate and rabbit corneal stroma.

PubMed

Hayes, Sally; Kamma-Lorger, Christina S; Boote, Craig; Young, Robert D; Quantock, Andrew J; Rost, Anika; Khatib, Yasmeen; Harris, Jonathan; Yagi, Naoto; Terrill, Nicholas; Meek, Keith M

2013-01-01

To examine the effect of riboflavin/UVA corneal crosslinking on stromal ultrastructure and hydrodynamic behaviour. One hundred and seventeen enucleated ungulate eyes (112 pig and 5 sheep) and 3 pairs of rabbit eyes, with corneal epithelium removed, were divided into four treatment groups: Group 1 (28 pig, 2 sheep and 3 rabbits) were untreated; Group 2 (24 pig) were exposed to UVA light (3.04 mW/cm(2)) for 30 minutes and Group 3 (29 pig) and Group 4 (31 pig, 3 sheep and 3 rabbits) had riboflavin eye drops applied to the corneal surface every 5 minutes for 35 minutes. Five minutes after the initial riboflavin instillation, the corneas in Group 4 experienced a 30 minute exposure to UVA light (3.04 mW/cm(2)). X-ray scattering was used to obtain measurements of collagen interfibrillar spacing, spatial order, fibril diameter, D-periodicity and intermolecular spacing throughout the whole tissue thickness and as a function of tissue depth in the treated and untreated corneas. The effect of each treatment on the hydrodynamic behaviour of the cornea (its ability to swell in saline solution) and its resistance to enzymatic digestion were assessed using in vitro laboratory techniques. Corneal thickness decreased significantly following riboflavin application (p<0.01) and also to a lesser extent after UVA exposure (p<0.05). With the exception of the spatial order factor, which was higher in Group 4 than Group 1 (p<0.01), all other measured collagen parameters were unaltered by cross-linking, even within the most anterior 300 microns of the cornea. The cross-linking treatment had no effect on the hydrodynamic behaviour of the cornea but did cause a significant increase in its resistance to enzymatic digestion. It seems likely that cross-links formed during riboflavin/UVA therapy occur predominantly at the collagen fibril surface and in the protein network surrounding the collagen.

The Effect of Riboflavin/UVA Collagen Cross-linking Therapy on the Structure and Hydrodynamic Behaviour of the Ungulate and Rabbit Corneal Stroma

PubMed Central

Hayes, Sally; Kamma-Lorger, Christina S.; Boote, Craig; Young, Robert D.; Quantock, Andrew J.; Rost, Anika; Khatib, Yasmeen; Harris, Jonathan; Yagi, Naoto; Terrill, Nicholas; Meek, Keith M.

2013-01-01

Purpose To examine the effect of riboflavin/UVA corneal crosslinking on stromal ultrastructure and hydrodynamic behaviour. Methods One hundred and seventeen enucleated ungulate eyes (112 pig and 5 sheep) and 3 pairs of rabbit eyes, with corneal epithelium removed, were divided into four treatment groups: Group 1 (28 pig, 2 sheep and 3 rabbits) were untreated; Group 2 (24 pig) were exposed to UVA light (3.04 mW/cm2) for 30 minutes and Group 3 (29 pig) and Group 4 (31 pig, 3 sheep and 3 rabbits) had riboflavin eye drops applied to the corneal surface every 5 minutes for 35 minutes. Five minutes after the initial riboflavin instillation, the corneas in Group 4 experienced a 30 minute exposure to UVA light (3.04 mW/cm2). X-ray scattering was used to obtain measurements of collagen interfibrillar spacing, spatial order, fibril diameter, D-periodicity and intermolecular spacing throughout the whole tissue thickness and as a function of tissue depth in the treated and untreated corneas. The effect of each treatment on the hydrodynamic behaviour of the cornea (its ability to swell in saline solution) and its resistance to enzymatic digestion were assessed using in vitro laboratory techniques. Results Corneal thickness decreased significantly following riboflavin application (p<0.01) and also to a lesser extent after UVA exposure (p<0.05). With the exception of the spatial order factor, which was higher in Group 4 than Group 1 (p<0.01), all other measured collagen parameters were unaltered by cross-linking, even within the most anterior 300 microns of the cornea. The cross-linking treatment had no effect on the hydrodynamic behaviour of the cornea but did cause a significant increase in its resistance to enzymatic digestion. Conclusions It seems likely that cross-links formed during riboflavin/UVA therapy occur predominantly at the collagen fibril surface and in the protein network surrounding the collagen. PMID:23349690

Evidence for Compression of Escherichia coli K12 Cells under the Effect of TiO₂ Nanoparticles.

PubMed

Zhukova, Lyudmila V

2015-12-16

It has been shown that treatment with titanium dioxide nanoparticles (TiO2 NPs) combined with near-ultraviolet (UV-A) irradiation or in certain dark conditions reduced the numbers of various microorganisms, but the mechanism of this effect remains unclear. In this study to further clarify the mechanism of the antibacterial effect of TiO2 NPs the physiological state of E. coli K12 cells was estimated after incubation with the NPs (0.2 g/L) for different periods of time, with or without UV-A irradiation. Cell incubation with TiO2 NPs, combined or not combined with UV-A irradiation, showed that inactive cells were located only within cell aggregates formed after incubation with TiO2 NPs and that the larger the aggregate, the greater the number of such cells. When the formation of large aggregates was prevented, exposure to NPs under UV-A irradiation failed to result in cell inactivation. A comparative analysis of fluorescence and optical microscopic images of the same aggregates showed that the location of inactivated cells coincided with the zone of increased optical density within the aggregate. After treatment with TiO2 NPs under UV-A for 30, 60, or 120 min cells within the aggregates were the first to be inactivated. Cells on which NPs irradiated more strongly (at the periphery of large aggregates and single) remained active for a longer time than cells within the aggregates. As the time of treatment increased, so did the degree of cell compaction, with some zones of the aggregates eventually transforming into an acellular mass. After UV-A irradiation the cell aggregates spontaneously moved toward each other and gradually fused into larger structures, indicating that such exposure enhanced mutual attraction of cells treated with the NPs. Present study provides evidence for hypothesis that bacterial cells covered with TiO2 NPs are inactivated due to their mutual attraction and consequent compression.