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Sample records for 8-mop mas uva

  1. Zingiber officinale (ginger) used to prevent 8-Mop associated nausea.

    PubMed

    Meyer, K; Schwartz, J; Crater, D; Keyes, B

    1995-08-01

    Patients undergoing photopheresis are required to ingest the drug 8-MOP as part of their treatment. This drug causes nausea as a side effect. Ginger taken prior to 8-MOP may substantially reduce this side effect. This study compared patients' nausea when taking 8-MOP with and without ginger. PMID:7646942

  2. The genotoxicity of UVA irradiation in Drosophila melanogaster and the synergistic action of 8-methoxypsoralen and UVA.

    PubMed

    Negishi, T; Tanabe, F; Hayatsu, H

    1992-08-01

    To study the genotoxicity of near-ultraviolet light (UVA) on a whole body, Drosophila melanogaster larvae were irradiated with UVA and the emerging flies were examined for the mutant wing spot formation. The genotoxicity of UVA was also assayed with the in vivo DNA-repair test using males with repair-deficiency at the mei-9 and mei-41 locus and the matching repair-proficient females. Third-instar larvae were placed in a plastic Petri dish, which was covered with soft glass, and irradiated with black light at 4-5 W/m2. This irradiation resulted in an increase in mutant wing-hair spots. After a 15 h irradiation (approximately 240 kJ/m2), the mutant clone frequencies found in the adult flies (spots/wing) were: 1.68 for the small single spots, 0.38 for the large single spots and 0.11 for the twin spots, while at zero time they were 0.68, 0.06 and 0.02 respectively. On the other hand, the UVA irradiation was negative in the in vivo DNA-repair test, indicating that the UVA-induced DNA lesion may not be subject to repair by the mei-9 and mei-41 functions. The presence of 8-methoxypsoralen (8-MOP) during the irradiation remarkably enhanced somatic mutations, and showed a strong DNA-damaging effect in the repair test. For example, a 15 h UVA irradiation with 26.7 microM 8-MOP resulted in a 14-fold increase in the number of twin spots per wing as compared with the frequency obtained on treatment with UVA alone. Treatment of the larvae with 8-MOP alone gave no mutant clones or DNA damage. A high frequency in twin spot formation was also observed in this UVA + 8-MOP treatment, indicating that extensive chromosomal recombinations took place in the somatic cells. PMID:1499094

  3. Kinetics of (/sup 14/C-5) 8-methoxypsoralen uptake by UVA irradiated and non-irradiated rabbit eye tissues

    SciTech Connect

    Malinin, G.I.; Glew, W.B.; Roberts, W.P.; Nigra, T.P.

    1981-05-01

    Total 8-methoxypsoralen (8-MOP) in intact and UVA irradiated rabbit eye tissues and its unaltered fraction in aqueous and eye lenses were determined over the 24 hours after i.v. injection of (/sup 14/C-5) and carrier 8-MOP at the concentration of 50 microCi and 5 mg/kg. No 8-MOP was detected at the end of 24 hours in intact and irradiated aqueous, vitreous and retina in contrast to one hour when the respective levels were congruent to 220, greater than 0 and congruent to 160 ng/g. Eye-plasma drug concentration ratios were less than 0.5 initially, but increased thereafter. While the average lens 8-MOP levels of congruent to 140 ng/g remained unchanged for 24 hours, no unaltered drug was detected beyond eight hours. Measurable amounts of label at the end of 24 hours also persisted in the cornea, iris, sclera and conjunctiva.

  4. 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. PMID:27427773

  5. Studies of DNA and chromosome damage in skin fibroblasts and blood lymphocytes from psoriasis patients treated with 8-methoxypsoralen and UVA irradiation

    SciTech Connect

    Bredberg, A.; Lambert, B.; Lindblad, A.; Swanbeck, G.; Wennersten, G.

    1983-08-01

    Exposure of human lymphocytes and skin fibroblasts in vitro to a single, clinically used dose of PUVA, i.e., 0.1 micrograms/ml of 8-methoxypsoralen (8-MOP) plus 0.9-4 J/cm2 of longwave ultraviolet radiation (UVA), lead to the formation of DNA damage as determined by alkaline elution, and to chromosome aberrations and sister chromatid exchanges (SCE). When lymphocyte-enriched plasma was obtained from psoriasis patients 2 h after oral intake of 8-MOP and then UVA irradiated (1.8-3.6 J/cm2) in vitro, an increased frequency of chromosome aberrations and SCE was observed. Normal levels of chromosome aberrations and SCE were found in lymphocytes of psoriasis patients after 3-30 weeks of PUVA treatment in vivo. A small but statistically significant increase in the SCE frequency was observed in the lymphocytes of psoriasis patients treated for 1-6 years with PUVA (mean 18.0 SCE/cell) as compared with before PUVA (mean 15.8, p less than 0.05). Skin fibroblasts of psoriasis patients analyzed 5 years after the start of PUVA treatment showed a normal number of SCE but a high fraction of filter-retained DNA in the alkaline elution assay, suggesting the presence of cross-linked DNA.

  6. Effects of 8-methoxypsoralen plus 365 nm UVA light on Candida albicans cells. An electron microscopic study.

    PubMed

    Scherwitz, C; Rassner, G; Martin, R

    1978-09-28

    Candida (C) albicans cells were exposed to 8-Methoxypsoralen (8-MOP) concentrations of 1.0 microgram/ml and 10.0 microgram/ml medium and irradiated with 365 nm light. The amount of energy emitted was 4.8 J/cm2. Two divergent types of cell damage occured concerning yeast cell cytoplasm and cell wall. Two hours after exposure cytoplasmic changes involving mitochondria, which showed irregularities in shape, blurred appearance or loss of mitochondrial cristae and outer membrane were seen. The number of vacuoles was increased. The cytoplasm showed large electron transparent areas, the cytoplasmic membrane disappeared in some areas completely. Nucleus and nuclear envelope usually remained intact in early stages. 24h after exposure conspicuous cell wall alterations were observed in addition to cytoplasmic changes. Newly produced cell wall material formed ball-like protrusions or was adherent sickle-shaped to the cell wall. The investigations strongly suggest that the results found after 8-MOP-UVA treatment of C. albicans cells can not be interpreted in the sense of a general cytotoxic effect. Apparently it takes the form of a combination of events involving regressive and progressive alterations. PMID:363068

  7. Effects of 8-methoxypsoralen plus 365 nm UVA light on Candida albicans cells. An electron microscopic study.

    PubMed

    Scherwitz, C; Rassner, G; Martin, R

    1978-01-01

    Candida (C.) albicans cells were exposed to 8-Methoxypsoralen (8-MOP) concentrations of 1.0 microgram/ml and 10.0 micrograms/ml medium and irradiated with 365 nm light. The amount of energy emitted was 4.8 J/cm2. Two divergent types of cell damage occured concerning yeast cell cytoplasm and cell wall. Two hours after exposure cytoplasmic changes involving mitochondria, which showed irregularities in shape, blurred appearance or loss of mitochondrial cristae and outer membrane were seen. The number of vacuoles was increased. The cytoplasm showed large electron transparent areas, the cytoplasmic membrane disappeared in some areas completely. Nucleus and nuclear envelope usually remained intact in early stages. 24 h after exposure conspicuous cell wall alterations were observed in addition to cytoplasmic changes. Newly produced cell wall material formed ball-like protrusions or was adherent sickle-shaped to the cell wall. The investigations strongly suggest that the results found after 8-MOP-UVA treatment of C. albicans cells can not be interpreted in the sense of a general cytotoxic effect. Apparently it takes the form of a combination of events involving regressive and progressive alterations. PMID:394689

  8. Human UVA exposures estimated from ambient UVA measurements.

    PubMed

    Kimlin, Michael G; Parisi, Alfio V; Downs, Nathan D

    2003-04-01

    The methods presented in this paper allow for the estimation of human UVA exposure using measured UVA irradiance values. Using measured broadband UVA irradiances over the period of a year, it was estimated that for humans in an upright posture and not moving the head with respect to the body, the nose received 26.5% of the available ambient UVA radiation, whilst the shoulders and vertex of the head received 81% and 100% respectively of the available ambient UVA radiation. Measurement of the exposure ratios for a series of solar zenith angles between 90 degrees and 0 degrees will allow extension of this technique to other latitudes. PMID:12760531

  9. Arctostaphylos uva urai, Bearberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Encylopedia of Fruit and Nuts is designed as a research reference source on temperate and tropical fruit and nut crops. Bearberry or kinnikinnick [Arctostaphylos uva-ursi (L.) Spreng., Ericaceae], has a circumboreal distribution. Most Arctostaphylos species (i.e A. patula Greene, A. viscida Parr...

  10. The biological effects of UVA radiation

    SciTech Connect

    Urbach, F.; Gange, R.

    1986-01-01

    Interest in the biological effects of longwave radiation has increased dramatically in the last few years. The contributors to this state of the art volume discuss the most current knowledge of biological effects of UVA and provide guidelines regarding acceptable human exposure to this type of radiation. Contents include: historical aspects of UVA effects; mechanisms of UVA photosensitization; photorecovery by UVA; photoaugmentation of UVB effects by UVA; effects of UVA radiation on tissues of the eye; new UVA sunscreen; and recommendations for future research and possible actions.

  11. Photopheresis with UV-A light and 8-methoxypsoralen leads to cell death and to release of blebs with anti-inflammatory phenotype in activated and non-activated lymphocytes

    SciTech Connect

    Stadler, K.; Frey, B.; Munoz, L.E.; Finzel, S.; Rech, J.; Fietkau, R.; Herrmann, M.; Hueber, A.; Gaipl, U.S.

    2009-08-14

    Background: Extracorporeal photopheresis is a therapy for treatment of autoimmune diseases, cutaneous T-cell lymphoma, organ graft rejection as well as graft-versus-host diseases. The exact mechanism how the combination of 8-methoxypsoralen plus UV-A irradiation (PUVA) acts is still unclear. We investigated the cell death of activated and non-activated lymphocytes after PUVA treatment as well as the rate of released blebs and their antigen composition. Results: In presence of 8-MOP, UV-A light highly significantly increased the cell death of activated lymphocytes. The same was observed to a lesser extent in non-activated cells. Blebs derived from activated lymphocytes after PUVA treatment showed the highest surface exposition of phosphatidylserine. These blebs also displayed a high exposure of the antigens CD5 and CD8 as well as a low exposure of CD28 and CD86. Conclusion: PUVA treatment exerts anti-inflammatory effects by inducing apoptosis and apoptotic cell-derived blebs with immune suppressive surface composition.

  12. Protein oxidation, UVA and human DNA repair.

    PubMed

    Karran, Peter; Brem, Reto

    2016-08-01

    Solar UVB is carcinogenic. Nucleotide excision repair (NER) counteracts the carcinogenicity of UVB by excising potentially mutagenic UVB-induced DNA lesions. Despite this capacity for DNA repair, non-melanoma skin cancers and apparently normal sun-exposed skin contain huge numbers of mutations that are mostly attributable to unrepaired UVB-induced DNA lesions. UVA is about 20-times more abundant than UVB in incident sunlight. It does cause some DNA damage but this does not fully account for its biological impact. The effects of solar UVA are mediated by its interactions with cellular photosensitizers that generate reactive oxygen species (ROS) and induce oxidative stress. The proteome is a significant target for damage by UVA-induced ROS. In cultured human cells, UVA-induced oxidation of DNA repair proteins inhibits DNA repair. This article addresses the possible role of oxidative stress and protein oxidation in determining DNA repair efficiency - with particular reference to NER and skin cancer risk. PMID:27324272

  13. Influence of solar UVA on erythemal irradiances.

    PubMed

    Parisi, A V; Turnbull, D J; Kimlin, M G

    2006-06-21

    Many materials in everyday use such as window glass in homes and offices, glass in sunrooms and greenhouses, vehicle glass and some brands of sunscreens act as a barrier to the shorter UVB wavelengths while transmitting some of the longer UVA wavelengths. This paper reports on the erythemal exposures due to the UVA waveband encountered over a 12-month period for a solar zenith angle (SZA) range of 4 degrees to 80 degrees and the resulting times required for an erythemal exposure of one standard erythemal dose (SED) due to the erythemal exposures to the UVA wavelengths. The minimum time for an exposure of one SED due to the UVA wavelengths in winter is approximately double that what it is in summer. The time period of 40 to 60 min was the most frequent length of time for an exposure of one SED with 60 to 80 min the next frequent length of time required for a one SED exposure. PMID:16757874

  14. In vitro UV-A protection factor (PF-UVA) of organic and inorganic sunscreens.

    PubMed

    Couteau, C; El-Boury, S; Paparis, E; Sébille-Rivain, V; Coiffard, L J M

    2009-01-01

    The objective of this research was to evaluate the efficacy of various sunscreen agents incorporated into an O/W emulsion. Within the scope of this study only an in vitro method was used. According to selected filter UVA, we can obtain more or less effective creams. With the seven available filters, we can cover a range of values between 2 and 12. In addition to these seven filters absorbing in UVA range, variously coated titanium dioxide and zinc oxide were tested as well. So it appears that the best organic UVA filter is anisotriazine at 10% (PF-UVA = 11.82). Its effectiveness is comparable with that of the titanium dioxide forms used at 25%. Photostability in Suntest showed that the more photostable UVA-filters are the benzophenones. PMID:19630696

  15. Synergistic damage by UVA radiation and pollutants.

    PubMed

    Burke, K E; Wei, H

    2009-01-01

    Not only is skin cancer by far the most common human cancer but also the incidence of skin cancer has been increasing at an alarming rate in recent decades. Fortunately, most people now realize that sun exposure causes unattractive photoaging and skin cancer, so they do apply sunscreens conscientiously. However, until recently, most sunscreens did not adequately protect against ultraviolet A (UVA) radiation. Although UVA is indeed less erythrogenic and less carcinogenic than UVB, UVA directly causes photoaging and enhances UVB-induced skin cancer. Furthermore, recent research demonstrates that UVA combined with environmental pollutants (including cigarette smoke) significantly increases the risk of skin cancer. Similarly, previous research demonstrated another synergy between environmental pollutants and UV: When ozone exposure precedes UV exposure, there is enhancement of UV-induced depletion of protective vitamin E from the skin's stratum corneum. This article reviews experimental evidence that environmental pollutants (such as benzo[a]pyrene (BaP), a commonly used index of environmental pollution) are photosensitizers that generate reactive oxygen species (ROS) when exposed to UVA radiation. This in turn causes oxidative and genetic damage, leading to unattractive photodamage and carcinogenesis. PMID:19651790

  16. Diversity of Biological Effects Induced by Longwave UVA Rays (UVA1) in Reconstructed Skin

    PubMed Central

    Marionnet, Claire; Pierrard, Cécile; Golebiewski, Christelle; Bernerd, Françoise

    2014-01-01

    Despite their preponderance amongst the ultraviolet (UV) range received on Earth, the biological impacts of longwave UVA1 rays (340–400 nm) upon human skin have not been investigated so thoroughly. Nevertheless, recent studies have proven their harmful effects and involvement in carcinogenesis and immunosuppression. In this work, an in vitro reconstructed human skin model was used for exploring the effects of UVA1 at molecular, cellular and tissue levels. A biological impact of UVA1 throughout the whole reconstructed skin structure could be evidenced, from morphology to gene expression analysis. UVA1 induced immediate injuries such as generation of reactive oxygen species and thymine dimers DNA damage, accumulating preferentially in dermal fibroblasts and basal keratinocytes, followed by significant cellular alterations, such as fibroblast apoptosis and lipid peroxidation. The full genome transcriptomic study showed a clear UVA1 molecular signature with the modulation of expression of 461 and 480 genes in epidermal keratinocytes and dermal fibroblasts, respectively (fold change> = 1.5 and adjusted p value<0.001). Functional enrichment analysis using GO, KEGG pathways and bibliographic analysis revealed a real stress with up-regulation of genes encoding heat shock proteins or involved in oxidative stress response. UVA1 also affected a wide panel of pathways and functions including cancer, proliferation, apoptosis and development, extracellular matrix and metabolism of lipids and glucose. Strikingly, one quarter of modulated genes was related to innate immunity: genes involved in inflammation were strongly up-regulated while genes involved in antiviral defense were severely down-regulated. These transcriptomic data were confirmed in dose-response and time course experiments using quantitative PCR and protein quantification. Links between the evidenced UVA1-induced impacts and clinical consequences of UVA1 exposure such as photo-aging, photo

  17. Diversity of biological effects induced by longwave UVA rays (UVA1) in reconstructed skin.

    PubMed

    Marionnet, Claire; Pierrard, Cécile; Golebiewski, Christelle; Bernerd, Françoise

    2014-01-01

    Despite their preponderance amongst the ultraviolet (UV) range received on Earth, the biological impacts of longwave UVA1 rays (340-400 nm) upon human skin have not been investigated so thoroughly. Nevertheless, recent studies have proven their harmful effects and involvement in carcinogenesis and immunosuppression. In this work, an in vitro reconstructed human skin model was used for exploring the effects of UVA1 at molecular, cellular and tissue levels. A biological impact of UVA1 throughout the whole reconstructed skin structure could be evidenced, from morphology to gene expression analysis. UVA1 induced immediate injuries such as generation of reactive oxygen species and thymine dimers DNA damage, accumulating preferentially in dermal fibroblasts and basal keratinocytes, followed by significant cellular alterations, such as fibroblast apoptosis and lipid peroxidation. The full genome transcriptomic study showed a clear UVA1 molecular signature with the modulation of expression of 461 and 480 genes in epidermal keratinocytes and dermal fibroblasts, respectively (fold change> = 1.5 and adjusted p value<0.001). Functional enrichment analysis using GO, KEGG pathways and bibliographic analysis revealed a real stress with up-regulation of genes encoding heat shock proteins or involved in oxidative stress response. UVA1 also affected a wide panel of pathways and functions including cancer, proliferation, apoptosis and development, extracellular matrix and metabolism of lipids and glucose. Strikingly, one quarter of modulated genes was related to innate immunity: genes involved in inflammation were strongly up-regulated while genes involved in antiviral defense were severely down-regulated. These transcriptomic data were confirmed in dose-response and time course experiments using quantitative PCR and protein quantification. Links between the evidenced UVA1-induced impacts and clinical consequences of UVA1 exposure such as photo-aging, photo-immunosuppression and

  18. UVA system for human cornea irradiation

    NASA Astrophysics Data System (ADS)

    Pereira, Fernando R. A.; Stefani, Mario; Otoboni, José A.; Richter, Eduardo H.; Rossi, Giuliano; Mota, Alessandro D.; Ventura, Liliane

    2009-02-01

    According to recent studies, an increase in corneal stiffness is a promising alternative for avoiding ectasias and for stagnating keratoconus of grades 1 and 2. The clinical treatment consists essentially of instilling Riboflavin (vitamin B2), in the cornea and then irradiating the corneal tissue, with UVA (365nm) radiation at 3mW/cm2 for 30min. This procedure provides collagen cross-linking in the corneal surface, increasing its stiffness. This work presents a system for UVA irradiation of the corneas at a peak wavelength of 365nm with adjustable power up to 5mW. The system has closed loop electronics to control the emitted power with 20% precision from the sated power output. The system is a prototype for performing corneal cross-linking and has been clinically tested. The closed loop electronics is a differential from the equipments available on the market.

  19. Utilising polyphenylene oxide for high exposure solar UVA dosimetry

    NASA Astrophysics Data System (ADS)

    Turnbull, D. J.; Schouten, P. W.

    2008-05-01

    A personal UV dosimeter that can quantitatively assess high exposure solar UVA exposures has been developed. The chemical polyphenylene oxide has been previously reported on its ability to measure high UVB exposures. This current research has found that polyphenylene oxide, cast in thin film form, is responsive to both the UVA and UVB parts of the solar spectrum. Further to this, the UVB wavelengths were filtered out with the use of mylar. This combined system responded to the UVA wavelengths only and underwent a change in optical absorbance as a result of UVA exposure. Preliminary results indicate that this UVA dosimeter saturates steadily when exposed to sunlight and can measure exposures of more than 20 MJ/m2 of solar UVA radiation with an uncertainty level of no more than ±5%.

  20. New insights in photoaging, UVA induced damage and skin types.

    PubMed

    Battie, Claire; Jitsukawa, Setsuko; Bernerd, Françoise; Del Bino, Sandra; Marionnet, Claire; Verschoore, Michèle

    2014-10-01

    UVA radiation is the most prevalent component of solar UV radiation; it deeply penetrates into the skin and induces profound alterations of the dermal connective tissue. In recent years, the detrimental effects of UVA radiation were more precisely demonstrated at cellular and molecular levels, using adequate methods to identify biological targets of UVA radiation and the resulting cascade impairment of cell functions and tissue degradation. In particular gene expression studies recently revealed that UVA radiation induces modulation of several genes confirming the high sensitivity of dermal fibroblasts to UVA radiation. The major visible damaging effects of UVA radiation only appear after years of exposure: it has been clearly evidenced that they are responsible for more or less early signs of photoageing and photocarcinogenesis. UVA radiation appears to play a key role in pigmented changes occurring with age, the major sign of skin photoaging in Asians. Skin susceptibility to photoaging alterations also depends on constitutive pigmentation. The skin sensitivity to UV light has been demonstrated to be linked to skin color type. PMID:25234829

  1. Vegetable surface sterilization system using UVA light-emitting diodes.

    PubMed

    Aihara, Mutsumi; Lian, Xin; Shimohata, Takaaki; Uebanso, Takashi; Mawatari, Kazuaki; Harada, Yumi; Akutagawa, Masatake; Kinouchi, Yohsuke; Takahashi, Akira

    2014-01-01

    Surface sterilization of fresh produce has been needed in the food manufacturing/processing industry. Here we report a UVA-LED (Ultra Violet A-Light Emitting Diode) system for surface sterilization that is safe, efficacious, low cost, and apparently harmless to fresh produce. To test the system, Escherichia coli strain DH5α was spot-inoculated onto vegetable tissues, and treated under UVA-LED. Tissues were homogenized and bacteria quantified by colony-forming assay. Possible effects of UVA-LED on vegetable quality were evaluated by HPLC. Tissue weight changes were checked after treatment at 4℃, 15℃, and 30℃. Bacterial inactivation by UVA-LED radiation was observed after a 10 min treatment and increased with increasing time of irradiation. The log survival ratio reached -3.23 after a 90 min treatment. Bacterial cells surviving treatment grew slowly compared to non-irradiated control cells. Cabbage tissue lost weight over time after treatment, and weight loss increased with increasing incubation temperature, but there was no difference between losses by UVA-LED treated and control tissues at any temperature tested. In addition, no differences of Vitamin C content in cabbage tissue were detected by HPLC after UVA-LED treatment. These results suggest that UVA-LED treatment has great potential for vegetable surface sterilization in the food manufacturing/processing industry. PMID:25264046

  2. Fluid flow dynamics in MAS systems

    NASA Astrophysics Data System (ADS)

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3 mm-rotor diameter has been analyzed for spinning rates up to 67 kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3 mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7 mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.

  3. Fluid flow dynamics in MAS systems.

    PubMed

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3mm-rotor diameter has been analyzed for spinning rates up to 67kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor. PMID:26073599

  4. Microvascular leakage of plasma proteins after PUVA and UVA

    SciTech Connect

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

    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 and is not based on a preexisting psoriasis.

  5. MAS NMR of HIV-1 protein assemblies

    NASA Astrophysics Data System (ADS)

    Suiter, Christopher L.; Quinn, Caitlin M.; Lu, Manman; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-04-01

    The negative global impact of the AIDS pandemic is well known. In this perspective article, the utility of magic angle spinning (MAS) NMR spectroscopy to answer pressing questions related to the structure and dynamics of HIV-1 protein assemblies is examined. In recent years, MAS NMR has undergone major technological developments enabling studies of large viral assemblies. We discuss some of these evolving methods and technologies and provide a perspective on the current state of MAS NMR as applied to the investigations into structure and dynamics of HIV-1 assemblies of CA capsid protein and of Gag maturation intermediates.

  6. MAS NMR of HIV-1 protein assemblies.

    PubMed

    Suiter, Christopher L; Quinn, Caitlin M; Lu, Manman; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-04-01

    The negative global impact of the AIDS pandemic is well known. In this perspective article, the utility of magic angle spinning (MAS) NMR spectroscopy to answer pressing questions related to the structure and dynamics of HIV-1 protein assemblies is examined. In recent years, MAS NMR has undergone major technological developments enabling studies of large viral assemblies. We discuss some of these evolving methods and technologies and provide a perspective on the current state of MAS NMR as applied to the investigations into structure and dynamics of HIV-1 assemblies of CA capsid protein and of Gag maturation intermediates. PMID:25797001

  7. 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

  8. Photopatch test reactivity: effect of photoallergen concentration and UVA dosaging.

    PubMed

    Hasan, T; Jansen, C T

    1996-06-01

    We have studied the influence of variations in allergen concentration and UVA dosaging on the results of photopatch testing with the Scandinavian standard photopatch series in 29 patients with photocontact and/or contact allergy to 1 or several of the allergens in that series. Photocontact test reactions were more sensitive to allergen dilution than plain contact test reactions. Even dilution from the standard 5% to 2.5% significantly reduced para-aminobenzoic acid photocontact test reactions. Reducing the UVA dose from the standard 5 J/cm2 to 2.5 or 1 J/cm2 in 2 out of 5 cases turned a significant (++) reaction into a doubtful one (+). Increasing the standard UVA dose of 5 J/ cm2 to 20-40 J/cm2 turned a single + photocontact reaction to trichlorcarbanilide and a single 1 + plain contact reaction to chlorhexidine into ++ reactions. In the majority of cases, however, neither photocontact nor plain contact test reactions were augemented by UVA doses up to 80 J/cm2. We conclude that a UVA dose of 5 J/cm2 is sufficient for eliciting photocontact allergic test reactions, and that a reduction of either the UVA dose level or the standard allergen concentrations of the Scandinavian photopatch test guidelines may cause loss of significant photocontact test reactions in a proportion of the cases. PMID:8879921

  9. Mas' Making and Pedagogy: Imagined Possibilities

    ERIC Educational Resources Information Center

    Fournillier, Janice B.

    2009-01-01

    In this article I draw on an ethnographic case study that examined mas' makers' perceptions of the learning/teaching practices at work in the production of costumes for Trinidad and Tobago's annual Carnival celebrations. During the 2005 Carnival season I spent four months in the field, my country of birth, and collected data through participant…

  10. UVA1 radiation triggers two different final apoptotic pathways.

    PubMed

    Godar, D E

    1999-01-01

    Because ultraviolet-A1 (UVA1; 340-400 nm) radiation is used therapeutically, this in vitro study addressed the question "how does it work?" To begin addressing this question, UVA1 radiation was first established to reduce the survival of transformed T and B lymphocytes in a linear dose-dependent manner using clonogenic reproductive assays, and that cell death occurs by apoptosis using transmission electron microscopy, Annexin V, and flow cytometry. The primary mechanism was determined to be immediate pre-programmed cell death, an apoptotic mechanism that does not require protein synthesis post-insult, by quantifying the apoptotic cells over time in the absence or presence of a translation inhibitor. To explore how UVA1 radiation induces immediate pre-programmed cell death apoptosis, reactive oxygen species and mitochondrial activity were altered during exposure using a variety of agents, while a specific fluorescent probe, 5,5',6,6'tetrachloro- 1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide, was used to examine mitochondrial transmembrane depolarization. To show that UVA1 mediates singlet-oxygen damage to the mitochondrial membranes, X-rays, UVB (290-320 nm), 8-methoxypsoralen and UVA, vitamin K3, anti-Fas antibody, and blocking antibody were the negative controls, while rose bengal or protoporphyrin IX with visible light were the positive controls. Cyclosporine A, which inhibits the mitochondrial megapore from opening, was used with singlet-oxygen and superoxide-anion generators to distinguish between the two final apoptotic pathways. The collective results show that UVA1 radiation primarily mediates singlet-oxygen damage triggering immediate pre-programmed cell death apoptosis (T < 20 min) by immediately opening the cyclosporine A-sensitive ("S" site) mitochondrial megapore, while superoxide anions initiate another cyclosporine A-insensitive ("P" site) final apoptotic pathway. PMID:9886256

  11. Ultra-low temperature MAS-DNP

    NASA Astrophysics Data System (ADS)

    Lee, Daniel; Bouleau, Eric; Saint-Bonnet, Pierre; Hediger, Sabine; De Paëpe, Gaël

    2016-03-01

    Since the infancy of NMR spectroscopy, sensitivity and resolution have been the limiting factors of the technique. Regular essential developments on this front have led to the widely applicable, versatile, and powerful spectroscopy that we know today. However, the Holy Grail of ultimate sensitivity and resolution is not yet reached, and technical improvements are still ongoing. Hence, high-field dynamic nuclear polarization (DNP) making use of high-frequency, high-power microwave irradiation of electron spins has become very promising in combination with magic angle sample spinning (MAS) solid-state NMR experiments. This is because it leads to a transfer of the much larger polarization of these electron spins under suitable irradiation to surrounding nuclei, greatly increasing NMR sensitivity. Currently, this boom in MAS-DNP is mainly performed at minimum sample temperatures of about 100 K, using cold nitrogen gas to pneumatically spin and cool the sample. This Perspective deals with the desire to improve further the sensitivity and resolution by providing "ultra"-low temperatures for MAS-DNP, using cryogenic helium gas. Different designs on how this technological challenge has been overcome are described. It is shown that stable and fast spinning can be attained for sample temperatures down to 30 K using a large cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas brings the additional advantage of sample spinning frequencies that can greatly surpass those achievable with nitrogen gas, due to the differing fluidic properties of these two gases. It is shown that using ultra-low temperatures for MAS-DNP results in substantial experimental sensitivity enhancements and according time-savings. Access to this temperature range is demonstrated to be both viable and highly pertinent.

  12. Ultra-low temperature MAS-DNP.

    PubMed

    Lee, Daniel; Bouleau, Eric; Saint-Bonnet, Pierre; Hediger, Sabine; De Paëpe, Gaël

    2016-03-01

    Since the infancy of NMR spectroscopy, sensitivity and resolution have been the limiting factors of the technique. Regular essential developments on this front have led to the widely applicable, versatile, and powerful spectroscopy that we know today. However, the Holy Grail of ultimate sensitivity and resolution is not yet reached, and technical improvements are still ongoing. Hence, high-field dynamic nuclear polarization (DNP) making use of high-frequency, high-power microwave irradiation of electron spins has become very promising in combination with magic angle sample spinning (MAS) solid-state NMR experiments. This is because it leads to a transfer of the much larger polarization of these electron spins under suitable irradiation to surrounding nuclei, greatly increasing NMR sensitivity. Currently, this boom in MAS-DNP is mainly performed at minimum sample temperatures of about 100K, using cold nitrogen gas to pneumatically spin and cool the sample. This Perspective deals with the desire to improve further the sensitivity and resolution by providing "ultra"-low temperatures for MAS-DNP, using cryogenic helium gas. Different designs on how this technological challenge has been overcome are described. It is shown that stable and fast spinning can be attained for sample temperatures down to 30K using a large cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas brings the additional advantage of sample spinning frequencies that can greatly surpass those achievable with nitrogen gas, due to the differing fluidic properties of these two gases. It is shown that using ultra-low temperatures for MAS-DNP results in substantial experimental sensitivity enhancements and according time-savings. Access to this temperature range is demonstrated to be both viable and highly pertinent. PMID:26920837

  13. UVA Phototransduction Drives Early Melanin Synthesis in Human Melanocytes

    PubMed Central

    Wicks, Nadine L.; Chan, Jason W.; Najera, Julia A.; Ciriello, Jonathan M.; Oancea, Elena

    2013-01-01

    Summary Exposure of human skin to solar ultraviolet radiation (UVR), a powerful carcinogen [1] comprising ~95% UVA and ~5% 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 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 five-fold after 24 hours. 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. PMID:22055294

  14. Application of radiochromic gel detector (FXG) for UVA dose measurements

    NASA Astrophysics Data System (ADS)

    Abukassem, Issam; Bero, Mamdouh A.

    2010-12-01

    Tissue equivalent radiochromic gel material containing ferrous ions, xylenol-orange ion indicator and gelatin as gelling agent (FXG) is known to be sensitive to γ- and X-rays; hence it has been used for ionizing radiation dosimetry. Changes in optical absorbance properties of FXG material over a wide region in the visible spectrum were found to be proportional to the radiation absorbed dose. An earlier study demonstrated the sensitivity of FXG gel detector to ultraviolet radiation and therefore that could give quantitative measure for UV exposure. This study focuses on the detection of UVA radiation (315-400 nm), which forms an important part (˜97%) of the natural solar UV radiation reaching the earth surface. A solar UV simulator device was used to deliver UVA radiation to FXG samples. The beam was optically modified to irradiate gel samples at an exposure level about 58 W/m 2, which is comparable to the summer natural UVA radiation measured outside the laboratory building at midday (˜60 W/m 2). Experimental results were used to generate mathematical second order formulas that give the relationship between UVA dose and optical absorbance changes observed at two wavelengths in the visible region of the spectrum—430 and 560 nm.

  15. NASA-UVa light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Swanson, Robert E.; Thornton, Earl A.; Wawner, Franklin E., Jr.

    1991-01-01

    The general objective of the NASA-UVa Light Aerospace Alloy and Structures Technology Program was to conduct research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures. The following research areas were actively investigated: (1) mechanical and environmental degradation mechanisms in advanced light metals and composites; (2) aerospace materials science; (3) mechanics of materials and composites for aerospace structures; and (4) thermal gradient structures.

  16. Sensing and Responding to UV-A in Cyanobacteria

    PubMed Central

    Moon, Yoon-Jung; Kim, Seung Il; Chung, Young-Ho

    2012-01-01

    Ultraviolet (UV) radiation can cause stresses or act as a photoregulatory signal depending on its wavelengths and fluence rates. Although the most harmful effects of UV on living cells are generally attributed to UV-B radiation, UV-A radiation can also affect many aspects of cellular processes. In cyanobacteria, most studies have concentrated on the damaging effect of UV and defense mechanisms to withstand UV stress. However, little is known about the activation mechanism of signaling components or their pathways which are implicated in the process following UV irradiation. Motile cyanobacteria use a very precise negative phototaxis signaling system to move away from high levels of solar radiation, which is an effective escape mechanism to avoid the detrimental effects of UV radiation. Recently, two different UV-A-induced signaling systems for regulating cyanobacterial phototaxis were characterized at the photophysiological and molecular levels. Here, we review the current understanding of the UV-A mediated signaling pathways in the context of the UV-A perception mechanism, early signaling components, and negative phototactic responses. In addition, increasing evidences supporting a role of pterins in response to UV radiation are discussed. We outline the effect of UV-induced cell damage, associated signaling molecules, and programmed cell death under UV-mediated oxidative stress. PMID:23208372

  17. Homogeneous UVA system for corneal cross-linking treatment

    NASA Astrophysics Data System (ADS)

    Ayres Pereira, Fernando R.; Stefani, Mario A.; Otoboni, José A.; Richter, Eduardo H.; Ventura, Liliane

    2010-02-01

    The treatment of keratoconus and corneal ulcers by collagen cross-linking using ultraviolet type A irradiation, combined with photo-sensitizer Riboflavin (vitamin B2), is a promising technique. The standard protocol suggests instilling Riboflavin in the pre-scratched cornea every 5min for 30min, during the UVA irradiation of the cornea at 3mW/cm2 for 30 min. This process leads to an increase of the biomechanical strength of the cornea, stopping the progression, or sometimes, even reversing Keratoconus. The collagen cross-linking can be achieved by many methods, but the utilization of UVA light, for this purpose, is ideal because of its possibility of a homogeneous treatment leading to an equal result along the treated area. We have developed a system, to be clinically used for treatment of unhealthy corneas using the cross-linking technique, which consists of an UVA emitting delivery device controlled by a closed loop system with high homogeneity. The system is tunable and delivers 3-5 mW/cm2, at 365nm, for three spots (6mm, 8mm and 10mm in diameter). The electronics close loop presents 1% of precision, leading to an overall error, after the calibration, of less than 10% and approximately 96% of homogeneity.

  18. Broadband Direct UVA irradiance measurement for clear skies evaluated using a smartphone.

    PubMed

    Igoe, D; Parisi, A V

    2015-12-01

    UVA wavelengths (320-400 nm) have been implicated in recent studies to contribute to melanoma induction and skin photoaging in humans and damage to plants. The use of smartphones in UVA observations is a way to supplement measurements made by traditional radiometric and spectroradiometric technology. Although the smartphone image sensor is not capable of determining broadband UVA irradiances, these can be reconstructed from narrowband irradiances, which the smartphone, with narrowband and neutral density filters, can quantify with discrepancies not exceeding 5 %. Three models that reconstruct direct broadband clear sky UVA were developed from narrowband irradiances derived from smartphone image sensor pixel data with coefficients of determination of between 0.97 and 0.99. Reasonable accuracy and precision in determining the direct broadband UVA was maintained for observations made with solar zenith angles as high as 70°. The developed method has the potential to increase the uptake of the measurement of broadband UVA irradiances. PMID:25449750

  19. UVA experimental and high energy physics. Final grant report

    SciTech Connect

    Cox, B.

    1999-10-07

    The period 1992--1997 was a mixture of frustrations and of accomplishments for the UVa HEP group. The experimental HEP group began this period with the completion of a truncated run of Experiment E771 at Fermilab in 1992. This experiment was designed to measure the cross section for beauty production in 800 GeV/c pN interactions. It succeeded in this goal as well as in obtaining one of the best limits on FCNC in charm decays by setting an upper limit on D{sup 0} {r_arrow} {mu}{sup +}{mu}{sup {minus}}. In addition, they were able to measure {Psi}, {Psi}, {chi}{sub 1},{chi}{sub 2} and upsilon production. Three UVa PhD theses have resulted from this experiment (as well as 12 other PhD's at other institutions). At the same time, the UVa experimental group was vigorously pursuing the goal of studying CP violation in B production. This took the form of a proposal to the SSC for a super fixed target facility, the SFT, which would focus on studies of B mesons. B. Cox was the spokesman of this experiment that had over thirty institutions. This proposal EOI-14 had a good reception by the SSC PAC. A R and D activity to prove the technique of crystal channeling was undertaken to prove the accelerator aspects of this proposal. This activity, known as E853 or CEX at Fermilab, resulted in proof of the crystal channeling technique as viable for the extraction of 20 TeV beam at the SSC. In addition to this activity, the UVa group investigated many other aspects of B physics at the SSC. They were among the leaders of the 1993 Snowmass meeting on B Physics at Hadronic Accelerators. The UVa HEP group worked vigorously on developing the ideas for B physics at the SSC, as evidenced by the many different studies listed in the publication list given, up to the very day the SSC was terminated by an act of Congress.

  20. 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

  1. 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

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

    PubMed

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

    2016-08-01

    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 (8J/cm(2)) 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

  3. Red light interferes in UVA-induced photoaging of human skin fibroblast cells.

    PubMed

    Niu, Tianhui; Tian, Yan; Ren, Qu; Wei, Lizhao; Li, Xiaoxin; Cai, Qing

    2014-01-01

    The possible regulation mechanism of red light was determined to discover how to retard UVA-induced skin photoaging. Human skin fibroblasts were cultured and irradiated with different doses of UVA, thus creating a photoaging model. Fibroblasts were also exposed to a subtoxic dose of UVA combined with a red light-emitting diode (LED) for five continuous days. Three groups were examined: control, UVA and UVA plus red light. Cumulative exposure doses of UVA were 25 J cm(-2), and the total doses of red light were 0.18 J cm(-2). Various indicators were measured before and after irradiation, including cell morphology, viability, β-galactosidase staining, apoptosis, cycle phase, the length of telomeres and the protein levels of photoaging-related genes. Red light irradiation retarded the cumulative low-dose UVA irradiation-induced skin photoaging, decreased the expression of senescence-associated β-galactosidase, upregulated SIRT1 expression, decreased matrix metalloproteinase MMP-1 and the acetylation of p53 expression, reduced the horizon of cell apoptosis and enhanced cell viability. Furthermore, the telomeres in UVA-treated cells were shortened compared to those of cells in the red light groups. These results suggest that red light plays a key role in the antiphotoaging of human skin fibroblasts by acting on different signaling transduction pathways. PMID:25039464

  4. 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. PMID:24691875

  5. 48 CFR 538.272 - MAS price reductions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false MAS price reductions. 538... Schedules 538.272 MAS price reductions. (a) Section 552.238-75, Price Reductions, requires the contractor to maintain during the contract period the negotiated price/discount relationship (and/or term and...

  6. 48 CFR 538.272 - MAS price reductions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false MAS price reductions. 538... Schedules 538.272 MAS price reductions. (a) Section 552.238-75, Price Reductions, requires the contractor to maintain during the contract period the negotiated price/discount relationship (and/or term and...

  7. 48 CFR 538.272 - MAS price reductions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false MAS price reductions. 538... Schedules 538.272 MAS price reductions. (a) Section 552.238-75, Price Reductions, requires the contractor to maintain during the contract period the negotiated price/discount relationship (and/or term and...

  8. 48 CFR 538.272 - MAS price reductions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false MAS price reductions. 538... Schedules 538.272 MAS price reductions. (a) Section 552.238-75, Price Reductions, requires the contractor to maintain during the contract period the negotiated price/discount relationship (and/or term and...

  9. Essential role of Nrf2 in keratinocyte protection from UVA by quercetin

    SciTech Connect

    Kimura, Shintarou; Warabi, Eiji; Yanagawa, Toru; Ma, Dongmei; Itoh, Ken; Ishii, Yoshiyuki; Kawachi, Yasuhiro; Ishii, Tetsuro

    2009-09-11

    Much of the cell injury caused by ultraviolet A (UVA) irradiation is associated with oxidative stress. Quercetin is a major natural polyphenol that is known to protect cells from UVA-induced damage. Here, we investigated the molecular mechanism of this protection. Quercetin pretreatment strongly suppressed UVA-induced apoptosis in human keratinocyte HaCaT cells, markedly increased protein levels of the transcription factor Nrf2, induced the expression of antioxidative genes, and dramatically reduced the production of reactive oxygen species following UVA irradiation. Importantly, these beneficial effects were greatly attenuated by downregulating Nrf2 expression. Thus, quercetin protects cells from UVA damage mainly by elevating intracellular antioxidative activity via the enhanced accumulation of a transcription factor for antioxidant genes, Nrf2.

  10. Computational structures technology and UVA Center for CST

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1992-01-01

    Rapid advances in computer hardware have had a profound effect on various engineering and mechanics disciplines, including the materials, structures, and dynamics disciplines. A new technology, computational structures technology (CST), has recently emerged as an insightful blend between material modeling, structural and dynamic analysis and synthesis on the one hand, and other disciplines such as computer science, numerical analysis, and approximation theory, on the other hand. CST is an outgrowth of finite element methods developed over the last three decades. The focus of this presentation is on some aspects of CST which can impact future airframes and propulsion systems, as well as on the newly established University of Virginia (UVA) Center for CST. The background and goals for CST are described along with the motivations for developing CST, and a brief discussion is made on computational material modeling. We look at the future in terms of technical needs, computing environment, and research directions. The newly established UVA Center for CST is described. One of the research projects of the Center is described, and a brief summary of the presentation is given.

  11. Protective effect of UV-A radiation during acclimation of the photosynthetic apparatus to UV-B treatment.

    PubMed

    Štroch, Michal; Materová, Zuzana; Vrábl, Daniel; Karlický, Václav; Šigut, Ladislav; Nezval, Jakub; Špunda, Vladimír

    2015-11-01

    We examined the acclimation response of the photosynthetic apparatus of barley (Hordeum vulgare L.) to a combination of UV-A and UV-B radiation (UVAB) and to UV-B radiation alone. Our aim was to evaluate whether UV-A radiation prevents UV-B-induced damage to the photosynthetic apparatus and whether UV-A pre-acclimation is required to mitigate the negative influence of UV-B radiation. Barley plants were grown from seeds under low photosynthetically active radiation (50 μmol m(-2) s(-1)) either in the absence or presence of UV-A radiation (UVA- and UVA+ plants, respectively). After 8 days of development, plants were exposed simultaneously to UV-A and UV-B radiation for the next 6 days. Additionally, UVA- plants were exposed to UV-B radiation alone. The UVA+ plants had a higher CO2 assimilation rate near the light-saturation region (A(N)) and a higher content of both total chlorophylls (Chls) and total carotenoids than the UVA- plants. Chls content, A(N), the potential quantum yield of photosystem II (PSII) photochemistry (F(V)/F(M)), the capacity of light-induced thermal energy dissipation and the efficiency of excitation energy transfer within PSII remained the same or even increased in both UVA+ and UVA- plants after UVAB treatment. On the contrary, exposure of UVA- plants to UV-B radiation itself led to a reduction in all these characteristics. We revealed that the presence of UV-A radiation during UVAB treatment not only mitigated but completely eliminated the negative effect of UV-B radiation on the functioning of the photosynthetic apparatus and that UV-A pre-acclimation was not crucial for development of this UV-A-induced resistance against UV-B irradiation. PMID:26233710

  12. Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists.

    PubMed

    Muggeridge, David J; Sculthorpe, Nicholas; Grace, Fergal M; Willis, Gareth; Thornhill, Laurence; Weller, Richard B; James, Philip E; Easton, Chris

    2015-08-01

    Dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance. Acute exposure to ultraviolet (UV)-A light also increases NO bioavailability and reduces BP. We conducted a randomized, counterbalanced placebo-controlled trial to determine the effects of UV-A light alone and in combination with nitrate on the responses to sub-maximal steady-state exercise and time trial (TT) performance. Nine cyclists (VO2max 53.1 ± 4.4 ml/kg/min) completed five performance trials comprising 10 min submaximal steady-state cycling followed by a 16.1 km TT. Following a familiarization the final four trials were preceded, in random order, by either (1) Nitrate gels (NIT) + UV-A, (2) Placebo (PLA) + UV-A, (3) NIT + Sham light (SHAM) and (4) PLA + SHAM (control). The NIT gels (2 × 60 ml gels, ~8.1 mmol nitrate) or a low-nitrate PLA were ingested 2.5 h prior to the trial. The light exposure consisted of 20 J/cm(2) whole body irradiation with either UV-A or SHAM light. Plasma nitrite was measured pre- and post-irradiation and VO2 was measured continuously during steady-state exercise. Plasma nitrite was higher for NIT + SHAM (geometric mean (95% CI), 332 (292-377) nM; P = 0.029) and NIT + UV-A (456 (312-666) nM; P = 0.014) compared to PLA + SHAM (215 (167-277) nM). Differences between PLA + SHAM and PLA + UV-A (282 (248-356) nM) were small and non-significant. During steady-state exercise VO2 was reduced following NIT + UVA (P = 0.034) and tended to be lower in NIT + SHAM (P = 0.086) but not PLA + UV-A (P = 0.381) compared to PLA + SHAM. Performance in the TT was significantly faster following NIT + UV-A (mean ± SD 1447 ± 41 s P = 0.005; d = 0.47), but not PLA + UV-A (1450 ± 40 s; d = 0.41) or NIT + SHAM (1455 ± 47 s; d = 0.28) compared to PLA + SHAM (1469 ± 52 s). These findings demonstrate that exposure to UV-A light alone does not alter the physiological responses to exercise or improve

  13. Broad-spectrum moisturizer effectively prevents molecular reactions to UVA radiation.

    PubMed

    Seité, Sophie; Reinhold, Katja; Jaenicke, Thomas; Brenden, Heidi; Krutmann, Jean; Grether-Beck, Susanne

    2012-12-01

    The damaging effects of UVA radiation have been well-documented. UVA radiation is known to induce molecular, cellular, and clinical damage. Such harm may lead to photoaging, immune system depression, altered gene expression, or oncogene and tumor suppressor gene modulation, all of which are partly responsible for the development of skin cancer. In parallel to an increased understanding of the added damage caused by UVA radiation, progress has been made in sunscreen formulation. A variety of UVA filters are now available for formulators to combine with UVB filters to reach high-level photostable protection using a minimum concentration of active ingredients. The efficacy of products that contain these UV filter combinations usually is determined by noninvasive assessments, which cause either UVA-induced erythema or skin pigmentation. However, the biologic relevance of these end points for UVA radiation-induced skin damage is unknown. In our study, we confirm that the assessment of UVA radiation-induced gene expression in skin specimens obtained from UVA-irradiated human skin by quantitative real-time polymerase chain reaction is a sensitive, reliable, and robust method to prove the efficacy of 2 daily moisturizers containing broad-spectrum sunscreen. Specifically, we demonstrate in vivo that topical application of a daily moisturizer with broad-spectrum sunscreen prevents UVA radiation-induced transcriptional expression of genes that are directly linked to skin aging (ie, matrix metalloproteinase 1 [MMP-1]) and also reflect the skin's antioxidative stress defense response (ie, catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx]). Furthermore, we demonstrate that the protection against UV-induced skin damage provided by products with different sun protection factor (SPF) but the same UVA protection factor (UVA-PF) is similar, which emphasizes the importance of high UVA protection to maintain unaltered essential biologic functions. These data

  14. 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. PMID:26971278

  15. Direct detection of singlet oxygen generated by UVA irradiation in human cells and skin.

    PubMed

    Baier, Jürgen; Maisch, Tim; Maier, Max; Landthaler, Michael; Bäumler, Wolfgang

    2007-06-01

    UVA light produces deleterious biological effects in which singlet oxygen plays a major role. These effects comprise a significant risk of carcinogenesis in the skin and cataract formation of the eye lens. Singlet oxygen is generated by UVA light absorption in endogenous molecules present in the cells. To elucidate the primary processes and sources of singlet oxygen in tissue, it is a major goal to uncover the hidden process of singlet oxygen generation, in particular in living tissue. When exposing keratinocytes or human skin in vivo to UVA laser light (355 nm) at 6 J/cm2, we measured the luminescence of singlet oxygen at 1,270 nm. This is a positive and direct proof of singlet oxygen generation in cells and skin by UVA light. Moreover, a clear signal of singlet oxygen luminescence was detected in phosphatidylcholine suspensions (water or ethanol) irradiated by UVA. Oxidized products of phosphatidylcholine are the likely chromophores because phosphatidylcholine itself does not absorb at 355 nm. The signal intensity was reduced by mannitol or super oxide dismutase. Additionally, the monochromatic UVA irradiation at 355 nm leads to upregulation of the key cytokine IL-12. This affects the balance of UV radiation on the immune system, which is comparable to effects of broadband UVA irradiation. PMID:17363921

  16. 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. PMID:25535873

  17. 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. PMID:27401663

  18. Glutathione peroxidase-1 inhibits UVA-induced AP-2{alpha} expression in human keratinocytes

    SciTech Connect

    Yu Lei; Venkataraman, Sujatha; Coleman, Mitchell C.; Spitz, Douglas R.; Wertz, Philip W.; Domann, Frederick E. . E-mail: frederick-domann@uiowa.edu

    2006-12-29

    In this study, we found a role for H{sub 2}O{sub 2} in UVA-induced AP-2{alpha} expression in the HaCaT human keratinocyte cell line. UVA irradiation not only increased AP-2{alpha}, but also caused accumulation of H{sub 2}O{sub 2} in the cell culture media, and H{sub 2}O{sub 2} by itself could induce the expression of AP-2{alpha}. By catalyzing the removal of H{sub 2}O{sub 2} from cells through over-expression of GPx-1, induction of AP-2{alpha} expression by UVA was abolished. Induction of transcription factor AP-2{alpha} by UVA had been previously shown to be mediated through the second messenger ceramide. We found that not only UVA irradiation, but also H{sub 2}O{sub 2} by itself caused increases of ceramide in HaCaT cells, and C2-ceramide added to cells induced the AP-2{alpha} signaling pathway. Finally, forced expression of GPx-1 eliminated UVA-induced ceramide accumulation as well as AP-2{alpha} expression. Taken together, these findings suggest that GPx-1 inhibits UVA-induced AP-2{alpha} expression by suppressing the accumulation of H{sub 2}O{sub 2}.

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

    SciTech Connect

    Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul; Kang, Keon Wook

    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, we 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.

  20. Contribution of UVA irradiance to the erythema and photoaging effects in solar and sunbed exposures.

    PubMed

    Sola, Yolanda; Lorente, Jerónimo

    2015-02-01

    Even though UVA irradiance had not been considered detrimental to human skin for years, nowadays it is recognized for its role in photoaging and other biological responses. The ratio UVA/UVB is about 17 at a solar zenith angle (SZA) of 20° and it is almost constant up to 60° when it rapidly increases since the UVB wavelengths (280-320nm) are more attenuated than the UVA waveband (320-400nm). For a constant SZA, the ratio increases with the ozone content. The UVA component of the solar erythemal irradiance ranges from 20% at 20° to 30% at 60°, whereas it varies from 50% to 80% in the two different types of measured sunbeds. Moreover, the different spectral distribution of the lamps used for artificial tanning leads frequently to high UVA doses. The biological responses related to skin photoaging (skin sagging and elastosis) could be around fourfold the equivalent solar irradiance at midday in summer midlatitudes and they can be important in unprotected UVA exposures to sunbeds. The UVA dose accumulated during the time required in reaching 1 minimum erythemal dose (MED) increases with the SZA since the exposure durations are longer. Indeed, seasonal differences in the mean UVA dose are observed due to variations in the ozone content that results in longer exposure times without erythema. Although an artificial tanning session is usually shorter than one hour, the UVA dose from sunbeds during the time for 1 MED for skin type II (250Jm(-2)) can be 2-4 times larger than the solar dose, depending on the lamp spectral emission. PMID:25579807

  1. [Is UV-A a cause of malignant melanoma?].

    PubMed

    Moan, J

    1994-03-20

    The first action spectrum for cutaneous malignant melanoma was published recently (2). This spectrum was obtained using the fish Xiphophorus. If the same action spectrum applies to humans, the following statements are true: Sunbathing products (agents to protect against the sun) that absorb UV-B radiation provide almost no protection against cutaneous malignant melanoma. UV-A-solaria are more dangerous than expected so far. If people are determined to use artificial sources of radiation for tanning, they should choose UV-B-solaria rather than UV-A-solaria. Fluorescent tubes and halogen lamps may have weak melanomagnetic effects. Ozone depletion has almost no effect on the incidence rates of CMM, since ozone absorbs very little UV-A radiation. Sunbathing products which contain UV-A-absorbing compounds or neutral filters (like titanium oxide) provide real protection against cutaneous malignant melanoma, at least if they are photochemically inert. PMID:8191472

  2. First record of Tenuipalpus uvae De Leon, 1962 (Acari: Tenuipalpidae) in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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)....

  3. Ultraviolet radiation dose calculation for algal suspensions using UVA and UVB extinction coefficients.

    PubMed

    Navarro, Enrique; Muñiz, Selene; Korkaric, Muris; Wagner, Bettina; de Cáceres, Miquel; Behra, Renata

    2014-03-01

    Although the biological importance of ultraviolet light (UVR) attenuation has been recognised in marine and freshwater environments, it is not generally considered in in vitro ecotoxicological studies using algal cell suspensions. In this study, UVA and UVB extinction were determined for cultures of algae with varying cell densities, and the data were used to calculate the corresponding extinction coefficients for both UVA and UVB wavelength ranges. Integrating the Beer-Lambert equation to account for changes in the radiation intensity reaching each depth, from the surface until the bottom of the experimental vessel, we obtained the average UVA and UVB intensity to which the cultured algal cells were exposed. We found that UVR intensity measured at the surface of Chlamydomonas reinhardtii cultures lead to a overestimation of the UVR dose received by the algae by 2-40 times. The approach used in this study allowed for a more accurate estimation of UVA and UVB doses. PMID:24607609

  4. UVA-induced erythema, pigmentation, and skin surface temperature changes are irradiance dependent

    SciTech Connect

    Kagetsu, N.; Gange, R.W.; Parrish, J.A.

    1985-11-01

    Human cutaneous erythemogenic and melanogenic responses to long-wave (UVA) ultraviolet radiation were investigated using irradiances ranging from 5-50 mW/cm2. Skin surface temperature changes resulting from the different irradiances were also compared. In general, threshold doses for erythema and pigmentation were higher when UVA was administered at the lowest irradiance (5 mW/cm2) than at the highest (50 mW/cm2). Erythema was maximal immediately after exposure to UVA. The most intense responses (erythema with edema, or intense pigmentation) were induced more frequently by the highest irradiance. Components of both the erythema and the pigment response to UVA are therefore irradiance-dependent. The greatest increase in skin surface temperature was observed after exposure to the highest irradiance.

  5. UVA-induced damage to DNA and proteins: direct versus indirect photochemical processes

    NASA Astrophysics Data System (ADS)

    Girard, P. M.; Francesconi, S.; Pozzebon, M.; Graindorge, D.; Rochette, P.; Drouin, R.; Sage, E.

    2011-01-01

    UVA has long been known for generating an oxidative stress in cells. In this paper we review the different types of DNA damage induced by UVA, i.e. strand breaks, bipyrimidine photoproducts, and oxidatively damaged bases. Emphasis is given to the mechanism of formation that is further illustrated by the presentation of new in vitro data. Examples of oxidation of proteins involved in DNA metabolism are also given.

  6. DNA damage in human skin fibroblasts exposed to UVA light used in clinical PUVA treatment

    SciTech Connect

    Bredberg, A.

    1981-06-01

    Human skin fibroblasts were irradiated with a clinically used UVA light source. The doses (1.1 and 3 J/cm2) were similar to those reaching the dermis during clinical PUVA treatment of psoriasis. DNA strand breaks, as determined by alkaline elution, were formed in a dose-dependent way and disappeared within 1 hr of postincubation at 37 degrees C. These findings have clinical implications since UVA-induced DNA damage may be accompanied by mutagenic and tumor promoting effects.

  7. Epidermal changes in human skin following irradiation with either UVB or UVA

    SciTech Connect

    Pearse, A.D.; Gaskell, S.A.; Marks, R.

    1987-01-01

    We have demonstrated previously that following UVB irradiation to normal volunteers there is an increase in epidermal and stratum corneum thickness and an increase in the thymidine autoradiographic labeling index. These changes are coupled with alterations in epidermal glucose-6-phosphate dehydrogenase and succinic dehydrogenase activities, despite the absence of erythema clinically. The use of a sunscreen did not completely prevent these changes. In this study, we have examined the effects of repeated irradiation of human skin with either UVB or UVA alone in order to compare the changes produced in the epidermis and to ascertain whether UVA irradiation could cause these. Irradiation with either UVB or UVA alone was found to increase the mean epidermal thickness, the mean stratum corneum thickness, and mean keratinocyte height significantly. Glucose-6-phosphate dehydrogenase activity was significantly increased throughout the epidermis, and succinic dehydrogenase activity was significantly decreased. The autoradiographic labeling index was significantly increased following UVB irradiation but not following UVA irradiation. These results demonstrate that UVA alone can have a direct effect on epidermal morphology and metabolism, suggesting that protection of skin from UV radiation should include adequate protection from UVA.

  8. Effects of UVA radiation on an established immune response in humans and sunscreen efficacy.

    PubMed

    Moyal, Dominique D; Fourtanier, Anny M

    2002-01-01

    It is well established that ultraviolet radiation has immunomodulatory effects which may be involved in skin cancer. Recent studies have shown that UVA radiation (320-400 nm) as well as UVB (290-320 nm) is immunosuppressive. This means that sunscreens which mainly absorb UVB (protection against erythema) may be less effective in preventing UVR-induced immunosuppression than broad-spectrum products. We have studied the effects of UVA exposure on the human delayed-type hypersensitivity response (DTH) and compared the efficacy of sunscreens having different levels of UVA protection under both solar-simulated radiation (SSR) chronic exposures or acute exposure and outdoor real-life solar exposure conditions. DTH was assessed using recall antigens. Our studies clearly demonstrate the role of UVA in the induction of photoimmunosuppression together with the need for sunscreen products providing efficient photoprotection throughout the entire UV spectrum. These data suggest that sun protection factor may not be sufficient to predict the ability of sunscreens for protection from UV-induced immune suppression. Determining the level of UVA protection is particularly necessary, because UVA seems to have a relatively low contribution to erythema but is highly involved in immunosuppression. PMID:12444956

  9. 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.

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

    PubMed

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

    2012-08-10

    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. PMID:22797534

  11. Effects of solar ultraviolet photons on mammalian cell DNA. [UVA (320-400 nm):a2

    SciTech Connect

    Peak, M.J.; Peak, J.G.

    1991-01-01

    This document presents information on the possible mechanisms of carcinogenesis caused by UVA (ultraviolet radiation in the 320--400 nm region). Most studies showing the carcinogenic effects of ultraviolet light have concentrated on UVB (280--320 nm). UVA had been considered harmless even though it penetrates biological tissues better than UVB. Recently, it has become apparent that UVA is also capable of causing damage to cellular DNA. This was unexpected because the DNA UV absorption spectrum indicates a negligible probability that photons of wavelengths longer than 320 nm will be directly absorbed. The most common defects induced in DNA by UVB are pyrimidine photoproducts, such as thymidine dimers. UVA photons produce defects resembling those caused by ionizing radiations: single- and double-strand breaks, and DNA-protein crosslinks. This paper also discusses the role of DNA repair mechanisms in UVA-induced defects and the molecular mechanisms of UVA damage induction. 38 refs. (MHB)

  12. Absorption, distribution, and excretion of 8-methoxypsoralen in HRA/Skh mice

    SciTech Connect

    Muni, I.A.; Schneider, F.H.; Olsson, T.A. III; King, M.

    1984-12-01

    The tissue distribution and excretion of (/sup 3/H)8-methoxypsoralen (8-MOP), a well-accepted therapeutic agent for the treatment of psoriasis, was studied in hairless HRA/Skh female mice. Mice were given single oral doses of 6 mg of (/sup 3/H)8-MOP or 5-(/sup 14/C)8-MOP/kg in corn oil. Radiochemical analyses of tissues and excreta were accomplished by liquid scintillation counting. The 8-MOP appeared to be rapidly absorbed through the gastrointestinal tract, where the tritium levels were highest, followed by skin, blood, and liver; levels were lowest in fat (adipose tissue). In female HRA/Skh mice which had not been irradiated with UVA (320-400 nm), 84% of the carbon-14 and 58% of the tritium were recovered in the urine and feces within 24 hours of oral administration of 5-(/sup 14/C)8-MOP or (/sup 3/H)8-MOP, respectively. Animals that were exposed to UVA and received (3H)8-MOP excreted approximately 12% less tritium in the urine and feces compared with the animals which received no UVA.

  13. NASA-UVA light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Thornton, Earl A.; Stoner, Glenn E.; Swanson, Robert E.; Wawner, Franklin E., Jr.; Wert, John A.

    1989-01-01

    The report on progress achieved in accomplishing of the NASA-UVA Light Aerospace Alloy and Structures Technology Program is presented. The objective is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys and associated thermal gradient structures in close collaboration with researchers. The efforts will produce basic understanding of material behavior, new monolithic and composite alloys, processing methods, solid and fluid mechanics analyses, measurement advances, and a pool of educated graduate students. The presented accomplishments include: research on corrosion fatigue of Al-Li-Cu alloy 2090; research on the strengthening effect of small In additions to Al-Li-Cu alloys; research on localized corrosion of Al-Li alloys; research on stress corrosion cracking of Al-Li-Cu alloys; research on fiber-matrix reaction studies (Ti-1100 and Ti-15-3 matrices containing SCS-6, SCS-9, and SCS-10 fibers); and research on methods for quantifying non-random particle distribution in materials that has led to generation of a set of computer programs that can detect and characterize clusters in particles.

  14. Structural biology applications of solid state MAS DNP NMR.

    PubMed

    Akbey, Ümit; Oschkinat, Hartmut

    2016-08-01

    Dynamic Nuclear Polarization (DNP) has long been an aim for increasing sensitivity of nuclear magnetic resonance (NMR) spectroscopy, delivering spectra in shorter experiment times or of smaller sample amounts. In recent years, it has been applied in magic angle spinning (MAS) solid-state NMR to a large range of samples, including biological macromolecules and functional materials. New research directions in structural biology can be envisaged by DNP, facilitating investigations on very large complexes or very heterogeneous samples. Here we present a summary of state of the art DNP MAS NMR spectroscopy and its applications to structural biology, discussing the technical challenges and factors affecting DNP performance. PMID:27095695

  15. MAS PFG NMR Studies of Mixtures in Porous Materials

    NASA Astrophysics Data System (ADS)

    Gratz, Marcel; Hertel, Stefan; Wehring, Markus; Schlayer, Stefan; Stallmach, Frank; Galvosas, Petrik

    2011-03-01

    Pulsed field gradient (PFG) and magic angle spinning (MAS) NMR techniques have been successfully combined for the study of mixture diffusion in porous materials. Using a modular setup of commercially available components, gradient pulses of up to ±2.6 T/m can be applied coinciding with fast sample rotation at the magic angle. Methods for the proper alignment of all components are presented along with protocols for MAS PFG NMR experiments. Finally, first diffusion measurements of n-hexane and benzene being adsorbed together in the metal-organic framework MOF-5 are presented.

  16. MAS2-8 radar and digital control unit

    NASA Technical Reports Server (NTRS)

    Oberg, J. M.; Ulaby, F. T.

    1974-01-01

    The design of the MAS 2-8 (2 to 8 GHz microwave-active spectrometer), a ground-based sensor system, is presented. A major modification in 1974 to the MAS 2-8, that of a control subsystem to automate the data-taking operation, is the prime focus. The digital control unit automatically changes all system parameters except FM rate and records the return signal on paper tape. The overall system operation and a detailed discussion of the design and operation of the digital control unit are presented.

  17. Structural biology applications of solid state MAS DNP NMR

    NASA Astrophysics Data System (ADS)

    Akbey, Ümit; Oschkinat, Hartmut

    2016-08-01

    Dynamic Nuclear Polarization (DNP) has long been an aim for increasing sensitivity of nuclear magnetic resonance (NMR) spectroscopy, delivering spectra in shorter experiment times or of smaller sample amounts. In recent years, it has been applied in magic angle spinning (MAS) solid-state NMR to a large range of samples, including biological macromolecules and functional materials. New research directions in structural biology can be envisaged by DNP, facilitating investigations on very large complexes or very heterogeneous samples. Here we present a summary of state of the art DNP MAS NMR spectroscopy and its applications to structural biology, discussing the technical challenges and factors affecting DNP performance.

  18. Carcinogenic effect of sequential artificial sunlight and UV-A irradiation in hairless mice. Consequences for solarium 'therapy'.

    PubMed

    Staberg, B; Wulf, H C; Poulsen, T; Klemp, P; Brodthagen, H

    1983-08-01

    The carcinogenic effect of artificial UV sunlight followed by UV-A irradiation in human solaria doses has been studied with the use of the hairless mouse as an animal model. Artificial sunlight exposure alone induced only a moderate skin tumor incidence (animals with at least one tumor) of 0.15 after one year, and UV-A irradiation alone induced no tumor formation. However, the combination of artificial sunlight exposure and subsequent UV-A irradiation significantly increased the tumor incidence to 0.72. We conclude that, in humans, tanning with UV-A for cosmetic purposes may not be an innocuous procedure. PMID:6870317

  19. 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

  20. Lonicera caerulea fruits reduce UVA-induced damage in hairless mice.

    PubMed

    Vostálová, Jitka; Galandáková, Adéla; Palíková, Irena; Ulrichová, Jitka; Doležal, Dalibor; Lichnovská, Radka; Vrbková, Jana; Rajnochová Svobodová, Alena

    2013-11-01

    UVA photons are less energetic than UVB photons but they are more abundant in solar radiation. Modern tools have shown that UVA light has serious adverse effects on the skin. We investigated the effect of consuming Lonicera caerulea berries on UVA-induced damage in SKH-1 mice. The mice were fed a diet containing L. caerulea berries (10%, w/w) for 14 days before a single UVA (30 J/cm(2)) treatment. Effects on haematological and antioxidant parameters were evaluated 4 and 24h after irradiation. The bioavailability of L. caerulea phenolics was also assessed. Consuming the L. caerulea berry-enriched diet caused reduced malondialdehyde production and increased catalase activity and glutathione levels were found in skin and erythrocytes. UVA-induced NADPH:quinone oxidoreductase-1 and gamma-L-glutamate-L-cysteine ligase protein in skin were reduced in mice fed L. caerulea berries. Enhanced heme oxygenase-1 level in skin, interleukin-17 in plasma and reduced interleukin-12 levels in plasma were found in the mice on the experimental diet. Histological (pyknotic) changes in the nuclei of basal cells induced by UVA exposure were reduced in L. caerulea berry consuming animals. HLPC-MS analysis showed high concentrations of hippuric acid, one of the main metabolites of aromatic amino acids and phenolic compounds, in skin, liver, urine and faeces of mice consuming the berries. Taken together, consumption of L. caerulea berries affords protection from the adverse effects of a single UVA exposure mainly via modulation of antioxidant parameters. PMID:23974431

  1. Quantitative Assessment of UVA-Riboflavin Corneal Cross-Linking Using Nonlinear Optical Microscopy

    PubMed Central

    Chai, Dongyul; Gaster, Ronald N.; Roizenblatt, Roberto; Juhasz, Tibor; Brown, Donald J.

    2011-01-01

    Purpose. Corneal collagen cross-linking (CXL) by the use of riboflavin and ultraviolet-A light (UVA) is a promising and novel treatment for keratoconus and other ectatic disorders. Since CXL results in enhanced corneal stiffness, this study tested the hypothesis that CXL-induced stiffening would be proportional to the collagen autofluorescence intensity measured with nonlinear optical (NLO) microscopy. Methods. Rabbit eyes (n = 50) were separated into five groups including: (1) epithelium intact; (2) epithelium removed; (3) epithelium removed and soaked in riboflavin, (4) epithelium removed and soaked in riboflavin, with 15 minutes of UVA exposure; and (5) epithelium removed and soaked in riboflavin, with 30 minutes of UVA exposure. Corneal stiffness was quantified by measuring the force required to displace the cornea 500 μm. Corneas were then fixed in paraformaldehyde and sectioned, and the collagen autofluorescence over the 400- to 450-nm spectrum was recorded. Results. There was no significant difference in corneal stiffness among the three control groups. Corneal stiffness was significantly and dose dependently increased after UVA (P < 0.0005). Autofluorescence was detected only within the anterior stroma of the UVA-treated groups, with no significant difference in the depth of autofluorescence between different UVA exposure levels. The signal intensity was also significantly increased with longer UVA exposure (P < 0.001). Comparing corneal stiffness with autofluorescence intensity revealed a significant correlation between these values (R2 = 0.654; P < 0.0001). Conclusions. The results of this study indicate a significant correlation between corneal stiffening and the intensity of collagen autofluorescence after CXL. This finding suggests that the efficacy of CXL in patients could be monitored by assessing collagen autofluorescence. PMID:21508101

  2. 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

    2015-01-01

    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

  3. Draft Genome Sequence of Geobacillus thermopakistaniensis Strain MAS1

    PubMed Central

    Rashid, Naeem; Ayyampalayam, Saravanaraj

    2014-01-01

    Geobacillus thermopakistaniensis strain MAS1 was isolated from a hot spring located in the Northern Areas of Pakistan. The draft genome sequence was 3.5 Mb and identified a number of genes of potential industrial importance, including genes encoding glycoside hydrolases, pullulanase, amylopullulanase, glycosidase, and alcohol dehydrogenases. PMID:24903880

  4. Resolution and polarization distribution in cryogenic DNP/MAS experiments

    PubMed Central

    Barnes, Alexander B.; Corzilius, Björn; Mak-Jurkauskas, Melody L.; Andreas, Loren B.; Bajaj, Vikram S.; Matsuki, Yoh; Belenky, Marina L.; Lugtenburg, Johan; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Herzfeld, Judith; Griffin, Robert G.

    2014-01-01

    This contribution addresses four potential misconceptions associated with high-resolution dynamic nuclear polarization/magic angle spinning (DNP/MAS) experiments. First, spectral resolution is not generally compromised at the cryogenic temperatures at which DNP experiments are performed. As we demonstrate at a modest field of 9 T (380 MHz 1H), 1 ppm linewidths are observed in DNP/MAS spectra of a membrane protein in its native lipid bilayer, and <0.4 ppm linewidths are reported in a crystalline peptide at 85 K. Second, we address the concerns about paramagnetic broadening in DNP/MAS spectra of proteins by demonstrating that the exogenous radical polarizing agents utilized for DNP are distributed in the sample in such a manner as to avoid paramagnetic broadening and thus maintain full spectral resolution. Third, the enhanced polarization is not localized around the polarizing agent, but rather is effectively and uniformly dispersed throughout the sample, even in the case of membrane proteins. Fourth, the distribution of polarization from the electron spins mediated via spin diffusion between 1H–1H strongly dipolar coupled spins is so rapid that shorter magnetization recovery periods between signal averaging transients can be utilized in DNP/MAS experiments than in typical experiments performed at ambient temperature. PMID:20454732

  5. Draft Genome Sequence of Geobacillus thermopakistaniensis Strain MAS1.

    PubMed

    Siddiqui, Masood Ahmed; Rashid, Naeem; Ayyampalayam, Saravanaraj; Whitman, William B

    2014-01-01

    Geobacillus thermopakistaniensis strain MAS1 was isolated from a hot spring located in the Northern Areas of Pakistan. The draft genome sequence was 3.5 Mb and identified a number of genes of potential industrial importance, including genes encoding glycoside hydrolases, pullulanase, amylopullulanase, glycosidase, and alcohol dehydrogenases. PMID:24903880

  6. 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

  7. Extracellular vesicles are transferred from melanocytes to keratinocytes after UVA irradiation

    PubMed Central

    Wäster, Petra; Eriksson, Ida; Vainikka, Linda; Rosdahl, Inger; Öllinger, Karin

    2016-01-01

    Ultraviolet (UV) irradiation induces skin pigmentation, which relies on the intercellular crosstalk of melanin between melanocytes to keratinocytes. However, studying the separate effects of UVA and UVB irradiation reveals differences in cellular response. Herein, we show an immediate shedding of extracellular vesicles (EVs) from the plasma membrane when exposing human melanocytes to UVA, but not UVB. The EV-shedding is preceded by UVA-induced plasma membrane damage, which is rapidly repaired by Ca2+-dependent lysosomal exocytosis. Using co-cultures of melanocytes and keratinocytes, we show that EVs are preferably endocytosed by keratinocytes. Importantly, EV-formation is prevented by the inhibition of exocytosis and increased lysosomal pH but is not affected by actin and microtubule inhibitors. Melanosome transfer from melanocytes to keratinocytes is equally stimulated by UVA and UVB and depends on a functional cytoskeleton. In conclusion, we show a novel cell response after UVA irradiation, resulting in transfer of lysosome-derived EVs from melanocytes to keratinocytes. PMID:27293048

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

    PubMed

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

    2014-02-01

    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. PMID:24491420

  9. 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. PMID:25500756

  10. Extracellular vesicles are transferred from melanocytes to keratinocytes after UVA irradiation.

    PubMed

    Wäster, Petra; Eriksson, Ida; Vainikka, Linda; Rosdahl, Inger; Öllinger, Karin

    2016-01-01

    Ultraviolet (UV) irradiation induces skin pigmentation, which relies on the intercellular crosstalk of melanin between melanocytes to keratinocytes. However, studying the separate effects of UVA and UVB irradiation reveals differences in cellular response. Herein, we show an immediate shedding of extracellular vesicles (EVs) from the plasma membrane when exposing human melanocytes to UVA, but not UVB. The EV-shedding is preceded by UVA-induced plasma membrane damage, which is rapidly repaired by Ca(2+)-dependent lysosomal exocytosis. Using co-cultures of melanocytes and keratinocytes, we show that EVs are preferably endocytosed by keratinocytes. Importantly, EV-formation is prevented by the inhibition of exocytosis and increased lysosomal pH but is not affected by actin and microtubule inhibitors. Melanosome transfer from melanocytes to keratinocytes is equally stimulated by UVA and UVB and depends on a functional cytoskeleton. In conclusion, we show a novel cell response after UVA irradiation, resulting in transfer of lysosome-derived EVs from melanocytes to keratinocytes. PMID:27293048

  11. Protective effects of antioxidants against UVA-induced DNA damage in human skin fibroblasts in culture.

    PubMed

    Emonet-Piccardi, N; Richard, M J; Ravanat, J L; Signorini, N; Cadet, J; Béani, J C

    1998-10-01

    Ultraviolet A radiation (UVA, 320-400 nm) is mutagenic and induces genomic damage to skin cells. N-acetyl-cysteine (NAC), selenium and zinc have been shown to have antioxidant properties and to exhibit protective effects against UVA cytotoxicity. The present work attempts to delineate the effect of these compounds on genomic integrity of human skin fibroblasts exposed to UVA radiation using the single cell gel electrophoresis (SCGE) or Comet assay. The cells were incubated with NAC (5 mM), sodium selenite (0.6 microM) or zinc chloride (100 microM). Then cells were embedded in low melting point agarose, and immediately submitted to UVA fluences ranging from 1 to 6J/cm2. In the Comet assay, the tail moment increased by 45% (1 J/cm2) to 89% (6J/cm2) in non-supplemented cells (p)<0.01). DNA damage was significantly prevented by NAC, Se and Zn, with a similar efficiency from 1 to 4J/cm2 (p < 0.05). For the highest UVA dose (6J/cm2), Se and Zn were more effective than NAC (p < 0.01). PMID:9860045

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

    SciTech Connect

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

    1995-04-01

    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 was 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.

  13. Adhesion of leukocytes to dermal endothelial cells is induced after single-dose, but reduced after repeated doses of UVA.

    PubMed

    Heckmann, M; Pirthauer, M; Plewig, G

    1997-12-01

    Approximately 20-50% of ultraviolet A (UVA) irradiation delivered to the skin surface may reach the human dermal microvascular endothelial cells (HDMEC) that play a pivotal role in cellular inflammatory tissue; however, the pathophysiologic role of HDMEC in UVA-induced skin changes is largely unknown. Based on previous in vivo and in vitro studies revealing UVA-induced expression of endothelial adhesion molecules, we studied isolated HDMEC under various conditions in order to further delineate the impact of UVA on these cells. The expression of cell adhesion molecules was determined by flow cytometry and the resulting changes of stable adhesion of leukocytes to endothelial cells were quantitated for granulocytes, lymphocytes, and monocytes using a newly developed multicellular adhesion assay. Additionally, antibody blocking experiments were performed to delineate the role of individual cell adhesion molecules in UVA-induced leukocyte adherence. High-dose polychromatic UVA (25 J per cm2, maximal emission at 375 nm) induced intercellular adhesion molecule-1 and E-selectin with different kinetics but correlating the adhesion of leukocyte subsets. This effect subsided, however, in the course of 3-6 daily applied UVA doses. Moreover, pro-inflammatory cytokine challenge by tumor necrosis factor-alpha and interleukin-1-alpha resulted in significantly weaker induction of intercellular adhesion molecule-1 and E-selectin in repeatedly UVA-exposed HDMEC. Differential quantitation of peripheral blood derived granulocytes, lymphocytes, and monocytes revealed reduced adhesion particularly of lymphocytes followed by monocytes and granulocytes compared with leukocyte adhesion to nonirradiated but cytokine-stimulated HDMEC. It is concluded that UVA substantially influences endothelial cell adhesion molecules expression and thus directly interferes with leukocyte adhesion to endothelial cells. Divergent UVA-induced effects in this respect can be attributed to the mode of UV exposure

  14. Does manganese protect cultured human skin fibroblasts against oxidative injury by UVA, dithranol and hydrogen peroxide?

    PubMed

    Parat, M O; Richard, M J; Leccia, M T; Amblard, P; Favier, A; Beani, J C

    1995-10-01

    Reactive oxygen species (ROS) are involved in the mechanism of photoaging and carcinogenesis. Skin is endowed with antioxidant enzymes including superoxide dismutases (SOD): cytosolic copper zinc SOD and mitochondrial manganese SOD. The aim of our study was to estimate the protective effect of manganese against oxidative injury on cultured human skin fibroblasts. Dithranol, hydrogen peroxide and UV-A radiation (375 nm) were employed as oxidative stressors. The supply of manganese chloride produced an increase in cellular content of this element up to 24 fold without concomitant elevation of MnSOD activity. Nevertheless, manganese protects cells against two of the three ROS generating systems assessed, namely hydrogen peroxyde and UV-A. This protective effect depends on the concentration of manganese in the medium, 0.1 mM and 0.2 mM protect against UVA cytotoxicity, only 0.2 mM protects against H2O2 cytotoxicity. PMID:7493040

  15. 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. PMID:25495870

  16. 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

  17. 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. PMID:27301251

  18. Apoptosis and morphological alterations after UVA irradiation in red blood cells of p53 deficient Japanese medaka (Oryzias latipes).

    PubMed

    Sayed, Alla El-Din Hamid; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-08-01

    Morphological alterations in red blood cells were described as hematological bioindicators of UVA exposure to investigate the sensitivity to UVA in wild type Japanese medaka (Oryzias latipes) and a p53 deficient mutant. The fewer abnormal red blood cells were observed in the p53 mutant fish under the control conditions. After exposure to different doses of UVA radiation (15min, 30min and 60min/day for 3days), cellular and nuclear alterations in red blood cells were analyzed in the UVA exposed fish compared with non-exposed controls and those alterations included acanthocytes, cell membrane lysis, swollen cells, teardrop-like cell, hemolyzed cells and sickle cells. Those alterations were increased after the UVA exposure both in wild type and the p53 deficient fish. Moreover, apoptosis analyzed by acridine orange assay showed increased number of apoptosis in red blood cells at the higher UVA exposure dose. No micronuclei but nuclear abnormalities as eccentric nucleus, nuclear budding, deformed nucleus, and bilobed nucleus were observed in each group. These results suggested that UVA exposure induced both p53 dependent and independent apoptosis and morphological alterations in red blood cells but less sensitive to UVA than Wild type in medaka fish. PMID:27203565

  19. Identification and transcriptional profiling of differentially expressed genes associated with response to UVA radiation in Drosophila melanogaster (Diptera: Drosophilidae).

    PubMed

    Zhou, Li-Jun; Zhu, Zhi-Hui; Liu, Zhen-Xing; Ma, Wei-Hua; Desneux, Nicolas; Lei, Chao-Liang

    2013-10-01

    Ultraviolet A (UVA) radiation, the major component of solar ultraviolet (UV) radiation reaching the earth's surface, leads to negative effects in insects, such as oxidative stress, photoreceptor damage, and cell death. To better understand the molecular mechanisms of insect response to UVA radiation, suppression subtractive hybridization (SSH) and real-time quantitative polymerase chain reaction approaches were combined to reveal differential transcript expression in Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae). In this study, two subtractive cDNA libraries were constructed and sequenced, obtaining 131 high-quality unique expressed sequence tags (ESTs) that were up- or downregulated in D. melanogaster exposed to UVA radiation for 0.5 h. Of the 131 ESTs, 102 unique ESTs were differentially expressed and classified into 10 functional categories. The results showed that UVA radiation induces expression of genes related to stress and defense response and metabolism. Potential transcription factor binding motifs upstream of these genes are associated with multiple signaling pathways that may help the insect cope with the stress of UVA radiation. To our knowledge, this is the first analysis of insect response to UVA radiation at the transcriptional level. Our results reveal that UVA radiation influences the expression profiles of stress-responsive genes and provide further insights into the mechanisms of adaptive response to UVA radiation stress. PMID:24331622

  20. Differential sensitivity of T lymphocytes and hematopoietic precursor cells to photochemotherapy with 8-methoxypsoralen and ultraviolet A light.

    PubMed

    Mabed, Mohamed; Coffe, Christian; Racadot, Evelyne; Angonin, Regis; Pavey, Jean-Jaques; Tiberghien, Pierre; Herve, Patrick

    2006-01-01

    The combination of 8-methoxypsoralen (8-MOP) and long wave ultraviolet radiation (UV-A) has immunomodulatory effects and might abolish both graft-vs-host and host-vs-graft reactions after allogeneic hematopoietic stem cell transplantation. In the present study, we have confirmed the sensitivity of T lymphocytes to 8-MOP treatment plus UV-A exposure as evidenced by the abrogation of the alloreactivity in mixed lymphocyte cultures as well as the inhibition of the response to phytohemagglutinin A. However, the clonogenic capacity of the bone marrow hematopoietic progenitors was inhibited with UV-A doses lower than the doses needed to inhibit T-lymphocytes alloreactivity. Moreover, long-term bone marrow cultures showed that 8-MOP plus UV-A treatment had detrimental effects on the more immature bone marrow stem cells. These data were confirmed when murine bone marrow graft was treated with 8-MOP, exposed to UV-A, then transplanted into semiallogeneic recipient mice. The treated cells could not maintain their clonogenic capacity in vivo resulting in death of all animals. Taken together, these data show that ex vivo 8-MOP plus UV-A treatment of the marrow graft cannot be used to prevent post-bone marrow transplantation alloreactivity. PMID:16208471

  1. 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.

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

    PubMed Central

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

    2014-01-01

    Summary Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. In order 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 dose 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. PMID:25417821

  3. Pilot Study for UVA-LED Disinfection of Escherichia coli in Water for Space and Earth Applications

    NASA Technical Reports Server (NTRS)

    Ragolta, Carolina

    2010-01-01

    To test the efficacy of UVA-LED disinfection, a solution of Escherichia coli was pumped through a modified drip flow reactor at a flow rate of 1 ml/min. The experiment was conducted in a controlled environment chamber to ensure that temperature did not cause disinfection. The reactor featured three wells with different treatments: UVA-LED irradiation, UVA-LEDs with Ti02, and UVA-LEDs with nanosilver. Samples from each well were taken throughout a 340 hour period, inactivated, assayed, and analyzed for E. coli disinfection. Results of the duplicate experiments indicated longer exposure times are needed for UVA-LED disinfection of E. coli in water. Further research would consider a longer sampling period and different test conditions, such as increased contact area and various flow rates.

  4. Effects of UV-A Radiation on Desmodesmus armatus: Changes in Growth Rate, Pigment Content and Morphological Appearance

    NASA Astrophysics Data System (ADS)

    Pálffy, Károly; Vörös, Lajos

    2006-10-01

    Laboratory cultures of Desmodesmus armatus (R. Chod.) Hegew. were grown under different levels of photosynthetically active radiation (PAR) supplemented with 3.75 mW . cm-2 UV-A radiation. Growth rate was monitored daily, chlorophyl-a concentration, total carotenoid content, cell number and the relative abundance of different coenobial forms was determined at the end of each experiment. Exposure to UV-A radiation resulted in an increasing inhibition of growth towards higher PAR levels, reaching 100% at 400 μmol . m-2 . s-1. Cellular carotenoid content was higher in the presence of UV-A radiation, on the other hand no differences were observed in cellular chlorophyll-a concentration. UV-A radiation also induced changes in coenobium formation with a decreasing proportion of 4-celled coenobia and an increase in the abundance of 2-celled and teratologic coenobia, suggesting that high intensity UV-A radiation may influence cell cycle events or morphology development.

  5. In vitro photosafety and efficacy screening of apigenin, chrysin and beta-carotene for UVA and VIS protection.

    PubMed

    Freitas, Juliana Vescovi; Gaspar, Lorena Rigo

    2016-06-30

    Currently most of sunscreens provide effective protection in the full UV range but lack VIS protection. The addition of effective antioxidants to sunscreens might afford suitable UV-VIS protection. Apigenin (API), chrysin (CRI) and beta-carotene (BTC) have shown potential for UV-VIS protection. This paper reports a photosafety and efficacy screening of such antioxidants through evaluation of the photostability, photoreactivity and phototoxicity as well as UVA/UVB ratio and critical wavelength. The assessment of the photostability, photoreactivity and phototoxicity of API, CRI and BTC, isolated and combined (CMB) was performed by HPLC, ROS assay and 3T3 NRU phototoxicity test, respectively. The phototoxicity test was also performed for CMB plus bemotrizinol (BMZ). The in vitro evaluation of the UVA protection was assessed by the determination of the UVA/UVB ratio and the critical wavelength. The antioxidants API, CRI, BTC and CMB were stable under UVA/VIS and VIS light. However weak photoreactivity after UVA/VIS irradiation was observed for API, CRI and CMB in the ROS assay. In the 3T3 NRU phototoxicity test, phototoxic potential was observed for CRI, BTC, CMB and CMB+BMZ after UVA/VIS exposure, and for BTC and CMB after VIS exposure. BMZ reduced the phototoxic potential of CMB in the VIS range. In the in vitro evaluation of UVA protection API, CRI, BTC, CMB and CMB+BMZ presented ultra UVA protection (UVA/UVB ratio>0.9) and exhibited critical wavelength close to or above 370nm. In conclusion, the use of API, CRI, BTC and their CMB aiming skin photoprotection could be considered safer in the VIS range. Furthermore, API presented the best performance in the photosafety screening among the studied antioxidants, since it was photostable and non-phototoxic in UVA/VIS and photostable, non-photoreactive and non-phototoxic in VIS range. PMID:27130544

  6. Coherence selection in double CP MAS NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Yang, Jen-Hsien; Chou, Fang-Chieh; Tzou, Der-Lii M.

    2008-11-01

    Applications of double cross-polarization (CP) magic-angle spinning (MAS) NMR spectroscopy, via 1H/ 15N and then 15N/ 13C coherence transfers, for 13C coherence selection are demonstrated on a 15N/ 13C-labeled N-acetyl-glucosamine (GlcNAc) compound. The 15N/ 13C coherence transfer is very sensitive to the settings of the experimental parameters. To resolve explicitly these parameter dependences, we have systematically monitored the 13C{ 15N/ 1H} signal as a function of the rf field strength and the MAS frequency. The data reveal that the zero-quantum coherence transfer, with which the 13C effective rf field is larger than that of the 15N by the spinning frequency, would give better signal sensitivity. We demonstrate in one- and two-dimensional double CP experiments that spectral editing can be achieved by tailoring the experimental parameters, such as the rf field strengths and/or the MAS frequency.

  7. Commercial facility site selection simulating based on MAS

    NASA Astrophysics Data System (ADS)

    Chao, Yi; Li, Qingquan; Zheng, Guizhou

    2008-10-01

    The location of commercial facility decides the benefit of the operator to a large degree. Existing location methods can express the static relationships between site selection result and location factors, but there still are some limites when express the dynamic and uncertain relationship between them. Hence, a dynamic, stochastic and forecastable location model should be built which can introduce the customer's behavior into the model and combine the macro pattern and micro spatial interaction. So the authors proposes Geosim-LM based on MAS. Geosim-LM has 3 kinds of agents, CustAgent, SiteAgent and GovAgent. They represent the customers, commercial fercilities and government. The land type, land price and traffic are the model environment. Then Geosim-LM is applied in the bank branches site evaluation and selection in Liwan district, Guangzhou. In existing bank branches site evaluation, there are 70% consistent in score grade between result of Geosim-LM after 200 round runing and actual rebust location. It proves the model is reliable and feasible. The conclusions can be get from the paper. MAS have advantages in location choice than existed methods. The result of Geosim-LM running can powerfully proves that building location model based on MAS is feasible.

  8. The MicroMAS CubeSat Mission

    NASA Astrophysics Data System (ADS)

    Cahoy, K.; Blackwell, W. J.; Allen, G.; Bury, M.; Efromson, R.; Galbraith, C.; Hancock, T.; Leslie, V.; Osaretin, I.; Retherford, L.; Scarito, M.; Shields, M.; Toher, D.; Wight, K.; Miller, D.; Marinan, A.; Paek, S.; Peters, E.; Schmidt, F. H.; Alvisio, B.; Wise, E.; Masterson, R.; Franzim Miranda, D.; Crail, C.; Kingsbury, R.; Souffrant, A.; Orrego, L.; Eslinger, G.; Nicholas, A.; Pong, C.

    2012-12-01

    The recently published Midterm Assessment of NASA's Implementation of the Decadal Survey finds that, "The nation's Earth observing system is beginning a rapid decline in capability as long-running missions end and key new missions are delayed, lost, or canceled. The projected loss of observing capability could have significant adverse consequences for science and society." In this presentation, we explore low-cost, mission-flexible, and rapidly deployable spaceborne sensors that can meet stringent performance requirements pervading the NASA Earth Science measurement programs, including especially the recommended NRC Decadal Survey missions. New technologies have enabled a novel approach toward this science observational goal, and in this paper we describe recent technology develop efforts to address the challenges above through the use of CubeSat radiometers. The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (30x10x10 cm, ~4kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately 500-km altitude. A MicroMAS flight unit is currently being developed in anticipation of a 2014 launch to be provided by NASA. A parabolic reflector is mechanically rotated as the spacecraft orbits the earth, thus directing a cross-track scanned beam with FWHM beamwidth of 2.4-degrees, yielding an approximately 25-km diameter footprint from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the earth's limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. A key technology feature is the development of an ultra-compact intermediate frequency processor module for channelization, detection, and A-to-D conversion. The antenna system and RF front

  9. 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

  10. Importance of UVA photoprotection as shown by genotoxic related endpoints: DNA damage and p53 status.

    PubMed

    Marrot, Laurent; Belaïdi, Jean-Philippe; Meunier, Jean-Roch

    2005-04-01

    In order to demonstrate the importance of photoprotection in the UVA range (320-400 nm), an in vitro approach where sun formulations are spread on a quartz slide, and placed over human keratinocytes in culture is proposed as a convenient test for photoprotection assessment at the DNA level. Using the comet assay, DNA strand breaks, oxidative DNA damage or drug-induced DNA breaks were assessed. Accumulation of p53 protein was also studied as a marker for UV-induced genotoxic stress. Such a method was used to compare two formulations with different photostability. Spectroradiometry showed that a photounstable formulation lost its effectiveness in UVA screening when pre-irradiated by simulated sunlight (UVB+UVA). As a consequence, it was also shown that this formulation was not as protective as the photostable one at the genomic level. These data demonstrate that the loss of absorbing efficiency within UVA wavelengths due to photounstability may have detrimental consequences leading to impairments implicated in genotoxic events. PMID:15748646

  11. [Life style, sun-bathing and tanning--what about UV-A solariums?].

    PubMed

    Thune, P

    1991-06-30

    This article considers the effects of ultraviolet (UV) light from the sun and UV-A sun beds on the skin. Sun worshipping and sun therapy has been en vogue for centuries, but in another way than used today. A changing lifestyle has led to an increase of various skin diseases, including skin cancer. Short wave UV-light (UV-B) in particular has been blamed for inducing not only erythema and pigmentation but also more chronic skin lesions. Long wave UV-light (UV-A) has been shown to be the cause of similar changes to the skin but the pigmentation is of another quality and affords less protection against the harmful effects of UV-B. A concept of sun reactive skin typing has been created. This is based on self-reported responses to an initial exposure to sun as regards tanning ability and erythema reaction. These two factors have certain practical consequences, not only for UV-phototherapy but also for a person's risk of developing skin cancer. Recently, several research groups and dermatologist have discouraged extensive use of UV-A sun beds because of side effects of varying degrees of seriousness. The possible implications of these side effects for the organism are not fully elucidated and may be more profound than known today. The British Photodermatology Group has issued more stringent rules for persons who despite advice to the contrary, still wish to use UV-A sun beds. PMID:1871738

  12. 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.

  13. Photoprotective Effects of Cycloheterophyllin against UVA-Induced Damage and Oxidative Stress in Human Dermal Fibroblasts.

    PubMed

    Huang, Cheng-Hua; Li, Hsin-Ju; Wu, Nan-Lin; Hsiao, Chien-Yu; Lin, Chun-Nan; Chang, Hsun-Hsien; Hung, Chi-Feng

    2016-01-01

    Ultraviolet (UV) radiation, particularly ultraviolet A (UVA), is known to play a major role in photoaging of the human skin. Many studies have demonstrated that UV exposure causes the skin cells to generate reactive oxygen species and activates the mitogen-activated protein kinase (MAPK) pathway. Previous studies have also demonstrated that cycloheterophyllin has an antioxidant effect and can effectively scavenge free radicals. Extending the aforementioned investigations, in this study, human dermal fibroblasts were used to investigate the protective effect of cycloheterophyllin against UV-induced damage. We found that cycloheterophyllin not only significantly increased cell viability, but also attenuated the phosphorylation of MAPK after UVA exposure. Furthermore, cycloheterophyllin could reduce hydrogen peroxide (H2O2) generation and down-regulate H2O2-induced MAPK phosphorylation. In the in vivo studies, the topical application of cycloheterophyllin before UVA irradiation significantly decreased trans-epidermal water loss (TEWL), erythema, and blood flow rate. These results indicate that cycloheterophyllin is a photoprotective agent that inhibits UVA-induced oxidative stress and damage, and could be used in the research on and prevention of skin photoaging. PMID:27583973

  14. Endonuclease IV Is the Main Base Excision Repair Enzyme Involved in DNA Damage Induced by UVA Radiation and Stannous Chloride

    PubMed Central

    Motta, Ellen S.; Souza-Santos, Paulo Thiago; Cassiano, Tuany R.; Dantas, Flávio J. S.; Caldeira-de-Araujo, Adriano; De Mattos, José Carlos P.

    2010-01-01

    Stannous chloride (SnCl2) and UVA induce DNA lesions through ROS. The aim of this work was to study the toxicity induced by UVA preillumination, followed by SnCl2 treatment. E. coli BER mutants were used to identify genes which could play a role in DNA lesion repair generated by these agents. The survival assays showed (i) The nfo mutant was the most sensitive to SnCl2; (ii) lethal synergistic effect was observed after UVA pre-illumination, plus SnCl2 incubation, the nfo mutant being the most sensitive; (iii) wild type and nfo mutants, transformed with pBW21 plasmid (nfo+) had their survival increased following treatments. The alkaline agarose gel electrophoresis assays pointed that (i) UVA induced DNA breaks and fpg mutant was the most sensitive; (ii) SnCl2-induced DNA strand breaks were higher than those from UVA and nfo mutant had the slowest repair kinetics; (iii) UVA + SnCl2 promoted an increase in DNA breaks than SnCl2 and, again, nfo mutant displayed the slowest repair kinetics. In summary, Nfo protects E. coli cells against damage induced by SnCl2 and UVA + SnCl2. PMID:20300433

  15. Varations of molecular weight estimation by HP-size exclusion chromatography with UVA versus online DOC detection.

    PubMed

    Her, Namguk; Amy, Gary; Foss, David; Chow, Jaeweon

    2002-08-01

    High performance size exclusion chromatography (HPSEC) with ultraviolet absorbance (UVA) detection has been widely utilized to estimate the molecular weight (MW) and MW distribution of natural organic matter (NOM). However, the estimation of MW with UVA detection is inherently inaccurate because UVA at 254 nm only detects limited components (mostly pi bonded molecules) of NOM, and the molar absorptivity of these different NOM constituents is not equal. In comparison, a SEC chromatogram obtained with a DOC detector showed significant differences compared to a corresponding UVA chromatogram, resulting in different MW values as well as different estimates of polydispersivity. The MWs of Suwannee River humic acid (SRHA), Suwannee River fulvic acid (SRFA), and various mixtures thereof were estimated with HPSEC coupled with UVA and DOC detectors. The results show that UVA is not an adequate detector for quantitative analysis of MW estimation but rather can be used only for limited qualitative analysis. The NOM in several natural waters (Irvine Ranch, California groundwater, and Barr Lake, Colorado surface water) were also characterized to demonstrate the different MWs obtained with the two detectors. The results of the SEC-DOC chromatograms revealed NOM constituent peaks that went undetected by UVA. Utilizing online DOC detection, a better representation of NOM MWs was suggested, with NOM displaying higher weight-averaged MW (Mw) and lower number-averaged MW (Mn) as well as higher polydispersivity. A method for estimation of the MWs of NOM fractional components and polydispersivities is presented. PMID:12188370

  16. 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.

  17. 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

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

    SciTech Connect

    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 dose (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.

  19. Activation of transcription factor AP-2 mediates UVA radiation- and singlet oxygen-induced expression of the human intercellular adhesion molecule 1 gene

    SciTech Connect

    Grether-Beck, S.; Olaizola-Horn, S.; Schmitt, H.; Grewe, M.

    1996-12-10

    UVA radiation is the major component of the UV solar spectrum that reaches the earth, and the therapeutic application of UVA radiation is increasing in medicine. Analysis of the cellular effects of UVA radiation has revealed that exposure of human cells to UVA radiation at physiological doses leads to increased gene expression and that this UVA response is primarily mediated through the generation of singlet oxygen. In this study, the mechanisms by which UVA radiation induces transcriptional activation of the human intercellular adhesion molecule 1 (ICAM-1) were examined. UVA radiation was capable of inducing activation of the human ICAM-1 promoter and increasing OCAM-1 mRNA and protein expression. These UVA radiation effects were inhibited by singlet oxygen quenchers, augmented by enhancement of singlet oxygen life-time, and mimicked in unirradiated cells by a singlet oxygen-generating system. UVA radiation as well as singlet oxygen-induced ICAM-1 promoter activation required activation of the transcription factor AP-2. Accordingly, both stimuli activated AP-2, and deletion of the putative AP-2-binding site abrogated ICAM-1 promoter activation in this system. This study identified the AP-2 site as the UVA radiation- and singlet oxygen-responsive element of the human ICAM-1 gene. The capacity of UVA radiation and/or singlet oxygen to induce human gene expression through activation of AP-2 indicates a previously unrecognized role of this transcription factor in the mammalian stress response. 38 refs., 3 figs., 3 tabs.

  20. 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.

  1. 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

  2. Cell damage by UVA radiation of a mercury microscopy lamp probed by autofluorescence modifications, cloning assay, and comet assay

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Krasieva, Tatiana B.; Bauer, Eckhard; Fiedler, Ursula; Berns, Michael W.; Tromberg, Bruce J.; Greulich, Karl O.

    1996-04-01

    Cell damage by low-power 365-nm radiation of a 50-W high-pressure mercury microscopy lamp was studied. Exposure of Chinese hamster ovary cells to ultraviolet-A (UVA) radiation > 10 kJ/m2 resulted in significant modifications of nicotinamide adenine dinucleotide attributed autofluorescence and inhibition of cell division. Single-cell gel electrophoresis (comet assay) revealed UVA-induced single-strand DNA breaks. According to these results, UVA excitation radiation in fluorescence microscopy may damage cells. This has to be considered in vital cell microscopy, e.g., in calcium measurements.

  3. UVA-induced oxidative stress in single cells probed by autofluorescence modifications, cloning assay, and comet assay

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten; Krasieva, Tatjana; Bauer, Eckhard; Fiedler, Ulrich; Berns, Michael W.; Tromberg, Bruce J.; Greulich, Karl O.

    1996-01-01

    Cell damage by low-power 365 nm radiation of a 50 W high-pressure mercury microscopy lamp was studied. UVA exposure to CHO cells resulted for radiant exposures greater than 10 kJ/m2 in significant modifications of NADH-attributed autofluorescence and in inhibition of cell division. Single cell gel electrophoresis (comet assay) revealed UVA-induced single strand DNA breaks. According to these results, UVA excitation radiation in fluorescence microscopy may damage cells. This has to be considered in vital cell microscopy, e.g. in calcium measurements.

  4. Milli-Arcsecond (MAS) Imaging of the Solar Corona

    NASA Astrophysics Data System (ADS)

    Davila, Joseph M.; Oktem, Figen S.; Kamalabadi, Farzad; O'Neill, John; Novo-Gradac, Anne-Marie; Daw, Adrian N.; Rabin, Douglas M.

    2016-05-01

    Dissipation in the solar corona is believed to occur in extremely thin current sheets of order 1-100 km. Emission from these hot but thin current sheets should be visible in coronal EUV emission lines. However, this spatial scale is far below the resolution of existing imaging instruments, so these dissipation sites have never been observed individually. Conventional optics cannot be manufactured with sufficient surface figure accuracy to obtain the required spatial resolution in the extreme-ultraviolet where these hot plasmas radiate. A photon sieve, a diffractive imaging element similar to a Fresnel zone plate, can be manufactured to provide a few milli-arcsec (MAS) resolution, with much more readily achievable tolerances than with conventional imaging technology. Prototype photon sieve elements have been fabricated and tested in the laboratory. A full-scale ultra-high resolution instrument will require formation flying and computational image deconvolution. Significant progress has been made in overcoming these challenges, and some recent results in these areas are discussed. A simple design for a sounding rocket concept demonstration payload is presented that obtains 80 MAS (0.080 arcsec) imaging with a 100 mm diameter photon sieve to image Fe XIV 334 and Fe XVI 335. These images will show the structure of the corona at a resolution never before obtained, and they will also allow a study of the temperature structure in the dissipation region.

  5. MAS C-Terminal Tail Interacting Proteins Identified by Mass Spectrometry- Based Proteomic Approach

    PubMed Central

    Tirupula, Kalyan C.; Zhang, Dongmei; Osbourne, Appledene; Chatterjee, Arunachal; Desnoyer, Russ; Willard, Belinda; Karnik, Sadashiva S.

    2015-01-01

    Propagation of signals from G protein-coupled receptors (GPCRs) in cells is primarily mediated by protein-protein interactions. MAS is a GPCR that was initially discovered as an oncogene and is now known to play an important role in cardiovascular physiology. Current literature suggests that MAS interacts with common heterotrimeric G-proteins, but MAS interaction with proteins which might mediate G protein-independent or atypical signaling is unknown. In this study we hypothesized that MAS C-terminal tail (Ct) is a major determinant of receptor-scaffold protein interactions mediating MAS signaling. Mass-spectrometry based proteomic analysis was used to comprehensively identify the proteins that interact with MAS Ct comprising the PDZ-binding motif (PDZ-BM). We identified both PDZ and non-PDZ proteins from human embryonic kidney cell line, mouse atrial cardiomyocyte cell line and human heart tissue to interact specifically with MAS Ct. For the first time our study provides a panel of PDZ and other proteins that potentially interact with MAS with high significance. A ‘cardiac-specific finger print’ of MAS interacting PDZ proteins was identified which includes DLG1, MAGI1 and SNTA. Cell based experiments with wild-type and mutant MAS lacking the PDZ-BM validated MAS interaction with PDZ proteins DLG1 and TJP2. Bioinformatics analysis suggested well-known multi-protein scaffold complexes involved in nitric oxide signaling (NOS), cell-cell signaling of neuromuscular junctions, synapses and epithelial cells. Majority of these protein hits were predicted to be part of disease categories comprising cancers and malignant tumors. We propose a ‘MAS-signalosome’ model to stimulate further research in understanding the molecular mechanism of MAS function. Identifying hierarchy of interactions of ‘signalosome’ components with MAS will be a necessary step in future to fully understand the physiological and pathological functions of this enigmatic receptor. PMID

  6. Protective effects of phenolic fraction of blue honeysuckle fruits against UVA-induced damage to human keratinocytes.

    PubMed

    Svobodová, Alena; Rambousková, Jana; Walterová, Daniela; Vostálová, Jitka

    2008-06-01

    In this study, the UVA (photo)protective activity of the phenolic fraction of L. caerulea fruits (PFLC) was assessed in human keratinocytes HaCaT. The keratinocytes were pre- or post-treated with PFLC (1-250 mg/l) and exposed to UVA irradiation (10-30 J/cm(2)). The results showed that both pre- and post-treatment with PFLC significantly suppressed UVA-induced ROS production, which was also revealed as a decrease in intracellular lipid peroxidation and elevation of reduced glutathione. Protection was concentration-dependent with a maximum at 50 mg/l. These results suggest that PFLC attenuates UVA-induced oxidative stress by reduction of ROS generation and ROS-mediated damage. For this reason, PFLC has potentially skin-protective functions against the deleterious effects of sunlight. PMID:18404271

  7. UVA-induced oxidative damage in retinal pigment epithelial cells after H2O2 or sparfloxacin exposure.

    PubMed

    Verna, L K; Holman, S A; Lee, V C; Hoh, J

    2000-01-01

    Retinal impairment is one of the leading causes of visual loss in an aging human population. To explore a possible cause for retinal damage in the human population, we have monitored DNA oxidation in human retinal pigment epithelial (RPE) cells after exposure to hydrogen peroxide (H2O2) or the quinolone antibacterial sparfloxacin. When H2O2- or sparfloxacin-exposed cells were further exposed to ultraviolet A (UVA) irradiation, oxidative damage to the DNA of these cells was greatly increased over baseline values. This RPE+pharmaceutical-UVA cell system was developed to mimic in vivo retinal degeneration, seen in mouse studies using quinolone and UVA exposure. DNA damage produced by sparfloxacin and UVA in RPE cells could be remedied by the use of antioxidants, indicating a possible in vivo method for prevention or minimization of retinal damage in humans PMID:11201054

  8. Skin Treatment with Pulsed Monochromatic UVA1 355 Device and Computerized Morphometric Analysis of Histochemically Identified Langerhans Cells

    PubMed Central

    Zerbinati, Nicola; Riva, Federica; Paulli, Marco; Parodi, Pier Camillo

    2016-01-01

    Fluorescent or metal halide lamps are widely used in therapeutic applications in dermatological diseases, with broadband or narrow band emission UVA/UVA1 (320–400 nm) obtained with suitable passive filters. Recently, it has been possible for us to use a new machine provided with solid state source emitting pulsed monochromatic UVA1 355 nm. In order to evaluate the effects of this emission on immunocells of the skin, human skin samples were irradiated with monochromatic 355 nm UVA1 with different energetic fluences and after irradiation Langerhans cells were labeled with CD1a antibodies. The immunohistochemical identification of these cells permitted evaluating their modifications in terms of density into the skin. Obtained results are promising for therapeutical applications, also considering that a monochromatic radiation minimizes thermic load and DNA damage in the skin tissues. PMID:27525266

  9. Somatic cell mutations caused by 365 nm LED-UVA due to DNA double-strand breaks through oxidative damage.

    PubMed

    Fang, Xing; Ide, Naohiro; Higashi, Sho-Ichi; Kamei, Yasuhiro; Toyooka, Tatsushi; Ibuki, Yuko; Kawai, Kazuaki; Kasai, Hiroshi; Okamoto, Keinosuke; Arimoto-Kobayashi, Sakae; Negishi, Tomoe

    2014-09-01

    Evidence is accumulating indicating that UVA (320-400 nm ultraviolet light) plays an important role in photo-carcinogenesis. UVA is thought to produce reactive oxygen species in irradiated cells through photo-activation of inherent photosensitizers, and was recently reported to cause DNA double-strand breaks (DSBs) in exposed cells. We have investigated the involvement of UVA in mutations and DNA damage in somatic cells using Drosophila melanogaster larvae. Using the Okazaki Large Spectrograph, we previously observed that longer wavelength UVA (>330 nm) was more mutagenic in post-replication repair-deficient D. melanogaster (mei-41) than in the nucleotide excision repair-deficient strain (mei-9). LED-light has recently been developed as a high-dose-rate UVA source. LED-UVA light (365 nm) was also more mutagenic in mei-41 than in mei-9. The mei-41 gene was shown to be an orthologue of the human ATR gene, which is involved in the repair of DSBs through phosphorylation of histone H2AX. In order to estimate the extent to which oxidative damage contributes to mutation, we established a new D. melanogaster strain (urate-null mutant) that is sensitive to oxidative damage and has a marker to detect somatic cell mutations. When somatic cell mutations were examined using this strain, LED-UVA was mutagenic in the urate-null strain at doses that were non-mutagenic in the urate-positive strain. In an effort to investigate the generation of DSBs, we examined the presence of phosphorylated histone H2AvD (H2AX D. melanogaster homologue). At high doses of LED-UVA (>800 kJ m(-2)), levels of phosphorylated H2AvD (γ-H2AvD) increased significantly in the urate-null strain. Moreover, the level of γ-H2AvD increased in the excision repair-deficient strain but not in the ATR-deficient strain following UVA-irradiation. These results supported the notion that the generation of γ-H2AvD was mediated by the function of the mei-41 gene. It was reported that ATR functions on DSB repair in D

  10. UVA-induced epigenetic regulation of P16(INK4a) in human epidermal keratinocytes and skin tumor derived cells.

    PubMed

    Chen, I-Peng; Henning, Stefan; Faust, Alexandra; Boukamp, Petra; Volkmer, Beate; Greinert, Rüdiger

    2012-01-01

    UVA-radiation (315-400 nm) has been demonstrated to be capable of inducing DNA damage and is regarded as a carcinogen. While chromosomal aberrations found in UVA-irradiated cells and skin tumors provided evidence of the genetic involvement in UVA-carcinogenesis, its epigenetic participation is still illusive. We thus analysed the epigenetic patterns of 5 specific genes that are involved in stem cell fate (KLF4, NANOG), telomere maintenance (hTERT) and tumor suppression in cell cycle control (P16(INK4a), P21(WAFI/CIPI)) in chronically UVA-irradiated HaCaT human keratinocytes. A striking reduction of the permissive histone mark H3K4me3 has been detected in the promoter of P16(INK4a) (4-fold and 9-fold reduction for 10 and 15 weeks UVA-irradiated cells, respectively), which has often been found deregulated in skin cancers. This alteration in histone modification together with a severe promoter hypermethylation strongly impaired the transcription of P16(INK4a) (20-fold and 40-fold for 10 weeks and 15 weeks UVA-irradiation, respectively). Analysis of the skin tumor-derived cells revealed the same severe impairment of the P16(INK4a) transcription attributed to promoter hypermethylation and enrichment of the heterochromatin histone mark H3K9me3 and the repressive mark H3K27me3. Less pronounced UVA-induced epigenetic alterations were also detected for the other genes, demonstrating for the first time that UVA is able to modify transcription of skin cancer associated genes by means of epigenetic DNA and histone alterations. PMID:21986889

  11. Angiotensin-(1-7)/Mas axis modulates fear memory and extinction in mice.

    PubMed

    Lazaroni, Thiago Luiz do Nascimento; Bastos, Cristiane Perácio; Moraes, Márcio Flávio Dutra; Santos, Robson Souza; Pereira, Grace Schenatto

    2016-01-01

    Inappropriate defense-alerting reaction to fear is a common feature of neuropsychiatric diseases. Therefore, impairments in brain circuits, as well as in molecular pathways underlying the neurovegetative adjustments to fear may play an essential role on developing neuropsychiatric disorders. Here we tested the hypothesis that interfering with angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis homeostasis, which appears to be essential to arterial pressure control, would affect fear memory and extinction. Mas knockout (MasKO) mice, in FVB/N background, showed normal cued fear memory and extinction, but increased freezing in response to context. Next, as FVB/N has poor performance in contextual fear memory, we tested MasKO in mixed 129xC57BL/6 background. MasKO mice behaved similarly to wild-type (WT), but memory extinction was slower in contextual fear conditioning to a weak protocol (1CS/US). In addition, delayed extinction in MasKO mice was even more pronounced after a stronger protocol (3CS/US). We showed previously that Angiotensin II receptor AT1 antagonist, losantan, rescued object recognition memory deficit in MasKO mice. Here, losartan was also effective. Memory extinction was accelerated in MasKO mice after treatment with losartan. In conclusion, we showed for the first time that Ang-(1-7)/Mas axis may modulate fear memory extinction. Furthermore, we suggest MasKO mice as an animal model to study post-traumatic stress disorder (PTSD). PMID:26642920

  12. Ultraviolet (UVB and UVA) photoprotector activity and percutaneous penetration of extracts obtained from Arrabidaea chica.

    PubMed

    Siraichi, Jackeline T G; Pedrochi, Franciana; Natali, Maria R M; Ueda-Nakamura, Tânia; Filho, Benedito P Dias; Bento, Antonio C; Baesso, Mauro L; Nakamura, Celso V

    2013-10-01

    The aim of this work is to investigate the photoprotection activity and toxicity level of formulations containing the extract and its fractions obtained from leaves of Arrabidaea chica. The ex vivo percutaneous penetration of the extract was evaluated using the photoacoustic spectroscopy technique. The formulation presented optical absorption in the ultraviolet region, including UVA and UVB. This formulation was obtained without adding inorganic UV filters, as is frequently used in commercial sunscreens. The results showed a penetration rate similar to those of commercial sunscreens with its presence on the skin surface at least 180 min after the application. This formulation presented no toxic effects evaluated using hematological, biochemical, and histological assays. The results suggest that the formulation from the leaves of A. chica provides substantial protection against UVA + UVB radiation with a possible advantage of being natural and free of inorganic compounds compared with the majority of available commercial sunscreens. PMID:24067575

  13. Long-term risks of psoralen and UV-A therapy for psoriasis

    SciTech Connect

    Farber, E.M.; Abel, E.A.; Cox, A.J.

    1983-05-01

    It has been more than eight years since photochemotherapy with methoxsalen and UV-A (psoralen and UV-A (PUVA)) was introduced for the treatment of psoriasis. This treatment remained under investigation until May 1982 because of concerns about possible chronic toxic effects. With recent Food and Drug Administration approval of PUVA therapy for severe psoriasis, strict drug labeling for administration and patient use and continued monitoring of side effects have become essential. The full effects of PUVA in regard to carcinogenicity, prematurelly induced aging of the skin, pigmentary changes, immunologic alterations, and ocular side effects are still unknown. A review of the risks of PUVA therapy is presented, with the aim of maintaining a proper perspective for its limited use in treating selected patients.

  14. Anode consumption on a subsea X-mas tree

    SciTech Connect

    Lye, R.E.

    1998-12-31

    Anode consumption and coating breakdown on a X-mas tree installed at the Troll Field in the Norwegian North Sea was investigated after 5 years. A comparison with a spare tree and one tree being exposed for only 3--4 months was done. The epoxy coating has several blisters, in particular on stainless steel surfaces. Water inside the blisters has a pH of 13-14 indicating that the cathodic reaction occurs inside them. The anode dimensions indicate an overall anode consumption of approximately 20%, while the design allows 27% after 5 years. This indicates that the original design is quite conservative. If the design had been done according to present day design rules, the conservatism would be reduced; an overall anode consumption of 23% is then likely (still less than allowed 27%).

  15. MODIS Airborne simulator (MAS) Final Report for CLASIC

    SciTech Connect

    Thomas Arnold; Steven Platnick

    2010-11-24

    The MAS was flown aboard the NASA ER-2 for the CLASIC field experiment, and for all data collected, provided calibrated and geolocated (Level-1B) radiance data for it’s 50 spectral bands (ranging in wavelength for 0.47 to 14.3 µm). From the Level-1B data, as directed in the Statement of Work, higher order (Level-2) data products were derived. The Level-2 products include: a) cloud optical thickness, b) cloud effective radius, c) cloud top height (temperature), d) cloud fraction, e) cloud phase products. Preliminary Level-1B and Level-2 products were provided during the field experiment (typically within one or two days of data collection). Final version data products were made available in December 2008 following considerable calibration analysis. Data collection, data processing (to Level-2), and discussion of the calibration work are summarized below.

  16. Food Waste Composting Study from Makanan Ringan Mas

    NASA Astrophysics Data System (ADS)

    Kadir, A. A.; Ismail, S. N. M.; Jamaludin, S. N.

    2016-07-01

    The poor management of municipal solid waste in Malaysia has worsened over the years especially on food waste. Food waste represents almost 60% of the total municipal solid waste disposed in the landfill. Composting is one of low cost alternative method to dispose the food waste. This study is conducted to compost the food waste generation in Makanan Ringan Mas, which is a medium scale industry in Parit Kuari Darat due to the lack knowledge and exposure of food waste recycling practice. The aim of this study is to identify the physical and chemical parameters of composting food waste from Makanan Ringan Mas. The physical parameters were tested for temperature and pH value and the chemical parameter are Nitrogen, Phosphorus and Potassium. In this study, backyard composting was conducted with 6 reactors. Tapioca peel was used as fermentation liquid and soil and coconut grated were used as the fermentation bed. Backyard composting was conducted with six reactors. The overall results from the study showed that the temperature of the reactors were within the range which are from 30° to 50°C. The result of this study revealed that all the reactors which contain processed food waste tend to produce pH value within the range of 5 to 6 which can be categorized as slightly acidic. Meanwhile, the reactors which contained raw food waste tend to produce pH value within the range of 7 to 8 which can be categorized as neutral. The highest NPK obtained is from Reactor B that process only raw food waste. The average value of Nitrogen is 48540 mg/L, Phosphorus is 410 mg/L and Potassium is 1550 mg/L. From the comparison with common chemical fertilizer, it shows that NPK value from the composting are much lower than NPK of the common chemical fertilizer. However, comparison with NPK of organic fertilizer shown only slightly difference value in NPK.

  17. Chemical shift referencing in MAS solid state NMR

    NASA Astrophysics Data System (ADS)

    Morcombe, Corey R.; Zilm, Kurt W.

    2003-06-01

    Solid state 13C magic angle spinning (MAS) NMR spectra are typically referenced externally using a probe which does not incorporate a field frequency lock. Solution NMR shifts on the other hand are more often determined with respect to an internal reference and using a deuterium based field frequency lock. Further differences arise in solution NMR of proteins and nucleic acids where both 13C and 1H shifts are referenced by recording the frequency of the 1H resonance of DSS (sodium salt of 2,2-dimethyl-2-silapentane-5-sulphonic acid) instead of TMS (tetramethylsilane). In this note we investigate the difficulties in relating shifts measured relative to TMS and DSS by these various approaches in solution and solids NMR, and calibrate adamantane as an external 13C standard for solids NMR. We find that external chemical shift referencing of magic angle spinning spectra is typically quite reproducible and accurate, with better than ±0.03 ppm accuracy being straight forward to achieve. Solid state and liquid phase NMR shifts obtained by magic angle spinning with external referencing agree with those measured using typical solution NMR hardware with the sample tube aligned with the applied field as long as magnetic susceptibility corrections and solvent shifts are taken into account. The DSS and TMS reference scales for 13C and 1H are related accurately using MAS NMR. Large solvent shifts for the 13C resonance in TMS in either deuterochloroform or methanol are observed, being +0.71 ppm and -0.74 ppm from external TMS, respectively. The ratio of the 13C resonance frequencies for the two carbons in solid adamantane to the 1H resonance of TMS is reported.

  18. Chemical shift referencing in MAS solid state NMR.

    PubMed

    Morcombe, Corey R; Zilm, Kurt W

    2003-06-01

    Solid state 13C magic angle spinning (MAS) NMR spectra are typically referenced externally using a probe which does not incorporate a field frequency lock. Solution NMR shifts on the other hand are more often determined with respect to an internal reference and using a deuterium based field frequency lock. Further differences arise in solution NMR of proteins and nucleic acids where both 13C and 1H shifts are referenced by recording the frequency of the 1H resonance of DSS (sodium salt of 2,2-dimethyl-2-silapentane-5-sulphonic acid) instead of TMS (tetramethylsilane). In this note we investigate the difficulties in relating shifts measured relative to TMS and DSS by these various approaches in solution and solids NMR, and calibrate adamantane as an external 13C standard for solids NMR. We find that external chemical shift referencing of magic angle spinning spectra is typically quite reproducible and accurate, with better than +/-0.03 ppm accuracy being straight forward to achieve. Solid state and liquid phase NMR shifts obtained by magic angle spinning with external referencing agree with those measured using typical solution NMR hardware with the sample tube aligned with the applied field as long as magnetic susceptibility corrections and solvent shifts are taken into account. The DSS and TMS reference scales for 13C and 1H are related accurately using MAS NMR. Large solvent shifts for the 13C resonance in TMS in either deuterochloroform or methanol are observed, being +0.71 ppm and -0.74 ppm from external TMS, respectively. The ratio of the 13C resonance frequencies for the two carbons in solid adamantane to the 1H resonance of TMS is reported. PMID:12810033

  19. Impact of UV-A radiation on erythemal UV and UV-index estimation over Korea

    NASA Astrophysics Data System (ADS)

    Park, Sang Seo; Lee, Yun Gon; Kim, Jung Hyun

    2015-12-01

    Because total UV (TUV) in the UV-A region is 100 times higher than in the UV-B region, UV-A is a considerable component when calculating erythemal UV (EUV) and UV-index. The ratio of EUV to TUV in the UV-A value [EUV(A)/TUV(A)] is investigated to convert the EUV(A) from TUV(A) for broadband observation. The representative value of EUV(A)/TUV(A), from the simulation study, is 6.9×10-4, changing from 6.1×10-4 to 7.0×10-4 as aerosol optical depth, total ozone and solar zenith angle change. By adopting the observational data of EUV(B) and TUV(A) from UV-biometer measurements at Yonsei University [(37.57°N, 126.95°E), 84 m above sea level], the EUV irradiance increases to 15% of EUV(B) due to the consideration of EUV(A) from the data of TUV(A) observation. Compared to the total EUV observed from the Brewer spectrophotometer at the same site, the EUV(B) from the UV-biometer observes only 95% of total EUV, and its underestimation is caused by neglecting the effect of UV-A. However, the sum of EUV(B) and EUV(A) [EUV(A+B)] from two UV-biometers is 10% larger than the EUV from the Brewer spectrophotometer because of the spectral overlap effect in the range 320-340 nm. The correction factor for the overlap effect adjusts 8% of total EUV.

  20. Protective effect of selenium and zinc on UV-A damage in human skin fibroblasts.

    PubMed

    Leccia, M T; Richard, M J; Beani, J C; Faure, H; Monjo, A M; Cadet, J; Amblard, P; Favier, A

    1993-10-01

    Ultraviolet A radiation participates in cytotoxicity and carcinogenesis of the skin by a mechanism involving the generation of reactive oxygen species. Endogenous antiradical defense systems utilize metalloenzymes including Se-dependent glutathione peroxidase and Cu and Zn superoxide dismutase. The aim of the present work was to determine the protective effect of two trace elements, Se and Zn, on cultured human diploid fibroblasts exposed to UV-A radiation (broad-spectrum source with a maximum intensity at 375 nm). Selenium in the culture medium (0.1 mg/L) in the form of sodium selenite increased the synthesis and activity of glutathione peroxidase by 60.5% in the absence of exposure to UV-A radiation and by 35% after irradiation with 5 J/cm2 (P = 0.043). The presence of this element significantly increased the survival of UV-A-irradiated fibroblasts (P < 0.0001). This confirms the essential role of Se in the detoxifying activity of the enzyme. In addition, thiobarbituric acid-reacting substances (TBAR), which are lipid peroxidation markers, decreased in the presence of exogenous Se: -19% and -22% without irradiation and after irradiation with 5 J/cm2 (P = 0.056). When Zn was added at the dose of 6.5 mg/L as ZnCl2, fibroblasts subjected to oxidizing stress induced by UV-A were protected from cytotoxicity (P < 0.0001). The TBAR production decreased significantly: -33% without irradiation and -34% after irradiation with 5 J/cm2 (P = 0.008). Superoxide dismutase activity, however, decreased after supplementing with Zn: -26% without irradiation and -20% after UV-A irradiation (P = 0.017). The antioxidant properties of Zn are thus apparently independent of superoxide dismutase activity. PMID:8248330

  1. Luteolin decreases the UVA-induced autophagy of human skin fibroblasts by scavenging ROS

    PubMed Central

    Yan, Miaomiao; Liu, Zhongrong; Yang, Huilan; Li, Cuihua; Chen, Hulin; Liu, Yan; Zhao, Minling; Zhu, Yingjie

    2016-01-01

    Luteolin (LUT) is a flavone, which is universally present as a constituent of traditional Chinese herbs, and certain vegetables and spices, and has been demonstrated to exhibit potent radical scavenging and cytoprotective properties. Although LUT has various beneficial effects on health, the effects of LUT on the protection of skin remain to be fully elucidated. The present study investigated whether LUT can protect human skin fibroblasts (HSFs) from ultraviolet (UV) A irradiation. It was found that, following exposure to different doses of UVA irradiation, the HSFs exhibited autophagy, as observed by fluorescence and transmission electron microscopy, and reactive oxygen species (ROS) bursts, analyzed by flow cytometry, to differing degrees. Following incubation with micromolar concentrations of LUT, ROS production decreased and autophagy gradually declined. In addition, the expression of hypoxia-inducible factor-1α and the classical autophagy-associated proteins, LC3 and Beclin 1 were observed by western blotting. Western blot analysis showed that the expression levels of HIF-1α, LC3-II and Beclin 1 gradually decreased in the UVA-irradiated HSFs following treatment with LUT. These data indicated that UVA-induced autophagy was mediated by ROS, suggesting the possibility of resistance against UV by certain natural antioxidants, including LUT. PMID:27430964

  2. Lactobacillus sakei lipoteichoic acid inhibits MMP-1 induced by UVA in normal dermal fibroblasts of human.

    PubMed

    You, Ga-Eun; Jung, Bong-Jun; Kim, Hye-Rim; Kim, Han-Geun; Kim, Tae-Rahk; Chung, Dae-Kyun

    2013-10-28

    Human skin is continuously exposed to ultraviolet (UV)-induced photoaging. UVA increases the activity of MMP-1 in dermal fibroblasts through mitogen-activated protein kinase (MAPK), p38, signaling. The irradiation of keratinocytes by UVA results in the secretion of the inflammatory cytokine, tumor necrosis factor-α (TNF-α), and the stimulation of MMP-1 in normal human dermal fibroblasts (NHDFs). Lipoteichoic acid (LTA) is a component of the cell wall of gram-positive Lactobacillus spp. of bacteria. LTA is well known as an anti-inflammation molecule. LTA of the bacterium Lactobacillus plantarum has an anti-photoaging effect, but the potential anti-photoaging effect of the other bacteria has not been examined to date. The current study showed that L. sakei LTA (sLTA) has an immune modulating effect in human monocyte cells. Our object was whether inhibitory effects of sLTA on MMP-1 are caused from reducing the MAPK signal in NHDFs. It inhibits MMP-1 and MAPK signaling induced by UVA in NHDFs. We also confirmed effects of sLTA suppressing TNF-α inducing MMP-1 in NHDFs. PMID:23851272

  3. The human melanocyte as a particular target for UVA radiation and an endpoint for photoprotection assessment.

    PubMed

    Marrot, L; Belaidi, J P; Meunier, J R; Perez, P; Agapakis-Causse, C

    1999-06-01

    The induction of DNA breaks by UVA (320-400 nm) in the nucleus of normal human melanocytes in culture was investigated using single cell gel electrophoresis, also called the comet assay. Endogenous pigment and/or melanin-related molecules were found to enhance DNA breakage: comets were more intense in melanocytes than in fibroblasts, in cells with high melanin content or after stimulation of melanogenesis by supplying tyrosine in the culture medium. After UVA doses where strong comets were observed, neither cytotoxicity nor stimulation of tyrosinase activity were detected. However, the accumulation of p53 protein suggested that cells reacted to genotoxic stress under these experimental conditions. The same approach was used to compare two sunscreens with identical sun protection factors but different UVA protection factors. The results presented in this paper suggest that human melanocytes may be used as a target cell to evidence broadspectrum photoprotection. Moreover, these data appear to be helpful in getting a better understanding of the role of sunlight in the initiating steps of melanocyte transformation. PMID:10378007

  4. Mechanism of Aloe Vera extract protection against UVA: shelter of lysosomal membrane avoids photodamage.

    PubMed

    Rodrigues, Daniela; Viotto, Ana Cláudia; Checchia, Robert; Gomide, Andreza; Severino, Divinomar; Itri, Rosangela; Baptista, Maurício S; Martins, Waleska Kerllen

    2016-03-01

    The premature aging (photoaging) of skin characterized by wrinkles, a leathery texture and mottled pigmentation is a well-documented consequence of exposure to sunlight. UVA is an important risk factor for human cancer also associated with induction of inflammation, immunosuppression, photoaging and melanogenesis. Although herbal compounds are commonly used as photoprotectants against the harmful effects of UVA, the mechanisms involved in the photodamage are not precisely known. In this study, we investigated the effects of Aloe Vera (Aloe barbadensis mil) on the protection against UVA-modulated cell killing of HaCaT keratinocytes. Aloe Vera exhibited the remarkable ability of reducing both in vitro and in vivo photodamage, even though it does not have anti-radical properties. Interestingly, the protection conferred by Aloe Vera was associated with the maintenance of membrane integrity in both mimetic membranes and intracellular organelles. The increased lysosomal stability led to a decrease in lipofuscinogenesis and cell death. This study explains why Aloe Vera extracts offer protection against photodamage at a cellular level in both the UV and visible spectra, leading to its beneficial use as a supplement in protective dermatological formulations. PMID:26815913

  5. Terrestrial humic substances in Daliao River and its estuary: optical signatures and photoreactivity to UVA light.

    PubMed

    Chen, Hao; Lei, Kun; Wang, Xuechun

    2016-04-01

    Fluorescent dissolved organic matter (FDOM) components were identified by Parallel Factor Analysis (PARAFAC) in surface water of Daliao River and its estuary with a focus on terrestrial humic substance-(HS)-like FDOM identified under two contrasting hydrological conditions. The hydrological conditions did not have noticeable effect on the spectral features of the terrestrial HS-like FDOM, but did affect the components' intensities and photoreactivity: (1) the intensities of terrestrial HS-like components were higher in the normal flow period than in the high flow period, and (2) a spectrally similar terrestrial HS-like FDOM identified under the two contrasting hydrological conditions showed distinct photoreactivity to the same dose of UVA illumination. The findings indicated that terrestrial HS was generated at lower intensities at the terrestrial sources during the high flow period than during the normal flow period and that the transport of terrestrial HS material through the river-estuary system was affected dominantly by seawater dilution along the salinity gradient while fine-tuned by solar UVA illumination. This study exemplifies the effect of hydrological conditions on optical signatures of terrestrial HS-like FDOM and their photoreactivity towards UVA illumination, improving our understanding of the dynamics of terrestrial HS material in river-estuary systems in the framework of the currently proposed new conceptual model for terrestrial organic matter. PMID:26627698

  6. Evaluation of UVA-induced oxidative stress using a highly sensitive chemiluminescence method

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Xing, Da; Zhu, Debin

    2005-02-01

    Oxidative stress is mainly mediated by reactive oxygen species (ROS). Evaluation of oxidative stress is helpful for choosing an appropriate method to protect the organism from the oxidative damage. In this study, a highly sensitive and simple chemiluminescence method is presented for the evaluation of radiation-induced oxidative stress in human peripheral lymphocytes. The lymphocytes were irradiated by ultraviolet radiation (320-400nm, UVA) with different doses. The ROS generated by the lymphocytes was detected by chemiluminescence method, using a highly sensitive chemiluminescence probe 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-α] pyrazin-3-one (MCLA). The cell viability was detected with Cell Counting Kit-8 (CCK-8). The malondialdehyde (MDA), a marker of lipid peroxidation and oxidative stress, and the total antioxidant capacity (TAC), a parameter that is taken as evidence of oxidative stress, were measured too. The results show that both chemiluminescence intensity, cell mortality and MDA concentration of lymphocytes grow with the increase of UVA dose range from 0.5 to 8 J/cm2, while the TAC decreases. There exists a positive relationship between cell oxidative damage degree and the chemiluminescence intensity of lymphocytes. This highly sensitive chemiluminescence method would potentially provide an easy way to evaluate the level of UVA-induced oxidative stress readily, sensitively and rapidly

  7. UVA-mediated down-regulation of MMP-2 and MT1-MMP coincides with impaired angiogenic phenotype of human dermal endothelial cells

    SciTech Connect

    Cauchard, Jean-Hubert; Robinet, Arnaud; Poitevin, Stephane; Bobichon, Helene; Maziere, Jean-Claude; Bellon, Georges; Hornebeck, William . E-mail: william.hornebeck@univ-reims.fr

    2006-06-30

    UVA irradiation, dose-dependently (5-20 J/cm{sup 2}), was shown to impair the morphogenic differentiation of human microvascular endothelial cells (HMECs) on Matrigel. Parallely, UVA down-regulated the expression of MMP-2 and MT1-MMP, both at the protein and the mRNA levels. On the contrary, the production of MMP-1 and TIMP-1 by HMECs increased following UVA treatment. The inhibitory effect of UVA on MMP expression and pseudotubes formation was mediated by UVA-generated singlet oxygen ({sup 1}O{sub 2}). The contribution of MT1-MMP, but not TIMP-1, to the regulation of HMECs' angiogenic phenotype following UVA irradiation was suggested using elastin-derived peptides and TIMP-1 blocking antibody, respectively.

  8. Electron spin resonance detection of oxygen radicals released by UVA-irradiated human fibroblasts

    NASA Astrophysics Data System (ADS)

    Souchard, J. P.; Pierlot, G.; Barbacanne, M. A.; Charveron, M.; Bonafé, J.-L.; Nepveu, F.

    1999-01-01

    This work reports the electron spin resonance (ESR) detection of oxygenated radicals (OR) released by cultured human fibroblasts after UVA (365 nm) exposure. 5,5-dimethyl-pyrroline-N-oxide (DMPO) was used as spin trap. After a UVA irradiation of one hour, followed by a latent period of at least 45 min., and an incubation time of 30 min. in a trapping medium containing DMPO, glucose, Na^+, K+ and Ca2+ an ESR signal was recorded. By contrast, an ESR signal was produced after only 15 min. incubation when calcium ionophore A23187 was used. Although the ESR signal was characteristic of the hydroxyl adduct DMPO-OH, the use of catalase and superoxide dismutase (SOD) revealed that UVA stimulated fibroblasts released the superoxide anion O2- in the medium. SOD, vitamin C and (+)-catechin inhibited the release of superoxide generated by human fibroblasts stimulated with A23187 calcium ionophore at 5 units/ml, 10-5 M and 2× 10-4 M, respectively. Dans ce travail nous présentons la détection par résonance de spin électronique (RSE) de radicaux oxygénés (RO) libérés par des fibroblastes humains en culture après irradiation aux UVA (365 nm). Le 5,5-diméthyl-1-pyrroline-N-oxyde (DMPO) a été utilisé comme piégeur de spin. Après une irradiation aux UVA d'une heure, suivie d'une période de latence d'au moins 45 min. et d'une incubation de 30 min. dans un milieu de piégeage composé de DMPO, glucose, Na^+, K+ et Ca2+, un signal RPE est enregistré. L'ionophore calcique A23187 entraîne l'apparition d'un signal RPE après seulement 15 min. d'incubation. Bien que le signal RPE obtenu corresponde à l'adduit DMPO-OH du radical hydroxyle, l'utilisation de catalase et de superoxyde dismutase (SOD) a révélé que les fibroblastes libéraient l'anion superoxyde dans le milieu de culture. Sur ce modèle cellulaire la SOD, la vitamine C et la (+) catéchine inhibent la production du radical superoxyde aux concentrations respectivement de 5 unités/ml, 10-5 M et 2× 10-4M.

  9. Measurement of Lens Protein Aggregation in Vivo Using Dynamic Light Scattering in a Guinea Pig/UVA Model for Nuclear Cataract

    PubMed Central

    Simpanya, M. Francis; Ansari, Rafat R.; Leverenz, Victor; Giblin, Frank J.

    2009-01-01

    The role of UVA radiation in the formation of human nuclear cataract is not well understood. We have previously shown that exposing guinea pigs for 5 months to a chronic low level of UVA light produces increased lens nuclear light scattering and elevated levels of protein disulfide. Here we have used the technique of dynamic light scattering (DLS) to investigate lens protein aggregation in vivo in the guinea pig/UVA model. DLS size distribution analysis conducted at the same location in the lens nucleus of control and UVA-irradiated animals showed a 28% reduction in intensity of small diameter proteins in experimental lenses compared with controls (P < 0.05). In addition, large diameter proteins in UVA-exposed lens nuclei increased five-fold in intensity compared to controls (P < 0.05). The UVA-induced increase in apparent size of lens nuclear small diameter proteins was three-fold (P < 0.01), and the size of large diameter aggregates was more than four-fold in experimental lenses compared with controls. The diameter of crystallin aggregates in the UVA-irradiated lens nucleus was estimated to be 350 nm, a size able to scatter light. No significant changes in protein size were detected in the anterior cortex of UVA-irradiated lenses. It is presumed that the presence of a UVA chromophore in the guinea pig lens (NADPH bound to zeta crystallin), as well as traces of oxygen, contributed to UVA-induced crystallin aggregation. The results indicate a potentially harmful role for UVA light in the lens nucleus. A similar process of UVA-irradiated protein aggregation may take place in the older human lens nucleus, accelerating the formation of human nuclear cataract. PMID:18627516

  10. The Role of JNK and p38 MAPK Activities in UVA-Induced Signaling Pathways Leading to AP-1 Activation and c-Fos Expression1

    PubMed Central

    Silvers, Amy L; Bachelor, Michael A; Bowden, G Timothy

    2003-01-01

    Abstract To further delineate ultraviolet A (UVA) signaling pathways in the human keratinocyte cell line HaCaT, we examined the potential role of mitogen-activated protein kinases (MAPKs) in UVA-induced activator protein-1 (AP-1) transactivation and c-Fos expression. UVA-induced phosphorylation of p38 and c-Jun N-terminal kinase (JNK) proteins was detected immediately after irradiation and disappeared after approximately 2 hours. Conversely, phosphorylation of extracellular signal-regulated kinase was significantly inhibited for up to 1 hour post-UVA irradiation. To examine the role of p38 and JNK MAPKs in UVA-induced AP-1 and c-fos transactivations, the selective pharmacologic MAPK inhibitors, SB202190 (p38 inhibitor) and SP600125 (JNK inhibitor), were used to independently treat stably transfected HaCaT cells in luciferase reporter assays. Both SB202190 and SP600125 dose-dependently inhibited UVA-induced AP-1 and c-fos transactivations. SB202190 (0.25–0.5 µM) and SP600125 (62–125 nM) treatments also primarily inhibited UVA-induced c-Fos expression. These results demonstrated that activation of both JNK and p38 play critical role in UVA-mediated AP-1 transactivation and c-Fos expression in these human keratinocyte cells. Targeted inhibition of these MAPKs with their selective pharmacologic inhibitors may be effective chemopreventive strategies for UVA-induced nonmelanoma skin cancer. PMID:14511403

  11. 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

  12. Mas-Mediated Antioxidant Effects Restore the Functionality of Angiotensin Converting Enzyme 2-Angiotensin-(1–7)-Mas Axis in Diabetic Rat Carotid

    PubMed Central

    Gomes, Mayara Santos; Restini, Carolina Baraldi Araujo

    2014-01-01

    We hypothesized that endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species during type I-diabetes impairs carotid ACE2-angiotensin-(1–7)-Mas axis functionality, which accounts for the impaired carotid flow in diabetic rats. We also hypothesized that angiotensin-(1–7) chronic treatment of diabetic rats restores carotid ACE2-angiotensin-(1–7)-Mas axis functionality and carotid flow. Relaxant curves for angiotensin II or angiotensin-(1–7) were obtained in carotid from streptozotocin-induced diabetic rats. Superoxide or hydrogen peroxide levels were measured by flow cytometry in carotid endothelial cells. Carotid flow was also determined. We found that endothelial AT1-activated NAD(P)H oxidase-driven generation of superoxide and hydrogen peroxide in diabetic rat carotid impairs ACE2-angiotensin-(1–7)-Mas axis functionality, which reduces carotid flow. In this mechanism, hydrogen peroxide derived from superoxide dismutation inhibits ACE2 activity in generating angiotensin-(1–7) seemingly by activating ICl,SWELL, while superoxide inhibits the nitrergic Mas-mediated vasorelaxation evoked by angiotensin-(1–7). Angiotensin-(1–7) treatment of diabetic rats restored carotid ACE2-angiotensin-(1–7)-Mas axis functionality by triggering a positive feedback played by endothelial Mas receptors, that blunts endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species. Mas-mediated antioxidant effects also restored diabetic rat carotid flow, pointing to the contribution of ACE2-angiotensin-(1–7)-Mas axis in maintaining carotid flow. PMID:24877125

  13. Decentralized method for complex task allocation in massive MAS

    NASA Astrophysics Data System (ADS)

    Brahmi, Zaki; Gammoudi, M. M.

    2008-06-01

    Task allocation is still a fundamental problem in Multi-Agents System (MAS). It allows the formation a coalition of agents to cooperate together in order to carry out a complex task. Generally, the process of task allocation requires calculating the value of all the possible allocations, then determining which optimal. In the context of Massive Multi-Agent Systems (MMAS), one agent generates all the possible coalitions and then calculates the value of each, is inefficient. Moreover, the traditional approaches based on the negotiation between agents, are impractical because of the complexity of communications between agents. In this paper we propose a decentralized method, based on grouping agents using the Formal Concepts Analysis (FCA) approach for the task allocation in MMAS. In our model, agents are fully cooperative and each task is composed of several subtasks. The proposed solution is based on two steps: i) computing groups of agents having similar characteristics in the objective to distribute the task allocation process among agents and minimize the communication between agents. ii) Finding the optimal allocation by sharing the task allocation process among groups of agents.

  14. Distributed Cooperation Solution Method of Complex System Based on MAS

    NASA Astrophysics Data System (ADS)

    Weijin, Jiang; Yuhui, Xu

    To adapt the model in reconfiguring fault diagnosing to dynamic environment and the needs of solving the tasks of complex system fully, the paper introduced multi-Agent and related technology to the complicated fault diagnosis, an integrated intelligent control system is studied in this paper. Based on the thought of the structure of diagnostic decision and hierarchy in modeling, based on multi-layer decomposition strategy of diagnosis task, a multi-agent synchronous diagnosis federation integrated different knowledge expression modes and inference mechanisms are presented, the functions of management agent, diagnosis agent and decision agent are analyzed, the organization and evolution of agents in the system are proposed, and the corresponding conflict resolution algorithm in given, Layered structure of abstract agent with public attributes is build. System architecture is realized based on MAS distributed layered blackboard. The real world application shows that the proposed control structure successfully solves the fault diagnose problem of the complex plant, and the special advantage in the distributed domain.

  15. Solar-UV-signature mutation prefers TCG to CCG: extrapolative consideration from UVA1-induced mutation spectra in mouse skin.

    PubMed

    Ikehata, Hironobu; Kumagai, Jun; Ono, Tetsuya; Morita, Akimichi

    2013-08-01

    UVA1 exerts its genotoxicity on mammalian skin by producing cyclobutane pyrimidine dimers (CPDs) in DNA and preferentially inducing solar-UV-signature mutations, C → T base substitution mutations at methylated CpG-associated dipyrimidine (Py-mCpG) sites, as demonstrated previously using a 364 nm laser as a UVA1 source and lacZ-transgenic mice that utilize the transgene as a mutational reporter. In the present study, we confirmed that a broadband UVA1 source induced the same mutation profiles in mouse epidermis as the UVA1 laser, generalizing the previous result from a single 364 nm to a wider wavelength range of UVA1 (340-400 nm). Combined with our previous data on the mutation spectra induced in mouse epidermis by UVB, UVA2 and solar UVR, we proved that the solar-UV-signature mutation is commonly observed in the wavelength range from UVB to UVA, and found that UVA1 induces this mutation more preferentially than the other shorter wavelength ranges. This finding indicates that the solar-UV-signature mutation-causing CPDs, which are known to prefer Py-mCpG sites, could be produced with the energy provided by the longer wavelength region of UVR, suggesting a photochemical reaction through the excitation of pyrimidine bases to energy states that can be accomplished by absorption of even low-energy UVR. On the other hand, the lower proportions of solar-UV-signature mutations observed in the mutation spectra for UVB and solar UVR indicate that the direct photochemical reaction through excited singlet state of pyrimidine bases, which can be accomplished only by high-energy UVR, is also involved in the mutation induction at those shorter wavelengths of UVR. We also found that the solar-UV signature prefers 5'-TCG-3' to 5'-CCG-3' as mutational target sites, consistent with the fact that UVA induces CPDs selectively at thymine-containing dipyrimidine sites and that solar UVR induces them preferably at Py-mCpG sites. However, the mutation spectrum in human p53 gene from non

  16. Evaluation of the protective effect of sunscreens on in vitro reconstructed human skin exposed to UVB or UVA irradiation.

    PubMed

    Bernerd, F; Vioux, C; Asselineau, D

    2000-03-01

    We have previously shown that skin reconstructed in vitro is a useful model to study the effects of UVB and UVA exposure. Wavelength-specific biological damage has been identified such as the formation of sunburn cells (SBC) and pyrimidine dimers after UVB irradiation and alterations of dermal fibroblasts after UVA exposure. These specific effects were selected to evaluate the protection afforded by two sunscreens after topical application on the skin surface. Simplified formulations having different absorption spectra but similar sun protection factors were used. One contained a classical UVB absorber, 2-ethylhexyl-p-methoxycinnamate. The other contained a broad-spectrum absorber called Mexoryl SX, characterized by its strong absorbing potency in the UVA range. Both filters were used at 5% in a simple water/oil vehicle. The evaluation of photoprotection on in vitro reconstructed skin revealed good efficiency for both preparations in preventing UVB-induced damage, as shown by SBC counting and pyrimidine dimer immunostaining. By contrast, only the Mexoryl SX-containing preparation was able to efficiently prevent UVA-specific damage such as dermal fibroblast disappearance. Our data further support the fact that skin reconstructed in vitro is a reliable system to evaluate the photoprotection provided by different sunscreens against specific UVB and UVA biological damage. PMID:10732449

  17. 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. PMID:18093761

  18. 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

  19. Thymol and Thymus Vulgaris L. activity against UVA- and UVB-induced damage in NCTC 2544 cell line.

    PubMed

    Calò, Rossella; Visone, Clementina M; Marabini, Laura

    2015-09-01

    Many authors focused on the research of natural compounds in order to protect skin from indirect (UVA) and direct (UVB) ultraviolet radiation side effects. The aim of this study to evaluate the protective effect of a dry extract from T. vulgaris L. and of its major synthetic compound thymol (about 60%), against oxidative and genotoxic UVA- and UVB damage. Experiments were reproduced in a low differentiated keratinocytes cell line (NCTC 2544) Cells were pretreated for 1h, in serum-free medium, with thymol (1μg/mL) or T. vulgaris L. (1.82μg/mL) then exposed to different UVA (8-24J/cm(2)) or UVB doses (0.016-0.72J/cm(2)). Immediately after the UV exposure the intracellular redox status was evaluated by ROS quantification and by LPO. Genotoxic aspects were evaluated 24h after the end of irradiations using the alkaline comet assay, the micronucleus formation assay and the immunostaining of phosphorylated H2AX histone protein (detected 1h after the end of UV exposure). Thymol and T. vulgaris L. extract inhibited ROS generation in UVA and UVB-irradiated cells. On the contrary, MDA formation was reduced only in UVA treated cells. Both agents decreased the DNA damage evaluated by the alkaline comet assay, but not in the micronucleus and H2AX tests probably because of the severity of damage (double strands) detected. PMID:26338540

  20. Investigation of riboflavin sensitized degradation of purine and pyrimidine derivatives of DNA and RNA under UVA and UVB.

    PubMed

    Joshi, Prakash C; Keane, Thomas C

    2010-10-01

    DNA and RNA undergo photodegradation in UVC (200-290nm) due to direct absorption by the purine and pyrimidine bases. Limited effects are observed under UVB (290-320nm) or UVA (320-400nm). We have observed that an endogenous photosensitizer, riboflavin (RF), upon exposure to UVB or UVA can extensively damage the DNA and RNA bases. Guanine, uracil, thymine, adenine and cytosine were degraded by 100%, 82%, 60.4%, 46.3% and 10.3% under UVA (12J) and by 100%, 54.1%, 38.9%, 42.2% and <1.0% under UVB (6J), respectively. Guanosine and deoxyguanosine were degraded by 98±1.0% and 80±1.0% under UVA (4J) and UVB (12J), respectively. With an exception of GMP (53-82%), dGMP (51-88%) and to some extent TMP (3-4%) the remaining nucleosides and nucleotides were resistant to RF-induced photodecomposition. The photodegradation of G derivatives by RF was 2-fold higher than a well known photodynamic agent rose bengal. A comparison of the intensities of UVA and UVB sources used in this study with natural sunlight suggests that exposure with the latter along with an endogenous photosensitizer can have similar effects on DNA and RNA depending upon the duration of exposure. PMID:20816939

  1. Synthesis and luminescent properties of ternary complex Eu(UVA)3Phen in nano-TiO2

    NASA Astrophysics Data System (ADS)

    Lü, Yu-guang; Gong, Zhong-ping; Gao, Hong-bing; Zhou, Shu-jing; Lü, Kui-lin; Wang, Ying; A, Du; Du, Hao-ran; Zhang, Li; Zhang, Fu-jun

    2015-01-01

    By introducing 2-hydroxy-4-methoxy-benzophenone (UVA) and 1,10-phenanthroline (Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra (MS) and infrared (IR) and ultraviolet (UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-TiO2 is prepared, and the nano-TiO2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide (ITO)/poly(N-vinylcar-bazole) (PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.

  2. A polychromatic action spectrum for photosensitivity to orally administered 8-methoxypsoralen in humans.

    PubMed

    Bech-Thomsen, N; Wulf, H C

    1994-01-01

    The action spectrum for producing minimal phototoxic erythema after oral administration of 8-methoxypsoralen (8-MOP) was determined in the range of 312-368 nm in 12 human volunteers using six different UV radiation sources. The peak sensitivity was found to be at 343 nm. The 8-MOP photosensitivity was at a high level (> or = 0.75 of maximum) between 336 and 355 nm. Conventional UVA radiation sources, like the Philips TL/09R tube, have a high energy output within 335 and 355 nm, and are therefore highly recommended in oral psoralen plus UVA radiation treatment. PMID:8313631

  3. Psychometric Comparison of the Motivation Assessment Scale (MAS) and the Questions about Behavioral Function (QABF)

    ERIC Educational Resources Information Center

    Koritsas, S.; Iacono, T.

    2013-01-01

    Background: The Motivation Assessment Scale (MAS) and the Questions About Behavioral Function (QABF) are frequently used to assess the learned function of challenging behaviour in people with intellectual disability (ID). The aim was to explore and compare the psychometric properties of the MAS and the QABF. Method: Seventy adults with ID and…

  4. 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. PMID:26940049

  5. A generic, computerized nuclear materials accountability system (NucMAS) and its layered products

    SciTech Connect

    Davis, Jr, J M

    1989-01-01

    NucMAS provides a material balance area with a computerized data management system for nuclear materials accountability. NucMAS is a generic application. It handles the data management and reporting functions for different processing facilities by storing all process-specific information as data rather than procedure. A NucMAS application is configured for each facility it supports. NucMAS and its layered products are compatible with three types of data clients. Core NucMAS has a screen-oriented user interface to support the accountability clerk as a client. Accountability clerks enter data from operating logs and laboratory analyses one to three days after actual processing. Layered products support process operators and automated systems as near-real-time and real-time data clients. The core and layered products use a data-driven approach which results in software that is configurable and maintainable. 3 refs., 5 figs.

  6. Contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to UV-A.

    PubMed

    Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Raveton, Muriel; Reynaud, Stéphane

    2013-09-15

    Mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. Because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. Numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. Mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure. This ecological feature may affect the general physiology of the insect, including the resistance status against insecticides. In the context of their contrasted breeding sites, we assessed the impact of low-energetic ultraviolet exposure on mosquito sensitivity to biological and chemical insecticides. We show that several mosquito detoxification enzyme activities (cytochrome P450, glutathione S-transferases, esterases) were increased upon low-energy UV-A exposure. Additionally, five specific genes encoding detoxification enzymes (CYP6BB2, CYP6Z7, CYP6Z8, GSTD4, and GSTE2) previously shown to be involved in resistance to chemical insecticides were found over-transcribed in UV-A exposed mosquitoes, revealed by RT-qPCR experiments. More importantly, toxicological bioassays revealed that UV-exposed mosquitoes were more tolerant to four main chemical insecticide classes (DDT, imidacloprid, permethrin, temephos), whereas the bioinsecticide Bacillus thuringiensis subsp. israelensis (Bti) appeared more toxic. The present article provides the first experimental evidence of the capacity of low-energy UV-A to increase mosquito tolerance to major chemical insecticides. This is also the first time that a metabolic resistance to chemical insecticides is linked to a higher susceptibility to a bioinsecticide. These results support the use of Bti as an efficient alternative to chemical insecticides when a metabolic resistance to chemicals has been developed by mosquitoes. PMID:23911355

  7. Preventive effects of tamarind seed coat extract on UVA-induced alterations in human skin fibroblasts.

    PubMed

    Phetdee, Khemjira; Rakchai, Racharat; Rattanamanee, Kwanchai; Teaktong, Thanasak; Viyoch, Jarupa

    2014-01-01

    One of the most damaging actions on skin is from solar radiation, particularly from its ultraviolet (UV) component, through the formation of oxidative species. Thus, an antioxidant strategy that prevents the formation of these oxidants could form the basis of an efficacious cutaneous protectant. Many herbal materials contain antioxidant polyphenols, and this study assessed the possibility that tamarind seed coat extract could fulfill this role. An alcoholic extract of the tamarind (Tamarindus indica L.) seed coat showed stronger antioxidant activity (2,2-diphenyl-1-picrylhydrazyl inhibition, EC(50) = 12.9 μg/ml) than L-ascorbic acid (EC(50) = 22.9 μg/ml) and α-tocopherol (EC(50) = 29.3 μg/ml). In cultured fibroblasts taken from human skin, hydrogen peroxide (100-1000 μM) damaged 62-92% of the cells compared to only 35-47% when the cells were preincubated in extract (200 μg/ml) for 24 h. UVA (40 J/cm2) irradiation of human fibroblasts damaged 25% of the cells but the death rate was reduced to 10% with extract. UV irradiation increased the proportion of cells arrest in G(0)/G(1) phase (from 59% to 78%) but this was largely prevented by the extract (64%), according to flow cytometry. Intracellular total glutathione of UVA-irradiated cells pretreated with the extract increased to 10-25% compared to the non-pretreated group at 24-72 h after irradiation. Fibroblasts typically increased matrix metalloproteinase-1 secretion after photodamage, and this is prevented by the extract. This is the first report showing that tamarind seed coat extract is an antioxidant and can protect human skin fibroblasts from cellular damage produced by UVA and thus may form the foundation for an antiaging cosmetic. PMID:24602819

  8. Mathematical modeling of cell proliferation dynamics in psoriatic epidermis sensitized by the furocoumarins under UVA radiation

    NASA Astrophysics Data System (ADS)

    Baskakov, Pavel V.; Stolnitz, Mikhail M.

    1997-02-01

    In the work the mathematical model is presented which describes the processes in the epidermis sensitized by the furocoumarins under UVA-radiation. The model describes the processes at three levels: molecular (the photochemical transformations of the psoralen molecules and their reactions with the DNA-molecules), cellular (proliferation, differentiation and repairing of injuries), and tissue (humoral regulation, space-time cell dynamics in the epidermis). The results of the numerical simulations of both the latent period and psoriasis manifestation are given. The therapeutical effect of the UV-radiation is considered in the framework of the model.

  9. 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

    2013-11-01

    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. PMID:24007865

  10. The Tryptophan-Derived Endogenous Aryl Hydrocarbon Receptor Ligand 6-Formylindolo[3,2-b]Carbazole Is a Nanomolar UVA Photosensitizer in Epidermal Keratinocytes.

    PubMed

    Park, Sophia L; Justiniano, Rebecca; Williams, Joshua D; Cabello, Christopher M; Qiao, Shuxi; Wondrak, Georg T

    2015-06-01

    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, endoplasmic reticulum 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

  11. Chronic exposure to Rhodobacter sphaeroides extract Lycogen™ prevents UVA-induced malondialdehyde accumulation and procollagen I down-regulation in human dermal fibroblasts.

    PubMed

    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

  12. 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

  13. Atypical Signaling and Functional Desensitization Response of MAS Receptor to Peptide Ligands

    PubMed Central

    Tirupula, Kalyan C.; Desnoyer, Russell; Speth, Robert C.; Karnik, Sadashiva S.

    2014-01-01

    MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1–7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1–7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data

  14. Base pairing enhances fluorescence and favors cyclobutane dimer formation induced upon absorption of UVA radiation by DNA.

    PubMed

    Banyasz, Akos; Vayá, Ignacio; Changenet-Barret, Pascale; Gustavsson, Thomas; Douki, Thierry; Markovitsi, Dimitra

    2011-04-13

    The photochemical properties of the DNA duplex (dA)(20)·(dT)(20) are compared with those of the parent single strands. It is shown that base pairing increases the probability of absorbing UVA photons, probably due to the formation of charge-transfer states. UVA excitation induces fluorescence peaking at ∼420 nm and decaying on the nanosecond time scale. The fluorescence quantum yield, the fluorescence lifetime, and the quantum yield for cyclobutane dimer formation increase upon base pairing. Such behavior contrasts with that of the UVC-induced processes. PMID:21417388

  15. The sunburn cell in hairless mouse epidermis: quantitative studies with UV-A radiation and mono- and bifunctional psoralens

    SciTech Connect

    Young, A.R.; Magnus, I.A.

    1982-10-01

    The production of the sunburn cell by UV-A radiation and topical psoralens in hairless mouse epidermis has been studied. It has been shown that the appearance of this cell is dependent on the dose of both UV-A radiation and of the psoralen. The time-course with 8-methoxypsoralen has peak sunburn cell numbers at 28 hr postirradiation. A comparison of 2 bifunctional (8-methoxypsoralen and 5-methoxypsoralen) and 2 monofunctional (angelicin and 3-carbethoxypsoralen) psoralens showed the former are more potent. This suggests that DNA crosslink lesions may play a rle in sunburn cell production.

  16. MasABK Proteins Interact with Proteins of the Type IV Pilin System to Affect Social Motility of Myxococcus xanthus

    PubMed Central

    Fremgen, Sarah; Williams, Amanda; Furusawa, Gou; Dziewanowska, Katarzyna; Settles, Matthew; Hartzell, Patricia

    2013-01-01

    Gliding motility is critical for normal development of spore-filled fruiting bodies in the soil bacterium Myxococcus xanthus. Mutations in mgl block motility and development but one mgl allele can be suppressed by a mutation in masK, the last gene in an operon adjacent to the mgl operon. Deletion of the entire 5.5 kb masABK operon crippled gliding and fruiting body development and decreased sporulation. Expression of pilAGHI, which encodes type IV pili (TFP) components essential for social (S) gliding, several cryptic pil genes, and a LuxR family protein were reduced significantly in the Δmas mutant while expression of the myxalamide operon was increased significantly. Localization and two-hybrid analysis suggest that the three Mas proteins form a membrane complex. MasA-PhoA fusions confirmed that MasA is an integral cytoplasmic membrane protein with a ≈100 amino acid periplasmic domain. Results from yeast two-hybrid assays showed that MasA interacts with the lipoprotein MasB and MasK, a protein kinase and that MasB and MasK interact with one another. Additionally, yeast two-hybrid analysis revealed a physical interaction between two gene products of the mas operon, MasA and MasB, and PilA. Deletion of mas may be accompanied by compensatory mutations since complementation of the Δmas social gliding and developmental defects required addition of both pilA and masABK. PMID:23342171

  17. Sealed rotors for in situ high temperature high pressure MAS NMR

    DOE PAGESBeta

    Hu, Jian Z.; Hu, Mary Y.; Zhao, Zhenchao; Xu, Souchang; Vjunov, Aleksei; Shi, Hui; Camaioni, Donald M.; Peden, Charles H. F.; Lercher, Johannes A.

    2015-07-06

    Magic angle spinning (MAS) nuclear magnetic resonance (NMR) investigations on heterogeneous samples containing solids, semi-solids, liquid and gases or a mixture of them under non-conventional conditions of a combined high pressure and high temperature, or cold temperature suffer from the unavailability of a perfectly sealed rotor. Here, we report the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are easy to use and are suitable for operation temperatures from below 0 to 250 °C and pressures up to 100 bar. As an example of potential applications we performed in situ MAS NMR investigations of AlPO₄-5 molecular sieve crystallization,more » a kinetic study of the cyclohexanol dehydration reaction using 13C MAS NMR, and an investigation of the metabolomics of intact biological tissue at low temperature using 1H HR-MAS NMR spectroscopy. The in situ MAS NMR experiments performed using the reported rotors allowed reproduction of the results from traditional batch reactions, while offering more detailed quantitative information at the molecular level, as demonstrated for the molecular sieve synthesis and activation energy measurements for cyclohexanol dehydration. The perfectly sealed rotor also shows promising application for metabolomics studies using 1H HR-MAS NMR.« less

  18. Sealed rotors for in situ high temperature high pressure MAS NMR

    SciTech Connect

    Hu, Jian Z.; Hu, Mary Y.; Zhao, Zhenchao; Xu, Souchang; Vjunov, Aleksei; Shi, Hui; Camaioni, Donald M.; Peden, Charles H. F.; Lercher, Johannes A.

    2015-07-06

    Magic angle spinning (MAS) nuclear magnetic resonance (NMR) investigations on heterogeneous samples containing solids, semi-solids, liquid and gases or a mixture of them under non-conventional conditions of a combined high pressure and high temperature, or cold temperature suffer from the unavailability of a perfectly sealed rotor. Here, we report the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are easy to use and are suitable for operation temperatures from below 0 to 250 °C and pressures up to 100 bar. As an example of potential applications we performed in situ MAS NMR investigations of AlPO₄-5 molecular sieve crystallization, a kinetic study of the cyclohexanol dehydration reaction using 13C MAS NMR, and an investigation of the metabolomics of intact biological tissue at low temperature using 1H HR-MAS NMR spectroscopy. The in situ MAS NMR experiments performed using the reported rotors allowed reproduction of the results from traditional batch reactions, while offering more detailed quantitative information at the molecular level, as demonstrated for the molecular sieve synthesis and activation energy measurements for cyclohexanol dehydration. The perfectly sealed rotor also shows promising application for metabolomics studies using 1H HR-MAS NMR.

  19. UV-A fluorescence of sunscreens and possible energy transfer to skin components

    NASA Astrophysics Data System (ADS)

    Krishnan, Rajagopal; Elmets, Craig A.; Nordlund, Thomas M.

    2008-02-01

    Photophysical studies of UV-B sunscreens showed a measurable UV-A emission from padimate O (2-ethylhexyl-4-(dimethylamino)benzoate). Since recent studies associate UV-A to skin cancer induction pathways, as well as skin aging, we studied the effect of padimate O emission when applied to skin. After application of padimate O to skin the emission spectrum of skin showed a large increase in the intensity of 470 nm peak. The 470 nm emission in skin arises from a skin component, possibly collagen, which absorbs at about 360 nm, where padimate O emits. The excitation spectra of skin with padimate O measured at an emission wavelength of 468 nm show a peak at 310 nm with a broad shoulder at about 350 nm to 370 nm, which increased in intensity with time. However, the excitation spectrum of skin with octyl salicylate (another UV-B emitting sunscreen) did not show such a shoulder or increase in intensity. Thus, we attribute the presence of a shoulder in the excitation spectrum of skin and the increase in its intensity as evidence for energy transfer from padimate O to collagen. The transfer mechanism is not clear.

  20. UVA radiation is highly mutagenic in cells that are unable to repair 7,8-dihydro-8-oxoguanine in Saccharomyces cerevisiae.

    PubMed

    Kozmin, S; Slezak, G; Reynaud-Angelin, A; Elie, C; de Rycke, Y; Boiteux, S; Sage, E

    2005-09-20

    UVA (320-400 nm) radiation constitutes >90% of the environmentally relevant solar UV radiation, and it has been proposed to have a role in skin cancer and aging. Because of the popularity of UVA tanning beds and prolonged periods of sunbathing, the potential deleterious effect of UVA has emerged as a source of concern for public health. Although generally accepted, the impact of DNA damage on the cytotoxic, mutagenic, and carcinogenic effect of UVA radiation remains unclear. In the present study, we investigated the sensitivity of a panel of yeast mutants affected in the processing of DNA damage to the lethal and mutagenic effect of UVA radiation. The data show that none of the major DNA repair pathways, such as base excision repair, nucleotide excision repair, homologous recombination, and postreplication repair, efficiently protect yeast from the lethal action of UVA radiation. In contrast, the results show that the Ogg1 DNA glycosylase efficiently prevents UVA-induced mutagenesis, suggesting the formation of oxidized guanine residues. Furthermore, sequence analysis of UVA-induced canavanine-resistant mutations reveals a bias in favor of GC-->TA events when compared with spontaneous or H(2)O(2)-, UVC-, and gamma-ray- induced canavanine-resistant mutations in the WT strain. Taken together, our data point out a major role of oxidative DNA damage, mostly 7,8-dihydro-8-oxoguanine, in the genotoxicity of UVA radiation in the yeast Saccharomyces cerevisiae. Therefore, the capacity of skin cells to repair 7,8-dihydro-8-oxoguanine may be a key parameter in the mutagenic and carcinogenic effect of UVA radiation in humans. PMID:16157879

  1. Effect of light irradiation and sex hormones on jurkat T cells: 17beta-estradiol but not testosterone enhances UVA-induced cytotoxicity in Jurkat lymphocytes.

    PubMed

    Cohly, Hari H P; Graham-Evans, Barbara; Ndebele, Kenneth; Jenkins, John K; McMurray, Robert; Yan, Jian; Yu, Hongtao; Angel, Michael F

    2005-04-01

    In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male sex hormones. CD4+ Jurkat T cells were plated in 96 well plates at 2 x 106 cells/ml and treated with 17beta-estradiol (EST) or testosterone (TE). These cells were irradiated by UVA light with an irradiance of 170 J/cm2 for 15min at a distance of 6 cm from the surface of the 96-well plate. Controls included cells not treated with hormones or UVA. The effects of EST and TE were investigated between 1 and 20 ng/mL. Cytotoxicity by fluorescein-diacetate staining and COMET assay generating single strand DNA cleavage, tail length and tail moment measurements were examined. The effect of estrogen (5ng/mL) on apoptosis and its mediators was further studied using DNA laddering and western blotting for bcl-2 and p53. We found that EST alone, without UVA, enhanced Jurkat T cell survival. However, EST exhibited a dose-related cytotoxicity in the presence of UVA; up to 28% at 20 ng/ml. TE did not alter UVA-induced cytotoxicity. Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed. COMET assay demonstrated the harmful effects of EST in the presence of UVA while EST without UVA. had no significant effect on the nuclear damage. Apoptosis was not present as indicated by the absence of DNA laddering on agarose gel electrophoresis at 5ng/ml EST or TE +/- UVA. Western blot showed that estrogen down regulated bcl-2 independently of UVA radiation while p53 was down regulated in the presence of UVA treatment. EST and TE have differential effects on UVA-induced cytotoxicity in Jurkat T-lymphocyte which suggested that women may be more susceptible

  2. Citron and lemon under the lens of HR-MAS NMR spectroscopy.

    PubMed

    Mucci, Adele; Parenti, Francesca; Righi, Valeria; Schenetti, Luisa

    2013-12-01

    High Resolution Magic Angle Spinning (HR-MAS) is an NMR technique that can be applied to semi-solid samples. Flavedo, albedo, pulp, seeds, and oil gland content of lemon and citron were studied through HR-MAS NMR spectroscopy, which was used directly on intact tissue specimens without any physicochemical manipulation. HR-MAS NMR proved to be a very suitable technique for detecting terpenes, sugars, organic acids, aminoacids and osmolites. It is valuable in observing changes in sugars, principal organic acids (mainly citric and malic) and ethanol contents of pulp specimens and this strongly point to its use to follow fruit ripening, or commercial assessment of fruit maturity. HR-MAS NMR was also used to derive the molar percentage of fatty acid components of lipids in seeds, which can change depending on the Citrus species and varieties. Finally, this technique was employed to elucidate the metabolic profile of mold flavedo. PMID:23871074

  3. BOREAS Level-2 MAS Surface Reflectance and Temperature Images in BSQ Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Newcomer, Jeffrey (Editor); Lobitz, Brad; Spanner, Michael; Strub, Richard; Lobitz, Brad

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Aircraft Data Acquisition Program focused on providing the research teams with the remotely sensed aircraft data products they needed to compare and spatially extend point results. The MODIS Airborne Simulator (MAS) images, along with other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes biophysical parameter maps such as surface reflectance and temperature. Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-2 MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C130 navigation data in a MAS scan model. The data are provided in binary image format files.

  4. BOREAS Level-1B MAS Imagery At-sensor Radiance, Relative X and Y Coordinates

    NASA Technical Reports Server (NTRS)

    Strub, Richard; Strub, Richard; Newcomer, Jeffrey A.; Ungar, Stephen

    2000-01-01

    For BOReal Ecosystem-Atmosphere Study (BOREAS), the MODIS Airborne Simulator (MAS) images, along with the other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes detailed land cover and biophysical parameter maps such as fraction of Photosynthetically Active Radiation (fPAR) and Leaf Area Index (LAI). Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-1b MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C-130 INS data in a MAS scan model. The data are provided in binary image format files.

  5. Cassini's Maneuver Automation Software (MAS) Process: How to Successfully Command 200 Navigation Maneuvers

    NASA Technical Reports Server (NTRS)

    Yang, Genevie Velarde; Mohr, David; Kirby, Charles E.

    2008-01-01

    To keep Cassini on its complex trajectory, more than 200 orbit trim maneuvers (OTMs) have been planned from July 2004 to July 2010. With only a few days between many of these OTMs, the operations process of planning and executing the necessary commands had to be automated. The resulting Maneuver Automation Software (MAS) process minimizes the workforce required for, and maximizes the efficiency of, the maneuver design and uplink activities. The MAS process is a well-organized and logically constructed interface between Cassini's Navigation (NAV), Spacecraft Operations (SCO), and Ground Software teams. Upon delivery of an orbit determination (OD) from NAV, the MAS process can generate a maneuver design and all related uplink and verification products within 30 minutes. To date, all 112 OTMs executed by the Cassini spacecraft have been successful. MAS was even used to successfully design and execute a maneuver while the spacecraft was in safe mode.

  6. Five Board Games for the Language Classroom: Uvas, Montana Rusa, El Futbol, La Corrida de Verbos, Paso a Paso.

    ERIC Educational Resources Information Center

    Snyder, Barbara

    A collection of five board games for the Spanish language classroom contains gameboards, game markers, and directions for each game. It also contains general instructions for the teacher about the classroom use of board games. The games include: "Uvas," for use in vocabulary development and cultural awareness; "Montana Rusa," for general…

  7. Study of fibroblast gene expression in response to oxidative stress induced by hydrogen peroxide or UVA with skin aging.

    PubMed

    Hazane-Puch, Florence; Bonnet, Mathilde; Valenti, Kita; Schnebert, Sylvianne; Kurfurst, Robin; Favier, Alain; Sauvaigo, Sylvie

    2010-01-01

    The skin aging process, implying oxidative stress, is associated with specific gene expression. Ultraviolet A (UVA) and hydrogen peroxide (H(2)O(2)) both generate reactive oxygen species (ROS) making them relevant in the study of skin cell responses to oxidative stresses. To investigate transcript expression associated with chronological skin aging and its modulation by two oxidative stresses, cDNA micro-arrays, composed of a set of 81 expressed sequence tag (EST) clones, were used to probe the patterns of transcript expression in human fibroblasts of five young (< 21 years-old) and five older (> 50 years-old) healthy females at basal levels and 24 h after exposure to UVA (7 J/cm2) and H(2)O(2) (20 mM). At the basal state, 22% of total genes were up-regulated in the older group. Although both stresses led to the same cell mortality, H(2)O(2) induced a stronger modulation of gene expression than UVA, with 19.5% of transcripts up-regulated versus 4%. The aging process affected the response to H(2)O(2) and even though cells from old donors presented higher basal levels of transcripts they were not able to regulate them in response to the stress. Interestingly, UVA had a specific strong inhibitory effect on the expression of chemokine (C-C) motif ligand 2 (CCL2) transcript, suggesting a possible mechanism for its anti-inflammatory and immunoregulatory roles. PMID:20299309

  8. 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. PMID:24445737

  9. Protective effects of ginseng leaf extract using enzymatic extraction against oxidative damage of UVA-irradiated human keratinocytes.

    PubMed

    Kim, Mi-Ryung; Lee, Hyun-Sun; Choi, Hyeon-Son; Kim, Sun Young; Park, Yooheon; Suh, Hyung Joo

    2014-06-01

    UVA is responsible for numerous biological effects on the skin, including premature aging characterized by wrinkles, leathery texture, and mottled pigmentation. The objective of this study was evaluating the protective effect of ginseng leaf extract prepared by Ultraflo L on skin from photodamage. Anti-wrinkle effect of ginseng leaf extract with or without Ultraflo L treatment were tested on human keratinocyte cells (HaCaT) irradiated with ultraviolet (UV) A. Ginseng leaves inhibited ROS generation, GHS depletion, and expression of MMP-2 and MMP-9 induced by UVA irradiation. The glutathione (GSH) content of the cells was significantly increased by over 25 μg mL(-1) of Ultraflo-treated extract (UTGL) as well as by over 100 μg mL(-1) of nonenzyme-treated extract (NEGL) compared to control. UTGL and NEGL treatments significantly decreased expression of metalloproteinase (MMP)-2 and 9 compared with control, but inhibitory effects of two groups on expression of MMPs were not significantly different. Overall, ULtraflo L-treated ginseng leaves inhibited ROS generation, GHS depletion, and expression of MMP-2 and MMP-9 in UVA photodamaged HaCat cells. From these results, enzyme-treated ginseng leaf extract has advantages over untreated ginseng leaves and have potential as a skin protective ingredient against UVA-induced photodamage. PMID:24736942

  10. Photoprotective effects of oxyresveratrol and Kuwanon O on DNA damage induced by UVA in human epidermal keratinocytes.

    PubMed

    Hu, Shuting; Chen, Feng; Wang, Mingfu

    2015-03-16

    Ultraviolet A not only plays a major part in photoaging and skin tanning but also induces genetic damage and mutation in the epidermal basal layer of human skin. The photoprotective effect of oxyresveratrol and kuwanon O, two phenolic compounds from the root extract of Morus australis, in human primary epidermal keratinocytes was investigated in this study. Both of them were nontoxic to cells at a concentration less than 10 and 0.5 μM, respectively. After pretreatment at the concentrations of 5 and 10 μM, oxyresveratrol increased cell viability, exhibited significant suppressions on UVA- or H2O2-induced cellular ROS. UVA-enhanced nitrotyrosine was also reduced by post-treatment with oxyresveratrol at theses concentrations. Kuwanon O presented similar inhibitions on cellular ROS and nitrotyrosine with lower concentrations (0.25 and 0.5 μM), but there is no significant protection on cell survival after UVA irradiation. Their photoprotective effects also involved the enhanced repair of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and cyclobutane pyrimidine dimers (CPDs) as mediated by the augment of p53 expression after UVA radiation. PMID:25588103

  11. A mineral sunscreen affords genomic protection against ultraviolet (UV) B and UVA radiation: in vitro and in situ assays.

    PubMed

    Cayrol, C; Sarraute, J; Tarroux, R; Redoules, D; Charveron, M; Gall, Y

    1999-08-01

    Ultraviolet (UV) radiation has been shown to be responsible for different biological effects on human skin, including the initiation of photocarcinogenesis. Both UVB and UVA have been described as mutagenic, but the processes by which they alter the DNA are different. Although cells can repair DNA damage, some deleterious mutations nevertheless appear and can promote cancer. The risk of photocarcinogenesis is acknowledged and the frequency of photogenodermatosis is increasing. In order to evaluate the protection efficacy of a high sun protection factor (SPF) mineral sunscreen against UVB- and UVA-induced genomic alterations, we have followed two approaches. First, we have tested the sunscreen for its ability to decrease the unscheduled DNA synthesis response in vitro in human fibroblasts, as an indirect measure of UVB-induced lesions (0.005 and 0.01 J/cm2), and second, we have verified its ability to reduce the in situ end-labelling intensity in human skin as a direct measure of UVA-induced single-strand breaks (10 J/cm2). Microscopic analysis clearly demonstrated the protective effect of the sunscreen against UVB and UVA. A dose-dependent effect of mineral sunscreens was observed. There was also a relationship between the SPF and genomic protection. By limiting the accumulation of UV-induced lesions on DNA, this mineral sunscreen could limit the mutation frequency. PMID:10468796

  12. Extracorporeal Photochemotherapy Of Cutaneous T Cell Lymphoma.

    NASA Astrophysics Data System (ADS)

    Gasparro, Francis P.

    1988-02-01

    A photochemotherapy based on the synergistic action of 8-methoxypsoralen (8-MOP) and long wavelength ultraviolet light (UVA, 320-400 nm) has been used extensively since 1974 for the treatment of psoriasis, a hyperprolifierative disease of the skin. More recently, this photochemotherapy has been used for the extracorporeal irradiation ot the blood of cutaneous T cell lymphoma (CTCL) patients in the leukemic stage of the disease. 8-MOP is ingested; two hours later when peak blood levels have been achieved the affected tissue is irradiated (skin in psoriasis and blood in CTCL). Using 8-MCP-DNA photoadduct formation as a cheillical actinometer, the effective dose of UVA radiation delivered to lymphocytes during photochemotherapy in the presence of erythrocytes was found to be ~1 J/cm2. In addition, a monoclonal antibody prepared in our laboratory was used in competitive ELISA assays to quantify the formation of 8-MOP photoadducts during the photochemotherapy.

  13. Potentiating Effect of UVA Irradiation on Anticancer Activity of Carboplatin Derivatives Involving 7-Azaindoles

    PubMed Central

    Štarha, Pavel; Trávníček, Zdeněk; Dvořák, Zdeněk; Radošová-Muchová, Tereza; Prachařová, Jitka; Vančo, Ján; Kašpárková, Jana

    2015-01-01

    The moderate-to-high in vitro cytotoxicity against ovarian A2780 (IC50 = 4.7–14.4 μM), prostate LNCaP (IC50 = 18.7–30.8 μM) and prostate PC-3 (IC50 = 17.6–42.3 μM) human cancer cell lines of the platinum(II) cyclobutane-1,1'-dicarboxylato complexes [Pt(cbdc)(naza)2] (1–6; cbdc = cyclobutane-1,1'-dicarboxylate(2-); naza = halogeno-substituted 7-azaindoles), derived from the anticancer metallodrug carboplatin, are reported. The complexes containing the chloro- and bromo-substituted 7-azaindoles (1, 2, and 4–6) showed a significantly higher (p < 0.05) cytotoxicity against A2780 cell line as compared to cisplatin used as a reference drug. Addition of the non-toxic concentration (5.0 μM) of L-buthionine sulfoximine (L-BSO, an effective inhibitor of γ-glutamylcysteine synthase) markedly increases the in vitro cytotoxicity of the selected complex 3 against A2780 cancer cell line by a factor of about 4.4. The cytotoxicity against A2780 and LNCaP cells, as well as the DNA platination, were effectively enhanced by UVA light irradiation (λmax = 365 nm) of the complexes, with the highest phototoxicity determined for compound 3, resulting in a 4-fold decline in the A2780 cells viability from 25.1% to 6.1%. The 1H NMR and ESI-MS experiments suggested that the complexes did not interact with glutathione as well as their ability to interact with guanosine monophosphate. The studies also confirmed UVA light induced the formation of the cis [Pt(H2O)2(cbdc`)(naza)] intermediate, where cbdc` represents monodentate-coordinated cbdc ligand, which is thought to be responsible for the enhanced cytotoxicity. This is further supported by the results of transcription mapping experiments showing that the studied complexes preferentially form the bifunctional adducts with DNA under UVA irradiation, in contrast to the formation of the less effective monofunctional adducts in dark. PMID:25875850

  14. Potentiating effect of UVA irradiation on anticancer activity of Carboplatin derivatives involving 7-azaindoles.

    PubMed

    Štarha, Pavel; Trávníček, Zdeněk; Dvořák, Zdeněk; Radošová-Muchová, Tereza; Prachařová, Jitka; Vančo, Ján; Kašpárková, Jana

    2015-01-01

    The moderate-to-high in vitro cytotoxicity against ovarian A2780 (IC50 = 4.7-14.4 μM), prostate LNCaP (IC50 = 18.7-30.8 μM) and prostate PC-3 (IC50 = 17.6-42.3 μM) human cancer cell lines of the platinum(II) cyclobutane-1,1'-dicarboxylato complexes [Pt(cbdc)(naza)2] (1-6; cbdc = cyclobutane-1,1'-dicarboxylate(2-); naza = halogeno-substituted 7-azaindoles), derived from the anticancer metallodrug carboplatin, are reported. The complexes containing the chloro- and bromo-substituted 7-azaindoles (1, 2, and 4-6) showed a significantly higher (p < 0.05) cytotoxicity against A2780 cell line as compared to cisplatin used as a reference drug. Addition of the non-toxic concentration (5.0 μM) of L-buthionine sulfoximine (L-BSO, an effective inhibitor of γ-glutamylcysteine synthase) markedly increases the in vitro cytotoxicity of the selected complex 3 against A2780 cancer cell line by a factor of about 4.4. The cytotoxicity against A2780 and LNCaP cells, as well as the DNA platination, were effectively enhanced by UVA light irradiation (λmax = 365 nm) of the complexes, with the highest phototoxicity determined for compound 3, resulting in a 4-fold decline in the A2780 cells viability from 25.1% to 6.1%. The 1H NMR and ESI-MS experiments suggested that the complexes did not interact with glutathione as well as their ability to interact with guanosine monophosphate. The studies also confirmed UVA light induced the formation of the cis [Pt(H2O)2(cbdc`)(naza)] intermediate, where cbdc` represents monodentate-coordinated cbdc ligand, which is thought to be responsible for the enhanced cytotoxicity. This is further supported by the results of transcription mapping experiments showing that the studied complexes preferentially form the bifunctional adducts with DNA under UVA irradiation, in contrast to the formation of the less effective monofunctional adducts in dark. PMID:25875850

  15. The Consistency of the Pandemic Simulations between the SEIR Model and the MAS Model

    NASA Astrophysics Data System (ADS)

    Toyosaka, Yuki; Hirose, Hideo

    There are two main methods for pandemic simulations: the SEIR model and the MAS model. The SEIR model can deal with simulations quickly for many homogeneous populations with simple ordinary differential equations; however, the model cannot accommodate many detailed conditions. The MAS model, the multi-agent simulation, can deal with detailed simulations under the many kinds of initial and boundary conditions with simple social network models. However, the computing cost will grow exponentially as the population size becomes larger. Thus, simulations in the large-scale model would hardly be realized unless supercomputers are available. By combining these two methods, we may perform the pandemic simulations in the large-scale model with lower costs. That is, the MAS model is used in the early stage of a pandemic simulation to determine the appropriate parameters to be used in the SEIR model. With these obtained parameters, the SEIR model may then be used. To investigate the validity of this combined method, we first compare the simulation results between the SEIR model and the MAS model. Simulation results of the MAS model and the SEIR model that uses the parameters obtained by the MAS model simulation are found to be close to each other.

  16. A Novel α/β-Hydrolase Gene IbMas Enhances Salt Tolerance in Transgenic Sweetpotato

    PubMed Central

    Song, Xuejin; He, Shaozhen; Liu, Qingchang

    2014-01-01

    Salt stress is one of the major environmental stresses in agriculture worldwide and affects crop productivity and quality. The development of crops with elevated levels of salt tolerance is therefore highly desirable. In the present study, a novel maspardin gene, named IbMas, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line ND98. IbMas contains maspardin domain and belongs to α/β-hydrolase superfamily. Expression of IbMas was up-regulated in sweetpotato under salt stress and ABA treatment. The IbMas-overexpressing sweetpotato (cv. Shangshu 19) plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbMas up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes, under salt stress. These findings suggest that overexpression of IbMas enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity. PMID:25501819

  17. Comparing the Effects of Lovastatin and Cornus Mas Fruit on Fibrinogen Level in Hypercholesterolemic Rabbits

    PubMed Central

    Asgary, Sedigheh; Rafieian-Kopaei, Mahmoud; Adelnia, Azadeh; Kazemi, Somayeh; Shamsi, Fatemeh

    2010-01-01

    BACKGROUND Atherosclerosis, which is a result of gradual deposition of lipids in the lower part of blood vessel endothelium, is the leading cause of mortality and morbidity around the world. It has been proved that some inflammatory blood markers such as fibrinogen can predict the risk for cardiovascular disease conditions, not only in cardiovascular patients, but also in those who do not have any manifestations of the atherosclerotic development. In this study, the effect of cornus mas l. was evaluated on fibrinogen of hypercholesterolemic rabbits and it was also compared with lovastatin drug. METHODS In this study, 25 New Zealand adult male rabbits were randomly divided into five groups of five. They were treated for 60 days by 5 different diets, namely basic, high cholesterol, regular plus 1 g/kgBW cornus mas L. powder, high cholesterol plus 1 g/kgBW cornus mas L. powder, and high cholesterol plus 10 mg/kgBW lovastatin. At the beginning and at the end of this period, blood samples were collected from the rabbits and their serum fibrinogen levels were measured. RESULTS Cornus mas L. powder and lovastatin significantly decreased fibrinogen levels in comparison with high cholesterol group (P < 0.05). Furthermore cornus mas L. powder could reduce the fibrinogen level more than lovastatin (P < 0.05). CONCLUSION The results indicated that consumption of cornus mas L. might be beneficial in atherosclerotic patients due to its reducing effects on fibrinogen. PMID:22577405

  18. Topical pimecrolimus and tacrolimus do not accelerate photocarcinogenesis in hairless mice after UVA or simulated solar radiation.

    PubMed

    Lerche, Catharina M; Philipsen, Peter A; Poulsen, Thomas; Wulf, Hans Christian

    2009-03-01

    Pimecrolimus and tacrolimus are topical calcineurin inhibitors developed specifically for the treatment of atopic eczema. Experience with long-term use of topical calcineurin inhibitors is limited and the risk of rare but serious adverse events remains a concern. We have previously demonstrated the absence of carcinogenic effect of tacrolimus alone and in combination with simulated solar radiation (SSR) on hairless mice. The aim of this study is to determine whether pimecrolimus accelerates photocarcinogenesis in combination with SSR or pimecrolimus and tacrolimus accelerate photocarcinogenesis in combination with UVA. We used 11 groups of 25 hairless female C3.Cg/TifBomTac immunocompetent mice (n = 275). Pimecrolimus cream or tacrolimus ointment was applied on their dorsal skin three times weekly followed by SSR (2, 4, or 6 standard erythema doses, SED) or UVA (25 J/cm(2)) 3-4 h later. This was done up to 365 days in the SSR-treated groups and up to 500 days in the UVA-treated groups. Pimecrolimus did not accelerate the time for development of the first, second or third tumor in any of the groups. Median time to the first tumor was 240 days for the control-2SED group compared with pimecrolimus-2SED group (233 days), control-4SED group (156 days) compared with pimecrolimus-4SED group (163 days) and control-6SED group (162 days) compared with pimecrolimus-6SED group (170 days). Only one mouse in each of the three UVA groups developed a tumor. We conclude that pimecrolimus in combination with SSR and both pimecrolimus and tacrolimus in combination with UVA do not accelerate photocarcinogenesis in hairless mice. PMID:19183401

  19. UVA-UVB Photoprotective Activity of Topical Formulations Containing Morinda citrifolia Extract

    PubMed Central

    Serafini, Mairim Russo; Detoni, Cassia Britto; Menezes, Paula dos Passos; Pereira Filho, Rose Nely; Fortes, Vanessa Silveira; Vieira, Maria José Fonseca; Guterres, Sílvia Stanisçuaski; de Albuquerque Junior, Ricardo Luiz Cavalcanti; Araújo, Adriano Antunes de Souza

    2014-01-01

    Exposure to solar radiation, particularly its ultraviolet (UV) component, has a variety of harmful effects on human health. Some of these effects include sunburn cell formations, basal and squamous cell cancers, melanoma, cataracts, photoaging of the skin, and immune suppression. The beneficial photoprotective effects of topical formulations with the extract, Morinda citrifolia, have not been investigated. This present study aims to investigate the potential benefits of M. citrifolia topical application on the dorsal skin of mice, exposed to UVA-UVB light. Using 7 days of treatment, [before (baseline values) and 20 h after UV exposure], the thickness, skin barrier damage (TEWL), erythema, and histological alterations were evaluated. The results showed that the formulations containing the extract protected the skin against UV-induced damage. PMID:25133171

  20. Effects of topical petrolatum and salicylic acid upon skin photoreaction to UVA.

    PubMed

    Birgin, Bahar; Fetil, Emel; Ilknur, Turna; Tahsin Güneş, Ali; Ozkan, Sebnem

    2005-01-01

    Various agents which can be used in combination can also interfere with phototherapy. In this study, the effects of topical petrolatum and 20% salicylic acid in petrolatum upon skin photoreaction to UVA were investigated, in an in vivo test. Minimal phototoxic dose (MPD) test was performed on 31 volunteers and the test was repeated with thin (0.1 cc/25 cm(2)) petrolatum, thick (0.3 cc/25 cm(2)) petrolatum, thin 20% salicylic acid in petrolatum, thick 20% salicylic acid in petrolatum and sunscreen. The effect of each agent on MPD was investigated. MPD was increased with thin and thick applications of all agents. Also, MPD was increased with 20% salicylic acid in petrolatum when compared with pure petrolatum, in the same thickness. The application of petrolatum and salicylic acid in petrolatum just before PUVA therapy is not recommended because of their blocking effects. PMID:15908297

  1. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1996-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. Three research areas are being actively investigated, including: (1) Mechanical and environmental degradation mechanisms in advanced light metals, (2) Aerospace materials science, and (3) Mechanics of materials for light aerospace structures.

  2. UVA-UVB photoprotective activity of topical formulations containing Morinda citrifolia extract.

    PubMed

    Serafini, Mairim Russo; Detoni, Cassia Britto; Menezes, Paula dos Passos; Pereira Filho, Rose Nely; Fortes, Vanessa Silveira; Vieira, Maria José Fonseca; Guterres, Sílvia Stanisçuaski; Cavalcanti de Albuquerque Junior, Ricardo Luiz; Araújo, Adriano Antunes de Souza

    2014-01-01

    Exposure to solar radiation, particularly its ultraviolet (UV) component, has a variety of harmful effects on human health. Some of these effects include sunburn cell formations, basal and squamous cell cancers, melanoma, cataracts, photoaging of the skin, and immune suppression. The beneficial photoprotective effects of topical formulations with the extract, Morinda citrifolia, have not been investigated. This present study aims to investigate the potential benefits of M. citrifolia topical application on the dorsal skin of mice, exposed to UVA-UVB light. Using 7 days of treatment, [before (baseline values) and 20 h after UV exposure], the thickness, skin barrier damage (TEWL), erythema, and histological alterations were evaluated. The results showed that the formulations containing the extract protected the skin against UV-induced damage. PMID:25133171

  3. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edger A., Jr.

    1996-01-01

    This progress report covers achievements made between January 1 and June 30, 1966 on the NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. . The accomplishments presented in this report are: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures. Collective accomplishments between January and June of 1996 include: 4 journal or proceedings publications, 1 NASA progress report, 4 presentations at national technical meetings, and 2 PhD dissertations published.

  4. Inactivation of conidia of Paecilomyces fumosoroseus by near-ultraviolet (UVB and UVA) and visible radiation.

    PubMed

    Fargues, J; Rougier, M; Goujet, R; Smits, N; Coustere, C; Itier, B

    1997-01-01

    The detrimental effects of solar radiation, especially the ultraviolet waveband, on quiescent conidia of Paecilomyces fumosoroseus were investigated. Conidia were irradiated by a high-intensity source, which emitted a continuous spectrum from 270 to 1100 nm and which was equipped with long-pass filters to block short wavelengths below 280, 295, 320, or 400 nm. After irradiation, conidia were tested for germinability, survival, and infectivity toward Spodoptera frugiperda larvae. It was demonstrated that the detrimental effects of light depended on irradiance in the shortest wavelengths. The UVB (280-320 and 295-320 nm) appeared to be the most detrimental part of natural radiation, although UVA (320-400 nm) was also harmful. Visible and near infrared radiations were less harmful than UV. Our results demonstrate that the irradiance of the UVB waveband should be considered as the pertinent factor for the detrimental effects of sunlight on the persistence of conidia of entomopathogenic fungi in insolated environments. PMID:9028931

  5. Authenticity markers in Aglianico, Uva di Troia, Negroamaro and Primitivo grapes.

    PubMed

    Tamborra, Pasquale; Esti, Marco

    2010-02-15

    Aglianico, Negroamaro, Uva di Troia, and Primitivo, non-aromatic red grapes of southern Italy, were analyzed with respect to berry varietal markers, namely anthocyanins, flavonols, hydroxycinnamoyl tartaric acids (HPLC-DAD) and glycosidic aroma precursors (GC-MS) together with shikimic acid (HPLC-UV). In this study, we confirmed that the relative amount of grape glycosidic precursors from various terpene families was a helpful varietal discriminating factor. An additional decisive contribution to varietal differentiation was also provided by shikimic acid, acetylated forms of anthocyanins, cyanidin-3-O-glucoside, trans-caftaric and trans-coutaric acids. A three-dimensional model of principal component analysis was adopted to evidence the study results. PMID:20103166

  6. UVA mediated synthesis of gold nanoparticles in pharmaceutical-grade heparin sodium solutions

    NASA Astrophysics Data System (ADS)

    Rodríguez-Torres, M. Del P.; Diaz-Torres, L. A.; Olmos-López, M.; Salas, P.; Gutiérrez, Clara

    2013-09-01

    A photochemical-based method in which UVA light (λ=366 nm) is used for synthesizing gold nanoparticles is presented by irradiating gold (III) chloride hydrate (HAuCl4) in the presence of pharmaceutical-grade heparin sodium (PGHEP) as a reducing and stabilizing agent in aqueous solution. Different HAuCl4 to PGHEP concentration ratios were exposed to UVA for up to seven hours. The as-synthesized nanoparticles were characterized by UV-VIS and Raman spectroscopy, transmission electron microscopy (TEM), and pH measurements. The synthesized AuNPs present spherical as well as anisotropic shapes, such as oval, triangular, hexagonal sheets, rods, and some other faceted forms, with dimensions ranging from 20 nm to 300 nm. All obtained products show good temporal stability in solution. Surface plasmons differ when varying HAuCl4 to PGHEP concentration ratio. The obtained samples exhibit two absorption peaks, one in the region between 500-600 nm, and another one in the near-IR between 900-1200 nm; both peaks shift to longer wavelengths and increase their absorption intensity as the HAuCl4 to PGHEP concentration ratio increase. TEM images show the change in nanoparticles yield as well as the shape and sizes change depending on HAuCl4 to PGHEP concentration ratio variation. Ph measurements suggest that acidic media promote anisotropic nanoparticle formation. Raman spectroscopy was used to find out which heparin sodium main groups attached to the nanoparticles surface, and in what amount. In summary, it is found that when modifying the reactants concentrations and keeping the UV exposition time as the only fixed parameter, different nanoparticles with distinctive characteristics can be attained.

  7. Carcinogenesis induced by UVA (365-nm) radiation: the dose-time dependence of tumor formation in hairless mice.

    PubMed

    de Laat, A; van der Leun, J C; de Gruijl, F R

    1997-05-01

    Although ultraviolet B (UVB wavelengths 280-315 nm) dominates the carcinogenic effect of sunlight, ultraviolet A (UVA 315-400 nm) is estimated to contribute 10-20% to the carcinogenic dose; a substantial background that is not affected by a depletion of the ozone layer. Furthermore, certain high-power modern tanning lamps emit mainly long wave UVA (UVA1; 340-400 nm). For a proper risk estimate of UVA exposure its carcinogenicity relative to that of UVB exposure needs to be determined more accurately. To this end we determined the dose-time relationship for skin tumor induction in hairless mice that were irradiated daily with custom-made Philips 365-nm sources. Irradiation of the group exposed to the highest of the four daily doses (430, 240, 140 and 75 kJ/m2) had to be discontinued because severe scratching set in after 3 months (no tumors). In the lower dose-groups the prevalence curves for skin carcinomas (percentage of tumor-bearing mice versus logarithm of time) ran virtually parallel, and were similar to those found with daily UVB exposure. However, the relationship between the daily dose (D) and the median tumor induction time (t50) appeared to differ: with UVB we found that t50 D(r) = constant, with r = 0.6, whereas with UVA1 we found r approximately 0.4. This would imply that 365-nm carcinogenesis shows less of a dose-dependency than UVB carcinogenesis, and that 365-nm radiation becomes more carcinogenic, relative to UVB, as the daily doses are lowered. This relative shift at low doses complicates extrapolation of UVB to UVA risks in humans. Based on the t50 from the lowest dose-group we found that the carcinogenicity at 365 nm (per J/m2) is 0.9 x 10(-4) times that at 293 nm, the wavelength of maximum carcinogenicity in hairless mice. This result for 365-nm carcinogenicity falls well within the margins of error of the wavelength dependency that was estimated earlier from experiments with broadband UV sources. PMID:9163689

  8. Phototherapy and photopharmacology

    SciTech Connect

    Gasparro, F.P.; Chan, G.; Edelson, R.L.

    1985-11-01

    The activation of 8-methoxypsoralen (8-MOP) by long-wavelength ultraviolet A light (UVA, 320-400 nm) induces the formation of interstrand cross-links in DNA. Psoralen plus UVA (PUVA) is widely used in the treatment of psoriasis, a hyperproliferative disease of the skin. A new psoralen plus UVA therapy has been developed in which the 8-MOP-containing blood of cutaneous T cell lymphoma (CTCL) patients is irradiated with UVA light extracorporeally (i.e., extracorporeal photopheresis). The first group of patients had the leukemic variant of CTCL. A regimen of two treatments on successive days at monthly intervals produced a clinical response in eight of 11 patients. In this review the properties of several psoralens (both naturally occurring and synthetic derivatives) are compared, using several assays (DNA cross-linking, inhibition of lymphocyte response to mitogen stimulation, and cell viability). The development of a panel of monoclonal antibodies that recognize 8-MOP-modified DNA is also described. These antibodies have been used to quantitate 8-MOP photoadduct levels in human DNA samples. In addition to the psoralens, the light activation of two other compounds, gilvocarcin and an insulin-psoralen conjugate, is described.

  9. The role of angiotensin-(1–7) receptor Mas in spermatogenesis in mice and rats

    PubMed Central

    Leal, Marcelo C; Pinheiro, Sérgio V B; Ferreira, Anderson J; Santos, Robson A S; Bordoni, Leonardo S; Alenina, Natalia; Bader, Michael; França, Luiz R

    2009-01-01

    Evidence regarding the components of the renin–angiotensin (Ang) system suggests that this system plays an important role in male reproduction. However, there are few data available in the literature on the effects of Ang-(1–7) on the male reproductive system. The present study investigated the effects of the genetic deletion and chronic blockage of Ang-(1–7) receptor Mas on spermatogenesis and male fertility. The localization of Mas in mouse and rat testes was determined by binding assays and immunofluorescence, whereas the testis structure and spermatogenic process were morphologically and stereologically analysed by light microscopy. Ang-(1–7) binding and immunofluorescence revealed the presence of Mas in the testes of mice and rats. Although the total numbers of Sertoli and Leydig cells per testis and Leydig cell size were similar in both wild-type and Mas-deficient mice, Mas−/– animals exhibited a significant reduction in testis weight and a greater volume of apoptotic cells, giant cells and vacuoles in the seminiferous epithelium. In both mice and rats, an increased number of apoptotic cells were found during meiosis. Due to disturbed spermatogenesis, daily sperm production was markedly reduced in Mas−/– mice. Moreover, chronic infusion of A-779 [an Ang-(1–7) antagonist] in rats significantly increased the total number of apoptotic cells and primary spermatocytes in particular stages of spermatogenesis. Taken together, these findings strongly suggest that Ang-(1–7) receptor Mas plays an important role in the regulation of spermatogenesis. PMID:19438767

  10. High-frequency dynamic nuclear polarization in MAS spectra of membrane and soluble proteins.

    PubMed

    Rosay, Melanie; Lansing, Jonathan C; Haddad, Kristin C; Bachovchin, William W; Herzfeld, Judith; Temkin, Richard J; Griffin, Robert G

    2003-11-12

    One of the principal promises of solid-state NMR (SSNMR) magic angle spinning (MAS) experiments has been the possibility of determining the structures of molecules in states that are not accessible via X-ray or solution NMR experiments-e.g., membrane or amyloid proteins. However, the low sensitivity of SSNMR often restricts structural studies to small-model compounds and precludes many higher-dimensional solid-state MAS experiments on such systems. To address the sensitivity problem, we have developed experiments that utilize dynamic nuclear polarization (DNP) to enhance sensitivity. In this communication, we report the successful application of MAS DNP to samples of cryoprotected soluble and membrane proteins. In particular, we have observed DNP signal enhancements of up to 50 in 15N MAS spectra of bacteriorhodopsin (bR) and alpha-lytic protease (alpha-LP). The spectra were recorded at approximately 90 K where MAS is experimentally straightforward, and the results suggest that the described protocol will be widely applicable. PMID:14599177

  11. A software framework for analysing solid-state MAS NMR data.

    PubMed

    Stevens, Tim J; Fogh, Rasmus H; Boucher, Wayne; Higman, Victoria A; Eisenmenger, Frank; Bardiaux, Benjamin; van Rossum, Barth-Jan; Oschkinat, Hartmut; Laue, Ernest D

    2011-12-01

    Solid-state magic-angle-spinning (MAS) NMR of proteins has undergone many rapid methodological developments in recent years, enabling detailed studies of protein structure, function and dynamics. Software development, however, has not kept pace with these advances and data analysis is mostly performed using tools developed for solution NMR which do not directly address solid-state specific issues. Here we present additions to the CcpNmr Analysis software package which enable easier identification of spinning side bands, straightforward analysis of double quantum spectra, automatic consideration of non-uniform labelling schemes, as well as extension of other existing features to the needs of solid-state MAS data. To underpin this, we have updated and extended the CCPN data model and experiment descriptions to include transfer types and nomenclature appropriate for solid-state NMR experiments, as well as a set of experiment prototypes covering the experiments commonly employed by solid-sate MAS protein NMR spectroscopists. This work not only improves solid-state MAS NMR data analysis but provides a platform for anyone who uses the CCPN data model for programming, data transfer, or data archival involving solid-state MAS NMR data. PMID:21953355

  12. Residue specific hydration of primary cell wall potato pectin identified by solid-state 13C single-pulse MAS and CP/MAS NMR spectroscopy.

    PubMed

    Larsen, Flemming H; Byg, Inge; Damager, Iben; Diaz, Jerome; Engelsen, Søren B; Ulvskov, Peter

    2011-05-01

    Hydration of rhamnogalacturonan-I (RG-I) derived from potato cell wall was analyzed by (13)C single-pulse (SP) magic-angle-spinning (MAS) and (13)C cross-polarization (CP) MAS nuclear magnetic resonance (NMR) and supported by (2)H SP/MAS NMR experiments. The study shows that the arabinan side chains hydrate more readily than the galactan side chains and suggests that the overall hydration properties can be controlled by modifying the ratio of these side chains. Enzymatic modification of native (NA) RG-I provided samples with reduced content of arabinan (sample DA), galactan (sample DG), or both side chains (sample DB). Results of these samples suggested that hydration properties were determined by the length and character of the side chains. NA and DA exhibited similar hydration characteristics, whereas DG and DB were difficult to hydrate because of the less hydrophilic properties of the rhamnose-galacturonic acid (Rha-GalA) backbone in RG-I. Potential food ingredient uses of RG-I by tailoring of its structure are discussed. PMID:21462966

  13. Technology Enhanced Learning for People with Intellectual Disabilities and Cerebral Paralysis: The MAS Platform

    NASA Astrophysics Data System (ADS)

    Colomo-Palacios, Ricardo; Paniagua-Martín, Fernando; García-Crespo, Ángel; Ruiz-Mezcua, Belén

    Education for students with disabilities now takes place in a wide range of settings, thus, including a wider range of assistive tools. As a result of this, one of the most interesting application domains of technology enhanced learning is related to the adoption of learning technologies and designs for people with disabilities. Following this unstoppable trend, this paper presents MAS, a software platform aimed to help people with severe intellectual disabilities and cerebral paralysis in their learning processes. MAS, as a technology enhanced learning platform, provides several tools that supports learning and monitoring for people with special needs, including adaptative games, data processing and monitoring tools. Installed in a special needs education institution in Madrid, Spain, MAS provides special educators with a tool that improved students education processes.

  14. Line shapes in CP/MAS NMR spectra of half-integer quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Hayashi, Shigenobu; Hayamizu, Kikuko

    1993-02-01

    Cross polarization (CP) from 1H to quadrupolar nuclei with S = 3/2 has been carried out under magic-angle-spinning (MAS) conditions for powder samples of Na 2B 4O 7·10H 2O and H 3BO 3. The line shapes in the CP/MAS NMR spectra are different from those in the spectra measured with the single pulse sequence combined with 1H dipolar decoupling. Furthermore, the line shapes are found to be dependent on the measuring conditions such as the pulse amplitude for the quadrupolar nuclei. The spin-locking experiments demonstrate that line shapes in CP/MAS NMR spectra are largely dependent on the spin-locking efficiency.

  15. Investigation of domain size in polymer membranes using double quantum filtered spin diffusion MAS NMR.

    SciTech Connect

    Fujimoto, Cy H.; Alam, Todd Michael; Cherry, Brian Ray; Cornelius, Christopher James

    2005-02-01

    Solid-state {sup 1}H magic angle spinning (MAS) NMR was used to investigate sulfonated Diels-Alder poly(phenlylene) polymer membranes. Under high spinning speed {sup 1}H MAS conditions, the proton environments of the sulfonic acid and phenylene polymer backbone are resolved. A double-quantum (DQ) filter using the rotor-synchronized back-to-back (BABA) NMR multiple-pulse sequence allowed the selective suppression of the sulfonic proton environment in the {sup 1}H MAS NMR spectra. This DQ filter in conjunction with a spin diffusion NMR experiment was then used to measure the domain size of the sulfonic acid component within the membrane. In addition, the temperature dependence of the sulfonic acid spin-spin relaxation time (T{sub 2}) was determined, providing an estimate of the activation energy for the proton dynamics of the dehydrated membrane.

  16. The sun protection factor (SPF) inadequately defines broad spectrum photoprotection: demonstration using skin reconstructed in vitro exposed to UVA, UVBor UV-solar simulated radiation.

    PubMed

    Bernerd, Françoise; Vioux, Corinne; Lejeune, François; Asselineau, Daniel

    2003-01-01

    Wavelength specific biological damage has been previously identified in human skin reconstructed in vitro. Sunburn cell and pyrimidine dimers were found after UVB exposure, and alterations of dermal fibroblasts after UVA exposure. These damages permitted us to discriminate UVB and UVA single absorbers. The present study shows that these biological effects can be obtained simultaneously by a combined UVB + UVA exposure using ultraviolet solar simulated light (UV-SSR), which represents a relevant UV source. In addition, the protection afforded by two broad spectrum sunscreen complex formulations was assessed after topical application. These two formulations displayed the same sun protection factor but different UVA protection factors determined by the persistent pigment darkening (PPD) method. Dose response experiments of UVA or UV-SSR showed that the preparation with the highest PF-UVA provided a better protection with regard to dermal damage compared to the other formulation. Using an original UVB source to obtain the UVB portion of SSR spectrum, the preparations provided the same protection. This study strikingly illustrates the fact that the photoprotection afforded by two sunscreen formulations having similar SPF values is not equal with regard to dermal damage related to photoaging. PMID:12804982

  17. Effect of supplemental UV-B and UV-A on phenolic accumulation, growth and photosynthesis in barley and soybean seedlings

    SciTech Connect

    Liu, Lan; Gitz, D.C. III; Huerta, A.J.; McClure, J.W. )

    1990-05-01

    Barley (Atlas 68) and soybeans (Williams, Pella and Hobbit) were grown under 260 {mu}E m{sup {minus}2} s{sup {minus}1} cool-white fluorescent light plus: (1) no supplemental illumination, (2) UV-B from Phillips FS40 lamps to simulate 30% O{sub 3} depletion at 40{degree}N, or (3) UV-A from Mylar-filtered FS40 lamps. In barley primary leaves, neither UV-A nor UV-B had any effect on the accumulation of flavonoids or ferulic acid in the epidermis. In contrast, in barley mesophyll flavonoids were increased ca. 40% by UV-A and ca. 80% by UV-B and mesophyll ferulic acid increased ca. 10 fold under either UV-A or UV-B. In soybean primary leaves UV-A had no effect on flavonoid (all were epidermal) accumulation in any variety, but UV-B increased flavonoid accumulation ca. 20% in Williams, 100% in Pella and almost 10-fold in Hobbit. UV-A and UV-B effects on growth rates and selected photosynthetic parameters will be presented.

  18. Control of skin infections by a combined action of ultraviolet A (from sun or UVA lamp) and hydrogen peroxide (HUVA therapy), with special emphasis on leprosy.

    PubMed

    Ahmad, S I

    2001-10-01

    Despite its abundance and certain therapeutic value, the importance of sunlight in the treatment of infectious skin diseases has not been fully exploited. One reason is that a sufficient amount of the damaging components of sunlight (UVC and most UVB) cannot reach us and the band of UV that can reach (UVA) is a poor inactivator of living cells. UVA, however, can be deleterious to cells in the presence of sensitizers and a number of biological and chemical sensitizers have been identified which can inactivate microbes in the presence of UVA. Of several known agents, I have selected hydrogen peroxide (H(2)O(2)) as a UVA sensitizer and propose that a combined action of H(2)O(2)and UVA (HUVA therapy) can be utilized in controlling skin infections of various types. Of particular interest is infection by Mycobacterium leprae, which is known to affect many millions of humans globally. H(2)O(2)being relatively cheap (and UVA from the sun being free) the cost of application, particularly in third-world countries where leprosy is more common, would be low and therefore the treatment can be employed on a wide scale. A further reason for proposing the use of H(2)O(2)is that, out of several agents we have tested, this was found to be the most potent; it is also easily able to reach target sites, very cheap, relatively safe and there is no known microbial resistance to HUVA. PMID:11601875

  19. A theoretical study of the UV absorption of 4-methylbenzylidene camphor: from the UVB to the UVA region.

    PubMed

    da Silva, Luís Pinto; Ferreira, Paulo J O; Miranda, Margarida S; Esteves da Silva, Joaquim C G

    2015-02-01

    In this study, a theoretical approach was used to study the UV absorption of the UVB filter, 4-methylbenzylidene camphor. The main objective of this work was to design new UVA filters based on this rather photo-stable compound, so that photo-degradation in this UV region can be avoided without the use of other molecules. This objective was achieved by the simultaneous addition of two appropriate substituents, which led to red-shifts of up to 0.69 eV while maintaining appreciable oscillator strength. Also, useful structure-energy relationships were derived, which allow for the development of more UVA filters based on 4-methylbenzylidene camphor. PMID:25521601

  20. 29Si and 27Al MAS NMR spectra of mullites from different kaolinites.

    PubMed

    He, Hongping; Guo, Jiugao; Zhu, Jianxi; Yuan, Peng; Hu, Cheng

    2004-04-01

    Mullites synthesized from four kaolinites with different random defect densities have been studied by 27Al and 29Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) and X-ray diffraction (XRD). All these mullites show the same XRD pattern. However, 29Si and 27Al MAS NMR spectra reveal that the mullites derived from kaolinites with high defect densities, have a sillimanite-type Al/Si ordering scheme and are low in silica, whereas those mullites derived from kaolinites with low defect densities, consist of both sillimanite- and mullite-type Al/Si ordering schemes and are rich in silica. PMID:15084323

  1. Apigenin inhibits UVA-induced cytotoxicity in vitro and prevents signs of skin aging in vivo.

    PubMed

    Choi, Sungjin; Youn, Jeungyeun; Kim, Karam; Joo, Da Hye; Shin, Shanghun; Lee, Jeongju; Lee, Hyun Kyung; An, In-Sook; Kwon, Seungbin; Youn, Hae Jeong; Ahn, Kyu Joong; An, Sungkwan; Cha, Hwa Jun

    2016-08-01

    Apigenin (4',5,7-trihydroxyflavone) is a flavone that has been reported to have anti-inflammatory, antioxidant and anti-carcinogenic properties. In this study, we investigated the protective effects of apigenin on skin and found that, in experiments using cells, apigenin restored the viability of normal human dermal fibroblasts (nHDFs), which had been decreased by exposure to ultraviolet (UV) radiation in the UVA range. Using a senescence-associated (SA)-β-gal assay, we also demonstrate that apigenin protects against the UVA-induced senescence of nHDFs. Furthermore, we found that apigenin decreased the expression of the collagenase, matrix metalloproteinase (MMP)-1, in UVA-irradiated nHDFs. UVA, which has been previously identified as a photoaging-inducing factor, has been shown to induce MMP-1 expression. The elevated expression of MMP-1 impairs the collagen matrix, leading to the loss of elasticity and skin dryness. Therefore, we examined the clinical efficacy of apigenin on aged skin, using an apigenin‑containing cream for clinical application. Specifically, we measured dermal density, skin elasticity and the length of fine wrinkles in subjects treated with apigenin cream or the control cream without apigenin. Additionally, we investigated the effects of the apigenin-containing cream on skin texture, moisture and transepidermal water loss (TEWL). From these experiments, we found that the apigenin‑containing cream increased dermal density and elasticity, and reduced fine wrinkle length. It also improved skin evenness, moisture content and TEWL. These results clearly demonstrate the biological effects of apigenin, demonstrating both its cellular and clinical efficacy, and suggest that this compound holds promise as an anti-aging cosmetic ingredient. PMID:27279007

  2. 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

  3. Pea aphid Acyrthosiphon pisum sequesters plant-derived secondary metabolite L-DOPA for wound healing and UVA resistance

    PubMed Central

    Zhang, Yi; Wang, Xing-Xing; Zhang, Zhan-Feng; Chen, Nan; Zhu, Jing-Yun; Tian, Hong-Gang; Fan, Yong-Liang; Liu, Tong-Xian

    2016-01-01

    Herbivores can ingest and store plant-synthesized toxic compounds in their bodies, and sequester those compounds for their own benefits. The broad bean, Vicia faba L., contains a high quantity of L-DOPA (L-3,4-dihydroxyphenylalanine), which is toxic to many insects. However, the pea aphid, Acyrthosiphon pisum, can feed on V. faba normally, whereas many other aphid species could not. In this study, we investigated how A. pisum utilizes plant-derived L-DOPA for their own benefit. L-DOPA concentrations in V. faba and A. pisum were analyzed to prove L-DOPA sequestration. L-DOPA toxicity was bioassayed using an artificial diet containing high concentrations of L-DOPA. We found that A. pisum could effectively adapt and store L-DOPA, transmit it from one generation to the next. We also found that L-DOPA sequestration verity differed in different morphs of A. pisum. After analyzing the melanization efficiency in wounds, mortality and deformity of the aphids at different concentrations of L-DOPA under ultraviolet radiation (UVA 365.0 nm for 30 min), we found that A. pisum could enhance L-DOPA assimilation for wound healing and UVA-radiation protection. Therefore, we conclude that A. pisum could acquire L-DOPA and use it to prevent UVA damage. This study reveals a successful co-evolution between A. pisum and V. faba. PMID:27006098

  4. DOC and UVA attenuation with soil aquifer treatment in the saturated zone of an artificial coastal sandfill.

    PubMed

    Chua, Lloyd H C; Lo, Edmond Y M; Shuy, Eng Ban; Robertson, Alexander P; Lim, Teik Thye; Tan, Soon Keat

    2010-01-01

    Results from a direct recharge experiment conducted in the field to investigate DOC and UVA(254) attenuation rates during the direct injection of UF treated wastewater into a artificial coastal sandfill are presented in this paper. Approximately 500 m(3) of ultra-filtered wastewater was injected into the saturated zone, over a period of 9 days. The movement of the plume was tracked over 80 days, during which time samples were obtained from multilevel samplers installed in transects across the drift axis of the plume. An analysis of fluorescein in the samples obtained during the drift of the UF plume showed that DOC and UVA were attenuated beyond rates predicted by conservative mixing, by up to a maximum of 45%. A degradation coefficient of 0.0175 day(-1) was found to be applicable for DOC degradation. After a drift period of 80 days, DOC and UVA reduced to approximately 4.5 mg/l and 0.100 cm(-1), respectively, from initial values of 8.06 mg/l and 0.199 cm(-1). PMID:20705995

  5. 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). PMID:26692512

  6. Pea aphid Acyrthosiphon pisum sequesters plant-derived secondary metabolite L-DOPA for wound healing and UVA resistance.

    PubMed

    Zhang, Yi; Wang, Xing-Xing; Zhang, Zhan-Feng; Chen, Nan; Zhu, Jing-Yun; Tian, Hong-Gang; Fan, Yong-Liang; Liu, Tong-Xian

    2016-01-01

    Herbivores can ingest and store plant-synthesized toxic compounds in their bodies, and sequester those compounds for their own benefits. The broad bean, Vicia faba L., contains a high quantity of L-DOPA (L-3,4-dihydroxyphenylalanine), which is toxic to many insects. However, the pea aphid, Acyrthosiphon pisum, can feed on V. faba normally, whereas many other aphid species could not. In this study, we investigated how A. pisum utilizes plant-derived L-DOPA for their own benefit. L-DOPA concentrations in V. faba and A. pisum were analyzed to prove L-DOPA sequestration. L-DOPA toxicity was bioassayed using an artificial diet containing high concentrations of L-DOPA. We found that A. pisum could effectively adapt and store L-DOPA, transmit it from one generation to the next. We also found that L-DOPA sequestration verity differed in different morphs of A. pisum. After analyzing the melanization efficiency in wounds, mortality and deformity of the aphids at different concentrations of L-DOPA under ultraviolet radiation (UVA 365.0 nm for 30 min), we found that A. pisum could enhance L-DOPA assimilation for wound healing and UVA-radiation protection. Therefore, we conclude that A. pisum could acquire L-DOPA and use it to prevent UVA damage. This study reveals a successful co-evolution between A. pisum and V. faba. PMID:27006098

  7. Homogeneous and heterogeneous degradation of caffeic acid using photocatalysis driven by UVA and solar light.

    PubMed

    Yáñez, Eliana; Santander, Paola; Contreras, David; Yáñez, Jorge; Cornejo, Lorena; Mansilla, Héctor D

    2016-01-01

    Waste water from the wine industry is characterized by a high concentration of dissolved organic matter and the presence of natural phenolic compounds with low biodegradability. High concentrations of phenolic compounds may cause environmental pollution and risks to human health. In this article caffeic acid (CA) was used as a model compound of wine effluent because it is refractory to the conventional wastewater treatments. The oxidation of caffeic acid in water solution (0.01 g L(-1)) by heterogeneous photocatalysis and photo-Fenton reaction was studied using UVA. The optimal conditions for each treatment were performed by multivariate experimental design. The optimal conditions for heterogeneous photocatalysis were pH 5.3 and 0.9 g L(-1) TiO2. In the case of photo-Fenton treatment, optimized variable were 82.4 μmol L(-1) of Fe(2+) and 558.6 μmol L(-1) of H2O2. The degradation profiles of CA were monitored by UV-Vis, HPLC, TOC and COD. To reach 90% of CA removal, 40 and 2 min of reaction, respectively, were required by heterogeneous and photo-Fenton processes, respectively. For comparison purposes, the reactions were also performed under solar light. The use of solar light does not change the efficiency of the photo-Fenton reaction, yet the performance of the heterogeneous process was significantly improved, reaching 90% of degradation in 15 min. PMID:26548918

  8. Temporal variation of erythemally effective UVB/UVA ratio at Chilton, UK.

    PubMed

    Hooke, R J; Pearson, A J; O'Hagan, J B

    2012-04-01

    An analysis of the temporal variation in the erythemally weighted UVB/UVA irradiance ratio using spectral data collected from a monitoring site in Chilton, UK (51°N) for the 5-y period from 2004 to 2008 is presented. The variation in the diurnal ratio was found to be bell-shaped, with minima on average 1 h after sunrise and before sunset. The minima were found to be indicative of the point at which UVB becomes undetectable by the spectroradiometer and therefore the outer boundary of useful data. A potential flaw entailed in the erythemal weighting of low-level spectral UV data is described. The peak daily ratio value was found to have a bell-shaped distribution over the course of a year with a maximum in July rather than at the summer solstice-a result explained by the ozone cycle. The peak daily ratio was found to vary by a factor of 4 over the course of the year; this range of variation was also found to occur over a single day in the summer. PMID:21807665

  9. Protective effect of porphyra-334 on UVA-induced photoaging in human skin fibroblasts.

    PubMed

    Ryu, Jina; Park, Su-Jin; Kim, In-Hye; Choi, Youn Hee; Nam, Taek-Jeong

    2014-09-01

    The significant increase in life expectancy is closely related to the growing interest in the impact of aging on the function and appearance of the skin. Skin aging is influenced by several factors, and solar ultraviolet (UV) irradiation is considered one of the most important causes of skin photoaging. The aim of this study was to examine the anti-photoaging role of porphyra-334 from Porphyra (P.) yezoensis, a mycosporine-like amino acid (MAA), using high-performance liquid chromatography (HPLC), and electrospray ionization‑mass spectrometry (ESI-MS). In the present study, extracted UV‑absorbing compounds from P. yezoensis included palythine, asterina-330 and porphyra-334. Porphyra-334 was the most abundant MAA in P. yezoensis, and it was therefore used for conducting antiphotoaging experiments. The effect of porphyra-334 on the prevention of photoaging was investigated by measuring reactive oxygen species (ROS) production and matrix metalloproteinase (MMP) levels, as well as extracellular matrix (ECM) components and protein expression in UVA‑irradiated human skin fibroblasts. Porphyra-334 suppressed ROS production and the expression of MMPs following UVA irradiation, while increasing levels of ECM components, such as procollagen, type I collagen, elastin. These results suggest that porphyra-334 has various applications in cosmetics and toiletries because of its anti‑photoaging activities and may serve as a novel anti-aging agent. PMID:24946848

  10. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Starke, Edgar A., Jr.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986, and continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between July 1 and December 31, 1993. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and critically, a pool of educated graduate students for aerospace technologies.

  11. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Starke, Edgar A., Jr.; Gangloff, Richard P.; Herakovich, Carl T.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1995-01-01

    The NASA-UVa Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. Here, we report on progress achieved between July 1 and December 31, 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  12. Phenylmercury degradation by heterogeneous photocatalysis assisted by UV-A light.

    PubMed

    Miranda, Cristian; Yáñez, Jorge; Contreras, David; Zaror, Claudio; Mansilla, Héctor D

    2013-01-01

    Photocatalytic degradation of phenylmercury was studied using TiO2 in aqueous suspension assisted by UV-A irradiation. Reaction conditions, such as pH and amount of TiO2 were set using a factorial design of experiments resulting in a greater influence of pH on phenylmercury degradation. Hg (II) reduction and simultaneous oxidation of aromatic group was observed. Optimum reaction conditions were obtained under nitrogen atmosphere at pH 10 and 0.35 g/L(-1) TiO2. Under these conditions almost 100% reduction of mercury was reached after 30 min UV irradiation. Total mercury reduction was achieved after 40 min reaction under saturated oxygen. Furthermore, phenol and diphenylmercury were identified as intermediate products of oxidation. It was observed that a major fraction of the reduced mercury was removed as metallic vapor by gas stripping, whereas a minor fraction was adsorbed on the catalyst surface, probably as Hg(OH)2. Under optimal conditions obtained by multivariable analysis, total mineralization of organic matter was achieved after about 60-min irradiation. PMID:23947701

  13. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program continues a high level of activity. Progress achieved between 1 Jan. and 30 Jun. 1993 is reported. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. The following projects are addressed: environmental fatigue of Al-Li-Cu alloys; mechanisms of localized corrosion and environmental fracture in Al-Cu-Li-Mg-Ag alloy X2095 and compositional variations; the effect of zinc additions on the precipitation and stress corrosion cracking behavior of alloy 8090; hydrogen interactions with Al-Li-Cu alloy 2090 and model alloys; metastable pitting of aluminum alloys; cryogenic fracture toughness of Al-Cu-Li + In alloys; the fracture toughness of Weldalite (TM); elevated temperature cracking of advanced I/M aluminum alloys; response of Ti-1100/SCS-6 composites to thermal exposure; superplastic forming of Weldalite (TM); research to incorporate environmental effects into fracture mechanics fatigue life prediction codes such as NASA FLAGRO; and thermoviscoplastic behavior.

  14. Genotoxicity of combined exposure to polycyclic aromatic hydrocarbons and UVA--a mechanistic study.

    PubMed

    Douki, Thierry; Ksoury, Zakaria; Marie, Caroline; Favier, Alain; Ravanat, Jean-Luc; Maitre, Anne

    2008-01-01

    Solar UV radiation and benzo[a]pyrene (BaP) are two carcinogenic agents. When combined, their deleterious properties are synergistic. In order to get insights into the underlying processes, we carried out a mechanistic study within isolated DNA photosensitized to UVA radiation by either BaP, its diol epoxide metabolite (BPDE) or the tetraol arising from the hydrolysis of this last molecule. Measurement of the level of the oxidized base 8-oxo-7,8-dihydroguanine revealed that BaP is a poor sensitizer while BPDE and tetraol are more potent ones. None of these compounds was found to photosensitize formation of cyclobutane pyrimidine dimers through triplet energy transfer. On the basis of the distribution of oxidized DNA bases, we could show that photosensitization of DNA by BPDE involves electron abstraction (Type I) while tetraol acts mainly through singlet oxygen production (Type II). Under our experimental conditions, Type I was the major photosensitization process, which shows the lack of involvement of tetraol in the observed photo-oxidation reaction. Finally, we could show that the adducts, resulting from the alkylation of DNA by BPDE, are very potent sensitizers. Indeed, they are located in the close vicinity of the double helix and thus perfectly placed to induce oxidation reactions. PMID:18466204

  15. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Here, we report on progress achieved between July I and December 31, 1996. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report are summarized as follows. Three research areas are being actively investigated, including: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures.

  16. NASA-UVA Light Aerospace Alloy and Structures Technology Program: LA(2)ST

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA(2)ST) Program continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. We report on progress achieved between July 1 and December 31, 1992. The objective of the LA(2)ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies.

  17. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Astrophysics Data System (ADS)

    Gangloff, Richard P.; Scully, John R.; Starke, Edgar A., Jr.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1994-03-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986, and continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between July 1 and December 31, 1993. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and critically, a pool of educated graduate students for aerospace technologies.

  18. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1994. These results were presented at the Fifth Annual NASA LA2ST Grant Review Meeting held at the Langley Research Center in July of 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, lightweight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  19. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1992-01-01

    The NASA-UVa Light Aerospace Alloy and Structure Technology (LAST) Program continues to maintain a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1992. The objectives of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of the next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with Langley researchers. Technical objectives are established for each research project. We aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report cover topics including: (1) Mechanical and Environmental Degradation Mechanisms in Advance Light Metals and Composites; (2) Aerospace Materials Science; (3) Mechanics of Materials and Composites for Aerospace Structures; and (4) Thermal Gradient Structures.

  20. Nucleolin stabilizes Bcl-X L messenger RNA in response to UVA irradiation.

    PubMed

    Zhang, Jack; Tsaprailis, George; Bowden, G Tim

    2008-02-15

    Our laboratory has previously reported that UVA irradiation can increase the expression of Bcl-X(L), an antiapoptotic molecule, by stabilizing its mRNA in cultured immortalized human keratinocytes. To understand the mechanism by which the Bcl-X(L) message is stabilized, we used a synthetic Bcl-X(L) 3'-untranslated region (UTR) to capture RNA-binding proteins. Nucleolin was identified as one of the binding proteins as determined by tandem mass spectrometry coupled to liquid chromatography analysis. Further study showed that nucleolin specifically recognized the AU-rich elements (AUUUA) in the 3'-UTR of the Bcl-X(L) mRNA and could stabilize the mRNA in vitro. Furthermore, overexpression of nucleolin stabilizes the Bcl-X(L) mRNA in HeLa cells, whereas reducing nucleolin by small interfering RNA shortens the Bcl-X(L) mRNA half-life. Interestingly, nucleolin physically interacted with polyadenylate [poly(A)]-binding protein through it RGG motifs. Its stabilizing effect on the Bcl-X(L) mRNA was dependent upon the presence of poly(A) tail. Based on these data, we propose a model in which nucleolin protects the Bcl-X(L) mRNA from nuclease degradation by enhancing the stability of the ribonucleoprotein loop structure. PMID:18281479

  1. Solid surface photochemistry of montmorillonite: mechanisms for the arsenite oxidation under UV-A irradiation.

    PubMed

    Yuan, Yanan; Wang, Yajie; Ding, Wei; Li, Jinjun; Wu, Feng

    2016-01-01

    Transformation of inorganic arsenic species has drawn great concern in recent decades because of worldwide and speciation-dependent pollution and the hazards that they pose to the environment and to human health. As(III) photooxidation in aquatic systems has received much attention, but little is known about photochemical transformation of arsenic species on top soil. As(III) photooxidation on natural montmorillonite under UV-A radiation was investigated by using a moisture- and temperature-controlled photochemical chamber with two black-light lamps. Initial As(III) concentration, pH, layer thickness, humic acid (HA) concentration, the presence of additional iron ions, and the contribution of reactive oxygen species (ROS) were examined. The results show that pH values of the clay layers greatly influenced As(III) photooxidation on montmorillonite. As(III) photooxidation followed the Langmuir-Hinshelwood model. HA and additional iron ions greatly promoted photooxidation, but excess Fe(II) competed with As(III) for oxidation by ROS. Scavenging experiments revealed that natural montmorillonite induced the conversion of As(III) to As(V) by generating ROS (mainly HO(•) and HO2(•)/O2(•-)) and that HO(•) radical was the predominant oxidant in this system. Our work demonstrates that photooxidation on the surface of natural clay minerals in top soil can be important to As(III) transformation. This allows understanding and predicting the speciation and behavior of arsenic on the soil surface. PMID:26194238

  2. Moderate MAS enhances local 1H spin exchange and spin diffusion

    NASA Astrophysics Data System (ADS)

    Roos, Matthias; Micke, Peter; Saalwächter, Kay; Hempel, Günter

    2015-11-01

    Proton NMR spin-diffusion experiments are often combined with magic-angle spinning (MAS) to achieve higher spectral resolution of solid samples. Here we show that local proton spin diffusion can indeed become faster at low (<10 kHz) spinning rates as compared to static conditions. Spin diffusion under static conditions can thus be slower than the often referred value of 0.8 nm2/ms, which was determined using slow MAS (Clauss et al., 1993). The enhancement of spin diffusion by slow MAS relies on the modulation of the orientation-dependent dipolar couplings during sample rotation and goes along with transient level crossings in combination with dipolar truncation. The experimental finding and its explanation is supported by density matrix simulations, and also emphasizes the sensitivity of spin diffusion to the local coupling topology. The amplification of spin diffusion by slow MAS cannot be explained by any model based on independent spin pairs; at least three spins have to be considered.

  3. Understanding the symmetric line shape in the 17O MAS spectra for hexagonal ice

    NASA Astrophysics Data System (ADS)

    Yamada, Kazuhiko; Oki, Shinobu; Deguchi, Kenzo; Shimizu, Tadashi

    2016-06-01

    Solid-state 17O Magic-Angle Spinning (MAS) nuclear magnetic resonance (NMR) spectra of 17O-enriched hexagonal ice, [17O]-Ih, between 173 and 253 K were presented. Marked changes in the line shape were clearly observed, indicating water molecular reorientation in the crystal structure. At 173 K, molecular motions were considered to be frozen and analysis of the 1D MAS spectrum yielded the following parameters: quadrupole coupling constant (CQ) = 6.6 ± 0.2 MHz and asymmetry parameter (ηQ) = 0.95 ± 0.05. At 232 K and above, contrary to the conventional explanation, pseudo-symmetric line shapes appeared in the 17O MAS NMR spectra arising from the contribution of second-order quadrupole interactions. As a chemical exchange model to describe these isotropic 17O MAS NMR spectra, a modified Ratcliffe model, which consider the effects of proton disorder, was proposed, and the resulting theoretical spectra could well reproduce the experimental spectra.

  4. Project MAS, 1982-1983. O.E.E. Evaluation Report.

    ERIC Educational Resources Information Center

    Villegas, Ana; Villegas, Jose

    This multi-site instructional program, in its first year of a three-year funding cycle, provided instruction in English as a Second Language (ESL) and native language arts, as well as bilingual instruction in various content areas, to 400 Spanish speaking students of limited English proficiency in grades 3-8. The functional goal of Project MAS,…

  5. Sealed Rotors for In Situ High Temperature High Pressure MAS NMR†

    PubMed Central

    Hu, Jian Zhi; Hu, Mary Y.; Zhao, Zhenchao; Xu, Suochang; Vjunov, Aleksei; Shi, Hui; Camaioni, Donald M.; Peden, Charles H. F.; Lercher, Johannes A.

    2015-01-01

    Here we present the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are used to study AlPO4-5 molecular sieve crystallization under hydrothermal conditions, high temperature high pressure cyclohexanol dehydration reaction, and low temperature metabolomics of intact biological tissue. PMID:26171928

  6. Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures

    NASA Astrophysics Data System (ADS)

    Matsuki, Yoh; Idehara, Toshitaka; Fukazawa, Jun; Fujiwara, Toshimichi

    2016-03-01

    Sensitivity enhancement of MAS NMR using dynamic nuclear polarization (DNP) is gaining importance at moderate fields (B0 < 9 T) and temperatures (T > 90 K) with potential applications in chemistry and material sciences. However, considering the ever-increasing size and complexity of the systems to be studied, it is crucial to establish DNP under higher field conditions, where the spectral resolution and the basic NMR sensitivity tend to improve. In this perspective, we overview our recent efforts on hardware developments, specifically targeted on improving DNP MAS NMR at high fields. It includes the development of gyrotrons that enable continuous frequency tuning and rapid frequency modulation for our 395 GHz-600 MHz and 460 GHz-700 MHz DNP NMR spectrometers. The latter 700 MHz system involves two gyrotrons and a quasi-optical transmission system that combines two independent sub-millimeter waves into a single dichromic wave. We also describe two cryogenic MAS NMR probe systems operating, respectively, at T ∼100 K and ∼30 K. The latter system utilizes a novel closed-loop helium recirculation mechanism, achieving cryogenic MAS without consuming any cryogen. These instruments altogether should promote high-field DNP toward more efficient, reliable and affordable technology. Some experimental DNP results obtained with these instruments are presented.

  7. Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures.

    PubMed

    Matsuki, Yoh; Idehara, Toshitaka; Fukazawa, Jun; Fujiwara, Toshimichi

    2016-03-01

    Sensitivity enhancement of MAS NMR using dynamic nuclear polarization (DNP) is gaining importance at moderate fields (B0<9T) and temperatures (T>90K) with potential applications in chemistry and material sciences. However, considering the ever-increasing size and complexity of the systems to be studied, it is crucial to establish DNP under higher field conditions, where the spectral resolution and the basic NMR sensitivity tend to improve. In this perspective, we overview our recent efforts on hardware developments, specifically targeted on improving DNP MAS NMR at high fields. It includes the development of gyrotrons that enable continuous frequency tuning and rapid frequency modulation for our 395 GHz-600 MHz and 460 GHz-700 MHz DNP NMR spectrometers. The latter 700 MHz system involves two gyrotrons and a quasi-optical transmission system that combines two independent sub-millimeter waves into a single dichromic wave. We also describe two cryogenic MAS NMR probe systems operating, respectively, at T ∼ 100K and ∼ 30K. The latter system utilizes a novel closed-loop helium recirculation mechanism, achieving cryogenic MAS without consuming any cryogen. These instruments altogether should promote high-field DNP toward more efficient, reliable and affordable technology. Some experimental DNP results obtained with these instruments are presented. PMID:26920836

  8. Sealed rotors for in situ high temperature high pressure MAS NMR.

    PubMed

    Hu, Jian Zhi; Hu, Mary Y; Zhao, Zhenchao; Xu, Suochang; Vjunov, Aleksei; Shi, Hui; Camaioni, Donald M; Peden, Charles H F; Lercher, Johannes A

    2015-09-11

    Here we present the design of reusable and perfectly sealed all-zirconia MAS rotors. The rotors are used to study AlPO4-5 molecular sieve crystallization under hydrothermal conditions, high temperature high pressure cyclohexanol dehydration reaction, and low temperature metabolomics of intact biological tissue. PMID:26171928

  9. 47 CFR 101.1317 - Competitive bidding procedures for mutually exclusive MAS EA applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Competitive bidding procedures for mutually exclusive MAS EA applications. 101.1317 Section 101.1317 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Multiple Address Systems...

  10. The Multidimensional Attitudes Scale toward Persons with Disabilities (MAS): Construction and Validation

    ERIC Educational Resources Information Center

    Findler, Liora; Vilchinsky, Noa; Werner, Shirli

    2007-01-01

    This study presents the development of a new instrument, the "Multidimensional Attitudes Scale Toward Persons With Disabilities" (MAS). Based on the multidimensional approach, it posits that attitudes are composed of three dimensions: affect, cognition, and behavior. The scale was distributed to a sample of 132 people along with a self-esteem…