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Sample records for previously photooxidized psoralen

  1. Photooxidative reactions of psoralens

    International Nuclear Information System (INIS)

    Potapenko, A.Ya.; Sukhorukov, V.L.

    1984-01-01

    The mechanism and biological significance of photooxidative reactions of psoralens are reviewed. Skin-photosensitizing activities of bifunctional and monofunctional psoralens are compared. Antioxidants tocopherols and butilated hydroxytoluene inhibit photochemical reactions of psoralens responsible for induction of erythema. The same antioxidants do not inhibit PUVA-therapy of psriasis. Though psoralens can generate singlet oxygen under UVA-irradiation (315 - 400 nm), nevertheless singlet oxygen does not play significant role in 8-methoxypsoralen (8-MOP) sensitized photooxidation of tocopherol or dihydroxyphenylalanine (DOPA). SH-compounds enhance the rate of 8-MOP sensitized photooxidation of DOPA by a factor of four, simultaneously the rate of oxidation of SH-groups is enhanced many fold in the presence of DOPA. Under UVA-irradiation in organic solvents psoralens are photooxidized. Dimeric photooxidized psoralens are easily destructed in water medium, their destruction induce oxidation of unsaturated lipids and DOPA. (author)

  2. Alkali reversal of psoralen cross-link for the targeted delivery of psoralen monoadduct lesion

    International Nuclear Information System (INIS)

    Yeung, A.T.; Dinehart, W.J.; Jones, B.K.

    1988-01-01

    Psoralen intercalates into double-stranded DNA and photoreacts mainly with thymines to form monoadducts and interstrand cross-links. The authors used an oligonucleotide model to demonstrate a novel mechanism: the reversal of psoralen cross-links by base-catalyzed rearrangement at 90 0 C (BCR). The BCR reaction is more efficient than the photoreversal reaction. They show that the BCR occurs predominantly on the furan side of a psoralen cross-link. The cleavage does not result in the breaking of the DNA backbone, and the thymine based freed from the cross-link by the cleavage reaction appears to be unmodified. Similarly, BCR of the furan-side monoadduct of psoralen removed the psoralen molecule and regenerated the unaltered native oligonucleotide. The pyrone-side psoralen monoadduct is relatively resistant to BCR. One can use BCR to perform efficient oligonucleotide-directed, site-specific delivery of a psoralen monoadduct. As a demonstration of this approach, they have hybridized a 19 base long oligonucleotide vehicle containing a furan-side psoralen monoadduct to a 56 base long complementary oligonucleotide target strand and formed a specific cross-link at the target site with 365-nm UV. Subsequent BCR released the oligonucleotide vehicle and deposited the psoralen at the target site

  3. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yun-bo

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs.

  4. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

    International Nuclear Information System (INIS)

    Shi, Yun-bo.

    1988-03-01

    This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs

  5. Mechanisms of PUVA (Psoralen + UVA) photochemotherapy

    International Nuclear Information System (INIS)

    Zarebska, Z.; Waszkowska, E.; Barszcz, D.

    1998-01-01

    Our studies are aimed at understanding the action of PUVA phototherapy on the lymphocytes membrane. The investigations are carried out on the model lecithins having in the second position oleic/linoleic acid as the majority of lecithins have. Previous investigations led to a discovery of a new class of photoadducts which accompany the photolytic breakdown of lecithin. The new photoadducts were obtained by irradiating a mixture of psoralen or 8-methoxypsoralen with p hosphatidylcholine; separated by HPLC or TLC and characterized by UV and NMR spectra and mass spectrometry. Kinetics of psoralen photolysis in the presence of lecithin was followed and the yield of the initial photoproducts was determined. The predominant reaction was a cycloaddition between one of the two photoreactive sites of psoralen (3,4-pyrone edge) and one of the olefinic bonds of the unsaturated fatty acid linked in the second position of the glycerol moiety of phosphatidylcholine. Two adducts were purified to homogeneity and characterized: an adduct of psoralen to oleic acid in lecithin (PCd1pal PSO) and two isomeric adducts to the free linoleic acid (d2 PSO). The extreme sensitivity of isolated photoproducts was encountered in the course of identification analysis (UV, NR and mass spectrometry). This was in contrast to the other stable psoralen cyclobutane adducts, like psoralen thymine or psoralen fatty-acid-methyl-ester. We assume that the short life-time of our adducts is associated with the presence of a -COOH end group in the free fatty acid, and its ester group -COO- in the lecithins. These compounds undergo hydrolysis/oxidation reactions in aqueous micelles and in the slightly hydrated methanol. The photoadducts are also photosensitive, e.g. the cyclobutane ring splits under laser beam (337 nm, 50 mJ) applied in the MALDI (Matrix Assisted Laser Desorption and Ionization) method for molecular mass estimation. With the more gentle method, LSIMS (Liquid Secondary Mass Spectrometry), molar

  6. Sharp kink of DNA at psoralen-cross-link site deduced from crystal structure of psoralen-thymine monoadduct

    International Nuclear Information System (INIS)

    Kim, S.H.; Peckler, S.; Graves, B.; Kanne, D.; Rapoport, H.; Hearst, J.E.

    1983-01-01

    Light-induced cross-linking of double-stranded nucleic acids by psoralens has been exploited to locate, in vivo or in vitro, those double-helical regions of DNA or RNA that can accommodate any structural changes caused by the psoralen cross-links. To determine three-dimensional structural parameters of the cross-link, we have solved the crystal structure of the psoralen-thymine monoadduct formed in photoreaction between calf thymus DNA and 8-methoxypsoralen (8MOP). There are eight possible configurations for psoralen-thymine monoadducts and 64 for diadducts. We describe here the structural details of a psoralen-thymine monoadduct obtained in a biological environment and the consequences of the photo-cross-link between 8MOP and double-helical DNA

  7. X-Ray Psoralen Activated Cancer Therapy (X-PACT)

    Science.gov (United States)

    Oldham, Mark; Yoon, Paul; Fathi, Zak; Beyer, Wayne F.; Adamson, Justus; Liu, Leihua; Alcorta, David; Xia, Wenle; Osada, Takuya; Liu, Congxiao; Yang, Xiao Y.; Dodd, Rebecca D.; Herndon, James E.; Meng, Boyu; Kirsch, David G.; Lyerly, H. Kim; Dewhirst, Mark W.; Fecci, Peter; Walder, Harold; Spector, Neil L.

    2016-01-01

    This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (pphosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which in-turn unleashes both short- and potentially long

  8. X-Ray Psoralen Activated Cancer Therapy (X-PACT.

    Directory of Open Access Journals (Sweden)

    Mark Oldham

    Full Text Available This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy: a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen that absorb x-rays and re-radiate (phosphoresce at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1, glioma (CT2A and sarcoma (KP-B cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor and radiation parameters (energy, dose, and dose rate were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001. We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001. Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA

  9. Differential causes of mutation and killing in Escherichia coli after psoralen plus light treatment: monoadducts and cross-links

    Energy Technology Data Exchange (ETDEWEB)

    Seki, T; Nozu, K [Nara Medical Univ., Kashihara (Japan); Kondo, S

    1978-01-01

    On treatment with 8-methoxypsoralen plus near uv light, an excision (uvrB/sup -/) strain of Escherichia coli showed about 3- and 10 times higher sensitivities to killing and mutation, respectively, than its parental strain. On re-irradiation with near uv in the absence of unbound psoralen, the uvrB/sup -/ strain pretreated with psoralen plus near uv showed a decrease in both survival and mutation. After treatment with psoralen plus near uv, re-irradiation of T7DNA in the absence of unbound psoralen caused an increase in the cross-linked fraction with an equivalent decrease in the non-cross-linked fraction. From these and previous results, it is concluded that monoadducts produced by treatment with psoralen plus near uv are converted to cross-links by further irradiation and that, in E.coli, monoadducts are responsible for the mutation induced by psoralen-plus-light whereas cross-links are the major cause of its lethal action.

  10. Psoralen phototherapy and the possible involvement of triplet excited states

    International Nuclear Information System (INIS)

    Bensasson, R.V.; Salet, E.J.; Land, E.J.

    1979-01-01

    Psoralens are important drugs used in the phototherapy of psoriasis and vitiligo. It has been predicted that the triplet excited state of psoralen is photoactive. The authors have employed pulse radiolysis and laser flash photolysis to determine the quantum yields of formation of the triplet states of psoralens and related molecules including 4'5' dihydropsoralen, a model for 4'5' psoralenpyrimidine mono-adducts. The triplet spectra were used to follow the reactions of the triplets with thymine and tryptophan. Such reactions may take place via a charge transfer mechanism. For 8-methoxy psoralen, in addition to triplet formation, photoionization was detected using high laser intensities. Although significant yields of psoralen triplets are formed, and some such triplets react with thymine, it is too early yet to say definitely whether or not the therapeutic action of psoralens is mediated via such triplet states. (Auth.)

  11. DNA-psoralen interaction: a single molecule experiment.

    Science.gov (United States)

    Rocha, M S; Viana, N B; Mesquita, O N

    2004-11-15

    By attaching one end of a single lambda-DNA molecule to a microscope coverslip and the other end to a polystyrene microsphere trapped by an optical tweezers, we can study the entropic elasticity of the lambda-DNA by measuring force versus extension as we stretch the molecule. This powerful method permits single molecule studies. We are particularly interested in the effects of the photosensitive drug psoralen on the elasticity of the DNA molecule. We have illuminated the sample with different light sources, studying how the different wavelengths affect the psoralen-DNA linkage. To do this, we measure the persistence length of individual DNA-psoralen complexes.

  12. Structure of DNA damaged by UV and psoralen

    International Nuclear Information System (INIS)

    Sung-hou Kim; Tomic, M.T.; Wemmer, D.E.; Pearlman, D.; Holbrook, S.

    1988-01-01

    The authors have used NMR methods to determine a three-dimensional model of an 8 base-pair DNA fragment cross-linked with psoralen. The duplex form of the self-complementary deoxyribonucleotide d-GGGTACCC, contains a psoralen cross-linkable site at the center of the duplex. The cross-link was formed by UV irradiation of a mixture of the purified DNA octamer and 4'-(aminomethyl)-4,5',8-trimethylpsoralen (AMT). Structural information was obtained using one and two-dimensional NMR techniques. Two-dimensional NOE experiments were used to assign the spectrum and estimate distances for many pairs of protons in the cross-linked DNA. Structural parameters obtained are qualitatively consistent with a previously proposed model for kinked and unwound cross-linked B-form DNA derived from crystallography and molecular modeling. The NMR derived model has a 53 degree bend into the major groove occuring primarily at the site of drug addition, and a 56 degree unwinding spanning the 8 base pair duplex. (author)

  13. Possible mechanism of psoralen phototoxicity not involving direct interaction with DNA

    International Nuclear Information System (INIS)

    Laskin, J.D.; Lee, E.; Yurkow, E.J.; Laskin, D.L.; Gallo, M.A.

    1985-01-01

    Psoralens in combination with ultraviolet light (UVA; 320-400 nm) are used in the photochemical treatment of a variety of skin diseases including vitiligo, a skin depigmentational disorder, and psoriasis, a disease of accelerated epidermal cell proliferation. Although it is generally assumed that the major site of action of the psoralens is DNA, the authors have obtained evidence that another site may be the primary target for these compounds. They have identified specific, saturable, high-affinity binding sites for 8-methoxypsoralen on HeLa cells and have detected specific binding of 8-methoxypsoralen to four other human cell lines and five mouse cell lines. In HeLa cells, specific binding is reversible and independent of the ability of the compound to intercalate into DNA. In addition, binding sites become covalently modified by the psoralen after UVA exposure. Specific binding of 8-[methyoxy- 3 H]methoxypsoralen constitutes 79% of the label bound to the cells. Scatchard analysis indicated two classes of psoralen binding sites. Based on these findings, the authors hypothesize that specific binding sites for psoralens on mammalian cells mediate, at least in part, psoralen-induced phototoxicity

  14. Structural Determinants of Photoreactivity of Triplex Forming Oligonucleotides Conjugated to Psoralens

    Science.gov (United States)

    Krishnan, Rajagopal; Oh, Dennis H.

    2010-01-01

    Triplex-forming oligonucleotides (TFOs) with both DNA and 2′-O-methyl RNA backbones can direct psoralen photoadducts to specific DNA sequences. However, the functional consequences of these differing structures on psoralen photoreactivity are unknown. We designed TFO sequences with DNA and 2′-O-methyl RNA backbones conjugated to psoralen by 2-carbon linkers and examined their ability to bind and target damage to model DNA duplexes corresponding to sequences within the human HPRT gene. While TFO binding affinity was not dramatically affected by the type of backbone, psoralen photoreactivity was completely abrogated by the 2′-O-methyl RNA backbone. Photoreactivity was restored when the psoralen was conjugated to the RNA TFO via a 6-carbon linker. In contrast to the B-form DNA of triplexes formed by DNA TFOs, the CD spectra of triplexes formed with 2′-O-methyl RNA TFOs exhibited features of A-form DNA. These results indicate that 2′-O-methyl RNA TFOs induce a partial B-to-A transition in their target DNA sequences which may impair the photoreactivity of a conjugated psoralen and suggest that optimal design of TFOs to target DNA damage may require a balance between binding ability and drug reactivity. PMID:20725628

  15. Structures of DNA containing psoralen crosslink and thymine dimer

    International Nuclear Information System (INIS)

    Kim, S.H.; Pearlman, D.A.; Holbrook, S.R.; Pirkle, D.

    1985-01-01

    UV irradiation by itself or in conjunction with other chemicals can cause covalent damages to DNA in living cells. To overcome the detrimental effect of DNA damage, cells developed a repair mechanism by which damaged DNA is repaired. In the absence of such repair, cell malfunction or cell death can occur. Two most studied radiation-induced DNA damage are thymine dimer formation by UV irradiation and psoralen crosslink by combination of psoralens and UV: In the former, two adjacent thymine bases on a strand of DNA are fused by forming cyclobutane ring, and in the latter, one pyrimidine on one DNA strand is crosslinked to another pyrimidine on the other strand via a psoralen. The authors' objective is to deduce the structure of DNA segment which contains a psoralen crosslink or a thymine dimer using the combination of results of X-ray crystallographic studies, molecular model building, and energy minimization. These structural features may be important for understanding the biological effects of such damages and for the recognition by the repair enzymes

  16. Photoreactivities and thermal properties of psoralen cross-links

    International Nuclear Information System (INIS)

    Yeung, A.T.; Jones, B.K.; Chu, C.T.

    1988-01-01

    The authors have studied the photoreaction of 8-methoxypsoralen (8-MOP), 4,5',8-trimethylpsoralen (TMP), and 4'-(hydroxymethyl)-4,5',8-trimethylpsoralen (HMT) with a pair of 18-base-long oligonucleotides in which a 14-base region is complementary. Only one 5'TpA site, favored for both monoadduct and cross-link formation with psoralen, is present in this oligonucleotide pair. They have used this model system to demonstrate, for the first time, strand specificity in the photoreaction of psoralen with DNA. They found that the two types of cross-links which form at this site have large differences in thermal stabilities. In addition, the denaturation of each cross-links isomer duplex occurred in at least three stages, which can be visualized as three bands in thermal equilibrium under the conditions of a denaturing polyacrylamide gel. This novel observation suggests that there are several domains differing in thermal stability in a psoralen cross-link

  17. Psoralen photomutagenic specificity in Salmonella typhimurium

    International Nuclear Information System (INIS)

    Koch, W.H.

    1986-01-01

    The cytotoxic and mutagenic specificity of two therapeutically employed psoralens was examined in several Ames Salmonella typhimurium strains with near ultraviolet light activation. Photomutagenic activity of 8-methoxypsoralen (8MOP) and 4,5',8-trimethylpsoralen (TMP) was found to be sequence-specific, and additionally was dependent on the level of DNA-repair proficiency. Phototoxicity was essentially identical in hisC3076, hisD3052 and hisG46 strains; uvrB - excision-repair-deficient bacteria were considerably more susceptible to lethal effects than wild-type parental strains. Finally, the data show that psoralens are potent frameshift photomutagens in Salmonella hisC3076 strains and demonstrate the potential utility of these strains in evaluating photomutagenic and phototoxic activity of new furocoumarin derivatives. (Auth.)

  18. Cross-linking and relaxation of supercoiled DNA by psoralen and light

    International Nuclear Information System (INIS)

    Yoakum, G.H.; Cole, R.S.

    1978-01-01

    Photoreaction of 4,5',8-trimethylpsoralen with superhelical ColE1 and ColE1amp DNA was studied. Changes in mobilities in agarose gels, formation of interstrand cross-links, and DNA strand breaks were determined. Psoralen and light treatment removed negative superhelical turns, and extensive treatments failed to produce positive superhelical turns in covalently closed plasmid DNA. The rate of relaxation of superhelical turns by psoralen photobinding appeared to be directly proportional to the number of superhelical turns remaining. A unique reaction mechanism is presented to explain these results. By this interpretation the initial rate of psoralen photobinding to superhelical DNA was estimated to be 3 times that for linear DNA, and the ratio of cross-linking to monofunctional adducts appears to be dependent on the superhelical conformation of the DNA. The estimated ratio of psoralen molecules bound to DNA strand breaks was 1.7 . 10 4 :1, and 70% of this breakage is caused by the light alone. (Auth.)

  19. The application of psoralens to the study of DNA structure, function and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Spielmann, Peter Hans [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1991-04-01

    A series of six nitroxide spin-labeled psoralens were designed, synthesized and tested as probes for DNA dynamics. The synthesis of these spin-labeled psoralen derivatives and their photoreactivity with double-stranded DNA fragments is described. The spin labels (nitroxides) were demonstrated to survive the uv irradiation required to bind the probe to the target DNA. EPR spectra of the photobound spin-labels indicate that they do not wobble with respect to the DNA on the time-scales investigated. The author has used psoralen modified DNA as a model for the study of DNA repair enzyme systems in human cell free extracts. He has shown that damage-induced DNA synthesis is associated with removal of psoralen adducts and therefore is "repair synthesis" and not an aberrant DNA synthesis reaction potentiated by deformation of the DNA by adducts. He has found that all DNA synthesis induced by psoralen monoadducts is the consequence of removal of these adducts. By the same approach he has obtained evidence that this in vitro system is capable of removing psoralen cross-links as well. Reported here are synthetic methods that make use of high intensity lasers coupled with HPLC purification to make homogeneous and very pure micromole quantities of furan-side monoadducted, cross-linked, and pyrone-side monoadducted DNA oligonucleotide. These molecules are currently being studied by NMR and X-ray crystallography. The application of the site-specifically psoralen modified oligonucleotide synthesized by these methods to the construction of substrates for the investigation of DNA repair is also discussed.

  20. Interplay between human high mobility group protein 1 and replication protein A on psoralen-cross-linked DNA

    DEFF Research Database (Denmark)

    Reddy, Madhava C; Christensen, Jesper; Vasquez, Karen M

    2005-01-01

    -DNA interstrand cross-link (ICL) to a specific site to determine the effect of HMGB proteins on recognition of these lesions. Our results reveal that human HMGB1 (but not HMGB2) binds with high affinity and specificity to psoralen ICLs, and interacts with the essential NER protein, replication protein A (RPA......), at these lesions. RPA, shown previously to bind tightly to these lesions, also binds in the presence of HMGB1, without displacing HMGB1. A discrete ternary complex is formed, containing HMGB1, RPA, and psoralen-damaged DNA. Thus, HMGB1 has the ability to recognize ICLs, can cooperate with RPA in doing so...

  1. Psoralen/UV inactivation of HIV-1-infected cells for use in cytologic and immunologic procedures

    International Nuclear Information System (INIS)

    Watson, A.J.; Klaniecki, J.; Hanson, C.V.

    1990-01-01

    A rapid procedure for the inactivation of HIV-1-infected cells using psoralen and ultraviolet (UV) light is described. Exposure of HIV-1-infected cells to 5 micrograms/ml psoralen followed by UV irradiation (320-380 nm) for 5 minutes yields cells that are noninfectious as assessed by extended infectivity assays. The psoralen/UV inactivation procedure described is effective with cells chronically or acutely infected with HIV-1 and is unaffected by cell densities up to 12 x 10(6)/ml. At 5 micrograms/ml psoralen does little damage to cellular permeability as shown by the ability of treated cells to exclude trypan blue and propidium iodide. Psoralen/UV treatment of HIV-1-infected cells does not cause a significant decrease in the reactivity of HIV-1 core and envelope antigens or cellular antigens to monoclonal antibodies. Experiments are presented demonstrating the use of these cells for flow cytometry studies and for cell surface labeling using the lactoperoxidase 125 I iodination procedure

  2. Pharmacokinetic and biopharmaceutic aspects of some psoralen derivatives used in dermatology

    International Nuclear Information System (INIS)

    Stolk, L.M.L.

    1982-01-01

    In the present thesis the pharmacokinetic and biopharmaceutic properties of some psoralen derivatives, that are used in photochemotherapy of dermatological diseases like vitiligo and psoriasis, are studied. Photochemotherapy is a combination of oral administration of one of the psoralen derivatives, 8-methoxypsoralen (8-MOP), 5-methoxypsoralen (5-MOP) or 4, 5', 8-trimethylpsoralen (TMP), and irradiation with long wave ultraviolet light, U.V.-A (320-400 nm), two hours later. This treatment is commonly called PUVA (Psoralen-UV-A). The purpose of the investigation was to develop an 8-MOP dosage form with a fast and reproducible absorption. Various dosage forms of 8-MOP were administered to volunteers and patients and 8-MOP concentrations in body fluids determined. Also the pharmacokinetic properties of 5-MOP and TMP were investigated in a pilot study. (Auth.)

  3. Psoralen-deoxyribonucleic acid photoreaction. Characterization of the monoaddition products from 8-methoxypsoralen and 4,5',8-trimethylpsoralen

    International Nuclear Information System (INIS)

    Kanne, D.; Straub, K.; Rapoport, H.; Hearst, J.E.

    1982-01-01

    The isolation and structural characterization are described of the major monoaddition products formed in the photoreaction of two naturally occurring psoralens, 8-methoxypsoralen and 4,5',8-trimethylpsoralen, with high molecular weight, double-stranded DNA. Hydrolysis of the psoralen-modified DNA and subsequent chromatography resulted in the isolation of four modified nucleosides from each psoralen. Structural characterization was accomplished by mass spectrometry and 1 H NMR analysis. The major products, accounting for 44 to 52% of the covalently bound psoralen, are two diastereomeric thymidine adducts formed by cycloaddition between the 5,6 double bond of the pyrimidine and the 4',5' (furan) double bond of the psoralen. All of the isolated adducts have cis-syn stereochemistry. The stereochemistry and product distribution of the adducts are determined in part by the constraints imposed by the DNA helix on the geometry of the noncovalent intercalation complex formed by psoralen and DNA prior to irradiation

  4. WE-FG-BRA-01: Cancer Treatment Utilizing Photo-Activation of Psoralen with KV X-Rays

    International Nuclear Information System (INIS)

    Oldham, M; Yoon, S; Meng, B; Adamson, J; Alcorta, D; Osada, T; Lyerly, K; Dewhirst, M; Fecci, P; Spector, N; Fathi, Z; Walder, H; Beyer, W

    2016-01-01

    Purpose: This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with immunogenic anti-cancer potential. Psoralen therapies have been limited due to the requirement for psoralen activation by UVA light. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and reradiate (phosphoresce) at UV wavelengths. Methods: The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry to investigate treatment induced apoptosis. Methylene blue staining, and WST assays were also used. X-PACT was then evaluated in an in-vivo pilot study on BALBc mice with syngeneic 4T1 tumors, including control arms for X-PACT components. Analysis focused on tumor growth delay. Results: A multivariable regression analysis of 36 independent in-vitro irradiation experiments demonstrated that X-PACT induces significant tumor cell apoptosis and cytotoxicity on all three tumor cell lines in-vitro (p<0.0001). Neither psoralen nor phosphor alone had a strongly significant effect. The in-vivo studies show a pronounced tumor growth delay when compared to controls (42% reduction at 25 days, p=0.0002). Conclusions: These studies demonstrate for the first time a therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation generate UVA light in-situ (including deep seated lesions) which in-turn photo-activates powerful anticancer therapeutics which

  5. WE-FG-BRA-01: Cancer Treatment Utilizing Photo-Activation of Psoralen with KV X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, M; Yoon, S; Meng, B; Adamson, J; Alcorta, D; Osada, T; Lyerly, K; Dewhirst, M; Fecci, P; Spector, N [Duke University Medical Center, Durham, NC (United States); Fathi, Z; Walder, H [Immunolighty LLc, Detroit, MI (United States); Beyer, W [QNS Group, Bahama, NC (United States)

    2016-06-15

    Purpose: This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with immunogenic anti-cancer potential. Psoralen therapies have been limited due to the requirement for psoralen activation by UVA light. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and reradiate (phosphoresce) at UV wavelengths. Methods: The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry to investigate treatment induced apoptosis. Methylene blue staining, and WST assays were also used. X-PACT was then evaluated in an in-vivo pilot study on BALBc mice with syngeneic 4T1 tumors, including control arms for X-PACT components. Analysis focused on tumor growth delay. Results: A multivariable regression analysis of 36 independent in-vitro irradiation experiments demonstrated that X-PACT induces significant tumor cell apoptosis and cytotoxicity on all three tumor cell lines in-vitro (p<0.0001). Neither psoralen nor phosphor alone had a strongly significant effect. The in-vivo studies show a pronounced tumor growth delay when compared to controls (42% reduction at 25 days, p=0.0002). Conclusions: These studies demonstrate for the first time a therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation generate UVA light in-situ (including deep seated lesions) which in-turn photo-activates powerful anticancer therapeutics which

  6. A method for fast determination of psoralens in oral solutions of phytomedicines using liquid chromatography.

    Science.gov (United States)

    Pires, Adriana Elias; Honda, Neli Kiko; Cardoso, Cláudia Andréa Lima

    2004-10-29

    A method for sample preparation and analysis by high performance liquid chromatography with UV detection (HPLC-UV) has been developed for routine analysis of psoralen and bergapten, photosensitizing compounds, in oral solutions of phytomedicines employed in Brazil for some illnesses. The linearity, accuracy, the inter- and intra-day precision of the procedure were evaluated. Calibration curves for psoralen and bergapten were linear in the range of 1.0-600.0 microg ml(-1) and 1.0-400.0 microg ml(-1) respectively. The recoveries of the psoralens in the oral solutions analysed were 94.43-99.97%. The percentage coefficient of variation (CV) of the quantitative analysis of the psoralens in the products analysis was within 5%. In inter-equipment study was employed gas chromatography-flame ionization (CG-FID) detection.

  7. Psoralen production in hairy roots and adventitious roots cultures of Psoralea coryfolia.

    Science.gov (United States)

    Baskaran, P; Jayabalan, N

    2009-07-01

    Psoralea corylifolia is an endangered plant producing various compounds of medical importance. Adventitious roots and hairy roots were induced in cultures prepared from hypocotyl explants. Psoralen content was evaluated in both root types grown either in suspension cultures or on agar solidified medium. Psoralen content was approximately 3 mg g(-1) DW in suspension grown hairy roots being higher than in solid grown hairy roots and in solid and suspension-grown adventitious roots.

  8. Combined effects of Psoralens and ultraviolet-B on growth, pigmentation and biochemical parameters of Abelmoschus esculentus L.

    Science.gov (United States)

    Kumari, Rima; Singh, Suruchi; Agrawal, S B

    2009-05-01

    The effects of pre-treatment of Psoralens (furocoumarin compounds) and supplemental ultraviolet-B (sUV-B) were studied on plant growth, photosynthetic and non-photosynthetic pigments, protein, phenylalanine ammonia lyase (PAL) activity and antioxidative defense potential as well as their ultimate effects on biomass production in Abelmoschus esculentus L. (Okra) plants. Psoralens are capable of absorbing radiant energy and stimulating the pigmentation of human skin when photo-activated in presence of UV-A or UV-B making them beneficial in the treatment of vitilago. Pre-treatment of Psoralens against sUV-B (pUV-B), stimulates higher production of UV-B protective pigments (flavonoids and carotenoids) and helps in maintaining its biomass against UV-B stress. Antioxidative defense system in the test plant was activated by combined treatment of Psoralens and sUV-B as evidenced by the enhanced activity of enzymatic (ascorbate peroxidase-APX, superoxide dismutase-SOD, POX) and non-enzymatic (ascorbic acid and phenol) antioxidants. Individual treatments of Psoralens and sUV-B showed inhibitory effect on various morphological traits i.e. reduction in plant height, leaf area and ultimately on biomass production. Our results clearly indicated that adverse effect of sUV-B on biomass production was ameliorated by pre- treatment with Psoralens.

  9. Bypass of a psoralen DNA interstrand cross-link by DNA polymerases beta, iota, and kappa in vitro

    Science.gov (United States)

    Smith, Leigh A.; Makarova, Alena V.; Samson, Laura; Thiesen, Katherine E.; Dhar, Alok; Bessho, Tadayoshi

    2012-01-01

    Repair of DNA inter-strand cross-links in mammalian cells involves several biochemically distinctive processes, including the release of one of the cross-linked strands and translesion DNA synthesis (TLS). In this report, we investigated in vitro TLS activity of psoralen DNA inter-strand cross-link by three DNA repair polymerases, DNA polymerase beta, kappa and iota. DNA polymerase beta is capable of bypassing a psoralen cross-link with a low efficiency. Cell extracts prepared from DNA polymerase beta knockout mouse embryonic fibroblast showed a reduced bypass activity of the psoralen cross-link and purified DNA polymerase beta restored the bypass activity. In addition, DNA polymerase iota mis-incorporated thymine across the psoralen cross-link and DNA polymerase kappa extended these mis-paired primer ends, suggesting that DNA polymerase iota may serve as an inserter and DNA polymerase kappa may play a role as an extender in the repair of psoralen DNA inter-strand cross-links. The results demonstrated here indicate that multiple DNA polymerases could participate in TLS steps in mammalian DNA inter-strand cross-link repair. PMID:23106263

  10. Receptor-mediated photo-cytotoxicity: synthesis of a photoactivatable psoralen derivative conjugated to insulin.

    Science.gov (United States)

    Gasparro, F P; Knobler, R M; Yemul, S S; Bisaccia, E; Edelson, R L

    1986-12-15

    4'-Aminomethyl-4,5',8-trimethylpsoralen has been chemically conjugated to insulin using a carbodiimide derivative. The psoralen moiety retains its photochemical reactivity as evidenced by its ability to crosslink DNA after exposure to long wavelength ultraviolet light (UVA, 320-400 nm). This chimeric molecule has been used to selectively kill a population of lymphocytes whose expression of insulin receptors has been stimulated with phytohemagglutinin. Insulin carries the psoralen into the cell via receptor-mediated endocytosis, where it is subsequently activated by exposure to UVA light. The UVA induced activity of AMT-insulin can be blocked by the presence of native insulin. The viability of unstimulated lymphocytes was not affected by AMT-insulin and UVA light. The hybrid insulin-psoralen molecule may be a prototype for a family of phototoxic drugs which can be selectively delivered to subsets of lymphocytes.

  11. Eosin-sensitized photooxidation of substituted phenylalanines and tyrosines

    Energy Technology Data Exchange (ETDEWEB)

    Rizzuto, F.; Spikes, J.D.

    1977-01-01

    The cosin-sensitized photooxidation of tyrosine and a number of compounds related to tyrosine (substituted phenylalanines) was studied by steady-state kinetic and flash photolysis techniques. In particular, the role of the phenolic group and the amino and carboxyl groups of the alanyl side chain in the photooxidation mechanism was investigated in detail. Several relationships between substrate structure and susceptibility to photooxidation as well as effects of substrate structure on photooxidation mechanisms were found. For example, phenylalanine is not photooxidizable, but substitution of electron-donating (activating) groups such as -OH (as in tyrosine) or -NH/sub 2/ (as in p-aminophenylalanine) results in rapidly photooxidized derivatives. However, substituting deactivating groups such as -Cl (as in p-chlorophenylalanine) or weakly activating groups such as -OCH/sub 3/ (as in 4-methoxyphenylalanine) result in non-photooxidizable derivatives. Substitution of additional activating groups to the ring of hydroxy-substituted phenylalanines results in increased rates of photooxidation, whereas additional deactivating groups result in decreased photooxidation rates. The rate-determining step in the photooxidation mechanism is shown to be dependent on the presence and position of an electron-donating substituent on the benzenoid ring. Only minor involvement of the side chain amino and carboxyl groups was found. Both singlet oxygen and hydrogen abstraction mechanisms are involved in the eosin-sensitized photooxidation of hydroxy-substituted phenylalanines (e.g., tyrosine). The hydrogen abstraction mechanism probably predominates at both pH 8 and 11.

  12. Effect of psoralen and near UV on vertebrate cells in culture: comparison of laser with standard lamp

    International Nuclear Information System (INIS)

    Peterson, S.P.; Berns, M.W.

    1978-01-01

    4'-Aminoethyl-4,5',8-trimethylpsoralen, a DNA photoreagent, was used in conjunction with near UV light to modify cell growth and morphology. Since near UV radiation is needed to trigger the photoreactions, various doses of classical and laser near UV light were exposed to cells growing in media containing psoralen. It was found that near UV light caused a reduction in cell viability as indicated by complete inhibition of growth. The specificity of psoralens for nucleic acids was also investigated by using a tritium labeled psoralen derivative and tracing its appearance in different fractions of DNA from treated and untreated cells. (author)

  13. Effect of psoralen and near uv on vertebrate cells in culture: comparison of laser with standard lamp

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, S P; Berns, M W [California Univ., Irvine (USA)

    1978-03-01

    4'-Aminoethyl-4,5',8-trimethylpsoralen, a DNA photoreagent, was used in conjunction with near uv light to modify cell growth and morphology. Since near uv radiation is needed to trigger the photoreactions, various doses of classical and laser near uv light were administerd to cells growing in media containing psoralen. It was found that near uv light caused a reduction in cell viability as indicated by complete inhibition of growth. The specificity of psoralens for nucleic acids was also investigated by using a tritium labeled psoralen derivative and tracing its appearance in different fractions of DNA from treated and untreated cells.

  14. Isolation and purification of psoralen and isopsoralen and their ...

    African Journals Online (AJOL)

    identified based on 1H-NMR, 13C-NMR spectra, the two compounds were identified as psoralen andisopsoralen, and their .... multi-point injection began when the tumor grew to 0.5 .... were no significant changes in the color and texture.

  15. Development and in vitro assessment of psoralen and resveratrol co-loaded ultradeformable liposomes for the treatment of vitiligo.

    Science.gov (United States)

    Doppalapudi, Sindhu; Mahira, Shaheen; Khan, Wahid

    2017-09-01

    Vitiligo is a de-pigmenting skin disorder characterized by white patches on skin due to partial or complete loss of melanocytes. Psoralen in combination with ultraviolet-A (PUVA) acts by stimulation of melanin content and tyrosinase activity in melanocytes. Resveratrol, a sirtuin activator and a potential anti-oxidant reduce oxidative stress which is one of the triggering factors for initiation of vitiligo. Despite their therapeutic activity, weak percutaneous permeability of psoralen and poor solubility of resveratrol hinders their effective topical administration. The aim of present study is to formulate ultradeformable liposomes (UDL) co-loaded with psoralen and resveratrol for evaluation of PUVA and anti-oxidant combination in vitiligo treatment. For this purpose, UDL composed of DC-Chol, cholesterol and sodium deoxy cholate were prepared for their co-delivery. Liposomal carriers were characterized and evaluated for their efficacy using B16F10 cell line. Free radical scavenging potential was also determined for these carriers by in vitro anti-oxidant assays. Optimal co-loaded UDL with particle size ranging from 120 to 130nm, zeta potential of +46.2mV, entrapment efficiency of 74.09% (psoralen) and 76.91% (resveratrol) were obtained. Compared to control, co-loaded UDL showed significant stimulation of melanin and tyrosinase activity with major contribution of psoralen. Further, co-loaded UDL also exhibited potential free radical scavenging activity where resveratrol played a key role. Hence, psoralen and resveratrol co-loaded UDL acts in vitiligo through dual mechanisms of action viz., stimulation of melanin and tyrosinase activity as well as by anti-oxidant activity. These findings indicate that psoralen and resveratrol co-loaded UDL has the promising therapeutic potential for the treatment of vitiligo. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Elongational viscosity of photo-oxidated LDPE

    Science.gov (United States)

    Rolón-Garrido, Víctor H.; Wagner, Manfred H.

    2014-05-01

    Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220°C to obtain the master curve at 170°C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method. The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, timedeformation separability is confirmed for all samples, independent of the degree of photo-oxidation.

  17. Photooxidative stress in plants

    International Nuclear Information System (INIS)

    Foyer, C.H.; Lelandais, M.; Kunert, K.J.

    1994-01-01

    The light-dependent generation of active oxygen species is termed photooxidative stress. This can occur in two ways: (1) the donation of energy or electrons directly to oxygen as a result of photosynthetic activity; (2) exposure of tissues to ultraviolet irradiation. The light-dependent destruction of catalase compounds the problem. Although generally detrimental to metabolism, superoxide and hydrogen peroxide may serve useful functions if rigorously controlled and compartmentalised. During photosynthesis the formation of active oxygen species is minimised by a number of complex and refined regulatory mechanisms. When produced, active oxygen species are eliminated rapidly by efficient antioxidative systems. The chloroplast is able to use the production and destruction of hydrogen peroxide to regulate the thermal dissipation of excess excitation energy. This is an intrinsic feature of the regulation of photosynthetic electron transport. Photoinhibition and photooxidation only usually occur when plants are exposed to stress. Active oxygen species are part of the alarm-signalling processes in plants. These serve to modify metabolism and gene expression so that the plant can respond to adverse environmental conditions, invading organisms and ultraviolet irradiation. The capacity of the antioxidative defense system is often increased at such times but if the response is not sufficient, radical production will exceed scavenging and ultimately lead to the disruption of metabolism. Oxidative damage arises in high light principally when the latter is in synergy with additional stress factors such as chilling temperatures or pollution. Environmental stress can modify the photooxidative processes in various ways ranging from direct involvement in light-induced free radical formation to the inhibition of metabolism that renders previously optimal light levels excessive. It is in just such situations that the capacity for the production of active oxygen species can exceed that

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

    International Nuclear Information System (INIS)

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

    1982-01-01

    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

  19. Catalytic photooxidation of pentachlorophenol using semiconductor nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    WILCOXON,JESS P.

    2000-04-17

    Pentachlorophenol (PCP) is a toxic chlorinated aromatic molecule widely used as fungicide, a bactericide and a wood preservation, and thus ubiquitous in the environment. The authors report photo-oxidation of PCP using a variety of nanosize semiconductor metal oxides and sulfides in both aqueous and polar organic solvents and compare the photo-oxidation kinetics of these nanoclusters to widely studied bulk powders like Degussa P-25 TiO{sub 2} and CdS. They study both the light intensity dependence of PCP photooxidation for nanosize SnO{sub 2} and the size dependence of PCP photooxidation for both nanosize SnO{sub 2} and MoS{sub 2}. They find an extremely strong size dependence for the latter which they attribute to its size-dependent band gap and the associated change in redox potentials due to quantum confinement of the hole-electron pair. The authors show that nanosize MoS{sub 2} with a diameter of d=3.0 nm and an absorbance edge of {approximately}450 nm is a very effective photooxidation catalyst for complete PCP mineralization, even when using only visible light irradiation.

  20. Wavelength dependence for the photoreactions of DNA-Psoralen monoadducts. 1. Photoreversal of monoadducts

    International Nuclear Information System (INIS)

    Shi, Y.; Hearst, J.E.

    1987-01-01

    The authors have studied the wavelength dependence for the photoreversal of a monoadducted psoralen derivative, HMT [4'(hydroxymethyl)-4,5',8-trimethylpsoralen], in a single-stranded deoxyoligonucleotide (5'-GAAGCTACGAGC-3'). The psoralen was covalently attached to the thymidine residue in the oligonucleotide as either a furan-side monoadduct, which is formed through the cycloaddition between the 4',5' double bond of the psoralen and the 5,6 double bond of the thymidine, or a pyrone-side monoadduct, which is formed through the cycloaddition between the 3,4 double bond of the psoralen and the 5,6 double bond of the thymidine. As a comparison, they have also investigated the wavelength-dependent photoreversal of the isolated thymidine-HMT monoadducts. All photoreversal action spectra correlate with the extinction spectra of the isolate monoadducts. In the case of the pyrone-side monoadduct, two absorption bands contribute to the photoreversal with a quantum yield of 2 x 10 -2 at wavelengths below 250 nm and 7 x 10 -3 at wavelengths from 287 to 314 nm. The incorporation of the monoadduct into the DNA oligomer had little effect upon the photoreversal rate. For the furan-side monoadduct at least three absorption bands contribute to the photoreversal. The quantum yield varied from 5 x 10 -2 at wavelengths below 250 nm to 7 x 10 -4 at wavelengths between 295 and 365 nm. In contrast to the case of the pyrone-side monoadduct, the incorporation of the furan-side monoadduct into the DNA oligomer reduced the photoreversal rate constant at wavelengths above 285 nm

  1. Isolation and purification of psoralen and isopsoralen and their ...

    African Journals Online (AJOL)

    Nude rat model of osteosarcoma was established; the rats were randomized into: normal saline group, psoralen low- and high-dose groups, isopsoralen low- and ... was used to observe heart, liver, spleen, lung, kidney, and tumor histopathology; and electron microscopy was used to observe the fine structure of tumor cells.

  2. Chromatin influence on the function and formation of the nuclear envelope shown by laser-induced psoralen photoreaction

    International Nuclear Information System (INIS)

    Peterson, S.P.; Berns, M.W.

    1978-01-01

    Potorous tridactylis (PTK 2 ) cells growing in culture were treated with psoralen derivatives and dividing cells were located by phase-contrast microscopy. Psoralens, light-sensitive DNA-photoadducting drugs, were reacted with mitotic chromosomes through exposure to 365-nm light from an argon laser micro-beam system. It was shown that following mitosis and photoreaction, cells without nuclear envelopes were produced when psoralen-treated cells received 60 light pulses over their entire chromosome complement. These 'non-nuclear membrane' cells were found to incorporate [ 3 H]uridine, and to a lesser extent, [ 3 H]thymidine by autoradiography. Reduction of the light exposure by half (30 near-u.v. pulses) over the entire chromosome complement in the presence of psoralen also produced non-nuclear-membrane cells as seen by light microscopy. Further examination of these cells (30 light pulses) by single-cell electron microscopy revealed that unlike the high light exposure (60 near-u.v. pulses), the low light dosage resulted in cells with membrane patches associated with their chromatin. Since neither actinomycin D nor cycloheximide impeded nuclear envelope reformation, the psoralen-DNA reaction is concluded to produce non-nuclear membrane by a mechanism other than transcription or translation inhibition. The association of Golgi with areas of nuclear membrane patches gives indirect evidence of a possible Golgi contribution to the reformation of the nuclear envelope after mitosis. It is concluded that DNA plays a role in envelope reformation. (author)

  3. Human XPC-hHR23B interacts with XPA-RPA in the recognition of triplex-directed psoralen DNA interstrand crosslinks

    DEFF Research Database (Denmark)

    Thoma, Brian S; Wakasugi, Mitsuo; Christensen, Jesper

    2005-01-01

    (NER), XPA-RPA, recognizes DNA ICLs. We now report the use of triplex technology to direct a site-specific psoralen ICL to a target DNA substrate to determine whether the human global genome NER damage recognition complex, XPC-hHR23B, recognizes this lesion. Our results demonstrate that XPC-hHR23B...... recognizes psoralen ICLs, which have a structure fundamentally different from other lesions that XPC-hHR23B is known to bind, with high affinity and specificity. XPC-hHR23B and XPA-RPA protein complexes were also observed to bind psoralen ICLs simultaneously, demonstrating not only that psoralen ICLs...... are recognized by XPC-hHR23B alone, but also that XPA-RPA may interact cooperatively with XPC-hHR23B on damaged DNA, forming a multimeric complex. Since XPC-hHR23B and XPA-RPA participate in the recognition and verification of DNA damage, these results support the hypothesis that interplay between components...

  4. Photo-oxidation of LDPE: Effects on elongational viscosity

    Science.gov (United States)

    Rolón-Garrido, Víctor H.; Wagner, Manfred H.

    2013-04-01

    Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220°C to obtain the master curve at 170°C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method. The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, time-deformation separability is confirmed for all samples, independent of the degree of photo-oxidation.

  5. Psoralen-UVA-treated psoriatic lesions

    International Nuclear Information System (INIS)

    Hashimoto, K.; Kohda, H.; Kumakiri, M.; Blender, S.L.; Willis, I.

    1978-01-01

    Psoralen-ultraviolet light (PUVA)-treated psoriatic lesions were studied for ultrastructural changes. In early stages of treatment, sunburn cells in the epidermis and bizarre giant cells in the dermis were more frequently observed. When clinical improvement was apparent, these changes had subsided. Dermal abnormality in long-term therapy consisted of a thick perivascular cost of amorphous substance. No abnormality was found in the epidermal keratinocytes in long-term therapy, except a clustering and giant cell formation of melanocytes, a heavy melanization of keratinocytes, and hyperkeratosis. Low-dose initiation and slow increment of both 8-methoxypsoralen and UVA is probably a reasonable regimen for benign dermatoses such as psoriasis because it will allow enough time for the skin to become more protected, while the therapeutic results are as satisfactory as in a high-dose schedule

  6. Photooxidation of polystyrene: irradiation at 254 and 365 nm

    International Nuclear Information System (INIS)

    Otocka, E.P.; Curran, S.; Porter, R.S.

    1983-01-01

    Studies have been made of the near surface photooxidation of atactic polystyrene films prepared in the absence of air. The samples were photooxidized on exposure to air at two frequencies, 254 and 365 nm, using a calibrated mercury irradiation source with filters. Most studies were made at 40 0 C and as a function of irradiation time with the reactions characterized by changes in molecular weight and composition. The former was evaluated by gel permeation chromatography and the latter by transmission Fourier transform infrared ir spectroscopy and by multiple-internal-reflectance ir spectra using different angles and different crystals to evaluate compositions as a function of film depth. Species identified in photooxidation include the generation of hydroperoxides and the appearance of carbonyl bands with the latter identified by the spectral shift associated with the exposure of the photooxidized polystyrene surface to ammonia. These results suggest that principal products of near-surface oxidation of polystyrene are carboxylic acids. 6 figures, 1 table

  7. Photooxidation stability of microcapsules in thermochromic prints

    Directory of Open Access Journals (Sweden)

    Mirela Rozic

    2018-03-01

    Full Text Available In this paper, photochemical stability of two thermochromic prints was investigated: vegetable oil based offset and UV curing screen printing ink. The obtained preliminary results can be used for further detailed examination of prints stability. It is well known that thermochromic printing inks are very unstabile when exsposed to UV irradiance and this is why they are mainly used for applications that are not directly exposed to sunlight. The results of the study show the heterogeneous nature of photooxidative degradation of thermochromic prints, and the opposite behaviour of photooxidation can be noticed comparing examined prints. Microcapsules in the UV curable screen print by fixation with polar polymer binder can create a new products stable to photoxidation. For this reason, the areas where the microcapsules and binder are bonded together are stable. Degraded only areas where binder is not related to microcapsules. Microcapsules in offset print do not have the ability to create new stabile forms due to smaller polarity and different chemical composition of the offset oxidized binder. In the offset print, the microcapsules are the least photooxidative stable and also cause lower photooxidative stability of the binder in contact with them. Cavities are formed in the areas where microcapsules are in contact with the binder, while the areas in which the binder is not in contact with microcapsules are not degraded.

  8. Laser microirradiation of Chinese hamster cells at wavelength 365 nm: effects of psoralen and caffeine

    International Nuclear Information System (INIS)

    Cremer, T.; Peterson, S.P.; Cremer, C.; Berns, M.W.

    1981-01-01

    Cells of a V79 subline of the Chinese hamster were microirradiated at wavelength 365 nm in the presence of the psoralen derivative, trioxsalen. Microirradiation was accomplished by a pulsed argon laser microbeam either in anaphase or in interphase 3 h after mitosis. Inhibition of clonal growth and formation of micronuclei at the first postirradiation mitosis were observed after microirradiation of anaphase chromosomes and of small parts of the interphase nucleus. Microirradiation of the cytoplasm beside the interphase nucleus or between the sets of chromosomes moving apart from each other in anaphase did not produce these effects. Anaphase experiments showed that only the daughter cell which received microirradiated chromatin exhibited an abnormal growth pattern. Most interestingly, shattering of the whole chromosome complement could be induced by microirradiation of small parts of the interphase nucleus and post-treatment with caffeine. Since microirradiation of chromatin in the absence of psoralen was not effective, we consider formation of psoralen photoadducts to nucleic acids in microirradiated chromatin to be the specific cause of the effects. We suggest that DNA photolesions in chromosome segments present in the microirradiated part of the nucleus can induce shattering of all the chromosomes in the microirradiated nucleus. Several possibilities are discussed to explain this unexpected finding

  9. A new psoralen-containing gel for topical PUVA therapy: development, and treatment results in patients with palmoplantar and plaque-type psoriasis, and hyperkeratotic eczema

    International Nuclear Information System (INIS)

    De Rie, M.A.; Van Eendenburg, J.P.; Versnick, A.C.; Stolk, L.M.L.; Bos, J.D.; Westerhof, W.

    1995-01-01

    Topical photochemotherapy with psoralen and its derivatives 4,5',8-trimethylpsoralen (TMP) and 8-methoxypsoralen (8-MOP), with UVA irradiation, was evaluated with regard to minimum phototoxic dose, concentration, timing of UVA irradiation and systemic and local side-effects, in healthy volunteers. Psoralen (0.005%) in aqueous gel was found to be superior to TMP and 8-MOP in aqueous gel. No hyperpigmentation was seen after topical PUVA treatment with psoralen in aqueous gel. Patients with plaque-type psoriasis (n=7), palmoplantar psoriasis (n=7) and hyperkeratotic eczema (n=2) were treated. Topical PUVA therapy was effective in most psoriasis patients, without the occurrence of local or systemic side-effects. Moreover, hyperkeratotic eczema patients who did not respond to conventional therapy showed partial remission. These results indicate that topical PUVA therapy with psoralen in aqueous gel is a useful therapeutic modality for treatment of psoriasis patients, and patients with recalcitrant dermatoses such as palmoplantar psoriasis and hyperkeratotic eczema. (author)

  10. Biodegradation of photo-oxidized lignite and characterization of the products

    Science.gov (United States)

    Li, Jiantao; Liu, Xiangrong; Yue, Zilin; Zhang, Yaowen

    2018-01-01

    Biodegradation of photo-oxidized Inner Mongolia lignite by pseudomonas aeruginosa was studied and the degradation percentage reached 56.27%, while the corresponding degradation percentage of the strain degrading raw Inner Mongolia lignite is only 23.16%. The degradation products were characterized. Proximate and ultimate analyses show that the higher oxygen content increased by photo-oxidation pretreatment maybe promoted the degradation process. Ultraviolet spectroscopy (UV) analysis of the liquid product reveals that it contains unsaturated structures and aromatic rings are the main structure units. Gas chromatography-mass spectrometry (GC-MS) analysis indicates that the main components of the ethyl acetate extracts are low molecular weight organic compounds, such as ketones, acids, hydrocarbons, esters and alcohols. Infrared spectroscopy (IR) analysis of raw lignite, photo-oxidized lignite and residual lignite demonstrates that the absorption peaks of functional groups in residual lignite disappeared or weakened obviously. Scanning electron microscopy (SEM) analysis manifests that small holes appear in photo-oxidized lignite surface, which may be promote the degradation process and this is only from the physical morphology aspects, so it can be inferred from the tests and analyses results that the more important reason of the high degradation percentage is mostly that the photo-oxidation pretreatment changes the chemical structures of lignite.

  11. Photooxidation of organic wastes using semiconductor nanoclusters. 1998 annual progress report

    International Nuclear Information System (INIS)

    Wilcoxon, J.P.

    1998-01-01

    'This report summarizes work after 1.5 years of a 3-year project. The authors efforts have focused on demonstration of photocatalysis of organic pollutants using nanosize MoS 2 . They investigated the effects of (1) bandgap, valence and conduction band energies; (2) surface modification of MoS 2 by deposition of metal and metal oxide islands to enhance electron transfer; and (3) use of semi-conductor semi-conductor composites to achieve improved charge separation and thus photooxidation of pollutants. They synthesized and studied nanosize MoS 2 of three different sizes and associated bandgaps and studied photoredox reactions of nanosize MoS 2 dispersed in solution and supported on a macroscopic powder. The latter would be the method of choice for use as a practical photocatalyst for water purification. As they emphasized in the original proposal, MoS 2 in nanosize form can be tuned to absorb various amounts of the solar spectrum. They discovered there is an optimal choice of absorbance characteristics and valence and conduction band levels which allow the rapid photo-oxidation of a chosen organic molecule. The advantages of having a photostable material with a tunable bandgap were demonstrated in an experiment where phenol destruction with visible (> 450 nm) light occurred at a dramatically faster rate with nanoscale MoS 2 catalysts compared to the best available previous material TiO 2 . This was the first demonstration of rapid photooxidation of an organic molecule using a completely photostable catalyst and only visible light. The possibility of transferring electrons or holes between nanoscale MoS 2 and other semiconductor materials in order to increase electron/hole lifetimes were explored. It was shown that small amounts ( 2 deposited on to TiO 2 can lead to significant (∼2) enhancements of phenol destruction rates. A number of different chemicals were photocatalyzed sucessfully to CO 2 , but most of the work centered on the destruction of phenol. This

  12. Exosomes play an important role in the process of psoralen reverse multidrug resistance of breast cancer.

    Science.gov (United States)

    Wang, Xiaohong; Xu, Chengfeng; Hua, Yitong; Sun, Leitao; Cheng, Kai; Jia, Zhongming; Han, Yong; Dong, Jianli; Cui, Yuzhen; Yang, Zhenlin

    2016-12-01

    Release of exosomes have been shown to play critical roles in drug resistance by delivering cargo. Targeting the transfer of exosomes from resistant cells to sensitive cells may be an approach to overcome some cases of drug resistance. In this study, we investigated the potential role of exosomes in the process of psoralen reverse multidrug resistance of MCF-7/ADR cells. Exosomes were isolated by differential centrifugation of culture media from MCF-7/ADR cells (ADR/exo) and MCF-7 parental cells (S/exo). Exosomes were characterized by morphology, exosomal markers and size distribution. The ability of ADR/exo to transfer multidrug resistance was assessed by MTT and real-time quantitative PCR. The different formation and secretion of exosomes were detected by immunofluorescence and transmission electron microscopy. Then we performed comparative transcriptomic analysis using RNA-Seq technology and real-time quantitative PCR to better understand the gene expression regulation in exosmes formation and release after psoralen treatment. Our data showed that exosomes derived from MCF-7/ADR cells were able to promote active sequestration of drugs and could induce a drug resistance phenotype by transferring drug-resistance-related gene MDR-1 and P-glycoprotein protein. Psoralen could reduce the formation and secretion of exosomes to overcome drug resistance. There were 21 differentially expressed genes. Gene ontology (GO) pathway analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the most significantly expressed genes were linked to PPAR and P53 signaling pathways which were related to exosomes formation, secretion and cargo sorting. Psoralen can affect the exosomes and induce the reduction of resistance transmission via exosomes might through PPAR and P53 signaling pathways, which might provide a novel strategy for breast cancer resistance to chemotherapy in the future.

  13. DNA unwinding induced by photoaddition of psoralen derivatives and determination of dark-binding equilibrium constants by gel electrophoresis

    International Nuclear Information System (INIS)

    Wiesehahn, G.; Hearst, J.E.

    1978-01-01

    Derivatives of furo[3,2-g]coumarin (psoralen) can bind to the DNA double helix and, in the presence of long-wavelength uv light, the bound psoralen may react covalently with pyrimidine residues on one or both strands of the helix. By using agarose gel electrophoresis, we have determined the unwinding angle associated with each of four different psoralen derivatives to be 28 0 +- 4 0 . For 4,5',8-trimethylpsoralen (trioxsalen) the unwinding angle was found to be independent of the initial DNA superhelix density in the range that is accessible to agarose gel electrophoresis. Also by using agarose gel electrophoresis, we have determined the unwinding angle for ethidium intercalation. This was done by the total relaxation of supercoiled DNA in the presence of a series of ethidium concentrations. By using published values for the association constant for ethidium binding to DNA and evaluating the final superhelix density (after removal of ethidium) of the DNA on gels, we calculated an unwinding angle of 29 0 +- 3 0 . Assuming an unwinding angle of 28 0 for the noncovalent intercalation of psoralen derivatives, we used the same procedure to determine intercalation binding constants. The association constants for 4'-aminomethyltrioxsalen were 300 to 1400 M -1 in NaCl at 0.2 to 0.05 M and 300 to 2500 M -1 in Mg 2+ at 4 to 0.5 mM. The association constant for 4'-hydroxymethyltrioxsalen in 0.5 mM Mg 2+ was determined to be 70 M -1

  14. Accessibility of ribosomal genes to trimethyl psoralen in nuclei of Physarum polycephalum

    International Nuclear Information System (INIS)

    Judelson, H.S.; Vogt, V.M.

    1982-01-01

    The authors have probed the accessibility of the genes for rRNA in Physarum polycephalum by using the photoreactive DNA cross-linking agent 4,5',8-trimethyl psoralen. Nuclei isolated from actively growing Physarum were treated with trimethyl psoralen and irradiated with 360-nm light in order to form cross-links. The palindromic, extrachromosomal rDNA then was isolated, and the positions of cross-links were determined by electron microscopy of the DNA under totally denaturing conditions. The results indicate that the frequency of cross-linking, after correction for base sequence bias of the reaction, is up to sixfold higher in the transcribed regions than in the central or the terminal spacer regions. There is no detectable heterogeneity among the different rDNA molecules or between the halves of a single molecule. Cross-linked molecules invariably occur in a linear as opposed to a cruciform structure. The preferential cross-linking of the transcribed region is nearly eliminated in spherules, a dormant transcriptionally inactive form in the Physarum life cycle

  15. Photooxidation Behavior of a LDPE/Clay Nanocomposite Monitored through Creep Measurements

    Directory of Open Access Journals (Sweden)

    Francesco Paolo La Mantia

    2017-07-01

    Full Text Available Creep behavior of polymer nanocomposites has not been extensively investigated so far, especially when its effects are combined with those due to photooxidation, which are usually studied in completely independent ways. In this work, the photooxidation behavior of a low density polyethylene/organomodified clay nanocomposite system was monitored by measuring the creep curves obtained while subjecting the sample to the combined action of temperature, tensile stress, and UV radiation. The creep curves of the irradiated samples were found to be lower than those of the non-irradiated ones and progressively diverging, because of the formation of branching and cross-linking due to photooxidation. This was further proved by the decrease of the melt index and the increase of the intrinsic viscosity; at the same time, the formation of carbonyl groups was observed. This behavior was more observable in the nanocomposite sample, because of its faster photooxidation kinetics.

  16. High formation of secondary organic aerosol from the photo-oxidation of toluene

    OpenAIRE

    L. Hildebrandt; N. M. Donahue; S. N. Pandis

    2009-01-01

    Toluene and other aromatics have long been viewed as the dominant anthropogenic secondary organic aerosol (SOA) precursors, but the SOA mass yields from toluene reported in previous studies vary widely. Experiments conducted in the Carnegie Mellon University environmental chamber to study SOA formation from the photo-oxidation of toluene show significantly larger SOA production than parameterizations employed in current air-quality models. Aerosol mass yields depend on experimental co...

  17. UV/Fenton photo-oxidation of Drimarene Dark Red (DDR) containing textile-dye wastewater

    Science.gov (United States)

    Hudaya, T.; Anthonios, J.; Septianto, E.

    2016-11-01

    Textile dye wastewater contains organic pollutants which are non-biodegradable, characterized by low BOD/COD ratio of typically Advanced Oxidation Processes (AOPs). One of the AOPs method which is the UV/H2O2/Fe2+ (or UV/Fenton) offers not only relatively low cost but also quite effective (in terms of color removal and reaction time) treatment. This particular research aimed to optimize the conditions of UV/Fenton photo-oxidation process for Drimarene Dark Red containing textile- dye wastewater. The two main operating conditions to be optimized were the initial concentration of H2O2 ranged between 0.022-0.078 %-w and the mol ratio of Fe2+: H2O2 was varied from 1: 13 up to 1: 45, using the Central Composite Design experimental matrix. The photo-oxidation was carried out at the optimum pH of 3 from some previous experiments. The best processing conditions of the photo-oxidation of Drimarene Dark Red (DDR) were found at the initial concentration of H2O2 at 0.050%-w and the mole ratio Fe2+: H2O2 of 1: 22. Under these conditions, the measured 2nd order pseudo-rate constantwas 0.021 M-1.min-1. The DDR color removal of 90% was surprisingly achievable within only 10 minutes reaction time.

  18. Sensitivity of Escherichia coli acrA Mutants to Psoralen plus Near-Ultraviolet Radiation

    DEFF Research Database (Denmark)

    Hansen, M. Trier

    1982-01-01

    The sensitivity to psoralen plus near-ultraviolet radiation (PUVA) was compared in a pair of E. coli strains differing at the acrA locus. Survival was determined for both bacteria and phage λ. AcrA mutant cells were 40 times more sensitive than wild type to the lethal effect of PUVA. Free λ phage...

  19. Optimization of Photooxidative Removal of Phenazopyridine from Water

    Science.gov (United States)

    Saeid, Soudabeh; Behnajady, Mohammad A.; Tolvanen, Pasi; Salmi, Tapio

    2018-05-01

    The photooxidative removal of analgesic pharmaceutical compound phenazopyridine (PhP) from aqueous solutions by UV/H2O2 system with a re-circulated photoreactor was investigated. Response surface methodology (RSM) was employed to optimize the effect of operational parameters on the photooxidative removal efficiency. The investigated variables were: the initial PhP and H2O2 concentrations, irradiation time, volume of solution and pH. The analysis of variance (ANOVA) of quadratic model demonstrated that the described model was highly significant. The predicted values of the photooxidative removal efficiency were found to be in a fair agreement with experimental values ( R 2 = 0.9832, adjusted R 2 = 0.9716). The model predicted that the optimal reaction conditions for a maximum removal of PhP (>98%) were: initial PhP concentration less than 23 mg L-1, initial concentration of H2O2 higher than 470 mg L-1, solution volume less than 500 mL, pH close to 2 and irradiation time longer than 6 min.

  20. Elongational rheology and cohesive fracture of photo-oxidated LDPE

    Energy Technology Data Exchange (ETDEWEB)

    Rolón-Garrido, Víctor H., E-mail: victor.h.rolongarrido@tu-berlin.de; Wagner, Manfred H. [Chair of Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin), Fasanenstrasse 90, D-10623 Berlin (Germany)

    2014-01-15

    It was found recently that low-density polyethylene (LDPE) samples with different degrees of photo-oxidation represent an interesting system to study the transition from ductile to cohesive fracture and the aspects of the cohesive rupture in elongational flow. Sheets of LDPE were subjected to photo-oxidation in the presence of air using a xenon lamp to irradiate the samples for times between 1 day and 6 weeks. Characterisation methods included Fourier transform infrared spectroscopy, solvent extraction method, and rheology in shear and uniaxial extensional flows. Linear viscoelasticity was increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by the carbonyl index, acid and aldehydes groups, and gel fraction. The molecular stress function model was used to quantify the experimental data, and the nonlinear model parameter β was found to be correlated with the gel content. The uniaxial data showed that the transition from ductile to cohesive fracture was shifted to lower elongational rates, the higher the gel content was. From 2 weeks photo-oxidation onwards, cohesive rupture occurred at every strain rate investigated. The true strain and true stress at cohesive fracture as well as the energy density applied to the sample up to fracture were analyzed. At low gel content, rupture was mainly determined by the melt fraction while at high gel content, rupture occurred predominantly in the gel structure. The strain at break was found to be independent of strain rate, contrary to the stress at break and the energy density. Thus, the true strain and not the stress at break or the energy density was found to be the relevant physical quantity to describe cohesive fracture behavior of photo-oxidated LDPE. The equilibrium modulus of the gel structures was correlated with the true strain at rupture. The stiffer the gel structure, the lower was the deformation tolerated before the sample breaks.

  1. Comparison of oral psoralen-UV-A with a portable tanning unit at home vs hospital-administered bath psoralen-UV-A in patients with chronic hand eczema - An open-label randomized controlled trial of efficacy

    NARCIS (Netherlands)

    van Coevorden, AM; Kamphof, WG; van Sonderen, E; Bruynzeel, DP; Coenraads, PJ

    2004-01-01

    Objective: To study whether oral psoralen-UV-A (PUVA) with a portable tanning unit at home is as effective as hospital-administered bath PUVA in patients with chronic hand eczema. Design: Open-label randomized controlled trial, with a 10-week treatment period and an 8-week follow-up period. Setting:

  2. SU-E-T-93: Activation of Psoralen at Depth Using Kilovoltage X-Rays: Physics Considerations in Implementing a New Teletherapy Paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, J; Yoon, P; Liu, L; Alcorta, D; Spector, N; Oldham, M [Duke University Medical Center, Durham, NC (United States); Nolan, M; Gieger, T [North Carolina State University, Raleigh, NC (United States); Walder, H; Fathi, Z; Beyer, W [Immunolight LLC, Detroit, MI (United States)

    2015-06-15

    Purpose: Psoralen is a UV-light activated anti-cancer biotherapeutic used for treating skin lesions (PUVA) and advanced cutaneous T-cell lymphoma (ECP). To date psoralen has not been used to treat deep seated tumors due to difficulty in generating UV-light at depth. We recently demonstrated psoralen activation at depth by introducing energy converting particles that absorb kV x-ray radiation and re-emit UV-light. Our in-vitro work found that 0.2–1Gy using 40–100kVp x-rays combined with psoralen and particles can induce a substantial apoptotic response beyond that expected from the sum of individual components. In preparation for a phase I clinical trial of canine companion animals, we address the physics and dosimetry considerations for applying this new teletherapy paradigm to an in-vivo setting. Methods: The kV on-board imaging (OBI) system mounted on a medical linear accelerator (Varian) was commissioned to deliver the prescribed dose (0.6Gy) using 80 and 100kVp. Dosimetric measurements included kVp, HVL, depth dose, backscatter factors, collimator and phantom scatter factors, field size factors, and blade leakage. Absolute dosimetry was performed following AAPM TG61 recommendations and verified with an independent kV dose meter. We also investigated collimated rotational delivery to minimize skin dose using simple dose calculations on homogeneous cylindrical phantoms. Results: Single beam delivery is feasible for shallow targets (<5cm) without exceeding skin tolerance, while a rotational delivery may be utilized for deeper targets; skin dose is ∼75% of target dose for 80kVp collimated rotational delivery to a 3cm target within a 20cm phantom. Heat loading was tolerable; 0.6Gy to 5cm can be delivered before the anode reaches 75% capacity. Conclusion: KV teletherapy for Psoralen activation in deep seated tissue was successfully commissioned for a Varian OBI machine for use in a phase I clinical trial in canines. Future work will use Monte Carlo dosimetry to

  3. Photodynamic antisense regulation of mRNA having a point mutation with psoralen-conjugated oligonucleotide.

    Science.gov (United States)

    Higuchi, Maiko; Yamayoshi, Asako; Kobori, Akio; Murakami, Akira

    2008-01-01

    Nucleic acid-based drugs, such as antisense oligonucleotide, ribozyme, and small interfering RNA, are specific compounds that inhibit gene expression at the post-transcriptional level. To develop more effective nucleic acid-based drugs, we focused on photo-reactive antisense oligonucleotides. We have optimized the structure of psoralen-conjugated oligonucleotide to improve their sequence selectivity and photo-crosslinking efficiency. Previously, we reported that photo reactive oligonucleotides containing 2'-O-psoralenyl-methoxyethyl adenosine (2'-Ps-eom) showed drastic photo-reactivity with a strictly sequence specific manner in vitro. In this report, we evaluated the binding ability toward intracellular target mRNA. The 2'-Ps-eom selectively photo-cross-linked to the target mRNA extracted from cells. The 2'-Ps-eom also cross-linked to target mRNA in cells. Furthermore, 2'-Ps-eom did not cross-link to mRNA having a mismatch base. These results suggest that 2'-Ps-eom is a powerful antisense molecule to inhibit the expression of mRNA having a point mutation.

  4. Photo-oxidative degradation of TiO{sub 2}/polypropylene films

    Energy Technology Data Exchange (ETDEWEB)

    García-Montelongo, X.L. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico); Martínez-de la Cruz, A., E-mail: azael70@yahoo.com.mx [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico); Vázquez-Rodríguez, S. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico); Torres-Martínez, Leticia M. [Facultad de Ingeniería Civil, Universidad Autónoma de Nuevo León, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico)

    2014-03-01

    Graphical abstract: - Highlights: • Photo-oxidative degradation of polypropylene is accelerated by TiO{sub 2} incorporation. • Weight loss, FTIR, SEM and GPC shown high degree of degradation of polypropylene. • A mechanism of the photo-degradation of polypropylene by TiO{sub 2} is proposed. - Abstract: Photo-oxidative degradation of polypropylene films with TiO{sub 2} nanoparticles incorporated was studied in a chamber of weathering with Xenon lamps as irradiation source. TiO{sub 2} powder with crystalline structure of anatase was synthesized by thermal treatments at 400 and 500 °C starting from a precursor material obtained by sol–gel method. Composites of TiO{sub 2}/polypropylene were prepared with 0.1, 0.5 and 1.0 wt% of TiO{sub 2}. The mixture of components was performed using a twin screw extruder, the resulting material was pelletized by mechanical fragmenting and then hot-pressed in order to form polypropylene films with TiO{sub 2} dispersed homogeneously. Photo-oxidative degradation process was followed by visual inspection, weight loss of films, scanning electron microscopy (SEM), infrared spectroscopy with Fourier transformed (FTIR), and gel permeation chromatography (GPC)

  5. Consequences of thermo- and photo-oxidation on end-use properties of pure PE

    International Nuclear Information System (INIS)

    Tireau, Jonathan; Van Schoors, Laetitia; Benzarti, Karim; Colin, Xavier

    2010-01-01

    Thin films of polyethylene have been exposed to thermal and photochemical accelerated agings at different temperatures and different UV intensities. In both cases, mechanical tests performed on aged samples revealed a severe embrittlement of the PE material. However, a multi-scale analysis showed that i) under thermal oxidative conditions, such embrittlement mainly resulted from a reduction of molecular mobility of the amorphous phase due to annealing phenomena, while ii) it was rather associated to a competition between chain scission and cross-linking processes under photo-oxidative conditions. As regards the oxidation mechanisms, it was found that thermo-oxidation is clearly initiated by a bimolecular decomposition of hydroperoxides, while photo-oxidation seems rather initiated by the photolysis of ketones and hydroperoxides. Over a critical threshold of the hydroperoxide concentration, thermolysis of hydroperoxides seems to predominate and even to control the overall photo-oxidation kinetics.

  6. Photochemotherapy - psoralens + UV-A(PUVA) - does it increase the risk for cancer. Fotokjemoterapi - psoralen + UV-A(PUVA) - oeket risiko for kreft

    Energy Technology Data Exchange (ETDEWEB)

    Harnes, D K; Thune, P [Ullevaal Hospital, Oslo (Norway)

    1993-01-01

    Photochemotherapy with psoralens + ultraviolet (UV)-A light (PUVA) has been used for about 16 years to treat psoriasis. Some reports have indicated a higher frequency of cutaneous squamous cell carcinoma among treated patients. The results are not consistent, however, and are not generally conceded. The material from Ullevaal Hospital comprises 585 patients who have been treated with PUVA from 1977 to 1991. Three patients developed cutaneous squamous cell carcinoma, but in one of them the tumour developed before start of PUVA treatment. The two others had received only very small doses. One of them had an intraepithelial cancer of the penis. In addition the authors registered various internal cancers in 25 patients. The Norwegian Cancer Registry compared the patient material with a matched control group as regards sex, age and age-specific incidence rate. There was no statistically significant difference in incidence between the patient and the control group. 15 refs., 1 tab.

  7. Aerosol and Photo-Oxidant Processes in the Eastern Mediterranean

    Czech Academy of Sciences Publication Activity Database

    Lazaridis, M.; Spyridaki, A.; Solberg, S.; Smolík, Jiří; Ždímal, Vladimír; Eleftheriadis, K.; Aleksandropoulos, V.; Hov, O.; Georgopoulos, P. G.

    2004-01-01

    Roč. 4, - (2004), s. 5455-5514 ISSN 1680-7367 Grant - others:ENVK2(XE) 1999-00052 Institutional research plan: CEZ:AV0Z4072921 Keywords : aerosol * mesoscale modeling * photo-oxidant processes Subject RIV: CF - Physical ; Theoretical Chemistry

  8. Natural montmorillonite induced photooxidation of As(III) in aqueous suspensions: Roles and sources of hydroxyl and hydroperoxyl/superoxide radicals

    International Nuclear Information System (INIS)

    Wang, Yajie; Xu, Jing; Li, Jinjun; Wu, Feng

    2013-01-01

    Highlights: • Natural montmorillonite contributes to photochemical oxidation of arsenite. • Ferrous ions significantly affect photochemical behavior of montmorillonite. • HO· and HO 2 ·/O 2 − · play different roles in this process. -- Abstract: Photooxidation of arsenite(As(III)) in a suspension of natural montmorillonite under the irradiation of metal halide lamp (λ ≥ 313 nm)has been investigated. The results showed that the natural montmorillonite induced the photooxidation of As(III) by generating hydroxyl radicals (HO·) and hydroperoxyl/superoxide radicals (HO 2 ·/O 2 − ·). HO· which was responsible for the As(III) photooxidation. Approximately 38% of HO· was generated by the photolysis of ferric ions, and the formation of the remaining 62% was strongly dependent on the HO 2 ·/O 2 − ·. The presence of free ironions (Fe 2+ and Fe 3+ ), made significant contributions to the photogeneration of these reactive oxygen species (ROS). The photooxidation of As(III) in natural montmorillonite suspensions was greatly influenced by the pH values. The photooxidation of As(III) by natural montmorillonite followed the Langmuir–Hinshelwood equation. In addition, the photooxidation of As(III) could be enhanced by the addition of humic acid. This work demonstrates that photooxidation may be an important environmental process for the oxidation of As(III) and may be a way to remove As(III) from acidic surface water containing iron-bearing clay minerals

  9. Protein Characterization of Javan Cobra (Naja sputatrix) Venom Following Sun Exposure and Photo-Oxidation Treatment

    Science.gov (United States)

    Sulistiyani; Biki, R. S.; Andrianto, D.

    2017-03-01

    Snake venom has always been known for its toxicity that can cause fatality, however, it is also one of the important biological resources to be used for disease treatment. In Indonesia, snake venom previously expose under the sun has been used for alternative treatment of some diseases such as dengue fever, atherosclerosis, cancer, and diabetes. There has been very little scientific evidence on the use of snake venom of Indonesia origin as well as its protein characteristic. Thus, the objective of this research is to characterize the protein content and the specific activity of the venom of Javan Cobra (N.sputatrix) when treated with sun exposure in comparison with photo-oxidation by ultraviolet. Qualitative analysis of protein contents was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The L-amino acid oxidase activity (LAAO) and the phospholipase A2 (PLA2) activities were determined using spectrophotometry. The venom’s protein was separated into 5 main protein bands with molecular weight ranging from 14 to 108 kDa. A time course study showed that the venom lost 91% of its LAAO activity and 96% of PLA2 activity after 6 hours of sun exposure. UV photo-oxidation carried out for 3 hours decreased 91% of LAAO activity, and almost diminished all of PLA2 activity (99.8%). These findings suggest that the exposure of N. sputatrix venom under the sun and UV photo-oxidation decreased its toxicity as shown by the significant reduction of the enzymes activity, but did not affect the protein’s integrity. Therefore, these approaches produced N.sputatrix venom with less toxicity but still withheld other characters of intact proteins.

  10. Shear and elongational rheology of photo-oxidative degraded HDPE and LLDPE

    Science.gov (United States)

    Wagner, Manfred Hermann; Zheng, Wang; Wang, Peng; Talamante, Sebastián Ramos; Narimissa, Esmaeil

    2017-05-01

    The effect of photo-oxidative degradation of high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) was investigated by linear and non-linear rheological measurements. The linear-viscoelastic rheological measurements were performed at different temperatures, while the elongational viscosity was measured at 170°C and at different strain rates. The rheological data are indicative of structural changes caused by photo-oxidative degradation including formation of long-chain branches (LCB), cross-linking, and chain scission, and they revealed a cyclic and continuing competition between chain scission and LCB/gel formation. These findings are supported by additional FTIR measurements and direct measurements of the gel content of the degraded samples.

  11. The contribution of medical physics to the development of psoralen photochemotherapy (PUVA) in the UK: a personal reminiscence

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, Brian [Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE (United Kingdom)

    2006-07-07

    Psoralen photochemotherapy (PUVA) is the combined treatment of skin disorders with a photosensitizing drug (Psoralen) and UltraViolet A radiation. The introduction of PUVA therapy has arguably been the most important development in dermatology over the past 30 years and from the first days of the treatment being introduced in the UK, British medical physicists were an integral part of the effort to establish it. Medical physicists have contributed to this development in a number of ways, from designing irradiation units in the early days of the technique, through to collaborating with dermatologists in prosecuting clinical and experimental studies aimed at improving patient outcomes. That the dose of UVA radiation is administered quantitatively, and not qualitatively, has probably been the single most important contribution made by several medical physicists over this period. However, despite concerns that were expressed almost 30 years ago about the accuracy with which UVA doses are administered to patients, the medical physics community still has some way to go before we can be satisfied that statements about UVA irradiance and dose can be made with confidence. (review)

  12. High throughput photo-oxidations in a packed bed reactor system.

    Science.gov (United States)

    Kong, Caleb J; Fisher, Daniel; Desai, Bimbisar K; Yang, Yuan; Ahmad, Saeed; Belecki, Katherine; Gupton, B Frank

    2017-12-01

    The efficiency gains produced by continuous-flow systems in conducting photochemical transformations have been extensively demonstrated. Recently, these systems have been used in developing safe and efficient methods for photo-oxidations using singlet oxygen generated by photosensitizers. Much of the previous work has focused on the use of homogeneous photocatalysts. The development of a unique, packed-bed photoreactor system using immobilized rose bengal expands these capabilities as this robust photocatalyst allows access to and elaboration from these highly useful building blocks without the need for further purification. With this platform we were able to demonstrate a wide scope of singlet oxygen ene, [4+2] cycloadditions and heteroatom oxidations. Furthermore, we applied this method as a strategic element in the synthesis of the high-volume antimalarial artemisinin. Copyright © 2017. Published by Elsevier Ltd.

  13. Salt effect on sensitized photooxidations. A kinetic approch to environmental decomposition of marine contaminants

    Directory of Open Access Journals (Sweden)

    María I. Gutiérrez

    1998-09-01

    Full Text Available The salt effect on the kinetics of singlet molecular oxygen [O2(1Δg]-mediated photooxidations of sea water contaminants was investigated. Two families of photooxidizable compounds were employed in the study: anthracene derivatives and phenols. The presence of salt (NaCl in H2O and LiCl in MeCN, in both cases in the range 0-0.45 M produces changes in the photooxidation rate. For solvent-polarity-dependent reactions, this behavior can be predicted, by knowing the solvent-polarity dependence of the rate constant for chemical reaction of the substrates with O2(1Δ g in non-saline solutions (kr. For the cases of photooxidations possessing solvent-polarity-independent or scantily-dependent kr values, the photooxidation rates decrease as the salt content in the solution increases, mainly due to a predominance of the physical quenching pathway. In addition, the quantum yield for O2(1 Δg generation (ΦΔ was determined in a series of saline solutions, in the range of 0-0.45 M in water and MeCN solutions, in the presence of NaCl and LiCl respectively. The Δ values are independent, within the experimental error on the salt content.

  14. Evaluation of the effects of photooxidized Echis carinatus venom on learning, memory and stress

    Directory of Open Access Journals (Sweden)

    C. M. Reddy

    2006-01-01

    Full Text Available Snake venoms are a mixture of complex proteins, which have many physical and pharmacological properties. Photochemical detoxification has been suggested to generate photooxidized Echis carinatus venom product (POECVP. Antigenically-active photooxidized species of Echis carinatus venom could be obtained by exposing the venom to ultraviolet radiation (UVR in the presence of methylene blue. The aim of the present study was to evaluate the effects of POECVP on learning, memory and stress in rats. Detoxification of the photooxidized venom was evident since the POECVP-treated group had longer survival time than the group of mice treated with Echis carinatus venom product (ECVP following intraperitoneal and intracerebral injections. Photooxidized Echis carinatus venom product showed antidepressant activity by prolonging sleep onset and shortening the duration of pentobarbitone-induced hypnosis in mice. In single and chronic dose studies with rats, we observed that POECVP significantly decreased the time needed to reach food in T-maze, shortened transfer latency in elevated plus-maze, and decreased immobility time in forced swim test. We concluded that although there is a possibility of employing POECVP in the treatment of depressive and chronic degenerative illnesses as a nonherbal and nonsynthetic alternative for patients not responding to the available therapy, further investigation is still needed.

  15. Effects of a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen and ultraviolet-A radiation on murine dendritic epidermal cells.

    Science.gov (United States)

    Aubin, F; Alcalay, J; Dall'Acqua, F; Kripke, M L

    1990-06-01

    Although some psoralens are therapeutically active in the treatment of cutaneous hyperproliferative diseases when combined with UVA (320-400 nm) radiation, the toxic effects of these compounds have led physicians to seek new photochemotherapeutic agents. One such agent is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional psoralen compound. We investigated the effects of repetitive treatments with TMAP plus UVA radiation on the number of dendritic immune cells in murine epidermis and on the induction of phototoxicity. Mice treated 3 times per week for 4 weeks with 129 microgram TMAP plus 10 kJ/m2 UVA radiation exhibited no gross or microscopic evidence of phototoxicity. During this treatment, the numbers of ATPase+, Ia+, and Thy-l+ dendritic epidermal cells were greatly reduced, and by the end of the treatment period, few dendritic immune cells could be detected. We conclude that morphological alterations of cutaneous immune cells can occur in the absence of overt phototoxicity, and that TMAP plus low-dose UVA radiation decreases the numbers of detectable Langerhans cells and Thy-1+ cells in murine skin.

  16. Study of photo-oxidative reactivity of sunscreening agents based on photo-oxidation of uric acid by kinetic Monte Carlo simulation

    International Nuclear Information System (INIS)

    Moradmand Jalali, Hamed; Bashiri, Hadis; Rasa, Hossein

    2015-01-01

    In the present study, the mechanism of free radical production by light-reflective agents in sunscreens (TiO 2 , ZnO and ZrO 2 ) was obtained by applying kinetic Monte Carlo simulation. The values of the rate constants for each step of the suggested mechanism have been obtained by simulation. The effect of the initial concentration of mineral oxides and uric acid on the rate of uric acid photo-oxidation by irradiation of some sun care agents has been studied. The kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for the production of free radicals by sun care agents. - Highlights: • The mechanism and kinetics of uric acid photo-oxidation by irradiation of sun care agents has been obtained by simulation. • The mechanism has been used for free radical production of TiO 2 (rutile and anatase), ZnO and ZrO 2 . • The ratios of photo-activity of ZnO to anastase, rutile and ZrO have been obtained. • By doubling the initial concentrations of mineral oxide, the rate of reaction was doubled. • The optimum ratio of initial concentration of mineral oxides to uric acid has been obtained

  17. New oxidation and photo-oxidation products of tryptophan

    International Nuclear Information System (INIS)

    Savige, W.E.

    1975-01-01

    Dye-sensitized photo-oxidation of tryptophan in water gives N'-formylkynurenine and (+-)-3a-hydroxy-1,2,3a,8,8a-hexahydropyrrolo[2,3-b] indole-2-carboxylic acid. The latter rearranges to oxindolyl-3-alanine on irradiation with UV light and reacts with thiols, including cysteine, in warm 20% acetic acid to give the corresponding 2-tryptophyl sulphides. (orig.) [de

  18. Comparison of chemical changes during photooxidation of polypropylene film and filament containing phthalocyanine pigment

    International Nuclear Information System (INIS)

    Ahmadi, Z.; Haghighat Kish, M.; Kotak, R.; Katbab, A. A.

    2008-01-01

    Photooxidation as an important process, which significantly affects the service life of the polypropylene products, has been the subject of much theoretical and experimental study. Pigments used often change the light stabilities of polypropylene. Out-door applications of pigmented polypropylene are now increasingly developed in products such as artificial grass. The aim of this work is to examine the effect of photo-oxidation on the structure of isotactic polypropylene (iPP) in film and filament forms, where phthalocyanine pigment is used. For production of films and filaments, iPP granules with MFI 25 g/10 min were used, with and without phthalocyanine pigment. Samples were exposed to xenon lamp for various time lengths. The extent of the changes in chemical and structural parameters was examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and wide angle x-ray diffraction. The results show that carbonyl and hydroperoxide indices increase during the exposure to the radiation. The changes in melting points of the samples were not significant after irradiation process. The effects of phthalocyanine pigment in the photooxidation of film and filament were different. Crystalline fractions of the non-pigmented filament samples decreased during the irradiation time while increased in film samples. Build up of hydroperoxide and carbonyl group in filament was higher than in film samples; that could be due to the differences in structural parameters. Crystallinity variations during photooxidation are related to the nucleation effect of the pigment, chemical crystallization and phase transformation

  19. Comparison of Chemical Changes During Photooxidation of Polypropylene Film and Filament Containing Phthalocyanine Pigment

    Directory of Open Access Journals (Sweden)

    Z. Ahmadi

    2008-02-01

    Full Text Available Photooxidation as an important process, which significantly affects the service life of the polypropylene products, has been the subject of much theoretical and experimental study. Pigments used often change the light stabilities of polypropylene. Out-door applications of pigmented polypr-opylene are now increasingly developed in products such as artificial grass. The aim of this work is to examine the effect of photo-oxidation on the structure of isotactic polypropylene (iPP in film and filament forms, where phthalocyanine pigment is used. For production of films and filaments, iPP granules with MFI 25 g/10min were used, with and without phthalocyanine pigment. Samples were exposed to xenon lamp for various time lengths. The extent of the changes in chemical and structural parameters was examined by differential scanning calorimetry, Fourier transform infrared spectroscopy and wide angle x-ray diffraction. The results show that carbonyl and hydroperoxide indices increase during the exposure to the radiation. The changes in melting points of the samples were not significant after irradiation process. The effects of phthalocyanine pigment in the photooxidation of filmand filament were different. Crystalline fractions of the non-pigmented filament samples decreased during the irradiation time while increased in film samples. Build up of hydroperoxide and carbonyl group in filament was higher than in film samples; that could be due to the differences in structural parameters. Crystallinity variations during photooxidation are related to the nucleation effect of the pigment, chemical crystallization and phase transformation.

  20. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    Data.gov (United States)

    U.S. Environmental Protection Agency — Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are...

  1. Study of photo-oxidative reactivity of sunscreening agents based on photo-oxidation of uric acid by kinetic Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Moradmand Jalali, Hamed; Bashiri, Hadis, E-mail: hbashiri@kashanu.ac.ir; Rasa, Hossein

    2015-05-01

    In the present study, the mechanism of free radical production by light-reflective agents in sunscreens (TiO{sub 2}, ZnO and ZrO{sub 2}) was obtained by applying kinetic Monte Carlo simulation. The values of the rate constants for each step of the suggested mechanism have been obtained by simulation. The effect of the initial concentration of mineral oxides and uric acid on the rate of uric acid photo-oxidation by irradiation of some sun care agents has been studied. The kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for the production of free radicals by sun care agents. - Highlights: • The mechanism and kinetics of uric acid photo-oxidation by irradiation of sun care agents has been obtained by simulation. • The mechanism has been used for free radical production of TiO{sub 2} (rutile and anatase), ZnO and ZrO{sub 2}. • The ratios of photo-activity of ZnO to anastase, rutile and ZrO have been obtained. • By doubling the initial concentrations of mineral oxide, the rate of reaction was doubled. • The optimum ratio of initial concentration of mineral oxides to uric acid has been obtained.

  2. Photophysical Behavior of Modified Xanthenic Dyes Embedded into Silsesquioxane Hybrid Films: Application in Photooxidation of Organic Molecules

    Directory of Open Access Journals (Sweden)

    Carolina V. Waiman

    2017-01-01

    Full Text Available Polymeric materials based on a bridged silsesquioxane with pendant dodecyl chains were synthesized and modified with different xanthenic dyes with the aim of developing a material with potential application in photooxidation of organic compounds. The employed dyes constitute a family of novel xanthenic chromophores with outstanding properties as singlet oxygen photosensitizers. The hybrid matrix was chosen for its enhanced properties such as flexibility and chemical resistance. The employed dyes were easily incorporated into the hybrid polymer obtaining homogeneous, transparent, and low-refractive-index materials. The polymeric films were characterized using UV-Vis absorption, fluorescence, and laser flash photolysis techniques. The ability of these materials to produce singlet oxygen was tested following the photooxidation of 9,10-dimethylanthracene which is a well-known chemical trap for singlet oxygen. High photooxidation efficiencies were observed for these materials, which present the advantage of being easily removed/collected from the solution where photooxidation takes place. While photobleaching of the incorporated dyes is commonly observed in the solution, it takes place very slowly when dyes are embedded in the hybrid matrix. These properties bode well for the potential use of these materials in novel wastewater purification strategies.

  3. THE FTIR STUDIES OF PHOTO-OXIDATIVE DEGRADATION OF POLYPROPYLENE

    Institute of Scientific and Technical Information of China (English)

    WEN Zaiqing; HU Xingzhou; SHEN Deyan

    1988-01-01

    The photo-oxidative degradation process of polypropylene film containing iron ions was investigated via FTIR and absorbance substraction technique. It is shown that the iron ions play an important role in the decomposition of hydroperoxide and the increase of the degradation rate of polypropylene film. Theamorphous region of PP film undergoes degradation prior to the crystalline one.

  4. Psoralens cleave pBR322 DNA under ultraviolet radiation

    International Nuclear Information System (INIS)

    Kagan, J.; Xinsheng Chen; Wang, T.P.

    1992-01-01

    Supercoiled (SC) pBR322 was used to probe the recent claim that 5-geranoxylpsoralen (5-GOP) did not photoreact with DNA. Contrary to expectations, 5-GOP was found to damage DNA in the presence of UV-A through two competing pathways; (a) single strand breaks, identified by the conversion of supercoiled into open circular and linear DNA, and (b) cross-linking, revealed by the fluence-dependent decrease in the extent of denaturation of the double stranded supercoiled DNA to single stranded circular DNA. In addition, a fluence-dependent modification reduced the ability of the restriction enzyme EcoR I to linearize the photosensitized DNA, and alkali-labile lesions were generated. Psoralen, 5-methoxypsoralen, and 8-methoxypsoralen, which are well-known to undergo cycloaddition to DNA, had a more pronounced effect on supercoiled DNA. Single strand breaks occurred more readily than with 5-GOP, and the surviving SC form remaining had reduced electrophoretic mobility in agarose gels. In all cases, the DNA damage was more prominent when oxygen was absent. (author)

  5. Ultrastructural modification of the plasma membrane in HUT 102 lymphoblasts by long-wave ultraviolet light, psoralen, and PUVA

    International Nuclear Information System (INIS)

    Malinin, G.I.; Lo, H.K.; Hornicek, F.J.; Malinin, T.I.

    1990-01-01

    Ultrastructural alterations of the plasma membrane in HUT 102 lymphoblasts were assessed after a 2-h interaction with a suprapharmacologic (15 micrograms/ml) concentration of 8-MOP, 2-h irradiation with UVA (2.1 mW/cm2), and the exposure of the HUT 102 cells to PUVA under the same conditions. The dark reaction of HUT cells with 8-MOP resulted in the disappearance of microvilli, the emergence of plasma-membrane-associated spherical bodies, formation of lamellar fungiform membrane evaginations, and, in approximately 1% of the cells, formation of uropods and cell capping. Except for uropod formation and cell capping, UVA has induced the same plasma-membrane alterations, and was more deleterious to structural cytoplasmic integrity than 8-MOP. Morphologic changes of the plasma membrane in PUVA-exposed cells tended to replicate structural alterations elicited independently during the dark reaction by suprapharmacologic 8-MOP concentrations. Partial retention of microvilli by cells after PUVA was the sole exception. In light of all available evidence we conclude that psoralen during the dark reactions interacts with plasma membrane lipids by as yet undisclosed mechanisms and that in addition to lipids, membrane proteins are also the primary target of the initial interaction of HUT 102 cells with psoralen during PUVA treatment

  6. Lifetimes of organic photovoltaics: photooxidative degradation of a model compound

    DEFF Research Database (Denmark)

    Norrman, K.; Alstrup, J.; Jørgensen, M.

    2006-01-01

    A poly phenylene vinylene (PPV-type) oligomer used in organic photovoltaics was designed to facilitate the interpretation of mass spectral data. A film of the oligomer was subjected to various degrees of illumination (1000 W m(-2), AM1.5) in air resulting in photooxidation of the material...

  7. Perturbations in carotenoid and porphyrin status result in differential photooxidative stress signaling and antioxidant responses.

    Science.gov (United States)

    Park, Joon-Heum; Jung, Sunyo

    2018-02-12

    We examined differential photooxidative stress signaling and antioxidant responses in rice plants treated with norflurazon (NF) and oxyfluorfen (OF), which are inhibitors of carotenoid and porphyrin biosynthesis, respectively. Plants treated with OF markedly increased levels of cellular leakage and malondialdehyde, compared with NF-treated plants, showing that OF plants suffered greater oxidative damage with respect to membrane integrity. The enhanced production of H 2 O 2 in response to OF, but not NF, indicates the important role of H 2 O 2 in activation of photooxidative stress signaling in OF plants. In response to NF and OF, the increased levels of free salicylic acid as well as maintenance of the redox ratio of ascorbate and glutathione pools to a certain level are considered to be crucial factors in the protection against photooxidation. Plants treated with OF greatly up-regulated catalase (CAT) activity and Cat transcript levels, compared with NF-treated plants. Interestingly, NF plants showed no noticeable increase in oxidative metabolism, although they did show considerable increases in ascorbate peroxidase (APX) and peroxidase activities and transcript levels of APX, as in OF plants. Our results suggest that perturbations in carotenoid and porphyrin status by NF and OF can be sensed by differential photooxidative stress signaling, such as that involving H 2 O 2 , redox state of ascorbate and glutathione, and salicylic acid, which may be responsible for at least part of the induction of ROS-scavenging enzymes. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Effect of NOx level on secondary organic aerosol (SOA formation from the photooxidation of terpenes

    Directory of Open Access Journals (Sweden)

    R. C. Flagan

    2007-10-01

    Full Text Available Secondary organic aerosol (SOA formation from the photooxidation of one monoterpene (α-pinene and two sesquiterpenes (longifolene and aromadendrene is investigated in the Caltech environmental chambers. The effect of NOx on SOA formation for these biogenic hydrocarbons is evaluated by performing photooxidation experiments under varying NOx conditions. The NOx dependence of α-pinene SOA formation follows the same trend as that observed previously for a number of SOA precursors, including isoprene, in which SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted decreases as NOx level increases. The NOx dependence of SOA yield for the sesquiterpenes, longifolene and aromadendrene, however, differs from that determined for isoprene and α-pinene; the aerosol yield under high-NOx conditions substantially exceeds that under low-NOx conditions. The reversal of the NOx dependence of SOA formation for the sesquiterpenes is consistent with formation of relatively low-volatility organic nitrates, and/or the isomerization of large alkoxy radicals leading to less volatile products. Analysis of the aerosol chemical composition for longifolene confirms the presence of organic nitrates under high-NOx conditions. Consequently the formation of SOA from certain biogenic hydrocarbons such as sesquiterpenes (and possibly large anthropogenic hydrocarbons as well may be more efficient in polluted air.

  9. Effect of Packaging Films on the Quality of Canola Oil under Photooxidation Conditions

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2015-01-01

    Full Text Available The objective of this study was to evaluate the influence of packaging films on the quality of canola oil which contains high concentration of fat under photooxidation condition and get the oxidation kinetics based on measuring the oxidation intensities including peroxide value, hexanal, and photosensitizer (chlorophyll. The canola oil was packaged by PET/CPP; KPET/PE was used for experiments. The change of light and oxygen transmission rate (OTR of PET/CPP which was considered as the typical fatty foods packaging film under different light intensities was also tested. The results show that the peroxide value increased rapidly under light conditions and fitted the zero order kinetics; also the oxygen transmission rate had great impact on it; hexanal fitted the zero order kinetic in oil whose package of low OTR generated a lot; however package in high OTR films changed very slowly that might be dependent on the performance of hexanal through plastic films. The degradation of chlorophyll fitted the first order kinetic and decreased quickly under light but was almost independent of OTR of transparent packaging material. Light reduced the oxygen barrier properties of the films, which should be considered as the photooxidation condition (and the photooxidation condition thus should be considered.

  10. Gas/particle partitioning of carbonyls in the photooxidation of isoprene and 1,3,5-trimethylbenzene

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2008-06-01

    Full Text Available A new denuder-filter sampling technique has been used to investigate the gas/particle partitioning behaviour of the carbonyl products from the photooxidation of isoprene and 1,3,5-trimethylbenzene. A series of experiments was performed in two atmospheric simulation chambers at atmospheric pressure and ambient temperature in the presence of NOx and at a relative humidity of approximately 50%. The denuder and filter were both coated with the derivatizing agent O-(2,3,4,5,6-pentafluorobenzyl-hydroxylamine (PFBHA to enable the efficient collection of gas- and particle-phase carbonyls respectively. The tubes and filters were extracted and carbonyls identified as their oxime derivatives by GC-MS. The carbonyl products identified in the experiments accounted for around 5% and 10% of the mass of secondary organic aerosol formed from the photooxidation of isoprene and 1,3,5-trimethylbenzene respectively.

    Experimental gas/particle partitioning coefficients were determined for a wide range of carbonyl products formed from the photooxidation of isoprene and 1,3,5-trimethylbenzene and compared with the theoretical values based on standard absorptive partitioning theory. Photooxidation products with a single carbonyl moiety were not observed in the particle phase, but dicarbonyls, and in particular, glyoxal and methylglyoxal, exhibited gas/particle partitioning coefficients several orders of magnitude higher than expected theoretically. These findings support the importance of heterogeneous and particle-phase chemical reactions for SOA formation and growth during the atmospheric degradation of anthropogenic and biogenic hydrocarbons.

  11. Photooxidation of nimbin and salannin, tetranortriterpenoids from the neem tree (Azadirachta indica)

    International Nuclear Information System (INIS)

    Jarvis, A.P.; Johnson, S.; Morgan, E.D.; Simmonds, M.S.J.; Blaney, W.M.

    1997-01-01

    Nimbin and salannin, major triterpenoids accompanying azadirachtin in extracts of neem (Azadirachta indica) seeds, were photooxidized by UV light in the presence of oxygen to more polar, unstable intermediates that rearranged on silica gel to two final products in which the furan ring had been oxidized to isomeric hydroxybutenolides. The isomeric hydroxybutenolides were also readily formed when a crude extract of triterpenoids from neem seeds was irradiated, and both isomers of salannin have been isolated from seeds. Photooxidation of nimbin and salannin proceeded much faster than that of azadirachtin. All photoproducts showed some biological activity against Spodoptera littoralis, Locusta migratoria, and Schistocerca gregaria. Isonimbinolide was as potent as azadirachtin at inhibiting feeding in all three species, and it also inhibited the growth of S. littoralis. Isosalanninolide showed potent antifeedant and growth inhibitory activity against S. littoralis

  12. An electron microscopic study of the photochemical cross-linking of DNA in guinea pig epidermis by psoralen derivatives

    International Nuclear Information System (INIS)

    Cech, T.; Pathak, M.A.; Biswas, R.K.

    1979-01-01

    Albino guinea pigs were treated with psoralen derivatives plus 320-400 nm ultraviolet radiation, and DNA was extracted from their epidermis. The DNA was assayed for the presence of interstrand cross-links by standard denaturation-renaturation assays and by a new technique, electron microscopy of the DNA under totally denaturing conditions. The latter method allows individual cross-links to be directly observed and counted. When either 4,5',8-trimethylpsoralen or 8-methoxypsoralen was applied topically to the skin (8-20 μg/cm 2 ) or administered orally (10-12 mg/kg body weight), followed by exposure to 320-400 nm ultraviolet radiation, most of the epidermal DNA was found to contain a high frequency of cross-links. For example, oral or topical trimethylpsoralen treatment gave an average of one cross-link per 250 nucleotide pairs or about 3 . 10 5 cross-links per guinea pig chromosome. When the dose of either drug was decreased 20-fold to the level used in the clinical treatment of psoriasis, however, no cross-links could be detected in the epidermal DNA. The electron microscopic assay is sensitive enough that one can put an upper limit of 1 cross-link per 10 6 nucleotide pairs (80 cross-links per chromosome) for the low dose studies. The significance of these findings to the understanding of the effectiveness of psoralens in psoriasis therapy is discussed. (Auth.)

  13. Oxidation and photo-oxidation of water on TiO2 surface

    DEFF Research Database (Denmark)

    Valdes, A.; Qu, Z.W.; Kroes, G.J.

    2008-01-01

    The oxidation and photo-oxidation of water on the rutile TiO2(110) surface is investigated using density functional theory (DFT) calculations. We investigate the relative stability of different surface terminations of TiO2 interacting with H2O and analyze the overpotential needed for the electrol...

  14. Structure of E. coli 16S RNA elucidated by psoralen crosslinking

    International Nuclear Information System (INIS)

    Thompson, J.F.; Hearst, J.E.

    1983-01-01

    E. coli 16S RNA in solution was photoreacted with hydroxymethyltrimethylpsoralen and long wave ultraviolet light. Positions of crosslinks were determined to high resolution by partially digesting the RNA with T 1 RNase, separating the crosslinked fragments by two-dimensional gel electrophoresis, reversing the crosslink, and sequencing the separated fragments. This method yielded the locations of crosslinks to +/-15 nucleotides. Even finer placement has been made on the basis of our knowledge of psoralen reactivity. Thirteen unique crosslinks were mapped. Seven crosslinks confirmed regions of secondary structure which had been predicted in published phylogenetic models, three crosslinks discriminated between phylogenetic models, and three proved the existence of new structures. The new structures were all long-range interactions which appear to be in dynamic equilibrium with local secondary structure. Because this technique yields direct information about the secondary structure of large RNAs, it should prove invaluable in studying the structure of other RNAs of all sizes

  15. Sites of termination of in vitro DNA synthesis on psoralen phototreated single-stranded templates

    International Nuclear Information System (INIS)

    Piette, J.; Hearst, J.

    1985-01-01

    Single-stranded DNA has been photochemically induced to react with 4'-hydroxymethyl-4,5',8-trimethylpsoralen (HMT) and used as substrate for DNA replication with E. coli DNA polymerase I large fragment. By using the dideoxy sequencing procedure, it is possible to map the termination sites on the template photoreacted with HMT. These sites occur at the nucleotides preceding each thymine residue (and a few cytosine residues), emphasizing the fact that in a single-stranded stretch of DNA, HMT reacts with each thymine residue without any specificity regarding the flanking base sequence of the thymine residues. In addition, termination of DNA synthesis due to psoralen-adducted thymine is not influenced by the efficiency of the 3'-5' exonuclease proof-reading activity of the DNA polymerase. (author)

  16. UV-A photooxidation of β-carotene in Triton X-100 micelles by nitrodiphenyl ether herbicides

    International Nuclear Information System (INIS)

    Orr, G.L.; Hogan, M.E.

    1985-01-01

    Photooxidation of β-carotene in Triton X-100 micelles was stimulated by lipophilic nitrodiphenyl ether herbicides at concentrations as low as 5 μM after 15 min in UV radiation (UV-A between 315 and 400 nm). Bleaching of β-carotene by acifluorfen-methyl [methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] was proportional to UV-A intensity and independent of pH. White light (400-700 nm) alone was without effect. At pH 6.5, 100 μM acifluorfen [sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate], a water-soluble nitrodiphenyl ether, stimulated photooxidation of β-carotene after 15 min in UV-A radiation. Activity of 200 μM acifluorfen was enhanced at pHs between 3.5 and 6.5. The chlorodiphenyl ether analogue of acifluorfen-methyl, methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate, exhibited little activity at 200 μM and 200 μM phenyl ether was without effect. Activation energy for acifluorfen-methyl stimulated β-carotene photooxidation near 20 and 30 0 C was 40.3 and 5.6 kJ mol -1 , respectively. Subsequent to UV-A exposure and placement into darkness no further bleaching of β-carotene was detected, indicating that reactive species were generated only in light and consumed quickly in darkness

  17. Impact of NOx and OH on secondary organic aerosol formation from β-pinene photooxidation

    Directory of Open Access Journals (Sweden)

    M. Sarrafzadeh

    2016-09-01

    Full Text Available In this study, the NOx dependence of secondary organic aerosol (SOA formation from photooxidation of the biogenic volatile organic compound (BVOC β-pinene was comprehensively investigated in the Jülich Plant Atmosphere Chamber. Consistent with the results of previous NOx studies we found increases of SOA yields with increasing [NOx] at low-NOx conditions ([NOx]0  <  30 ppb, [BVOC]0 ∕ [NOx]0  >  10 ppbC ppb−1. Furthermore, increasing [NOx] at high-NOx conditions ([NOx]0  >  30 ppb, [BVOC]0 ∕ [NOx]0  ∼  10 to  ∼  2.6 ppbC ppb−1 suppressed the SOA yield. The increase of SOA yield at low-NOx conditions was attributed to an increase of OH concentration, most probably by OH recycling in NO + HO2  →  NO2 + OH reaction. Separate measurements without NOx addition but with different OH primary production rates confirmed the OH dependence of SOA yields. After removing the effect of OH concentration on SOA mass growth by keeping the OH concentration constant, SOA yields only decreased with increasing [NOx]. Measuring the NOx dependence of SOA yields at lower [NO] ∕ [NO2] ratio showed less pronounced increase in both OH concentration and SOA yield. This result was consistent with our assumption of OH recycling by NO and to SOA yields being dependent on OH concentrations. Our results furthermore indicated that NOx dependencies vary for different NOx compositions. A substantial fraction of the NOx-induced decrease of SOA yields at high-NOx conditions was caused by NOx-induced suppression of new particle formation (NPF, which subsequently limits the particle surface where low volatiles condense. This was shown by probing the NOx dependence of SOA formation in the presence of seed particles. After eliminating the effect of NOx-induced suppression of NPF and NOx-induced changes of OH concentrations, the remaining effect of NOx on the SOA yield from

  18. DNA repair synthesis in human skin exposed to ultraviolet radiation used in PUVA (psoralen and UV-A) therapy for psoriasis

    International Nuclear Information System (INIS)

    Bishop, S.C.

    1979-01-01

    The ultraviolet radiation used in psoralen and UV-A (PUVA) therapy stimulated DNA repair activity in normal human skin and in the uninvolved skin from psoriatic patients. The activity detected by autoradiography increased linearly with exposure time. No stimulation was observed when the UV-B component was removed from the incident radiation by filtration through glass. Therefore UV-B damage to DNA was found responsible for the activity detected following exposure to the unfiltered PUVA light source. (author)

  19. Photooxidative damage to mammalian cells and proteins by visible light

    International Nuclear Information System (INIS)

    Packer, L.; Kellogg, E.W. III

    1980-01-01

    In the present article, studies carried out in our laboratory on the effects of visible irradiation and O 2 in a variety of target systems ranging from cultured mammalian cells to purified catalase are reviewed. We will relate these studies of photooxidative damage to a scheme for the propagation of intracellular damage which traces a number of the possible pro-oxidant and anti-oxidant pathways found in the cell

  20. Photooxidation of ethylene over Cu-modified and unmodified silica

    OpenAIRE

    Ichihashi, Yuichi; Matsumura, Yasuyuki

    2003-01-01

    Silica catalyzes photooxidation of ethylene to carbon dioxide and modification of copper on silica results in the lower reaction rate and partial production of ethylene oxide. The reaction does not proceed by the light irradiation through a color filter (λ>280 nm). ESR measurement indicates that radical oxygen species assignable T-shape Si − O3− can be produced on silica by UV irradiation at 77 K. The same species are also found on silica modified with copper by UV irradiation whi...

  1. Photochemotherapy - psoralens + UV-A(PUVA) - does it increase the risk for cancer?

    International Nuclear Information System (INIS)

    Harnes, D.K.; Thune, P.

    1993-01-01

    Photochemotherapy with psoralens + ultraviolet (UV)-A light (PUVA) has been used for about 16 years to treat psoriasis. Some reports have indicated a higher frequency of cutaneous squamous cell carcinoma among treated patients. The results are not consistent, however, and are not generally conceded. The material from Ullevaal Hospital comprises 585 patients who have been treated with PUVA from 1977 to 1991. Three patients developed cutaneous squamous cell carcinoma, but in one of them the tumour developed before start of PUVA treatment. The two others had received only very small doses. One of them had an intraepithelial cancer of the penis. In addition the authors registered various internal cancers in 25 patients. The Norwegian Cancer Registry compared the patient material with a matched control group as regards sex, age and age-specific incidence rate. There was no statistically significant difference in incidence between the patient and the control group. 15 refs., 1 tab

  2. Maintenance phase in psoralen-ultraviolet A phototherapy of early-stage mycosis fungoides. A critically appraised topic.

    Science.gov (United States)

    Grandi, V; Delfino, C; Pileri, A; Pimpinelli, N

    2017-08-01

    A 65-year-old patient affected by mycosis fungoides (MF) stage IB achieved complete remission (CR) after a cycle of PUVA phototherapy. The U.S. Cutaneous Lymphoma Consortium (USCLC) guidelines suggest that the patient should be kept in the maintenance phase, defined as a 'period of gradual decrease of frequency of UVL [ultraviolet light] while in clinical remission before discontinuation of phototherapy' by slowly tapering the number of psoralen-ultraviolet A (PUVA) applications over time up to clinical relapse. The USCLC guidelines also suggest a standardized schedule for the maintenance phase. Alternatively, the patient could end PUVA therapy and go straight to follow-up. The aim of this critically appraised topic (CAT) was to determine if a maintenance phase gives a significant benefit in terms of relapse rate (RR) and RFI in patients affected by early-stage MF who had achieved CR under PUVA phototherapy. Embase, PubMed and TRIP databases were searched for 'mycosis fungoides' AND [('photochemotherapy' OR 'puva') OR 'psoralen'] in June 2016. Three articles matched our inclusion criteria and are discussed in this CAT. In this field of research the literature is poor and the reported level of evidence is low. Only one of the studies was conducted prospectively, and none were randomized. No significant difference in terms of reduction in relapse rate or increase in RFI in patients who underwent a PUVA maintenance phase emerged when compared with those who went for simple follow-up. Further randomized clinical trials (RCTs) are required in order to evaluate maintenance phase vs. no treatment before it can be favoured as the standard protocol of treatment in early-stage MF. At the time of writing this paper, we report an ongoing Austrian multicentre RCT (Clinical Trial.gov identifier: NCT01686594) that will hopefully give useful results in this topic. © 2017 British Association of Dermatologists.

  3. Photo-oxidation of proteins and its role in cataractogenesis

    DEFF Research Database (Denmark)

    Davies, Michael Jonathan; Truscott, R J

    2001-01-01

    by the protein, or bound chromophore groups, thereby generating excited states (singlet or triplets) or radicals via photo-ionisation. The second major process involves indirect oxidation of the protein via the formation and subsequent reactions of singlet oxygen generated by the transfer of energy to ground...... state (triplet) molecular oxygen by either protein-bound, or other, chromophores. The basic principles behind these mechanisms of photo-oxidation of amino acids, peptides and proteins and the potential selectivity of damage are discussed. Emphasis is placed primarily on the intermediates...

  4. Heterogeneous Catalysis by Tetraethylammonium Tetrachloroferrate of the Photooxidation of Toluene by Visible and Near-UV Light

    Directory of Open Access Journals (Sweden)

    Kelsie R. Barnard

    2018-02-01

    Full Text Available Titanium dioxide is the most extensively used heterogeneous catalyst for the photooxidation of toluene and other hydrocarbons, but it has low utility for the synthesis of benzyl alcohol, of which little is produced, or benzaldehyde, due to further oxidation to benzoic acid and cresol, among other oxidation products, and eventually complete mineralization to CO2. Et4N[FeCl4] functions as a photocatalyst through the dissociation of chlorine atoms, which abstract hydrogen from toluene, and the photooxidation of toluene proceeds only as far as benzyl alcohol and benzaldehyde. Unlike TiO2, which requires ultraviolet (UV irradiation, Et4N[FeCl4] catalyzes the photooxidation of toluene with visible light alone. Even under predominantly UV irradiation, the yield of benzyl alcohol plus benzaldehyde is greater with Et4N[FeCl4] than with TiO2. Et4N[FeCl4] photocatalysis yields benzyl chloride as a side product, but it can be minimized by restricting irradiation to wavelengths above 360 nm and by the use of long irradiation times. The photonic efficiency of oxidation in one experiment was found to be 0.042 mol/einstein at 365 nm. The use of sunlight as the irradiation source was explored.

  5. Fluorescence photooxidation with eosin: a method for high resolution immunolocalization and in situ hybridization detection for light and electron microscopy

    Science.gov (United States)

    1994-01-01

    A simple method is described for high-resolution light and electron microscopic immunolocalization of proteins in cells and tissues by immunofluorescence and subsequent photooxidation of diaminobenzidine tetrahydrochloride into an insoluble osmiophilic polymer. By using eosin as the fluorescent marker, a substantial improvement in sensitivity is achieved in the photooxidation process over other conventional fluorescent compounds. The technique allows for precise correlative immunolocalization studies on the same sample using fluorescence, transmitted light and electron microscopy. Furthermore, because eosin is smaller in size than other conventional markers, this method results in improved penetration of labeling reagents compared to gold or enzyme based procedures. The improved penetration allows for three-dimensional immunolocalization using high voltage electron microscopy. Fluorescence photooxidation can also be used for high resolution light and electron microscopic localization of specific nucleic acid sequences by in situ hybridization utilizing biotinylated probes followed by an eosin-streptavidin conjugate. PMID:7519623

  6. Chamber simulation of photooxidation of dimethyl sulfide and isoprene in the presence of NOx

    Directory of Open Access Journals (Sweden)

    M. Jang

    2012-11-01

    Full Text Available To improve the model prediction for the formation of H2SO4 and methanesulfonic acid (MSA, aerosol-phase reactions of gaseous dimethyl sulfide (DMS oxidation products [e.g., dimethyl sulfoxide (DMSO] in aerosol have been included in the DMS kinetic model with the recently reported gas-phase reactions and their rate constants. To determine the rate constants of aerosol-phase reactions of both DMSO and its major gaseous products [e.g., dimethyl sulfone (DMSO2 and methanesulfinic acid (MSIA], DMSO was photooxidized in the presence of NOx using a 2 m3 Teflon film chamber. The rate constants tested in the DMSO kinetic mechanisms were then incorporated into the DMS photooxidation mechanism. The model simulation using the newly constructed DMS oxidation mechanims was compared to chamber data obtained from the phototoxiation of DMS in the presence of NOx. Within 120-min simulation, the predicted concentrations of MSA increase by 200–400% and those of H2SO4, by 50–200% due to aerosol-phase chemistry. This was well substantiated with experimental data. To study the effect of coexisting volatile organic compounds, the photooxidation of DMS in the presence of isoprene and NOx has been simulated using the newly constructed DMS kinetic model integrated with the Master Chemical Mechanism (MCM for isoprene oxidation, and compared to chamber data. With the high concentrations of DMS (250 ppb and isoprene (560–2248 ppb, both the model simulation and experimental data showed an increase in the yields of MSA and H2SO4 as the isoprene concentration increased.

  7. Nanoparticles with Embedded Porphyrin Photosensitizers for Photooxidation Reactions and Continuous Oxygen Sensing

    Czech Academy of Sciences Publication Activity Database

    Kubát, Pavel; Henke, P.; Berzediová, V.; Štěpánek, M.; Lang, Kamil; Mosinger, Jiří

    2017-01-01

    Roč. 9, č. 41 (2017), s. 36229-36238 ISSN 1944-8244 R&D Projects: GA ČR(CZ) GA16-15020S Institutional support: RVO:61388955 ; RVO:61388980 Keywords : photooxidation * polystyrene nanoparticles * porphyrins Subject RIV: CF - Physical ; Theoretical Chemistry; CA - Inorganic Chemistry (UACH-T) OBOR OECD: Physical chemistry; Inorganic and nuclear chemistry (UACH-T) Impact factor: 7.504, year: 2016

  8. Nanoparticles with Embedded Porphyrin Photosensitizers for Photooxidation Reactions and Continuous Oxygen Sensing

    Czech Academy of Sciences Publication Activity Database

    Kubát, Pavel; Henke, P.; Berzediová, V.; Štěpánek, M.; Lang, Kamil; Mosinger, Jiří

    2017-01-01

    Roč. 9, č. 41 (2017), s. 36229-36238 ISSN 1944-8244 R&D Projects: GA ČR(CZ) GA16-15020S Institutional support: RVO:61388955 ; RVO:61388980 Keywords : photooxidation * polystyrene nanoparticles * porphyrins Subject RIV: CF - Physical ; Theoretical Chemistry ; CA - Inorganic Chemistry (UACH-T) OBOR OECD: Physical chemistry ; Inorganic and nuclear chemistry (UACH-T) Impact factor: 7.504, year: 2016

  9. Psoralen-mediated virus photoinactivation in platelet concentrates: enhanced specificity of virus kill in the absence of shorter UVA wavelengths

    International Nuclear Information System (INIS)

    Margolis-Nunno, Henrietta; Robinson, Richard; Horowitz, Bernard; Ben-Hur, Ehud; Geacintov, N.E.

    1995-01-01

    Treatments with psoralens and long-wavelength ultraviolet radiation (UVA, 320-400 nm; PUVA) have shown efficacy for virus sterilization of platelet concentrates (PC). We have employed the psoralen derivative 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT), and have found that platelet integrity is best preserved when rutin, a flavonoid that quenches multiple reactive oxygen species, is present during AMT/UVA treatment of PC. In this report, we examine the effects of different UVA spectra under our standard PC treatment conditions (i.e. 50 μg/mL AMT, 0.35 mM rutin and 38 J/cm 2 UVA). Added vesicular stomatitis virus (VSV; ≥ 5.5 log 10 ) was completely inactivated with the simultaneous maintenance of the platelet aggregation response (> 90% of control) when a UVA light source with transmission mainly between 360 and 370 nm (narrow UVA1) was used. In contrast, with a broad-band UVA (320-400 nm; broad UVA) light source, the aggregation response was greatly compromised (< 50% of control) with only a minor increase in the rate of VSV kill. With this lamp, platelet function could be improved to about 75% of the control by adding a long-pass filter, which reduced the transmission of shorter (≤ 345 nm) UVA wavelengths (340-400 nm; UVA1). At equivalent levels of virus kill, aggregation function was always best preserved when narrow UVA1 was used for PUVA treatment. Even in the absence of AMT, and with or without rutin present, narrow UVA1 irradiation was better tolerated by platelets than was broad UVA. (author)

  10. Study of photo-oxidative reactivity of sunscreening agents based on photo-oxidation of uric acid by kinetic Monte Carlo simulation.

    Science.gov (United States)

    Moradmand Jalali, Hamed; Bashiri, Hadis; Rasa, Hossein

    2015-05-01

    In the present study, the mechanism of free radical production by light-reflective agents in sunscreens (TiO2, ZnO and ZrO2) was obtained by applying kinetic Monte Carlo simulation. The values of the rate constants for each step of the suggested mechanism have been obtained by simulation. The effect of the initial concentration of mineral oxides and uric acid on the rate of uric acid photo-oxidation by irradiation of some sun care agents has been studied. The kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for the production of free radicals by sun care agents. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. VOC removal and deodorization of effluent gases from an industrial plant by photo-oxidation, chemical oxidation, and ozonization.

    Science.gov (United States)

    Domeño, Celia; Rodríguez-Lafuente, Angel; Martos, J M; Bilbao, Rafael; Nerín, Cristina

    2010-04-01

    The efficiency of photo-oxidation, chemical oxidation by sodium hypochlorite, and ozonization for the industrial-scale removal of volatile organic compounds (VOCs) and odors from gaseous emissions was studied by applying these treatments (in an experimental system) to substances passing through an emission stack of a factory producing maize derivatives. Absorption and ozonization were the most efficient treatment, removing 75% and 98% of VOCs, respectively, while photo-oxidation only removed about 59%. The emitted chemical compounds and odors were identified and quantified by gas chromatography-mass spectrometry (in full-scan mode). In addition to presenting the results, their implications for selecting optimal processes for treating volatile emissions are discussed.

  12. High formation of secondary organic aerosol from the photo-oxidation of toluene

    Directory of Open Access Journals (Sweden)

    L. Hildebrandt

    2009-05-01

    Full Text Available Toluene and other aromatics have long been viewed as the dominant anthropogenic secondary organic aerosol (SOA precursors, but the SOA mass yields from toluene reported in previous studies vary widely. Experiments conducted in the Carnegie Mellon University environmental chamber to study SOA formation from the photo-oxidation of toluene show significantly larger SOA production than parameterizations employed in current air-quality models. Aerosol mass yields depend on experimental conditions: yields are higher under higher UV intensity, under low-NOx conditions and at lower temperatures. The extent of oxidation of the aerosol also varies with experimental conditions, consistent with ongoing, progressive photochemical aging of the toluene SOA. Measurements using a thermodenuder system suggest that the aerosol formed under high- and low-NOx conditions is semi-volatile. These results suggest that SOA formation from toluene depends strongly on ambient conditions. An approximate parameterization is proposed for use in air-quality models until a more thorough treatment accounting for the dynamic nature of this system becomes available.

  13. Effect of riboflavin on the photo-oxidative stability of vegetable oil in salad dressing.

    Science.gov (United States)

    Lee, Yoon-Hee; Lee, Jaesung; Min, David B; Pascall, Melvin A

    2014-01-01

    Differential scanning calorimetry (DSC), headspace oxygen and solid phase microextraction gas chromatography and peroxide value were used to evaluate the effect of riboflavin on the photo-oxidation of vegetable oil in salad dressing. Salad dressings with 0, 5, 20, 50 and 100 ppm added riboflavin were stored under light (2500 lux) at 25 °C for 5 days. Crystallisation peaks in the DSC thermograms of the oil samples shifted to lower temperatures and enthalpies decreased as the storage time increased. As the riboflavin concentrations increased from 0 to 100 ppm, the crystallisation enthalpies increased from 27 to 31 J/g and the maximum crystallisation temperature increased from -64 to -62 °C during the 5 day storage. Headspace oxygen depletion rates, the formation of volatile compounds and peroxide values of the salad dressing samples simultaneously decreased with the addition of riboflavin, showing that riboflavin protected the oil in salad dressing from photo-oxidation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. In vitro photooxidation of a crude Iranian petroleum maltenic fraction as a film over seawater in natural simulated conditions and identification of photoproducts

    International Nuclear Information System (INIS)

    Nahri-Niknafs, B.; Ghotbesharif, S.J.; Taghvaei, S.; Rustayian, A.H.

    2004-01-01

    Photooxidation is a transformation pathway for oil spilled in the marine environment. Most crude oils spilled at sea spread rapidly to form slicks over a large surface areas. Oil entering the seas can have a harmful impact on marine ecosystems and on the commercial and recreation resources of coastal areas. The spilled oil undergoes physical changes such as dispersion, photooxidation, evaporation, and dissolution. These changes are accompanied by changes in density, viscosity and interfacial tension. It is important to understand the effect petroleum photooxidation and degradation in order to determine the fate of the spilled oil in a marine environment. This study presents a reliable method for examining the nature of the photoproducts and the composition of the residual hydrocarbons on an oil film over seawater. In this study, the maltenic fraction of Iranian oil was exposed to sunlight as a film of oil over seawater. The authors examined the effect of ultraviolet illumination of gas chromatography-mass spectrometry and Fourier Transform Infrared analytical methods. The study revealed that the saturated hydrocarbons were resistant, but the aromatic hydrocarbons were found to be sensitive to photochemical degradation. The sensitivity of aromatic compounds to photooxidation was increased by increasing the size and alkyl substitution. 14 refs., 2 tabs., 1 fig

  15. Determination of residual 4'-aminomethyl-4,5',8-trimethylpsoralen and mutagenicity testing following psoralen plus UVA treatment of platelet suspensions

    International Nuclear Information System (INIS)

    Wagner, S.J.; Robinette, D.; Dodd, R.Y.; White, R.; Wolf, L.; Chapman, J.; Lawlor, T.E.

    1993-01-01

    Psoralens and UVa light have been used in the laboratory to study the inactivation of viruses that may be infrequently present in platelet concentrates prepared for transfusion. In order to evaluate safety aspects of the treatment of platelet suspensions with 4'-aminomethyl-4,5'8-trimethylpsoralen (AMT), the authors have investigated the residual levels and mutagenic potential of AMT after UVA phototreatment. The results suggest that residual available AMT is mutagenic in the AMES test and that the observed frameshift mutations may be caused by binding of AMt or its metabolites to nucleic acids in the absence of UVA light. (Author)

  16. Defense of cutaneous cells against uv irradiation. II. Restricted photomediated binding of trimethyl psoralen to pigmented skin in vivo

    International Nuclear Information System (INIS)

    Carter, D.M.; Jegasothy, B.V.; Condit, E.S.

    1973-01-01

    Distinct differences in grain distribution were seen in autoradiographs of pigmented and nonpigmented skin from spotted guinea-pig ears subjected to photosensitizing conditions by the topical application of tritiated trimethyl psoralen ( 3 H TMP) and exposure to uv irradiation at 365 nm. Grains were localized over cells throughout the epidermis in nonpigmented skin, but they were not seen beneath the stratum corneum in pigmented skin. Since TMP covalently binds to epidermal nucleic acids only after irradiation, these experiments demonstrate that the compacted melanized cells of the outer epidermis shield the DNA of underlying cells by severely restricting the penetration of uv light into the skin. (auth)

  17. Heterogeneity of accelerated photooxidation in commodity polymers stabilized by HAS: ESRI, IR, and MH study

    Czech Academy of Sciences Publication Activity Database

    Pilař, Jan; Michálková, Danuše; Šlouf, Miroslav; Vacková, Taťana; Dybal, Jiří

    2014-01-01

    Roč. 103, May (2014), s. 11-25 ISSN 0141-3910 R&D Projects: GA ČR GA202/09/2078 Institutional support: RVO:61389013 Keywords : hindered amine stabilizers * heterogeneity of photooxidation * electron spin resonance imaging Subject RIV: BO - Biophysics Impact factor: 3.163, year: 2014

  18. Complete and Partial Photo-oxidation of Dissolved Organic Matter Draining Permafrost Soils.

    Science.gov (United States)

    Ward, Collin P; Cory, Rose M

    2016-04-05

    Photochemical degradation of dissolved organic matter (DOM) to carbon dioxide (CO2) and partially oxidized compounds is an important component of the carbon cycle in the Arctic. Thawing permafrost soils will change the chemical composition of DOM exported to arctic surface waters, but the molecular controls on DOM photodegradation remain poorly understood, making it difficult to predict how inputs of thawing permafrost DOM may alter its photodegradation. To address this knowledge gap, we quantified the susceptibility of DOM draining the shallow organic mat and the deeper permafrost layer of arctic soils to complete and partial photo-oxidation and investigated changes in the chemical composition of each DOM source following sunlight exposure. Permafrost and organic mat DOM had similar lability to photomineralization despite substantial differences in initial chemical composition. Concurrent losses of carboxyl moieties and shifts in chemical composition during photodegradation indicated that photodecarboxylation could account for 40-90% of DOM photomineralized to CO2. Permafrost DOM had a higher susceptibility to partial photo-oxidation compared to organic mat DOM, potentially due to a lower abundance of phenolic moieties with antioxidant properties. These results suggest that photodegradation will likely continue to be an important control on DOM fate in arctic freshwaters as the climate warms and permafrost soils thaw.

  19. Photooxidation behaviour of HMS-PP

    International Nuclear Information System (INIS)

    Oliani, Washington L.; Parra, Duclerc F.; Lima, Luis F.C.P.; Lugao, Ademar B.

    2009-01-01

    The radiation process has played an important role to produce polymers with controlled rheological properties. The main scope of the study is to evaluate the stability of High melt strength polypropylene (HMS-PP) prepared by gamma irradiation of PP (spheres) under acetylene atmosphere followed by a heating step to terminate reactions, in different doses of 12.5 kGy and 20 kGy. The samples submitted to the natural ageing for a period of one year were characterized by: thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The fundamental process that is believed to be the most significant in the mechanism of photooxidative degradation is the formation of hydroperoxides. The high energy UV light is capable of initiating bond scission within the polymer backbone, which leads to further chemical modification of the bonds via scissions and chain reactions through formation of radical species. The results showed that in pristine and HMS-PP samples exposed to UV radiation, oxidation reactions occur, resulting in chain scissions. The reactions occur preferentially in the amorphous phase owing to the higher permeability of oxygen. (author)

  20. Photo-oxidation of gaseous ethanol on photocatalyst prepared by acid leaching of titanium oxide/hydroxyapatite composite

    International Nuclear Information System (INIS)

    Ono, Y.; Rachi, T.; Yokouchi, M.; Kamimoto, Y.; Nakajima, A.; Okada, K.

    2013-01-01

    Highlights: ► Photocatalyst powder was prepared by acid leaching of TiO 2 /apatite composite. ► The photocatalytic activity was evaluated from in situ FT-IR study using ethanol. ► Apatite in the composite had positive effect for the photo-oxidation of ethanol. ► The enhanced oxidation rate was explained by the difference in deactivation rate. - Abstract: Highly active photocatalysts were synthesized by leaching of heat-treated titanium dioxide (TiO 2 )/hydroxyapatite (HAp) powder with hydrochloric acid at 0.25, 0.50, 0.75 mol/l, and their photocatalytic activities were evaluated from in situ Fourier transform infrared (FT-IR) study of photo-oxidation of gaseous ethanol. By changing the acid concentration, the TiO 2 /HAp composite had different atomic ratios of Ca/Ti (0.0–2.8) and P/Ti (0.3–2.1). It was found that phosphate group remained on the surface of TiO 2 particle even in the sample treated with concentrated acid (0.75 mol/l). These acid-treated samples showed higher rates for ethanol photo-oxidation than the commercial TiO 2 powder, Degussa P25. The highest rate was obtained in the TiO 2 /HAp composite treated with the dilute (0.25 mol/l) acid in spite of its low content of TiO 2 photocatalyst. This enhanced photocatalytic activity was attributed to the result that the deactivation with repeated injections of ethanol gas was suppressed in the TiO 2 /HAp composites compared with the TiO 2 powders

  1. Development of the pilot system for radioactive laundry waste treatment using UV photo-oxidation process and reverse osmosis membrane

    International Nuclear Information System (INIS)

    Park, S. M.; Park, J. K.; Kim, J. B.; Shin, S. W.; Lee, M. C.

    1999-01-01

    The pilot system for radioactive liquid laundry waste was developed with treatment capacity 1ton/hr and set up in the Yonkwang unit No.4. The system is composed of tank module, reverse osmosis membrane system and UV/H2O2 photo-oxidation process unit. The R/O system consists of the BW unit for low concentration and the SW unit for high concentration. The BW unit possesses 4 of R/O membranes and it can concentrate the feed water volume down to 1/10. This concentrated feed water can be reduced again 1/10 in its volume in the SW unit which is composed of 4 of R/O membranes. The UV/H2O2 photo-oxidation process unit was determined for the detergent removal process. The pilot system was verified in its capability through the continuous operation and enrichment operation using the actual liquid waste of the power plant. The design criteria and data for the industrial system were yielded. The efficiency of the UV/H2O2 photo-oxidation process and the optimum operational procedure were analysed. The decontamination factor of radionuclides, cobalt and cesium was measured. This on-site test showed the experimental result of the DF more than 100 and concentration rate more than 100

  2. Impact of nano/micron vegetable carbon black on mechanical, barrier and anti-photooxidation properties of fish gelatin film.

    Science.gov (United States)

    Ding, Junsheng; Wu, Xiaomeng; Qi, Xiaona; Guo, Heng; Liu, Anjun; Wang, Wenhang

    2018-05-01

    In this paper, two kinds of commonly used vegetable carbon black (VCB, 3000 mesh; nano) at 50 g kg -1 concentration (based on dried gelatin) were added to 48 g kg -1 of fish gelatin (GEL) solutions and their effects on mechanical, barrier and anti-photooxidation properties of GEL films were investigated. From the SEM images, it was shown that compared with 3000 mesh VCB (1-2 μm), nano VCB (100-200 nm) made the microstructure of GEL film more compact and more gelatin chains were cross-linked by nano VCB. The addition of nano VCB significantly increased gelatin film strength with the greatest tensile strength of 52.589 MPa and stiffness with the highest Young's modulus of 968.874 MPa, but led to the reduction of film elongation. Also, the VCB presence significantly improved water vapour and oxygen barrier properties of GEL film. Importantly, nano VCB increased GEL film with better UV barrier property due to its stronger UV absorption nature when compared with micron VCB. This property could help in the preservation of oil samples in the photooxidation accelerated test. With improved properties, the nano VCB-reinforced GEL film may have great potential for application in the edible packaging field, especially for the anti-photooxidation property. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Dissecting long-term adjustments of photoprotective and photo-oxidative stress acclimation occurring in dynamic light environments

    Directory of Open Access Journals (Sweden)

    Shizue Matsubara

    2016-11-01

    Full Text Available Changes in light intensity directly affect the performance of the photosynthetic apparatus. Light energy absorbed in excess of cells’ needs leads to production of reactive oxygen species and photo-oxidative damage. Excess light in both constant and dynamic environments induces photoprotective acclimation in plants. Distinct sets of signals and regulatory mechanisms are involved in acclimatory adjustment of photoprotection and photosynthesis under constant and dynamic (fluctuating light conditions. We are still far away from drawing a comprehensive picture of acclimatory signal transduction pathways, particularly in dynamic environments. In this perspective article, we propose the use of Arabidopsis plants that produce H2O2 in chloroplasts (GO plants under atmospheric CO2 levels as a tool to study the mechanisms of long-term acclimation to photo-oxidative stress. In our opinion there are new avenues to future investigations on acclimatory adjustments and signal transduction occurring in plants under dynamic light environments.

  4. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    Science.gov (United States)

    Riedel, Theran P.; DeMarini, David M.; Zavala, Jose; Warren, Sarah H.; Corse, Eric W.; Offenberg, John H.; Kleindienst, Tadeusz E.; Lewandowski, Michael

    2018-04-01

    Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state atmospheric simulation chamber by irradiating mixtures of single aromatic VOCs, NOx, and ammonium sulfate seed aerosol in air. The 10 VOCs examined were benzene; toluene; ethylbenzene; o-, m-, and p-xylene; 1,2,4- and 1,3,5-trimethylbenzene; m-cresol; and naphthalene. Salmonella were exposed at the air-agar interface to the generated atmospheres for 1, 2, 4, 8, or 16 h. Dark-control exposures produced non-mutagenic atmospheres, illustrating that the gas-phase precursor VOCs were not mutagenic at the concentrations tested. Under irradiation, all but m-cresol and naphthalene produced mutagenic atmospheres, with potencies ranging from 2.0 (p-xylene) to 11.4 (ethylbenzene) revertants m3 mgC-1 h-1. The mutagenicity was due exclusively to direct-acting late-generation products of the photooxidation reactions. Gas-phase chemical analysis showed that a number of oxidized organic chemical species enhanced during the irradiated exposure experiments correlated (r ≥ 0.81) with the mutagenic potencies of the atmospheres. Molecular formulas assigned to these species indicated that they likely contained peroxy acid, aldehyde, alcohol, and other functionalities.

  5. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Directory of Open Access Journals (Sweden)

    C. J. Hennigan

    2011-08-01

    Full Text Available Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III. We investigated emissions from 12 different fuels commonly burned in North American wildfires. The experiments feature atmospheric and plume aerosol and oxidant concentrations; aging times ranged from 3 to 4.5 h. OA production, expressed as a mass enhancement ratio (ratio of OA to primary OA (POA mass, was highly variable. OA mass enhancement ratios ranged from 2.9 in experiments where secondary OA (SOA production nearly tripled the POA concentration to 0.7 in experiments where photo-oxidation resulted in a 30 % loss of the OA mass. The campaign-average OA mass enhancement ratio was 1.7 ± 0.7 (mean ± 1σ; therefore, on average, there was substantial SOA production. In every experiment, the OA was chemically transformed. Even in experiments with net loss of OA mass, the OA became increasingly oxygenated and less volatile with aging, indicating that photo-oxidation transformed the POA emissions. Levoglucosan concentrations were also substantially reduced with photo-oxidation. The transformations of POA were extensive; using levoglucosan as a tracer for POA, unreacted POA only contributed 17 % of the campaign-average OA mass after 3.5 h of exposure to typical atmospheric hydroxyl radical (OH levels. Heterogeneous reactions with OH could account for less than half of this transformation, implying that the coupled gas-particle partitioning and reaction of semi-volatile vapors is an important and potentially dominant mechanism for POA processing. Overall, the results illustrate that biomass burning emissions are subject to extensive chemical processing in the atmosphere, and the timescale for these transformations is rapid.

  6. Determination of phenols by flow injection and liquid chromatography with on-line quinine-sensitized photo-oxidation and quenched luminol chemiluminescence detection

    International Nuclear Information System (INIS)

    Zhang Wei; Danielson, Neil D.

    2003-01-01

    An on-line quinine-sensitized photo-oxidation with quenched chemiluminescence (CL) detection method is developed for phenols using flow injection (FI) and liquid chromatography (LC). This detection method is based on the decrease of light emission from the luminol CL reaction due to the photo-oxidation of phenols that scavenge the photogenerated reactive oxygen species (e.g. singlet oxygen ( 1 O 2 ) and superoxide (O 2 · - )). On-line photo-oxidation is achieved using a coil photo-reactor made from fluoroethylene-propylene copolymer tubing (3048 mmx0.25 mm i.d.) coiled around a mercury UV lamp. A buffer of pH 7 and a concentration of 350 μM for quinine sulfate are determined optimum for the sensitized photo-oxidation. Using a carrier system flow rate of 60 μl/min, calibration curves taken by FI for 10 phenolic compounds in aqueous solutions showed this decreasing sensitivity order: 4-chlorophenol, phenol, 4-nitrophenol, 3-hydroxy-L-kynurenine, 2-nitrophenol, salicylate, 3-nitrophenol, catechol, 2,4-dinitrophenol, and 2,4-dichlorophenol. This detection method using two tandem coil photo-reactors is also applied for the LC separation of phenol, 4-nitrophenol and 4-chlorophenol on an octadecyl (C18) silica LC column using acetonitrile-H 2 O (40:60, v/v) as a mobile phase. The quenched CL detection limits (about 1 μM or 20 pmol) for phenol and 4-chlorophenol are comparable to those for UV detection at 254 nm. Some selectivity in the quenched CL detection is evident by no interference in the FI phenol response even when benzaldehyde and phenethanol concentrations are 8 and 15 times that of phenol

  7. Photo-oxidation of gaseous ethanol on photocatalyst prepared by acid leaching of titanium oxide/hydroxyapatite composite

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Y., E-mail: ono-y@kanagawa-iri.go.jp [Mechanical and Material Engineering Division, Kanagawa Industrial Technology Center, Ebina, Kanagawa 243-0435 (Japan); Rachi, T.; Yokouchi, M.; Kamimoto, Y. [Mechanical and Material Engineering Division, Kanagawa Industrial Technology Center, Ebina, Kanagawa 243-0435 (Japan); Nakajima, A. [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8552 (Japan); Okada, K. [Materials and Structures Laboratory, Tokyo Institute of Technology, Midori, Yokohama, Kanagawa 226-8503 (Japan)

    2013-06-01

    Highlights: ► Photocatalyst powder was prepared by acid leaching of TiO{sub 2}/apatite composite. ► The photocatalytic activity was evaluated from in situ FT-IR study using ethanol. ► Apatite in the composite had positive effect for the photo-oxidation of ethanol. ► The enhanced oxidation rate was explained by the difference in deactivation rate. - Abstract: Highly active photocatalysts were synthesized by leaching of heat-treated titanium dioxide (TiO{sub 2})/hydroxyapatite (HAp) powder with hydrochloric acid at 0.25, 0.50, 0.75 mol/l, and their photocatalytic activities were evaluated from in situ Fourier transform infrared (FT-IR) study of photo-oxidation of gaseous ethanol. By changing the acid concentration, the TiO{sub 2}/HAp composite had different atomic ratios of Ca/Ti (0.0–2.8) and P/Ti (0.3–2.1). It was found that phosphate group remained on the surface of TiO{sub 2} particle even in the sample treated with concentrated acid (0.75 mol/l). These acid-treated samples showed higher rates for ethanol photo-oxidation than the commercial TiO{sub 2} powder, Degussa P25. The highest rate was obtained in the TiO{sub 2}/HAp composite treated with the dilute (0.25 mol/l) acid in spite of its low content of TiO{sub 2} photocatalyst. This enhanced photocatalytic activity was attributed to the result that the deactivation with repeated injections of ethanol gas was suppressed in the TiO{sub 2}/HAp composites compared with the TiO{sub 2} powders.

  8. Chilling-enhanced photooxidation: evidence for the role of singlet oxygen and superoxide in the breakdown of pigments and endogenous antioxidants

    International Nuclear Information System (INIS)

    Wise, R.R.; Naylor, A.W.

    1987-01-01

    Chilling temperatures (5 0 C) and high irradiance (1000 microeinsteins per square meter per second) were used to induce photooxidation in detached leaves of cucumber (Cucumis sativus L.), a chilling-sensitive plant. Chlorophyll a, chlorophyll b, β carotene, and three xanthophylls were degraded in a light-dependent fashion at essentially the same rate. Lipid peroxidation (measured as ethane evolution) showed an O 2 dependency. The levels of three endogenous antioxidants, ascorbate, reduced glutathione, and α tocopherol, all showed an irradiance-dependent decline. α-Tocopherol was the first antioxidant affected and appeared to be the only antioxidant that could be implicated in long-term protection of the photosynthetic pigments. Results from the application of antioxidants having relative selectivity for 1 O 2 , O 2 + , or OH indicated that both 1 O 2 and O 2 - were involved in the chilling- and light-induced lipid peroxidation which accompanied photooxidation. Application of D 2 O (which enhances the lifetime of 1 O 2 ) corroborated these results. Chilling under high light produced no evidence of photooxidative damage in detached leaves of chilling-resistant pea (Pisum sativum L.). Their results suggest a fundamental difference in the ability of pea to reduce the destructive effects of free-radical and 1 O 2 production in chloroplasts during chilling in high light

  9. Acute skin lesions following psoralen plus ultraviolet A radiation investigated by optical coherence tomography

    International Nuclear Information System (INIS)

    Liu, Z M; Zhong, H Q; Zhai, J; Wang, C X; Xiong, H L; Guo, Z Y

    2013-01-01

    Psoralen plus ultraviolet A radiation (PUVA) therapy is a very important clinical treatment of skin diseases such as vitiligo and psoriasis, but associated with an increased risk of skin photodamage, especially photoaging. In this work, optical coherence tomography (OCT), a novel non-invasive imaging technology, was introduced to investigate in vivo the photodamage induced by PUVA qualitatively and quantitatively. Balb/c mouse dorsal skin was treated with 8-methoxypsoralen (8-MOP), and then exposed to UVA radiation. OCT images of the tissues were obtained by an OCT system with a 1310 nm central wavelength. Skin thickness and the attenuation coefficient were extracted from the OCT images to analyze the degree of injury to mouse skin. The results demonstrated that PUVA-treated skin showed an increase in skin thickness, and a reduction of attenuation coefficient in the OCT signal compared with the control groups. The data also showed good correlation with the results observed in histological sections using hematoxylin and eosin staining. In conclusion, OCT is a promising tool for photobiological studies aimed at assessing the effect of PUVA therapy in vivo. (paper)

  10. Determination of residual 4'-aminomethyl-4,5',8-trimethylpsoralen and mutagenicity testing following psoralen plus UVA treatment of platelet suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, S.J.; Robinette, D.; Dodd, R.Y. (American Red Cross Blood Services, Rockville, MD (United States). Jerome H. Holland Lab. for Biomedical Sciences); White, R.; Wolf, L.; Chapman, J. (Baxter Biotech, Round Lake, IL (United States). Fenwal Labs.); Lawlor, T.E. (Hazleton Labs., Vienna, VA (United States). Molecular and Cellular Toxicology)

    1993-05-01

    Psoralens and UVa light have been used in the laboratory to study the inactivation of viruses that may be infrequently present in platelet concentrates prepared for transfusion. In order to evaluate safety aspects of the treatment of platelet suspensions with 4'-aminomethyl-4,5'8-trimethylpsoralen (AMT), the authors have investigated the residual levels and mutagenic potential of AMT after UVA phototreatment. The results suggest that residual available AMT is mutagenic in the AMES test and that the observed frameshift mutations may be caused by binding of AMt or its metabolites to nucleic acids in the absence of UVA light. (Author).

  11. 4,4',5'-trimethyl-8-azapsoralen, a new-photoreactive and non-skin-phototoxic bifunctional bioisoster of psoralen.

    Science.gov (United States)

    Vedaldi, D; Dall'Acqua, F; Caffieri, S; Baccichetti, F; Carlassare, F; Bordin, F; Chilin, A; Guiotto, A

    1991-01-01

    Photochemical and photobiological properties of a new isoster of psoralen, 4,4',5'-trimethyl-8-azapsoralen (4,4',5'-TMAP), have been studied. This compound shows a high DNA-photobinding rate, higher than that of 8-methoxypsoralen (8-MOP), forming both monoadducts and inter-strand cross-links. The yield of cross-links, however, is markedly lower than that of 8-MOP. Antiproliferative activity of 4,4',5'-TMAP, in terms of DNA synthesis inhibition in Ehrlich ascites tumor cells, is higher than that of 8-MOP. Mutagenic activity on E. coli WP2 R46+ cells appeared similar to or even lower than that of 8-MOP. This new compound applied on depilated guinea pig skin and irradiated with UVA did not show any skin-phototoxicity. On the basis of these properties 4,4',5'-TMAP appears to be a potential photochemotherapeutic agent.

  12. Kinetics of 25-hydroperoxycholesterol formation during photo-oxidation of crystalline cholesterol.

    Science.gov (United States)

    Medina-Meza, Ilce Gabriela; Rodriguez-Estrada, Maria Teresa; Lercker, Giovanni; Barnaba, Carlo; García, Hugo Sergio

    2014-06-01

    25-Hydroxycholesterol (25-OH), a side-chain product of cholesterol oxidation, has emerged as one of the important issues in food chemistry and biochemistry, because of its involvement in several human pathologies. This oxysterol is derived from both enzymatic and non-enzymatic pathways. However, the latter mechanism has been scarcely studied in either food or model systems. In this work, a kinetic model was developed to evaluate the formation of 25-OH and its precursor 25-hydroperoxycholesterol (25-OOH) during photo-oxidation of cholesterol for 28 days under fluorescent light. 25-OOH was estimated by an indirect method, using thin-layer chromatography coupled with gas chromatography-mass spectrometry. Peroxide value (POV) and cholesterol oxidation products (COPs) were determined. POV showed a hyperbolic behavior, typical of a crystalline system in which the availability of cholesterol is the limiting factor. Further reactions of hydroperoxides were followed; in particular, after photo-oxidation, 25-OOH (0.55 mg g(-1) ) and 25-OH (0.08 mg g(-1) ) were found in cholesterol, as well as seven other oxysterols, including 7-hydroxy and 5,6-epoxy derivatives. The application of kinetic models to the data showed good correlation with theoretical values, allowing derivation of the kinetic parameters for each oxidation route. The results of this work confirm that cholesterol in the crystalline state involves different oxidation patterns as compared to cholesterol in solution. Moreover, the numerical fit proved that hydroperoxidation is the rate-limiting step in 25-OH formation. © 2013 Society of Chemical Industry.

  13. Sex-related differences in photoinhibition, photo-oxidative stress and photoprotection in stinging nettle (Urtica dioica L.) exposed to drought and nutrient deficiency.

    Science.gov (United States)

    Simancas, Bárbara; Juvany, Marta; Cotado, Alba; Munné-Bosch, Sergi

    2016-03-01

    Dimorphic plant species can show distinct nutrient needs due to sex-related differences in nutrient allocation to reproductive structures, which can potentially affect their sensitivity to photoinhibition and photo-oxidative stress. Here, we investigated sex-related differences in the extent of photo-oxidative stress in male and female individuals of U. dioica exposed to a combination of severe drought and nutrient starvation. Male and female individuals of U. dioica subject to severe drought stress were exposed to various levels of nutrient availability. First, a set of plants grown under field conditions and exposed to summer drought was used to test the effects of nutrient supply (given as NPK fertilizer). Secondly, the effects of various phosphate concentrations in the nutrient solution were tested in drought-stressed potted plants. The Fv/Fm ratio (maximum efficiency of PSII photochemistry), photoprotection capacity (levels of carotenoids, including the xanthophyll cycle, and vitamins C and E), and the extent of lipid peroxidation (hydroperoxide levels) were measured. Results showed that an application of the NPK fertilizer to the soil had a positive effect on drought-stressed plants, reducing the extent of lipid peroxidation in both males and females. P deficiency led to residual photoinhibition, as indicated by significant reductions in the Fv/Fm ratio, and enhanced lipid peroxidation in females, but not in males. We conclude that (i) increased nutrient availability in the soil can alleviate photo-oxidative stress in drought-stressed U. dioica plants, and (ii) U. dioica plants show sexual secondary dimorphism in terms of photoinhibition and photo-oxidative stress, but this is only apparent when stress infringed on plants is very severe. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. VUV photo-oxidation of gaseous benzene combined with ozone-assisted catalytic oxidation: Effect on transition metal catalyst

    Science.gov (United States)

    Huang, Haibao; Lu, Haoxian; Zhan, Yujie; Liu, Gaoyuan; Feng, Qiuyu; Huang, Huiling; Wu, Muyan; Ye, Xinguo

    2017-01-01

    Volatile organic compounds (VOCs) cause the major air pollution concern. In this study, a series of ZSM-5 supported transition metals were prepared by impregnation method. They were combined with vacuum UV (VUV) photo-oxidation in a continuous-flow packed-bed reactor and used for the degradation of benzene, a typical toxic VOCs. Compared with VUV photo-oxidation alone, the introduction of catalysts can greatly enhance benzene oxidation under the help of O3, the by-products from VUV irradiation, via ozone-assisted catalytic oxidation (OZCO). The catalytic activity of transition metals towards benzene oxidation followed the order: Mn > Co > Cu > Ni > Fe. Mn achieved the best catalytic activity due to the strongest capability for O3 catalytic decomposition and utilization. Benzene and O3 removal efficiency reached as high as 97% and 100% after 360 min, respectively. O3 was catalytically decomposed, generating highly reactive oxidants such as rad OH and rad O for benzene oxidation.

  15. Chilling-enhanced photooxidation: evidence for the role of singlet oxygen and superoxide in the breakdown of pigments and endogenous antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Wise, R.R.; Naylor, A.W.

    1987-02-01

    Chilling temperatures (5/sup 0/C) and high irradiance (1000 microeinsteins per square meter per second) were used to induce photooxidation in detached leaves of cucumber (Cucumis sativus L.), a chilling-sensitive plant. Chlorophyll a, chlorophyll b, ..beta.. carotene, and three xanthophylls were degraded in a light-dependent fashion at essentially the same rate. Lipid peroxidation (measured as ethane evolution) showed an O/sub 2/ dependency. The levels of three endogenous antioxidants, ascorbate, reduced glutathione, and ..cap alpha.. tocopherol, all showed an irradiance-dependent decline. ..cap alpha..-Tocopherol was the first antioxidant affected and appeared to be the only antioxidant that could be implicated in long-term protection of the photosynthetic pigments. Results from the application of antioxidants having relative selectivity for /sup 1/O/sub 2/, O/sub 2//sup +/, or OH indicated that both /sup 1/O/sub 2/ and O/sub 2//sup -/ were involved in the chilling- and light-induced lipid peroxidation which accompanied photooxidation. Application of D/sub 2/O (which enhances the lifetime of /sup 1/O/sub 2/) corroborated these results. Chilling under high light produced no evidence of photooxidative damage in detached leaves of chilling-resistant pea (Pisum sativum L.). Their results suggest a fundamental difference in the ability of pea to reduce the destructive effects of free-radical and /sup 1/O/sub 2/ production in chloroplasts during chilling in high light.

  16. Evaluation of effects of photooxidized Vespa orientalis venom on memory and learning in rats

    Directory of Open Access Journals (Sweden)

    H Mukund

    2011-01-01

    Full Text Available Wasp venom is mixture of complex proteins that have several physical and pharmacological properties. The photochemical detoxification of Vespa orientalis venom is expected to generate photooxidized venom sac extract (PVSE. Antigenically active PVSE is obtained by exposing the venom sac extract (VSE of Vespa orientalis to ultraviolet radiation in the presence of methylene blue. The aim of the present work was to evaluate the effect of PVSE on learning and memory of rats. Detoxification of PVSE was evident since treated mice had longer survival time than the group of mice treated with VSE. Photooxidized VSE of V. orientalis revealed enhancement on learning and memory by shortening the time to reach food (TRF in T-maze. In a 28-day study with rats, we observed that PVSE significantly decreased transfer latency (TL in elevated plus maze (EPM, significantly increased step down latency (SDL, diminished step down errors (SDE and time spent in shock zone (TSS in step down avoidance test. Thus, we concluded that although there is a possibility of employing PVSE in the treatment of Alzheimer, dementia or neurodegenerative illness as a non-herbal and non-synthetic alternative for patients who do not respond to available therapy, further investigation is still required.

  17. Dityrosine, 3,4-Dihydroxyphenylalanine (DOPA), and radical formation from tyrosine residues on milk proteins with globular and flexible structures as a result of riboflavin-mediated photo-oxidation

    DEFF Research Database (Denmark)

    Dalsgaard, Trine Kastrup; Nielsen, Jacob Holm; Brown, Bronwyn

    2011-01-01

    Riboflavin-mediated photo-oxidative damage to protein Tyr residues has been examined to determine whether protein structure influences competing protein oxidation pathways in single proteins and protein mixtures. EPR studies resulted in the detection of Tyr-derived o-semiquione radicals, with thi......Riboflavin-mediated photo-oxidative damage to protein Tyr residues has been examined to determine whether protein structure influences competing protein oxidation pathways in single proteins and protein mixtures. EPR studies resulted in the detection of Tyr-derived o-semiquione radicals...

  18. Argonne National Laboratory's photo-oxidation organic mixed waste treatment system - installation and startup testing

    International Nuclear Information System (INIS)

    Shearer, T.L.; Nelson, R.A.; Torres, T.; Conner, C.; Wygmans, D.

    1997-01-01

    This paper describes the installation and startup testing of the Argonne National Laboratory (ANL-E) Photo-Oxidation Organic Mixed Waste Treatment System. This system will treat organic mixed (i.e., radioactive and hazardous) waste by oxidizing the organics to carbon dioxide and inorganic salts in an aqueous media. The residue will be treated in the existing radwaste evaporators. The system is installed in the Waste Management Facility at the ANL-E site in Argonne, Illinois. 1 fig

  19. Identification of quenchers of photoexcited States as novel agents for skin photoprotection.

    Science.gov (United States)

    Wondrak, Georg T; Jacobson, Myron K; Jacobson, Elaine L

    2005-02-01

    Photooxidative stress is a key mechanism in UVA-induced skin photodamage. Photoexcited states of endogenous UVA chromophores such as porphyrins, melanin precursors, and cross-link-fluorophores of skin collagen exert skin photodamage by direct reaction with substrate molecules (type I photosensitization) or molecular oxygen (type II), leading to formation of reactive oxygen species. Based on our previous research on the role of photoexcited states of endogenous skin chromophores as sensitizers of photooxidative stress, we describe here the identification of a novel class of chemopreventive agents for topical skin photoprotection: quenchers of photoexcited states (QPES). QPES compounds antagonize the harmful excited state chemistry of endogenous sensitizers by physical quenching, facilitating the harmless return of the sensitizer excited state to the electronic ground state by energy dissipation. To identify QPES compounds suitable for development, we designed a primary screening assay based on QPES suppression of photosensitized plasmid cleavage using conditions that exclude antioxidants. This screen is followed with a screen to test for nonsacrificial quenching of dye-sensitized singlet oxygen ((1)O(2)) formation by electron paramagnetic resonance detection of 2,2,6,6-tetramethyl-piperidine-1-oxyl, a stable free radical indicative of (1)O(2) formation. These initial screens identified a pyrrolidine pharmacophore with pronounced QPES activity, and l-proline and other noncytotoxic proline derivatives containing this pharmacophore were then screened for efficacy in cellular models of sensitized photodamage. These compounds showed QPES protection against dye-sensitized and psoralen-UVA-induced apoptosis and suppression of proliferation in cultured human skin keratinocytes and fibroblasts. Furthermore, QPES photoprotection of reconstructed full thickness human skin exposed to solar simulated light has been demonstrated.

  20. Mechanisms involved in the chemical inhibition of the Eosin-sensitized photooxidation of trypsin

    Energy Technology Data Exchange (ETDEWEB)

    Rizzuto, F.; Spikes, J.D.

    1975-01-01

    A large series of compounds was screened for ability to protect trypsin from eosin-sensitized photodynamic inactivation. Eosin-sensitized photooxidation reactions of this type typically proceed via the triplet state of the dye and often involve singlet state oxygen as the oxidizing entity. In order to determine the mechanisms by which trypsin is protected from photoinactivation, a number of good protective agents (inhibitors) and some non-protective agents were selected for more detailed flash photolysis studies. Good inhibitors such as p-phenylenediamine, n-propyl gallate, serotonin creatinine sulfate and p-toluenediamine competed efficiently with oxygen and with trypsin for reaction with the triplet state of eosin. The inhibitors were shown to quench triplet eosin to the ground state and/or reduce triplet eosin to form the semireduced eosin radical and an oxidized form of the inhibitor. In the latter case, oxidized inhibitor could react by a reverse electron transfer reaction with the semireduced eosin radical to regenerate ground state eosin and the inhibitor. The good inhibitors also competed effectively with trypsin for oxidation by semioxidized eosin, thus giving another possible protective mechanism. Non-inhibitors such as halogen ions and the paramagnetic ions Co/sup + +/, Cu/sup + +/ and Mn/sup + +/ reacted only slowly with triplet and with semioxidized eosin. The primary pathway for the eosin-sensitized photooxidation of trypsin at pH 8.0 involved singlet oxygen, although semioxidized eosin may also participate.

  1. Pro-oxidant activity of .alpha.-tocopherol during photooxidative degradation of polyolefins. ESRI and IR microspectroscopy studies

    Czech Academy of Sciences Publication Activity Database

    Pilař, Jan; Šlouf, Miroslav; Michálková, Danuše; Šloufová, I.; Vacková, Taťana; Dybal, Jiří

    2017-01-01

    Roč. 138, April (2017), s. 55-71 ISSN 0141-3910 R&D Projects: GA MZd(CZ) NV15-31269A; GA MŠk(CZ) LM2015064; GA ČR(CZ) GA14-17921S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : polymer photooxidation * stabilization * HAS Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.386, year: 2016

  2. Effects and mechanisms of eugenol, isoeugenol, coniferylaldehyde and dihydroeugenol on the riboflavin-sensitized photooxidation of α-terpinene in methanol.

    Science.gov (United States)

    Lee, Ju Yeon; Jung, Mun Yhung

    2017-04-01

    The effects of eugenol, isoeugenol, coniferylaldehyde, and dihydroeugenol on the riboflavin-sensitized photooxidation of α-terpinene in methanol were studied. Riboflavin greatly accelerated α-terpinene oxidation in methanol during light illumination, resulting in two major oxidation products (p-cymene and ascaridole). The results clearly showed the involvement of Type I and II mechanisms. All the eugenols exerted strong protective activity on riboflavin sensitized photooxidation of α-terpinene. Dihydroeugenol showed the highest protective activity, followed by isoeugenol, coniferylaldehyde, and eugenol, in a decreasing order. Dihydroeugenol greatly inhibited the production of ascaridole, but showed relatively low inhibitory activity on the formation of p-cymene. The protective activity of dihydroeugenol was higher than those of BHA, BHT and sodium azide. Sodium azide, a specific singlet oxygen quencher, showed strong inhibitory activity on the formation of ascaridole, but very low inhibitory activity on the formation of p-cymene, verifying the feasibility of mechanism study with the present model system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Measurement of photooxidants relevant to human biometeorology in an urban agglomeration (PHOTOX). Measurement of various hydrocarbons as precursors of photooxidants relevant to human biometeorology (KOVOX). Final report of Part 2; Erfassung von human-biometeorologisch relevanten Photooxidantien in einem Ballungsraum (PHOTOX). Erfassung verschiedener Kohlenwasserstoffe als Vorlaeufersubstanzen fuer human-biometeorologisch relevante Photooxidantien (KOVOX). Abschlussbericht zum Teil 2

    Energy Technology Data Exchange (ETDEWEB)

    Jakobi, G.; Fabian, P. [eds.

    1997-04-01

    The air-chemical components ozone and PAN (peroxy acetyl nitrate), their precursors NO and NO{sub 2} and the meteorological parameters air temperature, humidity, global radiation, wind direction and wind velocity were measured in the framework of a research project (PHOTOX - Measurement of photooxidants relevant to human biometeorology in an urban agglomeration) carried out by the Department of Bioclimatology and Pollution Research. Further, a wide range of anthropogenic and biogenic hydrocarbons, which are important groups of precursors of photooxidants and potential pollution factors, were measured in the framework of another research project (KOVOX - Measurement of various hydrocarbons as precursors of photooxidants relevant to human biometeorology). (orig/SR) [Deutsch] Die Messung der luftchemischen Komponenten Ozon und PAN (Peroxiacetylnitrat), deren Vorlaeufersubstanzen Stickstoffmonoxid (NO) und Stickstoffdioxid (NO{sub 2}) sowie deren meteorologischen Parameter Lufttemperatur, Luftfeuchtigkeit, Globalstrahlung, Windrichtung und Windgeschwindigkeit wurde im Rahmen des am Lehrstuhl fuer Bioklimatologie und Immisionsforschung laufenden Forschungsvorhabens ``Erfassung von human-biometeorologisch relevanten Photooxidantien in einem Ballungsraum (PHOTOX)`` durchgefuehrt. Des weiteren erfolgte die Messung einer breiten Palette anthropogener und biogener Kohlenwasserstoffe als wichtige Gruppen der Vorlaeufersubstanzen zur Photooxidantienbildung und moeglicher Wirkfaktoren, im Rahmen des Projektes ``Erfassung verschiedener Kohlenwasserstoffe als Vorlaeufersubstanzen fuer human-biometeorologisch relevante Photooxidantien (KOVOX)``. (orig./BW)

  4. Efficiency of repair of pyrimidine dimers and psoralen monoadducts in normal and xeroderma pigmentosum human cells

    International Nuclear Information System (INIS)

    Cleaver, J.E.; Charles, W.C.; Kong, S.H.

    1984-01-01

    Repair of DNA damage produced by ultraviolet light or 5-methylisopsoralen in normal and xeroderma pigmentosum human cells involves many similar steps. Aphidicolin and cytosine arabinoside block repair of both kinds of damage with similar efficiency, indicating that DNA polymerase α has a major role in repair for these lesions. In xeroderma pigmentosum cells of various complementation groups, the relative efficiency of excision repair for both ultraviolet- and 5-methylisopsoralen-induced damage was group A< C< D, indicating a close resemblance between both kinds of lesions in relation to the repair deficiencies in these groups. At high doses, the maximum rate of repair of damage by ultraviolet light was about twice that for methylisopsoralen damage, possibly because ultraviolet-induced damage forms a substrate that is more readily recognized and excised than that of the psoralen adducts. Differences in the structural distortions to DNA caused by these kinds of damage could be detected using single strand specific nucleases which excised dimers but not 5-MIP adducts from double strand DNA. (author)

  5. Biodegradation and photooxidation of crude oil under natural sunlight in the northern Gulf of Mexico

    Science.gov (United States)

    Bacosa, H. P.; Erdner, D.; Liu, Z.

    2016-02-01

    An enormous amount of oil was observed in the deep and surface waters of the northern Gulf of Mexico (nGoM) following the Deepwater Horizon (DWH) spill. While the oil degradation and bacterial communities in the deep-sea plume have been widely investigated, the effect of sunlight on oil and bacterial assemblages in surface waters have received less attention. In this study, we amended surface water collected near the DWH site with crude oil and/or Corexit dispersant and incubated under natural sunlight in the nGoM for 36 d in summer of 2013. The residual alkanes, polycyclic aromatic hydrocarbons (PAHs), and alkalyted PAHs were analyzed by GC-MS, and bacterial community was determined via pyrosequencing. The results show that n-alkane biodegradation rate constants (first order) were ca. ten-fold higher than the photooxidation rate constants. While biodegradation was characterized by a lag phase, photooxidation rate constants for the 2-3 ring and 4-5 ring PAHs, were 0.08-0.98 day-1 and 0.01-0.07 day-1, respectively. Compared to biodegradation, photooxidation increased the transformation of 4-5 ring PAHs by 70% and 3-4 ring alkylated PAHs by 36%. Sunlight significantly reduced bacterial diversity and a driver of shifts in bacterial community structure in oil and Corexit treatments. In amended treatments, sunlight increased the relative abundances of Alteromonas, Marinobacter, Labrenzia, Sandarakinotalea, Halomonas and Bartonella, while the dark treatments enriched Thalassobius, Winogradskyella, Alcanivorax, Formosa, Eubacterium, Erythrobacter, Natronocella, and Pseudomonas. This suggests that different bacteria are degrading the hydrocarbons in the dark and under light exposure. In a follow up study using DNA-Stable isotope probing (SIP), we identified the alkane and PAH degraders using 13C-labeled hexadecane and phenanthrene, respectively. The results of metagenomic and metatranscriptomic analyses in the light and dark incubations will be presented. For the first

  6. SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures

    Science.gov (United States)

    Chen, Chia-Li; Li, Lijie; Tang, Ping; Cocker, David R.

    2018-05-01

    SOA formation is not well predicted in current models in urban area. The interaction among multiple anthropogenic volatile organic compounds is essential for the SOA formation in the complex urban atmosphere. Secondary organic aerosol (SOA) from the photooxidation of naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as well as individual polycyclic aromatic hydrocarbons (PAHs) mixed with m-xylene or an atmospheric surrogate mixture was explored in the UCR CE-CERT environmental chamber under urban relevant low NOx and extremely low NOx (H2O2) conditions. Addition of m-xylene suppressed SOA formation from the individual PAH precursor. A similar suppression effect on SOA formation was observed during the surrogate mixture photooxidation suggesting the importance of gas-phase chemical reactivity to SOA formation. The SOA growth rate for different PAH-m-xylene mixtures was strongly correlated with initial [HO2]/[RO2] ratio but negatively correlated with initial m-xylene/NO ratio. Decreasing SOA formation was observed for increasing m-xylene/PAHs ratios and increasing initial m-xylene/NO ratio. The SOA chemical composition characteristics such as f44 versus f43, H/C ratio, O/C ratio, and the oxidation state of the carbon OSbarc were consistent with a continuously aging with the SOA exhibiting characteristics of both individual precursors. SOA formation from PAHs was also suppressed within an atmospheric surrogate mixture compared to the SOA formed from individual PAHs, indicating that atmospheric reactivity directly influences SOA formation from PAHs.

  7. Photochemical modelling of photo-oxidant levels over the Swiss plateau and emission reduction scenarios

    International Nuclear Information System (INIS)

    Rosselet, C.M.; Kerr, J.A.

    1993-05-01

    During summertime high pressure conditions, high photo-oxidant (O 3 , H 2 O 2 , PAN and others) levels are frequently observed in the planetary boundary layer in central Europe. It is well known that close to the earth's surface ozone is formed by complex reactions involving VOC, NO x , and sunlight. Substantial reductions of both precursors are needed to reduce photo-oxidant levels. In this context the reductions of the abundance of the precursors and the variation of their ratios is of great importance. Here we report model calculations from the Harwell Photochemical Trajectory Model of the levels of O 3 , H 2 O 2 and PAN along a trajectory over the Swiss Plateau from Lake Constance to Lake Geneva. These calculations are in satisfactory agreement with measurements made during the intensive observation period of the research program POLLUMET (Pollution and Meteorology in Switzerland). Sensitivity calculations of emission reduction scenarios indicate that on the Swiss Plateau the ozone production may be mainly NO x -limited; under conditions where the CO levels are closer to the upper limit within the range (120-600 ppbv). The calculated peak ozone level reduction caused by an exclusive NO x -emission reduction is about three times larger than that caused by an exclusive VOC reduction. The combined reduction of all precursor compounds is the most efficient strategy, although it is only marginally more efficient than the NO x -reduction scenario alone. (author) figs., tabs., 75 refs

  8. Perturbations in the Photosynthetic Pigment Status Result in Photooxidation-Induced Crosstalk between Carotenoid and Porphyrin Biosynthetic Pathways

    Directory of Open Access Journals (Sweden)

    Joon-Heum Park

    2017-11-01

    Full Text Available Possible crosstalk between the carotenoid and porphyrin biosynthetic pathways under photooxidative conditions was investigated by using their biosynthetic inhibitors, norflurazon (NF and oxyfluorfen (OF. High levels of protoporphyrin IX (Proto IX accumulated in rice plants treated with OF, whereas Proto IX decreased in plants treated with NF. Both NF and OF treatments resulted in greater decreases in MgProto IX, MgProto IX methyl ester, and protochlorophyllide. Activities and transcript levels of most porphyrin biosynthetic enzymes, particularly in the Mg-porphyrin branch, were greatly down-regulated in NF and OF plants. In contrast, the transcript levels of GSA, PPO1, and CHLD as well as FC2 and HO2 were up-regulated in NF-treated plants, while only moderate increases in FC2 and HO2 were observed in the early stage of OF treatment. Phytoene, antheraxanthin, and zeaxanthin showed high accumulation in NF-treated plants, whereas other carotenoid intermediates greatly decreased. Transcript levels of carotenoid biosynthetic genes, PSY1 and PDS, decreased in response to NF and OF, whereas plants in the later stage of NF treatment exhibited up-regulation of BCH and VDE as well as recovery of PDS. However, perturbed porphyrin biosynthesis by OF did not noticeably influence levels of carotenoid metabolites, regardless of the strong down-regulation of carotenoid biosynthetic genes. Both NF and OF plants appeared to provide enhanced protection against photooxidative damage, not only by scavenging of Mg-porphyrins, but also by up-regulating FC2, HO2, and Fe-chelatase, particularly with increased levels of zeaxanthin via up-regulation of BCH and VDE in NF plants. On the other hand, the up-regulation of GSA, PPO1, and CHLD under inhibition of carotenogenic flux may be derived from the necessity to recover impaired chloroplast biogenesis during photooxidative stress. Our study demonstrates that perturbations in carotenoid and porphyrin biosynthesis coordinate

  9. Perturbations in the Photosynthetic Pigment Status Result in Photooxidation-Induced Crosstalk between Carotenoid and Porphyrin Biosynthetic Pathways.

    Science.gov (United States)

    Park, Joon-Heum; Tran, Lien H; Jung, Sunyo

    2017-01-01

    Possible crosstalk between the carotenoid and porphyrin biosynthetic pathways under photooxidative conditions was investigated by using their biosynthetic inhibitors, norflurazon (NF) and oxyfluorfen (OF). High levels of protoporphyrin IX (Proto IX) accumulated in rice plants treated with OF, whereas Proto IX decreased in plants treated with NF. Both NF and OF treatments resulted in greater decreases in MgProto IX, MgProto IX methyl ester, and protochlorophyllide. Activities and transcript levels of most porphyrin biosynthetic enzymes, particularly in the Mg-porphyrin branch, were greatly down-regulated in NF and OF plants. In contrast, the transcript levels of GSA, PPO1 , and CHLD as well as FC2 and HO2 were up-regulated in NF-treated plants, while only moderate increases in FC2 and HO2 were observed in the early stage of OF treatment. Phytoene, antheraxanthin, and zeaxanthin showed high accumulation in NF-treated plants, whereas other carotenoid intermediates greatly decreased. Transcript levels of carotenoid biosynthetic genes, PSY1 and PDS , decreased in response to NF and OF, whereas plants in the later stage of NF treatment exhibited up-regulation of BCH and VDE as well as recovery of PDS . However, perturbed porphyrin biosynthesis by OF did not noticeably influence levels of carotenoid metabolites, regardless of the strong down-regulation of carotenoid biosynthetic genes. Both NF and OF plants appeared to provide enhanced protection against photooxidative damage, not only by scavenging of Mg - porphyrins, but also by up-regulating FC2, HO2 , and Fe-chelatase, particularly with increased levels of zeaxanthin via up-regulation of BCH and VDE in NF plants. On the other hand, the up-regulation of GSA, PPO1 , and CHLD under inhibition of carotenogenic flux may be derived from the necessity to recover impaired chloroplast biogenesis during photooxidative stress. Our study demonstrates that perturbations in carotenoid and porphyrin biosynthesis coordinate the

  10. Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile-butadiene-styrene model samples and historical objects.

    Science.gov (United States)

    Saviello, Daniela; Pouyet, Emeline; Toniolo, Lucia; Cotte, Marine; Nevin, Austin

    2014-09-16

    Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Gas phase precursors to anthropogenic secondary organic aerosol: detailed observations of 1,3,5-trimethylbenzene photooxidation

    Directory of Open Access Journals (Sweden)

    K. P. Wyche

    2009-01-01

    Full Text Available A series of photooxidation experiments were conducted in an atmospheric simulation chamber in order to investigate the oxidation mechanism and secondary organic aerosol (SOA formation potential of the model anthropogenic gas phase precursor, 1,3,5-trimethylbenzene. Alongside specific aerosol measurements, comprehensive gas phase measurements, primarily by Chemical Ionisation Reaction Time-of-Flight Mass Spectrometry (CIR-TOF-MS, were carried out to provide detailed insight into the composition and behaviour of the organic components of the gas phase matrix during SOA formation. An array of gas phase organic compounds was measured during the oxidation process, including several previously unmeasured primary bicyclic compounds possessing various functional groups. Analysis of results obtained during this study implies that these peroxide bicyclic species along with a series of ring opening products and organic acids contribute to SOA growth. The effect of varying the VOC/NOx ratio on SOA formation was explored, as was the effect of acid seeding. It was found that low NOx conditions favour more rapid aerosol formation and a higher aerosol yield, a result that implies a role for organic peroxides in the nucleation process and SOA growth.

  12. Psoralen plus ultraviolet A (PUVA soaks and UVB TL01 treatment for chronic hand dermatoses

    Directory of Open Access Journals (Sweden)

    Lisbeth Jensen

    2012-02-01

    Full Text Available Chronic eczematous hand dermatoses with and without contact allergies are complex diseases, which makes it a challenge to select the best treatment and obtain an optimal patient experience and a satisfactory treatment result. The aim of this study was to evaluate retrospectively the clinical effect and patient experience of local treatment with psoralen plus ultraviolet A (PUVA soaks and TL01 phototherapy for severe chronic hand dermatoses, and also to evaluate the quality of life for the subgroup of patients with allergic contact dermatitis including Compositae allergy. A retrospective evaluation of results for 94 consecutive patients having received a total of 121 treatment courses with local PUVA soaks or TL01 phototherapy for one of the following diagnoses (n=number of treatment courses: psoriasis (n=19, hyperkeratotic hand eczema (n=27, Pustulosis Palmoplantaris (PPP (n=22, vesicular eczema (n=16, Compositae dermatitis (n=24, and allergic contact dermatitis (n=13. Moreover, semi-structured interviews with 6 selected patients having multiple contact allergies including Compositae allergy were used to evaluate quality of life. As a result, we found that PUVA soaks has good effect in patients with psoriasis and hyperkeratotic hand eczema and local phototherapy for chronic hand dermatoses is a useful treatment option in selected cases.

  13. Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

    Science.gov (United States)

    C. J. Hennigan; M. A. Miracolo; G. J. Engelhart; A. A. May; A. A. Presto; T. Lee; A. P. Sullivan; G. R. McMeeking; H. Coe; C. E. Wold; W.-M. Hao; J. B. Gilman; W. C. Kuster; J. de Gouw; B. A. Schichtel; J. L. Collett; S. M. Kreidenweis; A. L. Robinson

    2011-01-01

    Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA) during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III). We investigated emissions from 12 different...

  14. VUV photoionization aerosol mass spectrometric study on the iodine oxide particles formed from O3-initiated photooxidation of diiodomethane (CH2I2)

    Czech Academy of Sciences Publication Activity Database

    Wei, N.; Hu, Ch.; Zhou, S.; Ma, Q.; Mikuška, Pavel; Večeřa, Zbyněk; Gai, Y.; Lin, X.; Gu, X.; Zhao, W.; Fang, B.; Zhang, W.; Chen, J.; Liu, F.; Shan, X.; Sheng, L.

    2017-01-01

    Roč. 7, č. 89 (2017), s. 56779-56787 ISSN 2046-2069 Institutional support: RVO:68081715 Keywords : iodine oxide particles * photooxidation * aerosol mass spectrometer Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.108, year: 2016

  15. Physiological and biochemical studies on the yellowing of spruce trees in higher altitudes. Pt. 1. Protection of pigments in the light-harvesting Chl-a/b-protein against photooxidation - the role of apoprotein and pigment organisation

    Energy Technology Data Exchange (ETDEWEB)

    Siefermanns-Harms, D.; Horsch, F.; Filby, W.G.; Fund, N.; Gross, S.; Hanisch, B.; Kilz, E.; Seidel, A.

    1988-04-01

    The light-harvesting Chl-a/b-protein complex (LHC) from Spinacea oleracia, Lactuca sativa and Picea abies is stable under strong white light (> 350 nm, 1000 w/m/sub 2/). Therefore, LHC preparations were used to examine requirements for the protection of LHC-bound pigments from photooxidation. - The presence of carotenoids in the LHC and their arrangement in close proximity with the chlorophylls are not sufficient for pigment protection under light. - An intact LHC apoprotein is required to protect the pigments from photooxidation. Evidently, the intact LHC apoprotein represents a barrier for O/sub 2/ limiting O/sub 2/ access to the microenvironment of the pigments. - The composition of the pigment fraction destroyed under light depends on the state of the LHC. If only the integrity of the apoprotein is impaired, both, chlorophylls and carotenoids are subjected to photooxidation.

  16. [Nature of the electron excited state in pigment redox reactions. II. Analysis of the scheme of primary processes in the photooxidation reaction of chlorophylls a and b and pheophytin a ].

    Science.gov (United States)

    Andreeva, N E; Barashkov, B I; Zakharova, G V; Shubin, V V; Chibisov, A K

    1978-01-01

    A scheme of primary reactions in photooxidation of pigments was considered assuming that electron transfer processes can occur via singlet excited as well as triplet states. The results of analysis are compared with the experimental data on relative yield values of chlorophylls a, b, and pheophytin a cation-radicals, as well as with the data on fluorescence quenching. A conclusion has been drawn that photooxidation of pigments proceeds exclusively via the triplet state. The dependence of rate constant quenching values of chlorophyll a triplet state by certain electron acceptors on values of half cell potentials was given.

  17. Monitoring of TiO2-catalytic UV-LED photo-oxidation of cyanide contained in mine wastewater and leachate.

    Science.gov (United States)

    Kim, Seong Hee; Lee, Sang Woo; Lee, Gye Min; Lee, Byung-Tae; Yun, Seong-Taek; Kim, Soon-Oh

    2016-01-01

    A photo-oxidation process using UV-LEDs and TiO2 was studied for removal of cyanide contained in mine wastewater and leachates. This study focused on monitoring of a TiO2-catalyzed LED photo-oxidation process, particularly emphasizing the effects of TiO2 form and light source on the efficiency of cyanide removal. The generation of hydroxyl radicals was also examined during the process to evaluate the mechanism of the photo-catalytic process. The apparent removal efficiency of UV-LEDs was lower than that achieved using a UV-lamp, but cyanide removal in response to irradiation as well as consumption of electrical energy was observed to be higher for UV-LEDs than for UV-lamps. The Degussa P25 TiO2 showed the highest performance of the TiO2 photo-catalysts tested. The experimental results indicate that hydroxyl radicals oxidize cyanide to OCN(-), NO2(-), NO3(-), HCO3(-), and CO3(2-), which have lower toxicity than cyanide. In addition, the overall efficacy of the process appeared to be significantly affected by diverse operational parameters, such as the mixing ratio of anatase and rutile, the type of gas injected, and the number of UV-LEDs used. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. VUV photo-oxidation of gaseous benzene combined with ozone-assisted catalytic oxidation: Effect on transition metal catalyst

    International Nuclear Information System (INIS)

    Huang, Haibao; Lu, Haoxian; Zhan, Yujie; Liu, Gaoyuan; Feng, Qiuyu; Huang, Huiling; Wu, Muyan; Ye, Xinguo

    2017-01-01

    Graphical abstract: Mn nanoparticles are highly dispersed on ZSM-5 and most efficient in benzene degradation in the VUV-OZCO process. - Highlights: • Vacuum UV irradiation is well combined with O_3 catalytic oxidation. • O_3 byproducts was used to enhance catalytic oxidation of VOCs. • Mn/ZSM-5 achieved the best catalytic activity for benzene degradation. - Abstract: Volatile organic compounds (VOCs) cause the major air pollution concern. In this study, a series of ZSM-5 supported transition metals were prepared by impregnation method. They were combined with vacuum UV (VUV) photo-oxidation in a continuous-flow packed-bed reactor and used for the degradation of benzene, a typical toxic VOCs. Compared with VUV photo-oxidation alone, the introduction of catalysts can greatly enhance benzene oxidation under the help of O_3, the by-products from VUV irradiation, via ozone-assisted catalytic oxidation (OZCO). The catalytic activity of transition metals towards benzene oxidation followed the order: Mn > Co > Cu > Ni > Fe. Mn achieved the best catalytic activity due to the strongest capability for O_3 catalytic decomposition and utilization. Benzene and O_3 removal efficiency reached as high as 97% and 100% after 360 min, respectively. O_3 was catalytically decomposed, generating highly reactive oxidants such as ·OH and ·O for benzene oxidation.

  19. VUV photo-oxidation of gaseous benzene combined with ozone-assisted catalytic oxidation: Effect on transition metal catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haibao, E-mail: seabao8@gmail.com [School of Environmental Science and Engineering, Sun Yat-Sen University (China); Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University) (China); Lu, Haoxian; Zhan, Yujie; Liu, Gaoyuan; Feng, Qiuyu; Huang, Huiling; Wu, Muyan; Ye, Xinguo [School of Environmental Science and Engineering, Sun Yat-Sen University (China)

    2017-01-01

    Graphical abstract: Mn nanoparticles are highly dispersed on ZSM-5 and most efficient in benzene degradation in the VUV-OZCO process. - Highlights: • Vacuum UV irradiation is well combined with O{sub 3} catalytic oxidation. • O{sub 3} byproducts was used to enhance catalytic oxidation of VOCs. • Mn/ZSM-5 achieved the best catalytic activity for benzene degradation. - Abstract: Volatile organic compounds (VOCs) cause the major air pollution concern. In this study, a series of ZSM-5 supported transition metals were prepared by impregnation method. They were combined with vacuum UV (VUV) photo-oxidation in a continuous-flow packed-bed reactor and used for the degradation of benzene, a typical toxic VOCs. Compared with VUV photo-oxidation alone, the introduction of catalysts can greatly enhance benzene oxidation under the help of O{sub 3}, the by-products from VUV irradiation, via ozone-assisted catalytic oxidation (OZCO). The catalytic activity of transition metals towards benzene oxidation followed the order: Mn > Co > Cu > Ni > Fe. Mn achieved the best catalytic activity due to the strongest capability for O{sub 3} catalytic decomposition and utilization. Benzene and O{sub 3} removal efficiency reached as high as 97% and 100% after 360 min, respectively. O{sub 3} was catalytically decomposed, generating highly reactive oxidants such as ·OH and ·O for benzene oxidation.

  20. Superhydrophobic Polyimide via Ultraviolet Photooxidation: The Evolution of Surface Morphology and Hydrophobicity under Different Ultraviolet Intensities

    Directory of Open Access Journals (Sweden)

    Hongyu Gu

    2015-01-01

    Full Text Available Ultraviolet (UV photooxidation has recently been developed to fabricate superhydrophobic polyimide (PI films in combination with fluoroalkylsilane modification. However, it remains unclear whether the surface morphology and hydrophobicity are sensitive to technical parameters such as UV intensity and radiation environment. Herein, we focus on the effects of UV intensity on PI surface structure and wettability to gain comprehensive understanding and more effective control of this technology. Scanning electron microscopy (SEM and atomic force microscopy (AFM results showed that UV intensity governed the evolutionary pattern of surface morphology: lower UV intensity (5 mW/cm2 facilitated in-plane expansion of dendritic protrusions while stronger UV (10 and 15 mW/cm2 encouraged localized growth of protrusions in a piling-up manner. Surface roughness and hydrophobicity maximized at the intensity of 10 mW/cm2, as a consequence of the slowed horizontal expansion and preferred vertical growth of the protrusions when UV intensity increased. Based on these results, the mechanism that surface micro/nanostructures developed in distinct ways when exposed to different UV intensities was proposed. Though superhydrophobicity (water contact angle larger than 150° can be achieved at UV intensity not less than 10 mW/cm2, higher intensity decreased the effectiveness. Therefore, the UV photooxidation under 10 mW/cm2 for 72 h is recommended to fabricate superhydrophobic PI films.

  1. Riboflavin enhances photo-oxidation of amino acids under simulated clinical conditions

    International Nuclear Information System (INIS)

    Bhatia, J.; Stegink, L.D.; Ziegler, E.E.

    1983-01-01

    In neonatal nurseries, solutions of amino acids with added vitamins may be exposed to relatively intense light from phototherapy units. Light, especially in the presence of photosensitizers such as certain vitamins, is capable of destroying amino acids. In the present study, the effect of riboflavin on amino acid concentrations in solutions exposed to light was studied. Solutions of crystalline amino acids with and without added riboflavin were infused into shielded collecting vessels for 24 hr under conditions simulating those occurring during phototherapy. Decreases in concentrations of some amino acids were observed with light exposure alone. Decreases in concentrations of methionine, proline, tryptophan, and tyrosine were significantly greater in the presence of riboflavin that in its absence. Riboflavin concentrations were also significantly reduced after light exposure. Although the losses of amino acids are probably not nutritionally significant, the photo-oxidation products are largely unknown and may be toxic

  2. Photooxidative desulfurization for diesel using Fe / N - TiO2 photocatalyst

    Science.gov (United States)

    Khan, Muhammad Saqib; Kait, Chong Fai; Mutalib, Mohd Ibrahim Abdul

    2014-10-01

    A series of N - TiO2 with different mol% N was synthesized via sol-gel method and characterized using thermal gravimetric analyzer and raman spectroscopy. 0.2 wt% Fe was incorporated onto the calcined (200°C) N - TiO2 followed by calcination at 200°C, 250°C and 300°C. Photooxidative desulfurization was conducted in the presence of 0.2wt% Fe / N - TiO2 with different mol% N with and without oxidant (H2O2). Oxidative desulfurization was only achieved when H2O2 was used while without H2O2 no major effect on the sulfur removal. 0.2Fe -30N - H2O2 photocatalysts showed best performance at all calcination temperatures as compared to other mol% N - H2O2 photocatalysts. 16.45% sulfur removal was achieved using photocatalysts calcined at 300 °C.

  3. Photooxidative removal of the herbicide Acid Blue 9 in the presence of hydrogen peroxide: modeling of the reaction for evaluation of electrical energy per order (E EO).

    Science.gov (United States)

    Khataee, Ali R; Khataee, Hamid R

    2008-09-01

    The present work deals with photooxidative removal of the herbicide, Acid Blue 9 (AB9), in water in the presence of hydrogen peroxide (H2O2) under UV light illumination (30 W). The influence of the basic operational parameters such as amount of H2O2, irradiation time and initial concentration of AB9 on the photodegradation efficiency of the herbicide was investigated. The degradation rate of AB9 was not appreciably high when the photolysis was carried out in the absence of H2O2 and it was negligible in the absence of UV light. The photooxidative removal of the herbicide was found to follow pseudo-first-order kinetic, and hence the figure-of-merit electrical energy per order (E Eo) was considered appropriate for estimating the electrical energy efficiency. A mathematical relation between the apparent reaction rate constant and H2O2 used was applied for prediction of the electricity consumption in the photooxidative removal of AB9. The results indicated that this kinetic model, based on the initial rates of degradation, provided good prediction of the E Eo values for a variety of conditions. The results also indicated that the UV/H2O2 process was appropriate as the effective treatment method for removal of AB9 from the contaminated wastewater.

  4. ANALYSIS OF SECONDARY ORGANIC AEROSOL COMPOUNDS FROM THE PHOTOOXIDATION OF D-LIMONENE IN THE PRESENCE OF NO X AND THEIR DETECTION IN AMBIENT PM 2.5

    Science.gov (United States)

    Chemical analysis of secondary organic aerosol (SOA) from the photooxidation of a d-limonene/NOx/air mixture was carried out. SOA, generated in a smog chamber, was collected on Zefluor filters. To determine the structural characteristics of the compounds, the filter sample...

  5. Sensitized photo-oxidation of thymidine by 2-methyl-1, 4-naphthoquinone. Characterization of the stable photoproducts

    International Nuclear Information System (INIS)

    Decarroz, C.; Cadet, J.; Murali Krishna, C.; Riesz, P.

    1986-01-01

    The near ultraviolet photolysis of an aerated aqueous solution of thymidine containing 2-methyl-1,4-naphthoquinone gives rise to two main classes of photoproducts as a result of the initial formation of a pyrimidine radical cation. These photo-oxidation products have been separated by high-performance liquid chromatography and further characterized by various spectroscopic techniques including fast atom bombardment mass spectrometry and high field 1 H and 13 C nuclear magnetic resonance analysis. This photoreaction constitutes an excellent model to study the chemical properties of the thymidine radical cation which is expected to be one of the primary consequences of the direct effects of ionizing radiation. (author)

  6. Oxygen optical gas sensing by reversible fluorescence quenching in photo-oxidized poly(9,9-dioctylfluorene) thin films.

    Science.gov (United States)

    Anni, M; Rella, R

    2010-02-04

    We investigated the fluorescence (FL) dependence on the environment oxygen content of poly(9,9-dioctylfluorene) (PF8) thin films. We show that the PF8 interactions with oxygen are not limited to the known irreversible photo-oxidation, resulting in the formation of Keto defects, but also reversible FL quenching is observed. This effect, which is stronger for the Keto defects than for the PF8, has been exploited for the realization of a prototype oxygen sensor based on FL quenching. The sensing sensitivity of Keto defects is comparable with the state of the art organic oxygen sensors based on phosphorescence quenching.

  7. A chromatographic method to analyze products from photo-oxidation of anthropogenic and biogenic mixtures of volatile organic compounds in smog chambers.

    Science.gov (United States)

    Pindado Jiménez, Oscar; Pérez Pastor, Rosa M; Vivanco, Marta G; Santiago Aladro, Manuel

    2013-03-15

    A method for quantifying secondary organic aerosol compounds (SOA) and water soluble secondary organic aerosol compounds (WSOA) produced from photo-oxidation of complex mixtures of volatile organic compounds (VOCs) in smog chambers by gas chromatography/mass spectrometry (GC/MS) has been developed. This method employs a double extraction with water and methanol jointly to a double derivatization with N,O-bis (trimethylsilil) trifluoroacetamide (BSTFA) and O-(2,3,4,5,6)-pentafluorobenzyl-hydroxylamine hydrochloride (PFBHA) followed by an analysis performed by GC/MS. The analytical procedure complements other methodologies because it can analyze SOA and WSOA compounds simultaneously at trace levels. As application, the methodology was employed to quantify the organic composition of aerosols formed in a smog chamber as a result of photo-oxidation of two different mixtures of volatile organic compounds: an anthropogenic mixture and a biogenic mixture. The analytical method allowed us to quantify up to 17 SOA compounds at levels higher than 20 ng m(-3) with reasonable recovery and a precision below 11%. Values found for applicability, selectivity, linearity, precision, recovery, detection limit, quantification limit and sensitivity demonstrated that the methodology can be satisfactorily applied to quantify SOA and WSOA. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. DETAILED ANALYSIS OF SOA ORIGINATING FROM THE PHOTOOXIDATION OF D-LIMONENE IN THE PRESENCE OF NO X AND UV LIGHT AND ITS IMPLICATION TO AMBIENT PM 2.5

    Science.gov (United States)

    A detailed analysis was carried out of the aerosol phase originated from the photooxidation of d-limonene in the presence of NOx and artificial light with the analytical emphasis on the identification of oxygenated organic compounds. The major components included six ...

  9. Psoriasis, Psoralen and Sunlight

    Directory of Open Access Journals (Sweden)

    R.P.C Naik

    1979-01-01

    Full Text Available Topical or oral administration of photoactive furocumarins followed by exposure to ultra violet light from artificial sources has been shown previously to clear psoriatic lesions. Sunlight has been chosen as the source of UVL m two separate paired comparison studies using topical and, oral 4,5, 8 trimethylpsoralen. Two out of 21 on topical therapy and none out of 6 patients on oral paired-comparison study showed faster clearance of the drug treated lesions compared to control sites.

  10. Molecular analysis by electron microscopy of the removal of psoralen-photoinduced DNA cross-links in normal and Fanconi's anemia fibroblasts

    International Nuclear Information System (INIS)

    Rousset, S.; Nocentini, S.; Revet, B.; Moustacchi, E.

    1990-01-01

    The induction and fate of psoralen-photoinduced DNA interstrand cross-links in the genome of Fanconi's anemia (FA) fibroblasts of complementation groups A and B, and of normal human fibroblasts, were investigated by quantitative analysis of totally denatured DNA fragments visualized by electron microscopy. 8-Methoxypsoralen (5 x 10(-5) M) interstrand cross-links were induced as a function of the near ultraviolet light dose. With time of postexposure incubation, a fraction of interstrand cross-links disappeared in all cell lines. However, 24 h after treatment, this removal was significantly lower in the two FA group A cell lines examined (34-39%) than in the FA group B and normal cell lines (43-53 and 47-57%, respectively). These data indicate that FA cells are at least able to recognize and incise interstrand cross-links, as normal cells do, although group A cells seem somewhat hampered in this process. This is in accord with data obtained on the same cell lines using another biochemical assay. Since the fate of cross-links in FA constituted a controversial matter, it is important to stress that two different methodologies applied to genetically well defined cell lines led to the same conclusions

  11. Characterization of secondary organic aerosol from photo-oxidation of gasoline exhaust and specific sources of major components.

    Science.gov (United States)

    Ma, Pengkun; Zhang, Peng; Shu, Jinian; Yang, Bo; Zhang, Haixu

    2018-01-01

    To further explore the composition and distribution of secondary organic aerosol (SOA) components from the photo-oxidation of light aromatic precursors (toluene, m-xylene, and 1,3,5-trimethylbenzene (1,3,5-TMB)) and idling gasoline exhaust, a vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) was employed. Peaks of the molecular ions of the SOA components with minimum molecular fragmentation were clearly observed from the mass spectra of SOA, through the application of soft ionization methods in VUV-PIMS. The experiments comparing the exhaust-SOA and light aromatic mixture-SOA showed that the observed distributions of almost all the predominant cluster ions in the exhaust-SOA were similar to that of the mixture-SOA. Based on the characterization experiments of SOA formed from individual light aromatic precursors, the SOA components with molecular weights of 98 and 110 amu observed in the exhaust-SOA resulted from the photo-oxidation of toluene and m-xylene; the components with a molecular weight of 124 amu were derived mainly from m-xylene; and the components with molecular weights of 100, 112, 128, 138, and 156 amu were mainly derived from 1,3,5-TMB. These results suggest that C 7 -C 9 light aromatic hydrocarbons are significant SOA precursors and that major SOA components originate from gasoline exhaust. Additionally, some new light aromatic hydrocarbon-SOA components were observed for the first time using VUV-PIMS. The corresponding reaction mechanisms were also proposed in this study to enrich the knowledge base of the formation mechanisms of light aromatic hydrocarbon-SOA compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. [Nature of the electron-excited state in redox reactions of pigments. I. Photooxidation of chlorophyll a by n-benzoquine].

    Science.gov (United States)

    Andreeva, N E; Barashkov, B I; Zakharova, G V; Shubin, V V; Chibisov, A K

    1977-01-01

    A method for studying the nature of electronic excited state under photooxidation is proposed. It is shown by an example of the oxidation of chlorophyll a with p-benzoquinone that the formation of cation-radicals of pigments proceeds only through the triplet state. On the basis of experimental data the values of the rate constants of formation of chlorophyll cation-radicals through the singlet-excited state (K2(1)--10(7) M-1 s-1) and triplet state (Kr=10(9) M-1 s-1) of the pigment are evaluated.

  13. Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-induced phototoxic reactions as well as depletion of Langerhans cells in human skin

    International Nuclear Information System (INIS)

    Gonzalez, S.; Pathak, M.A.; Fitzpatrick, T.B.; Cuevas, J.; Villarrubia, V.G.

    1997-01-01

    Sunburn, immune suppression, photo-aging, and skin cancers result from uncontrolled overexposure of human skin to solar ultraviolet radiation (UVR). Preventive measures, including photo-protection, are helpful and can be achieved by topical sun-screening agents. Polypodium leucotomos (PL) has been used for the treatment of inflammatory diseases and has shown some in vitro and in vivo immunomodulating properties. Its beneficial photo-protective effects in the treatment of vitiligo and its antioxidant properties encouraged us to evaluate in vivo the potentially useful photo-protective property of natural extract of PL after topical application or oral ingestion. Twenty-one healthy volunteers [either untreated or treated with oral psoralens (8-MOP or 5-MOP)] were enrolled in this study and exposed to solar radiation for evaluation of the following clinical parameters: immediate pigment darkening (IPD), minimal erythema dose (MED), minimal melanogenic dose (MMD), and minimal phototoxic dose (MPD) before and after topical or oral administration of PL. Immunohistochemical assessment of CD1a-expressing epidermal cells were also performed. PL was found to be photo-protective after topical application as well as oral administration. PL increased UV dose required for IPD (P<0.01), MED (P<0.001) and MPD (P<0.001). After oral administration of PL, MED increased 2.,8±0.59 times and MPD increased 2.75±0.5 and 6.8±1.3 times depending upon the type of psoralen used. Immunohistochemical study revealed photo-protection of Langherhans cells by oral as well as topical PL. The observed photo-protective activities of oral or topical PL reveal a new avenue in examining the potentially useful field of systemic photo-protection and suggests that PL can be used as adjunct treatment and can make photochemotherapy and phototherapy possibly safe and effective when the control of cutaneous phototoxicity to PUVA or UVB is a limiting factor in such photo-therapies. (au)

  14. Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-induced phototoxic reactions as well as depletion of Langerhans cells in human skin

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, S.; Pathak, M.A.; Fitzpatrick, T.B. [Massachusetts General Hospital, Harvard Medical School, Dept. of Dermatology, Boston, MA (United States); Cuevas, J. [Hospital Universitario de Guadalajara, Dept. of Pathology, Guadalajara (Spain); Villarrubia, V.G. [I.F. Cantabria SA, Medical Dept., Immunology Sect., Madrid (Spain)

    1997-12-31

    Sunburn, immune suppression, photo-aging, and skin cancers result from uncontrolled overexposure of human skin to solar ultraviolet radiation (UVR). Preventive measures, including photo-protection, are helpful and can be achieved by topical sun-screening agents. Polypodium leucotomos (PL) has been used for the treatment of inflammatory diseases and has shown some in vitro and in vivo immunomodulating properties. Its beneficial photo-protective effects in the treatment of vitiligo and its antioxidant properties encouraged us to evaluate in vivo the potentially useful photo-protective property of natural extract of PL after topical application or oral ingestion. Twenty-one healthy volunteers [either untreated or treated with oral psoralens (8-MOP or 5-MOP)] were enrolled in this study and exposed to solar radiation for evaluation of the following clinical parameters: immediate pigment darkening (IPD), minimal erythema dose (MED), minimal melanogenic dose (MMD), and minimal phototoxic dose (MPD) before and after topical or oral administration of PL. Immunohistochemical assessment of CD1a-expressing epidermal cells were also performed. PL was found to be photo-protective after topical application as well as oral administration. PL increased UV dose required for IPD (P<0.01), MED (P<0.001) and MPD (P<0.001). After oral administration of PL, MED increased 2.,8{+-}0.59 times and MPD increased 2.75{+-}0.5 and 6.8{+-}1.3 times depending upon the type of psoralen used. Immunohistochemical study revealed photo-protection of Langherhans cells by oral as well as topical PL. The observed photo-protective activities of oral or topical PL reveal a new avenue in examining the potentially useful field of systemic photo-protection and suggests that PL can be used as adjunct treatment and can make photochemotherapy and phototherapy possibly safe and effective when the control of cutaneous phototoxicity to PUVA or UVB is a limiting factor in such photo-therapies. (au). 50 refs.

  15. Photo-oxidation of PAHs with calcium peroxide as a source of the hydroxyl radicals

    Directory of Open Access Journals (Sweden)

    Kozak Jolanta

    2018-01-01

    Full Text Available The efficiency of the removal of selected PAHs from the pretreated coking wastewater with usage of CaO2, Fenton reagent (FeSO4 and UV rays are presented in this article. The investigations were carried out using coking wastewater originating from biological, industrial wastewater treatment plant. At the beginning of the experiment, the calcium peroxide (CaO2 powder as a source of hydroxyl radicals (OH• and Fenton reagent were added to the samples of wastewater. Then, the samples were exposed to UV rays for 360 s. The process was carried out at pH 3.5-3.8. After photo-oxidation process a decrease in the PAHs concentration was observed. The removal efficiency of selected hydrocarbons was in the ranged of 89-98%. The effectiveness of PAHs degradation was directly proportional to the calcium peroxide dose.

  16. Controlling photo-oxidation processes of a polyfluorene derivative: The effect of additives and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, G.R. [Laboratory of Polymers and Electronic Properties of Materials – UFOP, Ouro Preto, MG (Brazil); Nowacki, B. [Paulo Scarpa Polymer Laboratory – UFPR, Curitiba, PR (Brazil); Magalhães, A. [Instituto de Química, Universidade Estadual de Campinas – UNICAMP, Campinas, SP (Brazil); Azevedo, E.R. de [Instituto de Física de São Carlos, Universidade de São Paulo – USP, São Carlos, SP (Brazil); Sá, E.L. de [Chemistry Department, Federal University of Parana, Curitiba, PR (Brazil); Akcelrud, L.C. [Paulo Scarpa Polymer Laboratory – UFPR, Curitiba, PR (Brazil); Bianchi, R.F., E-mail: bianchi@iceb.ufop.br [Laboratory of Polymers and Electronic Properties of Materials – UFOP, Ouro Preto, MG (Brazil)

    2014-08-01

    The control of the photo degradation of a fluorene–vinylene–phenylene based-polymer, poly(9,9-di-hexylfluorenediylvinylene-alt-1,4-phenylenevinylene) (LaPPS16) was achieved by addition of a radical scavenger (RS) (enhancing photo resistance) or a radical initiator (RI) (reducing photo resistance). Photoluminescence, UV–Vis absorption, {sup 1}H NMR spectroscopies and gel permeation chromatography (GPC) revealed that the incorporating small amounts of RS or RI is an efficient way to control the rates of the photo-oxidation reactions, and thus to obtain the conjugated polymer with foreseeable degradation rates for applications in blue-light sensitive detectors for neonatal phototherapy. - Highlights: • Photo degradation control of a fluorene–vinylene–phenylene based polymer was achieved. • A radical scavenger enhanced photo resistance and radical initiator decreased it. • Color change rate with irradiation dose provided a basis for dosimeter construction.

  17. Local suppression of contact hypersensitivity in mice by a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen, and UVA radiation.

    Science.gov (United States)

    Aubin, F; Dall'Acqua, F; Kripke, M L

    1991-07-01

    Although psoralens plus UVA radiation (320-400 nm) have been widely used for the treatment of dermatologic diseases, the toxic effects of these agents have led investigators to develop new photochemotherapeutic compounds. One such compound is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional molecule. The purpose of this study was to examine the immunologic side effects of repeated treatment of C3H mice with TMAP plus UVA radiation. During this treatment, the number of ATPase+, la+, and Thy-1+ dendritic epidermal cells greatly decreased in the treated site, despite the lack of phototoxicity. The reduction in the number of detectable cutaneous immune cells was accompanied by a decrease in the induction of contact hypersensitivity to dinitrofluorobenzene applied to the treated skin, an impairment in the antigen-presenting activity of draining lymph node cells, and the presence of suppressor lymphoid cells in the spleen of unresponsive mice. Treatment with UVA radiation alone also reduced the number of ATPase+, Ia+, and Thy-1+ cells in the skin, but did not cause any detectable alterations in immune function. This implies that morphologic alterations in these cells do not necessarily indicate loss of function. Thus, although TMAP in combination with UVA radiation is not overtly phototoxic, it is highly immunosuppressive in mice.

  18. Phytohormone Interaction Modulating Fruit Responses to Photooxidative and Heat Stress on Apple (Malus domestica Borkh.

    Directory of Open Access Journals (Sweden)

    Carolina A. Torres

    2017-12-01

    Full Text Available Sun-related physiological disorders such as sun damage on apples (Malus domestica Borkh are caused by cumulative photooxidative and heat stress during their growing season triggering morphological, physiological, and biochemical changes in fruit tissues not only while it is on the tree but also after it has been harvested. The objective of the work was to establish the interaction of auxin (indole-3-acetic acid; IAA, abscisic acid (ABA, jasmonic acid (JA, salicylic acid (SA, and ethylene (ET and its precursor ACC (free and conjugated, MACC during development of sun-injury-related disorders pre- and post-harvest on apples. Peel tissue was extracted from fruit growing under different sun exposures (Non-exposed, NE; Exposed, EX and with sun injury symptoms (Moderate, Mod. Sampling was carried out every 15 days from 75 days after full bloom (DAFB until 120 days post-harvest in cold storage (1°C, > 90%RH. Concentrations of IAA, ABA, JA, SA, were determined using UHPLC mass spectrometry, and ET and ACC (free and conjugated MACC using gas chromatography. IAA was found not to be related directly to sun injury development, but it decreased 60% in sun exposed tissue, and during fruit development. ABA, JA, SA, and ethylene concentrations were significantly higher (P ≤ 0.05 in Mod tissue, but their concentration, except for ethylene, were not affected by sun exposure. ACC and MACC concentrations increased until 105 DAFB in all sun exposure categories. During post-harvest, ethylene climacteric peak was delayed on EX compared to Mod. ABA and SA concentrations remained stable throughout storage in both tissue. JA dramatically increased post-harvest in both EX and Mod tissue, and orchards, confirming its role in low temperature tolerance. The results suggest that ABA, JA, and SA together with ethylene are modulating some of the abiotic stress defense responses on sun-exposed fruit during photooxidative and heat stress on the tree.

  19. TiO2 assisted photo-oxidative pretreatment of wheat straw for biogas production

    DEFF Research Database (Denmark)

    Awais, Muhammad; Alvarado-Morales, Merlin; Tsapekos, Panagiotis

    Photo-catalytic oxidation is an advanced oxidation process in which a catalyst is used to absorb light energy and oxidize the target substrates such as organic polymers. A number of metal oxides and metal ions can efficiently increase substrate’s depolymerisation during the process of photo...... to be markedly higher in the pretreated samples that were exposed for 180min with 1.5 wt% and 2 wt% of TiO2 compared to the untreated wheat straw. Moreover, it was concluded that the products of lignin oxidation and also, the presence of TiO2 did not inhibit the AD process. Finally, UV treatment or TiO2 alone......-catalytic oxidation. Titanium oxide (TiO2) is a photo-catalyst that in its rutile and anatase forms presents the property to enhance the photo-oxidation of lignin-containing substrates. Due to lignin is one of the major obstacles in methane production from lignocellulosic biomass, its destruction is a necessary step...

  20. Effects of NOx and SO2 on the secondary organic aerosol formation from photooxidation of α-pinene and limonene

    Science.gov (United States)

    Zhao, Defeng; Schmitt, Sebastian H.; Wang, Mingjin; Acir, Ismail-Hakki; Tillmann, Ralf; Tan, Zhaofeng; Novelli, Anna; Fuchs, Hendrik; Pullinen, Iida; Wegener, Robert; Rohrer, Franz; Wildt, Jürgen; Kiendler-Scharr, Astrid; Wahner, Andreas; Mentel, Thomas F.

    2018-02-01

    Anthropogenic emissions such as NOx and SO2 influence the biogenic secondary organic aerosol (SOA) formation, but detailed mechanisms and effects are still elusive. We studied the effects of NOx and SO2 on the SOA formation from the photooxidation of α-pinene and limonene at ambient relevant NOx and SO2 concentrations (NOx: leading to a lack of particle surface for the organics to condense on and thus a significant influence of vapor wall loss on SOA mass yield. By compensating for the suppressing effect on nucleation of NOx, SO2 also compensated for the suppressing effect on SOA yield. Aerosol mass spectrometer data show that increasing NOx enhanced nitrate formation. The majority of the nitrate was organic nitrate (57-77 %), even in low-NOx conditions (nitrate contributed 7-26 % of total organics assuming a molecular weight of 200 g mol-1. SOA from α-pinene photooxidation at high NOx had a generally lower hydrogen to carbon ratio (H / C), compared to low NOx. The NOx dependence of the chemical composition can be attributed to the NOx dependence of the branching ratio of the RO2 loss reactions, leading to a lower fraction of organic hydroperoxides and higher fractions of organic nitrates at high NOx. While NOx suppressed new particle formation and SOA mass formation, SO2 can compensate for such effects, and the combining effect of SO2 and NOx may have an important influence on SOA formation affected by interactions of biogenic volatile organic compounds (VOCs) with anthropogenic emissions.

  1. The effects of a solar eclipse on photo-oxidants in different areas of China

    Directory of Open Access Journals (Sweden)

    J.-B. Wu

    2011-08-01

    Full Text Available This study investigates the effects of the total solar eclipse of 22 July 2009 on surface ozone and other photo-oxidants over China. A box model was used to study the sensitivity of ozone to the limb darkening effect during an eclipse event, and to show that the impact on ozone is small (less than 0.5 %. In addition, the regional model WRF-Chem was applied to study the effects of the eclipse on meteorological and chemical parameters, focusing on different regions in China. Chemical and meteorological observations were used to validate the model and to show that it can capture the effects of the total solar eclipse well. Model calculations show distinct differences in the spatial distributions of meteorological and chemical parameters with and without the eclipse. The maximum impacts of the eclipse occur over the area of totality, where there is a decrease in surface temperature of 1.5 °C and decrease in wind speed of 1 m s−1. The maximum impacts on atmospheric pollutants occur over parts of north and east China where emissions are greater, with an increase of 5 ppbv in NO2 and 25 ppbv in CO and a decrease of 10 ppbv in O3 and 4 ppbv in NO. This study also demonstrates the effects of the solar eclipse on surface photo-oxidants in different parts of China. Although the sun was obscured to a smaller extent in polluted areas than in clean areas, the impacts of the eclipse in polluted areas are greater and last longer than they do in clean areas. In contrast, the change in radical concentrations (OH, HO2 and NO3 in clean areas is much larger than in polluted areas mainly because of the limited source of radicals in these areas. The change in radical concentrations during the eclipse reveals that nighttime chemistry dominates in both clean and polluted areas. As solar eclipses provide a natural opportunity to test more thoroughly our understanding of atmospheric chemistry, especially that

  2. Assessing the influence of NOx concentrations and relative humidity on secondary organic aerosol yields from α-pinene photo-oxidation through smog chamber experiments and modelling calculations

    Science.gov (United States)

    Stirnweis, Lisa; Marcolli, Claudia; Dommen, Josef; Barmet, Peter; Frege, Carla; Platt, Stephen M.; Bruns, Emily A.; Krapf, Manuel; Slowik, Jay G.; Wolf, Robert; Prévôt, Andre S. H.; Baltensperger, Urs; El-Haddad, Imad

    2017-04-01

    Secondary organic aerosol (SOA) yields from the photo-oxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23-29 %) and high (60-69 %) relative humidity (RH), various NOx / VOC ratios (0.04-3.8) and with different aerosol seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination of a scanning mobility particle sizer and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer was used to determine SOA mass concentration and chemical composition. We used a Monte Carlo approach to parameterize smog chamber SOA yields as a function of the condensed phase absorptive mass, which includes the sum of OA and the corresponding bound liquid water content. High RH increased SOA yields by up to 6 times (1.5-6.4) compared to low RH. The yields at low NOx / VOC ratios were in general higher compared to yields at high NOx / VOC ratios. This NOx dependence follows the same trend as seen in previous studies for α-pinene SOA. A novel approach of data evaluation using volatility distributions derived from experimental data served as the basis for thermodynamic phase partitioning calculations of model mixtures in this study. These calculations predict liquid-liquid phase separation into organic-rich and electrolyte phases. At low NOx conditions, equilibrium partitioning between the gas and liquid phases can explain most of the increase in SOA yields observed at high RH, when in addition to the α-pinene photo-oxidation products described in the literature, fragmentation products are added to the model mixtures. This increase is driven by both the increase in the absorptive mass and the solution non-ideality described by the compounds' activity coefficients. In contrast, at high NOx, equilibrium partitioning alone could not explain the strong increase in the yields with RH. This suggests that other processes, e.g. reactive uptake of semi-volatile species into the liquid phase, may occur and be

  3. Biological effects and repair of damage photoinduced by a derivative of psoralen substituted at the 3,4 reaction site

    International Nuclear Information System (INIS)

    Averbeck, D.; Moustacchi, E.; Bisagni, E.

    1978-01-01

    A newly-synthesized linear psoralen derivative, 3-carbethoxypsoralen is shown to bind to yeast nucleic acids after 365-nm light treatment. As compared to 8-methoxypsoralen, a well-known bifunctional furocoumarin, 3-carbethoxypsoralen exhibits a high photoaffinity for DNA in vivo. Both compounds bind and photoreact more efficiently in vivo than in vitro. In contrast to 8-methoxypsoralen, 3-carbethoxypsoralen does not form cross-links in yeast DNA as demonstrated by heat denaturation-reassociation studies at least in the ranges of doses used. Thus 3-carbethoxypsoralen reacts as a monofunctional compound. Wild-type cells of Saccharomyces cerevisiae are 6 times more resistant to 3-carbethoxypsoralen than to 8-methoxypsoralen plus 365 nm light treatment in terms of lethal effect. In comparison to angelicin, another monofunctional (but angular) furocoumarin, 3-carbethoxypsoralen is more photoreactive. When the photoaffinity for DNA of 8-methoxypsoralen and 3-carbethoxypsoralen are considered in relation to photoinduced cell killing, it is clear that monoadducts are very efficiently repaired in wild-type cells. In contrast to the additivity obtained with 8-methoxypsoralen, a synergistic interaction of the two different repair pathways blocked by the rad 2 and the rad 9 mutation is observed after 3-carbethoxypsoralen plus 365 nm light. Dark holding experiments show that the excision repair function which is present in wild-type and radsub(9-4) cells is important for dark recovery. (Auth.)

  4. Formulation and evaluation of antipsoriatic gel using natural excipients

    OpenAIRE

    Raghupatruni Jhansi Laxmi; R. Karthikeyan; P. Srinivasa Babu; R.V.V. Narendra Babu

    2013-01-01

    Objective: To develop topical gel formulations of Psoralen using natural excipients to minimize the side effects of synthetic drugs. Methods: The Psoralen gel formulations were prepared using different natural gums and polymers. The physicochemical compatibility between Psoralen and other excipients was confirmed by using Fourier transform infrared spectroscopy. All prepared gel formulations were evaluated for drug content uniformity, viscosity, pH, and stability. The release of psoralen f...

  5. An observer-blinded randomized controlled pilot trial comparing localized immersion psoralen-ultraviolet A with localized narrowband ultraviolet B for the treatment of palmar hand eczema.

    Science.gov (United States)

    Brass, D; Fouweather, T; Stocken, D D; Macdonald, C; Wilkinson, J; Lloyd, J; Farr, P M; Reynolds, N J; Hampton, P J

    2017-12-13

    Hand eczema is a common inflammatory dermatosis that causes significant patient morbidity. Previous studies comparing psoralen-ultraviolet A (PUVA) with narrowband ultraviolet B (NB-UVB) have been small, nonrandomized and retrospective. To conduct an observer-blinded randomized controlled pilot study using validated scoring criteria to compare immersion PUVA with NB-UVB for the treatment of chronic hand eczema unresponsive to topical steroids. Sixty patients with hand eczema unresponsive to clobetasol propionate 0·05% were randomized to receive either immersion PUVA or NB-UVB twice weekly for 12 weeks with assessments at intervals of 4 weeks. The primary outcome measure was the proportion of patients achieving 'clear' or 'almost clear' Physician's Global Assessment (PGA) response at 12 weeks. Secondary outcome measures included assessment of the modified Total Lesion and Symptom Score (mTLSS) and the Dermatology Life Quality index (DLQI). In both treatment arms, 23 patients completed the 12-week assessment for the primary outcome measure. In the PUVA group, five patients achieved 'clear' and eight 'almost clear' [intention-to-treat (ITT) response rate 43%]. In the NB-UVB group, two achieved 'clear' and five 'almost clear' (ITT response rate 23%). For the secondary outcomes, median mTLSS scores were similar between groups at baseline (PUVA 9·5, NB-UVB 9) and at 12 weeks (PUVA 3, NB-UVB 4). Changes in DLQI were similar, with improvements in both groups. In this randomized pilot trial recruitment was challenging. After randomization, there were acceptable levels of compliance and safety in each treatment schedule, but lower levels of retention. Using validated scoring systems - PGA, mTLSS and DLQI - as measures of treatment response, the trial demonstrated that both PUVA and NB-UVB reduced the severity of chronic palmar hand eczema. © 2017 British Association of Dermatologists.

  6. Integrated photooxidative extractive deep desulfurization using metal doped TiO2 and eutectic based ionic liquid

    Science.gov (United States)

    Zaid, Hayyiratul Fatimah Mohd; Kait, Chong Fai; Mutalib, Mohamed Ibrahim Abdul

    2016-11-01

    A series of metal doped TiO2 namely Fe/TiO2, Cu/TiO2 and Cu-Fe/TiO2 were synthesized and characterized, to be used as a photocatalyst in the integrated photooxidative extractive deep desulfurization for model oil (dodecane) and diesel fuel. The order of the photocatalytic activity was Cu-Fe/TiO2 followed by Cu/TiO2 and then Fe/TiO2. Cu-Fe/TiO2 was an effective photocatalyst for sulfur conversion at ambient atmospheric pressure. Hydrogen peroxide was used as the source of oxidant and eutectic-based ionic liquid as the extractant. Sulfur conversion in model oil reached 100%. Removal of sulfur from model oil was done by two times extraction with a removal of 97.06% in the first run and 2.94% in the second run.

  7. Dynamic Architecture of Eukaryotic DNA Replication Forks In Vivo, Visualized by Electron Microscopy.

    Science.gov (United States)

    Zellweger, Ralph; Lopes, Massimo

    2018-01-01

    The DNA replication process can be heavily perturbed by several different conditions of genotoxic stress, particularly relevant for cancer onset and therapy. The combination of psoralen crosslinking and electron microscopy has proven instrumental to reveal the fine architecture of in vivo DNA replication intermediates and to uncover their remodeling upon specific conditions of genotoxic stress. The replication structures are stabilized in vivo (by psoralen crosslinking) prior to extraction and enrichment procedures, allowing their visualization at the transmission electron microscope. This chapter outlines the procedures required to visualize and interpret in vivo replication intermediates of eukaryotic genomic DNA, and includes an improved method for enrichment of replication intermediates, compared to previously used BND-cellulose columns.

  8. Preparation of psoralen polymer-lipid hybrid nanoparticles and their reversal of multidrug resistance in MCF-7/ADR cells.

    Science.gov (United States)

    Huang, Qingqing; Cai, Tiange; Li, Qianwen; Huang, Yinghong; Liu, Qian; Wang, Bingyue; Xia, Xi; Wang, Qi; Whitney, John C C; Cole, Susan P C; Cai, Yu

    2018-11-01

    Multidrug resistance (MDR) is the leading cause of failure for breast cancer in the clinic. Thus far, polymer-lipid hybrid nanoparticles (PLN) loaded chemotherapeutic agents has been used to overcome MDR in breast cancer. In this study, we prepared psoralen polymer-lipid hybrid nanoparticles (PSO-PLN) to reverse drug resistant MCF-7/ADR cells in vitro and in vivo. PSO-PLN was prepared by the emulsification evaporation-low temperature solidification method. The formulation, water solubility and bioavailability, particle size, zeta potential and entrapment efficiency, and in vitro release experiments were optimized in order to improve the activity of PSO to reverse MDR. Optimal formulation: soybean phospholipids 50 mg, poly(lactic-co-glycolic) acid (PLGA) 15 mg, PSO 3 mg, and Tween-80 1%. The PSO-PLN possessed a round appearance, uniform size, exhibited no adhesion. The average particle size was 93.59 ± 2.87 nm, the dispersion co-efficient was 0.249 ± 0.06, the zeta potential was 25.47 ± 2.84 mV. In vitro analyses revealed that PSO resistance index was 3.2, and PSO-PLN resistance index was 5.6, indicating that PSO-PLN versus MCF-7/ADR reversal effect was significant. Moreover, PSO-PLN is somewhat targeted to the liver, and has an antitumor effect in the xenograft model of drug-resistant MCF-7/ADR cells. In conclusion, PSO-PLN not only reverses MDR but also improves therapeutic efficiency by enhancing sustained release of PSO.

  9. The Effect of Transition Metal Doping on the Photooxidation Process of Titania-Clay Composites

    Directory of Open Access Journals (Sweden)

    Judit Ménesi

    2008-01-01

    Full Text Available Montmorillonite-TiO2 composites containing various transition metal ions (silver, copper, or nickel were prepared, and their photocatalytic efficiencies were tested in the degradation of ethanol vapor at 70% relative humidity. Two light sources, UV-rich ( = 254 nm and visible ( = 435 nm, were used. The kinetics of degradation was monitored by gas chromatography. It was established that, in the case of each catalyst, ethanol degradation was more efficient in UV-C ( = 254 nm than in visible light, furthermore, these samples containing silver or copper ions were in each case about twice more efficient than P25 TiO2 (Degussa AG. used as a reference. In photooxidation by visible light, TiO2/clay samples doped with silver or copper were also more efficient than the reference sample, P25 TiO2. We show that doping metal ions can also be delivered to the surface of the support by ion exchange and significantly alters the optical characteristics of the TiO2/clay composite.

  10. Plasma Rich in Growth Factors Enhances Wound Healing and Protects from Photo-oxidative Stress in Dermal Fibroblasts and 3D Skin Models.

    Science.gov (United States)

    Anitua, Eduardo; Pino, Ander; Jaen, Pedro; Orive, Gorka

    2016-01-01

    Optimal skin repair has been a desired goal for many researchers. Recently, plasma rich in growth factors (PRGF) has gained importance in dermatology proving it is beneficial effects in wound healing and cutaneous regeneration. The anti-fibrotic, pro-contractile and photo-protective effect of PRGF on dermal fibroblasts and 3D skin models has been evaluated. The effect against TGFβ1 induced myofibroblast differentiation was tested. Cell contractile activity over collagen gel matrices was analyzed and the effect against UV derived photo-oxidative stress was assessed. The effectiveness of PRGF obtained from young aged and middle aged donors was compared. Furthermore, 3D organotypic skin explants were used as human skin models with the aim of analyzing ex vivo cutaneous preventive and regenerative photo-protection after UV exposure. TGFβ1 induced myofibroblast levels decreased significantly after treatment with PRGF while the contractile activity increased compared to the control group. After UV irradiation, cell survival was promoted while apoptotic and ROS levels were noticeably reduced. Photo-exposed 3D explants showed higher levels of metabolic activity and lower levels of necrosis, cell damage, irritation and ROS formation when treated with PRGF. The histological integrity and connective tissue fibers showed lower signals of photodamage among PRGF injected skin models. No significant differences for the assessed biological outcomes were observed when PRGF obtained from young aged and middle aged donors were compared. These findings suggest that this autologous approach might be useful for antifibrotic wound healing and provide an effective protection against sun derived photo-oxidative stress regardless the age of the patient.

  11. Effect of ultraviolet radiation in the photo-oxidation of High Density Polyethylene and Biodegradable Polyethylene films

    International Nuclear Information System (INIS)

    Martínez-Romo, A; Mota, R González; Bernal, J J Soto; Candelas, I Rosales; Reyes, C Frausto

    2015-01-01

    One of the most widely used plastics in the world is the High density polyethylene (HDPE), it is a stable material due to its carbon-carbon bonds, causing their slow degradation; which is why we are looking for alternative ways to accelerate the degradation process of this polymer. An alternative is the addition of oxidized groups in its molecular structure, which results in the development of polymers susceptible to biodegradation (PE-BIO). In this paper, HDPE and PE-BIO films were exposed to UV-B radiation (320-280 nm) at different exposure times, 0-60 days. The effects of UV radiation in samples of HDPE and PE-BIO were characterized using infrared spectroscopy with attenuated total reflectance (ATR). The results show that the exposed materials undergo changes in their molecular structure, due to the infrared bands formed which corresponds to the photo-oxidation of HDPE and PE films when submitted to UV-B radiation

  12. Photobiological activity of 4-methylpsoralen and 4-methyl-4', 5'-dihydropsoralen with respect to lethal and mutagenic effects on E. coli, and prophage induction

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H. (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

    1984-06-01

    The lethal and mutagenic effects on E. coli as well as the induction of prophage lambda were determined after treatment with 4-methylpsoralen, 8-methoxypsoralen, psoralen or 4-methyl-4',5'-dihydropsoralen and UV-A irradiation. All psoralens used caused photokilling and photomutagenesis of strains H/r30R and Hs30R. 4-Methylpsoralen was more efficient for killing and for the induced mutation than 8-methoxypsoralen or psoralen in view of the dose modification factor. This finding can be explained by the methylation effect of psoralen. 4-Methylpsoralen induced more mutation in Hs30R than in H/r30R. Monofunctional 4-methyl-4',5'-dihydropsoralen required much higher fluence than bifunctional psoralens to kill cells and to induce the mutation. When the induced mutation frequency was expressed as a function of survival, mutagenic efficiency ranked in the following order: 8-methoxypsoralen > psoralen > 4-methylpsoralen > 4-methyl-4',5'-dihydropsoralen. 4-Methylpsoralen was 3-4-fold less mutagenic than 8-methoxypsoralen in this plot. Lytic growth of prophage in E. coli AB1157 (lambda) was induced by the treatment. When the bifunctional psoralens were used, the maximum induced fraction was larger than 20%. However, it was only 2% when 4-methyl-4',5'-dihydropsoralen was used.

  13. Effect of different reversed micelles on autooxidation and photooxidation of stripped corn oil

    Directory of Open Access Journals (Sweden)

    Schwarz, K.

    2003-03-01

    Full Text Available The effect of reversed micelles (RMs in combination with α -tocopherol and Trolox was evaluated on the autooxidation and photooxidation of stripped corn oil. Oxidation was followed by measuring hydroperoxide and hexanal formation. RMs affected the oil oxidation stability to a degree depending on the surfactant used. Lecithin RMs caused a stronger decrease in oxidation than polyglyceryl-3-oleate RMs and methylglucose dioleate RMs. All RMs reduced the inhibition of oxidation when added in combination with external antioxidant.El efecto de miscelas inversas (RMs en combinación con α-tocoferol y Trolox fue evaluado en la autooxidación y fotooxidación de aceite de maíz libre de antioxidantes. La oxidación fue seguida por la medida de la formación de hexanal e hidroperóxido. Las RMs influyeron en la estabilidad de la oxidación del aceite dependiendo del tensioactivo usado. Las RMs de lecitina causaron una mayor disminución en la oxidación que las RMs de poligliceril-3-oleato y las RMs de metilglucosa dioleato. Todas las RMs redujeron la inhibición de la oxidación cuando se añadieron en combinación con antioxidantes externos.

  14. Photoprotection due to pigmentation and epidermal thickness after repeated exposure to ultraviolet light and psoralen plus ultraviolet A therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bech-Thomsen, N.; Wulf, H.C. [Rigshospitalet, The National Univ. Hospital, Dept. of Dermatology, Lab. of Photobiology, Copenhagen (Denmark)

    1995-10-01

    Tanning and thickening of the epidermis are cardinal defensive responses of human skin to ultraviolet (UV) radiation that lead to increased photoprotection. Earlier studies have shown that skin pigmentation can be used to predict minimal erythema dose and minimal phototoxic dose. In this study it was calculated how much of the increase in photoprotection after 4 weeks of repeated exposure to suberythemogenic doses of either UVA or UVB radiation sources or psoralen plus UVA (PUVA) therapy that was attributable to melanogenesis. The backs of 12 volunteers were exposed to 6 different UVA and UVB radiation sources 9 times during 4 weeks. Skin pigmentation was assessed by skin reflectance measuring. Photoprotection was determined from the minimal erythema dose. Melanogenesis accounted for 63-95% of the increase in photoprotection after 4 weeks of exposure to UVA radiation. Exposure to two UVB sources induced a significant increase in photoprotection but not in pigmentation. Melanogenesis accounted only for 6-11% of the increase in photoprotection after 4 weeks of UVB exposure. The pigmentary and photoprotective responses to PUVA therapy were followed in 14 patients. After 2 weeks of exposure, the increase in photoprotection was significantly higher than predicted form the increase in skin pigmentation. After 4 weeks, melanogenesis accounted for only 36% of the increase in photoprotection. This study shows that melanogenesis accounts for the increased photoprotection after 2 weeks of exposure to UVA radiation, but after 4 weeks other protective mechanisms occur during suberythemal UVB exposure and during PUVA therapy the importance of skin pigmentation in the overall photoprotection gradually decreases during a 4-week irradiation period. (au) 17 refs.

  15. Photoprotection due to pigmentation and epidermal thickness after repeated exposure to ultraviolet light and psoralen plus ultraviolet A therapy

    International Nuclear Information System (INIS)

    Bech-Thomsen, N.; Wulf, H.C.

    1995-01-01

    Tanning and thickening of the epidermis are cardinal defensive responses of human skin to ultraviolet (UV) radiation that lead to increased photoprotection. Earlier studies have shown that skin pigmentation can be used to predict minimal erythema dose and minimal phototoxic dose. In this study it was calculated how much of the increase in photoprotection after 4 weeks of repeated exposure to suberythemogenic doses of either UVA or UVB radiation sources or psoralen plus UVA (PUVA) therapy that was attributable to melanogenesis. The backs of 12 volunteers were exposed to 6 different UVA and UVB radiation sources 9 times during 4 weeks. Skin pigmentation was assessed by skin reflectance measuring. Photoprotection was determined from the minimal erythema dose. Melanogenesis accounted for 63-95% of the increase in photoprotection after 4 weeks of exposure to UVA radiation. Exposure to two UVB sources induced a significant increase in photoprotection but not in pigmentation. Melanogenesis accounted only for 6-11% of the increase in photoprotection after 4 weeks of UVB exposure. The pigmentary and photoprotective responses to PUVA therapy were followed in 14 patients. After 2 weeks of exposure, the increase in photoprotection was significantly higher than predicted form the increase in skin pigmentation. After 4 weeks, melanogenesis accounted for only 36% of the increase in photoprotection. This study shows that melanogenesis accounts for the increased photoprotection after 2 weeks of exposure to UVA radiation, but after 4 weeks other protective mechanisms occur during suberythemal UVB exposure and during PUVA therapy the importance of skin pigmentation in the overall photoprotection gradually decreases during a 4-week irradiation period. (au) 17 refs

  16. Ruta graveolens Extracts and Metabolites against Spodoptera frugiperda.

    Science.gov (United States)

    Ayil-Gutiérrez, Benjamin A; Villegas-Mendoza, Jesús M; Santes-Hernndez, Zuridai; Paz-González, Alma D; Mireles-Martínez, Maribel; Rosas-García, Ninfa M; Rivera, Gildardo

    2015-11-01

    The biological activity of Ruta graveolens leaf tissue extracts obtained with different solvents (ethyl acetate, ethanol, and water) and metabolites (psoralen, 2- undecanone and rutin) against Spodoptera frugiperda was evaluated. Metabolites levels in extracts were quantified by HPLC and GC. Ethyl acetate and ethanol extracts showed 94% and 78% mortality, respectively. Additionally, psoralen metabolite showed a high mortality as cypermethrin. Metabolite quantification in extracts shows the presence of 2-undecanone (87.9 µmoles mg(-1) DW), psoralen (3.6 µmoles mg(-1) DW) and rutin (0.001 pmoles mg(-1) DW). We suggest that these concentrations of 2-undecanone and psoralen in R. graveolens leaf tissue extracts could be responsible for S. frugiperda mortality.

  17. Inactivation of viruses in platelet suspensions that retain their in vitro characteristics: Comparison of psoralen-ultraviolet A and merocyanine 540-visible light methods

    International Nuclear Information System (INIS)

    Dodd, R.Y.; Moroff, G.; Wagner, S.; Dabay, M.H.; Dorfman, E.; George, V.; Ribeiro, A.; Shumaker, J.; Benade, L.E.

    1991-01-01

    The ability of two fundamentally different photochemical procedures to inactivate model viruses in platelet suspensions was compared. Merocyanine 540 (MC 540) with visible light was used as an example of an oxygen-dependent chemical-directed at the viral membrane, and aminomethyl trimethyl psoralen (AMT) with ultraviolet A light (UVA) was used as an example of a nucleic acid-directed system. Antiviral conditions in petri dishes were identified and the effects of these procedures on platelet suspensions in plastic storage containers were studied. Concentrations of photochemicals in the 10 to 150 mumol range with 30 to 60 minutes of visible light (MC 540) or 1 to 2 minutes of UVA (AMT) readily inactivated 5 to 6 log10 of vesicular stomatitis virus (VSV) and other model viruses in platelet suspensions, provided the plasma concentration was reduced to about 15 percent by the use of a synthetic platelet storage medium. Extracellular pH, morphology scores, and aggregation response dropped markedly when platelets were treated with MC 540 and visible light. However, treatment with 136 mumol per L of AMT and 1 to 3 minutes of UVA could inactivate 5 log10 of VSV in platelet suspensions with retention of platelet characteristics for 4 days, particularly if oxygen levels were reduced during treatment. These studies demonstrate that AMT-UVA treatment meets the initial requirements for virus inactivation in platelet suspensions

  18. Photo-oxidation products of α-pinene in coarse, fine and ultrafine aerosol: A new high sensitive HPLC-MS/MS method

    Science.gov (United States)

    Feltracco, Matteo; Barbaro, Elena; Contini, Daniele; Zangrando, Roberta; Toscano, Giuseppa; Battistel, Dario; Barbante, Carlo; Gambaro, Andrea

    2018-05-01

    Oxidation products of α-pinene represent a fraction of organic matter in the environmental aerosol. α-pinene is one of most abundant monoterpenes released in the atmosphere by plants, located typically in boreal, temperate and tropical forests. This primary compound reacts with atmospheric oxidants, such as O3, O2, OH radicals and NOx, through the major tropospheric degradation pathway for many monoterpenes under typical atmospheric condition. Although several studies identified a series of by-products deriving from the α-pinene photo-oxidation in the atmosphere, such as pinic and cis-pinonic acid, the knowledge of the mechanism of this process is partially still lacking. Thus, the investigation of the distribution of these acids in the different size aerosol particles provides additional information on this regard. The aim of this study is twofold. First, we aim to improve the existing analytical methods for the determination of pinic and cis-pinonic acid in aerosol samples, especially in terms of analytical sensitivity and limits of detection (LOD) and quantification (LOQ). We even attempted to increase the knowledge of the α-pinene photo-oxidation processes by analysing, for the first time, the particle-size distribution up to nanoparticle level of pinic and cis-pinonic acid. The analysis of aerosol samples was carried out via high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer. The instrumental LOD values of cis-pinonic and pinic acid are 1.6 and 1.2 ng L-1 while LOQ values are 5.4 and 4.1 ng L-1, respectively. Samples were collected by MOUDI II™ cascade impactor with twelve cut-sizes, from March to May 2016 in the urban area of Mestre-Venice (Italy). The range concentrations in the aerosol samples were from 0.1 to 0.9 ng m-3 for cis-pinonic acid and from 0.1 to 0.8 ng m-3 for pinic acid.

  19. Cloud Processing of Secondary Organic Aerosol from Isoprene and Methacrolein Photooxidation.

    Science.gov (United States)

    Giorio, Chiara; Monod, Anne; Brégonzio-Rozier, Lola; DeWitt, Helen Langley; Cazaunau, Mathieu; Temime-Roussel, Brice; Gratien, Aline; Michoud, Vincent; Pangui, Edouard; Ravier, Sylvain; Zielinski, Arthur T; Tapparo, Andrea; Vermeylen, Reinhilde; Claeys, Magda; Voisin, Didier; Kalberer, Markus; Doussin, Jean-François

    2017-10-12

    Aerosol-cloud interaction contributes to the largest uncertainties in the estimation and interpretation of the Earth's changing energy budget. The present study explores experimentally the impacts of water condensation-evaporation events, mimicking processes occurring in atmospheric clouds, on the molecular composition of secondary organic aerosol (SOA) from the photooxidation of methacrolein. A range of on- and off-line mass spectrometry techniques were used to obtain a detailed chemical characterization of SOA formed in control experiments in dry conditions, in triphasic experiments simulating gas-particle-cloud droplet interactions (starting from dry conditions and from 60% relative humidity (RH)), and in bulk aqueous-phase experiments. We observed that cloud events trigger fast SOA formation accompanied by evaporative losses. These evaporative losses decreased SOA concentration in the simulation chamber by 25-32% upon RH increase, while aqueous SOA was found to be metastable and slowly evaporated after cloud dissipation. In the simulation chamber, SOA composition measured with a high-resolution time-of-flight aerosol mass spectrometer, did not change during cloud events compared with high RH conditions (RH > 80%). In all experiments, off-line mass spectrometry techniques emphasize the critical role of 2-methylglyceric acid as a major product of isoprene chemistry, as an important contributor to the total SOA mass (15-20%) and as a key building block of oligomers found in the particulate phase. Interestingly, the comparison between the series of oligomers obtained from experiments performed under different conditions show a markedly different reactivity. In particular, long reaction times at high RH seem to create the conditions for aqueous-phase processing to occur in a more efficient manner than during two relatively short cloud events.

  20. Combination therapy with cyclosporine and psoralen plus ultraviolet a in the patients with severe alopecia areata: a retrospective study with a self-controlled design.

    Science.gov (United States)

    Park, Kui Young; Jang, Woo Sun; Son, In Pyeong; Choi, Sun Young; Lee, Moo Yeol; Kim, Beom Joon; Kim, Myeung Nam; Ro, Byung In

    2013-02-01

    Alopecia areata (AA) is believed to be an organ-specific autoimmune disease in which a mononuclear cell infiltrate develops in and around anagen hair follicles. There is no definitive therapy for AA. We sought to determine whether the combination therapy of cyclosporine and psoralen plus ultraviolet A (PUVA) could be an effective treatment for severe AA. A total of 41 patients with severe AA were treated with oral cyclosporine and topical PUVA. Cyclosporine was given at an initial daily dose of 200 mg for adult and 100 mg for children for periods of up to 16 weeks. Eight-methoxypsoralen (Methoxsalen) was applied topically 20 minutes prior to ultraviolet A (UVA) exposure, and the patients were irradiated with UVA twice a week for 16 weeks. Of the total 41 patients, 2 (7.3%) patients were lost to follow-up, and 1 (2.4%) patient discontinued the treatment due to abdominal discomfort. Six (14.6%) patients were treated for less than 12 weeks. Of remaining 32 patients, 3 (9.4%) showed excellent response, 3 (9.4%) showed good response, 12 (37.5%) showed fair response, and 14 (43.7%) showed poor response. Although limited by its uncontrolled character, this study shows that the combination therapy with cyclosporine and PUVA may be an additional choice for severe and recalcitrant AA.

  1. Effect of nitrogen oxides (NO and NO2) and toluene on SO2 photooxidation, nucleation and growth: A smog chamber study

    Science.gov (United States)

    Li, Kangwei; Chen, Linghong; White, Stephen J.; Han, Ke; Lv, Biao; Bao, Kaiji; Wu, Xuecheng; Gao, Xiang; Azzi, Merched; Cen, Kefa

    2017-08-01

    The formation and growth of new particles has recently been shown to have a significant influence on Chinese haze pollution, and sulfuric acid has long been recognized as a major contributor to new particle formation. In this study, four comparison groups of experiments related to SO2 photooxidation, as well as aerosol nucleation and growth, have been conducted in the CAPS-ZJU (Complex Air Pollution Study-Zhejiang University) smog chamber. These were conducted either under SO2/NOx or SO2/toluene gas-phase environments in the absence of seed particles. During aerosol nucleation and growth process, several physical properties such as mass, size and effective density were measured simultaneously by Scanning Mobility Particle Sizer (SMPS) and Differential Mobility Analyzer-Aerosol Particle Mass Analyzer-Condensation Particle Counter (DMA-APM-CPC). The effective density of new particles decreased from 1.8 to 1.35 g/cm3 as the particle size increased from 20 to 65 nm. The single particle mass showed good power-law relationship with mobility diameter, with an average mass-mobility exponent of 2.885. A new algorithm and a reference density of 1.38 g/cm3 based on size-resolved single particle mass (SPM) were proposed to calculate the mass concentration of new particles. Two methods based on Log Normal and Max Concentration were applied to derive particle growth rate (GR), and data merging from both methods was implemented to decrease calculation uncertainty. Meanwhile, both continuous nucleation and inhibition of further growth in sub-20 nm size range were observed in different experiments depending on composition, and possible reasons were analyzed. The presence of NO was found to suppress nucleation and subsequent aerosol growth; while the presence of NO2 or toluene promoted it. It was concluded that decreasing NOx (NO or NO2) or increasing toluene may promote SO2 photooxidation, nucleation and subsequent aerosol growth, all of which is significant for deeper

  2. Induction of SCE by DNA cross-links in human fibroblasts exposed to 8-MOP and UVA irradiation

    International Nuclear Information System (INIS)

    Bredberg, A.; Lambert, B.

    1983-01-01

    To study the SCE-inducing effect of psoralen cross-links in the DNA of normal, human fibroblasts, cell cultures were exposed to PUVA (0.2-1 μg of 8-MOP per ml, followed by UVA irradiation at 0.04 J/cm 2 ) and carefully washed to remove non-covalently bound psoralen. Some cell cultures were then given a second dose of UVA (1.1 J/cm 2 ), either immediately after PUVA or 1-3 days later. By this type of treatment, cells with different proportions of DNA cross-links are obtained. The initial PUVA treatment will mainly give rise to psoralen monoadducts and only few cross-links in the DNA, and the second UVA irradiation will convert a number of the psoralen monoadducts into cross-links. (orig./AJ)

  3. Cross-talk between cognate and noncognate RpoE sigma factors and Zn(2+)-binding anti-sigma factors regulates photooxidative stress response in Azospirillum brasilense.

    Science.gov (United States)

    Gupta, Namrata; Gupta, Ankush; Kumar, Santosh; Mishra, Rajeev; Singh, Chhaya; Tripathi, Anil Kumar

    2014-01-01

    Azospirillum brasilense harbors two redox-sensitive Zinc-binding anti-sigma (ZAS) factors (ChrR1 and ChrR2), which negatively regulate the activity of their cognate extra-cytoplasmic function (ECF) σ factors (RpoE1 and RpoE2) by occluding their binding to the core enzyme. Both pairs of RpoE-ChrR control responses to photooxidative stress. The aim of this study was to investigate whether the two RpoE-ChrR pairs cross-talk while responding to the stress. In silico analysis showed a high sequence similarity between ChrR1 and ChrR2 proteins, but differences in redox sensitivity. Using in silico and in vitro methods of protein-protein interaction, we have shown that both ChrR1 and ChrR2 proteins physically bind to their noncognate RpoE proteins. Restoration of the phenotypes of chrR1::Tn5 and chrR2::Km mutants related to carotenoid biosynthesis and photooxidative stress tolerance by expressing chrR1 or chrR2 provided in vivo evidence for the cross-talk. In addition, up- or down-regulation of several identical proteins by expressing chrR1 or chrR2 in the chrR1::Tn5 mutant provided another in vivo evidence for the cross-talk. Although multiple redox-sensitive ZAS anti-σ factors occur in some Gram-positive bacteria, no cross-talk is reported among them. We report here, for the first time, that the two ZAS anti-σ factors of A. brasilense also interact with their noncognate σ factors and affect gene expression. The two redox-sensitive ZAS anti-σ factors in A. brasilense may interact with their cognate as well as noncognate ECF σ factors to play an important role in redox homeostasis by facilitating recovery from the oxidative stress.

  4. Photo-oxidation of histidine peptides yields high concentrations of unstable peroxides

    International Nuclear Information System (INIS)

    Policarpio, V.V.; Hawkins, C.L.; Davies, M.J.

    2003-01-01

    Oxidation of proteins by UV, and visible light in the presence of sensitizers, results in side chain modification as well as aggregation and fragmentation. In particular, singlet oxygen has been reported to oxidize Met, Trp, Tyr, Cys and His side chains in a selective manner. In this study the oxidation of histidine and its derivatives, and His-containing peptides is examined using a range of sensitizers, to determine whether peroxides are major intermediates, and the mechanism of formation of these species. Visible light-sensitised oxidation of Gly-His-Gly in the presence of oxygen and rose bengal gives unstable substrate-derived peroxides with the peroxide yield increasing with increasing photolysis time. Similar behaviour was detected with other photosensitizers, though the peroxide yields varied with the sensitizer at identical concentrations with rose bengal > aluminium phthalocyanine > hematoporphyrin IX > zinc phthalocyanine > tetrakisporphine. The peroxide yield was decreased in the presence of azide and enhanced when deuterium oxide was employed as the solvent, consistent with peroxide formation being singlet oxygen mediated. Experiments using anoxic conditions gave low yields of peroxides confirming the oxygen-dependence of these reactions. HPLC analysis showed rapid loss of the parent peptide, with subsequent formation of both stable and unstable products; these are currently being characterized by MS and NMR. Similar behavior has been observed with other His derivatives. The yield of singlet oxygen formed in these reactions has been estimated using a bleaching assay (N, N-dimethyl-4-nitrosoaniline). Quantification of singlet oxygen formation and Gly-His-Gly derived peroxide during rose bengal-mediated photooxidation indicated a conversion efficiency of the initial singlet oxygen into substrate-derived peroxides of ca. 75% indicating that peroxide formation is a highly efficient and major reaction pathway

  5. The effect of cartilage and bone density of mushroom-shaped, photooxidized, osteochondral transplants: an experimental study on graft performance in sheep using transplants originating from different species

    Directory of Open Access Journals (Sweden)

    Hilbe Monika

    2005-12-01

    Full Text Available Abstract Background Differences in overall performance of osteochondral photooxidized grafts were studied in accordance of their species origin and a new, more rigorous cleansing procedure using alcohol during preparation. Methods Photooxidized mushroom-shaped grafts of bovine, ovine, human and equine origin were implanted in the femoral condyles of 32 sheep (condyles: n = 64. No viable chondrocytes were present at the time of implantation. Grafts were evaluated at 6 months using plastic embedded sections of non-decalcified bone and cartilage specimens. Graft incorporation, the formation of cyst-like lesions at the base of the cartilage junction as well as cartilage morphology was studied qualitatively, semi-quantitatively using a score system and quantitatively by performing histomorphometrical measurements of percentage of bone and fibrous tissue of the original defects. For statistical analysis a factorial analysis of variance (ANOVA- test was applied. Results Differences of graft performance were found according to species origin and cleansing process during graft preparation. According to the score system cartilage surface integrity was best for equine grafts, as well as dislocation or mechanical stability. The equine grafts showed the highest percentage for bone and lowest for fibrous tissue, resp. cystic lesions. The new, more rigorous cleansing process decreased cartilage persistence and overall graft performance. Conclusion Performance of grafts from equine origin was better compared to bovine, ovine and human grafts. The exact reason for this difference was not proven in the current study, but could be related to differences in density of cartilage and subchondral bone between species.

  6. Explicit modelling of SOA formation from α-pinene photooxidation: sensitivity to vapour pressure estimation

    Directory of Open Access Journals (Sweden)

    R. Valorso

    2011-07-01

    Full Text Available The sensitivity of the formation of secondary organic aerosol (SOA to the estimated vapour pressures of the condensable oxidation products is explored. A highly detailed reaction scheme was generated for α-pinene photooxidation using the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A. Vapour pressures (Pvap were estimated with three commonly used structure activity relationships. The values of Pvap were compared for the set of secondary species generated by GECKO-A to describe α-pinene oxidation. Discrepancies in the predicted vapour pressures were found to increase with the number of functional groups borne by the species. For semi-volatile organic compounds (i.e. organic species of interest for SOA formation, differences in the predicted Pvap range between a factor of 5 to 200 on average. The simulated SOA concentrations were compared to SOA observations in the Caltech chamber during three experiments performed under a range of NOx conditions. While the model captures the qualitative features of SOA formation for the chamber experiments, SOA concentrations are systematically overestimated. For the conditions simulated, the modelled SOA speciation appears to be rather insensitive to the Pvap estimation method.

  7. Phototherapy and photopharmacology

    International Nuclear Information System (INIS)

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

    1985-01-01

    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

  8. Inactivated human platelet lysate with psoralen: a new perspective for mesenchymal stromal cell production in Good Manufacturing Practice conditions.

    Science.gov (United States)

    Castiglia, Sara; Mareschi, Katia; Labanca, Luciana; Lucania, Graziella; Leone, Marco; Sanavio, Fiorella; Castello, Laura; Rustichelli, Deborah; Signorino, Elena; Gunetti, Monica; Bergallo, Massimiliano; Bordiga, Anna Maria; Ferrero, Ivana; Fagioli, Franca

    2014-06-01

    Mesenchymal stromal cells (MSC) are ideal candidates for regenerative and immunomodulatory therapies. The use of xenogeneic protein-free Good Manufacturing Practice-compliant growth media is a prerequisite for clinical MSC isolation and expansion. Human platelet lysate (HPL) has been efficiently implemented into MSC clinical manufacturing as a substitute for fetal bovine serum (FBS). Because the use of human-derived blood materials alleviates immunologic risks but not the transmission of blood-borne viruses, the aim of our study was to test an even safer alternative than HPL to FBS: HPL subjected to pathogen inactivation by psoralen (iHPL). Bone marrow samples were plated and expanded in α-minimum essential medium with 10% of three culture supplements: HPL, iHPL and FBS, at the same time. MSC morphology, growth and immunophenotype were analyzed at each passage. Karyotype, tumorigenicity and sterility were analyzed at the third passage. Statistical analyses were performed. The MSCs cultivated in the three different culture conditions showed no significant differences in terms of fibroblast colony-forming unit number, immunophenotype or in their multipotent capacity. Conversely, the HPL/iHPL-MSCs were smaller, more numerous, had a higher proliferative potential and showed a higher Oct-3/4 and NANOG protein expression than did FBS-MSCs. Although HPL/iHPL-MSCs exhibit characteristics that may be attributable to a higher primitive stemness than FBS-MSCs, no tumorigenic mutations or karyotype modifications were observed. We demonstrated that iHPL is safer than HPL and represents a good, Good Manufacturing Practice-compliant alternative to FBS for MSC clinical production that is even more advantageous in terms of cellular growth and stemness. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  9. Effect of humidity on the composition of isoprene photooxidation secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    T. B. Nguyen

    2011-07-01

    Full Text Available The effect of relative humidity (RH on the composition and concentrations of gas-phase products and secondary organic aerosol (SOA generated from the photooxidation of isoprene under high-NOx conditions was investigated. Experiments were performed with hydrogen peroxide as the OH precursor and in the absence of seed aerosol. The relative yields of most gas-phase products were the same regardless of initial water vapor concentration with exception of hydroxyacetone and glycolaldehyde, which were considerably affected by RH. A significant change was observed in the SOA composition, with many unique condensed-phase products formed under humid (90 % RH vs. dry (<2 % RH conditions, without any detectable effect on the rate and extent of the SOA mass growth. There is a 40 % reduction in the number and relative abundance of distinct particle-phase nitrogen-containing organic compounds (NOC detected by high resolution mass spectrometry. The suppression of condensation reactions, which produce water as a product, is the most important chemical effect of the increased RH. For example, the total signal from oligomeric esters of 2-methylglyceric acid was reduced by about 60 % under humid conditions and the maximum oligomer chain lengths were reduced by 7–11 carbons. Oligomers formed by addition mechanisms, without direct involvement of water, also decreased at elevated RH but to a much smaller extent. The observed reduction in the extent of condensation-type oligomerization at high RH may have substantial impact on the phase characteristics and hygroscopicity of the isoprene aerosol. The reduction in the amount of organic nitrates in the particle phase has implications for understanding the budget of NOC compounds.

  10. Molecular characterization of brown carbon (BrC) chromophores in secondary organic aerosol generated from photo-oxidation of toluene.

    Science.gov (United States)

    Lin, Peng; Liu, Jiumeng; Shilling, John E; Kathmann, Shawn M; Laskin, Julia; Laskin, Alexander

    2015-09-28

    Atmospheric brown carbon (BrC) is a significant contributor to light absorption and climate forcing. However, little is known about a fundamental relationship between the chemical composition of BrC and its optical properties. In this work, light-absorbing secondary organic aerosol (SOA) was generated in the PNNL chamber from toluene photo-oxidation in the presence of NOx (Tol-SOA). Molecular structures of BrC components were examined using nanospray desorption electrospray ionization (nano-DESI) and liquid chromatography (LC) combined with UV/Vis spectroscopy and electrospray ionization (ESI) high-resolution mass spectrometry (HRMS). The chemical composition of BrC chromophores and the light absorption properties of toluene SOA (Tol-SOA) depend strongly on the initial NOx concentration. Specifically, Tol-SOA generated under high-NOx conditions (defined here as initial NOx/toluene of 5/1) appears yellow and mass absorption coefficient of the bulk sample (MACbulk@365 nm = 0.78 m(2) g(-1)) is nearly 80 fold higher than that measured for the Tol-SOA sample generated under low-NOx conditions (NOx/toluene atmosphere.

  11. Effects of NOx and SO2 on the secondary organic aerosol formation from photooxidation of α-pinene and limonene

    Directory of Open Access Journals (Sweden)

    D. Zhao

    2018-02-01

    Full Text Available Anthropogenic emissions such as NOx and SO2 influence the biogenic secondary organic aerosol (SOA formation, but detailed mechanisms and effects are still elusive. We studied the effects of NOx and SO2 on the SOA formation from the photooxidation of α-pinene and limonene at ambient relevant NOx and SO2 concentrations (NOx: < 1to 20 ppb, SO2: < 0.05 to 15 ppb. In these experiments, monoterpene oxidation was dominated by OH oxidation. We found that SO2 induced nucleation and enhanced SOA mass formation. NOx strongly suppressed not only new particle formation but also SOA mass yield. However, in the presence of SO2 which induced a high number concentration of particles after oxidation to H2SO4, the suppression of the mass yield of SOA by NOx was completely or partly compensated for. This indicates that the suppression of SOA yield by NOx was largely due to the suppressed new particle formation, leading to a lack of particle surface for the organics to condense on and thus a significant influence of vapor wall loss on SOA mass yield. By compensating for the suppressing effect on nucleation of NOx, SO2 also compensated for the suppressing effect on SOA yield. Aerosol mass spectrometer data show that increasing NOx enhanced nitrate formation. The majority of the nitrate was organic nitrate (57–77 %, even in low-NOx conditions (<  ∼  1 ppb. Organic nitrate contributed 7–26 % of total organics assuming a molecular weight of 200 g mol−1. SOA from α-pinene photooxidation at high NOx had a generally lower hydrogen to carbon ratio (H ∕ C, compared to low NOx. The NOx dependence of the chemical composition can be attributed to the NOx dependence of the branching ratio of the RO2 loss reactions, leading to a lower fraction of organic hydroperoxides and higher fractions of organic nitrates at high NOx. While NOx suppressed new particle formation and SOA mass formation, SO2 can compensate for such effects, and the

  12. Measurements of photo-oxidation products from the reaction of a series of alkyl-benzenes with hydroxyl radicals during EXACT using comprehensive gas chromatography

    Directory of Open Access Journals (Sweden)

    J. F. Hamilton

    2003-01-01

    Full Text Available Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCxGC. A GCxGC system has been developed which utilises valve modulation and independent separations as a function of both volatility and polarity. A number of carbonyl-type compounds were identified during a series of reactions carried out at the European Photoreactor (EUPHORE, a large volume outdoor reaction chamber in Valencia, Spain. Experiments were carried as part of the EXACT project (Effects of the oXidation of Aromatic Compounds in the Troposphere. Two litre chamber air samples were cryo-focused, with a sampling frequency of 30 minutes, allowing the evolution of species to be followed over oxidation periods of 3-6 hours. To facilitate product identification, several carbonyl compounds, which were possible products of the photo-oxidation, were synthesised and used as reference standards. For toluene reactions, observed oxygenated intermediates found included the co-eluting pair a-angelicalactone/4-oxo-2-pentenal, maleic anhydride, citraconic anhydride, benzaldehyde and p-methyl benzoquinone. In the p-xylene experiment, the products identified were E/Z-hex-3-en-2,5-dione and citraconic anhydride. For 1,3,5-TMB reactions, the products identified were 3,5-dimethylbenzaldehyde, 3,5-dimethyl-3H-furan-2-one and 3-methyl-5-methylene-5H-furan-2-one. Preliminary quantification was carried out on identified compounds using liquid standards. Comparison of FTIR and GCxGC for the measurement of the parent aromatics generally showed good agreement. Comparison of the concentrations observed by GCxGC to concentration-time profiles simulated using the Master Chemical Mechanism, MCMv3, demonstrates that this mechanism significantly over-predicts the concentrations of many product compounds and highlights the

  13. Long-term Simulation of Photo-oxidants and Particulate Matter Over Europe With The Eurad Modeling System

    Science.gov (United States)

    Memmesheimer, M.; Friese, E.; Jakobs, H. J.; Feldmann, H.; Ebel, A.; Kerschgens, M. J.

    During recent years the interest in long-term applications of air pollution modeling systems (AQMS) has strongly increased. Most of these models have been developed for the application to photo-oxidant episodes during the last decade. In this contribu- tion a long-term application of the EURAD modeling sytem to the year 1997 is pre- sented. Atmospheric particles are included using the Modal Aerosol Dynamics Model for Europe (MADE). Meteorological fields are simulated by the mesoscale meteoro- logical model MM5, gas-phase chemistry has been treated with the RACM mecha- nism. The nesting option is used to zoom in areas of specific interest. Horizontal grid sizes are 125 km for the reginal scale, and 5 km for the local scale covering the area of North-Rhine-Westfalia (NRW). The results have been compared to observations of the air quality network of the environmental agency of NRW for the year 1997. The model results have been evaluated using the data quality objectives of the EU direc- tive 99/30. Further improvement for application of regional-scale air quality models is needed with respect to emission data bases, coupling to global models to improve the boundary values, interaction between aerosols and clouds and multiphase modeling.

  14. Effect of UV-irradiation on immunological and histochemical markers of Langerhans cells in normal appearing skin of psoriatic patients

    International Nuclear Information System (INIS)

    Tjernlund, U.; Juhlin, L.

    1982-01-01

    A total of 12 patients with moderately severe psoriasis was treated with psoralen baths and/or ultraviolet radiation. Punch biopsies were taken for mimunological markers and shave biopsies for ATPase detection. As immunological marker immunosorbent purified antibodies against Ia antigens and monoclonal antigens against thymocyte antigens were used. The study showed that in the clinical relevant situation PUVA treatment had a more profound effect on the immunological markers of epidermal Langerhans cells than had light treatment without psoralens. With UV treatment without psoralens the ATPase activity of the Langerhans cells seemed to be more influenced than the immunological markers. (orig.)

  15. Effects on surface atmospheric photo-oxidants over Greece during the total solar eclipse event of 29 March 2006

    Directory of Open Access Journals (Sweden)

    P. Zanis

    2007-12-01

    Full Text Available This study investigates the effects of the total solar eclipse of 29 March 2006 on surface air-quality levels over Greece based on observations at a number of sites in conjunction with chemical box modelling and 3-D air-quality modelling. Emphasis is given on surface ozone and other photooxidants at four Greek sites Kastelorizo, Finokalia (Crete, Pallini (Athens and Thessaloniki, which are located at gradually increasing distances from the path of the eclipse totality and are characterized by different air pollution levels. The eclipse offered the opportunity to test our understanding of air pollution build-up and the response of the gas-phase chemistry of photo-oxidants during a photolytical perturbation using both a photochemical box model and a regional air-quality offline model based on the modeling system WRF/CAMx. At the relatively unpolluted sites of Kastelorizo and Finokalia no clear signal of the solar eclipse on surface O3, NO2 and NO concentrations can be deduced from the observations while there is no correlation of observed O3, NO2 and NO with observed global radiation. The box and regional model simulations for the two relatively unpolluted sites indicate that the calculated changes in net ozone production rates between eclipse and non eclipse conditions are rather small compared to the observed short-term ozone variability. Furthermore the simulated ozone lifetime is in the range of a few days at these sites and hence the solar eclipse effects on ozone can be easily masked by local and regional transport. At the polluted sites of Thessaloniki and Pallini, the solar eclipse effects on O3, NO2 and NO concentrations are revealed from both the measurements and modeling with the net effect being a decrease in O3 and NO and an increase in NO2 as NO2 formed from the reaction of O3 with NO while at the same time NO2 is

  16. A non-inferiority randomized controlled clinical trial comparing Unani formulation & psoralen plus ultraviolet A sol in chronic plaque psoriasis.

    Science.gov (United States)

    Khanna, Neena; Nazli, Tamanna; Siddiqui, Khalid Mahmud; Kalaivani, Mani

    2018-01-01

    Though Unani medications have been used for centuries to treat psoriasis, there is paucity of published studies which have systematically evaluated their efficacy and safety. This study was conducted to establish non-inferiority of Unani medications (oral UNIM-401 and topical UNIM-403) vs psoralen plus ultraviolet A (PUVA) sol in treatment of moderate-severe chronic plaque psoriasis (CPP) in achieving psoriasis area severity index (PASI) 75 at 12 wk and to estimate proportion of patients who relapsed in follow up period of 12 weeks, after having achieved PASI 50. In this randomized, controlled trial patients with CPP were block randomized to receive either Unani treatment (147 patients) or PUVA sol (140 patients) for 12 weeks. Percentage reduction in PASI was determined in each patient at 12 wk to calculate number of patients who achieved PASI 75 as also to estimate median of percentage reduction in PASI in each group. All patients who achieved PASI 50 at 12 weeks were followed up for another 12 wk to determine proportion of patients who relapsed. Of the 287 patients randomized, 84 of 147 in Unani group and 67 of 140 in PUVA sol group completed 12 weeks of treatment. On intention-to-treat (ITT) analysis, the response in patients on Unani medication was not inferior to those receiving PUVA sol, in attaining PASI 75 (16.3% in Unani group vs 15.7% in the PUVA sol group). Median of percentage reduction of PASI at 12 wk from baseline in Unani group (68.2%; -60, 100) and PUVA sol group (63%; -15.7, 100) was comparable. Proportion of patients who relapsed at 24 wk was comparable in both groups. However, frequency of clinical side effects was significantly higher (P =0.001) in PUVA sol group (16.4%) compared to Unani group (2%). The findings of the present study indicated that oral UNIM-401 and topical UNIM-403 were effective and well tolerated therapeutic options in patients with moderate-severe CPP.

  17. Modelling of the photooxidation of toluene: conceptual ideas for validating detailed mechanisms

    Directory of Open Access Journals (Sweden)

    V. Wagner

    2003-01-01

    Full Text Available Toluene photooxidation is chosen as an example to examine how simulations of smog-chamber experiments can be used to unravel shortcomings in detailed mechanisms and to provide information on complex reaction systems that will be crucial for the design of future validation experiments. The mechanism used in this study is extracted from the Master Chemical Mechanism Version 3 (MCM v3 and has been updated with new modules for cresol and g-dicarbonyl chemistry. Model simulations are carried out for a toluene-NOx experiment undertaken at the European Photoreactor (EUPHORE. The comparison of the simulation with the experimental data reveals two fundamental shortcomings in the mechanism: OH production is too low by about 80%, and the ozone concentration at the end of the experiment is over-predicted by 55%. The radical budget was analysed to identify the key intermediates governing the radical transformation in the toluene system. Ring-opening products, particularly conjugated g-dicarbonyls, were identified as dominant radical sources in the early stages of the experiment. The analysis of the time evolution of radical production points to a missing OH source that peaks when the system reaches highest reactivity. First generation products are also of major importance for the ozone production in the system. The analysis of the radical budget suggests two options to explain the concurrent under-prediction of OH and over-prediction of ozone in the model: 1 missing oxidation processes that produce or regenerate OH without or with little NO to NO2 conversion or 2 NO3 chemistry that sequesters reactive nitrogen oxides into stable nitrogen compounds and at the same time produces peroxy radicals. Sensitivity analysis was employed to identify significant contributors to ozone production and it is shown how this technique, in combination with ozone isopleth plots, can be used for the design of validation experiments.

  18. Improving the Photo-Oxidative Performance of Bi2MoO6 by Harnessing the Synergy between Spatial Charge Separation and Rational Co-Catalyst Deposition.

    Science.gov (United States)

    Wu, Xuelian; Hart, Judy N; Wen, Xiaoming; Wang, Liang; Du, Yi; Dou, Shi Xue; Ng, Yun Hau; Amal, Rose; Scott, Jason

    2018-03-21

    It has been reported that photogenerated electrons and holes can be directed toward specific crystal facets of a semiconductor particle, which is believed to arise from the differences in their surface electronic structures, suggesting that different facets can act as either photoreduction or photo-oxidation sites. This study examines the propensity for this effect to occur in faceted, plate-like bismuth molybdate (Bi 2 MoO 6 ), which is a useful photocatalyst for water oxidation. Photoexcited electrons and holes are shown to be spatially separated toward the {100} and {001}/{010} facets of Bi 2 MoO 6 , respectively, by facet-dependent photodeposition of noble metals (Pt, Au, and Ag) and metal oxides (PbO 2 , MnO x , and CoO x ). Theoretical calculations revealed that differences in energy levels between the conduction bands and valence bands of the {100} and {001}/{010} facets can contribute to electrons and holes being drawn to different surfaces of the plate-like Bi 2 MoO 6 . Utilizing this knowledge, the photo-oxidative capability of Bi 2 MoO 6 was improved by adding an efficient water oxidation co-catalyst, CoO x , to the system, whereby the extent of enhancement was shown to be governed by the co-catalyst location. A greater oxygen evolution occurred when CoO x was selectively deposited on the hole-rich {001}/{010} facets of Bi 2 MoO 6 compared to when CoO x was randomly located across all of the facets. The elevated performance exhibited for the selectively loaded CoO x /Bi 2 MoO 6 was ascribed to the greater opportunity for hole trapping by the co-catalyst being accentuated over other potentially detrimental effects, such as the co-catalyst acting as a recombination medium and/or covering reactive sites. The results indicate that harnessing the synergy between the spatial charge separation and the co-catalyst location on the appropriate facets of plate-like Bi 2 MoO 6 can promote its photocatalytic activity.

  19. Photoproduction of One-Electron Reducing Intermediates by Chromophoric Dissolved Organic Matter (CDOM): Relation to O2- and H2O2 Photoproduction and CDOM Photooxidation.

    Science.gov (United States)

    Zhang, Yi; Blough, Neil V

    2016-10-06

    A molecular probe, 3-amino-2,2,5,5,-tetramethy-1-pyrrolydinyloxy (3ap), was employed to determine the formation rates of one-electron reducing intermediates generated photochemically from both untreated and borohydride-reduced Suwanee River fulvic and humic acids (SRFA and SRHA, respectively). This stable nitroxyl radical reacts rapidly with reducing radicals and other one-electron reductants to produce a relatively stable product, the hydroxylamine, which can be derivatized with fluorescamine, separated by HPLC and quantified fluorimetrically. We provide evidence that O 2 and 3ap compete for the same pool(s) of photoproduced reducing intermediates, and that under appropriate experimental conditions, the initial rate of hydroxylamine formation (R H ) can provide an estimate of the initial rate of superoxide (O 2 - ) formation. However, comparison of the initial rates of H 2 O 2 formation (R H2O2 ) to that of R H show far larger ratios of R H /R H2O2 (∼6-13) than be accounted for by simple O 2 - dismutation (R H /R H2O2 = 2), implying a significant oxidative sink of O 2 - (∼67-85%). Because of their high reactivity with O 2 - and their likely importance in the photochemistry of CDOM, we suggest that coproduced phenoxy radicals could represent a viable oxidative sink. Because O 2 - /phenoxy radical reactions can lead to more highly oxidized products, O 2 - could be playing a far more significant role in the photooxidation of CDOM than has been previously recognized.

  20. Or mutation leads to photo-oxidative stress responses in cauliflower (Brassica oleracea) seedlings during de-etiolation.

    Science.gov (United States)

    Men, Xiao; Dong, Kang

    2013-11-01

    The Orange (Or) gene is a gene mutation that can increase carotenoid content in plant tissues normally devoid of pigments. It affects plastid division and is involved in the differentiation of proplastids or non-colored plastids into chromoplasts. In this study, the de-etiolation process of the wild type (WT) cauliflower (Brassica oleracea L. var. botrytis) and Or mutant seedlings was investigated. We analyzed pigment content, plastid development, transcript abundance and protein levels of genes involved in the de-etiolation process. The results showed that Or can increase the carotenoid content in green tissues, although not as effectively as in non-green tissues, and this effect might be caused by the changes in biosynthetic pathway genes at both transcriptional and post-transcriptional levels. There was no significant difference in the plastid development process between the two lines. However, the increased content of antheraxanthin and anthocyanin, and higher expression levels of violaxanthin de-epoxidase gene (VDE) suggested a stress situation leading to photoinhibition and enhanced photoprotection in the Or mutant. The up-regulated expression levels of the reactive oxygen species (ROS)-induced genes, ZAT10 for salt tolerance zinc finger protein and ASCORBATE PEROXIDASE2 (APX2), suggested the existence of photo-oxidative stress in the Or mutant. In summary, abovementioned findings provide additional insight into the functions of the Or gene in different tissues and at different developmental stages.

  1. Relationship of O2 Photodesorption in Photooxidation of Acetone on TiO2

    International Nuclear Information System (INIS)

    Henderson, Michael A.

    2008-01-01

    Organic photooxidation on TiO2 invariably involves the coexistence of organic species with oxygen on the surface at the same time. In the case of acetone and oxygen, both species exhibit their own interesting photochemistry on TiO2, but interdependences between the two are not understood. In this study, a rutile TiO2(110) surface possessing 7% surface oxygen vacancy sites is used as a model surface to probe the relationship between O2 photodesorption and acetone photodecomposition. Temperature programmed desorption (TPD) and photon stimulated desorption (PSD) measurements indicate that coadsorbed oxygen is essential to acetone photodecomposition on this surface, however the form of oxygen (molecular and dissociative) is not known. The first steps in acetone photodecomposition on TiO2(110) involve thermal activation with oxygen to form an acetone diolate ((CH3)2COO) species followed by photochemical decomposition to adsorbed acetate (CH3COO) and an ejected CH3 radical that is detected in PSD. Depending on the surface conditions, O2 PSD is also observed during the latter process. However, the time scales for the two PSD events (CH3 and O2) are quite different, with the former occurring at ∼10 times faster than the latter. By varying the preheating conditions or performing pre-irradiation on an O2 exposed surface, it becomes clear that the two PSD events are uncorrelated. That is, the O2 species responsible for O2 PSD is not a significant participant in the photochemistry of acetone on TiO2(110) and likely originates from a minority form of O2 on the surface. The CH3 and O2 PSD events do not appear to be in competition with each other suggesting either that ample charge carriers exist under the experimental conditions employed or that different charge carriers or excitation mechanisms are involved

  2. Impact of UV radiation on activity of linear furanocoumarins and Bacillus thuringiensis var. kurstaki against Spodoptera exigua: Implications for tritrophic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Trumble, J.T.; Moar, W.J.; Brewer, M.J.; Carson, W.G. (Univ. of California, Riverside (United States))

    1991-05-01

    Acidic fogs with a pH of 2.0 and duration of 2 hr did not reduce the efficacy of Bacillus thuringiensis var. kurstaki. Therefore, the impact of UV radiation was investigated on the interactions between (1) levels of the antibacterial linear furanocoumarins psoralen, bergapten, and xanthotoxin in Apium graveolens (L.) occurring following a 2.0 pH acidic fog episode, (2) the noctuid Spodoptera exigua, and (3) a sublethal dosage of the microbial pathogen B. thuringiensis var. kurstaki. Mean time to pupation in the absence of UV radiation was significantly extended by the addition of either psoralens or B. thuringiensis. Larvae developing on diets containing B. thuringiensis plus psoralens required nearly 40% longer to pupate than controls, but their effects were additive as the interaction was not significant. Mean time to mortality, a weighted average time of death, was not significantly affected by any of the treatments. In a 2 {times} 2 {times} 2 factorial analysis, all main effects reduced survival significantly, as did the three-way interaction. Thus, antagonistic interactions with psoralens that would reduce the effectiveness of B. thuringiensis in the field were not observed. When pairs of main effects were nested within the two levels of the third factor, several two-way interactions were found. Interestingly, the activity of B. thuringiensis and the psoralens, individually or in combination, was enhanced by exposure to UV radiation. Implications of this research are discussed for both natural and agricultural ecosystems.

  3. Impact of UV radiation on activity of linear furanocoumarins and Bacillus thuringiensis var. kurstaki against Spodoptera exigua: Implications for tritrophic interactions

    International Nuclear Information System (INIS)

    Trumble, J.T.; Moar, W.J.; Brewer, M.J.; Carson, W.G.

    1991-01-01

    Acidic fogs with a pH of 2.0 and duration of 2 hr did not reduce the efficacy of Bacillus thuringiensis var. kurstaki. Therefore, the impact of UV radiation was investigated on the interactions between (1) levels of the antibacterial linear furanocoumarins psoralen, bergapten, and xanthotoxin in Apium graveolens (L.) occurring following a 2.0 pH acidic fog episode, (2) the noctuid Spodoptera exigua, and (3) a sublethal dosage of the microbial pathogen B. thuringiensis var. kurstaki. Mean time to pupation in the absence of UV radiation was significantly extended by the addition of either psoralens or B. thuringiensis. Larvae developing on diets containing B. thuringiensis plus psoralens required nearly 40% longer to pupate than controls, but their effects were additive as the interaction was not significant. Mean time to mortality, a weighted average time of death, was not significantly affected by any of the treatments. In a 2 x 2 x 2 factorial analysis, all main effects reduced survival significantly, as did the three-way interaction. Thus, antagonistic interactions with psoralens that would reduce the effectiveness of B. thuringiensis in the field were not observed. When pairs of main effects were nested within the two levels of the third factor, several two-way interactions were found. Interestingly, the activity of B. thuringiensis and the psoralens, individually or in combination, was enhanced by exposure to UV radiation. Implications of this research are discussed for both natural and agricultural ecosystems

  4. Response of the diatom Phaeodactylum tricornutum to photooxidative stress resulting from high light exposure.

    Directory of Open Access Journals (Sweden)

    Nuno Domingues

    Full Text Available The response of microalgae to photooxidative stress resulting from high light exposure is a well-studied phenomenon. However, direct analyses of photosystem II (PSII D1 protein (the main target of photoinhibition in diatoms are scarce. In this study, the response of the diatom model species Phaeodactylum tricornutum to short-term exposure to high light was examined and the levels of D1 protein determined immunochemically. Low light (LL acclimated cells (40 µmol photons m(-2 s(-1 subjected to high light (HL, 1,250 µmol photons m(-2 s(-1 showed rapid induction of non-photochemical quenching (NPQ and ca. 20-fold increase in diatoxanthin (DT concentration. This resulted from the conversion of diadinoxanthin (DD to DT through the activation of the DD-cycle. D1 protein levels under LL decreased about 30% after 1 h of the addition of lincomycin (LINC, a chloroplast protein synthesis inhibitor, showing significant D1 degradation and repair under low irradiance. Exposure to HL lead to a 3.2-fold increase in D1 degradation rate, whereas average D1 repair rate was 1.3-x higher under HL than LL, leading to decreased levels of D1 protein under HL. There were significant effects of both HL and LINC on P. tricornutum maximum quantum yield of PSII (F(v/F(m, showing a reduction of active PSII reaction centres. Partial recovery of F(v/F(m in the dark demonstrates the photosynthetic resilience of this diatom to changes in the light regime. P. tricornutum showed high allocation of total protein to D1 and an active D1-repair cycle to limit photoinhibition.

  5. Detection of Misdistribution of Tyrosinase from Melanosomes to Lysosomes and Its Upregulation under Psoralen/Ultraviolet A with a Melanosome-Targeting Tyrosinase Fluorescent Probe.

    Science.gov (United States)

    Zhou, Jin; Shi, Wen; Li, Lihong; Gong, Qiuyu; Wu, Xiaofeng; Li, Xiaohua; Ma, Huimin

    2016-04-19

    Tyrosinase is regarded as an important biomarker of melanoma cancer, and its metabolism is closely related to some severe skin diseases such as vitiligo. Since tyrosinase is mainly located in the melanosomes of melanocytes, a probe that can specifically detect and image tysosinase in melanosomes would be in urgent demand to study the behavior of the enzyme in cells, but unfortunately, no melanosome-targeting tyrosinase fluorescent probe has been reported so far to the best of our knowledge. In this work, we have developed such a new probe, Mela-TYR, which bears morpholine as a melanosome-targeting group and 4-aminophenol as a tyrosinase reaction group. The probe exhibits not only a highly sensitive and selective off-on response to tyrosinase via oxidization cleavage, but also an accurate targeting ability toward the acidic organelles of melanosomes and lyososomes, which is validated by colocalization experiments with mCherry-tagged melanosomes as well as DND-99 (a commercial dye). The probe has been used to image the relative contents of tyrosinase in different cells. Notably, because of the tyrosinase deficiency in normal lysosomes, the probe only fluoresces in melanosomes in principle although it can accumulate in other acidic organelles like lysosomes. By virtue of this property, the misdistribution of tyrosinase from melanosomes to lysosomes in murine melanoma B16 cells under the stimulation of inulavosin is imaged in real time for the first time. Moreover, the upregulation of melanosomal tyrosinase in live B16 cells under the stimulation of psoralen/ultraviolet A is detected with our probe, and this upregulation is further verified by standard colorimetric assay. The probe provides a simple, visual method to study the metabolism of tyrosinase in cells and shows great potential in clinical diagnosis and treatments of tyrosinase-associated diseases.

  6. Continuous Photo-Oxidation in a Vortex Reactor: Efficient Operations Using Air Drawn from the Laboratory.

    Science.gov (United States)

    Lee, Darren S; Amara, Zacharias; Clark, Charlotte A; Xu, Zeyuan; Kakimpa, Bruce; Morvan, Herve P; Pickering, Stephen J; Poliakoff, Martyn; George, Michael W

    2017-07-21

    We report the construction and use of a vortex reactor which uses a rapidly rotating cylinder to generate Taylor vortices for continuous flow thermal and photochemical reactions. The reactor is designed to operate under conditions required for vortex generation. The flow pattern of the vortices has been represented using computational fluid dynamics, and the presence of the vortices can be easily visualized by observing streams of bubbles within the reactor. This approach presents certain advantages for reactions with added gases. For reactions with oxygen, the reactor offers an alternative to traditional setups as it efficiently draws in air from the lab without the need specifically to pressurize with oxygen. The rapid mixing generated by the vortices enables rapid mass transfer between the gas and the liquid phases allowing for a high efficiency dissolution of gases. The reactor has been applied to several photochemical reactions involving singlet oxygen ( 1 O 2 ) including the photo-oxidations of α-terpinene and furfuryl alcohol and the photodeborylation of phenyl boronic acid. The rotation speed of the cylinder proved to be key for reaction efficiency, and in the operation we found that the uptake of air was highest at 4000 rpm. The reactor has also been successfully applied to the synthesis of artemisinin, a potent antimalarial compound; and this three-step synthesis involving a Schenk-ene reaction with 1 O 2 , Hock cleavage with H + , and an oxidative cyclization cascade with triplet oxygen ( 3 O 2 ), from dihydroartemisinic acid was carried out as a single process in the vortex reactor.

  7. Slow photon amplification of gas-phase ethanol photo-oxidation in titania inverse opal photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Jovic, Vedran, E-mail: vjov001@aucklanduni.ac.nz [School of Chemical Sciences, Science Centre, Building 301, 23 Symonds Street, Auckland 92019 (New Zealand); Idriss, Hicham, E-mail: IdrissH@sabic.com [Corporate Research and Development (CRD), Saudi Basic Industries Corporation (SABIC) at KAUST (Saudi Arabia); Waterhouse, Geoffrey I.N., E-mail: g.waterhouse@auckland.ac.nz [School of Chemical Sciences, Science Centre, Building 301, 23 Symonds Street, Auckland 92019 (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology (New Zealand); Dodd Walls Centre for Photonic and Quantum Technologies (New Zealand)

    2016-11-10

    Here we describe the successful fabrication of six titania inverse opal (TiO{sub 2} IO) photocatalysts with fcc[1 1 1] pseudo photonic band gaps (PBGs) tuned to span the UV–vis region. Photocatalysts were fabricated by a colloidal crystal templating and sol-gel approach – a robust and highly applicable bottom-up scheme which allowed for precise control over the geometric and optical properties of the TiO{sub 2} IO photocatalysts. Optical properties of the TiO{sub 2} IO thin films were investigated in detail by UV–vis transmittance and reflectance measurements. The PBG along the fcc[1 1 1] direction in the TiO{sub 2} IOs was dependent on the inter-planar spacing in the [1 1 1] direction, the incident angle of light and the refractive index of the medium filling the macropores in the IOs, in agreement with a modified Bragg’s law expression. Calculated photonic band structures for the photocatalysts revealed a PBG along the Γ → L direction at a/λ ∼ 0.74, in agreement with the experimental optical data. By coupling the low frequency edge of the PBG along the [1 1 1] direction with the electronic absorption edge of anatase TiO{sub 2}, a two-fold enhancement in the rate of gas phase ethanol photo-oxidation in air was achieved. This enhancement appears to be associated with a ‘slow photon’ effect that acts to both enhance TiO{sub 2} absorption and inhibit spontaneous emission (i.e. suppress electron-hole pair recombination).

  8. Genotoxic activity of 4,4',5'-trimethylazapsoralen on plasmid DNA.

    Science.gov (United States)

    Lagatolla, C; Dolzani, L; Granzotto, M; Monti-Bragadin, C

    1998-01-01

    The genotoxic activities of 8-methoxypsoralen (8-MOP) and 4,4',5'-trimethylazapsoralen (4,4',5'-TMAP) on plasmid DNA have been compared. In a previous work, 4,4',5'-TMAP, a methyl derivative of a psoralen isoster, had shown potential photochemotherapeutic activity. The mutagenic activity of mono- and bifunctional lesions caused by these compounds was evaluated both after UVA irradiation, which causes the formation of both kinds of lesions, and after a two-step irradiation procedure of the psoralen-plasmid DNA complex, which allowed monoadducts and interstrand crosslinks to be studied separately. Furthermore, we used a procedure that allowed us to evaluate both the mutagenic and recombinogenic activity of the two compounds. Results indicate that the most important difference between 8-MOP and 4,4',5'-TMAP consists in their mode of photoreaction with DNA rather than in their mutagenic potential. In fact, in all of the experimental procedures, 4,4',5'-TMAP shows a lower ability than 8-MOP to generate interstrand crosslinks. However, when comparable toxicity levels are reached, the two compounds show the same mutagenic potentiality.

  9. SU-C-204-06: Monte Carlo Dose Calculation for Kilovoltage X-Ray-Psoralen Activated Cancer Therapy (X-PACT): Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Mein, S [Duke University Medical Physics Graduate Program (United States); Gunasingha, R [Department of Radiation Safety, Duke University Medical Center (United States); Nolan, M [Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University (United States); Oldham, M; Adamson, J [Department of Radiation Oncology, Duke University Medical Center (United States)

    2016-06-15

    promise for accurate quantification of dose for this novel psoralen X-ray therapy. Funding Support, Disclosures, & Conflict of Interest: The Monte Carlo simulation work was not funded; Drs. Adamson & Oldham have received funding from Immunolight LLC for X-PACT research.

  10. Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

    Science.gov (United States)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vázquez, M.; Borrás, E.; Ródenas, M.

    2014-06-01

    The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound (VOC) that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high-performance liquid chromatography mass spectrometry (HPLC-ITMS), high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18 and 29% for an initial VOC mixing ratio of 212 and 460 ppbv (parts per billion by volume) respectively; using a VOC:NOx ratio of ~5:1. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high-resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro-functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O:C ratios, where functionalisation rather than fragmentation is mainly observed as a result of the stability of the ring. The SOA species observed can be characterised as semi-volatile to low-volatility oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

  11. Oxidative potential of secondary organic aerosols produced from photooxidation of different hydrocarbons using outdoor chamber under ambient sunlight

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Sabo-Attwood, Tara; Robinson, Sarah E.

    2016-04-01

    The oxidative potential of various secondary organic aerosols (SOA) was measured using dithiothreitol (DTT) assay to understand how organic aerosols react with cellular materials. SOA was produced via the photooxidation of four different hydrocarbons (toluene, 1,3,5-trimethylbenzene, isoprene and α-pinene) in the presence of NOx using a large outdoor photochemical smog chamber. The DTT consumption rate was normalized by the aerosol mass, which is expressed as DTTmass. Toluene SOA and isoprene SOA yielded higher DTTmass than 1,3,5-trimethylbenzene SOA or α-pinene SOA. In order to discover the correlation between the molecular structure and oxidative potential, the DTT responses of selected model compounds were also measured. Among them, conjugated aldehydes, quinones, and H2O2 showed considerable DTT response. To investigate the correlation between DTT response and cell responses in vitro, the expression of biological markers, i.e. IL-6, IL-8, and HMOX-1 were studied using small airway epithelial cells. Higher cellular expression of IL-8 was observed with toluene SOA exposure compared to 1,3,5-trimethylbenzene SOA exposure, which aligned with the results from DTT assay. Our study also suggests that within the urban atmosphere, the contribution of toluene SOA and isoprene SOA to the oxidative potential of ambient SOA will be more significant than that of α-pinene SOA.

  12. The Arabidopsis aba4-1 mutant reveals a specific function for neoxanthin in protection against photooxidative stress.

    Science.gov (United States)

    Dall'Osto, Luca; Cazzaniga, Stefano; North, Helen; Marion-Poll, Annie; Bassi, Roberto

    2007-03-01

    The aba4-1 mutant completely lacks neoxanthin but retains all other xanthophyll species. The missing neoxanthin in light-harvesting complex (Lhc) proteins is compensated for by higher levels of violaxanthin, albeit with lower capacity for photoprotection compared with proteins with wild-type levels of neoxanthin. Detached leaves of aba4-1 were more sensitive to oxidative stress than the wild type when exposed to high light and incubated in a solution of photosensitizer agents. Both treatments caused more rapid pigment bleaching and lipid oxidation in aba4-1 than wild-type plants, suggesting that neoxanthin acts as an antioxidant within the photosystem II (PSII) supercomplex in thylakoids. While neoxanthin-depleted Lhc proteins and leaves had similar sensitivity as the wild type to hydrogen peroxide and singlet oxygen, they were more sensitive to superoxide anions. aba4-1 intact plants were not more sensitive than the wild type to high-light stress, indicating the existence of compensatory mechanisms of photoprotection involving the accumulation of zeaxanthin. However, the aba4-1 npq1 double mutant, lacking zeaxanthin and neoxanthin, underwent stronger PSII photoinhibition and more extensive oxidation of pigments than the npq1 mutant, which still contains neoxanthin. We conclude that neoxanthin preserves PSII from photoinactivation and protects membrane lipids from photooxidation by reactive oxygen species. Neoxanthin appears particularly active against superoxide anions produced by the Mehler's reaction, whose rate is known to be enhanced in abiotic stress conditions.

  13. Identifying the distinct features of geometric structures for hole trapping to generate radicals on rutile TiO₂(110) in photooxidation using density functional theory calculations with hybrid functional.

    Science.gov (United States)

    Wang, Dong; Wang, Haifeng; Hu, P

    2015-01-21

    Using density functional theory calculations with HSE 06 functional, we obtained the structures of spin-polarized radicals on rutile TiO2(110), which is crucial to understand the photooxidation at the atomic level, and further calculate the thermodynamic stabilities of these radicals. By analyzing the results, we identify the structural features for hole trapping in the system, and reveal the mutual effects among the geometric structures, the energy levels of trapped hole states and their hole trapping capacities. Furthermore, the results from HSE 06 functional are compared to those from DFT + U and the stability trend of radicals against the number of slabs is tested. The effect of trapped holes on two important steps of the oxygen evolution reaction, i.e. water dissociation and the oxygen removal, is investigated and discussed.

  14. The effect of polyamines on the photochemical reactivity of DNA

    International Nuclear Information System (INIS)

    Ben-Hur, E.; Hebrew Univ., Jerusalem

    1975-01-01

    The effects of diaminopentane (cadaverine), diaminoethane and the polyamine, spermine, on the photoreactions of 4,5', 8-trimethylpsoralen with DNA were studied. Near ultraviolet (UV) light (360 nm) irradiation of psoralen with DNA results in the formation of psoralen monoadducts with pyrimidine bases and DNA interstrand crosslinks. The polyamines studied reduced the rate of both photoreactions to the same extent by a factor of 1.5-2.0. The magnitude of the effect increased with polyamine concentration. Effectiveness was in the order spermine > cadaverine > diaminoethane. This is also the same order for stabilization of the DNA double-helix. Under conditions of higher DNA stability (higher ionic strength), higher polyamine concentrations were required to obtain an effect which was smaller than at low ionic strength. It is concluded that the photoreactions of psoralen with pyrimidines in DNA require some distortion of the double-helix. This distortion is made more difficult in the presence of stabilizing agents like polyamines and therefore the rate of the reaction is reduced. If crosslinking of DNA by psoralen is a two-step reaction then it must be concluded that the second step does not require further distortion. Consistently with the above, polyamines also reduced the UV-induced dimerization of thymine in DNA, although to a lesser extent. (author)

  15. The reactivities of furocoumarin excited states with DNA in solution. A laser flash photolysis and fluorescence study.

    Science.gov (United States)

    Beaumont, P C; Parsons, B J; Navaratnam, S; Phillips, G O; Allen, J C

    1980-07-29

    The effect of DNA on both the fluorescence emission spectra and yields and lifetimes of the triplet stae of psoralen and 8-methoxypsoralen in aqueous solution has been determined. The changes in the fluorescence spectra are similar in nature for both of these furocoumarins and are attributed to binding of the drug to DNA. The yield of the 8-methoxypsoralen triplet state when bound to DNA was found to be similar, if not identical, to that measured in the absence of DNA. This contrasts sharply with data obtained for psoralen from which it is concluded that either the yield of bound psoralen triplet states is very low, if not zero, or that the lifetime of such species is less than 50 ns. The relevance of this data to the molecular basis of skin photosensitisation by furocoumarins is discussed.

  16. RpoH2 sigma factor controls the photooxidative stress response in a non-photosynthetic rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kumar, Santosh; Rai, Ashutosh Kumar; Mishra, Mukti Nath; Shukla, Mansi; Singh, Pradhyumna Kumar; Tripathi, Anil Kumar

    2012-12-01

    Bacteria belonging to the Alphaproteobacteria normally harbour multiple copies of the heat shock sigma factor (known as σ(32), σ(H) or RpoH). Azospirillum brasilense, a non-photosynthetic rhizobacterium, harbours five copies of rpoH genes, one of which is an rpoH2 homologue. The genes around the rpoH2 locus in A. brasilense show synteny with that found in rhizobia. The rpoH2 of A. brasilense was able to complement the temperature-sensitive phenotype of the Escherichia coli rpoH mutant. Inactivation of rpoH2 in A. brasilense results in increased sensitivity to methylene blue and to triphenyl tetrazolium chloride (TTC). Exposure of A. brasilense to TTC and the singlet oxygen-generating agent methylene blue induced several-fold higher expression of rpoH2. Comparison of the proteome of A. brasilense with its rpoH2 deletion mutant and with an A. brasilense strain overexpressing rpoH2 revealed chaperone GroEL, elongation factors (Ef-Tu and EF-G), peptidyl prolyl isomerase, and peptide methionine sulfoxide reductase as the major proteins whose expression was controlled by RpoH2. Here, we show that the RpoH2 sigma factor-controlled photooxidative stress response in A. brasilense is similar to that in the photosynthetic bacterium Rhodobacter sphaeroides, but that RpoH2 is not involved in the detoxification of methylglyoxal in A. brasilense.

  17. The Arabidopsis aba4-1 Mutant Reveals a Specific Function for Neoxanthin in Protection against Photooxidative Stress[W

    Science.gov (United States)

    Dall'Osto, Luca; Cazzaniga, Stefano; North, Helen; Marion-Poll, Annie; Bassi, Roberto

    2007-01-01

    The aba4-1 mutant completely lacks neoxanthin but retains all other xanthophyll species. The missing neoxanthin in light-harvesting complex (Lhc) proteins is compensated for by higher levels of violaxanthin, albeit with lower capacity for photoprotection compared with proteins with wild-type levels of neoxanthin. Detached leaves of aba4-1 were more sensitive to oxidative stress than the wild type when exposed to high light and incubated in a solution of photosensitizer agents. Both treatments caused more rapid pigment bleaching and lipid oxidation in aba4-1 than wild-type plants, suggesting that neoxanthin acts as an antioxidant within the photosystem II (PSII) supercomplex in thylakoids. While neoxanthin-depleted Lhc proteins and leaves had similar sensitivity as the wild type to hydrogen peroxide and singlet oxygen, they were more sensitive to superoxide anions. aba4-1 intact plants were not more sensitive than the wild type to high-light stress, indicating the existence of compensatory mechanisms of photoprotection involving the accumulation of zeaxanthin. However, the aba4-1 npq1 double mutant, lacking zeaxanthin and neoxanthin, underwent stronger PSII photoinhibition and more extensive oxidation of pigments than the npq1 mutant, which still contains neoxanthin. We conclude that neoxanthin preserves PSII from photoinactivation and protects membrane lipids from photooxidation by reactive oxygen species. Neoxanthin appears particularly active against superoxide anions produced by the Mehler's reaction, whose rate is known to be enhanced in abiotic stress conditions. PMID:17351115

  18. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    International Nuclear Information System (INIS)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal

  19. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal.

  20. Spectroscopic properties and photoreactivity with DNA of new monofunctional pyridopsoralens

    International Nuclear Information System (INIS)

    Blais, J.; Vigny, P.; Moron, J.; Bisagni, E.

    1984-01-01

    New psoralen derivatives have been synthesized in order to enhance their affinity towards DNA. The spectral properties (absorption, fluorescence emission, fluorescence quantum yield) and the photostability of pyrido[3,4-c]psoralen are first reported. The drastic changes observed in the solubility and in the fluorescence emission when these compounds are added to native DNA give evidence of the formation of non covalent dark complexes. Upon UV irradiation (365 nm) of the complexes, a photobinding occurs. Heat denaturation and renaturation experiments of modified DNA show that only monoadducts are formed. From the analysis of their fluorescence properties the involvement of the 4',5' double bond is assumed. The monofunctional character has also been established for psoralens having a fused pyridine ring in the 4',5' site. However, a fused tetrahydropyrido group in the 4',5' site is inefficient to inactivate this reactive site. (author)

  1. Spectroscopic properties and photoreactivity with DNA of new monofunctional pyridopsoralens

    Energy Technology Data Exchange (ETDEWEB)

    Blais, J.; Vigny, P. (Institut Curie et Universite Paris VI (France). Lab. de Physique et Chimie Biomoleculaire); Moron, J.; Bisagni, E. (Lab. de Synthese Organique, Institut Curie, Orsay (France). Section de Biologie)

    1984-02-01

    New psoralen derivatives have been synthesized in order to enhance their affinity towards DNA. The spectral properties (absorption, fluorescence emission, fluorescence quantum yield) and the photostability of pyrido(3,4-c)psoralen are first reported. The drastic changes observed in the solubility and in the fluorescence emission when these compounds are added to native DNA give evidence of the formation of non covalent dark complexes. Upon UV irradiation (365 nm) of the complexes, a photobinding occurs. Heat denaturation and renaturation experiments of modified DNA show that only monoadducts are formed. From the analysis of their fluorescence properties the involvement of the 4',5' double bond is assumed. The monofunctional character has also been established for psoralens having a fused pyridine ring in the 4',5' site. However, a fused tetrahydropyrido group in the 4',5' site is inefficient to inactivate this reactive site.

  2. Exploring surface photoreaction dynamics using pixel imaging mass spectrometry (PImMS)

    Science.gov (United States)

    Kershis, Matthew D.; Wilson, Daniel P.; White, Michael G.; John, Jaya John; Nomerotski, Andrei; Brouard, Mark; Lee, Jason W. L.; Vallance, Claire; Turchetta, Renato

    2013-08-01

    A new technique for studying surface photochemistry has been developed using an ion imaging time-of-flight mass spectrometer in conjunction with a fast camera capable of multimass imaging. This technique, called pixel imaging mass spectrometry (PImMS), has been applied to the study of butanone photooxidation on TiO2(110). In agreement with previous studies of this system, it was observed that the main photooxidation pathway for butanone involves ejection of an ethyl radical into vacuum which, as confirmed by our imaging experiment, undergoes fragmentation after ionization in the mass spectrometer. This proof-of-principle experiment illustrates the usefulness and applicability of PImMS technology to problems of interest within the surface science community.

  3. Biotransformation of furanocoumarins by Cunninghamella elegans

    Directory of Open Access Journals (Sweden)

    Ghada Ismail El-shahat Ali Attia

    2015-06-01

    Full Text Available Biotransformation of Furanocoumarins; psoralen (1, bergapten (2, xanthotoxin (3 and imperatorin (4 was explored by Cunninghamella elegans NRRL 1392, revealing the metabolism of psoralen (1 and bergapten (2 into bergaptol (5, while xanthotoxin (3 and imperatorin (4 were converted into xanthotoxol (6. On the other hand unexpected conversion of xanthotoxin (3 into 3,4 dihydroxanthotoxin (7 occurred. The structure of the isolated pure metabolites was established using physical and spectroscopic techniques including, melting points, IR, 1H NMR, 13C NMR and mass spectroscopy.

  4. Photo(chemotherapy for Vitiligo

    Directory of Open Access Journals (Sweden)

    Güzin Özarmağan

    2010-12-01

    Full Text Available Vitiligo is a skin disease having an impact on the quality of life. Phototherapy or photochemotherapy are the first-line treatment choices in generalized vitiligo and are among the most effective treatment modalities either alone or in combination with other therapies. Treatment methods with ultraviolet include oral / topical psoralen plus UVA (PUVA, psoralen plus sunlight (PUVAsol, UVA, broadband UVB, narrowband UVB, excimer laser, monochromatic excimer light and sunlight. This review focuses on the modalities, principals and studies of UV treatment in vitiligo.

  5. Acute exposure to UV-B sensitizes cucumber, tomato, and Arabidopsis plants to photooxidative stress by inhibiting thermal energy dissipation and antioxidant defense

    International Nuclear Information System (INIS)

    Moon, Yu-Ran; Lee, Min-Hee; Chung, Byung-Yeoup; Kim, Jin-Hong; Tovuu, Altanzaya; Lee, Choon-Hwan; Park, Youn-Il

    2011-01-01

    The purpose of this study was to characterize a change in Non-photochemical quenching (NPQ) upon exposure to ultraviolet-B (UV-B), the xanthophyll cycle-dependent and -independent NPQs were compared in Cucumis sativus, Lycopersicum esculentum, and Arabidopsis thaliana leaves. The xanthophyll cycle-dependent NPQ was dramatically but reversibly suppressed by UV-B radiation. This suppression was correlated more strongly with a marked decrease in photosynthetic electron transport rather than changes in xanthophyll cycle enzymes such as violaxanthin de-epoxidase and zeaxanthin epoxidase. Accordingly, the UV-B-induced suppression of NPQ cannot be attributed to changes in expressions of violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP). However, suppression of the xanthophyll cycle-dependent NPQ could only account for the 77 K fluorescence emission spectra of thylakoid membranes and the increased level of 1 O 2 production, but not for the decreased levels of hydroxyl radical O 2 - production and H 2 O 2 scavenging. These results suggest that a gradual reduction of H 2 O 2 scavenging activity as well as a transient and reversible suppression of thermal energy dissipation may contribute differentially to increased photooxidative damages in cucumber, tomato, and Arabidopsis plants after acute exposure to UV-B radiation. (author)

  6. Understanding isoprene photooxidation using observations and modeling over a subtropical forest in the southeastern US

    Directory of Open Access Journals (Sweden)

    L. Su

    2016-06-01

    Full Text Available The emission, dispersion, and photochemistry of isoprene (C5H8 and related chemical species in the convective boundary layer (CBL during sunlit daytime were studied over a mixed forest in the southeastern United States by combining ground-based and aircraft observations. Fluxes of isoprene and monoterpenes were quantified at the top of the forest canopy using a high-resolution proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS. Snapshot (∼  2 min sampling duration vertical profiles of isoprene, methyl vinyl ketone (MVK + methacrolein (MACR, and monoterpenes were collected from aircraft every hour in the CBL (100–1000 m. Both ground-based and airborne collected volatile organic compound (VOC data are used to constrain the initial conditions of a mixed-layer chemistry model (MXLCH, which is applied to examine the chemical evolution of the O3–NOx–HOx–VOC system and how it is affected by boundary layer dynamics in the CBL. The chemical loss rate of isoprene (∼  1 h is similar to the turbulent mixing timescale (0.1–0.5 h, which indicates that isoprene concentrations are equally dependent on both photooxidation and boundary layer dynamics. Analysis of a model-derived concentration budget suggests that diurnal evolution of isoprene inside the CBL is mainly controlled by surface emissions and chemical loss; the diurnal evolution of O3 is dominated by entrainment. The NO to HO2 ratio (NO : HO2 is used as an indicator of anthropogenic impact on the CBL chemical composition and spans a wide range (1–163. The fate of hydroxyl-substituted isoprene peroxyl radical (HOC5H8OO·; ISOPOO is strongly affected by NO : HO2, shifting from NO-dominant to NO–HO2-balanced conditions from early morning to noontime. This chemical regime change is reflected in the diurnal evolution of isoprene hydroxynitrates (ISOPN and isoprene hydroxy hydroperoxides (ISOPOOH.

  7. Gas-phase products and secondary organic aerosol formation from the ozonolysis and photooxidation of myrcene

    Science.gov (United States)

    Böge, Olaf; Mutzel, Anke; Iinuma, Yoshiteru; Yli-Pirilä, Pasi; Kahnt, Ariane; Joutsensaari, Jorma; Herrmann, Hartmut

    2013-11-01

    In this study, the ozone and OH-radical reactions of myrcene were investigated in an aerosol chamber (at 292-295 K and 50% relative humidity) to examine the gas-phase oxidation products and secondary organic aerosol (SOA) formation. The ozone reaction studies were performed in the presence and absence of CO, which serves as an OH radical scavenger. In the photooxidation experiments OH radicals were generated by photolysis of methyl nitrite. The ozonolysis of myrcene in the presence of CO resulted in a substantial yield of 4-vinyl-4-pentenal (55.3%), measured as m/z 111 plus m/z 93 using proton transfer reaction-mass spectrometry (PTR-MS) and confirmed unambiguously as C7H10O by denuder measurements and HPLC/ESI-TOFMS analysis of its 2,4-dinitrophenylhydrazine (DNPH) derivative. Additionally, the formation of two different organic dicarbonyls with m/z 113 and a molecular formula of C6H8O2 were observed (2.1%). The yields of these dicarbonyls were higher in the ozonolysis experiments without an OH scavenger (5.4%) and even higher (13.8%) in the myrcene OH radical reaction. The formation of hydroxyacetone as a direct product of the myrcene reaction with ozone with a molar yield of 17.6% was also observed. The particle size distribution and volume concentrations were monitored and facilitated the calculation of SOA yields, which ranged from 0 to 0.01 (ozonolysis in the presence of CO) to 0.39 (myrcene OH radical reaction). Terpenylic acid was found in the SOA samples collected from the ozonolysis of myrcene in the absence of an OH scavenger and the OH radical-initiated reaction of myrcene but not in samples collected from the ozonolysis in the presence of CO as an OH radical scavenger, suggesting that terpenylic acid formation involves the reaction of myrcene with an OH radical. A reaction mechanism describing the formation of terpenylic acid is proposed.

  8. New Limonoids from Hortia oreadica and Unexpected Coumarin from H. superba Using Chromatography over Cleaning Sephadex with Sodium Hypochlorite

    Directory of Open Access Journals (Sweden)

    Vanessa G.P. Severino

    2014-08-01

    Full Text Available Previous investigations of H. oreadica reported the presence of a wide spectrum of complex limonoids and dihydrocinnamic acids. Our interest in the Rutaceae motivated a reinvestigation of H. oreadica, H. brasiliana and H. superba searching for other secondary metabolites present in substantial amounts for taxonomic analysis. In a continuation of the investigation of the H. oreadica, three new limonoids have now been isolated 9α-hydroxyhortiolide A, 11β-hydroxyhortiolide C and 1(S*-acetoxy-7(R*-hydroxy-7-deoxoinchangin. All the isolated compounds from the Hortia species reinforce its position in the Rutaceae. With regard to limonoids the genus produces highly specialized compounds, whose structural variations do not occur in any other member of the Rutaceae, thus, it is evident from limonoid data that Hortia takes an isolated position within the family. In addition, H. superba afforded the unexpected coumarin 5-chloro-8-methoxy-psoralen, which may not be a genuine natural product. Solid-state cross-polarisation/magic-angle-spinning 13C nuclear magnetic resonance, X-Ray fluorescence and Field-emission gun scanning electron microscopy experiments show that the Sephadex LH-20 was modified after treatment with NaOCl, suggesting that when xanthotoxin (8-methoxy-psoralen was extracted from cleaning of the gel column, chlorination of the aromatic system occurred.

  9. Photooxidative removal of Hg0 from simulated flue gas using UV/H2O2 advanced oxidation process: Influence of operational parameters

    International Nuclear Information System (INIS)

    Zhang, Bo; Zhong, Zhaoping; Ding, Kuan; Yu, Lulu

    2014-01-01

    Element mercury (Hg 0 ) from flue gas is difficult to remove because of its low solubility in water and high volatility. A new technology for photooxidative removal of Hg 0 with an ultraviolet (UV)/H 2 O 2 advanced oxidation process is studied in an efficient laboratory-scale bubble column reactor. Influence of several key operational parameters on Hg 0 removal efficiency is investigated. The results show that an increase in the UV light power, H 2 O 2 initial concentration or H 2 O 2 solution volume will enhance Hg 0 removal. The Hg 0 removal is inhibited by an increase of the Hg 0 initial concentration. The solution initial pH and pH conditioning agent have a remarkable synergistic effect. The highest Hg 0 removal efficiencies are achieved at the UV light power of 36W, H 2 O 2 initial concentration of 0.125 mol/L, Hg 0 initial concentration of 25.3 - g/Nm 3 , solution initial pH of 5, H 2 O 2 solution volume of 600 ml, respectively. In addition, the O 2 percentage has little effect on the Hg 0 removal efficiency. This study is beneficial for the potential practical application of Hg 0 removal from coal-fired flue gas with UV/H 2 O 2 advanced oxidation process

  10. Molecular characterization of urban organic aerosol in tropical India: contributions of primary emissions and secondary photooxidation

    Directory of Open Access Journals (Sweden)

    P. Q. Fu

    2010-03-01

    Full Text Available Organic molecular composition of PM10 samples, collected at Chennai in tropical India, was studied using capillary gas chromatography/mass spectrometry. Fourteen organic compound classes were detected in the aerosols, including aliphatic lipids, sugar compounds, lignin products, terpenoid biomarkers, sterols, aromatic acids, hydroxy-/polyacids, phthalate esters, hopanes, Polycyclic Aromatic Hydrocarbons (PAHs, and photooxidation products from biogenic Volatile Organic Compounds (VOCs. At daytime, phthalate esters were found to be the most abundant compound class; however, at nighttime, fatty acids were the dominant one. Di-(2-ethylhexyl phthalate, C16 fatty acid, and levoglucosan were identified as the most abundant single compounds. The nighttime maxima of most organics in the aerosols indicate a land/sea breeze effect in tropical India, although some other factors such as local emissions and long-range transport may also influence the composition of organic aerosols. However, biogenic VOC oxidation products (e.g., 2-methyltetrols, pinic acid, 3-hydroxyglutaric acid and β-caryophyllinic acid showed diurnal patterns with daytime maxima. Interestingly, terephthalic acid was maximized at nighttime, which is different from those of phthalic and isophthalic acids. A positive relation was found between 1,3,5-triphenylbenzene (a tracer for plastic burning and terephthalic acid, suggesting that the field burning of municipal solid wastes including plastics is a significant source of terephthalic acid. Organic compounds were further categorized into several groups to clarify their sources. Fossil fuel combustion (24–43% was recognized as the most significant source for the total identified compounds, followed by plastic emission (16–33%, secondary oxidation (8.6–23%, and microbial/marine sources (7.2–17%. In contrast, the contributions of terrestrial plant waxes (5.9–11% and biomass burning (4.2–6.4% were relatively

  11. Phototherapeutic, photobiologic, and photosensitizing properties of khellin

    International Nuclear Information System (INIS)

    Morliere, P.; Hoenigsmann, H.A.; Averbeck, D.; Dardalhon, M.; Hueppe, G.O.; Ortel, B.; Santus, R.; Dubertret, L.

    1988-01-01

    Khellin, whose chemical structure closely resembles that of psoralen, is reported to be an efficient drug for treating vitiligo when combined with ultraviolet A irradiation. Photobiological activity on yeast is found to be much lower than that of bifunctional psoralens such as 5-methoxypsoralen. In vitro experiments reveal that khellin is a poor photosensitizer. It behaves as a monofunctional agent with respect to DNA photoaddition. It does not photoinduce cross-links in DNA in vitro or in Chinese hamster cells in vivo. This behavior may explain the low photogenotoxicity in yeast and the lack of phototoxic erythemal response when treating vitiligo with khellin

  12. In-cloud multiphase behaviour of acetone in the troposphere: gas uptake, Henry's law equilibrium and aqueous phase photooxidation.

    Science.gov (United States)

    Poulain, Laurent; Katrib, Yasmine; Isikli, Estelle; Liu, Yao; Wortham, Henri; Mirabel, Philippe; Le Calvé, Stéphane; Monod, Anne

    2010-09-01

    Acetone is ubiquitous in the troposphere. Several papers have focused in the past on its gas phase reactivity and its impact on tropospheric chemistry. However, acetone is also present in atmospheric water droplets where its behaviour is still relatively unknown. In this work, we present its gas/aqueous phase transfer and its aqueous phase photooxidation. The uptake coefficient of acetone on water droplets was measured between 268 and 281K (γ=0.7 x 10(-2)-1.4 x 10(-2)), using the droplet train technique coupled to a mass spectrometer. The mass accommodation coefficient α (derived from γ) was found in the range (1.0-3.0±0.25) x 10(-2). Henry's law constant of acetone was directly measured between 283 and 298K using a dynamic equilibrium system (H((298K))=(29±5)Matm(-1)), with the Van't Hoff expression lnH(T)=(5100±1100)/T-(13.4±3.9). A recommended value of H was suggested according to comparison with literature. The OH-oxidation of acetone in the aqueous phase was carried out at 298K, under two different pH conditions: at pH=2, and under unbuffered conditions. In both cases, the formation of methylglyoxal, formaldehyde, hydroxyacetone, acetic acid/acetate and formic acid/formate was observed. The formation of small amounts of four hydroperoxides was also detected, and one of them was identified as peroxyacetic acid. A drastic effect of pH was observed on the yields of formaldehyde, one hydroperoxide, and, (to a lesser extent) acetic acid/acetate. Based on the experimental observations, a chemical mechanism of OH-oxidation of acetone in the aqueous phase was proposed and discussed. Atmospheric implications of these findings were finally discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Stabilization of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine thin film morphology with UV light

    Energy Technology Data Exchange (ETDEWEB)

    Tomović, A.Ž.; Markešević, N. [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Scarpellini, M.; Bovio, S. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Lucenti, E. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Institute of Molecular Science and Technology of CNR, via Golgi 19, 20133 Milan (Italy); Milani, P. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy); Zikic, R. [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Jovanović, V.P., E-mail: vladimir.jovanovic@ipb.ac.rs [Institute of Physics, University of Belgrade, Pregrevica 118, 11000 Belgrade (Serbia); Srdanov, V.I. [Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMAINA), Università di Milano, Via Celoria 16, 20133 Milan (Italy)

    2014-07-01

    Owing to their low glass transition temperature, T{sub g}, amorphous thin films of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) undergo morphological changes even at room temperature. It has been noticed previously that exposure to UV light can increase apparent T{sub g} of TPD films and thus stabilize their morphology. However, the reason behind increase in structural stability was not examined at the time. Here we present evidence that TPD molecules undergo photo-oxidation in air when exposed to λ ≈ 350 nm radiation and that less than 5% of the photo-oxidized species are needed to prevent dewetting of thin TPD films. We propose that photo-oxidized TPD species bind strongly to both ordinary TPD molecules and to terminal hydroxyl groups at the substrate surface, which decreases mobility of TPD molecules and makes thin TPD film less prone to morphology changes. - Highlights: • We made variable thickness TPD films and exposed them to UV light under ambient conditions. • Mass spectroscopy and proton NMR measurements of irradiated and pristine TPD films • TPD molecules undergo oxidation process under UV light irradiation. • Dipole–dipole interactions may be responsible for stabilization of morphological changes.

  14. Structural specificity in the lethal and mutagenic activity of furocoumarins in yeast cells

    International Nuclear Information System (INIS)

    Averbeck, D.; Chandra, P.; Biswas, R.K.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Frankfurt am Main

    1975-01-01

    Using monofunctional (Angelicin) and bifunctional furocoumarins (Psoralen and 8 Methoxypsoralen) plus 365 nm light it is shown that both kinds of damage, the induced monoadducts and/or crosslinks in DNA, provoke lethal and mutagenic effects in haploid and diploid cells of Saccharomyces cerevisiae. Bifunctional furocoumarins are about 20 times more effective in cell killing than Angelicin. Diploid cells are always more resistant than haploid cells. Dark repair (agar holding) increases survival. This effect can be at least in part correlated to the release of bound material from DNA in dark repair conditions. Bifunctional psoralens (10 μg/ml) are at least 10-fold more effective in inducing nuclear gene back mutations (his - to HIS + ) than Angelicin (10 μg/ml) plus 365 nm light or 254 nm ultraviolet light. In contrast cytoplasmic 'petite' (rho-) mutations are about as frequently induced by Angelicin plus 365 nm light as by 254 nm UV light. Bifunctional furocoumarins are less effective. The frequency of cytoplasmic 'petite' mutations per survivors decreases during dark repair conditions more efficiently after Angelicin than after Psoralen plus 365 nm light treatment. (orig.) [de

  15. TiO_2 assisted photo-oxidation of wastewater prior to voltammetric determination of trace metals: Eco-friendly alternative to traditional digestion methods

    International Nuclear Information System (INIS)

    Lejbt, Beata; Ospina-Alvarez, Natalia; Miecznikowski, Krzysztof; Krasnodębska-Ostręga, Beata

    2016-01-01

    Highlights: • Cheap and eco-friendly method using anatase-assisted photodecomposition to pre-treat wastewater samples prior to trace metal analysis. • Addition of polyvinylidene fluoride did not affect the efficiency of organic matter decomposition. • TiO_2 assisted photo-oxidation procedure is equally effective than ICP MS determination after UV assisted digestion with H_2O_2 addition. - Abstract: Voltammetry is a sensitive method for metal determination and one alternative to ICP MS, but its limitation is the influence of the organic matrix on the measurements. To avoid those interferences, wet digestion with H_2O_2 accelerated with UV irradiation is applied and evaporation of excess of reagents is required. In this study, photolytic oxidation in quartz tubes with anatase was carried out, using as object of study wastewater samples with high amount of organic matter. Cadmium and lead determination was carried out in order to test metal recoveries. Lead recoveries reached c.a 85% for UV digestion with hydrogen peroxide, 98% for digestion with anatase immobilized with polyvinylidene fluoride (N-metylo-2-pirolidon) and c.a 103% for digestion with immobilized anatase (anatase in gum). The results obtained showed the usefulness of TiO_2 layer as an oxidation medium. An easy, cheap and eco-friendly digestion method of surfactants without any reagent has been developed, with equal sensitivity but and the same detection limit of traditional digestion methods.

  16. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Yu, Zechen

    2017-08-01

    When hydrocarbons (HCs) are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs). These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes) and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs) to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t = 30 min) of dithiothreitol (DTTt), a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2-5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC / NOx ratio from 30 to 5). The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm) was determined over an extended period of reaction time (t = 2 h) to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC / NOx ratio: 5-36 ppbC ppb-1) applied in this study, the amount of organic hydroperoxides was

  17. TiO{sub 2} assisted photo-oxidation of wastewater prior to voltammetric determination of trace metals: Eco-friendly alternative to traditional digestion methods

    Energy Technology Data Exchange (ETDEWEB)

    Lejbt, Beata; Ospina-Alvarez, Natalia; Miecznikowski, Krzysztof, E-mail: kmiecz@chem.uw.edu.pl; Krasnodębska-Ostręga, Beata, E-mail: bekras@chem.uw.edu.pl

    2016-12-01

    Highlights: • Cheap and eco-friendly method using anatase-assisted photodecomposition to pre-treat wastewater samples prior to trace metal analysis. • Addition of polyvinylidene fluoride did not affect the efficiency of organic matter decomposition. • TiO{sub 2} assisted photo-oxidation procedure is equally effective than ICP MS determination after UV assisted digestion with H{sub 2}O{sub 2} addition. - Abstract: Voltammetry is a sensitive method for metal determination and one alternative to ICP MS, but its limitation is the influence of the organic matrix on the measurements. To avoid those interferences, wet digestion with H{sub 2}O{sub 2} accelerated with UV irradiation is applied and evaporation of excess of reagents is required. In this study, photolytic oxidation in quartz tubes with anatase was carried out, using as object of study wastewater samples with high amount of organic matter. Cadmium and lead determination was carried out in order to test metal recoveries. Lead recoveries reached c.a 85% for UV digestion with hydrogen peroxide, 98% for digestion with anatase immobilized with polyvinylidene fluoride (N-metylo-2-pirolidon) and c.a 103% for digestion with immobilized anatase (anatase in gum). The results obtained showed the usefulness of TiO{sub 2} layer as an oxidation medium. An easy, cheap and eco-friendly digestion method of surfactants without any reagent has been developed, with equal sensitivity but and the same detection limit of traditional digestion methods.

  18. A Model Study of the Photochemical Fate of As(III in Paddy-Water

    Directory of Open Access Journals (Sweden)

    Luca Carena

    2017-03-01

    Full Text Available The APEX (Aqueous Photochemistry of Environmentally-occurring Xenobiotics software previously developed by one of us was used to model the photochemistry of As(III in paddy-field water, allowing a comparison with biotic processes. The model included key paddy-water variables, such as the shielding effect of the rice canopy on incident sunlight and its monthly variations, water pH, and the photochemical parameters of the chromophoric dissolved organic matter (CDOM occurring in paddy fields. The half-life times (t1/2 of As(III photooxidation to As(V would be ~20–30 days in May. In contrast, the photochemical oxidation of As(III would be much slower in June and July due to rice-canopy shading of radiation because of plant growth, despite higher sunlight irradiance. At pH < 8 the photooxidation of As(III would mainly be accounted for by reaction with transient species produced by irradiated CDOM (here represented by the excited triplet states 3CDOM*, neglecting the possibly more important reactions with poorly known species such as the phenoxy radicals and, to a lesser extent, with the hydroxyl radicals (HO•. However, the carbonate radicals (CO3•− could be key photooxidants at pH > 8.5 provided that the paddy-water 3CDOM* is sufficiently reactive toward the oxidation of CO32−. In particular, if paddy-water 3CDOM* oxidizes the carbonate anion with a second-order reaction rate constant near (or higher than 106 M−1·s−1, the photooxidation of As(III could be quite fast at pH > 8.5. Such pH conditions can be produced by elevated photosynthetic activity that consumes dissolved CO2.

  19. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Directory of Open Access Journals (Sweden)

    H. Jiang

    2017-08-01

    Full Text Available When hydrocarbons (HCs are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs. These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t =  30 min of dithiothreitol (DTTt, a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2–5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC ∕ NOx ratio from 30 to 5. The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm was determined over an extended period of reaction time (t =  2 h to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC ∕ NOx ratio: 5–36 ppbC ppb−1 applied in

  20. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  1. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light

    International Nuclear Information System (INIS)

    Bauluz, C.; Vidania, R.

    1990-01-01

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adducts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ('hot spots'). (author)

  2. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light. Localizacion puntual de mutaciones producidas en PBR322 por tratamiento con 8-metoxipsoraleno mas luz ultravioleta-A

    Energy Technology Data Exchange (ETDEWEB)

    Bauluz, C.; Vidania, R.

    1990-01-01

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adduts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ([sup h]ot spots[sup )]. (author)

  3. Mutation spectrum produced on PBR322 by 8-Methoxypsoralen plus UV-A light; Localizacion puntual de mutaciones producidas en PBR322 por tratamiento con 8-metoxipsoraleno mas luz ultravioleta-A

    Energy Technology Data Exchange (ETDEWEB)

    Bauluz, C.; Vidania, R.

    1990-12-31

    The mutagenic effect of 8-MOP+UVA (PUVA treatment) on pBR322 has been analysed by determining the frequency of mutation in the tet gene and identifying the type and position of the mutations produced inside a 276 pb-fragment (Bam-H1-SalI) of the same gene. pBR322 DNA was irradiated with UVA light in the presence of increasing concentrations of 8-Methoxypsoralen (8-MOP). The number of psoralen adducts formed in pBR322 upon that treatment ranged from 0 to 10.7 adducts per plasmid molecule. Modified DNA samples were used to transform several strains of E. Coli (differing in their repair capacities), both in constitutive conditions and after sos pre-induction by 254 nm-irradiation of cells. Mutation frequencies in the tet gene showed to increase in the wild type and uvrA strains along with the number of psoralen adduts per plasmid molecule; higher mutation frequencies were found in cells that had been previously irradiated to induce the SOS expression. Mutant plasmids were isolated from ApRTcS colonies and sequenced by the method of Maxam and Gilbert. Mutations appeared to be unique in most of the cases and were always punctual, i.e. affecting only to one base pair. The relative positions of the mutations showed a high frequency of coincidence among the sequenced fragments, indicating the existence of several DNA regions with high probability to mutated ({sup h}ot spots{sup )}. (author)

  4. The photoreaction between furocoumarins and various DNA with different base compositions

    International Nuclear Information System (INIS)

    Dall'Acqua, F.; Vedaldi, D.; Recher, M.

    1978-01-01

    The photoreactivity of psoralen and 8-methylpsoralen towards various samples of DNA having different base-pair compositions has been studied. The total photobinding capacity shown by the two furocoumarins increases by increasing the content of A-T, confirming the data previously obtained using synthetic polynucleotides. The amount of monofunctional fluorescent 4',5'-cycloadducts and of the cross-linkages formed during the photoreaction is not parallel to the content of A-T, but is highest when the A-T content is between 50 and 60%, while it decreases as the content of A-T is lowered or increased. The possible binding site for the formation of 4',5'-monofunctional cycloadducts as well as of cross-linkages is discussed. (author)

  5. Phototoxicity activity of Psoralea drupacea L. using Atremia salina bioassay system

    Directory of Open Access Journals (Sweden)

    Mohammad Ramezani

    2011-07-01

    Conclusion: The result showed that P. drupacea methanolic extract and chloroform fraction have phototoxicity in A. salina bioassay system and their toxic effect is related to phototoxic constituents such as psoralen.

  6. Preoperative screening: value of previous tests.

    Science.gov (United States)

    Macpherson, D S; Snow, R; Lofgren, R P

    1990-12-15

    To determine the frequency of tests done in the year before elective surgery that might substitute for preoperative screening tests and to determine the frequency of test results that change from a normal value to a value likely to alter perioperative management. Retrospective cohort analysis of computerized laboratory data (complete blood count, sodium, potassium, and creatinine levels, prothrombin time, and partial thromboplastin time). Urban tertiary care Veterans Affairs Hospital. Consecutive sample of 1109 patients who had elective surgery in 1988. At admission, 7549 preoperative tests were done, 47% of which duplicated tests performed in the previous year. Of 3096 previous results that were normal as defined by hospital reference range and done closest to the time of but before admission (median interval, 2 months), 13 (0.4%; 95% CI, 0.2% to 0.7%), repeat values were outside a range considered acceptable for surgery. Most of the abnormalities were predictable from the patient's history, and most were not noted in the medical record. Of 461 previous tests that were abnormal, 78 (17%; CI, 13% to 20%) repeat values at admission were outside a range considered acceptable for surgery (P less than 0.001, frequency of clinically important abnormalities of patients with normal previous results with those with abnormal previous results). Physicians evaluating patients preoperatively could safely substitute the previous test results analyzed in this study for preoperative screening tests if the previous tests are normal and no obvious indication for retesting is present.

  7. Variation in the thermionic work function of semiconductor powders exposed to electromagnetic radiation

    Science.gov (United States)

    Bourasseau, S.; Martin, J. R.; Juillet, F.; Teichner, S. J.

    1977-01-01

    The study of the variation of thermoelectronic work function potential of TiO2 in the presence of isobutane shows that this gas is not adsorbed on this solid, in either the presence or the absence of ultraviolet radiation. These results, as well as those obtained in a previous work, lead to the mechanism of the photo-oxidation of isobutane at room temperature, in which excited atomic oxygen is the active species.

  8. Near-infrared branding efficiently correlates light and electron microscopy.

    Science.gov (United States)

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  9. Vitiligo

    Science.gov (United States)

    ... more often from an artificial source like a UVA lamp. This turns the affected skin pink, which ... the ultraviolet light used is UVB instead of UVA. UVB treatment doesn't require psoralen, eliminating some ...

  10. Dermatology Procedures

    Science.gov (United States)

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

  11. Photosensitization and phototherapy with furocoumarins: A quantum-chemical study

    International Nuclear Information System (INIS)

    Serrano-Perez, Juan Jose; Serrano-Andres, Luis; Merchan, Manuela

    2008-01-01

    The effect of electromagnetic radiation on biological objects extends from heating to complex photochemistry, and includes DNA alteration, that properly modified in damaged cells may entail beneficial effects. In this regard, psoralen + UV-A (PUVA) therapy, in which furocoumarins, psoralen-like chromophores, are used as photosensitizers and photoreactants with DNA bases, is one of the most promising strategies against a plethora of diseases. Understanding the underlying photochemical mechanisms is crucial to design effective drugs without undesired side effects. We have undertaken a quantum-mechanical study on the photophysics and photochemistry of furocoumarins, analyzing firstly the most efficient way in which the lowest excited triplet state, as protagonist of the photosensitizing action, is populated from the initially promoted singlet states, and secondly the basics of the formation of furocoumarin-DNA photoadducts

  12. BVOCs concentration in the Reunion Island tropical forests and the impact on photooxidants formation during the BIO-MAIDO 2015 campaign.

    Science.gov (United States)

    Colomb, Aurelie; Duflot, Valentin; Tulet, Pierre; Flores, Olivier; Fournel, Jacques; Strasberg, Dominique; Deguillaume, Laurent; Vaitilingom, Mickael; Burnet, Frederic; Bourrianne, Thierry

    2016-04-01

    BVOCs from Reunion Forest and the role of BVOCs as precursors of photooxidants will be discussed.

  13. CORONA-INDUCED PHOTOXIDATION OF ALCOHOLS AND HYDROCARBONS OVER TIO2 IN THE ABSENCE OF A UV LIGHT SOURCE - A NOVEL AND ENVIRONMENTALLY FRIENDLY METHOD FOR OXIDATION

    Science.gov (United States)

    Corona-induced photooxidation is a novel oxidation methodology for the efficient oxidation of alcohols and hydrocarbons utilizing the advantage of both the high oxidizing power of ozone formed in the reactor as well as the photooxidation capability of the UV light generated durin...

  14. Comparison of model results obtained with several European regional air quality models

    NARCIS (Netherlands)

    Hass, H.; Builtjes, P.J.H.; Simpson, D.; Stern, R.

    1997-01-01

    An intercomparison study has been performed with four photo-oxidant dispersion models (EMEP, EURAD, LOTOS and REM3) which are currently capable of performing photo-oxidant formation calculations over larger path of Europe. The models, in principle, were run in the mode in which they are normally

  15. Are CH2O measurements in the marine boundary layer suitable for testing the current understanding of CH4 photooxidation?: A model study

    Science.gov (United States)

    Wagner, V.; von Glasow, R.; Fischer, H.; Crutzen, P. J.

    2002-02-01

    On the basis of a data set collected during the Indian Ocean Experiment (INDOEX) campaign 1999, we investigated the formaldehyde (CH2O) budget in the southern Indian Ocean (SIO). With a photochemical box model we simulated the contribution of methane and nonmethane volatile organic compounds to the CH2O budget. To identify the reactions and model constraints that introduce the largest uncertainties in the modeled CH2O concentration, we carried out a local sensitivity analysis. Furthermore, a Monte Carlo method was used to assess the global error of the model predictions. According to this analysis the 2σ uncertainty in the modeled CH2O concentration is 49%. The deviation between observed (200 +/- 70 parts per trillion by volume (pptv) (2σ)) and modeled (224 +/- 110 pptv (2σ)) daily mean CH2O concentration is 12%. However, the combined errors of model and measurement are such that deviations as large as 65% are not significant at the 2σ level. Beyond the ``standard'' photochemistry we analyzed the impact of halogen and aerosol chemistry on the CH2O concentration and investigated the vertical distribution of CH2O in the marine boundary layer (MBL). Calculations with the Model of Chemistry Considering Aerosols indicate that, based on the current understanding, halogen chemistry and aerosol chemistry have no significant impact on the CH2O concentration under conditions encountered in the SIO. However, a detailed investigation including meteorological effects such as precipitation scavenging and convection reveals an uncertainty in state-of-the-art model predictions for CH2O in the MBL that is too large for a meaningful test of the current understanding of CH4 photooxidation.

  16. Effects of water temperature on photosensitization in bath-PUVA therapy with 8-methoxypsoralen

    Energy Technology Data Exchange (ETDEWEB)

    Gruss, C.; Kobyletzki, G. von; Reuther, T.; Husebo, L.; Altmeyer, P. [Ruhr-Univ. of Bochum, Bochum (Germany); Behrens, S.; Kerscher, M. [Univ. of Ulm, Dept. of Dermatology, Ulm (Germany)

    1998-10-01

    The pharmacokinetic aspects of bath-PUVA are not completely clarified. Therefore, we determined the phototoxic response of human skin following psoralen baths at temperatures ranging from 32 deg. C to 42 deg. C (71.6-107.6 deg. F) and UVA doses ranging from 0.5 to 5.5 J/cm{sup 2}. The highest therapeutical photosensitization (i.e. lowest minimal phototoxic dose) was assessed at temperatures of 37 deg. C (98.6 deg. F) and above. Photosensitization was significantly decreased at lower temperatures. These data indicate that a bath temperature of 37 deg. C (98.6 deg. F) should be used to gain optimal therapeutic efficiency in a clinical setting. Furthermore, in order to minimize the risk of adverse phototoxic effects in bath-PUVA, it is important to use a constant temperature during the psoralen bath. (au) 13 refs.

  17. Effects of water temperature on photosensitization in bath-PUVA therapy with 8-methoxypsoralen

    International Nuclear Information System (INIS)

    Gruss, C.; Kobyletzki, G. von; Reuther, T.; Husebo, L.; Altmeyer, P.; Behrens, S.; Kerscher, M.

    1998-01-01

    The pharmacokinetic aspects of bath-PUVA are not completely clarified. Therefore, we determined the phototoxic response of human skin following psoralen baths at temperatures ranging from 32 deg. C to 42 deg. C (71.6-107.6 deg. F) and UVA doses ranging from 0.5 to 5.5 J/cm 2 . The highest therapeutical photosensitization (i.e. lowest minimal phototoxic dose) was assessed at temperatures of 37 deg. C (98.6 deg. F) and above. Photosensitization was significantly decreased at lower temperatures. These data indicate that a bath temperature of 37 deg. C (98.6 deg. F) should be used to gain optimal therapeutic efficiency in a clinical setting. Furthermore, in order to minimize the risk of adverse phototoxic effects in bath-PUVA, it is important to use a constant temperature during the psoralen bath. (au)

  18. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to a combination of lycopene, vitamin E, lutein and selenium and protection of the skin from UV-induced (including photo-oxidative) damage pursuant to Article 13

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to a combination of lycopene, vitamin E, lutein and selenium and protection of the skin from UV-induced (including photo-oxidative) damage. The Panel considers that the combination of lycopene, vitamin E, lutein and selenium is sufficiently characterised. The claimed effect refers to the photo...... could be drawn from this study for the scientific substantiation of the claim. The Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of lycopene, vitamin E, lutein and selenium and protection of the skin from UV-induced (including......-protective activity of the food, delaying the appearance of UV-induced erythema and decreasing its intensity. The target population proposed by the applicant is healthy adults in the general population, and in particular people with sensitive skin. The Panel considers that protection of the skin from UV...

  19. Antifungal constituents of Melicope borbonica

    DEFF Research Database (Denmark)

    Simonsen, Henrik Toft; Adsersen, Anne; Bremner, Paul

    2004-01-01

    -methoxycoumarin, cedrelopsin and psoralen], two sesquiterpenes (alpha-curcumene and 3,6-epidioxy-1,10-bisaboladiene), eugenol, methyleugenol and a lignan (sesamin) were isolated. None of the isolated constituents exhibited antiin fl ammatory activity in vitro. No alkaloids were detected....

  20. 49 CFR 173.23 - Previously authorized packaging.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Previously authorized packaging. 173.23 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.23 Previously authorized packaging. (a) When the regulations specify a packaging with a specification marking...

  1. Methoxsalen-induced macular toxicity

    Directory of Open Access Journals (Sweden)

    Aditya Maitray

    2017-01-01

    Full Text Available Psoralen compounds such as methoxsalen are photosensitizer agents used in conjunction with ultraviolet A (UVA radiation exposure as photochemotherapy (Psoralens and ultraviolet-A therapy [PUVA therapy] for certain epidermal skin disorders such as psoriasis and vitiligo. Methoxsalen has been shown to be associated with premature cataract formation by forming adducts with lens proteins following oral administration and subsequent UVA exposure. Hence, the use of UV-filtering glasses is recommended during PUVA therapy sessions. Ocular tissues can be exposed to its photosensitizing effect with subsequent UV radiation exposure through sunlight if the patient was to be without protective eye glasses, potentially causing macular toxicity. Till date, there have been no reports in the literature of any posterior segment ocular toxicity arising from methoxsalen use. Here, we describe a case of a bilateral macular toxicity in a middle-aged male treated with methoxsalen for vitiligo.

  2. 22 CFR 40.91 - Certain aliens previously removed.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a result...

  3. Photoelectrochemical kinetics of Eosin Y-sensitized zinc oxide films investigated by scanning electrochemical microscopy under illumination with different LED

    International Nuclear Information System (INIS)

    Shen Yan; Tefashe, Ushula Mengesha; Nonomura, Kazuteru; Loewenstein, Thomas; Schlettwein, Derck; Wittstock, Gunther

    2009-01-01

    The overall efficiency of the light-induced charge separation in dye-sensitized solar cells depends on the kinetic competition between back electron transfer and dye regeneration processes by a redox electrolyte. In a previous study, the reduction of the intermittently formed photo-oxidized dye molecules by iodide ions in the electrolyte phase was investigated using the feedback mode of a scanning electrochemical microscope (SECM) and a quantitative model had been derived. Here we provide a more thorough experimental verification of this model by variation of the excitation wavelength, light intensities and mediator concentrations. Nanoporous ZnO/Eosin Y films prepared by self-assembly were used as model electrodes and were used with an iodide/triiodide electrolyte. The experimentally found effective rate constants could be related to the rate constant for the reaction of the dissolved donor with photo-oxidized Eosin Y bound to ZnO and the absorption spectrum of the dye and confirmed the assumption made in the derivation of the model. For the regeneration process of Eosin Y, a rate constant of k ox with different light emitting diodes and light intensities is determined.

  4. Photoelectrochemical kinetics of Eosin Y-sensitized zinc oxide films investigated by scanning electrochemical microscopy under illumination with different LED

    Energy Technology Data Exchange (ETDEWEB)

    Shen Yan; Tefashe, Ushula Mengesha [Department of Pure and Applied Chemistry, Faculty of Mathematics and Natural Sciences, Carl von Ossietzky University of Oldenburg, D-26111 Oldenburg (Germany); Nonomura, Kazuteru; Loewenstein, Thomas; Schlettwein, Derck [Institute of Applied Physics, Justus Liebig University of Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Wittstock, Gunther, E-mail: gunther.wittstock@uni-oldenburg.d [Department of Pure and Applied Chemistry, Faculty of Mathematics and Natural Sciences, Carl von Ossietzky University of Oldenburg, D-26111 Oldenburg (Germany)

    2009-12-30

    The overall efficiency of the light-induced charge separation in dye-sensitized solar cells depends on the kinetic competition between back electron transfer and dye regeneration processes by a redox electrolyte. In a previous study, the reduction of the intermittently formed photo-oxidized dye molecules by iodide ions in the electrolyte phase was investigated using the feedback mode of a scanning electrochemical microscope (SECM) and a quantitative model had been derived. Here we provide a more thorough experimental verification of this model by variation of the excitation wavelength, light intensities and mediator concentrations. Nanoporous ZnO/Eosin Y films prepared by self-assembly were used as model electrodes and were used with an iodide/triiodide electrolyte. The experimentally found effective rate constants could be related to the rate constant for the reaction of the dissolved donor with photo-oxidized Eosin Y bound to ZnO and the absorption spectrum of the dye and confirmed the assumption made in the derivation of the model. For the regeneration process of Eosin Y, a rate constant of k{sub ox} with different light emitting diodes and light intensities is determined.

  5. Radiation inactivation of T7 phage

    International Nuclear Information System (INIS)

    Becker, D.; Redpath, J.L.; Grossweiner, L.I.

    1978-01-01

    The radiation inactivation of T7 phage by 25-MeV electron pulses has been measured in various media containing a wide concentration range of radical scavenging solutes and in the presence of protective and sensitizing agents. The dependence of sensitivity on pulse dose, from 1 mrad to 3.6 krad, is attributed to radical depletion via bimolecular processes. The survival data are analyzed by extending target theory to include diffusive reactions of primary and secondary radicals generated in the medium. It is concluded that OH radicals are the principal primary inactivating species and that secondary radicals from Br - , CNS - , uracil, glucose, ribose, sucrose, tyrosine, and histidine are lethal to some extent. In nutrient broth or 100 mM histidine, psoralen derivatives, Actinomycin D, and Mitomycin C are anoxic sensitizers. It is proposed that the psoralens promote the formation of non-strand break lesions as the sensitization mechanism. The target theory based on diffusional kinetics is applicable to other systems including single cells

  6. Impact of previously disadvantaged land-users on sustainable ...

    African Journals Online (AJOL)

    Impact of previously disadvantaged land-users on sustainable agricultural ... about previously disadvantaged land users involved in communal farming systems ... of input, capital, marketing, information and land use planning, with effect on ...

  7. Determining root correspondence between previously and newly detected objects

    Science.gov (United States)

    Paglieroni, David W.; Beer, N Reginald

    2014-06-17

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  8. Photo-stability and time-resolved photoluminescence study of colloidal CdSe/ZnS quantum dots passivated in Al{sub 2}O{sub 3} using atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chih-Yi [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China); Mao, Ming-Hua, E-mail: mhmao@ntu.edu.tw [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China); Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2016-08-28

    We report photo-stability enhancement of colloidal CdSe/ZnS quantum dots (QDs) passivated in Al{sub 2}O{sub 3} thin film using the atomic layer deposition (ALD) technique. 62% of the original peak photoluminescence (PL) intensity remained after ALD. The photo-oxidation and photo-induced fluorescence enhancement effects of both the unpassivated and passivated QDs were studied under various conditions, including different excitation sources, power densities, and environment. The unpassivated QDs showed rapid PL degradation under high excitation due to strong photo-oxidation in air while the PL intensity of Al{sub 2}O{sub 3} passivated QDs was found to remain stable. Furthermore, recombination dynamics of the unpassivated and passivated QDs were investigated by time-resolved measurements. The average lifetime of the unpassivated QDs decreases with laser irradiation time due to photo-oxidation. Photo-oxidation creates surface defects which reduces the QD emission intensity and enhances the non-radiative recombination rate. From the comparison of PL decay profiles of the unpassivated and passivated QDs, photo-oxidation-induced surface defects unexpectedly also reduce the radiative recombination rate. The ALD passivation of Al{sub 2}O{sub 3} protects QDs from photo-oxidation and therefore avoids the reduction of radiative recombination rate. Our experimental results demonstrated that passivation of colloidal QDs by ALD is a promising method to well encapsulate QDs to prevent gas permeation and to enhance photo-stability, including the PL intensity and carrier lifetime in air. This is essential for the applications of colloidal QDs in light-emitting devices.

  9. Perturbations of carotenoid and tetrapyrrole biosynthetic pathways result in differential alterations in chloroplast function and plastid signaling

    International Nuclear Information System (INIS)

    Park, Joon-Heum; Jung, Sunyo

    2017-01-01

    In this study, we used the biosynthetic inhibitors of carotenoid and tetrapyrrole biosynthetic pathways, norflurazon (NF) and oxyfluorfen (OF), as tools to gain insight into mechanisms of photooxidation in rice plants. NF resulted in bleaching symptom on leaves of the treated plants, whereas OF treatment developed a fast symptom of an apparent necrotic phenotype. Both plants exhibited decreases in photosynthetic efficiency, as indicated by F v /F m . NF caused severe disruption in thylakoid membranes, whereas OF-treated plants exhibited disruption of chloroplast envelope and plasma membrane. Levels of Lhca and Lhcb proteins in photosystem I (PSI) and PSII were reduced by photooxidative stress in NF- and OF-treated plants, with a greater decrease in NF plants. The down-regulation of nuclear-encoded photosynthesis genes Lhcb and rbcS was also found in both NF- and OF-treated plants, whereas plastid-encoded photosynthetic genes including RbcL, PsaC, and PsbD accumulated normally in NF plants but decreased drastically in OF plants. This proposes that the plastids in NF plants retain their potential to develop thylakoid membranes and that photobleaching is mainly controlled by nuclear genes. Distinct photooxidation patterns between NF- and OF-treated plants developed differential signaling, which might enable the plant to coordinate the expression of photosynthetic genes from the nuclear and plastidic genomes. - Highlights: • Two modes of photooxidation by carotenoid and tetrapyrrole biosynthetic inhibitors. • We examine differential alterations in chloroplast function and plastid signaling. • NF and OF cause differential alterations in chloroplast ultrastructure and function. • Photooxidation coordinates photosynthetic gene expression from nucleus and plastid.

  10. One-pot four component synthesis of novel 3-furyl coumarin ...

    Indian Academy of Sciences (India)

    solids by column chromatography in quantitative yield and characterized with1H NMR, 13C NMR, IR and FAB mass. Keywords. ... lated from the plants such as microminutin, micromelin, psoralen, 8-methoxypsoralen have important properties in medicinal chemistry and biophotochemistry.11 It is well documented that by ...

  11. TiO2 Photocatalyzed Oxidation of Free and Complex Metallic Cyanides.

    Energy Technology Data Exchange (ETDEWEB)

    Valladares, J. E.; Esteghamatdarsthad, B.; Renteria, J.

    2006-07-01

    The TiO2 photo catalyzed oxidation of free cyanide and transition metal cyanide complexes often found in industrial mining wastes were studied. The photoreactor system used was a UV illuminated and stirred tank with suspended particles of TiO2. After to determine the optimization parameters such as light intensity, concentration of complex and free cyanides, in ideal conditions, the effect of the presence of different type of anions was also studied. The model substances chosen were potassium cyanide and cyanides complexes of Iron, Cobalt and Copper in a strong alkaline solution (pH = 11.0 - 12.0). The experimental results indicate that in the case of the hexaferricyanide complex Fe(CN)6 3, the reaction occur in two steps. The first step is the breakdown of the metal-cyanide bond (photo-dissociation) forming free cyanide (CN-) and Fe3+ ions. The second step is the photo-oxidation of the free cyanides formed before. The ions Fe3+ and OH- present in the alkaline solution, precipitate as iron hydroxide Fe(OH)3. During the photo-dissociation step of the iron complex, free CN- ions produced reaches a maximum concentration before it is eliminated by photo-oxidation. The free cyanide produced from the hexaferricyanide complex disappears rapidly at a velocity of 64.6 + - 5.0 ?M/min. This rate of photo-oxidation is comparable with the experiments using just alkaline solutions of potassium cyanide ('free cyanides'). In contrast, in alkaline solutions of cyanide complexes of Cu and Co the rate of photo-oxidation was substantially reduced (6.17+ - 0.80 ?M/min and 0.04 + - 0.010 ?M/min, respectively) and do not show any initial increase of free cyanides in the suspension. The slower rate of photo-oxidation suggests the formation of very stable hydroxyl-cyanide polymeric metallic complexes in the reaction mix. The photo-oxidation pathway of the nitrogen oxide products was also investigated and found that the final product consists mainly of nitrate ions. (Author)

  12. Erlotinib-induced rash spares previously irradiated skin

    International Nuclear Information System (INIS)

    Lips, Irene M.; Vonk, Ernest J.A.; Koster, Mariska E.Y.; Houwing, Ronald H.

    2011-01-01

    Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one earlier chemotherapy treatment. Approximately 75% of the patients treated with erlotinib develop acneiform skin rashes. A patient treated with erlotinib 3 months after finishing concomitant treatment with chemotherapy and radiotherapy for non-small cell lung cancer is presented. Unexpectedly, the part of the skin that had been included in his previously radiotherapy field was completely spared from the erlotinib-induced acneiform skin rash. The exact mechanism of erlotinib-induced rash sparing in previously irradiated skin is unclear. The underlying mechanism of this phenomenon needs to be explored further, because the number of patients being treated with a combination of both therapeutic modalities is increasing. The therapeutic effect of erlotinib in the area of the previously irradiated lesion should be assessed. (orig.)

  13. Gas-phase Precursors to Anthropogenic SOA: Using the MCM to Probe Detailed Observations of Aromatic Photo-oxidation

    Science.gov (United States)

    Rickard, A. R.; Wyche, K. P.; Metzger, A.; Monks, P. S.; Ellis, A. M.; Baltensperger, U.; Pilling, M. J.; Jenkin, M. E.

    2008-12-01

    The formation of photochemical ozone and particulate matter are major priorities in the determination of European air quality policies. Predictions of the future state of the atmosphere and the development of appropriate mitigation strategies rely on models, which necessarily incorporate chemistry. The Master Chemical Mechanism (MCM, http://mcm.leeds.ac.uk/MCM) is a near-explicit chemical mechanism originally conceived to model ozone formation in Europe but now also employed as a benchmark mechanism in a wide variety of applications where chemical detail is required. The MCM currently describes the detailed gas- phase tropospheric degradation of a 135 primary emitted volatile organic compounds (VOCs) leading to a mechanism containing ca. 5900 species and 13500 reactions. In order that the MCM continues to be a state-of-the-art resource for the atmospheric science community it resides under a constant regime of evaluation, development and improvement. Individual VOC photochemical mechanisms are evaluated using data obtained, under a variety of atmospheric conditions, from highly instrumented smog chambers. Smog chamber experiments are crucial, not only for mechanism evaluation, but also for mechanism development. Findings obtained from combined model and chamber studies can additionally provide key insight for guiding the directions of future laboratory experiments. Recently, the MCM was updated to MCMv3.1 in order to take into account recent advancements in the understanding of aromatic photo-oxidation, an important class of anthropogenic VOCs. As well as constituting precursors to secondary organic aerosol (SOA), aromatics generally have high photochemical ozone creation potentials (POCPs) and hence contribute significantly towards tropospheric ozone formation. In the work presented, a detailed gas-phase photochemical chamber box model, incorporating the MCMv3.1 degradation mechanism for 1,3,5-trimethylbenzene (TMB), has been used to simulate data measured during

  14. Repair and cell cycle response in cells exposed to environmental biohazards. Progress report, June 1, 1980-May 31, 1981

    International Nuclear Information System (INIS)

    Billen, D.; Hadden, C.T.

    1981-01-01

    Research progress for the period June 1, 1980 through May 31, 1981 is reported. Topics include: (1) repair of damage by psoralen plus near-uv light; (2) in vitro repair of transforming DNA; (3) photobiology of halogenated DNA; and (4) DNA repair in toluene-treated Escherichia coli containing BU-DNA

  15. Human embryonic stem cells have enhanced repair of multiple forms of DNA damage

    DEFF Research Database (Denmark)

    Maynard, Scott; Swistowska, Anna Maria; Lee, Jae Wan

    2008-01-01

    cells compared with various differentiated murine cells. Using single-cell gel electrophoresis (comet assay) we found that human embryonic stem cells (BG01, I6) have more efficient repair of different types of DNA damage (generated from H2O2, UV-C, ionizing radiation, or psoralen) than human primary...

  16. Characterization of aerosol photooxidation flow reactors: heterogeneous oxidation, secondary organic aerosol formation and cloud condensation nuclei activity measurements

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2011-03-01

    Full Text Available Motivated by the need to develop instrumental techniques for characterizing organic aerosol aging, we report on the performance of the Toronto Photo-Oxidation Tube (TPOT and Potential Aerosol Mass (PAM flow tube reactors under a variety of experimental conditions. The PAM system was designed with lower surface-area-to-volume (SA/V ratio to minimize wall effects; the TPOT reactor was designed to study heterogeneous aerosol chemistry where wall loss can be independently measured. The following studies were performed: (1 transmission efficiency measurements for CO2, SO2, and bis(2-ethylhexyl sebacate (BES particles, (2 H2SO4 yield measurements from the oxidation of SO2, (3 residence time distribution (RTD measurements for CO2, SO2, and BES particles, (4 aerosol mass spectra, O/C and H/C ratios, and cloud condensation nuclei (CCN activity measurements of BES particles exposed to OH radicals, and (5 aerosol mass spectra, O/C and H/C ratios, CCN activity, and yield measurements of secondary organic aerosol (SOA generated from gas-phase OH oxidation of m-xylene and α-pinene. OH exposures ranged from (2.0 ± 1.0 × 1010 to (1.8 ± 0.3 × 1012 molec cm−3 s. Where applicable, data from the flow tube reactors are compared with published results from the Caltech smog chamber. The TPOT yielded narrower RTDs. However, its transmission efficiency for SO2 was lower than that for the PAM. Transmission efficiency for BES and H2SO4 particles was size-dependent and was similar for the two flow tube designs. Oxidized BES particles had similar O/C and H/C ratios and CCN activity at OH exposures greater than 1011 molec cm−3 s, but different CCN activity at lower OH exposures. The O/C ratio, H/C ratio, and yield of m-xylene and α-pinene SOA was strongly affected by reactor design and

  17. Automatic electromagnetic valve for previous vacuum

    International Nuclear Information System (INIS)

    Granados, C. E.; Martin, F.

    1959-01-01

    A valve which permits the maintenance of an installation vacuum when electric current fails is described. It also lets the air in the previous vacuum bomb to prevent the oil ascending in the vacuum tubes. (Author)

  18. Independent Research Program Annual Report FY88

    Science.gov (United States)

    1989-04-01

    tetraphenylporhine acetate dichlorotris( triphenylphosphine )ruthenium (11) Table 4. Effect of Candidate Catalysts on Discoloration Reactions of Adsorbed... reaction products will pairs. These oxides also promote photooxidative be identified and accurately quantified by GC, reactions of organic molecules...Photooxidation rate of reaction w-as .•bout 3.3 x 10-4 M/min between 12 and 36 hours. Beyond 36 hrs of A Rayonet Photochemical Chamber Reactor irradiation, the

  19. Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate

    International Nuclear Information System (INIS)

    Clough, A.; Skjemstad, J.O.

    2000-01-01

    The amount of organic carbon physically protected by entrapment within aggregates and through polyvalent cation organic matter bridging was determined on non-calcareous and calcareous soils. The composition of organic carbon in whole soils and 13 C NMR analysis. High energy photo-oxidation was carried out on <53 μm fractions and results from the NMR spectra showed 17-40% of organic carbon was in a condensed aromatic form, most likely charcoal (char). The concept that organic material remaining after photo-oxidation may be physically protected within aggregates was investigated by treating soils with a mild acid prior to photo-oxidation. More organic material was protected in the calcareous than the non-calcareous soils, regardless of whether the calcium occurred naturally or was an amendment. Acid treatment indicated that the presence of exchangeable calcium reduced losses of organic material upon photo-oxidation by about 7% due to calcium bridging. These results have implications for N fertiliser recommendations based upon organic carbon content. Firstly, calcium does not impact upon degradability of organic material to an extent likely to affect N fertiliser recommendations. Secondly, standard assessment techniques overestimate active organic carbon content in soils with high char content. Copyright (2000) CSIRO Publishing

  20. PENGARUH FOTOOKSIDASI UV-C TERHADAP SIFAT FISIKOKIMIA DAN BAKING EXPANSION PATI SAGU (Metroxylon sago

    Directory of Open Access Journals (Sweden)

    Eduard Fransisco Tethool

    2017-09-01

    Full Text Available Native Sago starch is difficult to used in industry because of the limitations of its phisycochemical properties. The aim of this research was to studied effect of UV-C photo-oxidation on  physicochemical properties and baking expansion of sago starch. Five slurries ratio (starch : water ratio: 1:2; 1:4; 1:6; 1:8; and 1:10 were oxidized with UV-C irradiation for 20 minutes, and then compared with native sago starch. The results showed that UV-C photo-oxidation increasing amylose content and paste viscosity, but decreasing swelling power and solubility, and carbonyl and carboxyl content. Used of UV-C as a photooxidator effective to increasing baking expansion characteristic, and the best slurry ratio was 1:6, which has 6.97 ml/g specific volume or 33.7% increased from native sago starch (5.22 ml/g

  1. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2012-01-31

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  2. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2011-01-01

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  3. Reoperative sentinel lymph node biopsy after previous mastectomy.

    Science.gov (United States)

    Karam, Amer; Stempel, Michelle; Cody, Hiram S; Port, Elisa R

    2008-10-01

    Sentinel lymph node (SLN) biopsy is the standard of care for axillary staging in breast cancer, but many clinical scenarios questioning the validity of SLN biopsy remain. Here we describe our experience with reoperative-SLN (re-SLN) biopsy after previous mastectomy. Review of the SLN database from September 1996 to December 2007 yielded 20 procedures done in the setting of previous mastectomy. SLN biopsy was performed using radioisotope with or without blue dye injection superior to the mastectomy incision, in the skin flap in all patients. In 17 of 20 patients (85%), re-SLN biopsy was performed for local or regional recurrence after mastectomy. Re-SLN biopsy was successful in 13 of 20 patients (65%) after previous mastectomy. Of the 13 patients, 2 had positive re-SLN, and completion axillary dissection was performed, with 1 having additional positive nodes. In the 11 patients with negative re-SLN, 2 patients underwent completion axillary dissection demonstrating additional negative nodes. One patient with a negative re-SLN experienced chest wall recurrence combined with axillary recurrence 11 months after re-SLN biopsy. All others remained free of local or axillary recurrence. Re-SLN biopsy was unsuccessful in 7 of 20 patients (35%). In three of seven patients, axillary dissection was performed, yielding positive nodes in two of the three. The remaining four of seven patients all had previous modified radical mastectomy, so underwent no additional axillary surgery. In this small series, re-SLN was successful after previous mastectomy, and this procedure may play some role when axillary staging is warranted after mastectomy.

  4. In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations

    International Nuclear Information System (INIS)

    Cherrier, J.

    2005-01-01

    Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO 2 could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO 2 was used as the indicator of hydrocarbon degradation and (delta) 13 C analysis of the resultant CO 2 was used to evaluate the source of the respired CO 2 (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time

  5. 77 FR 70176 - Previous Participation Certification

    Science.gov (United States)

    2012-11-23

    ... participants' previous participation in government programs and ensure that the past record is acceptable prior... information is designed to be 100 percent automated and digital submission of all data and certifications is... government programs and ensure that the past record is acceptable prior to granting approval to participate...

  6. Avaliação da degradação térmica e fotooxidativa do ABS Automotivo Thermal degradation and Photo-oxidation of the ABS used for automotive applications

    Directory of Open Access Journals (Sweden)

    Elisabete M. S. Sanchez

    1999-12-01

    Full Text Available A degradação do ABS foi avaliada após envelhecimento térmico (ASTM D794 e fotooxidativo (ASTM G53 e G24. Essas condições foram escolhidas na tentativa de simular as condições a que esse polímero é submetido durante seu ciclo de vida como componente automobilístico. As mudanças ocorridas no ABS envelhecido pelos três métodos, em diferentes tempos, foram caracterizadas por ensaios mecânicos de tração e impacto, pelo índice de fluidez, pelo índice de carbonilas (FT-IR, pelo índice de amarelecimento e por fotografias ampliadas das fraturas de impacto. Os resultados mostraram que cada técnica utilizada fornece uma resposta característica em função do método de envelhecimento utilizado. A aplicação de técnicas de análise multivariada aos resultados permitiu uma visualização da degradação do material em função das técnicas de envelhecimento.The ABS degradation was investigated after thermal- (80°C and photo-oxidative ageing (ASTM G53 and G24. These conditions were selected to simulate a car interior and the ABS lifetime weatherability. ABS changes were characterised by mechanical properties, melt flow index, carbonyl index (FT-IR, yellowing index and macro-photography of impact fracture. The results showed that each technique gives a characteristically answer for the ageing method. The multivariate analysis provided the degradation view as a function of the ageing method.

  7. Start-up of a free water surface constructed wetland for treating olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Michailides Michail

    2015-01-01

    Full Text Available An olive mill's existing evaporation pond was separated into five cells and transformed into a free water surface constructed wetland. The constructed wetland was used as a post-treatment stage for olive mill wastewater (OMW. Wastewater was previously treated by an aerobic trickling filter. The influent concentrations in the constructed wetland were 27400 mg.L-1, 4800 mg.L-1, 105 mg.L-1 and 770 mg.L-1 for COD, phenols, ortho-phosphate and TKN, respectively. Despite the rather high influent concentrations, the performance of the constructed wetland was very good since after the 60-day start-up operation period it achieved removal rates of about 94%, 95%, 95% and 98% for COD, phenols, ortho-phosphate and TKN, respectively. The major pollutant removal processes can be attributed to both biological processes occurring in the wetland and photo-oxidation. Laboratory-scale experiments with OMW from fifth cell of the wetland revealed that the net contribution of photo-oxidation after 112 hours of simulated solar radiation at 765 W/m2 (i.e. about 38 days of sunlight irradiation was 18% and 31% removal for COD and phenols, respectively. In the constructed wetland, the total removal reached 81% and 86% for COD and phenols, respectively, for the same time period (38 days.

  8. Spectroscopic and vibrational analysis of the methoxypsoralen system: A comparative experimental and theoretical study

    Science.gov (United States)

    Liu, Y.; Yuan, H.; Vo-Dinh, T.

    2013-03-01

    Raman spectra measurements and density functional theory (DFT) calculations were performed to investigate three psoralens: 5-amino-8-methoxypsoralen (5-A-8-MOP), 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP) with the aim of differentiating these similar bioactive molecules. The Raman spectra were recorded in the region 300-3500 cm-1. All three psoralens were found to have similar Raman spectrum in the region 1500-1650 cm-1. 5-A-8-MOP can be easily differentiated from 5-MOP or 8-MOP based on the Raman spectrum. The Raman spectrum differences at 651 and 795 cm-1 can be used to identify 5-MOP from 8-MOP. The theoretically computed vibrational frequencies and relative peak intensities were compared with experimental data. DFT calculations using the B3LYP method and 6-311++G(d,p) basis set were found to yield results that are very comparable to experimental Raman spectra. Detailed vibrational assignments were performed with DFT calculations and the potential energy distribution (PED) obtained from the Vibrational Energy Distribution Analysis (VEDA) program.

  9. Phototoxicity and photoallergy.

    Science.gov (United States)

    Epstein, J H

    1999-12-01

    Photosensitivity may be phototoxic or photoallergic. Phototoxicity is much more common. There are 2 types of phototoxicity: photodynamic, which requires oxygen, and nonphotodynamic, which does not. Reactions induced by porphyrin molecules, coal tar derivatives, and many drugs are photodynamic. The reaction induced by psoralens, for the most part, is nonphotodynamic. Acute phototoxic reactions are characterized by erythema and edema followed by hyperpigmentation. Long-term ultraviolet phototoxicity results in chronic sun damage and skin cancer formation. Also, certain chemicals such as psoralen molecules and coal tar are photocarcinogenic. Phototoxic reactions to certain drugs produce unusual clinical patterns, that is lichenoid eruptions, dyschromia, photo-onycholysis, and pseudoporphyria. Photoallergy is an uncommon acquired altered reactivity dependent on an immediate antibody or a delayed cell mediated reaction. Solar urticaria is an example of the former, whereas photoallergy to exogenous chemicals is an example of the latter. Photoallergy to systemic drugs does occur but is difficult to characterize. The action spectrum for photoreactions to exogenous agents usually at least includes the ultraviolet A rays for both phototoxicity and photoallergy.

  10. [Prevalence of previously diagnosed diabetes mellitus in Mexico.

    Science.gov (United States)

    Rojas-Martínez, Rosalba; Basto-Abreu, Ana; Aguilar-Salinas, Carlos A; Zárate-Rojas, Emiliano; Villalpando, Salvador; Barrientos-Gutiérrez, Tonatiuh

    2018-01-01

    To compare the prevalence of previously diagnosed diabetes in 2016 with previous national surveys and to describe treatment and its complications. Mexico's national surveys Ensa 2000, Ensanut 2006, 2012 and 2016 were used. For 2016, logistic regression models and measures of central tendency and dispersion were obtained. The prevalence of previously diagnosed diabetes in 2016 was 9.4%. The increase of 2.2% relative to 2012 was not significant and only observed in patients older than 60 years. While preventive measures have increased, the access to medical treatment and lifestyle has not changed. The treatment has been modified, with an increase in insulin and decrease in hypoglycaemic agents. Population aging, lack of screening actions and the increase in diabetes complications will lead to an increase on the burden of disease. Policy measures targeting primary and secondary prevention of diabetes are crucial.

  11. Synthetic models related to DNA-intercalating molecules. Interactions between 8-alkoxypsoralen and adenine

    International Nuclear Information System (INIS)

    Decout, J.L.; Lhomme, J.

    1983-01-01

    To investigate the interactions and the photoreactions between furocoumarins and adenine, compounds in which a psoralen molecule is linked by different polymethylene bridges have been synthesised. Ring-ring intramolecular interactions are observed by UV spectroscopy. Thermodynamic parameters of these hydrophobic interactions are determined by the study of the variation of the hypochromic effect with temperature. (author)

  12. Ubiquitin-specific protease 2 decreases p53-dependent apoptosis in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Wei, Tianling; Biskup, Edyta; Gjerdrum, Lise Mette Rahbek

    2016-01-01

    expression is 50% lower in CTCL cell lines (MyLa2000, SeAx and Hut-78) than in normal T-cells. USP2 is expressed in neoplastic cells in early, plaque-stage mycosis fungoides (MF) and is downregulated in advanced tumor stages. Upon treatment with psoralen with UVA (PUVA) or a p53 activator, nutlin3a, USP2...

  13. 75 FR 76056 - FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT:

    Science.gov (United States)

    2010-12-07

    ... SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT: STATUS: Closed meeting. PLACE: 100 F Street, NE., Washington, DC. DATE AND TIME OF PREVIOUSLY ANNOUNCED MEETING: Thursday, December 9, 2010 at 2 p.m. CHANGE IN THE MEETING: Time change. The closed...

  14. Implant breast reconstruction after salvage mastectomy in previously irradiated patients.

    Science.gov (United States)

    Persichetti, Paolo; Cagli, Barbara; Simone, Pierfranco; Cogliandro, Annalisa; Fortunato, Lucio; Altomare, Vittorio; Trodella, Lucio

    2009-04-01

    The most common surgical approach in case of local tumor recurrence after quadrantectomy and radiotherapy is salvage mastectomy. Breast reconstruction is the subsequent phase of the treatment and the plastic surgeon has to operate on previously irradiated and manipulated tissues. The medical literature highlights that breast reconstruction with tissue expanders is not a pursuable option, considering previous radiotherapy a contraindication. The purpose of this retrospective study is to evaluate the influence of previous radiotherapy on 2-stage breast reconstruction (tissue expander/implant). Only patients with analogous timing of radiation therapy and the same demolitive and reconstructive procedures were recruited. The results of this study prove that, after salvage mastectomy in previously irradiated patients, implant reconstruction is still possible. Further comparative studies are, of course, advisable to draw any conclusion on the possibility to perform implant reconstruction in previously irradiated patients.

  15. 28 CFR 10.5 - Incorporation of papers previously filed.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Incorporation of papers previously filed... CARRYING ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.5 Incorporation of papers previously filed. Papers and documents already filed with the Attorney General pursuant to the said act and...

  16. Arsenic removal from water employing a combined system: photooxidation and adsorption.

    Science.gov (United States)

    Lescano, Maia; Zalazar, Cristina; Brandi, Rodolfo

    2015-03-01

    A combined system employing photochemical oxidation (UV/H2O2) and adsorption for arsenic removal from water was designed and evaluated. In this work, a bench-scale photochemical annular reactor was developed being connected alternately to a pair of adsorption columns filled with titanium dioxide (TiO2) and granular ferric hydroxide (GFH). The experiences were performed by varying the relation of As concentration (As (III)/As (V) weight ratio) at constant hydrogen peroxide concentration and incident radiation. Experimental oxidation results were compared with theoretical predictions using an intrinsic kinetic model previously obtained. In addition, the effectiveness of the process was evaluated using a groundwater sample. The mathematical model of the entire system was developed. It could be used as an effective tool for the design and prediction of the behaviour of these types of systems. The combined technology is efficient and promising for arsenic removal to small and medium scale.

  17. Phototransformation of membrane lipids and its role in biomembrane function change under the effect of UV-radiation

    International Nuclear Information System (INIS)

    Roshchupkin, D.I.; Anosov, A.K.; Murina, M.A.; Lordkipanidze, A.T.

    1988-01-01

    The papers devoted to the investigation of photochemical transformations of lipid under the effect of UV radiation of biological membranes are reviewed. The mechanism of peroxide photooxidation of mebrane lipid is considered. Data on the effect of antioxidants and the structure state of membranes on the process of peroxide photooxidation of lipid are presented. The problem on the role of this process under the effect of UV-radiation on blood and skin of mammals is discussed. 48 refs.; 4 refs

  18. Alleviation of Low-Temperature Photoinhibition in Gamma-Irradiated Red Pepper (Capsicum annuum L.) Plants

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, J.S.; An, B.C.; Chung, B.Y.

    2006-01-01

    We studied the radiation-induced stress resistance in red pepper leaves under conditions of low-temperature photoinhibition or artificially induced photo-oxidative stress. Plants irradiated with 4, 8, or 16-Gy gamma rays were more resistant to both stress factors than were the controls. However, exposure to a low temperature for 12 h with illumination or photo-oxidative treatment for 1 h differentially affected the irradiated leaves, although they had similar stress intensities as defined by their maximal photochemical efficiencies (Fv/Fm)

  19. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  20. A photo-oxidation procedure using UV radiation/H{sub 2}O{sub 2} for decomposition of wine samples - Determination of iron and manganese content by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter N.L. dos [Departamento de Ciencias Exatas e da Terra, Universidade do Estado da Bahia, Salvador, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)], E-mail: wlopes@uneb.br; Brandao, Geovani C.; Portugal, Lindomar A.; David, Jorge M.; Ferreira, Sergio L.C. [Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)

    2009-06-15

    This paper proposes the use of photo-oxidation with UV radiation/H{sub 2}O{sub 2} as sample pretreatment for the determination of iron and manganese in wines by flame atomic absorption spectrometry (FAAS). The optimization involved the study of the following variables: pH and concentration of buffer solution, concentrated hydrogen peroxide volume and irradiation time. The evaluation of sample degradation was monitored by measuring the absorbance at the maximum wavelength of red wine (530 nm). Using the experimental conditions established during the optimization (irradiation time of 30 min, oxidant volume of 2.5 mL, pH 10, and a buffer concentration of 0.15 mol L{sup - 1}), this procedure allows the determination of iron and manganese with limits of detection of 30 and 22 {mu}g L{sup - 1}, respectively, for a 5 mL volume of digested sample. The precision levels, expressed as relative standard deviation (RSD), were 2.8% and 0.65% for iron and 2.7% and 0.54% for manganese for concentrations of 0.5 and 2.0 mg L{sup - 1}, respectively. Addition/recovery tests for evaluation of the accuracy were in the ranges of 90%-111% and 95%-107% for iron and manganese, respectively. This digestion procedure has been applied for the determination of iron and manganese in six wine samples. The concentrations varied from 1.58 to 2.77 mg L{sup - 1} for iron and from 1.30 to 1.91 mg L{sup - 1} for manganese. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level)

  1. A previous hamstring injury affects kicking mechanics in soccer players.

    Science.gov (United States)

    Navandar, Archit; Veiga, Santiago; Torres, Gonzalo; Chorro, David; Navarro, Enrique

    2018-01-10

    Although the kicking skill is influenced by limb dominance and sex, how a previous hamstring injury affects kicking has not been studied in detail. Thus, the objective of this study was to evaluate the effect of sex and limb dominance on kicking in limbs with and without a previous hamstring injury. 45 professional players (males: n=19, previously injured players=4, age=21.16 ± 2.00 years; females: n=19, previously injured players=10, age=22.15 ± 4.50 years) performed 5 kicks each with their preferred and non-preferred limb at a target 7m away, which were recorded with a three-dimensional motion capture system. Kinematic and kinetic variables were extracted for the backswing, leg cocking, leg acceleration and follow through phases. A shorter backswing (20.20 ± 3.49% vs 25.64 ± 4.57%), and differences in knee flexion angle (58 ± 10o vs 72 ± 14o) and hip flexion velocity (8 ± 0rad/s vs 10 ± 2rad/s) were observed in previously injured, non-preferred limb kicks for females. A lower peak hip linear velocity (3.50 ± 0.84m/s vs 4.10 ± 0.45m/s) was observed in previously injured, preferred limb kicks of females. These differences occurred in the backswing and leg-cocking phases where the hamstring muscles were the most active. A variation in the functioning of the hamstring muscles and that of the gluteus maximus and iliopsoas in the case of a previous injury could account for the differences observed in the kicking pattern. Therefore, the effects of a previous hamstring injury must be considered while designing rehabilitation programs to re-educate kicking movement.

  2. Subsequent childbirth after a previous traumatic birth.

    Science.gov (United States)

    Beck, Cheryl Tatano; Watson, Sue

    2010-01-01

    Nine percent of new mothers in the United States who participated in the Listening to Mothers II Postpartum Survey screened positive for meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for posttraumatic stress disorder after childbirth. Women who have had a traumatic birth experience report fewer subsequent children and a longer length of time before their second baby. Childbirth-related posttraumatic stress disorder impacts couples' physical relationship, communication, conflict, emotions, and bonding with their children. The purpose of this study was to describe the meaning of women's experiences of a subsequent childbirth after a previous traumatic birth. Phenomenology was the research design used. An international sample of 35 women participated in this Internet study. Women were asked, "Please describe in as much detail as you can remember your subsequent pregnancy, labor, and delivery following your previous traumatic birth." Colaizzi's phenomenological data analysis approach was used to analyze the stories of the 35 women. Data analysis yielded four themes: (a) riding the turbulent wave of panic during pregnancy; (b) strategizing: attempts to reclaim their body and complete the journey to motherhood; (c) bringing reverence to the birthing process and empowering women; and (d) still elusive: the longed-for healing birth experience. Subsequent childbirth after a previous birth trauma has the potential to either heal or retraumatize women. During pregnancy, women need permission and encouragement to grieve their prior traumatic births to help remove the burden of their invisible pain.

  3. Use of Doehlert and constrained mixture designs in the development of a photo-oxidation procedure using UV radiation/H2O2 for decomposition of landfill leachate samples and determination of metals by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Marcos A. Bezerra

    2015-03-01

    Full Text Available This work proposes the use of photo-oxidation degradation with UV radiation/H2O2 as sample treatment for the determination of Fe, Zn, Mn, Ni and Co in municipal solid waste landfill leachate by flame atomic absorption spectrometry (FAAS. Three variables (pH, irradiation time and buffer concentration were optimized using Doehlert design and the proportions of mixture components submitted to UV radiation (leachate sample, buffer solution and H2O2 30%, v/v were optimized using a constrained mixture design. Using the experimental conditions established, this procedure allows limits of detection of 0.075, 0.025, 0.010, 0.075 and 0.041 µg mL-1, and the precision levels expressed as relative standard (%RSD, 0.5 µg mL-1 were 3.6, 1.8, 1.3, 3.3 and 1.7%, for Fe, Mn, Zn, Ni and Co respectively. Recovery tests were carried out for evaluation of the procedure accuracy and recoveries were between 92 and 106% for the studied metals. This procedure has been applied for the analysis of the landfill leachate collected in Jequié, a city of the southwestern region of the State of Bahia, Brazil. The results were compared with those obtained by acid digestion. There was no significant difference between the results obtained by the two methods based on paired t-test at 95% confidence level.

  4. Photochemical reactions of nucleic acids and their constituents of photobiological relevance

    International Nuclear Information System (INIS)

    Saito, I.; Sugiyama, H.; Matsuura, T.

    1983-01-01

    A review is given of the papers published from 1977 to May 1983 on the UV-induced photochemical reactions of nucleic acids and their constituents of photobiological relevance where the structures of photoproducts have been fully characterized. Among the topics discussed are photoadditions relevant to nucleic acid-protein photocrosslinking, photoreactions with psoralens and nucleic acids and photochemical reactions of polynucleotides. (U.K.)

  5. Dark membrane lysis and photosensitization by 3-carbethoxypsoralen

    Energy Technology Data Exchange (ETDEWEB)

    Muller-Runkel, R.; Grossweiner, L.I. (Illinois Inst. of Tech., Chicago (USA). Dept. of Physics)

    1981-03-01

    Aqueous solutions of 3-carbethoxypsoralen (3-CPs) induced lysis of egg lecithin liposomes and whole human erythrocytes in the dark. Near-UV irradiation of 3-CPs sensitized the inactivation of lysozyme attributed to the production of reactive radical intermediates. The implications of these findings for the use of 3-CPs as a sensitizer in psoralen + UV-A (PUVA) therapy of psoriasis are discussed.

  6. STAT3/5-dependent IL9 overexpression contributes to neoplastic cell survival in mycosis fungoides

    DEFF Research Database (Denmark)

    Vieyra-Garcia, Pablo A.; Wei, Tianling; Naym, David Gram

    2016-01-01

    preparations. To explore the mechanism of IL9 secretion, we knocked down STAT3/5 and IRF4 by siRNA transfection in CTCL cell lines receiving psoralen+UVA (PUVA) ± anti-IL9 antibody. To further examine the role of IL9 in tumor development, the EL-4 T-cell lymphoma model was used in C57BL/6 mice.  Results...

  7. Previously unknown species of Aspergillus.

    Science.gov (United States)

    Gautier, M; Normand, A-C; Ranque, S

    2016-08-01

    The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

  8. 22 CFR 40.93 - Aliens unlawfully present after previous immigration violation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens unlawfully present after previous... TO BOTH NONIMMIGRANTS AND IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.93 Aliens unlawfully present after previous immigration violation. An alien described...

  9. Inflammatory responses to secondary organic aerosols (SOA generated from biogenic and anthropogenic precursors

    Directory of Open Access Journals (Sweden)

    W. Y. Tuet

    2017-09-01

    Full Text Available Cardiopulmonary health implications resulting from exposure to secondary organic aerosols (SOA, which comprise a significant fraction of ambient particulate matter (PM, have received increasing interest in recent years. In this study, alveolar macrophages were exposed to SOA generated from the photooxidation of biogenic and anthropogenic precursors (isoprene, α-pinene, β-caryophyllene, pentadecane, m-xylene, and naphthalene under different formation conditions (RO2 + HO2 vs. RO2 + NO dominant, dry vs. humid. Various cellular responses were measured, including reactive oxygen and nitrogen species (ROS/RNS production and secreted levels of cytokines, tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6. SOA precursor identity and formation condition affected all measured responses in a hydrocarbon-specific manner. With the exception of naphthalene SOA, cellular responses followed a trend where TNF-α levels reached a plateau with increasing IL-6 levels. ROS/RNS levels were consistent with relative levels of TNF-α and IL-6, due to their respective inflammatory and anti-inflammatory effects. Exposure to naphthalene SOA, whose aromatic-ring-containing products may trigger different cellular pathways, induced higher levels of TNF-α and ROS/RNS than suggested by the trend. Distinct cellular response patterns were identified for hydrocarbons whose photooxidation products shared similar chemical functionalities and structures, which suggests that the chemical structure (carbon chain length and functionalities of photooxidation products may be important for determining cellular effects. A positive nonlinear correlation was also detected between ROS/RNS levels and previously measured DTT (dithiothreitol activities for SOA samples. In the context of ambient samples collected during summer and winter in the greater Atlanta area, all laboratory-generated SOA produced similar or higher levels of ROS/RNS and DTT activities. These results

  10. Storage Stability Improvement of Copolymer Grafted Polypropylene-AcrylicAcid (PP-AA), by means of Various After Treatment Processes

    International Nuclear Information System (INIS)

    Gitopadmojo, Isminingsih

    2000-01-01

    Polypropylene yams that have been subjected to irradiation induced graftco-polymerization with acrylic acid, have gained its moisture regain and dyeability, that fulfilled the requirement as textile material for garment.However, the copolymer grafted PP-AA has suffered from degradation in thestorage, which was indicated in the previous study that the strengthretention has dropped tremendously by photo-oxidation or photo-degradation.After treatments of PP-AA yams with chemical compound that was able toprevent further photo-oxidation, will be expected to improve the stability ofPP-AA in storage. In this research activity, the polypropylene (PP) yams weresubjected to irradiation induced graft co-polymerization by means ofγ-Ray Co-60 as irradiation source with acrylic acid (AA) as monomer.Various after treatments were subjected to the grafted PP-AA yams such asalkalisation process; dyeing (anionic dyes, cationic dyes and nonionic dyes);as well as processing with optical brightening agent and UV stabilizer,separately. The PP-AA yams (before and after treatment) were subjected tostorage from 1 month up to 42 months, and then being tested for theirmoisture regain, strength retention and elongation at breaks. The samplesbeing stored for 12 months were subjected to radical analysis. It isconcluded from the experiment that after treatment of grafted PP-AA by meansof those various processes were able to improve the stability of copolymergrafted PP-AA in storage. The presence of peroxide radical in the ESR(electron spin resonance) spectrum on PP-AA yams before treatment and theones after treated with alkaline and being stored for 12 months haveindicated the presence of photo oxidation or photo degradation, while thepresence of poly enyl radical in the ESR spectrum of after treated PP-AA withdyes having azo and azine compound as chromophore, as well as with UVstabilizer with carbonyl as chromophore and being stored for 12 months haveproved that its presence have protected such

  11. 18 CFR 154.302 - Previously submitted material.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Previously submitted material. 154.302 Section 154.302 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... concurrently with the rate change filing. There must be furnished to the Director, Office of Energy Market...

  12. Subsequent pregnancy outcome after previous foetal death

    NARCIS (Netherlands)

    Nijkamp, J. W.; Korteweg, F. J.; Holm, J. P.; Timmer, A.; Erwich, J. J. H. M.; van Pampus, M. G.

    Objective: A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to

  13. Left ventricular asynergy score as an indicator of previous myocardial infarction

    International Nuclear Information System (INIS)

    Backman, C.; Jacobsson, K.A.; Linderholm, H.; Osterman, G.

    1986-01-01

    Sixty-eight patients with coronary heart disease (CHD) i.e. a hisotry of angina of effort and/or previous 'possible infarction' were examined inter alia with ECG and cinecardioangiography. A system of scoring was designed which allowed a semiquantitative estimate of the left ventricular asynergy from cinecardioangiography - the left ventricular motion score (LVMS). The LVMS was associated with the presence of a previous myocardial infarction (MI), as indicated by the history and ECG findings. The ECG changes specific for a previous MI were associated with high LVMS values and unspecific or absent ECG changes with low LVMS values. Decision thresholds for ECG changes and asynergy in diagnosing a previous MI were evaluated by means of a ROC analysis. The accuracy of ECG in detecting a previous MI was slightly higher when asynergy indicated a 'true MI' than when autopsy result did so in a comparable group. Therefore the accuracy of asynergy (LVMS ≥ 1) in detecting a previous MI or myocardial fibrosis in patients with CHD should be at least comparable with that of autopsy (scar > 1 cm). (orig.)

  14. Reasoning with Previous Decisions: Beyond the Doctrine of Precedent

    DEFF Research Database (Denmark)

    Komárek, Jan

    2013-01-01

    in different jurisdictions use previous judicial decisions in their argument, we need to move beyond the concept of precedent to a wider notion, which would embrace practices and theories in legal systems outside the Common law tradition. This article presents the concept of ‘reasoning with previous decisions...... law method’, but they are no less rational and intellectually sophisticated. The reason for the rather conceited attitude of some comparatists is in the dominance of the common law paradigm of precedent and the accompanying ‘case law method’. If we want to understand how courts and lawyers......’ as such an alternative and develops its basic models. The article first points out several shortcomings inherent in limiting the inquiry into reasoning with previous decisions by the common law paradigm (1). On the basis of numerous examples provided in section (1), I will present two basic models of reasoning...

  15. On the Tengiz petroleum deposit previous study

    International Nuclear Information System (INIS)

    Nysangaliev, A.N.; Kuspangaliev, T.K.

    1997-01-01

    Tengiz petroleum deposit previous study is described. Some consideration about structure of productive formation, specific characteristic properties of petroleum-bearing collectors are presented. Recommendation on their detail study and using of experience on exploration and development of petroleum deposit which have analogy on most important geological and industrial parameters are given. (author)

  16. Design, Synthesis and Antifungal Activity of Psoralen Derivatives

    Directory of Open Access Journals (Sweden)

    Xiang Yu

    2017-10-01

    Full Text Available A series of linear furanocoumarins with different substituents have been designed and synthesized. Their structures were confirmed by 1H-NMR spectroscopy, high resolution mass spectra (EI-MS, IR, and X-ray single-crystal diffraction. All of the target compounds were evaluated in vitro for their antifungal activity against Rhizoctorzia solani, Botrytis cinerea, Alternaria solani, Gibberella zeae, Cucumber anthrax, and Alternaria leaf spot at 100 μg/mL, and some of the designed compounds exhibited potential antifungal activities. Compound 3a (67.9% exhibited higher activity than the control Osthole (66.1% against Botrytis cinerea. Furthermore, compound 4b (62.4% represented equivalent antifungal activity as Osthole (69.5% against Rhizoctonia solani. The structure-activity relationship (SAR study demonstrates that linear furanocoumarin moiety has an important effect on the antifungal activity, promoting the idea of the coumarin ring as a framework that might be exploited in the future.

  17. Photoprotective effect of a psoralen-UVA-induced tan

    International Nuclear Information System (INIS)

    Gschnait, F.; Brenner, W.; Wolff, K.

    1978-01-01

    To determine whether a tan produced by 8-MOP and UVA protects from subsequent solar light irradiation, volunteers were irradiated with unfiltered Xenon arc light before and 10 days after a 1 week's course of four 8-MOP-UVA treatments. Evaluation of the minimal erythema doses and of histological changes before and after 8-MOP-UVA treatment revealed that the 8-MOP-UVA induced tan protected against the erythemogenic and cell damaging effects of Xenon arc light. Unscheduled repair DNA synthesis, used as a measure for UVB-induced DNA damage and repair, was also investigated in skin irradiated with the Xenon arc before and after 8-MOP-UVA induced tanning. Both the number of grains per sparse labeled cell and the number of sparse labeled cells per 1000 cells, were found to be significantly lower in tanned skin; taking decreased unscheduled repair DNA synthesis as a measure for decreased DNA-damage, these findings also demonstrate a photoprotective effect of the 8-MOP-UVA induced tan. (orig.) [de

  18. Coumarins and alkaloids in shoot culture of Ruta graveolens L.

    Directory of Open Access Journals (Sweden)

    Halina Ekiert

    2014-01-01

    Full Text Available A shoot culture of Ruta graveolens L. (Rutaceae was maintained in the stationary liquid phase. From the cultured shoots seven compounds were isolated and identified as psoralen, bergapten, xanthotoxin, isopimpinellin (linear furanocoumarins, rutamarin (linear dihydrofuranocoumarin, kokusaginine and skimmianine (furanoquinoline alkaloids by spectral methods. The compounds are known as secondary metabolites of the intact plant, as well as its cell and tissue cultures.

  19. Dark membrane lysis and photosensitization by 3-carbethoxypsoralen

    International Nuclear Information System (INIS)

    Muller-Runkel, R.; Grossweiner, L.I.

    1981-01-01

    Aqueous solutions of 3-carbethoxypsoralen (3-CPs) induced lysis of egg lecithin liposomes and whole human erythrocytes in the dark. Near-UV irradiation of 3-CPs sensitized the inactivation of lysozyme attributed to the production of reactive radical intermediates. The implications of these findings for the use of 3-CPs as a sensitizer in psoralen + UV-A (PUVA) therapy of psoriasis are discussed. (author)

  20. Functionalizing carbon nitride with heavy atom-free spin converters for enhanced 1 O 2 generation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenting; Han, Congcong; Zhang, Qinhua; Zhang, Qinggang; Li, Zhongtao; Gosztola, David J.; Wiederrecht, Gary P.; Wu, Mingbo

    2018-05-01

    advanced photosensitizers for singlet oxygen (1O2) generation. However, the intersystem crossing (ISC) process is quite insufficient in carbon nitride, limiting the 1O2 generation. Here, we report a facile and general strategy to confined benzophenone as a heavy atom-free spin converter dopant in carbon nitride via the facile copolymerization. With proper energy level matching between the heavy atom-free spin converter and various ligands based on carbon nitride precursors, the proper combination can decrease the singlet-triplet energy gap (DEST) and hence generate 1O2 effectively. Due to its significant and selectivity for 1O2 generation, the as-prepared carbon nitride-based photosensitizer shows a high selective photooxidation activity for 1,5-dihydroxy-naphthalene (1,5-DHN). The product yield reached 71.8% after irradiation for 60 min, which was higher than that of cyclometalated PtII complexes (53.6%) in homogeneous photooxidation. This study can broaden the application of carbon nitride in the field of selective heterogeneous photooxidation due to simple operation, low cost, and high efficiency, making it a strong candidate for future industrialization.

  1. Should previous mammograms be digitised in the transition to digital mammography?

    International Nuclear Information System (INIS)

    Taylor-Phillips, S.; Gale, A.G.; Wallis, M.G.

    2009-01-01

    Breast screening specificity is improved if previous mammograms are available, which presents a challenge when converting to digital mammography. Two display options were investigated: mounting previous film mammograms on a multiviewer adjacent to the workstation, or digitising them for soft copy display. Eight qualified screen readers were videotaped undertaking routine screen reading for two 45-min sessions in each scenario. Analysis of gross eye and head movements showed that when digitised, previous mammograms were examined a greater number of times per case (p=0.03), due to a combination of being used in 19% more cases (p=0.04) and where used, looked at a greater number of times (28% increase, p=0.04). Digitising previous mammograms reduced both the average time taken per case by 18% (p=0.04) and the participants' perceptions of workload (p < 0.05). Digitising previous analogue mammograms may be advantageous, in particular in increasing their level of use. (orig.)

  2. Pellitorine, an extract of Tetradium daniellii, is an antagonist of the ion channel TRPV1.

    Science.gov (United States)

    Oláh, Zoltán; Rédei, Dóra; Pecze, László; Vizler, Csaba; Jósvay, Katalin; Forgó, Péter; Winter, Zoltán; Dombi, György; Szakonyi, Gerda; Hohmann, Judit

    2017-10-15

    Transient Receptor Potential Vanilloid 1 (TRPV1) confers noxious heat and inflammatory pain signals in the peripheral nervous system. Clinical trial of resiniferatoxin from Euphorbia species is successfully aimed at TRPV1 in cancer pain management and heading toward new selective painkiller status that further validates this target for drug discovery efforts. Evodia species, used in traditional medicine for hundreds of years, are a recognised source of different TRPV1 agonists, but no antagonist has yet been reported. In a search for painkiller leads, we noted for the first time a TRPV1 antagonist activity in the fresh fruits of Tetradium daniellii (Benn.) T.G. Hartley (syn. Evodia hupehensis Dode). Through a combination of extraction and purification methods with functional TRPV1-specific Ca 2+ uptake assays (bioactivity-guided fractionation/isolation/purification); we isolated a new painkiller candidate that is a distant structural homologue of capsiate exovanilloids and endovanilloids such as anandamide, but a putative competitive inhibitor of the TRPV1. Four additional inactive compounds (N-isobutyl-4,5-epoxy-2E-decadienamide, geranylpsoralen, 8-(7',8'-epoxygeranyloxy)psoralen, and xanthotoxol) were also co-purified with pellitorine. Their structures were established by extensive 1D- and 2D-NMR spectroscopic analysis. 1 H- and 13 C NMR determination of the chemical structure revealed it to be pellitorine, (2E,4E)-N-(2-methylpropyl)deca-2,4-dienamide, which can compete structurally with algesics released in inflammation. In contrast to previous isolates from Evodia species, pellitorine blocked capsaicin-evoked Ca 2+ uptake with an IC 50 of 154 µg/ml (0.69 mM/l). N-Isobutyl-4,5-epoxy-2E-decadienamide and geranylpsoralen, 8-(7',8'-epoxygeranyloxy)psoralen, and xanthotoxol did not affect the TRPV1. This is the first evidence that pellitorine, an aliphatic alkylamide analogue of capsaicin, can serve as an antagonist of the TRPV1 and may inhibit exovanilloid

  3. 14 CFR 121.406 - Credit for previous CRM/DRM training.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Credit for previous CRM/DRM training. 121... previous CRM/DRM training. (a) For flightcrew members, the Administrator may credit CRM training received before March 19, 1998 toward all or part of the initial ground CRM training required by § 121.419. (b...

  4. Challenging previous conceptions of vegetarianism and eating disorders.

    Science.gov (United States)

    Fisak, B; Peterson, R D; Tantleff-Dunn, S; Molnar, J M

    2006-12-01

    The purpose of this study was to replicate and expand upon previous research that has examined the potential association between vegetarianism and disordered eating. Limitations of previous research studies are addressed, including possible low reliability of measures of eating pathology within vegetarian samples, use of only a few dietary restraint measures, and a paucity of research examining potential differences in body image and food choice motives of vegetarians versus nonvegetarians. Two hundred and fifty-six college students completed a number of measures of eating pathology and body image, and a food choice motives questionnaire. Interestingly, no significant differences were found between vegetarians and nonvegetarians in measures of eating pathology or body image. However, significant differences in food choice motives were found. Implications for both researchers and clinicians are discussed.

  5. Iron promotion of the TiO2 photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    International Nuclear Information System (INIS)

    Castro, Camilo A.; Centeno, Aristobulo; Giraldo, Sonia A.

    2011-01-01

    Highlights: → Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO 2 . → Fe 3+ enhances the TiO 2 photooxidation of azo dyes while decreases that of phenol. → UV irradiation leads to a decrease in photooxidation activity of Fe-TiO 2 photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO 2 (Fe-TiO 2 ) was studied under ultraviolet (UV), visible (vis) and simultaneous UV-vis irradiations using a solar light simulator. Photocatalysts were characterized by means of XRD, SEM-EDX, FTIR and DRS. Fe 3+ species, identified in XPS analyses, were responsible of the increased absorption of visible light. Moreover, DRS analyses showed a decrease in the bandgap due to Fe 3+ loading. Photocatalystic tests proved that Fe modification enhanced the TiO 2 photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO 2 samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO 2 suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe 3+ promotion of the electron caption in the photosensitization process of TiO 2 by Or-II acting as a sensitizer. Such process leads to the Or-II photooxidation under UV-vis irradiation by losing energy in electron transferring processes to sensitize TiO 2 , and, the formation of reactive oxygen species promoted by the injected electron to the TiO 2 conduction band.

  6. Response to health insurance by previously uninsured rural children.

    Science.gov (United States)

    Tilford, J M; Robbins, J M; Shema, S J; Farmer, F L

    1999-08-01

    To examine the healthcare utilization and costs of previously uninsured rural children. Four years of claims data from a school-based health insurance program located in the Mississippi Delta. All children who were not Medicaid-eligible or were uninsured, were eligible for limited benefits under the program. The 1987 National Medical Expenditure Survey (NMES) was used to compare utilization of services. The study represents a natural experiment in the provision of insurance benefits to a previously uninsured population. Premiums for the claims cost were set with little or no information on expected use of services. Claims from the insurer were used to form a panel data set. Mixed model logistic and linear regressions were estimated to determine the response to insurance for several categories of health services. The use of services increased over time and approached the level of utilization in the NMES. Conditional medical expenditures also increased over time. Actuarial estimates of claims cost greatly exceeded actual claims cost. The provision of a limited medical, dental, and optical benefit package cost approximately $20-$24 per member per month in claims paid. An important uncertainty in providing health insurance to previously uninsured populations is whether a pent-up demand exists for health services. Evidence of a pent-up demand for medical services was not supported in this study of rural school-age children. States considering partnerships with private insurers to implement the State Children's Health Insurance Program could lower premium costs by assembling basic data on previously uninsured children.

  7. Abiraterone in metastatic prostate cancer without previous chemotherapy

    NARCIS (Netherlands)

    Ryan, Charles J.; Smith, Matthew R.; de Bono, Johann S.; Molina, Arturo; Logothetis, Christopher J.; de Souza, Paul; Fizazi, Karim; Mainwaring, Paul; Piulats, Josep M.; Ng, Siobhan; Carles, Joan; Mulders, Peter F. A.; Basch, Ethan; Small, Eric J.; Saad, Fred; Schrijvers, Dirk; van Poppel, Hendrik; Mukherjee, Som D.; Suttmann, Henrik; Gerritsen, Winald R.; Flaig, Thomas W.; George, Daniel J.; Yu, Evan Y.; Efstathiou, Eleni; Pantuck, Allan; Winquist, Eric; Higano, Celestia S.; Taplin, Mary-Ellen; Park, Youn; Kheoh, Thian; Griffin, Thomas; Scher, Howard I.; Rathkopf, Dana E.; Boyce, A.; Costello, A.; Davis, I.; Ganju, V.; Horvath, L.; Lynch, R.; Marx, G.; Parnis, F.; Shapiro, J.; Singhal, N.; Slancar, M.; van Hazel, G.; Wong, S.; Yip, D.; Carpentier, P.; Luyten, D.; de Reijke, T.

    2013-01-01

    Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. In this double-blind study, we randomly assigned

  8. Squamous cell carcinoma arising in previously burned or irradiated skin

    International Nuclear Information System (INIS)

    Edwards, M.J.; Hirsch, R.M.; Broadwater, J.R.; Netscher, D.T.; Ames, F.C.

    1989-01-01

    Squamous cell carcinoma (SCC) arising in previously burned or irradiated skin was reviewed in 66 patients treated between 1944 and 1986. Healing of the initial injury was complicated in 70% of patients. Mean interval from initial injury to diagnosis of SCC was 37 years. The overwhelming majority of patients presented with a chronic intractable ulcer in previously injured skin. The regional relapse rate after surgical excision was very high, 58% of all patients. Predominant patterns of recurrence were in local skin and regional lymph nodes (93% of recurrences). Survival rates at 5, 10, and 20 years were 52%, 34%, and 23%, respectively. Five-year survival rates in previously burned and irradiated patients were not significantly different (53% and 50%, respectively). This review, one of the largest reported series, better defines SCC arising in previously burned or irradiated skin as a locally aggressive disease that is distinct from SCC arising in sunlight-damaged skin. An increased awareness of the significance of chronic ulceration in scar tissue may allow earlier diagnosis. Regional disease control and survival depend on surgical resection of all known disease and may require radical lymph node dissection or amputation

  9. Possible Detection of Perchlorates by the Sample Analysis at Mars (SAM) Instrument: Comparison with Previous Missions

    Science.gov (United States)

    Navarro-Gonzalex, Rafael; Sutter, Brad; Archer, Doug; Ming, Doug; Eigenbrode, Jennifer; Franz, Heather; Glavin, Daniel; McAdam, Amy; Stern, Jennifer; McKay, Christopher; hide

    2013-01-01

    The first chemical analysis of soluble salts in the soil was carried out by the Phoenix Lander in the Martian Arctic [1]. Surprisingly, chlorine was present as magnesium or calcium perchlorate at 0.4 to 0.6 percent. Additional support for the identification of perchlorate came from the evolved gas analysis which detected the release of molecular oxygen at 350-550C [1]. When Mars-like soils from the Atacama Desert were spiked with magnesium perchlorate (1 percent) and heated using the Viking GC-MS protocol, nearly all the organics were combusted but a small amount was chlorinated, forming chloromethane and dichloromethane [2]. These chlorohydrocarbons were detected by the Viking GC-MS experiments when the Martian soil was analyzed but they were considered to be terrestrial contaminants [3]. Reinterpretation of the Viking results suggests Analysis at Mars (SAM) instrument on board the Mars Science Laboratory (MSL) ran four samples from an aeolian bedform named Rocknest. The samples analyzed were portioned from the fifth scoop at this location. The samples were heated to 835C at 35C/min with a He flow. The SAM QMS detected a major oxygen release (300-500C) [5], coupled with the release of chlorinated hydrocarbons (chloromethane, dichloromethane, trichloromethane, and chloromethylpropene) detected both by SAM QMS and GC-MS derived from known Earth organic contaminants in the instrument [6]. Calcium perchlorate appears to be the best candidate for evolved O2 in the Rocknest samples at this time but other Cl species (e.g., chlorates) are possible and must be evaluated. The potential detection of perchlorates in Rocknest material adds weight to the argument that both Viking Landers measured signatures of perchlorates. Even if the source of the organic carbon detected is still unknown, the chlorine source was likely Martian. Two mechanisms have been hypothesized for the formation of soil perchlorate: (1) Atmospheric oxidation of chlorine; and (2) UV photooxidation of

  10. Dissociation in decision bias mechanism between probabilistic information and previous decision

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKaneko

    2015-05-01

    Full Text Available Target detection performance is known to be influenced by events in the previous trials. It has not been clear, however, whether this bias effect is due to the previous sensory stimulus, motor response, or decision. Also it remains open whether or not the previous trial effect emerges via the same mechanism as the effect of knowledge about the target probability. In the present study, we asked normal human subjects to make a decision about the presence or absence of a visual target. We presented a pre-cue indicating the target probability before the stimulus, and also a decision-response mapping cue after the stimulus so as to tease apart the effect of decision from that of motor response. We found that the target detection performance was significantly affected by the probability cue in the current trial and also by the decision in the previous trial. While the information about the target probability modulated the decision criteria, the previous decision modulated the sensitivity to target-relevant sensory signals (d-prime. Using functional magnetic resonance imaging, we also found that activation in the left intraparietal sulcus was decreased when the probability cue indicated a high probability of the target. By contrast, activation in the right inferior frontal gyrus was increased when the subjects made a target-present decision in the previous trial, but this change was observed specifically when the target was present in the current trial. Activation in these regions was associated with individual-difference in the decision computation parameters. We argue that the previous decision biases the target detection performance by modulating the processing of target-selective information, and this mechanism is distinct from modulation of decision criteria due to expectation of a target.

  11. Dissociation in decision bias mechanism between probabilistic information and previous decision

    Science.gov (United States)

    Kaneko, Yoshiyuki; Sakai, Katsuyuki

    2015-01-01

    Target detection performance is known to be influenced by events in the previous trials. It has not been clear, however, whether this bias effect is due to the previous sensory stimulus, motor response, or decision. Also it remains open whether or not the previous trial effect emerges via the same mechanism as the effect of knowledge about the target probability. In the present study, we asked normal human subjects to make a decision about the presence or absence of a visual target. We presented a pre-cue indicating the target probability before the stimulus, and also a decision-response mapping cue after the stimulus so as to tease apart the effect of decision from that of motor response. We found that the target detection performance was significantly affected by the probability cue in the current trial and also by the decision in the previous trial. While the information about the target probability modulated the decision criteria, the previous decision modulated the sensitivity to target-relevant sensory signals (d-prime). Using functional magnetic resonance imaging (fMRI), we also found that activation in the left intraparietal sulcus (IPS) was decreased when the probability cue indicated a high probability of the target. By contrast, activation in the right inferior frontal gyrus (IFG) was increased when the subjects made a target-present decision in the previous trial, but this change was observed specifically when the target was present in the current trial. Activation in these regions was associated with individual-difference in the decision computation parameters. We argue that the previous decision biases the target detection performance by modulating the processing of target-selective information, and this mechanism is distinct from modulation of decision criteria due to expectation of a target. PMID:25999844

  12. Cardiovascular magnetic resonance in adults with previous cardiovascular surgery.

    Science.gov (United States)

    von Knobelsdorff-Brenkenhoff, Florian; Trauzeddel, Ralf Felix; Schulz-Menger, Jeanette

    2014-03-01

    Cardiovascular magnetic resonance (CMR) is a versatile non-invasive imaging modality that serves a broad spectrum of indications in clinical cardiology and has proven evidence. Most of the numerous applications are appropriate in patients with previous cardiovascular surgery in the same manner as in non-surgical subjects. However, some specifics have to be considered. This review article is intended to provide information about the application of CMR in adults with previous cardiovascular surgery. In particular, the two main scenarios, i.e. following coronary artery bypass surgery and following heart valve surgery, are highlighted. Furthermore, several pictorial descriptions of other potential indications for CMR after cardiovascular surgery are given.

  13. Previously unreported abnormalities in Wolfram Syndrome Type 2.

    Science.gov (United States)

    Akturk, Halis Kaan; Yasa, Seda

    2017-01-01

    Wolfram syndrome (WFS) is a rare autosomal recessive disease with non-autoimmune childhood onset insulin dependent diabetes and optic atrophy. WFS type 2 (WFS2) differs from WFS type 1 (WFS1) with upper intestinal ulcers, bleeding tendency and the lack ofdiabetes insipidus. Li-fespan is short due to related comorbidities. Only a few familieshave been reported with this syndrome with the CISD2 mutation. Here we report two siblings with a clinical diagnosis of WFS2, previously misdiagnosed with type 1 diabetes mellitus and diabetic retinopathy-related blindness. We report possible additional clinical and laboratory findings that have not been pre-viously reported, such as asymptomatic hypoparathyroidism, osteomalacia, growth hormone (GH) deficiency and hepatomegaly. Even though not a requirement for the diagnosis of WFS2 currently, our case series confirm hypogonadotropic hypogonadism to be also a feature of this syndrome, as reported before. © Polish Society for Pediatric Endocrinology and Diabetology.

  14. Outcome Of Pregnancy Following A Previous Lower Segment ...

    African Journals Online (AJOL)

    Background: A previous ceasarean section is an important variable that influences patient management in subsequent pregnancies. A trial of vaginal delivery in such patients is a feasible alternative to a secondary section, thus aiding to reduce the ceasarean section rate and its associated co-morbidities. Objective: To ...

  15. Cryptococcal meningitis in a previously healthy child | Chimowa ...

    African Journals Online (AJOL)

    An 8-year-old previously healthy female presented with a 3 weeks history of headache, neck stiffness, deafness, fever and vomiting and was diagnosed with cryptococcal meningitis. She had documented hearing loss and was referred to tertiary-level care after treatment with fluconazole did not improve her neurological ...

  16. 24 CFR 1710.552 - Previously accepted state filings.

    Science.gov (United States)

    2010-04-01

    ... of Substantially Equivalent State Law § 1710.552 Previously accepted state filings. (a) Materials... and contracts or agreements contain notice of purchaser's revocation rights. In addition see § 1715.15..., unless the developer is obligated to do so in the contract. (b) If any such filing becomes inactive or...

  17. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, Florens N.; Cohen, Joeri; Blom, Nico A.; Delhaas, Tammo; Helbing, Wim A.; Lam, Jan; Sobotka-Plojhar, Marta A.; Temmerman, Arno M.; Sreeram, Narayanswani

    2004-01-01

    BACKGROUND: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. OBJECTIVE: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  18. Sudden unexpected death in children with a previously diagnosed cardiovascular disorder

    NARCIS (Netherlands)

    Polderman, F.N.; Cohen, Joeri; Blom, N.A.; Delhaas, T.; Helbing, W.A.; Lam, J.; Sobotka-Plojhar, M.A.; Temmerman, Arno M.; Sreeram, N.

    2004-01-01

    Background: It is known that children with previously diagnosed heart defects die suddenly. The causes of death are often unknown. Objective: The aim of the study was to identify all infants and children within the Netherlands with previously diagnosed heart disease who had a sudden unexpected death

  19. 75 FR 20933 - Airworthiness Directives; Arrow Falcon Exporters, Inc. (previously Utah State University...

    Science.gov (United States)

    2010-04-22

    ... Hawkins and Powers Aviation, Inc.); S.M.&T. Aircraft (previously US Helicopters, Inc., UNC Helicopter, Inc... Joaquin Helicopters (previously Hawkins and Powers Aviation, Inc.); S.M.&T. Aircraft (previously US...

  20. UVA1 a promising approach for scleroderma

    Science.gov (United States)

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

    2017-01-01

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

  1. Photobinding of 3H 8-methoxypsoralen to monkey intraocular tissues

    International Nuclear Information System (INIS)

    Lerman, S.; Megaw, J.; Gardner, K.; Takei, Y.; Franks, Y.; Gammon, A.

    1984-01-01

    Young (less than 1 year) and old (greater than 15 years) Rhesus monkeys were utilized in this study in order to determine whether ultraviolet (UV) radiation at ambient levels induces psoralen photobinding in primate eyes (in particular the lens and retina). Unilateral aphakia or pseudophakia was induced surgically and the eyes were allowed to heal. The animals then were given a single intraperitoneal injection of 3 H 8-methoxypsoralen (8-MOP) and immediately exposed to BLB lights (of measured radiation intensity at the corneal surface). The animals were killed at varying time periods (2-6 weeks), and the eyes were removed immediately. One-half of each cornea and lens was frozen for subsequent optical spectroscopy and the remaining ocular tissues were fixed for histopathologic studies and autoradiography. These data demonstrate that low level UV radiation (less than 0.4 mW/cm2) can cause 8-MOP photobinding to lens proteins and DNA and to aphakic, pseudophakic, and young phakic primate retinas. The older phakic primate lens serves as a protective UV filter and prevents psoralen photobinding within the retina. These data suggest that older aphakes and pseudophakes may require UV radiation protection to prevent direct as well as photosensitized retinal photodamage

  2. Distribution Assessments of Coumarins from Angelicae Pubescentis Radix in Rat Cerebrospinal Fluid and Brain by Liquid Chromatography Tandem Mass Spectrometry Analysis

    Directory of Open Access Journals (Sweden)

    Yan-Fang Yang

    2018-01-01

    Full Text Available Angelicae Pubescentis Radix (APR is a widely-used traditional Chinese medicine. Pharmacological studies have begun to probe its biological activities on neurological disorders recently. To assess the brain penetration and distribution of APR, a validated ultra-performance liquid chromatography tandem mass spectrometry method was applied to the simultaneous determinations of the main coumarins from APR in the rat cerebrospinal fluid (CSF and brain after oral administration of APR extract, including psoralen, xanthotoxin, bergapten, isoimperatorin, columbianetin, columbianetin acetate, columbianadin, oxypeucedanin hydrate, angelol B, osthole, meranzin hydrate and nodakenetin. Most of the tested coumarins entered the rat CSF and brain quickly, and double-peak phenomena in concentration-time curves were similar to those of their plasma pharmacokinetics. Columbianetin had the highest concentration in the CSF and brain, while psoralen and columbianetin acetate had the largest percent of CSF/plasma and brain/plasma, indicating that these three coumarins may be worthy of further research on the possible nervous effects. Correlations between the in vivo brain distributions and plasma pharmacokinetics of these coumarins were well verified. These results provided valuable information for the overall in vivo brain distribution characteristics of APR and also for its further studies on the active substances for the central nervous system.

  3. Distribution Assessments of Coumarins from Angelicae Pubescentis Radix in Rat Cerebrospinal Fluid and Brain by Liquid Chromatography Tandem Mass Spectrometry Analysis.

    Science.gov (United States)

    Yang, Yan-Fang; Zhang, Lei; Yang, Xiu-Wei

    2018-01-20

    Angelicae Pubescentis Radix (APR) is a widely-used traditional Chinese medicine. Pharmacological studies have begun to probe its biological activities on neurological disorders recently. To assess the brain penetration and distribution of APR, a validated ultra-performance liquid chromatography tandem mass spectrometry method was applied to the simultaneous determinations of the main coumarins from APR in the rat cerebrospinal fluid (CSF) and brain after oral administration of APR extract, including psoralen, xanthotoxin, bergapten, isoimperatorin, columbianetin, columbianetin acetate, columbianadin, oxypeucedanin hydrate, angelol B, osthole, meranzin hydrate and nodakenetin. Most of the tested coumarins entered the rat CSF and brain quickly, and double-peak phenomena in concentration-time curves were similar to those of their plasma pharmacokinetics. Columbianetin had the highest concentration in the CSF and brain, while psoralen and columbianetin acetate had the largest percent of CSF/plasma and brain/plasma, indicating that these three coumarins may be worthy of further research on the possible nervous effects. Correlations between the in vivo brain distributions and plasma pharmacokinetics of these coumarins were well verified. These results provided valuable information for the overall in vivo brain distribution characteristics of APR and also for its further studies on the active substances for the central nervous system.

  4. Production of Molecular Iodine and Tri-iodide in the Frozen Solution of Iodide: Implication for Polar Atmosphere.

    Science.gov (United States)

    Kim, Kitae; Yabushita, Akihiro; Okumura, Masanori; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Blaszczak-Boxe, Christopher S; Min, Dae Wi; Yoon, Ho-Il; Choi, Wonyong

    2016-02-02

    The chemistry of reactive halogens in the polar atmosphere plays important roles in ozone and mercury depletion events, oxidizing capacity, and dimethylsulfide oxidation to form cloud-condensation nuclei. Among halogen species, the sources and emission mechanisms of inorganic iodine compounds in the polar boundary layer remain unknown. Here, we demonstrate that the production of tri-iodide (I3(-)) via iodide oxidation, which is negligible in aqueous solution, is significantly accelerated in frozen solution, both in the presence and the absence of solar irradiation. Field experiments carried out in the Antarctic region (King George Island, 62°13'S, 58°47'W) also showed that the generation of tri-iodide via solar photo-oxidation was enhanced when iodide was added to various ice media. The emission of gaseous I2 from the irradiated frozen solution of iodide to the gas phase was detected by using cavity ring-down spectroscopy, which was observed both in the frozen state at 253 K and after thawing the ice at 298 K. The accelerated (photo-)oxidation of iodide and the subsequent formation of tri-iodide and I2 in ice appear to be related with the freeze concentration of iodide and dissolved O2 trapped in the ice crystal grain boundaries. We propose that an accelerated abiotic transformation of iodide to gaseous I2 in ice media provides a previously unrecognized formation pathway of active iodine species in the polar atmosphere.

  5. 40 CFR 152.93 - Citation of a previously submitted valid study.

    Science.gov (United States)

    2010-07-01

    ... Data Submitters' Rights § 152.93 Citation of a previously submitted valid study. An applicant may demonstrate compliance for a data requirement by citing a valid study previously submitted to the Agency. The... the original data submitter, the applicant may cite the study only in accordance with paragraphs (b...

  6. Investigation of previously derived Hyades, Coma, and M67 reddenings

    International Nuclear Information System (INIS)

    Taylor, B.J.

    1980-01-01

    New Hyades polarimetry and field star photometry have been obtained to check the Hyades reddening, which was found to be nonzero in a previous paper. The new Hyades polarimetry implies essentially zero reddening; this is also true of polarimetry published by Behr (which was incorrectly interpreted in the previous paper). Four photometric techniques which are presumed to be insensitive to blanketing are used to compare the Hyades to nearby field stars; these four techniques also yield essentially zero reddening. When all of these results are combined with others which the author has previously published and a simultaneous solution for the Hyades, Coma, and M67 reddenings is made, the results are E (B-V) =3 +- 2 (sigma) mmag, -1 +- 3 (sigma) mmag, and 46 +- 6 (sigma) mmag, respectively. No support for a nonzero Hyades reddening is offered by the new results. When the newly obtained reddenings for the Hyades, Coma, and M67 are compared with results from techniques given by Crawford and by users of the David Dunlap Observatory photometric system, no differences between the new and other reddenings are found which are larger than about 2 sigma. The author had previously found that the M67 main-sequence stars have about the same blanketing as that of Coma and less blanketing than the Hyades; this conclusion is essentially unchanged by the revised reddenings

  7. Process cells dismantling of EUREX pant: previous activities

    International Nuclear Information System (INIS)

    Gili, M.

    1998-01-01

    In the '98-'99 period some process cells of the EUREX pant will be dismantled, in order to place there the liquid wastes conditioning plant 'CORA'. This report resumes the previous activities (plant rinsing campaigns and inactive Cell 014 dismantling), run in the past three years and the drawn experience [it

  8. Photolysis of petroleum

    International Nuclear Information System (INIS)

    Bobra, M.

    1992-05-01

    A study was conducted to examine the chemical and physical changes that occur in oils as a result of photooxidation. A literature review of recent studies in petroleum photochemistry revealed reported effects of photo-induced reactions in petroleum, including changes in color, polymerization, solidification, increases in solubility and toxicity, and changes in interfacial properties. A list of products reported as a result of photolysis of petroleum is presented, including such compounds as aldehydes, ketones, esters, and lactones. The photoreactivity of various petroleum components is discussed and mechanisms of photooxidation of petroleum are suggested. In the experimental portion of the study, a variety of crude oils and petroleum products were used to determine how different oils are affected by photolysis, and to examine the importance of photolysis as a weathering process. Photooxidation products from several oils were isolated and identified, including aliphatic and aromatic acids, alcohols, and phenols. Some physical manifestations attributed to photolysis included yellowing, formation of precipitates or crusts, increases in density and viscosity with time, increases of asphaltene content in some oils, changes in pH of the surrounding water, and emulsification. 51 refs., 38 figs., 18 tabs

  9. 75 FR 39143 - Airworthiness Directives; Arrow Falcon Exporters, Inc. (previously Utah State University); AST...

    Science.gov (United States)

    2010-07-08

    ... (previously Precision Helicopters, LLC); Robinson Air Crane, Inc.; San Joaquin Helicopters (previously Hawkins... (Previously Hawkins & Powers Aviation); S.M. &T. Aircraft (Previously Us Helicopter Inc., UNC Helicopters, Inc...

  10. Obstructive pulmonary disease in patients with previous tuberculosis ...

    African Journals Online (AJOL)

    Obstructive pulmonary disease in patients with previous tuberculosis: Pathophysiology of a community-based cohort. B.W. Allwood, R Gillespie, M Galperin-Aizenberg, M Bateman, H Olckers, L Taborda-Barata, G.L. Calligaro, Q Said-Hartley, R van Zyl-Smit, C.B. Cooper, E van Rikxoort, J Goldin, N Beyers, E.D. Bateman ...

  11. Matched cohort study of external cephalic version in women with previous cesarean delivery.

    Science.gov (United States)

    Keepanasseril, Anish; Anand, Keerthana; Soundara Raghavan, Subrahmanian

    2017-07-01

    To evaluate the efficacy and safety of external cephalic version (ECV) among women with previous cesarean delivery. A retrospective study was conducted using data for women with previous cesarean delivery and breech presentation who underwent ECV at or after 36 weeks of pregnancy during 2011-2016. For every case, two multiparous women without previous cesarean delivery who underwent ECV and were matched for age and pregnancy duration were included. Characteristics and outcomes were compared between groups. ECV was successful for 32 (84.2%) of 38 women with previous cesarean delivery and 62 (81.6%) in the control group (P=0.728). Multivariate regression analysis confirmed that previous cesarean was not associated with ECV success (odds ratio 1.89, 95% confidence interval 0.19-18.47; P=0.244). Successful vaginal delivery after successful ECV was reported for 19 (59.4%) women in the previous cesarean delivery group and 52 (83.9%) in the control group (P<0.001). No ECV-associated complications occurred in women with previous cesarean delivery. To avoid a repeat cesarean delivery, ECV can be offered to women with breech presentation and previous cesarean delivery who are otherwise eligible for a trial of labor. © 2017 International Federation of Gynecology and Obstetrics.

  12. Attribute and topology based change detection in a constellation of previously detected objects

    Science.gov (United States)

    Paglieroni, David W.; Beer, Reginald N.

    2016-01-19

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  13. Outcomes With Edoxaban Versus Warfarin in Patients With Previous Cerebrovascular Events

    DEFF Research Database (Denmark)

    Rost, Natalia S; Giugliano, Robert P; Ruff, Christian T

    2016-01-01

    BACKGROUND AND PURPOSE: Patients with atrial fibrillation and previous ischemic stroke (IS)/transient ischemic attack (TIA) are at high risk of recurrent cerebrovascular events despite anticoagulation. In this prespecified subgroup analysis, we compared warfarin with edoxaban in patients with ver......BACKGROUND AND PURPOSE: Patients with atrial fibrillation and previous ischemic stroke (IS)/transient ischemic attack (TIA) are at high risk of recurrent cerebrovascular events despite anticoagulation. In this prespecified subgroup analysis, we compared warfarin with edoxaban in patients...... with versus without previous IS/TIA. METHODS: ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind trial of 21 105 patients with atrial fibrillation randomized to warfarin (international normalized ratio......). Because only HDER is approved, we focused on the comparison of HDER versus warfarin. RESULTS: Of 5973 (28.3%) patients with previous IS/TIA, 67% had CHADS2 (congestive heart failure, hypertension, age, diabetes, prior stroke/transient ischemic attack) >3 and 36% were ≥75 years. Compared with 15 132...

  14. 75 FR 66009 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2010-10-27

    ... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously the Lancair... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously The Lancair...-15895. Applicability (c) This AD applies to the following Cessna Aircraft Company (type certificate...

  15. [Fatal amnioinfusion with previous choriocarcinoma in a parturient woman].

    Science.gov (United States)

    Hrgović, Z; Bukovic, D; Mrcela, M; Hrgović, I; Siebzehnrübl, E; Karelovic, D

    2004-04-01

    The case of 36-year-old tercipare is described who developed choriocharcinoma in a previous pregnancy. During the first term labour the patient developed cardiac arrest, so reanimation and sectio cesarea was performed. A male new-born was delivered in good condition, but even after intensive therapy and reanimation occurred death of parturient woman with picture of disseminate intravascular coagulopathia (DIK). On autopsy and on histology there was no sign of malignant disease, so it was not possible to connect previous choricarcinoma with amniotic fluid embolism. Maybe was place of choriocarcinoma "locus minoris resistentiae" which later resulted with failure in placentation what was hard to prove. On autopsy we found embolia of lung with a microthrombosis of terminal circulation with punctiformis bleeding in mucous, what stands for DIK.

  16. Numerical simulation of the shot peening process under previous loading conditions

    International Nuclear Information System (INIS)

    Romero-Ángeles, B; Urriolagoitia-Sosa, G; Torres-San Miguel, C R; Molina-Ballinas, A; Benítez-García, H A; Vargas-Bustos, J A; Urriolagoitia-Calderón, G

    2015-01-01

    This research presents a numerical simulation of the shot peening process and determines the residual stress field induced into a component with a previous loading history. The importance of this analysis is based on the fact that mechanical elements under shot peening are also subjected to manufacturing processes, which convert raw material into finished product. However, material is not provided in a virgin state, it has a previous loading history caused by the manner it is fabricated. This condition could alter some beneficial aspects of the residual stress induced by shot peening and could accelerate the crack nucleation and propagation progression. Studies were performed in beams subjected to strain hardening in tension (5ε y ) before shot peening was applied. Latter results were then compared in a numerical assessment of an induced residual stress field by shot peening carried out in a component (beam) without any previous loading history. In this paper, it is clearly shown the detrimental or beneficial effect that previous loading history can bring to the mechanical component and how it can be controlled to improve the mechanical behavior of the material

  17. Does previous use affect litter box appeal in multi-cat households?

    Science.gov (United States)

    Ellis, J J; McGowan, R T S; Martin, F

    2017-08-01

    It is commonly assumed that cats actively avoid eliminated materials (especially in multi-cat homes), suggesting regular litter box cleaning as the best defense against out-of-box elimination. The relationship between previous use and litter box appeal to familiar subsequent users is currently unknown. The purpose of this study was to investigate the relationship between previous litter box use and the identity of the previous user, type of elimination, odor, and presence of physical/visual obstructions in a multi-cat household scenario. Cats preferred a clean litter box to a dirty one, but the identity of the previous user had no impact on preferences. While the presence of odor from urine and/or feces did not impact litter box preferences, the presence of odorless faux-urine and/or feces did - with the presence of faux-feces being preferred over faux-urine. Results suggest neither malodor nor chemical communication play a role in litter box preferences, and instead emphasize the importance of regular removal of physical/visual obstructions as the key factor in promoting proper litter box use. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Hypomutability in Fanconi anemia cells is associated with increased deletion frequency at the HPRT locus

    International Nuclear Information System (INIS)

    Papadopoulo, D.; Guillouf, C.; Moustacchi, E.; Mohrenweiser, H.

    1990-01-01

    Fanconi anemia (FA) is an inherited human disorder associated with a predisposition to cancer and characterized by anomalies in the processing of DNA cross-links and certain monoadducts. The authors reported previously that the frequency of psoralen-photoinduced mutations at the HPRT locus is lower in FA cells than in normal cells. This hypomutability is shown here to be associated with an increased frequency of deletions in the HPRT gene when either a mixture of cross-links and monoadducts or monoadducts alone are induced. Molecular analysis of mutants in the HPRT gene was carried out. In normal cells the majority of spontaneous and induced mutants are point mutations whereas in FA deletion mutations predominate. In that case a majority of mutants were found to lack individual exons or small clusters of exons whereas in normal cells large (complete or major gene loss) and small deletions are almost equally represented. Thus they propose that the FA defect lies in a mutagenic pathway that, in normal cells, involves by passing lesions and subsequent gap filling by a recombinational process during replication

  19. Low-dose computed tomography image restoration using previous normal-dose scan

    International Nuclear Information System (INIS)

    Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2011-01-01

    Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use

  20. Secondary aerosol formation from photochemical aging of aircraft exhaust in a smog chamber

    Directory of Open Access Journals (Sweden)

    M. A. Miracolo

    2011-05-01

    Full Text Available Field experiments were performed to investigate the effects of photo-oxidation on fine particle emissions from an in-use CFM56-2B gas turbine engine mounted on a KC-135 Stratotanker airframe. Emissions were sampled into a portable smog chamber from a rake inlet installed one-meter downstream of the engine exit plane of a parked and chocked aircraft. The chamber was then exposed to sunlight and/or UV lights to initiate photo-oxidation. Separate tests were performed at different engine loads (4, 7, 30, 85 %. Photo-oxidation created substantial secondary particulate matter (PM, greatly exceeding the direct PM emissions at each engine load after an hour or less of aging at typical summertime conditions. After several hours of photo-oxidation, the ratio of secondary-to-primary PM mass was on average 35 ± 4.1, 17 ± 2.5, 60 ± 2.2, and 2.7 ± 1.1 for the 4, 7, 30, and 85 % load experiments, respectively. The composition of secondary PM formed strongly depended on load. At 4 % load, secondary PM was dominated by secondary organic aerosol (SOA. At higher loads, the secondary PM was mainly secondary sulfate. A traditional SOA model that accounts for SOA formation from single-ring aromatics and other volatile organic compounds underpredicts the measured SOA formation by ~60 % at 4 % load and ~40 % at 85 % load. Large amounts of lower-volatiliy organic vapors were measured in the exhaust; they represent a significant pool of SOA precursors that are not included in traditional SOA models. These results underscore the importance of accounting for atmospheric processing when assessing the influence of aircraft emissions on ambient PM levels. Models that do not account for this processing will likely underpredict the contribution of aircraft emissions to local and regional air pollution.

  1. Research Note Effects of previous cultivation on regeneration of ...

    African Journals Online (AJOL)

    We investigated the effects of previous cultivation on regeneration potential under miombo woodlands in a resettlement area, a spatial product of Zimbabwe's land reforms. We predicted that cultivation would affect population structure, regeneration, recruitment and potential grazing capacity of rangelands. Plant attributes ...

  2. Enhancement of cutaneous delayed hypersensitivity reactions by a single exposure to UV-A or PUVA

    International Nuclear Information System (INIS)

    Moberg, S.; Mobacken, H.

    1982-01-01

    The influence of irradiation with UV-A and PUVA (8-methoxy-psoralen and UV-A) on delayed hypersensitivity reactions to microbial antigens was studied in healthy human individuals. Skin reactions to Candida albicans antigen and PPD were enhanced by UV-A als well as by PUVA compared with nonirradiated tests. A statistically significant difference was reached with UV-A for both antigens. For PUVA, erythemogenic doses to Candida tests produced a significant increase of response. (orig.)

  3. Females use self-referent cues to avoid mating with previous mates

    OpenAIRE

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-01-01

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that...

  4. Photodegradation of polymer-dispersed perylene di-imide dyes

    Science.gov (United States)

    Tanaka, Nobuaki; Barashkov, Nikolay; Heath, Jerry; Sisk, Wade N.

    2006-06-01

    Polymer-dispersed perylene di-imide dye photodegradation is investigated by monitoring the fluorescence intensity as a function of 532 nm laser pulses. Anaerobically irradiated polymer-dye films exhibited an accelerated decrease in fluorescence intensity, which was partially recovered upon exposure to oxygen. Decelerated photodegradation rates were observed for perylene di-imide ethanol solutions upon the addition of a singlet oxygen quenching antioxidant. These observations suggest reversible photoreduction and type II photo-oxidation as important photodegradation mechanisms. Type II photo-oxidation for perylene red 532 nm irradiation is supported by a singlet oxygen quantum yield of 0.09±0.03, determined via detection of time-resolved O2 (a1Δg —> X3∑g-) infrared phosphorescence.

  5. Energy transfer mechanisms in photobiological reactions. Final report, 1 April 1960--31 March 1979. [Photodynamic processes in selected biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Spikes, J.D.

    1979-03-31

    This project was concerned primarily with studies of the mechanisms of the sensitized photooxidation of selected biomolecules using a variety of phtosensitizers. Such reactions are often termed photodynamic processes. In particular we have carried out steady-state kinetic studies, flash photolysis and spectral studies, and product formation studies of the sensitized photooxidation of the five susceptible amino acids (cycteine, histidine, methonine, tryptophan, and tyrosine) and their derivatives, as well as purines and pyrimidines. A number of studies were also carried out on the mechanisms of the photodynamic inactivation of enzymes (trypsin, ribonuclease, lysozyme). Mechanism of photosensitization were studied using a variety of sensitizers including flavins, porphyrins, and a number of synthetic dyes (substituted fluoresceins, acridines, thyazines).

  6. Does the patients′ educational level and previous counseling affect their medication knowledge?

    Directory of Open Access Journals (Sweden)

    Abdulmalik M Alkatheri

    2013-01-01

    Conclusions: The education level of the patient and previous counseling are positively linked to medication knowledge. Knowledge of the medications′ side effects proved to be the most difficult task for the participants in this study, requiring the highest level of education, and was improved by previous counseling.

  7. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged ..... I am still riding the cloud … I hope it lasts. .... as a way of creating a climate and culture in schools where individuals are willing to explore.

  8. Predictive factors for the development of diabetes in women with previous gestational diabetes mellitus

    DEFF Research Database (Denmark)

    Damm, P.; Kühl, C.; Bertelsen, Aksel

    1992-01-01

    OBJECTIVES: The purpose of this study was to determine the incidence of diabetes in women with previous dietary-treated gestational diabetes mellitus and to identify predictive factors for development of diabetes. STUDY DESIGN: Two to 11 years post partum, glucose tolerance was investigated in 241...... women with previous dietary-treated gestational diabetes mellitus and 57 women without previous gestational diabetes mellitus (control group). RESULTS: Diabetes developed in 42 (17.4%) women with previous gestational diabetes mellitus (3.7% insulin-dependent diabetes mellitus and 13.7% non...... of previous patients with gestational diabetes mellitus in whom plasma insulin was measured during an oral glucose tolerance test in late pregnancy a low insulin response at diagnosis was found to be an independent predictive factor for diabetes development. CONCLUSIONS: Women with previous dietary...

  9. Kidnapping Detection and Recognition in Previous Unknown Environment

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2017-01-01

    Full Text Available An unaware event referred to as kidnapping makes the estimation result of localization incorrect. In a previous unknown environment, incorrect localization result causes incorrect mapping result in Simultaneous Localization and Mapping (SLAM by kidnapping. In this situation, the explored area and unexplored area are divided to make the kidnapping recovery difficult. To provide sufficient information on kidnapping, a framework to judge whether kidnapping has occurred and to identify the type of kidnapping with filter-based SLAM is proposed. The framework is called double kidnapping detection and recognition (DKDR by performing two checks before and after the “update” process with different metrics in real time. To explain one of the principles of DKDR, we describe a property of filter-based SLAM that corrects the mapping result of the environment using the current observations after the “update” process. Two classical filter-based SLAM algorithms, Extend Kalman Filter (EKF SLAM and Particle Filter (PF SLAM, are modified to show that DKDR can be simply and widely applied in existing filter-based SLAM algorithms. Furthermore, a technique to determine the adapted thresholds of metrics in real time without previous data is presented. Both simulated and experimental results demonstrate the validity and accuracy of the proposed method.

  10. Application of advanced oxidation processes for cleaning of industrial water generated in wet dedusting of shaft furnace gases.

    Science.gov (United States)

    Czaplicka, Marianna; Kurowski, Ryszard; Jaworek, Katarzyna; Bratek, Łukasz

    2013-01-01

    The paper presents results of studies into advanced oxidation processes in 03 and 03/UV systems. An advanced oxidation process (AOP) was conducted to reduce the load of impurities in circulating waters from wet de-dusting of shaft furnace gases. Besides inorganic impurities, i.e. mainly arsenic compounds (16 g As L(-1) on average), lead, zinc, chlorides and sulphates, the waters also contain some organic material. The organic material is composed of a complex mixture that contains, amongst others, aliphatic compounds, phenol and its derivatives, pyridine bases, including pyridine, and its derivatives. The test results show degradation of organic and inorganic compounds during ozonation and photo-oxidation processes. Analysis of the solutions from the processes demonstrated that the complex organic material in the industrial water was oxidized in ozonation and in photo-oxidation, which resulted in formation of aldehydes and carboxylic acids. Kinetic degradation of selected pollutants is presented. Obtained results indicated that the O3/UV process is more effective in degradation of organic matter than ozonation. Depending on the process type, precipitation of the solid phase was observed. The efficiency of solid-phase formation was higher in photo-oxidation with ozone. It was found that the precipitated solid phase is composed mainly of arsenic, iron and oxygen.

  11. Automated system for on-line determination of dimethylarsinic and inorganic arsenic by hydride generation-atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chaparro, L.L.; Leal, L.O. [Renewable Energy and Environmental Protection Department, Advanced Materials Research Center (CIMAV), Chihuahua, Chihuahua (Mexico); Ferrer, L.; Cerda, V. [University of the Balearic Islands, Department of Chemistry, Palma de Mallorca (Spain)

    2012-09-15

    A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 {mu}g L{sup -1}, respectively. The repeatability values accomplished were of 2.4 and 1.8 %, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation. (orig.)

  12. Differential Antioxidant Responses and Perturbed Porphyrin Biosynthesis after Exposure to Oxyfluorfen and Methyl Viologen in Oryza sativa.

    Science.gov (United States)

    Pham, Nhi-Thi; Kim, Jin-Gil; Jung, Sunyo

    2015-07-21

    We compared antioxidant responses and regulation of porphyrin metabolism in rice plants treated with oxyfluorfen (OF) or methyl viologen (MV). Plants treated with MV exhibited not only greater increases in conductivity and malondialdehyde but also a greater decline in Fv/Fm, compared to plants treated with OF. MV-treated plants had greater increases in activities of superoxide dismutase (SOD) and catalase (CAT) as well as transcript levels of SODA and CATA than OF-treated plants after 28 h of the treatments, whereas increases in ascorbate peroxidase (APX) activity and transcript levels of APXA and APXB were greater in OF-treated plants. Both OF- and MV-treated plants resulted in not only down-regulation of most genes involved in porphyrin biosynthesis but also disappearance of Mg-porphyrins during the late stage of photooxidative stress. By contrast, up-regulation of heme oxygenase 2 (HO2) is possibly part of an efficient antioxidant response to compensate photooxidative damage in both treatments. Our data show that down-regulated biosynthesis and degradation dynamics of porphyrin intermediates have important roles in photoprotection of plants from perturbed porphyrin biosynthesis and photosynthetic electron transport. This study suggests that porphyrin scavenging as well as strong antioxidative activities are required for mitigating reactive oxygen species (ROS) production under photooxidative stress caused by OF and MV.

  13. Outcome of trial of scar in patients with previous caesarean section

    International Nuclear Information System (INIS)

    Khan, B.; Bashir, R.; Khan, W.

    2016-01-01

    Medical evidence indicates that 60-80% of women can achieve vaginal delivery after a previous lower segment caesarean section. Proper selection of patients for trial of scar and vigilant monitoring during labour will achieve successful maternal and perinatal outcome. The objective of our study is to establish the fact that vaginal delivery after one caesarean section has a high success rate in patients with previous one caesarean section for non-recurrent cause. Methods: The study was conducted in Ayub Teaching Abbottabad, Gynae-B Unit. All labouring patients, during the study period of five years, with previous one caesarean section and between 37 weeks to 41 weeks of gestation for a non-recurrent cause were included in the study. Data was recorded on special proforma designed for the purpose. Patients who had previous classical caesarean section, more than one caesarean section, and previous caesarean section with severe wound infection, transverse lie and placenta previa in present pregnancy were excluded. Foetal macrosomia (wt>4 kg) and severe IUGR with compromised blood flow on Doppler in present pregnancy were also not considered suitable for the study. Patients who had any absolute contraindication for vaginal delivery were also excluded. Results: There were 12505 deliveries during the study period. Total vaginal deliveries were 8790 and total caesarean sections were 3715. Caesarean section rate was 29.7%. Out of these 8790 patients, 764 patients were given a trial of scar and 535 patients delivered successfully vaginally (70%). Women who presented with spontaneous onset of labour were more likely to deliver vaginally (74.8%) as compared to induction group (27.1%). Conclusion: Trial of vaginal birth after caesarean (VBAC) in selected cases has great importance in the present era of the rising rate of primary caesarean section. (author)

  14. Study of functional-performance deficits in athletes with previous ankle sprains

    Directory of Open Access Journals (Sweden)

    hamid Babaee

    2008-04-01

    Full Text Available Abstract Background: Despite the importance of functional-performance deficits in athletes with history of ankle sprain few, studies have been carried out in this area. The aim of this research was to study relationship between previous ankle sprains and functional-performance deficits in athletes. Materials and methods: The subjects were 40 professional athletes selected through random sampling among volunteer participants in soccer, basketball, volleyball and handball teams of Lorestan province. The subjects were divided into 2 groups: Injured group (athletes with previous ankle sprains and healthy group (athletes without previous ankle sprains. In this descriptive study we used Functional-performance tests (figure 8 hop test and side hop test to determine ankle deficits and limitations. They participated in figure 8 hop test including hopping in 8 shape course with the length of 5 meters and side hop test including 10 side hop repetitions in course with the length of 30 centimeters. Time were recorded via stopwatch. Results: After data gathering and assessing information distributions, Pearson correlation was used to assess relationships, and independent T test to assess differences between variables. Finally the results showed that there is a significant relationship between previous ankle sprains and functional-performance deficits in the athletes. Conclusion: The athletes who had previous ankle sprains indicated functional-performance deficits more than healthy athletes in completion of mentioned functional-performance tests. The functional-performance tests (figure 8 hop test and side hop test are sensitive and suitable to assess and detect functional-performance deficits in athletes. Therefore we can use the figure 8 hop and side hop tests for goals such as prevention, assessment and rehabilitation of ankle sprains without spending too much money and time.

  15. The prevalence of previous self-harm amongst self-poisoning patients in Sri Lanka

    DEFF Research Database (Denmark)

    Mohamed, Fahim; Perera, Aravinda; Wijayaweera, Kusal

    2011-01-01

    BACKGROUND: One of the most important components of suicide prevention strategies is to target people who repeat self-harm as they are a high risk group. However, there is some evidence that the incidence of repeat self-harm is lower in Asia than in the West. The objective of this study...... was to investigate the prevalence of previous self-harm among a consecutive series of self-harm patients presenting to hospitals in rural Sri Lanka. METHOD: Six hundred and ninety-eight self-poisoning patients presenting to medical wards at two hospitals in Sri Lanka were interviewed about their previous episodes...... of self-harm. RESULTS: Sixty-one (8.7%, 95% CI 6.7-11%) patients reported at least one previous episode of self-harm [37 (10.7%) male, 24 (6.8%) female]; only 19 (2.7%, 95% CI 1.6-4.2%) patients had made more than one previous attempt. CONCLUSION: The low prevalence of previous self-harm is consistent...

  16. Charged-particle thermonuclear reaction rates: IV. Comparison to previous work

    International Nuclear Information System (INIS)

    Iliadis, C.; Longland, R.; Champagne, A.E.; Coc, A.

    2010-01-01

    We compare our Monte Carlo reaction rates (see Paper II of this issue) to previous results that were obtained by using the classical method of computing thermonuclear reaction rates. For each reaction, the comparison is presented using two types of graphs: the first shows the change in reaction rate uncertainties, while the second displays our new results normalized to the previously recommended reaction rate. We find that the rates have changed significantly for almost all reactions considered here. The changes are caused by (i) our new Monte Carlo method of computing reaction rates (see Paper I of this issue), and (ii) newly available nuclear physics information (see Paper III of this issue).

  17. Analysis of previous perceptual and motor experience in breaststroke kick learning

    Directory of Open Access Journals (Sweden)

    Ried Bettina

    2015-12-01

    Full Text Available One of the variables that influence motor learning is the learner’s previous experience, which may provide perceptual and motor elements to be transferred to a novel motor skill. For swimming skills, several motor experiences may prove effective. Purpose. The aim was to analyse the influence of previous experience in playing in water, swimming lessons, and music or dance lessons on learning the breaststroke kick. Methods. The study involved 39 Physical Education students possessing basic swimming skills, but not the breaststroke, who performed 400 acquisition trials followed by 50 retention and 50 transfer trials, during which stroke index as well as rhythmic and spatial configuration indices were mapped, and answered a yes/no questionnaire regarding previous experience. Data were analysed by ANOVA (p = 0.05 and the effect size (Cohen’s d ≥0.8 indicating large effect size. Results. The whole sample improved their stroke index and spatial configuration index, but not their rhythmic configuration index. Although differences between groups were not significant, two types of experience showed large practical effects on learning: childhood water playing experience only showed major practically relevant positive effects, and no experience in any of the three fields hampered the learning process. Conclusions. The results point towards diverse impact of previous experience regarding rhythmic activities, swimming lessons, and especially with playing in water during childhood, on learning the breaststroke kick.

  18. Iodine-131 induced hepatotoxicity in previously healthy patients with Grave's disease.

    Science.gov (United States)

    Jhummon, Navina Priya; Tohooloo, Bhavna; Qu, Shen

    2013-01-01

    To describe the association of the rare and serious complication of liver toxicity in previously healthy Grave's disease (GD) patients after the treatment with radioactive iodine (131)I (RAI). We report the clinical, laboratory and pathologic findings of 2 cases of severe liver toxicity associated with the treatment with RAI in previously healthy patients with GD. Clinical examination and laboratory investigations excluded viral hepatitis, autoimmune hepatitis, granulomatous disease, primary biliary disease, extrahepatic biliary obstruction, and heart failure. Case 1: A previously healthy 52-years old man reportedly having a typical GD but following RAI treatment, concomitantly developed severe liver toxicity that required 1 week of treatment in hospital. Case 2: A previously healthy 34-years old woman is reported as having a typical GD but developed jaundice following RAI treatment that required several weeks of in hospital treatment in the hepato-biliary department. In both cases, the liver dysfunction resolved after intensive treatment with hepato-protective agents. In this report the therapeutic considerations as well as the pathogenetic possibilities are reviewed. To the best of our knowledge, this is the first description of the association observed, which is rare but may be severe and should be considered in any case of thyrotoxicosis where a liver dysfunction develops after the treatment with radioactive iodine (131)I.

  19. The job satisfaction of principals of previously disadvantaged schools

    African Journals Online (AJOL)

    The aim of this study was to identify influences on the job satisfaction of previously disadvantaged school principals in North-West Province. Evans's theory of job satisfaction, morale and motivation was useful as a conceptual framework. A mixedmethods explanatory research design was important in discovering issues with ...

  20. 75 FR 57844 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2010-09-23

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Previously Held by Israel Aircraft Industries, Ltd.): Amendment 39-16438. Docket No. FAA-2010-0555... (Type Certificate previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and Gulfstream 200...

  1. 77 FR 64767 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-10-23

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... airworthiness directive (AD) for certain Gulfstream Aerospace LP (Type Certificate previously held by Israel... Certificate previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and Gulfstream 200 airplanes...

  2. 78 FR 11567 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2013-02-19

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Model Gulfstream G150... Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.): Amendment 39...

  3. 76 FR 70040 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2011-11-10

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Aerospace LP (type certificate previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and... new AD: 2011-23-07 Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft...

  4. 76 FR 6525 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2011-02-07

    ... Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia Aircraft... following new AD: 2011-03-04 Cessna Aircraft Company (Type Certificate Previously Held by Columbia Aircraft... the following Cessna Aircraft Company (type certificate previously held by Columbia Aircraft...

  5. ATLANTIC DIP: simplifying the follow-up of women with previous gestational diabetes.

    LENUS (Irish Health Repository)

    Noctor, E

    2013-11-01

    Previous gestational diabetes (GDM) is associated with a significant lifetime risk of type 2 diabetes. In this study, we assessed the performance of HbA1c and fasting plasma glucose (FPG) measurements against that of 75 g oral glucose tolerance testing (OGTT) for the follow-up screening of women with previous GDM.

  6. VBAC Scoring: Successful vaginal delivery in previous one caesarean section in induced labour

    International Nuclear Information System (INIS)

    Raja, J.F.; Bangash, K.T.; Mahmud, G.

    2013-01-01

    Objective: To develop a scoring system for the prediction of successful vaginal birth after caesarean section, following induction of labour with intra-vaginal E2 gel (Glandin). Methods: The cross-sectional study was conducted from January 2010 to August 2011, at the Pakistan Institute of Medical Sciences in Islamabad. Trial of labour in previous one caesarean section, undergoing induction with intra-vaginal E2 gel, was attempted in 100 women. They were scored according to six variables; maternal age; gestation; indications of previous caesarean; history of vaginal birth either before or after the previous caesarean; Bishop score and body mass index. Multivariate and univariate logistic regression analysis was used to develop the scoring system. Results: Of the total, 67 (67%) women delivered vaginally, while 33 (33%) ended in repeat caesarean delivery. Among the subjects, 55 (55%) women had no history of vaginal delivery either before or after previous caesarean section; 15 (15%) had history of vaginal births both before and after the previous caesarean; while 30 (30%) had vaginal delivery only after the previous caesarean section. Rates of successful vaginal birth after caesarean increased from 38% in women having a score of 0-3 to 58% in patients scoring 4-6. Among those having a score of 7-9 and 10-12, the success rates were 71% and 86% respectively. Conclusion: Increasing scores correlated with the increasing probability of vaginal birth after caesarean undergoing induction of labour. The admission VBAC scoring system is useful in counselling women with previous caesarean for the option of induction of labour or repeat caesarean delivery. (author)

  7. 75 FR 28485 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2010-05-21

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.): Amendment 39... previously held by Israel Aircraft Industries, Ltd.) Model Gulfstream 100 airplanes; and Model Astra SPX and...

  8. First-principles method for calculating the rate constants of internal-conversion and intersystem-crossing transitions.

    Science.gov (United States)

    Valiev, R R; Cherepanov, V N; Baryshnikov, G V; Sundholm, D

    2018-02-28

    A method for calculating the rate constants for internal-conversion (k IC ) and intersystem-crossing (k ISC ) processes within the adiabatic and Franck-Condon (FC) approximations is proposed. The applicability of the method is demonstrated by calculation of k IC and k ISC for a set of organic and organometallic compounds with experimentally known spectroscopic properties. The studied molecules were pyrromethene-567 dye, psoralene, hetero[8]circulenes, free-base porphyrin, naphthalene, and larger polyacenes. We also studied fac-Alq 3 and fac-Ir(ppy) 3 , which are important molecules in organic light emitting diodes (OLEDs). The excitation energies were calculated at the multi-configuration quasi-degenerate second-order perturbation theory (XMC-QDPT2) level, which is found to yield excitation energies in good agreement with experimental data. Spin-orbit coupling matrix elements, non-adiabatic coupling matrix elements, Huang-Rhys factors, and vibrational energies were calculated at the time-dependent density functional theory (TDDFT) and complete active space self-consistent field (CASSCF) levels. The computed fluorescence quantum yields for the pyrromethene-567 dye, psoralene, hetero[8]circulenes, fac-Alq 3 and fac-Ir(ppy) 3 agree well with experimental data, whereas for the free-base porphyrin, naphthalene, and the polyacenes, the obtained quantum yields significantly differ from the experimental values, because the FC and adiabatic approximations are not accurate for these molecules.

  9. Effect of rutin on virus inactivation by AMT in combination with ultraviolet-A irradiation in platelet concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yoshiko; Abe, Hideki; Ikebuchi, Kenji; Sekiguchi, Sadayoshi [Hokkaido Red Cross Blood Center, Sapporo (Japan)

    1999-10-01

    Treatment with psoralens and ultraviolet-A (UVA) irradiation have been found to be effective for virus sterilization of platelet concentrates (PCs). We report here a virus inactivation method using a combination of psoralen derivative 4'-aminomethyl-4,5', 8-trimethylpsoralen (AMT) and UVA irradiation (AMT/UVA). Further, we also investigated the effect of rutin, a radical scavenger, on the inactivation of vesicular stomatitis virus (VSV) as a model virus administered in PCs and platelet functions were investigated. Spiked VSV (about 5log{sub 10}) in PCs was inactivated by a combination of AMT (50 {mu}g/ml) and 5.2 J/cm{sup 2} UVA irradiation in the absence of rutin. To obtain equivalent levels of VSV kill in the presence of 0.35 mM rutin, treatment with 13.0 J/cm{sup 2} of UVA irradiation with AMT was performed. When PCs were treated under each condition in which 5log{sub 10} VSV was inactivated by AMT/UVA with or without rutin, platelet aggregation function was maintained for more than 80% of untreated platelets. These findings indicate that the presence of rutin during AMT/UVA treatment conferred no beneficial effect. In addition, overnight storage of PCs with AMT induced 40% loss of platelet aggregation in response to 10{mu}M ADP. The findings suggest that UVA irradiation is required immediately after the addition of AMT. (author)

  10. Uji Efektivitas Jeruk Nipis (Citrus aurantifolia dalam Mempercepat Laju Disinfeksi Bakteri Escheria Coli pada Proses Solar Water Disinfection

    Directory of Open Access Journals (Sweden)

    Saprian Saprian

    2015-08-01

    Full Text Available Solar Water Disinfection (SODIS memerlukan waktu rata-rata berkisar antara 5-6 jam untuk dapat membunuh bakteri 3-4 Log pada air berkapasitas maksimal 2 liter atau 1 jam dengan suhu di atas 50°C. Penelitian terbaru menunjukkan bahwa dengan mengkombinasikan SODIS dengan psoralens, zat aktif seperti yang terdapat pada jeruk Lemon (Citrus Limon dapat menginaktivasi bakteri hingga 5,6 Log reduksi dalam rentang waktu 30 menit pada suhu 29°C. Mengingat faktor ketersediaan dan harga jeruk lemon di Indonesia maka pada penelitian ini dilakukan pengamatan dengan menggunakan jeruk nipis (Citrus aurantifolia. Penelitian ini dilakukan untuk mengetahui seberapa besar potensi jeruk nipis untuk dipergunakan dalam mempercepat laju disinfeksi pada proses SODIS. Adapun faktor-faktor yang akan dipelajari terkait dengan hubungan antara variasi dosis jeruk nipis, perubahan pH dan suhu air terhadap efisiensi inaktivasi bakteri yang mampu dihasilkan. Variasi jeruk nipis yang digunakan adalah 0%, 2%, 4% dan 6% dengan variasi waktu 0 menit, 30 menit, 60 menit dan 120 menit. Hasil penelitian menunjukkan bahwa perlakuan SODIS dengan menggunakan jeruk nipis mampu menginaktivasi E. coli sebesar 5.4 Log dengan waktu 1 jam pada suhu 32°C. Hal ini menunjukkan bahwa Jeruk nipis berpotensi untuk digunakan dalam mempercepat laju disinfeksi E. coli pada air minum. Kata Kunci : SODIS, E.coli, Psoralens, Jeruk Nipis

  11. Previous climatic alterations are caused by the sun

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2003-01-01

    The article surveys the scientific results of previous research into the contribution of the sun to climatic alterations. The author concludes that there is evidence of eight cold periods after the last ice age and that the alterations largely were due to climate effects from the sun. However, these effects are only causing a fraction of the registered global warming. It is assumed that the human activities are contributing to the rest of the greenhouse effect

  12. 76 FR 1349 - Airworthiness Directives; Cessna Aircraft Company (Cessna) (Type Certificate A00003SE Previously...

    Science.gov (United States)

    2011-01-10

    ... Airworthiness Directives; Cessna Aircraft Company (Cessna) (Type Certificate A00003SE Previously Held by... Company (Type Certificate A00003SE previously held by Columbia Aircraft Manufacturing (previously The... Cessna Aircraft Company (Cessna) (Type Certificate A00003SE previously held by Columbia Aircraft...

  13. SONOGRAPHIC PREDICTION OF SCAR DEHISCENCE IN WOMEN WITH PREVIOUS CAESAREAN SECTION

    Directory of Open Access Journals (Sweden)

    Shubhada Suhas Jajoo

    2018-01-01

    Full Text Available BACKGROUND Caesarean section (Sectio Caesarea is a surgical method for the completion of delivery. After various historical modifications of operative techniques, modern approach consists in the transverse dissection of the anterior wall of the uterus. The rate of vaginal birth after caesarean section was significantly reduced from year to year and the rate of repeated caesarean section is increased during the past 10 years. Evaluation of scar thickness is done by ultrasound, but it is still debatable size of thick scar that would be guiding “cut-off value” for the completion of the delivery method. To better assess the risk of uterine rupture, some authors have proposed sonographic measurement of lower uterine segment thickness near term assuming that there is an inverse correlation between LUS thickness and the risk of uterine scar defect. Therefore, this assessment for the management of women with prior CS may increase safety during labour by selecting women with the lowest risk of uterine rupture. The aim of the study is to study the diagnostic accuracy of sonographic measurements of the Lower Uterine Segment (LUS thickness near term in predicting uterine scar defects in women with prior Caesarean Section (CS. We aim to ascertain the best cut-off values for predicting uterine rupture. MATERIALS AND METHODS 100 antenatal women with history of previous one LSCS who come to attend antenatal clinic will be assessed for scar thickness by transabdominal ultrasonography and its correlation with intraoperative findings. This prospective longitudinal study was conducted for 1 year after IEC approval with inclusion criteria previous one LSCS. Exclusion criteria- 1 Previous myomectomy scar; 2 Previous 2 LSCS; 3 Previous hysterotomy scar. RESULTS Our findings indicate that there is a strong association between degree of LUS thinning measured near term and the risk of uterine scar defect at birth. In our study, optimal cut-off value for predicting

  14. Protein (Viridiplantae): 765946 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available s tolerance to multiple environmental stresses and reduces photooxidative damage ... 41938:10941 3629:10941 ... 214909:10941 ... 3640:10941 ... 3641:10941 ... Encodes a chloroplast protein that induce

  15. Rapid fish stock depletion in previously unexploited seamounts: the ...

    African Journals Online (AJOL)

    Rapid fish stock depletion in previously unexploited seamounts: the case of Beryx splendens from the Sierra Leone Rise (Gulf of Guinea) ... A spectral analysis and red-noise spectra procedure (REDFIT) algorithm was used to identify the red-noise spectrum from the gaps in the observed time-series of catch per unit effort by ...

  16. Photoreactivity of 5-methoxypsoralen with calf thymus DNA upon excitation in the UV A

    Energy Technology Data Exchange (ETDEWEB)

    Sa E Melo, T.; Santus, R. (Museum National d' Histoire Naturelle, Paris (France)); Morliere, P.; Dubertret, L. (Hopital Franco-Musulman, 93 - Bobigny (France))

    1984-01-01

    The photoaddition of 5-methoxy-psoralen to DNA has been studied as a function of the excitation wavelength in the 310-405 nm region. The predominant monoadduct formed in these irradiation conditions (quantum yield: 3x10/sup -3/) is the fluorescent 4',5' monoadduct (fluorescence quantum yield: 0.1) which is stable under irradiation at wavelength lambda > 370 nm. This cycloadduct is rapidly transformed into the diadduct with a quantum yield of 0.03 upon irradiation at shorter wavelengths.

  17. Photoreactivity of 5-methoxypsoralen with calf thymus DNA upon excitation in the UV A

    International Nuclear Information System (INIS)

    Sa E Melo, T.; Santus, R.; Morliere, P.; Dubertret, L.

    1984-01-01

    The photoaddition of 5-methoxy-psoralen to DNA has been studied as a function of the excitation wavelength in the 310-405 nm region. The predominant monoadduct formed in these irradiation conditions (quantum yield: 3x10 -3 ) is the fluorescent 4',5' monoadduct (fluorescence quantum yield: 0.1) which is stable under irradiation at wavelength lambda > 370 nm. This cycloadduct is rapidly transformed into the diadduct with a quantum yield of 0.03 upon irradiation at shorter wavelengths. (orig.)

  18. Choice of contraception after previous operative delivery at a family ...

    African Journals Online (AJOL)

    Choice of contraception after previous operative delivery at a family planning clinic in Northern Nigeria. Amina Mohammed‑Durosinlorun, Joel Adze, Stephen Bature, Caleb Mohammed, Matthew Taingson, Amina Abubakar, Austin Ojabo, Lydia Airede ...

  19. Poly-epiphyseal overgrowth: description of a previously unreported skeletal dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Pazzaglia, Ugo E.; Bonaspetti, Giovanni [University of Brescia, Orthopaedic Clinic, Brescia (Italy); Beluffi, Giampiero [Fondazione IRCCS Policlinico San Matteo, Department of Paediatric Radiology, Pavia (Italy); Marchi, Antonietta; Bozzola, Mauro; Savasta, Salvatore [Fondazione IRCCS Policlinico San Matteo, Paediatric Clinic, University of Pavia, Pavia (Italy)

    2007-10-15

    A skeletal dysplasia with previously unreported features is presented. Its evolution was characterized by growth abnormalities of bones without involvement of other organs. Advanced bone age, increased stature and irregular epiphyseal ossification with stippling of the main long bones were documented. Physeal overgrowth was massive in the left proximal humerus and femur. Furthermore, the hip joint appeared fused with an abundant mass of pathological calcific tissue extending from the femur to the ilium. Pathological epiphyses were characterized by anarchic cartilaginous proliferation with multiple ossification centres, while lamellar bone apposition and remodelling were normal. The observed bone changes were different from those in any previously reported syndrome, metabolic defect or bone dysplasia. However, they clearly indicated a defect of endochondral ossification with some resemblance to phenotypes observed in dysplasia epiphysealis hemimelica. (orig.)

  20. Poly-epiphyseal overgrowth: description of a previously unreported skeletal dysplasia

    International Nuclear Information System (INIS)

    Pazzaglia, Ugo E.; Bonaspetti, Giovanni; Beluffi, Giampiero; Marchi, Antonietta; Bozzola, Mauro; Savasta, Salvatore

    2007-01-01

    A skeletal dysplasia with previously unreported features is presented. Its evolution was characterized by growth abnormalities of bones without involvement of other organs. Advanced bone age, increased stature and irregular epiphyseal ossification with stippling of the main long bones were documented. Physeal overgrowth was massive in the left proximal humerus and femur. Furthermore, the hip joint appeared fused with an abundant mass of pathological calcific tissue extending from the femur to the ilium. Pathological epiphyses were characterized by anarchic cartilaginous proliferation with multiple ossification centres, while lamellar bone apposition and remodelling were normal. The observed bone changes were different from those in any previously reported syndrome, metabolic defect or bone dysplasia. However, they clearly indicated a defect of endochondral ossification with some resemblance to phenotypes observed in dysplasia epiphysealis hemimelica. (orig.)

  1. HEART TRANSPLANTATION IN PATIENTS WITH PREVIOUS OPEN HEART SURGERY

    Directory of Open Access Journals (Sweden)

    R. Sh. Saitgareev

    2016-01-01

    Full Text Available Heart Transplantation (HTx to date remains the most effective and radical method of treatment of patients with end-stage heart failure. The defi cit of donor hearts is forcing to resort increasingly to the use of different longterm mechanical circulatory support systems, including as a «bridge» to the follow-up HTx. According to the ISHLT Registry the number of recipients underwent cardiopulmonary bypass surgery increased from 40% in the period from 2004 to 2008 to 49.6% for the period from 2009 to 2015. HTx performed in repeated patients, on the one hand, involves considerable technical diffi culties and high risks; on the other hand, there is often no alternative medical intervention to HTx, and if not dictated by absolute contradictions the denial of the surgery is equivalent to 100% mortality. This review summarizes the results of a number of published studies aimed at understanding the immediate and late results of HTx in patients, previously underwent open heart surgery. The effect of resternotomy during HTx and that of the specifi c features associated with its implementation in recipients previously operated on open heart, and its effects on the immediate and long-term survival were considered in this review. Results of studies analyzing the risk factors for perioperative complications in repeated recipients were also demonstrated. Separately, HTx risks after implantation of prolonged mechanical circulatory support systems were examined. The literature does not allow to clearly defi ning the impact factor of earlier performed open heart surgery on the course of perioperative period and on the prognosis of survival in recipients who underwent HTx. On the other hand, subject to the regular fl ow of HTx and the perioperative period the risks in this clinical situation are justifi ed as a long-term prognosis of recipients previously conducted open heart surgery and are comparable to those of patients who underwent primary HTx. Studies

  2. The pathogenicity of genetic variants previously associated with left ventricular non-compaction

    DEFF Research Database (Denmark)

    Abbasi, Yeganeh; Jabbari, Javad; Jabbari, Reza

    2016-01-01

    BACKGROUND: Left ventricular non-compaction (LVNC) is a rare cardiomyopathy. Many genetic variants have been associated with LVNC. However, the number of the previous LVNC-associated variants that are common in the background population remains unknown. The aim of this study was to provide...... an updated list of previously reported LVNC-associated variants with biologic description and investigate the prevalence of LVNC variants in healthy general population to find false-positive LVNC-associated variants. METHODS AND RESULTS: The Human Gene Mutation Database and PubMed were systematically...... searched to identify all previously reported LVNC-associated variants. Thereafter, the Exome Sequencing Project (ESP) and the Exome Aggregation Consortium (ExAC), that both represent the background population, was searched for all variants. Four in silico prediction tools were assessed to determine...

  3. Prevalent musculoskeletal pain as a correlate of previous exposure to torture

    DEFF Research Database (Denmark)

    Olsen, Dorte Reff; Montgomery, Edith; Bojholm, S

    2006-01-01

    AIM: To research possible associations between previous exposure to specific torture techniques and prevalent pain in the head and face, back, and feet. METHODS: 221 refugees, 193 males and 28 females, previously exposed to torture in their home country, were subject to a clinical interview...... was general abuse of the whole body (OR 5.64, 95% CI 1.93-16.45). CONCLUSION: In spite of many factors being potentially co-responsible for prevalent pain, years after the torture took place it presents itself as strongly associated with specific loci of pain, with generalized effects, and with somatizing....

  4. High frequency monitoring revels new insights into baseflow DOM processing

    Science.gov (United States)

    Khamis, K.; Bradley, C.; Blaen, P.; Krause, S.; Hannah, D. M.

    2017-12-01

    Dissolved organic matter (DOM) is important for myriad biogeochemical processes in river ecosystems. Currently, however, we have limited knowledge of DOM dynamics under low flow conditions as most previous studies have focused largely on storm event dynamics. Field deployable fluorescence technology offers new opportunities to explore diurnal DOM dynamics at finer time-steps and for longer periods than previously possible, thus providing new insights into in-stream DOM processing. In this study, we collected hourly fluorescence data (Spring - Fall) and a suite of hydro-climatological variables from two contrasting UK headwater watersheds: the urban Bourn Brook, Birmingham (52° 26' N, 1° 55' W) and agricultural Mill Haft, Shropshire (52° 48' N, 2° 14' W). We hypothesised that diurnal dynamics in humic-like fluorescence (Peak C; Ex. 365 nm / Em. 490 nm) would be driven by photo-oxidation processes; while tryptophan-like fluorescence (Peak T; Ex. 285 nm / Em. 345 nm) would respond to diurnal biomass production cycles. Wavelet analysis identified significant diurnal variations in Peak C for both the Bourn Brook and Mill Haft, with the strongest signal in early summer. While the amplitude was broadly similar between sites, peak timing and consistency differed, the Bourn Brook displayed peaks in the early morning (04:00 ± 2.2 h) and Mill Haft in early evening (19:00 ± 6.6 h). Cross wavelet analysis identified strong coherence with SW radiation for the urban stream but stronger relationships with discharge for the agricultural system. Hence, results from the Bourn Brook support our hypothesis regarding Peak C photo-oxidation processes but for Mill Haft, discharge (DOM dilution) appeared to be the key control. Contrary to our hypothesis, no strong diurnal pattern was identified for Peak T for either system. From this, we infer that the low levels of Peak T produced were rapidly taken up by bacteria and/or that productivity in these systems was low. Future work on in

  5. Payload specialist Reinhard Furrer show evidence of previous blood sampling

    Science.gov (United States)

    1985-01-01

    Payload specialist Reinhard Furrer shows evidence of previous blood sampling while Wubbo J. Ockels, Dutch payload specialist (only partially visible), extends his right arm after a sample has been taken. Both men show bruises on their arms.

  6. Analysis of previous screening examinations for patients with breast cancer

    International Nuclear Information System (INIS)

    Lee, Eun Hye; Cha, Joo Hee; Han, Dae Hee; Choi, Young Ho; Hwang, Ki Tae; Ryu, Dae Sik; Kwak, Jin Ho; Moon, Woo Kyung

    2007-01-01

    We wanted to improve the quality of subsequent screening by reviewing the previous screening of breast cancer patients. Twenty-four breast cancer patients who underwent previous screening were enrolled. All 24 took mammograms and 15 patients also took sonograms. We reviewed the screening retrospectively according to the BI-RADS criteria and we categorized the results into false negative, true negative, true positive and occult cancers. We also categorized the causes of false negative cancers into misperception, misinterpretation and technical factors and then we analyzed the attributing factors. Review of the previous screening revealed 66.7% (16/24) false negative, 25.0% (6/24) true negative, and 8.3% (2/24) true positive cancers. False negative cancers were caused by the mammogram in 56.3% (9/16) and by the sonogram in 43.7% (7/16). For the false negative cases, all of misperception were related with mammograms and this was attributed to dense breast, a lesion located at the edge of glandular tissue or the image, and findings seen on one view only. Almost all misinterpretations were related with sonograms and attributed to loose application of the final assessment. To improve the quality of breast screening, it is essential to overcome the main causes of false negative examinations, including misperception and misinterpretation. We need systematic education and strict application of final assessment categories of BI-RADS. For effective communication among physicians, it is also necessary to properly educate them about BI-RADS

  7. Previous utilization of service does not improve timely booking in ...

    African Journals Online (AJOL)

    Previous utilization of service does not improve timely booking in antenatal care: Cross sectional study ... Journal Home > Vol 24, No 3 (2010) > ... Results: Past experience on antenatal care service utilization did not come out as a predictor for ...

  8. Radioiodine treatment of recurrent hyperthyroidism in patients previously treated for Graves' disease by subtotal thyroidectomy

    DEFF Research Database (Denmark)

    Vestergaard, H; Laurberg, P

    1992-01-01

    showed a higher sensitivity to radioiodine, with more cases of early hypothyroidism, than non-operated patients. However, after 50 months of follow-up the outcome was identical. The results indicate that frequent assessment is necessary after radioiodine treatment of previously operated patients, since......Radioiodine therapy is often employed for treatment of patients with relapse of hyperthyroidism due to Graves' disease, after previous thyroid surgery. Little is known about the outcome of this treatment compared to patients with no previous surgery. A total of 20 patients who had received surgical...... treatment for Graves' hyperthyroidism 1-46 years previously and with relapse of the hyperthyroidism, and 25 patients with hyperthyroidism due to Graves' disease and no previous thyroid surgery were treated with radioiodine, following the same protocol. Early after treatment the previously operated patients...

  9. Personality disorders in previously detained adolescent females: a prospective study

    NARCIS (Netherlands)

    Krabbendam, A.; Colins, O.F.; Doreleijers, T.A.H.; van der Molen, E.; Beekman, A.T.F.; Vermeiren, R.R.J.M.

    2015-01-01

    This longitudinal study investigated the predictive value of trauma and mental health problems for the development of antisocial personality disorder (ASPD) and borderline personality disorder (BPD) in previously detained women. The participants were 229 detained adolescent females who were assessed

  10. The long-term consequences of previous hyperthyroidism

    DEFF Research Database (Denmark)

    Hjelm Brandt Kristensen, Frans

    2015-01-01

    Thyroid hormones affect every cell in the human body, and the cardiovascular changes associated with increased levels of thyroid hormones are especially well described. As an example, short-term hyperthyroidism has positive chronotropic and inotropic effects on the heart, leading to a hyperdynamic...... with CVD, LD and DM both before and after the diagnosis of hyperthyroidism. Although the design used does not allow a stringent distinction between cause and effect, the findings indicate a possible direct association between hyperthyroidism and these morbidities, or vice versa....... vascular state. While it is biologically plausible that these changes may induce long-term consequences, the insight into morbidity as well as mortality in patients with previous hyperthyroidism is limited. The reasons for this are a combination of inadequately powered studies, varying definitions...

  11. Influence of previous experience on resistance training on reliability of one-repetition maximum test.

    Science.gov (United States)

    Ritti-Dias, Raphael Mendes; Avelar, Ademar; Salvador, Emanuel Péricles; Cyrino, Edilson Serpeloni

    2011-05-01

    The 1-repetition maximum test (1RM) has been widely used to assess maximal strength. However, to improve accuracy in assessing maximal strength, several sessions of the 1RM test are recommended. The aim of this study was to analyze the influence of previous resistance training experience on the reliability of 1RM test. Thirty men were assigned to the following 2 groups according to their previous resistance training experience: no previous resistance training experience (NOEXP) and more than 24 months of resistance training experience (EXP). All subjects performed the 1RM tests in bench press and squat in 4 sessions on distinct days. There was a significant session × group effect in bench press (F = 3.09; p reliability of the 1RM test is influenced by the subject's previous experience in resistance training. Subjects without experience in resistance training require more practice and familiarization and show greater increases in maximal strength between sessions than subjects with previous experience in resistance training.

  12. Preparation of Silver Immobilised TiO2-Hectorite for Phenol Removal and Eschericia coli Desinfection

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2013-03-01

    Full Text Available Preparation of silver immobilized TiO2-Hectorite and its application in phenol photooxidation and Eschericia coli bacteria desinfection has been conducted. Material was obtained by two steps of synthesis: preparation of TiO2-Hectorite and silver immobilization into TiO2-Hectorite. Physico-chemical characterization to the prepared material compared to raw hectorite was conducted by X-ray Diffraction, gas sorption analyzer, scanning electron microscope and DRUV-Visible spectrophotometry and for photoactivity study, phenol photooxidation and Eschericia coli desinfection were investigated. The results indicated that the modification to hectorite material improve the physico-chemical character related to its role as photo-catalyst. Kinetic study of phenol photooxidation revealed the role of TiO2 pillarization and silver immobilization in enhancing rate of reaction as well as increased photoactivity of the materials in E. coli desinfection. © 2013 BCREC UNDIP. All rights reservedReceived: 28th September 2012; Revised: 7th December 2012; Accepted: 20th Decemberber 2012[How to Cite: I. Fatimah (2013. Preparation of Silver Immobilised TiO2-Hectorite for Phenol Removal and Eschericia coli Desinfection. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (3: 191-197. (doi:10.9767/bcrec.7.3.4047.191-197][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4047.191-197 ] View in  |

  13. Perturbations of carotenoid and tetrapyrrole biosynthetic pathways result in differential alterations in chloroplast function and plastid signaling.

    Science.gov (United States)

    Park, Joon-Heum; Jung, Sunyo

    2017-01-22

    In this study, we used the biosynthetic inhibitors of carotenoid and tetrapyrrole biosynthetic pathways, norflurazon (NF) and oxyfluorfen (OF), as tools to gain insight into mechanisms of photooxidation in rice plants. NF resulted in bleaching symptom on leaves of the treated plants, whereas OF treatment developed a fast symptom of an apparent necrotic phenotype. Both plants exhibited decreases in photosynthetic efficiency, as indicated by F v /F m . NF caused severe disruption in thylakoid membranes, whereas OF-treated plants exhibited disruption of chloroplast envelope and plasma membrane. Levels of Lhca and Lhcb proteins in photosystem I (PSI) and PSII were reduced by photooxidative stress in NF- and OF-treated plants, with a greater decrease in NF plants. The down-regulation of nuclear-encoded photosynthesis genes Lhcb and rbcS was also found in both NF- and OF-treated plants, whereas plastid-encoded photosynthetic genes including RbcL, PsaC, and PsbD accumulated normally in NF plants but decreased drastically in OF plants. This proposes that the plastids in NF plants retain their potential to develop thylakoid membranes and that photobleaching is mainly controlled by nuclear genes. Distinct photooxidation patterns between NF- and OF-treated plants developed differential signaling, which might enable the plant to coordinate the expression of photosynthetic genes from the nuclear and plastidic genomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Differential Antioxidant Responses and Perturbed Porphyrin Biosynthesis after Exposure to Oxyfluorfen and Methyl Viologen in Oryza sativa

    Directory of Open Access Journals (Sweden)

    Nhi-Thi Pham

    2015-07-01

    Full Text Available We compared antioxidant responses and regulation of porphyrin metabolism in rice plants treated with oxyfluorfen (OF or methyl viologen (MV. Plants treated with MV exhibited not only greater increases in conductivity and malondialdehyde but also a greater decline in Fv/Fm, compared to plants treated with OF. MV-treated plants had greater increases in activities of superoxide dismutase (SOD and catalase (CAT as well as transcript levels of SODA and CATA than OF-treated plants after 28 h of the treatments, whereas increases in ascorbate peroxidase (APX activity and transcript levels of APXA and APXB were greater in OF-treated plants. Both OF- and MV-treated plants resulted in not only down-regulation of most genes involved in porphyrin biosynthesis but also disappearance of Mg-porphyrins during the late stage of photooxidative stress. By contrast, up-regulation of heme oxygenase 2 (HO2 is possibly part of an efficient antioxidant response to compensate photooxidative damage in both treatments. Our data show that down-regulated biosynthesis and degradation dynamics of porphyrin intermediates have important roles in photoprotection of plants from perturbed porphyrin biosynthesis and photosynthetic electron transport. This study suggests that porphyrin scavenging as well as strong antioxidative activities are required for mitigating reactive oxygen species (ROS production under photooxidative stress caused by OF and MV.

  15. Iodine-131 induced hepatotoxicity in previously healthy patients with Grave’s disease

    Science.gov (United States)

    2013-01-01

    Objective To describe the association of the rare and serious complication of liver toxicity in previously healthy Grave’s disease (GD) patients after the treatment with radioactive iodine 131I (RAI). Case presentation We report the clinical, laboratory and pathologic findings of 2 cases of severe liver toxicity associated with the treatment with RAI in previously healthy patients with GD. Clinical examination and laboratory investigations excluded viral hepatitis, autoimmune hepatitis, granulomatous disease, primary biliary disease, extrahepatic biliary obstruction, and heart failure. Case 1: A previously healthy 52-years old man reportedly having a typical GD but following RAI treatment, concomitantly developed severe liver toxicity that required 1 week of treatment in hospital. Case 2: A previously healthy 34-years old woman is reported as having a typical GD but developed jaundice following RAI treatment that required several weeks of in hospital treatment in the hepato-biliary department. In both cases, the liver dysfunction resolved after intensive treatment with hepato-protective agents. In this report the therapeutic considerations as well as the pathogenetic possibilities are reviewed. Conclusion To the best of our knowledge, this is the first description of the association observed, which is rare but may be severe and should be considered in any case of thyrotoxicosis where a liver dysfunction develops after the treatment with radioactive iodine 131I. PMID:23497434

  16. Antimetabolites in cataract surgery to prevent failure of a previous trabeculectomy.

    Science.gov (United States)

    Thomas, Roger E; Crichton, Andrew; Thomas, Bennett C

    2014-07-28

    Patients having cataract surgery have often earlier undergone a trabeculectomy for glaucoma. However, cataract surgery may be associated with failure of the previous glaucoma surgery and antimetabolites may be used with cataract surgery to prevent such failure. There is no systematic review on whether antimetabolites with cataract surgery prevent failure of a previous trabeculectomy. To assess the effects of antimetabolites with cataract surgery on functioning of a previous trabeculectomy. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 June 2014. We also searched the Science Citation Index database (July 2013) and reference lists of potentially relevant studies. Randomised controlled trials (RCTs) of antimetabolites with cataract surgery in people with a functioning trabeculectomy. Two review authors independently reviewed the titles and abstracts from the electronic searches. Two review authors independently assessed relevant full-text articles and entered data. We identified no RCTs to test the effectiveness of antimetabolites with cataract surgery in individuals with the intention of preventing failure of a previous trabeculectomy. There are no RCTs of antimetabolites with cataract surgery in people with a functioning trabeculectomy. Appropriately powered RCTs

  17. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  18. Bilateral orbital infarction and retinal detachment in a previously undiagnosed sickle cell hemoglobinopathy African child

    Science.gov (United States)

    Helen, Onakpoya Oluwatoyin; Ajite, K. O.; Oyelami, O. A.; Asaleye, C. M.; Adeoye, A. O.

    2013-01-01

    Bone infarction involving the orbit in sickle cell disease is not common. Bilateral orbital infarction in a previously undiagnosed sickle cell hemoglobinopathy has not been previously reported. In this report, we present a case of an 11-year-old previously undiagnosed sickle cell disease Nigerian girl with severe acute bilateral orbital infarction and retinal detachment to highlight that hemoglobinopathy induced orbital infarction should be considered in African children with acute onset proptosis with or without previous history of sickle cell hemoglobinopathy. PMID:23901183

  19. Previous Employment and Job Satisfaction Conditions: The Case of Regional Administration

    Science.gov (United States)

    Amalia, Myronaki; Nikolaos, Antonakas

    2009-08-01

    In the present work we study the different dimensions of satisfaction and the way of constitution of satisfaction of an important sample of the employees in the Regional administration of Crete and in their connection with the variable of the previous employment. We found statistically important differences for the components of satisfaction from the life, collaboration in and outside from the department, in the social satisfaction and the variable of the years in the service (labour group with satisfaction than the other previous employment groups. In the other hand the group with many years in the service presents bigger satisfaction than the other groups. Finally, is important to note that the sample present some interesting characteristics.

  20. Haemophilus influenzae type f meningitis in a previously healthy boy

    DEFF Research Database (Denmark)

    Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle

    2013-01-01

    Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib...

  1. Effect of media composition, including gelling agents, on isolation of previously uncultured rumen bacteria.

    Science.gov (United States)

    Nyonyo, T; Shinkai, T; Tajima, A; Mitsumori, M

    2013-01-01

    The aim of this study was to develop novel anaerobic media using gellan gum for the isolation of previously uncultured rumen bacteria. Four anaerobic media, a basal liquid medium (BM) with agar (A-BM), a modified BM (MBM) with agar (A-MBM), an MBM with phytagel (P-MBM) and an MBM with gelrite (G-MBM) were used for the isolation of rumen bacteria and evaluated for the growth of previously uncultured rumen bacteria. Of the 214 isolates composed of 144 OTUs, 103 isolates (83 OTUs) were previously uncultured rumen bacteria. Most of the previously uncultured strains were obtained from A-MBM, G-MBM and P-MBM, but the predominant cultural members, isolated from each medium, differed. A-MBM and G-MBM showed significantly higher numbers of different OTUs derived from isolates than A-BM (P rumen bacteria were isolated from all media used, the ratio of previously uncultured bacteria to total isolates was increased in A-MBM, P-MBM and G-MBM. © 2012 The Society for Applied Microbiology.

  2. Impulsivity moderates the relationship between previous quit failure and cue-induced craving.

    Science.gov (United States)

    Erblich, Joel; Michalowski, Alexandra

    2015-12-01

    Poor inhibitory control has been shown to be an important predictor of relapse to a number of drugs, including nicotine. Indeed, smokers who exhibit higher levels of impulsivity are thought to have impaired regulation of urges to smoke, and previous research has suggested that impulsivity may moderate cue-induced cigarette cravings. To that end, we conducted a study to evaluate the interplay between failed smoking cessation, cue-induced craving, and impulsivity. Current smokers (n=151) rated their cigarette cravings before and after laboratory to exposure to smoking cues, and completed questionnaires assessing impulsivity and previous failed quit attempts. Findings indicated that shorter duration of previous failed quit attempts was related to higher cue-induced cigarette craving, especially among smokers with higher levels of impulsivity. Results underscore the importance of considering trait impulsivity as a factor in better understanding the management of cue-induced cravings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Interpretations of Fundus Autofluorescence from Studies of the Bisretinoids of the Retina

    OpenAIRE

    Sparrow, Janet R.; Yoon, Kee Dong; Wu, Yalin; Yamamoto, Kazunori

    2010-01-01

    Elevated fundus autofluorescence signals can reflect enhanced lipofuscin in RPE cells, augmented fluorescence due to photooxidation, and/or excess bisretinoid fluorophores in photoreceptor cells due to mishandling of vitamin A aldehyde by dysfunctional cells.

  4. Impaired insulin-stimulated nonoxidative glucose metabolism in glucose-tolerant women with previous gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Vestergaard, H; Kühl, Carl Erik

    1996-01-01

    Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes.......Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes....

  5. [ANTITHROMBOTIC MEDICATION IN PREGNANT WOMEN WITH PREVIOUS INTRAUTERINE GROWTH RESTRICTION].

    Science.gov (United States)

    Neykova, K; Dimitrova, V; Dimitrov, R; Vakrilova, L

    2016-01-01

    To analyze pregnancy outcome in patients who were on antithrombotic medication (AM) because of previous pregnancy with fetal intrauterine growth restriction (IUGR). The studied group (SG) included 21 pregnancies in 15 women with history of previous IUGR. The patients were on low dose aspirin (LDA) and/or low molecular weight heparin (LMWH). Pregnancy outcome was compared to the one in two more groups: 1) primary group (PG) including the previous 15 pregnancies with IUGR of the same women; 2) control group (CG) including 45 pregnancies of women matched for parity with the ones in the SG, with no history of IUGR and without medication. The SG, PG and CG were compared for the following: mean gestational age (g.a.) at birth, mean birth weight (BW), proportion of cases with early preeclampsia (PE), IUGR (total, moderate, and severe), intrauterine fetal death (IUFD), neonatal death (NND), admission to NICU, cesarean section (CS) because of chronic or acute fetal distress (FD) related to IUGR, PE or placental abruption. Student's t-test was applied to assess differences between the groups. P values < 0.05 were considered statistically significant. The differences between the SG and the PG regarding mean g. a. at delivery (33.7 and 29.8 w.g. respectively) and the proportion of babies admitted to NICU (66.7% vs. 71.4%) were not statistically significant. The mean BW in the SG (2114,7 g.) was significantly higher than in the PG (1090.8 g.). In the SG compared with the PG there were significantly less cases of IUFD (14.3% and 53.3% respectively), early PE (9.5% vs. 46.7%) moderate and severe IUGR (10.5% and 36.8% vs. 41.7% and 58.3%). Neonatal mortality in the SG (5.6%) was significantly lower than in the PG (57.1%), The proportion of CS for FD was not significantly different--53.3% in the SG and 57.1% in the PG. On the other hand, comparison between the SG and the CG demonstrated significantly lower g.a. at delivery in the SG (33.7 vs. 38 w.g.) an lower BW (2114 vs. 3094 g

  6. Synthesis, autoxidation and photooxidation of hindered pyrrole derivatives. Hindered pyrrolic nitroxide radicals; Synthese, autoxydation et photoxidation de pyrroles encombres radicaux nitroxydes pyrroliques encombres

    Energy Technology Data Exchange (ETDEWEB)

    Ramasseul, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    2,5-di-t-butyl and 2,3,5-tri-t-butyl pyrrole are prepared from pinacoline and their structure is confirmed by comparison with 2,5-di-t-butyl furan and thiophene (I.R., U.V. and N.M.R. {sup 13}C satellites observation giving J{sub 13{sub C-H}} and J{sub H{sub 3}-H{sub 4}}). The sensitized photooxidation of these hindered pyrroles gives corresponding hydroperoxides which most likely structure is determined using physical and chemical methods. Oxidation of 2,5-di-t-butyl and 2,3,5-tri-t-butyl pyrrole by hydrogen peroxide in presence of inorganic per-acid of by p-nitro-perbenzoic acid does not give the pyrrolic nitroxides in contrast with secondary amines. Some N-hydroxypyrroles are then prepared from pinacoline and ethyl pivaloyl-acetate. Their oxidation by lead dioxide gives the corresponding pyrrolic nitroxides. 2,5-di-t-butyl 3,4-di-ethoxycarbonyl pyrryl 1-oxy is isolated and studied spectroscopically (visible and U.V., E.P.R.). In marked contrast with ordinary nitroxides it does not show solvent effect. It can be compared with 2,4-di-t-butyl cyclopentadienone, a carbon analog. For both, the long wave length transition does not show the usual n - {pi}* behaviour; that is confirmed by E.P.R. Using Huckel method for pyrrolic nitroxide skeleton, it is possible to have a good interpretation of experimental data. (author) [French] Les di-t-butyl 2,5 et tri-t-butyl-2,3,5 pyrrole sont synthetises a partir de la pinacoline et leur structure confirmee par comparaison avec les di-t-butyl-2,5 furanne et thiophene (I.R., U.V. et R.M.N.: observation des satellites {sup 13}C conduisant a la mesure des J{sub 13{sub C-H}} et J{sub H{sub 3}{sub -H{sub 4}}). La photoxydation sensibilisee de ces pyrroles encombres conduit aux hydroperoxydes correspondants dont la structure la plus probable est determinee par les methodes physicochimiques. L'oxydation des di-t-butyl-2,5 et tri-t-butyl-2,3,5 pyrrole par l'eau oxygenee en presence de peracide mineral ou par l'acide p

  7. A comparison of morbidity associated with placenta previa with and without previous caesarean sections

    International Nuclear Information System (INIS)

    Baqai, S.; Siraj, A.; Noor, N.

    2018-01-01

    To compare the morbidity associated with placenta previa with and without previous caesarean sections. Study Design: Retrospective comparative study. Place and Duration of Study: From March 2014 till March 2016 in the department of Obstetrics and Gynaecology at PNS Shifa hospital Karachi. Material and Methods: After the approval from hospital ethical committee, antenatal patients with singleton pregnancy of gestational age >32 weeks, in the age group of 20-40 years diagnosed to have placenta previa included in the study. All patients with twin pregnancy less than 20 years and more than 40 years of age were excluded. The records of all patients fulfilling the inclusion criteria were reviewed. Data had been collected for demographic and maternal variables, placenta previa, history of previous lower segment caesarean section (LSCS), complications associated with placenta previa and techniques used to control blood loss were recorded. Results: During the study period, 6879 patients were delivered in PNS Shifa, out of these, 2060 (29.9%) had caesarean section out of these, 47.3% patients had previous history of LSCS. Thirty three (1.6%) patients were diagnosed to have placenta previa and frequency of placenta previa was significantly higher in patients with previous history of LSCS than previous normal delivery of LSCS i.e. 22 vs. 11 (p=0.023). It was observed that the frequency of morbidly adherent placenta (MAP) and Intensive care unit (ICU) stay were significantly higher in patients with previous history of LSCS than previous history of normal delivery. Conclusion: Frequency of placenta previa was significantly higher in patients with history of LSCS. Also placenta previa remains a major risk factor for various maternal complications. (author)

  8. Let the sun shine in: mechanisms and potential for therapeutics in skin photodamage.

    Science.gov (United States)

    Wondrak, Georg T

    2007-05-01

    Photoaging and photocarcinogenesis are the two Janus faces of skin photodamage. Reactivity-based design of prototype agents that antagonize, modulate and reverse the chemistry of skin photodamage holds promise in delivering unprecedented therapeutic benefit. In contrast to structure-based approaches that use selective ligands to target macromolecules, reactivity-based drug discovery uses chemical reagents as therapeutics to target reactive chemical species as key mediators of skin photo-oxidative stress. The following classes of reactivity-based agents for skin photoprotection can be distinguished based on their mechanism of action: direct antagonists of photo-oxidative stress (sunscreens, quenchers of photo-excited states, antioxidants, redox modulators and glycation inhibitors) and skin photo-adaptation inducers (nuclear factor erythroid 2-related factor 2 [Nrf2] activators, heat-shock response inducers and metallothionein inducers).

  9. Photochemical Production and Behavior of Hydroperoxyacids in Heterotrophic Bacteria Attached to Senescent Phytoplanktonic Cells

    Directory of Open Access Journals (Sweden)

    Frédéric Vaultier

    2013-06-01

    Full Text Available The photooxidation of cellular monounsaturated fatty acids was investigated in senescent phytoplanktonic cells (Emiliania huxleyi and in their attached bacteria under laboratory controlled conditions. Our results indicated that UV-visible irradiation of phytodetritus induced the photooxidation of oleic (produced by phytoplankton and bacteria and cis-vaccenic (specifically produced by bacteria acids. These experiments confirmed the involvement of a substantial singlet oxygen transfer from senescent phytoplanktonic cells to attached bacteria, and revealed a significant correlation between the concentration of chlorophyll, a photosensitizer, in the phytodetritus and the photodegradation state of bacteria. Hydroperoxyacids (fatty acid photoproducts appeared to be quickly degraded to ketoacids and hydroxyacids in bacteria and in phytoplanktonic cells. This degradation involves homolytic cleavage (most likely induced by UV and/or transition metal ions and peroxygenase activity (yielding epoxy acids.

  10. Studies of transfer reactions of photosensitized electrons involving complexes of transition metals in view of solar energy storage

    International Nuclear Information System (INIS)

    Takakubo, Masaaki

    1984-01-01

    This research thesis addresses electron transfer reactions occurring during photosynthesis, for example, photosensitized reaction in which chlorophyll is the sensitizer. More specifically, the author studied experimentally electron photo-transfers with type D sensitizers (riboflavin, phenoxazine and porphyrin), and various complexes of transition metals. After a presentation of these experiments, the author describes the photosensitisation process (photo-physics of riboflavin, oxygen deactivation, sensitized photo-oxidation and photo-reduction). The theoretical aspect of electron transfer is then addressed: generalities, deactivation of the riboflavin triplet, initial efficiency of electron transfer. Experimental results on three basic processes (non-radiative deactivation, energy transfer, electron transfer) are interpreted in a unified way by using the non-radiative transfer theory. Some applications are described: photo-electrochemical batteries, photo-oxidation and photo-reduction of the cobalt ion

  11. Complication of cesarean section: pregnancy on the cicatrix of a previous cesarean section.

    Science.gov (United States)

    Wang, Weimin; Long, Wenqing; Yu, Qunhuan

    2002-02-01

    To probe into the clinical manifestation, diagnosis, as well as treatment of pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester. Analysis of 14 patients with pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester was made after conservative treatment by drugs from January 1996 to December 1999. The 14 patients with a pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester were painless, had slight vaginal bleeding, and concurrently had increased serum beta-subunit human chorionic gonadotropin (beta-HCG). Doppler ultrasonic examination revealed an obvious enlargement of the previous cesarean section cicatrix in the uterine isthmus, and found a gestational sac or mixed mass attached to the cicatrice, with a very thin myometrium between the gestational sac and bladder walls. Among the 14 patients, 12 patients had crystalline trichosanthes injected into the cervix, mifepristone taken orally, or methotrexate in the form of intramuscular injection. Following this procedure, their serum beta-HCG dropped to normal. The other 2 patients had a total hysterectomy. Pregnancy on the cicatrix of a previous cesarean section at the uterine isthmus in the first trimester is a complication of cesarean section. Early diagnosis and effective conservative treatment by drugs are instrumental in decreasing the potential occurrence of uterine rupture, which is also conducive to preserving the patient's future fertility.

  12. National Rates of Uterine Rupture are not Associated with Rates of Previous Caesarean Delivery

    DEFF Research Database (Denmark)

    Colmorn, Lotte B.; Langhoff-Roos, Jens; Jakobsson, Maija

    2017-01-01

    % of all Nordic deliveries. Information on the comparison population was retrieved from the national medical birth registers. Incidence rate ratios by previous caesarean delivery and intended mode of delivery after caesarean were modelled using Poisson regression. RESULTS: The incidence of uterine rupture......BACKGROUND: Previous caesarean delivery and intended mode of delivery after caesarean are well-known individual risk factors for uterine rupture. We examined if different national rates of uterine rupture are associated with differences in national rates of previous caesarean delivery and intended...... was 7.8/10 000 in Finland and 4.6/10 000 in Denmark. Rates of caesarean (21.3%) and previous caesarean deliveries (11.5%) were highest in Denmark, while the rate of intended vaginal delivery after caesarean was highest in Finland (72%). National rates of uterine rupture were not associated...

  13. Books Average Previous Decade of Economic Misery

    Science.gov (United States)

    Bentley, R. Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20th century since the Depression, we find a strong correlation between a ‘literary misery index’ derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade. PMID:24416159

  14. [Photodrugtherapy of psoriasis with oral psoralen and black light therapy].

    Science.gov (United States)

    Corrales Padilla, H

    1975-01-01

    Oral 4, 5', 8 trimethoxypsoralen (TMP) or 8-M-methoxypsoralen (8 MP) plus black light therapy of psoriasis produced disappearing of lesions in 6 out of 8 pacients treated with TMP and in 6 out of 7 treated with 8 MP. In three patients treated with the first drug, a paired comparision demonstrated that the ingestion of it, when followed of black exposure, is more effective than the exposure to conventional ultraviolet light. Parrish et al. have shown this for oral methoxalen and long wave ultraviolet light. Combined TMP or 8-MP and black light therapy inhibits epidermal DNA synthesis and this is the scientific base of its application in the therapy of psoriasis, disease in which an accelerated celular cicle and DNA synthesis has been postulated.

  15. Linoleic acid, thymine, and tryptophan radiosensitization by protoporphyrin in presence of oxygene

    International Nuclear Information System (INIS)

    Champel, P.; Mignot, M.A.; Pillement, B.; Fontenil, L.; Rocquet, G.

    Sensitizing effect induced by protoporphyrin, an active molecule in photooxidation is studied. Studied substances are tryptophan, thymine, linoleic acid, each component representing one of the great groups of biological components, nucleic acid, proteins, lipids [fr

  16. Nematicidal activity of furanocoumarins from parsley against Meloidogyne spp.

    Science.gov (United States)

    Caboni, Pierluigi; Saba, Marco; Oplos, Chrisostomos; Aissani, Nadhem; Maxia, Andrea; Menkissoglu-Spiroudi, Urania; Casu, Laura; Ntalli, Nikoletta

    2015-08-01

    This report describes activity against Meloidogyne spp. and chemical characterisation of the essential oil and methanol extract of Petroselinum crispum aerial parts. The study was based on the hypothesis that P. crispum could be used as an intercrop and soil amendment in tomato culture for nematode control. The methanol extract and the essential oil exhibited significant nematicidal activity against M. incognita, M. hapla and M. arenaria, the first being the most sensitive species, with EC50 /72 h values of 140 ± 15 and 795 ± 125 mg L(-1) for the extract and oil respectively. The most abundant furanocoumarin compounds in the methanolic extract were xanthotoxin, psoralen, bergapten and oxypeucedanin; levels ranged from 1.77 to 46.04 mg kg(-1) wet weight. The EC50 /24 h values of xanthotoxol, psoralen and xanthotoxin against M. incognita were 68 ± 33, 147 ± 88 and 200 ± 21 mg L(-1) respectively. The addition of fresh parsley paste to soil reduced the number of M. incognita females and plant galls on tomato roots; EC50 values were 24.79 and 28.07 mg g(-1) respectively. Moreover, parsley paste enhanced tomato growth in a dose-response manner. Parsley exhibits promising nematicidal activity as an organic amendment and as a source of nematotoxic furanocoumarins. © 2014 Society of Chemical Industry.

  17. Comparing ultraviolet light A photo(chemo)therapy with Methotrexate protocol in childhood localized scleroderma: Evidence from systematic review and meta-analysis approach.

    Science.gov (United States)

    Marrani, Edoardo; Foeldvari, Ivan; Lopez, Jordi Anton; Cimaz, Rolando; Simonini, Gabriele

    2018-03-14

    Localized scleroderma is a skin fibrosing disorder that, if untreated, may result in severe disability. The purpose of this systematic review is to compare the present evidence concerning the effectiveness of Methotrexate versus phototherapy, alone or associated with Psoralen, in childhood localized scleroderma. A systematic search between January 1996 and May 2017 was performed to identify studies investigating the efficacy of Methotrexate (MTX) or phototherapy (UVA) for treating localized scleroderma with onset ≤18 years. Due to a lack of validated clinical criteria, four clinical response criteria were used to assess the treatment efficacy as primary outcome. We determined a combined estimate of the proportion of children responding to MTX and UVA. A total of 19 studies was included (8 MTX; 11 UVA). In the methotrexate group, 193 children were included in the analysis; in the phototherapy group, a total of 48 treated children. For both groups age, disease subtype, glucocorticoids (GCs) use, and side effects of treatment were also analyzed. The meta-analysis suggested that UVA and MTX protocols have both a favorable effect in active lesions of childhood localized scleroderma. However, MTX resulted significantly superior to UVA, with or without Psoralen. Our study supports the combination of MTX and GCs in patients with a high risk of complication. Phototherapy with UVA1 could represent a therapeutic option in patients with limited scleroderma, where lesions do not cross joints and they do not lead to potential cosmetic changes. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. 77 FR 59242 - Extension of a Previously Approved Collection; Public Charters

    Science.gov (United States)

    2012-09-26

    ... previous notice. DATES: Comments on this notice should be received by October 26, 2012: attention OMB/OST... operator's advertising, selling or operating the charter. If the prospectus information were not collected...

  19. Total hip arthroplasty after a previous pelvic osteotomy: A systematic review and meta-analysis.

    Science.gov (United States)

    Shigemura, T; Yamamoto, Y; Murata, Y; Sato, T; Tsuchiya, R; Wada, Y

    2018-06-01

    There are several reports regarding total hip arthroplasty (THA) after a previous pelvic osteotomy (PO). However, to our knowledge, until now there has been no formal systematic review and meta-analysis published to summarize the clinical results of THA after a previous PO. Therefore, we conducted a systematic review and meta-analysis of results of THA after a previous PO. We focus on these questions as follows: does a previous PO affect the results of subsequent THA, such as clinical outcomes, operative time, operative blood loss, and radiological parameters. Using PubMed, Web of Science, and Cochrane Library, we searched for relevant original papers. The pooling of data was performed using RevMan software (version 5.3, Cochrane Collaboration, Oxford, UK). A p-value50%, significant heterogeneity was assumed and a random-effects model was applied for the meta-analysis. A fixed-effects model was applied in the absence of significant heterogeneity. Eleven studies were included in this meta-analysis. The pooled results indicated that there was no significant difference in postoperative Merle D'Aubigne-Postel score (I 2 =0%, SMD=-0.15, 95% CI: -0.36 to 0.06, p=0.17), postoperative Harris hip score (I 2 =60%, SMD=-0.23, 95% CI: -0.50 to 0.05, p=0.10), operative time (I 2 =86%, SMD=0.37, 95% CI: -0.09 to 0.82, p=0.11), operative blood loss (I 2 =82%, SMD=0.23, 95% CI: -0.17 to 0.63, p=0.25), and cup abduction angle (I 2 =43%, SMD=-0.08, 95% CI: -0.25 to 0.09, p=0.38) between THA with and without a previous PO. However, cup anteversion angle of THA with a previous PO was significantly smaller than that of without a previous PO (I 2 =77%, SMD=-0.63, 95% CI: -1.13 to -0.13, p=0.01). Systematic review and meta-analysis of results of THA after a previous PO was performed. A previous PO did not affect the results of subsequent THA, except for cup anteversion. Because of the low quality evidence currently available, high-quality randomized controlled trials are required

  20. Dermatoscopy of blue vitiligo.

    Science.gov (United States)

    Chandrashekar, L

    2009-07-01

    Blue vitiligo is a distinct variant of vitiligo characterized by a blue-grey appearance of the skin, which corresponds histologically with absence of epidermal melanocytes and presence of numerous dermal melanophages. A 23-year-old woman of Indian origin with Fitzpatrick skin type V presented with a 1-month history of normoaesthetic depigmented macules over the right forearm, dorsa of the hands and right areola. The macule over the right forearm had a bluish tinge. A clinical diagnosis of vitiligo vulgaris with blue vitiligo was made. Dermatoscopy of the interface between the blue macule and the hypopigmented macule revealed a linear depigmented macule in the centre with multiple blue dots and absence of epidermal melanin on the side of the blue macule, and reticular pigmentation with a few depigmented macules and scattered blue dots over the side of the hypopigmented macule. Blue vitiligo was described previously in a patient seropositive for human immunodeficiency virus, and believed to represent postinflammatory hyperpigmentation in areas bordering the vitiliginous patches as a result of psoralen ultraviolet A treatment. This case is unusual because of its rarity and the description of the associated dermatoscopical findings.

  1. Response to deep TMS in depressive patients with previous electroconvulsive treatment.

    Science.gov (United States)

    Rosenberg, Oded; Zangen, Abraham; Stryjer, Rafael; Kotler, Moshe; Dannon, Pinhas N

    2010-10-01

    The efficacy of transcranial magnetic stimulation (TMS) in the treatment of major depression has already been shown. Novel TMS coils allowing stimulation of deeper brain regions have recently been developed and studied. Our study is aimed at exploring the possible efficacy of deep TMS in patients with resistant depression, who previously underwent electroconvalsive therapy (ECT). Using Brainsway's deep TMS H1 coil, six patients who previously underwent ECT, were treated with 120% power of the motor threshold at a frequency of 20 Hz. Patients underwent five sessions per week, up to 4 weeks. Before the study, patients were evaluated using the Hamilton depression rating scale (HDRS, 24 items), the Hamilton anxiety scale, and the Beck depression inventory and were again evaluated after 5, 10, 15, and 20 daily treatments. Response to treatment was considered a reduction in the HDRS of at least 50%, and remission was considered a reduction of the HDRS-24 below 10 points. Two of six patients responded to the treatment with deep TMS, including one who achieved full remission. Our results suggest the possibility of a subpopulation of depressed patients who may benefit from deep TMS treatment, including patients who did not respond to ECT previously. However, the power of the study is small and similar larger samples are needed. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Adverse obstetric outcomes in women with previous cesarean for dystocia in second stage of labor.

    Science.gov (United States)

    Jastrow, Nicole; Demers, Suzanne; Gauthier, Robert J; Chaillet, Nils; Brassard, Normand; Bujold, Emmanuel

    2013-03-01

    To evaluate obstetric outcomes in women undergoing a trial of labor (TOL) after a previous cesarean for dystocia in second stage of labor. A retrospective cohort study of women with one previous low transverse cesarean undergoing a first TOL was performed. Women with previous cesarean for dystocia in first stage and those with previous dystocia in second stage were compared with those with previous cesarean for nonrecurrent reasons (controls). Multivariable regressions analyses were performed. Of 1655 women, those with previous dystocia in second stage of labor (n = 204) had greater risks than controls (n = 880) to have an operative delivery [odds ratio (OR): 1.5; 95% confidence intervals (CI) 1.1 to 2.2], shoulder dystocia (OR: 2.9; 95% CI 1.1 to 8.0), and uterine rupture in the second stage of labor (OR: 4.9; 95% CI 1.1 to 23), and especially in case of fetal macrosomia (OR: 29.6; 95% CI 4.4 to 202). The median second stage of labor duration before uterine rupture was 2.5 hours (interquartile range: 1.5 to 3.2 hours) in these women. Previous cesarean for dystocia in the second stage of labor is associated with second-stage uterine rupture at next delivery, especially in cases of suspected fetal macrosomia and prolonged second stage of labor. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  3. 78 FR 47546 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2013-08-06

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Model... Aviation Authority of Israel (CAAI), which is the aviation authority for Israel, has issued Israeli...

  4. Neighborhood of 16S rRNA nucleotides U788/U789 in the 30S ribosomal subunit determined by site-directed crosslinking.

    OpenAIRE

    Mundus, D; Wollenzien, P

    1998-01-01

    Site-specific photo crosslinking has been used to investigate the RNA neighborhood of 16S rRNA positions U788/ U789 in Escherichia coli 30S subunits. For these studies, site-specific psoralen (SSP) which contains a sulfhydryl group on a 17 A side chain was first added to nucleotides U788/U789 using a complementary guide DNA by annealing and phototransfer. Modified RNA was purified from the DNA and unmodified RNA. For some experiments, the SSP, which normally crosslinks at an 8 A distance, was...

  5. Photosensitized oxidation of DNA and its components

    International Nuclear Information System (INIS)

    Decarroz, Chantal.

    1982-09-01

    Chemical changes in DNA components during the photodynamic effect are responsible for Mutagenic and carcinogenic phenomena. Basically two competitive mechanisns involving respectively a charge transfer (type I) and singlet oxygen (type II) are implicated in reactions photo-sensitized by different agents (acridines, phenothiazines, porphyrins, flavins, psoralenes...). A study of the photosensitized oxidation of DNA itself was approached through characterization of the main final products in the case of purine nucleosides. Methyl-2 naphthoquinone - 1,4 (vitamin K 3 ) displays a special photosensitization mechanism involving a cation radical type of intermediary [fr

  6. MCNP HPGe detector benchmark with previously validated Cyltran model.

    Science.gov (United States)

    Hau, I D; Russ, W R; Bronson, F

    2009-05-01

    An exact copy of the detector model generated for Cyltran was reproduced as an MCNP input file and the detection efficiency was calculated similarly with the methodology used in previous experimental measurements and simulation of a 280 cm(3) HPGe detector. Below 1000 keV the MCNP data correlated to the Cyltran results within 0.5% while above this energy the difference between MCNP and Cyltran increased to about 6% at 4800 keV, depending on the electron cut-off energy.

  7. 77 FR 44113 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-07-27

    ... Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel Aircraft... Aerospace LP (Type Certificate previously held by Israel Aircraft Industries, Ltd.) Model Gulfstream G150... to the manufacturer. This action was prompted by a report from the Civil Aviation Authority of Israel...

  8. 77 FR 58323 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-09-20

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... Previously Held by Israel Aircraft Industries, Ltd.) Model Gulfstream G150 airplanes. This proposed AD was.... Discussion The Civil Aviation Authority of Israel (CAAI), which is the aviation authority for Israel, has...

  9. 77 FR 32069 - Airworthiness Directives; Gulfstream Aerospace LP (Type Certificate Previously Held by Israel...

    Science.gov (United States)

    2012-05-31

    ... Aerospace LP (Type Certificate Previously Held by Israel Aircraft Industries, Ltd.) Airplanes AGENCY... previously held by Israel Aircraft Industries, Ltd.) Model Galaxy and Gulfstream 200 airplanes. This proposed... receive about this proposed AD. Discussion The Civil Aviation Authority of Israel (CAAI), which is the...

  10. Association between previous splenectomy and gastric dilatation-volvulus in dogs: 453 cases (2004-2009).

    Science.gov (United States)

    Sartor, Angela J; Bentley, Adrienne M; Brown, Dorothy C

    2013-05-15

    To evaluate the association between previous splenectomy and gastric dilatation-volvulus (GDV) in dogs. Multi-institutional retrospective case-control study. Animals-151 dogs treated surgically for GDV and 302 control dogs with no history of GDV. Computerized records of dogs evaluated via exploratory laparotomy or abdominal ultrasonography were searched, and dogs with GDV and dogs without GDV (control dogs) were identified. Two control dogs were matched with respect to age, body weight, sex, neuter status, and breed to each dog with GDV. Data were collected on the presence or absence of the spleen for both dogs with GDV and control dogs. Conditional logistic regression analysis was used to investigate the association of previous splenectomy with GDV. 6 (4%) dogs in the GDV group and 3 (1%) dogs in the control group had a history of previous splenectomy. The odds of GDV in dogs with a history of previous splenectomy in this population of dogs were 5.3 times those of dogs without a history of previous splenectomy (95% confidence interval, 1.1 to 26.8). For the patients in the present study, there was an increased odds of GDV in dogs with a history of splenectomy. Prophylactic gastropexy may be considered in dogs undergoing a splenectomy, particularly if other risk factors for GDV are present.

  11. Cloning and analysis of the ascorbate peroxidase gene promoter ...

    African Journals Online (AJOL)

    enoh

    2012-03-22

    Mar 22, 2012 ... physiological function of BnAPX in plant response to photooxidative stress, 1562 bp upstream sequence of ... Many light-responsive cis-elements were revealed in this .... element, CGTCA-motif is a MeJA responsive element.

  12. Scientific opinion on the evaluation of substances as acceptable previous cargoes for edible fats and oils

    DEFF Research Database (Denmark)

    Petersen, Annette

    Shipping of edible fats and oils into Europe is permitted in bulk tanks, provided that the previous cargo is included in a positive list. The European Commission requested EFSA to evaluate the acceptability as previous cargoes for fats and oils the substances calcium lignosulphonate, methyl acetate...... the criteria for acceptability as previous cargoes. Due to uncertainties, mainly with regard to the composition and toxicity of the low molecular mass fraction, and the fact that the toxicological database is limited to the 40–65 grade and does not cover all grades of calcium lignosulphonate shipped...... as previous cargoes, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) concluded that calcium lignosulphonate does not meet the criteria for acceptability as a previous cargo. Only food-grade ammonium sulphate meets the criteria for acceptability as a previous cargo due to uncertainties about...

  13. Do emotional intelligence and previous caring experience influence student nurse performance? A comparative analysis.

    Science.gov (United States)

    Stenhouse, Rosie; Snowden, Austyn; Young, Jenny; Carver, Fiona; Carver, Hannah; Brown, Norrie

    2016-08-01

    Reports of poor nursing care have focused attention on values based selection of candidates onto nursing programmes. Values based selection lacks clarity and valid measures. Previous caring experience might lead to better care. Emotional intelligence (EI) might be associated with performance, is conceptualised and measurable. To examine the impact of 1) previous caring experience, 2) emotional intelligence 3) social connection scores on performance and retention in a cohort of first year nursing and midwifery students in Scotland. A longitudinal, quasi experimental design. Adult and mental health nursing, and midwifery programmes in a Scottish University. Adult, mental health and midwifery students (n=598) completed the Trait Emotional Intelligence Questionnaire-short form and Schutte's Emotional Intelligence Scale on entry to their programmes at a Scottish University, alongside demographic and previous caring experience data. Social connection was calculated from a subset of questions identified within the TEIQue-SF in a prior factor and Rasch analysis. Student performance was calculated as the mean mark across the year. Withdrawal data were gathered. 598 students completed baseline measures. 315 students declared previous caring experience, 277 not. An independent-samples t-test identified that those without previous caring experience scored higher on performance (57.33±11.38) than those with previous caring experience (54.87±11.19), a statistically significant difference of 2.47 (95% CI, 0.54 to 4.38), t(533)=2.52, p=.012. Emotional intelligence scores were not associated with performance. Social connection scores for those withdrawing (mean rank=249) and those remaining (mean rank=304.75) were statistically significantly different, U=15,300, z=-2.61, p$_amp_$lt;0.009. Previous caring experience led to worse performance in this cohort. Emotional intelligence was not a useful indicator of performance. Lower scores on the social connection factor were associated

  14. Elemental analysis of chamber organic aerosol using an aerodyne high-resolution aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    P. S. Chhabra

    2010-05-01

    Full Text Available The elemental composition of laboratory chamber secondary organic aerosol (SOA from glyoxal uptake, α-pinene ozonolysis, isoprene photooxidation, single-ring aromatic photooxidation, and naphthalene photooxidation is evaluated using Aerodyne high-resolution time-of-flight mass spectrometer data. SOA O/C ratios range from 1.13 for glyoxal uptake experiments to 0.30–0.43 for α-pinene ozonolysis. The elemental composition of α-pinene and naphthalene SOA is also confirmed by offline mass spectrometry. The fraction of organic signal at m/z 44 is generally a good measure of SOA oxygenation for α-pinene/O3, isoprene/high-NOx, and naphthalene SOA systems. The agreement between measured and estimated O/C ratios tends to get closer as the fraction of organic signal at m/z 44 increases. This is in contrast to the glyoxal uptake system, in which m/z 44 substantially underpredicts O/C. Although chamber SOA has generally been considered less oxygenated than ambient SOA, single-ring aromatic- and naphthalene-derived SOA can reach O/C ratios upward of 0.7, well within the range of ambient PMF component OOA, though still not as high as some ambient measurements. The spectra of aromatic and isoprene-high-NOx SOA resemble that of OOA, but the spectrum of glyoxal uptake does not resemble that of any ambient organic aerosol PMF component.

  15. Exercise induced ST elevation and residual myocardial ischemia in previous myocardial infarction

    International Nuclear Information System (INIS)

    Shimonagata, Tsuyoshi; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Saito, Muneyasu; Sumiyoshi, Tetsuya

    1987-01-01

    The purpose of this study was to evaluate the clinical significance of stress induced ST elevation on infarcted area in 65 patients with previous myocardial infarction (single vessel disease) who had stress thallium scan. Stress induced ST changes on infarcted area were compared with quantitative assessment of myocardial ischemia (thallium ischemic score; TIS) and extent of myocardial infarction (defect score; DS) derived from circumferential profile analysis. In patients with previous myocardial infarction in less than 3 month from the onset (n = 36), left ventricular ejection fraction (LVEF) and extent of abnormal LV wall motion were not significantly different between patients with stress induced ST elevation ( ≥ 2 mm, n = 26) and those with stress induced ST elevation ( < 2 mm, n = 10), while, in patients with previous myocardial infarction in more than 3 month (n = 29), patients with stress induced ST elevation ( ≥ 2 mm, n = 15) showed left ventricular dyskinesis more frequently than those with ST elevation ( < 2 mm, n = 14). In addition, the former showed significantly higher DS and significantly lower TIS than the latter. In patients with previous myocardial infarction in less than 3 month, patients with ST elevation ( ≥ 2 mm, n = 15) with prominent upright T wave (n = 15) had transient thallium defect in infarcted area in 73 % and they had significantly higher LVEF and TIS than those with ST elevation ( < 2 mm, n = 11). These results indicated that ST elevation in infarcted area reflect different significance according to the recovery of injured myocardium and stress induced ST elevation with prominent upright T wave in infarcted area reflect residual myocardial ischemia in less than 3 month from the onset of myocardial infarction. (author)

  16. How to prevent type 2 diabetes in women with previous gestational diabetes?

    DEFF Research Database (Denmark)

    Pedersen, Anne Louise Winkler; Terkildsen Maindal, Helle; Juul, Lise

    2017-01-01

    OBJECTIVES: Women with previous gestational diabetes (GDM) have a seven times higher risk of developing type 2 diabetes (T2DM) than women without. We aimed to review the evidence of effective behavioural interventions seeking to prevent T2DM in this high-risk group. METHODS: A systematic review...... of RCTs in several databases in March 2016. RESULTS: No specific intervention or intervention components were found superior. The pooled effect on diabetes incidence (four trials) was estimated to: -5.02 per 100 (95% CI: -9.24; -0.80). CONCLUSIONS: This study indicates that intervention is superior...... to no intervention in prevention of T2DM among women with previous GDM....

  17. Fish quality – linking previous infections to the quality of consumers’ fillet

    DEFF Research Database (Denmark)

    The quality of the fish meat is dependent upon a wide range of biological and non-biological factors. In the present study it has been established that previous infections by Vibrio anguillarum in rainbow trout (Oncorhynchus mykiss) influence the quality of the fish meat (fillet) at slaughter more...... than after the fish have recovered from the infection. The texture of the fillet analysed by sensory analysis showed changes, which could be explained by previous tissue damage caused by the infection. These changes indicated formation of scars in affected tissue during the processes of tissue repair......, which gave rise to a more fibrous, tougher and flaky texture of the fillets....

  18. Technique for sparing previously irradiated critical normal structures in salvage proton craniospinal irradiation

    International Nuclear Information System (INIS)

    McDonald, Mark W; Wolanski, Mark R; Simmons, Joseph W; Buchsbaum, Jeffrey C

    2013-01-01

    Cranial reirradiation is clinically appropriate in some cases but cumulative radiation dose to critical normal structures remains a practical concern. The authors developed a simple technique in 3D conformal proton craniospinal irradiation (CSI) to block organs at risk (OAR) while minimizing underdosing of adjacent target brain tissue. Two clinical cases illustrate the use of proton therapy to provide salvage CSI when a previously irradiated OAR required sparing from additional radiation dose. The prior radiation plan was coregistered to the treatment planning CT to create a planning organ at risk volume (PRV) around the OAR. Right and left lateral cranial whole brain proton apertures were created with a small block over the PRV. Then right and left lateral “inverse apertures” were generated, creating an aperture opening in the shape of the area previously blocked and blocking the area previously open. The inverse aperture opening was made one millimeter smaller than the original block to minimize the risk of dose overlap. The inverse apertures were used to irradiate the target volume lateral to the PRV, selecting a proton beam range to abut the 50% isodose line against either lateral edge of the PRV. Together, the 4 cranial proton fields created a region of complete dose avoidance around the OAR. Comparative photon treatment plans were generated with opposed lateral X-ray fields with custom blocks and coplanar intensity modulated radiation therapy optimized to avoid the PRV. Cumulative dose volume histograms were evaluated. Treatment plans were developed and successfully implemented to provide sparing of previously irradiated critical normal structures while treating target brain lateral to these structures. The absence of dose overlapping during irradiation through the inverse apertures was confirmed by film. Compared to the lateral X-ray and IMRT treatment plans, the proton CSI technique improved coverage of target brain tissue while providing the least

  19. Pollution monitoring by dosimetry and passive diffusion sampling for evaluation of environmental conditions for paintings in microclimate frames

    DEFF Research Database (Denmark)

    Grøntoft, Terje; Odlyha, Marianne; Mottner, P.

    2010-01-01

    from a synthetic polymer and the Resin Mastic coated Piezo electric Quartz Crystals (RM-PQC) respond to photo-oxidation and showed higher values outside than inside the mc-frames. Two other dosimeters, the Glass Slide Dosimeter (GSD) and the Lead coated Piezo electric Quartz Crystals (L-PQC) respond......Pollutants and their potential degradation of paintings have been measured for the first time in microclimate frames (mc-frames), which are used to protect paintings. The pollutants that were measured include both inorganic pollutants, which originate mainly from external sources, and organic...... samplers were used together with different types of dosimeters. Results show that the dosimeters respond to either the photo-oxidizing conditions or the level of volatile organic acids in the environments both in the museums and within the mc-frames. Two dosimeters, the Early Warning Organic (EWO) made...

  20. Aortic pseudoaneurysm detected on external jugular venous distention following a Bentall procedure 10 years previously.

    Science.gov (United States)

    Fukunaga, Naoto; Shomura, Yu; Nasu, Michihiro; Okada, Yukikatsu

    2010-11-01

    An asymptomatic 49-year-old woman was admitted for the purpose of surgery for aortic pseudoaneurysm. She had Marfan syndrome and had undergone an emergent Bentall procedure 10 years previously. About six months previously, she could palpate distended bilateral external jugular veins, which became distended only in a supine position and without any other symptoms. Enhanced computed tomography revealed an aortic pseudoaneurysm originating from a previous distal anastomosis site. During induction of general anesthesia in a supine position, bilateral external jugular venous distention was remarkable. Immediately after a successful operation, distention completely resolved. The present case emphasizes the importance of physical examination leading to a diagnosis of asymptomatic life-threatening diseases in patients with a history of previous aortic surgery.

  1. Relationship of deer and moose populations to previous winters' snow

    Science.gov (United States)

    Mech, L.D.; McRoberts, R.E.; Peterson, R.O.; Page, R.E.

    1987-01-01

    (1) Linear regression was used to relate snow accumulation during single and consecutive winters with white-tailed deer (Odocoileus virginianus) fawn:doe ratios, mosse (Alces alces) twinning rates and calf:cow ratios, and annual changes in deer and moose populations. Significant relationships were found between snow accumulation during individual winters and these dependent variables during the following year. However, the strongest relationships were between the dependent variables and the sums of the snow accumulations over the previous three winters. The percentage of the variability explained was 36 to 51. (2) Significant relationships were also found between winter vulnerability of moose calves and the sum of the snow accumulations in the current, and up to seven previous, winters, with about 49% of the variability explained. (3) No relationship was found between wolf numbers and the above dependent variables. (4) These relationships imply that winter influences on maternal nutrition can accumulate for several years and that this cumulative effect strongly determines fecundity and/or calf and fawn survivability. Although wolf (Canis lupus L.) predation is the main direct mortality agent on fawns and calves, wolf density itself appears to be secondary to winter weather in influencing the deer and moose populations.

  2. [Electronic cigarettes - effects on health. Previous reports].

    Science.gov (United States)

    Napierała, Marta; Kulza, Maksymilian; Wachowiak, Anna; Jabłecka, Katarzyna; Florek, Ewa

    2014-01-01

    Currently very popular in the market of tobacco products have gained electronic cigarettes (ang. E-cigarettes). These products are considered to be potentially less harmful in compared to traditional tobacco products. However, current reports indicate that the statements of the producers regarding to the composition of the e- liquids not always are sufficient, and consumers often do not have reliable information on the quality of the product used by them. This paper contain a review of previous reports on the composition of e-cigarettes and their impact on health. Most of the observed health effects was related to symptoms of the respiratory tract, mouth, throat, neurological complications and sensory organs. Particularly hazardous effects of the e-cigarettes were: pneumonia, congestive heart failure, confusion, convulsions, hypotension, aspiration pneumonia, face second-degree burns, blindness, chest pain and rapid heartbeat. In the literature there is no information relating to passive exposure by the aerosols released during e-cigarette smoking. Furthermore, the information regarding to the use of these products in the long term are not also available.

  3. Wives without husbands: gendered vulnerability to sexually transmitted infections among previously married women in India.

    Science.gov (United States)

    Walters, Kimberly; Dandona, Rakhi; Walters, Lawrence C; Lakshmi, Vemu; Dandona, Lalit; Schneider, John A

    2012-01-01

    Using population-based and family structural data from a high HIV-prevalence district of Southern India, this paper considers four suggested social scenarios used to explain the positive correlation between HIV prevalence and previously married status among Indian women: (1) infection from and then bereavement of an infected husband; (2) abandonment after husbands learn of their wives' HIV status; (3) economic instability after becoming previously married, leading women to seek financial support through male partners; and (4) the social status of being previously married exposing women to sexual harassment and predation. By also considering seroprevalence of two other common sexually transmitted infections (STIs), herpes and syphilis, in a combined variable with HIV, we limit the likelihood of the first two scenarios accounting for the greater part of this correlation. Through a nuanced analysis of household residences patterns (family structure), standard of living, and education, we also limit the probability that scenario three explains a greater portion of the correlation. Scenario four emerges as the most likely explanation for this correlation, recognizing that other scenarios are also possible. Further, the interdisciplinary literature on the social position of previously married women in India strongly supports the suggestion that, as a population, previously married women are sexually vulnerable in India. Previously married status as an STI risk factor requires further biosocial research and warrants concentrated public health attention.

  4. AbobotulinumtoxinA Efficacy and Safety in Children With Equinus Foot Previously Treated With Botulinum Toxin.

    Science.gov (United States)

    Dabrowski, Edward; Bonikowski, Marcin; Gormley, Mark; Volteau, Magali; Picaut, Philippe; Delgado, Mauricio R

    2018-05-01

    The effects of botulinum toxin are transient, and repeat injections are required in children with lower-limb spasticity. However, the efficacy of botulinum toxin in patients who have received previous injections has remained largely unexplored. We present subgroup analyses of a phase III study conducted in ambulatory children (aged two to 17) with spastic equinus foot. Patients were randomized to single doses of abobotulinumtoxinA 10 U/kg/leg, 15 U/kg/leg, or placebo injected into the gastrocnemius-soleus complex (one or both legs). The first analysis was prespecified to review the effect of abobotulinumtoxinA in children previously treated with botulinum toxin versus those children new to the treatment; a second post hoc analysis evaluated the effect of abobotulinumtoxinA in children who changed botulinum toxin formulation. Of the 241 randomized patients, 113 had previously received botulinum toxin, including 86 who had been treated with another formulation. In both analyses, muscle tone (Modified Ashworth Scale) and the Physicians Global Assessment, at week 4, improved with abobotulinumtoxinA treatment versus placebo, regardless of baseline botulinum toxin status. Placebo responses in patients new to treatment were consistently higher than in the previously treated group. These results demonstrate similar abobotulinumtoxinA efficacy and safety profiles in children with spasticity who are new to botulinum toxin treatment and those children who were previously treated. The efficacy and safety of abobotulinumtoxinA treatment in these previously treated patients were comparable with the overall trial population, indicating that doses of 10 and 15 U/kg/leg are suitable starting doses for children with spasticity regardless of the previous botulinum toxin preparation used. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Survival of dental implants placed in sites of previously failed implants.

    Science.gov (United States)

    Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    2017-11-01

    To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. The Effects of the Previous Outcome on Probabilistic Choice in Rats

    Science.gov (United States)

    Marshall, Andrew T.; Kirkpatrick, Kimberly

    2014-01-01

    This study examined the effects of previous outcomes on subsequent choices in a probabilistic-choice task. Twenty-four rats were trained to choose between a certain outcome (1 or 3 pellets) versus an uncertain outcome (3 or 9 pellets), delivered with a probability of .1, .33, .67, and .9 in different phases. Uncertain outcome choices increased with the probability of uncertain food. Additionally, uncertain choices increased with the probability of uncertain food following both certain-choice outcomes and unrewarded uncertain choices. However, following uncertain-choice food outcomes, there was a tendency to choose the uncertain outcome in all cases, indicating that the rats continued to “gamble” after successful uncertain choices, regardless of the overall probability or magnitude of food. A subsequent manipulation, in which the probability of uncertain food varied within each session as a function of the previous uncertain outcome, examined how the previous outcome and probability of uncertain food affected choice in a dynamic environment. Uncertain-choice behavior increased with the probability of uncertain food. The rats exhibited increased sensitivity to probability changes and a greater degree of win–stay/lose–shift behavior than in the static phase. Simulations of two sequential choice models were performed to explore the possible mechanisms of reward value computations. The simulation results supported an exponentially decaying value function that updated as a function of trial (rather than time). These results emphasize the importance of analyzing global and local factors in choice behavior and suggest avenues for the future development of sequential-choice models. PMID:23205915

  7. Increased risk of default among previously treated tuberculosis cases in the Western Cape Province, South Africa.

    Science.gov (United States)

    Marx, F M; Dunbar, R; Hesseling, A C; Enarson, D A; Fielding, K; Beyers, N

    2012-08-01

    To investigate, in two urban communities with high tuberculosis (TB) incidence and high rates of TB recurrence, whether a history of previous TB treatment is associated with treatment default. Retrospective cohort study of TB cases with an episode of treatment recorded in the clinic-based treatment registers between 2002 and 2007. Probabilistic record linkage was used to ascertain treatment history of TB cases back to 1996. Based on the outcome of their most recent previous treatment episode, previously treated cases were compared to new cases regarding their risk of treatment default. Previous treatment success (adjusted odds ratio [aOR] 1.79; 95%CI 1.17-2.73), previous default (aOR 6.18, 95%CI 3.68-10.36) and previous failure (aOR 9.72, 95%CI 3.07-30.78) were each independently associated with treatment default (P default were male sex (P = 0.003) and age 19-39 years (P risk of treatment default, even after previous successful treatment. This finding is of particular importance in a setting where recurrent TB is very common. Adherence to treatment should be ensured in new and retreatment cases to increase cure rates and reduce transmission of TB in the community.

  8. Modular femoral component for conversion of previous hip surgery in total hip arthroplasty.

    Science.gov (United States)

    Goldstein, Wayne M; Branson, Jill J

    2005-09-01

    The conversion of previous hip surgery to total hip arthroplasty creates a durable construct that is anatomically accurate. Most femoral components with either cemented or cementless design have a fixed tapered proximal shape. The proximal femoral anatomy is changed due to previous hip surgery for fixation of an intertrochanteric hip fracture, proximal femoral osteotomy, or a fibular allograft for avascular necrosis. The modular S-ROM (DePuy Orthopaedics Inc., Warsaw, Ind) hip stem accommodates these issues and independently prepares the proximal and distal portion of the femur. In preparation and implantation, the S-ROM hip stem creates less hoop stresses on potentially fragile stress risers from screws and thin bone. The S-ROM hip stem also prepares a previously distorted anatomy by milling through cortical bone that can occlude the femoral medullar canals and recreate proper femoral anteversion and reduces the risk of intraoperative or postoperative periprosthetic fracture due to the flexible titanium-slotted stem. The S-ROM femoral stem is recommended for challenging total hip reconstructions.

  9. Photodegradation of bisphenol A polycarbonate

    NARCIS (Netherlands)

    Diepens, M.; Gijsman, P.

    2007-01-01

    When bisphenol A polycarbonate is subjected to weathering conditions this polymer shows two different degradation mechanisms depending on the used irradiation wavelengths, i.e. photo-oxidation and photo-Fries rearrangement. The relative importance of these mechanisms in outdoor exposure conditions

  10. Origin of choriocarcinoma in previous molar pregnancy proved by DNA analysis

    International Nuclear Information System (INIS)

    Vojtassak, J.; Repiska, V.; Konecna, B.; Zajac, V.; Korbel, M.; Danihel, L.

    1996-01-01

    A 17-year old woman had in a short time period (seven months) a very exciting reproduction history. Molar pregnancy in December 1993, choriocarcinoma in January 1994 and induced abortion in June 1994. DNA analysis proved the origin of the choriocarcinoma in the previous molar pregnancy. (author)

  11. Influence of previous knowledge in Torrance tests of creative thinking

    OpenAIRE

    Aranguren, María; Consejo Nacional de Investigaciones Científicas y Técnicas CONICET

    2015-01-01

    The aim of this work is to analyze the influence of study field, expertise and recreational activities participation in Torrance Tests of Creative Thinking (TTCT, 1974) performance. Several hypotheses were postulated to explore the possible effects of previous knowledge in TTCT verbal and TTCT figural university students’ outcomes. Participants in this study included 418 students from five study fields: Psychology;Philosophy and Literature, Music; Engineering; and Journalism and Advertisin...

  12. Females use self-referent cues to avoid mating with previous mates.

    Science.gov (United States)

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-12-07

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry.

  13. Validation of the Online version of the Previous Day Food Questionnaire for schoolchildren

    Directory of Open Access Journals (Sweden)

    Raquel ENGEL

    Full Text Available ABSTRACT Objective To evaluate the validity of the web-based version of the Previous Day Food Questionnaire Online for schoolchildren from the 2nd to 5th grades of elementary school. Methods Participants were 312 schoolchildren aged 7 to 12 years of a public school from the city of Florianópolis, Santa Catarina, Brazil. Validity was assessed by sensitivity, specificity, as well as by agreement rates (match, omission, and intrusion rates of food items reported by children on the Previous Day Food Questionnaire Online, using direct observation of foods/beverages eaten during school meals (mid-morning snack or afternoon snack on the previous day as the reference. Multivariate multinomial logistic regression analysis was used to evaluate the influence of participants’ characteristics on omission and intrusion rates. Results The results showed adequate sensitivity (67.7% and specificity (95.2%. There were low omission and intrusion rates of 22.8% and 29.5%, respectively when all food items were analyzed. Pizza/hamburger showed the highest omission rate, whereas milk and milk products showed the highest intrusion rate. The participants who attended school in the afternoon shift presented a higher probability of intrusion compared to their peers who attended school in the morning. Conclusion The Previous Day Food Questionnaire Online possessed satisfactory validity for the assessment of food intake at the group level in schoolchildren from the 2nd to 5th grades of public school.

  14. [Parathyroid cancer in a patient with previous history of hypernephroma: a clinical case].

    Science.gov (United States)

    Martín Navarro, J; Mendoza, E; Mateos, P; Cereceda, A; Coca, S

    2007-01-01

    We report the clinical case of a 55 year-old male patient, with a previous history of nephrectomy by hypernephroma sixteen years ago, first presenting hypercalcemia and rising of intact parathyroid hormone (iPTH) levels. A localization study revealed an intrathyroid nodule with cystic appearance. After undergoing a hemi-thyroidectomy, the patient is diagnosed with parathyroid carcinoma. This article analyzes previously published cases presenting parathyroidal pathologies associated with hypernephroma. A broader differential diagnosis--including the screening of parathyroidal pathologies should be considered in patients with hypercalcemia and hypernephroma.

  15. Advanced Wastewater Photo-oxidation System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Pioneer Astronautics proposes an advanced photocatalytic oxidation reactor for enhancing the reliability and performance of Water Recovery Post Processing systems...

  16. Streptococcus agalactiae endocarditis presenting as acalculous cholecystitis in a previously well woman.

    LENUS (Irish Health Repository)

    Brewer, Linda

    2013-01-01

    This case report describes the unusual presentation of a previously very well woman with Streptococcus agalactiae endocarditis in the emergency department. History, examination and preliminary laboratory and radiological investigations supported a diagnosis of acalculous cholecystitis, for which she was given intravenous broad spectrum antimicrobial therapy. One day following admission, the patient deteriorated and became unresponsive. Subsequent MRI of the brain revealed multiple bihemispheric cerebral emboli and a large, mobile mitral valve thrombus was visualised on her transoesophageal echocardiogram. S agalactiae was cultured from venous blood samples and her antimicrobial cover was adjusted accordingly. Despite her presumed guarded prognosis, this patient made a remarkable recovery. To our knowledge, the association of S agalactiae endocarditis with acalculous cholecystitis has not been previously described.

  17. Granulomatous lobular mastitis: report of a case with previously undescribed histopathological abnormalities.

    Science.gov (United States)

    Axelsen, R A; Reasbeck, P

    1988-10-01

    A 41-yr-old multiparous woman presented with a discrete breast lump which proved histologically to be an example of granulomatous lobular mastitis. The clinical and histological features were similar to those noted in previous reports. Additional histological features in the present case were an intense mononuclear cell infiltration of lobular and ductal epithelium, associated with nuclear fragments morphologically suggestive of apoptosis. These appearances, which have not previously been described, are illustrated, together with the more classical features of the condition well demonstrated by the present case. The novel histological features noted here suggest that the development of granulomatous lobular mastitis may be at least in part immunologically mediated, and that the cellular infiltrates seen may be a manifestation of cell-mediated destruction of mammary epithelium.

  18. Initial results of CyberKnife treatment for recurrent previously irradiated head and neck cancer

    International Nuclear Information System (INIS)

    Himei, Kengo; Katsui, Kuniaki; Yoshida, Atsushi

    2003-01-01

    The purpose of this study was to evaluate the efficacy of CyberKnife for recurrent previously irradiated head and neck cancer. Thirty-one patients with recurrent previously irradiated head and neck cancer were treated with a CyberKnife from July 1999 to March 2002 at Okayama Kyokuto Hospital were retrospectively studied. The accumulated dose was 28-80 Gy (median 60 Gy). The interval between CyberKnife treatment and previous radiotherapy was 0.4-429.5 months (median 16.3 months). Primary lesions were nasopharynx: 7, maxillary sinus: 6, tongue: 5, ethmoid sinus: 3, and others: 1. The pathology was squamous cell carcinoma: 25, adenoid cystic carcinoma: 4, and others: 2. Symptoms were pain: 8, and nasal bleeding: 2. The prescribed dose was 15.0-40.3 Gy (median 32.3 Gy) as for the marginal dose. The response rate (complete response (CR)+partial response (PR)) and local control rate (CR+PR+no change (NC)) was 74% and 94% respectively. Pain disappeared for 4 cases, relief was obtained for 4 cases and no change for 2 cases and nasal bleeding disappeared for 2 cases for an improvement of symptoms. An adverse effects were observed as mucositis in 5 cases and neck swelling in one case. Prognosis of recurrent previously irradiated head and neck cancer was estimated as poor. Our early experience shows that CyberKnife is expected to be feasible treatment for recurrent previously irradiated head and neck cancer, and for the reduction adverse effects and maintenance of useful quality of life (QOL) for patients. (author)

  19. Pulmonary Aspergillosis in a Previously Healthy 13-Year-Old Boy

    Directory of Open Access Journals (Sweden)

    Jonathan H. Rayment

    2016-01-01

    Full Text Available Chronic granulomatous disease (CGD is a rare, polygenic primary immunodeficiency. In this case report, we describe a previously healthy 13-year-old boy who presented with multifocal pulmonary aspergillosis and was subsequently diagnosed with an autosomal recessive form of chronic granulomatous disease. CGD has a variable natural history and age of presentation and should be considered when investigating a patient with recurrent or severe infections with catalase-positive organisms.

  20. [Meningitis and white matter lesions due to Streptococcus mitis in a previously healthy child].

    Science.gov (United States)

    Yiş, Reyhan; Yüksel, Ciğdem Nükhet; Derundere, Umit; Yiş, Uluç

    2011-10-01

    Streptococcus mitis, an important member of viridans streptococci, is found in the normal flora of the oropharynx, gastrointestinal tract, female genital tract and skin. Although it is of low pathogenicity and virulence, it may cause serious infections in immunocompromised patients. Meningitis caused by S.mitis has been described in patients with previous spinal anesthesia, neurosurgical procedure, malignancy, bacterial endocarditis with neurological complications and alcoholics, but it is rare in patients who are previously healthy. In this report, a rare case of meningoencephalitis caused by S.mitis developed in a previously healthy child has been presented. A previously healthy eight-year-old girl who presented with fever, altered state of consciousness, and headache was hospitalized in intensive care unit with the diagnosis of meningitis. Past history revealed that she was treated with amoxicillin-clavulanate for acute sinusitis ten days before her admission. Whole blood count revealed the followings: hemoglobin 13 g/dl, white blood cell count 18.6 x 109/L (90% neutrophils), platelet count 200 x 109/L and 150 leucocytes were detected on cerebrospinal fluid (CSF) examination. Protein and glucose levels of CSF were 80 mg/dl and 40 mg/dl (concomitant blood glucose 100 mg/dl), respectively. Brain magnetic resonance imaging (MRI) revealed widespread white matter lesions, and alpha-hemolytic streptococci were grown in CSF culture. The isolate was identified as S.mitis with conventional methods, and also confirmed by VITEK2 (bioMerieux, France) and API 20 STREP (bioMerieux, France) systems. Isolate was found susceptible to penicillin, erythromycin, clindamycin, tetracycline, cefotaxime, vancomycin and chloramphenicol. Regarding the etiology, echocardiography revealed no vegetation nor valve pathology, and peripheral blood smear showed no abnormality. Immunoglobulin and complement levels were within normal limits. Ongoing inflammation in maxillary sinuses detected in