Science.gov

Sample records for a-533-838 carbazole violet

  1. 75 FR 25209 - Carbazole Violet Pigment 23 from India: Rescission of Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ... International Trade Administration A-533-838 Carbazole Violet Pigment 23 from India: Rescission of... duty order on carbazole violet pigment 23 (CVP 23) from India for the period of December 1, 2008...) (Initiation Notice). We initiated the review with respect to Meghmani Pigments (Meghmani) based on its...

  2. 21 CFR 73.3107 - Carbazole violet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... intended coloring effect. (2) Authorization for this use shall not be construed as waiving any of...

  3. 21 CFR 73.3107 - Carbazole violet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... intended coloring effect. (2) Authorization for this use shall not be construed as waiving any of...

  4. 75 FR 14468 - Carbazole Violet Pigment 23 From China and India

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... COMMISSION Carbazole Violet Pigment 23 From China and India AGENCY: United States International Trade... carbazole violet pigment 23 from India and the antidumping duty orders on carbazole violet pigment 23 from... whether revocation of the countervailing duty order on carbazole violet pigment 23 from India and...

  5. 75 FR 52930 - Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping Duty Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping... changed-circumstances review of the antidumping duty order on carbazole violet pigment 23 from India to.... See Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty...

  6. 76 FR 24855 - Carbazole Violet Pigment 23 From India: Rescission of Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Rescission of Administrative Review... carbazole violet pigment 23 (CVP 23) from India for the period of December 1, 2009, through November 30... Antidumping Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77988 (December 29, 2004). On January...

  7. 75 FR 27815 - Carbazole Violet Pigment 23 From China and India; Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... (Review) Carbazole Violet Pigment 23 From China and India; Determinations On the basis of the record \\1... countervailing duty order on carbazole violet pigment 23 from India would be likely to lead to continuation or... that revocation of the antidumping duty orders on carbazole violet pigment 23 from China and...

  8. 75 FR 33243 - Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty... India for the period January 1, 2007, through December 31, 2007. See Carbazole Violet Pigment 23 from India: Preliminary Results of Countervailing Duty Administrative Review, 75 FR 977 (January 7,...

  9. 75 FR 29719 - Carbazole Violet Pigment 23 From India: Continuation of Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Continuation of Countervailing Duty.... See Notice of Countervailing Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77995 (December... the CVD order on CVP-23 from India pursuant to section 751(c) of the Tariff Act of 1930, as...

  10. 75 FR 38076 - Carbazole Violet Pigment 23 from India: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... International Trade Administration Carbazole Violet Pigment 23 from India: Final Results of Antidumping Duty... administrative review of the antidumping duty order on carbazole violet pigment 23 (CVP 23) from India. The... Pigment 23 from India: Preliminary Results of Antidumping Duty Administrative Review, 74 FR...

  11. 75 FR 34699 - Carbazole Violet Pigment 23 from India: Rescission of Countervailing Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... International Trade Administration Carbazole Violet Pigment 23 from India: Rescission of Countervailing Duty... opportunity to request an administrative review of the countervailing duty order on Carbazole Violet Pigment..., 2009, we received a request from Meghmani Pigments requesting an administrative review of...

  12. 75 FR 25840 - Carbazole Violet Pigment 23 from the People's Republic of China: Extension of Time Limit for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... International Trade Administration Carbazole Violet Pigment 23 from the People's Republic of China: Extension of... preliminary results of the administrative review of the antidumping duty order on carbazole violet pigment 23.... See Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary Results...

  13. 76 FR 55003 - Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary Intent To Rescind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... International Trade Administration Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary... conducting an administrative review of the antidumping duty order on carbazole violet pigment 23 (CVP 23... on CVP 23 from the PRC. See Antidumping Duty Order: Carbazole Violet Pigment 23 From the...

  14. 77 FR 1463 - Carbazole Violet Pigment 23 From the People's Republic of China: Final Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-10

    ... International Trade Administration Carbazole Violet Pigment 23 From the People's Republic of China: Final... carbazole violet pigment 23 (CVP-23) from the People's Republic of China (PRC).\\1\\ This administrative... Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary Intent To Rescind...

  15. 75 FR 62765 - Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty Changed-Circumstances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty.... See Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping Duty Changed..., water) are not included within the scope of the order. The merchandise subject to the order...

  16. 75 FR 29718 - Carbazole Violet Pigment 23 From India and the People's Republic of China: Continuation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... International Trade Administration Carbazole Violet Pigment 23 From India and the People's Republic of China... carbazole violet pigment 23 (CVP-23) from India and the People's Republic of China (PRC) would likely lead... and the ITC instituted sunset reviews of the antidumping duty orders on CVP-23 from India and the...

  17. 75 FR 10759 - Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty Changed-Circumstances Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... International Trade Administration Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty... antidumping duty order on carbazole violet pigment 23 from India with respect to Meghmani Pigments. EFFECTIVE... 23 (CVP 23) from India. See Notice of Amended Final Determination of Sales at Less Than Fair...

  18. 75 FR 23239 - Carbazole Violet Pigment 23 From India: Extension of Time Limit for Final Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Carbazole Violet Pigment 23 From India: Extension of Time Limit for Final... administrative review of the antidumping duty order on CVP 23 from India. See Carbazole Violet Pigment 23...

  19. 75 FR 977 - Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing... pigment 23 (CVP-23) from India for the period January 1, 2007, through December 31, 2007. We preliminarily... Pigment 23 from India, 69 FR 77995 (December 29, 2004) (CVP-23 Order). On December 1, 2008, the...

  20. 75 FR 12497 - Carbazole Violet Pigment 23 from India and the People's Republic of China: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... International Trade Administration Carbazole Violet Pigment 23 from India and the People's Republic of China...) from India and the People's Republic of China (PRC) pursuant to section 751(c) of the Tariff Act of... reviews of the antidumping duty orders on CVP 23 from India and the PRC\\1\\ pursuant to section 751(c)...

  1. 75 FR 26716 - Carbazole Violet Pigment 23 from India: Extension of Time Limit for Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ... [Federal Register Volume 75, Number 91 (Wednesday, May 12, 2010)] [Notices] [Page 26716] [FR Doc No: 2010-11320] DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23 from India: Extension of Time Limit for Final Results of Countervailing Duty Administrative Review AGENCY: Import...

  2. 75 FR 13257 - Carbazole Violet Pigment 23 from India: Final Results of the Expedited Five-year (Sunset) Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... International Trade Administration Carbazole Violet Pigment 23 from India: Final Results of the Expedited Five... Pigment 23 (CVP-23) ] from India pursuant to section 751(c) of the Tariff Act of 1930, as amended (the Act... merchandise includes the crude pigment in any form (e.g., dry powder, paste, wet cake) and finished pigment...

  3. 76 FR 5137 - Initiation of Antidumping and Countervailing Duty Administrative Reviews

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ....A. INDIA: Carbazole Violet Pigment 23 A-533-838 12/1/09-11/30/10 Meghmani Pigments \\3\\ Certain Hot... Tata Steel Limited THE PEOPLE'S REPUBLIC OF CHINA: Carbazole 12/1/09-11/30/10 Violet Pigment 23 \\4\\ A... qualify for a separate rate, all other exporters of Carbazole Violet Pigment 23 from the People's...

  4. 75 FR 36630 - Carbazole Violet Pigment 23 from the People's Republic of China: Final Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-28

    ... calculation for Trust Chem. Specifically, in calculating the surrogate financial ratios, the Department has..., general and administrative expenses (SG&A). As a result, the surrogate financial ratios for factory... Violet Pigment 23 from the People's Republic of China: Surrogate Values for the Final Results,''...

  5. 77 FR 71579 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... INDIA: Carbazole Violet Pigment 23 12/1/11-11/30/12 A-533-838 INDIA: Certain Hot-Rolled Carbon Steel...-583-815 THE PEOPLE'S REPUBLIC OF CHINA: Cabazole Violet Pigments 23 12/1/11-11/30/12 A-570-892 Cased...-813 INDIA: Carbazole Violet Pigment 23 1/1/11-12/31/11 C-533-839 INDIA: Certain Hot-Rolled...

  6. 21 CFR 73.3107 - Carbazole violet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... additive in contact lenses in amounts not to exceed the minimum reasonably required to accomplish the... respect to the contact lens in which the color additive is used. (c) Labeling. The label of the...

  7. 21 CFR 73.3107 - Carbazole violet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... additive in contact lenses in amounts not to exceed the minimum reasonably required to accomplish the... respect to the contact lens in which the color additive is used. (c) Labeling. The label of the...

  8. 21 CFR 73.3107 - Carbazole violet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... additive in contact lenses in amounts not to exceed the minimum reasonably required to accomplish the... respect to the contact lens in which the color additive is used. (c) Labeling. The label of the...

  9. Method for metabolizing carbazole in petroleum

    DOEpatents

    Kayser, Kevin J.; Kilbane, II, John J.

    2005-09-13

    A method for selective cleavage of C--N bonds genes that encode for at least one enzyme suitable for conversion of carbazole to 2-aminobiphenyl-2,3-diol are combined with a gene encoding an amidase suitable for selectively cleaving a C--N bond in 2-aminobiphenyl-2,3-diol, forming an operon that encodes for cleavage of both C--N bonds of said carbazole. The operon is inserted into a host culture which, in turn, is contacted with the carbazole, resulting in selective cleavage of both C--N bonds of the carbazole. Also disclosed is a new microorganism that expresses a carbazole degradation trait constitutively and a method for degrading carbazole employing this microorganism.

  10. 27 CFR 21.111 - Gentian violet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....111 Gentian violet. (a) Gentian violet (methyl violet, methylrosaniline chloride) occurs as a dark.... (d) Insoluble matter. Not to exceed 0.25 percent when tested by the following method: Transfer...

  11. 27 CFR 21.111 - Gentian violet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....111 Gentian violet. (a) Gentian violet (methyl violet, methylrosaniline chloride) occurs as a dark.... (d) Insoluble matter. Not to exceed 0.25 percent when tested by the following method: Transfer...

  12. 27 CFR 21.111 - Gentian violet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....111 Gentian violet. (a) Gentian violet (methyl violet, methylrosaniline chloride) occurs as a dark.... (d) Insoluble matter. Not to exceed 0.25 percent when tested by the following method: Transfer...

  13. 27 CFR 21.111 - Gentian violet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....111 Gentian violet. (a) Gentian violet (methyl violet, methylrosaniline chloride) occurs as a dark.... (d) Insoluble matter. Not to exceed 0.25 percent when tested by the following method: Transfer...

  14. 27 CFR 21.111 - Gentian violet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....111 Gentian violet. (a) Gentian violet (methyl violet, methylrosaniline chloride) occurs as a dark.... (d) Insoluble matter. Not to exceed 0.25 percent when tested by the following method: Transfer...

  15. Carbazole hydroxylation by the filamentous fungi of the Cunninghamella species.

    PubMed

    Zawadzka, K; Bernat, P; Felczak, A; Lisowska, K

    2015-12-01

    Nitrogen heterocyclic compounds, especially carbazole, quinolone, and pyridine are common types of environmental pollutants. Carbazole has a toxic influence on living organisms, and the knowledge of its persistence and bioconversion in ecosystems is still not complete. There is an increasing interest in detoxification of hazardous xenobiotics by microorganisms. In this study, the ability of three filamentous fungi of the Cunninghamella species to eliminate carbazole was evaluated. The Cunninghamella elegans IM 1785/21Gp and Cunninghamella echinulata IM 2611 strains efficiently removed carbazole. The IM 1785/21Gp and IM 2611 strains converted 93 and 82 % of the initial concentration of the xenobiotic (200 mg L(-1)) after 120 h incubation. 2-Hydroxycarbazole was for the first time identified as a carbazole metabolite formed by the filamentous fungi of the Cunninghamella species. There was no increase in the toxicity of the postculture extracts toward Artemia franciscana. Moreover, we showed an influence of carbazole on the phospholipid composition of the cells of the tested filamentous fungi, which indicated its harmful effect on the fungal cell membrane. The most significant modification of phospholipid levels after the cultivation of filamentous fungi with the addition of carbazole was showed for IM 1785/21Gp strain.

  16. Microgap ultra-violet detector

    DOEpatents

    Wuest, Craig R.; Bionta, Richard M.

    1994-01-01

    A microgap ultra-violet detector of photons with wavelengths less than 400 run (4000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse.

  17. Microgap ultra-violet detector

    DOEpatents

    Wuest, C.R.; Bionta, R.M.

    1994-09-20

    A microgap ultra-violet detector of photons with wavelengths less than 400 run (4,000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap is disclosed. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse. 2 figs.

  18. Antitumoral activity of trisubstituted dihydrobenzo(a)carbazoles. Part III.

    PubMed

    Segall, A; Pizzorno, M T

    2000-10-01

    Two recently synthesized, trisubstituted dihydrobenzo(a)carbazoles were investigated regarding their anti-HIV and antitumoral activity. The compounds showed some activity against melanoma, renal cancer and breast cancer cell lines.

  19. Cytogenetic toxicity of gentian violet and crystal violet on mammalian cells in vitro.

    PubMed

    Au, W; Pathak, S; Collie, C J; Hsu, T C

    1978-11-01

    The cytogenetic toxicity of gentian violet in Chinese hamster CHO cells in vitro has been studied by analyzing (1) squash preparations from direct fixation for recording mitotic anomalies and (2) air-dried preparations (with colcemid--hypotonic pretreatments) for recording metaphase chromosome aberrations. It was concluded that this compound is a mitotic poison as well as a clastogen in vitro. Its clastogenic property was confirmed in 5 other different mammalian cel types. 10 samples of different gentian violet and crystal violet were surveyed and all were shown to be clastogenic. Unless in vivo studies prove otherwise, gentian violet and crystal violet should be regarded as biohazardous substances.

  20. 21 CFR 73.2775 - Manganese violet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good...

  1. 21 CFR 73.2775 - Manganese violet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good...

  2. 21 CFR 73.2775 - Manganese violet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good...

  3. 21 CFR 73.2775 - Manganese violet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... less than 93 percent. (c) Uses and restrictions. Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good...

  4. Carbazole degradation in the soil microcosm by tropical bacterial strains

    PubMed Central

    Salam, Lateef B.; Ilori, Matthew O.; Amund, Olukayode O.

    2015-01-01

    In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonas sp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g) after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized) soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg), 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg), 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1 h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days) and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments. PMID:26691461

  5. Tuning the ambipolar charge transport properties of tricyanovinyl-substituted carbazole-based materials.

    PubMed

    Reig, Marta; Bagdziunas, Gintautas; Volyniuk, Dmytro; Grazulevicius, Juozas V; Velasco, Dolores

    2017-03-01

    A series of push-pull carbazole-based compounds has been experimentally and theoretically characterized in combination with the X-ray analysis of the corresponding single crystals. The introduction of the strong electron-withdrawing tricyanovinyl group in the carbazole core affords electron-transporting ability in addition to the characteristic hole-transporting properties exhibited by donor carbazole derivatives.

  6. Carbazole-based polymers for organic photovoltaic devices.

    PubMed

    Li, Jiaoli; Grimsdale, Andrew C

    2010-07-01

    Polymers based upon 2,7-disubstituted carbazole have recently become of great interest as electron-donating materials in organic photovoltaic devices. In this tutorial review the synthesis of such polymers and their relative performances in such devices are surveyed. In particular structure-property relationships are investigated and the potential for the rational design of materials for high efficiency solar cells is discussed. In the case of the 2,7-carbazole homopolymer it has been found that electron acceptors other than fullerenes produce higher energy conversion efficiencies. To get around possible problems with the build-up of charge density at the 3- and 6-positions and to improve the solar light harvesting ability of the polymers by reducing the bandgap, ladder- and step-ladder type 2,7-carbazole polymers have been synthesised. The fully ladderised polymers gave very poor results in devices, but efficiencies of over 1% have been obtained from a step-ladder polymer with a diindenocarbazole monomer unit. Donor-acceptor copolymers containing 2,7-carbazole donors and various electron-accepting comonomer units have been prepared. An efficiency of 6% has been reported from a device using such a copolymer and by suitable choice of the acceptor comonomer, polymers can be designed with potential theoretical power conversion efficiencies of 10%. While such efficiencies remain to be obtained, the results to date certainly suggest that carbazole-based polymers and copolymers are among the most promising materials yet proposed for obtaining high efficiency organic solar cells.

  7. Halogenated carbazoles induce cardiotoxicity in developing zebrafish (Danio rerio) embryos.

    PubMed

    Fang, Mingliang; Guo, Jiehong; Chen, Da; Li, An; Hinton, David E; Dong, Wu

    2016-10-01

    Halogenated carbazoles are increasingly identified as a novel class of environmental contaminants. However, no in vivo acute toxicity information on those compounds was available. In the present study, an in vivo zebrafish embryonic model (Danio rerio) was used to investigate the developmental toxicity of those halogenated carbazoles. The results suggested that acute toxicity was structure-dependent. Two of the 6 tested carbazoles, 2,7-dibromocarbazole (27-DBCZ) and 2,3,6,7-tetrachlorocarbazole, showed obvious developmental toxicity at nanomolar levels. The typical phenotypes were similar to dioxin-induced cardiotoxicity, including swollen yolk sac, pericardial sac edema, elongated and unlooped heart, and lower jaw shortening. During embryonic development 27-DBCZ also induced a unique pigmentation decrease. Gene expression and protein staining of cytochrome P4501A (CYP1A) showed that both halogenated carbazoles could induce CYP1A expression at the micromolar level and primarily in the heart area, which was similar to dioxin activity. Further, aryl hydrocarbon receptor-(AhR)2 gene knockdown with morpholino confirmed that the acute cardiotoxicity is AhR-dependent. In conclusion, the results demonstrate that halogenated carbazoles represent yet another class of persistent organic pollutants with dioxin-like activity in an in vivo animal model. Environ Toxicol Chem 2016;35:2523-2529. © 2016 SETAC.

  8. Spectral properties of carbazole-containing polymers with phosphore groups in the main chain

    NASA Astrophysics Data System (ADS)

    Bogdal, D.; Yashchuk, V.; Pielichowski, Jan; Kushnir, K.; Warzala, M.; Kudrya, Vladislav

    2002-12-01

    The absorption, fluorescence and phosphorescence of the carbazole-containg polymers with phosphore groups in the main chain of two types and without spacer were studied. It was shown that spectral properties of pf2-sep polymer are connected mainly with optical transitions in individual carbazole chromophores. The optical properties of pf2-conj polymer are rather different comparative to the pf2-sep. That is caused by perturbation carbazole groups electron system by phosphor-groups and influence carbazole groups each other. This perturbation takes place under special relative geometrical displacement of carbazole and phosphor groups.

  9. White organic light-emitting diodes based on electroplex from polyvinyl carbazole and carbazole oligomers blends

    NASA Astrophysics Data System (ADS)

    Chen, Fei-Peng; Xu, Bin; Zhao, Zu-Jin; Tian, Wen-Jing; Lü, Ping; Im, Chan

    2010-03-01

    White organic light-emitting diodes with a blue emitting material fluorene-centred ethylene-liked carbazole oligomer (Cz6F) doped into polyvinyl carbazole (PVK) as the single light-emitting layer are reported. The optical properties of Cz6F, PVK, and PVK:Cz6F blends are studied. Single and double layer devices are fabricated by using PVK: Cz6F blends, and the device with the configuration of indium tin oxide (ITO)/PVK:Cz6F/tris(8-hydroxyquinolinate)aluminium (Alq3)/LiF/A1 exhibits white light emission with Commission Internationale de l'Éclairage chromaticity coordinates of (0.30, 0.33) and a brightness of 402 cd/m2. The investigation reveals that the white light is composed of a blue-green emission originating from the excimer of Cz6F molecules and a red emission from an electroplex from the PVK:Cz6F blend films.

  10. Dame Sheila Patricia Violet Sherlock.

    PubMed

    Pepys, Mark

    2003-01-01

    Dame Sheila Patricia Violet Beckett Sherlock was the world's leading female physician-scientist of the twentieth century. Her brilliant, wide-ranging, original contributions to the investigation, diagnosis, classification, epidemiology, pathogenesis and management of liver disease played a leading role in the establishment of hematology as a medical specialty. Her rigorous, highly focused, studies combined experimental and laboratory investigations with meticulous clinical observation, encompassed most aspects of liver function, disease and treatment, and led directly to enormous benefit for millions of patients. Her remarkable individual personality also had a profound influence not only on her medical and scientific specialty but also on several generations of physicians throughout the world. She was the first female professor of medicine and head of a department of medicine in the UK, and the pioneer of women in modern medicine. The importance of her contributions to knowledge and her massive influence on training in and the practice of medicine related to liver disease were recognized by a glittering array of honours and awards from professional societies and academic institutions throughout the world, including 19 honorary degrees, and, very belatedly, election to Fellowship of The Royal Society in the last year of her life.

  11. Synthesis and Characterization of Carbazole-Linked Porphyrin Tweezers.

    PubMed

    Chang, Yi; Michelin, Clément; Bucher, Léo; Desbois, Nicolas; Gros, Claude P; Piant, Sébastien; Bolze, Frédéric; Fang, Yuanyuan; Jiang, Xiaoqin; Kadish, Karl M

    2015-08-17

    Herein the synthesis, spectroscopic characterization, two-photon absorption and electrochemical properties of 3,6-disubstituted carbazole tweezers is reported. A dimer resulting from a Glaser homocoupling was isolated during a Sonogashira coupling reaction between a diethynyl-carbazole spacer and a 5-bromo-triarylporphyrin and the properties of this original compound were compared with the 3,6-disubstituted carbazole bisporphyrin tweezers. The dyads reported herein present a two-photon absorption maximum at 920 nm with two-photon absorption cross-section in the 1200 GM range. Despite a strong linear absorption in the Soret region and moderate fluorescence quantum yield, they both lead to a high brightness reaching 30 000 M(-1)  cm(-1) .

  12. Synthesis of Carbazoles and Carbazole-Containing Heterocycles via Rhodium-Catalyzed Tandem Carbonylative Benzannulations.

    PubMed

    Song, Wangze; Li, Xiaoxun; Yang, Ka; Zhao, Xian-liang; Glazier, Daniel A; Xi, Bao-min; Tang, Weiping

    2016-04-01

    Polycyclic aromatic compounds are important constituents of pharmaceuticals and other materials. We have developed a series of Rh-catalyzed tandem carbonylative benzannulations for the synthesis of tri-, tetra-, and pentacyclic heterocycles from different types of aryl propargylic alcohols. These tandem reactions provide efficient access to highly substituted carbazoles, furocarbazoles, pyrrolocarbazoles, thiophenocarbazoles, and indolocarbazoles. While tricyclic heterocycles could be derived from vinyl aryl propargylic alcohols, tetra- and pentacyclic heterocycles were synthesized from diaryl propargylic alcohols. The tandem carbonylative benzannulation is initiated by a π-acidic rhodium(I) catalyst-mediated nucleophilic addition to alkyne to generate a key metal-carbene intermediate, which is then trapped by carbon monoxide to form a ketene species for 6π electrocyclization. Overall, three bonds and two rings are formed in all of these tandem carbonylative benzannulation reactions.

  13. Synthesis and characterizations of carbazole-isoindigo-carbazole oligomers for photovoltaic application

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Young; Lee, Song-Mi; Lee, Soo-Hyoung; Kim, Dong-Hee; Lee, Sang Hee; Lee, Youn-Sik

    2016-08-01

    6,6‧-Dibromo-N,N‧-(2-octyldodecanyl)isoindigo was coupled to either 4-(N-carbazolyl)phenyl boronic acid or 9-phenyl-9H-carbazole-3-boronic acid to give two different conjugated molecules of P-II-P and C-II-C, respectively. The optical band gap/HOMO levels of P-II-P and C-II-C were 1.90/-5.60 eV and 1.85/-5.39 eV, respectively. Based on the experimental and calculation data, C-II-C is more highly conjugated than P-II-P. The performances of C-II-C-based photovoltaic devices were better than those of P-II-P-based devices, with the best power conversion efficiency of 0.44%.

  14. Cresyl violet: a red fluorescent Nissl stain.

    PubMed

    Alvarez-Buylla, A; Ling, C Y; Kirn, J R

    1990-08-01

    Cresyl violet is widely used by neurobiologists to visualize Nissl substance in bright-field microscopy. Here we describe a method for using this dye as a red fluorescent Nissl stain. Unlike the bright-field staining technique, fluorescent cresyl is compatible with other fluorescent dyes and tracers, such as fluorescein, Fluoro-Gold and Fast Blue. The procedure requires only minor modifications of routine bright-field cresyl staining, the most significant being dilution of the stain. Thus, fluorescent red cresyl violet is simple to implement and may be of general use in fluorescence microscopy.

  15. 21 CFR 589.1000 - Gentian violet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... violation of the Federal Food, Drug, and Cosmetic Act (the act), in the absence of a regulation providing... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentian violet. 589.1000 Section 589.1000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL...

  16. 21 CFR 73.2775 - Manganese violet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity. The color additive... extent that such other impurities may be avoided by good manufacturing practice: Ash (at 600 °C), not... substances, not more than 6 percent. pH of filtrate of 10 grams color additive (shaken occasionally for...

  17. 21 CFR 589.1000 - Gentian violet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gentian violet. 589.1000 Section 589.1000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... section 512 of the act, or an index listing under section 572 of the act, or an effective notice...

  18. Photophysical processes of some carbazole derivatives and benzimidazole derivatives

    NASA Astrophysics Data System (ADS)

    Zhang, Caihong; Feng, Liheng; Chen, Zhaobin

    2006-03-01

    The photophysical properties of N-(1-naphthyl)-carbazole (1-NACZ), N-(2-naphthyl)-carbazole (2-NACZ), N-(1-naphthyl)-benzimidazole (1-NABI) and N-(2-naphthyl)-benzimidazole (2-NABI) were studied. The emission wavelengths of 1-NACZ and 2-NACZ were very sensitive to the polarity of solvents. The magnitude of change in the dipole moment was calculated based on the Lippert-Mataga equation. 1-NACZ and 2-NACZ had higher change in the dipole moment than that of 1-NABI and 2-NABI . The optical properties, including fluorescence quantum yield and fluorescence decay times, were determined in different polarity solvents. These gave the evidence about the intramolecular charge transfer character in the excited singlet state of 1-NACZ and 2-NACZ.

  19. Benzoylpyridine-carbazole based TADF materials and devices (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Cheng, Chien-Hong

    2016-09-01

    In this report, several benzoylpyridine-carbazole based fluorescence materials bearing carbazolyl or 4-(t-butyl)carbazolyl groups at the ortho, meta and para carbons of the benzoyl ring, were synthesized and studied for their TADF properties. Some of these molecules show very small ΔEST < 0.05 eV and transient PL characteristics indicate that they are thermally activated delayed fluorescence (TADF) materials. In general, they show low fluorescence efficiencies in solutions, but the efficiencies increase drastically in the thin films with some reaching more than 90%. For examples, o- and m-dicarbazolyl substituted DCBPy (2,5-di(9H-carbazol-9-yl)phenyl)(pyridin-4-yl)methanone) and DTCBPy ((3,5-bis(3,6-di-tert-butyl-9H-carbazol-9-yl)phenyl)(pyridin-4-yl)methanone) in cyclohexane show fluorescence efficiencies of 14 and 36%, but in the thin films, the values increase to 88.0 and 91.4%, respectively. Based on the TDDFT calculation, the HOMOs of DCBPy and DTCBPy are mainly distributed over the two carbazolyl groups and slightly extended to the phenyl ring. The LUMOs are mostly localized on the BPy core and slightly extended to the phenyl ring. There is a small degree of spatial overlap between the HOMO and LUMO in these two molecules. The OLEDs using DCBPy and DTCBPy as dopants emit blue and green light with EQEs of 24.0 and 27.2%, respectively, and with low efficiency roll-off at practical brightness level. The crystal structure of DTCBPy reveals a substantial interaction between the ortho donor (carbazolyl) and acceptor (4-pyridylcarbonyl) unit. The interaction between donor and acceptor substituents likely plays a key role to achieve very small ΔEST with high photoluminescence. In addition to the above two compounds, we also prepared a series of different benzoylpyridine-carbazole derivatives, the results will also be reported.

  20. Quantitative analysis of bioactive carbazole alkaloids in Murraya koenigii.

    PubMed

    Joshi, Trapti; Mahar, Rohit; Singh, Sumit K; Srivastava, Piush; Shukla, Sanjeev K; Mishra, Dipak K; Bhatta, R S; Kanojiya, Sanjeev

    2015-02-01

    Carbazole alkaloids induce apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway and they are targeted as potential anticancer agents. Thus, the naturally occurring carbazole alkaloids become important as precursors for lead optimization in drug development. A method based on ultra performance liquid chromatography coupled with photodiode-array detection was developed using reverse phase isocratic elution with 85:15 acetonitrile and ammonium acetate buffer (5 mM). Seven samples of Murrya koenigii (L.) Spreng. from north-central India (Uttar Pradesh) were analyzed. All three targeted analytes, koenimbidine (mk1), koenimbine (mk2) and mahanimbine (mk3), were well separated within 4.0 min with linearity of the calibration curves (r2 > 0.999). The limits of detection and quantification of mk1, mk2 and mk3 were 0.7, 0.4, 0.04 μg/mL and 2.14, 1.21, 0.12 μg/mL, respectively. The natural abundance of mk1, mk2 and mk3 was 0.06-0.20, 0.04-0.69 and 0.13-0.42%, w/w, respectively, in the dried powdered leaves, whereas, the tissue specific distribution of carbazole alkaloids was observed in the order of predominance, mk1 leaf>root>fruit>stem, mk2 fruit>leaf >stem>root, and mk3 fruit>leaf>root>stem. The developed method was validated for limits of detection and quantification, repeatability, accuracy, precision and stability. This is the first report on the natural abundance of the major carbazole alkaloids in M. koenigii and the method developed can be used in HPLC/UPLC systems.

  1. Novel carbazole/fluorene hybrids: host materials for blue phosphorescent OLEDs.

    PubMed

    Shih, Ping-I; Chiang, Chih-Long; Dixit, Ajay Kumar; Chen, Ching-Kun; Yuan, Mao-Chuan; Lee, Rei-Yuen; Chen, Chin-Ti; Diau, Eric Wei-Guang; Shu, Ching-Fong

    2006-06-22

    [reaction: see text] A series of carbazole/fluorene (CBZm-Fn) hybrids were effectively synthesized through Friedel-Crafts-type substitution of the carbazole rings. These compounds were thermally and morphologically stable host materials for OLED applications. Efficient blue phosphorescent OLEDs were obtained when employing CBZ1-F2 as the host and FIrpic as the guest.

  2. Synthesis of spirocyclic carbazole- and acridine-lactams.

    PubMed

    Würdemann, Martina; Christoffers, Jens

    2010-04-21

    Spirocyclic carbazole- and acridine-lactams were prepared by Fischer-indole or Friedländer-quinoline synthesis starting from spirocyclic ketones with a lactam ring. All annulation products were obtained as mixtures of separable regioisomers, which differ only in the position of one methyl group. The starting materials were prepared from 2-pyrrolidone and 2-piperidone by a sequence of protection (by N-allylation), alpha-acylation, iron-catalyzed Michael reaction followed by Robinson-annulation, palladium-catalyzed N-deprotection and catalytic hydrogenation. The overall yields of this six-step sequence are 13 and 17%, respectively, and the racemic ketones are obtained as single diastereoisomers.

  3. Carbazole functionalized isocyanide brushes in heterojunction photovoltaic devices.

    PubMed

    Lim, Eunhee; Gao, Feng; Schwartz, Erik; Cornelissen, Jeroen J L M; Nolte, Roeland J M; Rowan, Alan E; Greenham, Neil C; Do, Lee-Mi

    2012-01-01

    In this work, carbazole-containing polyisocyanide (PIACz) brushes were used for photovoltaic devices. A photovoltaic device was fabricated on top of the brushes by spin-coating a suitable acceptor and evaporating an Al cathode. Devices with a poly(N-vinylcarbazole) (PVK) bulk polymer were also prepared for comparison. Interestingly, the brushes showed better photovoltaic characteristics as compared to the blended PVK system. This is attributed to the specific morphologies of the polyisocyanide brushes, which provide a large interfacial area between the donor and acceptor for efficient photogeneration. It was found that the device performance varied according to the molecular size of the incorporated acceptors.

  4. A complete gear system in N-benzoyl-carbazole derivatives.

    PubMed

    Tabata, Hidetsugu; Kayama, Susumu; Takahashi, Yuka; Tani, Norihiko; Wakamatsu, Shintaro; Tasaka, Tomohiko; Oshitari, Tetsuta; Natsugari, Hideaki; Takahashi, Hideyo

    2014-03-07

    2',6'-Disubstituted N-benzoylated carbazole derivatives were found to exhibit atropisomerism. The bulky substituents restricted rotation about the N-C7' and C7'-C1' bonds to separate four atropisomers, in which rotation about the C7'-C1' bond was in perfect concert with rotation about the N-C7' bond. Complete geared rotation without slippage at 37 °C for 7 days was observed for the first time. Conformational analysis clarified the preference for the gear system over other internal conversion pathways.

  5. Indigenous and enhanced mineralization of pyrene, benzo(a)pyrene, and carbazole in soils

    SciTech Connect

    Grosser, R.J.; Warshawsky, D.; Vestal, J.R. )

    1991-12-01

    The authors studied the mineralization of pyrene, carbazole, and benzo(a)pyrene in soils obtained from three abandoned coal gasification plants in southern Illinois. The soils had different histories of past exposure to hydrocarbon contamination and different amounts of total organic carbon, microbial biomass, and microbial activity. Mineralization was measured by using serum bottle radiorespirometry. The levels of indigenous mineralization of {sup 14}C-labeled compounds ranged from 10 to 48% for pyrene, from undetectable to 46% for carbazole, and from undetectable to 25% for benzo(a)pyrene following long-term (<180-day) incubations. Pyrene and carbazole were degraded with short or no lag periods in all soils, but benzo(a)pyrene mineralization occurred after a 28-day lag period. Mineralization was not dependent on high levels of microbial biomass and activity in the soils. Bacterial cultures that were capable of degrading pyrene and carbazole were isolated by enrichment, grown in pure culture, and reintroduced into soils. Reintroduction of a pyrene-degrading bacterium enhanced mineralization to a level of 55% within 2 days, compared with a level of 1% for the indigenous population. The carbazole degrader enhanced mineralization to a level of 45% after 7 days in a soil that showed little indigenous carbazole mineralization. The pyrene and carbazole degraders which they isolated were identified as a Mycobacterium sp. and Xanthamonas sp., respectively.

  6. Modulation of π-spacer of carbazole-carbazole based organic dyes toward high efficient dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Chitpakdee, Chirawat; Jungsuttiwong, Siriporn; Sudyoadsuk, Taweesak; Promarak, Vinich; Kungwan, Nawee; Namuangruk, Supawadee

    2017-03-01

    The effects of type and position of π-linker in carbazole-carbazole based dyes on their performance in dye-sensitized solar cells (DSSCs) were investigated by DFT and TDDFT methods. The calculated electronic energy level, electron density composition, charge injection and charge recombination properties were compared with those of the high performance CCT3A dye synthesized recently. It is found that that mixing a benzothiadizole (B) unit with two thiophene (T) units in the π-spacer can greatly shift absorption wavelength to near infrared region and enhance the light harvesting efficiency (LHE) resulting in increasing of short-circuit current density (Jsc), whereas a thienothiophene unit does not affect those properties. However, a B should be not directly connected to the anchoring group of the dye because it brings electrolyte to the TiO2 surface which may increase charge recombination rate and consequently decrease open circuit voltage (Voc). This work shows how type and position of the π-linker affect the performance of DSSCs, and how to modulate those properties. We predicted that the designed dye derived from insertion of the B unit in between the two T units would have higher performance than CCT3A dye. The insight understanding from this study is useful for further design of higher performance dyes by molecular engineering.

  7. The metabolism and mode of action of gentian violet.

    PubMed

    Docampo, R; Moreno, S N

    1990-01-01

    Gentian violet has been used in medicine for almost 100 years: as an antiseptic for external use, as an antihelminthic agent by oral administration, and more recently, as a blood additive to prevent transmission of Chagas' disease. To date, no serious side effects have been reported when used externally. However, oral administration can cause gastrointestinal irritation, and intravenous injection can cause depression in the white blood cell count. Surprisingly, no acute toxic side effects were reported after administration of large amounts of gentian violet-treated blood. No studies have been done on long-term effects (chronic toxicity, carcinogenicity) of gentian violet-treated blood either in humans or in laboratory animals. Gentian violet is a mutagen, a mitotic poison, and a clastogen. The carcinogenic effects of gentian violet in rodents have been reported recently. In addition, a number of triphenylmethane-classed dyes, of which gentian violet is a member, have been recognized as animal and human carcinogens. A photodynamic action of gentian violet, apparently mediated by a free-radical mechanism, has been described in bacteria and in T. cruzi. However, the main target of gentian violet toxicity in the dark is the mitochondrion. Gentian violet is actively demethylated by liver microsomes from different animals and is reduced to leucogentian violet by intestinal microflora. Although the first process may represent a detoxication reaction, the second pathway may have toxicological significance because the completely demethylated derivative leucopararosaniline has been demonstrated to be carcinogenic in rats. A free-radical derivative of gentian violet is also formed by the action of rat liver microsomes, but whether this radical is involved in the cytotoxic effects of gentian violet in mammalian cells remains to be elucidated. Other pathways of gentian violet metabolism have recently been investigated that involve its oxidative N-demethylation by peroxidases

  8. Novel Carbazole (Cbz)-Based Carboxylated Functional Monomers: Design, Synthesis, and Characterization

    PubMed Central

    Mondal, Ejabul; Lellouche, Jean-Paul; Naddaka, Maria

    2015-01-01

    A series of novel functional carbazole (Cbz)-based carboxylated monomers were synthesized and characterized. A Clauson-Kaas procedure, a deprotection step, amide coupling, and hydrolysis were utilized as key chemical reactions towards the multistep synthesis of monomers in good to excellent isolated yields. The design strategy was further extended to complex carbazole-COOH monomers incorporated arylazo groups as photoreactive moieties. In addition, photoreactive hybrid carbazole (Cbz)-pyrrole (Pyr)-based carboxylated monomers, comprising a pyrrole core linking a carbazole and a photoreactive phenylazide or benzophenone moiety through an amide spacer in the molecular structure, were also synthesized. The latter can be utilized for surface modification of polymeric films in their monomeric form or as polymeric microparticles (MPs). PMID:26478845

  9. On the violet flux of N type carbon stars

    NASA Astrophysics Data System (ADS)

    Faulkner, Danny R.; Honeycutt, R. Kent; Johnson, Hollis R.

    1988-01-01

    New six-color violet photometry of 26 carbon stars is presented. These observations reveal the shape of the spectrum between 3400 and 4500 A and provide a measurement of the violet flux deficiency. The strength of the 11.5-micron SiC emission feature was also measured using ground-based infrared spectrophotometry and the IRAS low-resolution spectral catalog. The lack of correlation between the 11.5-micron emission and the violet flux deficiency leads to the conclusion that SiC is not the predominant violet opacity source in N type carbon stars. The violet photometry presented here does not quantitatively agree with previous spectrophotometry that supported C3 as the opacity source. The observations alone do not rule out the C3 opacity, but when they are combined with IUE data, the C3 opacity appears less plausible.

  10. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    SciTech Connect

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  11. Intramolecular Electronic Coupling in the Thiophene-Bridged Carbazole-Based Diporphyrin.

    PubMed

    Maeda, Chihiro; Takata, Mototsugu; Honsho, Asami; Ema, Tadashi

    2016-12-02

    The Glaser coupling reaction of ethynyl-substituted carbazole-based isophlorins provided butadiyne-bridged dimers, which were transformed into the thiophene-bridged dimers via the annulation reaction. Oxidation of these isophlorin dimers afforded carbazole-based diporphyrins. Notable electronic interactions in the diporphyrins have been confirmed by means of UV/vis-near-infrared (NIR) absorption spectroscopy, cyclic voltammetry (CV) measurements, and density functional theory (DFT) calculations.

  12. Azo-Carbazole Polymethacrylates as Single-Component Electro-Optic Materials

    DTIC Science & Technology

    2007-11-02

    previously. Sample Preparation The n-variable spacer poly( azo carbazole) (PAC-n) polymers used in this study were cast as films onto transparent...electric field poling and photoinduced birefringence. Once an electro-optic thin film sandwich of azo polymer is brought to Tg , application of an...and coefficients obtained from curve fitting. Figure 1. Azo -carbazole polymer cast as a thin film (top), an electro-optic sandwich (center), and an

  13. The Swift Ultra-Violet/Optical Telescope

    NASA Astrophysics Data System (ADS)

    Roming, P. W. A.; Hunsberger, S. D.; Nousek, J. A.; Mason, K. O.; Breeveld, A. A.

    2003-05-01

    The Ultra-Violet/Optical Telescope (UVOT) aboard the Swift Gamma-ray Burst Observatory provides the Swift mission with the capability of detecting the early UV/optical photons of GRB afterglows. The UVOT is a Ritchey-Chrétien telescope with MCP intensified CCD detectors that can operate in either a photon-timing mode or an imaging mode while providing sub-arcsecond resolution. A filter wheel houses sensitive broadband UV and visual filters for determining photometric redshifts. The filter wheel also accommodates UV and visual grisms for performing low-resolution spectroscopy. We present an overview of the instrument as well as a summary of the calibration results. We also discuss some of the science to be accomplished with the UVOT. This work is sponsored at Penn State by NASA's Office of Space Science through contract NAS5-00136, and at MSSL by funding from PPARC.

  14. [Environmental Behaviors and Ecotoxicology of the Emerging Contaminants Polyhalogenated Carbazoles].

    PubMed

    Lin, Kun-de; Chen, Yan-qiu; Yuan, Dong-xing

    2016-04-15

    Polyhalogenated carbazoles (PHCs), with a complex chemical structure similar to polychlorinated dibenzofurans, are a class of emerging environmental organic contaminants. There are 135 congeners for PHCs with a pure halogenation. Most of PHCs are not man-made products. Although PHCs in the environment were firstly discovered in the 1980s, these emerging halogenated compounds were not seriously considered until recent years. Recently, more than 20 PHCs have been detected in sediment and soil samples. In addition, studies have shown that PHCs exhibited dioxin-like toxicity and were persistent and bioaccumulative. Therefore, it is very important to understand the distribution, origins and ecotoxicology of PHCs for a better assessment of their environmental risks. To date, research on the environmental behaviors of PHCs is relatively limited and warrants further investigations. In this review, the environmental distribution, source, analytical methods and toxicity of PHCs were summarized and future research needs were outlined.

  15. The Swift Ultra-Violet/Optical Telescope

    NASA Astrophysics Data System (ADS)

    Roming, Peter; Hunsberger, Sally; Nousek, John; Ivanushkina, Mariya; Mason, Keith; Breeveld, Alice; Gehrels, Neil

    2004-05-01

    The Ultra-Violet/Optical Telescope (UVOT) is one of three telescopes on board the Swift Gamma-Ray Burst Mission. It supplies the Swift mission with the ability to detect the early UV and optical photons of GRB afterglows. The UVOT is of a modified Ritchey-Chrétien design with MCP intensified CCD detectors that provide sub-arcsecond resolution while operating in both a photon-timing and an imaging mode. A filter wheel accommodates broadband UV and visual filters for determining photometric redshifts in the range of 1.5 < z < 4.4. The filter wheel also houses UV and visual grisms for low-resolution spectroscopy. The UVOT will help answer questions about GRBs such as: how many times has reionization occurred in the Universe; what is the nature of dark bursts; what is the initial Lorentz factor of the fireball; and are there subclasses or new classes of GRBs? This work is sponsored at Penn State by NASA's Office of Space Science through contract NAS5-00136, and at MSSL by funding from PPARC.

  16. Further study of the genetic toxicity of gentian violet.

    PubMed

    Au, W; Butler, M A; Bloom, S E; Matney, T S

    1979-02-01

    The genetic toxicity of gentian violet was studied with the Ames and the Rosenkranz bacterial assays as well as the cytogenetic assays (Chinese hamster ovary cells in vitro in the presence of rat-liver S-9 fractions, the chicken-embryo and mouse-bone-marrow cells in vivo). Gentian violet was found to be toxic but not mutagenic in the Ames assay. However, it was active in the Rosenkranz assay causing reparable DNA damage. The presence of S-9 in the in vitro cytogenetic assay and in the bacterial assays showed that the activity of gentian violet could be reduced or eliminated. In the in vivo assays, gentian violet was not clastogenic and failed to induce sister-chromatid exchanges. However, gentian violet proved to be highly toxic to growing chick embryos at high dosage and depressed mitotic activities in mouse bone marrow after prolonged treatment. Our study suggested that gentian violet can be inactivated by the liver detoxification system. However, it is potentially hazardous to cells that are exposed to the dye directly (e.g. skin epithelium and cell lining of the gastrointestinal tract).

  17. Targeted therapy of oral hairy leukoplakia with gentian violet.

    PubMed

    Bhandarkar, Sulochana S; MacKelfresh, Jamie; Fried, Levi; Arbiser, Jack L

    2008-04-01

    Oral hairy leukoplakia (OHL) is a common oral manifestation of HIV infection. Clinically, these lesions appear as white plaques on the edges of the tongue. Pathophysiologically, these lesions occur because of infection of oral epithelium with Epstein-Barr virus (EBV). No universally effective therapy exists for OHL. We have previously shown that EBV infection and EBV viral products induce the generation of reactive oxygen. We have also demonstrated that the Food and Drug Administration-approved over-the-counter medication gentian violet is a potent inhibitor of reactive oxygen species. We thus chose to treat a patient with biopsy-proven OHL with topical gentian violet. Gentian violet solution was applied topically to the tongue of a patient with OHL. Complete clinical resolution was noted after three treatments. Treatment with topical gentian violet resulted in resolution of the lesions. Further studies with larger numbers of patients are required. The application of gentian violet can be used as a method to OHL treatment. Gentian violet is an inexpensive and safe therapy and, given that it inhibits reactive oxygen, this old therapy is now a targeted novel therapy.

  18. Metallophyte status of violets of the section Melanium.

    PubMed

    Hermann, Bothe; Katarina, Vogel-Mikuš; Paula, Pongrac; Matevž, Likar; Neva, Stepic; Primož, Pelicon; Primož, Vavpetič; Luka, Jeromel; Marjana, Regvar

    2013-11-01

    Violets from metal-enriched soils have controversially been described as both heavy-metal accumulators and excluders in the literature. The present study solves the issue for violets of the section Melanium (zinc violets, Viola lutea ssp. calaminaria and V. lutea ssp. westfalica; hartsease or wild pansy, Viola tricolor; and mountain pansy, V. lutea). The aims were to determine the concentrations of heavy metals in the soil and in the roots and shoots of field-collected plants, to evaluate the potential impact of colonisation by arbuscular mycorrhizal fungi on heavy-metal concentrations in the plant tissues, and to quantitatively define the localisation of the elements in root cross-sections. When these violets grow in low-metal soils, higher concentrations of the heavy metals were found in the roots and shoots than in the soil, whereas the opposite was seen in samples from high-metal soils. Under all field conditions examined, the roots of all of these species were colonised by arbuscular mycorrhizal fungi. However, V. tricolor was marginally colonised when the concentrations of Zn and P were higher in the soil. Determination of the spatial distribution of the elements in root cross-sections of these violets indicates tissue-specific deposition of elements within the vascular tissue, the cortex, and the rhizodermis. These data indicate that violets of the section Melanium are heavy-metal excluders.

  19. Facile synthesis of indolo[3,2-a]carbazoles via Pd-catalyzed twofold oxidative cyclization

    PubMed Central

    Yang, Chao; Lin, Kai; Huang, Lan; Pan, Wei-dong

    2016-01-01

    A rapid and efficient route has been developed for the synthesis of 9-methoxycarbonylindolo[3,2-a]carbazole derivatives. The key steps in this approach involved an aromatic amination and an oxidative biaryl coupling. Via the present route, indolo[3,2-a]carbazole derivatives are available in 3–4 steps based on commercially available starting materials. PMID:28144317

  20. Analytical and preparative chromatographic procedures for obtaining pure cresyl violet and cresyl red from commercial cresyl violet.

    PubMed

    Urrutia, M N; Ortiz, C S

    2015-04-01

    Cresyl violet and cresyl red, components of commercial cresyl violet acetate, were separated and purified using preparative column liquid chromatography. The stationary phase was silica gel and gradient elution was carried out using chloroform:methanol. The purified dyes were obtained in high yield; 51% of the original lot was recovered as cresyl violet and 40% as cresyl red. Separated materials were characterized by nuclear magnetic resonance and mass spectroscopy; UV-visible and Fourier-transform infrared spectra also were obtained for samples of pure cresyl violet and cresyl red. The colored constituents of the commercial dye lot were identified using thin layer chromatography and reverse phase high performance liquid chromatography. Both methodologies were suitable for routine testing; reverse phase high performance liquid chromatography is an appropriate tool for quality control and high resolution identification of these compounds.

  1. Facile preparation of stable palygorskite/methyl violet@SiO2 "Maya Violet" pigment.

    PubMed

    Zhang, Yujie; Zhang, Junping; Wang, Aiqin

    2015-11-01

    Maya Blue pigment has attracted considerable attention owing to their extraordinary stability. The growing interest in this field has largely expanded the study of Maya Blue-like pigments. Inspired by Maya Blue, a stable palygorskite/methyl violet@SiO2 (PAL/MV@SiO2) "Maya Violet" pigment was fabricated via adsorption of MV by PAL, and then deposition of a layer of SiO2 on the surface by polycondensation of tetraethoxysilane (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB). The weight ratio of MV to PAL is as high as 10%. The pigments were characterized by scanning electron microscopy and a variety of analytical techniques, e.g., Fourier Transform infrared spectroscopy and zeta potential. The results indicate that MV molecules are fixed onto the exterior surface, the grooves and at the entrances of the channels of PAL. The PAL/MV@SiO2 pigment shows excellent stability against chemical attacks, e.g., 0.1 M HCl, 0.1 M NaOH and various organic solvents. Different from Maya Blue, grinding and heating treatment are virtually ineffective in improving stability of the PAL/MV pigment. CTAB and the SiO2 layer formed on the surface of PAL/MV contribute greatly to the improved stability of the pigment due to shielding effect. The optimal CTAB/TEOS/ammonia/H2O molar ratio for the surface modification of PAL/MV is 0.24/1/2.89/495.

  2. Synthesis of novel carbazole based styryl: rational approach for photophysical properties and TD-DFT.

    PubMed

    Sekar, Nagaiyan; Umape, Prashant G; Kothavale, Shantaram; Deshmukh, Mininath

    2014-09-01

    The synthesis and solvatochromic behavior of four novel carbazole based fluorescent styryl dyes were explained. In chlorinated solvents such as DCM and chloroform, these dyes show bathochromic shift in their absorption as well as emission. The styryl dyes 6b and 6c show solid state yellow fluorescence. DFT and TD-DFT computations were performed to study structural, molecular, electronic and photophysical properties of these dyes. The computed absorption and emission wavelength values are found to be in good agreement with the experimental results. The photophysical properties of these 1-styryl carbazole dyes are also compared with the recently reported 3-styrl carbazole dyes. The unique behavior of dye 6d is well explained by its optimized geometry found in the excited state. Ratio of ground to excited state dipole moment of the synthesized novel styryl compounds were calculated by Bakhshiev and Bilot-Kawski correlations.

  3. Tuning Coordination in s-Block Carbazol-9-yl Complexes

    PubMed Central

    Ortu, Fabrizio; Moxey, Graeme J; Blake, Alexander J; Lewis, William; Kays, Deborah L

    2015-01-01

    1,3,6,8-Tetra-tert-butylcarbazol-9-yl and 1,8-diaryl-3,6-di(tert-butyl)carbazol-9-yl ligands have been utilized in the synthesis of potassium and magnesium complexes. The potassium complexes (1,3,6,8-tBu4carb)K(THF)4 (1; carb=C12H4N), [(1,8-Xyl2-3,6-tBu2carb)K(THF)]2 (2; Xyl=3,5-Me2C6H3) and (1,8-Mes2-3,6-tBu2carb)K(THF)2 (3; Mes=2,4,6-Me3C6H2) were reacted with MgI2 to give the Hauser bases 1,3,6,8-tBu4carbMgI(THF)2 (4) and 1,8-Ar2-3,6-tBu2carbMgI(THF) (Ar=Xyl 5, Ar=Mes 6). Structural investigations of the potassium and magnesium derivatives highlight significant differences in the coordination motifs, which depend on the nature of the 1- and 8-substituents: 1,8-di(tert-butyl)-substituted ligands gave π-type compounds (1 and 4), in which the carbazolyl ligand acts as a multi-hapto donor, with the metal cations positioned below the coordination plane in a half-sandwich conformation, whereas the use of 1,8-diaryl substituted ligands gave σ-type complexes (2 and 6). Space-filling diagrams and percent buried volume calculations indicated that aryl-substituted carbazolyl ligands offer a steric cleft better suited to stabilization of low-coordinate magnesium complexes. PMID:25783772

  4. Tuning coordination in s-block carbazol-9-yl complexes.

    PubMed

    Ortu, Fabrizio; Moxey, Graeme J; Blake, Alexander J; Lewis, William; Kays, Deborah L

    2015-04-27

    1,3,6,8-Tetra-tert-butylcarbazol-9-yl and 1,8-diaryl-3,6-di(tert-butyl)carbazol-9-yl ligands have been utilized in the synthesis of potassium and magnesium complexes. The potassium complexes (1,3,6,8-tBu4carb)K(THF)4 (1; carb = C12H4N), [(1,8-Xyl2-3,6-tBu2carb)K(THF)]2 (2; Xyl = 3,5-Me2C6H3) and (1,8-Mes2-3,6-tBu2carb)K(THF)2 (3; Mes = 2,4,6-Me3C6H2) were reacted with MgI2 to give the Hauser bases 1,3,6,8-tBu4carbMgI(THF)2 (4) and 1,8-Ar2-3,6-tBu2carbMgI(THF) (Ar = Xyl 5, Ar = Mes 6). Structural investigations of the potassium and magnesium derivatives highlight significant differences in the coordination motifs, which depend on the nature of the 1- and 8-substituents: 1,8-di(tert-butyl)-substituted ligands gave π-type compounds (1 and 4), in which the carbazolyl ligand acts as a multi-hapto donor, with the metal cations positioned below the coordination plane in a half-sandwich conformation, whereas the use of 1,8-diaryl substituted ligands gave σ-type complexes (2 and 6). Space-filling diagrams and percent buried volume calculations indicated that aryl-substituted carbazolyl ligands offer a steric cleft better suited to stabilization of low-coordinate magnesium complexes.

  5. Catalyst‐Driven Scaffold Diversity: Selective Synthesis of Spirocycles, Carbazoles and Quinolines from Indolyl Ynones

    PubMed Central

    Liddon, John T. R.; James, Michael J.; Clarke, Aimee K.; O'Brien, Peter

    2016-01-01

    Abstract Medicinally relevant spirocyclic indolenines, carbazoles and quinolines can each be directly synthesised selectively from common indolyl ynone starting materials by catalyst variation. The high yielding, divergent reactions all proceed by an initial dearomatising spirocyclisation reaction to generate an intermediate vinyl–metal species, which then rearranges selectively by careful choice of catalyst and reaction conditions. PMID:27124236

  6. The binding modes of carbazole derivatives with telomere G-quadruplex

    NASA Astrophysics Data System (ADS)

    Zhang, Xiu-feng; Zhang, Hui-juan; Xiang, Jun-feng; Li, Qian; Yang, Qian-fan; Shang, Qian; Zhang, Yan-xia; Tang, Ya-lin

    2010-10-01

    It is reported that carbazole derivatives can stabilize G-quadruplex DNA structure formed by human telomeric sequence, and therefore, they have the potential to serve as anti-cancer agents. In this present study, in order to further explore the binding mode between carbazole derivatives and G-quadruplex formed by human telomeric sequence, two carbazole iodides (BMVEC, MVEC) molecules were synthesized and used to investigate the interaction with the human telomeric parallel and antiparallel G-quadruplex structures by NMR, CD and molecular modeling study. Interestingly, it is the pivotal the cationic charge pendant groups of pyridinium rings of carbazole that plays an essential role in the stabilizing and binding mode of the human telomeric sequences G-quadruplex structure. It was found that BMVEC with two cationic charge pendant groups of pyridinium rings of 9-ethylcarbazole cannot only stabilize parallel G-quadruple of Hum6 by groove binding and G-tetrad stacking modes and antiparallel G-quadruplex of Hum22 by groove binding, but also induce the formation of mixed G-quadruplex of Hum22. While MVEC with one cationic charge pendant groups of pyridinium ring only can bind with the parallel G-quadruplex of Hum6 by the stacking onto the G4 G-tetrad and could not interact with the G-quadruplex of Hum22.

  7. 21 CFR 82.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1602 D&C Violet No. 2. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of §...

  8. 21 CFR 82.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1602 D&C Violet No. 2. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of §...

  9. 21 CFR 82.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1602 D&C Violet No. 2. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of §...

  10. 21 CFR 82.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1602 D&C Violet No. 2. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of §...

  11. 21 CFR 82.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS Drugs and Cosmetics § 82.1602 D&C Violet No. 2. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of §...

  12. Improving Student Results in the Crystal Violet Chemical Kinetics Experiment

    ERIC Educational Resources Information Center

    Kazmierczak, Nathanael; Vander Griend, Douglas A.

    2017-01-01

    Despite widespread use in general chemistry laboratories, the crystal violet chemical kinetics experiment frequently suffers from erroneous student results. Student calculations for the reaction order in hydroxide often contain large asymmetric errors, pointing to the presence of systematic error. Through a combination of "in silico"…

  13. Electrochemical Studies of the TIN(4)-Pyrocatechol Violet System

    DTIC Science & Technology

    1987-10-01

    34Preconcentratlon of Environmental Tin and Its Determination Using Catechol Violet," Analyst, Vol. 107 (1982), pp. 654-58. 12. W. D. Wakley and L. P. Varga ...1) Code 5131, M. H. Salazar (1) 2 Naval Ordnance Station, Indian Head 8Code E, Pollution Abatement Program Masager (1) Technical LUbrary (1) 3 Naval

  14. Cu-catalyzed arylation of the amino group in the indazole ring: regioselective synthesis of pyrazolo-carbazoles.

    PubMed

    Anil Kumar, K; Kannaboina, Prakash; Dhaked, Devendra K; Vishwakarma, Ram A; Bharatam, Prasad V; Das, Parthasarathi

    2015-02-07

    Cu(II)-catalyzed cross-coupling of various aryl boronic acids with 5 and 6-amino indazoles has resulted in (arylamino)-indazoles. These (arylamino)-indazoles have been utilized in synthesizing medicinally important pyrazole-fused carbazoles via Pd(II)-catalyzed cross-dehydrogenative coupling (CDC). This combined N-arylation/C-H arylation strategy has been successfully applied to the regioselective synthesis of polyheterocycles 3,6-dihydropyrazolo[3,4-c]carbazoles and 1,6-dihydro pyrazolo[4,3-c]carbazoles. Quantum chemical analysis has been carried out to understand the regioselectivity and to trace the potential energy surface of the entire reaction upon 5-N-aryl-indazole conversion to the corresponding carbazole.

  15. 21 CFR 74.2602 - D&C Violet No. 2.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may...

  16. 21 CFR 74.2602 - D&C Violet No. 2.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements of § 74.1602(a)(1) and (b). (b) Uses and restrictions. The color additive D&C Violet No. 2 may...

  17. Photoporation and cell transfection using a violet diode laser

    NASA Astrophysics Data System (ADS)

    Paterson, L.; Agate, B.; Comrie, M.; Ferguson, R.; Lake, T. K.; Morris, J. E.; Carruthers, A. E.; Brown, C. T. A.; Sibbett, W.; Bryant, P. E.; Gunn-Moore, F.; Riches, A. C.; Dholakia, Kishan

    2005-01-01

    The introduction and subsequent expression of foreign DNA inside living mammalian cells (transfection) is achieved by photoporation with a violet diode laser. We direct a compact 405 nm laser diode source into an inverted optical microscope configuration and expose cells to 0.3 mW for 40 ms. The localized optical power density of ~1200 MW/m2 is six orders of magnitude lower than that used in femtosecond photoporation (~104 TW/m2). The beam perforates the cell plasma membrane to allow uptake of plasmid DNA containing an antibiotic resistant gene as well as the green fluorescent protein (GFP) gene. Successfully transfected cells then expand into clonal groups which are used to create stable cell lines. The use of the violet diode laser offers a new and simple poration technique compatible with standard microscopes and is the simplest method of laser-assisted cell poration reported to date.

  18. Polymers containing isolated phenylvinyl substituted carbazole rings as electroactive materials for OLEDs

    NASA Astrophysics Data System (ADS)

    Griniene, Raimonda; Tavgeniene, Daiva; Grigalevičius, Saulius

    2016-05-01

    Polymers containing pendent 3-(2-phenylvinyl)carbazole moieties have been synthesized by the multi-step synthetic route. The polymers represent materials of high thermal stability with initial thermal degradation temperatures exceeding 370 °C. The glass transition temperatures of the amorphous materials were in the rage of 56-65 °C. The electron photoemission spectra of thin layers of the polymers showed ionization potentials of about 5.6 eV. Hole-transporting properties of the polymeric materials were tested in the structures of organic light emitting diodes with Alq 3 as the green emitter. The device containing hole-transporting layers of poly{9-[6-(3-methyloxetan-3-ylmethoxy)hexyl]-3-(2-phenylvinyl)carbazole} exhibited the best overall performance with a maximum photometric efficiency of about 4.0 cd/A and maximum brightness exceeding 6430 cd/m2.

  19. Conformational polymorphs and solid-state polymerization of 9-(1,3-butadiynyl)carbazole derivatives

    NASA Astrophysics Data System (ADS)

    Tabata, Hideyuki; Kuwamoto, Kazunori; Okuno, Tsunehisa

    2016-02-01

    The novel diacetylenes, 9-(5-(4-nitrophenoxy)penta-1,3-diyn-1-yl)-9H-carbazole (1) and 4-((5-(9H-carbazol-9-yl)penta-2,4-diyn-1-yl)oxy)benzonitrile (2), were prepared and characterized by crystallographic analyses. Compound 1 gave two conformational polymorphs, 1-(I) and 1-(II), whose differences were concluded to originate in intermolecular interactions among nitrophenyl groups. Crystal 1-(I) and 2 had suitable molecular arrangements for solid-state polymerization and polymerized by thermal annealing to give crystalline polydiacetylenes (PDAs). While an arrangement of 1-(II) was unsuitable for the polymerization. The PDAs showed broad absorption from UV to near IR region (ca. 900 nm), suggesting effective expansion of π-conjugated system by carbazolyl groups.

  20. Carbazole Scaffold in Medicinal Chemistry and Natural Products: A Review from 2010-2015.

    PubMed

    Tsutsumi, Lissa S; Gündisch, Daniela; Sun, Dianqing

    2016-01-01

    9H-carbazole is an aromatic molecule that is tricyclic in nature, with two benzene rings fused onto a 5-membered pyrrole ring. Obtained from natural sources or by synthetic routes, this scaffold has gained much interest due to its wide range of biological activity upon modifications, including antibacterial, antimalarial, anticancer, and anti-Alzheimer properties. This review reports a survey of the literature on carbazole-containing molecules and their medicinal activities from 2010 through 2015. In particular, we focus on their in vitro and in vivo activities and summarize structure-activity relationships (SAR), mechanisms of action, and/or cytotoxicity/selectivity findings when available to provide future guidance for the development of clinically useful agents from this template.

  1. Hydroxyalkylation with cyclic sulfates: synthesis of carbazole derived CB(2) ligands with increased polarity.

    PubMed

    Lueg, Corinna; Galla, Fabian; Frehland, Bastian; Schepmann, Dirk; Daniliuc, Constantin G; Deuther-Conrad, Winnie; Brust, Peter; Wünsch, Bernhard

    2014-01-01

    In order to increase the polarity of the potent CB2 ligand 1a, the homologous hydroxyalkyl carbazoles 2a-c were prepared and pharmacologically evaluated. An important step in the synthesis is the hydroxyalkylation of carbazole with cyclic sulfates providing the 2-hydroxyethyl and 3-hydroxypropyl derivatives 5a and 5b in a one-step reaction. The final propionamides 2a-c were prepared using the recently reported coupling reagent COMU®. The X-ray crystal structure of 2c displays an almost coplanar arrangement of the 3-phenyl-1,2,4-oxadiazole biaryl system. The increased polarity of 2a is associated with an almost 100-fold reduced CB2 affinity. The 3-hydroxypropyl derivative 2b represents the best compromise between lipophilicity and CB2 affinity (Ki  = 33 nM).

  2. Calix[3]carbazole: A C3-symmetrical receptor for barium ion

    NASA Astrophysics Data System (ADS)

    Yang, Zhaozheng; Tian, Zhangmin; Yang, Peng; Deng, Tuo; Li, Gang; Zhou, Xue; Chen, Yan; Zhao, Liang; Shen, Hongyan

    2017-03-01

    The binding ability of calix[3]carbazole (1) to metal ions has been investigated. It is found that 1 could serve as a non crown ether based, C3-symmetrical receptor for Ba2 + via the marriage of cation-π and cation-dipole interactions. FID assay further illustrates that 1 could selectively interact with Ba2 + over Pd2 +. A possible binding mechanism for [1-Ba2 +] complex is proposed.

  3. Lewis acid catalyzed cascade reaction to carbazoles and naphthalenes via dehydrative [3 + 3]-annulation.

    PubMed

    Wang, Shaoyin; Chai, Zhuo; Wei, Yun; Zhu, Xiancui; Zhou, Shuangliu; Wang, Shaowu

    2014-07-03

    A novel Lewis acid catalyzed dehydrative [3 + 3]-annulation of readily available benzylic alcohols and propargylic alcohols was developed to give polysubstituted carbazoles and naphthalenes in moderate to good yields with water as the only byproduct. The reaction was presumed to proceed via a cascade process involving Friedel-Crafts-type allenylation, 1,5-hydride shift, 6π-eletrocyclization, and Wagner-Meerwein rearrangement.

  4. Identification and Optimization of an Aminoalcohol-Carbazole Series with Antimalarial Properties

    PubMed Central

    2013-01-01

    Recent observations on the emergence of artemisinin resistant parasites have highlighted the need for new antimalarial treatments. An HTS campaign led to the identification of the 1-(1-aminopropan-2-ol)carbazole analogues as potent hits against Plasmodium falciparum K1 strain. The SAR study and optimization of early ADME and physicochemical properties direct us to the selection of a late lead compound that shows good efficacy when orally administrated in the in vivo P. berghei mouse model. PMID:24900603

  5. Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads▿

    PubMed Central

    Wang, Xia; Gai, Zhonghui; Yu, Bo; Feng, Jinhui; Xu, Changyong; Yuan, Yong; Lin, Zhixin; Xu, Ping

    2007-01-01

    Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and κ-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, Fe3O4 nanoparticles were prepared by a coprecipitation method, and the average particle size was about 20 nm with 49.65-electromagnetic-unit (emu) g−1 saturation magnetization. When the mixture of gellan gel and the Fe3O4 nanoparticles served as an immobilization support, the magnetically immobilized cells were prepared by an ionotropic method. The biodegradation experiments were carried out by employing free cells, nonmagnetically immobilized cells, and magnetically immobilized cells in aqueous phase. The results showed that the magnetically immobilized cells presented higher carbazole biodegradation activity than nonmagnetically immobilized cells and free cells. The highest biodegradation activity was obtained when the concentration of Fe3O4 nanoparticles was 9 mg ml−1 and the saturation magnetization of magnetically immobilized cells was 11.08 emu g−1. Additionally, the recycling experiments demonstrated that the degradation activity of magnetically immobilized cells increased gradually during the eight recycles. These results support developing efficient biocatalysts using magnetically immobilized cells and provide a promising technique for improving biocatalysts used in the biodegradation of not only carbazole, but also other hazardous organic compounds. PMID:17827304

  6. The Quantification of Glycosaminoglycans: A Comparison of HPLC, Carbazole, and Alcian Blue Methods

    PubMed Central

    Frazier, Sarah B.; Roodhouse, Kevin A.; Hourcade, Dennis E.; Zhang, Lijuan

    2010-01-01

    Glycosaminoglycans (GAGs) are linear polysaccharides that are found in the extracellular matrix and biological fluids of animals where they interact with hundreds of proteins and perform a variety of critical roles. There are five classes of animal GAGs: heparan sulfate (HS), chondroitin sulfate (CS), dermatan sulfate (DS), keratan sulfate (KS), and hyaluronan (HA). Many biological functions can be monitored directly by their impact on GAG quantity. Thus, simple, sensitive, and robust GAG quantification methods are needed for the development of biomarkers. We have systematically compared three available GAG quantification assays including an HPLC-based assay, a simplified Alcian Blue assay, and a miniaturized carbazole assay. The carbazole and Alcian Blue assays were reproducible and simple to perform in general lab settings, but had important limitations: The carbazole assay could not detect KS and it overestimated GAGs that were contaminated with salts or dissolved in PBS. The Alcian Blue assay detected only those GAGs that were sulfated. In contrast, while the HPLC method was time-consuming, it was a robust and sensitive assay that not only detected all GAGs but also quantified glucosamine-GAGs and galactosamine-GAGs simultaneously. The HPLC assay was not affected by salt or level of GAG sulfation and it yielded reproducible values for all types of GAGs tested. These results suggest that an automated HPLC assay would be generally useful for the routine measurement of a panel of GAG-based biomarkers while the carbazole assay and the Alcian Blue assays could prove valuable for more specific purposes. PMID:20640171

  7. Carbazole alkaloids from Murraya koenigii trigger apoptosis and autophagic flux inhibition in human oral squamous cell carcinoma cells.

    PubMed

    Utaipan, Tanyarath; Athipornchai, Anan; Suksamrarn, Apichart; Jirachotikoon, Canussanun; Yuan, Xiaohong; Lertcanawanichakul, Monthon; Chunglok, Warangkana

    2017-01-01

    Carbazole alkaloids, a major constituent of Murraya koenigii (L.) Sprengel (Rutaceae), exhibit biological effects such as anticancer activity via the induction of apoptosis, and they represent candidate chemotherapeutic agents. Oral squamous cell carcinoma (OSCC) is the most prevalent cancer of the oral cavity and a growing and serious health problem worldwide. In this study, we investigated the anticancer properties and mechanisms of action of two carbazole alkaloids derived from M. koenigii leaves, mahanine and isomahanine, in the OSCC cell line CLS-354. At 15 μM, mahanine and isomahanine were cytotoxic to CLS-354 cells, triggering apoptosis via caspase-dependent and -independent mechanisms. Autophagosomes, visualised using monodansylcadaverine (MDC) labelling, were numerous in carbazole alkaloid-treated cells. Mahanine and isomahanine markedly induced the expression of the autophagosome marker microtubule-associated protein 1 light chain 3, type II (LC3B-II). Genetic and chemical inhibition of autophagy via silencing of the Autophagy protein 5 gene and exposure to bafilomycin A1 (BafA1), respectively, did not arrest carbazole alkaloid-induced apoptosis, indicating that it occurs independently of autophagic activation. Surprisingly, both carbazole alkaloids caused increased accumulation of p62/sequestosome1 (p62/SQSTM1), with coordinated expression of LC3B-II and cleaved caspase-3, suggesting inhibition of autophagic flux. Our results suggest that inhibition of autophagic flux is associated with carbazole alkaloid-induced apoptosis. Our findings provide evidence of a novel cytotoxic action of natural carbazole alkaloids and support their use as candidate chemotherapeutic agents for the treatment of OSCC.

  8. Vascular barrier protective effects of 3-N- or 3-O-cinnamoyl carbazole derivatives.

    PubMed

    Ku, Sae-Kwang; Lee, Jee-Hyun; O, Yuseok; Lee, Wonhwa; Song, Gyu-Yong; Bae, Jong-Sup

    2015-10-01

    In this Letter, we investigated the barrier protective effects of 3-N-(MeO)n-cinnamoyl carbazoles (BS 1; n=1, BS 2; n=2, BS 3; n=3) and 3-O-(MeO)3-cinnamoyl carbazole (BS 4) against high-mobility group box 1 (HMGB1)-mediated vascular disruptive responses in human umbilical vein endothelial cells (HUVECs) and in mice for the first time. Data showed that BS 2, BS 3, and BS 4, but not BS 1, inhibited HMGB1-mediated vascular disruptive responses and transendothelial migration of human neutrophils to HUVECs. BS 2, BS3, and BS 4 also suppressed HMGB1-induced hyperpermeability and leukocyte migration in mice. Interestingly, the barrier protective effects of BS 3 and BS 4 were better than those of BS 2. These results suggest that the number of methoxy groups substituted on the cinnamamide or cinnamate moiety of the 9H-3-carbazole derivative is an important pharmacophore for the barrier protective effects of these compounds.

  9. Detoxification of fluorene, phenanthrene, carbazole, and p-cresol as studied by the Microtox

    SciTech Connect

    Renoux, A.Y.; Millette, D.; Samson, R.

    1995-12-31

    A column experiment was conducted in order to study the evolution of the toxicity of creosote-related compound mixtures during aerobic biodegradation in a saturated hydrodynamic groundwater environment. The Microtox assay was used to characterize the toxicity of phenanthrene, fluorene, carbazole and p-cresol, separately and in mixtures, and to evaluate their detoxification during biodegradation. Phenanthrene, fluorene and p-cresol, separately solubilized in an aqueous phase, produced toxic effects on P. phosphoreum luminescence emission; 15 min-IC50 values of 140 {micro}g/L, 600 {micro}g/L and 1,500 {micro}g/L respectively were determined. Carbazole appeared as poorly toxic. The detoxification of the mixture solutions was demonstrated after having passed through the columns. Phenanthrene, fluorene and carbazole combined at different proportion produced between 24.4% and 49.3% of inhibition, whereas at the last port of the columns the inhibition values of the outflows averaged 6%. The presence of 10,000 {micro}g/L of p-cresol enhanced this efficiency of detoxification, since the inhibition of the mixture with the other compounds, which was 81.4% before injection, decreased to 15.8% after having passed through the first 5 cm of the column, and was not detectable at its last two pores. The acute toxicity test corroborated the chemical analysis, reflecting the compound elimination.

  10. Color-Tunable Solid-State Fluorescence Emission from Carbazole-Based BODIPYs.

    PubMed

    Maeda, Chihiro; Todaka, Takumi; Ueda, Tomomi; Ema, Tadashi

    2016-05-23

    Several carbazole-based boron dipyrromethene (BODIPY) dyes were synthesized by organometallic approaches. Thiazole, benzothiazole, imidazole, benzimidazole, triazole, and indolone substituents were introduced at the 1-position of the carbazole moiety, and boron complexation of each dipyrrin generated the corresponding compounds 1, 2 a, and 3-6. The properties of these products were investigated by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, X-ray crystallography, and DFT calculations. These compounds exhibited large Stokes shifts, and compounds 1, 2 a, and 3-5 fluoresced both in solution and in the solid state. Complex 2 a showed the highest fluorescence quantum yield (ΦF ) in the solid state, therefore boron complexes of the carbazole-benzothiazole hybrids 2 b-f, which had several different substituents, were prepared and the effects of the substituents on the photophysical properties of the compounds were examined. The fluorescence properties showed good correlation with the results of crystal-packing analyses, and the dyes exhibited color-tunable solid-state fluorescence.

  11. Synthesis and antitumor activity of novel N-substituted carbazole imidazolium salt derivatives

    PubMed Central

    Liu, Lan-Xiang; Wang, Xue-Quan; Zhou, Bei; Yang, Li-Juan; Li, Yan; Zhang, Hong-Bin; Yang, Xiao-Dong

    2015-01-01

    A series of novel N-substituted carbazole imidazolium salt derivatives has been prepared and investigated for their cytotoxic activity against five human tumor cell lines by MTS assay. The results indicated that the existence of 5,6-dimethyl-benzimidazole ring, substitution of the imidazolyl-3-position with a 2-bromobenzyl or naphthylacyl group, as well as alkyl chain length between carbazole and imidazole ring were important for the antitumor activity. Compound 61, bearing a 2-bromobenzyl substituent at position-3 of the 5,6-dimethyl-benzimidazole, showed powerful inhibitory activities and was more selective to HL-60, SMMC-7721, MCF-7 and SW480 cell lines with IC50 values 0.51–2.48 μM. Mechanism of action studies revealed that this new compound could remarkably induce cell cycle arrest and apoptosis in SMMC-7721 cells. This work provides alternative novel way for future drug development based on carbazole and imidazolium salt scaffolds. PMID:26287982

  12. Photoinduced grating formation in a polymer containing azo-carbazole dyes.

    PubMed

    Kawabe, Yutaka; Fukuzawa, Kodai; Uemura, Takuya; Matsuura, Katsufumi; Yoshikawa, Toshio; Nishide, Jun-ichi; Sasabe, Hiroyuki

    2012-09-20

    Although some azo-carbazole derivatives attached on or doped into inert polymers are known to show photorefractive effect without external electric field, the origin of their asymmetric energy transfer in two-beam coupling experiments were unknown. We made the two-beam coupling experiment followed by sample translation and one-beam diffraction at 633 nm for thick films composed of 3-[(4-nitrophenyl)]azo-9H-carbazole-9-ethanol (NACzEtOH) and poly(methylmethacrylate), finding that photoinduced gratings grew in several minutes accompanied with phase displacement of the gratings, but the phase shift was not always synchronized with the refractive index modulation. We reformulated the Kogelnik's coupled-wave theory with strict energy conservation law for analysis. Comparison of the grating growth and erasure at 532 nm to Disperse Red 1 (DR1), the most well-known azo dye showed that the photoisomerization was dominant at this wavelength and that the azo-carbazole dyes were faster in response time and more resistive to erasure than DR1.

  13. Dry deposition, concentration and gas/particle partitioning of atmospheric carbazole

    NASA Astrophysics Data System (ADS)

    Esen, Fatma; Tasdemir, Yücel; Cindoruk, S. Sıddık

    2010-03-01

    The atmospheric concentrations and dry deposition of carbazole were measured to present the temporal changes, gas/particle partitioning and magnitude of fluxes. Atmospheric samples were collected from July 2004 to May 2005 at four different sites in Bursa, Turkey. The average total (gas and particulate) carbazole concentrations were 7.6 ± 9.9 ng m - 3 in Gulbahce (Residential), 1.1 ± 1.2 ng m - 3 in BUTAL (Traffic), 3.3 ± 5.0 ng m - 3 in BOID (Industrial), and 1.2 ± 0.7 ng m - 3 in the Uludag University Campus (UU) (Suburban). Experimental gas/particle partition coefficient ( Kp) was determined using the study results and compared with Kp values calculated from octanol-air and soot-air + octanol partitioning models. Total dry deposition fluxes of carbazole were 290 ± 484 ng m - 2 d - 1 in BUTAL and 72 ± 67 ng m - 2 d - 1 in the UU Campus. Particulate phase dry deposition velocities were 0.81 ± 0.78 cm s - 1 and 0.90 ± 1.53 cm s - 1 for BUTAL and the UU Campus, respectively. On the other hand, gas-phase mass transfer coefficients were calculated to be 0.34 ± 0.29 cm s - 1 and 0.26 ± 0.17 cm s - 1 for BUTAL and the UU Campus, respectively.

  14. Persistence of gentian violet and leucogentian violet in channel catfish (ictalurus punctatus) muscle after water-borne exposure.

    PubMed

    Thompson, H C; Rushing, L G; Gehring, T; Lochmann, R

    1999-02-19

    Gentian violet is a triphenylmethane dye that is an antifungal/antiparastic agent. GV is similar to malachite green that has been used in the aquaculture industry for treatment or prevention of external fungal and parasitic infections in fish and fish eggs although it (MG) is not approved for this use. For these reasons, GV's potential for misuse by the aquaculture industry is high. The uptake and depletion of gentian violet (GV) were determined in channel catfish (Ictalurus punctatus) after water-borne exposure (100 ng ml(-1), 1 h) under simulated aquaculture farming conditions. Leucogentian violet (LGV) was rapidly formed, concentrated in the muscle tissue, and very slowly eliminated from muscle tissue. An isocratic (60% acetonitrile-40% water; 0.05 M ammonium acetate buffer, pH 4.5) HPLC system consisting of a 5 microm LC-CN 250x4.6 mm I.D. column, a 20x2.0 mm I.D. PbO2 oxidative post-column, and a UV-VIS detector set at 588 nm were used to determine uptake and depletion of tissue residues of GV and LGV with time. GV was rapidly depleted and converted to its major metabolite, LGV, which was detected out to 79 days. Therefore, LGV is the appropriate target analyte for monitoring exposure of channel catfish to GV.

  15. 3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic-organic hybrid perovskite solar cells.

    PubMed

    Li, Wei; Otsuka, Munechika; Kato, Takehito; Wang, Yang; Mori, Takehiko; Michinobu, Tsuyoshi

    2016-01-01

    The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic-organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility.

  16. Dispersive charge transport due to strong charge dipole interactions of cyano-group in the cyano-carbazole based molecular glass

    NASA Astrophysics Data System (ADS)

    Oh, Dong Keun; Hong, Sung Mok; Lee, Cheol Eui; Kim, B.-S.; Jin, J.-I.

    2005-12-01

    Using the time of flight (ToF) method, we investigated the bipolar charge transport for two glass-forming molecules containing carbazole and cyano-carbazole moiety. The enhanced electron mobility was observed in the cyano-carbazole compound. From the numerical method based the Laplace formalism, the distribution of hole trapping energy was obtained for the carbazole compound. This result was compared with the exponential distribution extracted from dispersion parameter for the cyano-carbazole material. Considering charge-dipole interactions as a reason for the disordered trapping mechanism, we discussed dispersive charge transport induced by a strong dipolar (i.e. cyano) group by comparing the distributions of hole trapping sites for two compounds.

  17. Analysis of incurred crystal violet in Atlantic salmon (Salmo salar L.): comparison between the analysis of crystal violet as an individual parent and leucocrystal violet and as total crystal violet after oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone.

    PubMed

    Chan, D; Tarbin, J A; Stubbings, G; Kay, J; Sharman, M

    2012-01-01

    Due to on-going concern about the occurrence of triphenylmethane dye residues in fish destined for human consumption, a depletion study of crystal violet in salmon was carried out. Atlantic salmon less than 12 months old were exposed to crystal violet in fresh water at 15°C and subsequently sampled at 1, 7, 14, 28, 63 and 91 days after exposure. The salmon were then analysed by two analytical methods. In the first method, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) was used to oxidise leucocrystal violet to its parent form. Total parent crystal violet was then analysed by LC-MS/MS. In the second method, crystal violet and leucocrystal violet were analysed individually by LC-MS/MS without oxidation. Both methods gave comparable results for total crystal violet concentrations, with a correlation of r(2)=0.69. Statistical treatment for 88 incurred salmon samples showed no significant difference between the two sets of results with t=1.68 and t(crit)=1.99. Up to 98% of crystal violet was metabolised to its leuco form in the salmon after 1 day of exposure and could be detected at significant concentrations (approximately 20 µg kg(-1)) 91 days after exposure. The depletion data also suggest that crystal violet has a half-life of approximately 15-16 days in salmon.

  18. Palladium-catalyzed arylation of 2H-chromene: a new entry to pyrano[2,3-c]carbazoles.

    PubMed

    Ranjith Reddy, K; Siva Reddy, A; Dhaked, Devendra K; Rasheed, S K; Pathania, Anup Singh; Shankar, Ravi; Malik, Fayaz; Das, Parthasarathi

    2015-09-21

    Pyrano[2,3-c]carbazoles which are biologically valuable and synthetically challenging frameworks are synthesized in high yields over five steps from commercially available resorcinol. Palladium-catalyzed arylation remains a key step in this novel strategy. The versatility of this protocol has been demonstrated by the synthesis of naturally occurring alkaloid clauraila C and 7-methoxyglycomaurin. The anti-proliferative activity of these designed compounds (5a, 5f, and 5l) has been evaluated in a cancer cell line (MOLT-4). The molecular docking study revealed that this pyrano[2,3-c]carbazole class of molecules selectively occupies the colchicine binding site of the tubulin-polymer.

  19. Photochemical Synthesis of Complex Carbazoles: Evaluation of Electronic Effects in Both UV- and Visible-Light Methods in Continuous Flow.

    PubMed

    Hernandez-Perez, Augusto C; Caron, Antoine; Collins, Shawn K

    2015-11-09

    An evaluation of both a visible-light- and UV-light-mediated synthesis of carbazoles from various triarylamines with differing electronic properties under continuous-flow conditions has been conducted. In general, triarylamines bearing electron-rich groups tend to produce higher yields than triarylamines possessing electron-withdrawing groups. The incorporation of nitrogen-based heterocycles, as well as halogen-containing arenes in carbazole skeletons, was well tolerated, and often synthetically useful complementarity was observed between the UV-light and visible-light (photoredox) methods.

  20. Crystal structures of three carbazole derivatives: 12-ethyl-7-phenyl­sulfonyl-7H-benzofuro[2,3-b]carbazole, (1), 2-(4,5-dimeth­oxy-2-nitro­phen­yl)-4-hy­droxy-9-phenyl­sulfonyl-9H-carbazole-3-carbaldehyde, (2), and 12-phenyl-7-phenyl­sulfonyl-7H-benzofuro[2,3-b]carbazole, (3)

    PubMed Central

    Gangadharan, Rajeswari; Narayanan, P.; Sethusankar, K.; Saravanan, Velu; Mohanakrishnan, Arasambattu K.

    2016-01-01

    The three title compounds, C26H19NO3S, (1), C27H20N2O8S, (2), and C30H19NO3S, (3), are carbazole derivatives, where (1) and (3) are heterocycle-containing carbazoles with a benzo­furan moiety fused to a carbazole unit. In (2), a di­meth­oxy­nitro­phenyl ring is attached to the carbazole moiety. In the three derivatives, a phenyl­sulfonyl group is attached to the N atom of the carbazole unit. Compound (1) crystallizes with two independent mol­ecules in the asymmetric unit (A and B). The carbazole skeleton in the three compounds is essentially planar. In compound (1), the benzene ring of the phenyl­sulfonyl moiety is almost orthogonal to the carbazole moiety, with dihedral angles of 85.42 (9) and 84.52 (9)° in mol­ecules A and B, respectively. The benzene ring of the phenyl­sulfonyl group in compounds (2) and (3) are inclined to the carbazole moiety, making dihedral angles of 70.73 (13) and 81.73 (12)°, respectively. The S atom has a distorted tetra­hedral configuration in all three compounds. In the crystals, C—H⋯O hydrogen bonds give rise to R 2 2(12) inversion dimers for compound (1), and to R 2 2(24) inversion dimers and R 4 4(40) ring motifs for compound (2). The crystal packing in (1) also features C—H⋯π and π–π inter­actions [shortest inter­centroid distance = 3.684 (1) Å], leading to supra­molecular three-dimensional aggregation. In the crystal of compound (2), the combination of the various C—H⋯O hydrogen bonds leads to the formation of a three-dimensional network. In the crystal of compound (3), mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains running parallel to the a axis, and the chains are linked by C—H⋯π inter­actions, forming corrugated sheets parallel to the ab plane. PMID:27980821

  1. Compositional changes in red and violet smoke mixes after combustion

    SciTech Connect

    Buchanan, M.V.; Rubin, I.B.; Moneyhun, J.H.

    1983-01-01

    Anthraquinone-derived dyes are commonly used in colored dye mixes prepared for signal smoke grenades. Biological studies have shown, however, that a number of these dyes exhibit bacterial mutagenicity. In addition, these dyes are similar in structure to several polycyclic aromatic hydrocarbons which are well-known carcinogens. The grenades contain not only anthraquinone-derived dyes, but also a pyrotechnic fuel and cooling and starting mixes consisting primarily of potassium chlorate and nitrate, sodium bicarbonate, and sulfur. These dyes are volatilized at temperatures up to 550/sup 0/C during the detonation of the grenade, which could subject the dyes to oxidative and pyrolytic reactions that could result in a variety of reaction by-products. As part of a program to investigate possible environmental and occupational risks of the colored smoke dyes and in signal grenades, two colored smoke mixes, red and violet, have been studied both before and after detonation to evaluate any differences in composition due to the combustion process. This report focuses primarily on the separation and identification of the components of the original and combusted red and violet smoke mixes. The conditions for the detonation of the smoke grenades and sampling of the combusted smoke mixes are also discussed.

  2. The thermodynamic properties of 2-aminobiphenyl (an intermediate in the carbazole/hydrogen reaction network)

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.

    1990-12-01

    Catalytic hydrodenitrogenation (HDN) is a key step in upgrading processes for conversion of heavy petroleum, shale oil, tar sands, and the products of the liquefaction of coal to economically viable products. This research program provides accurate experimental thermochemical and thermophysical properties for key organic nitrogen-containing compounds present in the range of alternative feedstocks, and applies the experimental information to thermodynamic analyses of key HDN reaction networks. This report is the first in a series that will lead to an analysis of a three-ring HDN system; the carbazole/hydrogen reaction network. 2-Aminobiphenyl is the initial intermediate in the HDN pathway for carbazole, which consumes the least hydrogen possible. Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2-aminobiphenyl are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c). Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for selected temperatures between 298.15 K and 820 K. The critical temperature and critical density were determined for 2-aminobiphenyl with the d.s.c., and the critical pressure was derived. The Gibbs energies of formation are used in thermodynamic calculations to compare the feasibility of the initial hydrogenolysis step in the carbazole/H{sub 2} network with that of its hydrocarbon and oxygen-containing analogous; i.e., fluorene/H{sub 2} and dibenzofuran/H{sub 2}. Results of the thermodynamic calculations are compared with those of batch-reaction studies reported in the literature. 57 refs., 8 figs., 18 tabs.

  3. Large third-order nonlinear optical response of conjugated copolymers consisting of fluorene and carbazole units

    NASA Astrophysics Data System (ADS)

    Zhan, Xiaowei; Liu, Yunqi; Zhu, Daoben; Liu, Xuchun; Xu, Gang; Ye, Peixian

    2002-08-01

    Off-resonant third-order nonlinear optical properties using degenerate four-wave mixing measurements in solution at 1064 nm have been studied for novel π-conjugated, processible, optically transparent and thermally stable copolymers constituted of carbazole and fluorene. The second-order hyperpolarizability γ1111 per repeat unit of the polymer containing alkyne segment (Cz-PFE) is as high as 6.5×10 -31 esu. The large nonlinearity of Cz-PFE is attributed to its rigid planar and intrachain charge transfer structure.

  4. Static and time-resolved spectroscopy of carbazole-based oligomers with phenylene/thiophene/furan

    NASA Astrophysics Data System (ADS)

    Zhao, Xiangjie; Liu, Yingliang; Meng, Kang; Zeng, Qi; Wang, Shufeng; Gong, Qihuang

    2008-06-01

    Steady-state and picosecond transient spectroscopy measurements are applied to study the photo-physics of three carbazolenevinylene derivatives: alternatively conjugated oligomer of alkylated carbazole and phenylene/thiophene/furan (PBC/PBT/PBF), bridged by vinyl group. Their fluorescence spectra show a bathochromic phenomenon towards solvent polarity. The fluorescence decays of PBF are found to be bi-exponential, while those of PBT and PBC are simple single exponential. It is suggested that PBF is non-planar conformation at ground state and twists to planar conformation after excitation. This chain twisting process of PBF is verified by viscosity dependent fluorescence decay.

  5. Fabrication of poly(vinyl carbazole) waveguides by oxygen ion implantation

    NASA Astrophysics Data System (ADS)

    Ghailane, Fatima; Manivannan, Gurusamy; Knystautas, Émile J.; Lessard, Roger A.

    1995-08-01

    Polymer waveguides were fabricated by ion implantation involving poly(vinyl carbazole) films. This material was implanted by oxygen ions (O ++ ) of energies ranging from 50 to 250 keV. The ion doses varied from 1010 to 1015 ions / cm2. The conventional prism-film coupler method was used to determine the waveguiding nature of the implanted and unimplanted films. The increase of the surface refractive index in the implanted layer has been studied by measuring the effective refractive index (neff) for different optical modes. Electron spectroscopy chemical analysis measurements were also performed to assess the effect of ion implantation on the polymer matrix.

  6. Examination of the Mechanism of Rh2(II)-Catalyzed Carbazole Formation Using Intramolecular Competition Experiments

    PubMed Central

    Stokes, Benjamin J.; Richert, Kathleen J.; Driver, Tom G.

    2009-01-01

    The use of a rhodium(II) carboxylate catalyst enables the mild and stereoselective formation of carbazoles from biaryl azides. Intramolecular competition experiments of triaryl azides suggested the source of the selectivity. A primary intramolecular kinetic isotope effect was not observed and correlation of the product ratios with Hammett σ+-values produced a plot with two intersecting lines with opposite ρ-values. These data suggest that electronic donation by the biaryl π-system accelerates the formation of rhodium nitrenoid and that C–N bond formation occurs through a 4π-electron-5-atom electrocyclization. PMID:19663433

  7. 21 CFR 500.29 - Gentian violet for use in animal feed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentian violet for use in animal feed. 500.29... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS GENERAL Specific Administrative Rulings and Decisions § 500.29 Gentian violet for use in animal feed. The Food and Drug Administration has determined...

  8. 21 CFR 74.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive D&C Violet No. 2 is principally 1-hydroxy -4- -9,10-anthracenedione. (2) Color additive mixtures for... suitable and that are listed in part 73 of this chapter as safe for use in color additive mixtures...

  9. 21 CFR 74.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive D&C Violet No. 2 is principally 1-hydroxy -4- -9,10-anthracenedione. (2) Color additive mixtures for... suitable and that are listed in part 73 of this chapter as safe for use in color additive mixtures...

  10. 21 CFR 74.2602 - D&C Violet No. 2.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements... safely used for coloring externally applied cosmetics in amounts consistent with good...

  11. 21 CFR 74.2602 - D&C Violet No. 2.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements... safely used for coloring externally applied cosmetics in amounts consistent with good...

  12. 21 CFR 74.2602 - D&C Violet No. 2.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2602 D&C Violet No. 2. (a) Identity and specifications. The color additive D&C Violet No. 2 shall conform in identity and specifications to the requirements... safely used for coloring externally applied cosmetics in amounts consistent with good...

  13. Simulation théorique du spectre d'absorption UV du carbazole et de quelques molécules analogues. Theoretical simulation of UV absorption spectrum of carbazole and some homocyclic analogues

    NASA Astrophysics Data System (ADS)

    Kabouchi, B.; Kenfack Assongo, C.; Cazeau-Dubroca, C.

    2001-04-01

    The UV absorption spectra structures of carbazole, fluorene and dibenzofurane are studied using the atom monopole-dipole interaction (AMDI) model and atomic dipolar polarisabilities and effective charge given by Fraga. The absorption spectra corresponding to these molecules and their self-associations are presented. The original obtained results are discussed and compared to previous works.

  14. Indolo[2,3-b]carbazole synthesized from a double-intramolecular Buchwald-Hartwig reaction: its application for a dianchor DSSC organic dye.

    PubMed

    Su, Jia-Yi; Lo, Chun-Yuan; Tsai, Chih-Hung; Chen, Chih-Han; Chou, Shu-Hua; Liu, Shih-Hung; Chou, Pi-Tai; Wong, Ken-Tsung

    2014-06-20

    A new synthetic strategy for indolo[2,3-b]carbazole via a double-intramolecular Buchwald-Hartwig reaction has been established. The N-alkylated indolo[2,3-b]carbazole then was adopted as the geometry-fixed core for the synthesis of a new molecule (ICZDTA) bearing two bithiophene π-bridged 2-cyanoacrylic acid groups as the bidentate anchor. The bidentate anchoring together with efficient HOMO (indolo[2,3-b]carbazole) → LUMO (TiO2 nanocluster) electron transfer leads to the successful development of ICZDTA-based DSSC with a power conversion efficiency of 6.02%.

  15. Regio-selective synthesis of diversely substituted benzo[a]carbazoles through Rh(iii)-catalyzed annulation of 2-arylindoles with α-diazo carbonyl compounds.

    PubMed

    Li, Bin; Zhang, Beibei; Zhang, Xinying; Fan, Xuesen

    2017-01-19

    A novel synthetic approach toward benzo[a]carbazoles or 6-amino benzo[a]carbazoles containing an unprotected NH unit through Rh(iii)-catalyzed cascade reactions of 2-arylindoles or 2-arylindole-3-carbonitriles with α-diazo carbonyl compounds has been established. To our knowledge, this is the first example in which the NH unit of indole is used as a directing group for an intramolecular C(sp(2))-H bond functionalization to give benzo[a]carbazole derivatives. Notably, this method features easily obtainable substrates, good functional group tolerance, excellent regio-selectivity, and high atom-efficiency.

  16. Natural product leads for drug discovery: isolation, synthesis and biological evaluation of 6-cyano-5-methoxyindolo[2,3-a]carbazole based ligands as antibacterial agents.

    PubMed

    Guo, Songpo; Tipparaju, Suresh K; Pegan, Scott D; Wan, Baojie; Mo, Shunyan; Orjala, Jimmy; Mesecar, Andrew D; Franzblau, Scott G; Kozikowski, Alan P

    2009-10-15

    Indolo[2,3-a]carbazole based inhibitors were synthesized from readily available indigo via a seven-step linear synthetic sequence with a moderate overall yield. The inhibitors were selectively and readily functionalized at the nitrogen on the indole portion of the carbazole unit. The synthesized analogs displayed moderate inhibitory activities toward Bacillus anthracis and Mycobacterium tuberculosis, indicating that indolo[2,3-a]carbazoles could serve as promising leads in the development of new drugs to combat anthrax and tuberculosis infections.

  17. The response characteristics of tetrazolium violet solutions to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Emi-Reynolds, G.; Kovács, András; Fletcher, J. J.

    2007-08-01

    The dosimetry characteristics of various solutions of tetrazolium violet, TV, (2,5-diphenyl-3-(1-naphthyl)-2H-tetrazolium chloride) to gamma irradiation are reported. The optical absorption spectra of these solutions show peaks between 400 and 600 nm with a shoulder at around 550 nm. The dose response of the optical absorbance values of aqueous and aqueous-alcoholic solutions containing different concentrations of TV was measured in the 250 Gy up to 75 kGy dose range. The formation of formazan product was observed due to radiolytic reduction in both solutions. Its formation was found more pronounced in N 2-saturated as well as in alkaline solutions. The results indicate that the 1 mM TV solution can be used for food irradiation and medical sterilization dosimetry at gamma irradiation facilities.

  18. The Swift Ultra-Violet/Optical Telescope (UVOT)

    NASA Astrophysics Data System (ADS)

    Roming, Peter W. A.; Hunsberger, S. D.; Nousek, John A.; Ivanushkina, Mariya; Mason, Keith O.; Breeveld, Alice A.

    2004-09-01

    The Ultra-Violet/Optical Telescope (UVOT), one of three telescopes to fly on the Swift Gamma-ray Burst Observatory, is capable of detecting the early UV/optical photons and performing long-term UV/optical observations of GRB afterglows. The UVOT is a Ritchey-Chretien telescope with MCP intensified CCD detectors which operate in either a photon-timing or an imaging mode while providing sub-arcsecond resolution. A filter wheel accommodates broadband UV and visual filters for photometric studies including determination of photometric redshifts. UV and visual grisms for low-resolution spectroscopy are also housed in the filter wheel. We present a brief overview of the UVOT, calibration results, and science to be carried out.

  19. Assembly of BODIPY-carbazole dyes with liposomes to fabricate fluorescent nanoparticles for lysosomal bioimaging in living cells.

    PubMed

    Lv, Hai-Juan; Zhang, Xiao-Tai; Wang, Shu; Xing, Guo-Wen

    2017-01-31

    Two BODIPY-carbazole dye based fluorescent probes BCA and BCAS were designed, synthesized and encapsulated by liposomes to obtain fluorescent nanoparticles BCA-FNP and BCAS-FNP. The fluorescence imaging showed that BCA-FNP was membrane-permeable and capable of localizing lysosomes in living cells.

  20. Gentian violet exhibits activity against biofilms formed by oral Candida isolates obtained from HIV-infected patients.

    PubMed

    Traboulsi, Rana S; Mukherjee, Pranab K; Chandra, Jyotsna; Salata, Robert A; Jurevic, Richard; Ghannoum, Mahmoud A

    2011-06-01

    The effect of gentian violet against Candida albicans and non-Candida albicans biofilms formed on polymethylmethacrylate strips was evaluated using a dry weight assay and confocal laser scanning microscopy. The ability of gentian violet to inhibit Candida albicans germination was also assessed. Gentian violet activity against Candida biofilms was demonstrated by a reduction in dry weight, disruption of biofilm architecture, and reduced biofilm thickness. Additionally, gentian violet inhibited Candida germination in a concentration-dependent manner.

  1. [Qualitative Determination of Organic Vapour Using Violet and Visible Spectrum].

    PubMed

    Jiang, Bo; Hu, Wen-zhong; Liu, Chang-jian; Zheng, Wei; Qi, Xiao-hui; Jiang, Ai-li; Wang, Yan-ying

    2015-12-01

    Vapours of organic matters were determined qualitatively employed with ultraviolet-visible absorption spectroscopy. Vapours of organic matters were detected using ultraviolet-visible spectrophotometer employing polyethylene film as medium, the ultraviolet and visible absorption spectra of vegetable oil vapours of soybean oil, sunflower seed oil, peanut oil, rapeseed oil, sesame oil, cotton seed oil, tung tree seed oil, and organic compound vapours of acetone, ethyl acetate, 95% ethanol, glacial acetic acid were obtained. Experimental results showed that spectra of the vegetable oil vapour and the organic compound vapour could be obtained commendably, since ultra violet and visible spectrum of polyethylene film could be deducted by spectrograph zero setting. Different kinds of vegetable oils could been distinguished commendably in the spectra since the λ(max), λ(min), number of absorption peak, position, inflection point in the ultra violet and visible spectra obtained from the vapours of the vegetable oils were all inconsistent, and the vapours of organic compounds were also determined perfectly. The method had a good reproducibility, the ultraviolet and visible absorption spectra of the vapours of sunflower seed oil in 10 times determination were absolutely the same. The experimental result indicated that polyethylene film as a kind of medium could be used for qualitative analysis of ultraviolet and visible absorption spectroscopy. The method for determination of the vapours of the vegetable oils and organic compounds had the peculiarities of fast speed analysis, well reproducibility, accuracy and reliability and low cost, and so on. Ultraviolet and visible absorption spectrum of organic vapour could provide feature information of material vapour and structural information of organic compound, and provide a novel test method for identifying vapour of compound and organic matter.

  2. Polyethers with pendent phenylvinyl substituted carbazole rings as polymers for hole transporting layers of OLEDs

    NASA Astrophysics Data System (ADS)

    Griniene, R.; Liu, L.; Tavgeniene, D.; Sipaviciute, D.; Volyniuk, D.; Grazulevicius, J. V.; Xie, Z.; Zhang, B.; Leduskrasts, K.; Grigalevicius, S.

    2016-01-01

    Polyethers containing pendent 3-(2-phenylvinyl)carbazole moieties have been synthesized by the multi-step synthetic routes. Full characterization of their structures is presented. The polymers represent materials of high thermal stability with initial thermal degradation temperatures exceeding 370 °C. The glass transition temperatures of the amorphous materials were in the range of 56-658 °C. The electron photoemission spectra of thin layers of the polymers showed ionization potentials of about 5.6 eV. Hole-transporting properties of the polymeric materials were tested in the structures of organic light emitting diodes with Alq3 as the green emitter and electron transporting layer. The device containing hole-transporting layers of poly{9-[6-(3-methyloxetan-3-ylmethoxy)hexyl]-3-(2-phenylvinyl)carbazole} exhibited the best overall performance with a maximum photometric efficiency of about 4.0 cd/A and maximum brightness exceeding 6430 cd/m2.

  3. Structure-properties relationship of carbazole and fluorene hybrid trimers: experimental and theoretical approaches.

    PubMed

    Tomkeviciene, Ausra; Grazulevicius, Juozas V; Volyniuk, Dmytro; Jankauskas, Vygintas; Sini, Gjergji

    2014-07-21

    Synthesis and properties of fluorene and carbazole derivatives having three electrophores per molecule with different architectures are reported. The synthesized compounds possess high thermal stabilities with 5% weight loss temperatures exceeding 350 °C. They form glasses with glass transition temperatures ranging from 60 to 68 °C. Cyclovoltammetric experiments revealed the high electrochemical stability of the fluorene trimer. In contrast, 2- and 2,7-fluorenyl substituted carbazole derivatives show irreversible oxidation in the CV experiments. The electron photoemission spectra of the films of the synthesized compounds revealed ionization potentials of 5.65-5.89 eV. Hole drift mobilities in the amorphous layers of the synthesized compounds reach 10(-2) cm(2) V(-1) s(-1) at high electric fields, as established by a xerographic time-of-flight technique. DFT calculations show that HOMO and LUMO orbitals of the compounds are very similar in energy and shape. The similar hole mobilities observed for the three compounds are discussed in the frame of the Marcus theory. An important influence of the alkyl groups on the ionization potentials and on the hole mobilities was also observed and its origin is discussed.

  4. HPLC analysis of 5H-benzo[a]carbazole with antifungal activity.

    PubMed

    Segall, A I; Vitale, M F; Perez, V L; Pizzorno, M T

    2003-04-01

    A sensitive and simple high-performance liquid chromatographic (HPLC) method for the assay of 6,11-dihydro-2-methoxy-5H-benzo[a]carbazole (1) and 6,11-dihydro-2-methoxy-11-[2-(1-piperidinyl)]ethyl-5H-benzo[a]carbazole (2) was developed. The procedure is based on the use of the reversed-phase high-performance liquid chromatographic (RP-HPLC) method with UV detector. Each analysis required no longer than 11 min. A linear relationship between the concentration of both the drugs and the UV absorbance at 254 nm was obtained. This linearity was maintained over the concentration ranged from 5 to 80 microg/ml. The detection limits were found to be 1.6 and 0.7 ng for compounds 1 and 2. The quantitation limits were found to be 5.3 and 2.5 ng for compounds 1 and 2, respectively. For recovery studies, several determinations were carried out. Recovery values ranged from 98 to 102.1% for compound 1 and from 98.4 to 101.6% for compound 2. Method precision was also evaluated and RSD% found was less than 2%. This method was applied without any interference from degradation products.

  5. Synthesis of Main Chain Poly(carbazole)s via CuAAC

    SciTech Connect

    Chen, Zheng; Dreyer, Daniel R; Wu, Zong-Quan; Wiggins, Kelly M; Bielawski, Christopher W.

    2011-01-24

    The synthesis and characterization of a novel family of main-chain carbazole-containing polymers using copper-catalyzed azide-alkyne cycloaddition chemistry is reported. The reactions were performed under mild conditions using readily available copper catalysts and ligands, which afforded polymeric products with Mws up to 18 kDa. Using a range of techniques, the polymers were found to exhibit a glass transition temperature (Tg) of 85 °C, high thermal stability (Td = 274 °C), and high photoluminescent quantum efficiency (Φf = 0.29; λem = 448 nm), which underscore their potential for use in organic light-emitting diodes or other emissive devices, particularly where efficient blue emission is of value. The approach described offers practical advantages over other synthetic methods used to prepare main-chain carbazole-containing polymers, especially with regard to the lack of need for rigorously inert conditions and the absence of byproducts generated during the polymerization reaction.

  6. Formation of photo-induced index grating in azo-carbazole dye-doped polymer

    NASA Astrophysics Data System (ADS)

    Kawabe, Yutaka; Fukuzawa, Kodai; Uemura, Takuya; Matsuura, Katsufumi; Yoshikawa, Toshio; Nishide, Jun-ichi; Sasabe, Hiroyuki

    2012-10-01

    An azo-carbazole dye, 3-[(4-Nitrophenyl)azo]-9H-carbazole-9-ethanol (NACzEtOH), and its relatives doped in polyacrylate films have been known to show `photorefractive' effect without external electric field even in symmetric optical alignment. We have already observed strong energy transfer due to phase-shifted grating by two-beam coupling experiments made for NACzEtOH doped PMMA films. Although the operation mechanism is still unknown, the high efficiency of diffraction is very promising for the application to real-time holography. For the convenience of analysis, we modified Kogelnik's theory for thick grating by correcting the constraint condition and applied it to evaluate refractive index modulation and other parameters quantitatively. In order to clarify the operation mechanism, we conducted the writing and erasing of gratings by using red and green laser beams and analyzed the diffraction magnitude and response dynamics, showing that the response time strongly depended on the writing wavelength, and that the grating formation and its phase shift were not always synchronized.

  7. Synthesis, photophysical and electrochemical properties of two novel carbazole-based dye molecules

    NASA Astrophysics Data System (ADS)

    Zhang, Qing; Zhu, Weiju; Fang, Min; Yin, Fangfang; Li, Cun

    2015-01-01

    Two carbazole-based dye molecules: 3-(6-benzothiazol-2-yl-9H-hexylcarbazole-3-yl)-2-cyano-acylic acid (D3) and 3-[5-(6-benzothiazol-2-yl-9H-hexylcarbazole-3-yl)-thiophen-2-yl]-2-cyan-acylic acid (D4) were synthesized by an approach from carbazole derivate using Vilsmeier-Haack, Suzuki cross-coupling and Knoevenagel reactions. Their physical and electrochemical properties were investigated. D3 and D4 exhibit different optical properties, such as UV absorption, photoluminescence, fluorescence quantum yield and fluorescence lifetime in different solvents. Compared with D3 without a thiophene unit, the maximum absorption wavelength of D4 red-shift obviously and its fluorescence intensity is also enhanced. A shift of the EHOMO and ELUMO is observed for D3 (EHOMO = 2.06 V, ELUMO = -1.39 V vs. NHE) and D4 (EHOMO = 1.73 V, ELUMO = -1.33 V vs. NHE). D3 and D4 can be used as dyes for dye-sensitized solar cells (DSSCs) with TiO2 nanomaterial because their EHOMO are lower than the conduction band edge of TiO2 [-0.5 V (vs. NHE)] and their ELUMO are higher than the I3-/I- redox potential [0.42 V (vs. NHE)].

  8. Smart windows application of carbazole and triazine based star shaped architecture.

    PubMed

    Guzel, Merve; Soganci, Tugba; Ayranci, Rukiye; Ak, Metin

    2016-08-03

    A novel triazine-based, star shape and electroactive monomer, 2,4,6-tris(2-(9H-carbazol-9-yl)ethoxy)-1,3,5-triazine (TCZ) which contains 2,4,6-trichloro-1,3,5-triazine as the core and 2-(9H-carbazol-9-yl)ethanol as the arms, was successfully synthesized. After electrochemical polymerization of the TCZ monomer, called PTCZ, the polymer shows superior optoelectronic and thermal properties due to its unique three-dimensional shape and highly-branched structure in comparison with linear analogues. Electrochromic studies exhibited that PTCZ has turquoise color in the oxidized state and is transparent in the neutral state. Due to the fact that the redox color characteristics of PTCZ are indispensable for smart windows, a PTCZ-based electrochromic device was formed with PEDOT as complementary coloring material. A potential range of -1.5 to +1.8 V was determined to be suitable for operating the PTCZ/PEDOT device between transparent and blue colors. Characterizations of the device were performed in term of switching times, optical contrast, optical memory and redox stability.

  9. Biodegradation of crystal violet by the white rot fungus phanerochaete chrysosporium

    SciTech Connect

    Bumpus, J.A.; Brock, B.J.

    1988-01-01

    Biodegradation of crystal violet (N,N,N',N',N',N''- hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,N',N',N'' -pentamethylpararosaniline, N,N,N',N'' -tetramethylpararosaniline, and N,N',N'' -trimethylpararosaniline) formed by sequential N-demethylation of the parent compound. Metabolite formation also occurred when crystal violet was incubated with the extracellular fluid obtained from ligninolytic cultures of this fungus, provided that an H2O2-generating system was supplied. This, as well as the fact that a purified ligninase catalyzed N-demethylation of crystal violet, demonstrated that biodegradation of crystal violet by this fungus is dependent, at least in part, upon its lignin-degrading system. In addition to crystal violet, six other triphenylmethane dyes (pararosaniline, cresol red, bromphenol blue, ethyl violet, malachite green, and brilliant green) were shown to be degraded by the lignin-degrading system of this fungus.

  10. 1,2-Di­hydro­spiro­[carbazole-3(4H),2′-[1,3]dioxolane

    PubMed Central

    Bjerrum, Janni Vester; Ulven, Trond; Bond, Andrew D.

    2009-01-01

    In the title compound, C14H15NO2, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the dioxolane ring points to one side of the carbazole plane. Neighbouring mol­ecules form edge-to-face inter­actions in which the NH group is directed towards an adjacent carbazole unit, with a shortest H⋯C contact of 2.72 Å. These inter­actions arrange the mol­ecules into one-dimensional herringbone-type motifs, which pack so that the methyl­ene groups of the dioxolane ring lie over the face of a neighbouring carbazole unit with a shortest H⋯C contact of 2.85 Å. PMID:21582234

  11. The Blue–Violet Color of Pentamethylbismuth: A Visible Spin‐Orbit Effect

    PubMed Central

    2016-01-01

    Abstract Two‐component relativistic time‐dependent density functional theory calculations with spin‐orbit coupling predict yellow and orange–red absorption for BiPh5 and BiMe5, respectively, providing an excellent explanation for their respective violet and blue–violet colors. According to the calculations, the visible absorption is clearly attributable to a single transition from a ligand‐based HOMO to a low‐energy LUMO with a significant contribution from a relativistically stabilized Bi 6s orbital. Surprisingly, scalar releativistic calculations completely fail to reproduce the observed visible absorption and place it at the violet/near‐UV borderline instead. PMID:28168144

  12. 3-Methoxy-2-methyl-carbazole-1,4-quinone, carbazomycins D and F from Streptomyces sp. CMU-JT005.

    PubMed

    Ruanpanun, Pornthip; Dame, Zerihun Teklemariam; Laatsch, Hartmut; Lumyong, Saisamorn

    2011-09-01

    3-Methoxy-2-methyl-carbazole-1,4-quinone (1) together with carbazomycins D (2) and F (3) were isolated from the crude extract of Streptomyces CMU-JT005, an actinomycete with nematicidal activity. 3-Methoxy-2-methyl-carbazole-1,4-quinone is reported here for the first time from nature. In this paper, we describe the isolation and structure elucidation of the compounds together with the characterization of the Streptomyces strain CMU-JT005.

  13. Photophysical properties and computational investigation on substituent effects on the structural and electronic properties of 3,6-di(thiophene-2-yl)-carbazole-based derivatives

    NASA Astrophysics Data System (ADS)

    Sriyab, Suwannee; Gleeson, Matthew Paul; Hannongbua, Supa; Suramitr, Songwut

    2016-12-01

    A series of 3,6-carbazole-based derivatives, 3,6-CzTh-(1), 3,6-CzTh-(2), 3,6-CzTh-(3) and 3,6-CzTh-(4), were synthesized to investigate the influence of structural distortion on intramolecular charge transfer (ICT) complexation between the conjugation components and carbazole core unit of the 3,6-carbazole-based derivatives. The 3,6-carbazole-based derivatives were synthesized and analysed using UV-Visible, photoluminescence spectroscopy and DFT calculations. The electron-donating substituents on the carbazole core unit, which was linked by formyl and acetyl at the 3,6-positions of the carbazole core so as to directly involve the electron-donating edge substituents in backbone, exhibited conjugation breaks in the middle of the carbazole core units. The break lead to a planar structure with an extraordinary ability to stabilize on the excited state resulting in a strong fluorescence quantum yield (Vfluo ≈ 0.6-0.7). The results of the Time-dependent density functional theory (TD-DFT) calculations were in agreement with the experimental results, and indicated that the low fluorescence of 3,6-CzTh-(1) and 3,6-CzTh-(2) is derived not only from intersystem crossing but also from internal conversion due to the proximity effect; this inference was also supported by the measurements of the photoluminescence spectra at low temperatures. In addition, factors leading efficiently to non-radiative processes were shown to be absent in 3,6-CzTh-(3) and 3,6-CzTh-(4). This work deepens our understanding of 3,6-di(thiophen-2-yl)-carbazole-based derivatives and provides insight into the future design of novel materials for improved fluorescence efficiencies and optoelectronic devices.

  14. Plasmid pCAR3 Contains Multiple Gene Sets Involved in the Conversion of Carbazole to Anthranilate†

    PubMed Central

    Urata, Masaaki; Uchimura, Hiromasa; Noguchi, Haruko; Sakaguchi, Tomoya; Takemura, Tetsuo; Eto, Kaori; Habe, Hiroshi; Omori, Toshio; Yamane, Hisakazu; Nojiri, Hideaki

    2006-01-01

    The carbazole degradative car-I gene cluster (carAaIBaIBbICIAcI) of Sphingomonas sp. strain KA1 is located on the 254-kb circular plasmid pCAR3. Carbazole conversion to anthranilate is catalyzed by carbazole 1,9a-dioxygenase (CARDO; CarAaIAcI), meta-cleavage enzyme (CarBaIBbI), and hydrolase (CarCI). CARDO is a three-component dioxygenase, and CarAaI and CarAcI are its terminal oxygenase and ferredoxin components. The car-I gene cluster lacks the gene encoding the ferredoxin reductase component of CARDO. In the present study, based on the draft sequence of pCAR3, we found multiple carbazole degradation genes dispersed in four loci on pCAR3, including a second copy of the car gene cluster (carAaIIBaIIBbIICIIAcII) and the ferredoxin/reductase genes fdxI-fdrI and fdrII. Biotransformation experiments showed that FdrI (or FdrII) could drive the electron transfer chain from NAD(P)H to CarAaI (or CarAaII) with the aid of ferredoxin (CarAcI, CarAcII, or FdxI). Because this electron transfer chain showed phylogenetic relatedness to that consisting of putidaredoxin and putidaredoxin reductase of the P450cam monooxygenase system of Pseudomonas putida, CARDO systems of KA1 can be classified in the class IIA Rieske non-heme iron oxygenase system. Reverse transcription-PCR (RT-PCR) and quantitative RT-PCR analyses revealed that two car gene clusters constituted operons, and their expression was induced when KA1 was exposed to carbazole, although the fdxI-fdrI and fdrII genes were expressed constitutively. Both terminal oxygenases of KA1 showed roughly the same substrate specificity as that from the well-characterized carbazole degrader Pseudomonas resinovorans CA10, although slight differences were observed. PMID:16672458

  15. Gentian violet induces wtp53 transactivation in cancer cells.

    PubMed

    Garufi, Alessia; D'Orazi, Valerio; Arbiser, Jack L; D'Orazi, Gabriella

    2014-04-01

    Recent studies suggest that gentian violet (GV) may have anticancer activity by inhibiting for instance NADPH oxidases (Nox genes) whose overexpression is linked to tumor progression. Nox1 overexpression has been shown to inhibit transcriptional activity of the oncosuppressor p53, impairing tumor cell response to anticancer drugs. The tumor suppressor p53 is a transcription factor that, upon cellular stress, is activated to induce target genes involved in tumor cell growth inhibition and apoptosis. Thus, its activation is important for efficient tumor eradication. In this study, we examined the effect of GV on wild-type (wt) p53 activity in cancer cells. We found that GV was able to overcome the inhibitory effect of the NADPH oxidase Nox1 on p53 transcriptional activity. For the first time we show that GV was able to directly induce p53/DNA binding and transcriptional activity. In vitro, GV markedly induced cancer cell death and apoptotic marker PARP cleavage in wtp53-carrying cells. GV-induced cell death was partly inhibited in cells deprived of p53, suggesting that the anticancer activity of GV may partly depend on p53 activation. GV is US Food and Drug Administration approved for human use and may, therefore, have therapeutic potential in the management of cancer through p53 activation.

  16. Gentian violet induces wtp53 transactivation in cancer cells

    PubMed Central

    GARUFI, ALESSIA; D’ORAZI, VALERIO; ARBISER, JACK L.; D’ORAZI, GABRIELLA

    2014-01-01

    Recent studies suggest that gentian violet (GV) may have anticancer activity by inhibiting for instance NADPH oxidases (Nox genes) whose overexpression is linked to tumor progression. Nox1 overexpression has been shown to inhibit transcriptional activity of the oncosuppressor p53, impairing tumor cell response to anticancer drugs. The tumor suppressor p53 is a transcription factor that, upon cellular stress, is activated to induce target genes involved in tumor cell growth inhibition and apoptosis. Thus, its activation is important for efficient tumor eradication. In this study, we examined the effect of GV on wild-type (wt) p53 activity in cancer cells. We found that GV was able to overcome the inhibitory effect of the NADPH oxidase Nox1 on p53 transcriptional activity. For the first time we show that GV was able to directly induce p53/DNA binding and transcriptional activity. In vitro, GV markedly induced cancer cell death and apoptotic marker PARP cleavage in wtp53-carrying cells. GV-induced cell death was partly inhibited in cells deprived of p53, suggesting that the anticancer activity of GV may partly depend on p53 activation. GV is US Food and Drug Administration approved for human use and may, therefore, have therapeutic potential in the management of cancer through p53 activation. PMID:24535435

  17. TOPICAL REVIEW: InGaN-based violet laser diodes

    NASA Astrophysics Data System (ADS)

    Nakamura, S.

    1999-06-01

    High-efficiency light-emitting diodes emitting amber, green, blue and ultraviolet light have been obtained through the use of InGaN active layers instead of GaN active layers. The localized energy states caused by In composition fluctuation in the InGaN active layer seem to be related to the high efficiency of the InGaN-based emitting devices. Long-lifetime violet InGaN multi-quantum-well/GaN/AlGaN separate-confinement heterostructure laser diodes (LDs) were successfully fabricated using epitaxially laterally overgrown GaN by reducing a large number of threading dislocations originating from the interface between GaN and sapphire substrate. The threading dislocations shorten the lifetime of the LDs through an increase of the threshold current density. The LDs with cleaved mirror facets showed an output power as high as 30 mW under room-temperature continuous-wave (CW) operation with a stable fundamental transverse mode. The lifetime of the LDs at a constant output power of 5 mW was estimated to be approximately 3000 h under CW operation at an ambient temperature of 50 °C. These results indicate that these LDs already can be used for many real applications, such as digital versatile disks, laser printers, sensors and exciting light sources as a commercial product with a high output power and a high reliability.

  18. Novel conjugates of aminoadamantanes with carbazole derivatives as potential multitarget agents for AD treatment

    PubMed Central

    Bachurin, Sergey O.; Shevtsova, Elena F.; Makhaeva, Galina F.; Grigoriev, Vladimir V.; Boltneva, Natalia P.; Kovaleva, Nadezhda V.; Lushchekina, Sofya V.; Shevtsov, Pavel N.; Neganova, Margarita E.; Redkozubova, Olga M.; Bovina, Elena V.; Gabrelyan, Alexey V.; Fisenko, Vladimir P.; Sokolov, Vladimir B.; Aksinenko, Alexey Yu; Echeverria, Valentina; Barreto, George E.; Aliev, Gjumrakch

    2017-01-01

    A new group of compounds, promising for the design of original multitarget therapeutic agents for treating neurodegenerative diseases, based on conjugates of aminoadamantane and carbazole derivatives was synthesized and investigated. Compounds of these series were found to interact with a group of targets that play an important role in the development of this type of diseases. First of all, these compounds selectively inhibit butyrylcholinesterase, block NMDA receptors containing NR2B subunits while maintaining the properties of MK-801 binding site blockers, exert microtubules stabilizing properties, and possess the ability to protect nerve cells from death at the calcium overload conditions. The leading compound C-2h has been shown the most promising effects on all analyzed parameters. Thus, these compounds can be regarded as promising candidates for the design of multi-target disease-modifying drugs for treatment of AD and/or similar neuropathologies. PMID:28358144

  19. A new cytotoxic carbazole alkaloid and two new other alkaloids from Clausena excavata.

    PubMed

    Peng, Wen-Wen; Zeng, Guang-Zhi; Song, Wei-Wu; Tan, Ning-Hua

    2013-07-01

    One new carbazole alkaloid, excavatine A (1), and two additional new alkaloids, excavatine B (2) and excavatine C (3), were isolated from the stems and leaves of Clausena excavata Burm.f. (Rutaceae). Their structures were determined on the basis of detailed spectroscopic analyses, especially 2D-NMR and HR-EI-MS data. Compounds 1-3 were tested for their cytotoxic activities against A549, HeLa, and BGC-823 cancer cell lines, and for their antimicrobial activities against Candida albicans and Staphylococcus aureus. Only 1 exhibited cytotoxicity against A549 and HeLa cell lines with the IC50 values of 5.25 and 1.91 μg/ml, respectively.

  20. Photochemical and nonphotochemical hole burning in dimethyl-s-tetrazine in a polyvinyl carbazole film

    SciTech Connect

    Cuellar, E.; Castro, G.

    1981-01-01

    Hole burning as well as fluorescence line narrowing experiments have been performed on the system dimethyl-s-tetrazine in polyvinyl carbazole films at low temperatures. The first singlet electronic absorption bands are typical (300 cm-1 wide) of inhomogeneously broadened bands of guest molecules in amorphous organic hosts. In this paper, evidence is presented for both photochemical and nonphotochemical hole burning. The narrowest holes observed were lorentzian, had a width of 0.44 cm-1 at 1.8 K, and are believed to be of nonphotochemical origin. A model which envisions the guest molecules to occupy different sites in the polymer host with a distribution of energy barriers between sites is used to describe these observations. Finally, the fast (20 ps) relaxation time implied by the 0.44 cm-1 lorentzian linewidth is interpreted as indicative of the rate of site interconversion in the excited state.

  1. N-(2-Ethylhexyl)carbazole: A New Fluorophore Highly Suitable as a Monomolecular Liquid Scintillator.

    PubMed

    Montbarbon, Eva; Sguerra, Fabien; Bertrand, Guillaume H V; Magnier, Élodie; Coulon, Romain; Pansu, Robert B; Hamel, Matthieu

    2016-08-16

    The synthesis, photophysical properties, and applications in scintillation counting of N-(2-ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC-501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1-methylnaphthalene (1-MeNapht), and 4-isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC-501 A.

  2. Synthesis and antiproliferative activity of some ellipticine-like 11H-pyrido[a]carbazole derivatives.

    PubMed

    Ferlin, Maria Grazia; Gia, Ornella; Dalla Via, Lisa

    2011-10-04

    Some modified 11H-pyrido[a]carbazoles (11H-PyC) and their corresponding tetrahydro derivatives (11H-THPyC) were prepared. A common multistep pathway characterized by conventional reactions, including a Fischer-indole-type synthesis, yielded the tetracyclic compounds. To improve cytotoxicity, 11H-PyC and 11H-THPyC derivatives were endowed with a diethylaminoethyl side chain. The antiproliferative activity was assessed in three human tumor cell lines, and a number of derivatives showed a cytotoxic effect in agreement with their capacity to form a molecular intercalative complex with DNA and to interfere with the relaxation activity of DNA topoisomerase II. In contrast, three derivatives that exhibited significant antiproliferative efficacy, showed no inhibition of topoisomerase II, thus suggesting an unexpected and novel mode of action for these ellipticine-like compounds independent of topoisomerase II activity.

  3. Novel conjugates of aminoadamantanes with carbazole derivatives as potential multitarget agents for AD treatment.

    PubMed

    Bachurin, Sergey O; Shevtsova, Elena F; Makhaeva, Galina F; Grigoriev, Vladimir V; Boltneva, Natalia P; Kovaleva, Nadezhda V; Lushchekina, Sofya V; Shevtsov, Pavel N; Neganova, Margarita E; Redkozubova, Olga M; Bovina, Elena V; Gabrelyan, Alexey V; Fisenko, Vladimir P; Sokolov, Vladimir B; Aksinenko, Alexey Yu; Echeverria, Valentina; Barreto, George E; Aliev, Gjumrakch

    2017-03-30

    A new group of compounds, promising for the design of original multitarget therapeutic agents for treating neurodegenerative diseases, based on conjugates of aminoadamantane and carbazole derivatives was synthesized and investigated. Compounds of these series were found to interact with a group of targets that play an important role in the development of this type of diseases. First of all, these compounds selectively inhibit butyrylcholinesterase, block NMDA receptors containing NR2B subunits while maintaining the properties of MK-801 binding site blockers, exert microtubules stabilizing properties, and possess the ability to protect nerve cells from death at the calcium overload conditions. The leading compound C-2h has been shown the most promising effects on all analyzed parameters. Thus, these compounds can be regarded as promising candidates for the design of multi-target disease-modifying drugs for treatment of AD and/or similar neuropathologies.

  4. A pigment-producing spoilage bacterium responsible for violet discoloration of refrigerated market milk and cream.

    PubMed

    SEITZ, E W; ELLIKER, P R; SANDINE, W E

    1961-07-01

    A psychrophilic strain of bacteria identified as Chromobacterium lividum was established as the causative agent of an outbreak of violet discoloration in refrigerated, pasteurized retail milk and cream. The organism was rod-shaped, gram-negative, and produced viscid colonies with abundant violet pigment on Tryptone glucose yeast extract agar. Growth was abundant at 4 C but none occurred at 37 C. Growth in milk was characterized by a dark violet ring at the surface after a few days, and the deep violet color gradually extended through the product in older cultures. Some proteolysis occurred. The pigment appeared to be similar to that of other known species of Chromobacterium and assisted in identification of the genus of the causative organism. The isolated strain of C. lividum was destroyed by exposure to 56 C for 5 min which suggested postpasteurization contamination as the source of the spoilage organism in commercial milk and cream.

  5. 21 CFR 74.2602a - Ext. D&C Violet No. 2.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 0.2 percent. p- Toluidine, not more than 0.1 percent. p- Toluidine sulfonic acids, sodium salts, not... acid. (b) Specifications. Ext. D&C Violet No. 2 shall conform to the following specifications and...

  6. 21 CFR 74.2602a - Ext. D&C Violet No. 2.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 0.2 percent. p- Toluidine, not more than 0.1 percent. p- Toluidine sulfonic acids, sodium salts, not... acid. (b) Specifications. Ext. D&C Violet No. 2 shall conform to the following specifications and...

  7. 21 CFR 74.2602a - Ext. D&C Violet No. 2.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 0.2 percent. p- Toluidine, not more than 0.1 percent. p- Toluidine sulfonic acids, sodium salts, not... acid. (b) Specifications. Ext. D&C Violet No. 2 shall conform to the following specifications and...

  8. 21 CFR 74.2602a - Ext. D&C Violet No. 2.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 0.2 percent. p- Toluidine, not more than 0.1 percent. p- Toluidine sulfonic acids, sodium salts, not... acid. (b) Specifications. Ext. D&C Violet No. 2 shall conform to the following specifications and...

  9. 21 CFR 74.2602a - Ext. D&C Violet No. 2.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 0.2 percent. p- Toluidine, not more than 0.1 percent. p- Toluidine sulfonic acids, sodium salts, not... acid. (b) Specifications. Ext. D&C Violet No. 2 shall conform to the following specifications and...

  10. Biodegradation of hazardous triphenylmethane dye methyl violet by Rhizobium radiobacter (MTCC 8161).

    PubMed

    Parshetti, Ganesh; Saratale, Ganesh; Telke, Amar; Govindwar, Sanjay

    2009-09-01

    Rhizobium radiobacter MTCC 8161 completely decolorized methyl violet (10 mg l(-1)) within 8 h both at static and shaking conditions. The decolorization time increased with increasing dye concentration. The effect of different carbon and nitrogen sources on the decolorization of methyl violet was studied. The maximum decolorization was observed in the presence of sucrose (1%) and urea (1%). UV-Visible, HPLC and FTIR analysis of extracted products confirmed biodegradation of methyl violet. The significant increase in the activities of lignin peroxidase and aminopyrine N-demethylase in the cells obtained after decolorization indicated involvement of these enzymes in the decolorization process. In addition to methyl violet, this strain also shows an ability to decolorize various industrial dyes, (red HE7B, yellow 4G, blue 2B, navy blue HE22, red M5B and red HE3B).

  11. Properties, theoretical study and crystal structure of 3-benzothiazole-9-ethyl carbazole.

    PubMed

    Gu, Yingchun; Lin, Dayong; Fei, Xuening; Wang, Cuihong; Li, Ling; Tang, Yalin; Zhou, Jianguo

    2016-09-01

    The title compound of 3-benzothiazole-9-ethyl carbazole was synthesized by the reaction of 3-aldehyde-9-ethyl carbazole and 2-aminothiophenol. The compound was characterized by (1) H nuclear magnetic resonance (NMR) and mass spectrometry (MS). Its crystal structure was obtained and determined by single crystal X-ray diffraction. The results showed that the crystal belongs to the orthorhombic crystal system and the cell parameters of space group P2(1)2(1)2(1) were a = 5.6626 (12) Å, b = 12.606 (3) Å, c = 22.639 (5) Å, α = 90°, β = 90°, γ = 90°, V = 1616.0 (6) Å(3) , Z = 4, Dc = 1.350 mg/m(3) . The UV-vis and fluorescence spectra were also studied preliminarily. The fluorescence spectra of the title compound with bovine serum albumin (BSA) showed that BSA could be marked with the compound and the stability constant between them was 0.82 × 10(7)  M(-1) . Meanwhile, the crystal and molecule were theoretically surveyed by density functional tight-binding (DFTB). The results showed that there was an orbital overlap for lowest unoccupied molecular orbital (LUMO) between the neighbouring molecules for the crystal, which is different from the molecule structure. It was also showed that the crystal structure is a non-conductor. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Understanding the domino reaction between 3-chloroindoles and methyl coumalate yielding carbazoles. A DFT study.

    PubMed

    Domingo, Luis R; Sáez, José A; Emamian, Saeed R

    2015-02-21

    The molecular mechanism of the reaction between N-methyl-3-chloroindole and methyl coumalate yielding carbazole has been studied using DFT methods at the MPWB1K/6-311G(d,p) level in toluene. This reaction is a domino process that comprises three consecutive reactions: (i) a polar Diels-Alder (P-DA) reaction between indole and methyl coumalate yielding two stereoisomeric [2 + 4] cycloadducts (CAs); (ii) the elimination of HCl from these CAs affording two stereoisomeric intermediates; and (iii) the extrusion of CO2 in these intermediates, finally yielding the carbazole. This P-DA reaction proceeds in a completely regioselective and slightly exo selective fashion. In spite of the highly polar character of this P-DA reaction, it presents a high activation enthalpy of 21.8 kcal mol(-1) due to the loss of the aromatic character of the indole during the C-C bond formation. Thermodynamic calculations suggest that the P-DA reaction is the rate-determining step of this domino reaction; in addition, the initial HCl elimination in the formal [2 + 4] CAs is kinetically favoured over the extrusion of CO2. Although the P-DA reaction is kinetically and thermodynamically very unfavourable, the easier HCl and CO2 elimination from the [2 + 4] CAs together with the strong exergonic character of the CO2 extrusion makes the P-DA reaction irreversible. An ELF topological analysis of the bonding changes along the P-DA reaction supports a two-stage one-step mechanism. An analysis of the global DFT reactivity indices at the ground state of the reagents confirms the highly polar character of this P-DA reaction. Finally, the complete regioselectivity of the studied reactions can be explained using the Parr functions.

  13. 21 CFR 74.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false D&C Violet No. 2. 74.1602 Section 74.1602 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive...

  14. 21 CFR 74.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false D&C Violet No. 2. 74.1602 Section 74.1602 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive...

  15. 21 CFR 74.1602 - D&C Violet No. 2.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false D&C Violet No. 2. 74.1602 Section 74.1602 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Drugs § 74.1602 D&C Violet No. 2. (a) Identity. (1) The color additive...

  16. Photo Inactivation of Streptococcus mutans Biofilm by Violet-Blue light.

    PubMed

    Gomez, Grace F; Huang, Ruijie; MacPherson, Meoghan; Ferreira Zandona, Andrea G; Gregory, Richard L

    2016-09-01

    Among various preventive approaches, non-invasive phototherapy/photodynamic therapy is one of the methods used to control oral biofilm. Studies indicate that light at specific wavelengths has a potent antibacterial effect. The objective of this study was to determine the effectiveness of violet-blue light at 380-440 nm to inhibit biofilm formation of Streptococcus mutans or kill S. mutans. S. mutans UA159 biofilm cells were grown for 12-16 h in 96-well flat-bottom microtiter plates using tryptic soy broth (TSB) or TSB with 1 % sucrose (TSBS). Biofilm was irradiated with violet-blue light for 5 min. After exposure, plates were re-incubated at 37 °C for either 2 or 6 h to allow the bacteria to recover. A crystal violet biofilm assay was used to determine relative densities of the biofilm cells grown in TSB, but not in TSBS, exposed to violet-blue light. The results indicated a statistically significant (P < 0.05) decrease compared to the non-treated groups after the 2 or 6 h recovery period. Growth rates of planktonic and biofilm cells indicated a significant reduction in the growth rate of the violet-blue light-treated groups grown in TSB and TSBS. Biofilm viability assays confirmed a statistically significant difference between violet-blue light-treated and non-treated groups in TSB and TSBS. Visible violet-blue light of the electromagnetic spectrum has the ability to inhibit S. mutans growth and reduce the formation of S. mutans biofilm. This in vitro study demonstrated that violet-blue light has the capacity to inhibit S. mutans biofilm formation. Potential clinical applications of light therapy in the future remain bright in preventing the development and progression of dental caries.

  17. Direct-writing of inverted domains in lithium niobate using a continuous wave ultra violet laser.

    PubMed

    Muir, A C; Sones, C L; Mailis, S; Eason, R W; Jungk, T; Hoffman, A; Soergel, E

    2008-02-18

    The inversion of ferroelectric domains in lithium niobate by a scanning focused ultra-violet laser beam (lambda = 244 nm) is demonstrated. The resulting domain patterns are interrogated using piezoresponse force microscopy and by chemical etching in hydrofluoric acid. Direct ultra-violet laser poling was observed in un-doped congruent, iron doped congruent and titanium in-diffused congruent lithium niobate single crystals. A model is proposed to explain the mechanism of domain inversion.

  18. Strong ultraviolet and violet emissions from ZnO/TiO2 multilayer thin films

    NASA Astrophysics Data System (ADS)

    Xu, Linhua; Zheng, Gaige; Wu, Hongyan; Wang, Junfeng; Gu, Fang; Su, Jing; Xian, Fenglin; Liu, Zhanhui

    2013-06-01

    ZnO/TiO2 multilayer thin films were prepared by electron beam evaporation and the influence of annealing temperature on their structural and optical properties was investigated. The analyses of X-ray diffraction (XRD) show that TiO2 in the as-deposited ZnO/TiO2 multilayer thin film as well as in that one annealed at 300 °C is amorphous. When the annealing temperature is increased up to 400 °C, the TiO2 is transformed into a brookite phase. Eventually, the TiO2 is transformed into an anatase phase with the annealing temperature rising up to 500 °C. However, ZnO in these composite films all crystallizes in a wurtzite structure and has a preferred orientation along the (0 0 2) direction whether the ZnO/TiO2 multilayer thin film is annealed or not. The photoluminescence spectra show that all the samples have two strong emission peaks including an ultraviolet (UV) peak and a violet peak. The strong UV and violet co-emissions in ZnO materials is seldom reported previously. With the increase of annealing temperature, both the UV and violet emissions are enhanced. However, the intensity of UV emission is increased faster than that of the violet emission under the same annealing temperature. The mechanism of the violet emission and the reason for the variations of the UV and violet emissions with the different annealing temperatures are analyzed.

  19. Decolorization and biotransformation of triphenylmethane dye, methyl violet, by Aspergillus sp. isolated from Ladakh, India.

    PubMed

    Kumar, C Ganesh; Mongolla, Poornima; Basha, Anver; Joseph, Joveeta; Sarma, V U M; Kamal, Ahmed

    2011-03-01

    Methyl violet, used extensively in the commercial textile industry and as a biological stain, is a hazardous recalcitrant. Aspergillus sp. strain CB-TKL-1 isolated from a water sample from Tsumoriri Lake, Karzok, Ladakh, India, was found to completely decolorize methyl violet within 24 h when cultured under aerobic conditions at 25 degrees C. The rate of decolorization was determined by monitoring the decrease in the absorbance maxima of the dye by UV-visible spectroscopy. The decolorization of methyl violet was optimal at pH 5.5 and 30 degrees C when agitated at 200 rpm. Addition of glucose or arabinose (2%) as a carbon source and sodium nitrate or soyapeptone (0.2%) as a nitrogen source enhanced the decolorization ability of the culture. Furthermore, the culture exhibited a maximum decolorization rate of methyl violet after 24 h when the C:N ratio was 10. Nine N-demethylated decolorized products of methyl violet were identified based on UV-visible spectroscopy, Fourier transform infrared (FTIR), and LC-MS analyses. The decolorization of methyl violet at the end of 24 h generated mono-, di-, tri-, tetra-, penta-, and hexa-Ndemethylated intermediates of pararosaniline. The variation of the relative absorption peaks in the decolorized sample indicated a linear decrease of hexa-N-demethylated compounds to non-N-demethylated pararosaniline, indicating a stepwise N-demethylation in the decolorization process.

  20. Initial Conservative Management of Exomphalos Major with Gentian Violet

    PubMed Central

    Ferdous, KMN

    2012-01-01

    Aim: The purpose of the study was to assess the results of topical use of gentian violet (GV), among the babies with exomphalos major in our institute. Methods: The study was carried out retrospectively in a tertiary care hospital during the period from 2005 to 2010 inclusive. Exomphalos patients were classified as major if diameter was >5 cm and/or had liver in the sac as content. These patients were initially preferentially treated conservatively with topical 1% GV over the sac resultig a ventral hernia to be repaired later. Results: A total of 84 exomphalos patients were admitted during the study period. Among them, 37 neonates (26 males and 11 females) had exomphalos major (EM). Ten of them were prenatally diagnosed. The mean gestational age at delivery was 35 weeks, and mean birth weight was 2.1 Kg. Mean age at presentation was 3.7 days. Thirty (81%) had other associated anomalies, mostly cardiac (66.6%) and pulmonary (46.6%). Ten patients with EM needed early operation because of ruptured sac, and other anomalies. There were 2 pre-operative and 8 postoperative deaths in this subgroup. Twenty seven patients were treated conservatively, among these 4 died of overwhelming sepsis. Remaining 23 patients left the hospital with a ventral hernia planned to be repaired at 1 year of age. Overall mortality in our series was 37.83%. Conclusion: Initial conservative treatment of the sac with GV results in satisfactory outcome for infants with EM who cannot undergo immediate closure. PMID:26023410

  1. Investigation of ultra violet (UV) resistance for high strength fibers

    NASA Astrophysics Data System (ADS)

    Said, M. A.; Dingwall, Brenda; Gupta, A.; Seyam, A. M.; Mock, G.; Theyson, T.

    Ultra long duration balloons (ULDB), currently under development by the National Aeronautics and Space Administration (NASA), requires the use of high strength fibers in the selected super-pressure pumpkin design. The pumpkin shape balloon concept allows clear separation of the load transferring functions of the major structural elements of the pneumatic envelope, the tendons and the film. Essentially, the film provides the gas barrier and transfers only local pressure load to the tendons. The tendons, in the mean time, provide the global pressure containing strength. In that manner, the strength requirement for the film only depends on local parameters. The tendon is made of p-phenylene-2,6-benzobisoxazole (PBO) fibers, which is selected due to its high strength to weight ratio when compared to other high performance, commercially available, fibers. High strength fibers, however, are known to degrade upon exposure to light, particularly at short wavelengths. This paper reports the results of an investigation of the resistance of four commercial high strength fibers to ultra violet (UV) exposure. The results indicate that exposing high strength fibers in continuous yarn form to UV led to serious loss in strength of the fibers except for Spectra® fibers. The adverse changes in mechanical behavior occurred over short duration of exposure compared to the 100 day duration targeted for these missions. UV blocking finishes to improve the UV resistance of these fibers are being investigated. The application of these specially formulated coatings is expected to lead to significant improvement of the UV resistance of these high performance fibers. In this publication, we report on the mechanical behavior of the fibers pre- and post-exposure to UV, but without application of the blocking finishes.

  2. Transcriptomic insight into terpenoid and carbazole alkaloid biosynthesis, and functional characterization of two terpene synthases in curry tree (Murraya koenigii)

    PubMed Central

    Meena, Seema; Rajeev Kumar, Sarma; Dwivedi, Varun; Kumar Singh, Anup; Chanotiya, Chandan S.; Akhtar, Md. Qussen; Kumar, Krishna; Kumar Shasany, Ajit; Nagegowda, Dinesh A.

    2017-01-01

    Curry tree (Murraya koenigii L.) is a rich source of aromatic terpenes and pharmacologically important carbazole alkaloids. Here, M. koenigii leaf transcriptome was generated to gain insight into terpenoid and alkaloid biosynthesis. Analysis of de novo assembled contigs yielded genes for terpene backbone biosynthesis and terpene synthases. Also, gene families possibly involved in carbazole alkaloid formation were identified that included polyketide synthases, prenyltransferases, methyltransferases and cytochrome P450s. Further, two genes encoding terpene synthases (MkTPS1 and MkTPS2) with highest in silico transcript abundance were cloned and functionally characterized to determine their involvement in leaf volatile formation. Subcellular localization using GFP fusions revealed the plastidial and cytosolic localization of MkTPS1 and MkTPS2, respectively. Enzymatic characterization demonstrated the monoterpene synthase activity of recombinant MkTPS1, which produced primarily (−)-sabinene from geranyl diphosphate (GPP). Recombinant MkTPS2 exhibited sesquiterpene synthase activity and formed (E,E)-α-farnesene as the major product from farnesyl diphosphate (FPP). Moreover, mRNA expression and leaf volatile analyses indicated that MkTPS1 accounts for (−)-sabinene emitted by M. koenigii leaves. Overall, the transcriptome data generated in this study will be a great resource and the start point for characterizing genes involved in the biosynthetic pathway of medicinally important carbazole alkaloids. PMID:28272514

  3. Culture of the green microalga Botryococcus braunii Showa with LED irradiation eliminating violet light enhances hydrocarbon production and recovery.

    PubMed

    Atobe, Sueko; Saga, Kiyotaka; Maeyama, Haruko; Fujiwara, Kazuhiro; Okada, Shigeru; Imou, Kenji

    2014-01-01

    The green microalga Botryococcus braunii (B. braunii), race B, was cultured under light-emitting diode (LED) irradiation with and without violet light. This study examined the effect of violet light on hydrocarbon recovery and production in B. braunii. C34 botryococcene hydrocarbons were efficiently extracted by thermal pretreatments at lower temperatures when the alga was cultured without violet light. The hydrocarbon content was also higher (approximately 3%) in samples cultured without violet light. To elucidate the mechanism of effective hydrocarbon recovery and production, we examined structural components of the extracellular matrix (ECM). The amounts of extracellular carotenoids and water-soluble polymers extracted by thermal pretreatment from the ECM were decreased when the alga was cultured without violet light. These results indicate that LED irradiation without violet light is more effective for hydrocarbon recovery and production in B. braunii. Furthermore, structural ECM components are closely involved in hydrocarbon recovery and production in B. braunii.

  4. 4-Fluoro-N-methyl-N-(1,2,3,4-tetra­hydro­carbazol-3-yl)benzene­sulfonamide

    PubMed Central

    Rasmussen, Kaspar Gothardt; Ulven, Trond; Bond, Andrew D.

    2009-01-01

    In the title compound, C19H19FN2O2S, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the plane of the fluoro­phenyl ring forms a dihedral angle of 41.5 (1)° with respect to the carbazole mean plane. The crystal structure is segregated into layers containing the carbazole units and fluoro­phenyl rings in alternate (200) planes. The carbazole units form centrosymmetric face-to-face inter­actions [inter­planar separation = 4.06 (1) Å] and edge-to-face inter­actions in which the N—H group is directed towards an adjacent carbazole face, with a shortest H⋯C contact of 2.53 Å. The fluoro­phenyl rings form face-to-face contacts with an approximate inter­planar separation of 3.75 Å and a centroid–centroid distance of 4.73 (1) Å. PMID:21582475

  5. High-Efficiency Perovskite Solar Cells Based on New TPE Compounds as Hole Transport Materials: The Role of 2,7- and 3,6-Substituted Carbazole Derivatives.

    PubMed

    Zhu, Linna; Shan, Yahan; Wang, Rui; Liu, Debei; Zhong, Cheng; Song, Qunliang; Wu, Fei

    2017-03-28

    In this work, four tetraphenylethylene (TPE)-centered hole transport materials (HTMs), with 2,7- or 3,6-substituted carbazole derivatives as periphery groups are deliberately synthesized and characterized. Their photophysical properties, energy levels, and photovoltaic performances are systematically investigated, and their performances as HTMs are discussed with respect to the different substituent positions on the carbazole moiety. It is interesting to find that the TPE-based HTMs with 2,7-carbazole substituents rival the 3,6-carbazole substituents in hole mobility and hole extraction ability. A high power conversion efficiency of up to 16.74 % is achieved for the devices based on the 2,7-carbazole periphery arms, which is even higher than the one of the "star" HTM Spiro-OMeTAD (2,2-7,7-tetrakis(N,N'-diparamethoxy-phenylamine 9,9'-spirobifluorene) under the same conditions. As far as we know, this is the highest efficiency achieved in tetraphenylethylene derivatives.

  6. Localization of the Violet and Yellow Receptor Cells in the Crayfish Retinula

    PubMed Central

    Eguchi, Eisuke; Waterman, Talbot H.; Akiyama, Jiro

    1973-01-01

    Cellular identification of color receptors in crayfish compound eyes has been made by selective adaptation at 450 nm and 570 nm, wavelengths near the λmax's of the two retinular cell classes previously demonstrated. By utilizing earlier evidence, the concentration of lysosome-related bodies (LRB) was used to measure relative light adaptation and thus wavelength sensitivity in 665 retinular cells from six eyes. The observed particle distributions demonstrate the following. Both violet and yellow receptors occur ordinarily in each retinula. Of the seven regular retinular cells two (R3 and R4 using Eguchi's numbering [1965]) have mean sensitivities significantly greater to violet and less to yellow than the other five. The latter apparently comprise "pure" yellow receptors (R1 and R7) and mixed yellow and violet receptors (R2, R5, and R6). Explanations of such ambiguity requiring two visual pigments in single retinular cells or intercellular coupling of adjacent neuroreceptors are apparently precluded by previous evidence. Present data imply alternatively some positional variability in the violet pair's location in individual retinulas. Thus R3 and R4 are predominantly the violet receptors but in some retinulas R2 and R3 or R4 and R5 (or rarely some other cell pairs) may be. The retinal distribution of such variations has yet to be determined. In agreement with intracellular recordings the blue and yellow cells here identified belong to both the vertical and horizontal e-vector sensitive channels. PMID:4755845

  7. Bioremediation of crystal violet using air bubble bioreactor packed with Pseudomonas aeruginosa.

    PubMed

    El-Naggar, Manal A; El-Aasar, Samy A; Barakat, Khlood I

    2004-12-01

    Seven water and sediment samples were collected and tested for decolorizing crystal violet. Pseudomonas aeruginosa was the most effective isolate for dye decolorization. The LC(50) of the crystal violet (115 mg/l) was measured using Artemia salina as a biomarker. The effect of different heavy metals on crystal violet decolorization was investigated. Cd(2+) and Fe(3+) ions showed marginal enhancement of the decolorization process, the rate was 1.35 mg/l/h compared to 1.25 mg/l/h for the control. Phenol and m-cresol showed no effect on crystal violet decolorization, meanwhile p-cresol and p-nitrophenol reduced the decolorization rate to 1.07 and 0.01 mg/l/h, respectively. P. aeruginosa cells were immobilized by entrapment in agar-alginate beads. The beads were cultivated and reused in Erlenmeyer flask and in an air bubble column bioreactor and they enhanced the crystal violet decolorization rate to 3.33 and 7.5 mg/l/h, respectively.

  8. Comparison of violet diode laser with CO II laser in surgical performance of soft tissues

    NASA Astrophysics Data System (ADS)

    Hatayama, H.; Kato, J.; Inoue, A.; Akashi, G.; Hirai, Y.

    2007-02-01

    The violet diode laser (405nm) has recently begun to be studied for surgical use and authors reported the soft tissue could be effectively incised by irradiation power of even less than 1W. The wavelength of this laser is highly absorbed by hemoglobin, myoglobin or melanin pigment. Cutting or ablating soft tissues by lower irradiation power might be preferable for wound healing. The CO II laser is known to be preferable for low invasive treatment of soft tissues and widely used. The CO II laser light (10.6μm) is highly absorbed by water and proper for effective ablation of soft tissues. In this paper, we report the comparison of the violet diode laser with the CO II laser in surgical performance of soft tissues. Tuna tissue was used as an experimental sample. In the case of the violet diode laser, extensive vaporization of tissue was observed after the expansion of coagulation. Carbonization of tissue was observed after the explosion. On the other hand, consecutive vaporization and carbonization were observed immediately after irradiation in the case of CO II laser. The violet diode laser could ablate tissue equivalently with the CO II laser and coagulate larger area than the CO II laser. Therefore the violet diode laser might be expectable as a surgical tool which has excellent hemostatis.

  9. Toward quantum-dot cellular automata units: thiolated-carbazole linked bisferrocenes

    NASA Astrophysics Data System (ADS)

    Arima, Valentina; Iurlo, Matteo; Zoli, Luca; Kumar, Susmit; Piacenza, Manuel; Della Sala, Fabio; Matino, Francesca; Maruccio, Giuseppe; Rinaldi, Ross; Paolucci, Francesco; Marcaccio, Massimo; Cozzi, Pier Giorgio; Bramanti, Alessandro Paolo

    2012-01-01

    Quantum-dot Cellular Automata (QCA) exploit quantum confinement, tunneling and electrostatic interaction for transistorless digital computing. Implementation at the molecular scale requires carefully tailored units which must obey several structural and functional constraints, ranging from the capability to confine charge efficiently on different `quantum-dot centers'--in order to sharply encode the Boolean states--up to the possibility of having their state blanked out upon application of an external signal. In addition, the molecular units must preserve their geometry in the solid state, to interact electrostatically in a controlled way. Here, we present a novel class of organometallic molecules, 6-3,6-bis(1-ethylferrocen)-9H-carbazol-9-yl-6-hexan-1-thiols, which are engineered to satisfy all such crucial requirements at once, as confirmed by electrochemistry and scanning tunneling microscopy measurements, and first principles density functional calculations.Quantum-dot Cellular Automata (QCA) exploit quantum confinement, tunneling and electrostatic interaction for transistorless digital computing. Implementation at the molecular scale requires carefully tailored units which must obey several structural and functional constraints, ranging from the capability to confine charge efficiently on different `quantum-dot centers'--in order to sharply encode the Boolean states--up to the possibility of having their state blanked out upon application of an external signal. In addition, the molecular units must preserve their geometry in the solid state, to interact electrostatically in a controlled way. Here, we present a novel class of organometallic molecules, 6-3,6-bis(1-ethylferrocen)-9H-carbazol-9-yl-6-hexan-1-thiols, which are engineered to satisfy all such crucial requirements at once, as confirmed by electrochemistry and scanning tunneling microscopy measurements, and first principles density functional calculations. Electronic supplementary information (ESI

  10. Crystal structures of two new carbazole derivatives: 12-(4-nitro­phen­yl)-7-phenyl­sulfonyl-7H-benzofuro[2,3-b]carbazole and 2-methyl-4-(4-nitro­phen­yl)-9-phenyl­sulfonyl-9H-thieno[2,3-b]carbazole

    PubMed Central

    Swaminathan, K.; Narayanan, P.; Sethusankar, K.; Saravanan, Velu; Mohanakrishnan, Arasambattu K.

    2016-01-01

    The title compounds, C30H18N2O5S, (I), and C27H18N2O4S2, (II), are carbazole derivatives with a phenyl­sulfonyl group and a nitro­phenyl group attached to the carbazole moiety in identical positions in both mol­ecules. A benzo­furan ring system in (I) and a methyl­thio­phene ring in (II) are fused with the respective carbazole moieties on the same sides. The mean plane of the carbazole ring system makes a dihedral angle of 3.17 (7)° with the benzo­furan ring system in (I) and a dihedral angle of 3.39 (11)° with the methyl­thio­phene ring in (II), implying that both fused units are essentially planar. The mean planes of the carbazole ring systems in both the compounds are almost orthogonal to the respective nitro-substituted phenyl rings, making dihedral angles of 75.64 (10) and 77.63 (12)° in compounds (I) and (II), respectively. In (I), the phenyl­sulfonyl ring system is positionally disordered with a refined occupancy ratio of 0.63 (2):0.37 (2). In both compounds, the mol­ecular structures are stabilized by intra­molecular C—H⋯O hydrogen bonds, generating S(6) ring motifs with the sulfone group O atoms. In the crystal of compound (I), mol­ecules are linked by pairs of C—H⋯O hydrogen bonds, which generate R 2 2(18) inversion dimers, and inter­connected by C(14) chains running along the c-axis direction, whereas in compound (II), the C—H⋯O hydrogen bonds generate R 4 3(37) ring motifs. In the crystals of both compounds, C—H⋯O hydrogen-bonded sheets are formed lying parallel to (10-1). In addition, C—H⋯π and offset π–π inter­actions [inter­centroid distance = 3.7158 (14) Å in (I) and 3.9040 (15) Å in (II)] are also present in the crystals of both compounds. PMID:27980820

  11. Post-Katrina fecal contamination in Violet Marsh near New Orleans.

    PubMed

    Furey, John S; Fredrickson, Herbert; Foote, Chris; Richmond, Margaret

    2007-06-01

    Fecal material entrained in New Orleans flood waters was pumped into the local environment. Violet Marsh received water pumped from St. Bernard Parish and the Lower Ninth Ward. Sediment core samples were collected from canals conducting water from these areas to pump stations and from locations within Violet Marsh. Viable indicator bacteria and fecal sterols were used to assess the levels of fecal material in sediment deposited after the levee failures and deeper sediments deposited before. Most of the cores had fecal coliform levels that exceed the biosolids criterion. All of the cores had fecal sterols that exceeded the suggested environmental quality criterion. Our data show both a long history of fecal contamination in Violet Marsh and an increase in fecal loading corresponding to the failure of the levee system. The work was performed as part of the Interagency Performance Evaluation Task Force investigation into the consequences of the failures of the New Orleans levee system.

  12. Oxidation kinetics of crystal violet by potassium permanganate in acidic medium

    NASA Astrophysics Data System (ADS)

    Khan, Sameera Razi; Ashfaq, Maria; Mubashir; Masood, Summyia

    2016-05-01

    The oxidation kinetics of crystal violet (a triphenylmethane dye) by potassium permanganate was focused in an acidic medium by the spectrophotometric method at 584 nm. The oxidation reaction of crystal violet by potassium permanganate is carried out in an acidic medium at different temperatures ranging within 298-318 K. The kinetic study was carried out to investigate the effect of the concentration, ionic strength and temperature. The reaction followed first order kinetics with respect to potassium permanganate and crystal violet and the overall rate of the reaction was found to be second order. Thermodynamic activation parameters like the activation energy ( E a), enthalpy change (Δ H*), free energy change (Δ G*), and entropy change (Δ S*) have also been evaluated.

  13. Solvatochromic effect and kinetics of methyl violet reduction with potassium iodide in water-isopropanol mixtures

    NASA Astrophysics Data System (ADS)

    Ashfaq, Maria; Saeed, Rehana; Khan, Sameera Razi; Masood, Summyia

    2016-12-01

    The solvent influence on the reduction kinetics of methyl violet with iodide in binary mixture of aqueous isopropanol was investigated spectrophotometrically. The absorption spectra of methyl violet were recorded in water, aqueous isopropanol and absolute isopropanol. In these solvents λmax was in the range from 580.5 to 582.5 nm. The CNIBS/R-K model was used to calculate the solvatochromic parameters in a binary mixture; polynomial equation was also applied to describe the experimental data. The transition energies ( E T) were calculated. They show bathochromic shift with the decrease in the polarity of the solvent. The temperature was varied from 298-318 K, while the pH of the reaction was maintained at 4.99 and 6.00. The reduction reaction was found to be first order by potassium iodide and zero order by methyl violet. The thermodynamic parameters were also evaluated to support the kinetic data.

  14. Oxadiazole-carbazole polymer (POC)-Ir(ppy)3 tunable emitting composites

    NASA Astrophysics Data System (ADS)

    Bruno, Annalisa; Borriello, Carmela; Di Luccio, Tiziana; Sessa, Lucia; Concilio, Simona; Haque, Saif A.; Minarini, Carla

    2017-04-01

    POC polymer is an oxadiazole-carbazole copolymer we have previously synthetized and established as light emitting material in Organic Light Emitting Devices (OLEDs), although POC quantum yield emission efficiency and color purity still need to be enhanced. On the other hand, tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) complexes, namely Ir(ppy)3 are among the brightest luminophores employed in green light emitting devices. Our aim, in this work, is to take advantage of Ir(ppy)3 bright emission by combining the Ir complex with blue emitting POC to obtain tunable light emitting composites over a wide range of the visible spectrum. Here we have investigated the optical proprieties POC based nanocomposites with different concentrations of Ir(ppy)3, ranging from 1 to 10 wt%. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to the dopants, resulting in white-emitting composites. The most intense and stable emission has been found when POC was doped with about 5 wt% concentration of Ir(ppy)3.

  15. Carbazole-containing polyphenylquinolines as a basis for optoelectronic materials with white luminescence

    SciTech Connect

    Svetlichnyi, V. M.; Aleksandrova, E. L.; Nekrasova, T. N.; Smyslov, R. Yu.; Miagkova, L. A.; Matyushina, N. V.

    2012-04-15

    The photophysical properties of poly-2,2 Prime -(1-dodecyl carbazole-4,7-yl)-6,6 Prime -(oxy)-bis-(4-phenylquinoline) in a solution, as a film, and in a poly(methyl methacrylate) or poly-N-vinylcarbazole host matrix have been studied. Considerable positive solvatochromism in the photoluminescence spectra, compared with solvatochromism in the absorption spectra, indicates that the dipole moment of the donor-acceptor complex increases in the excited state. Calculations show that the dipole moments of the complex in the ground and excited states differ by more than an order of magnitude. Upon transition to films, photoluminescence is observed in the entire visible spectral range (white luminescence). The intensity of the white luminescence grows by an order of magnitude when the polymer is dispersed in a poly(methyl methacrylate) matrix. The integrated photosensitivity and parameters of the photogeneration process (quantum yield of carrier photogeneration, quantum yield of free carrier formation, and thermalization radii) have been determined.

  16. Discovery of a Carbazole-Derived Lead Drug for Human African Trypanosomiasis

    PubMed Central

    Thomas, Sarah M.; Purmal, Andrei; Pollastri, Michael; Mensa-Wilmot, Kojo

    2016-01-01

    The protozoan parasite Trypanosoma brucei causes the fatal illness human African trypanosomiasis (HAT). Standard of care medications currently used to treat HAT have severe limitations, and there is a need to find new chemical entities that are active against infections of T. brucei. Following a “drug repurposing” approach, we tested anti-trypanosomal effects of carbazole-derived compounds called “Curaxins”. In vitro screening of 26 compounds revealed 22 with nanomolar potency against axenically cultured bloodstream trypanosomes. In a murine model of HAT, oral administration of compound 1 cured the disease. These studies established 1 as a lead for development of drugs against HAT. Pharmacological time-course studies revealed the primary effect of 1 to be concurrent inhibition of mitosis coupled with aberrant licensing of S-phase entry. Consequently, polyploid trypanosomes containing 8C equivalent of DNA per nucleus and three or four kinetoplasts were produced. These effects of 1 on the trypanosome are reminiscent of “mitotic slippage” or endoreplication observed in some other eukaryotes. PMID:27561392

  17. Asymmetric energy transfer and optical diffraction in novel molecular glass with carbazole moiety

    NASA Astrophysics Data System (ADS)

    Tsutsumi, Naoto; Eguchi, Junya; Sakai, Wataru

    2006-12-01

    Asymmetric energy transfer and optical diffraction under optically interfered beams was presented in composites with novel star-shaped molecular glass end-caped by carbazole moiety, α,α',α″-tris-(4-(carbazoryl)- n-hexyloxyphenyl)-1,3,5-triisopropylbenzene (Tris). Composite consisted of Tris as host matrix, 2,4,7-trinitro-9-fluorenone (TNF) as a sensitizer, ( S)-(-)-1-(4-nitrophenyl)-2-pyrrolidine-methanol (NPP) as a nonlinear optical dye and either tricresyl phosphate (TCP), n-butyl benzyl phthalate (BBP), diphenyl phthalate (DPP), or dicyclohexyl phthalate (DCP) as a plasticizer. Asymmetric two beam coupling (asymmetric energy transfer) and beam diffraction were achieved with no external field. Glass transition temperature of the composites plays an important role for these phenomena of asymmetric energy transfer and optical diffraction with no external field. Highest net gain coefficient of 59.7 cm -1 with optical gain of 151.3 cm -1 and absorption coefficient of 91.6 cm -1 was obtained for Tris/NPP/DPP/TNF (35/20/40/5) composite. TNF anion produced by laser illumination plays a key role of beam diffraction and asymmetric two beam coupling in the composites.

  18. New chromophores based on combination of ethylenedioxythiophene and carbazole fragments: synthesis and optoelectronic properties

    NASA Astrophysics Data System (ADS)

    Bakiev, A. N.; Mayorova, O. A.; Gorbunov, A. A.; Lunegov, I. V.; Shklyaeva, E. V.; Abashev, G. G.

    2016-12-01

    Two new D-π-A chromophores composed of an electron-donating carbazole unit linked through π- bridges, bearing 3,4-ethylenedioxythiophene (EDOT) moiety, with an electron withdrawing dicyanovinyl group (DCV) were successfully synthesized involving Suzuki or Heck cross-coupling and Knöevenagel reactions as the key steps. The obtained compounds absorb light over a broad spectral range, including the visible spectrum. The HOMO/LUMO energies and band gap energy values (Eg) were calculated on the basis of the experimental optical and electrochemical data: HOMO, LUMO, Eg (eV), -5.51, -3.14, 2.37 (4), -5.34, -3.14, 2.20 (7). The presence of the HC=CH unit in compound 7 resulted in the increase of the HOMO energy level, the decrease of a band gap value and red shifts of the absorption and emission bands in comparison with those of 4. Large Stokes shifts and broadband luminescence inherent to both chromophores suggest their use as materials for luminescent solar collectors (LSCs). The obtained compounds demonstrated good solubility and suitable thin-film forming properties. For this reason, they may be suitable for solution-processable photovoltaic applications.

  19. Study on the Synthesis and Spectra of a Novel Kind of Carbozole Benzothiazole Indole Styryl Cyanine Dye with a Carbazole Bridged Chain.

    PubMed

    Fei, Xuening; Hao, Yachao; Gu, Yingchun; Li, Chao; Yu, Lu

    2014-03-01

    Based on the frequently-used cyanine dye probe thiazole orange (TO) and Cy3, a novel kind of styryl cyanine dye was designed and synthesized. Carbazole was inserted into the structures of two cyanine dyes, TO and Cy3, to act as a bridge to link the benzothiazole and indole. This modification resulted in a novel kind of carbozole benzothiazole indole cyanine dye with a carbazole-bridged chain. The dyes were characterized by HNMR and MS. The spectra of the novel dyes were also studied and the results showed that the fluorescence wavelength of novel carbazole benzothiazole indole cyanine dye shifted red, the Stokes shift and Fluorescence quantum yields increased and the fluorescence intensity was enhanced compared to that of TO. These results indicated that the novel dye could be used as an excellent fluorescent probe in biological labeling.

  20. Thermal ring contraction of dibenz[b,f]azepin-5-yl radicals: new routes to pyrrolo[3,2,1-jk]carbazoles.

    PubMed

    Crawford, Lynne A; McNab, Hamish; Mount, Andrew R; Wharton, Stuart I

    2008-09-05

    Flash vacuum pyrolysis (FVP) of N-allyl- or N-benzyldibenz[b,f]azepine at temperatures from 750 to 950 degrees C gives pyrrolo[3,2,1-jk]carbazole as the major product. The mechanism of the ring contraction involves dibenzazepin-1-yl radical formation, followed by transannular attack and formation of a 2-(indol-1-yl)phenyl radical which cyclizes. The mechanism is supported by independent generation of 2-(indol-1-yl)phenyl radicals by two different methods, and the use of 1-(2-nitrophenyl)indole as a radical generator gives an optimized synthetic route to pyrrolo[3,2,1-jk]carbazole (54% overall yield in two steps from indole). The first substituted pyrrolo[3,2,1-jk]carbazoles have been synthesized by FVP methods and also by reactions of the parent compound with electrophiles, leading to a range of 4-substituted pyrrolocarbazoles.

  1. Synthesis, photophysics, electrochemistry, thermal stability and electroluminescent performances of a new europium complex with bis(β-diketone) ligand containing carbazole group.

    PubMed

    Liu, Jian; Liang, Quan-Bin; Wu, Hong-Bin

    2016-09-07

    We synthesized a new europium complex [Eu(ecbpd)3 (Phen)] with bis(β-diketone) ligand containing a carbazole group, in which ecbpd and Phen are dehydro-3,3'-(9-ethyl-9H-carbazole-3,6-diyl)bis(1-phenylpropane-1,3-dione) and 1,10-phenanthroline, respectively. Its UV/vis and photoluminescent spectra, quantum yield, luminescence lifetime, electrochemistry, thermal stability and electroluminescent performances were studied. This europium complex showed low efficiency luminescence, which is probably due to the mismatching energy levels of its ligand and Eu(3)(+) , as well as the double Eu(3)(+) core resonance.

  2. Fluorescent styryl dyes based on novel 4-methoxy-9-methyi-9H-carbazole-3-carbaldehyde--synthesis, photophysical properties and DFT computations.

    PubMed

    Umape, Prashant G; Gawale, Yogesh; Sekar, Nagaiyan

    2014-07-01

    Novel carbazole based styryl derivatives (6a-6c) having styryl group at third position and a methoxy substitution were synthesized by condensing 4-methoxy-9-methyl-9H-carbazole-3-carbaldehyde 3 and different active methylene derivatives (5a-5c). Evaluated photophysical properties of these synthesized novel chromophores, studied the effect of solvent polarity on absorption, emission and quantum yield of these styryl derivatives. DFT and TD-DFT computations are carried out to study structural, molecular, electronic and photophysical parameters of dyes. The ratio of ground state to excited state dipole moment was calculated using Bakhshiev and Kawski-Chamma-Viallet correlations.

  3. A Palladium-Catalyzed Method for the Synthesis of Carbazoles via Tandem C-H Functionalization and C-N Bond Formation

    PubMed Central

    Tsang, W. C. Peter; Munday, Rachel H.; Brasche, Gordon; Zheng, Nan; Buchwald, Stephen L.

    2009-01-01

    The development of a new method for the assembly of unsymmetrical carbazoles is reported. The strategy involves the selective intramolecular functionalization of an arene C-H bond and the formation of a new arene C-N bond. The substitution pattern of the carbazole product can be controlled by the design of the biaryl amide substrate, and the method is compatible with a variety of functional groups. The utility of the new protocol was demonstrated by the concise synthesis of three natural products from commercially available materials. PMID:18761437

  4. Comparison of methylene blue/gentian violet stain to Gram's stain for the rapid diagnosis of gonococcal urethritis in men.

    PubMed

    Taylor, Stephanie N; DiCarlo, Richard P; Martin, David H

    2011-11-01

    We compared a simple, one-step staining procedure using a mixture of methylene blue and gentian violet to Gram stain for the detection of gonococcal urethritis. The sensitivity and specificity of both Gram stain and methylene blue/gentian violet stain were 97.3% and 99.6%, respectively. There was a 100% correlation between the 2 methods.

  5. Partial degradation mechanisms of malachite green and methyl violet B by Shewanella decolorationis NTOU1 under anaerobic conditions.

    PubMed

    Chen, C-H; Chang, C-F; Liu, S-M

    2010-05-15

    This work demonstrated that Shewanella decolorationis NTOU1 decolorized 200 mg l(-1) of crystal violet, malachite green, or methyl violet B within 2-11h under anaerobic conditions at 35 degrees C. The initial color removal rate of malachite green was highest, while that of methyl violet was lowest. GC/MS analyses of the intermediate compounds produced during and after decolorization of malachite green and methyl violet B suggested that biodegradation of these dyes involved reduction to leuco form, N-demethylation, and reductive splitting of the triphenyl rings. The number of N-methylated groups of these dyes might have influenced decolorization rates and the reductive splitting of the triphenyl rings of these dyes. Cytotoxicity and antimicrobial test data showed that malachite green and methyl violet B solution (100 mg l(-1)) were toxic. Toxicity of the dyes decreased after their decolorization, but further incubation resulted in increased toxicity.

  6. 7-Phenyl-sulfonyl-2,3-dihydro-7H-1,4-benzodioxino[6,7-b]carbazole.

    PubMed

    Kanchanadevi, J; Dhayalan, V; Mohanakrishnan, A K; Anbalagan, G; Chakkaravarthi, G; Manivannan, V

    2010-11-20

    In the title compound, C(24)H(17)NO(4)S, the phenyl ring makes a dihedral angle of 88.12 (5)° with the carbazole unit. The mol-ecular structure is stabilized by weak intra-molecular C-H⋯O inter-actions and the crystal packing exhibits weak inter-molecular C-H⋯O and C-H⋯π inter-actions. Two C atoms of the 2,3-dihydro-1,4-dioxine fragment are disordered over two positions with site-occupancy factors of 0.718 (11) and 0.282 (11).

  7. A Methoxydiphenylamine-Substituted Carbazole Twin Derivative: An Efficient Hole-Transporting Material for Perovskite Solar Cells.

    PubMed

    Gratia, Paul; Magomedov, Artiom; Malinauskas, Tadas; Daskeviciene, Maryte; Abate, Antonio; Ahmad, Shahzada; Grätzel, Michael; Getautis, Vytautas; Nazeeruddin, Mohammad Khaja

    2015-09-21

    The small-molecule-based hole-transporting material methoxydiphenylamine-substituted carbazole was synthesized and incorporated into a CH3NH3PbI3 perovskite solar cell, which displayed a power conversion efficiency of 16.91%, the second highest conversion efficiency after that of Spiro-OMeTAD. The investigated hole-transporting material was synthesized in two steps from commercially available and relatively inexpensive starting reagents. Various electro-optical measurements (UV/Vis, IV, thin-film conductivity, hole mobility, DSC, TGA, ionization potential) have been carried out to characterize the new hole-transporting material.

  8. A New Star-shaped Carbazole Derivative with Polyhedral Oligomeric Silsesquioxane Core: Crystal Structure and Unique Photoluminescence Property.

    PubMed

    Xu, Zixuan; Yu, Tianzhi; Zhao, Yuling; Zhang, Hui; Zhao, Guoyun; Li, Jianfeng; Chai, Lanqin

    2016-01-01

    A new inorganic–organic hybrid material based on polyhedral oligomeric silsesquioxane (POSS) capped with carbazolyl substituents, octakis[3-(carbazol-9-yl)propyldimethylsiloxy]-silsesquioxane (POSS-8Cz), was successfully synthesized and characterized. The X-ray crystal structure of POSS-8Cz were described. The photophysical properties of POSS-8Cz were investigated by using UV–vis,photoluminescence spectroscopic analysis. The hybrid material exhibits blue emission in the solution and the solid film.The morphology and thermal stablity properties were measured by X-ray diffraction (XRD) and TG-DTA analysis.

  9. NLOphoric Carbazole-Containing Push-Pull Extended Styryl Chromophores: Study of Photophysical Properties by Solvatochromic and DFT Method.

    PubMed

    Telore, Rahul D; Sekar, Nagaiyan

    2016-07-01

    Carbazole based extended Donor-π-Acceptor styryl dyes with intramolecular charge transfer characteristics were examined for their linear and nonlinear optical properties using solvatochromism, shifts in emission and density functional theory computations. All the extended styryls demonstrated positive solvatochromism. The extended styryl dyes showed largely improved photophysical properties and large Stokes shifts. The donor-acceptor interactions of the extended styryls were investigated by using generalized Mulliken-Hush method. Oscillator strengths and transition state dipole moments have been studied to understand charge transfer within the molecules. The nonlinear optical properties of the extended styryl were investigated by solvatochromic and density functional theory method.

  10. Violet LED light enhances the recruitment of a thrip predator in open fields.

    PubMed

    Ogino, Takumi; Uehara, Takuya; Muraji, Masahiko; Yamaguchi, Terumi; Ichihashi, Takahisa; Suzuki, Takahiro; Kainoh, Yooichi; Shimoda, Masami

    2016-09-08

    The predatory bug Orius sauteri is an indigenous natural enemy of thrips and whiteflies in Asian countries. To put these bugs to practical use in pest management, methods to attract and retain the bugs in agricultural fields are needed. We previously showed that violet light (405 nm) attracts O. sauteri selectively. Many thrips and whiteflies are attracted to UV or green light. In this study, we examined the effect of violet-LED illumination on O. sauteri in pesticide-free eggplant (Solanum melongena L.) cultivation. In three cultivation trials, the density of O. sauteri on eggplant leaves was consistently higher in the illuminated plots; at least twice that of the non-illuminated plots. Simultaneously, the density of thrips declined markedly to less than half that of the non-illuminated plots. We identified three positive effects of violet light including an "immediate-effect" on predator attraction, a "persistent-effect" on predator reproduction, and a "secondary-effect" on the food web structure. Our results showed that illumination with violet light provides a powerful tool for integrated pest management. This is the first report on the use of illumination to manipulate the behavior of natural enemies.

  11. Color-Pure Violet-Light-Emitting Diodes Based on Layered Lead Halide Perovskite Nanoplates.

    PubMed

    Liang, Dong; Peng, Yuelin; Fu, Yongping; Shearer, Melinda J; Zhang, Jingjing; Zhai, Jianyuan; Zhang, Yi; Hamers, Robert J; Andrew, Trisha L; Jin, Song

    2016-07-26

    Violet electroluminescence is rare in both inorganic and organic light-emitting diodes (LEDs). Low-cost and room-temperature solution-processed lead halide perovskites with high-efficiency and color-tunable photoluminescence are promising for LEDs. Here, we report room-temperature color-pure violet LEDs based on a two-dimensional lead halide perovskite material, namely, 2-phenylethylammonium (C6H5CH2CH2NH3(+), PEA) lead bromide [(PEA)2PbBr4]. The natural quantum confinement of two-dimensional layered perovskite (PEA)2PbBr4 allows for photoluminescence of shorter wavelength (410 nm) than its three-dimensional counterpart. By converting as-deposited polycrystalline thin films to micrometer-sized (PEA)2PbBr4 nanoplates using solvent vapor annealing, we successfully integrated this layered perovskite material into LEDs and achieved efficient room-temperature violet electroluminescence at 410 nm with a narrow bandwidth. This conversion to nanoplates significantly enhanced the crystallinity and photophysical properties of the (PEA)2PbBr4 samples and the external quantum efficiency of the violet LED. The solvent vapor annealing method reported herein can be generally applied to other perovskite materials to increase their grain size and, ultimately, improve the performance of optoelectronic devices based on perovskite materials.

  12. Violet LED light enhances the recruitment of a thrip predator in open fields

    PubMed Central

    Ogino, Takumi; Uehara, Takuya; Muraji, Masahiko; Yamaguchi, Terumi; Ichihashi, Takahisa; Suzuki, Takahiro; Kainoh, Yooichi; Shimoda, Masami

    2016-01-01

    The predatory bug Orius sauteri is an indigenous natural enemy of thrips and whiteflies in Asian countries. To put these bugs to practical use in pest management, methods to attract and retain the bugs in agricultural fields are needed. We previously showed that violet light (405 nm) attracts O. sauteri selectively. Many thrips and whiteflies are attracted to UV or green light. In this study, we examined the effect of violet-LED illumination on O. sauteri in pesticide-free eggplant (Solanum melongena L.) cultivation. In three cultivation trials, the density of O. sauteri on eggplant leaves was consistently higher in the illuminated plots; at least twice that of the non-illuminated plots. Simultaneously, the density of thrips declined markedly to less than half that of the non-illuminated plots. We identified three positive effects of violet light including an “immediate-effect” on predator attraction, a “persistent-effect” on predator reproduction, and a “secondary-effect” on the food web structure. Our results showed that illumination with violet light provides a powerful tool for integrated pest management. This is the first report on the use of illumination to manipulate the behavior of natural enemies. PMID:27604315

  13. [Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

    PubMed

    Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

    2011-12-01

    With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

  14. Fluorescence screening of leucomalachite green and leucogentian violet residues in catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tripheylmethane dyes malachite green (MG) and gentian violet (GV) are effective fungicides, ectoparasiticides and disinfectants in aquaculture. This practice may leave toxic residues in seafood which is not allowed by FDA and many regulatory agencies worldwide. In this work, residues of their me...

  15. Adsorption of Crystal Violet Dye Using Zeolite A Synthesized From Coal Fly Ash

    NASA Astrophysics Data System (ADS)

    Jumaeri; Kusumastuti, E.; Santosa, S. J.; Sutarno

    2017-02-01

    Adsorption of Crystal Violet (CV) dye using zeolite A synthesized from coal fly ash (ZA) has been done. Effect of pH, contact time, and the initial concentration of dye adsorption was studied in this adsorption. Model experimental of adsorption isotherms and adsorption kinetics were also studied. The adsorption is done in a batch reactor at room temperature. A total of 0.01 g of zeolite A was added to the Erlenmeyer flask 50 mL containing 20 mL of the dye solution of Crystal Violet in a variety of conditions of pH, contact time and initial concentration. Furthermore, Erlenmeyer flask and its contents were shaken using an orbital shaker at a speed of 200 rpm. After a specified period of adsorption, the solution was centrifuged for 2 minutes so that the solids separated from the solution. The concentration of the dye after adsorption determined using Genesis-20 Spectrophotometer. The results showed that the Zeolite A synthesized from coal fly ash could be used as an effective adsorbent for Crystal Violet dye. The optimum adsorption occurs at pH 6, and contact time 45 minutes. At the initial concentration of 2 to 6 mg/L, adsorption is reduced from 79 to 62.8%. Crystal Violet dye adsorption in zeolite A fulfilled kinetic model of pseudo-order 2 and model of Freundlich adsorption isotherm.

  16. [Active carbon from Thalia dealbata residues: its preparation and adsorption performance to crystal violet].

    PubMed

    Chu, Shu-Yi; Yang, Min; Xiao, Ji-Bo; Zhang, Jun; Zhu, Yan-Ping; Yan, Xiang-Jun; Tian, Guang-Ming

    2013-06-01

    By using phosphoric acid as activation agent, active carbon was prepared from Thalia dealbata residues. The BET specific surface area of the active carbon was 1174.13 m2 x g(-1), micropore area was 426.99 m2 x g(-1), and average pore diameter was 3.23 nm. An investigation was made on the adsorption performances of the active carbon for crystal violet from aqueous solution under various conditions of pH, initial concentration of crystal violet, contact time, and contact temperature. It was shown that the adsorbed amount of crystal violet was less affected by solution pH, and the adsorption process could be divided into two stages, i. e., fast adsorption and slow adsorption, which followed the pseudo-second-order kinetics model. At the temperature 293, 303, and 313 K, the adsorption process was more accordance with Langmuir isotherm model, and the maximum adsorption capacity was 409.83, 425.53, and 438.59 mg x g(-1), respectively. In addition, the adsorption process was spontaneous and endothermic, and the randomness of crystal violet molecules increased.

  17. Consequences of Ultra-Violet Irradiation on the Mechanical Properties of Spider Silk

    PubMed Central

    Lai, Wee Loong; Goh, Kheng Lim

    2015-01-01

    The outstanding combination of high tensile strength and extensibility of spider silk is believed to contribute to the material’s toughness. Thus, there is great interest in engineering silk for biomedical products such as suture or implants. Additionally, over the years, many studies have also sought to enhance the mechanical properties of spider silk for wider applicability, e.g., by irradiating the material using ultra-violet radiation. However, the limitations surrounding the use of ultra-violet radiation for enhancing the mechanical properties of spider silk are not well-understood. Here, we have analyzed the mechanical properties of spider silk at short ultra-violet irradiation duration. Specimens of spider silk were subjected to ultra-violet irradiation (254-nm wavelength, i.e. UVC) for 10, 20, and 30 min, respectively, followed by tensile test to rupture to determine the strength (maximum stress), extensibility (rupture strain), and toughness (strain energy density to rupture). Controls, i.e., specimens that did not received UVC, were also subjected to tensile test to rupture to determine the respective mechanical properties. One-way analysis of variance reveals that these properties decrease significantly (p < 0.05) with increasing irradiation duration. Among the three mechanical parameters, the strength of the spider silk degrades most rapidly; the extensibility of the spider silk degrades the slowest. Overall, these changes correspond to the observed surface modifications as well as the bond rupture between the peptide chains of the treated silk. Altogether, this simple but comprehensive study provides some key insights into the dependence of the mechanical properties on ultra-violet irradiation duration. PMID:26378587

  18. Identification of methyl violet 2B as a novel blocker of focal adhesion kinase signaling pathway in cancer cells

    SciTech Connect

    Kim, Hwan; Kim, Nam Doo; Lee, Jiyeon; Han, Gyoonhee; Sim, Taebo

    2013-07-26

    Highlights: •FAK signaling cascade in cancer cells is profoundly inhibited by methyl violet 2B. •Methyl violet 2B identified by virtual screening is a novel allosteric FAK inhibitor. •Methyl violet 2B possesses extremely high kinase selectivity. •Methyl violet 2B suppresses strongly the proliferation of cancer cells. •Methyl violet 2B inhibits focal adhesion, invasion and migration of cancer cells. -- Abstract: The focal adhesion kinase (FAK) signaling cascade in cancer cells was profoundly inhibited by methyl violet 2B identified with the structure-based virtual screening. Methyl violet 2B was shown to be a non-competitive inhibitor of full-length FAK enzyme vs. ATP. It turned out that methyl violet 2B possesses extremely high kinase selectivity in biochemical kinase profiling using a large panel of kinases. Anti-proliferative activity measurement against several different cancer cells and Western blot analysis showed that this substance is capable of suppressing significantly the proliferation of cancer cells and is able to strongly block FAK/AKT/MAPK signaling pathways in a dose dependent manner at low nanomolar concentration. Especially, phosphorylation of Tyr925-FAK that is required for full activation of FAK was nearly completely suppressed even with 1 nM of methyl violet 2B in A375P cancer cells. To the best of our knowledge, it has never been reported that methyl violet possesses anti-cancer effects. Moreover, methyl violet 2B significantly inhibited FER kinase phosphorylation that activates FAK in cell. In addition, methyl violet 2B was found to induce cell apoptosis and to exhibit strong inhibitory effects on the focal adhesion, invasion, and migration of A375P cancer cells at low nanomolar concentrations. Taken together, these results show that methyl violet 2B is a novel, potent and selective blocker of FAK signaling cascade, which displays strong anti-proliferative activities against a variety of human cancer cells and suppresses adhesion

  19. Halogenated indigo dyes: a likely source of 1,3,6,8-tetrabromocarbazole and some other halogenated carbazoles in the environment.

    PubMed

    Parette, Robert; McCrindle, Robert; McMahon, Katherine S; Pena-Abaurrea, Miren; Reiner, Eric; Chittim, Brock; Riddell, Nicole; Voss, Gundula; Dorman, Frank L; Pearson, Wendy N

    2015-05-01

    In recent years, a number of halogenated carbazoles have been detected in environmental samples. These emerging contaminants have been shown to be persistent and possess dioxin-like toxicological potential. The goal of this research was to examine the literature to determine likely anthropogenic origin(s) of halogenated carbazoles in the environment. The scientific literature indicated a number of pathways by which 1,3,6,8-tetrabromocarbazole could form in the manufacture of 5,5',7,7'-tetrabromoindigo. The U.S. production history of 5,5',7,7'-tetrabromoindigo correlates well with the concentration rise, decline, and disappearance of 1,3,6,8-tetrabromocarbazole in dated Lake Michigan sediments. Additionally, other halogenated carbazoles that have been found in environmental sediments can be explained by the production of other halogenated indigo dyes. 1,8-dibromo-3,6-dichlorocarbazole can be accounted for by the manufacture of 7,7'-dibromo-5,5'-dichloroindigo, while 1,3,6,8-tetrachlorocarbazole was found at relatively high concentration near the outfall of a U.S. manufacturer of 5,5',7,7'-tetrachloroindigo. Carbazoles containing an iodo-substituent can be explained by the use of iodine as a catalyst in the manufacture of halogenated indigo dyes. 3,6-Dichlorocarbazole measured in soils and dibromocarbazoles measured in more recently deposited sediments are not easily rationalized on the basis of an indigo related source and may be related to other anthropogenic sources or natural origins.

  20. Effect of Different Alkyl Groups at the N-Position on the Luminescence of Carbazole-Based β-Diketonate Europium(III) Complexes

    NASA Astrophysics Data System (ADS)

    He, Pei; Wang, Huihui; Liu, Shenggui; Shi, Jianxin; Wang, Gang; Gong, Menglian

    2009-10-01

    A series of carbazole-based β-diketone derivatives and their europium(III) ternary complexes Eu(N-Cx)3phen were designed and synthesized, where N-Cx denotes carbazole-based β-diketonates with different alkyl substituents at N-position of the carbazole ring and phen is 1,10-phenethroline. Thermogravimetric analysis (TGA) shows that the decomposition temperature of the complexes is over 360 °C. UV-visible absorption spectroscopy, photoluminescence (PL), and the luminescence quantum yield of the Eu(III) complexes were measured and compared with each other, and the effect of different substituted-alkyls at N-position in the carbazole ring on the photoluminescence was discussed in details, indicating there exists a competition between the absorption capacity and the energy transfer efficiency for the complexes when the structure of the substituted-alkyls changes. The triplet state energy levels of the β-diketonate ligands in the complexes are higher than that of the lowest excited level of Eu3+ ion, 5D0, so the photoluminescence mechanism of the Eu(III) complexes was proposed as a ligand-sensitized luminescence process. Red LEDs were fabricated by precoating the complexes onto 395 nm emitting InGaN chips. All the results show that this series of Eu(III) complexes is a promising candidate as a red component in fabrication of NUV-based white LEDs.

  1. Effect of different alkyl groups at the N-position on the luminescence of carbazole-based beta-diketonate europium(III) complexes.

    PubMed

    He, Pei; Wang, Huihui; Liu, Shenggui; Shi, Jianxin; Wang, Gang; Gong, Menglian

    2009-11-19

    A series of carbazole-based beta-diketone derivatives and their europium(III) ternary complexes Eu(N-Cx)(3)phen were designed and synthesized, where N-Cx denotes carbazole-based beta-diketonates with different alkyl substituents at N-position of the carbazole ring and phen is 1,10-phenethroline. Thermogravimetric analysis (TGA) shows that the decomposition temperature of the complexes is over 360 degrees C. UV-visible absorption spectroscopy, photoluminescence (PL), and the luminescence quantum yield of the Eu(III) complexes were measured and compared with each other, and the effect of different substituted-alkyls at N-position in the carbazole ring on the photoluminescence was discussed in details, indicating there exists a competition between the absorption capacity and the energy transfer efficiency for the complexes when the structure of the substituted-alkyls changes. The triplet state energy levels of the beta-diketonate ligands in the complexes are higher than that of the lowest excited level of Eu(3+) ion, (5)D(0), so the photoluminescence mechanism of the Eu(III) complexes was proposed as a ligand-sensitized luminescence process. Red LEDs were fabricated by precoating the complexes onto 395 nm emitting InGaN chips. All the results show that this series of Eu(III) complexes is a promising candidate as a red component in fabrication of NUV-based white LEDs.

  2. Quantitative electrochemical and electrochromic behavior of terthiophene and carbazole containing conjugated polymer network film precursors: EC-QCM and EC-SPR.

    PubMed

    Taranekar, Prasad; Fulghum, Timothy; Baba, Akira; Patton, Derek; Advincula, Rigoberto

    2007-01-16

    A comparative analysis of the copolymerization behavior between an electro-active terthiophene and a carbazole moiety of a conjugated polymer precursor was investigated using electrochemical and hyphenated electrochemical methods. Five different precursor polymers were first synthesized and characterized using NMR, IR, and GPC. The polymers include homopolymers of individual electro-active groups (P3T, P-CBZ) and different compositions of 25, 50, and 75% (P3TC-25, P3TC50, and P3TC-75) with respect to the two electro-active groups. Since the oxidation potentials of terthiophene and carbazole lie very close to each other, highly cross-linked copolymer films of varying extent were produced depending on the composition. The copolymerization extent was found to be dependent primarily on the amount of the terthiophene, which in this case provided for a more efficient carbazole polymerization and copolymerization than with just carbazole alone (homopolymer). The extent of copolymerization, electrochromic properties, and viscoelastic changes was quantitatively investigated using a number of hyphenated electrochemistry techniques: spectro-electrochemistry, electrochemical quartz crystal microbalance studies (EC-QCM), and electrochemical surface plasmon resonance spectroscopy (EC-SPR). Each technique revealed a unique aspect of the electrocopolymerization behavior that was used to define structure-property relationships and the deposition/copolymerization mechanism.

  3. [N6-dipeptide derivatives of the N12-ribosyl-indolo[2,3-a]carbazole].

    PubMed

    Goryunova, O V; Zakharchuk, G M; Zhukova, O S; Fetisova, L V; Kuzmina, N E

    2014-01-01

    N6-derivatives of N12-ribosyl-indolo[2,3-a]pirrolo[3,4-c]carbazole-5,7-dione are synthesized as potential antitumor agents, in which an atom of N6-pyrrole part of heterocycle is included into the dipeptide residual of the general formula >N6-(CH2)n-CO-Ala/βAla-OMe (n = 2 or 3). These compounds are derived by reacting of 13-methyl-12-(2,3,4-three-O-acetyl-β-D-ribopyranosyl)indolo[2,3-a]furano[3,4-c] carbazole-5,7-dione with dipeptides, having an unreplaced N-amino end-group, in DMF at 130°C, wherein the nitrogen atom of peptide amino group replaces oxygen O6 in furan ring of heterocycle and is embedded in imide nitrogen atom of pyrrole N6. The ability of the obtained compounds to inhibit growth of SKOV3 human ovarian carcinoma cells was studied, only derivative with radical >N6-(CH2)3-CO-L-Ala-OMe showed cytotoxic activity with an inhibitory concentration of IC50 = 8 μM.

  4. Biodegradation of crystal violet using Burkholderia vietnamiensis C09V immobilized on PVA-sodium alginate-kaolin gel beads.

    PubMed

    Cheng, Ying; Lin, HongYan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravi

    2012-09-01

    The strain, Burkholderia vietnamiensis C09V was immobilized on PVA-alginate-kaolin gel beads as a biomaterial to improve the degradation of crystal violet from aqueous solution. The results show that 98.6% (30 mg L(-1)) crystal violet was removed from aqueous solution using immobilized cells on PVA-alginate-kaolin gel beads, while 94.0% crystal violet was removed by free cells after degradation at the pH 5 and 30°C for 30 h. Kinetics studies show that the pseudo-second-order kinetics well described the adsorption of crystal violet on the PVA-alginate-kaolin beads. Biodegradation of crystal violet on immobilized cells was fitted well by first-order reaction kinetics, indicating that CV was adsorbed onto kaolin and followed their degradation by immobilized cells onto the the PVA-alginate-kaolin beads. Characterization with SEM shows that cells attached well to the surface of PVA-alginate-kaolin beads, leading to improved crystal violet transfer from aqueous solution to immobilized cells. In addition, UV-vis show that the absorption peak at 588 nm was reduced by the degraded N-bond linkages, as well as the formation of degrading products were observed by Fourier transform infrared (FTIR). These results suggest that crystal violet was biodegraded to N,N-dimethylaminophenol and Michler's Ketone prior to these intermediates being further degraded.

  5. Prevention of Chagas' disease resulting from blood transfusion by treatment of blood: toxicity and mode of action of gentian violet.

    PubMed

    Docampo, R; Moreno, S N; Gadelha, F R; de Souza, W; Cruz, F S

    1988-12-01

    Blood transfusion is the second most important mechanism of transmission of Chagas' disease. Gentian violet, a cationic dye, is currently used in blood banks in endemic areas in attempts to eliminate such transmission. A photodynamic action of gentian violet has been demonstrated in Trypanosoma cruzi. Visible light causes photoreduction of gentian violet to a carbon-centered radical. Under aerobic conditions this free radical autooxidizes generating superoxide anion whose dismutation yields hydrogen peroxide. This photodynamic action of gentian violet is thus probably mediated by the oxygen reduction products. Since irradiation with visible light in the presence of sodium ascorbate reduces the effective dose and time of contact of the dye with T. cruzi-infected blood, a possible application of these findings can be envisaged. In addition to this photodynamic action, an uncoupling effect of gentian violet on mitochondrial oxidative phosphorylation has been described in rat liver and T. cruzi mitochondria. Gentian violet released respiratory control, hindered ATP synthesis, enhanced ATPase activity, released the inhibition of State 3 respiration by oligomycin, and produced swelling of isolated rat liver mitochondria or T. cruzi mitochondria in situ. Taken together, these results indicate that the T. cruzi mitochondrion is the main target of gentian violet toxicity in the dark.

  6. Albanian violets of the section Melanium, their morphological variability, genetic similarity and their adaptations to serpentine or chalk soils.

    PubMed

    Słomka, Aneta; Godzik, Barbara; Szarek-Łukaszewska, Grażyna; Shuka, Lulëzim; Hoef-Emden, Kerstin; Bothe, Hermann

    2015-02-01

    Violets of the section Melanium from Albanian serpentine and chalk soils were examined for their taxonomic affiliations, their ability to accumulate heavy metals and their colonization by arbuscular mycorrhizal fungi (AMF). The sequence analysis of the ITS1-5.8S rDNA-ITS2 region showed that all the sampled six Albanian violets grouped between Viola lutea and Viola arvensis, but not with Viola tricolor. The fine resolution of the ITS sequences was not sufficient for a further delimitation of the Albanian violets within the V. lutea-V. arvensis clade. Therefore, the Albanian violets were classified by a set of morphological characters. Viola albanica, Viola dukadjinica and Viola raunsiensis from serpentine soils as well as Viola aetolica from a chalk meadow were unambiguously identified, whereas the samples of Viola macedonica showed high morphological variability. All the violets, in both roots and shoots contained less than or similar levels of heavy metals as their harboring soils, indicating that they were heavy metal excluders. All the violets were strongly colonized by AMF with the remarkable exception of V. albanica. This violet lived as a scree creeper in shallow serpentine soil where the concentration of heavy metals was high but those of P, K and N were scarce.

  7. Violets of the section Melanium, their colonization by arbuscular mycorrhizal fungi and their occurrence on heavy metal heaps.

    PubMed

    Słomka, A; Kuta, E; Szarek-Łukaszewska, G; Godzik, B; Kapusta, P; Tylko, G; Bothe, H

    2011-07-15

    Violets of the sections Melanium were examined for their colonization by arbuscular mycorrhizal fungi (AMF). Heartsease (Viola tricolor) from several heavy metal soils was AMF-positive at many sites but not at extreme biomes. The zinc violets Viola lutea ssp. westfalica (blue zinc violet) and ssp. calaminaria (yellow zinc violet) were always AMF-positive on heavy metal soils as their natural habitats. As shown for the blue form, zinc violets germinate independently of AMF and can be grown in non-polluted garden soils. Thus the zinc violets are obligatorily neither mycotrophs nor metalophytes. The alpine V. lutea, likely ancestor of the zinc violets, was at best poorly colonized by AMF. As determined by atomic absorption spectrometry, the contents of Zn and Pb were lower in AMF colonized plants than in the heavy metal soils from where the samples had been taken. AMF might prevent the uptake of toxic levels of heavy metals into the plant organs. Dithizone staining indicated a differential deposition of heavy metals in tissues of heartsease. Leaf hairs were particularly rich in heavy metals, indicating that part of the excess of heavy metals is sequestered into these cells.

  8. Ultrafast intramolecular charge transfer with N-(4-cyanophenyl)carbazole. Evidence for a LE precursor and dual LE + ICT fluorescence.

    PubMed

    Galievsky, Victor A; Druzhinin, Sergey I; Demeter, Attila; Mayer, Peter; Kovalenko, Sergey A; Senyushkina, Tamara A; Zachariasse, Klaas A

    2010-12-09

    The photophysics of N-(4-cyanophenyl)carbazole (NP4CN) was investigated by using absorption and fluorescence spectra, picosecond fluorescence decays, and femtosecond transient absorption. In the nonpolar n-hexane as well as in the polar solvent acetonitrile (MeCN), a locally excited (LE) state is detected, as a precursor for the intramolecular charge transfer (ICT) state. A LE → ICT reaction time τ(2) at 22 °C of 0.95 ps in ethyl cyanide (EtCN) and 0.32 ps in MeCN is determined from the decay of the LE excited state absorption (ESA) maximum around 620 nm. In the ESA spectrum of NP4CN in n-hexane at a pump-probe delay time of 100 ps, an important contribution of the LE band remains alongside the ICT band, in contrast to what is observed in EtCN and MeCN. This shows that a LE ⇄ ICT equilibrium is established in this solvent and the ICT reaction time of 0.5 ps is equal to the reciprocal of the sum of the forward and backward ICT rate constants 1/(k(a) + k(d)). In the photostationary S(0) → S(n) absorption spectrum of NP4CN in n-hexane and MeCN, an additional CT absorption band appears, absent in the sum of the spectra of its electron donor (D) and acceptor (A) subgroups carbazole and benzonitrile. This CT band is located at an energy of ∼4000 cm(-1) lower than for N-phenylcarbazole (NPC), due to the larger electron affinity of the benzonitrile moiety of NP4CN than the phenyl subunit of NPC. The fluorescence spectrum of NP4CN in n-hexane at 25 °C mainly consists of a structured LE emission, with a small ICT admixture, indicating that a LE → ICT reaction just starts to occur under these conditions. In di-n-pentyl ether (DPeE) and di-n-butyl ether (DBE), a LE emission is found upon cooling at the high-energy edge of the ICT fluorescence band, caused by the onset of dielectric solvent relaxation. This is not the case in more polar solvents, such as diethyl ether (DEE) and MeCN, in which a structureless ICT emission band fully overlaps the strongly quenched LE

  9. Structural and photophysical properties of HPPCO (4-hydroxy-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-6-one) derivatives

    NASA Astrophysics Data System (ADS)

    Jeong, Yong-Kwang; Kim, Min-Ah; Lee, Hyo-Sung; Kim, Jong-Moon; Lee, Sung Woo; Kang, Jun-Gill

    2015-01-01

    Proton-substitution effects of 4-hydroxy-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-6-one (HPPCO) on structural and photophysical properties were presented. HPPCO crystallized in the orthorhombic space group Pbca with an intermolecular hydrogen bonding between OH and oxygen atom of the carbonyl. The proton-substituted derivatives, 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl acetate (OPPCA) and 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl benzoate (OPPCB), crystallized in the monoclinic P21/c space group. For OPPCA and OPPCB, a weak interaction between carbonyl oxygen atom in the substituted group and carbon atom in the fused ring was responsible for three-dimensional arrangements. In addition, 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl furan-2-carboxylate (OPPCF), and 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl naphthoate (OPPCN) were also synthesized. HPPCO and the four derivatives excited by ultraviolet (UV) light produced blue emission. Proton substitution of the OH group significantly increased the radiative transitions and moderately decreased the non-radiative transitions. Consequently the luminescence quantum yields of the derivatives enhanced more than 4.6-fold, no matter what the groups were substituted. Structural and optical properties were further determined using density functional theory (DFT) and ZINDO calculations. The planar structure of the pyridocarbazole-fused ring resulted in π → π* electronic transitions within the main frame, with an additional transition from the n(O) of carbonyl to the π* of the main frame. The three excited states that arose from these transitions were responsible for the blue luminescence.

  10. Structural and photophysical properties of HPPCO (4-hydroxy-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-6-one) derivatives.

    PubMed

    Jeong, Yong-Kwang; Kim, Min-Ah; Lee, Hyo-Sung; Kim, Jong-Moon; Lee, Sung Woo; Kang, Jun-Gill

    2015-01-05

    Proton-substitution effects of 4-hydroxy-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-6-one (HPPCO) on structural and photophysical properties were presented. HPPCO crystallized in the orthorhombic space group Pbca with an intermolecular hydrogen bonding between OH and oxygen atom of the carbonyl. The proton-substituted derivatives, 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl acetate (OPPCA) and 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl benzoate (OPPCB), crystallized in the monoclinic P2₁/c space group. For OPPCA and OPPCB, a weak interaction between carbonyl oxygen atom in the substituted group and carbon atom in the fused ring was responsible for three-dimensional arrangements. In addition, 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl furan-2-carboxylate (OPPCF), and 6-oxo-5-phenyl-6H-pyrido[3,2,1-jk]carbazol-4-yl naphthoate (OPPCN) were also synthesized. HPPCO and the four derivatives excited by ultraviolet (UV) light produced blue emission. Proton substitution of the OH group significantly increased the radiative transitions and moderately decreased the non-radiative transitions. Consequently the luminescence quantum yields of the derivatives enhanced more than 4.6-fold, no matter what the groups were substituted. Structural and optical properties were further determined using density functional theory (DFT) and ZINDO calculations. The planar structure of the pyridocarbazole-fused ring resulted in π→π(*) electronic transitions within the main frame, with an additional transition from the n(O) of carbonyl to the π(*) of the main frame. The three excited states that arose from these transitions were responsible for the blue luminescence.

  11. Adsorption of Basic Violet 14 in aqueous solutions using KMnO4-modified activated carbon.

    PubMed

    Shi, Qianqian; Zhang, Jian; Zhang, Chenglu; Nie, Wei; Zhang, Bo; Zhang, Huayong

    2010-03-01

    In this paper, an activated carbon was prepared from Typha orientalis and then treated with KMnO(4) and used for the removal of Basic Violet 14 from aqueous solutions. KMnO(4) treatment influenced the physicochemical properties of the carbon and improved its adsorption capacity. Adsorption experiments were then conducted with KMnO(4)-modified activated carbon to study the effects of carbon dosage (250-1500 mg/L), pH (2-10), ion strength (0-0.5 mol/L), temperature, and contact time on the adsorption of Basic Violet 14 from aqueous solutions. The equilibrium data were analyzed by the Langmuir and Freundlich isotherms and fitted well with the Langmuir model. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to evaluate the kinetic data and the pseudo-second-order kinetics was the best with good correlation.

  12. Adsorption of crystal violet onto functionalised multi-walled carbon nanotubes: Equilibrium and kinetic studies.

    PubMed

    Sabna, V; Thampi, Santosh G; Chandrakaran, S

    2016-12-01

    Synthetic dyes present in effluent from textile, paper and paint industries contain crystal violet (CV), a known carcinogenic agent. This study investigates the modification of multiwalled carbon nanotubes by acid reflux method and equilibrium and kinetic behaviour of adsorption of CV onto functionalized multi-walled carbon nanotubes (fMWNTs) in batch system. High stability of the fMWNTs suspension in water indicates the hydrophilicity of fMWNTs induced due to the formation of functional groups that make hydrogen bonds with water molecules. fMWNTs were characterized by Fourier Transform Infra Red (FTIR) spectroscopy and the functional groups present on the fMWNTs were confirmed. Characteristic variation was observed in the FTIR spectra of fMWNTs after adsorption of crystal violet onto it. Adsorption characteristics were evaluated as a function of system variables such as contact time, dosage of fMWNTs and initial concentration and pH of the crystal violet solution. Adsorption capacity of fMWNTs and percentage removal of the dye increased with increase in contact time, adsorbent dosage and pH but declined with increase in initial concentration of the dye. fMWNTs showed higher adsorption capacity compared to that of pristine MWNTs. Data showed good fit with the Langmuir and Freundlich isotherm models and the pseudo-second order kinetic model; the maximum adsorption capacity was 90.52mg/g. Kinetic parameters such as rate constants, equilibrium adsorption capacities and regression coefficients were estimated. Results indicate that fMWNTs are an effective adsorbent for the removal of crystal violet from aqueous solution.

  13. Ultra-violet light-emitting diode calibration system for timing large area scintillation detectors

    NASA Astrophysics Data System (ADS)

    Naumov, P. Yu; Runtso, M. F.; Naumov, P. P.; Maklyaev, E. F.; Kaplin, V. A.; Fomin, V. S.; Razzhivin, I. S.; Melikyan, Yu A.

    2017-01-01

    Timing large area plastic scintillation detectors are developing for the space gamma-ray telescopes now. For the in-flight calibration of these detectors the use of ultra-violet light-emitting diode, irradiating the 1 m long detector module at the center of its lateral side is suggested. The results of the measurements show the possibility of this calibration system implementation as for amplitude as for timing properties monitoring.

  14. Violet laser power sensor based on micro-fiber coated with methyl blue-functionalized reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Tian, Zhengwen; Zhang, Jun; Yang, Bing; Yu, Jianhui; Chen, Zhe; Tang, Jieyuan; Luo, Yunhan; Cai, Xiang; Tan, Shaozao; Lu, Huihui

    2014-05-01

    A novel all fiber-optic power sensor of violet laser based on methyl blue-functionalized reduced graphene oxide (MB-rGO) film coated on a microfiber (MF) was proposed. The experiments show that when the violet laser illuminating onto the MB-rGO film with power variation from 0.03mw to 12.8mw, the transmitted optical power of the MF changes with a relative variation of ~2.7dB. The novel power sensor of violet laser possesses a sensitivity of ~0.22dB/mw in 1550nm. Furthermore, the MB-rGO-based all fiber-optic violet power sensor is easy to fabricate, compatible with fiberoptic systems and possesses high potentiality in photonics applications such as all fiber-optic broadband sensors, switches and modulators.

  15. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    SciTech Connect

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-15

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H{sub 2}CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn{sub 5}(μ{sub 3}-OH){sub 2}(2,7-CDC){sub 4}(DEF){sub 2}] (1) (DEF=N,N-diethylformamide), [Zn{sub 2}(2,7-CDC){sub 2}(DABCO)(H{sub 2}O)]·5DMF·H{sub 2}O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn{sub 2}(2,7-CDC){sub 2}(bpea)]·3DMA·2 H{sub 2}O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle–wheel [Zn{sub 2}(COO){sub 4}] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle–wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied. - Graphical abstract: A new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid, was used to construct Zn(II) metal-organic frameworks, including a novel self-catenated network with the rare 3D alb-3,6-C2/c net and two pcu-type networks based on an unprecedented pentanuclear clusters and the common paddle–wheel units. The compounds show blue fluorescent properties. Display Omitted - Highlights: • MOFs with a new carbazole-based dicarboxylate ligand. • New pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building unit. • The rare self-catenated 3D alb-3,6-C2/c net.

  16. Broadband Photoreceptors Are Involved in Violet Light Preference in the Parasitoid Fly Exorista Japonica

    PubMed Central

    Tokushima, Yoshiaki; Uehara, Takuya; Yamaguchi, Terumi; Arikawa, Kentaro; Kainoh, Yooichi

    2016-01-01

    Phototaxis has been described in many insects, which are often attracted to specific wavelengths of light. However, little is known about phototaxis in parasitoid insect species that are potentially useful for integrated pest management. In this study, we investigated the wavelength dependency of the phototactic behavior of the parasitoid fly Exorista japonica and its possible mechanism. Multiple-choice tests with six monochromatic stimuli revealed that the flies were specifically attracted to violet light peaking at 405 nm, which was unexpected because insects are generally attracted to ultraviolet or green light. We measured the spectral sensitivity of the compound eye, and found that the sensitivity peaked at 340 nm, as in other brachyceran flies. We used statistical modeling and optimization of the process parameters to predict the type of photoreceptor contributing to the violet preference. The analysis revealed that the wavelength preference could be explained by linear models of the quanta received by photoreceptors, including the R1-6 broadband receptors. The broadband receptors appear to contribute positively, whereas the R7-8 narrowband receptors contribute negatively to achieve the violet preference; i.e., spectral opponency might be involved. PMID:27532635

  17. Sensitive detection of malachite green and crystal violet by nonlinear laser wave mixing and capillary electrophoresis.

    PubMed

    Maxwell, Eric J; Tong, William G

    2016-05-01

    An ultrasensitive label-free antibody-free detection method for malachite green and crystal violet is presented using nonlinear laser wave-mixing spectroscopy and capillary zone electrophoresis. Wave-mixing spectroscopy provides a sensitive absorption-based detection method for trace analytes. This is accomplished by forming dynamic gratings within a sample cell, which diffracts light to create a coherent laser-like signal beam with high optical efficiency and high signal-to-noise ratio. A cubic dependence on laser power and square dependence on analyte concentration make wave mixing sensitive enough to detect molecules in their native form without the use of fluorescent labels for signal enhancement. A 532 nm laser and a 635 nm laser were used for malachite green and crystal violet sample excitation. The use of two lasers of different wavelengths allows the method to simultaneously detect both analytes. Selectivity is obtained through the capillary zone electrophoresis separation, which results in characteristic migration times. Measurement in capillary zone electrophoresis resulted in a limit of detection of 6.9 × 10(-10)M (2.5 × 10(-19) mol) for crystal violet and 8.3 × 10(-11)M (3.0 × 10(-20) mol) for malachite green at S/N of 2.

  18. A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection

    SciTech Connect

    Ma, Lun; Chen, Wei; Jiang, Ke; Liu, Xiao-tang

    2014-03-14

    We prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583 nm due to the d-d transition of Mn ions, an intense violet emission at 420 nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu{sup 2+} doping but only appears at certain Eu{sup 2+} concentrations. It is found that the intensity of the 420 nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583 nm is not. The ratio of fluorescence intensities at 420 nm and 583 nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420 nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection.

  19. Studies on the utility of plant cellulose waste for the bioadsorption of crystal violet dye.

    PubMed

    Mahesh, S; Kumar, G Vijay; Agrawal, Pushpa

    2010-05-01

    Several synthetic dyes employed in textile and food industries are discharged into aquatic environment. These visible pollutants in water damage environment, as they are carcinogenic and toxic to humans. The use of cost effective and ecofriendly plant cellulose based adsorbents have been studied in batch experiments as an alternative and effective substitution of activated carbon for the removal of toxic dyes from waste water. Adsorbents prepared from sugarcane baggase, were successfully used to remove certain textile dye such as crystal violet from an aqueous solution. The present investigation potentiate the use of sugarcane baggase, pretreated with formaldehyde (referred as Raw Baggase) and sulphuric acid (referred as Chemically Activated Baggase), for the removal of crystal violet dye from simulated waste water. Experiments were carried out at neutral pH with various parameters like dye concentration, temperature, contact time and adsorbent dosage. Efficiency of raw baggase was found better than chemically activated baggase for adsorption of crystal violet dye. The data obtained perfectly fits in the Freundlich adsorption isotherm.

  20. Demonstration of the Replacement of the Dyes and Sulfur in the M18 Red and Violet Smoke Grenades

    DTIC Science & Technology

    2008-09-10

    System MDAP Mandatory Procedures for Major Defense Acquisition Program MIDAS Munitions Items Disposition Action System MIL-HDBK Military Handbook ...sulfur and other components of the M18 red and violet smoke grenades. The substitution of a sugar-chlorate formulation smoke, as well as less toxic...smoke formula for the violet smoke grenade (DODIC G955) and the new ESTCP formulation was completed (Appendix J). Eleven of twenty four rats died

  1. Microfluidic biosensor array with integrated poly(2,7-carbazole)/fullerene-based photodiodes for rapid multiplexed detection of pathogens.

    PubMed

    Matos Pires, Nuno Miguel; Dong, Tao

    2013-11-25

    A multiplexed microfluidic biosensor made of poly(methylmethacrylate) (PMMA) was integrated into an array of organic blend heterojunction photodiodes (OPDs) for chemiluminescent detection of pathogens. Waterborne Escherichia coli O157:H7, Campylobacter jejuni and adenovirus were targeted in the PMMA chip, and detection of captured pathogens was conducted by poly(2,7-carbazole)/fullerene OPDs which showed a responsivity over 0.20 A/W at 425 nm. The limits of chemiluminescent detection were 5 × 10(5) cells/mL for E. coli, 1 × 10(5) cells/mL for C. jejuni, and 1 × 10(-8) mg/mL for adenovirus. Parallel analysis for all three analytes in less than 35 min was demonstrated. Further recovery tests illustrated the potential of the integrated biosensor for detecting bacteria in real water samples.

  2. Synthesis, spectroscopic characterization and structural investigations of new adduct compound of carbazole with picric acid: DNA binding and antimicrobial studies

    NASA Astrophysics Data System (ADS)

    Saravanabhavan, Munusamy; Sathya, Krishnan; Puranik, Vedavati G.; Sekar, Marimuthu

    2014-01-01

    Carbazole picrate (CP), a new organic compound has been synthesized, characterized by various analytical and spectroscopic technique such as FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. An orthorhombic geometry was proposed based on single crystal XRD study. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it was stable up to 170 °C. Further, the newly synthesized title compound was tested for its in vitro antibacterial and antifungal activity against various bacterial and fungal species. Also, the compound was tested for its binding activity with Calf thymus (CT) DNA and the results show a considerable interaction between CP and CT-DNA.

  3. Specific indolo[3,2,1-jk]carbazole conducting thin-film materials production by selective substitution.

    PubMed

    Henry, John B; Wharton, Stuart I; Wood, Elanor R; McNab, Hamish; Mount, Andrew R

    2011-06-02

    Selectively substituted indolo[3,2,1-jk] carbazole (IC) molecules have been synthesized through flash vacuum pyrolysis (FVP) and then electro-oxidized, resulting in the formation of redox-active and electronically conducting thin films consisting exclusively of three highly luminescent dimer species, the 2,2'-, 2,10'-, and 10,10'-coupled dimers. DFT calculation has enabled both the accurate calculation of monomer oxidation potentials and the prediction of the nature of the resulting dimers through consideration of the coupling of the oxidized monomer radical cations. This demonstrates that substituted ICs represent a class of molecules able to form redox-active and conducting dimer films of controlled composition upon oxidation and that DFT calculations can be used to inform the synthesis of specific IC monomers most likely to both produce electronically conducting thin-film materials and yield specific luminescent dimers with desirable materials properties.

  4. Spectroscopic studies on 9H-carbazole-9-(4-phenyl) boronic acid pinacol ester by DFT method

    NASA Astrophysics Data System (ADS)

    Sas, E. B.; Kurt, M.; Can, M.; Horzum, N.; Atac, A.

    2016-08-01

    9H-Carbazole-9-(4-phenyl) boronic acid pinacol ester (9-CPBAPE) molecule was investigated by FT-IR, Raman, UV-vis, 1H and 13C NMR spectra. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H, 13C NMR and UV-vis spectra were recorded in dimethyl sulfoxide (DMSO) solution. The results of theoretical calculations for the spectra of the title molecule were compared with the experimental spectra. The highest occupied molecular orbital (HOMO) the lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential (MEP) analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G (d,p) basis set calculations using the Gaussian 09 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analyses were performed using GaussSum 2.2 program.

  5. Three-Arm, Biotin-Tagged Carbazole-Dicyanovinyl-Chlorambucil Conjugate: Simultaneous Tumor Targeting, Sensing, and Photoresponsive Anticancer Drug Delivery.

    PubMed

    Venkatesh, Yarra; Karthik, S; Rajesh, Y; Mandal, Mahitosh; Jana, Avijit; Singh, N D Pradeep

    2016-12-19

    The design, synthesis, and in vitro biological studies of a biotin-carbazole-dicyanovinyl-chlorambucil conjugate (Bio-CBZ-DCV-CBL; 6) are reported. This conjugate (6) is a multifunctional single-molecule appliance composed of a thiol-sensor DCV functionality, a CBZ-derived phototrigger as well as fluorescent reporter, and CBL as the anticancer drug, and Bio as the cancer-targeting ligand. In conjugate 6, the DCV bond undergoes a thiol-ene click reaction at pH<7 with intracellular thiols, thereby shutting down internal charge transfer between the donor CBZ and acceptor DCV units, resulting in a change of the fluorescence color from green to blue, and thereby, sensing the tumor microenvironment. Subsequent photoirradiation results in release of the anticancer drug CBL in a controlled manner.

  6. From Sediment to Top Predators: Broad Exposure of Polyhalogenated Carbazoles in San Francisco Bay (U.S.A.).

    PubMed

    Wu, Yan; Tan, Hongli; Sutton, Rebecca; Chen, Da

    2017-02-21

    The present study provides the first comprehensive investigation of polyhalogenated carbazoles (PHCZs) contamination in an aquatic ecosystem. PHCZs have been found in soil and aquatic sediment from several different regions, but knowledge of their bioaccumulation and trophodynamics is extremely scarce. This work investigated a suite of 11 PHCZ congeners in San Francisco Bay (United States) sediment and organisms, including bivalves (n = 6 composites), sport fish (n = 12 composites), harbor seal blubber (n = 18), and bird eggs (n = 8 composites). The most detectable congeners included 3,6-dichlorocarbazole (36-CCZ), 3,6-dibromocarbazole (36-BCZ), 1,3,6-tribromocarbazole (136-BCZ), 1,3,6,8-tetrabromocarbazole (1368-BCZ), and 1,8-dibromo-3,6-dichlorocarbazole (18-B-36-CCZ). The median concentrations of ΣPHCZs were 9.3 ng/g dry weight in sediment and ranged from 33.7 to 164 ng/g lipid weight in various species. Biomagnification was observed from fish to harbor seal and was mainly driven by chlorinated carbazoles, particularly 36-CCZ. Congener compositions of PHCZs differed among species, suggesting that individual congeners may be subject to different bioaccumulation or metabolism in species occupying various trophic levels in the studied aquatic system. Toxic equivalent (TEQ) values of PHCZs were determined on the basis of their relative effect potencies (REP) compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The median TEQ was 1.2 pg TEQ/g dry weight in sediment and 4.8-19.5 pg TEQ/g lipid weight in biological tissues. Our study demonstrated the broad exposure of PHCZs in San Francisco Bay and their characteristics of bioaccumulation and biomagnification along with dioxin-like effects. These findings raise the need for additional research to better elucidate their sources, environmental behavior, and fate in global environments.

  7. Validation of an LC-MS/MS method for malachite green (MG), leucomalachite green (LMG), crystal violet (CV) and leucocrystal violet (LCV) residues in fish and shrimp.

    PubMed

    Ascari, Jociani; Dracz, Sérgio; Santos, Flávio A; Lima, J A; Diniz, Maria Helena G; Vargas, Eugênia A

    2012-01-01

    A quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous analyses of malachite green (MG), crystal violet (CV) and its major metabolites, leucomalachite green (LMG) and leucocrystal violet (LCV) residues in fish and shrimp samples has been validated. Fish and shrimp samples were extracted with citrate buffer/acetonitrile, and the extracts were purified on strong cation-exchange (SCX) solid-phase extraction (SPE) cartridge. After conversion of LMG into MG using a post column oxidation reactor containing lead (IV) oxide (PbO(2)), the effluents were analysed. Residues were analysed using positive-ion electrospray ionisation (ESI). Identification and quantification of analytes were based on the ion transitions monitored by multiple reaction monitoring (MRM). Validation of the method was carried out in accordance with the Decision 2002/657/EC, which establishes criteria and procedures for the validation of methods. The following parameters were determined: decision limit (CCα), detection capability (CCβ), linearity, accuracy, precision, selectivity, specificity and matrix effect. The decision limits (CCα) for MG, LMG, CV and LCV were 0.164, 0.161, 0.248 and 0.860 µg kg(-1). The respective detection capabilities (CCβ) were 0.222, 0.218, 0.355 and 1.162 µg kg(-1). Typical recoveries (intermediate precision) in shrimp, for MG, CV, LMG and LCV for 2.0 µg kg(-1) level fortified samples using the optimised procedure were in the range 69%, 97%, 80.3% and 71.8%, respectively. The findings demonstrate the suitability of the method to detect simultaneously MG, CV and its metabolite (LMG and LCV) in fish and shrimp.

  8. “Transition-metal-free” synthesis of carbazoles by photostimulated reactions of 2′-halo[1,1′-biphenyl]-2-amines.

    PubMed

    Guerra, Walter D; Rossi, Roberto A; Pierini, Adriana B; Barolo, Silvia M

    2015-01-16

    An efficient and simple protocol for the preparation of a series of 9H-carbazoles by photostimulated SRN1 substitution reactions is presented. Substituted 9H-carbazoles were synthesized in low to excellent yields (up to 96%) through an intramolecular C–N bond formation of 2′-halo[1,1′-biphenyl]-2-amines by the photoinitiated SRN1 mechanism under mild and “transition-metal-free” conditions. The biphenylamines used as substrates were obtained with isolated yields ranging from 21% to 84% by two approaches: (A) the cross-coupling Suzuki–Miyaura reaction and (B) the radical arylation of anilines. Some key aspects of the proposed mechanism were evaluated at the B3LYP/6-311+G* level.

  9. Synthesis, photophysical, and electrochemical properties of wide band gap tetraphenylsilane-carbazole derivatives: Effect of the substitution position and naphthalene side chain

    NASA Astrophysics Data System (ADS)

    Ho, Kar Wei; Ariffin, A.

    2016-12-01

    Four tetraphenylsilane-carbazole derivatives with wide bandgaps (3.38-3.55 eV) were synthesized. The effects of the substitution position and of the presence of naphthalene groups on the photophysical, electrochemical and thermal properties were investigated. The derivatives exhibited maximum absorption peaks ranging from 293 to 304 nm and maximum emission peaks ranging from 347 to 386 nm. Changing the carbazole substitution position on the tetraphenylsilane did not significantly change the photophysical and electrochemical properties. However, p-substituted compounds exhibited higher glass transition temperatures than m-substituted compounds. Naphthalene groups with bulky structures had extended the conjugation lengths that red-shifted both the absorption and emission spectra. The LUMO level was decreased, which reduced the optical bandgap and triplet energy level. However, the naphthalene groups significantly improved the thermal stability by increasing the glass transition temperature of the compounds.

  10. Magnetic solid-phase extraction for determination of the total malachite green, gentian violet and leucomalachite green, leucogentian violet in aquaculture water by high-performance liquid chromatography with fluorescence detection.

    PubMed

    Zhao, Jiao; Wei, Daqiao; Yang, Yaling

    2016-06-01

    In this study, magnetic multi-walled carbon nanotube nanoparticles were synthesized and used as the adsorbent for the sums of malachite green, gentian violet and leucomalachite green, leucogentian violet in aquaculture water samples followed by high performance liquid chromatography with fluorescence detection. This method was based on in situ reduction of chromic malachite green, gentian violet to colorless leucomalachite green, leucogentian violet with potassium borohydride, respectively. The obtained adsorbent combines the advantages of carbon nanotubes and Fe3 O4 nanoparticles in one material for separation and preconcentration of the reductive dyes in aqueous media. The structure and properties of the prepared nanoparticles were characterized by transmission and scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The main parameters affecting the adsorption recoveries were investigated and optimized, including reducing agent concentration, type and amount of sorbent, sample pH, and eluting conditions. Under the optimum conditions, the limits of detection in this method were 0.22 and 0.09 ng/mL for malachite green and gentian violet, respectively. Product recoveries ranged from 87.0 to 92.8% with relative standard deviations from 4.6 to 5.9%. The results indicate that the sorbent is a suitable material for the removal and concentration of triphenylmethane dyes from polluted environmental samples.

  11. BC3EE2,9B, a synthetic carbazole derivative, upregulates autophagy and synergistically sensitizes human GBM8901 glioblastoma cells to temozolomide

    PubMed Central

    CHEN, CHIEN-MIN; SYU, JHIH-PU; WAY, TZONG-DER; HUANG, LI-JIAU; KUO, SHENG-CHU; LIN, CHUNG-TIEN; LIN, CHIH-LI

    2015-01-01

    Glioblastoma multiforme (GBM) is the most fatal form of human brain cancer. Although temozolomide (TMZ), an oral alkylating chemotherapeutic agent, improves the survival rate, the prognosis of patients with GBM remains poor. Naturally occurring carbazole alkaloids isolated from curry leaves (Murraya koenigii Spreng.) have been shown to possess a wide range of anticancer properties. However, the effects of carbazole derivatives on glioblastoma cells remain poorly understood. In the present study, anti-glioblastoma profiles of a series of synthetic carbazole derivatives were evaluated in vitro. The most promising derivative in this series was BC3EE2,9B, which showed significant anti-proliferative effects in GBM8401 and GBM8901 cells. BC3EE2,9B also triggered cell-cycle arrest, most prominently at the G1 stage, and suppressed glioblastoma cell invasion and migration. Furthermore, BC3EE2,9B induced autophagy-mediated cell death and synergistically sensitized GBM cells to TMZ cytotoxicity. The possible mechanism underlying BC3EE2,9B-induced autophagy may involve activation of adenosine monophosphate-activated protein kinase and the attenuation of the Akt and mammalian target of the rapamycin downstream signaling pathway. Taken together, the present results provide molecular evidence for the mode of action governing the ability of BC3EE2,9B to sensitize drug-resistant glioblastoma cells to the chemotherapeutic agent TMZ. PMID:26329365

  12. Experimental and theoretical studies on new 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-alkyl-10H-phenothiazine-3-carbaldehydes

    NASA Astrophysics Data System (ADS)

    Stalindurai, Kesavan; Gokula Krishnan, Kannan; Nagarajan, Erumaipatty Rajagounder; Ramalingan, Chennan

    2017-02-01

    Synthesis of fused heterocyclic aldehydes with carbazole (CZ) structural motif linked at C-7 position on phenothiazines (PTZ), 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-butyl-10H-phenothiazine-3-carbaldehyde (1) and 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-hexyl-10H-phenothiazine-3-carbaldehyde (2) has been accomplished and are characterized through experimental and computational techniques. The optimized structure with their bonding aspects and vibrational frequencies of the same have been examined utilizing DFT-B3LYP technique with a basis set 6-311++G(d,p). In the optimized structures of 1 and 2, the bond lengths and bond angles are in accord with their corresponding reported analogous. The vibrational frequencies resulted from experimental as well as theoretical are in well accord with each other. Further, the results of polarizabilities, first order hyperpolarizabilities and dipole moment of 1 and 2 imply that these could be utilized for the preparation of NLO crystals which might generate second order harmonic waves.

  13. Adsorption of Crystal violet on raw and acid-treated montmorillonite, K10, in aqueous suspension.

    PubMed

    Sarma, Gautam Kumar; Sen Gupta, Susmita; Bhattacharyya, Krishna G

    2016-04-15

    Crystal violet is used as a dye in cotton and silk textiles, paints and printing ink. The dye is hazardous and exposure to it may cause permanent injury to the cornea and conjunctiva including permanent blindness, and in severe cases, may lead to respiratory and kidney failure. The present work describes removal of Crystal violet from aqueous solution by adsorption on raw and acid-treated montmorillonite, K10. The clay mineral was treated with 0.25 and 0.50 M sulfuric acid and the resulting materials were characterized by XRD, zeta potential, SEM, FTIR, cation exchange capacity, BET surface area and pore volume measurements. The influences of pH, interaction time, adsorbent amount, and temperature on adsorption were monitored and explained on the basis of physico-chemical characteristics of the materials. Basic pH generally favors adsorption but considerable removal was possible even under neutral conditions. Adsorption was very rapid and equilibrium could be attained in 180 min. The kinetics conformed to second order model. Langmuir monolayer adsorption capacity of raw montmorillonite K10 was 370.37 mg g(-1) whereas 0.25 M and 0.50 M acid treated montmorillonite K10 had capacities of 384.62 and 400.0 mg g(-1) respectively at 303 K. Adsorption was exothermic and decreased in the temperature range of 293-323 K. Thermodynamically, the process was spontaneous with Gibbs energy decreasing with rise in temperature. The results suggest that montmorillonite K10 and its acid treated forms would be suitable for removing Crystal violet from aqueous solution.

  14. Jupiter's Belt-Zone Boundary in Near-Infrared and Violet Light

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mosaics of a belt-zone boundary near Jupiter's equator in violet (top panel) and near-infrared (bottom panel) light. The four images that make up each of these mosaics were taken within a few minutes of each other. Sunlight at 757 nanometers (near-infrared) penetrates deep into Jupiter's troposphere before being absorbed or scattered by clouds to the Galileo spacecraft. This wavelength reveals the features of the lower visible cloud deck. Sunlight at 415 nanometers (violet) is a scattered or absorbed to varying degrees in different parts of Jupiter's atmosphere depending on the types and concentrations of cloud particles and chemicals that color Jupiter's atmosphere. The near-infrared mosaic primarily shows cloud features. The violet mosaic has three distinct regions: it is brightest at the latitude of the jet (horizontally across the center of the mosaic), moderately bright north of the jet, and dark and patchy south of the jet.

    North is at the top. The mosaic covers latitudes -13 to +3 degrees and is centered at longitude 282 degrees West. The smallest resolved features are tens of kilometers in size. These images were taken on November 5th, 1996, at a range of 1.2 million kilometers by the Solid State Imaging system aboard NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  15. Oxidation preventative capping layer for deep-ultra-violet and soft x-ray multilayers

    DOEpatents

    Prisbrey, Shon T.

    2004-07-06

    The invention uses iridium and iridium compounds as a protective capping layer on multilayers having reflectivity in the deep ultra-violet to soft x-ray regime. The iridium compounds can be formed in one of two ways: by direct deposition of the iridium compound from a prepared target or by depositing a thin layer (e.g., 5-50 angstroms) of iridium directly onto an element. The deposition energy of the incoming iridium is sufficient to activate the formation of the desired iridium compound. The compounds of most interest are iridium silicide (IrSi.sub.x) and iridium molybdenide (IrMo.sub.x).

  16. Matrix dependent changes in metachromasy of crystal violet in Langmuir-Blodgett films

    NASA Astrophysics Data System (ADS)

    Shil, Ashis; Saha, Mitu; Debnath, Chandan; Hussain, S. A.; Bhattacharjee, D.

    2016-11-01

    This communication reports the effect of building matrices and nano clay platelets on the aggregation pattern of a water soluble cationic fluorescent dye Crystal Violet (CV) in Langmuir-Blodgett (LB) Films. When stearic acid (SA) was used as a building matrix, pressure induced changes in metachromasy was observed in the SA-CV complex LB films with a characteristic J-band formed at the longer wavelength side. On the other hand, clay incorporated hybrid LB films showed high degree of control over H-dimeric band. Isotherm characteristics, Brewster Angle Microscopic (BAM) images, UV-vis absorption and fluorescence characteristic studies were employed to investigate this result.

  17. Gentian violet: a 19th century drug re-emerges in the 21st century.

    PubMed

    Maley, Alexander M; Arbiser, Jack L

    2013-12-01

    Gentian violet (GV) has a long and varied history as a medicinal agent. Historically used as an antibacterial and antifungal, recent reports have shown its utility as an antitypranosomal, antiviral and anti-angiogenic agent. The objective of this article is to summarize evidence regarding the efficacy and safety of GV use in dermatology. Recent discoveries have found novel targets of GV, namely NADPH oxidase in mammalian cells and thioredoxin reductase 2 in bacterial, fungal and parasitic cells. These discoveries have expanded the use of GV in the 21st century. Given that GV is well tolerated, effective and inexpensive, its use in dermatology is predicted to increase.

  18. Exploring the temporally resolved electron density evolution in extreme ultra-violet induced plasmas

    NASA Astrophysics Data System (ADS)

    van der Horst, R. M.; Beckers, J.; Nijdam, S.; Kroesen, G. M. W.

    2014-07-01

    We measured the electron density in an extreme ultra-violet (EUV) induced plasma. This is achieved in a low-pressure argon plasma by using a method called microwave cavity resonance spectroscopy. The measured electron density just after the EUV pulse is 2.6 × 1016 m-3. This is in good agreement with a theoretical prediction from photo-ionization, which yields a density of 4.5 × 1016 m-3. After the EUV pulse the density slightly increases due to electron impact ionization. The plasma (i.e. electron density) decays in tens of microseconds.

  19. Computational Chemistry Approach to Interpret the Crystal Violet Adsorption on Golbasi Lignite Activated Carbon

    NASA Astrophysics Data System (ADS)

    Depci, Tolga; Sarikaya, Musa; Prisbrey, Keith A.; Yucel, Aysegul

    2016-10-01

    In this paper, adsorption mechanism of Crystal Violet (CV) dye from the aqueous solution on the activated carbon prepared from Golbasi lignite was explained and interpreted by a computational chemistry approach and experimental studies. Molecular dynamic simulations and Ab initio frontier orbital analysis indicated relatively high energy and electron transfer processes during adsorption, and molecular dynamics simulations showed CV dye molecules moving around on the activated carbon surface after adsorption, facilitating penetration into cracks and pores. The experimental results supported to molecular dynamic simulation and showed that the monolayer coverage occurred on the activated carbon surface and each CV dye ion had equal sorption activation energy.

  20. Adsorption Capability of Cationic Dyes (Methylene Blue and Crystal Violet) onto Poly-γ-glutamic Acid.

    PubMed

    Ogata, Fumihiko; Nagai, Noriaki; Kawasaki, Naohito

    2017-01-01

    In this study, the adsorption capability of cationic dyes, which were methylene blue and crystal violet, by poly-γ-glutamic acid (PGA) in a single or binary solution system was investigated. The effect of the molecular weight of PGA, initial dye concentration, solution pH, and temperature on the adsorption of dyes was evaluated. The adsorption mechanism of dyes onto PGA was the interaction between -COOH group on the PGA surface and the polarity groups of dyes. These results indicated that PGA is useful for removal of dyes and cationic organic compounds from a single or binary solution system.

  1. High light extraction efficiency in bulk-GaN based volumetric violet light-emitting diodes

    SciTech Connect

    David, Aurelien Hurni, Christophe A.; Aldaz, Rafael I.; Cich, Michael J.; Ellis, Bryan; Huang, Kevin; Steranka, Frank M.; Krames, Michael R.

    2014-12-08

    We report on the light extraction efficiency of III-Nitride violet light-emitting diodes with a volumetric flip-chip architecture. We introduce an accurate optical model to account for light extraction. We fabricate a series of devices with varying optical configurations and fit their measured performance with our model. We show the importance of second-order optical effects like photon recycling and residual surface roughness to account for data. We conclude that our devices reach an extraction efficiency of 89%.

  2. Demonstration of lipofuscin and Nissl bodies in crystal violet stained sections using a fluorescence technique or pyronin Y stain.

    PubMed

    Terr, L I

    1986-09-01

    This paper presents two simple, reliable methods for identification of lipofuscin and Nissl bodies in the same section. One method shows that lipofuscin stained with crystal violet retains its ability to fluoresce and can be observed under the fluorescence microscope after the stain has faded. Fading is accompanied by a gradual increase in the intensity of the fluorescence and is complete in about 5 min. Exciting illumination from this part of the spectrum also substantially fades staining of other autofluorescing tissue elements, such as lipids. Nonfluorescing structures, such as Nissl bodies, remain stained. By changing from transillumination with tungsten light to epifluorescent illumination and vice versa, both types of structures--Nissl bodies and lipofuscin--can be identified in the same section. The second technique uses pyronin Y for staining Nissl bodies in preparations previously stained with crystal violet. Nissl bodies are stained pink but lipofuscin remains violet. Lipofuscin in these sections also remains autofluorescent after the crystal violet stain has faded under violet or near-UV light.

  3. Liquid phase adsorption of Crystal violet onto activated carbons derived from male flowers of coconut tree.

    PubMed

    Senthilkumaar, S; Kalaamani, P; Subburaam, C V

    2006-08-25

    Adsorption of Crystal violet, a basic dye onto phosphoric and sulphuric acid activated carbons (PAAC and SAAC), prepared from male flowers coconut tree has been investigated. Equilibrium data were successfully applied to study the kinetics and mechanism of adsorption of dye onto both the carbons. The kinetics of adsorption was found to be pseudo second order with regard to intraparticle diffusion. The pseudo second order is further supported by the Elovich model, which in turn intensifies the fact of chemisorption of dye onto both the carbons. Quantitative removal of dye at higher initial pH of dye solution reveals the basic nature of the Crystal violet and acidic nature of the activated carbons. Influence of temperature on the removal of dye from aqueous solution shows the feasibility of adsorption and its endothermic nature. Mass transfer studies were also carried out. The adsorption capacities of both the carbons were found to be 60.42 and 85.84 mg/g for PAAC and SAAC, respectively. Langmuir's isotherm data were used to design single-stage batch adsorption model.

  4. Automatic determination of coenzyme Q10 in food using cresyl violet encapsulated into magnetoliposomes.

    PubMed

    Román-Pizarro, Vanessa; Fernández-Romero, Juan Manuel; Gómez-Hens, Agustina

    2017-04-15

    A new type of magnetoliposomes (MLs), containing hydrophobic magnetic-gold nanoparticles and the long wavelength fluorophore cresyl violet, has been used for the determination of coenzyme Q10 (CoQ10). MLs were concentrated just before the detector, using a flow system and an external electromagnet device. The subsequent introduction of Triton X-100 and CoQ10 causes the MLs lysis and the cresyl violet oxidation, obtaining a decrease in the fluorescence signal. The dynamic range of the calibration graph was 0.03-0.50μmolL(-1) CoQ10, and the detection limit was 0.008μmolL(-1). The precision (relative standard deviation) was in the range of 1.3-4.5%. The method showed a sampling frequency of 12h(-1) and was applied to the determination of CoQ10 in several food samples. The results were compared with those obtained using a previously described chromatographic method. Also, recovery values were in the range of 83.5-101.3%.

  5. Photocatalytic studies of crystal violet dye using mn doped and PVP capped ZnO nanoparticles.

    PubMed

    Mittal, Manish; Sharma, Manoj; Pandey, O P

    2014-04-01

    Mn (0.5%, 1%, 1.5% and 2%) doped and undoped ZnO nanoparticles (NPs) capped with PVP (1.0%) were successfully synthesized via co-precipitation approach using zinc acetate, sodium hydroxide and manganese acetate as precursors. Structural analysis was performed by XRD confirming phase purity and crystalline wurtzite structure. TEM results show average particle size 15-20 nm and 22-25 nm for Mn (1%) and Mn (2%) doped ZnO NPs respectively. Manganese (Mn) doping has led to reduction in band gap which facilitate the absorption of radiation in visible region. The Photocatalytic activity of undoped and Mn (0.5%,1%,1.5% and 2%) doped NPs was analyzed via degradation of crystal violet (CV) dye. The crystal violet decomposition rate of undoped and Mn doped NPs were studied under UV-visible region. It is observed from degradation studies that the doping has a pronounced effect on the photocatalytic activity of ZnO NPs. Kinetic studies shows that photo degradation of CV follow a pseudo first-order kinetic law. Experiments for reusability of Mn (1%) doped with PVP (1%) capped ZnO were also performed to determine the stability of as prepared sample. It shows an increase in catalytic activity of NPs by small amount when exposed to UV irradiation for 3 h. Photoluminescence and UV-Visible absorption spectroscopy studies were also performed for studying the effect of UV irradiation on the surface of ZnO NPs.

  6. The effect of chlorhexidine and gentian violet on the adherence of Candida spp. to urinary catheters.

    PubMed

    Camacho, D P; Gasparetto, A; Svidzinski, T I E

    2007-05-01

    Urinary tract infection associated with catheters is the most common infection in the hospital environment. The adherence of microorganisms to the surface is a determining factor in colonization and infection. Antiseptics such as chlorhexidine and gentian violet have been shown to be effective against yeasts, as well as having low toxicity and being low-cost. The objective of the present study was to evaluate whether prior treatment of siliconized latex urinary catheters with antiseptics reduces the adherence of yeasts. Two reference strains of C. albicans (ATCC 645448 and ATCC 90028) and six strains isolated from catheter, two each of C. albicans, C. tropicalis, and C. parapsilosis, were used. An in vitro study of adherence was carried out with previously treated catheters, in separate experiments of 1 h and 24 h of incubation under continued shaking. The relative hydrophobicity of the cell surface of the yeasts before and after 1 h of exposure to chlorhexidine was determined. The results demonstrated that both treatments were effective in controlling the adherence of yeast to the catheter (P < 0.0001), and that the hydrophobicity of the eight strains significantly increased after contact with chlorhexidine (P < 0.0001). These results suggest that the antimicrobial activity of chlorhexidine and gentian violet reduces the adherence of the microorganisms to the catheter.

  7. Equilibrium and kinetic studies of methyl violet sorption by agricultural waste.

    PubMed

    Hameed, B H

    2008-06-15

    In this work, sunflower (Helianthus annuus L.) seed hull (SSH), an agricultural waste, was evaluated for its ability to remove methyl violet (MV) from aqueous solutions. Sorption isotherm of MV onto the SSH was determined at 30 degrees C with the initial concentrations of MV in the range of 25-300 mg/L. The equilibrium data were analyzed using the Langmuir, Freundlich and Temkin isotherm models. The equilibrium process was described well by the Freundlich isotherm model. The maximum SSH sorption capacity was found to be 92.59 mg/L at 30 degrees C. The kinetic data were studied in terms of the pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The pseudo-second-order model best described the sorption process. A single-stage batch-adsorber design of the adsorption of MV onto SSH was studied based on the Freundlich isotherm equation. The results indicated that sunflower seed hull was an attractive candidate for removing methyl violet from aqueous solution.

  8. Fluorine-doped zinc oxide thin films: influence of precursor flow rate on violet luminescence

    NASA Astrophysics Data System (ADS)

    Muthukumar, Anusha; Dakshnamoorthy, Arivuoli

    2015-06-01

    Fluorine-doped zinc oxide (FZO) thin films were deposited by the aerosol-assisted chemical vapor deposition method with variable precursor flow rates (0.5-2.5 ml/min). X-ray diffraction patterns revealed the polycrystalline hexagonal wurtzite structure of the derived FZO nanocrystalline thin films. Extensive crystallinity analysis of the film deposited at 1 ml/min was done by grazing incidence X-ray diffraction. Field emission scanning electron microscope images apparent the gradual evolution from spherical grains and hexagonal platelet like surface morphology with increased flow rate. Optical transparency and photoluminescence (PL) are strongly influenced by flow rate. PL intensity and transparency increase with decreased flow rate. The optical bandgap was tuned significantly by increase in flow rate and especially tuned the PL emission from violet to UV. High intense violet PL observed at flow rate of 1 ml/min and radiative transition of electrons from zinc vacancies level to the conduction band were found. Crystallinity, growth rate and roughness increase with increased flow rate.

  9. An analysis on effecting factors of ultra-violet imaging appliance in corona discharge

    NASA Astrophysics Data System (ADS)

    Han, Xiao; Yang, Ning; Yuan, Shuai; Bi, Jiangang

    2014-11-01

    In this paper, the operating principle of daylight UV imagers was introduced first, emphasizing the SBUV(solar blind UV) technology, which utilizes the fact that ultra violet between 240nm~280nm is being absorbed by the ozone so that signals detected on earth in this spectral range originate on earth. And then several influencing factors were explained, including observation distance, observing angle, imager gain settings and environmental conditions. Experimental data measured in the UHV(ultra high-voltage) DC converter station in Changzhi, Shanxi, China were analyzed using SRA(single regression analysis) method, and mathematical equations with acceptable deviation were calculated, with simulating curves plotted. The results show that environmental conditions including humidity and temperature, observation distance and imager gain settings all contribute to the measuring result, exhibiting as exponential function and convex function respectively. Concluded from the above analysis and calculation, observing conditions of a clear observing angle at the same observation distance with mediate gain settings on days of low humidity were recommended. This conclusion may guide further ultra-violet imaging appliance in high-voltage electrical devices corona discharge sensing.

  10. Evaluation of the photodegradation of crystal violet upon light exposure by mass spectrometric and spectroscopic methods.

    PubMed

    Weyermann, Céline; Kirsch, Dieter; Vera, César Costa; Spengler, Bernhard

    2009-03-01

    Crystal violet is a very common dye in ballpoint ink. Recent research suggests that the degradation of triarylmethane dyes gives an indication of the age of a ballpoint pen entry on a document. The main problem for the quantitative evaluation of the degradation is that it is highly dependent on the exposure to light. Moreover additional factors, such as additives and substrate play an important role in this process. The aim of this work is to compare the degradation pathways of the pure dye in water and ethanol upon exposure to xenon light by UV/VIS spectrophotometry and laser desorption ionization. Significant differences have been observed in the products and the kinetics of the degradation. N-demethylation, an expected decomposition process, was found to take place only in aqueous solution and kinetics calculations showed that the degradation occurred 2.5 times faster in ethanol compared to water. The degradation of crystal violet in inks from four ballpoint pens on paper was also studied for entries made over 2-3 years. It was observed that degradation reactions were quenched by the presence of another dye due to competitive absorption. It was also observed that the thickness of a stroke (concentration of ink) influenced the degradation process. In the absence of light only one ballpoint pen showed slight degradation. A better understanding of the influence of the paper, ink composition, and storage conditions is necessary to interpret correctly the age of an ink based on the degradation of dyes.

  11. Measurement and Analysis of CN Violet System in Laser-Induced Plasma

    NASA Astrophysics Data System (ADS)

    Behery, Sultan A.; Parigger, Christian G.

    2014-03-01

    Pulsed, infrared Nd:YAG laser radiation is utilized to ablate material from carbon-containing samples in air. Time-resolved measurements of the micro-plasma show well-developed diatomic spectra of the CN violet system. Of Interest are interferences from the C2 Deslandres D'Azambuja system in the CN spectra, as previously noted in experiments with CO2 laser radiation focused into CO2 gas expanding into air. The recombination emission spectra from diatomic species, e.g., CN or C2, clearly indicate temperatures in excess of 6000 Kelvin. Studies of the CO2 TEA laser-induced micro-plasmas show these highly excited, high-temperature molecular transitions several tens of microseconds after plasma generation, mixed with signatures of Stark-broadened atomic lines. Spectroscopic fitting with accurate molecular line strengths of superposed emission spectra is of current interest, including study of the C2 Deslandres D'Azambuja system near the 4-4 band of the CN Δv = 0 sequence of the CN B2Σ+ --> X2Σ+ Violet System. In addition, discussed are physics phenomena associated with laser-induced optical breakdown. Laser-induced plasma applications include characterization of carbon and nitrogen containing materials.

  12. Enhanced tetrazolium violet reduction of Salmonella spp. by magnesium addition to the culture media.

    PubMed

    Junillon, Thomas; Morand, Lucie; Flandrois, Jean Pierre

    2014-09-01

    Tetrazolium salts (TTZ), such as tetrazolium violet (TV), have been widely used for microbiological studies. The formation of the colored formazan product due to bacterial reduction of the uncolored reagent is extensively exploited to stain cells or colonies in agar or on filters. But an important toxic effect of tetrazolium salts on bacteria exists that limits their use at high concentrations, impairing the efficient staining of the colonies. This is especially the case for Salmonella spp. where we observed, using a classic photometric approach and mathematical modeling of the growth, an important impact of tetrazolium violet on the apparent growth rate below the inhibitory concentration. In this study, we demonstrate that adding magnesium to the medium in the presence of TV leads to a significant increase in the apparent growth rate. Moreover, when higher TV concentrations are used which lead to total inhibition of Salmonella strains, magnesium addition to the culture media allows growth and TV reduction. This effect of magnesium may allow the use of higher TTZ concentrations in liquid growth media and enhance bacteria detection capabilities.

  13. Chemical characterization and toxicologic evaluation of airborne mixtures: chemical characterization of combusted inventory red and violet smoke mixes

    SciTech Connect

    Rubin, I.B.; Buchanan, M.V.; Moneyhun, J.H.

    1982-10-01

    Red and violet smoke grenades (Grenade, Hand, Smoke, M18) were combusted within canvas tents and the combustion products were sampled and analyzed. Uncombusted red and violet smoke mixes from the same lots used to fill the combusted grenades were also analyzed. Approximately ten percent of the major dye component of the red smoke mix, methylaminoanthraquinone (MAA) was converted to aminoanthraquinones (1-AA and 2-AA). The violet smoke mix was formulated to contain 1,4-diamino-2,3-dihydroanthraquinone (DAA) and MAA. Upon combustion the DAA was converted almost completely to diaminoanthraquinone (DAA) which was a minor constituent of the uncombusted mix. As in the combusted red smoke mix, it was found that MAA was partially converted to aminoanthraquinones.

  14. Evolution and biogeography of the woody Hawaiian violets (Viola, Violaceae): arctic origins, herbaceous ancestry and bird dispersal.

    PubMed

    Ballard, H E; Sytsma, K J

    2000-10-01

    Specialists studying the genus Viola have consistently allied the Hawaiian violets comprising section Nosphinium--most of which are subshrubs or treelets--with putatively primitive subshrubs in certain South American violet groups. Hawaiian violets also possess inflorescences, a floral disposition otherwise found only in other genera of the Violaceae, thus strengthening the hypothesis of a very ancient origin for the Hawaiian species. A survey of phylogenetic relationships among infrageneric groups of Viola worldwide using nuclear rDNA internal transcribed spacer (ITS) sequences revealed a dramatically different biogeographic origin for the Hawaiian violets: A monophyletic Hawaiian clade was placed in a close sister relationship with the amphi-Beringian tundra violet, V. langsdorffii s. 1., in a highly derived position. This remarkable and unforeseen relationship received strong clade support values across analyses, and monophyly of the Hawaiian lineage was further indicated by a unique 26-base-pair deletion in section Nosphinium. The high polyploid base chromosome number (n approximately equal to 40) in the Hawaiian violets relates them to Alaskan and eastern Siberian populations in the polyploid V. langsdorffii complex. More than 50 species of the 260 allochthonous birds wintering in the Hawaiian Islands are found to breed in the Arctic, occupying habitats in which individual birds might have encountered ancestral V. langsdorffii populations and served as dispersers to the central Pacific region. Acquisition of derived morphological traits (e.g., arborescence and inflorescences), significance of a confirmed Arctic origin for a component of the Hawaiian flora, and the likelihood of other "cryptic" Arctic elements in the Hawaiian flora deserving independent molecular phylogenetic corroboration are discussed.

  15. A novel violet/blue light-emitting device based on Ce2Si2O7

    NASA Astrophysics Data System (ADS)

    Li, Ling; Wang, Shenwei; Mu, Guangyao; Yin, Xue; Ou, Kai; Yi, Lixin

    2015-11-01

    Rare-earth silicates are highly efficient materials for silicon-based light sources. Here we report a novel light-emitting device based on Ce2Si2O7. Intense violet/blue electroluminescence was observed, with a turn-on voltage of about 13 V. The violet/blue emission is attributed to 4f-5d transitions of the Ce3+ ions in Ce2Si2O7, which are formed by interfacial reaction of CeO2 and Si. Electroluminescence and photoluminescence mechanisms of the Ce2Si2O7 light-emitting device are also discussed.

  16. A novel violet/blue light-emitting device based on Ce2Si2O7

    PubMed Central

    Li, Ling; Wang, Shenwei; Mu, Guangyao; Yin, Xue; Ou, Kai; Yi, Lixin

    2015-01-01

    Rare-earth silicates are highly efficient materials for silicon-based light sources. Here we report a novel light-emitting device based on Ce2Si2O7. Intense violet/blue electroluminescence was observed, with a turn-on voltage of about 13 V. The violet/blue emission is attributed to 4f–5d transitions of the Ce3+ ions in Ce2Si2O7, which are formed by interfacial reaction of CeO2 and Si. Electroluminescence and photoluminescence mechanisms of the Ce2Si2O7 light-emitting device are also discussed. PMID:26564241

  17. Determination of crystal violet in seawater and seafood samples through off-line molecularly imprinted SPE followed by HPLC with diode-array detection.

    PubMed

    Lian, Ziru; Wang, Jiangtao

    2013-03-01

    A highly selective sample cleanup procedure combined with molecularly imprinted SPE was developed for the isolation of crystal violet from seawater and seafood samples. The molecularly imprinted polymer was prepared using crystal violet as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. The crystal violet-imprinted polymer was used as the selective sorbent for the SPE of crystal violet. An off-line molecularly imprinted SPE method followed by HPLC with diode-array detection for the analysis of crystal violet was also established. Good linearity on the molecularly imprinted SPE columns was obtained from 0 to 200 μg/L (R(2) > 0.99). The result demonstrated that the proposed method can be used for the direct determination of crystal violet in seawater and seafood samples. Finally, five samples were analyzed and the following crystal violet concentrations were obtained: 0.92 and 0.52 μg/L in two seawater samples, as well as 0.36 and 0.27 μg/kg in two seafood samples. There is no crystal violet detected in the third seawater sample.

  18. Spectroscopy and decay dynamics of jet-cooled carbazole and N-ethylcarbazole and their homocyclic analogues

    NASA Astrophysics Data System (ADS)

    Auty, A. R.; Jones, A. C.; Phillips, D.

    1986-03-01

    Fluorescence excitation spectra of supersonic jet-cooled carbazole (C) and N-ethylcarbazole (EC) are reported together with those of their homocyclic analogues fluorene (F) and 9-ethylfluorene (EF). Fluorescence spectra of C and EC have been measured following excitation at energies up to ≈ 1300 cm -1 above the S 1 origin and reveal that the onset of intramolecular vibrational redistribution occurs at around 900 cm -1 for both molecules, with redistribution being more extensive in the ethylated molecule. In C and EC, a number of modes are active in vibronically coupling the S 1 and S 2 states and Duschinsky mixing of these modes is apparent in the spectra. The fluorescence lifetimes of both C and EC show a slowly decreasing trend with increasing excitation energy in the range 0-1500 cm -1 excess vibrational energy; vibrational redistribution does not appear to enhance the rate of non-radiative decay in either molecule. Comparison of lifetime values under supersonic jet conditions with solution phase results indicates that solvation produces a considerable increase in the rate of intersystem crossing in these molecules.

  19. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    NASA Astrophysics Data System (ADS)

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-01

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H2CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn5(μ3-OH)2(2,7-CDC)4(DEF)2] (1) (DEF=N,N-diethylformamide), [Zn2(2,7-CDC)2(DABCO)(H2O)]·5DMF·H2O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn2(2,7-CDC)2(bpea)]·3DMA·2 H2O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn5(μ3-OH)2(COO)8] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle-wheel [Zn2(COO)4] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle-wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied.

  20. A carbazole alkaloid deactivates mTOR through the suppression of rictor and that induces apoptosis in lung cancer cells.

    PubMed

    Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Bhuyan, Mantu; Barua, Nabin C; Baruah, Pranab K; Babu, Santi Prasad Sinha; Bhattacharya, Samir

    2015-07-01

    Non-small cell lung cancer (NSCLC) is known to be a difficult cancer to treat because of its poor prognosis, limited option for surgery, and resistance to chemo or radiotherapy. In this study, we have demonstrated that suppression of rictor expression in A549 and H1299 NSCLC cells by mahanine, a carbazole alkaloid, disrupted constitutive activation of mTOR and Akt. Mahanine suppression of rictor gene expression and consequent attenuation of its protein expression affected the inhibition of mTOR (Ser-2481) and Akt (Ser-473) phosphorylation. Since mahanine treatment revealed this new insight of rictor-mTOR relationship, we examined an association between mTOR activation with rictor expression. Interestingly, in rictor knockdown (KD) NSCLC cells, mTOR activation was significantly impaired. Transfection of rictor over-expression vector into the NSCLC cells reversed this situation. In fact, both rictor KD and mahanine treated cells showed considerably depleted phospho-mTOR level. These results indicate that rictor is required to maintain constitutive activation of mTOR in lung cancer cells. When mTOR kinase activity in rictor KD cells was examined with Akt as substrate, a significant reduction of Akt phosphorylation indicated impairment of mTOR kinase potentiality. Disruption of mTOR and Akt activation caused drastic mortality of NSCLC cancer cells through apoptosis. Hence, our study reveals a new dimension in mTOR-rictor relationship, where rictor stands to be a suitable therapeutic target for lung cancer.

  1. Impact of intramolecular twisting and exciton migration on emission efficiency of multifunctional fluorene-benzothiadiazole-carbazole compounds

    NASA Astrophysics Data System (ADS)

    Karpicz, R.; Puzinas, S.; Krotkus, S.; Kazlauskas, K.; Jursenas, S.; Grazulevicius, J. V.; Grigalevicius, S.; Gulbinas, V.

    2011-05-01

    Novel donor-acceptor compounds consisting of singly bonded fluorene (Fl), benzothiadiazole (BT), and carbazole (Cz) functional units in the same molecule were investigated. Analysis of the optical spectra and fluorescence transients of the compounds revealed the domination of intramolecular charge transfer (ICT) states with high fluorescence quantum yield (72%-85%). A similar Cz-Fl-Cz compound exhibiting 100% fluorescence quantum yield and no ICT character was also studied as a reference to reveal the impact of electron-accepting BT groups. Thorough examination of the optical properties of the compounds in different media, i.e., dilute solution and polymer matrix, indicated their twisted conformations due to steric hindrance in the ground state and flattened geometry in the excited state for both reference and ICT compounds. Remarkable fluorescence efficiency losses (amounting to 70%) observed upon casting the molecular solutions into neat films were determined to originate from the low-fluorescent twisted conformers and migration-facilitated exciton quenching. The majority of emission efficiency losses (over 70%) were caused by the twisted conformers, whereas only less than 30% by exciton-migration-induced nonradiative deactivation.

  2. Benzo[a]carbazole-Based Donor-π-Acceptor Type Organic Dyes for Highly Efficient Dye-Sensitized Solar Cells.

    PubMed

    Qian, Xing; Zhu, Yi-Zhou; Chang, Wen-Ying; Song, Jian; Pan, Bin; Lu, Lin; Gao, Huan-Huan; Zheng, Jian-Yu

    2015-05-06

    A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV-visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm(-2), a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.

  3. Characterization of Gordonia sp. strain F.5.25.8 capable of dibenzothiophene desulfurization and carbazole utilization.

    PubMed

    Santos, S C C; Alviano, D S; Alviano, C S; Pádula, M; Leitão, A C; Martins, O B; Ribeiro, C M S; Sassaki, M Y M; Matta, C P S; Bevilaqua, J; Sebastián, G V; Seldin, L

    2006-07-01

    A dibenzothiophene (DBT)-degrading bacterial strain able to utilize carbazole as the only source of nitrogen was identified as Gordonia sp. F.5.25.8 due to its 16S rRNA gene sequence and phenotypic characteristics. Gas chromatography (GC) and GC-mass spectroscopy analyses showed that strain F.5.25.8 transformed DBT into 2-hydroxybiphenyl (2-HBP). This strain was also able to grow using various organic sulfur or nitrogen compounds as the sole sulfur or nitrogen sources. Resting-cell studies indicated that desulfurization occurs either in cell-associated or in cell-free extracts of F.5.25.8. The biological responses of F.5.25.8 to a series of mutagens and environmental agents were also characterized. The results revealed that this strain is highly tolerant to DNA damage and also refractory to induced mutagenesis. Strain F.5.25.8 was also characterized genetically. Results showed that genes involved in desulfurization (dsz) are located in the chromosome, and PCR amplification was observed with primers dszA and dszB designed based on Rhodococcus genes. However, no amplification product was observed with the primer based on dszC.

  4. Nitrogen-containing microporous conjugated polymers via carbazole-based oxidative coupling polymerization: preparation, porosity, and gas uptake.

    PubMed

    Chen, Qi; Liu, De-Peng; Luo, Min; Feng, Li-Juan; Zhao, Yan-Chao; Han, Bao-Hang

    2014-01-29

    Facile preparation of microporous conjugated polycarbazoles via carbazole-based oxidative coupling polymerization is reported. The process to form the polymer network has cost-effective advantages such as using a cheap catalyst, mild reaction conditions, and requiring a single monomer. Because no other functional groups such as halo groups, boric acid, and alkyne are required for coupling polymerization, properties derived from monomers are likely to be fully retained and structures of final polymers are easier to characterize. A series of microporous conjugated polycarbazoles (CPOP-2-7) with permanent porosity are synthesized using versatile carbazolyl-bearing 2D and 3D conjugated core structures with non-planar rigid conformation as building units. The Brunauer-Emmett-Teller specific surface area values for these porous materials vary between 510 and 1430 m(2) g(-1) . The dominant pore sizes of the polymers based on the different building blocks are located between 0.59 and 0.66 nm. Gas (H2 and CO2 ) adsorption isotherms show that CPOP-7 exhibits the best uptake capacity for hydrogen (1.51 wt% at 1.0 bar and 77 K) and carbon dioxide (13.2 wt% at 1.0 bar and 273 K) among the obtained polymers. Furthermore, its high CH4 /N2 and CO2 /N2 adsorption selectivity gives polymer CPOP-7 potential application in gas separation.

  5. Charge carrier mobility in conjugated organic polymers: simulation of an electron mobility in a carbazole-benzothiadiazole-based polymer

    NASA Astrophysics Data System (ADS)

    Li, Yaping; Lagowski, Jolanta B.

    2011-08-01

    Inorganic (mostly silicon based) solar cells are important devices that are used to solve the world energy and environmental needs. Now days, organic solar cells are attracting considerable attention in the field of photovoltaic cells because of their low cost and processing flexibility. Often conjugated polymers are used in the construction of the organic solar cells. We study the conjugated polymers' charge transport using computational approach that involves the use of the density functional theory (DFT), semiempirical (ZINDO), and Monte Carlo (MC) theoretical methods in order to determine their transfer integrals, reorganization energies, transfer rates (with the use of Marcus-Hush equation) and mobilities. We employ the experimentally determined three dimensional (3D) structure of poly(9,9'-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) to estimate the electron mobility in a similar co-alternating polymer consisting of carbazole and benzothiadiazole units (C8BT). In agreement with our previous work, we found that including an orientational disorder in the crystal reduces the electron mobility in C8BT. We hope that the proposed computational approach can be used to predict charge mobility in organic materials that are used in solar cells.

  6. Optical biosensor with poly[N-nonyl-3,6-bis(ethylenedioxythiophene)carbazole] matrix for monitoring of phenol derivatives

    NASA Astrophysics Data System (ADS)

    Jedrychowska, Agnieszka; Malecha, Karol; Cabaj, Joanna; Sołoducho, Jadwiga

    2014-08-01

    The aim of the research was to develop an enzymatic, optical biosensor which provides quick and convenient determination of phenolic compounds in aqueous solutions. The biosensing strategy concerns design, fabrication and testing of a miniature ceramic-based biosensor which is destined for in-situ substrate monitoring. The base of the measuring system was fabricated using low temperature co-fired ceramics (LTCC) technology. The biocatalyst - laccase- was immobilized on the thin film of poly[N-nonyl-3,6-bis(ethylenedioxythiophene)carbazole] which provided good binding of the enzyme to the substrate and positively affected on the catalytic activity of the protein. In order to evaluate properties of the designed biosensor, its response for various concentrations of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diamonnium sal (ABTS) was measured. The optical biosensor produced by presented method could find applications in many fields, i.e. for detection of phenolic compounds in food products and beverages, in industry for control of technological processes or for environmental monitoring

  7. TDDFT investigation of the electronic structures and photophysical properties of fluorescent extended styryl push-pull chromophores containing carbazole unit.

    PubMed

    Gupta, Vinod D; Tathe, Abhinav B; Padalkar, Vikas S; Patil, Vikas S; Phatangare, Kiran R; Umape, Prashant G; Ramasami, Ponnadurai; Sekar, Nagaiyan

    2013-11-01

    Push-pull chromophores attached to carbazole based π-conjugating spacers bearing N-alkylamino donors, cyanovinyl and carbethoxy acceptors have been studied by the means of UV-Visible measurements. The intramolecular charge transfer (ICT) of these π-conjugated systems has also been tested by investigating the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. Density Functional Theory [B3LYP/6-31G(d)] and Time Dependent Density Functional Theory [TD-B3LYP/6-31G(d)] computations have been used to have more understanding of the structural, molecular, electronic and photophysical parameters of push-pull dyes. The largest wavelength difference between the experimental and computed electronic absorption maxima was 45 nm. For emission, a largest difference of 61 nm was observed. The ground state and excited state dipole moments in different solvents were determined using experimental solvatochromic data and computed Onsager radii. The dipole moments of the molecules in the excited state were observed to be higher than in the ground state.

  8. Green synthesis and third-order nonlinear optical properties of 6-(9H-carbazol-9-yl) hexyl acetate

    NASA Astrophysics Data System (ADS)

    Chen, Baili; Geng, Feng; Luo, Xuan; Zhong, Quanjie; Zhang, Qingjun; Fang, Yu; Huang, Chuanqun; Yang, Ruizhuang; Shao, Ting; Chen, Shufan

    2016-10-01

    An extremely simple and green approach for the synthesis of photoelectric material 6-(9H-carbazol-9-yl) hexy-acetate (CHA) has been described in detail. The molecular structure of CHA was identified with Fourier transform infrared (FT-IR) spectra and 1H Nuclear Magnetic Resonance (1H NMR) spectroscopy. The optical absorption of CHA was recorded using ultraviolet-visible (UV-vis) spectrum. Notably, the reaction was accomplished in water medium instead of traditional toxic solvents (e.g., benzene and chloroform). The yield of CHA is up to 99%, which is increased by 13% compared with the traditional method. The approach developed by us makes it possible to achieve commercial production of CHA. Moreover, the thermal stability of CHA was studied with thermogravimetric (TG) and derivative thermogravimetric (DTG) method. The third-order nonlinear optical (NLO) properties of CHAn (obtained by new method) and CHAt (obtained by traditional method) have been studied by a Z-scan technique at 440 nm. The thermal decomposition temperature is above 200 °C. The third-order NLO of CHAn and CHAt are the same. The third-order NLO susceptibility χ (3) and two photon Figures of Merit (FOMs) of CHA are 1.58 × 10-8 (esu) and 4.55, respectively. The results reveal that CHA may be a promising candidate for all-optical switching application.

  9. Bias Selectable Dual Band AlGaN Ultra-violet Detectors

    NASA Technical Reports Server (NTRS)

    Yan, Feng; Miko, Laddawan; Franz, David; Guan, Bing; Stahle, Carl M.

    2007-01-01

    Bias selectable dual band AlGaN ultra-violet (UV) detectors, which can separate UV-A and UV-B using one detector in the same pixel by bias switching, have been designed, fabricated and characterized. A two-terminal n-p-n photo-transistor-like structure was used. When a forward bias is applied between the top electrode and the bottom electrode, the detectors can successfully detect W-A and reject UV-B. Under reverse bias, they can detect UV-B and reject UV-A. The proof of concept design shows that it is feasible to fabricate high performance dual-band UV detectors based on the current AlGaN material growth and fabrication technologies.

  10. Gentian Violet: A 19th Century Drug Re-Emerges in the 21st Century

    PubMed Central

    Maley, Alexander M.; Arbiser, Jack L.

    2013-01-01

    Gentian violet (GV) has a long and varied history as a medicinal agent. Historically used as an anti-bacterial and anti-fungal, recent reports have shown its utility as an anti-typranosomal, anti-viral and anti-angiogenic agent. The objective of this paper is to summarize evidence regarding the efficacy, and safety of GV use in dermatology. Recent discoveries have found novel targets of GV, namely NADPH oxidase in mammalian cells and thioredoxin reductase 2 in bacterial, fungal, and parasitic cells. These discoveries have expanded the use of GV in the 21st century. Given that GV is well tolerated, effective and inexpensive, its use in dermatology is predicted to increase. PMID:24118276

  11. Detection of biological warfare agents using ultra violet-laser induced fluorescence LIDAR.

    PubMed

    Joshi, Deepti; Kumar, Deepak; Maini, Anil K; Sharma, Ramesh C

    2013-08-01

    This review has been written to highlight the threat of biological warfare agents, their types and detection. Bacterial biological agent Bacillus anthracis (bacteria causing the disease anthrax) which is most likely to be employed in biological warfare is being discussed in detail. Standoff detection of biological warfare agents in aerosol form using Ultra violet-Laser Induced Fluorescence (UV-LIF) spectroscopy method has been studied. Range-resolved detection and identification of biological aerosols by both nano-second and non-linear femto-second LIDAR is also discussed. Calculated received fluorescence signal for a cloud of typical biological agent Bacillus globigii (Simulants of B. anthracis) at a location of ~5.0 km at different concentrations in presence of solar background radiation has been described. Overview of current research efforts in internationally available working UV-LIF LIDAR systems are also mentioned briefly.

  12. Insight into biosorption equilibrium, kinetics and thermodynamics of crystal violet onto Ananas comosus (pineapple) leaf powder

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sagnik; Chowdhury, Shamik; Saha, Papita Das

    2012-06-01

    Biosorption performance of pineapple leaf powder (PLP) for removal of crystal violet (CV) from its aqueous solutions was investigated. To this end, the influence of operational parameters such as pH, biosorbent dose, initial dye concentration and temperature were studied employing a batch experimental setup. The biosorption process followed the Langmuir isotherm model with high correlation coefficients ( R 2 > 0.99) at different temperatures. The maximum monolayer biosorption capacity was found to be 78.22 mg g-1 at 293 K. The kinetic data conformed to the pseudo-second-order kinetic model. The activation energy of the system was calculated as 58.96 kJ mol- 1 , indicating chemisorption nature of the ongoing biosorption process. A thermodynamic study showed spontaneous and exothermic nature of the biosorption process. Owing to its low cost and high dye uptake capacity, PLP has potential for application as biosorbent for removal of CV from aqueous solutions.

  13. A novel vacuum ultra violet lamp for metastable rare gas experiments.

    PubMed

    Daerr, Heiner; Kohler, Markus; Sahling, Peter; Tippenhauer, Sandra; Arabi-Hashemi, Ariyan; Becker, Christoph; Sengstock, Klaus; Kalinowski, Martin B

    2011-07-01

    We report on a new design of a vacuum ultra violet (VUV) lamp for direct optical excitation of high laying atomic states, e.g., for excitation of metastable rare gas atoms. The lamp can be directly mounted to ultra-high vacuum vessels (p ≤ 10(-10)mbar). It is driven by a 2.45 GHz microwave source. For optimum operation, it requires powers of ~20 W. The VUV light is transmitted through a magnesium fluoride window, which is known to have a decreasing transmittance for VUV photons with time. In our special setup, after a run-time of the VUV lamp of 550 h the detected signal continuously decreased to 25% of its initial value. This corresponds to a lifetime increase of two orders of magnitude compared to previous setups or commercial lamps.

  14. A method for impregnating nylon transfer membranes with leucocrystal violet for enhancing and lifting bloody impressions.

    PubMed

    Michaud, Amy L; Brun-Conti, Leanora

    2004-05-01

    The objective of this research project was to demonstrate a quick and easy method for impregnating nylon transfer membranes with leucocrystal violet (LCV) for the purpose of lifting and enhancing impressions made in blood. A stamp that would simulate fine detail found in fingerprints or footwear was used to create impressions on a variety of substrates. Four different LCV formulations were tested to determine the effectiveness of the prepared membranes in lifting and enhancing the impressions. Further investigation involved the feasibility of using the LCV membranes in the field by studying the shelf life and storage of the impregnated membranes and the longevity of the lifted impressions. One of the formations studied demonstrated superior lifting and enhancing capabilities, as well as a prolonged shelf life and a resilience of the lifted impressions, thus proving LCV to be an extremely valuable technique.

  15. Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares (Invited Review)

    NASA Astrophysics Data System (ADS)

    Milligan, Ryan O.

    2015-12-01

    The extreme ultra-violet (EUV) portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature- and density-sensitive line ratios, Doppler-shifted emission lines, nonthermal broadening, abundance measurements, differential emission measure profiles, continuum temperatures and energetics, among others. In this article I review some of the recent advances that have been made using these techniques to infer physical properties of heated plasma at footpoint and ribbon locations during the initial stages of solar flares. I primarily focus on studies that have utilised spectroscopic EUV data from Hinode/EUV Imaging Spectrometer (EIS) and Solar Dynamics Observatory/EUV Variability Experiment (SDO/EVE), and I also provide some historical background and a summary of future spectroscopic instrumentation.

  16. True covariance simulation of the EUVE (extreme ultra violet explorer) update filter

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, I. Y.; Harman, R. R.

    1990-01-01

    This paper presents a covariance analysis of the performance and sensitivity of the attitude determination Extended Kalman Filter (EKF) used by the onboard computer (OBC) of the Extreme Ultra Violet Explorer (EUVE) spacecraft. The linearized dynamics and measurement equations of the error states are used in formulating the 'truth model' describing the order of the systems involved. The 'design model' used by the OBC EKF is then obtained by reducing the order of the truth model. The covariance matrix of the EKF which uses the reduced order model is not the correct covariance of the EKF estimation error. A 'true covariance analysis' has to be carried out in order to evaluate the correct accuracy of the OBC generated estimates. The results of such analysis are presented which indicate both the performance and the sensitivity of the OBC EKF.

  17. Detection of biological warfare agents using ultra violet-laser induced fluorescence LIDAR

    NASA Astrophysics Data System (ADS)

    Joshi, Deepti; Kumar, Deepak; Maini, Anil K.; Sharma, Ramesh C.

    This review has been written to highlight the threat of biological warfare agents, their types and detection. Bacterial biological agent Bacillus anthracis (bacteria causing the disease anthrax) which is most likely to be employed in biological warfare is being discussed in detail. Standoff detection of biological warfare agents in aerosol form using Ultra violet-Laser Induced Fluorescence (UV-LIF) spectroscopy method has been studied. Range-resolved detection and identification of biological aerosols by both nano-second and non-linear femto-second LIDAR is also discussed. Calculated received fluorescence signal for a cloud of typical biological agent Bacillus globigii (Simulants of B. anthracis) at a location of ˜5.0 km at different concentrations in presence of solar background radiation has been described. Overview of current research efforts in internationally available working UV-LIF LIDAR systems are also mentioned briefly.

  18. Violet-Pigmented Pseudomonads With Antifungal Activity From the Rhizosphere of Beans

    PubMed Central

    Ayers, W. A.; Papavizas, G. C.

    1963-01-01

    Bean rhizosphere bacteria antagonistic to four root-infecting fungi and an antibiotic produced by these bacteria were studied. The bacteria were violet-pigmented gram-negative rods, probably belonging to the genus Pseudomonas. The antibiotic, which was localized largely in the bacterial cell mass, was easily extracted with acetone. It was selectively active against a wide variety of plant-pathogenic and saprophytic fungi tested in vitro but was relatively inactive against bacteria. The compound, partially purified by chromatography, was soluble in all organic solvents tried, but nearly insoluble in water. It demonstrated no characteristic ultraviolet- or visible-absorption spectrum and was chemically unidentified. The antagonistic bacteria or crude antibiotic applied to buried buckwheat segments suppressed the colonization of this substrate by Rhizoctonia spp. The data suggested that the bacteria or the antibiotic may play a role in the suppression of root-infecting fungi in soil. PMID:16349643

  19. Photodegradation of Acid Violet 7 with AgBr-ZnO under highly alkaline conditions.

    PubMed

    Krishnakumar, B; Swaminathan, M

    2012-12-01

    The photocatalytic activity of AgBr-ZnO was investigated for the degradation of Acid Violet 7 (AV 7) in aqueous solution using UV-A light. AgBr-ZnO is found to be more efficient than commercial ZnO and prepared ZnO at pH 12 for the mineralization of AV 7. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization have been analyzed. Expect oxone, other oxidants decrease the degradation efficiency. Addition of metal ions and anions decrease the degradation efficiency of AgBr-ZnO significantly. The mineralization of AV 7 has also been confirmed by COD measurements. The mechanism of degradation by AgBr-ZnO is proposed to explain its higher activity under UV light. The catalyst is found to be reusable.

  20. Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

    NASA Astrophysics Data System (ADS)

    Aydogmus, Ramazan; Depci, Tolga; Sarikaya, Musa; Riza Kul, Ali; Onal, Yunus

    2016-10-01

    The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

  1. Unpredictable adsorption and visible light induced decolorization of nano rutile for the treatment of crystal violet

    NASA Astrophysics Data System (ADS)

    Dong, Yanling; Liu, Yang; Lu, Dingze; Zheng, Feng; Fang, Pengfei; Zhang, Haining

    2017-04-01

    Photocatalysts containing different ratios of anatase and rutile are prepared via heat treatment of Degussa P-25 titania. X-ray diffraction (XRD), Bruuauer-Emmett-Teller (BET), ultraviolet-visible light diffuse reflectance spectra (DRS), Raman spectra (Raman), positron annihilation lifetime spectra (PAL) and temperature-programmed desorption (TPD) are applied to investigate the phase composition of the synthesized catalysts. Using crystal violet (CV) as the target pollutant, the unexpected visible light decolorization of rutile is observed. Despite the decreased specific surface area, the as-synthesized rutile samples exhibit much higher adsorption capability of CV than P-25 does, which in turn leads to improved photoreaction efficiency. Since the rutile samples can't absorb the visible light, the degradation under visible light irradiation is attributed to self-sensitization of CV on the surface of rutile.

  2. GaN photonic-crystal surface-emitting laser at blue-violet wavelengths.

    PubMed

    Matsubara, Hideki; Yoshimoto, Susumu; Saito, Hirohisa; Jianglin, Yue; Tanaka, Yoshinori; Noda, Susumu

    2008-01-25

    Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths.

  3. Removal of Basic Violet 14 from aqueous solution using sulphuric acid activated materials.

    PubMed

    Suresh, S

    2016-01-01

    In this study the adsorption of Basic Violet, 14 from aqueous solution onto sulphuric acid activated materials prepared from Calophyllum inophyllum (CS) and Theobroma cacao (TS) shells were investigated. The experimental data were analysed by Langmuir, Freundlich and Temkin isotherm models. The results showed that CS has a superior adsorption capacity compared to the TS. The adsorption capacity was found to be 1416.43 mg/g for CS and 980.39 mg/g for TS. The kinetic data results at different concentrations were analysed using pseudo first-order and pseudo-second order model. Boyd plot indicates that the dye adsorption onto CS and TS is controlled by film diffusion. The adsorbents were characterised by scanning electron microscopy. The materials used in this study were economical waste products and hence can be an attractive alternative to costlier adsorbents for dye removal in industrial wastewater treatment processes.

  4. Controllable Assembly and Spectroscopic Behavior of Brilliant Cresyl Violet in Different Environments

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Song, J.-P.; Guo, Y.; Shuang, Sh.-M.; Dong, Ch.

    2017-01-01

    In this paper, the aggregation behavior of brilliant cresyl violet (BCV) was studied using UV-vis absorption spectroscopy. BCV aggregation depends not only on the properties of the solvent and electrolyte, and the temperature and concentration of the dye solution, but also on the anionic surfactant. The results demonstrate that Nafion triggers trimer formation. Graphene oxide adjusts the relative position of dye molecules on the template through the electrostatic force and π-π stacking interactions to form highly ordered H-aggregates. However, BCV molecules on the graphene surface form the so-called J-aggregates after removal of the oxygen-containing surface groups by hydrazine reduction. The major driving forces affecting BCV aggregation are the electrostatic force, π-π stacking interactions, and hydrogen-bonding interactions.

  5. Terrific Trichomes (and Other Specialised Cells) in African Violets: How to Get a Lot from One Plant in the Classroom

    ERIC Educational Resources Information Center

    Cottrell, Vicki M.

    2013-01-01

    African violet (genus "Saintpaulia") was identified as a particularly suitable genus for the study of specialised plant cells in the classroom using microscopes. The techniques described here involve simple preparation without staining. The cells and structures that can be investigated include: trichomes (hairs); stomata; guard cells and…

  6. Effect of gentian violet on the growth of the N and T RFLP types of the Aspergillus niger aggregate.

    PubMed

    Bragulat, M Rosa; Cabañes, F Javier

    2008-09-01

    Taxa included in the Aspergillus niger aggregate are difficult to distinguish by phenotypic characterization. In this work, the effect of gentian violet on the growth of the N and T RFLP types of A. niger aggregate strains has been investigated. In total, 105 strains from different sources and origins, including reference cultures and field isolates were studied. Type N and T RFLP patterns, ochratoxin A production and the effect of different concentrations of gentian violet on the growth were determined in these strains. Forty nine strains belonged to the N type and 56 strains to the T type. Sixteen out of the 105 strains assayed were OTA producers. All the OTA-producing species belonged to the RFLP type N and none of the T type strains was able to produce OTA. Approximately 90% of the N type strains grew in the presence of 25 ppm of gentian violet. Only five N type strains did not grow on this medium. One of these strains was A. niger ATCC 22343, a well documented induced mutant strain and the remaining four strains belonged to the new species A. brasiliensis. On the contrary, all the T type strains failed to grow on this medium after 3 days of incubation (sensitivity 89.79%; specificity 100%). The use of growth in gentian violet as an additional character for classification and identification purposes in this taxonomic group may be useful because no phenotypic methods have yet been found that can distinguish between these species.

  7. HPLC Determination and MS Confirmation of Malachite Green, Gentian Violet, and Their Leuco Metabolites in Catfish Muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Residues of malachite green (MG), gentian violet (GV), and their leuco metabolites in catfish muscle were individually determined by HPLC using visible and fluorescence detectors. This detection scheme obviated a PbO2 column that converts leuco forms to chromatic forms for visible detection, thus el...

  8. Anthocyanins, colour and antioxidant properties of eggplant (Solanum melongena L.) and violet pepper (Capsicum annuum L.) peel extracts.

    PubMed

    Sadilova, Eva; Stintzing, Florian C; Carle, Reinhold

    2006-01-01

    Acetone extracts from eggplant (Solanum melongena L.) and violet pepper (Capsicum annuum L.) peels both belonging to the Solanaceae plant family were characterized with respect to their anthocyanin profiles, colour qualities and antioxidant capacities. According to HPLC-DAD-MS3 analyses the major anthocyanin in eggplant was delphinidin-3-rutinoside, while the predominant pigment in violet pepper was assigned to delphinidin-3-trans-coumaroylrutinoside-5-glucoside. Since virtually all anthocyanins were delphinidin-based, the effect of acylation and glycosylation patterns on colour stability and antioxidant capacity could be assessed. Application of two in vitro-assays for antioxidant capacity assessment revealed that eggplant generally exhibited higher values compared to violet pepper which was ascribed to 3,5-diglycosylated structures predominating in the latter. The higher extent of acylation in violet pepper was reflected by a more purplish colour shade of the extracts, but did not translate into a higher stability against fading which again was attributed to additional glycosyl substitution at C5. These findings support the relevance of structure-related activities of anthocyanins both for understanding food colour and their particular nutritional value.

  9. Violet diode laser-induced chlorophyll fluorescence: a tool for assessing mosaic disease severity in cassava (Manihot esculenta Crantz) cultivars.

    PubMed

    Anderson, Benjamin; Eghan, Moses J; Asare-Bediako, Elvis; Buah-Bassuah, Paul K

    2012-01-01

    Violet diode laser-induced chlorophyll fluorescence was used in agronomical assessment (disease severity and average yield per plant). Because cassava (Manihot esculenta Crantz) is of economic importance, improved cultivars with various levels of affinity for cassava mosaic disease were investigated. Fluorescence data correlated with cassava mosaic disease severity levels and with the average yield per plant.

  10. Radiochromic leuco dye micelle hydrogels: II. Low diffusion rate leuco crystal violet gel

    NASA Astrophysics Data System (ADS)

    Babic, Steven; Battista, Jerry; Jordan, Kevin

    2009-11-01

    Radiation-sensitive hydrogels offer the capability of verifying intricate dose distributions in three-dimensional (3D) space conveniently in a single measurement with sub-millimetre spatial resolution. In this study, a new radiochromic hydrogel called leuco crystal violet (LCV) micelle gel is introduced. Upon irradiation, LCV converts to crystal violet (CV+). Triton X-100 micelles are used to provide the required hybrid-interfacing environment to dissolve LCV. The diffusion coefficient of the LCV gel has been measured to be 0.036 ± 0.001 mm2 h-1, which is a factor of 25 times less than the standard radiochromic ferrous xylenol-orange (FX) gel; LCV gels without Triton X-100 micelles have a diffusion coefficient of 0.33 ± 0.02 mm2 h-1. The LCV gel formulation contains: 1 mM LCV, 25 mM trichloroacetic acid, 4 mM Triton X-100 and 4% w/w gelatin. The primary innovative feature of this 3D hydrogel is that the radiation-induced CV+ dye is more soluble in the Triton X-100 micelles than in the surrounding water which consequently leads to more stable post-irradiation dose distributions. A dosimetric characterization revealed that the dose response is reproducible to within 1% over three separate batches, independent of energy, dose rate and dose fractionation but is affected by the temperature (~4% per °C) during irradiation. LCV micelle gels scanned optically with a yellow light source are a promising system for 3D dose verification. They may prove to be, especially, useful for scanning large volume dosimeters (i.e. 20 cm) since they are easily manufactured, transparent and near colourless prior to irradiation.

  11. ABCG2-mediated dyecycle violet efflux defined side population in benign and malignant prostate

    PubMed Central

    Mathew, Grinu; Timm, Earl A.; Sotomayor, Paula; Godoy, Alejandro; Montecinos, Viviana P.; Smith, Gary J.; Huss, Wendy J.

    2010-01-01

    The efflux of Hoechst 33342 by ATP-binding cassette protein G2 (ABCG2) membrane pump allows reproducible identification of a subpopulation of cells by flow cytometric analysis termed the “side population” (SP). The SP identified by constitutive Hoechst efflux contains the stem/progenitor cell population from bone marrow and many solid organs, including prostate. DyeCycle Violet (DCV) is a cell membrane permeable, fluorescent vital dye that intercalates into DNA and is a substrate for ABCG2-mediated efflux. Therefore, DCV was evaluated in this study as a tool for identification of the SP from prostate cancer cell lines and from freshly harvested human prostate tissue. SPs that demonstrated ABCG2-mediated efflux of DCV were identified in the human prostate cancer cell lines CWR-R1, DU-145 and RWPE-1, but not in the BPH-1, LAPC-4 or PC-3 cell lines. Additionally, a SP was identified in enzymatically disaggregated prostate tumors from Transgenic Adenocarcinoma of Mouse Prostate (TRAMP), human benign prostate tissue and human prostate cancer tissue. The causal role of ABCG2-mediated efflux of DCV in the identification of the SP was confirmed by loss of the SP by incubation with the specific inhibitor of ABCG2, Fumitremorgin C. Expression of ABCG2 in the SP cells was confirmed by qRT-PCR and immunofluorescence analysis. Consequently, DCV represents an important new tool for isolation of viable candidate stem cells/cancer stem cells as a SP from cultured prostate cell lines, and prostate tissue specimens, without the requirement for instrumentation with ultra-violet excitation capability and minimizing the risk of damage to DNA in the sorted population. PMID:19270533

  12. Determination of crystal violet in water by direct solid phase spectrophotometry after rotating disk sorptive extraction.

    PubMed

    Manzo, Valentina; Navarro, Orielle; Honda, Luis; Sánchez, Karen; Inés Toral, M; Richter, Pablo

    2013-03-15

    The microextraction of crystal violet (CV) from water samples into polydimethylsiloxane (PDMS) using the rotating disk sorptive extraction (RDSE) technique was performed. The extracting device was a small Teflon disk that had an embedded miniature magnetic stirring bar and a PDMS (560 μL) film attached to one side of the disk using double-sided tape. The extraction involves a preconcentration of CV into the PDMS, where the analyte is then directly quantified using solid phase spectrophotometry at 600 nm. Different chemical and extraction device-related variables were studied to achieve the best sensitivity for the determination. The optimum extraction was performed at pH 14 because under this condition, CV is transformed to the neutral and colorless species carbinol, which can be quantitatively transferred to the PDMS phase. Although the colorless species is the chemical form extracted in the PDMS, an intense violet coloration appeared in the phase because the -OH bond in the carbinol molecule is weakened through the formation of hydrogen bonds with the oxygen atoms of the PDMS, allowing the resonance between the three benzene rings to compensate for the charge deficit on the central carbon atom of the molecule. The accuracy and precision of the method were evaluated in river water samples spiked with 10 and 30 μg L(-1) of CV, yielding a relative standard deviation of 6.2% and 8.4% and a recovery of 98.4% and 99.4%, respectively. The method detection limit was 1.8 μg L(-1) and the limit of quantification was 5.4 μg L(-1), which can be decreased if the sample volume is increased.

  13. Radiochromic leuco dye micelle hydrogels: II. Low diffusion rate leuco crystal violet gel.

    PubMed

    Babic, Steven; Battista, Jerry; Jordan, Kevin

    2009-11-21

    Radiation-sensitive hydrogels offer the capability of verifying intricate dose distributions in three-dimensional (3D) space conveniently in a single measurement with sub-millimetre spatial resolution. In this study, a new radiochromic hydrogel called leuco crystal violet (LCV) micelle gel is introduced. Upon irradiation, LCV converts to crystal violet (CV(+)). Triton X-100 micelles are used to provide the required hybrid-interfacing environment to dissolve LCV. The diffusion coefficient of the LCV gel has been measured to be 0.036 +/- 0.001 mm(2) h(-1), which is a factor of 25 times less than the standard radiochromic ferrous xylenol-orange (FX) gel; LCV gels without Triton X-100 micelles have a diffusion coefficient of 0.33 +/- 0.02 mm(2) h(-1). The LCV gel formulation contains: 1 mM LCV, 25 mM trichloroacetic acid, 4 mM Triton X-100 and 4% w/w gelatin. The primary innovative feature of this 3D hydrogel is that the radiation-induced CV(+) dye is more soluble in the Triton X-100 micelles than in the surrounding water which consequently leads to more stable post-irradiation dose distributions. A dosimetric characterization revealed that the dose response is reproducible to within 1% over three separate batches, independent of energy, dose rate and dose fractionation but is affected by the temperature ( approximately 4% per degree C) during irradiation. LCV micelle gels scanned optically with a yellow light source are a promising system for 3D dose verification. They may prove to be, especially, useful for scanning large volume dosimeters (i.e. 20 cm) since they are easily manufactured, transparent and near colourless prior to irradiation.

  14. Crystal violet combined with Merocyanine 540 for the ex vivo purging of hematopoietic stem cell grafts.

    PubMed

    Miyagi, Kiyoko; Sampson, Reynée W; Sieber-Blum, Maya; Sieber, Fritz

    2003-07-01

    The purpose of this study was to determine in a preclinical purging model, how effective crystal violet-mediated photodynamic therapy (CV-PDT) is against solid tumor and drug-resistant mutant tumor cells, and if certain limitations of CV-PDT can be overcome by using crystal violet (CV) in combination with the membrane-active photosensitizer, Merocyanine 540 (MC540). When used under conditions that preserved an adequate fraction of normal human granulocyte/macrophage progenitors (CFU-GM), CV-PDT failed to achieve meaningful reductions of DU145 prostate, H69 small cell lung cancer, and MDA-MB-435S breast cancer cells. Melphalan-resistant L1210/L-PAM1, adriamycin-resistant P388/ADR, and adriamycin-resistant HL-60/ADR leukemia cells were markedly less sensitive to CV-PDT than their wild-type counterparts, whereas cisplatin-resistant H69/CDDP cells were more sensitive than wild-type H69 cells. Sequential exposure to MC540- and CV-PDT under conditions that preserved an adequate fraction (73% and 29%, respectively) of normal CD34-positive hematopoietic stem cells and granulocyte/macrophage progenitors was highly effective against H69 (99.997% reduction) and H69/CDDP (99.999% reduction) cells, but ineffective against HL-60/ADR, MDA-MB-435S, and DU145 cells. CV thus shows only limited promise as a single-modality purging agent. However, in certain situations, clinically meaningful tumor cell depletions can be obtained by using CV in combination with a second photosensitizer such as MC540.

  15. Enhanced violet photoemission of nanocrystalline fluorine doped zinc oxide (FZO) thin films

    NASA Astrophysics Data System (ADS)

    Anusha, Muthukumar; Arivuoli, D.; Manikandan, E.; Jayachandran, M.

    2015-09-01

    Highly stable fluorine doped nanocrystalline zinc oxide thin films were prepared on corning glass substrates by aerosol assisted chemical vapor deposition (AACVD) at variable deposition temperature of 360 °C, 380 °C and 420 °C. Especially, the optimum deposition temperature was investigated for high intense violet emission. The film crystallinity improved with the increasing deposition temperature and highly textured film was obtained at 420 °C. The films exhibited surface morphology variation from spherical to platelets due to deposition temperature effect, analyzed by field emission scanning electron microscope (FE-SEM). Higher growth rate observed at 420 °C which leads larger grains and lowest resistivity of ∼5.77 Ω cm among the deposited films which may be due to reduction in zinc vacancies and grain boundary area. Zinc vacancies are acts as electron killer centres. UV-visible spectra indicated higher transmittance (83-90%) in the visible region. Red shift of optical absorption edges associated with the increase in particle size consistent well with the XRD results. Reduced E2(high) intensity was observed in Raman spectra, for the film deposited at 380 °C which indicates decreased oxygen incorporation confirmed by PL spectra. Especially, enhanced violet emission observed at 3.06 eV for the films deposited at 380 °C due to electronic transition from the defect level of zinc vacancies to the conduction band, probably attributed to enhanced incorporation of 'F' into 'O' sites associated with increased Zn vacancies and also decreased oxygen incorporation consistent with the electrical and Raman analyses.

  16. Spectral Analysis and Crystal Structures of 4-(4-Methylphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole and 4-(4-Methoxyphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole.

    PubMed

    Kalyana Sundar, J; Natarajan, S; Chitra, S; Paul, Nidhin; Manisankar, P; Muthusubramanian, S; Suresh, J

    2011-01-01

    The crystal structures of 4-(4-methylphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIa) and 4-(4-methoxyphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIb) were elucidated by single crystal X-ray diffraction. Compound (IIa), C28H25N, crystallizes in the triclinic system, space group P-1, with a = 8.936(2) Å, b = 10.490(1) Å, c = 11.801(1) Å, α = 102.69(5) (°) ,  β = 103.27(3) (°) , γ = 93.80(1) (°) , and Z = 2. The compound (IIb), C28H25NO, crystallizes in the monoclinic system, space group P21/a, with a = 11.376(5) Å, b = 14.139(3) Å, c = 13.237(4) Å, β = 97.41(3) (°) , and Z = 4. In both the structures, the pyrido ring adopts a twist boat conformation and the carbazole molecule has the twisted envelope structure with C3 and C13 at the flap. No classical hydrogen bonds are observed in the crystal structures. Details of the preparation, structures, and spectroscopic properties of the new compounds are discussed.

  17. 7-Phenyl­sulfonyl-2,3-dihydro-7H-1,4-benzodioxino[6,7-b]carbazole

    PubMed Central

    Kanchanadevi, J.; Dhayalan, V.; Mohanakrishnan, A. K.; Anbalagan, G.; Chakkaravarthi, G.; Manivannan, V.

    2010-01-01

    In the title compound, C24H17NO4S, the phenyl ring makes a dihedral angle of 88.12 (5)° with the carbazole unit. The mol­ecular structure is stabilized by weak intra­molecular C—H⋯O inter­actions and the crystal packing exhibits weak inter­molecular C—H⋯O and C—H⋯π inter­actions. Two C atoms of the 2,3-dihydro-1,4-dioxine fragment are disordered over two positions with site-occupancy factors of 0.718 (11) and 0.282 (11). PMID:21589548

  18. Synthesis and cytotoxicities of 7-aza rebeccamycin analogues bearing various substituents on the sugar moiety, on the imide nitrogen and on the carbazole framework.

    PubMed

    Messaoudi, Samir; Anizon, Fabrice; Léonce, Stéphane; Pierré, Alain; Pfeiffer, Bruno; Prudhomme, Michelle

    2005-10-01

    The synthesis of a family of rebeccamycin analogues in which one indole unit has been replaced by a 7-azaindole moiety is described. Substitutions have been carried out on the imide nitrogen, on the carbazole framework and on the sugar part. Compounds with a lactam upper heterocycle have also been prepared. The cytotoxicities of the newly synthesized compounds toward four tumor cell lines, one murine leukemia (L1210) and three human tumor cell lines (prostate carcinoma DU145, colon carcinoma HT29, and non-small cell lung carcinoma A549) have been evaluated and compared to those of rebeccamycin and parent non-aza and aza compounds.

  19. Photocaging of Single and Dual (Similar or Different) Carboxylic and Amino Acids by Acetyl Carbazole and its Application as Dual Drug Delivery in Cancer Therapy.

    PubMed

    Venkatesh, Yarra; Rajesh, Y; Karthik, S; Chetan, A C; Mandal, Mahitosh; Jana, Avijit; Singh, N D Pradeep

    2016-11-18

    A new fluorescent photoremovable protecting group (FPRPG) based on acetylcarbazole framework has been explored for the first time release of single and dual (similar or different) substrates from single chromophore. Mechanistic studies of the photorelease process revealed that photorelease of two (similar or different) substrates from acetyl carbazole proceeds via a stepwise pathway. Further, we constructed photoresponsive dual drug delivery system (DDS) to release two different anticancer drugs (caffeic acid and chlorambucil, 1 equiv each). In vitro study reveals that our DDS exhibit excellent properties like biocompatibility, cellular uptake, and photoregulated dual drug release.

  20. Carbazole Linked NIR Aza-BODIPY Dyes as Triplet Sensitizers and Photoacoustic Contrast Agents for Deep Tissue Imaging.

    PubMed

    Sekar, Nagaiyan; D, Ramaiah; Gawale, Yogesh; N, Adarsh; J, Joseph; Pramanik, M; Kalva, S K

    2017-02-22

    Four novel N-ethylcarbazole linked aza-BODIPY dyes (8a-b and 9a-b) were synthesized and characterized. The presence of N-ethylcarbazole moiety shifts their absorption and fluorescence spectra to the near-infrared region, ca. 650-730 nm, of electromagnetic spectra. These dyes possess strong molar absorptivity in the range of 3-4 x 104 M-1cm-1 with low fluorescence quantum yields. The triplet excited state as well as singlet oxygen generation of these dyes were enhanced upon iodination at the core position. The core iodinated dyes 9a-b showed excellent triplet quantum yield of ca. 90% and 75% with singlet oxygen generation efficiency of ca. 70% and 60% when compared to the parent dyes. The derivatives 8a-b showed dual absorption profiles in contrast to the dyes 9a-b, which has the characteristic absorption band of the aza-BODIPY dyes. DFT calculations revealed the electron density is spread over the iodine and dipyrromethene plane of, 9a-b, whereas in 8a-b the electron density distributed on carbazole ring as well as dipyrromethene plane of aza-BODIPY. The uniqueness of these aza-BODIPY systems is that they exhibit efficient triplet state quantum yields, high singlet oxygen generation yields and good photostability. Further we explored the photoacoustic (PA) characteristics of these aza-BODIPY dyes, and observed efficient PA signals for 8a compared to blood serum with in vitro deep tissue imaging, thereby confirming its use as a promising photoacoustic contrast agent.

  1. Novel carbazole-phenothiazine dyads for dye-sensitized solar cells: a combined experimental and theoretical study.

    PubMed

    Marotta, Gabriele; Reddy, Marri Anil; Singh, Surya Prakash; Islam, Ashraful; Han, Liyuan; De Angelis, Filippo; Pastore, Mariachiara; Chandrasekharam, Malapaka

    2013-10-09

    We report a joint experimental and computational work on new organic donor-acceptor dye sensitizers in which a carbazole (CZ) and a phenothiazine (PTZ) units are linked together by an alkyl C6H13, while two different anchoring groups are employed: the cyanoacrylic acid (CS1A, CSORG1) and the rhodanine-3-acetic acid (CS4A, CSORG4). The CZ moiety has multiple roles of (i) acting as an extra-electron donor portion, providing more electron density on the PTZ; (ii) suppressing the back-electron transfer from TiO2 to the electrolyte by forming a compact insulating dye layer; (iii) modulating dye aggregation on the semiconductor surface; and (iv) acting as an antenna, collecting photons and, through long-range energy transfer, redirecting the captured energy to the dye sensitizer. We show that the introduction of the CZ donor remarkably enhances the photovoltaic performances of the rhodanine-based dye, compared to the corresponding simple PTZ dye, with more than a two-fold increase in the overall efficiencies, while it does not bring beneficial effects in the case of the cyanoacrylic-based sensitizer. Based on quantum mechanical calculations and experimental measurements, we show that, in addition to a favored long-range energy transfer, which increases the light absorption in the blue region of the spectrum, the presence of the CZ unit in the CSORG4 dye effectively induces a beneficial aggregation pattern on the semiconductor surface, yielding a broadened and red-shifted light absorption, accounting for the two-fold increase in the generated photocurrent.

  2. Endoscopic diagnosis of invasion depth for early colorectal carcinomas: a prospective comparative study of narrow-band imaging, acetic acid, and crystal violet.

    PubMed

    Zhang, Jing-Jing; Gu, Li-Yang; Chen, Xiao-Yu; Gao, Yun-Jie; Ge, Zhi-Zheng; Li, Xiao-Bo

    2015-02-01

    Several studies have validated the effectiveness of narrow-band imaging (NBI) in estimating invasion depth of early colorectal cancers. However, comparative diagnostic accuracy between NBI and chromoendoscopy remains unclear. Other than crystal violet, use of acetic acid as a new staining method to diagnose deep submucosal invasive (SM-d) carcinomas has not been extensively evaluated. We aimed to assess the diagnostic accuracy and interobserver agreement of NBI, acetic acid enhancement, and crystal violet staining in predicting invasion depth of early colorectal cancers. A total of 112 early colorectal cancers were prospectively observed by NBI, acetic acid, and crystal violet staining in sequence by 1 expert colonoscopist. All endoscopic images of each technique were stored and reassessed. Finally, 294 images of 98 lesions were selected for evaluation by 3 less experienced endoscopists. The accuracy of NBI, acetic acid, and crystal violet for real-time diagnosis was 85.7%, 86.6%, and 92.9%, respectively. For image evaluation by novices, NBI achieved the highest accuracy of 80.6%, compared with that of 72.4% by acetic acid, and 75.8% by crystal violet. The kappa values of NBI, acetic acid, and crystal violet among the 3 trainees were 0.74 (95% CI 0.65-0.83), 0.68 (95% CI 0.59-0.77), and 0.70 (95% CI 0.61-0.79), respectively. For diagnosis of SM-d carcinoma, NBI was slightly inferior to crystal violet staining, when performed by the expert endoscopist. However, NBI yielded higher accuracy than crystal violet staining, in terms of less experienced endoscopists. Acetic acid enhancement with pit pattern analysis was capable of predicting SM-d carcinoma, comparable to the traditional crystal violet staining.

  3. COMPARISON OF BLOOD PROTEIN AND TARGET ORGAN DNA AND PROTEIN BINDING FOLLOWING TOPICAL APPLICATION OF BENZO[A]PYRENE AND 7H-DIBENZO[C,G]CARBAZOLE TO MICE

    EPA Science Inventory

    7H-Dibenzo[c,g]carbazole (DBC) induces skin and liver tumors in mice following topical application, whereas benzo[a]pyrene (BP) induces only skin tumors. DBC also binds to liver DNA to a much greater extent than does BP. The present study examined factors that might account for t...

  4. 21 CFR 73.3117 - 16,23-Dihydrodinaphtho[2,3-a:2′,3′-i] naphth [2′,3′:6,7] indolo [2,3-c] carbazole-5,10,15,17,22...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false 16,23-Dihydrodinaphtho naphth indolo carbazole-5,10,15,17,22,24-hexone. 73.3117 Section 73.3117 Food and Drugs FOOD AND DRUG ADMINISTRATION... minimum reasonably required to accomplish the intended coloring effect. (2) Authorization for this...

  5. 21 CFR 73.3117 - 16,23-Dihydrodinaphtho[2,3-a:2′,3′-i] naphth [2′,3′:6,7] indolo [2,3-c] carbazole-5,10,15,17,22...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false 16,23-Dihydrodinaphtho naphth indolo carbazole-5,10,15,17,22,24-hexone. 73.3117 Section 73.3117 Food and Drugs FOOD AND DRUG ADMINISTRATION... minimum reasonably required to accomplish the intended coloring effect. (2) Authorization for this...

  6. Inhibiting effect of sulfur and oxygen compounds on carbazole hydrogenitrogenation on NiMo/Al sub 2 O sub 3 catalysts and relation to gas-phase acidity

    SciTech Connect

    Nagai, M.; Ogino, T. )

    1987-04-01

    The inhibiting effect of various sulfur and oxygen compounds on carbazole hydrodenitrogenation on NiMo/Al{sub 2}O{sub 3} catalysts has been studied. The reactions were carried out with a flow microreactor at 260-360{degree}C and 10.1 MPa total pressure. A major denitrogenated product was bicyclohexyl, and a hydrogenated compound was tetrahydrocarbazole, accompanied by small amounts of perhydrocarbazole and hexahydrocarbazole. Sulfidation of the reduced catalyst increased the activity of the catalyst at all temperatures. At 360{degree}C, the presence of the sulfur and oxygen compounds depressed the denitrogenation of perhydrocarbazole to bicyclohexyl on the reduced and sulfided catalyst which was a rate-determining step. At lower temperatures, all the additives affected the hydrogenation of carbazole to tetrahydrocarbazole which was not in equilibrium and resulted in a decrease of denitrogenation. The denitrogenation of perhydrocarbazole was assumed to follow the Langmuir-type equation, allowing for competitive adsorption of perhydrocarbazole and additives on the denitrogenated sites. The relationship between the inhibiting effect of the additives and their gas-phase acidity was also discussed.

  7. Synthesis, photophysical and charge-transporting properties of a novel asymmetric indolo [3,2-b]carbazole derivative containing benzothiazole and diphenylamino moieties

    NASA Astrophysics Data System (ADS)

    Shi, Heping; Yuan, Jiandong; Dong, Xiuqing; Cheng, Fangqin

    2014-12-01

    A novel asymmetric donor-π-donor-π-acceptor compound, 2-benzothiazolyl-8-diphenylamino-5,11-dihexylindolo[3,2-b]carbazole (BDDAICZ), has been successfully synthesized by introducing a benzothiazole moiety (as an electron-acceptor) and a diphenylamino moiety (as an electron-donor) to 2-position and 8-position of indolo[3,2-b]carbazole moiety (as a skeleton and an electron-donor), and characterized by elemental analysis, 1H NMR, 13C NMR and MS. The thermal, electrochemical properties of BDDAICZ were characterized by thermogravimetric analysis combined with electrochemistry. The absorption and emission spectra of BDDAICZ was experimentally determined in several solvents and computed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The calculated absorption and emission wavelengths are coincident with the measured data. The ionization potential (IP), the electron affinity (EA) and reorganization energy of BDDAICZ were also investigated using density functional theory (DFT). Charge-transporting properties of BDDAICZ were characterized by OLEDs devices fabricated by using it as charge-transport layers. The results show that BDDAICZ has excellent thermal stability, electrochemical stability and hole-transporting properties, indicating its potential application as a hole-transporting material in OLEDs devices.

  8. Synthesis, photophysical and charge-transporting properties of a novel asymmetric indolo [3,2-b]carbazole derivative containing benzothiazole and diphenylamino moieties.

    PubMed

    Shi, Heping; Yuan, Jiandong; Dong, Xiuqing; Cheng, Fangqin

    2014-12-10

    A novel asymmetric donor-π-donor-π-acceptor compound, 2-benzothiazolyl-8-diphenylamino-5,11-dihexylindolo[3,2-b]carbazole (BDDAICZ), has been successfully synthesized by introducing a benzothiazole moiety (as an electron-acceptor) and a diphenylamino moiety (as an electron-donor) to 2-position and 8-position of indolo[3,2-b]carbazole moiety (as a skeleton and an electron-donor), and characterized by elemental analysis, (1)H NMR, (13)C NMR and MS. The thermal, electrochemical properties of BDDAICZ were characterized by thermogravimetric analysis combined with electrochemistry. The absorption and emission spectra of BDDAICZ was experimentally determined in several solvents and computed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The calculated absorption and emission wavelengths are coincident with the measured data. The ionization potential (IP), the electron affinity (EA) and reorganization energy of BDDAICZ were also investigated using density functional theory (DFT). Charge-transporting properties of BDDAICZ were characterized by OLEDs devices fabricated by using it as charge-transport layers. The results show that BDDAICZ has excellent thermal stability, electrochemical stability and hole-transporting properties, indicating its potential application as a hole-transporting material in OLEDs devices.

  9. Selective dispersion of single-walled carbon nanotubes with specific chiral indices by poly(N-decyl-2,7-carbazole).

    PubMed

    Lemasson, Fabien A; Strunk, Timo; Gerstel, Peter; Hennrich, Frank; Lebedkin, Sergei; Barner-Kowollik, Christopher; Wenzel, Wolfgang; Kappes, Manfred M; Mayor, Marcel

    2011-02-02

    Physico-chemical methods to sort single-walled carbon nanotubes (SWNTs) by chiral index are presently lacking but are required for in-depth experimental analysis and also for potential future applications of specific species. Here we report the unexpected selectivity of poly(N-decyl-2,7-carbazole) to almost exclusively disperse semiconducting SWNTs with differences of their chiral indices (n - m) ≥ 2 in toluene. The observed selectivity complements perfectly the dispersing features of the fluorene analogue poly(9,9-dialkyl-2,7-fluorene), which disperses semiconducting SWNTs with (n - m) ≤ 2 in toluene. The dispersed samples are further purified by density gradient centrifugation and analyzed by photoluminescence excitation spectroscopy. All-atom molecular modeling with decamer model compounds of the polymers and (10,2) and (7,6) SWNTs suggests differences in the π-π stacking interaction as origin of the selectivity. We observe energetically favored complexes between the (10,2) SWNT and the carbazole decamer and between the (7,6) SWNT and the fluorene decamer, respectively. These findings demonstrate that subtle structural changes of polymers lead to selective solvation of different families of carbon nanotubes. Furthermore, chemical screening of closely related polymers may pave the way toward simple, low-cost, and index-specific isolation of SWNTs.

  10. Phtophysical processes involved within the bichromophoric system 9-benzotriazole-1-ylmethyl-9H-carbazole and its role as an artificial photosynthetic device

    NASA Astrophysics Data System (ADS)

    Mandal, Paulami; Misra, Tapas; De, Asish; Ghosh, Sanjib; Chaudhury, Shyamal Roy; Chowdhury, Joydeep; Ganguly, Tapan

    2007-03-01

    From both steady state and fluorescence lifetime measurements it reveals that due to photoexcitation of benzotriazole (BZ) part of the bichromophore, 9(1-H-benzotriazole-lylmethyl)-9H-carbazole (BHC), singlet-singlet energy transfer takes place to populate the lowest excited singlet of carbazole (CZ). CZ, thus being excited indirectly via energy transfer process, undergoes strong charge transfer (CT) reaction with the surrounding polar medium acetonitrile (ACN). On the other hand, very weak CT band was apparent when CZ part, within BHC, was directly excited. In less polar tetrahydrofuran (THF) and polar benzonitrile (BN) environment, lack of formation of CT band strongly suggests in favor of the electron-accepting behavior of ACN. Moreover, by measuring the emission spectra of BHC in microcrystals and of 30 bilayers mixed LB film at high mole fraction of BHC molecules, the possibility of excimer formation or aggregation has been ruled out. Thus, BHC, when dissolved in ACN, acts as a triad system of BZ-CZ-ACN where BZ acts as an antenna molecule and CZ as a reaction center. The possible role of the bichromophoric system BHC as an artificial photosynthetic or solar energy conversion device has been hinted.

  11. OFF-ON-OFF Dual Emission at Visible and UV Wavelengths from Carbazole Functionalized β-Diketonate Europium(III) Complex.

    PubMed

    Imai, Yuki; Kawai, Tsuyoshi; Yuasa, Junpei

    2016-06-23

    This work demonstrates dual emission "OFF-ON-OFF" switching at visible and UV wavelengths of a carbazole functionalized β-diketone (LH) by a simple change of a europium(III) ion (Eu(3+)) concentration in the submicromolar concentration range. In the presence of 0.25 equiv of Eu(3+) (5 μM), LH forms a luminescent 4:1 complex ([Eu(3+)(L(-))4](-)) exhibiting dual emission at 357 and 613 nm resulting from the local excitation of the carbazole ring and ligand-sensitized luminescence from the Eu(3+)-β-diketonate unit, respectively. The 4:1 complex begins to convert into a 2:1 complex ([Eu(3+)(L(-))2](+)) via a 3:1 complex [Eu(3+)(L(-))3] above a molar ratio ([Eu(3+)]/[LH]) of 0.25, which provides the opportunity for binding of solvent methanol molecules to the vacant site of the Eu(3+) ion in the complex ([Eu(3+)(L(-))2(MeOH)n](+)). The OH oscillators of coordinated methanol molecules facilitate the nonradiative pathway of the Eu(3+) emission; hence the emission at 613 nm almost disappears above the 0.50 equivalent of Eu(3+) (11 μM), while the UV emission at 357 nm remains mostly constant over the whole concentration range.

  12. Measuring the Photocatalytic Breakdown of Crystal Violet Dye using a Light Emitting Diode Approach

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; Underwood, Lauren W.; O'Neal, Duane; Pagnutti, Mary; Davis, Bruce A.

    2009-01-01

    A simple method to estimate the photocatalytic reactivity performance of spray-on titanium dioxide coatings for transmissive glass surfaces was developed. This novel technique provides a standardized method to evaluate the efficiency of photocatalytic material systems over a variety of illumination levels. To date, photocatalysis assessments have generally been conducted using mercury black light lamps. Illumination levels for these types of lamps are difficult to vary, consequently limiting their use for assessing material performance under a diverse range of simulated environmental conditions. This new technique uses an ultraviolet (UV) gallium nitride (GaN) light emitting diode (LED) array instead of a traditional black light to initiate and sustain photocatalytic breakdown. This method was tested with a UV-resistant dye (crystal violet) applied to a titanium dioxide coated glass slide. Experimental control is accomplished by applying crystal violet to both titanium dioxide coated slides and uncoated control slides. A slide is illuminated by the UV LED array, at various light levels representative of outdoor and indoor conditions, from the dye side of the slide. To monitor degradation of the dye over time, a temperature-stabilized white light LED, whose emission spectrum overlaps with the dye absorption spectrum, is used to illuminate the opposite side of the slide. Using a spectrometer, the amount of light from the white light LED transmitted through the slide as the dye degrades is monitored as a function of wavelength and time and is subsequently analyzed. In this way, the rate of degradation for photocatalytically coated versus uncoated slide surfaces can be compared. Results demonstrate that the dye absorption decreased much more rapidly on the photocatalytically coated slides than on the control uncoated slides, and that dye degradation is dependent on illumination level. For photocatalytic activity assessment purposes, this experimental configuration and

  13. Bioremoval of Basic Violet 3 and Acid Blue 93 by Pseudomonas putida and its adsorption isotherms and kinetics.

    PubMed

    Arunarani, A; Chandran, Preethy; Ranganathan, B V; Vasanthi, N S; Sudheer Khan, S

    2013-02-01

    Basic Violet 3 and Acid Blue 93 are the most important group of synthetic colourants extensively used in textile industries for dyeing cotton, wool, silk and nylon. Release of these dye pollutants in to the environment adversely affects the human health and aquatic organisms. The present study we used Pseudomonas putida MTCC 4910 for the adsorptive removal of Basic Violet 3 and Acid Blue 93 from the aqueous solutions. The pH (4-9) and NaCl concentrations (1mM-1M) did not influence the adsorption process. The equilibrium adsorption process fitted well to Freundlich model than Langmuir model. The kinetics of adsorption fitted well by pseudo-second-order. Thus in the present study an attempt has been made to exploit the dye removal capability of P. putida MTCC 4910, and it was found to be an efficient microbe that could be used for bio removal of dyes from textile effluents.

  14. Small Integrated Optical Head Device Using a Blue-Violet Laser Diode for Blu-ray Disc System

    NASA Astrophysics Data System (ADS)

    Manoh, Kiyoshi; Yoshida, Hiroshi; Kobayashi, Takashi; Takase, Motohiro; Yamauchi, Kiyoshi; Fujiwara, Satoshi; Ohno, Tsuyoshi; Nishi, Noriaki; Ozawa, Masafumi; Ikeda, Masao; Tojyo, Tsuyoshi; Taniguchi, Tadashi

    2003-02-01

    We report the first integrated optical head device using a blue-violet laser diode (LD), which is a key device for realizing a small and thin Blu-ray Disc drive. While integrating seven optical elements and semiconductor chips into one device by adopting a molded optical element with high transmittance to the blue-violet wavelength, both small aberration and the small device size of 11 mm× 6 mm× 4.1 mm have been realized. We have also improved heat dissipation efficiency from this device to the base unit by adopting a newly developed package. At this time, we have implemented a performance evaluation of this small head device and have confirmed its good read/write performance as well as its adequate tolerances required for the Blu-ray Disc system.

  15. Planar super-oscillatory lens for sub-diffraction optical needles at violet wavelengths

    PubMed Central

    Yuan, Guanghui; Rogers, Edward T. F.; Roy, Tapashree; Adamo, Giorgio; Shen, Zexiang; Zheludev, Nikolay I.

    2014-01-01

    Planar optical lenses are fundamental elements of miniaturized photonic devices. However, conventional planar optical lenses are constrained by the diffraction limit in the optical far-field due to the band-limited wavevectors supported by free-space and loss of high-spatial-frequency evanescent components. As inspired by Einstein's radiation ‘needle stick', electromagnetic energy can be delivered into an arbitrarily small solid angle. Such sub-diffraction optical needles have been numerically investigated using diffractive optical elements (DOEs) together with specially polarized optical beams, but experimental demonstration is extremely difficult due to the bulky size of DOEs and the required alignment precision. Planar super-oscillatory lenses (SOLs) were proposed to overcome these constraints and demonstrated that sub-diffraction focal spots can actually be formed without any evanescent waves, making far-field, label-free super-resolution imaging possible. Here we extend the super-oscillation concept into the vectorial-field regime to work with circularly polarized light, and experimentally demonstrate, for the first time, a circularly polarized optical needle with sub-diffraction transverse spot size (0.45λ) and axial long depth of focus (DOF) of 15λ using a planar SOL at a violet wavelength of 405 nm. This sub-diffraction circularly polarized optical needle has potential applications in circular dichroism spectroscopy, super-resolution imaging, high-density optical storage, heat-assisted magnetic recording, nano-manufacturing and nano-metrology. PMID:25208611

  16. Ammonium sulfide-assisted hydrothermal activation of palygorskite for enhanced adsorption of methyl violet.

    PubMed

    Tian, Guangyan; Wang, Wenbo; Kang, Yuru; Wang, Aiqin

    2016-03-01

    Herein, palygorskite (PAL) was activated via a simple hydrothermal process in the presence of ammonium sulfide, and the effects of activation on the microstructure, physico-chemical feature and adsorption behaviors of PAL were intensively investigated. The hydrothermal process evidently improved the dispersion of PAL crystal bundles, increased surface negative charges and built more active -Si-O(-) groups served as the new "adsorption sites". The adsorption property of the activated PAL for Methyl Violet (MV) was systematically investigated by optimizing the adsorption variables, including pH, ionic strength, contact time and initial MV concentration. The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV (from 156.05 to 218.11mg/g). The kinetics for MV adsorption followed pseudo second-order kinetic models, while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model. The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of -X-O(-) are the prominent driving forces for the adsorption process.

  17. Violet Light Exposure Can Be a Preventive Strategy Against Myopia Progression.

    PubMed

    Torii, Hidemasa; Kurihara, Toshihide; Seko, Yuko; Negishi, Kazuno; Ohnuma, Kazuhiko; Inaba, Takaaki; Kawashima, Motoko; Jiang, Xiaoyan; Kondo, Shinichiro; Miyauchi, Maki; Miwa, Yukihiro; Katada, Yusaku; Mori, Kiwako; Kato, Keiichi; Tsubota, Kinya; Goto, Hiroshi; Oda, Mayumi; Hatori, Megumi; Tsubota, Kazuo

    2017-02-01

    Prevalence of myopia is increasing worldwide. Outdoor activity is one of the most important environmental factors for myopia control. Here we show that violet light (VL, 360-400nm wavelength) suppresses myopia progression. First, we confirmed that VL suppressed the axial length (AL) elongation in the chick myopia model. Expression microarray analyses revealed that myopia suppressive gene EGR1 was upregulated by VL exposure. VL exposure induced significantly higher upregulation of EGR1 in chick chorioretinal tissues than blue light under the same conditions. Next, we conducted clinical research retrospectively to compare the AL elongation among myopic children who wore eyeglasses (VL blocked) and two types of contact lenses (partially VL blocked and VL transmitting). The data showed the VL transmitting contact lenses suppressed myopia progression most. These results suggest that VL is one of the important outdoor environmental factors for myopia control. Since VL is apt to be excluded from our modern society due to the excessive UV protection, VL exposure can be a preventive strategy against myopia progression.

  18. Leuco-crystal-violet micelle gel dosimeters: I. Influence of recipe components and potential sensitizers.

    PubMed

    Nasr, A T; Alexander, K; Schreiner, L J; McAuley, K B

    2015-06-21

    Radiochromic leuco crystal violet (LCV) micelle gel dosimeters are promising three-dimensional radiation dosimeters because of their spatial stability and suitability for optical readout. The effects of surfactant type and surfactant concentration on dose sensitivity of LCV micelle gels are tested, demonstrating that dose sensitivity and initial colour of the gel increases with increasing Triton x-100 (Tx100) concentration. Using Cetyl Trimethyl Ammonium Bromide (CTAB) in place of Tx100 produces gels that are nearly colourless prior to irradiation, but reduces the dose sensitivity. The separate effects of Tri-chloro acetic acid concentration and pH are investigated, revealing that controlling the pH near 3.6 is crucial for achieving high dose sensitivity. The sensitizing effect of chlorinated species on dose sensitivity is tested using 2,2,2-trichloroethanol (TCE), chloroform, and 1,1,1-trichloro-2-methyl-2-propanol hemihydrate. TCE gives the largest improvement in dose sensitivity and is recommended for use in micelle gel dosimeters because it is less volatile and safer to use than chloroform. Preliminary experiments on a new gel containing CTAB as the surfactant and TCE show that this new gel gives a dose sensitivity that is 24% higher than that of previous LCV micelle gels and is nearly colourless prior to irradiation.

  19. Biodegradation of Basic Violet 3 by Candida krusei isolated from textile wastewater.

    PubMed

    Deivasigamani, Charumathi; Das, Nilanjana

    2011-11-01

    Basic Violet 3 (BV) belongs to the most important group of synthetic colorants and is used extensively in textile industries. It is considered as xenobiotic compound which is recalcitrant to biodegradation. As Candida krusei could not use BV as sole carbon source, experiments were conducted to study the effect of cosubstrates on decolorization of BV in semi synthetic medium using glucose, sucrose, lactose, maltose, yeast extract, peptone, urea and ammonium sulphate. Maximum decolorization (74%) was observed in media supplemented with sucrose. Use of sugarcane bagasse extract as sole nutrient source showed 100% decolorization of BV within 24 h under optimized condition. UV-visible, FTIR spectral analysis and HPLC analysis confirmed the biodegradation of BV. Six degradation products were isolated and identified. We propose the biodegradation pathway for BV which occurs via stepwise reduction and demethylation process to yield mono-, di-, tri-, tetra-, penta- and hexa-demethylated BV species which was degraded completely. The study of the enzymes responsible for decolorization showed the activities of lignin peroxidase, lacasse, tyrosinase, NADH-DCIP reductase, MG reductase and azoreductase in cells before and after decolorization. A significant increase in activities of NADH-DCIP reductase and laccase was observed in the cells after decolorization. The yeast C. krusei could show the ability to decolorize the textile dye BV using inexpensive source like sugarcane bagasse extract for decolorization.

  20. Development of electrochemiluminescent inhibition method for determination of gentian violet in aquatic water

    NASA Astrophysics Data System (ADS)

    Wang, Sui; Hao, Tingting; Yu, Xinwei; Gai, Panpan; Guo, Zhiyong

    2012-04-01

    Gentian violet (GV) was found to quench the electrochemiluminescence (ECL) of the tris(2,2'-bipyridyl)ruthenium(II)/tris-n-propylamine (Ru(bpy)32+-TPA) system at a glass carbon electrode (GCE). Based on the ECL signal changes, a simple and ultrasensitive detection method for GV in aquatic water was established. Under the optimized conditions, the quenched ECL intensity versus the logarithm of the concentration of GV was linear over a concentration range from 1.0 × 10-10 to 5.0 × 10-7 mol L-1, and the limit of detection (LOD) was found to be 4.5 × 10-12 mol L-1 (S/N = 3). The results obtained by the ECL system were better than other reported methods in literatures in terms of sensitivity or linear response range. The method was successfully applied to determine GV in aquatic water, and the relative standard deviations (RSDs) were found less than 6.3%, and the recoveries were obtained from 98.7 to 111.0%. Moreover, a possible mechanism of the quenching effect was primarily discussed based on UV-visible absorption spectra, cyclic voltammograms and IECL-E curves.

  1. Effect of different EBL structures on deep violet InGaN laser diodes performance

    NASA Astrophysics Data System (ADS)

    Alahyarizadeh, Gh.; Amirhoseiny, M.; Hassan, Z.

    2016-01-01

    Some specific designs on band structure near the active region, including the modifications of the material and thickness of the electron blocking layer (EBL), in the deep violet InGaN laser diodes (LDs) are investigated numerically with the ISE TCAD software. The analyses focus on electron and hole carrier injection efficiency, carrier distributions, electron leakage, and radiative recombination, subsequently, optical material gain, and optical intensity. The results indicate that for the ternary AlGaN EBL, the lowest threshold current and the highest output power, slope efficiency, and DQE have been obtained for the 15 nm EBL thickness with 0.22 Al mole fraction. In addition, a comparative study has been conducted on the performance characteristics of the LD structures with a ternary AlGaN EBL and a quaternary AlInGaN EBL with an output emission wavelength at 390 nm. The simulation results showed that the using quaternary AlInGaN EBL effectively improves the LD performance characteristics.

  2. The complete mitochondrial genome of the Violet-spotted reef lobster Enoplometopus debelius (Crustacea, Astacidea, Enoplometopidae).

    PubMed

    Ahn, Dong-Ha; Min, Gi-Sik; Park, Joong-Ki; Kim, Sanghee

    2016-05-01

    The violet-spotted reef lobster Enoplometopus debelius Holthuis, 1983 (Decapoda, Astacidea, Enoplometopidae) is found in the tropical reef areas of the Indo-Pacific region, and is a highly prized and very popular species in the aquarium trade industry. The complete mitochondrial genome of E. debelius has 15,641 base pairs consisting of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region of 746 bp. The base composition of E. debelius is 36.4% A, 35.3% T, 18.1% C, 10.3% G, and the species has an AT content of 71.7%. The E. debelius mitogenome was found to have a gene arrangement and transcriptional polarity identical to that of the Homarus americanus mitogenome, a representative of the arthropod ground pattern. Here, we present the complete mitogenome sequence of E. debelius, which is the first in the superfamily Enoplometopoidea. These data will provide a useful molecular resource for the phylogenetic study of the infraorder Astacidea/order Decapoda.

  3. Leuco-crystal-violet micelle gel dosimeters: I. Influence of recipe components and potential sensitizers

    NASA Astrophysics Data System (ADS)

    Nasr, A. T.; Alexander, K.; Schreiner, L. J.; McAuley, K. B.

    2015-06-01

    Radiochromic leuco crystal violet (LCV) micelle gel dosimeters are promising three-dimensional radiation dosimeters because of their spatial stability and suitability for optical readout. The effects of surfactant type and surfactant concentration on dose sensitivity of LCV micelle gels are tested, demonstrating that dose sensitivity and initial colour of the gel increases with increasing Triton x-100 (Tx100) concentration. Using Cetyl Trimethyl Ammonium Bromide (CTAB) in place of Tx100 produces gels that are nearly colourless prior to irradiation, but reduces the dose sensitivity. The separate effects of Tri-chloro acetic acid concentration and pH are investigated, revealing that controlling the pH near 3.6 is crucial for achieving high dose sensitivity. The sensitizing effect of chlorinated species on dose sensitivity is tested using 2,2,2-trichloroethanol (TCE), chloroform, and 1,1,1-trichloro-2-methyl-2-propanol hemihydrate. TCE gives the largest improvement in dose sensitivity and is recommended for use in micelle gel dosimeters because it is less volatile and safer to use than chloroform. Preliminary experiments on a new gel containing CTAB as the surfactant and TCE show that this new gel gives a dose sensitivity that is 24% higher than that of previous LCV micelle gels and is nearly colourless prior to irradiation.

  4. Simultaneous sorption of crystal violet and 2-naphthol to bentonite with different CECs.

    PubMed

    Wei, Jingming; Zhu, Runliang; Zhu, Jianxi; Ge, Fei; Yuan, Peng; He, Hongping; Ming, Chen

    2009-07-15

    This work was to examine the feasibility and efficiency to use bentonite for simultaneous removal of cationic dyes and hydrophobic organic carbons (HOCs) from water. The sorption capacities of crystal violet (CV) on two bentonites and one activated carbon were compared. Simultaneous sorption of CV and 2-naphthol on the two bentonites were tested, and the removal efficiencies of 2-naphthol by the simultaneous sorption method and by CV modified bentonite was also compared. The experimental results in this study showed that the bentonite is more effective in sorption of CV than the activated carbon. With the sorption of CV, bentonite surfaces were altered from hydrophilicity to hydrophobicity, and thus 2-naphthol could be simultaneously removed. The aromatic effect between CV and 2-naphthol was supposed to be the primary driving force for the sorption of 2-naphthol. The simultaneous sorption method was shown to be more effective in the sorption of 2-naphthol than the CV modified bentonite. Results of this work could provide novel information for the treatment of wastewater containing both cationic dyes and HOCs.

  5. Effects of ultra violet radiation on the soluble proteins of human hair.

    PubMed

    Fedorkova, M V; Smolina, N V; Mikhalchik, E V; Balabushevich, N G; Ibragimova, G A; Gadzhigoroeva, A G; Dmitrieva, E I; Dobretsov, G E

    2014-11-01

    Exposure of hair fibers from healthy volunteers to Ultra Violet Radiation (UVR) under laboratory conditions enhanced protein elution from the hair tresses into a buffer solution (pH 10.5). At the same time the UVR decreased the intensity of tryptophan fluorescence in the eluted proteins. After mechanical homogenization of these hair samples, the increase of soluble protein was registered for UVR treated hair as well as the rise in sulfhydryl group content of these proteins. Analysis of soluble proteins from hair samples homogenized before and after protein elution has shown that mainly proteins rich in sulfhydryl groups were eluted and as a result sulfhydryl content of proteins in hair shaft decreased. The hypothesis concerning the effects of environmental factors on the properties of hair shaft proteins was examined, the proximal and distal parts of normal hair (0-5 cm and 15-20 cm from hair root) were compared. In the distal parts there was a higher quantity of soluble proteins registered after homogenization, with decreased sulfhydryl group content and tryptophan fluorescence. It could be supposed that this difference results from the steady rupture of cystine in sulfur bridges and tryptophan under exposure to environmental factors (mainly, UVR), followed by elution of the resulting peptides.

  6. Investigation on the interaction of the toxicant, gentian violet, with bovine hemoglobin.

    PubMed

    Liu, Yan; Lin, Jingjing; Chen, Mingmao; Song, Ling

    2013-08-01

    Gentian violet (GV) is a well-known triarylmethane dye that is used in aquacultural, industrial and medicinal fields. But concerns in growing number have been paid to its potential health problems to human beings and its hazardous effects to environment. Herein, the toxic interaction of GV with bovine hemoglobin (BHb) was investigated by a series of spectroscopic methods and molecular modeling method. The fluorescence emission profile exhibited a remarkable quenching upon addition of GV to the buffered aqueous solution of BHb and the analysis of results revealed the dominant role of static quenching mechanism in GV-BHb interaction. The negative ΔH and positive ΔS values demonstrated that the electrostatic interactions mainly stabilized this toxicantprotein complex. Synchronous fluorescence, UV-Vis absorption and CD spectroscopic studies proved that the conformational change of BHb was induced by GV's combination. Molecular modeling studies exhibited the binding mode of GV-BHb complex and the detailed information of related driving forces. During the (1)H nuclear magnetic resonance spectra ((1)H NMR) study, the chemical shift perturbation and spin-lattice relaxation times of different protons were further used to investigate the interaction of GV with BHb and the results indicated that GV bound orientationally to BHb.

  7. Evaluation of the genotoxicity of gentian violet in bacterial and mammalian cell systems.

    PubMed

    Aidoo, A; Gao, N; Neft, R E; Schol, H M; Hass, B S; Minor, T Y; Heflich, R H

    1990-01-01

    Previous studies indicate that gentian violet (GV), a triphenylmethane dye used in agriculture and human medicine, is a clastogen in vitro and a carcinogen in chronically exposed mice and rats. Data on its genotoxic activity, however, have been incomplete and partly contradictory. Mutagenesis and DNA damage experiments were conducted to re-evaluate the genotoxic potential of GV in both bacterial and mammalian cell systems. GV was mutagenic in Salmonella typhimurium tester strains TA97 and TA104, but there was little mutagenic activity detected in strains TA98 and TA100. A rat liver homogenate fraction (S9) tended to increase mutagenicity. The major microsomal metabolites of GV, pentamethylpararosaniline and N,N,N',N'-tetramethylpararosaniline were less mutagenic in TA97 and TA104, while N,N,N',N"-tetramethylpararosaniline was a weak mutagen in Salmonella. GV was not mutagenic in Chinese hamster ovary (CHO) cell strain CHO-K1-BH4, and was a questionable mutagen in CHO-AS52 cells. While GV produced DNA damage as measured by sedimentation of nucleotids derived from B6C3F1 mouse lymphocytes treated in vitro, no damage was found in lymphocytes isolated from mice dosed with GV. GV was also a weak producer of gene amplification in an SV40-transformed Chinese hamster cell line. The results indicate that GV is a point mutagen in bacteria; however, since similar exposure conditions produced weak mutagenic activity in mammalian cells, GV may be carcinogenic by virtue of its clastogenic activity.

  8. Degradation of crystal violet by an FeGAC/H2O2 process.

    PubMed

    Chen, Chiing-Chang; Chen, Wen-Ching; Chiou, Mei-Rung; Chen, Sheng-Wei; Chen, Yao Yin; Fan, Huan-Jung

    2011-11-30

    Because of the growing concern over highly contaminated crystal violet (CV) wastewater, an FeGAC/H(2)O(2) process was employed in this research to treat CV-contaminated wastewater. The experimental results indicated that the presence of iron oxide-coated granular activated carbon (FeGAC) greatly improved the oxidative ability of H(2)O(2) for the removal of CV. For instance, the removal efficiencies of H(2)O(2), GAC, FeGAC, GAC/H(2)O(2) and FeGAC/H(2)O(2) processes were 10%, 44%, 40%, 43% and 71%, respectively, at test conditions of pH 3 and 7.4mM H(2)O(2). FeGAC/H(2)O(2) combined both the advantages of FeGAC and H(2)O(2). FeGAC had a good CV adsorption ability and could effectively catalyze the hydrogen peroxide oxidation reaction. Factors (including pH, FeGAC dosage and H(2)O(2) dosage) affecting the removal of CV by FeGAC/H(2)O(2) were investigated in this research as well. In addition, the reaction intermediates were separated and identified using HPLC-ESI-MS. The N-demethylation step might be the main reaction pathway for the removal of CV. The reaction mechanisms for the process proposed in this research might be useful for future application of this technology to the removal of triphenylmethane (TPM) dyes.

  9. Suppression of NF-κB Activation By Gentian Violet Promotes Osteoblastogenesis and Suppresses Osteoclastogenesis

    PubMed Central

    Yamaguchi, M.; Vikulina, T.; Arbiser, J.L.; Weitzmann, M.N.

    2015-01-01

    Skeletal mass is regulated by the coordinated action of bone forming osteoblasts and bone resorbing osteoclasts. Accelerated rates of bone resorption relative to bone formation lead to net bone loss and the development of osteoporosis, a devastating disease that predisposes the skeleton to fractures. Bone fractures are associated with significant morbidity and in the case of hip fractures, high mortality. Gentian violet (GV), a cationic triphenylmethane dye, has long been used as an antifungal and antibacterial agent and is presently under investigation as a potential chemotherapeutic and antiangiogenic agent. However, effects on bone cells have not been previously reported and the mechanisms of action of GV, are poorly understood. In this study we show that GV suppresses receptor activator of NF-κB ligand (RANKL)-induced differentiation of RAW264.7 osteoclast precursors into mature osteoclasts, but paradoxically stimulates the differentiation of MC3T3 cells into mineralizing osteoblasts. These actions stem from the capacity of GV to suppress activation of the nuclear factor kappa B (NF-κB) signal transduction pathway that is required for osteoclastogenesis, but inhibitory to osteoblast differentiation and activity. Our data reveal that GV is an inhibitor of NF-κB activation and may hold promise for modulation of bone turnover to promote a balance between bone formation and bone resorption, favorable to gain of bone mass. PMID:25056540

  10. Adsorption of crystal violet with diatomite earth&carbon by a modification of hydrothermal carbonization process.

    PubMed

    Zhang, Yanzhuo; Li, Jun; Chen, Guanghui; Bian, Wei; Lu, Yun; Li, Wenjing; Zheng, Zhaoming; Cheng, Xiaojie

    2016-01-01

    The high colority and difficulty of decolorization are the most important tasks on printing and dyeing wastewater. This study investigates the ability of diatomite earth&carbon (DE&C) as an adsorbent to removal crystal violet (CV) from aqueous solutions. Fourier transform infrared spectroscopy results indicate the importance of functional groups during the adsorption of CV. The obtained N2 adsorption-desorption isotherm values accord with well IUPAC type II. Our calculations determined a surface area of 73.15 m(2) g(-1) for DE&C and an average pore diameter of 10.56 nm. Equilibrium data of the adsorption process fitted very well to the Langmuir model (R(2) > 0.99). The results of kinetics study showed that the pseudo-second-order model fitted to the experimental data well. The thermodynamic parameters were also evaluated. ΔH° <0, ΔS° > 0 and ΔG° < 0 demonstrated that the adsorption process was spontaneous and exothermic for dye. Furthermore the positive value of ΔS° reflected good affinity of the CV dye.

  11. Effect of Montmorillonite Modification on Ultra Violet Radiation Cured Nanocomposite Filled with Glycidyl Methacrylate Modified Kenaf

    NASA Astrophysics Data System (ADS)

    Rozyanty, A. R.; Rozman, H. D.; Zhafer, S. F.; Musa, L.; Zuliahani, A.

    2016-06-01

    In this study nanocomposite cured by ultra violet radiation, were produced using modified montmorillonite (MMT) as reinforcing agent, chemically modified kenaf bast fiber as filler and unsaturated polyester as the matrix. Kenaf bast fiber was chemically modified with glycidyl methacrylate (GMA) whilst MMT were modified with cetyl trimethyl ammonium bromide (CTAB) and glycidyl methacrylate (GMA). Fixed 12 percent of GMA modified kenaf bast fiber with different percentage (i.e., 1, 3 and 5) of unmodified and modified MMT loading was used to produce the composite. The performed of GMA reaction with hydroxyl group of cellulose in kenaf bast fiber was evaluated using Fourier Transform infrared (FTIR) spectroscopy. GMA-MMT filled composite showed higher mechanical properties than MMT and CTAB-MMT filled composite. However, the increase of MMT, CTAB-MMT and GMA- MMT loading resulted in the reduction of mechanical properties. Scanning electron microscopy (SEM) analysis showed the evidence of compatibility enhancement between MMT and kenaf bast fiber with unsaturated polyester matrix.

  12. III-Nitride-on-silicon microdisk lasers from the blue to the deep ultra-violet

    NASA Astrophysics Data System (ADS)

    Sellés, J.; Crepel, V.; Roland, I.; El Kurdi, M.; Checoury, X.; Boucaud, P.; Mexis, M.; Leroux, M.; Damilano, B.; Rennesson, S.; Semond, F.; Gayral, B.; Brimont, C.; Guillet, T.

    2016-12-01

    We present a series of microdisk lasers realized within the same GaN-on-Si photonic platform scheme, and operating at room temperature under pulsed optical pumping over a broad spectral range extending over λ = 275 nm-470 nm. The III-nitride microdisks embed either binary GaN/AlN multiple quantum wells (MQWs) for UV operation, or ternary InGaN/GaN MQWs for violet and blue operation. This demonstrates the versatility of this nitride-on-silicon platform, and the realization on this platform of efficient active layers for lasing action over a 200 nm broad UV to visible spectral range. We probe the lasing threshold carrier density over the whole spectral range and found that it is similar whatever the emission wavelength for these Q > 1000 microdisk resonators with a constant material quality until quantum confined Stark effect takes over. The threshold is also found independent of microdisk diameters from 3 to 12 μm, with a β factor intermediate between the one of vertical cavity lasers and the one of small modal volume "thresholdless" lasers.

  13. New Twist on an Old Favorite: Gentian Violet and Methylene Blue Antibacterial Foams

    PubMed Central

    Edwards, Karen

    2016-01-01

    Significance: Absorptive antibacterial dressings that assist in controlling bioburden without risks of cytotoxicity or residual absorption can be effectively used for prolonged periods throughout the wound healing continuum. Recent Advances: Until recently, gentian violet and methylene blue (GV/MB) antibacterial dressings have been commercially available only in polyvinyl alcohol (PVA) foam; polyurethane (PU) foam bonded with GV and MB with thin film backing is now commercially available. GV/MB PU foam does not require hydration or a necessary secondary dressing. GV/MB PVA and PU foam dressings were recently granted FDA clearance as antibacterial dressings, as opposed to bacteriostatic dressings as previously classified. Within the class of antibacterial dressings, GV/MB foam dressings are of lower cost alternative to silver- or iodine-based antibacterial dressings with no risk of absorption of any of the foam components into the tissues. Critical Issues: Control of wound bioburden levels by antibacterial agents and absorption of excess exudate are crucial in preventing infections that drastically increase the price of wound care. Use of GV/MB dressings may improve wound healing outcomes and decrease overall costs through super absorption, promotion of autolytic debridement, bioburden reduction, ease of use, and decreased dressing change frequency. Future Directions: Evolution in resistant bacterial strains will drive continual changes in advanced wound care products. Demand will increase for economically priced, versatile wound care dressings that assist in debridement, maintain a moist wound environment, absorb and trap bacterial debris, and decrease dressing change frequency. PMID:26858911

  14. Biocompatibility of the vital dye Acid Violet-17 on retinal pigment epithelial cells

    PubMed Central

    Tura, Ayşegül; Alt, Aizhan; Lüke, Julia; Grisanti, Salvatore; Haritoglou, Christos; Meyer, Carsten H; Nassar, Khaled; Lüke, Matthias

    2016-01-01

    Purpose To examine the viability and differentiation of retinal pigment epithelial (RPE) cells after exposure to the vital dye Acid Violet-17 (AV-17). Methods Bovine RPE cells were incubated with AV-17 (0.0625–0.5 mg/mL) for 30 seconds or 5 minutes. Viability was determined by live/dead staining, cleaved CASP3 immunostainings, and MTT test. Actin cytoskeleton was visualized by Alexa 488-phalloidin. Immunocytochemistry was performed to determine the levels of ZO-1, CTNNB1, and KRT19. Results Exposure to AV-17 at the concentrations of 0.25–0.5 mg/mL resulted in a dose-dependent decrease in viability, the loss of ZO-1 from tight junctions, translocation of CTNNB1 into the cytoplasm and nucleus, disarrangement of the actin cytoskeleton, and a slight increase in KRT19. Conclusion AV-17 at a concentration <0.125 mg/mL is likely to be well tolerated by the RPE cells, whereas the concentrations from 0.25 mg/mL onward can reduce viability and induce dedifferentiation particularly after long-term exposure. PMID:27536056

  15. Synthesis and Characterisation of Silica-Modified Titania for Photocatalytic Decolouration of Crystal Violet.

    PubMed

    Shahid, Mohammad; El Saliby, Ibrahim; Tijing, Leonard D; McDonagh, Andrew; Park, Se Min; Lee, Kwang Young; Shon, Ho Kyong; Kim, Jong-Ho

    2015-07-01

    In the past few years, silica-modified titania has drawn increasing attention due to their special properties making them ideal candidates for a wide range of applications. In this study, we report a novel method for the synthesis of silica-modified titania by a sol-gel method using sodium silicate solution (1 M). The hydrolysis and condensation reactions of titanium dioxide (TiO2, Degussa Aeroxide® P25) in sodium silicate solution proceeded with citric acid (3 M) as a catalyst. The orbital shaking method was followed for the removal of sodium salt formed during the sol-gel process. Solvent exchange was carried out using methanol and hexane. Finally, chemical modification of the gel was conducted using trimethylchlorosilane followed by ambient pressure drying. The obtained silica-modified titania was characterised for nanostructural analysis using scanning electron microscopy and transmission electron microscopy. The nitrogen adsorption-desorption measurements were employed to investigate the BET surface area, pore structure and pore volume of specimens. Thermal gravimetric analysis showed exothermic peaks at temperature range of 90-190 °C representing the oxidation of organic groups from--Si-R network. The silica-modified titania showed high photocatalytic activity and an easy recovery using crystal violet as model water pollutant.

  16. Compact fiber-optic flurosensor using high-power continuous-wave violet diode laser

    NASA Astrophysics Data System (ADS)

    Johansson, Ann; Gustafsson, Ulf; Palsson, Sara; Svanberg, Sune

    2003-10-01

    In this work a compact fluorosensor has been built for point-monitoring and imaging applications. The instrument has been applied in fluorescence studies on green vegetation and on malignant tissue. The instrument is based on a violet diode laser, an integrated spectrometer and optical fibers for light delivery and collection of the fluorescence signal. This combination makes the system very compact. The high laser output power allows for coupling of the laser light into a hyperspectral diagnostic imaging instrument, developed and built by Science and Technology International. In point-monitoring mode, the instrument has been tested on superficial skin tumors and when using δ-aminolevulinic acid induced protoporphyrin IX as a tumor sensitizer, good contrast between normal and malignant tissue was achieved, clearly demonstrating its feasibility in cancer diagnostics. In imaging mode, the instrument functioned solely as a light source, coupling the excitation light into the hyperspectral imaging instrument. The set-up was tested by studying chlorophyll fluorescence from vegetation. The fluorescence signal showed a low signal-to-noise ratio mainly because of inefficient light coupling into the imaging instrument.

  17. Theoretical study of the dissociation energy and the red and violet band systems of CN

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1987-01-01

    The dissociation energy (D sub O) of CN is determined to be 7.65 + or - 0.06 eV. This corresponds to delta H sub f (CN) = 105.3 + or - 1.5 kcal/mole, in excellent agreement with Engleman and Rouse (1975), but considerably larger than the recent value deduced from shock-tube studies by Colket (1984). The result is obtained not only from extensive ab initio MRCI calculations using a very large Gaussian basis set, but also from extrapolation of the directly computed value by comparison of computed and experimental results fo NO, C2, and N2. As an additional calibration of the methods, the D sub O value for CN was computed from the corresponding value for CN(-) using the experimental electron affinity data. The lifetime of the nu prime = 0 level of the violet (B 2 sigma + yields X 2 sigma +) system was computed to be 62.4 ns, in good agreement with both experiment and previous calculations. Lifetimes for the red (A 2 pi yields X 2 sigma +) system decrease with increasing nu prime, which is consistent both with the recent experiment and calculations. While the computed lifetimes are significantly longer that those obtained from the experiment, they are shorter than those deduced from an analysis of the solar spectrum. However the D sub O and f (sub OO) are consistent with Lambert's model for the solar spectrum.

  18. Differential Spectral Imaging of the CN Violet Band in Laser-Induced Plasmas on TNT Simulant Molecules

    NASA Astrophysics Data System (ADS)

    Merten, J.; Jones, M.; Hoke, S.; Allen, S.

    2014-11-01

    Dual channel emission imaging of m-nitrobenzoic acid and benzoic acid was performed in order to visualize the morphology of the CN violet band emission of a TNT analogue. The CN channel was corrected for continuum emission using a simultaneously imaged background channel. Simultaneous dual channel imaging alleviated problems with shot to shot variation in the plasma morphology due to the friable substrates and showed differences between plasmas formed on the two targets.

  19. Molecular and structural characterization of some violet phosphate pigments for their non-invasive identification in modern paintings

    NASA Astrophysics Data System (ADS)

    Anselmi, C.; Vagnini, M.; Cartechini, L.; Grazia, C.; Vivani, R.; Romani, A.; Rosi, F.; Sgamellotti, A.; Miliani, C.

    2017-02-01

    A complete non-invasive characterization by XRF, XRD, near-FTIR and UV-Vis reflectance spectroscopy has been performed on some commercially available violet pigments as well as on pure violet Co-salts also known to be used as pigments. The obtained results show that, after a preliminary elemental characterization, the studied pigments can be easily identified by near-FTIR and UV-Vis spectroscopies since they exhibit peculiar spectral bands in these regions. Among the analyzed samples emerged that the pigment 45350 - "Manganviolett" from Kremer consists of two α- and β-NH4MnP2O7 polymorphs, being α-NH4MnP2O7 the most abundant one; furthermore we found that the pigment R1215D -"Cobalt violet" by Winsor & Newton (no longer available since 2006) displays spectral features that match exactly those of 45820-"Kobaltviolett hell" from Kremer and both are composed by cobalt ammonium phosphate hydrate. Such non-invasive study allowed for the identification of "Manganese Violet" (α-NH4MnP2O7) and anhydrous cobalt phosphate (Co3(PO4)2) on some Boccioni's paintings during MOLAB in situ measurements at the Museo del Novecento (Milano). The spectrum of sample 6 shows, as expected, the O-P-O bending and P-O stretching vibrational multiple bands in the ranges of 420-700 cm-1 and 1000-1250 cm-1, while the peaks located at 760 and 912 cm-1 are attributed to the symmetric and antisymmetric P-O-P vibrations that are typical of the pyrophosphate group. [4]. Characteristic stretching and bending absorptions of the NH4+ cation are visible in the range 3300-3000 cm-1, and at about 1450-1400 cm-1. Typical spectral features of kaolin are visible at 3620 and 3694 cm-1[5].

  20. Quenching of fluorescence by crystal violet and its use to differentiate between surface-bound and internalized bacteria

    NASA Astrophysics Data System (ADS)

    Mathew, S.; Lim, Y. C.; Kishen, A.

    2008-06-01

    Phagocytosis is a complex process involving attachment, ingestion and intracellular processing of bacteria by phagocytes. A great difficulty in the evaluation of this process is to differentiate between attachment of the particles to the cell surface and internalization of the particles by the cells. Various techniques have been used to differentiate internalized and surface-attached bacteria in cultured cells, but only a few permit differentiations between surface-bound and internalized bacteria. In this study the quenching of fluorescence by crystal violet on acridine orange stained bacterial biofilm and planktonic bacterial cells is used to differentiate between surface-bound and internalized bacteria within macrophages. Method: One week old Enterococcus faecalis biofilm was grown on perspex and glass substrates in All-Culture medium (nutrient-rich condition) and phosphate buffered saline (nutrient-deprived condition). As model systems, human monocytic (THP-1) and histiocytic (U937) cell lines were used. These cell lines were incubated with the biofilm bacteria for 4 hrs in CO II incubator at 37 °C. The cells and bacteria were stained with acridine orange and quenched with crystal violet to distinguish between surface-bound and internalized bacteria. Results: The presence of green-fluorescing internalized bacteria was detected within the macrophages under the planktonic, nutrient-rich and nutrient-deprived biofilm conditions. All infecting bacteria take up acridine orange and fluoresced green, crystal violet quenched the fluorescence of extra-cellular adhering bacteria so that only fluorescent intracellular bacteria would be visible under fluorescent light microscopy.

  1. Isolation and Characterization of Paracoccus sp. GSM2 Capable of Degrading Textile Azo Dye Reactive Violet 5

    PubMed Central

    Bheemaraddi, Mallikarjun C.; Shivannavar, Channappa T.; Gaddad, Subhashchandra M.

    2014-01-01

    A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L) within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v). UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2. PMID:24883397

  2. Isolation and characterization of Paracoccus sp. GSM2 capable of degrading textile azo dye Reactive Violet 5.

    PubMed

    Bheemaraddi, Mallikarjun C; Patil, Santosh; Shivannavar, Channappa T; Gaddad, Subhashchandra M

    2014-01-01

    A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L) within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0-9.0 and 25-40 °C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v). UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2.

  3. Intense, stable and excitation wavelength-independent photoluminescence emission in the blue-violet region from phosphorene quantum dots.

    PubMed

    Ge, Shuaipeng; Zhang, Lisheng; Wang, Peijie; Fang, Yan

    2016-06-06

    Nanoscale phosphorene quantum dots (PQDs) with few-layer structures were fabricated by pulsed laser ablation of a bulk black phosphorus target in diethyl ether. An intense and stable photoluminescence (PL) emission of the PQDs in the blue-violet wavelength region is clearly observed for the first time, which is attributed to electronic transitions from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) and occupied molecular orbitals below the HOMO (H-1, H-2), respectively. Surprisingly, the PL emission peak positions of the PQDs are not red-shifted with progressively longer excitation wavelengths, which is in contrast to the cases of graphene and molybdenum disulphide quantum dots. This excitation wavelength-independence is derived from the saturated passivation on the periphery and surfaces of the PQDs by large numbers of electron-donating functional groups which cause the electron density on the PQDs to be dramatically increased and the band gap to be insensitive to the quantum size effect in the PQDs. This work suggests that PQDs with intense, stable and excitation wavelength-independent PL emission in the blue-violet region have a potential application as semiconductor-based blue-violet light irradiation sources.

  4. Intense, stable and excitation wavelength-independent photoluminescence emission in the blue-violet region from phosphorene quantum dots

    NASA Astrophysics Data System (ADS)

    Ge, Shuaipeng; Zhang, Lisheng; Wang, Peijie; Fang, Yan

    2016-06-01

    Nanoscale phosphorene quantum dots (PQDs) with few-layer structures were fabricated by pulsed laser ablation of a bulk black phosphorus target in diethyl ether. An intense and stable photoluminescence (PL) emission of the PQDs in the blue-violet wavelength region is clearly observed for the first time, which is attributed to electronic transitions from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) and occupied molecular orbitals below the HOMO (H-1, H-2), respectively. Surprisingly, the PL emission peak positions of the PQDs are not red-shifted with progressively longer excitation wavelengths, which is in contrast to the cases of graphene and molybdenum disulphide quantum dots. This excitation wavelength-independence is derived from the saturated passivation on the periphery and surfaces of the PQDs by large numbers of electron-donating functional groups which cause the electron density on the PQDs to be dramatically increased and the band gap to be insensitive to the quantum size effect in the PQDs. This work suggests that PQDs with intense, stable and excitation wavelength-independent PL emission in the blue-violet region have a potential application as semiconductor-based blue-violet light irradiation sources.

  5. Intense, stable and excitation wavelength-independent photoluminescence emission in the blue-violet region from phosphorene quantum dots

    PubMed Central

    Ge, Shuaipeng; Zhang, Lisheng; Wang, Peijie; Fang, Yan

    2016-01-01

    Nanoscale phosphorene quantum dots (PQDs) with few-layer structures were fabricated by pulsed laser ablation of a bulk black phosphorus target in diethyl ether. An intense and stable photoluminescence (PL) emission of the PQDs in the blue-violet wavelength region is clearly observed for the first time, which is attributed to electronic transitions from the lowest unoccupied molecular orbital (LUMO) to the highest occupied molecular orbital (HOMO) and occupied molecular orbitals below the HOMO (H-1, H-2), respectively. Surprisingly, the PL emission peak positions of the PQDs are not red-shifted with progressively longer excitation wavelengths, which is in contrast to the cases of graphene and molybdenum disulphide quantum dots. This excitation wavelength-independence is derived from the saturated passivation on the periphery and surfaces of the PQDs by large numbers of electron-donating functional groups which cause the electron density on the PQDs to be dramatically increased and the band gap to be insensitive to the quantum size effect in the PQDs. This work suggests that PQDs with intense, stable and excitation wavelength-independent PL emission in the blue-violet region have a potential application as semiconductor-based blue-violet light irradiation sources. PMID:27265198

  6. Brain transcriptome of the violet-eared waxbill Uraeginthus granatina and recent evolution in the songbird genome

    PubMed Central

    Balakrishnan, Christopher N.; Chapus, Charles; Brewer, Michael S.; Clayton, David F.

    2013-01-01

    Songbirds are important models for the study of social behaviour and communication. To complement the recent genome sequencing of the domesticated zebra finch, we sequenced the brain transcriptome of a closely related songbird species, the violet-eared waxbill (Uraeginthus granatina). Both the zebra finch and violet-eared waxbill are members of the family Estrildidae, but differ markedly in their social behaviour. Using Roche 454 RNA sequencing, we generated an assembly and annotation of 11 084 waxbill orthologues of 17 475 zebra finch genes (64%), with an average transcript length of 1555 bp. We also identified 5985 single nucleotide polymorphisms (SNPs) of potential utility for future population genomic studies. Comparing the two species, we found evidence for rapid protein evolution (ω) and low polymorphism of the avian Z sex chromosome, consistent with prior studies of more divergent avian species. An intriguing outlier was putative chromosome 4A, which showed a high density of SNPs and low evolutionary rate relative to other chromosomes. Genome-wide ω was identical in zebra finch and violet-eared waxbill lineages, suggesting a similar demographic history with efficient purifying natural selection. Further comparisons of these and other estrildid finches may provide insights into the evolutionary neurogenomics of social behaviour. PMID:24004662

  7. An LED Approach for Measuring the Photocatalytic Breakdown of Crystal Violet Dye

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; Underwood, Lauren W.; ONeal, Duane; Pagnutti, Mary; Davis, Bruce A.

    2009-01-01

    A simple technique to assess the reactivity of photocatalytic coatings sprayed onto transmissive glass surfaces was developed. This new method uses ultraviolet (UV) gallium nitride (GaN) light-emitting diodes (LEDs) to drive a photocatalytic reaction (the photocatalytic breakdown of a UV-resistant dye applied to a surface coated with the semiconductor titanium dioxide); and then a combination of a stabilized white light LED and a spectrometer to track the dye degradation as a function of time. Simple, standardized evaluation techniques that assess photocatalytic materials over a variety of environmental conditions, including illumination level, are not generally available and are greatly needed prior to in situ application of photocatalytic technologies. To date, much research pertaining to this aspect of photocatalysis has been limited and has focused primarily on laboratory experiments using mercury lamps. Mercury lamp illumination levels are difficult to control over large ranges and are temporally modulated by line power, limiting their use in helping to understand and predict how photocatalytic materials will behave in natural environmental settings and conditions. The methodology described here, using steady-state LEDs and time series spectroradiometric techniques, is a novel approach to explore the effect of UV light on the photocatalytic degradation of a UV resistant dye (crystal violet). GaN UV LED arrays, centered around 365 nm with an adjustable DC power supply, are used to create a small, spatially uniform light field where the steady state light level can be varied over three to four orders of magnitude. For this study, a set of glass microscope slides was custom coated with a thinly sprayed layer of photocatalytic titanium dioxide. Crystal violet was then applied to these titanium-dioxide coated slides and to uncoated control slides. The slides were then illuminated at various light levels from the dye side of the slide by the UV LED array. To monitor

  8. Indirect differential pulse voltammetric determination of aluminum by a pyrocatechol violet-modified electrode

    SciTech Connect

    Chen, G.; Bi, S.; Dai, L.; Cao, M.; Chen, Y. Wang, X.

    1999-03-01

    Aluminum is one of the abundant elements in the earth`s crust. It has been considered to be a causative agent for various neurological disorders such as Alzheimer Senile, presenile dementia and amyotrophic lateral sclerosis. It is also very harmful to plants and aquatic organisms. Therefore, the determination of Al is very important. A Pyrocatechol Violet (PCV) modified electrode for the voltammetric determination of aluminum is reported. The modified electrode is simply prepared by dip-coating a pyrolytic graphite electrode in a NaAc-HAc buffer solution of PCV. Optimum experimental conditions for aluminum determination include a 0.2 mol/L NaAc-HAc buffer solution of pH 4.8, a PCV concentration of 0.02 mol/L used to modify the electrode and the use of differential-pulse mode for measurement. The peak currents of differential pulse voltammograms (DPV) decrease with the addition of Al into the buffer solution while the peak potentials remain the same. The decreasing value of peak current {Delta}i{sub p} is linear with Al concentration in the range of 1{times}10{sup {minus}8} to 1{times}10{sup {minus}7} mol/L and 1{times}10{sup {minus}7} to 1{times}10{sup {minus}6} mol/L. The detection limit is 5{times}10{sup {minus}9} mol/L and the relative standard deviation for 4{times}10{sup {minus}8} mol/L Al is 2.9% (n=8). The stability of this electrode is satisfactory. No serious interference is found. This method has been applied to determine Al in drinking water samples.

  9. A Large Catalog of Homogeneous Ultra-Violet/Optical GRB Afterglows: Temporal and Spectral Evolution

    NASA Astrophysics Data System (ADS)

    Roming, Peter W. A.; Koch, T. Scott; Oates, Samantha R.; Porterfield, Blair L.; Bayless, Amanda J.; Breeveld, Alice A.; Gronwall, Caryl; Kuin, N. P. M.; Page, Mat J.; de Pasquale, Massimiliano; Siegel, Michael H.; Swenson, Craig A.; Tobler, Jennifer M.

    2017-02-01

    We present the second Swift Ultra-Violet/Optical Telescope (UVOT) gamma-ray burst (GRB) afterglow catalog, greatly expanding on the first Swift UVOT GRB afterglow catalog. The second catalog is constructed from a database containing over 120,000 independent UVOT observations of 538 GRBs first detected by Swift, the High Energy Transient Explorer 2 (HETE2), the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), the Interplanetary Network (IPN), Fermi, and Astro-rivelatore Gamma a Immagini Leggero (AGILE). The catalog covers GRBs discovered from 2005 January 17 to 2010 December 25. Using photometric information in three UV bands, three optical bands, and a “white” or open filter, the data are optimally coadded to maximize the number of detections and normalized to one band to provide a detailed light curve. The catalog provides positional, temporal, and photometric information for each burst, as well as Swift Burst Alert Telescope and X-ray Telescope (XRT) GRB parameters. Temporal slopes are provided for each UVOT filter. The temporal slope per filter of almost half the GRBs are fit with a single power law, but one to three breaks are required in the remaining bursts. Morphological comparisons with the X-ray reveal that ∼ 75 % of the UVOT light curves are similar to one of the four morphologies identified by Evans et al. (2009). The remaining ∼ 25 % have a newly identified morphology. For many bursts, redshift- and extinction-corrected UV/optical spectral slopes are also provided at 2 × 103, 2 × 104, and 2 × 105 s.

  10. Tunable light source with GaN-based violet laser diode

    NASA Astrophysics Data System (ADS)

    Omori, Masaki; Mori, Naoki; Dejima, Norihiro

    2013-03-01

    GaN based violet Laser Diode has been applying for the industrial market with unique high potential characters. It has possibility Replacing Gas lasers, Dye Lasers, SHG lasers and Solid-state Lasers and more. Diode based laser extreme small and low costs at the high volume range. In addition GaN Laser has high quality with long lifetime and has possibility to cover the wide wavelength range as between 375 to 520nm. However, in general, diode based laser could only lase with Longitudinal Multi Mode. Therefore applicable application field should be limited and it was difficult to apply for the analysis. Recently, Single Longitudinal Mode laser with GaN diode has also be accomplished with external cavity by Nichia Corporation. External cavity laser achieved at least much higher than 20dB SMSR. The feature of installing laser is that Laser on the front facet with AR coating to avoid chip mode lasing. In general, external cavity laser has been required precision of mechanical assembly and Retention Capability. Nichia has gotten rid of the issue with Intelligence Cavity and YAG Laser welding assembly technique. This laser has also been installed unique feature that the longitudinal mode could be maintained to Single Mode lasing with installing internal functional sensors in the tunable laser.*1,*2 This tunable laser source could lock a particular wavelength optionally between 390 to 465nm wavelength range. As the results, researcher will have benefit own study and it will be generated new market with the laser in the near future.

  11. Urinary Concentrations of Benzophenone-Type Ultra Violet Light Filters and Semen Quality

    PubMed Central

    Buck Louis, Germaine M.; Chen, Zhen; Kim, Sungduk; Sapra, Katherine J.; Bae, Jisuk; Kannan, Kurunthachalam

    2015-01-01

    Objective To assess benzophenone-type ultra violet (UV) filter concentrations, chemicals used in sunscreen and personal care products, and semen endpoints. Design Cohort. Setting 16 counties in Michigan and Texas Participants 413 men provided semen and urine samples, 2005–2009. Five UV filters were quantified (ng/mL) in urine using liquid chromatography-triple-quadrupole mass spectrometry: BP-1 (2,4-dihydroxybenzophenone), BP-2 (2,2′,4,4′-tetrahydroxybenzophenone), BP-3 (2-hydroxy-4-methoxybenzophenone), BP-8 (2,2′-dihydroxy-4-methoxybenzophenone), and 4-OH-BP (4-hydroxybenzophenone). Using linear regression, beta coefficients (β) and 95% confidence intervals (CIs) for each chemical dichotomized at the 75th percentile and Box-Cox transformed semen endpoint were estimated, after adjusting for age, BMI, cotinine, season, and site. Interventions None. Main Outcome Measures 35 semen endpoints. Results BP-2 was associated with diminished sperm concentration (β=−0.74; 95% CI −1.41, −0.08), straight (β=−4.57; 95% CI −8.95, −0.18) and linear movement (β=−3.15; 95% CI −6.01, −0.30), more immature (β=0.38; 95% CI 0.15, 0.62) sperm, and a decreased percentage of other tail abnormalities (β=−0.16; 95% CI −0.31, −0.01). BP-8 was associated with decreased hypo-osmotic swelling (β=−2.57; 95% CI −4.86, −0.29) and higher acrosome area (β=1.14; 95% CI 0.01, 2.26). No associations were observed for BP-1, BP-3 or 4OH-BP. Conclusion The findings suggest that specific UV filters may be associated with some aspects of semen endpoints, but await future corroboration. PMID:26253817

  12. Measuring SO2 ship emissions with an ultra-violet imaging camera

    NASA Astrophysics Data System (ADS)

    Prata, A. J.

    2013-11-01

    Over the last few years fast-sampling ultra-violet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical fluxes ~1-10 kg s-1) and natural sources (e.g. volcanoes; typical fluxes ~10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and fluxes. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and fluxes of SO2 (typical fluxes ~0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the fluxes and path concentrations can be retrieved in real-time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and fluxes determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (>10 Hz) from a single camera. Typical accuracies ranged from 10-30% in path concentration and 10-40% in flux estimation. Despite the ease of use and ability to determine SO2 fluxes from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes.

  13. Studies on 405nm blue-violet diode laser with external grating cavity

    NASA Astrophysics Data System (ADS)

    Li, Bin; Gao, Jun; Zhao, Jun; Yu, Anlan; Luo, Shiwen; Xiong, Dongsheng; Wang, Xinbing; Zuo, Duluo

    2016-03-01

    Spectroscopy applications of free-running laser diodes (LD) are greatly restricted as its broad band spectral emission. And the power of a single blue-violet LD is around several hundred milliwatts by far, it is of great importance to obtain stable and narrow line-width laser diodes with high efficiency. In this paper, a high efficiency external cavity diode laser (ECDL) with high output power and narrow band emission at 405 nm is presented. The ECDL is based on a commercially available LD with nominal output power of 110 mW at an injection current of 100 mA. The spectral width of the free-running LD is about 1 nm (FWHM). A reflective holographic grating which is installed on a home-made compact adjustable stage is utilized for optical feedback in Littrow configuration. In this configuration, narrow line-width operation is realized and the effects of grating groove density as well as the groove direction related to the beam polarization on the performances of the ECDL are experimentally investigated. In the case of grating with groove density of 3600 g/mm, the threshold is reduced from 21 mA to 18.3 mA or 15.6 mA and the tuning range is 3.95 nm or 6.01 nm respectively when the grating is orientated in TE or TM polarization. In addition, an output beam with a line-width of 30 pm and output power of 92.7 mW is achieved in TE polarization. With these narrow line-width and high efficiency, the ECDL is capable to serve as a light source for spectroscopy application such as Raman scattering and laser induced fluorescence.

  14. Is ultra-violet radiation the main force shaping molecular evolution of varicella-zoster virus?

    PubMed Central

    2011-01-01

    Background Varicella (chickenpox) exhibits a characteristic epidemiological pattern which is associated with climate. In general, primary infections in tropical regions are comparatively less frequent among children than in temperate regions. This peculiarity regarding varicella-zoster virus (VZV) infection among certain age groups in tropical regions results in increased susceptibility during adulthood in these regions. Moreover, this disease shows a cyclic behavior in which the number of cases increases significantly during winter and spring. This observation further supports the participation of environmental factors in global epidemiology of chickenpox. However, the underlying mechanisms responsible for this distinctive disease behavior are not understood completely. In a recent publication, Philip S. Rice has put forward an interesting hypothesis suggesting that ultra-violet (UV) radiation is the major environmental factor driving the molecular evolution of VZV. Discussion While we welcomed the attempt to explain the mechanisms controlling VZV transmission and distribution, we argue that Rice's hypothesis takes lightly the circulation of the so called "temperate VZV genotypes" in tropical regions and, to certain degree, overlooks the predominance of such lineages in certain non-temperate areas. Here, we further discuss and present new information about the overwhelming dominance of temperate VZV genotypes in Mexico regardless of geographical location and climate. Summary UV radiation does not satisfactorily explain the distribution of VZV genotypes in different tropical and temperate regions of Mexico. Additionally, the cyclic behavior of varicella does not shown significant differences between regions with different climates in the country. More studies should be conducted to identify the factors directly involved in viral spreading. A better understanding of the modes of transmissions exploited by VZV and their effect on viral fitness is likely to facilitate

  15. Two Types of Aurora on Mars as Observed by MAVEN's Imaging UltraViolet Spectrograph

    NASA Astrophysics Data System (ADS)

    Schneider, N. M.; Deighan, J.; Jain, S.; Stiepen, A.; Stewart, I. F.; Larson, D. E.; Mitchell, D. L.; Mazelle, C. X.; Lee, C.; Lillis, R. J.; Evans, J. S.; Brain, D. A.; Stevens, M. H.; McClintock, W. E.; Chaffin, M.; Crismani, M. M. J.; Holsclaw, G. M.; Lefèvre, F.; Lo, D.; Clarke, J. T.; Montmessin, F.; Jakosky, B. M.

    2015-12-01

    The Imaging UltraViolet Spectrograph (IUVS) on the MAVEN spacecraft has detected two distinct types of auroral emission on Mars. First, we report the discovery of a low altitude, diffuse aurora spanning much of Mars' northern hemisphere coincident with a solar energetic particle outburst. IUVS observed northerly latitudes during late December 2014, detecting auroral emission in virtually all nightside observations for ~5 days spanning virtually all geographic longitudes. The vertical profile showed emission down to ~70 km altitude (1 microbar), deeper than confirmed at any other planet. The onset and duration of emission coincide with the observed arrival of solar energetic particles up to 200 keV precipitating directly and deeply into the atmosphere. Preliminary modeling of the precipitation, energy deposition and spectral line emission yields good matches to the observations. These observations represent a new class of planetary auroras produced in the Martian middle atmosphere. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit aurora more globally than Earth. Second, we confirm the existence of small patches of discrete aurora near crustal magnetic fields in Mars' southern hemisphere, as observed previously by SPICAM on Mars Express (Bertaux et al., Nature, 435, 790-794 (2005)). IUVS observed southern latitudes in July and August 2015, detecting discrete auroral emission in ~1% of suitable observations. Limb scans resolved both vertically and along-slit indicate this type of auroral emission was patchy on the scale of ~40 km, and located at higher altitudes ~140 km. The higher altitudes imply a lower energy of precipitating particles. The mix of spectral emissions also differed signficiantly from the discrete aurora, indicating different excitation and quenching processes. We will discuss the observed properties of the aurora and associated charged particle precipitation, as well as the broader implications of this high

  16. Synthesis, spectral and third-order nonlinear optical properties of terpyridine Zn(II) complexes based on carbazole derivative with polyether group

    NASA Astrophysics Data System (ADS)

    Kong, Ming; Liu, Yanqiu; Wang, Hui; Luo, Junshan; Li, Dandan; Zhang, Shengyi; Li, Shengli; Wu, Jieying; Tian, Yupeng

    2015-01-01

    Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on carbazole derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.

  17. Rotationally resolved S1<-- S0 electronic spectra of fluorene, carbazole, and dibenzofuran: evidence for Herzberg-Teller coupling with the S2 state.

    PubMed

    Yi, John T; Alvarez-Valtierra, Leonardo; Pratt, David W

    2006-06-28

    Rotationally resolved fluorescence excitation spectra of the S1 <-- S0 origin bands and higher vibronic bands of fluorene (FLU), carbazole (CAR), and dibenzofuran (DBF) have been observed and assigned. Analyses of these data show that replacement of the CH2 group in FLU with a NH group in CAR and an O atom in DBF produces only localized changes in structure, in the ground state. But the three molecules exhibit different changes in geometry when they are excited by light. The S1 states of the three molecules also are electronically very different. The S1 <-- S0 transition moments of CAR and DBF are parallel to the C2 symmetry axis whereas the corresponding transition moment in FLU is perpendicular to this axis. Herzberg-Teller coupling involving the S2 state also has been observed in the spectra of higher vibronic bands of CAR and DBF. Possible reasons for these behaviors are discussed.

  18. Rotationally resolved S1<--S0 electronic spectra of fluorene, carbazole, and dibenzofuran: Evidence for Herzberg-Teller coupling with the S2 state

    NASA Astrophysics Data System (ADS)

    Yi, John T.; Alvarez-Valtierra, Leonardo; Pratt, David W.

    2006-06-01

    Rotationally resolved fluorescence excitation spectra of the S1←S0 origin bands and higher vibronic bands of fluorene (FLU), carbazole (CAR), and dibenzofuran (DBF) have been observed and assigned. Analyses of these data show that replacement of the CH2 group in FLU with a NH group in CAR and an O atom in DBF produces only localized changes in structure, in the ground state. But the three molecules exhibit different changes in geometry when they are excited by light. The S1 states of the three molecules also are electronically very different. The S1←S0 transition moments of CAR and DBF are parallel to the C2 symmetry axis whereas the corresponding transition moment in FLU is perpendicular to this axis. Herzberg-Teller coupling involving the S2 state also has been observed in the spectra of higher vibronic bands of CAR and DBF. Possible reasons for these behaviors are discussed.

  19. Chain folding controlled by an isomeric repeat unit: helix formation versus random aggregation in acetylene-bridged carbazole-bipyridine co-oligomers.

    PubMed

    Divya, Kizhmuri P; Sreejith, Sivaramapanicker; Suresh, Cherumuttathu H; Philips, Divya S; Ajayaghosh, Ayyappanpillai

    2013-07-01

    An unprecedented, positional effect of the isomeric repeat unit on chain folding in donor–acceptor-linked oligomers, which contain alternating bipyridine and carbazole moieties that are connected through an acetylinic linkage, is reported. 4,4′-Linked oligomer 1 adopts an intrachain helical conformation (CD-active) in CHCl3/MeCN (20:80 v/v), whereas oligomer 2, which contains an isomeric 6,6′-linkage, forms interchain randomly coiled aggregates (CD-inactive). The substitution position plays a significant role in controlling the variations in electronic effects and dipole moments around the bipyridyl moiety, which are responsible for this observed phenomenon. Two model compounds of oligomers 1 and 2 (3 and 4, respectively) were prepared and their properties were compared. A systematic investigation of the photophysical and CD properties of these structures, as well as theoretical studies, support our conclusions.

  20. Electropolymerization molecularly imprinted polymer (E-MIP) SPR sensing of drug molecules: pre-polymerization complexed terthiophene and carbazole electroactive monomers.

    PubMed

    Pernites, Roderick; Ponnapati, Ramakrishna; Felipe, Mary Jane; Advincula, Rigoberto

    2011-01-15

    A novel chemosensitive ultrathin film with high selectivity was developed for the detection of naproxen, paracetamol, and theophylline using non-covalent electropolymerized molecular imprinted polymers (E-MIP). A series of monofunctional and bifunctional H-bonding terthiophene and carbazole monomers were compared for imprinting these drugs without the use of a separate cross-linker. A key step is the fast and efficient potentiostatic method of washing the template, which facilitated enhanced real-time sensing by surface plasmon resonance (SPR) spectroscopy. Various surface characterizations (contact angle, ellipsometry, XPS, AFM) of the E-MIP film verified the templating and release of the drug from the cross-linked conducting polymer film.

  1. An unusual case of OD-allotwinning: 9,9′-(2,5-dibromo-1,4-phenylene)bis[9H-carbazole

    PubMed Central

    Kautny, Paul; Schwartz, Thomas; Fröhlich, Johannes

    2017-01-01

    9,9′-(2,5-Dibromo-1,4-phenylene)bis[9H-carbazole] (1) crystallizes as a category I order–disorder (OD) structure composed of non-polar layers of one kind with B2/m(1)1 layer symmetry. The crystals are made up of the two polytypes with a maximum degree of order (MDO). The monoclinic MDO1 polytype (B21/d) possesses an orthorhombic B-centered lattice and appears in two orientations, which are related by reflection at (100). The orthorhombic MDO2 polytype (F2dd) has a doubled b-axis and appears in two orientations, which are related by inversion. The crystal structures of both polytypes were determined in a concurrent refinement. The MDO1:MDO2 ratio is 69:31.

  2. White light-emitting nanocomposites based on an oxadiazole-carbazole copolymer (POC) and InP/ZnS quantum dots

    NASA Astrophysics Data System (ADS)

    Bruno, Annalisa; Borriello, Carmela; Di Luccio, Tiziana; Nenna, Giuseppe; Sessa, Lucia; Concilio, Simona; Haque, Saif A.; Minarini, Carla

    2013-11-01

    In this work, we studied energetic and optical proprieties of a polyester-containing oxadiazole and carbazole units that we will indicate as POC. This polymer is characterized by high photoluminescence activity in the blue region of the visible spectrum, making it suitable for the development of efficient white-emitting organic light emission devices. Moreover, POC polymer has been combined with two red emitters InP/ZnS quantum dots (QDs) to obtain nanocomposites with wide emission spectra. The two types of QDs have different absorption wavelengths: 570 nm [InP/ZnS(570)] and 627 nm [InP/ZnS(627)] and were inserted in the polymer at different concentrations. The optical properties of the nanocomposites have been investigated and compared to the ones of the pure polymer. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to QDs, resulting in white-emitting nanocomposites.

  3. Immobilization of urease on poly(N-vinyl carbazole)/stearic acid Langmuir-Blodgett films for application to urea biosensor.

    PubMed

    Singhal, Rahul; Gambhir, Anamika; Pandey, M K; Annapoorni, S; Malhotra, B D

    2002-08-01

    Urease was immobilized in mixed monolayers of poly(N-vinyl carbazole) (PNVK) and stearic acid (SA) formed at an air-water interface. The monolayers were transferred onto indium-tin-oxide (ITO) coated glass plates using Langmuir-Blodgett (LB) film deposition technique. Urease immobilized on PNVK/SA LB films, characterized using FTIR and UV-visible spectroscopy, was found to exhibit increased stability over a wide pH (6.5-8.5) and temperature (25-50 degrees C) range. Potentiometric measurements on these urease electrodes were carried out using an ammonium ion analyzer. Two values for K(m)(app) were obtained at lower and higher concentrations of substrate urea.

  4. Incorporation of Hexa-peri-hexabenzocoronene (HBC) into Carbazole-Benzo-2,1,3-thiadiazole Copolymers to Improve Hole Mobility and Photovoltaic Performance.

    PubMed

    Gao, Chen; Jiang, Pei; Shi, Keli; Ma, Di; Li, Yongfang; Yu, Gui; Li, Xiaoyu; Wang, Haiqiao

    2016-03-04

    Hexa-peri-hexabenzocoronene (HBC) is a discotic-shaped conjugated molecule with strong π-π stacking property, high intrinsic charge mobility, and good self-assembly properties. For a long time, however, organic photovoltaic (OPV) solar cells based on HBC demonstrated low power conversion efficiencies (PCEs). In this study, two conjugated terpolymers, poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5'-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)-5 HBC and PCDTBT-10 HBC, were synthesized by incorporating different amounts of HBC as the third component into poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5'-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) through Suzuki coupling polymerization. For comparison, the donor-acceptor (D-A) conjugated dipolymer PCDTBT was also synthesized to investigate the effect of HBC units on conjugated polymers. The HBC-containing polymers exhibited higher thermal stabilities, broader absorption spectra, and lower highest-occupied molecular orbital (HOMO) energy levels. In particular, the field-effect mobilities were enhanced by more than one order of magnitude after the incorporation of HBC into the conjugated polymer backbone on account of increased interchain π-π stacking interactions. The bulk heterojunction (BHJ) polymer solar cells (PSCs) fabricated with the polymers as donor and PC71 BM as acceptor demonstrated gradual improvement of open-circuit voltage (VOC ) and short-circuit current (JSC ) with the increase in HBC content. As a result, the PCEs were improved from 3.21 % for PCDTBT to 3.78 % for PCDTBT-5 HBC and then to 4.20 % for PCDTBT-10 HBC.

  5. Substituent effects in nitro derivatives of carbazoles investigated by comparison of low-temperature crystallographic studies with density functional theory (DFT) calculations.

    PubMed

    Gajda, Katarzyna; Zarychta, Bartosz; Kopka, Katarzyna; Daszkiewicz, Zdzisław; Ejsmont, Krzysztof

    2014-10-01

    The crystal structure of 9H-carbazole, C12H9N, (I), has been redetermined at low temperature for use as a reference structure in a comparative study with the structures of 1-nitro-9H-carbazole, C12H8N2O2, (II), and 9-nitrocarbazole, C12H8N2O2, (III). The molecule of (I) has crystallographically imposed mirror symmetry (Z' = 0.5). All three solid-state structures are slightly nonplanar, the dihedral angles between the planes of the arene and pyrrole rings ranging from 0.40 (7)° in (III) to 1.82 (18)° in (II). Nevertheless, a density functional theory (DFT) study predicts completely planar conformations for the isolated molecules. To estimate the influence of nitro-group substitution on aromaticity, the HOMA (harmonic oscillator model of aromaticity) descriptor of π-electron delocalization has been calculated in each case. The HOMA indices for the isolated and solid-state molecules are relatively consistent and decrease in value for aromatic rings that are substituted with a π-electron-withdrawing nitro group. Substitution of the arene ring influences the π-electron delocalization in the ring only weakly, showing strong resistance to a perturbation of its geometry, contrary to what is observed for nitro substitution of the five-membered heterocyclic pyrrole ring. In (II), the molecules are arranged in near-planar dimers connected to each other by strong N-H···O hydrogen bonds that stack parallel to the crystallographic b axis. A similar stacking arrangement is observed in (III), although here the stacked structure is formed by stand-alone molecules.

  6. Treatment of Helicobacter pylori Infection with Intra-Gastric Violet Light Phototherapy – a Pilot Clinical Trial

    PubMed Central

    Lembo, Anthony J; Ganz, Robert A; Sheth, Sunil; Cave, David; Kelly, Ciaran; Levin, Philip; Kazlas, Peter T; Baldwin, Paul C; Lindmark, William R; McGrath, Jonathan R; Hamblin, Michael R

    2009-01-01

    Background and Objective Helicobacter pylori infects the mucus layer of the human stomach and causes peptic ulcers and adenocarcinoma. We have previously shown that H. pylori accumulates photoactive porphyrins making the organism susceptible to inactivation by light, and that small spot endoscopic illumination with violet light reduced bacterial load in human stomachs. This study assessed the feasibility and safety of whole-stomach intra-gastric violet phototherapy for the treatment of H. pylori infection. Study Design/Materials and Methods A controlled, prospective pilot trial was conducted using a novel light source consisting of laser diodes and diffusing fibers to deliver 408-nm illumination at escalating total fluences to the whole stomach. Eighteen adults (10 female) with H. pylori infection were treated at 3 U.S. academic endoscopy centers. Quantitative bacterial counts were obtained from biopsies taken from the antrum, body and fundus, and serial urea breath tests. Results The largest reduction in bacterial load was in the antrum (>97%), followed by body (>95%) and fundus (>86%). There was a correlation between log reduction and initial bacterial load in the antrum. There was no dose-response seen with increasing illumination times. The urea breath test results indicated that the bacteria repopulated in days following illumination. Conclusion Intragastric violet light phototherapy is feasible and safe and may represent a novel approach to eradication of H. pylori, particularly in patients who have failed standard antibiotic treatment. This was a pilot study involving a small number of patients. Further research is needed to determine if phototherapy can be effective for eradicating H. pylori. PMID:19533762

  7. Study of Surface Enhanced Raman Scattering of Alizarin and Crystal Violet Dyes

    NASA Astrophysics Data System (ADS)

    Gopal, Ram; Swarnkar, Raj Kumar

    2010-06-01

    Surface enhanced Raman scattering (SERS) plays a vital role in analytical chemistry to characterize ultra trace quantity of organic compounds and biological samples. Two mechanisms have been considered to explain the SERS effect. The main contribution arises from a huge enhancement of the local electromagnetic field close to surface roughness of the metal structures, due to the excitation of a localized surface plasmon, while a further enhancement can be observed for molecules adsorbed onto specific sites when resonant charge transfer occurs. SERS signals have been observed from adsorbates on many metallic surfaces like Ag, Au, Ni, Cu etc. Additionally, metal oxide nanoparticles also show SERS signals It has now been established that SERS of analyte material is highly dependent on the type of substrate involved. Many types of nanostructures like nanofilms, nanorods, nanospheres etc. show highly efficient SERS signals. In particular, there are two routes available for the synthesis of these nanomaterials: the chemical route and the physical route. Chemical route involves many types of reducing agents and capping agents which can interfere in origin and measurement of these signals. The physical route avoids these anomalies and therefore it is suitable for the study of SERS phenomenon. Pulsed laser ablation in liquid medium is an excellent top down technique to produce colloidal solution of nanoparticles with desired shape and size having surface free from chemical contamination, which is essential requirement for surface application of nanoparticles. The present work deals with the study of SERS of Crystal violet dye and Alizarin group dye on Cu@ Cu_2O and Ag colloidal nanoparticles synthesized by pulsed laser ablation. M. Fleishchmann, P. J. Hendra, and A. J. McQuillian Chem. Phys. Lett., 26, 163, 1974. U. Wenning, B. Pettinger, and H. Wetzel Chem. Phys. Lett., 70, 49, 1980. S. C. Singh, R. K. Swarnkar, P. Ankit, M. C. Chattopadhyaya, and R. Gopal AIP Conf. Proc

  8. The solar extreme ultra-violet corona: Resolved loops and the unresolved active region corona

    NASA Astrophysics Data System (ADS)

    Cirtain, Jonathan Wesley

    In this work, physical characteristics of the solar corona as observed in the Extreme Ultra-Violet (EUV) regime are investigated. The focus will be the regions of intense EUV radiation generally found near the locations of sunspots. These regions are commonly called active regions. Multiple space- based observing platforms have been deployed in the last decade; it is possible to use several of these observatories in combination to develop a more complete picture of the solar corona. Joint Observing Program 146 was created to collect spectroscopic intensities using the Coronal Diagnostic Spectrometer on Solar and Heliospheric Observatory and EUV images using NASA's Transition Region and Coronal Explorer. The emission line intensities are analyzed to develop an understanding of the temperature and density of the active region coronal plasma. However, the performance of the CDS instrument in the spatial and temporal domains is limited and to compensate for these limitations, data collected by the TRACE instrument provide a high spatial and temporal resolution set of observations. One of the most exciting unsolved problems in solar astrophysics is to understand why the corona maintains a temperature roughly two orders of magnitude higher than the underlying material. A detailed investigation of the coronal emission has provided constraints on models of the heating mechanism, since the temperature, density and evolution of emission rates for multiple ionic species are indicative of the mechanism(s) working to heat the corona. The corona appears to consist of multiple unresolved structures as well as resolved active region structures, called coronal loops. The purpose of the present work is to determine the characteristics of the unresolved background corona. Using the characterizations of the coronal unresolved background, results for loops after background subtraction are also presented. This work demonstrates the magnitude of the unresolved coronal emission with

  9. Synthesis of CdSe quantum dots with luminescence in the violet region of the solar spectrum.

    PubMed

    Shukla, Nisha; Nigra, Michael M

    2010-01-01

    We have designed a simple, one-step synthesis of CdSe quantum dots with photoluminescence frequencies ranging from the red through to the violet region of the solar spectrum. The photoluminescence peaks have FWHM of 30 nm indicating absorption over a narrow range of wavelengths. The effect of solvent type and solvent boiling point on the physical and photoluminescence properties of the quantum dots has been studied. High boiling point, non-polar solvents shift the photoluminescence peak to longer wavelengths and low boiling point, polar solvents shift the photoluminescence peak to shorter wavelengths.

  10. Crystal Violet Lactone Salicylaldehyde Hydrazone Zn(II) Complex: a Reversible Photochromic Material both in Solution and in Solid Matrix

    NASA Astrophysics Data System (ADS)

    Li, Kai; Li, Yuanyuan; Tao, Jing; Liu, Lu; Wang, Lili; Hou, Hongwei; Tong, Aijun

    2015-09-01

    Crystal violet lactone (CVL) is a classic halochromic dye which has been widely used as chromogenic reagent in thermochromic and piezochromic systems. In this work, a very first example of CVL-based reversible photochromic compound was developed, which showed distinct color change upon UV-visible light irradiation both in solution and in solid matrix. Moreover, metal complex of CVL salicylaldehyde hydrozone was facilely synthesized, exhibiting reversible photochromic properties with good fatigue resistance. It was served as promising solid material for photo-patterning.

  11. Crystal Violet Lactone Salicylaldehyde Hydrazone Zn(II) Complex: a Reversible Photochromic Material both in Solution and in Solid Matrix.

    PubMed

    Li, Kai; Li, Yuanyuan; Tao, Jing; Liu, Lu; Wang, Lili; Hou, Hongwei; Tong, Aijun

    2015-09-28

    Crystal violet lactone (CVL) is a classic halochromic dye which has been widely used as chromogenic reagent in thermochromic and piezochromic systems. In this work, a very first example of CVL-based reversible photochromic compound was developed, which showed distinct color change upon UV-visible light irradiation both in solution and in solid matrix. Moreover, metal complex of CVL salicylaldehyde hydrozone was facilely synthesized, exhibiting reversible photochromic properties with good fatigue resistance. It was served as promising solid material for photo-patterning.

  12. Tuning emission in violet, blue, green and red in cubic GaN/InGaN/GaN quantum wells

    NASA Astrophysics Data System (ADS)

    Orozco Hinostroza, I. E.; Avalos-Borja, M.; Compeán García, V. D.; Zamora, C. Cuellar; Rodríguez, A. G.; López Luna, E.; Vidal, M. A.

    2016-02-01

    Light emission in the three primary colors was achieved in cubic GaN/InGaN/GaN heterostructures grown by molecular beam epitaxy on MgO substrates in a single growth process. A heterostructure with four quantum wells with a width of 10 nm was grown; this quantum wells width decrease the segregation effect of In. Photoluminescence emission produced four different emission signals: violet, blue, green-yellow and red. Thus, we were able to tune energy transitions in the visible spectrum modifying the In concentration in cubic InxGa1-xN ternary alloy.

  13. Crystal Violet Lactone Salicylaldehyde Hydrazone Zn(II) Complex: a Reversible Photochromic Material both in Solution and in Solid Matrix

    PubMed Central

    Li, Kai; Li, Yuanyuan; Tao, Jing; Liu, Lu; Wang, Lili; Hou, Hongwei; Tong, Aijun

    2015-01-01

    Crystal violet lactone (CVL) is a classic halochromic dye which has been widely used as chromogenic reagent in thermochromic and piezochromic systems. In this work, a very first example of CVL-based reversible photochromic compound was developed, which showed distinct color change upon UV-visible light irradiation both in solution and in solid matrix. Moreover, metal complex of CVL salicylaldehyde hydrozone was facilely synthesized, exhibiting reversible photochromic properties with good fatigue resistance. It was served as promising solid material for photo-patterning. PMID:26412101

  14. Extraction-spectrophotometric determination of boron with 4,6-Di-tert-butyl-3-methoxycatechol and ethyl violet.

    PubMed

    Oshima, M; Shibata, K; Gyouten, T; Motomizu, S; Tôei, K

    1988-05-01

    4,6-Di-tert-butyl-3-methoxycatechol (DBMC) has been developed as a new reagent for boron, the complex anion formed being extracted as an ion-associate with Ethyl Violet into toluene, and the absorbance measured at 610 nm. The calibration graph is linear up to 0.43 mug of boron, the molar absorptivity is 1.02 x 10(5) 1.mole(-1).cm(-1) and the relative standard deviation 1.2%. The method has been applied to the determination of boron in sea-water and river water with satisfactory results.

  15. Solar-energy production and energy-efficient lighting: photovoltaic devices and white-light-emitting diodes using poly(2,7-fluorene), poly(2,7-carbazole), and poly(2,7-dibenzosilole) derivatives.

    PubMed

    Beaupré, Serge; Boudreault, Pierre-Luc T; Leclerc, Mario

    2010-02-23

    World energy needs grow each year. To address global warming and climate changes the search for renewable energy sources with limited greenhouse gas emissions and the development of energy-efficient lighting devices are underway. This Review reports recent progress made in the synthesis and characterization of conjugated polymers based on bridged phenylenes, namely, poly(2,7-fluorene)s, poly(2,7-carbazole)s, and poly(2,7-dibenzosilole)s, for applications in solar cells and white-light-emitting diodes. The main strategies and remaining challenges in the development of reliable and low-cost renewable sources of energy and energy-saving lighting devices are discussed.

  16. Rh(III)-Catalyzed Cascade Annulation/C-H Activation of o-Ethynylanilines with Diazo Compounds: One-Pot Synthesis of Benzo[a]carbazoles via 1,4-Rhodium Migration.

    PubMed

    Guo, Songjin; Yuan, Kai; Gu, Meng; Lin, Aijun; Yao, Hequan

    2016-10-05

    A Rh(III)-catalyzed cascade annulation/C-H activation of o-ethynylanilines with diazo compounds has been developed. This concise method allows for the rapid formation of a number of benzo[a]carbazoles in high yields, exhibiting good functional group tolerance and scalability. The key to the success of this approach involves one C-N bond and two C-C bond formation, and an aryl-to-aryl 1,4-rhodium migration.

  17. Crystallization and preliminary X-ray diffraction analyses of the redox-controlled complex of terminal oxygenase and ferredoxin components in the Rieske nonhaem iron oxygenase carbazole 1,9a-dioxygenase

    SciTech Connect

    Matsuzawa, Jun; Aikawa, Hiroki; Umeda, Takashi; Ashikawa, Yuji; Suzuki-Minakuchi, Chiho; Kawano, Yoshiaki; Fujimoto, Zui; Okada, Kazunori; Yamane, Hisakazu; Nojiri, Hideaki

    2014-09-25

    A crystal was obtained of the complex between reduced terminal oxygenase and oxidized ferredoxin components of carbazole 1,9a-dioxygenase. The crystal belonged to space group P2{sub 1} and diffracted to 2.25 Å resolution. The initial reaction in bacterial carbazole degradation is catalyzed by carbazole 1,9a-dioxygenase, which consists of terminal oxygenase (Oxy), ferredoxin (Fd) and ferredoxin reductase components. The electron-transfer complex between reduced Oxy and oxidized Fd was crystallized at 293 K using the hanging-drop vapour-diffusion method with PEG 3350 as the precipitant under anaerobic conditions. The crystal diffracted to a maximum resolution of 2.25 Å and belonged to space group P2{sub 1}, with unit-cell parameters a = 97.3, b = 81.6, c = 116.2 Å, α = γ = 90, β = 100.1°. The V{sub M} value is 2.85 Å{sup 3} Da{sup −1}, indicating a solvent content of 56.8%.

  18. Henry's law constant, octanol-air partition coefficient and supercooled liquid vapor pressure of carbazole as a function of temperature: application to gas/particle partitioning in the atmosphere.

    PubMed

    Odabasi, Mustafa; Cetin, Banu; Sofuoglu, Aysun

    2006-02-01

    The Henry's law constant for carbazole was experimentally determined between 5 and 35 degrees C using a gas-stripping technique. The following equation was obtained for dimensionless Henry's law constant (H') versus temperature (T, K): ln H' = -3982(T,K)(-1) + 1.01. Temperature-dependent octanol-air partition coefficients (KOA) and supercooled liquid vapor pressures (PL,Pa) of carbazole were also determined using the GC retention time method. The temperature dependence of KOA and PL were explained by the following: log KOA = 4076/(T,K) - 5.65, log PL(Pa) = -3948(T,K)(- 1) + 11.48. The gas and particle-phase carbazole concentrations measured previously in Chicago, IL in 1995 was used for gas/particle partitioning modeling. Octanol based absorptive partitioning model consistently underpredicted the gas/particle partition coefficients (Kp) for all sampling periods. However, overall there was a good agreement between the measured Kp and soot-based model predictions.

  19. Crystal structure of 5,6-bis(9H-carbazol-9-yl)benzo[c][1,2,5]thiadiazole: distortion from a hypothetical higher-symmetry structure.

    PubMed

    Averkiev, Boris B; Davydenko, Iryna; Wang, Xu; Barlow, Stephen; Marder, Seth R

    2017-04-01

    Nucleophilic substitution of F atoms in 5,6-difluorobenzo[c][1,2,5]thiadiazole (DFBT) for carbazole could be potentially interesting as a novel way of synthesizing building blocks for new conjugated materials for applications in organic chemistry. The crystal structures of 5,6-bis(9H-carbazol-9-yl)benzo[c][1,2,5]thiadiazole (DCBT), C30H18N4S, and its hydrate, C30H18N4S·0.125H2O, were investigated using single-crystal X-ray analysis. The hydrate contains two symmetry-independent DCBT molecules. The dihedral angles between the plane of the central benzothiadiazole fragment and that of the carbazole units vary between 50.8 and 69.9°, indicating conformational flexibility of the DCBT molecule in the crystals, which is consistent with quantum chemical calculations. The analysis of the crystal packing of DCBT revealed that the experimental triclinic structure could be described as a distortion from a hypothetical higher-symmetry monoclinic structure. The quantum chemical calculations of two possible monoclinic structures, which are related to the experimental structure by a shifting of molecular layers, showed that the proposed structures are higher in energy by 5.4 and 10.1 kcal mol(-1). This energy increase is caused by less dense crystal packings of the symmetric structures, which results in a decrease of the number of intermolecular interactions.

  20. Relaxation dynamics of 2,7- and 3,6-distyrylcarbazoles in solutions and in solid films: mechanism for efficient nonradiative deactivation in the 3,6-linked carbazole.

    PubMed

    Wang, Tsai-Te; Chung, Szu-Min; Wu, Fang-Iy; Shu, Ching-Fong; Diau, Eric Wei-Guang

    2005-12-22

    We performed time-resolved spectral investigations of two distyrylcarbazole derivatives, 2,7- and 3,6-distyrylcarbazole (2,7-DPVTCz and 3,6-DPVTCz, respectively), in dilute toluene solution and in solid films mixed with poly(methyl methacrylate) (PMMA). The lifetime of 2,7-DPVTCz in its excited state in solution is approximately 100 times as great as that of 3,6-DPVTCz, consistent with their photophysical nature. The former shows intense emission, but the latter is nearly nonfluorescent in a free environment. Moreover, the lifetime of 3,6-DPVTCz in its excited state increased also approximately 100 times when the molecule was encapsulated in a 3,6-DPVTCz/PMMA solid film, indicating that intramolecular motion of the molecule significantly affects the observed relaxation dynamics in a confined environment. Calculations on the excited states indicate that an efficient intersystem crossing is activated upon twisting of the bridged C-C single bond in a free 3,6-linked carbazole; such efficient deactivation is impractical in 2,7-linked carbazole or for 3,6-linked carbazole in a PMMA matrix. Information obtained from experiments on femtosecond fluorescence enables us to distinguish crucial relaxation processes in the excited state for a profound understanding of the details of vibrational and electronic relaxations of 3,6-DPVTCz in solution.

  1. Exposure to Crystal Violet, Its Toxic, Genotoxic and Carcinogenic Effects on Environment and Its Degradation and Detoxification for Environmental Safety.

    PubMed

    Mani, Sujata; Bharagava, Ram Naresh

    2016-01-01

    Crystal Violet (CV), a triphenylmethane dye, has been extensively used in human and veterinary medicine as a biological stain, as a textile dye in textile processing industries and also used to provide a deep violet color to paints and printing ink. CV is also used as a mutagenic and bacteriostatic agent in medical solutions and antimicrobial agent to prevent the fungal growth in poultry feed. Inspite of its many uses, CV has been reported as a recalcitrant dye molecule that persists in environment for a long period and pose toxic effects in environment. It acts as a mitotic poison, potent carcinogen and a potent clastogene promoting tumor growth in some species of fish. Thus, CV is regarded as a biohazard substance. Although, there are several physico-chemical methods such as adsorption, coagulation and ion-pair extraction reported for the removal of CV, but these methods are insufficient for the complete removal of CV from industrial wastewaters and also produce large quantity of sludge containing secondary pollutants. However, biological methods are regarded as cost-effective and eco-friendly for the treatment of industrial wastewaters, but these methods also have certain limitations. Therefore, there is an urgent need to develop such eco-friendly and cost-effective biological treatment methods, which can effectively remove the dye from industrial wastewaters for the safety of environment, as well as human and animal health.

  2. Solving the 170-Year-Old Mystery About Red-Violet and Blue Transient Intermediates in the Gmelin Reaction.

    PubMed

    Gao, Yin; Toubaei, Abouzar; Kong, Xianqi; Wu, Gang

    2015-11-23

    The Gmelin reaction between nitroprusside and sulfides in aqueous solution is known to produce two transient intermediates with distinct colors: an initial red-violet intermediate that subsequently converts into a blue intermediate. In this work, we use a combination of multinuclear ((17) O, (15) N, (13) C) NMR, UV/Vis, IR spectroscopic techniques and quantum chemical computation to show unequivocally that the red-violet intermediate is [Fe(CN)5 N(O)S](4-) and the blue intermediate is [Fe(CN)5 N(O)SS)](4-) . While the formation of [Fe(CN)5 N(O)S](4-) has long been postulated in the literature, this study provides the most direct proof of its structure. In contrast, [Fe(CN)5 N(O)SS)](4-) represents the first example of any metal coordination complex containing a perthionitro ligand. The new reaction pathways found in this study not only provide clues for the mode of action of nitroprusside for its pharmacological activity, but also have broader implications to the biological role of H2 S, potential reactions between H2 S and nitric oxide donor compounds, and the possible biological function of polysulfides.

  3. Evaluation of crystal violet decolorization assay for minimal inhibitory concentration detection of primary antituberculosis drugs against Mycobacterium tuberculosis isolates*

    PubMed Central

    Coban, Ahmet Yilmaz; Akbal, Ahmet Ugur; Uzun, Meltem; Cayci, Yeliz Tanriverdi; Birinci, Asuman; Durupinar, Belma

    2016-01-01

    In this study we evaluated the crystal violet decolorization assay (CVDA) for detection of minimum inhibitory concentration (MIC) of antituberculosis drugs. 53 isolates were tested in this study and 13 of them were multidrug resistant (MDR) isolates. The antibiotics concentrations were 2-0.06 mg/L for isoniazid (INH) and rifampicin (RIF) and were 16-0.25 mg/L for streptomycin (STM) and ethambutol (EMB). Crystal violet (CV-25 mg/L) was added into the microwells on the seventh day of incubation and incubation was continued until decolorization. Decolorization of CV was the predictor of bacterial growth. Overall agreements for four drugs were detected as 98.1%, and the average time was detected as 9.5 ± 0.89 day after inoculation. One isolate for INH and two isolates for STM were determined resistant in the reference method, but susceptible by the CVDA. One isolate was susceptible to EMB by the reference method, but resistant by the CVDA. All results were concordant for RIF. This study shows that CVDA is a rapid, reliable and suitable for determination of MIC values of Mycobacterium tuberculosis. And it can be used easily especially in countries with limited-sources. PMID:27304025

  4. Highly sensitive UVA and violet photodetector based on single-layer graphene-TiO2 heterojunction.

    PubMed

    Liang, Feng-Xia; Zhang, Deng-Yue; Wang, Jiu-Zhen; Kong, Wei-Yu; Zhang, Zhi-Xiang; Wang, Yi; Luo, Lin-Bao

    2016-11-14

    A highly sensitive ultraviolet A (UVA) and violet photodetector based on p-type single-layer graphene (SLG)-TiO2 heterostructure was fabricated by transferring chemical vapor deposition derived SLG on the surface of commercial single-crystal TiO2 wafer. Optoelectronic analysis reveals the as-fabricated Schottky junction PD was highly sensitive to light illumination in UVA and violet range, with peak sensitivity at 410 nm and excellent stability and reproducibility, but virtually blind to illumination with wavelength less than 350 nm or more than 460 nm. The on/off ratio of the device was calculated to be 6.8 × 104, which is better than the majority of previously reported TiO2 based PDs. What is more, the rise/fall time were estimated to be 0.74/1.18 ms, much faster than other TiO2 based counterparts. The totality of the above result signifies that the present SLG-TiO2 Schottky junction photodetector may have promising application in future high-speed, high-sensitivity optoelectronic nanodevices and systems.

  5. Cellular physiological effects of the MV Kyowa violet fuel-oil spill on the hard coral, Porites lobata.

    PubMed

    Downs, Craig A; Richmond, Robert H; Mendiola, Woon Jaye; Rougée, Luc; Ostrander, Gary K

    2006-12-01

    The grounding of the Merchant Vessel (MV) Kyowa Violet on a coral reef near Yap, Federated States of Micronesia, in December 2002 resulted in the release of an estimated 55,000 to 80,000 gallons of intermediate fuel oil grade 180. The immediate impact was the widespread coating of mangroves and the intertidal zone along more than 8 km of coastline. Of greater concern, however, was the partitioning of the fuel oil in the water column, leading to chronic exposure of organisms in the ecosystem for a considerable period after the initial event. Herein, we report on our examination of one coral species, Porites lobata, nearly three months after the initial exposure. We investigated whether changes in cellular physiology were consistent with the pathological profile that results from the interaction of corals with polycyclic aromatic hydrocarbons, the principal constituent of fuel oil. Specifically, we document, to our knowledge for the first time, changes in the cellular physiological condition of an exposed coral population affected by a fuel-oil spill. We also provide evidence that the observed changes are consistent with a recent exposure to fuel oil, as evidenced by the presence of characteristic cellular lesions attributed to polycyclic aromatic hydrocarbons. Finally, our data support a model for a mechanistic relationship between the cellular pathological profile of the coral and a recent petroleum exposure, such as the MV Kyowa Violet fuel oil spill.

  6. Effect of QW thickness and numbers on performance characteristics of deep violet InGaN MQW lasers

    NASA Astrophysics Data System (ADS)

    Alahyarizadeh, Gh.; Amirhoseiny, M.; Hassan, Z.

    2015-03-01

    The performance characteristics of deep violet indium gallium nitride (InGaN) multiquantum well (MQW) laser diodes (LDs) with an emission wavelength of around 390 nm have been investigated using the integrated system engineering technical computer aided design (ISE-TCAD) software. A comparative study on the effect of quantum well (QW) thickness and number on electrical and optical performance of deep violet In0.082Ga0.918N/GaN MQW LDs have been carried out. The simulation results showed that the highest slope efficiency and external differential quantum efficiency (DQE), as well as the lowest threshold current are obtained when the number of wells is two. The different QW thickness values of 2.2, 2.5, 2.8, 3 and 3.2 nm were compared and the best results were achieved for 2.5 nm QW thickness. The radiative recombination rate decreases with increasing QW thickness because of decreasing electron and hole carrier densities in wells. By increasing QW thickness, output power decreases and threshold current increases.

  7. Radiation hardness of AlxGa1-xN photodetectors exposed to Extreme UltraViolet (EUV) light beam

    NASA Astrophysics Data System (ADS)

    Malinowski, Pawel E.; John, Joachim; Barkusky, Frank; Duboz, Jean Yves; Lorenz, Anne; Cheng, Kai; Derluyn, Joff; Germain, Marianne; De Moor, Piet; Minoglou, Kyriaki; Bayer, Armin; Mann, Klaus; Hochedez, Jean-Francois; Giordanengo, Boris; Borghs, Gustaaf; Mertens, Robert

    2009-05-01

    We report on the results of fabrication and optoelectrical characterization of Gallium Nitride (GaN) based Extreme UltraViolet (EUV) photodetectors. Our devices were Schottky photodiodes with a finger-shaped rectifying contact, allowing better penetration of light into the active region. GaN layers were epitaxially grown on Silicon (111) by Metal- Organic-Chemical Vapor Deposition (MOCVD). Spectral responsivity measurements in the Near UltraViolet (NUV) wavelength range (200-400 nm) were performed to verify the solar blindness of the photodetectors. After that the devices were exposed to the EUV focused beam of 13.5 nm wavelength using table-top EUV setup. Radiation hardness was tested up to a dose of 3.3Â.1019 photons/cm2. Stability of the quantum efficiency was compared to the one measured in the same way for a commercially available silicon based photodiode. Superior behavior of GaN devices was observed at the wavelength of 13.5 nm.

  8. Spectrally-isolated violet to blue wavelength generation by cascaded degenerate four-wave mixing in a photonic crystal fiber.

    PubMed

    Yuan, Jinhui; Kang, Zhe; Li, Feng; Zhang, Xianting; Zhou, Guiyao; Sang, Xinzhu; Wu, Qiang; Yan, Binbin; Zhou, Xian; Wang, Liang; Zhong, Kangping; Wang, Kuiru; Yu, Chongxiu; Tam, Hwa Yaw; Wai, P K A

    2016-06-01

    Generation of spectrally-isolated wavelengths in the violet to blue region based on cascaded degenerate four-wave mixing (FWM) is experimentally demonstrated for the first time in a tailor-made photonic crystal fiber, which has two adjacent zero dispersion wavelengths (ZDWs) at 696 and 852 nm in the fundamental mode. The influences of the wavelength λp and the input average power Pav of the femtosecond pump pulses on the phase-matched frequency conversion process are studied. When femtosecond pump pulses at λp of 880, 870, and 860 nm and Pav of 500 mW are coupled into the normal dispersion region close to the second ZDW, the first anti-Stokes waves generated near the first ZDW act as a secondary pump for the next FWM process. The conversion efficiency ηas2 of the second anti-Stokes waves, which are generated at the violet to blue wavelengths of 430, 456, and 472 nm, are 4.8, 6.48, and 9.66%, for λp equalling 880, 870, and 860 nm, respectively.

  9. Identification of gentian violet concentration that does not stain oral mucosa, possesses anti-candidal activity and is well tolerated.

    PubMed

    Jurevic, R J; Traboulsi, R S; Mukherjee, P K; Salata, R A; Ghannoum, M A

    2011-05-01

    Gentian violet (GV) is recommended for initial treatment of oral candidiasis in HIV-infected patients in resource-limited settings. Currently GV is not used because of its staining effects. In this study, we investigated the staining capacity of three different concentrations of GV to determine a concentration that does not cause staining. The selected concentration that did not cause staining was evaluated for its physical stability and antifungal activity. Fifteen healthy participants were randomized to rinse twice daily for 14 days with one of three GV concentrations: 0.1%, 0.0085%, or 0.00165%. Oral examination and intra-oral photographs were performed at baseline and at the end of therapy. Participants responded to a questionnaire to assess adverse events. Antifungal activity was evaluated using the Clinical and Laboratory Standard Institute methodology. GV at a concentration of 0.00165% did not stain the oral mucosa and was well tolerated. GV at a concentration of 0.00165% was stable and possessed antifungal activity when stored at certain temperatures for different time periods. Gentian violet solution at the concentration of 0.00165% does not stain the oral mucosa, is stable and possesses potent antifungal activity.

  10. Efficient photodegradation of methyl violet dye using TiO2/Pt and TiO2/Pd photocatalysts

    NASA Astrophysics Data System (ADS)

    Saeed, Khalid; Khan, Idrees; Gul, Tamanna; Sadiq, Mohammad

    2017-02-01

    Titanium oxide supported palladium (TiO2/Pd) and titanium oxide supported platinum (TiO2/Pt) nanoparticles were prepared from their precursors through the incipient wetness method. The TiO2/Pd and TiO2/Pt nanoparticles were characterized by scanning electron microscopy (SEM), and energy dispersive X-rays (EDX), while the photodegradation study of methyl violet was performed by UV/VIS spectrophotometry. The morphological study shows that the Pd and Pt were well deposited on the surface of TiO2, which was confirmed by EDX. Both TiO2/Pd and TiO2/Pt nanoparticles were used as photocatalysts for the photodegradation of methyl violet in aqueous media under UV-light irradiation. The photodegradation study revealed that the TiO2/Pd and TiO2/Pt nanoparticles degraded about 95 and 78% of dye within 20 min, respectively. The effect of various parameters such as catalyst dosage, concentration of dye, and medium on the photocatalytic degradation was examined. The activity of recovered TiO2/Pd and TiO2/Pt nanoparticles was studied.

  11. Reproductive biology of the violet-chested hummingbird in Venezuela and comparisons with other tropical and temperate hummingbirds

    USGS Publications Warehouse

    Fierro-Calderon, K.; Martin, T.E.

    2007-01-01

    We provide details on the breeding biology of the Violet-chested Hummingbird (Sternoclyta cyanopectus) based on 67 nests studied in Yacambu?? National Park, Venezuela, from 2002 through 2006. Clutch size was two white eggs, usually laid every other day. Fresh egg mass (0.95 ?? 0.14 g) was 15% of female mass. Incubation and nestling periods were 20.4 ?? 0.3 and 26.0 ?? 0.4 days, respectively. Nest attentiveness increased from 60% in early incubation to 68% in late incubation. The female spent 50% of her time brooding young nestlings, but ceased brooding by 13 days of age. Only the female fed the young, with a low rate of nest visitation (3.3 trips per hour) that did not increase with age of the young. Growth rate based on nestling mass (K = 0.28) was slow. Daily predation rates decreased across stages and were 0.064 ?? 0.044, 0.033 ?? 0.008, and 0.020 ?? 0.006 during the egg-laying, incubation, and nestling periods, respectively. Most, but not all, life history traits of the Violet-chested Hummingbird were similar to those reported for other tropical and temperate hummingbirds, providing further evidence that this family shows a relatively narrow range of life history variation. ?? The Cooper Ornithological Society 2007.

  12. Synthesis and photoluminescence of violet-blue phosphor Ba10(PO4)6F2: Eu2+

    NASA Astrophysics Data System (ADS)

    Huang, Yumei; Zhang, Xinguo; Pan, Jialiang

    2017-01-01

    A violet-blue phosphor of Ba10(PO4)6F2: Eu2+ was prepared by high-temperature solid state reaction. Luminescence, concentration quenching and thermal stability of Ba10(PO4)6F2: Eu2+ are systematically investigated. The phosphor exhibits a broadband UV absorption and a violet-blue emission peaking at 420 nm with corresponding CIE coordinates of (0.163, 0.024). It is found that Eu2+ ions occupy 9-coordinated Ba(1) and 7-coordinated Ba(2) site in Ba10(PO4)6F2, and therefore generate two emission sub-bands at 415 and 433 nm. The optimal concentration of Eu2+ is 5 mol% according to emission intensity and the quenching mechanism is verified to be a dipole-dipole interaction. Ba10(PO4)6F2: 0.05Eu2+ phosphor shows good thermal stability with 81% of room temperature intensity at 180 °C.

  13. Fixed-bed column studies on biosorption of crystal violet from aqueous solution by Citrullus lanatus rind and Cyperus rotundus

    NASA Astrophysics Data System (ADS)

    Bharathi, Kandaswamy Suyamboo; Ramesh, SriKrishna Perumal Thanga

    2013-12-01

    In this study, fixed-bed column experiments were performed to investigate the biosorption potential of two agricultural wastes, Citrullus lanatus rind and Cyperus rotundus to remove Crystal violet (CV) from aqueous solution. The experiments were conducted to study the effects of important parameters such as bed depth (10-30 cm), flow rate (10-20 mL min-1) and initial dye concentration (10-25 mg L-1). Different models like Bed Depth Service Time (BDST) model, Thomas model and Yoon-Nelson model were applied to the experimental sorption data. In the biosorption of Crystal violet by both the sorbents, the BDST model fitted well with the experimental data in the initial region of the breakthrough curve. Also, Yoon-Nelson model was found to show good agreement with the experimental kinetic results as compared to the Thomas model. The sorbents were found to be very potential, as it showed good sorption capacities of 46.68 and 54.24 mg g-1 for CV biosorption by Citrullus lanatus rind and Cyperus rotundus. Recovery of dye was made by eluting 1 N CH3COOH through the exhausted column in downward direction.

  14. Using violet laser-induced chlorophyll fluorescence emission spectra for crop yield assessment of cowpea (Vigna unguiculata (L) Walp) varieties

    NASA Astrophysics Data System (ADS)

    Anderson, Benjamin; Buah-Bassuah, Paul K.; Tetteh, Jonathan P.

    2004-07-01

    The use of violet laser-induced chlorophyll fluorescence (LICF) emission spectra to monitor the growth of five varieties of cowpea in the University of Cape Coast Botanical Garden is presented. Radiation from a continuous-wave violet laser diode emitting at 396 nm through a fibre is closely incident on in vivo leaves of cowpea to excite chlorophyll fluorescence, which is detected by an integrated spectrometer with CCD readout. The chlorophyll fluorescence spectra with peaks at 683 and 731 nm were used for growth monitoring of the cowpea plants over three weeks and analysed using Gaussian spectral functions with curve fitted parameters to determine the peak positions, area under the spectral curve and the intensity ratio F683/F731. The variation in the intensity ratio of the chlorophyll bands showed sensitive changes indicating the photosynthetic activity of the cowpea varieties. A discussion of the fluorescence result as compared to conventional assessment is presented with regard to discrimination between the cowpea varieties in terms of crop yield performance.

  15. Assessment of in vitro lymphokine activated killer (LAK) cell activity against renal cancer cell lines and its suppression by serum factor using crystal violet assay.

    PubMed

    Kanamaru, H; Yoshida, O

    1989-01-01

    Lymphokine activated killer (LAK) cell activity against renal cancer cell lines was assessed in vitro using a crystal violet assay. A standard 4-h 51chromium release assay and a 48-h crystal violet assay showed that both natural killer-susceptible (NC65) and -resistant (ACHN) renal cancer cell lines were sensitive to LAK cells which had been generated by a 3-day incubation of peripheral blood mononuclear cells (PBMC) with recombinant interleukin 2 (rIL-2). Optimal LAK activity was generated by a 5-day culture of PBMC with 1 U rIL-2/ml. LAK activity was enhanced by the presence of IL-2 in the crystal violet assay system, while it was suppressed by fresh autologous serum. The suppressive effect was found in serum from both normal donors and patients with metastatic renal cell carcinoma, suggesting that non-specific suppressive factor(s) affecting LAK cell activity were present in human sera.

  16. Delineating the extent of anterior capsulorhexis with gentian violet using capsulorhexis marker: a preliminary study of efficacy and toxicity in an animal model

    PubMed Central

    Hassaballa, Mohamed Abdel Moneim; Osman, Amr Abd el-Latif

    2011-01-01

    Background: The purpose of this study was to evaluate the efficacy and safety of a new instrument to optimize the size, shape, and centration of anterior capsulorhexis. Methods: The study was divided into two parts. The first part was done in 10 goats’ eyes. A specially designed capsulorhexis marker was used. The lower edge of the instrument was stained by gentian violet and then applied to the anterior capsule to produce a circular mark of 5.5 mm. In five eyes, the gentian violet was applied to the marker using a corneal marking pen; in the remaining five eyes, the gentian violet was applied using a corneal marking pad. In the second part, the toxicity of gentian violet was tested as follows: ten albino rabbits received a gentian violet injection into the anterior chamber in one eye (experimental group) and an equal volume of balanced salt solution in the fellow eye (control group). Five rabbits were sacrificed one day after surgery and the remaining five rabbits after one week. Results: In the first part, there was no difficulty in the introduction or removal of the instrument from all eyes. In the first two eyes, the circular mark was diffuse due to sliding of the marker on the surface of the anterior capsule. In the remaining eight eyes, there was a well-centered, rounded mark which was adequately stained. In the second part, there was no histopathological evidence of corneal toxicity in either group. There was loss of ganglion cells from the neurosensory retina one day after surgery in one eye from the experimental group. At one week, there was no evidence of retinal toxicity in any of the rabbits. Conclusion: This capsulorhexis marker can guide the surgeon to a better centration and proper sizing of anterior capsulorhexis using gentian violet staining. More refinement of the instrument is needed to be able to use it in human eyes. PMID:21750617

  17. Continuous-wave violet generation at 373.5 nm by frequency-doubled power-scaled near-infrared emitting Pr:YAlO3 laser

    NASA Astrophysics Data System (ADS)

    Fibrich, Martin; Jelínková, Helena

    2013-10-01

    We report on a continuous-wave Pr:YAlO3 laser operating at a wavelength of 373.5 nm in a power-scaled resonator arrangement. Violet light generation has been achieved by intracavity frequency doubling of the near-infrared emitting Pr:YAP laser at a fundamental wavelength of 747 nm. For active medium pumping, two GaN laser diodes providing up to 1 W of output power each at 448 nm were used. By employing BBO crystal as a nonlinear medium, more than 46 mW of violet radiation has been obtained.

  18. A shock-tube determination of the CN ground state dissociation energy and electronic transition moments for the CN violet and red band systems

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.; Nicholls, R. W.

    1973-01-01

    The CN ground state dissociation energy and the sum of squares of the electronic transition moments of the CN violet bands have been simultaneously determined from spectral emission measurements behind incident shock waves. The unshocked test gases were composed of various CO2-CO-N2-Ar mixtures, and the temperatures behind the incident shocks ranged from 3500 to 8000 K. The variation of the electronic transition moment with internuclear separation was found to be small for both the CN violet and red band systems.

  19. Carboxylate ligands induced structural diversity of zinc(II) coordination polymers based on 3,6-bis(imidazol-1-yl)carbazole: Syntheses, structures and photocatalytic properties

    SciTech Connect

    Cheng, Hong-Jian Tang, Hui-Xiang; Shen, Ya-Li; Xia, Nan-Nan; Yin, Wen-Yu; Zhu, Wei; Tang, Xiao-Yan; Ma, Yun-Sheng; Yuan, Rong-Xin

    2015-12-15

    Solvothermal reactions of Zn(NO{sub 3}){sub 2}·6H{sub 2}O with 3,6-bis(1-imidazolyl)carbazole (3,6-bmcz) and 1,4-benzenedicarboxylic acid (1,4-H{sub 2}bdc), p-phenylenediacetic acid (p-H{sub 2}pda), benzophenone-4,4-dicarboxylic acid (H{sub 2}bpda) afforded three coordination polymers [Zn(1,4-bdc)(3,6-bmcz)]{sub n} (1), {[Zn(p-pda)(3,6-bmcz)]·1.5H_2O}{sub n} (2) and {[Zn(bpda)(3,6-bmcz)]·0.25H_2O}{sub n} (3). Complexes 1–3 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. Complex 1 shows 3D structure with 2D nets inclined polycatenation. Complexes 2 and 3 possess an extended 3D supramolecular architecture based on their respective 2D layers through hydrogen-bonding interactions and the π···π stacking interactions. The solid state luminescent and optical properties of 1–3 at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methylene blue in polluted water was explored. - Graphical abstract: Reactions of Zn(NO{sub 3}){sub 2} and 3,6-(1-imidazolyl)carbazole with 1,4-benzenedicarboxylic acid, p-phenylenediacetic acid or benzophenone-4,4-dicarboxylic acid afforded three coordination polymers with different topologies and photocatalytic activity. - Highlights: • Reactions of 1,4-H{sub 2}bdc, p-H{sub 2}pda or H{sub 2}bpda with 3,6-bmcz and Zn(II) gave three CPs. • Complex 1 is a 3D entanglement. • Complex 2 or 3 is a 3D supramolecular structure based on different 2D layers. • Complex 2 exhibited good catalytic activity of methylene blue photodegradation.

  20. Determination of residues of three triphenylmethane dyes and their metabolites (malachite green, leuco malachite green, crystal violet, leuco crystal violet, and brilliant green) in aquaculture products by LC/MS/MS: first action 2012.25.

    PubMed

    Hurtaud-Pessel, Dominique; Couëdor, Pierrick; Verdon, Eric; Dowell, Dawn

    2013-01-01

    During the AOAC Annual Meeting held from September 30 to October 3, 2012 in Las Vegas, NV, the Expert Review Panel (ERP) on Veterinary Drug Residues reviewed data for the method for determination of residues of three triphenylmethane dyes and their metabolites (malachite green, leuco malachite green, crystal violet, leuco crystal violet, and brilliant green) in aquaculture products by LC/MS/MS, previously published in the Journal of Chromatography A 1218, 1632-1645 (2006). The method data were reviewed and compared to the standard method performance requirements (SMPRs) found in SMPR 2009.001, published in AOAC's Official Methods of Analysis, 19th Ed. (2012). The ERP determined that the data were acceptable, and the method was approved AOAC Official First Action. The method uses acetonitrile to isolate the analyte from the matrix. Then determination is conducted by LCIMS/MS with positive electrospray ionization. Accuracy ranged from 100.1 to 109.8% for samples fortified at levels of 0.5, 0.75, 1.0, and 2.0 microg/kg. Precision ranged from 2.0 to 10.3% RSD for the intraday samples and 1.9 to 10.6% for the interday samples analyzed over 3 days. The described method is designed to accurately operate in the analytical range from 0.5 to 2 microg/kg, where the minimum required performance limit for laboratories has been fixed in the European Union at 2.0 microg/kg for these banned substances and their metabolites. Upper levels of concentrations (1-100 microg/kg) can be analyzed depending on the different optional calibrations used.

  1. Adsorption of methyl violet from aqueous solution using gum xanthan/Fe3O4 based nanocomposite hydrogel.

    PubMed

    Mittal, H; Kumar, Vaneet; Saruchi; Ray, Suprakas Sinha

    2016-08-01

    This research paper reports the utilization of gum xanthan-grafted-polyacrylic acid and Fe3O4 magnetic nanoparticles based nanocomposite hydrogel (NCH) for the highly effective adsorption of methyl violet (MV) from aqueous solution. Synthesized NCH was characterized using various techniques, such as FTIR, XRD, SEM-EDS, TEM and BET. Adsorption behavior of NCH was studied for the adsorption of MV and it was found to remove 99% dye from the solution. Adsorption process followed Langmuir isotherm model (qe=642mg/g) and pseudo-second-order kinetics model. Thermodynamic studies suggested that the adsorption process was endothermic and spontaneous. Moreover, the adsorbent was successfully utilized for successive five cycles of adsorption-desorption.

  2. Removal of the methyl violet 2B dye from aqueous solution using sustainable adsorbent Artocarpus odoratissimus stem axis

    NASA Astrophysics Data System (ADS)

    Kooh, Muhammad Raziq Rahimi; Dahri, Muhammad Khairud; Lim, Linda B. L.

    2016-10-01

    This study investigates the potential of the stem axis of Artocarpus odoratissimus fruit (TSA) as an adsorbent for the removal of methyl violet 2B (MV). The functional group analysis was carried out using Fourier-transform infrared spectroscopy. Investigation of the effects of pH and ionic strength provide insights on the involvement of electrostatic attraction and hydrophobic-hydrophobic attraction between the adsorbent and adsorbates. Kinetics models (pseudo-first-order, pseudo-second-order, Weber-Morris and Boyd) and isotherm models (Langmuir, Freundlich and Dubinin-Raduskevich) were used for characterising the adsorption process. The Langmuir model predicted a high q m of 263.7 mg g-1. Thermodynamics studies indicate the adsorption system is spontaneous, endothermic and physical sorption dominant. The spent adsorbent was successfully regenerated using water and obtained adsorption capacity close to the unused adsorbent even after fifth cycle of washing.

  3. Adsorptive removal of crystal violet dye by a local clay and process optimization by response surface methodology

    NASA Astrophysics Data System (ADS)

    Loqman, Amal; El Bali, Brahim; Lützenkirchen, Johannes; Weidler, Peter G.; Kherbeche, Abdelhak

    2016-12-01

    The current study relates to the removal of a dye [crystal violet (CV)] from aqueous solutions through batch adsorption experiment onto a local clay from Morocco. The clay was characterized by X-ray diffraction, IR spectroscopy, X-ray fluorescence, scanning electron microscope, Brunauer-Emmett-Teller analysis and Fraunhofer diffraction method. The influence of independent variables on the removal efficiency was determined and optimized by response surface methodology using the Box-Behnken surface statistical design. The model predicted maximum adsorption of 81.62% under the optimum conditions of operational parameters (125 mg L-1 initial dye concentration, 2.5 g L-1 adsorbent dose and time of 43 min). Practically, the removal ranges in 27.4-95.3%.

  4. The use of vapour phase ultra-violet spectroscopy for the analysis of arson accelerants in fire scene debris.

    PubMed

    McCurdy, R J; Atwell, T; Cole, M D

    2001-12-01

    A method has been developed for the analysis of arson accelerants in fire scene debris by vapour phase ultra-violet (UV) spectroscopy. The method is rapid, inexpensive, simple to use and is sufficiently sensitive and discriminating to be of use for the analysis of crime scene samples. Application to casework samples is described. On occasion, the method offers additional information to that which can be obtained by gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) and represents a useful adjunct to these techniques. In addition, the method offers advantages where the use of GC-MS analysis of arson accelerants in fire scene debris is not a practical proposition.

  5. An Innovative Scalp-Dyeing Technique with Gentian Violet Solution During Follicular Unit Extraction for White-Haired Follicular Units

    PubMed Central

    Moon, Min Seon

    2017-01-01

    There exist some restrictions and difficulties in performing follicular unit extraction (FUE) in white-haired patients, for several reasons. In this paper, we introduce a novel technique for visualizing white hair during the punching procedure and graft preparation in FUE for white-haired patients. In white-haired older male patients, we dyed the surrounding scalp skin purple with a gentian violet solution-stained toothpick. Our method has several advantages: surgeons can easily focus on the center of the follicular unit and rapidly perform punching, they can recognize the condition of the harvested follicular units during FUE, and the hair transplant team can secure a clear view for trimming and loading into the implanter. We suggest that scalp dyeing in difficult FUE procedures, especially in patients with white hair, may be a simple method that provides a good visualization for donor site harvesting and for microdissection. PMID:28352608

  6. Quantitative super-resolution localization microscopy of DNA in situ using Vybrant® DyeCycle™ Violet fluorescent probe

    PubMed Central

    Żurek-Biesiada, Dominika; Szczurek, Aleksander T.; Prakash, Kirti; Best, Gerrit; Mohana, Giriram K.; Lee, Hyun-Keun; Roignant, Jean-Yves; Dobrucki, Jurek W.; Cremer, Christoph; Birk, Udo

    2016-01-01

    Single Molecule Localization Microscopy (SMLM) is a recently emerged optical imaging method that was shown to achieve a resolution in the order of tens of nanometers in intact cells. Novel high resolution imaging methods might be crucial for understanding of how the chromatin, a complex of DNA and proteins, is arranged in the eukaryotic cell nucleus. Such an approach utilizing switching of a fluorescent, DNA-binding dye Vybrant® DyeCycle™ Violet has been previously demonstrated by us (Żurek-Biesiada et al., 2015) [1]. Here we provide quantitative information on the influence of the chemical environment on the behavior of the dye, discuss the variability in the DNA-associated signal density, and demonstrate direct proof of enhanced structural resolution. Furthermore, we compare different visualization approaches. Finally, we describe various opportunities of multicolor DNA/SMLM imaging in eukaryotic cell nuclei. PMID:27054149

  7. Quantitative super-resolution localization microscopy of DNA in situ using Vybrant® DyeCycle™ Violet fluorescent probe.

    PubMed

    Żurek-Biesiada, Dominika; Szczurek, Aleksander T; Prakash, Kirti; Best, Gerrit; Mohana, Giriram K; Lee, Hyun-Keun; Roignant, Jean-Yves; Dobrucki, Jurek W; Cremer, Christoph; Birk, Udo

    2016-06-01

    Single Molecule Localization Microscopy (SMLM) is a recently emerged optical imaging method that was shown to achieve a resolution in the order of tens of nanometers in intact cells. Novel high resolution imaging methods might be crucial for understanding of how the chromatin, a complex of DNA and proteins, is arranged in the eukaryotic cell nucleus. Such an approach utilizing switching of a fluorescent, DNA-binding dye Vybrant® DyeCycle™ Violet has been previously demonstrated by us (Żurek-Biesiada et al., 2015) [1]. Here we provide quantitative information on the influence of the chemical environment on the behavior of the dye, discuss the variability in the DNA-associated signal density, and demonstrate direct proof of enhanced structural resolution. Furthermore, we compare different visualization approaches. Finally, we describe various opportunities of multicolor DNA/SMLM imaging in eukaryotic cell nuclei.

  8. Adsorption and subsequent partial photodegradation of methyl violet 2B on Cu/Al layered double hydroxides

    NASA Astrophysics Data System (ADS)

    Guzmán-Vargas, Ariel; Lima, Enrique; Uriostegui-Ortega, Gisselle A.; Oliver-Tolentino, Miguel A.; Rodríguez, Esaú E.

    2016-02-01

    Uncalcined Cu/Al LDH was studied as adsorbent and photocatalyst in the adsorption and subsequent photodegradation of methyl violet 2B dye (MV2B). Physicochemical characterization was carried out by XRD, FTIR, UV-vis, including photoactive properties, DSC/TGA and SEM. Kinetic and thermodynamic models showed great affinity and sorption capacity, the maximum adsorption capacity was 361.0 mg g-1 obtained by Langmuir model, in addition, the results showed that the dye was adsorbed on the LDH surface. Photocatalytic activity was evaluated in the MV2B dye photodegradation process, and it was confirmed by the presence rad OH radicals monitored by EPR spin trapping technique, additionally, COD and TOC parameters were measured, 13C NMR showed differences for the adsorbed and photodegraded samples.

  9. Photoconversion of DAPI following UV or violet excitation can cause DAPI to fluoresce with blue or cyan excitation.

    PubMed

    Piterburg, M; Panet, H; Weiss, A

    2012-04-01

    4'-6-Diamidino-2-phenylindole is a fluorescent dye commonly used to visualize deoxyribonucleic acid or cell nuclei in fixed cell preparations, and is often used together with fluorescein or green fluorescent protein, which can be excited without exciting 4'-6-Diamidino-2-phenylindole. It is assumed that when using typical fluorescein or green fluorescent protein filter cubes, 4'-6-Diamidino-2-phenylindole will not be observed. In this paper, we show that following observation of 4'-6-Diamidino-2-phenylindole using UV or violet excitation, it may become sensitive to the blue/cyan excitation used in fluorescein/green fluorescent protein filter cubes. This has serious implications for the use of 4'-6-Diamidino-2-phenylindole together with widely used green fluorophores in double labelling experiments.

  10. Removal of Acid Violet 17 from aqueous solutions by adsorption onto activated carbon prepared from sunflower seed hull.

    PubMed

    Thinakaran, N; Baskaralingam, P; Pulikesi, M; Panneerselvam, P; Sivanesan, S

    2008-03-01

    The adsorption of Acid Violet 17 (AV17) was carried out using various activated carbons prepared from sunflower seed hull (SSH), an agricultural solid waste by-product. The effect of parameters such as agitation time, initial dye concentration, adsorbent dosage, pH and temperature were studied. The Langmuir and Freundlich isotherm models were applied and the Langmuir model was found to best report the equilibrium isotherm data. Langmuir adsorption capacity was found to be 116.27 mg/g. Kinetic data followed pseudo-second-order kinetics. Maximum colour removal was observed at pH 2.0. It was observed that the rate of adsorption improves with increasing temperature and the process is endothermic. The adsorbent surface was analysed with a scanning electron microscope. The results indicate that activated sunflower seed hull could be an attractive option for colour removal from dilute industrial effluents.

  11. Modification of the photocatalytic activity of TiO2 by β-Cyclodextrin in decoloration of ethyl violet dye

    PubMed Central

    Velusamy, Ponnusamy; Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam

    2012-01-01

    The photocatalytic decoloration of an organic dye, ethyl violet (EV), has been studied in the presence of TiO2 and the addition of β-Cyclodextrin (β-CD) with TiO2 (TiO2-β-CD) under UV-A light irradiation. The different operating parameters like initial concentration of dye, illumination time, pH and amount of catalyst used have also been investigated. The photocatalytic decoloration efficiency is more in the TiO2-β-CD/UV-A light system than TiO2/UV-A light system. The mineralization of EV has been confirmed by Chemical Oxygen Demand (COD) measurements. The complexation patterns have been confirmed with UV–Visible and FT-IR spectral data and the interaction between TiO2 and β-CD have been characterized by powder XRD analysis and UV–Visible diffuse reflectance spectroscopy. PMID:25685468

  12. Crystal violet as an i-motif structure probe for reversible and label-free pH-driven electrochemical switch.

    PubMed

    Zhang, Xi Yuan; Luo, Hong Qun; Li, Nian Bing

    2014-06-15

    A simple pH-induced electrochemical switch based on an i-motif structure is developed by using crystal violet as a selective electrochemical probe for the i-motif structure. Thiol-modified cytosine-rich single-strand oligonucleotide (C-rich ssDNA) can be self-assembled on the gold electrode surface via gold-sulfur interaction. Crystal violet is employed as an electrochemical probe for the i-motif structure because of its capability of binding with the i-motif structure through an end-stacking mode. In acidic aqueous solution, crystal violet may approach the electrode surface owing to the formation of the i-motif structure, resulting in an obvious signal, so-called "ON" state. Whereas in neutral or basic aqueous solution, the i-motif structure unfolds to dissociative single strand, which causes crystal violet to leave from the electrode surface, and a weak signal is obtained, so-called "OFF" state. In addition, in the range of pH 4.6-7.3, the increase in current has a good linear relationship (R=0.989) with pH value in the testing solutions. This pH-driven electrochemical switch has the advantages of simplicity, sensitivity, high selectivity, and good reversibility. Furthermore, it provides a possible platform for pH measurement.

  13. The Role of Porphyrin-Free-Base in the Electronic Structures and Related Properties of N-Fused Carbazole-Zinc Porphyrin Dye Sensitizers

    PubMed Central

    Li, Xing-Yu; Zhang, Cai-Rong; Wu, You-Zhi; Zhang, Hai-Min; Wang, Wei; Yuan, Li-Hua; Yang, Hua; Liu, Zi-Jiang; Chen, Hong-Shan

    2015-01-01

    Dye sensitizers can significantly affect power conversion efficiency of dye-sensitized solar cells (DSSCs). Porphyrin-based dyes are promising sensitizers due to their performances in DSSCs. Here, based upon a N-fused carbazole-zinc porphyrin-free-base porphyrin triad containing an ethynyl-linkage (coded as DTBC), the novel porphyrin dyes named DTBC-MP and DTBC-TP were designed by varying the porphyrin-free-base units in the π conjugation of DTBC in order to study the effect of porphyrin-free-base in the modification of electronic structures and related properties. The calculated results indicate that, the extension of the conjugate bridge with the porphyrin-free-base unit results in elevation of the highest occupied molecular orbital (HOMO) energies, decrease of the lowest unoccupied molecular orbital (LUMO) energies, reduction of the HOMO-LUMO gap, red-shift of the absorption bands, and enhancement of the absorbance. The free energy changes demonstrate that introducing more porphyrin-free-base units in the conjugate bridge induces a faster rate of electron injection. The transition properties and molecular orbital characters suggest that the different transition properties might lead to a different electron injection mechanism. In terms of electronic structure, absorption spectra, light harvesting capability, and free energy changes, the designed DTBC-TP is a promising candidate dye sensitizer for DSSCs. PMID:26610469

  14. D-π-A-π-A Strategy to Design Benzothiadiazole-carbazole-based Conjugated Polymer with High Solar Cell Voltage and Enhanced Photocurrent.

    PubMed

    Zhou, Manxi; Wang, Min; Zhu, Lei; Yang, Zhenqing; Jiang, Chao; Cao, Dapeng; Li, Qifang

    2015-12-01

    The theoretical calculations are used to find that D-π-A-π-A style conjugated polymer PC-TBTBT is more efficient for solar cells application than the D-π-A analog PC-TBT because the D-π-A-π-A structure has a narrower band gap and higher molar absorption coefficient and redshift spectrum. Motivated by the theoretical prediction, 5,6-bis(octyloxy)-2,1,3-benzothiadiazole and 2,7-carbazole are adopted to synthesize the D-π-A-π-A style PC-TBTBT (M(w) = 31.1 kDa) and D-π-A analog PC-TBT (M(w) = 87.5 kDa) by Suzuki coupling reaction. Experimental results confirm that D-π-A-π-A PC-TBTBT-based solar cell shows a power conversion efficiency (PCE) of 4.74% with high V(OC) of 0.99 V and enhanced J(SC) of 9.70 mA cm(-2). The PCE and J(SC) achieve improvements of 17% and 26%, respectively, compared to the D-π-A PC-TBT-based solar cell.

  15. Solvatochromic effect in absorption and emission spectra of star-shaped bipolar derivatives of 1,3,5-triazine and carbazole. A time-dependent density functional study.

    PubMed

    Baryshnikov, Gleb V; Bondarchuk, Sergey V; Minaeva, Valentina A; Ågren, Hans; Minaev, Boris F

    2017-02-01

    A series of three star-shaped compounds containing both donor (carbazole) and acceptor (2,4,6-triphenyl-1,3,5-triazine) moieties linked through various linking bridges was studied theoretically at the linear response TD-DFT level of theory to describe their absorption and fluorescence spectra. The concept of a localized charge-transfer excited state has been applied successfully to explain the observed strong solvatochromic effect in the emission spectra of the studied molecules, which can be utilized for the fabrication of color tunable solution-processable OLEDs. The concept is in particularly applicable to donor-acceptor species with a C 3 symmetry point group where the static dipole moment changes dramatically upon electronic excitation. An important peculiarity of the studied molecules is that they are characterized by non-zero values of the HOMO and LUMO orbitals in the same common part of molecular space that provides a large electric dipole transition moment for both light absorption and emission. Graphical abstract Star-shaped C 3 symmetry point group derivatives for color tunable OLEDs.

  16. Electronic and optical properties of novel carbazole-based donor-acceptor compounds for applications in blue-emitting organic light-emitting diodes

    DOE PAGES

    Legaspi, Christian M.; Stubbs, Regan E.; Yaron, David J.; ...

    2015-08-20

    We report that organic light-emitting diodes (OLEDs) have received a significant attention over the past decade due to their energy-saving potential. We have recently synthesized two novel carbazole-based donor-acceptor compounds and analyzed their optical properties to determine their suitability for use as blue emitters in OLEDs. These compounds show remarkable photo-stability and high quantum yields in the blue region of the spectrum. In addition, they have highly solvatochromic emission. In non-polar solvents, bright, blue-shifted (λmax ≈ 398 nm), and highly structured emission is seen. With increasing solvent dielectric constant, the emission becomes weaker, red-shifted (λmax ≈ 507 nm), and broad.more » We aim to determine the underlying cause of these changes. Electronic structure calculations indicate the presence of multiple excited states with comparable oscillator strength. These states are of interest because there are several with charge-transfer (CT) character, and others centered on the donor moiety. We theorize that CT states play a role in the observed changes in emission lineshape and may promote charge mobility for electrofluorescence in OLEDs. In the future, we plan to use Stark spectroscopy to analyze the polarity of excited states and transient absorption spectroscopy to observe the dynamics in the excited state.« less

  17. Electronic and optical properties of novel carbazole-based donor-acceptor compounds for applications in blue-emitting organic light-emitting diodes

    SciTech Connect

    Legaspi, Christian M.; Stubbs, Regan E.; Yaron, David J.; Peteanu, Linda A.; Sfeir, Matthew Y.; Kemboi, Abraham; Picker, Jesse; Fossum, Eric

    2015-08-20

    We report that organic light-emitting diodes (OLEDs) have received a significant attention over the past decade due to their energy-saving potential. We have recently synthesized two novel carbazole-based donor-acceptor compounds and analyzed their optical properties to determine their suitability for use as blue emitters in OLEDs. These compounds show remarkable photo-stability and high quantum yields in the blue region of the spectrum. In addition, they have highly solvatochromic emission. In non-polar solvents, bright, blue-shifted (λmax ≈ 398 nm), and highly structured emission is seen. With increasing solvent dielectric constant, the emission becomes weaker, red-shifted (λmax ≈ 507 nm), and broad. We aim to determine the underlying cause of these changes. Electronic structure calculations indicate the presence of multiple excited states with comparable oscillator strength. These states are of interest because there are several with charge-transfer (CT) character, and others centered on the donor moiety. We theorize that CT states play a role in the observed changes in emission lineshape and may promote charge mobility for electrofluorescence in OLEDs. In the future, we plan to use Stark spectroscopy to analyze the polarity of excited states and transient absorption spectroscopy to observe the dynamics in the excited state.

  18. Synthesis and photovoltaic performance of novel polymeric metal complex sensitizer with benzodithiophene or carbazole derivative as donor in dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Liao, Yanlong; Hu, Jiaomei; Zhu, Chunxiao; Liu, Ye; Chen, Xu; Chen, Chenqi; Zhong, Chaofan

    2016-03-01

    Four donor-acceptor (D-A) types of novel conjugated polymeric metal complex dyes (P1-P4) with Zn (II) or Cd (II) complexes as the electron acceptors and benzodithiophene or carbazole derivative as the electron donors were designed and prepared, as promising sensitizers for dye-sensitized solar cells (DSSCs). Diaminomaleonitrile acted as ancillary ligand. The structures of the polymers were confirmed, and their thermal, optical, electrochemical, and photovoltaic properties were investigated. All conjugated polymers exhibit good thermal stability with onset decomposition temperatures with 5% weight loss over 315 °C, broad absorption with the onset of absorption at 588 nm in the visible region, and relatively lower HOMO energy levels from -5.54 to -5.71 eV. The DSSC device based on P2 which containing Cd(II) as coordination metal ion and benzodithiophene derivative as donor exhibited the highest power conversion efficiency of 2.18% under the AM 1.5 G (100 mW cm-2) sunlight illumination with an open-circuit voltage of Voc = 0.68 V, a short current density of Jsc = 4.85 mA cm-2, and a fill factor of FF = 66.2%, respectively. Therefore, these results provide a new way to design dye sensitizers for DSSCs.

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

    PubMed Central

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

    2014-01-01

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

  20. Luminescence properties of 4-hydroxy-5-phenylpyrido[3,2,1-jk]carbazol-6-one: solvatochromism and sensitivity to amine solution.

    PubMed

    Lee, Hyo-Sung; Kim, Hyun-Joon; Kang, Jun-Gill

    2011-08-01

    A detailed photophysical analysis of 4-hydroxy-5-phenylpyrido[3,2,1-jk]carbazol-6-one (HPPCO) is presented. When exposed to UV light, the compound produced deep blue to green luminescence, depending on the solvent. The luminescence peak shifts with the Gutmann donor number (DN) of the solvent and the proton substitution affects luminescence; a correlation between quantum yield and decay time indicated that proton transfer plays a key role in the observed solvatochromism. The ground-state deprotonation of HPPCO was apparently evidenced from the absorption and/or the excitation spectra in the solvents with large DN values. DFT and ZINDO calculations on the structural and optical properties have shown that deprotonation increases the contribution of oxygen atoms to the HOMO, thereby lowering the transition energy from the HOMO to the LUMO. Because the luminescence properties of HPPCO depend on proton transfer, it may be used to detect and quantitate amines in solution. The sensitivity of the luminescence to various amines was ∼10(5) M(-1) and was more effective in ethanol than in methanol.

  1. The production and characterisation of novel conducting redox-active oligomeric thin films from electrooxidised indolo[3,2,1-jk]carbazole.

    PubMed

    Wharton, Stuart I; Henry, John B; McNab, Hamish; Mount, Andrew R

    2009-01-01

    Indolo[3,2,1-jk]carbazole (IC) has been synthesised on a gram scale by flash vacuum pyrolysis. In contrast to a previous suggestion, IC is planar and it is also highly fluorescent, with a solution quantum yield of 0.41. Electro-oxidation of IC at a rotating disc electrode resulted in the passage of steady-state currents and the reproducible formation of conducting, redox-active films with constituent species that are also highly fluorescent. Unusually for coupled electroactive N-heterocyclic systems, electrochemical and spectroscopic characterisation revealed the film to consist exclusively of three redox-active (2,2', 5,5' and 2,5' coupled) IC dimers with no polymeric products. Calculations showed this coupling pattern to be consistent with IC radical-cation coupling through the accessible sites of highest unpaired electron density. The unusual combination of a high dimer second oxidation potential and a negligible dimer-dimer coupling rate explains the lack of further coupling. The identities of the dimeric species were confirmed by independent syntheses involving the Suzuki-Miyaura coupling of IC boronic acids as the key step. Electro-oxidation of the IC system therefore offers a ready route to novel conducting, redox-active molecular films and their redox-active, luminescent dimer constituents.

  2. Carbazole Dye-Sensitized Solar Cells Studied from Femtoseconds to Seconds-Effect of Additives in Cobalt- and Iodide-Based Electrolytes.

    PubMed

    Sobuś, Jan; Kubicki, Jacek; Burdziński, Gotard; Ziółek, Marcin

    2015-09-21

    Comprehensive studies of all charge-separation processes in efficient carbazole dye-sensitized solar cells are correlated with their photovoltaic parameters. An important role of partial, fast electron recombination from the semiconductor nanoparticles to the oxidized dye is revealed; this takes place on the picosecond and sub-nanosecond timescales. The charge-transfer dynamics in cobalt tris(bipyridyl) based electrolytes and iodide-based electrolyte is observed to depend on potential-determining additives in a similar way. Upon addition of 0.5 M 4-tert-butylpiridine to both types of electrolytes, the stability of the cells is greatly improved; the cell photovoltage increases by 150-200 mV, the electron injection rate decreases about five times (from 5 to 1 ps(-1) ), and fast recombination slows down about two to three times. Dye regeneration proceeds at a rate of about 1 μs(-1) in all electrolytes. Electron recombination from titania to cobalt electrolytes is much faster than that to iodide ones.

  3. AhR ligands, malassezin, and indolo[3,2-b]carbazole are selectively produced by Malassezia furfur strains isolated from seborrheic dermatitis.

    PubMed

    Gaitanis, George; Magiatis, Prokopios; Stathopoulou, Konstantina; Bassukas, Ioannis D; Alexopoulos, Evangelos C; Velegraki, Aristea; Skaltsounis, Alexios-Leandros

    2008-07-01

    Malassezia yeasts are connected with seborrheic dermatitis (SD) whereas M. furfur pathogenicity is associated with the production of bioactive indoles. In this study, the production of indoles by M. furfur isolates from healthy and diseased skin was compared, the respective HPLC patterns were analyzed, and substances that are preferentially synthesized by strains isolated from SD lesions were isolated and characterized. Malassezin, pityriacitrin, indole-3-carbaldehyde, and indolo[3,2-b]carbazole (ICZ) were isolated by HPLC from extracts of M. furfur grown in L-tryptophan agar, and identified by nuclear magnetic resonance and mass spectroscopy. Of these, ICZ, a potent ligand of the aryl hydrocarbon receptor (AhR), is described for the first time to our knowledge as a M. furfur metabolite. HPLC-photodiode array detection analysis of strain extracts from 7 healthy subjects and 10 SD patients showed that M. furfur isolates from only SD patients consistently produce malassezin and ICZ. This discriminatory production of AhR agonists provides initial evidence for a previously unreported mechanism triggering development of SD and indicates that the variable pathogenicity patterns recorded for M. furfur-associated SD conditions may be attributed to selective production (P<0.001) of measurable bioactive indoles.

  4. Biochar pyrolyzed from MgAl-layered double hydroxides pre-coated ramie biomass (Boehmeria nivea (L.) Gaud.): Characterization and application for crystal violet removal.

    PubMed

    Tan, Xiao-Fei; Liu, Yun-Guo; Gu, Yan-Ling; Liu, Shao-Bo; Zeng, Guang-Ming; Cai, Xiaoxi; Hu, Xin-Jiang; Wang, Hui; Liu, Si-Mian; Jiang, Lu-Hua

    2016-12-15

    A novel biochar/MgAl-layered double hydroxides composite (CB-LDH) was prepared for the removal of crystal violet from aqueous solution by pyrolyzing MgAl-LDH pre-coated ramie stem (Boehmeria nivea (L.) Gaud.). Pyrolysis played dual role for both converting biomass into biochar and calcining MgAl-LDH during the pyrolysis process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and zeta potential analysis were used to characterize the CB-LDH. The results of characterization suggested that the calcined LDH was successfully synthesized and coated on biochar. The resulted CB-LDH had higher total pore volume and more functional groups than the pristine biochar. Adsorption experimental data fitted well with the pseudo-second order kinetics model and the Freundlich isotherm model. The rate-controlled step was controlled by film-diffusion initially and then followed by intra-particle diffusion. Thermodynamic analysis showed that the adsorption of crystal violet was a spontaneous and endothermic process. The higher pH and temperature of the solution enhanced the adsorption performance. CB-LDH could also have excellent ability for the removal of crystal violet from the actual industrial wastewater and groundwater with high ionic strength. LDH adsorption, electrostatic attraction, pore-filling, π-π interaction and hydrogen bond might be the main mechanisms for crystal violet adsorption on CB-LDH. The results of this study indicated that CB-LDH is a sustainable and green adsorbent with high performance for crystal violet contaminated wastewater treatment and groundwater remediation.

  5. Small Molecule Reversible Inhibitors of Bruton’s Tyrosine Kinase (BTK): Structure–Activity Relationships Leading to the Identification of 7-(2-Hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9 H -carbazole-1-carboxamide (BMS-935177)

    SciTech Connect

    De Lucca, George V.; Shi, Qing; Liu, Qingjie; Batt, Douglas G.; Beaudoin Bertrand, Myra; Rampulla, Rick; Mathur, Arvind; Discenza, Lorell; D’Arienzo, Celia; Dai, Jun; Obermeier, Mary; Vickery, Rodney; Zhang, Yingru; Yang, Zheng; Marathe, Punit; Tebben, Andrew J.; Muckelbauer, Jodi K.; Chang, ChiehYing J.; Zhang, Huiping; Gillooly, Kathleen; Taylor, Tracy; Pattoli, Mark A.; Skala, Stacey; Kukral, Daniel W.; McIntyre, Kim W.; Salter-Cid, Luisa; Fura, Aberra; Burke, James R.; Barrish, Joel C.; Carter, Percy H.; Tino, Joseph A.

    2016-09-08

    Bruton’s tyrosine kinase (BTK) belongs to the TEC family of nonreceptor tyrosine kinases and plays a critical role in multiple cell types responsible for numerous autoimmune diseases. This article will detail the structure–activity relationships (SARs) leading to a novel second generation series of potent and selective reversible carbazole inhibitors of BTK. With an excellent pharmacokinetic profile as well as demonstrated in vivo activity and an acceptable safety profile, 7-(2-hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9H-carbazole-1-carboxamide 6 (BMS-935177) was selected to advance into clinical development.

  6. Focused ion beam and field-emission microscopy of metallic filaments in memory devices based on thin films of an ambipolar organic compound consisting of oxadiazole, carbazole, and fluorene units

    USGS Publications Warehouse

    Pearson, Christopher; Bowen, Leon; Lee, Myung Won; Fisher, Alison L.; Linton, Katherine E.; Bryce, Martin R.; Petty, Michael C.

    2013-01-01

    We report on the mechanism of operation of organic thin film resistive memory architectures based on an ambipolar compound consisting of oxadiazole, carbazole, and fluorene units. Cross-sections of the devices have been imaged by electron microscopy both before and after applying a voltage. The micrographs reveal the growth of filaments, with diameters of 50 nm–100 nm, on the metal cathode. We suggest that these are formed by the drift of aluminium ions from the anode and are responsible for the observed switching and negative differential resistance phenomena in the memory devices.

  7. Incorporating two different chromophores onto a silicon atom: the crystal structure and photophysical properties of 9-{4-[(9,9-dimethyl-9H-fluoren-2-yl)dimethylsilyl]phenyl}-9H-carbazole.

    PubMed

    Lee, Ah-Rang; Han, Won-Sik

    2015-03-01

    The crystal structure of the title bifunctional silicon-bridged compound, C(35)H(31)NSi, (I), has been determined. The compound crystallizes in the centrosymmetric space group P2(1)/c. In the crystal structure, the pairs of aryl rings in the two different chromophores, i.e. 9-phenyl-9H-carbazole and 9,9-dimethyl-9H-fluorene, are positioned orthogonally. In the crystal packing, no classical hydrogen bonding is observed. UV-Vis absorption and fluorescence emission spectra show that the central Si atom successfully breaks the electronic conjugation between the two different chromophores, and this was further analysed by density functional theory (DFT) calculations.

  8. Focused ion beam and field-emission microscopy of metallic filaments in memory devices based on thin films of an ambipolar organic compound consisting of oxadiazole, carbazole, and fluorene units

    NASA Astrophysics Data System (ADS)

    Pearson, Christopher; Bowen, Leon; Lee, Myung-Won; Fisher, Alison L.; Linton, Katharine E.; Bryce, Martin R.; Petty, Michael C.

    2013-05-01

    We report on the mechanism of operation of organic thin film resistive memory architectures based on an ambipolar compound consisting of oxadiazole, carbazole, and fluorene units. Cross-sections of the devices have been imaged by electron microscopy both before and after applying a voltage. The micrographs reveal the growth of filaments, with diameters of 50 nm-100 nm, on the metal cathode. We suggest that these are formed by the drift of aluminium ions from the anode and are responsible for the observed switching and negative differential resistance phenomena in the memory devices.

  9. A compact and efficient hyper coherent light source of visible violet laser diode based on Pound-Drever-Hall technique

    NASA Astrophysics Data System (ADS)

    Sasaki, Wakao; Yashiro, Hideyuki; Miura, Yukio; Mizutani, Kouki; Nakajima, Jun

    2007-09-01

    In the present work, we have developed an efficient and well stablized hyper coherent diode laser light source as compact as even portable using commercially available visible 400 nm band laser diodes. The attained coherence of the present system can always be controlled at the best condition indifferent to changes in its settled environmental conditions by applying Pound-Drever-Hall technique in which the frequency of a 160mW type 405nm GaN violet laser diode is locked to a reference Fabry-Perot cavity by negative electrical feedback for the injection current of the laser diode based on FM sideband technique. In addition to this frequency stabilization system, we have also realized a stability evaluation system that can measure the Allan variance of the frequency fluctuations of our frequency stabilized laser source in real-time basis by using simple devices of a portable computer and a digital signal processing unit. As a result, we have accomplished a compact and efficient hyper coherent laser system which can always perform its optimum conditions even if the environmental conditions around the laser are to be dynamically changed when used in a field basis. The attained values of power spectral density (PSD) of FM noise calculated from the error signals of our system under controlled condition were better by about 1~2 orders than typical values of free-running conditions in the fourier frequency domain from 100Hz to 300kHz. The best achieved value of PSD was about 2.56×10 7 [Hz2/Hz] in the fourier frequency domain from 100Hz to 1kHz, while as for the Allan variance as another measure of frequency stability, the achieved value of the minimum square root of Allan variance was 3.46×10 -11 in a 400nm type violet laser diode at integration time of 10 ms, which has been well comparable to the hyper coherent condition for the laser diode light sources.

  10. Successful Treatment of Severe Tungiasis in Pigs Using a Topical Aerosol Containing Chlorfenvinphos, Dichlorphos and Gentian Violet

    PubMed Central

    Mutebi, Francis; von Samson-Himmelstjerna, Georg; Feldmeier, Hermann; Waiswa, Charles; Bukeka Muhindo, Jeanne; Krücken, Jürgen

    2016-01-01

    Background In endemic communities, zoonotic tungiasis, a severe skin disease caused by penetrating female sand fleas, is a public health hazard causing significant human and animal morbidity. No validated drugs are currently available for treatment of animal tungiasis. Due to the reservoir in domestic animals, integrated management of human and animal tungiasis is required to avert its negative effects. Methods and principal findings A topical aerosol containing chlorfenvinphos 4.8%, dichlorphos 0.75% and gentian violet 0.145% licensed to treat tick infestations, myiasis and wound sepsis in animals in the study area, was tested for its potential tungicidal effects in a randomized controlled field trial against pig tungiasis in rural Uganda. Animals with at least one embedded flea were randomized in a treatment (n = 29) and a control (n = 26) group. One week after treatment, 58.6% of the treated pigs did not show any viable flea lesion whereas all control pigs had at least one viable lesion. After treatment the number of viable lesions (treated median = 0, overall range = 0–18 vs. control median = 11.5, range = 1–180) and the severity score for estimating acute pathology in pig tungiasis (treated median = 1, range = 0–3.5 vs. control median = 7, range = 0–25) were significantly lower in treated than in control pigs (p < 0.001). In the treatment group the median number of viable flea lesions decreased from 8.5 to 0 (p < 0.001). Similarly, the median acute severity score dropped from 6 to 1 (p < 0.001). Every pig in the treatment group showed a decrease in the number of viable fleas and tungiasis-associated acute morbidity while medians for both increased in the control group. Conclusions The study demonstrates that a topical treatment based on chlorfenvinphos, dichlorphos and gentian violet is highly effective against pig tungiasis. Due to its simplicity, the new approach can be used for the treatment of individual animals as well as in mass campaigns. PMID

  11. Delineation of G-Quadruplex Alkylation Sites Mediated by 3,6-Bis(1-methyl-4-vinylpyridinium iodide)carbazole-Aniline Mustard Conjugates.

    PubMed

    Chen, Chien-Han; Hu, Tsung-Hao; Huang, Tzu-Chiao; Chen, Ying-Lan; Chen, Yet-Ran; Cheng, Chien-Chung; Chen, Chao-Tsen

    2015-11-23

    A new G-quadruplex (G-4)-directing alkylating agent BMVC-C3M was designed and synthesized to integrate 3,6-bis(1-methyl-4-vinylpyridinium iodide)carbazole (BMVC) with aniline mustard. Various telomeric G-4 structures (hybrid-2 type and antiparallel) and an oncogene promoter, c-MYC (parallel), were constructed to react with BMVC-C3M, yielding 35 % alkylation yield toward G-4 DNA over other DNA categories (<6 %) and high specificity under competition conditions. Analysis of the intact alkylation adducts by electrospray ionization mass spectroscopy (ESI-MS) revealed the stepwise DNA alkylation mechanism of aniline mustard for the first time. Furthermore, the monoalkylation sites and intrastrand cross-linking sites were determined and found to be dependent on G-4 topology based on the results of footprinting analysis in combination with mass spectroscopic techniques and in silico modeling. The results indicated that BMVC-C3M preferentially alkylated at A15 (H26), G12 (H24), and G2 (c-MYC), respectively, as monoalkylated adducts and formed A15-C3M-A21 (H26), G12-C3M-G4 (H24), and G2-C3M-G4/G17 (c-MYC), respectively, as cross-linked dialkylated adducts. Collectively, the stability and site-selective cross-linking capacity of BMVC-C3M provides a credible tool for the structural and functional characterization of G-4 DNAs in biological systems.

  12. Synthesis, characterization and properties of novel blue light emitting discrete π-functional polymer consisting of carbazole and anthracene units and their applications in polymer light emitting diodes

    NASA Astrophysics Data System (ADS)

    Gopal, Ram; Huang, Yi-Chiang; Lee, Hsu-Feng; Chang, Ming-Sien; Huang, Wen-Yao

    2017-03-01

    A new novel blue light emitting polymer containing carbazole and anthracene derivatives has been successfully synthesized via polycondensation chemical reaction of diol and difluoro monomers. An effort has been made to raise the band gap of blue light emitter by lowering the conjugation extent in the backbone. The synthesized blue polymer exhibits decent solubility, good process ability, high thermal stability, high glass transition temperature (272 °C) and the decomposition temperature of 358 °C. The UV-vis absorption spectra and photoluminescence spectra depict that the light emission lies in blue region. The solid state photoluminescence (PL) spectra of the polymer (λPL=456 nm) shows red shift (Δλ = 37 nm) as compared with the corresponding solution PL spectra, presumably due to lower intermolecular distance in solid state. The multi-layered polymer light emitting diode was fabricated, using blue polymer with ITO/PEDOT: PSS/BP/LiF/Al architecture. The luminance-voltage (L-V) and current density-voltage (J-V) curves show a maximum luminance of 7544 cd m-2, a maximum emission efficiency of 4.2 cd A-1, a maximum current density of 453 mA cm-2 at a turn-on voltage of 4.5 V. Moreover, the PLED instigate pure blue EL emission, stable at 436 nm with outstanding CIE coordinates of (x = 0.15, y = 0.08), which is close to the pure NTSC blue coordinates of (0.14, 0.08). [Figure not available: see fulltext.

  13. Induction of long interspersed nucleotide element-1 (L1) retrotransposition by 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct.

    PubMed

    Okudaira, Noriyuki; Iijima, Kenta; Koyama, Takayoshi; Minemoto, Yuzuru; Kano, Shigeyuki; Mimori, Akio; Ishizaka, Yukihito

    2010-10-26

    Long interspersed nucleotide element-1 (L1) is a retroelement comprising about 17% of the human genome, of which 80-100 copies are competent as mobile elements (retrotransposition: L1-RTP). Although the genetic structures modified during L1-RTP have been clarified, little is known about the cellular signaling cascades involved. Herein we found that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct postulated as a candidate physiological ligand of the aryl hydrocarbon receptor (AhR), induces L1-RTP. Notably, RNA-interference experiments combined with back-transfection of siRNA-resistant cDNAs revealed that the induction of L1-RTP by FICZ is dependent on AhR nuclear translocator-1 (ARNT1), a binding partner of AhR, and the activation of cAMP-responsive element-binding protein. However, our extensive analyses suggested that AhR is not required for L1-RTP. FICZ stimulated the interaction of the L1-encoded open reading frame-1 (ORF1) and ARNT1, and recruited ORF1 to chromatin in a manner dependent on the activation of mitogen-activated protein kinase. Along with our additional observations that the cellular cascades for FICZ-induced L1-RTP were different from those of L1-RTP triggered by DNA damage, we propose that the presence of the cellular machinery of ARNT1 mediates L1-RTP. A possible role of ARNT1-mediated L1-RTP in the adaptation of living organisms to environmental changes is discussed.

  14. An efficient removal of crystal violet dye from waste water by adsorption onto TLAC/Chitosan composite: A novel low cost adsorbent.

    PubMed

    Jayasantha Kumari, H; Krishnamoorthy, P; Arumugam, T K; Radhakrishnan, S; Vasudevan, D

    2017-03-01

    A composite of Typha latifolia activated carbon (TLAC) (a novel, low cost absorbent) and chitosan (TLAC/Chitosan composite) was prepared. The composite was characterised using IR spectra, XRD, FESEM and Pore size studies. Its effectivity was tested for the removal of crystal violet dye from aqueous solutions. The effect of pH, dose rate and initial dye concentration was evaluated. The adsorption isotherm, kinetics and thermodynamic parameters were studied. Langmuir and Freundlich isotherm models were found fit effectively for the dye adsorption data in the present study. The adsorption followed pseudo-second order kinetics. The evaluated thermodynamic parameters show a spontaneous and exothermic reaction. Overall, this study indicates TLAC/Chitosan composite as an effective adsorbent for the removal of crystal violet dye from aqueous solutions.

  15. Post-column reaction for simultaneous analysis of chromatic and leuco forms of malachite green and crystal violet by high-performance liquid chromatography with photometric detection

    USGS Publications Warehouse

    Allen, J.L.; Meinertz, J.R.

    1991-01-01

    The chromatic and leuco forms of malachite green and crystal violet were readily separated and detected by a sensitive and selective high-performance liquid chromatographic procedure. The chromatic and leuco forms of the dyes were separated within 11 min on a C18 column with a mobile phase of 0.05 M sodium acetate and 0.05 M acetic acid in water (19%) and methanol (81%). A reaction chamber, containing 10% PbO2 in Celite 545, was placed between the column and the spectrophotometric detector to oxidize the leuco forms of the dyes to their chromatic forms. Chromatic and leuco malachite green were quantified by their absorbance at 618 nm; and chromatic and leuco Crystal Violet by their absorbance at 588 nm. Detection limits for chromatic and leuco forms of both dyes ranged from 0.12 to 0.28 ng. A linear range of 1 to 100 ng was established for both forms of the dyes.

  16. Efficient degradation of crystal violet in magnetic CuFe2O4 aqueous solution coupled with microwave radiation.

    PubMed

    Chen, Hongzhe; Yang, Shaogui; Chang, Jiao; Yu, Kai; Li, Dongfang; Sun, Cheng; Li, Aimin

    2012-09-01

    Nanoscale copper ferrite was prepared by co-precipitation method, while citrate acid assisted method was used as reference. Microwave-induced degradation of crystal violet was performed with synthesized copper ferrite, and the behavior of copper ferrite in this process was studied by X-ray photoelectron spectroscopy, SEM/EDS and vector network analyzer. Microwave radiation could greatly enhance the activity of copper ferrite in organic oxidation. The variant of copper and iron on the surface and in the inner core of copper ferrite was studied here. Copper ferrite presents relatively low dielectric loss. Meanwhile, microwave radiation makes a faster degradation than conventional heating process, indicating an indispensable non-thermal effect of microwave with copper ferrite in the process. Microwave induced holes could be responsible for the efficient degradation. The effect of annealing on crystallization and degradation process was considered here, and the intermediates and products were studied by GC-MS and LC-MS to provide a comprehensively evaluation of degradation.

  17. HPLC determination and MS confirmation of malachite green, gentian violet, and their leuco metabolite residues in channel catfish muscle.

    PubMed

    Chen, Guoying; Miao, Shui

    2010-06-23

    Residues of malachite green (MG), gentian violet (GV), and their leuco metabolites in channel catfish muscle were individually determined by HPLC using diode array and fluorescence detectors and confirmed by tandem mass spectrometry. This detection scheme obviates a PbO(2) reactor that converts leuco forms to chromatic forms for absorbance detection, therefore eliminating uncertainties in oxidant depletion and data integrity. Extraction was performed once in pH 3 McIlvaine buffer and acetonitrile, followed by cleanup using a polymeric strong cation-exchange column. Liquid-liquid extraction was excluded to provide an environmentally responsible and relatively rapid protocol. Spectrometric limits of detection (LOD; S/N = 3) for MG (lambda = 620 nm) and GV (lambda = 588 nm) were 0.38 and 0.26 ng/g with 44.5-49.2% and 92.2-101.4% recoveries (1-10 ng/g, n = 6), respectively. Fluorometric LOD (S/N = 3) for LMG and LGV (lambda(ex) = 266 nm, lambda(em) = 360 nm) were 0.10 and 0.09 ng/g with 74.3-84.5% and 80.6-86.5% recoveries (1-10 ng/g, n = 6), respectively. This simplified protocol saves costs and meets the sensitivity requirements set by the Food and Drug Administration and the European Union.

  18. Tinea Capitis: Mixed or Consecutive Infection with White and Violet Strains of Trichophyton violaceum: A Diagnostic or Therapeutic Challenge

    PubMed Central

    Goyal, Roma

    2015-01-01

    Tinea capitis is a common dermatophyte infection affecting scalp and hair of pre-pubertal children. With introduction of Griseofulvin in 1958, there has been considerable improvement in the treatment of tinea capitis. A seven-year-old male child was brought to the dermatology clinic. He presented with diffuse white scaly patches of alopecia on scalp of one-year duration. The child was sent to the microbiology section of the National Health laboratory, Botswana for the collection of the samples. The samples consisted of scalp scrapings and few plucked hairs from the suspicious areas, which were collected by swab and scalpel blade methods. Potassium hydroxide (10% KOH) mounts were prepared for scales and hair samples. Scales were positive for fungal elements and endothrix type of perforation was seen in hair. Cultures on Sabouraud’s dextrose agar (SDA) and Derm agar were incubated at 25°C, which yielded white variant of Trichophyton violaceum after two weeks of incubation. T. vioaceum (white variant) grew in all the plates. After six weeks of treatment with griseofulvin, the repeat culture grew only T. violaceum (violet strain). The child showed a definite clinical improvement. PMID:26814801

  19. Vacuum ultra-violet damage and damage mitigation for plasma processing of highly porous organosilicate glass dielectrics

    SciTech Connect

    Marneffe, J.-F. de Lukaszewicz, M.; Porter, S. B.; Vajda, F.; Rutigliani, V.; Verdonck, P.; Baklanov, M. R.; Zhang, L.; Heyne, M.; El Otell, Z.; Krishtab, M.; Goodyear, A.; Cooke, M.

    2015-10-07

    Porous organosilicate glass thin films, with k-value 2.0, were exposed to 147 nm vacuum ultra-violet (VUV) photons emitted in a Xenon capacitive coupled plasma discharge. Strong methyl bond depletion was observed, concomitant with a significant increase of the bulk dielectric constant. This indicates that, besides reactive radical diffusion, photons emitted during plasma processing do impede dielectric properties and therefore need to be tackled appropriately during patterning and integration. The detrimental effect of VUV irradiation can be partly suppressed by stuffing the low-k porous matrix with proper sacrificial polymers showing high VUV absorption together with good thermal and VUV stability. In addition, the choice of an appropriate hard-mask, showing high VUV absorption, can minimize VUV damage. Particular processing conditions allow to minimize the fluence of photons to the substrate and lead to negligible VUV damage. For patterned structures, in order to reduce VUV damage in the bulk and on feature sidewalls, the combination of both pore stuffing/material densification and absorbing hard-mask is recommended, and/or the use of low VUV-emitting plasma discharge.

  20. Simultaneous and sequential adsorption of crystal violet and 2-naphthol onto montmorillonite: a microstructural and thermodynamic study.

    PubMed

    Zhu, Jianxi; Wei, Jingming; Zhu, Runliang; Qing, Yanhong; Ge, Fei; Yuan, Peng; He, Hongping

    2010-01-01

    Thermodynamic analysis of simultaneous and sequential adsorption of crystal violet (CV) and 2-naphthol adsorption on montmorillonite has been conducted, and the changes of microstructure of the clay after adsorption were investigated using X-ray diffraction (XRD). The basal spacing and structural order of CV and 2-naphthol adsorbed montmorillonites varied with different CV loadings. In principle, larger basal spacing was resulted from a higher loading of CV in montmorillonites. The excellent structural order of the resultant hybrids is achieved in samples with 0.50-0.75 CEC (cation exchange capacity) loadings of CV. The effects of temperature and ionic strength on the adsorption of CV and 2-naphthol on montmorillonite were also investigated. The Freundlich isotherm model was applied for curve-fitting of the equilibrium isotherm data. The resulting thermodynamics parameters suggested that the sorption process was a spontaneous exothermic process in the case of low CV concentrations. The negative values of Gibbs free energy in all of the adsorption processes indicated that these processes are spontaneous processes. With the increase of CV concentration, the sequential adsorption of 2-naphthol onto montmorillonite proved to be an endothermic process.

  1. Experimental design approach applied to the elimination of crystal violet in water by electrocoagulation with Fe or Al electrodes.

    PubMed

    Durango-Usuga, Paula; Guzmán-Duque, Fernando; Mosteo, Rosa; Vazquez, Mario V; Peñuela, Gustavo; Torres-Palma, Ricardo A

    2010-07-15

    An experimental design methodology was applied to evaluate the decolourization of crystal violet (CV) dye by electrocoagulation using iron or aluminium electrodes. The effects and interactions of four parameters, initial pH (3-9), current density (6-28 A m(-2)), substrate concentration (50-200 mg L(-1)) and supporting electrolyte concentration (284-1420 mg L(-1) of Na(2)SO(4)), were optimized and evaluated. Although the results using iron anodes were better than for aluminium, the effects and interactions of the studied parameters were quite similar. With a confidence level of 95%, initial pH and supporting electrolyte concentration showed limited effects on the removal rate of CV, whereas current density, pollutant concentration and the interaction of both were significant. Reduced models taking into account significant variables and interactions between variables have shown good correlations with the experimental results. Under optimal conditions, almost complete removal of CV and chemical oxygen demand were obtained after electrocoagulation for 5 and 30 min, using iron and aluminium electrodes, respectively. These results indicate that electrocoagulation with iron anodes is a rapid, economical and effective alternative to the complete removal of CV in waters. Evolutions of pH and residual iron or aluminium concentrations in solution are also discussed.

  2. Electrochemical degradation of crystal violet with BDD electrodes: effect of electrochemical parameters and identification of organic by-products.

    PubMed

    Palma-Goyes, Ricardo E; Guzmán-Duque, Fernando L; Peñuela, Gustavo; González, Ignacio; Nava, Jose L; Torres-Palma, Ricardo A

    2010-09-01

    This paper explores the applicability of electrochemical oxidation on a triphenylmethane dye compound model, hexamethylpararosaniline chloride (or crystal violet, CV), using BDD anodes. The effect of the important electrochemical parameters: current density (2.5-15 m A cm(-2)), dye concentration (33-600 mg L(-1)), sodium sulphate concentration (7.1-50.0 g L(-1)) and initial pH (3-11) on the efficiency of the electrochemical process was evaluated. The results indicated that while the current density was lower than the limiting current density, no side products (hydrogen peroxide, peroxodisulphate, ozone and chlorinated oxidizing compounds) were generated and the degradation, through OH radical attack, occurred with high efficiency. Analysis of intermediates using GC-MS investigation identified several products: N-methylaniline, N,N-dimethylaniline, 4-methyl-N,N-dimethylaniline, 4-methyl-N-methylaniline, 4-dimethylaminophenol, 4-dimethylaminobenzoic acid, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino) diphenylmethane, 4-(4-dimethylaminophenyl)-N,N-dimethylaniline, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino) benzophenone. The presence of these aromatic structures showed that the main CV degradation pathway is related to the reaction of CV with the OH radical. Under optimal conditions, practically 100% of the initial substrate and COD were eliminated in approximately 35 min of electrolysis; indicating that the early CV by-products were completely degraded by the electrochemical system.

  3. Batch and continuous (fixed-bed column) biosorption of crystal violet by Artocarpus heterophyllus (jackfruit) leaf powder.

    PubMed

    Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik

    2012-04-01

    In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions.

  4. Redox cycling effect on the surface-enhanced Raman scattering signal of crystal violet molecules at nanostructured interdigitated array electrodes.

    PubMed

    Islam, Md Monirul; Ueno, Kosei; Misawa, Hiroaki

    2010-01-01

    Nanostructured interdigitated array (IDA) electrodes with different inter-electrode spacing were demonstrated to improve the detection sensitivity of short-lived electroactive species and to follow interfacial dynamics by their surface-enhanced Raman scattering (SERS) functionality. Nanostructured IDA electrodes fabricated using electron beam lithography were used for an electrochemical SERS study of irreversible electroactive species, crystal violet (CV), in an aqueous KCl solution in single and generation-collection (GC) mode experiments. The GC mode enabled us to amplify the SERS intensity. An inter-electrode spacing dependent study found the maximum number of redox cycling, collection efficiency and amplification of the SERS intensity. Its SERS function disclosed the potential-dependent dynamics of CV molecules at the electrode surface, which was not observed in the redox current. Miniaturized nanostructured IDA electrodes are of great importance for developing lab on chip devices, and are useful for analyzing dynamical features within small space/volume domains, which require small amounts and/or concentration of analytes.

  5. Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

    PubMed

    Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

    2010-01-01

    Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

  6. Comparison of Fecal Coliform Agar and Violet Red Bile Lactose Agar for Fecal Coliform Enumeration in Foods

    PubMed Central

    Leclercq, A.; Wanegue, C.; Baylac, P.

    2002-01-01

    A 24-h direct plating method for fecal coliform enumeration with a resuscitation step (preincubation for 2 h at 37 ± 1°C and transfer to 44 ± 1°C for 22 h) using fecal coliform agar (FCA) was compared with the 24-h standardized violet red bile lactose agar (VRBL) method. FCA and VRBL have equivalent specificities and sensitivities, except for lactose-positive non-fecal coliforms such as Hafnia alvei, which could form typical colonies on FCA and VRBL. Recovery of cold-stressed Escherichia coli in mashed potatoes on FCA was about 1 log unit lower than that with VRBL. When the FCA method was compared with standard VRBL for enumeration of fecal coliforms, based on counting carried out on 170 different food samples, results were not significantly different (P > 0.05). Based on 203 typical identified colonies selected as found on VRBL and FCA, the latter medium appears to allow the enumeration of more true fecal coliforms and has higher performance in certain ways (specificity, sensitivity, and negative and positive predictive values) than VRBL. Most colonies clearly identified on both media were E. coli and H. alvei, a non-fecal coliform. Therefore, the replacement of fecal coliform enumeration by E. coli enumeration to estimate food sanitary quality should be recommended. PMID:11916678

  7. Resonance light scattering of 1-hydroxypyrene-ethyl violet-anionic surfactant system and its analytical application.

    PubMed

    Ou-Yang, Yun Fu; Wang, Yong Sheng; Mi, Xian Wen; Xue, Jin Hua; Wang, Ying

    2007-05-01

    A novel method for the rapid and sensitive analysis of 1-hydroxypyrene (1-OHP) in human urine has been developed that uses a resonance light scattering (RLS) technique. The assay was based on the interaction of ethyl violet (EV) with 1-hydroxypyrene to form an ion-associate complex, which resulted in the enhancement of RLS intensity and the appearance of new RLS spectra. In the presence of anionic surfactant, the maximum RLS peak of the system was located at 396 nm at pH 8.0. Under the optimum conditions, it was found that the enhanced RLS intensity was directly proportional to the concentration of 1-hydroxypyrene in the range of 4.0 - 982 microg l(-1). The detection limit was 1.2 microg l(-1) and the recoveries of 1-hydroxypyrene were 92.8 - 102.3% (n = 6). The proposed method was successfully applied to the analysis of human urine samples. The results of 1-hydroxypyrene were in agreement with those obtained by the method of high-performance liquid chromatography.

  8. Application of ionic liquid-based microwave-assisted extraction of malachite green and crystal violet from water samples.

    PubMed

    Gao, Zhanqi; Liu, Tingfeng; Yan, Xiaoju; Sun, Cheng; He, Huan; Yang, Shaogui

    2013-03-01

    A simple, environment friendly and efficient technique, ionic liquid-based microwave-assisted extraction was first used to determine malachite green and crystal violet (CV) from water samples coupled to HPLC. The key parameters influencing extraction efficiency were investigated, such as the type of ionic liquids, the volume of ionic liquid, extraction time, and so on. Under the optimum conditions, good reproducibility of the extraction performance was obtained (RSD, 1.0% for malachite green (MG) and 5.9% for CV, n = 5). Good linearity (0.10-25 μg L(-1)) was observed with correlation coefficients between 0.9991 and 0.9964. The detection limits of MG and CV were 0.080 and 0.030 μg L(-1), respectively. The proposed method had been successfully applied to determine MG and CV in real water samples with recoveries ranging from 95.4 to 102.8%. Compared with the previous technologies, the proposed method required less extraction time (2 min), and provided lower detection limits and higher enrichment factors. Moreover, there were no volatile and hazardous organic solvents released. Based on these simple, environment friendly, rapid, and highly efficient results, the proposed approach provides a new and promising alternative for simultaneously extracting trace amounts of MG and CV from water.

  9. Improvement of mannitol lysine crystal violet brilliant green agar for the selective isolation of H2S-positive Salmonella.

    PubMed

    Kodaka, H; Mizuochi, S; Honda, T; Yamaguchi, K

    2000-12-01

    Mannitol lysine crystal violet brilliant green agar (MLCB) is widely used in Japan for Salmonella isolation because the medium has been commercially available. Colonies of Salmonella on MLCB appear colorless with black centers due to H2S gas production; however, most Citrobacter freundii also produce H2S gas. In order to distinguish H2S-positive Salmonella from C. freundii we have improved MLCB. To MLCB was added 1% lactose (L-MLCB). The relation for pH and black center colony formation was examined. The pH of MLCB and L-MLCB inoculated with Salmonella species was slightly acid after 7 h, but the pH of L-MLCB inoculated with C. freundii did not become acid for 24 h. The colony of C. freundii did not have a black center because the production of acid from lactose lowers the pH below 10 where it is needed for H2S to react with iron to produce black pigments. Of 99 Salmonella strains including 13 serotypes tested, all strains had the same colony morphologies on MLCB and L-MLCB. When MLCB and L-MLCB were evaluated with 36 C. freundii strains isolated from foods, only colonies on MLCB had black centers. We conclude that L-MLCB is useful for detection of nonlactose-fermenting, H2S-positive Salmonella in food samples.

  10. Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis

    PubMed Central

    Coban, Ahmet Yilmaz; Akbal, Ahmet Ugur; Bicmen, Can; Albay, Ali; Sig, Ali Korhan; Uzun, Meltem; Selale, Deniz Sertel; Ozkutuk, Nuri; Surucuoglu, Suheyla; Albayrak, Nurhan; Ucarman, Nilay; Ozkutuk, Aydan; Esen, Nuran; Ceyhan, Ismail; Ozyurt, Mustafa; Bektore, Bayhan; Aslan, Gonul; Delialioğlu, Nuran; Alp, Alpaslan

    2016-01-01

    The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1–7. In the phase 2, 156 clinical isolates were tested in the center 1–6, center 8–11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2–96.8% for INH and 98.1–98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries. PMID:27982061

  11. Microaerophilic Symmetric Reductive Cleavage of Reactive Azo Dye-Remazole Brilliant Violet 5R by Consortium VIE6: Community Synergism.

    PubMed

    Shah, Binal; Jain, Kunal; Jiyani, Hardik; Mohan, Venkata; Madamwar, Datta

    2016-11-01

    The textile-dyeing industry is rated as one of the foremost industrial sectors that explodes large amount of pollutants to the environment. Reactive azo dye degradation, being a major constituent of these pollutants and perilous material, has been constantly receiving scientific attention. In textile industry, use of Remazole Brilliant Violet 5R (RBV5R) as reactive azo dyes is more frequent. Highly competent, RBV5R-degrading bacterial consortium VIE6 was developed from the soil of the Vatva Industrial Estate, Gujarat, India. Consortium VIE6 comprised of five bacterial strains Bacillus sp. DMB1, Staphylococcus sp. DMB2, Escherichia sp. DMB3, Enterococcus sp. DMB4, and Pseudomonas sp. DMB5. These strains convened a better decolorization efficiency between 200 and 1000 mg/L of dye concentration and were much stable at pH 6.5, 37 °C. Azoreductase, laccase, and lignin peroxidase activities of consortium showed significant variation throughout the degradation process indicating the different metabolic capabilities of the existing microflora. The community interactions and synergism were shown to facilitate the biotransformation of RBV5R by combination of various electron donors. Voltammograms revealed the variations in electron discharge properties which coincide with the dynamics of community derived using qPCR assays. The variation in catabolic capabilities of the individual strains was observed during active metabolism of RBV5R degradation pertaining to the aerobic and facultative functions.

  12. Impact of thermal crosstalk between emitters on power roll-over in nitride-based blue-violet laser bars

    NASA Astrophysics Data System (ADS)

    Śpiewak, P.; Wasiak, M.; Kuc, M.; Stańczyk, Sz; Perlin, P.; Nakwaski, W.; Sarzała, R. P.

    2017-02-01

    This paper investigates the effect of thermal crosstalk between the emitters of a laser bar composed of nitride-based blue-violet lasers on power roll-over, with the aid of a comprehensive self-consistent computer simulation. The main goal is to develop a method of reducing the impact of mutual interactions between the emitters on laser radiation power. Suggestions are made for possible design optimization of nitride-based laser bars, to reduce their power roll-over effect. Efficient room-temperature continuous-wave operation was found to depend mostly on laser bar width. For wider bars, increasing the number of emitters appears to raise the emitted power. For narrower laser bars, this effect can better be achieved by thermal optimization of an individual emitter. How the bar is mounted on the heat sink is an important factor. The heat sink should also be much larger than the bar. Using a p-down mounting can significantly improve laser bar performance.

  13. Violet and blue upconversion luminescence in Tm3+/Yb3+ codoped Y2O3 transparent ceramic

    NASA Astrophysics Data System (ADS)

    Hou, Xiaorui; Zhou, Shengming; Lin, Hui; Teng, Hao; Li, Yukun; Li, Wenjie; Jia, Tingting

    2010-04-01

    Tm3+/Yb3+ codoped Y2O3 transparent ceramics were fabricated and characterized from the point of upconversion luminescence. All the samples exhibited high transparency not only in near-infrared band but also in visible region. Under 980 nm excitation, the ceramics gave upconversion luminescence with very intense blue (485 nm) and considerably intense violet (360 nm) emissions. It was worthy to point out that the upconversion luminescence contained six emission bands, which dispersed in the region from 294 to 809 nm. The strongest blue emission (485 nm) was obtained with (Tm0.002Yb0.03Y0.958Zr0.01)2O3 ceramic (Yb/Tm=15). The mechanism of all upconversion emission bands were investigated in detail. The absorption, emission, and gain cross-section of blue emission (485 nm) were calculated, which indicated that Tm3+/Yb3+ codoped Y2O3 transparent ceramic has tremendous potential in short wavelength laser.

  14. Effectiveness of photochemical and sonochemical processes in degradation of Basic Violet 16 (BV16) dye from aqueous solutions

    PubMed Central

    2012-01-01

    In this study, degradation of Basic Violet 16 (BV16) by ultraviolet radiation (UV), ultrasonic irradiation (US), UV/H2O2 and US/H2O2 processes was investigated in a laboratory-scale batch photoreactor equipped with a 55W immersed-type low-pressure mercury vapor lamp and a sonoreactor with high frequency (130kHz) plate type transducer at 100W of acoustic power. The effects of initial dye concentration, concentration of H2O2 and solution pH and presence of Na2SO4 was studied on the sonochemical and photochemical destruction of BV16 in aqueous phase. The results indicated that in the UV/H2O2 and US/H2O2 systems, a sufficient amount of H2O2 was necessary, but a very high H2O2 concentration would inhibit the reaction rate. The optimum H2O2 concentration was achieved in the range of 17 mmol/L at dye concentration of 30 mg/L. A degradation of 99% was obtained with UV/H2O2 within 8 minutes while decolorization efficiency by using UV (23%), US (<6%) and US/H2O2(<15%) processes were negligible for this kind of dye. Pseudo-first order kinetics with respect to dyestuffs concentrations was found to fit all the experimental data. PMID:23369268

  15. Multiple shifts between violet and ultraviolet vision in a family of passerine birds with associated changes in plumage coloration

    PubMed Central

    Ödeen, Anders; Pruett-Jones, Stephen; Driskell, Amy C.; Armenta, Jessica K.; Håstad, Olle

    2012-01-01

    Colour vision in diurnal birds falls into two discrete classes, signified by the spectral sensitivity of the violet- (VS) or ultraviolet-sensitive (UVS) short wavelength-sensitive type 1 (SWS1) single cone. Shifts between sensitivity classes are rare; three or four are believed to have happened in the course of avian evolution, one forming UVS higher passerines. Such shifts probably affect the expression of shortwave-dominated plumage signals. We have used genomic DNA sequencing to determine VS or UVS affinity in fairy-wrens and allies, Maluridae, a large passerine family basal to the known UVS taxa. We have also spectrophotometrically analysed male plumage coloration as perceived by the VS and UVS vision systems. Contrary to any other investigated avian genus, Malurus (fairy-wrens) contains species with amino acid residues typical of either VS or UVS cone opsins. Three bowerbird species (Ptilonorhynchidae) sequenced for outgroup comparison carry VS opsin genes. Phylogenetic reconstructions render one UVS gain followed by one or more losses as the most plausible evolutionary scenario. The evolution of avian ultraviolet sensitivity is hence more complex, as a single shift no longer explains its distribution in Passeriformes. Character correlation analysis proposes that UVS vision is associated with shortwave-reflecting plumage, which is widespread in Maluridae. PMID:21976683

  16. Catalytic effect of supported metal ion complexes on the induced oxidative degradation of pyrocatechol violet by hydrogen peroxide.

    PubMed

    Gemeay, Ali H; Mansour, Ikhlas A; El-Sharkawy, Rehab G; Zaki, Ahmed B

    2003-07-01

    Kinetics of the oxidative degradation of pyrocatechol violet dye (PCV) [2-[(3,4-dihydroxyphenyl)(3-hydroxy-4-oxocyclohexa-2,5-dien-1-ylidene) methyl]-benzenesulfonic acid] by H(2)O(2) catalyzed by supported transition metal complexes have been studied. The reaction was followed by conventional UV-vis spectrophotometer at lambda(max)=440 nm in a buffer solution at pH 5.1. The supports used were silica gel and cation exchange resins (Dowex-50W, 2 and 8% DVB), while the complexes were [Cu(amm)(4)](2+), [Cu(en)(2)](2+), [Cu(ma)(4)](2+), [Co(amm)(6)](2+), and [Ni(amm)(6)](2+) (amm=ammonia, en=ethylenediamine, and ma=methylamine). The reaction exhibited first-order kinetics with respect to [PCV] and [H(2)O(2)]. The reactivity of the catalysts is correlated with the redox potential of the metal ions, the type of support, and the amount of supported complexes. The rate of the reaction increases with increasing pH and the addition of NaCl. Addition of SDS and CTAB showed inhibiting effects. The reaction is enthalpy-controlled as confirmed from the isokinetic relationship. A reaction mechanism involved the generation of free radicals as an oxidant has been proposed.

  17. Bandgap-tailored NiO nanospheres: an efficient photocatalyst for the degradation of crystal violet dye solution

    NASA Astrophysics Data System (ADS)

    Vahini, Raja; Kumar, Puvaneswaran Senthil; Karuthapandian, Swaminathan

    2016-08-01

    Bandgap-tailored NiO nanospheres were successfully synthesized by facile precipitation method for the first time and characterized by XRD, EDX, SEM, TEM, FTIR, UV and PL. Interestingly, the modification of the band gap was observed using UV-Vis (DRS) spectroscopy, and the observed band gap is 3.31 eV. The morphology of the materials was analysed by SEM and TEM which show the sphere like structures of NiO with the particle size of ~20 nm. The efficiency of the materials was examined by the degradation of crystal violet dye under UV light illumination. The complete degradation was achieved within 60 min, and the mechanism of the degradation were also been proposed. In addition, the degradation of rhodamine B (RhB) and methylene blue dye solution was also carried out to extend the practical applications of NiO nanospheres. The involvement of reactive oxidative species (ROS) was found out by trapping experiment, and the ROS is superoxide radical anion.

  18. Potential suppressive effects of gentian violet on human breast cancer MDA-MB-231 cells in vitro: Comparison with gemcitabine

    PubMed Central

    Yamaguchi, Masayoshi; Murata, Tomiyasu

    2016-01-01

    Gentian violet (GV), a cationic triphenylmethane dye, is used as an antifungal and antibacterial agent. Recently, attention has been focused on GV as a potential chemotherapeutic and antiangiogenic agent. The present study was undertaken to determine the suppressive effects of GV on human breast cancer MDA-MB-231 cells in vitro. The proliferation of MDA-MB-231 cells was suppressed by culture with GV (1–200 nM). The suppressive effects of GV on cell proliferation were not potentiated in the presence of various inhibitors that induce cell cycle arrest in vitro. This finding suggested that GV inhibits G1 and G2/M phase cell cycle arrest in MDA-MB-231 cells. The suppressive effects of GV on proliferation are mediated through the inhibition of various signaling pathways or nuclear transcription in vitro. Moreover, the suppressive effects of GV on cell proliferation were compared with that of gemcitabine, a strong antitumor agent that induces nuclear DNA damage. Notably, the culture with gemcitabine >50 nM suppressed cell proliferation, while the effects of GV were observed at >1 nM. The suppressive effects of gemcitabine on cell proliferation were not potentiated by GV. Overall, the present study demonstrated that GV exhibits a potential suppressive effect on the proliferation of human breast cancer MDA-MB-231 cells in vitro. PMID:27446479

  19. The different effects of oxygen and air DBD plasma byproducts on the degradation of methyl violet 5BN.

    PubMed

    Chen, Guangliang; Zhou, Mingyan; Chen, Shihua; Chen, Wenxing

    2009-12-30

    Through a novel design of the dielectric barrier discharge (DBD) plasma plume used in fabric-fiber surface modification, its discharge byproducts mainly including downstream gases and ultraviolet light were used to treat the dye solution. The different influence of oxygen and air DBD plasmas on the degradation of methyl violet 5BN (MV-5BN), which is widely used in textile industry, was investigated in this paper. The results showed that the cooperation between ultraviolet light and active species generated by the DBD plasma can decolorize MV-5BN effectively, and the chromophore peaks attributed to the -NN- bonds in MV-5BN molecule disappeared entirely when the azo dye solutions were treated for 25 min by the air and oxygen DBD plasmas. The degradation reaction followed an exponential kinetics over time, and the peak of aromatic derivatives at 209 nm in UV-vis spectra increased nearly 2.7 times when the dye solution was treated for 30 min by air DBD plasma. However, the oxygen DBD plasma could deplete the aromatic derivatives entirely. It is found that the formation of O(3) and NO(x) in the downstream gases of air and oxygen plasmas may be responsible for the different effects on the azo dye degradation.

  20. Generation of a 2.2 nJ picosecond optical pulse with blue-violet wavelength using a GaInN master oscillator power amplifier

    NASA Astrophysics Data System (ADS)

    Koda, Rintaro; Takiguchi, Yoshiro; Kono, Shunsuke; Watanabe, Hideki; Hanzawa, Yasunari; Nakajima, Hiroshi; Shiozaki, Masaki; Sugawara, Nobuhiro; Kuramoto, Masaru; Narui, Hironobu

    2015-07-01

    We report the generation of a picosecond optical pulse with 2.2 nJ pulse energy at blue-violet wavelengths using a GaN-based mode-locked laser diode (MLLD) and a semiconductor optical amplifier (SOA). The picosecond optical pulse generated by MLLD at a frequency of 812 MHz was amplified effectively by SOA. We optimized SOA with a widely flared waveguide structure to generate a high optical pulse energy.

  1. Equilibrium, kinetics and mechanism modeling and simulation of basic and acid dyes sorption onto jute fiber carbon: Eosin yellow, malachite green and crystal violet single component systems.

    PubMed

    Porkodi, K; Vasanth Kumar, K

    2007-05-08

    Batch experiments were carried out for the sorption of eosin yellow, malachite green and crystal violet onto jute fiber carbon (JFC). The operating variables studied are the initial dye concentration, initial solution pH, adsorbent dosage and contact time. Experimental equilibrium data were fitted to Freundlich, Langmuir and Redlich-Peterson isotherm by non-linear regression method. Langmuir isotherm was found to be the optimum isotherm for eosin yellow/JFC system and Freundlich isotherm was found to be the optimum isotherm for malachite green/JFC and crystal violet/JFC system at equilibrium conditions. The sorption capacities of eosin yellow, malachite green and crystal violet onto JFC according to Langmuir isotherm were found to 31.49 mg/g, 136.58 mg/g, 27.99 mg/g, respectively. A single stage batch adsorber was designed for the adsorption of eosin yellow, malachite green and crystal violet onto JFC based on the optimum isotherm. A pseudo second order kinetic model well represented the kinetic uptake of dyes studied onto JFC. The pseudo second order kinetic model successfully simulated the kinetics of dye uptake process. The dye sorption process involves both surface and pore diffusion with predominance of surface diffusion at earlier stages. A Boyd plot confirms the external mass transfer as the rate limiting step in the dye sorption process. The influence of initial dye concentration on the dye sorption process was represented in the form of dimensionless mass transfer numbers (Sh/Sc(0.33)) and was found to be agreeing with the expression:

  2. Microwave treated Salvadora oleoides as an eco-friendly biosorbent for the removal of toxic methyl violet dye from aqueous solution--A green approach.

    PubMed

    Din, Muhammad Imran; Hussain, Zaib; Munir, Hifza; Naz, Amber; Intisar, Azeem; Makshoof, M Nouman; Mirza, M Latif

    2016-01-01

    In the present study, microwave treated Salvadora oleoides (MW-SO) has been investigated as a potential biosorbent for the removal of toxic methyl violet dye. A batch adsorption method was experimented for biosorptive removal of toxic methyl violet dye from the aqueous solution. The effect of various operating variables, viz., adsorbent dosage, pH, contact time and temperature on the removal of the dye was studied and it was found that nearly 99% removal of the dye was possible under optimum conditions. Kinetic study revealed that a pseudo-second-order mechanism was predominant and the overall process of the dye adsorption involved more than one step. Hence, in order to investigate the rate determining step, intra-particle diffusion model was applied. Adsorption equilibrium study was made by analyzing Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) adsorption isotherm models and the biosorption data was found to be best represented by the Langmuir model. The biosorption efficiency of MW-SO was also compared with unmodified material, Salvadora oleoides (SO). It was found that the sorption capacity (qmax) increased from 58.5 mg/g to 219.7 mg/g on MW treatment. Determination of thermodynamic parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) confirmed the spontaneous, endothermic and feasible nature of the adsorption process. The preparation of MW-SO did not require any additional chemical treatment and a high percentage removal of methyl violet dye was obtained in much lesser time. Thus, it is in agreement with the principles of green chemistry. The results of the present research work suggest that MW-SO can be used as an environmentally friendly and economical alternative biosorbent for the removal of methyl violet dye from aqueous solutions.

  3. A fiber-optic violet sensor by using the surface grating formed by a photosensitive hybrid liquid crystal film on side-polished fiber

    NASA Astrophysics Data System (ADS)

    Yu, Jianhui; Li, Haozhi; Hsiao, V. K.; Liu, Weiping; Tang, Jieyuan; Zhai, Yanfang; Du, Yao; Zhang, Jun; Xiao, Yi; Chen, Zhe

    2013-09-01

    A fiber-optic violet sensor is demonstrated by using the surface grating formed by a photosensitive liquid crystal (LC) hybrid film on the flat area of side-polished fiber (SPF). The surface grating is constructed through a periodic intensity illuminating the hybrid LC film, where the periodic intensity is created by a phase mask through which the violet light passes. Experiment shows that a loss peak appears in the transmission spectrum between 1520 and 1620 nm, and this loss peak shifts toward shorter wavelength as the 405 nm light power increases. The wavelength shift of the peak shows very good linearity with the irradiation power between 30 and 80 mW cm-2. The very high sensitivity of the light power sensor is measured to be 1.154 nm (mW cm-2)-1, which implies that the minimum change of power intensity that can be detected is 0.866 µW cm-2 for this sensor under the limited wavelength resolution of 0.001 nm of the optical spectrum analyzer. For UV light, much higher sensitivity will be further obtained, as the LC hybrid is more sensitive to UV light than to violet light.

  4. Repurposing Synechocystis PCC6803 UirS-UirR as a UV-Violet/Green Photoreversible Transcriptional Regulatory Tool in E. coli.

    PubMed

    Ramakrishnan, Prabha; Tabor, Jeffrey J

    2016-07-15

    We have previously engineered green/red and red/far red photoreversible E. coli phytochrome and cyanobacteriochrome (CBCR) two-component systems (TCSs) and utilized them to program tailor-made gene expression signals for gene circuit characterization. Here, we transport the UV-violet/green photoreversible CBCR TCS UirS-UirR from Synechocystis PCC6803 to E. coli. We demonstrate that the promoter of the small RNA csiR1, previously shown to be activated by inorganic carbon stress, is a UirS-UirR output. Additionally, in contrast to a recently proposed sequestration model, we show that the sensor histidine kinase UirS phosphorylates the response regulator UirR to activate PcsiR1 transcription in response to UV-violet light. Finally, we measure changes in UirS-UirR output minutes after a change in light input and exploit these rapid dynamics to program a challenging gene expression signal with high predictability. UirS-UirR is the first engineered transcriptional regulatory tool activated exclusively by UV-violet light, and the most blue shifted photoreversible transcriptional regulatory tool.

  5. Enhanced mechanism investigation on violet-blue emission of ZnO films by incorporating Al and Zn to form ZnO-Al-Zn films

    NASA Astrophysics Data System (ADS)

    Chen, Haixia; Ding, Jijun; Wang, Xiaomeng; Wang, Xiaojun; Chen, Guoxiang; Ma, Li

    2016-12-01

    ZnO, ZnO-Zn, ZnO-Al0.10-Zn and ZnO-Al0.15-Zn are deposited on glass substrates by radio frequency and direct current magnetron co-sputtering. Photoluminescence (PL) measurements show that the optical performances of samples are strongly dependent on both Al and Zn incoprations. The origin of the defect-related PL emission has been investigated for a long time. Several different hypotheses have been proposed, however, they are still under investigation. Especially for the blue emissions, its origins have been debated intensely for more than thirty years because of its sparsity and instability. In this paper, both violet and blue emissions are observed in all the samples. PL emission decreases sharply as Zn is doped in ZnO to form ZnO-Zn film. However, as both Al and Zn are simultaneously doped in ZnO to form ZnO-Al0.10-Zn film, PL emission conversely increases and attains the maxima. In addition, PL emission decreases again with the increase of Al target power to form ZnO-Al0.15-Zn film. We concluded that violet-blue emission is ascribed to defect types in reverse change trend with interstitial Zn, such as Zn vacancies. This is different from previous universal hypothesis that violet-blue emission is from interstitial Zn defects.

  6. Violet/blue chrysanthemums--metabolic engineering of the anthocyanin biosynthetic pathway results in novel petal colors.

    PubMed

    Brugliera, Filippa; Tao, Guo-Qing; Tems, Ursula; Kalc, Gianna; Mouradova, Ekaterina; Price, Kym; Stevenson, Kim; Nakamura, Noriko; Stacey, Iolanda; Katsumoto, Yukihisa; Tanaka, Yoshikazu; Mason, John G

    2013-10-01

    Chrysanthemums (Chrysanthemum×morifolium Ramat.) are an important cut-flower and potted plant crop in the horticultural industry world wide. Chrysanthemums express the flavonoid 3'-hydroxylase (F3'H) gene and thus accumulate anthocyanins derived from cyanidin in their inflorescences which appear pink/red. Delphinidin-based anthocyanins are lacking due to the deficiency of a flavonoid 3', 5'-hydroxylase (F3'5'H), and so violet/blue chrysanthemum flower colors are not found. In this study, together with optimization of transgene expression and selection of the host cultivars and gene source, F3'5'H genes have been successfully utilized to produce transgenic bluish chrysanthemums that accumulate delphinidin-based anthocyanins. HPLC analysis and feeding experiments with a delphinidin precursor identified 16 cultivars of chrysanthemums out of 75 that were predicted to turn bluish upon delphinidin accumulation. A selection of eight cultivars were successfully transformed with F3'5'H genes under the control of different promoters. A pansy F3'5'H gene under the control of a chalcone synthase promoter fragment from rose resulted in the effective diversion of the anthocyanin pathway to produce delphinidin in transgenic chrysanthemum flower petals. The resultant petal color was bluish, with 40% of total anthocyanidins attributed to delphinidin. Increased delphinidin levels (up to 80%) were further achieved by hairpin RNA interference-mediated silencing of the endogenous F3'H gene. The resulting petal colors were novel bluish hues, not possible by hybridization breeding. This is the first report of the production of anthocyanins derived from delphinidin in chrysanthemum petals leading to novel flower color.

  7. Determining the degradation efficiency and mechanisms of ethyl violet using HPLC-PDA-ESI-MS and GC-MS

    PubMed Central

    2012-01-01

    Background The discharge of wastewater that contains high concentrations of reactive dyes is a well-known problem associated with dyestuff activities. In recent years, semiconductor photocatalysis has become more and more attractive and important since it has a great potential to contribute to such environmental problems. One of the most important aspects of environmental photocatalysis is in the selection of semiconductor materials like ZnO and TiO2, which are close to being two of the ideal photocatalysts in several respects. For example, they are relatively inexpensive, and they provide photo-generated holes with high oxidizing power due to their wide band gap energy. In this work, nanostructural ZnO film on the Zn foil of the Alkaline-Manganese Dioxide-Zinc Cell was fabricated to degrade EV dye. The major innovation of this paper is to obtain the degradation mechanism of ethyl violet dyes resulting from the HPLC-PDA-ESI-MS analyses. Results The fabrication of ZnO nanostructures on zinc foils with a simple solution-based corrosion strategy and the synthesis, characterization, application, and implication of Zn would be reported in this study. Other objectives of this research are to identify the reaction intermediates and to understand the detailed degradation mechanism of EV dye, as model compound of triphenylmethane dye, with active Zn metal, by HPLC-ESI-MS and GC-MS. Conclusions ZnO nanostructure/Zn-foils had an excellent potential for future applications on the photocatalytic degradation of the organic dye in the environmental remediation. The intermediates of the degradation process were separated and characterized by the HPLC-PDA-ESI-MS and GC-MS, and twenty-six intermediates were characterized in this study. Based on the variation of the amount of intermediates, possible degradation pathways for the decolorization of dyes are also proposed and discussed. PMID:22748361

  8. The effects of management and environmental variation on population stage structure in three river-corridor violets

    NASA Astrophysics Data System (ADS)

    Eckstein, R. Lutz; Danihelka, Jiří; Hölzel, Norbert; Otte, Annette

    2004-03-01

    Population stage structure of plants, i.e., the density and frequency of individuals in different stages of the life cycle, is a crucial aspect of population viability that depends on a variety of factors. In this paper, we evaluated the effects of (i) management and year, (ii) location (population) and time (year) and (iii) of local habitat quality and population factors on population stage structure of three morphologically similar, closely related violets from floodplains, Viola elatior, V. pumila and V. stagnina. We hypothesised that owing to similar life cycles there should be no significant differences in population stage structure among species. We analysed population stage structure in managed vs. abandoned populations to test whether a proposed effect of management acts through the creation of regeneration niches. We further tried to identify which habitat factors are responsible for possible management effects. We established permanent plots (0.25 m 2) in 27 populations of the species in two different regions (Rhine floodplains, Germany; Dyje River floodplains, Czech Republic) and recorded frequency and density of seedlings, small and large vegetative plants and small and large flowering plants during 2 years. There were significant differences among species, indicating that the species have different life histories. Furthermore, there was a significant effect of management on population stage structure in two of the species. Management significantly increased the proportion of seedlings, over and above possible differences between regions. In our data set, the effects of spatial variation among populations were generally larger than the effects of temporal variation. The only factor that affected the density of life-cycle stages was the cover of bryophytes, while the cover of higher plants, litter or soil (local habitat quality), or isolation and population size (population factors) had no effects.

  9. Specific ultra-violet absorbance as an indicator measurement of merucry sources in an Adirondack River basin

    USGS Publications Warehouse

    Burns, Douglas A.; Aiken, George R.; Bradley, Paul M.; Journey, Celeste; Schelker, Jakob

    2013-01-01

    The Adirondack region of New York has been identified as a hot spot where high methylmercury concentrations are found in surface waters and biota, yet mercury (Hg) concentrations vary widely in this region. We collected stream and groundwater samples for Hg and organic carbon analyses across the upper Hudson River, a 493 km2 basin in the central Adirondacks to evaluate and model the sources of variation in filtered total Hg (FTHg) concentrations. Variability in FTHg concentrations during the growing seasons (May-Oct) of 2007-2009 in Fishing Brook, a 66-km2 sub-basin, was better explained by specific ultra-violet absorbance at 254 nm (SUVA254), a measure of organic carbon aromaticity, than by dissolved organic carbon (DOC) concentrations, a commonly used Hg indicator. SUVA254 was a stronger predictor of FTHg concentrations during the growing season than during the dormant season. Multiple linear regression models that included SUVA254 values and DOC concentrations could explain 75 % of the variation in FTHg concentrations on an annual basis and 84 % during the growing season. A multiple linear regression landscape modeling approach applied to 27 synoptic sites across the upper Hudson basin found that higher SUVA254 values are associated with gentler slopes, and greater riparian area, and lower SUVA254 values are associated with an increasing influence of open water. We hypothesize that the strong Hg?SUVA254 relation in this basin reflects distinct patterns of FTHg and SUVA254 that are characteristic of source areas that control the mobilization of Hg to surface waters, and that the seasonal influence of these source areas varies in this heterogeneous basin landscape.

  10. SERS active Ag encapsulated Fe@SiO2 nanorods in electromagnetic wave absorption and crystal violet detection.

    PubMed

    Senapati, Samarpita; Srivastava, Suneel Kumar; Singh, Shiv Brat; Kulkarni, Ajit R

    2014-11-01

    The present work is focused on the preparation of Fe nanorods by the chemical reduction of FeCl3 (aq) using NaBH4 in the presence of glycerol as template followed by annealing of the product at 500°C in the presence of H2 gas flow. Subsequently, its surface has been modified by silica followed by silver nanoparticles to form silica coated Fe (Fe@SiO2) and Ag encapsulated Fe@SiO2 nanostructure employing the Stöber method and silver mirror reaction respectively. XRD pattern of the products confirmed the formation of bcc phase of iron and fcc phase of silver, though silica remained amorphous. FESEM images established the growth of iron nanorods from the annealed product and also formation of silica and silver coating on its surface. The appearance of the characteristics bands in FTIR confirmed the presence of SiO2 on the Fe surface. Magnetic measurements at room temperature indicated the ferromagnetic behavior of as prepared iron nanorods, Fe@SiO2 and silver encapsulated Fe@SiO2 nanostructures. All the samples exhibited strong microwave absorption property in the high frequency range (10GHz), though it is superior for Ag encapsulated Fe@SiO2 (-14.7dB) compared with Fe@SiO2 (-9.7dB) nanostructures of the same thickness. The synthesized Ag encapsulated Fe@SiO2 nanostructure also exhibited the SERS phenomena, which is useful in the detection of the carcinogenic dye crystal violet (CV) upto the concentration of 10(-10)M. All these findings clearly demonstrate that the Ag encapsulated Fe@SiO2 nanostructure could efficiently be used in the environmental remediation.

  11. The role of human cytochrome P4503A4 in biotransformation of tissue-specific derivatives of 7H-dibenzo[c,g]carbazole

    SciTech Connect

    Mesarosova, Monika; Valovicova, Zuzana; Srancikova, Annamaria; Krajcovicova, Zdenka; Milcova, Alena; Sokolova, Romana; Schmuczerova, Jana; Topinka, Jan; Gabelova, Alena

    2011-09-15

    The environmental pollutant 7H-dibenzo[c,g]carbazole (DBC) and its derivative, 5,9-dimethylDBC (DiMeDBC), produced significant and dose-dependent levels of micronuclei followed by a substantial increase in the frequency of apoptotic cells in the V79MZh3A4 cell line stably expressing the human cytochrome P450 (hCYP) 3A4. In contrast, neither micronuclei nor apoptosis were found in cells exposed to the sarcomagenic carcinogen, N-methylDBC (N-MeDBC). A slight but significant level of gene mutations and DNA adducts detected in V79MZh3A4 cells treated with N-MeDBC, only at the highest concentration (30 {mu}M), revealed that this sarcomagenic carcinogen was also metabolized by hCYP3A4. Surprisingly, DBC increased the frequency of 6-thioguanine resistant (6-TG{sup r}) mutations only at the highest concentration (30 {mu}M), while DiMeDBC failed to increase the frequency of these mutations. The resistance to 6-thioguanine is caused by the mutations in the hypoxanthine-guanine phosphoribosyltransferase (Hprt) gene. The molecular analysis of the coding region of Hprt gene showed a deletion of the entire exon 8 in DiMeDBC-induced 6-TG{sup r} mutants, while no changes in the nucleotide sequences were identified in 6-TG{sup r} mutants produced by DBC and N-MeDBC. Based on our results, we suggest that hCYP3A4 is involved in the metabolism of DBC and its tissue-specific derivatives. While hCYP3A4 probably plays an important role in biotransformation of the liver carcinogens, DBC and DiMeDBC, it might only have a marginal function in N-MeDBC metabolism. - Highlights: > DBC activation via CYP3A4 resulted in micronuclei, DNA adduct formation and mutations in V79MZh3A4 cells. > The CYP3A4-mediated DiMeDBC activation caused micronuclei followed by apoptosis in V79MZh3A4 cells. > The genotoxic effects produced by N-MeDBC in V79MZh3A4 cells were negligible. > The hCYP3A4 may play an important role in DBC and DiMeDBC metabolism. > The CYP3A4 might only have a marginal function in N

  12. Fabrication and characterization of p-ZnO:(P,N)/n-ZnO:Al homojunction ultra-violet (UV) light emitting diodes (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Rafiudeen, Amiruddin; Reddy, T. Srinivasa; Cheemadan, Shaheer; Kumar, M. C. Santhosh

    2015-10-01

    ZnO possess distinctive characteristics such as low cost, wide band gap (3.36 eV) and large exciton binding energy (60meV). As the band gap lies in ultra violet (UV) region, ZnO is considered as a novel material for the fabrication of ultra violet light emitting diodes (UV-LEDs). However, ZnO being intrinsic n-type semiconductor the key challenge lies in realization of stable and reproducible p-type ZnO. In the present research dual acceptor group-V elements such as P and N are simultaneously doped in ZnO films to obtain the p-type characteristics. The deposition is made by programmable spray pyrolysis technique upon glass substrates at 697K. The optimum doping concentration of P and N were found to be 0.75 at% which exhibits hole concentration of 4.48 x 10^18 cm-3 and resistivity value of 9.6 Ω.cm. The deposited p-ZnO were found to be stable for a period over six months. Highly conducting n-type ZnO films is made by doping aluminum (3 at%) which exhibits higher electron concentration of 1.52 x 10^19 cm-3 with lower electrical resistivity of 3.51 x 10-2 Ω.cm. The structural, morphological, optical and electrical properties of the deposited n-ZnO and p-ZnO thin films are investigated. An efficient p-n homojunction has been fabricated using the optimum p-ZnO:(P,N) and n-ZnO:Al layers. The current-voltage (I-V) characteristics show typical rectifying characteristics of p-n junction with a low turn on voltage. Electroluminescence (EL) studies reveals the fabricated p-n homojunction diodes exhibits strong emission features in ultra-violet (UV) region around 378 nm.

  13. Light-curing efficiency of dental adhesives by gallium nitride violet-laser diode determined in terms of ultimate micro-tensile strength.

    PubMed

    Kameyama, Atsushi; Kato, Junji; De Munck, Jan; Hatayama, Hitoshi; Haruyama, Akiko; Yoshinari, Masao; Takase, Yasuaki; Van Meerbeek, Bart; Tsunoda, Masatake

    2011-01-01

    The purpose of this study was to evaluate whether violet-laser diode (VLD) can be used as light-curing source. The ultimate (micro-)tensile strength (μTS) of three adhesives was determined when cured by VLD in comparison with curing by two different types of commercial LED light-curing units. One VLD (VLM 500) and two LED units (Curenos and G-Light Prima) were used to cure the adhesive resin of the two-step self-etch adhesives Clearfil SE Bond, Tokuso Mac Bond II, and FL-Bond II. A 0.6-mm thick acrylic mould was filled with adhesive resin and cured for 60 s. After 24-h water storage, specimens were trimmed into an hourglass shape with a width of 1.2 mm at the narrowest part, after which the μTS was determined (n=10). In addition, the light transmittance of each adhesive was characterized using a UV-vis-NIR spectrometer. No significant difference in curing efficiency between VLD and LED were observed for both Tokuso Mac Bond II and FL-Bond II (p>0.05). For Clearfil SE Bond, the μTS of VLD-cured specimens was higher than that of the specimens cured by the LED Curenos unit (p<0.05). Spectrometry revealed that this marked difference must be attributed to a different light transmittance of Clearfil SE Bond for visible blue light versus for the lower area of UV and visible violet light. In conclusion, A GaN-based violet laser diode can be used as light-curing source to initiate polymerization of dental resins.

  14. A Violet Martian Sky

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These clouds from Sol 15 have a new look. As water ice clouds cover the sky, the sky takes on a more bluish cast. This is because small particles (perhaps a tenth the size of the martian dust, or one-thousandth the thickness of a human hair) are bright in blue light, but almost invisible in red light. Thus, scientists expect that the ice particles in the clouds are very small. The clouds were imaged by the Imager for Mars Pathfinder (IMP).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  15. Spatial Dosimetry with Violet Diode Laser-Induced Fluorescence of Water-Equivalent Radio-Fluorogenic Gels

    NASA Astrophysics Data System (ADS)

    Sandwall, Peter A., II

    The following work describes investigations of spatial dosimetry using laser-induced fluorescence of a radio-fluorogenic detector embedded within water-equivalent media. The chemical composition of a gelatin-based coumarin-3-carboxylic acid detector was investigated and dose response characterized. Violet diode (405nm) excitation sources were explored and laser-induced fluorescence (LIF) employed to obtain the pattern of fluorescent emission yielding images of the integrated spatial dose distribution. The design of a three-dimensional reader is proposed to provide a foundation for future work. Radio-fluorogenic processes create fluorescent products in response to ionizing radiation. Water radiolysis produced by ionizing radiation yields hydroxyl free radicals that readily hydroxylate coumarin-3-carboxylic acid to 7-hydroxy-coumarin-3-carboxylic acid, a derivative of umbelliferone. Umbelliferone is a known fluorophore, exhibiting peak excitation in the UV to near UV range of 365-405nm with a visible 445nm blue emission. Coumarin-3-carboxlyic acid has been studied in an aqueous gelatin matrix. The radio-fluorogenic coumarin-gelatin detector has been shown to respond to an absorbed dose of ionizing radiation in a measureable manner. The detector was studied with respect to concentration of gelatin and coumarin in the presence of pH buffers. Dose response of the detector was investigated with regard to ionizing radiation type, energy, and rate of irradiation. Results demonstrate a functional detector. Patterns of energy deposition were formed in response to ionizing radiation produced by a sealed-source of radioactive Ir-192 embedded in the gelatin matrix of the detector. Spatial distributions of absorbed dose were recorded and analyzed as a function of fluorescent emission. The distribution of energy deposition was imaged with LIF excitation by a divergent beam of 405nm light and determined by analysis of digital image pixel intensity values displaying the 445nm

  16. Pharmacological properties of 2,3,3a,4,5,6-hexahydro-8-methyl-1H-pyrazino [3,2,1-j,k]carbazol hydrochloride (pirlindole), a new antidepressant.

    PubMed

    Mashkovsky, M D; Andrejeva, N I

    1981-01-01

    The hydrochloride salt of 2,3,3a,4,5,6-hexahydro-8-methyl-1H-pyrazino[3,2,1-j,k]carbazol hydrochloride (pirlindole) exerts pharmacological effects typical of antidepressants. This compound antagonizes the depressant effects of reserpine and tetrabenazine and potentiates the central effects of amphetamine and l-dopa. It also enhances the head-twitch effect of 5-hydroxy-tryptophan, the effects of noradrenaline, adrenaline, serotonin, tyramine on blood pressure as well as the hypertensive and tremor activities of tryptamine. Pirlindole inhibits the neuronal uptake of noradrenaline and exerts reversible, short-lasting anti-MAO activity. It does not possess anti-cholinergic activity. Clinical trials have shown pirlindole to be effective as an antidepressive drug.

  17. Spectrometric measurements and DFT studies on new complex of copper (II) with 2-((E)-9-ethyl-3-(2-(6-(4-methylpyridin-2-yl)pyridin-3-yl)vinyl)-9H-carbazole

    NASA Astrophysics Data System (ADS)

    Zhang, Haoyang; Hu, Jie; Zhao, Jianying; Zhang, Yu

    2016-11-01

    The molecular structure of a new complex of copper (II) with (E)-9-ethyl-3-(2-(6-(4-methylpyridin-2-yl)pyridin-3-yl)vinyl)-9H-carbazole ([Cu2(emppc)2Cl2]Cl2) was optimized with B3LYP/LanL2DZ, PBE1PBE/LanL2DZ and M062X/LanL2DZ theoretical level. The ligand, (E)-9-ethyl-3-(2-(6-(4-methylpyridin-2-yl)pyridin-3-yl)vinyl)-9H-carbazole (emppc), binds to Cu(II) ions with a bi-dentate mode, two Cl- serve as bridging ligand, each Cu(II) ion has a highly distorted tetrahedron coordination geometry. With M062X/LanL2DZ theoretical level, the calculated interaction energies of Cu(II) with coordination atoms N are between 183.3-200.0 kJ mol- 1 for α spin and 319.4-324.9 kJ mol- 1 for β spin, and interaction energies of Cu(II) with coordination atoms Cl atom are 248.0-252.4 kJ mol- 1 for α spin and 332.6-333.6 kJ mol- 1 for β spin. The experimental Fourier transform infrared spectrum was assigned. The calculated IR based on B3LYP/LanL2DZ, PBE1PBE/LanL2DZ and M062X/LanL2DZ methods were performed and compared with experimental results. The UV-Vis experimental spectra of [Cu2(emppc)2Cl2]Cl2 was measured in methanol solution. The calculated electronic spectrum was performed with TD/M062X and PCM-TD/M062X methods with LanL2DZ basis set. The nature bond orbital analysis and temperature dependence of the thermodynamic properties were calculated with the same methods.

  18. Low-cost nanoparticles sorbent from modified rice husk and a copolymer for efficient removal of Pb(II) and crystal violet from water.

    PubMed

    Masoumi, Arameh; Hemmati, Khadijeh; Ghaemy, Mousa

    2016-03-01

    In this work, preparation of adsorbent nanoparticles based on treated low-value agricultural by-product rice husk (TARH), and poly(methylmethacrylate-co-maleic anhydride), poly(MMA-co-MA), is reported for the removal of Pb(II) ion and Crystal violet dye from water. The prepared adsorbent was characterized by FT-IR, SEM, AFM, DLS, BET and Zeta potential. The metal ion adsorption capability was determined for rice husk (RH), TARH, crosslinked poly(MMA-co-MA) (CNR), and CNR@TARH nanoparticles. Different factors affecting the adsorption of Pb(II) such as pH, contact time, initial metal ion concentration and also temperature were studied to investigate adsorption isotherms, kinetics and thermodynamics. For the four tested adsorption isotherm models, the equilibrium sorption data for CNR@TARH nanoparticles obeyed the Langmuir isotherm equation with maximum sorption capacity of 93.45 mg g(-1). The kinetic adsorption data fitted best the Lagergren pseudo-second order model. Regeneration of adsorbent was easily performed by adsorption/desorption experiments followed for 4 cycles. Finally, the ability of the nanoparticles to remove Crystal violet dye from aqueous solution was also investigated by varying the initial dye concentration, pH and immersion time and the adsorption mechanism followed the second-order kinetic model.

  19. Determination of malachite green, crystal violet and their leuco-metabolites in fish by HPLC-VIS detection after immunoaffinity column clean-up.

    PubMed

    Xie, Jie; Peng, Tao; Chen, Dong-Dong; Zhang, Qing-Jie; Wang, Guo-Min; Wang, Xiong; Guo, Qi; Jiang, Fan; Chen, Dan; Deng, Jian

    2013-01-15

    A high performance liquid chromatography method with visible detection (HPLC-VIS) for the determination of malachite green (MG), crystal violet (CV), leucomalachite green (LMG), and leucocrystal violet (LCV) in fish has been developed after clean-up through an immunoaffinity column (IAC). Residues were simultaneously extracted from fish muscle with acetonitrile and ammonium acetate buffer. The leuco-forms, LMG and LCV, were oxidized quantitatively to the chromic CV and MG by reaction with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Extracts were then purified on an IAC which prepared by immobilizing the anti-MG-CV antibodies by the sol-gel method. Finally, the eluents were analyzed by HPLC-VIS. The limits of detection were 0.15, 0.1, 0.18 and 0.14ng/g for MG, CV, LMG and LCV, respectively. The average recoveries in samples fortified with MG, CV, LMG and LCV over the range 0.5-10ng/g were from 71.6% to 96.8% with RSDs of 5.1-12.3% (n=6). This novel method was confirmed by liquid chromatography-tandem mass spectrometry with electrospray interface in positive mode using multiple reaction monitoring.

  20. [Simultaneous determination of residues of malachite green, crystal violet and their leuco metabolites in aquatic products by liquid chromatography-tandem mass spectrometry].

    PubMed

    Zhu, Kuanzheng; Wang, Peng; Lin, Yanfei; Xiao, Songjian; Mei, Surong

    2007-01-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of the residues of malachite green (MG), eucomalachite green (LMG), crystal violet (CV) and leucocrystal violet (LCV) in aquatic products. The target analytes were extracted from homogenized samples with a mixture of acetonitrile and ammonium acetate buffer, partitioned against methylene chloride, and purified on tandem neutral alumina and PRS solid-phase extraction (SPE) cartridges. Chromatographic separation was achieved by using a ZORBAX SB-C18 column with an isocratic mobile phase consisting of ammonium acetate (0.5 mmol/L) and acetonitrile (10: 90, v/v) without on-line post-column oxidation with PbO2 which had been widely used in the previous methods. Identification and quantification were performed using multiple reaction monitoring (MRM) with one precursor ion, and two product ions for each analyte and electrospray ionization in positive mode. The limits of detection were 0.5 ng/g. The recoveries were in the range of 77.6% - 98.1%, and the relative standard deviations were less than 8.2%. The results showed that the method is suitable for the determination of residues of MG, LMG, CV and LCV in aquatic products.