X-ray induced visible luminescence of porphyrins.

abstract：:The role of water molecules in spectral tuning of proteins has been left largely unexplored. This topic is important because changing hydrogen bond patterns during the activation process may lead to spectral shifts which can be of diagnostic value for the underlying structures. Arguments put forward in this article ar...

journal_title：Photochemistry and photobiology

authors： Sekharan S

更新日期：2009-03-01 00:00:00

abstract：:We have been able to identify a blue fluorophore from the low-molecular weight soluble fraction of human adult nondiabetic brunescent cataract lenses as xanthurenic acid 8-O-beta-D-glucoside (XA8OG) (excitation = 338 nm and emission = 440 nm). To determine the role of this fluorophore in the lens, we have examined its...

journal_title：Photochemistry and photobiology

authors： Thiagarajan G,Shirao E,Ando K,Inoue A,Balasubramanian D

更新日期：2002-09-01 00:00:00

abstract：:Carp (Cyprinus carpio) were repeatedly exposed to 0, 60, 120 and 240 mJ/cm2 ultraviolet B (UVB) radiation three times in 1 week (short-term exposure) or 12 times in 4 weeks (long-term exposure). The effect of UVB on the functioning of the carp immune system was studied on day 2 after the final irradiation. After short...

journal_title：Photochemistry and photobiology

authors： Markkula SE,Salo HM,Immonen AK,Jokinen EI

更新日期：2005-05-01 00:00:00

abstract：:Generating accurate population-specific public health messages regarding sun protection requires knowledge about seasonal variation in sun exposure in different environments. To address this issue for a subtropical area of Australia, we used polysulphone badges to measure UVR for the township of Nambour (26 degrees la...

journal_title：Photochemistry and photobiology

authors： Neale RE,Hamilton AR,Janda M,Gies P,Green AC

更新日期：2010-03-01 00:00:00

abstract：:N2-hydroxyisocytosine and 1-methyl-N2-hydroxyisocytosine were studied using a matrix isolation technique combined with infrared absorption spectroscopy. For N2-hydroxyisocytosine isolated in an Ar matrix (at 10 K), two imino-oxo isomers, one with the hydroxyimino =N-OH group directed toward the N1-H group (the form ca...

journal_title：Photochemistry and photobiology

authors： Lapinski L,Nowak MJ,Kwiatkowski JS,Leszczynski J

更新日期：2003-03-01 00:00:00

abstract：:The progressive loss of visual faculties with advancing age is attributed, sometimes, mainly to allegedly inevitable optical deterioration, such as clouding of the media, or again to neurosenescence, as typified by cell-death. The relevant factors are assessed, and it is not thought likely that changes in normal ocula...

journal_title：Photochemistry and photobiology

authors： Weale RA

更新日期：1989-09-01 00:00:00

abstract：:Solar ultraviolet-B radiation (UVB) is essential for epidermal vitamin D production. We aimed to quantitate the relationship between personal solar UV exposure and serum 25hydroxy vitamin D (25[OH]D) concentration. Blood was collected for 25(OH)D analysis in 207 South Australian adults aged 27-61 years. At the time of...

journal_title：Photochemistry and photobiology

authors： Nair-Shalliker V,Clements M,Fenech M,Armstrong BK

更新日期：2013-01-01 00:00:00

abstract：:Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, cont...

journal_title：Photochemistry and photobiology

authors： Soares BM,Alves OA,Ferreira MV,Amorim JC,Sousa GR,Silveira Lde B,Prates RA,Avila TV,Baltazar Lde M,de Souza Dda G,Santos DA,Modolo LV,Cisalpino PS,Pinotti M

更新日期：2011-03-01 00:00:00

abstract：:After 50 years of studies on photobiomodulation (PBM), there is still so much to investigate to understand the laser light-nonplant cells interactions. The current scientific knowledge allows to say that the phenomena induced by PBM are based on cellular pathways that are the key points of cell life. The mitochondria ...

journal_title：Photochemistry and photobiology

authors： Amaroli A,Ferrando S,Benedicenti S

更新日期：2019-01-01 00:00:00

abstract：:The two-photon photolysis of liquid CCl4 with 25 ps pulses of 266 nm light has been studied and compared with similar studies with high energy radiation. Both neutral and ionic species are produced from excited states and ionization. The emphasis of the study is on the ionic processes, while some data related to excit...

journal_title：Photochemistry and photobiology

authors： Zhang G,Thomas JK

更新日期：2006-01-01 00:00:00

abstract：:Molecular cloning techniques were employed to obtain hybrid luciferases with their alpha and beta subunits encoded by luxA and luxB genes, respectively, from Xenorhabdus luminescens strain HW or Vibrio fischeri. Although the two wild-type luminous bacteria are phylogenetically diverged, the hybrid luciferase Xf compri...

journal_title：Photochemistry and photobiology

authors： Xi L,Tu SC

更新日期：1993-04-01 00:00:00

abstract：:The binding interactions of three naphthalimide derivatives with heteropoly nucleic acids have been evaluated using fluorescence, absorption and circular dichroism spectroscopies. Mono- and bifunctionalized naphthalimides exhibit sequence-dependent variations in their affinity toward DNA. The heteropoly nucleic acids,...

journal_title：Photochemistry and photobiology

authors： McMasters S,Kelly LA

更新日期：2007-07-01 00:00:00

abstract：:To determine the origin of the UV-specific CC to TT tandem mutation at the CC site, we made a duplex DNA decamer containing a uracil cis-syn cyclobutane dimer (CBD) as the deaminated model of a cytosine dimer. Two-dimensional 1H-NMR spectroscopy studies were performed on this sequence where two adenines (Ade) were opp...

journal_title：Photochemistry and photobiology

authors： Lee HM,Kim JK

更新日期：2002-10-01 00:00:00

abstract：:Photodynamic therapy (PDT) of cancer induces oxidative stress, which intervenes in the expression of cytokines by tumor cells. The cytokines might have either a positive or a negative impact on tumor eradication. Here, we studied the expression of cytokines vascular endothelial growth factor (VEGF) and interleukin-1al...

journal_title：Photochemistry and photobiology

authors： Dabkeviciene D,Sasnauskiene A,Leman E,Kvietkauskaite R,Daugelaviciene N,Stankevicius V,Jurgelevicius V,Juodka B,Kirveliene V

更新日期：2012-03-01 00:00:00

abstract：:The photodegradation of the S(+)- and R(-)-ketoprofen (KP) enantiomers in the bovine serum albumin matrix was studied by steady-state photolysis with the use of lambda(irr) > 320 nm and transient absorption spectroscopy with lambda(exc) = 355 nm, at 1/1 and 2/1 KP/BSA molar ratios. R(-)-KP was found to be more labile ...

journal_title：Photochemistry and photobiology

authors： Monti S,Manet I,Manoli F,Morrone R,Nicolosi G,Sortino S

更新日期：2006-01-01 00:00:00

abstract：:We previously reported that a low level of lysosomal photodamage potentiated the phototoxic effect of subsequent mitochondrial photodamage mediated by the benzoporphyrin derivative (BPD) in murine hepatoma 1c1c7 cells. This was attributed to release of Ca2+ from damaged lysosomes and a calpain-mediated conversion of t...

journal_title：Photochemistry and photobiology

authors： Kessel D,Reiners JJ Jr

更新日期：2017-11-01 00:00:00

abstract：:This article is a highlight of the study by Stamenkovic and Hanelt in this issue of Photochemistry and Photobiology describing the high-irradiance photophysiology of several strains of freshwater chlorophyte microalgal genus, Cosmarium. These strains exhibit distinct differences in how combined thermal- high irradianc...

journal_title：Photochemistry and photobiology

authors： Neale P

更新日期：2013-07-01 00:00:00

abstract：:The quenching of the benzophenone triplet by lysozyme and its constituent amino acids in aqueous solutions have been studied. Native lysozyme quenches the benzophenone triplet with a high rate constant, 4 x 10(9) M-1 s-1. The quenching process takes place with production of significant amounts of free ketyl radicals, ...

journal_title：Photochemistry and photobiology

authors： Encinas MV,Lissi EA,Vasquez M,Olea AF,Silva E

更新日期：1989-05-01 00:00:00

abstract：:In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of different energies to determine whether or not He-Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four ene...

journal_title：Photochemistry and photobiology

authors： Perveen R,Ali Q,Ashraf M,Al-Qurainy F,Jamil Y,Raza Ahmad M

更新日期：2010-09-01 00:00:00

abstract：:Sapphyrins and a series of related porphyrinoid macrocycles have been investigated as potential agents for the treatment of leishmaniasis. The effectiveness of the compounds was evaluated in vitro upon incubation with Leishmania tarentolae or L. panamensis amastigotes and promastigotes. Their effectiveness was also as...

journal_title：Photochemistry and photobiology

authors： Hooker JD,Nguyen VH,Taylor VM,Cedeño DL,Lash TD,Jones MA,Robledo SM,Vélez ID

更新日期：2012-01-01 00:00:00

abstract：:Channel and pump rhodopsins use energy from light absorbed by a covalently bound retinal chromophore to transport ions across membranes of microbial cells. Ion transfer steps, including proton transfer, can couple to changes in protein conformational dynamics and water positions. Although general principles of how mic...

journal_title：Photochemistry and photobiology

authors： Bondar AN,Smith JC

更新日期：2017-11-01 00:00:00

abstract：:In an attempt to develop an efficient chemotherapeutic agent targeted at malignant cells that express receptors to gonadotropin releasing hormone (GnRH) we coupled [D-Lys6]GnRH covalently to an emodin derivative, i.e. emodic acid (Emo) to yield [D-Lys6(Emo)]GnRH. Emodin is a naturally occurring anthraquinone which is ...

journal_title：Photochemistry and photobiology

authors： Rahimipour S,Bilkis I,Péron V,Gescheidt G,Barbosa F,Mazur Y,Koch Y,Weiner L,Fridkin M

更新日期：2001-08-01 00:00:00

abstract：:There are controversial reports in the literature concerning the reactivity of singlet oxygen ((1)O(2)) with the redox probe 2',7'-dichlorodihydrofluorescein (DCFH). By carefully preparing solutions in which (1)O(2) is quantitatively generated in the presence of DCFH, we were able to show that the formation rate of th...

journal_title：Photochemistry and photobiology

authors： Daghastanli NA,Itri R,Baptista MS

更新日期：2008-09-01 00:00:00

abstract：:Topical 6,4,4'-trimethylangelicin (TMA) plus UVA was used to induce intense epidermal pigmentation in inbred HRA.HRII-c/+/Skh hairless pigmented mice over a 13 day period. Subsequent UVB/UVA exposure was used to assess the photoprotective properties of this tan using skin tumors as an endpoint. Comparisons were always...

journal_title：Photochemistry and photobiology

authors： Kipp C,Lewis EJ,Young AR

更新日期：1998-01-01 00:00:00

abstract：:A targeting strategy based on the selective enzyme-mediated activation of polymeric photosensitizer prodrugs (PPP) within pathological tissue has led to the development of agents with the dual ability to detect and treat cancer. Herein, a detailed study of a simple model system for these prodrugs is described. We prep...

journal_title：Photochemistry and photobiology

authors： Campo MA,Gabriel D,Kucera P,Gurny R,Lange N

更新日期：2007-07-01 00:00:00

abstract：:Patients infected with human immunodeficiency virus (HIV) have a high prevalence of UV radiation-responsive skin diseases including psoriasis, pruritus, eosinophilic folliculitis and eczemas. On the other hand, UV has been shown to suppress T cell-mediated immune responses and to induce activation and replication of H...

journal_title：Photochemistry and photobiology

authors： Adams ML,Houpt KR,Cruz PD Jr

更新日期：1996-08-01 00:00:00

abstract：:The decay processes of the lowest excited singlet and triplet states of five heteropsoralens (HPS) were investigated by steady-state and shift-phase fluorometry and by laser-flash photolysis in different solvents. The emission spectra of HPS are detectable only in trifluoroethanol (TFE), where fluorescence lifetimes (...

journal_title：Photochemistry and photobiology

authors： Aloisi GG,Elisei F,Moro S,Miolo G,Dall'Acqua F

更新日期：2000-05-01 00:00:00

abstract：:Cumulative and intermittent sun exposure are risk factors for skin cancer, highlighting the need to monitor exposure during childhood. There is currently very little available information concerning the accuracy of self-reported levels of sun exposure, particularly for very young children. In this study, UV radiation ...

journal_title：Photochemistry and photobiology

authors： O'Riordan DL,Stanton WR,Eyeson-Annan M,Gies P,Roy C

更新日期：2000-01-01 00:00:00

abstract：:The energetic characteristics of selected reaction steps in the bacterial luciferase-catalyzed luminescence reaction were examined by computation using the MNDO-PM3 method. Specifically, a three-step model was proposed to account for the reaction between oxygen and reduced riboflavin 5'-phosphate (1,5H2-FMN) to genera...

journal_title：Photochemistry and photobiology

authors： Wada N,Sugimoto T,Watanabe H,Tu SC

更新日期：1999-07-01 00:00:00

abstract：:Leaf discs, enclosed in a photoacoustic (PA) chamber, generate two types of PA gas-uptake signals under certain conditions. Type I is manifested by a severe signal decrease that develops slowly under very low-light intensity and often reaches negative values. It is partially reversed by low-intensity far-red light. Ty...

journal_title：Photochemistry and photobiology

authors： Malkin S,Havaux M

更新日期：2001-10-01 00:00:00