查看更多>>摘要：The colorful agaricoid fruiting bodies of dermocyboid Cortinarii owe their magnificent hue to a mixture of anthraquinone (AQ) pigments. Recently, it was discovered that some of these fungal anthraquinones have an impressive photopharmacological effect. The question, therefore, arises as to whether these pigments are also of ecological or functional significance. According to the optimal defense hypothesis, toxic molecules should be enriched in spore-producing structures, such as the gills of agarics. To test this hypothesis, we studied the distribution of fungal AQs in the fruiting body of Cortinarius rubrophyllus. The fungus belongs to the well-studied Cortinarius subgenus Dermocybe but has not been chemically characterized. Here, we report on the pigment profile of this beautiful fungus and focus on the distribution of anthraquinone pigments in the fruiting body for the first time. Here it is statistically confirmed that the potent photosensitizer emodin is significantly enriched in the gills. Furthermore, we show that the extract is photoactive against cancer cells and bacteria.
Zhikhoreva, A. A.Belashov, A., VIgnatov, E. S.Gelfond, M. L....
13页
查看更多>>摘要：The paper presents steady-state and time-resolved experiments on photophysical processes associated with photodynamic inactivation of infections provided by nebulization of Radachlorin photosensitizer solution. As models of surfaces subjected to photodynamic inactivation we used glass, plant leaf, mushroom cap peel and superficial fascia of chicken and salmon skin flaps. The oxygen content in the photosensitizer solution was varied by blowing with atmospheric air and with pure oxygen. It was shown that singlet oxygen was generated efficiently in the aerosol jet and that its amount increased noticeably at higher oxygen concentrations. The kinetics of photosensitizer photobleaching on different surfaces were found to be significantly different with characteristic decay times varying from seconds for leaf and glass to minutes for fascial flaps. This observation was attributed to much faster oxygen depletion on rough crumbly surfaces of biological samples due to effective oxidation reactions occurred. The singlet oxygen generation and degradation times, and the relative quantum yield were determined on different surfaces by recording time-resolved phosphorescence at about 1270 nm under normoxic and hyperoxic conditions and analyzed on the basis of the set of master equations. The results obtained provide reference marks for choosing optimal irradiation durations for photodynamic inactivation of pathogenic infectious agents (bacteria, mycobacteria, fungi, viruses) on mucous membranes, including the tracheobronchial tree.
查看更多>>摘要：Ag doped Sn3O4 Nanostructure and immobilized on hyperbranched polypyrrole is investigated in this project. The product was synthesized by the hydrothermal synthesis method. The surface and structural characteristics of the product was studied by different instrumental analysis. The fabricated nanocomposites was utilized as a nano photocatalyst in the removal of methylene blue dye. The crystallography results depicts the triclinic phase of Sn3O4 with the crystallite size 36.3 nm. The band gap of the Ag-Sn3O4/hyperbranched polypyrrole was found 1.50 eV from kubelka-munk measurements. The specific surface area was increased in the presence of the hyperbranched polypyrrole as compared to Ag-Sn3O4 samples. The photo-catalytic activity of composites was found 100.0% degradation of CR in 30 min under visible light irradiation. The catalytic kinetic was followed from the first kinetic model. Moreover, the Ag/Sn3O4/hyperbranched polypyrrole was applied as a bactericidal agent against Streptococcus pneumoniae, and Pseudomonas aeruginosa bacteria. Determination of Streptococcus pyogenes as a pathogenic bacteria was investigated by using aptamer/Ag/Sn3O4/hyperbranched polypyrrole in peroxidase activity. The detection limit of S. pyogenes was 71.0 CFU/mL by using the nano-aptamer.
查看更多>>摘要：Iron-catalyzed oxidative stress generates reactive oxygen species in the kidney and induces oxidative damage including lipid, protein, and DNA modifications which induces renal injury and may lead to cancer. An analysis of oxidative stress dynamics by reactive oxygen species has not been performed non-invasively in real time in intact kidneys and is a significant challenge in biology and medicine. Here, I report that MCLA-800 is a near-infrared chemiluminescent probe that visualizes the dynamics of superoxide anion (O-2(center dot)-) production and the upstream generation of reactive oxygen species in living rat kidneys suffering acute renal oxidative stress induced by intraperitoneal administration of iron(3+)-nitrilotriacetate (Fe3+-NTA) as a representative Fe3+ chelate. MCLA-800 was intravenously injected at 250 nmol/kg body weight and immediately transported to the kidneys with the emitting light dependent on O-2(center dot)- production. The magnitude of O-2(center dot)- production correlated with the Fe3+-NTA dose. O-2(center dot)- was continuously produced in the blood stream following Fe3+-NTA injection at 0.15 mmol/kg body weight, while peak production in the renal cortex occurred at 24 h, then decreased to the background level at 72 h. This study clearly revealed the dynamics of Fe3+-NTA-mediated O-2(center dot)- production in the living kidney by chemiluminescent imaging of O-2(center dot)- production using MCLA-800.
Kaladchibachi, SevagNegelspach, David C.Zeitzer, Jamie M.Fernandez, Fabian-Xose...
14页
查看更多>>摘要：The central pacemaker of flies, rodents, and humans generates less robust circadian output signals across normative aging. It is not well understood how changes in light sensitivity might contribute to this phenomenon. In the present study, we summarize results from an extended data series (n = 5681) showing that the locomotor activity rhythm of aged Drosophila can phase-shift normally to intermittently spaced episodes of bright polychromatic light exposure (600 lx) but that deficits emerge in response to 8, 16, and 120-millisecond flashes of narrowband blue (lambda(m), 452 nm) and green (lambda(m), 525 nm) LED light. For blue, phase-resetting of the activity rhythm of older flies is not as energy efficient as it is in younger flies at the fastest flash-exposures tested (8 milliseconds), suggesting there might be different floors of light duration necessary to incur photohabituation in each age group. For green, the responses of older flies are universally crippled relative to those of younger flies across the slate of protocols we tested. The difference in green flash photosensitivity is one of the most salient age-related phenotypes that has been documented in the circadian phase-shifting literature thus far. These data provide further impetus for investigations on pacemaker aging and how it might relate to changes in the circadian system's responses to particular sequences of light exposure tuned for wavelength, intensity, duration, and tempo.
Takahashi, AkiraBui, Thi Kim NganEmoto, TakahiroMawatari, Kazuaki...
10页
查看更多>>摘要：Herpes simplex virus type 1 (HSV-1) is an enveloped virus that mainly infects humans. Given its high global prevalence, disinfection is critical for reducing the risk of infection. Ultraviolet-light-emitting diodes (UV-LEDs) are eco-friendly irradiating modules with different peak wavelengths, but the molecules degraded by UV-LED irradiation have not been clarified. To identify the target viral molecules of UV-LEDs, we exposed HSV-1 sus-pensions to UV-LED irradiation at wavelengths of 260-, 280-, 310-, and 365-nm and measured viral DNA, pro-tein, and lipid damage and infectivity in host cells. All UV-LEDs substantially reduced by inhibiting host cell transcription, but 260-and 280-nm UV-LEDs had significantly stronger virucidal efficiency than 310-and 365-nm UV-LEDs. Meanwhile, 260-and 280-nm UV-LEDs induced the formation of viral DNA photoproducts and the degradation of viral proteins and some phosphoglycerolipid species. Unlike 260-and 280-nm UV-LEDs, 310-and 365-nm UV-LEDs decreased the viral protein levels, but they did not drastically change the levels of viral DNA photoproducts and lipophilic metabolites. These results suggest that UV-LEDs reduce the infectivity of HSV-1 by targeting different viral molecules based on the peak wavelength. These findings could facilitate the optimization of UV-LED irradiation for viral inactivation.
Zhikhoreva, A. A.Belashov, A., VIgnatov, E. S.Gelfond, M. L....
13页
查看更多>>摘要：The paper presents steady-state and time-resolved experiments on photophysical processes associated with photodynamic inactivation of infections provided by nebulization of Radachlorin photosensitizer solution. As models of surfaces subjected to photodynamic inactivation we used glass, plant leaf, mushroom cap peel and superficial fascia of chicken and salmon skin flaps. The oxygen content in the photosensitizer solution was varied by blowing with atmospheric air and with pure oxygen. It was shown that singlet oxygen was generated efficiently in the aerosol jet and that its amount increased noticeably at higher oxygen concentrations. The kinetics of photosensitizer photobleaching on different surfaces were found to be significantly different with characteristic decay times varying from seconds for leaf and glass to minutes for fascial flaps. This observation was attributed to much faster oxygen depletion on rough crumbly surfaces of biological samples due to effective oxidation reactions occurred. The singlet oxygen generation and degradation times, and the relative quantum yield were determined on different surfaces by recording time-resolved phosphorescence at about 1270 nm under normoxic and hyperoxic conditions and analyzed on the basis of the set of master equations. The results obtained provide reference marks for choosing optimal irradiation durations for photodynamic inactivation of pathogenic infectious agents (bacteria, mycobacteria, fungi, viruses) on mucous membranes, including the tracheobronchial tree.
查看更多>>摘要：ATP production by mitochondria isolated from Saccharomyces cerevisiae cells was accelerated upon both direct and indirect mitochondrial photo-activation (MPA). The extent of direct MPA was dependent on the wavelength of excitation light. Direct MPA was created by light in cytochrome c spectral absorption bands (440, 520 and 550 nm), this light was absorbed producing electronically excited cytochrome c, and the excitation energy of the latter was used in the ATP production chain. The activity of cytochrome c was tested with 600 nm light, where cytochrome c does not absorb, and thus ATP production rate remained the same as in darkness. Note that ATP production rates were significantly larger under light at 550, 520 and 440 nm. Therefore, photo-activation of cytochrome c was the first step of MPA synthesis of ATP. Indirect MPA of ATP production also proceeded via electronically excited cytochrome c, by energy transfer from electronically excited Co/BN film to cytochrome c located in the inner mitochondrial membrane (IMM). Co/BN excitons were generated by photons absorbed by the Co/BN film, which was not in contact with the mitochondrial sample. Next, these excitons propagated along the Co/BN film to the part of the film that was in contact with the mitochondrial sample. There the exciton energy was transferred to cytochrome c located in the IMM, producing electronically excited cytochrome c. Thus, excited cytochrome c was generated in a way different from that of direct MPA. Next, the energy of excited cytochrome c was used in activated ATP synthesis, with virtually the same effect for 519 and 427 nm excitation. Thus, the first step of ATP synthesis in indirect MPA was the exciton energy transfer from Co/BN film to cytochrome c located in the IMM, producing an electronically excited cytochrome c molecule. A phenomenological mechanism of direct and indirect MPA was proposed, and the model parameters were obtained by fitting the model to the experimental data. However, more information is needed before the detailed mechanism of ATP synthesis activation by electronically excited cytochrome c could be understood. The present results support the earlier proposed hypothesis of indirect MPA of ATP production in vertebrate retina in daylight.
NSTL
Elsevier