Biologically Active Cyanine Dyes as Probes for the Identification of Active Oxygen Species

Hori, Hitoshi; Nakagawa, Yasuaki; Hiroshi, Ojima; Takehiro, Niijima; Terada, Hiroshi

doi:10.1007/978-1-4615-3428-0_27

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…The freezing pretreatment seemed to significantly improve the whiteness of instant rice when drying at the temperature below 160C. The whiter color of instant rice with freezing pretreatment could be due to starch retrogradation of cooked rice when freezing; the molecules of gelatinized starch re‐associated to form crystallites and translucent grains became opaque grains (Hiroshi and Yoshinori, n.d.). The results also showed that the VFB‐dried samples were significantly whiter than the SMA‐MVFB ones, except the unfrozen samples dried at 110 and 135C.…”

Section: Resultsmentioning

confidence: 99%

Effects of Freezing Pretreatment, Microwave-Assisted Vibro-Fluidized Bed Drying and Drying Temperature on Instant Rice Production and Quality

Sripinyowanich

Noomhorm

2012

Journal of Food Processing and Preservation

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Three drying factors including pre-drying treatment (freezing), microwave-assisted drying (single-mode applicator-microwave vibro-fluidized bed [SMA-MVFB] and vibro-fluidized bed [VFB] drying) and drying temperatures (110-185C) were varied to investigate their effects on drying characteristics, energy consumption and instant rice quality. During drying cooked rice from 60 to 10% (wet basis), drying rate increased, whereas drying time decreased with the three drying factors. The highest drying rate of 0.554 g water/g dry matter·min and the shortest drying time of 2 min were obtained from SMA-MVFB drying of frozen cooked rice at 185C. This treatment also required the lowest energy of 0.204 kWh. However, in terms of product quality, unfrozen cooked rice subjected to VFB drying at 160C was superior as it was ranged in the whitest class, had the lowest bulk density and shrinkage values, and presented the best rehydration characteristic. After rehydration, it was whiter, bigger and softer than freshly cooked rice. PRACTICAL APPLICATIONSInstant rice has many advantages such as short preparation time, ease to carry and long shelf life. However, the existing products are not popular due to their poorer quality and higher price as compared with freshly cooked rice. As new food technology has continuously emerged, potential assessment of new technology for instant rice production would be imperative. Cooked rice is a difficult-to-handle material to be dried because of its sticky nature. So, a specific dryer is required to prevent agglomeration of cooked rice. Therefore, the effect of a new hybrid single-mode applicator-microwave vibro-fluidized bed (SMA-MVFB) drying on instant rice production and quality was investigated. In addition, a porous structure of instant rice is vital to ensuring its good rehydration capability and claimed to be improved by freezing before drying. Consequently, this study presented potential applications of SMA-MVFB drying and freezing pretreatment as well as drying temperature for preparing instant rice with good quality.

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Section: Resultsmentioning

confidence: 99%

Effects of Freezing Pretreatment, Microwave-Assisted Vibro-Fluidized Bed Drying and Drying Temperature on Instant Rice Production and Quality

Sripinyowanich

Noomhorm

2012

Journal of Food Processing and Preservation

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“…Instead, we attribute reaction to the formation of a radical adduct between • OH and the dye. Such addition reactions are well-known, especially for aromatic hydrocarbons, and are often described as Fenton-type reactions that lead to decomposition of the chromophore …”

Section: Resultsmentioning

confidence: 99%

“…Such addition reactions are well-known, especially for aromatic hydrocarbons, 82 and are often described as Fenton-type reactions that lead to decomposition of the chromophore. 83 The bromine anion radical, Br 2 −• , is a powerful one-electron oxidant (E 0 OX (Br 2 −• /2Br − ) = 1.63 V vs NHE) 73 that evolves through oxidation of bromide ions by the hydroxyl radical (Scheme 2). The Br 2 −• radical exhibits an absorption maximum at ∼350 nm (Figure 6B) and, in the absence of an easily oxidizable substrate, decays on the microsecond time scale (Figure 6B, inset).…”

Section: The Derived K Fmentioning

confidence: 99%

Pulse Radiolysis Investigation of Radicals Derived from Water-Soluble Cyanine Dyes: Implications for Super-resolution Microscopy

2021

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Light-induced blinking, an inherent feature of many forms of super-resolution microscopy, has been linked to transient reduction of the fluorescent cyanine dye used as an imaging agent. There is, however, only scant literature information related to one-electron reduced cyanine dyes, especially in an aqueous environment. Here, we examine a small series of cyanine dyes, possessing disparate π-conjugation lengths, under selective reducing or oxidizing conditions. The experiment allows recording of both differential absorption spectra and decay kinetics of the resultant one-electron reduced or oxidized transient species in water. Relative to the ground state, absorption transitions for the various radicals are weak and somewhat broadened but do allow correlation with the π-conjugation length. In all cases, absorption maxima lie to the blue of the main ground-state transition. Under anaerobic conditions, the transient species decay on the microsecond to millisecond time scale, with the mean lifetime depending on molecular structure, radiation dose, and dye concentration. The experimental absorption spectra recorded for the one-electron reduced radicals and the presumed dimer cation radical compare well to spectra obtained from time-dependent density functional theory calculations. The results allow conclusions to be drawn regarding the plausibility of the reduced species being responsible for light-induced blinking in direct stochastic optical reconstruction microscopy.

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Effects of Atmospheric Ozone on Microarray Data Quality

et al. 2003

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A data anomaly was observed that affected the uniformity and reproducibility of fluorescent signal across DNA microarrays. Results from experimental sets designed to identify potential causes (from microarray production to array scanning) indicated that the anomaly was linked to a batch process; further work allowed us to localize the effect to the posthybridization array stringency washes. Ozone levels were monitored and highly correlated with the batch effect. Controlled exposures of microarrays to ozone confirmed this factor as the root cause, and we present data that show susceptibility of a class of cyanine dyes (e.g., Cy5, Alexa 647) to ozone levels as low as 5-10 ppb for periods as short as 10-30 s. Other cyanine dyes (e.g., Cy3, Alexa 555) were not significantly affected until higher ozone levels (> 100 ppb). To address this environmental effect, laboratory ozone levels should be kept below 2 ppb (e.g., with filters in HVAC) to achieve high quality microarray data.

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Biologically Active Cyanine Dyes as Probes for the Identification of Active Oxygen Species

Cited by 3 publications

References 8 publications

Effects of Freezing Pretreatment, Microwave-Assisted Vibro-Fluidized Bed Drying and Drying Temperature on Instant Rice Production and Quality

Effects of Freezing Pretreatment, Microwave-Assisted Vibro-Fluidized Bed Drying and Drying Temperature on Instant Rice Production and Quality

Pulse Radiolysis Investigation of Radicals Derived from Water-Soluble Cyanine Dyes: Implications for Super-resolution Microscopy

Effects of Atmospheric Ozone on Microarray Data Quality

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