&lt;title&gt;Accurate measurements of biologically effective ultraviolet radiation&lt;/title&gt;

Morys, Marian; Berger, Daniel

doi:10.1117/12.163506

Cited by 17 publications

(12 citation statements)

References 6 publications

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“…As NADPH is a highly fluorescent molecule, it can be visualized under a fluorescence microscope using an excitation wavelength of 340 nm. Although this method is sensitive and selective for ATP, it has significant drawbacks that include its limited dynamic range, the phototoxicity caused by ultraviolet illumination (Morys & Berger , Wiedenmann et al . ), the need for exogenous NADP that may itself affect cell responses (Ying ) and the irreversible depletion of extracellular ATP for NADPH synthesis.…”

Section: Discussionmentioning

confidence: 99%

Novel method for real-time monitoring of ATP release reveals multiple phases of autocrine purinergic signalling during immune cell activation

et al. 2014

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Aims The activation of immune cells must be tightly regulated to allow an effective immune defense while limiting collateral damage to host tissues. Cellular ATP release and autocrine stimulation of purinergic receptors are recognized as critical regulators of immune cell activation. However, the study of purinergic signaling has been hampered by the short half-life of the released ATP and its breakdown products as well as the lack of real-time imaging methods to study spatiotemporal dynamics of ATP release. Methods To overcome these limitations, we optimized imaging methods that allow monitoring of ATP release with conventional microscopy using the recently developed small molecular ATP probes 1-2Zn(II) and 2-2Zn(II) for imaging of ATP in the extracellular space and release at the surface of living cells. Results 1-2Zn(II) allowed imaging of <1 µM ATP in the extracellular space, while 2-2Zn(II) provided unprecedented insights into the spatiotemporal dynamics of ATP release from neutrophils and T cells. Stimulation of these cells caused virtually instantaneous ATP release, which was followed by a second phase of ATP release that was localized to the immune synapse of T cells and the leading edge of polarized neutrophils. Imaging these ATP signaling processes along with mitochondrial probes provided evidence for a close spatial relationship between mitochondrial activation and localized ATP release in T cells and neutrophils. Conclusion We believe that these novel live cell imaging methods can be used to define the roles of purinergic signaling in immune cell activation and in the regulation of other complex physiological processes.

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Section: Discussionmentioning

confidence: 99%

Novel method for real-time monitoring of ATP release reveals multiple phases of autocrine purinergic signalling during immune cell activation

et al. 2014

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“…This is because the filter in the instrument approximates the erythemal flux. Therefore it is expected that Erythemal action spectrum ~ #1500 UV-Biometer real response the angular response is not so critical as its duplication across the network and stability with time [Morys and Berger, 1993]. However, results may not suffice where a more detailed understanding of the short-term radiation field is required and spectroradiometer measurements are not available.…”

Section: Introductionmentioning

confidence: 99%

Spectral dependence in the cosine response of broadband UV instruments

Kuchinke¹,

Núñez²

2001

J. Geophys. Res.

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Abstract. The erythemal UV biometer, a product of the original Robertson-Berger meter, is now widely used across the globe for routine UV measurements. They are employed to measure the erythemal response to radiation, however, the filter present in such instruments rarely mimics the erythemal curve. As such, the relative spectral response of each instrument is generally different from the erythemal response curve. Thus calibration of the detector is dependent upon wavelength as well as solar zenith angle. In this study, measurements were compared for the purpose of characterizing a new cosine response function (CRF) for the broadband detector. Concurrent measurements of spectral and broadband erythemal UV data have been undertaken at the University of Tasmania in Hobart, Australia. Measurements spanned solar zenith angles (SZA) of 21 ø-74ø, total ozone values of 220 -320 Dobson units and relatively small aerosol optical depths. The CRF is both wavelength and SZA dependent and applicable to all broadband UV-B instruments based on the original Robertson-Berger design. A methodology is presented for incorporation of the CRF into the calibration scheme. The concept of spectral multipliers is introduced, which are unique to each broadband instrument and correct for the wavelength dependence of the CRF. A method is then described for ongoing calibration of the detector based on model data alone. The scheme is then tested with real data to validate its reliability. Overall, by nature of the simultaneous characterisation of both spectral and cosine response, the CRF allows for a more robust calibration standard by which measurements and intercomparisons can be made.

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“…[3] Of the instruments available commercially, the Robertson-Berger meter offers opportunities for filling out data from high quality point measurements. It is a relatively inexpensive, portable broadband instrument measuring UV-B radiation modulated by the erythema skin response curve [Morys and Berger, 1993;McKinlay and Diffey, 1987]. This instrument type, dating back to the mid-seventies, has been used for long-term monitoring of UV erythema irradiance around the globe [Scotto et al, 1988;Josefsson, 1996;Weatherhead et al, 1997;Roy et al, 1997].…”

Section: Introductionmentioning

confidence: 99%

Using broadband erythemal UV instruments to measure relative irradiance

Núñez

Kuchinke

Gies³

2002

J.‐Geophys.‐Res.

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[1] This study examines the accuracy of the model 501A UV biometer in taking measurements relative to a predetermined background condition. The UVSPEC model with the discrete ordinates radiative transfer (DISORT) algorithm was used to mimic a range of radiation environments covering differing zenith angles, aerosol, and cloud regimes. These data were used to model typical responses for two hypothetical biometers with differing spectral and cosine responses. A ratio was then calculated between the irradiance for any zenith angle, atmospheric opacity, and ozone load and the irradiance for the same zenith angle and ozone load but for a clean atmosphere with 95-km visibility conditions. Both virtual instruments gave very similar ratios for a wide variety of aerosol loads, cloud cover, and zenith angles. Furthermore, the instrument ratios also agreed with ratios predicted by an instrument with a perfect cosine response and responding to the erythema curve. The above theoretical results were tested with three model 501A biometers that were sampling the same environment for a three-month period in Hobart, Australia. Ratios were calculated for each instrument between any 10-min measured average irradiance and the instrument value predicted for the same ozone load and zenith angle but for cloudless conditions. Instrument ratios for solar zenith angles less than 70°a gree closely with each other, with a coefficient of variance exceeding 0.99 and RMS errors of between 1 and 2%. Finally, the data may be turned into absolute corrected irradiance by using the UVSPEC calculations as discussed in the paper. INDEX TERMS:3359 Meteorology and Atmospheric Dynamics: Radiative processes; 3394 Meteorology and Atmospheric Dynamics: Instruments and techniques; 0360 Atmospheric Composition and Structure: Transmission and scattering of radiation; 1694 Global Change: Instruments and techniques; KEYWORDS: ultraviolet irradiance, UV erythemal irradiance, broadband radiometers, relative irradiance Citation: Nunez, M., C. Kuchinke, and P. Gies, Using broadband erythemal UV instruments to measure relative irradiance,

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<title>Accurate measurements of biologically effective ultraviolet radiation</title>

Cited by 17 publications

References 6 publications

Novel method for real-time monitoring of ATP release reveals multiple phases of autocrine purinergic signalling during immune cell activation

Novel method for real-time monitoring of ATP release reveals multiple phases of autocrine purinergic signalling during immune cell activation

Spectral dependence in the cosine response of broadband UV instruments

Using broadband erythemal UV instruments to measure relative irradiance

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