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Fluorescent light - Citavi Atteia, Ariane; Adrait, Annie; Brugière, Sabine; Tardif, Marianne; van Lis, Robert; Deusch, Oliver et al. (2009): A proteomic survey of Chlamydomonas reinhardtii mitochondria sheds new light on the metabolic plasticity of the organelle and on the nature of the {alpha}-proteobacterial mitochondrial ancestor. In: Molecular biology and evolution. Online verfügbar unter doi:10.1093/molbev/msp068. Abstract Mitochondria play a key role in the life and death of eukaryotic cells, yet the full spectrum of mitochondrial functions is far from being fully understood, especially in photosynthetic organisms. To advance our understanding of mitochondrial functions in a photosynthetic cell, an extensive proteomic survey of Percoll-purified mitochondria from the metabolically versatile, hydrogen-producing green alga Chlamydomonas reinhardtii was performed. Different fractions of purified mitochondria from Chlamydomonas cells grown under aerobic conditions were analyzed by nano-liquid chromatography-electrospray ionization-mass spectrometry (MS) after protein separation on SDS-PAGE or on blue-native (BN)-PAGE. Of the 496 non-redundant proteins identified, 149 are known or predicted to reside in other cellular compartments and were thus excluded from the molecular and evolutionary analyses of the Chlamydomonas proteome. The mitochondrial proteome of the photosynthetic alga reveals important lineage-specific differences with other mitochondrial proteomes, reflecting the high metabolic diversity of the organelle. Some mitochondrial metabolic pathways in Chlamydomonas appear to combine typical mitochondrial enzymes and bacterial-type ones whereas others are unknown among mitochondriate eukaryotes. The comparison of the Chlamydomonas proteins to their identifiable homologs predicted from 354 sequenced genomes indicated that Arabidopsis is the most closely related non-algal eukaryote. Furthermore, this phylogenomic analysis shows that free-living alpha-proteobacteria from the metabolically versatile orders Rhizobiales and Rhodobacterales better reflect the gene content of the ancestor of the chlorophyte mitochondria than parasitic alpha-proteobacteria with reduced and specialized genomes. Bubenheim, D. L.; Sargis, R.; Wilson, D. (1995): Spectral changes in metal halide and high-pressure sodium lamps equipped with electronic dimming. In: HortScience : a publication of the American Society for Horticultural Science, Jg. 30, H. 5, S. 1086–1089. Electronic dimming of high-intensity discharge lamps offers control of Abstract photosynthetic photon flux (PPF) but is often characterized as causing significant spectral changes. Growth chambers with 400-W metal halide (MH) and highpressure sodium (HPS) lamps were equipped with a dimmer system using siliconcontrolled rectifiers (SCR) as high-speed switches. Phase control operation turned the line power off for some period of the alternating current cycle. At full power, the electrical input to HPS and MH lamps was 480 W (root mean squared) and could be decreased to 267 W and 428 W, respectively, before the arc was extinguished. Concomitant with this decrease in input power, PPF decreased by 60% in HPS and 50% in MH. The HPS lamp has characteristic spectral peaks at 589 and 595 nm. As power to the HPS lamps was decreased, the 589-nm peak remained constant while the 595-nm peak decreased, equaling the 589-nm peak at 345-W input, and the 589-nm peak was almost absent at 270-W input. The MH lamp has a broader spectral output but also has a peak at 589 nm and another smaller peak at 545 nm. As input power to the MH lamps decreased, the peak at 589 diminished to equal the 545-nm peak. As input power approached 428 W, the 589-nm peak shifted to 570 nm. While the spectrum changed as input power was decreased in the MH and HPS lamps, the phytochrome equilibrium ratio (Pfr : Ptot) remains unchanged for both lamp types. Schlagwörter Dose-Response Relationship, Radiation; Environment, Controlled; Light; Lightingmethods; Photons; Photosynthesis; Phytochrome; Plant Physiological Phenomena; Plantsgrowth & developmentmetabolismradiation effects Dilsaver, S. C.: Neurobiologic effects of bright artificial light. In: Brain research. Brain research reviews, Jg. 14,

Fluorescent light - Citavi H. 4, S. 311–333. Abstract

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Bright light is an effective treatment of winter depression. Study of the effects of this treatment on mechanisms thought to be involved in the pathophysiology of depressive disorders is reviewed. Measurement of a physiological parameter, namely the change in core temperature using an intraperitoneally implanted radio transmitter sensitive to temperature in freely moving rats, indicates that treatment with bright light under various experimental conditions tends to powerfully subsensitize muscarinic and nicotinic mechanisms. Pulses of bright light during the phase delay portions of the PRC blunt sensitivity to clonidine. Our studies with bright light are consistent with those indicating that heterocyclic antidepressants and a monoamine oxidase inhibitor produce subsensitivity to the thermic effects of nicotine. Reports of the influences of full-spectrum bright light and its impact on targeted neurotransmitter mechanisms call attention to the anatomical substratum mediating its effects. Possible receptor changes are measurable using receptor binding techniques and quantitative autoradiography. The physiological effects of this interesting treatment raises questions of its impact on coupling mechanisms and second messengers. Amitriptylinepharmacology; Animals; Antidepressive Agentspharmacology; Braindrug effectsphysiology; Clonidinepharmacology; Darkness; Depressive Disordertherapy; Humans; Light; Lighting; Nicotinepharmacology; Oxotremorinepharmacology; Phototherapy; Rats; Reference Values; Stress, Psychological

Eames, Matthew E.; Wang, Jia; Pogue, Brian W.; Dehghani, Hamid: Wavelength band optimization in spectral near-infrared optical tomography improves accuracy while reducing data acquisition and computational burden. In: Journal of biomedical optics, Jg. 13, H. 5, S. 54037. Online verfügbar unter doi:10.1117/1.2976425. Abstract Multispectral near-infrared (NIR) tomographic imaging has the potential to provide information about molecules absorbing light in tissue, as well as subcellular structures scattering light, based on transmission measurements. However, the choice of possible wavelengths used is crucial for the accurate separation of these parameters, as well as for diminishing crosstalk between the contributing chromophores. While multispectral systems are often restricted by the wavelengths of laser diodes available, continuous-wave broadband systems exist that have the advantage of providing broadband NIR spectroscopy data, albeit without the benefit of the temporal data. In this work, the use of large spectral NIR datasets is analyzed, and an objective function to find optimal spectral ranges (windows) is examined. The optimally identified wavelength bands derived from this method are tested using both simulations and experimental data. It is found that the proposed method achieves images as qualitatively accurate as using the full spectrum, but improves crosstalk between parameters. Additionally, the judicious use of these spectral windows reduces the amount of data needed for full spectral tomographic imaging by 50%, therefore increasing computation time dramatically. Schlagwörter Algorithms; Image Enhancementmethods; Image Interpretation, ComputerAssistedmethods; Information Storage and Retrievalmethods; Infrared Raysdiagnostic use; Phantoms, Imaging; Reproducibility of Results; Sensitivity and Specificity; Spectroscopy, Near-Infraredinstrumentationmethods; Tomography, Opticalinstrumentationmethods Hall, John L. (2006): Defining and measuring optical frequencies: the optical clock opportunity--and more (Nobel lecture). In: Chemphyschem : a European journal of chemical physics and physical chemistry, Jg. 7, H. 11, S. 2242–2258. Online verfügbar unter doi:10.1002/cphc.200600457. Abstract Four long-running currents in laser technology met and merged in 1999-2000. Two of these were the quest toward a stable repetitive sequence of ever-shorter optical pulses and, on the other hand, the quest for the most time-stable, unvarying optical frequency possible. The marriage of ultrafast- and ultrastable lasers was brokered mainly by two international teams and became exciting when a special "designer"

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microstructure optical fiber was shown to be nonlinear enough to produce "white light" from the femtosecond laser pulses, such that the output spectrum embraced a full optical octave. Then, for the first time, one could realize an optical frequency interval equal to the comb's lowest frequency, and count out this interval as a multiple of the repetition rate of the femtosecond pulse laser. This "gear-box" connection between the radiofrequency standard and any/all optical frequency standards came just as sensitivity-enhancing ideas were maturing. The four-way union empowered an explosion of accurate frequency measurement results in the standards field and prepared the way for refined tests of some of our cherished physical principles, such as the time-stability of some of the basic numbers in physics (e.g. the "fine-structure" constant, the speed of light, certain atomic mass ratios), and the equivalence of time-keeping by clocks based on different physics. The stable laser technology also allows time-synchronization between two independent femtosecond lasers so exact they can be made to appear as if the source were a single laser. By improving pump-probe experiments, one important application will be in bond-specific spatial scanning of biological samples. This next decade in optical physics should be a blast!

Hargreaves, J. A.; Thompson, G. W. (1989): Ultraviolet light and dental caries in children. In: Caries research, Jg. 23, H. 5, S. 389–392. Animal experimental work has suggested that ultraviolet radiation reduces dental Abstract caries incidence. The opportunity to complete a study on children in the 1-ppm water fluoridated community of Wetaskiwin, Alberta, Canada, through an experimental school design study, became possible between 1982 and 1984 as in winter children have to travel to and from school during hours of darkness. Two classrooms at the four primary schools in the city had full spectrum lighting introduced and the 102 children entering grade 5 spent 22 months of study in the same classrooms; 83 (81%) remained in the trial. Each child had DMFT, DMFS, including degree of caries involvement, gingivitis and oral hygiene indices recorded. Results showed that children receiving the full spectrum light had very low or no increase in caries incidence over the 22-month period compared with controls. DMFS findings, excluding 'sticky fissures' over the 22-month period, increased from 2.67 to 3.23 in the group receiving full spectrum light, compared with an increase of 2.32 to 4.46 in the control group (p less than 0.001). Schlagwörter Alberta; Child; DMF Index; Dental Cariesepidemiologyprevention & control; Female; Humans; Lighting; Male; Ultraviolet Rays Hofstetter, John R.; Hofstetter, Amelia R.; Hughes, Amanda M.; Mayeda, Aimee R. (2005): Intermittent longwavelength red light increases the period of daily locomotor activity in mice. In: Journal of circadian rhythms, Jg. 3, S. 8. Online verfügbar unter doi:10.1186/1740-3391-3-8. Abstract BACKGROUND: We observed that a dim, red light-emitting diode (LED) triggered by activity increased the circadian periods of lab mice compared to constant darkness. It is known that the circadian period of rats increases when vigorous wheel-running triggers full-spectrum lighting; however, spectral sensitivity of photoreceptors in mice suggests little or no response to red light. Thus, we decided to test the following hypotheses: dim red light illumination triggered by activity (LEDfb) increases the circadian period of mice compared to constant dark (DD); covering the LED prevents the effect on period; and DBA2/J mice have a different response to LEDfb than C57BL6/J mice. METHODS: The irradiance spectra of the LEDs were determined by spectrophotometer. Locomotor activity of C57BL/6J and DBA/2J mice was monitored by passive-infrared sensors and circadian period was calculated from the last 10 days under each light condition. For constant dark (DD), LEDs were switched off. For LED feedback (LEDfb), the red LED came on when the mouse was active and switched off seconds after activity stopped. For taped LED the red LED was switched on but covered with black tape. Single and multifactorial ANOVAs and post-hoc t-tests were done. RESULTS: The circadian period of mice

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was longer under LEDfb than under DD. Blocking the light eliminated the effect. There was no difference in period change in response to LEDfb between C57BL/6 and DBA/2 mice. CONCLUSION: An increase in mouse circadian period due to dim far-red light (1 lux at 652 nm) exposure was unexpected. Since blocking the light stopped the response, sound from the sensor's electronics was not the impetus of the response. The results suggest that red light as background illumination should be avoided, and indicator diodes on passive infrared motion sensors should be switched off.

James, Francine O.; Walker, Claire D.; Boivin, Diane B. (2004): Controlled exposure to light and darkness realigns the salivary cortisol rhythm in night shift workers. In: Chronobiology international, Jg. 21, H. 6, S. 961–972. The efficacy of a light/darkness intervention designed to promote circadian Abstract adaptation to night shift work was tested in this combined field and laboratory study. Six full-time night shift workers (mean age+/-SD:37.1+/-8.1yrs) were provided an intervention consisting of an intermittent exposure to full-spectrum bright white light (approximately 2000 lux) in the first 6h of their 8 h shift, shielding from morning light by tinted lenses (neutral gray density, 15% visual light transmission), and regular sleep/darkness episodes in darkened quarters beginning 2h after the end of each shift. Five control group workers (41.1+/-9.9 yrs) were observed in the presence of a regular sleep/darkness schedule only. Constant routines (CR) performed before and after a sequence of approximately 12 night shifts over 3 weeks revealed that treatment group workers displayed significant shifts in the time of peak cortisol expression and realignment of the rhythm with the night-oriented schedule. Smaller phase shifts, suggesting an incomplete adaptation to the shift work schedule, were observed in the control group. Our observations support the careful control of the pattern of light and darkness exposure for the adaptation of physiological rhythms to night shift work. Schlagwörter Adaptation, Physiological; Adult; Biological Clocksphysiology; Circadian Rhythmphysiology; Darkness; Employment; Female; Humans; Hydrocortisonemetabolism; Light; Male; Middle Aged; Phototherapy; Salivachemistry; Work Schedule Tolerance Kligman, L. H. (1987): Full spectrum solar radiation as a cause of dermal photodamage: UVB to infrared. In: Acta dermato-venereologica. Supplementum, Jg. 134, S. 53–61. Schlagwörter Agingpathology; Animals; Humans; Infrared Raysadverse effects; Skinradiation effects; Sunlightadverse effects; Sunscreening Agentstherapeutic use; Ultraviolet Raysadverse effects Lam, R. W.; Buchanan, A.; Clark, C. M.; Remick, R. A. (1991): Ultraviolet versus non-ultraviolet light therapy for seasonal affective disorder. In: The Journal of clinical psychiatry, Jg. 52, H. 5, S. 213–216. Abstract Although light therapy has been shown to be effective in the treatment of seasonal affective disorder (SAD), little research has been done to determine which light wavelengths affect treatment outcome. In this triple crossover study the authors compared 1 week of light therapy in which bright (2500 lux), full-spectrum fluorescent light, with and without blockade of the ultraviolet (UV) spectrum, was used with a dim (500 lux) light control in 11 SAD patients. The dim light condition had no significant antidepressant effects as measured by the Hamilton Rating Scale for Depression (HAM-D), the Beck Depression Inventory (BDI), and an atypical depressive symptom (ATYP) score. The UV-light condition significantly reduced HAM-D, BDI, and ATYP scores, whereas the UV-blocked condition significantly reduced only the ATYP score. These results suggest that the UV-spectrum in light therapy may have a differential effect on typical and atypical symptoms in SAD. Schlagwörter Depressive Disorderpsychologytherapy; Evaluation Studies as Topic; Female; Humans; Light; Male; Personality Inventory; Phototherapymethods; Psychiatric Status Rating Scales; Research Design; Seasons; Ultraviolet Rays; Ultraviolet

Fluorescent light - Citavi Therapy London, W. P. (1987): Full-spectrum classroom light and sickness in pupils. In: Lancet, Jg. 2, H. 8569, S. 1205–1206. Schlagwörter Child; Child, Preschool; Humans; Lightadverse effects; Morbidity; Schools Martin, J. L.; Migus, A.; Poyart, C.; Lecarpentier, Y.; Astier, R.; Antonetti, A. (1983): Spectral evidence for subpicosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. In: The EMBO journal, Jg. 2, H. 10, S. 1815–1819. Abstract We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference spectra revealed the appearance of a deoxy species with tau approximately equal to 250-300 fs. The transient deoxy species in myoglobin and hemoglobin evidenced a 3-4 nm red shift of their delta A spectra compared with the equilibrium delta A spectrum. This shift was not observed after photodissociation of the carbon monoxide liganded protoheme. We proposed that the 250 fs time constant corresponding to the appearance of the deoxy-like species is related to the displacement of the ferrous iron out of the heme plane. Consequently, the small red shift of the delta A spectra observed in photodissociated hemoproteins may be tentatively attributed to changes in the vibrational modes of either the proximal histidine-Fe2+ bond and/or of the N4 porph-Fe-N epsilon His (F8) bent. Schlagwörter Animals; Hemeproteinsmetabolism; Hemoglobinsmetabolism; Horses; Humans; Kinetics; Myocardiummetabolism; Myoglobinmetabolism; Photolysis; Spectrophotometry; Time Factors Mayeda, A.; Mannon, S.; Hofstetter, J.; Adkins, M.; Baker, R.; Hu, K.; Nurnberger, J. (1998): Effects of indirect light and propranolol on melatonin levels in normal human subjects. In: Psychiatry research, Jg. 81, H. 1, S. 9–17. Abstract An indirect lighting protocol was developed to measure nocturnal melatonin suppression by light in normal human subjects. Goals were to minimize both discomfort due to staring intensely at a bright light source, and behavioral variation due to wandering gaze. Subjects sat with a bank of five full-spectrum light sources placed behind them. Lights reflecting off the surfaces before each subject produced a hemisphere of light that measured 500 lx +/- 5%. Subjects retired to bed in darkness by midnight and then sat in the hemisphere of light from 02.00 h to 04.00 h. Blood for melatonin was drawn at 20-30-min intervals from midnight to 06.00 h. Plasma melatonin was measured by radioimmunoassay. The indirect lighting protocol was used to compare the effects of 500 lx light to dark (21 subjects) and to study varying light intensities from 300 to 2000 lx (7 subjects). We studied the effects of the sitting posture in very dim light of 20-30 lx (6 subjects). We also studied the effects of propranolol plus dark and propranolol plus 500 lx light on melatonin levels. Subjects received placebo, 10 mg propranolol or 40 mg propranolol orally at 23.00 h, and were then exposed to either the dark or light condition. Melatonin levels obtained with the indirect lighting protocol were consistent with studies using direct lighting; light of 500 lx significantly suppressed nocturnal melatonin and suppression was dose related between 300 and 2000 lx. Sitting in dim light had no significant effect on melatonin suppression when compared with the supine posture in the dark in six subjects. Propranolol caused a dose-dependent decrease in melatonin levels in both the dark and the light. There was no relationship between suppression of melatonin by propranolol and suppression by light. Schlagwörter Adolescent; Adrenergic beta-Antagonistspharmacology; Adult; Dose-Response Relationship, Drug; Female; Humans; Light; Male; Melatoninmetabolism; Middle Aged; Propranololpharmacology

Fluorescent light - Citavi McColl, S. L.; Veitch, J. A. (2001): Full-spectrum fluorescent lighting: a review of its effects on physiology and health. In: Psychological medicine, Jg. 31, H. 6, S. 949–964. BACKGROUND: Full-spectrum fluorescent lighting (FSFL) has been credited with Abstract causing dramatic beneficial effects on a wide variety of behaviours, mental health outcomes and physical health effects, as compared to other fluorescent lamp types. These effects are hypothesized to occur because of similarity between FSFL emissions and daylight, which is said to have evolutionary superiority over other light sources. METHOD: This review, covering the period 1941-1999, critically considers the evidence for direct effects of FSFL through skin absorption as well as indirect effects on hormonal and neural processes. CONCLUSIONS: Overall, the evidence does not show dramatic effects of fluorescent lamp type on behaviour or health, neither does it support the evolutionary hypothesis. Schlagwörter Arousalphysiology; Brainphysiology; Calciummetabolism; Evolution; Female; Fluorescence; Health Status; Humans; Hydrocortisoneurine; Hyperbilirubinemiatherapy; Light; Male; Melatoninurine; Phototherapy; Psychomotor Performancephysiology; Seasonal Affective Disordertherapy; Skinradiation effects; Stress, Psychologicalmetabolism; Sympathetic Nervous Systemphysiology; Vitamin Dmetabolism Midwinter, M. J.; Arendt, J. (1991): Adaptation of the melatonin rhythm in human subjects following night-shift work in Antarctica. In: Neuroscience letters, Jg. 122, H. 2, S. 195–198. Abstract Different environmental conditions, particularly daylength and intensity of natural light, may influence the ability of shiftworkers to adapt to the abrupt phase-shifts of 24 h time cues imposed by the nature of their work. We have investigated this problem in terms of the circadian rhythm of the pineal hormone melatonin in nightshift workers on the British Antarctic Survey Base at Halley (75 degrees South). Melatonin production was assessed by measurement of its major urinary metabolite 6-sulphatoxymelatonin (aMT6s) by radio-immunoassay in sequential urine samples collected for 48 h at weekly intervals. The acrophase of the melatonin rhythm was significantly delayed from 5.22 h. min to 14.54 h. min (summer) and 8.73 h.min to 13.23 h.min (winter) during a week of night-shift work. Readaptation of the rhythm following night-shift work was markedly slower during the Antarctic winter taking 3 weeks compared to summer where the baseline phase position was re-established after 1 week. Morning and evening treatment (08.0009.00 h, 16.00-17.00 h) with bright (greater than 2500 lux) full spectrum white light did not significantly modify this phenomenon in summer, but a trend to faster adaptation with light treatment was seen in winter. These observations are likely to be of importance to shift-workers in temperate zones. Further investigations of phase-shifting techniques, such as appropriately timed bright light and administration of melatonin itself, are indicated, particularly in relation to performance at work. Schlagwörter Adult; Analysis of Variance; Antarctic Regions; Circadian Rhythm; Darkness; Humans; Light; Male; Melatoninbloodsecretion; Seasons; Work Schedule Tolerance Moyal, Dominique D.; Fourtanier, Anny M. (2008): Broad-spectrum sunscreens provide better protection from solar ultraviolet-simulated radiation and natural sunlight-induced immunosuppression in human beings. In: Journal of the American Academy of Dermatology, Jg. 58, H. 5 Suppl 2, S. S149-54. Online verfügbar unter doi:10.1016/j.jaad.2007.04.035. Abstract BACKGROUND: It is well established that ultraviolet (UV) radiation induces immunomodulatory effects that may be involved in skin cancer. Recent studies have shown that UVA (320-400 nm) and UVB (290-320 nm) radiation are immunosuppressive. As a result, sunscreens, which mainly absorb UVB, may be less effective in preventing UV radiation-induced immunosuppression than broadspectrum products. OBJECTIVE: We sought to study the effects of UVA exposure on human delayed-type hypersensitivity (DTH) response and compare the efficacy

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of sunscreens having different levels of sun-protection factor (SPF) and UVA protection against both solar-simulated radiation and outdoor real-life sunlight exposure conditions. METHODS: DTH was assessed using a kit which includes 7 recall antigens that most of the participants encountered during childhood immunization. Evaluation of DTH test response was made 48 hours after test application before and after UV exposure with or without sunscreens. RESULTS: In unprotected participants, the response to DTH tests was significantly reduced irrespective of UV types of exposure (full-spectrum UVA, long UVA, solar-simulated radiation). A UVB sunscreen failed to protect from solar-simulated radiation-induced immunosuppression. In contrast, a broad-spectrum sunscreen with the same SPF but providing a high protection in the UVA range significantly reduced local UVinduced immunosuppression and prevented the distant effects. In the outdoor study, as compared with DTH responses obtained before sun exposure, no alteration of immune response was detected when the skin was protected by a broad-spectrum sunscreen having a high protection level in the UVA (SPF 25, UVA protection factor 14). Conversely a broad-spectrum sunscreen with lower protection against UVA (SPF 25, UVA protection factor 6) failed to prevent UV-impaired response. LIMITATIONS: These results have been obtained after repeated exposure. Additional experiments obtained under acute exposure are in progress. CONCLUSION: These findings clearly demonstrated the role of UVA in the induction of photoimmunosuppression together with the need for sunscreen products providing efficient photoprotection throughout the entire UV spectrum. Absorption; Adolescent; Adult; Female; Humans; Hypersensitivity, Delayedimmunologyprevention & control; Immune Toleranceimmunology; Male; Radiation Dosage; Skinradiation effects; Skin Neoplasmsprevention & control; Sunlightadverse effects; Sunscreening Agentspharmacologytherapeutic use; Ultraviolet Raysadverse effects

Owen, J.; Arendt, J. (1992): Melatonin suppression in human subjects by bright and dim light in antarctica: time and season-dependent effects. In: Neuroscience letters, Jg. 137, H. 2, S. 181–184. Abstract Full-spectrum light, of sufficiently high intensity, will suppress the secretion of melatonin at night in humans. Individual sensitivity to such suppression is variable, and the factors determining such sensitivity are largely unknown. By analogy with animal work previous short or long-term exposure to different light intensities may be an important determinant. We exploited the Antarctic environment to investigate these possibilities. Groups of healthy men, living on the British Antarctic Survey Base at Halley (75 degrees South) were exposed to dim (range 290-310 lux) and bright (range 2100-2300 lux) light either from 01.00-02.00 h or 05.00-0.600 h, both in winter and in summer. Plasma melatonin concentrations were determined by radioimmunoassay in serial blood samples taken before, during and after light treatment, and in control (darkness) conditions. Light suppression of melatonin was more effective in the latter part of the night in winter and this was particularly welldifferentiated for dim light. Schlagwörter Adult; Antarctic Regions; Humans; Light; Male; Melatoninblood; Seasons; Time Factors Pascal, Andrew A.; Liu, Zhenfeng; Broess, Koen; van Oort, Bart; van Amerongen, Herbert; Wang, Chao et al. (2005): Molecular basis of photoprotection and control of photosynthetic light-harvesting. In: Nature, Jg. 436, H. 7047, S. 134–137. Online verfügbar unter doi:10.1038/nature03795. Abstract In order to maximize their use of light energy in photosynthesis, plants have molecules that act as light-harvesting antennae, which collect light quanta and deliver them to the reaction centres, where energy conversion into a chemical form takes place. The functioning of the antenna responds to the extreme changes in the intensity of sunlight encountered in nature. In shade, light is efficiently harvested in photosynthesis. However, in full sunlight, much of the energy absorbed is not needed and there are vitally important switches to specific antenna states, which

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safely dissipate the excess energy as heat. This is essential for plant survival, because it provides protection against the potential photo-damage of the photosynthetic membrane. But whereas the features that establish high photosynthetic efficiency have been highlighted, almost nothing is known about the molecular nature of the dissipative states. Recently, the atomic structure of the major plant light-harvesting antenna protein, LHCII, has been determined by X-ray crystallography. Here we demonstrate that this is the structure of a dissipative state of LHCII. We present a spectroscopic analysis of this crystal form, and identify the specific changes in configuration of its pigment population that give LHCII the intrinsic capability to regulate energy flow. This provides a molecular basis for understanding the control of photosynthetic light-harvesting. Chlorophyllmetabolism; Crystallization; Crystallography, X-Ray; Fluorescence; Light; Light-Harvesting Protein Complexeschemistrymetabolismradiation effects; Models, Molecular; Photosynthesisphysiologyradiation effects; Photosystem II Protein Complexchemistrymetabolismradiation effects; Pigments, Biologicalchemistrymetabolism; Plantschemistrymetabolismradiation effects; Protein Structure, Tertiary; Spectrum Analysis, Raman; Structure-Activity Relationship

Pathak, M. A.; Fanselow, D. L. (1983): Photobiology of melanin pigmentation: dose/response of skin to sunlight and its contents. In: Journal of the American Academy of Dermatology, Jg. 9, H. 5, S. 724–733. A randomized double-blind clinical trial involving twenty-two volunteers was Abstract conducted in two locations (Orlando, FL, and St. Paul, MN) to test the efficacy of the newly designed ultraviolet monitor badges (Sun Timers), described in another paper by us in this issue of the Journal, 1 and to establish the relationship between spectral band exposure dose and the biologic responses of erythema and pigmentation. Individuals with skin types II, III, and IV, exhibiting differences in reactivity to solar radiation, were exposed to varying doses of full-spectrum sunlight through templates mounted on the lower portion of the back. Simultaneously, on the upper portion of the back, the same volunteers were exposed through two different types of polyester filters that transmitted ultraviolet A (UVA) and visible radiation. Using templates with windows, exposures to full-spectrum sunlight, UVA, and visible radiation were carried out to 1, 2, 3, 6, and 9 sunburn units (approximately 30-270 millijoules/cm2 between 10:30 A.M. and 3:30 P.M. daylight time in mid summer), measured with the aid of a Robertson-Berger meter and an IL700 International Light radiometer. Erythema and pigmentation resulting from these exposures were graded (double-blind) immediately after exposure, at 24 hours, and after 5 days. Numerical skin response ratings at each exposure dose for different spectral bands were then averaged and plotted. It was found that the UVB monitor response was predictive of a 24-hour erythema response and 5-day pigmentation response within 30% of the biologic average for skin types II, III, and IV. UVA radiation stimulated melanogenesis. The minimal melanogenic dose (MMD) for skin type II was the same as the minimal erythemogenic dose (MED). The MMD for individuals of skin types III and IV was distinctly less than their MED. Thus, melanogenesis can be stimulated with a suberythemal dose of UVB or UVA radiation. The sun protection factor values of melanin for melanized skin have been estimated to vary from 1.0 (skin type II) to 4.3 (skin types V and VI). Schlagwörter Clinical Trials as Topic; Dose-Response Relationship, Radiation; Double-Blind Method; Humans; Melaninsbiosynthesis; Random Allocation; Skin Pigmentationradiation effects; Sunburnetiology; Sunlight; Time Factors Pitts, D. G.; Cullen, A. P. (1981): Determination of infrared radiation levels for acute ocular cataractogenesis. In: Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie. Albrecht von Graefe's archive for clinical and experimental ophthalmology, Jg. 217, H. 4, S. 285–297. Abstract One hundred pigmented rabbit eyes and ten primate eyes were exposed to infrared (IR) radiation in the 715 to 1,400 nm wavelength range and to the full spectrum

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output from a 5,000 W Xenon high-pressure source. The ocular exposures were evaluated independently with a slitlamp by two researchers and classified for ocular damage. The primary ocular lesions resulting from exposure to IR radiation were corneal, iritic, and lenticular. Corneal damage varied from epithelial haze to epithelial erosion but no endothelial damage was found. The iris showed stromal haze and swelling. Lenticular changes showed small white dots that, occur at the level of the anterior cortex. All lens damage depended on iris involvement. Ocular damage was related to the rate of delivery of the IR radiation since the data show that as the irradiance level increases, the radiant exposure threshold decreases. Exposures for the full spectrum were found to be additive for irradiance levels at 4 W.cm-2 and above. The threshold radiant exposures for the full spectrum of 750 J.cm-2 for the cornea, 1,000 J.cm-2 for the iris, and 2,000 J.cm-2 for the lens were essentially identical to the IR exposure thresholds for the same irradiance levels. The primate threshold radiant exposure was a factor of six above the respective rabbit thresholds. Animals; Cataractetiology; Corneal Diseasesetiology; Dose-Response Relationship, Radiation; Infrared Raysadverse effects; Iris Diseasesetiology; Macaca fascicularis; Rabbits; Radiobiologyinstrumentation; Xenon

Reichow, Alan W.; Citek, Karl; Edlich, Richard F. (2006): Ultraviolet and short wavelength visible light exposure: why ultraviolet protection alone is not adequate. In: Journal of long-term effects of medical implants, Jg. 16, H. 4, S. 315–325. Abstract The danger of exposure to ultraviolet (UV) radiation in both the natural environment and artificial occupational settings has long been recognized by national and international standards committees and worker safety agencies. There is an increasing body of literature that suggests that protection from UV exposure is not enough. Unprotected exposure to the short wavelengths of the visible spectrum, termed the "blue light hazard", is gaining acceptance as a true risk to long-term visual health. Global standards and experts in the field are now warning that those individuals who spend considerable time outdoors should seek sun filter eyewear with high impact resistant lenses that provide 100% UV filtration, high levels of blue light filtration, and full visual field lens/frame coverage as provided by high wrap eyewear. The Skin Cancer Foundation has endorsed certain sunglasses as "product[s]...effective [as] UV filter[s] for the eyes and surrounding skin". However, such endorsement does not necessarily mean that the eyewear meets all the protective needs for outdoor use. There are several brands that offer products with such protective characteristics. Performance sun eyewear by Nike Vision, available in both corrective and plano (nonprescription) forms, is one such brand incorporating these protective features. Schlagwörter Environmental Exposure; Eyeradiation effects; Eye Protective Devicesstandards; Humans; Radiation Protectionstandards; Ultraviolet Raysadverse effects Rice, J.; Mayor, J.; Tucker, H. A.; Bielski, R. J. (1995): Effect of light therapy on salivary melatonin in seasonal affective disorder. In: Psychiatry research, Jg. 56, H. 3, S. 221–228. Abstract To investigate the role of a light-induced advance in the timing of the melatonin rhythm in seasonal affective disorder, 11 depressed patients underwent 2 weeks of light therapy with full spectrum or cool white light. Evening saliva samples were collected before and after each week of treatment and assayed for melatonin to determine the time of onset of nocturnal secretion. Both treatments reduced depression scores, advanced the timing of the melatonin rhythm, and increased melatonin concentrations. Time of onset of the nocturnal increase in melatonin did not differ between clinical responders and nonresponders, suggesting that a phase advance in the onset of nocturnal melatonin secretion is not sufficient to induce clinical remission in seasonal affective disorder. Schlagwörter Adult; Analysis of Variance; Circadian Rhythmphysiology; Female; Humans; Male; Melatoninanalysis; Middle Aged; Phototherapy; Psychiatric Status Rating Scales;

Fluorescent light - Citavi Salivachemistry; Seasonal Affective Disorderphysiopathologypsychologytherapy Ross, J. K.; Arendt, J.; Horne, J.; Haston, W. (1995): Night-shift work in Antarctica: sleep characteristics and bright light treatment. In: Physiology & behavior, Jg. 57, H. 6, S. 1169–1174. Changes in sleep parameters during and after night-shift and the effects of bright Abstract white (2500-3000 1x) and dim red (> 500 1x) light treatment on re adaptation after night-shift during winter were studied in 14 men on the British Antarctic Survey Base of Halley (75 degrees south). Subjects kept daily sleep diaries and mood ratings from one week before to three weeks after night-shift and received either full-spectrum white or dim red light treatment from 1100 to 1300 h daily during the first week after night-shift. Plasma melatonin (for 24 h at the end of weeks 1, 2 and 4), and urinary 6-sulfatoxymelatonin (aMT6s, for 48 h weekly) were measured. A significant (MANOVA; p < 0.05) improvement in sleep was seen during night shift (latency and duration) and with bright light treatment (latency). Melatonin and aMT6s rhythms delayed by 7-8 h during night-shift. The white light group readapted slowly, apparently by phase delay, as assessed by aMT6s measurement. The red light group readapted slightly, but significantly (ANOVA, p < 0.01) faster than the white light group. Schlagwörter Adaptation, Psychologicalphysiology; Adult; Affectphysiology; Antarctic Regions; Body Temperaturephysiology; Humans; Male; Melatoninanalogs & derivativesurine; Phototherapy; Sleepphysiology Rudorfer, M. V.; Skwerer, R. G.; Rosenthal, N. E. (1993): Biogenic amines in seasonal affective disorder: effects of light therapy. In: Psychiatry research, Jg. 46, H. 1, S. 19–28. Wintertime measures of central and peripheral monoamine neurotransmitter system Abstract activity in 17 medication-free depressed patients with seasonal affective disorder (SAD) were compared with those in eight healthy volunteers. Mean cerebrospinal fluid (CSF) concentrations of the principal metabolites of norepinephrine (NE), serotonin, and dopamine did not differ between the two groups, nor did mean basal or orthostatically stimulated plasma NE levels. Patients' pretreatment depression ratings were inversely correlated with resting plasma NE concentrations. Fourteen SAD patients were clear responders to 2 weeks of full-spectrum bright light treatment. Neither the transmitter measures nor their interrelatedness was affected significantly by phototherapy. Schlagwörter Adult; Bipolar Disordercerebrospinal fluidpsychologytherapy; Depressive Disordercerebrospinal fluidpsychologytherapy; Female; Homovanillic Acidcerebrospinal fluid; Humans; Hydroxyindoleacetic Acidcerebrospinal fluid; Male; Methoxyhydroxyphenylglycolcerebrospinal fluid; Middle Aged; Neurotransmitter Agentscerebrospinal fluid; Norepinephrineblood; Personality Inventory; Phototherapy; Seasonal Affective Disordercerebrospinal fluidpsychologytherapy Rust, Jennifer A.; Nóbrega, Joaquim A.; Calloway, Clifton P.; Jones, Bradley T. (2005): Fraunhofer effect atomic absorption spectrometry. In: Analytical chemistry, Jg. 77, H. 4, S. 1060–1067. Abstract The dark lines in the solar spectrum were discovered by Wollaston and cataloged by Fraunhofer in the early days of the 19th century. Some years later, Kirchhoff explained the appearance of the dark lines: the sun was acting as a continuum light source and metals in the ground state in its atmosphere were absorbing characteristic narrow regions of the spectrum. This discovery eventually spawned atomic absorption spectrometry, which became a routine technique for chemical analysis in the mid-20th century. Laboratory-based atomic absorption spectrometers differ from the original observation of the Fraunhofer lines because they have always employed a separate light source and atomizer. This article describes a novel atomic absorption device that employs a single source, the tungsten coil, as both the generator of continuum radiation and the atomizer of the analytes. A 25-microL aliquot of sample is placed on the tungsten filament removed

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from a commercially available 150-W light bulb. The solution is dried and ashed by applying low currents to the coil in a three-step procedure. Full power is then applied to the coil for a brief period. During this time, the coil produces white light, which may be absorbed by any metals present in the atomization cloud produced by the sample. A high-resolution spectrometer with a charge-coupled device detector monitors the emission spectrum of the coil, which includes the dark lines from the metals. Detection limits are reported for seven elements: 5 pg of Ca (422.7 nm); 2 ng of Co (352.7 nm); 200 pg of Cr (425.4 nm); 7 pg of Sr (460.7 nm); 100 pg of Yb (398.8 nm); 500 pg of Mn (403.1 nm); and 500 pg of K (404.4 nm). Simultaneous multielement analyses are possible within a 4-nm spectral window. The relative standard deviations for the seven metals are below 8% for all metals except for Ca (10.7%), which was present in the blank at measurable levels. Analysis of a standard reference material (drinking water) resulted in a mean percent recovery of 91%. This report attempts to give an historical perspective on the development of a novel atomic spectrometer based on the Fraunhofer effect.

Saltarelli, C. G.; Coppola, C. P. (1979): Influence of visible light on organ weights of mice. In: Laboratory animal science, Jg. 29, H. 3, S. 319–322. Abstract Hau:ICR mice separated by sex, were reared for 30 days under various fluorescent lamps: pink, blue, black UV, cool white and full spectrum. Body weights and absolute organ weights were compared. After light exposure, female body weights were not significantly different between any groups; however, a difference in male body weights was observed. Light affected the weights of the pituitary, adrenals, kidneys and prostate in male mice and the adrenals, thyroid and pineal glands in females. The weight of adrenal glands of both males and females were most sensitive to changes in lighting. Schlagwörter Adrenal Glandsradiation effects; Animals; Body Weightradiation effects; Female; Light; Male; Micegrowth & development; Organ Sizeradiation effects; Pineal Glandradiation effects; Pituitary Glandradiation effects; Sex Factors Schramm, J. Mark; Warner, Dave; Hardesty, Robert A.; Oberg, Kerby C. (2003): A unique combination of infrared and microwave radiation accelerates wound healing. In: Plastic and reconstructive surgery, Jg. 111, H. 1, S. 258–266. Online verfügbar unter doi:10.1097/01.PRS.0000033065.10876.2E. Light or electromagnetic radiation has been reported to enhance wound healing. Abstract The use of selected spectra, including infrared and microwave, has been described; however, no studies to date have examined the potential benefit of combining these spectra. In this study, a device that emits electromagnetic radiation across both the infrared and microwave ranges was used. To test the effects of this unique electromagnetic radiation spectrum on wound healing, two clinically relevant wound-healing models (i.e., tensile strength of simple incisions and survival of McFarlane flaps) were selected. After the creation of a simple full-thickness incision (n = 35 rats) or a caudally based McFarlane flap (n = 33 rats), animals were randomly assigned to one of three treatment groups: untreated control, infrared, or combined electromagnetic radiation. Treatment was administered for 30 minutes, twice daily for 18 days in animals with simple incisions, and 15 days in animals with McFarlane flaps. The wound area or flap was harvested and analyzed, blinded to the treatment regimens. A p value of less than 0.05 obtained by analysis of variance was considered to be statistically significant. Animals receiving combined electromagnetic radiation demonstrated increased tensile strength (2.62 N/mm2) compared with animals receiving infrared radiation (2.36 N/mm2) or untreated controls (1.73 N/mm2, p < 0.001). Animals with McFarlane flaps receiving combined electromagnetic radiation had increased flap survival (78.0 percent) compared with animals receiving infrared radiation (69.7 percent) and untreated controls (63.1 percent, p < 0.01). Thus, combined electromagnetic radiation provided a distinct advantage in wound healing that might augment current treatment regimens. Schlagwörter Animals; Electromagnetic Fields; Equipment and Supplies; Graft Survivalradiation

Fluorescent light - Citavi effects; Infrared Raystherapeutic use; Microwavestherapeutic use; Necrosis; Rats; Rats, Sprague-Dawley; Skinsurgery; Surgical Flaps; Tensile Strength; Wound Healingradiation effects Shedpure, M.; Pati, A. K. (1995): The pineal gland: structural and functional diversity. In: Indian journal of experimental biology, Jg. 33, H. 9, S. 625–640. The article reviews the work carried out on pineal structure and function in Abstract vertebrates. The pineal has undergone striking changes in structure during the course of evolution from lamprey to mammals. In the primitive vertebrates, structure of the pineal is very much similar to that of the retina of the eyes and it acts as a direct photosensory organ. It acts as a photosensory and secretory organ in a number of species. Interestingly, the pineal complex among the reptiles presents the full spectrum of its morphological possibilities. There is a gradual regression of light sensitive pineal structure during the course of avian line of evolution. Further, it has been unequivocally accepted that mammalian pineal is an endocrine organ. The pineal is a prominent secretory organ, in mammals, which synthesises and secretes a number of exocrine and endocrine substances, such as indoles, peptides, various enzymes, amino acids and their derivatives, lipids, carbohydrates, and inorganic constituents. Pineal plays an important role in regulation of seasonal breeding in various vertebrate species. It is also considered as one of the most important components of the vertebrate circadian system and is a principal source of rhythmically produced melatonin. Apart from the above mentioned functions, pineal also influences thermoregulation, electrolyte metabolism, intermediary metabolism, hemopoiesis, immune system and behaviour. Schlagwörter Animals; Evolution; Humans; Pineal Glandanatomy & histologyinnervationphysiology; Vertebratesanatomy & histologyphysiology Shinosaki, K.; Inouye, T.; Ukai, S.; Toi, S. (1992): Half-field sinusoidally modulated light stimulation at subject's alpha frequency. In: Electroencephalography and clinical neurophysiology, Jg. 83, H. 6, S. 372–377. Abstract Interhemispheric responses of alpha activity were investigated by use of half-field sinusoidally modulated light (SML) stimulation at the subject's alpha frequency. The left and right visual half-fields as well as full-field were separately stimulated by the SML. The power spectrum of SML responses, averaged with Wiener filtering, was obtained at the left and the right occipital area (O1 and O2) in 11 normal subjects. Power in each hemisphere, phase difference and coherence between O1 and O2 were estimated at an alpha frequency. A laterality index of power was defined as (P(l)-P(r))/(P(l) + P(r)) where P(l) is a power value at O1, and P(r) at O2. In most of the subjects, laterality index decreased in the order: left half-field, full-field and right half-field stimulation. This relationship revealed greater SML responses on the ipsilateral occipital area. There were significant differences in laterality index among 3 visual field conditions, thus showing that full-field responses ranged in lateralization between the left and right half-field responses in most of the subjects. This hemispheric distribution suggests that half-field SML stimulation affected alpha activity selectively in each hemisphere, mostly in the ipsilateral hemisphere. Schlagwörter Adult; Alpha Rhythm; Female; Functional Laterality; Humans; Occipital Lobephysiology; Photic Stimulationmethods Sigurdsson, V.; Knulst, A. C.; van Weelden, H. (1997): Phototherapy of acne vulgaris with visible light. In: Dermatology (Basel, Switzerland), Jg. 194, H. 3, S. 256–260. Abstract BACKGROUND: Sun exposure has a beneficial effect on acne vulgaris, but it is not clear which wavelengths contribute to the favourable effect. OBJECTIVE: The aim of the study was to investigate the effect of visible light on acne vulgaris and define the most effective wavelengths. METHODS: Thirty patients (15 men and 15 women) with mild to moderate acne vulgaris, involving the face and/or the back and/or the chest, were treated with three different light sources. They were treated 3 times a week, for a total of 7 weeks, each field for 20 min per session. RESULTS:

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All the light sources using 'full spectrum', green and violet improved the acne, leading to 14% (p > 0.10), 22% (p < 0.05) and 30% (p < 0.02) improvement, respectively. No statistically significant differences between the three different light sources were found, although there was a tendency that violet light was better than the other light qualities. No side-effects were observed. CONCLUSION: Visible light is a moderately effective alternative for treatment of acne vulgaris. Acne Vulgarispathologytherapy; Adolescent; Adult; Back; Color; Facial Dermatosespathologytherapy; Female; Humans; Light; Male; Patient Dropouts; Patient Satisfaction; Phototherapymethods; Radiation Dosage; Remission Induction; Thorax

Siopes, T. D. (1984): The effect of full-spectrum fluorescent lighting on reproductive traits of caged turkey hens. In: Poultry science, Jg. 63, H. 6, S. 1122–1128. Abstract Large White turkey breeder hens were exposed to either incandescent or fullspectrum (FS) fluorescent lighting during two 20-week reproductive cycles in closed confinement. Data were recorded for body weights, feed intake, and reproductive traits. Body weights and feed intake were similar between treatments in both egg laying cycles. In addition, there were no significant differences in egg production, fertility, hatchability, or poult weight between the incandescent and FS fluorescent light treatment in either the first or second year egg laying cycle. It was concluded that exposure of breeder turkey hens to FS fluorescent light in closed confinement results in reproductive performance similar to that obtained with incandescent lighting. Schlagwörter Animals; Body Weight; Eating; Female; Fluorescence; Housing, Animal; Light; Oviposition; Reproduction; Turkeysphysiology Veitch, J. A.; McColl, S. L. (2001): A critical examination of perceptual and cognitive effects attributed to fullspectrum fluorescent lighting. In: Ergonomics, Jg. 44, H. 3, S. 255–279. Abstract Full-spectrum fluorescent lighting (FSFL) has been credited with causing dramatic improvements in vision, perception and cognitive performance as compared with other fluorescent lamp types. These effects are hypothesized to occur because of similarity between FSFL emissions and daylight, which is said to have evolutionary superiority over other light sources. This review, covering 1945-98, critically considers the evidence for these claims. In general, poor-quality research has resulted in an absence of simple deterministic effects that can be confidently attributed to fluorescent lamp type. Promising avenues for lighting behaviour research include investigations of cognitive mediators of lighting-behaviour relationships, and flicker rates and colour rendering effects on visual processing, appearance judgements and affect. Good lighting solutions are more complex than lamp type specification. Schlagwörter Cognition; Humans; Job Satisfaction; Lighting; Task Performance and Analysis; Visual Perception; Workplace Wallow, I. H.; Birngruber, R.; Gabel, V. P.; Hillenkamp, F.; Lund, O. I. (1975): [Retinal reactions to intense light. I. Threshold lesions. Experimental, morphological and clinical studies of pathological and therapeutic effects of laser and white light]. In: Advances in ophthalmology = Fortschritte der Augenheilkunde = Progrès en ophtalmologie, Jg. 31, S. 159–232. Abstract The effects of intense light produced by an argon laser, a helium-neon laser and a xenon are photocoagulator in the retinas of gray chinchilla rabbits, cynomolgus monkeys, and rhesus monkeys were studied clinically and histopathologically including electron microscopy. An improved experimental set-up was used allowing a very good consistency of the inflicted lesions. Threshold lesions were produced in chinchilla rabbits and cynomolgus monkeys by an argon laser and a helium-neon laser. The lesions were evaluated ophthalmoscopically and histograms were drawn indicating ophthalmoscopic ED50 values. For the two lasers examined these values were 12 and 17 mW, respectively, for exposure durations in the range of the blink

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reflex (125-150 msec). Histopathologically, ophthalmoscopic threshold lesions of both laser types showed evidence of thermal damage of the outer retinal half. This damage was principally identical in both species involving the retinal pigment epithelium and the full extension of the photoreceptor cells up to their synapses within the outer plexiform layer. The ophthalmoscopic threshold value was associated, therefore, with an irreversible loss of visual function within the retinal area concerned. No evidence for primary sites of significant energy absorption within the neural retina was found. The width of ophthalmoscopic threshold lesions was determined by measuring within the histologic sections with a microscope and a calibrated graticule the extension of damage at the level of the retinal pigment epithelium and at the level of the outer nuclear layer. In the cynomolgus monkey for ophthalmoscopic argon laser threshold lesions the extension at the level of the RPE was 70-80 mum in diameter and at the level of the outer nuclear layer it was 40-50 mum in diameter. Laser lesions that had a diameter of 60 mum at the level of the RPE and of 30 mum at the level of the outer nuclear layer were ophthalmoscopically subvisible. It is concluded that probably also in man such laser lesions, as well as various other pathologic changes of this size or smaller, cannot be evaluated by clinical ophthalmoscopy. The ophthalmoscopic threshold was correlated with a histopathologic threshold as defined by minimal histopathologic damage. Very likely, such damage lies within the range of functional recovery, and the histopathologic threshold demarcates at the same time the decisive functional threshold. The conversion ratio between histopathologic-functional and ophthalmoscopic threshold for argon lesions in cynomolgus monkeys was somewhat greater than 3, e.i. the ophthalmoscopic threshold was more than 3 times higher than the histopathologic-functional threshold. Using this data together with additional biologic and optical considerations, a safety threshold for man for cwlasers within the visible spectrum was estimated to be 1-2 mW. Animals; Argon; Fundus Oculi; Haplorhini; Helium; Humans; Laser Therapy; Lasersmethods; Macaca; Macaca fascicularis; Neon; Pigment Epithelium of Eyepathologyultrastructure; Rabbits; Retinapathologysurgeryultrastructure; Retinal Diseasesetiologypathology

Young, S.; Diffey, B. (1985): Influence of monochromator bandwidth on the erythema action spectrum in the UVB region. In: Photo-dermatology, Jg. 2, H. 6, S. 383–387. The minimal erythema dose (MED) was determined in 10 subjects at wavelengths Abstract of 300, 310 and 320 nm using an irradiation monochromator. At each of the three central wavelengths, three determinations of the MED were carried out using full bandwidths at half maximum intensity of 5, 10 and 20 nm. The relative erythemal effectiveness of the radiation for each combination of wavelength and bandwidth agreed well with that calculated assuming photoaddition, or linear additivity between wavelengths. Schlagwörter Adolescent; Adult; Erythemaetiology; Female; Humans; Male; Middle Aged; Radiation Dosage; Ultraviolet Rays Zane, Cristina; Capezzera, Rossana; Pedretti, Alessandra; Facchinetti, Elena; Calzavara-Pinton, Piergiacomo (2008): Non-invasive diagnostic evaluation of phototherapeutic effects of red light phototherapy of acne vulgaris. In: Photodermatology, photoimmunology & photomedicine, Jg. 24, H. 5, S. 244–248. Online verfügbar unter doi:10.1111/j.1600-0781.2008.00368.x. Abstract BACKGROUND: During the past few years, various phototherapeutic protocols with full-spectrum visible light or selected wavebands have been investigated in the treatment of acne vulgaris with variable results. METHODS: Fifteen women suffering from moderate acne vulgaris of the face were exposed to 20 J/cm(2) of broad-band red (lambda: 600-750 nm) light twice weekly for 4 weeks. In addition, with the aim to improve the present knowledge of the mechanisms of action of phototherapy, we measured skin sebum, pH, hydration and trans-epidermal water loss (TEWL). Lesions of the trunk were not irradiated and served as controls.

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RESULTS: A significant improvement of acne lesions and a significant decrease of skin sebum excretion and TEWL of the face were registered at the end of the therapy and at the 3-month follow-up visit. The results could be related to a reduced follicular colonization of Propionibacterium acnes, in that it was lethally damaged by photoactivated endogenous porphyrins. CONCLUSION: The present findings seem to indicate that red light phototherapy may represent an effective, well-tolerated, safe, simple and inexpensive treatment option for moderate acne vulgaris. Acne Vulgarispathologytherapy; Adolescent; Adult; Female; Humans; Hydrogen-Ion Concentration; Light; Phototherapy; Skinpathology; Water

Zawilska, J. B. (1996): Melatonin as a chemical indicator of environmental light-dark cycle. In: Acta neurobiologiae experimentalis, Jg. 56, H. 3, S. 757–767. Melatonin (N-acetyl-5-methoxytryptamine) is an evolutionary highly conserved Abstract molecule that plays an important role in conveying the clock and calendar information to all living organisms, including man. Melatonin is synthesized in the rhythmic fashion, primarily by the pineal gland, and, to a lesser degree, by extrapineal tissues-namely the retina, the Harderian gland, and the gastrointestinal tract. The rhythm of the hormone production, with maximal levels occurring at night in darkness, is generated by an endogenous circadian clock(s) and is synchronized with the photoperiodic environment to which animals are exposed. This brief outline surveys data on the regulation of rhythmic melatonin biosynthesis by a circadian pacemaker and light (full spectrum white light and monochromatic lights with wavelengths both in the visible and invisible range). Additionally, possible applications of this chronobiotic compound in agriculture and in medicine in the treatment of circadian rhythm sleep disorders are discussed. Schlagwörter Animals; Circadian Rhythmphysiology; Humans; Male; Melatoninmetabolismphysiology; Photoperiod; Seasons