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11.
12.
Maria Angeles Bonmati-Carrion Raquel Arguelles-Prieto Maria Jose Martinez-Madrid Russel Reiter Ruediger Hardeland Maria Angeles Rol Juan Antonio Madrid 《International journal of molecular sciences》2014,15(12):23448-23500
Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system. 相似文献
13.
A digital-image-processing algorithm is described for automatically measuring the diameters of cashmere-goat fibres from microscope images. A correction factor is used to remove bias when fibres are out of focus. Diameters are estimated to within a standard error of 4%. 相似文献
14.
Papaioannou T Preyer NW Fang Q Brightwell A Carnohan M Cottone G Ross R Jones LR Marcu L 《Applied optics》2004,43(14):2846-2860
Fiber-optic probes are widely used in optical spectroscopy of biological tissues and other turbid media. Only limited information exists, however, on the ways in which the illumination-collection geometry and the overall probe design influence the interrogation of media. We have investigated both experimentally and computationally the effect of probe-to-target distance (PTD) on the diffuse reflectance collected from an isotropically (Lambertian) scattering target and an agar-based tissue phantom. Studies were conducted with three probes characterized by either common (single-fiber) or separate (two bifurcated multifiber probes) illumination and collection channels. This study demonstrates that PTD, probe design, and tissue scattering anisotropy influence the extent of the transport of light into the medium, the light-collection efficiency, and the sampling volume of collected light. The findings can be applied toward optimization of fiber-optic probe designs for quantitative optical spectroscopy of turbid media including biological tissues. 相似文献
15.
A principal research area in biomolecular computing is the development of analytical methods for evaluating computational fidelity and efficiency. In this work, the equilibrium theory of the DNA helix-coil transition is reviewed and expanded, as applied to the analysis and design of oligonucleotide-based computers. After a review of the equilibrium apparatus for modeling the helix-coil transition for single dsDNA species, application to complex hybridizing systems is discussed, via decomposition into component equilibria, which are presumed to proceed independently. The alternative approach, which involves estimation of a mean error probability per hybridized structure, or computational incoherence, is then presented, along with a discussion of a special-case exact solution (directed dimer formation), and an approximate general solution, applicable to conditions of uniform fractional-saturation. In order to clarify the opposing nature of the predictions of these two models, simulations are presented for the uniform saturation solution for , as applied to a small Tag–Antitag (TAT) system, along with the behavior expected via isolated melting curves. By a comparison with the predictions of a recent, TAT-specific solution for , the views provided by these generalized approximate models are shown to define the opposing limits of a more general error-response. 相似文献
16.
The passage of light through slowly varying nonuniform photonic crystal structures is treated using Hamiltonian optics. The approach allows the inverse design of complex and highly compact optical elements as well as providing insight and an appealing physical picture. It can also be used to treat the trapping and deflection of light at distributed defects in one- and two-dimensional (2-D) crystals, and to study the frequency-dependent time delay in chirped one-dimensional (1-D) fiber 相似文献
17.
Lucia Marseglia Gabriella D’Angelo Sara Manti Salvatore Aversa Teresa Arrigo Russel J. Reiter Eloisa Gitto 《International journal of molecular sciences》2015,16(1):1209-1220
Exogenous melatonin is used in a number of situations, first and foremost in the treatment of sleep disorders and jet leg. However, the hypnotic, antinociceptive, and anticonvulsant properties of melatonin endow this neurohormone with the profile of a drug that modulates effects of anesthetic agents, supporting its potential use at different stages during anesthetic procedures, in both adults and children. In light of these properties, melatonin has been administered to children undergoing diagnostic procedures requiring sedation or general anesthesia, such as magnetic resonance imaging, auditory brainstem response tests and electroencephalogram. Controversial data support the use of melatonin as anxiolytic and antinociceptive agents in pediatric patients undergoing surgery. The aim of this review was to evaluate available evidence relating to efficacy and safety of melatonin as an analgesic and as a sedative agent in children. Melatonin and its analogs may have a role in antinociceptive therapies and as an alternative to midazolam in premedication of adults and children, although its effectiveness is still controversial and available data are clearly incomplete. 相似文献
18.
Antonino Gulino Russel G. Egdell Ignazio Fragalà 《Journal of the American Ceramic Society》1998,81(3):757-759
Compact pressure causes a martensitic transformation of partially stabilized tetragonal bismuth-doped ZrO2 powders to the monoclinic phase. A similar effect is not observed when pelletization, followed by firing, of amorphous bismuth/ZrO2 is performed. The stress-induced transition has been monitored via X-ray diffractometry, Raman spectroscopy, and Fourier transform infrared reflectivity. Surface bismuth segregation, which involves few ionic planes, has been probed by angle-resolved X-ray photoelectron spectroscopy. The bismuth segregation enthalpy has been evaluated. 相似文献
19.
Sung Ho Ha Russel Navarro Menchavez Yoon-Mo Koo 《Korean Journal of Chemical Engineering》2010,27(5):1360-1365
Nuclear power has once again attracted from all over the world due to many factors including the rise in oil process and environmental
concerns on greenhouse gas emission resulting in global warming. However, spent fuel from nuclear power reactors is an enormous
problem both from radiation hazard and economical point of view. Therefore, this review presents an overview of application
of ionic liquids (ILs) in spent fuel reprocessing, particularly in the extraction of high-level radioactive aqueous waste
from the processing of nuclear fuel. 相似文献
20.
Renal elimination of the bromosulfophthalein-glutathione conjugate (BSP-GSH) after its i.v. administration in the rat in vivo is negligible. In our study we wanted to establish whether the high albumin-binding of BSP-GSH constitutes the major restrictive factor toward the urinary excretion of the compound. The renal disposition of BSP-GSH was studied in the isolated rat kidney during perfusions with or without albumin in the perfusate. The urinary clearance of BSP-GSH in the absence of albumin was very low (< 60 microliters/min) as compared to the inulin clearance (approximately 300 microliters/min). This indicates that albumin-binding is not the major reason for the low urinary clearance of BSP-GSH. Addition of albumin to the perfusate further decreased the urinary excretion by 60%. BSP-GSH is metabolized by the kidney into two major metabolites: the cysteinylglycine conjugate and the di-glutathione conjugate. Both metabolites appear in perfusate, which suggests that BSP-GSH undergoes tubular (re-)uptake. The di-glutathione conjugate is further metabolized to the di-cysteinylglycine conjugate. The di-glutathione conjugate and the di-cysteinylglycine conjugate are the major urinary components and the urinary elimination of BSP-GSH may depend on their formation. Inhibition of gamma-glutamyl transpeptidase activity with acivicin largely prevented the degradation to the cysteinylglycine and dicysteinylglycine conjugates of BSP. The total rate of urinary excretion, however, was only slightly lowered by acivicin. Apparently, cleavage of the gamma-glutamyl moiety is not relevant for the total urinary elimination of BSP-GSH. 相似文献