Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure

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.     

Slag Characterization: A Necessary Tool for Modeling and Simulating Refractory Corrosion on a Pilot Scale

The slag in pyrometallurgical operations plays a major role affecting the life of furnace refractory. As such, comprehensive mineralogical and chemical slag examination, physical property determination including the slag melting point or liquidus, and viscosity are necessary for precise understanding of a slag. At the RHI Technology Center Leoben, Austria, the main objective of slag characterization work is to reach a better understanding of refractory corrosion. This corrosion testwork is performed at the laboratory and pilot scale. Typically, corrosion tests are performed in an induction furnace or rotary kiln, with the main purpose being the improved selection of the most suitable refractory products to improve refractory performance in operating metallurgical furnaces. This article focuses on characterization of samples of six non-ferrous, customer-provided slags. This includes slag from a copper Peirce-Smith converter, a short rotary furnace for lead smelting, a titania-processing furnace, and a Ni-Cu top blowing rotary converter (TBRC) plant.     

Alternating Current Electrophoretic Deposition of Antibacterial Bioactive Glass-Chitosan Composite Coatings

Alternating current (AC) electrophoretic deposition (EPD) was used to produce multifunctional composite coatings combining bioactive glass (BG) particles and chitosan. BG particles of two different sizes were used, i.e., 2 μm and 20–80 nm in average diameter. The parameter optimization and characterization of the coatings was conducted by visual inspection and by adhesion strength tests. The optimized coatings were investigated in terms of their hydroxyapatite (HA) forming ability in simulated body fluid (SBF) for up to 21 days. Fourier transform infrared (FTIR) spectroscopy results showed the successful HA formation on the coatings after 21 days. The first investigations were conducted on planar stainless steel sheets. In addition, scaffolds made from a TiAl4V6 alloy were considered to show the feasibility of coating of three dimensional structures by EPD. Because both BG and chitosan are antibacterial materials, the antibacterial properties of the as-produced coatings were investigated using E. coli bacteria cells. It was shown that the BG particle size has a strong influence on the antibacterial properties of the coatings.     

城市森林

重庆是中国最年轻的直辖市,城市规划建设大有可为,完全有条件建成一个大家公认的宜居城市,一个环境优美的城市,一个交通顺畅的城市,甚至变成一个森林城市。一个有希望、有活力的地方,要敢于设想和设计自己的美好未来。——薄熙来(重庆市长)     

Analgesic,Anxiolytic and Anaesthetic Effects of Melatonin: New Potential Uses in Pediatrics

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.     

Topographically induced self-deformation of the nuclei of cells: dependence on cell type and proposed mechanisms

Osteosarcoma-derived cell lines (SaOs-2, MG63) have recently been shown to deform their nucleus considerably in response to surface topography. Such a deformation had not been described previously. Here we present results on additional cell lines, including cancerous (OHS4, U2OS), immortalized (F/STRO-1⁺A and FHSO6) and healthy cells (HOP). The cancerous cells were found to deform extensively, the immortalized cells showed small deformations, whereas the healthy cells showed deformation only at short incubation times. These results suggest a strong link between the malignant transformation of cells and the state of the cytoskeletal network. We propose mechanisms to explain the deformation in which the cytoskeleton either pushes down on the nucleus during spreading or pulls it down upon adhesion to the pillars.