New roles for vitamin D

The importance of vitamin D in maintaining bone health is well established. However, it has recently been suggested that vitamin D might reduce total mortality and reduce the incidence of cardiovascular disease, cancer and type 2 diabetes. This article critically evaluates the evidence for this suggestion and concludes that while there is some experimental support for the suggested effects on total mortality, cardiovascular disease and colorectal cancer, the suggested effects on type 2 diabetes and prostate cancer lack serious experimental support. Nevertheless, since many cells have the capacity to produce biologically active vitamin D and respond to it through vitamin D receptors then new roles of vitamin D are likely to emerge in the near future. In the meantime, studies specifically designed to investigate effects of vitamin D on these chronic diseases are needed rather than relying on the results of studies designed for other purposes.     

Fluorescent properties of organic carbon in cave dripwaters: Effects of filtration, temperature and pH

For the first time the specific fluorescent characteristics of organic carbon (OC) in sequentially filtered cave dripwater samples have been studied and the proportions of organic carbon in each size fraction quantified. We examined the effects of pH, temperature and filtration on the fluorescent properties of OC sampled from four drip points in different seasons. Dripwaters were sampled from both normal (pH 7.5-8.5) and hyper-alkaline (pH 9-13) drip points in Poole's Cavern, Buxton, UK, which provides a model system for understanding the effects of pH on the chemical properties of OC. At high-pH values, charge stabilisation of OC is greatly enhanced, resulting in 10-20 times more coarse colloidal and particulate (> 100 nm) organic carbon than in lower pH dripwaters; indicating that destabilisation (e.g. charge shielding) of colloidal OC is an important process control on the transmission of OC in cave dripwaters at near-neutral pH. OC fluorescence in high-pH dripwaters exhibited a high degree of pH sensitivity between pH 10 and 12, consistent with substantial changes in the coordination or neighbouring environment of fluorescent acidic functional groups. Inner-filter effects (IFE) associated with the coarse colloidal and particulate fraction of OM mask the true fluorescent signal, so that size fractionation is necessary to obtain a signal which is correlated with the concentration of organic carbon. Fluorescence intensities in the samples studied were best correlated with organic carbon with a dimension < 100 nm. These results have important implications for the use of fluorescence as a tracer in hydrogeological studies.     

建立低碳城市规划实施手段:从城市热岛效应模型分解控规指标

通过分析城市热岛效应与城市规划研究的关系,提出了在绿色建筑和低碳城市设计要求中控制城市热岛效应的重要性,以及面临的规划管理操作问题.然后建立城市规划方案热岛效应预测模型,从城市规划的操作应用角度提出热岛效应的控制指标,并分析规划设计可以影响的控制因素,以指导城市控规编制规范.同时,以北京地区某低碳社区详细规划项目为实例,量化评价了规划方案的热岛效应指标,以及与热岛相关的控规地块指标对降低热岛效应的贡献度.最终将减缓热岛效应的目标,分解为法定城市规划管理体制内的发展控制手段.     

Plasmonic Color Filters for CMOS Image Sensor Applications

We report on the optical properties of plasmonic hole arrays as they apply to requirements for plasmonic color filters designed for state-of-the-art Si CMOS image sensors. The hole arrays are composed of hexagonally packed subwavelength sized holes on a 150 nm Al film designed to operate at the primary colors of red, green, and blue. Hole array plasmonic filters show peak transmission in the 40-50% range for large (>5 × 5 μm(2)) size filters and maintain their filtering function for pixel sizes as small as ～1 × 1 μm(2), albeit at a cost in transmission efficiency. Hole array filters are found to robust with respect to spatial crosstalk between pixel within our detection limit and preserve their filtering function in arrays containing random defects. Analysis of hole array filter transmittance and crosstalk suggests that nearest neighbor hole-hole interactions rather than long-range interactions play the dominant role in the transmission properties of plasmonic hole array filters. We verify this via a simple nearest neighbor model that correctly predicts the hole array transmission efficiency as a function of the number of holes.     

Materials and designs for wirelessly powered implantable light-emitting systems

Strategies are presented to achieve bendable and stretchable systems of microscale inorganic light-emitting diodes with wireless powering schemes, suitable for use in implantable devices. The results include materials strategies, together with studies of the mechanical, electronic, thermal and radio frequency behaviors both in vitro and in in-vivo animal experiments.     

Mesoporous nitrogen-doped carbon-glass ceramic cathodes for solid-state lithium-oxygen batteries

The composite of nitrogen-doped carbon (N-C) blend with lithium aluminum germanium phosphate (LAGP) was studied as cathode material in a solid-state lithium-oxygen cell. Composite electrodes exhibit high electrochemical activity toward oxygen reduction. Compared to the cell capacity of N-C blend cathode, N-C/LAGP composite cathode exhibits six times higher discharge cell capacity. A significant enhancement in cell capacity is attributed to higher electrocatalytic activity and fast lithium ion conduction ability of LAGP in the cathode.     

Fast image restoration without boundary artifacts.

Fast Fourier transform (FFT)-based restorations are fast, but at the expense of assuming that the blurring and deblurring are based on circular convolution. Unfortunately, when the opposite sides of the image do not match up well in intensity, this assumption can create significant artifacts across the image. If the pixels outside the measured image window are modeled as unknown values in the restored image, boundary artifacts are avoided. However, this approach destroys the structure that makes the use of the FFT directly applicable, since the unknown image is no longer the same size as the measured image. Thus, the restoration methods available for this problem no longer have the computational efficiency of the FFT. We propose a new restoration method for the unknown boundary approach that can be implemented in a fast and flexible manner. We decompose the restoration into a sum of two independent restorations. One restoration yields an image that comes directly from a modified FFT-based approach. The other restoration involves a set of unknowns whose number equals that of the unknown boundary values. By summing the two, the artifacts are canceled. Because the second restoration has a significantly reduced set of unknowns, it can be calculated very efficiently even though no circular convolution structure exists.     

Design and construction of an optoelectronic crossbar switchcontaining a terabit per second free-space optical interconnect

The completed detailed design and initial phases of construction of an optoelectronic crossbar demonstrator are presented. The experimental system uses hybrid very large scale integrated optoelectronics technology whereby InGaAs-based detectors and modulators are flip-chip bonded onto silicon integrated circuits. The system aims to demonstrate a 1-Tb/s aggregate data input/output to a single chip by means of free-space optics