Solar ultraviolet irradiation of human cornea, lens, and retina: equations of ocular irradiation

Photochemical damage of ocular tissues by solar radiation depends on the spectral composition of the radiation in the environment, the geometry of the coupling of that radiation to the eye, the spectral transmittances of the ocular components and any auxiliary lenses used, the spectral sensitivity of the irradiated tissue, the accumulated exposure dose, and the action of repair processes. This paper provides formulas for quantitative estimation of corneal, lenticular, and retinal UV irradiances from the sunlit environment under clear sky conditions. Applications of these formulas for ocular irradiation will be presented in subsequent papers for the cornea, lens, and retina, and the results will be evaluated using weighting functions for the sensitivity of ocular tissue.     

Dietary fatty acids regulate cholesterol induction of liver CYP7α1 expression and bile acid production

In the present study we investigated the effects of dietary fats containing predominantly PUFA, monounsaturated FA (MUFA), or saturated FA (SFA) on lipid profile and liver cholesterol 7α-hydroxylase (CYP7α1) mRNA expression and bile acid production in C57BL/6J mice. The animals (n=75) were randomly divided into five groups and fed a basic chow diet (AIN-93G) (BC diet), a chow diet with 1g/100g of cholesterol (Chol diet), a chow diet with 1g/100g of cholesterol and 14g/100g of safflower oil (Chol+PUFA diet), a chow diet with 1g/100g of cholesterol and olive oil (Chol+MUFA diet), or a chow diet with 1g/100g of cholesterol and myristic acid (Chol+SFA diet) for 6 wk. The results showed that the Chol+SFA diet decreased CYP7α1 gene expression and bile acid pool size, resulting in increased blood and liver cholesterol levels. Addition of PUFA and MUFA to a 1% cholesterol diet increased the bile acid pool production or bile acid excretion and simultaneously decreased liver cholesterol accumulation despite decreased CYP7α1 mRNA expression. The results indicate that the decreased bile acid pool size induced by the SFA diet is related to inhibition of the liver CYP7α1 gene expression, but an increased bile acid pool size and improved cholesterol homeostasis are disassociated from the liver CYP7α1 gene expression.     

界面酸碱配位作用对粘合性能影响的研究

通过测定参照液在固体表面的接触角并计算接触体系的粘附功及其酸碱作用成份,研究了带碱性基团的丙烯酰胺——天然橡胶接枝聚合物和带酸性基团的丙烯酸——天然橡胶接枝聚合物表面的酸碱配位作用及其对粘合性能的贡献.     

Feature subset selection and ranking for data dimensionality reduction

A new unsupervised forward orthogonal search (FOS) algorithm is introduced for feature selection and ranking. In the new algorithm, features are selected in a stepwise way, one at a time, by estimating the capability of each specified candidate feature subset to represent the overall features in the measurement space. A squared correlation function is employed as the criterion to measure the dependency between features and this makes the new algorithm easy to implement. The forward orthogonalization strategy, which combines good effectiveness with high efficiency, enables the new algorithm to produce efficient feature subsets with a clear physical interpretation     

A real-time QRS detection method based on moving-averaging incorporating with wavelet denoising

In this paper, a simple moving average-based computing method for real-time QRS detection is proposed. In addition, for signal preprocessing our detection algorithm also incorporates a wavelet-based denoising procedure to effectively reduce the noise level for electrocardiogram (ECG) data. The overall computational structure of the proposed algorithm allows the QRS detection to be performed and implemented in real-time with high time- and memory-efficiency. Algorithm performance was evaluated against the MIT-BIH Arrhythmia Database. The numerical results indicated that the novel algorithm finally achieved about 99.5% of the detection rate for the standard database, and also, it could function reliably even under the condition of poor signal quality in the measured ECG data.     

Coupled lateral bending-torsional vibration sensitivity of atomic force microscope cantilever

We study the influence of the contact stiffness and the ration between cantilever and tip lengths on the resonance frequencies and sensitivities of lateral cantilever modes. We derive expressions to determine both the effective resonance frequency and the mode sensitivity of an atomic force microscope (AFM) rectangular cantilever. Once the contact stiffness is given, the resonance frequency and the sensitivity of the vibration modes can be obtained from the expression. The results show that each mode has a different resonant frequency to variations in contact stiffness and each frequency increased until it eventually reached a constant value at very high contact stiffness. The low-order vibration modes are more sensitive to vibration than the high-order mode when the contact stiffness is low. However, the situation is reversed when the lateral contact stiffness became higher. Furthermore, increasing the ratio of tip length to cantilever length increases the vibration frequency and the sensitivity of AFM cantilever.     

Lead-free multilayer piezoelectric transformer

In this article, a multilayer piezoelectric transformer based on lead-free Mn-doped 0.94(Bi(12)Na(12))TiO(3)-0.06BaTiO(3) ceramics is presented. This piezoelectric transformer, with a multilayered construction in the thickness direction, is 8.3 mm long, 8.3 mm wide, and 2.3 mm thick. It operates in the second thickness extensional vibration mode. For a temperature rise of 20 degrees C, the transformer has an output power of >0.3 W. With a matching load resistance of 10 Omega, its maximum efficiency approaches 81.5%, and the maximum voltage gain is 0.14. It has potential to be used in low voltage power supply units such as low power adapter and other electronic circuits.