数字视频广播系统概述

今天 ,尽管我们在家里收看的仍然是模拟电视节目 ,但是当你通过卫星电视网、有线电视网或开路电视网观看电视节目时 ,你已经位于电视数字传输的最后一个环节 ,它正在经历着一场数字化革命 ,以达到电视节目的全数字化传输。在电视数字化的进程中 ,国际组织ＤＶＢ(ＤｉｇｉｔａｌＶｉｄｅｏＢｒｏａｄｃａｓｔｉｎｇ)提出了全套的解决方案 :数字卫星电视 (ＤＶＢ -Ｓ)、数字有线电视 (ＤＶＢ -Ｃ)、数字开路电视 (ＤＶＢ -Ｔ) ,这意味着电视节目数字化的时代已经到来 !在欧洲 ,从 1991年开始 ,电视台、家电产品生产厂家和标准制订者坐到一起 ,…     

遂宁白禅寺电航工程围堰防渗质量浅析

白禅寺电航工程临时围堰由两期组成，围堰防渗采用高喷灌浆和静压灌浆相结合，两期围堰闭气效果差，漏水比较大，从地质、设计、施工几方面对围堰防渗质量进行分析，目的是为以后类似工程提供经验。     

Delayed effects of chronic low-dose high linear energy transfer (LET) radiation on mice in vivo

In the present work, the delayed effects of chronic high linear energy transfer (LET) radiation in polychromatic erythrocytes (PCEs) of mice bone marrow were investigated in vivo. Irradiation of the two-month-old SHK white mongrel random-bred male mice was performed in the radiation field behind the concrete shield of the accelerator of 70 GeV protons to accumulate doses of 0.005-0.16 Gy. The dependence of the biological response on dose, adaptive response (AR) and genomic instability (GI) in F(1) and F(2) generations from males irradiated with doses of 0.005 and 0.16 Gy and from males exposed to combined action of immunomodulator-bendazol hydrochloride (BH) and of 0.16 Gy irradiation, were examined using the micronucleus formation test. The data demonstrated that irradiation of mice with these doses lead to an increase in the level of cytogenetic damage and induces no AR. With analysis of the bone marrow radiosensitivity to 1.5 Gy of X rays and the capacity to AR it was found that the chronic high-LET irradiation of parents induced the GI at least two generations. The combined exposure to BH and the dose of 0.16 Gy induces no AR in F(0) generation but induces AR in F(1) and F(2) offspring.     

H2AX phosphorylation in response to DNA double-strand break formation during bystander signalling: effect of microRNA knockdown

Upon DNA double-strand break (DSB) formation, hundreds of H2AX molecules in the chromatin flanking the break site are phosphorylated on serine residue 139, termed gamma-H2AX, so that virtually every DSB site in a nucleus can be visualised within 10 min of its formation using an antibody to gamma-H2AX. One application of this sensitive assay is to examine the induction of DNA double-strand damage in subtle non-targeted cellular effects such as the bystander effect. Here whether microRNA (miRNA) serve as a primary signalling mechanism for bystander effect propagation by comparing matched human colon carcinoma cell lines with wild-type or depleted levels of mature miRNAs was investigated. No major differences were found in the levels of induced gamma-H2AX foci in the tested cell lines, indicating that though miRNAs play a role in bystander effect manifestation, they appear not to be the primary bystander signalling molecules in the formation of bystander effect-induced DSBs.     

The effect of various levels of chitosan in rat diet on vitamins assimilation under their combined deficiency

he effect of chitosan inclusion in the semi-synthetic diet of rats at a dose of 0,24 and 0,9% of dry weight on vitamin assimilation under combined moderate and deep deficiency has been studied. Four-week introduction of chitosan did not have a significant effect on levels of vitamins C, B1, B2 and A in the liver of animals, on vitamin B2 blood plasma concentration and thiamine and riboflavin urinary excretion regardless of the degree of vitamin deficiency intensity. The significantly decrease of vitamin E blood plasma concentration has been observed at high dose of chitosan in the diet under moderate vitamin deficiency, whereas under deep deficit such reduction has been detected even at a low dose. Thus, long-term chitosan inclusion in the diet under existing polyhypovitaminosis can lead to the deterioration of the sufficiency with fat-soluble vitamins.     

Modern presentation of role of nutrition and genetic factors in the development of metabolic syndrome

The role of dietary and hereditary factors in the development of metabolic syndrome is discussed in this review.     

Medical and prophylactic properties lipids and antioxidants derived from sea hydrobionts

Recent researches in the field of studying medical-preventive activity of lipids and natural antioxidants derived from sea hydrobionts at carbohydrate and lipid metabolic imbalances were analyzed. On experimental models of hyperlipidemia and a diabetes the optimum dozes and polyunsaturated fat acids omega-3/omega-6 in structure of phospho- and glycolipids derived from sea macrophytes Sargassum pallidum, Ulva fenestrata, Zostera marina, and also antioxidants-- polyhydroxynaphthoquinone a echinochrome. A derived from flat sea urchin Scaphechinus mirabilis and mixes of polyphenols from sea grass Zostera marina were determined. Prospective mechanisms of polar lipids, containing various polyunsaturated fat acids and specified above antioxidants are presented on the basis of the received results and the analysis of published data.     

To substantiation of vitamin and mineral level in fortified food products

This review outlines the scientific rationale and commentary for the introduction of sanitary rules and norms governing the enrichment of foods of mass consumption with vitamins and minerals, which were harmonized with EU documents and Codex Alimentarius.     

High-throughput optical quality control of lipid multilayers fabricated by dip-pen nanolithography

Surface supported phospholipid multilayers are promising materials for nanotechnology because of their tendency to self-organize, their innate biocompatibility, the possibility to encapsulate other materials within the multilayers, and the ability to control the multilayer thickness between ～ 2 and 100 nm during fabrication. Dip-pen nanolithography (DPN) is an atomic force microscopy (AFM) based fabrication method that allows high-throughput fabrication and integration of a variety of micro- and nanostructured materials including lipid multilayers, with areal throughputs on the scale of cm(2) min(-1). Although multilayer thickness is a critical feature that determines the functionality of the lipid multilayer structures (for instance as carriers for other materials as well as optical scattering properties), reliable height characterization by AFM is slow (on the order of μm(2) min(-1)) and a bottleneck in the lithographic process. Here we describe a novel optical method to reliably measure the height of fluorescent multilayers with thicknesses above 10 nm, and widths above the optical diffraction limit based on calibrating the fluorescence intensity using one-time AFM height measurements. This allows large surface areas to be rapidly and quantitatively characterized using a standard fluorescence microscope. Importantly, different pattern dimensions (0D dots, 1D lines or 2D squares) require different calibration parameters, indicating that shape influences the optical properties of the structured lipid multilayers. This method has general implications in the systematic and high-throughput optical characterization of nanostructure-function relationships.