256排Revolution多参数调节下低剂量心脏冠脉成像应用

目的:研究256排Revolution多参数调节下低剂量扫描心脏冠脉成像(Coronary computed tomographic angiography,CCTA)的应用。方法:回顾性分析2016年3月15日至5月15日间在我院256排CT行CCTA的患者,分为心率稳定试验组(n=54例)和心率不稳定试验组(n=41例),同时选取在我院64排VCT行CCTA的患者为对照组(n=116例),对三组CCTA图像质量行主观和客观评估,比较有效辐射剂量的差异。结果:256排CT检查成功率和图像质量的主观评价均优于对照组(P0.05);信噪比(SNR)、对比噪声比(CNR)与对照组差异无统计学意义(P0.05);但有效辐射剂量明显降低(P0.05)。结论:256排CT多参数调节下检查冠脉在保证图像质量下可有效降低辐射剂量。     

Concepts of aggregation and their quantification: A critical review with some new results and applications

Various indices of spatial patterns based on plot counts are reviewed for theoretical population models appropriate to ecological studies. It is seen that many of the indices proposed in the literature are essentially equivalent to either the index ω= σ²/μ or to the index γ= (σ²-μ)/μ², thus providing a variety of motiviations and interpretations of these two indices as measures of spatial patterns. A vector approach to measuring spatial patterns which suggests both a unifying relationship between these indices and an extension of them is proposed. This leads to an interpretation of the measures of spatial patterns in terms of the transition probabilities of a pure birth process.     

On Some Nuisance Parameter Free Uniformly Most Powerful Tests

TAKEUCHI (1969) provides a uniformly most powerful (UMP) one side test for testing the location parameter of the two parameters exponential model when the scale parameter is unknown. The power of his similar size α test depends, however, on the unknown scale parameter. In this case and in more general situations when there exists a sufficient statistic for the nuisance parameter, the theory of generalized THOMPSON's distributions, more specifically, the Thompsonization of a test statistic, LAURENT (1959, 1972) provides a UMP test whose power does not depend on the nuisance parameter. Examples of application of the general nuisance parameter free test procedure include here the truncated exponential, the inverse Gaussian, and the geometric distributions.     

Use of the Score Statistic for Testing Goodness-of-Fit of Some Generalised Distributions

The use of the score statistic to test whether a generalised distribution gives an improved fit over a non-generalised distribution is recommended. The score statistic for a generalised exponential family is derived. Several specific examples are given.     

Bacterial pigments and their applications

Natural pigments sourced from ores, insects, plants and animals were the colorants used since prehistoric period. Synthetic dyes which took the place of natural pigments in the middle of 19th century still rule the field to the maximum extent in spite of its hazardous effect to humans, animals and environment. As an alternative to synthetic pigments, bacterial pigments due to their better biodegradability and higher compatibility with the environment, offer promising avenues for various applications. The industry is now able to produce some bacterial pigments for applications in food, pharmaceuticals, cosmetics and textiles. Extraction of bacterial pigments in relatively pure and concentrated forms is the main technological challenge. Optimization of fermentation process and the medium components are reported as key strategies for economic recovery of pigments. Research work needs to be carried out to formulate the fermentation media for each bacterial pigment on large scale by using economical and easily available sources for commercial process. Recent advances in synthetic biology, metabolic engineering efforts of bacteria will greatly expand the pigments that could be produced economically in sufficient amounts for industrial application. This review summarizes the current technology status and challenges, economics, novel strategies for production of bacterial pigments and metabolic engineering of bacteria with a focus on applications of bacterial pigments in food industry, pharmaceutical industry, dyeing as well as on other applications.     

黄素依赖型卤化酶及其应用研究进展

卤化物是农业、制药业和化学工业的重要原料,主要以化学法合成,该法具有环境不友好和合成条件苛刻等劣势。天然卤化物生物合成途径的关键酶为卤化酶,包括卤过氧化物酶(haloperoxidase,HPO)、α-酮戊二酸依赖型卤化酶(α-ketoglutarate dependent halogenase,KG-Hal)、S-腺苷甲硫氨酸依赖型卤化酶(S-adenosylmethionine-dependenthalogenase)和黄素依赖型卤化酶(flavin-dependent halogenase,FDH)。其中,黄素依赖型卤化酶因其分布广泛、具有底物特异性和卤化位点选择性,是最具开发潜力的卤化酶。因此,本文对黄素依赖型卤化酶的结构、类型、催化机制及其应用研究进展进行综述,对利用基因分析和基因筛选方法寻找新型黄素依赖型卤化酶进行了展望。本综述有助于拓展黄素依赖型卤化酶的类型及其催化机制的知识,推动黄素依赖型卤化酶及其酶工程的研究,为新型卤化物的合成提供技术思路。     

Protein microarrays and their applications

In recent years, the importance of proteomic works, such as protein expression, detection and identification, has grown in the fields of proteomic and diagnostic research. This is because complete genome sequences of humans, and other organisms, progress as cellular processing and controlling are performed by proteins as well as DNA or RNA. However, conventional protein analyses are time-consuming; therefore, high throughput protein analysis methods, which allow fast, direct and quantitative detection, are needed. These are so-called protein microarrays or protein chips, which have been developed to fulfill the need for high-throughput protein analyses. Although protein arrays are still in their infancy, technical development in immobilizing proteins in their native conformation on arrays, and the development of more sensitive detection methods, will facilitate the rapid deployment of protein arrays as high-throughput protein assay tools in proteomics and diagnostics. This review summarizes the basic technologies that are needed in the fabrication of protein arrays and their recent applications.     

Restriction endonucleases and their applications

Restriction endonucleases are deoxyribonucleases which cleave double-stranded DNA into fragments. With only one exception, all restriction endonucleases recognize short, non-methylated DNA sequences. Restriction endonucleases can be divided into two groups based on the position of the cleavage site relative to the recognition sequence. Class I restriction endonucleases cleave double-stranded DNA at positions outside the recognition sequence and generate fragments of random size. The cleavage sites of Class II restriction endonucleases are located, in most cases, within the recognition sequence. Most of the Class II restriction endonucleases recognize 4, 5, or 6 base pair palindromes and generate fragments with either flush ends or staggered ends. DNA fragments with staggered ends contain 3, 4, or 5 nucleotide single-stranded tails called ‘sticky ends’. DNA fragments produced by Class II restriction endonuclease cleavage can be separated on gels according to their molecular weight. The fragments can be isolated from the gel and used for sequence analysis to elucidate genetic information stored in DNA. Further, an isolated fragment can be inserted into a small extrachromosomal DNA, e.g. plasmid, phage or viral DNA, and its replication and expression can be studied in clones of prokaryotic or eukaryotic cells. Restriction endonucleases and cloning technology are powerful modern tools for attacking genetic problems in medicine, agriculture and industrial microbiology.     

Low-temperature extremophiles and their applications

Psychrophilic (cold-adapted) organisms and their products have potential applications in a broad range of industrial, agricultural and medical processes. In order for growth to occur in low-temperature environments, all cellular components must adapt to the cold. This fact, in combination with the diversity of Archaea, Bacteria and Eucarya isolated from cold environments, highlights the breadth and type of biological products and processes that might be exploited for biotechnology. Relative to this undisputed potential, psychrophiles and their products are under-utilised in biotechnology; however, recent advances, particularly with cold-active enzymes, herald rapid growth for this burgeoning field.     

Spider silks and their applications

Spider silks are characterized by remarkable diversity in their chemistry, structure and functions, ranging from orb web construction to adhesives and cocoons. These unique materials have prompted efforts to explore potential applications of spider silk equivalent to those of silkworm silks, which have undergone 5,000 years of domestication and have a variety of uses, from textiles to biomedical materials. Recent progress in genetic engineering of spider silks and the development of new chimeric spider silks with enhanced functions and specific characteristics have advanced spider silk technologies. Further progress in yields of expressed spider-silk proteins, in the control of self-assembly processes and in the selective exploration of material applications is anticipated in the future. The unique features of spider silks, the progress and challenges in the cloning and expression of these silks, environmentally triggered silk assembly and disassembly and the formation of fibers, films and novel chimeric composite materials from genetically engineered spider silks will be reviewed.     

Catalytic antibodies and their applications

Catalytic antibodies (CAbs) occur naturally in healthy individuals where they may form part of the innate immune system, but are preferentially found in those with autoimmune disease. CAbs can also be artificially engineered or elicited by immunizations. Their mechanisms of action include nucleophilic catalysis, induction of conformational strain, coordination with metal ions, and stabilization of transition states. Recent applications of CAbs with clinical significance include the conversion of cocaine to a non-psychoactive form, the degradation of nicotine, activation of prodrugs for targeted chemotherapy, protection from ultraviolet radiation, inhibition of HIV infectivity, and the destruction of aggregates of beta-amyloid implicated in Alzheimer's disease. Artificial CAbs are likely to find increasing applications in research, clinical medicine, diagnostics and manufacturing.     

Model animals and their applications

<正>Looking back a decade ago when I decided to usemodel animalto name our newly established institute,my outrageous boldness can only be described by the old Chinese slang,newborn calf could never sense the danger of tiger.     

Archaeal lipids and their biotechnological applications

The lipids of Archaea, based on glycerol isopranoid ethers, can be used taxonomically to distinguish between phenotypic subgroups of the domain to delineate them clearly from all other organisms. This review is a general survey of the structural features of archaeal lipids and how they relate to survival in the harsh environments in which the Archaea live. The molecular organization of archaeal lipids in monolayers, artificial black membranes and vesicles and the unique properties and possible biotechnological applications of liposomes of the lipids are presented. The results with these liposomes are compared with similar data obtained with synthetic compounds which mimic the structure of archaeal lipids. Studies on computer simulation are also reported.A. Gambacorta is with the istituto per la Chimica di Molecole di interesse Biologico, CNR via Toiano 6, 80072 Arco Felice, Napoli, Italy; A Gliozzi is with the Dipartimento di Fisica, Università di Genova, via Dodecanneso 33, 16146 Genova, Italy. M. De Rosa is with the Istituto di Biochimica delle Macromolecole. Seconda Università di Napoli, via Costantinopoli 16, 80132 Napoli, Italy.     

Phototrophic biofilms and their potential applications

Phototrophic biofilms occur on surfaces exposed to light in a range of terrestrial and aquatic environments. Oxygenic phototrophs like diatoms, green algae, and cyanobacteria are the major primary producers that generate energy and reduce carbon dioxide, providing the system with organic substrates and oxygen. Photosynthesis fuels processes and conversions in the total biofilm community, including the metabolism of heterotrophic organisms. A matrix of polymeric substances secreted by phototrophs and heterotrophs enhances the attachment of the biofilm community. This review discusses the actual and potential applications of phototrophic biofilms in wastewater treatment, bioremediation, fish-feed production, biohydrogen production, and soil improvement.     

Lactobacillus surface layers and their applications

Surface (S-) layers are crystalline arrays of proteinaceous subunits present as the outermost component of cell wall in several species of the genus Lactobacillus, as well as in many other bacteria and Archaea. Despite the high similarity of the amino acid composition of all known S-layer proteins, the overall sequence similarity is, however, surprisingly small even between the Lactobacillus S-layer proteins. In addition, the typical characteristics of Lactobacillus S-layer proteins, distinguishing them from other S-layer proteins, are small size and high-predicted pI value. Several lactobacilli possess multiple S-layer protein genes, which can be differentially or simultaneously expressed. To date, the characterized functions of Lactobacillus S-layers are involved in mediating adhesion to different host tissues. A few applications for the S-layer proteins of lactobacilli already exist, including their use as antigen delivery vehicles.     

蛋白质组学的相关技术及应用

当今分子生物学领域内,蛋白质组已成为研究的热点。基因组相对较稳定,而且各种细胞或生物体的基因组结构有许多基本相似的特征;蛋白质组是动态的,随内外界刺激而变化。对蛋白质组的研究可以使我们更容易接近对生命过程的认识。但同时对数千种(甚至更多)蛋白质特性的研究也是一个很大的技术挑战。双相凝肢电泳、质谱、酵母双杂交技术以及生物信息学的发展在一定程度上解决了这一技术难题。本对此类技术及其在各领域的应用作一简要介绍。