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关键词： 国际交流   合作   检验检疫   科技工作   食品安全  

摘要： 2011年10月21日,AOAC（国际官定分析检测协会）中国区年度大会暨2011食品安全技术与标准国际研讨会在青岛落下帷幕。会议在主办方中国国家认证认可监督管理委员会和AOAC中国区分部及承办方山东检验检疫局食品农产品中心精心组织下,取得了圆满成功.

关键词： 食品包装纸   中国食品产业   塑料包装   自然降解   塑料制品   水果保鲜纸   纸包装   合成纸   常德卷烟厂   可食  

摘要： 中国食品产业网2011-10-13报道:长期以来,食品包装大量应用塑料制品,由于塑料极难自然降解,造成严重的环境污染。因此,一些发达国家已部分限制塑料包装的使用。为此。

关键词： 微生物检验   医院感染   监控中的作用  

摘要： 医院感染（HI）又称为医院获得性感染（HAI）,是指入院患者或医院工作人员由于院内病菌感染并产生临床症状的一种感染.医院感染包括传染源、传播途径和易感人群三个环节,每个环节都和微生物学检验关系密切.近年来由于抗生素的不合理使用及介入性治疗、放射治疗和化学药物治疗的广泛开展,监测和控制医院感染,加强微生物学检验工作有助于及时发现传染源,保护易感人群和阻断传播途径,对监测和控制医院感染有着重要影响.

关键词： 痕迹检验技术   交通肇事案件  

摘要： 长期以来,技术人员在应用痕迹检验技术勘验和检验交通肇事案件时,往往只考虑到特殊痕迹检验中整体分离痕迹和轮胎印痕来认定肇事车辆,对于其他痕迹在确定案件的性质,侦查方向有着特殊作用却少有所知。本文通过一系列具体的交通肇事案件,说明整个痕迹检验技术在交通肇事案件现场中的有着广泛应用,对交通肇事案件的侦破具有积极的意义。

关键词： 检测技术   食品安全  

摘要： 阐述如何发挥质量技术机构在食品安中的作用。

关键词： Class size   Classroom processes   Teacher pupil interaction   Classroom engagement   Classroom observations  

摘要： It is widely recognized that we need to know more about effects of class size on classroom interactions and pupil behavior. This paper extends research by comparing effects on pupil classroom engagement and teacher-pupil interaction, and examining if effects vary by pupil attainment level and between primary and secondary schools. Systematic observations were carried out on 686 pupils in 49 schools. Multilevel regression methods were used to examine relationships between class size and observation measures, controlling for potentially confounding factors like pupil attainment. At primary and secondary levels smaller classes led to pupils receiving more individual attention from teachers, and having more active interactions with them. Classroom engagement decreased in larger classes, but, contrary to expectation, this was particularly marked for lower attaining pupils at secondary level. Low attaining pupils can therefore benefit from smaller classes at secondary level in terms of more individual attention and facilitating engagement in learning. (C) 2011 Elsevier Ltd. All rights reserved.

关键词： cellulose   large-scale convergence   leaf temperature   oxygen isotope   tree canopy  

摘要： The idea that photosynthesis-weighted tree canopy leaf temperature (T-can delta) can be resolved through analysis of oxygen isotope composition in tree wood cellulose (delta O-18(wc)) has led to the observation of boreal-to-subtropical convergence of T-can delta to c. 20 degrees C. To further assess the validity of the large-scale convergence of T-can delta, we used the isotope approach to perform calculation of T-can delta for independent delta O-18(wc) data sets that have broad coverage of climates. For the boreal-to-subtropical data sets, we found that the deviation of T-can delta from the growing season temperature systemically increases with the decreasing mean annual temperature. Across the whole data sets we calculated a mean T-can delta of 19.48 degrees C and an SD of 2.05 degrees C, while for the tropical data set, the mean T-can delta was 26.40 +/- 1.03 degrees C, significantly higher than the boreal-to-subtropical mean. Our study thus offers independent isotopic support for the concept that boreal-to-subtropical trees display conserved T-can delta near 20 degrees C. The isotopic analysis cannot distinguish between the possibility that leaf temperatures are generally elevated above ambient air temperatures in cooler environments and the possibility that leaf temperature equals air temperature, whereas the leaf/air temperature at which photosynthesis occurs has a weighted average of near 20 degrees C in cooler environments. Future work will separate these potential explanations.

关键词： proteinaceous binding media   historic pigments   C?H stretching region   Raman microscopy   PCA  

摘要： This work seeks to identify the slight changes in the characteristic C?H stretching region (3100-2800 cm(-1)) of a protein-based binder and fatty acid esters from egg yolk, which may occur in complex paint samples due to the presence of particular pigments. To date, this protein regionwhere historic pigments do not show characteristic Raman bandshas not been used to identify possible interactions between painting materials, in spite of its potential due to the mentioned feature. This study is based on the investigation of pure egg yolk model samples and tempera model samples prepared by mixing this binder with some historic pigments (cinnabar, raw Sienna, lead white, gypsum, calcite, azurite, lapis lazuli and smalt) as binary samples. All samples were analyzed in this region by Raman microscopy (RM) coupled with principal component analysis (PCA) for three color groups (red, white and blue) separately. The results show relevant spectral changes in the C?H stretching region of amino acids and polyunsaturated fatty acids esters of the egg yolk binder, particularly in the azurite, lead white and gypsum-based tempera samples. Lesser interactions were discerned in the tempera samples made with smalt, as well as shift in the region of polyunsaturated fatty acid esters of the egg yolk binder in the cinnabar and raw Sienna-based tempera paintings. No interactions were recognized between the egg yolk and the pigments calcite and lapis lazuli. The effectiveness of applying RM combined with PCA for identifying interaction processes between binders and pigments is demonstrated. Copyright (C) 2011 John Wiley & Sons, Ltd.

关键词： MOLECULE-molecule collisions   CARBOHYDRATES   GLYCOSIDASES   CELLULASE   TRICHODERMA reesei   ALANINE  

摘要： Proteins employ aromatic residues for carbohydrate binding in a wide range of biological functions. Glycoside hydrolases, which are ubiquitous in nature, typically exhibit tunnels, clefts, or pockets lined with aromatic residues for processing carbohydrates. Mutation of these aromatic residues often results in significant activity differences on insoluble and soluble substrates. However, the thermodynamic basis and molecular level role of these aromatic residues remain unknown. Here, we calculate the relative ligand binding free energy by mutating tryptophans in the Trichoderma reesei family 6 cellulase (Ce16A) to alanine. Removal of aromatic residues near the catalytic site has little impact on the ligand binding free energy, suggesting that aromatic residues immediately upstream of the active site are not directly involved in binding, but play a role in the glucopyranose ring distortion necessary for catalysis. Removal of aromatic residues at the entrance and exit of the Ce16A tunnel, however, dramatically impacts the binding affinity, suggesting that these residues play a role in chain acquisition and product stabilization, respectively. The roles suggested from differences in binding affinity are confirmed by molecular dynamics and normal mode analysis. Surprisingly, our results illustrate that aromatic-carbohydrate interactions vary dramatically depending on the position in the enzyme tunnel. As aromatic-carbohydrate interactions are present in all carbohydrate-active enzymes, these results have implications for understanding protein structure-function relationships in carbohydrate metabolism and recognition, carbon turnover in nature, and protein engineering strategies for biomass utilization. Generally, these results suggest that nature employs aromatic-carbohydrate interactions with a wide range of binding affinities for diverse functions.

关键词： Breath analysis   Disease identification   Sparse representation   Diabetes   Blood glucose levels  

摘要： It has been discovered that some compounds in human breath can be used to detect some diseases and monitor the development of the conditions. A sensor system in tandem with certain data evaluation algorithm offers an approach to analyze the compositions of breath. Currently, most algorithms rely on the generally designed pattern recognition techniques rather than considering the specific characteristics of data. They may not be suitable for odor signal identification. This paper proposes a Sparse Representation-based Classification (SRC) method for breath sample identification. The sparse representation expresses an input signal as the linear combination of a small number of the training signals, which are from the same category as the input signal. The selection of a proper set of training signals in representation, therefore, gives us useful cues for classification. Two experiments were conducted to evaluate the proposed method. The first one was to distinguish diabetes samples from healthy ones. The second one aimed to classify these diseased samples into different groups, each standing for one blood glucose level. To illustrate the robustness of this method, two different feature sets, namely, geometry features and principle components were employed. Experimental results show that the proposed SRC outperforms other common methods, such as K Nearest Neighbor (KNN), Linear Discriminant Analysis (LDA), Artificial Neural Network (ANN), and Support Vector Machine (SVM), irrespective of the features selected. (C) 2011 Elsevier B.V. All rights reserved.