类黄酮化合物抑制恶性疟原虫的预测模型

建立预测类黄酮化合物抑制恶性疟原虫株活性定量的模型,并确定影响类黄酮化合物活性的主要因素。本文选用了38个结构不同的类黄酮化合物作为数据集,采用多元线性同归法及主成分分析法分析每个化合物的220个分子参数,建立最优的预测模型。比较用不同方法建立的模型,结果发现带logP参数的向后筛选法为最优方法,所建模型统计结果良好(训练集相关系数R~2=0.81,标准训练误差SEE=0.27),模型代入检验集数据时结果也令人满意(检验集相关系数R~2=0.83,标准检验误差SEP=0.39),可靠性和预测性较强。脂水分配系数的对数logP为模型重要影响参数。建模和确定影响因素有助于筛选新型类黄酮抗疟疾药物和研发。     

Impact of incomplete DNase I treatment on human macrophage proteome analysis

The aim of our study was to analyze the proteomic pattern of human macrophages obtained over a 4 year period from blood donors. The purpose was to simulate a long-term clinical study to assess the application of 2-D DIGE technique for differential proteomic analysis of these scarce samples. Bioinformatic analysis of 2-D DIGE gels of 19 different cultures of macrophages assessed whether they did or did not contain at least specific five spots identified by MS as being or containing bovine deoxyribonuclease I (DNase I). Bovine DNase I was used during sample treatment to remove nucleic acids from protein extracts. Macrophages were classified in two groups, which appeared to be differentiated by the completeness of DNase I treatment. Further detailed analysis revealed a different proteomic pattern of macrophage protein samples according to the completeness of this treatment. The major group of proteins affected, accounting for one third of the differentially expressed proteins, included proteins involved in cell motion and actin cytoskeleton reorganization. The use of DNase I for the removal of nucleic acids from protein samples must be avoided in proteomic studies since it can generate bias in the analysis of protein expression patterns.     

应用于食品工业中的生物传感器

对食品及其生产加工过程中的生物传感器进行综述。主要包括食品鲜度测定；蛋白及氨基酸的测定；糖、醇、酸的分析及菌数的测定。     

计算机软件在食品营养学教学中的应用

食品营养学是高职院校营养检测和食品类专业重要的课程。营养学教学过程中,多个项目都需要学生在掌握大量数据信息基础上进行数据处理,计算机软件可以使学生更有效的进行信息的整理。应加强职业教育现代教学技术的运用,立足于提高学生的职业能力。     

Online analysis of in vitro resistance to antimalarial drugs through nonlinear regression

Malaria remains one of the leading causes of morbidity and mortality worldwide which is partly due to the emergence of the parasite resistance to antimalarial drugs. In vitro testing of drugs allows an early detection of resistance. The common parameter used for the monitoring of resistance is the concentration that inhibits 50% of the parasite's activity (IC₅₀). Various methods of calculation are already used but none of them consider new available tools nor display the precision of IC₅₀ estimation. We proposed an approach based on the inhibitory sigmoid E_max model, which is often used in pharmacology, with estimation of IC₅₀ through nonlinear regression using a standard function of the R software. To facilitate the usage of that tool we have developed an online version available on the website ICEstimator (ICEstimator website http://www.antimalarial-icestimator.net/, 2009) [1]. This website is used by various teams in the world and the user can do the analysis without knowing R using the GUI. This article describes version 2.1 of this website and shows illustration on five different real examples.     

PLC在生产膨化食品片材中的应用

本文介绍了PLC在生产膨化食品片材中的应用,控制系统基于SIMATIC S7-200PLC和MD204L文本显示器。论述了生产工艺要求,控制系统的硬件组成和软件设计。     

食品抽检登记助手软件的开发

为了提高食品抽检工作中样品信息的录入速度,本文开发了一个食品抽检登记助手软件。该软件通过调用百度智能云提供的通用文字识别功能,自动识别食品生产经营者证照及食品包装上的文字;利用正则表达式提取和保存识别结果中抽检管理系统需要的相关信息。在测试中,该软件对食品样品相关信息的提取准确率超过了98%。利用这种方式代替传统的人工录入方式,提高了工作效率。     

西门子S7-1200的设计与应用 第5讲 食品生产线喷嘴控制的S7-1200设计

PWM是一种周期固定、脉冲宽度可以调节的脉冲输出,是数字量输出。在S7-1200 PLC中,它提供两个输出通道用于高速脉冲输出,分别可以组态为PTO或PWM,本案例则充分利用了PWM功能来实现了食品生产线的喷嘴控制,取得了良好的效果。     

Characteristics of the Plasmodium falciparum PK5 ATP-binding site: implications for the design of novel antimalarial agents

Increasing worldwide resistance of Plasmodium falciparum (P. falciparum) to traditional chemotherapy strategies such as chloroquine and mefloquine demonstrates the urgent need for the discovery of novel chemotherapeutic agents in the fight against malaria. The recent discovery of P. falciparum Protein Kinase 5 (PfPK5) invites the possibility of selectively targeting the life cycle of P. falciparum in order to prevent cerebral malaria. PfPK5 bears a high degree of sequence identity (>58%) to a structurally conserved family of mammalian kinases known as the cyclin-dependent kinases (CDKs). The CDKs are the key regulatory elements governing the ordered progression of the mammalian cell cycle. With numerous X-ray crystal structures of CDK2 to provide a structural template, here we present a three-dimensional structural model of PfPK5 constructed using computer-based homology modeling techniques. Our model was used to compare the ATP binding site of PfPK5 with that of the mammalian kinase CDK2. Furthermore, kinase-ligand interactions of PfPK5 with known inhibitors were investigated and compared to available crystal structures of CDK2 with inhibitors bound. The focus of the study is to identify similarities and differences between the ATP binding sites of the two kinases that can be exploited for future rational drug design.     

An implementation of the nudged elastic band algorithm and application to the reaction mechanism of HGXPRTase from Plasmodium falciparum

The understanding of transition processes, such as chemical reactions, is a central topic in theoretical molecular science. A common approach for investigating such processes is to calculate paths between reactant and product structures that are representative of the transition. Many approaches have been proposed to determine such paths but, in this paper, we examine the nudged elastic band algorithm which was recently introduced by Jónsson and co-workers and has been used to study a wide range of transition problems. We describe our implementation of the method in the simulation program Dynamo and some modifications to the original algorithm that we found improve its efficiency. The use of the method is illustrated by an application to the reaction mechanism of the enzyme hypoxanthine-guanine-xanthine phosphoribosyltransferase from Plasmodium falciparum.     

迈思肯条码扫描器QX-830帮助食品工厂提高生产自动化管理

条码技术的应用在食品饮料生产行业的应用,大大提高了工艺运行质量和产品管理效率。本文介绍了迈思肯条码扫描技术在某跨国食品制造公司的应用实例,通过阐述该其技术特点和所显示的优越性,展现了这项新技术在食品饮料生产行业的前景。     

Congestion Control in the Internet: Inspiration from Balanced Food Chains in the Nature

Congestion in the Internet is the main reason for reduced performance and poor quality of service; therefore, a good congestion control system is essential. The current work proposes that the congestion control problem in the Internet can be inspired from natural population control tactics. Toward this idea, the congestion window size of each connection is viewed as population size of a species and then congestion control problem is redefined as population control of these windows species (W). This paper defines a three-trophic food chain and gives a model to control population size of W species within this food chain. Simulation results show that the proposed algorithm leads to a fair, stable and high-performance congestion control scheme.

基于多Agent的蚂蚁觅食过程仿真研究

复杂系统的仿真研究是复杂系统研究领域的一个热点问题.研究表明,传统的建模仿真方法无法很好地刻画复杂系统,而基于多智能体(Agent)的建模仿真方法是当前研究复杂系统的最有力工具之一,有必要进行深入研究.在简单介绍复杂系统以及基于多Agent的建模仿真方法的研究概况后,以蚂蚁觅食过程为研究对象,进行基于多Agent的建模仿真实验,结果表明基本多Agent的建模仿真方法非常适合复杂系统的研究,具有很大的发展空间.     

In silico study of subtilisin-like protease 1 (SUB1) from different Plasmodium species in complex with peptidyl-difluorostatones and characterization of potent pan-SUB1 inhibitors

Plasmodium falciparum subtilisin-like protease 1 (SUB1) is a novel target for the development of innovative antimalarials. We recently described the first potent difluorostatone-based inhibitors of the enzyme ((4S)-(N-((N-acetyl-l-lysyl)-l-isoleucyl-l-threonyl-l-alanyl)-2,2-difluoro-3-oxo-4-aminopentanoyl)glycine (1) and (4S)-(N-((N-acetyl-l-isoleucyl)-l-threonyl-l-alanylamino)-2,2-difluoro-3-oxo-4-aminopentanoyl)glycine (2)). As a continuation of our efforts towards the definition of the molecular determinants of enzyme-inhibitor interaction, we herein propose the first comprehensive computational investigation of the SUB1 catalytic core from six different Plasmodium species, using homology modeling and molecular docking approaches. Investigation of the differences in the binding sites as well as the interactions of our inhibitors 1,2 with all SUB1 orthologues, allowed us to highlight the structurally relevant regions of the enzyme that could be targeted for developing pan-SUB1 inhibitors. According to our in silico predictions, compounds 1,2 have been demonstrated to be potent inhibitors of SUB1 from all three major clinically relevant Plasmodium species (P. falciparum, P. vivax, and P. knowlesi). We next derived multiple structure-based pharmacophore models that were combined in an inclusive pan-SUB1 pharmacophore (SUB1-PHA). This latter was validated by applying in silico methods, showing that it may be useful for the future development of potent antimalarial agents.     

基于食品药品供应链质量协同的社会共治实现机制

食品药品安全社会共治本质上是一项制度安排的体制变革。在社会共治中,如何解决好多主体参与的个体理性与集体理性之间的矛盾是一个难题。本文根据文献研究元分析方法,从供应链质量协同视角考察食品药品安全社会共治的实现机制,由此探讨食品药品供应链质量协同中的协同契约设计与全供应链信息披露机制,认为不同权力结构下多主体协同管理需求及其激励机制设计,是构建食品药品供应链质量协同契约设计的前提。同时,建设基于云计算环境的食品药品安全社会共治信息共享机制,是构建食品药品供应链质量协同的运作环境,这是推动食品药品供应链质量协同社会共治制度实现机制的两个关键举措。     

Can Interface Cues Nudge Modeling of Food Consumption? Experiments on a Food‐Ordering Website

Following the nudging perspective, this research investigates how technology interface could cue heuristics that influence decisions. A field study showed that interface cues on a food‐ordering website signaling the amount of food other users consume could trigger an anchoring heuristic and induce individuals to model that amount when deciding their own consumption volume. A laboratory experiment further showed that the anchoring cue tends to induce the modeling behavior of individuals without them being aware of its influence, and such an influence was especially pronounced when resources for cognitive deliberation were limited. Altogether, this research suggests that interface cues could function as nudges and influence decisions at a relatively automatic level. Implications for technology design and intervention are discussed.     

CCNDB—中国烹调和营养数据库的设计与实现

本文描述了中国烹调和营养数据库(CCNDB)的结构设计。CCNDB 包括中国烹调数据库(CCDB)和中国食品营养成分数据库(CFCDB)以及程序系统,由下面四个部分组成:1.CFCDB 中经标准格式化的400多种常用食品原料成份:水、蛋白质、脂肪、碳水化合物、灰分、热量、钙、磷、铁、胡萝卜素、维生素 A、维生素 B1、维生素 B2、维生素 C、尼克酸以及胆固醇。2.CCDB 中标准格式化的300多种经特殊挑选的中国菜肴;其中包括原料、原料量以及准备、制作过程等。3.为 CFCDB 和 CCDB 设计的管理系统用以工作文件生成、错误检查、接口转换以及各种形式的标准化等。4.执行程序系统,包括十种功能,用户可方便地以会话方式使用。     

三菱A700系列变频器的设计与应用 第1讲 食品输送带的变速控制

交流电机比直流电机经济耐用得多,因而被广泛应用于各行各业。在实际应用场合,往往要求交流电机能随意调节转速,以便获得满意的使用效果,但它在这方面比起直流电机而言就要逊色地多,于是不得不借助其它手段达到调速目的。本文通过食品输送带的变频控制方案来了解变频器的最简单应用。     

A colorimetric biosensor for the detection of foodborne bacteria

We have synthesized 10,12-pentacosadyinoic acid (PCDA) + N-[(2-tetradecanamide)-ethyl]-ribonamide (TDER) vesicles to determine the colorimetric response induced by pathogenic bacteria (Staphylococcus aureus and Escherichia coli). The addition of bacterial supernatants caused a colorimetric transition in TDER/PCDA vesicles, even in diluted concentrations, indicating that chemical interactions occur between the vesicles and bacterial compounds. Bacterial substrates released from S. aureus induced a greater color change compared to the color change induced by E. coli. S. aureus metabolites also induced a greater color change when TDER/PCDA vesicles were incorporated into the cellulose strips. We determined the energy involved in the interaction between the bacterial substrates and the TDER/PCDA vesicles to be exothermic (and very high) for both bacterial supernatants. In addition, we analyzed the colorimetric transition in the presence of other molecules, using apple juice as a food matrix. Both apple juice and apple juice inoculated with bacterial substrates induced a TDER/PCDA color change; however, the S. aureus supernatant induced a slightly greater color change in the vesicles both in the suspension and in the cellulose strips. TDER/PCDA vesicles show great potential to be used as a biosensor to detect food pathogens in intelligent food packaging.