3,103 research outputs found

    ASMPKS: an analysis system for modular polyketide synthases

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Polyketides are secondary metabolites of microorganisms with diverse biological activities, including pharmacological functions such as antibiotic, antitumor and agrochemical properties. Polyketides are synthesized by serialized reactions of a set of enzymes called polyketide synthase(PKS)s, which coordinate the elongation of carbon skeletons by the stepwise condensation of short carbon precursors. Due to their importance as drugs, the volume of data on polyketides is rapidly increasing and creating a need for computational analysis methods for efficient polyketide research. Moreover, the increasing use of genetic engineering to research new kinds of polyketides requires genome wide analysis.</p> <p>Results</p> <p>We describe a system named ASMPKS (Analysis System for Modular Polyketide Synthesis) for computational analysis of PKSs against genome sequences. It also provides overall management of information on modular PKS, including polyketide database construction, new PKS assembly, and chain visualization. ASMPKS operates on a web interface to construct the database and to analyze PKSs, allowing polyketide researchers to add their data to this database and to use it easily. In addition, the ASMPKS can predict functional modules for a protein sequence submitted by users, estimate the chemical composition of a polyketide synthesized from the modules, and display the carbon chain structure on the web interface.</p> <p>Conclusion</p> <p>ASMPKS has powerful computation features to aid modular PKS research. As various factors, such as starter units and post-processing, are related to polyketide biosynthesis, ASMPKS will be improved through further development for study of the factors.</p

    Acute post-cardiopulmonary bypass left atrial thrombosis after mitral valvuloplasty and left atrial thrombectomy

    Get PDF
    A patient with mitral stenosis and multiple left atrial thrombi underwent valvuloplasty and thrombectomy. While closing the sternum after completing the cardiopulmonary bypass, a new left atrial thrombus was detected by transesophageal echocardiography. We used heparin for the prevention of new thrombus formation and closed the wound after meticulous bleeding control. Three months later, there was no residual thrombus in the left atrium according to the echocardiographic study

    Improving bread quality using Deinococcus geothermalis glycogen branching enzyme

    Get PDF
    Glycogen branching enzyme(GBE) catalyzes transglycosylation reaction producing α-1,6-glucosidic linkages by cleaving an α-1,4-glucosidic linkage. Deinococcus geothermalis GBE (DgGBE) has the unique activity to form a large number of short oligosaccharide side chains(degree of polymerization 3~5) from the reaction with amylose. To observe the influence of DgGBE on bread quaility, we added 100 unit of the enzyme per kg of the flour at the step of mixing dough. During the fermentation, DgGBE treated dough showed 50~100% larger volume than control. After baking, the total volume and the specific volume of DgGBE treated loaf showed about 10% larger than those of control. The baked breads were sliced to 2cm of depth and stored in 25 degrees celcius, and then the texture was evaluated by texture analyzer during storage time. Hardness and Chewiness of DgGBE treadted bread increased slowly to compared with those of the control. DgGBE treated bread showed a significant effect on antistaling. 1. Shupeng Wua, Yu Liu , Qiaojuan Yan , Zhengqiang Jiang (2014) Gene cloning, functional expression and characterisation of a novel glycogen branching enzyme from Rhizomucor miehei and its application in wheat breadmaking. Food Chemistry 159 (2014) 85-94 2. José Manuel Amigo , Arantxa del Olmo Alvarez , Merete Møller Engelsen , Henrik Lundkvist , Søren Balling Engelsen (2016) Staling of white bread crumb and effect of maltogenic α-amylases. Part 1 : Spatial distribution and kinetic modeling of hardness and resilience. Food Chemistry 208 (2016) 318-32

    Development of screening method for the selection of mutants to improve the substrate specificity of Pyrococcus furiosus thermostable amylase

    Get PDF
    Pyrococcus furiosus thermostable amylase (PFTA) shows the activities of both a cyclodextrin hydrolyzing enzyme and an α-amylase. To improve the substrate affinity and hydrolyzing activity against cyclodextrins, the saturation mutagenesis on the residue of PFTA active site was carried out. After the mutagenesis, the new screening method was needed to select appropriate mutants efficiently from various mutants. Among the α-, β-, γ-cyclodextrins, only β-cyclodextrin makes the complex with phenolphthalein. When added the β-cyclodextrin into phenolphthalein reagent, the color of the solution was changed red to colorless under alkaline condition. In this study, we developed screening method by using 24-well plate and phenolphthalein to compare the activity of PFTA mutants. Escherichia coli MC1061 was used as a host for the expression of various recombinant plasmids and cultured in 24-well plate with Luria-Bertani broth containing kanamycin. After cell lysis by heat treatment, each cell extracts were reacted with β-cyclodextrin at 70℃. Reacted mixtures were put into 96-well plate with NaOH solution and then add the phenolphthalein reagent respectively. Lastly, the absorbance of the mixture was measured at 550 nm. The substrate specificity of PFTA mutants was compared from the difference of absorbance. References 1. Sung-Jae Yang, Hee-Seob Lee, Cheon-Seok Park, Yong-Ro Kim, Tae-Wha Moon, and Kwan-Hwa Park. 2004. Enzymatic Analysis of an Amylolytic Enzyme from the Hyperthermophilic Archaeon Pyrococcus furiosus Reveals Its Novel Catalytic Properties as both an α-Amylase and a Cyclodextrin-Hydrolyzing Enzyme. APPL. ENVIRON. MICROBIOL. 70:5988-5995 2. Anuj Goel, Sanjay N. Nene. 1995. Modifications in the Phenolphthalein Method for Spectrophotometric Estimation of Beta Cyclodextrin. Starch/Starke. 47:399-40

    Optimal Strategies for a Knowledge Workers Acquisition Problem with Expanding and Volatile Demand: Train Internally or Recruit Externally?

    Get PDF
    The aim of this paper is to consider the process of supplying trained workers with knowledge and skills for upcoming business opportunities, and of training apprentices prepared to meet future demands in an IT service firm. As the demand for new workers has fluctuations, a firm should employ a buffer workforce such as apprentices or interns. However, as a result of rapid development of a business, the buffer‟s capacity may be exceeded, thus requiring the company to recruit skilled workers from outside the firm. It is thus important for a firm to map out a strategy for manpower planning so as to fulfill the demands of new business and minimize operation costs related to training apprentices and recruiting experienced workers. This paper first analyzes the demand and supply of workers for IT service in a knowledge-intensive field. It then presents optimal human resource planning via the familiar method of stochastic process - queueing analysis

    A Sensitivity Analysis on the Impact of Uncertanties of the Supply and Demand of a Workforce on a Recruiting Strategy in an IT Service Company

    Get PDF
    This paper investigates a managerial problem related to human resource planning for an IT service company which mainly carries out time-base projects. As the demand for new workers is subject to wide fluctuations, the firm should hire workers in advance and train them. However, the firm should urgently recruit skilled workers from outside the firm due to the shortages in the workforce. Hence, it is important for the firm to design an optimal human resource planning program so as to fulfill the needs of new IT service projects and minimize operation costs, though this involves a trade-off between holding excess workers to prepare for upcoming demand and recruiting experienced workers. This paper presents a quantitative model that describes the stochastic behavior of the supply and demands of the workforce. Numerical results pertaining to the optimal solution are given via a simulation

    Factors influencing mothers’ intention to vaccinate their elementary school sons against human papillomavirus

    Get PDF
    Purpose The purpose of this study was to identify the factors influencing mothers’ intention to vaccinate their elementary-school sons against human papillomavirus (HPV). Methods The participants were 151 mothers of fourth- to sixth-grade boys at three elementary schools in Daejeon, Korea. The data were analyzed using SPSS for Windows version 25.0. Descriptive statistics, the independent t-test, one-way analysis of variance, the Mann–Whitney U test, Pearson correlation coefficients, and multiple regression analysis were used. Results The mothers’ score for intention to vaccinate their sons against HPV was 5.04 out of 7. Self-efficacy (β=.60, p<.001) and subjective norms towards HPV vaccination (β=.30, p<.001) were significant factors influencing mothers’ intention to vaccinate their elementary-school sons against HPV. These factors accounted for 81.0% of HPV vaccination intention among mothers (F=160.84, p<.001). Conclusion The results of this study suggest that to increase the HPV vaccination rate for elementary-school boys, it is necessary to develop intervention strategies to improve mothers’ self-efficacy and subjective norms towards HPV vaccination and to verify the effects of those strategies. This research provides a foundation for designing interventions to increase the HPV vaccination rate of elementary-school boys

    Effects of moxibustion for constipation treatment: a systematic review of randomized controlled trials

    Get PDF
    Several studies reported that moxibustion was effective in treating constipation. This systematic review assesses the clinical evidence for or against moxibustion for treating constipation. Twelve databases were searched from their inception to March 2010. Only randomized clinical trials (RCTs) were included if they compared moxibustion with placebo, sham treatment, drug therapy or no treatment. The methodological quality of these RCTs was assessed with the Cochrane risk of bias analysis. All three RCTs included in the study had a high risk of bias. Two included studies found favorable effects of moxibustion. The third RCT showed significant effects in the moxibustion group. Given that the methodological quality of all RCTs was poor, the results from the present review are insufficient to suggest that moxibustion is an effective treatment for constipation. More rigorous studies are warranted

    Gap Analysis Between the Level of Heat Wave Adaptation Policy and Heat Wave Effects in South Korean Municipalities

    Get PDF
    This study aims to analyze the gap between the level of heat wave adaptation policies and heat wave effects in South Korean municipalities. First, the types of industries in municipalities were classified using factor analysis and cluster analysis. Second, the level of heat wave adaptation policy in the municipalities was assessed using a fuzzy analytic hierarchy process analysis. Third, the gap between the level of heat wave adaptation policy and the heat wave effect was analyzed. The results show that the heat wave adaptation policies were established in accordance with the heat wave effects to at least some degree. However, closer to the long-term future (2095), the policies have not sufficiently matched the level of heat wave effects. The proportion of municipalities with insufficient levels of heat wave adaptation policies against the heat wave effects was higher among urban-type municipalities. The analysis results suggest two policy implications. First, the heat wave adaptation policies of municipalities should be established through continuous feedback on the predictions of future heat wave effects. Second, urban-type municipalities should strengthen their planning authority and competence by securing a professional workforce and budgets for the establishment of heat wave adaptation policies

    Alpha-tocopherol exerts protective function against the mucotoxicity of particulate matter in amphibian and human goblet cells

    Get PDF
    Exposure to particulate matter (PM) in ambient air is known to increase the risk of cardiovascular disorders and mortality. The cytotoxicity of PM is mainly due to the abnormal increase of reactive oxygen species (ROS), which damage cellular components such as DNA, RNA, and proteins. The correlation between PM exposure and human disorders, including mortality, is based on long-term exposure. In this study we have investigated acute responses of mucus-secreting goblet cells upon exposure to PM derived from a heavy diesel engine. To this end, we employed the mucociliary epithelium of amphibian embryos and human Calu-3 cells to examine PM mucotoxicity. Our data suggest that acute exposure to PM significantly impairs mucus secretion and results in the accumulation of mucus vesicles in the cytoplasm of goblet cells. RNA-seq analysis revealed that acute responses to PM exposure significantly altered gene expression patterns; however, known regulators of mucus production and the secretory pathway were not significantly altered. Interestingly, pretreatment with alpha-tocopherol nearly recovered the hyposecretion of mucus from both amphibian and human goblet cells. We believe this study demonstrates the mucotoxicity of PM and the protective function of alpha-tocopherol on mucotoxicity caused by acute PM exposure from heavy diesel engines
    corecore