Science.gov

Sample records for modified organisms gmo

  1. [Genetically modified organisms (GMO): toxicological aspects].

    PubMed

    Ludwicki, J K

    1998-01-01

    The genetically modified organisms (GMO) are one of the major public concerns partially due to the activity of the non-governmental organizations which believe that public opinion must be duly informed on what leaves the laboratories and enters the environment or is proposed as food. This article discusses some major toxicological and nutritional aspects of GMO designed as food for humans. The range of current use of GMOs, potential hazards for humans, safety assessment, allergenic concerns, and some aspects of the use of marker genes are discussed in regard to human safety. The need for relevant regulations is stressed.

  2. JRC GMO-Amplicons: a collection of nucleic acid sequences related to genetically modified organisms

    PubMed Central

    Petrillo, Mauro; Angers-Loustau, Alexandre; Henriksson, Peter; Bonfini, Laura; Patak, Alex; Kreysa, Joachim

    2015-01-01

    The DNA target sequence is the key element in designing detection methods for genetically modified organisms (GMOs). Unfortunately this information is frequently lacking, especially for unauthorized GMOs. In addition, patent sequences are generally poorly annotated, buried in complex and extensive documentation and hard to link to the corresponding GM event. Here, we present the JRC GMO-Amplicons, a database of amplicons collected by screening public nucleotide sequence databanks by in silico determination of PCR amplification with reference methods for GMO analysis. The European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) provides these methods in the GMOMETHODS database to support enforcement of EU legislation and GM food/feed control. The JRC GMO-Amplicons database is composed of more than 240 000 amplicons, which can be easily accessed and screened through a web interface. To our knowledge, this is the first attempt at pooling and collecting publicly available sequences related to GMOs in food and feed. The JRC GMO-Amplicons supports control laboratories in the design and assessment of GMO methods, providing inter-alia in silico prediction of primers specificity and GM targets coverage. The new tool can assist the laboratories in the analysis of complex issues, such as the detection and identification of unauthorized GMOs. Notably, the JRC GMO-Amplicons database allows the retrieval and characterization of GMO-related sequences included in patents documentation. Finally, it can help annotating poorly described GM sequences and identifying new relevant GMO-related sequences in public databases. The JRC GMO-Amplicons is freely accessible through a web-based portal that is hosted on the EU-RL GMFF website. Database URL: http://gmo-crl.jrc.ec.europa.eu/jrcgmoamplicons/ PMID:26424080

  3. JRC GMO-Amplicons: a collection of nucleic acid sequences related to genetically modified organisms.

    PubMed

    Petrillo, Mauro; Angers-Loustau, Alexandre; Henriksson, Peter; Bonfini, Laura; Patak, Alex; Kreysa, Joachim

    2015-01-01

    The DNA target sequence is the key element in designing detection methods for genetically modified organisms (GMOs). Unfortunately this information is frequently lacking, especially for unauthorized GMOs. In addition, patent sequences are generally poorly annotated, buried in complex and extensive documentation and hard to link to the corresponding GM event. Here, we present the JRC GMO-Amplicons, a database of amplicons collected by screening public nucleotide sequence databanks by in silico determination of PCR amplification with reference methods for GMO analysis. The European Union Reference Laboratory for Genetically Modified Food and Feed (EU-RL GMFF) provides these methods in the GMOMETHODS database to support enforcement of EU legislation and GM food/feed control. The JRC GMO-Amplicons database is composed of more than 240 000 amplicons, which can be easily accessed and screened through a web interface. To our knowledge, this is the first attempt at pooling and collecting publicly available sequences related to GMOs in food and feed. The JRC GMO-Amplicons supports control laboratories in the design and assessment of GMO methods, providing inter-alia in silico prediction of primers specificity and GM targets coverage. The new tool can assist the laboratories in the analysis of complex issues, such as the detection and identification of unauthorized GMOs. Notably, the JRC GMO-Amplicons database allows the retrieval and characterization of GMO-related sequences included in patents documentation. Finally, it can help annotating poorly described GM sequences and identifying new relevant GMO-related sequences in public databases. The JRC GMO-Amplicons is freely accessible through a web-based portal that is hosted on the EU-RL GMFF website. Database URL: http://gmo-crl.jrc.ec.europa.eu/jrcgmoamplicons/.

  4. Recommendations from a meeting on health implications of genetically modified organism (GMO).

    PubMed

    Amofah, George

    2014-06-01

    The Ghana Public Health Association organized a scientific seminar to examine the introduction of genetically modified organisms into public use and the health consequences. The seminar was driven by current public debate on the subject. The seminar identified some of the advantages of GMOs and also the health concerns. It is clear that there is the need to enhance local capacity to research the introduction and use of GMOs; to put in place appropriate regulatory mechanisms including particularly the labeling of GMO products and post-marketing surveillance for possible negative health consequences in the long term. Furthermore the appropriate state agency should put in place advocacy strategies to keep the public informed about GMOs.

  5. Finding the joker among the maize endogenous reference genes for genetically modified organism (GMO) detection.

    PubMed

    Paternò, Annalisa; Marchesi, Ugo; Gatto, Francesco; Verginelli, Daniela; Quarchioni, Cinzia; Fusco, Cristiana; Zepparoni, Alessia; Amaddeo, Demetrio; Ciabatti, Ilaria

    2009-12-09

    The comparison of five real-time polymerase chain reaction (PCR) methods targeted at maize ( Zea mays ) endogenous sequences is reported. PCR targets were the alcohol dehydrogenase (adh) gene for three methods and high-mobility group (hmg) gene for the other two. The five real-time PCR methods have been checked under repeatability conditions at several dilution levels on both pooled DNA template from several genetically modified (GM) maize certified reference materials (CRMs) and single CRM DNA extracts. Slopes and R(2) coefficients of all of the curves obtained from the adopted regression model were compared within the same method and among all of the five methods, and the limit of detection and limit of quantitation were analyzed for each PCR system. Furthermore, method equivalency was evaluated on the basis of the ability to estimate the target haploid genome copy number at each concentration level. Results indicated that, among the five methods tested, one of the hmg-targeted PCR systems can be considered equivalent to the others but shows the best regression parameters and a higher repeteability along the dilution range. Thereby, it is proposed as a valid module to be coupled to different event-specific real-time PCR for maize genetically modified organism (GMO) quantitation. The resulting practicability improvement on the analytical control of GMOs is discussed.

  6. Role of the "National Reference Centre for Genetically Modified Organisms (GMO) detection" in the official control of food and feed.

    PubMed

    Ciabatti, I; Marchesi, U; Froiio, A; Paternò, A; Ruggeri, M; Amaddeo, D

    2005-08-01

    The National Reference Centre for Genetically Modified Organisms (GMO) detection was established in 2002 within the Istituto Zooprofilattico Sperimentale Lazio e Toscana, with the aim of providing scientific and technical support to the National Health System and to the Ministry of Health within the scope of the regulation of GMO use in food and feed.The recently adopted EU legislation on GMOs (Regulation CE no. 1829/2003 and no. 1830/2003) introduced more rigorous procedures for the authorisation, labelling and analytical control of food and feed consisting, containing or derived from GMOs. The National Reference Centre, besides its institutional tasks as one of the laboratories of the Italian National Health System, collects and analyses data and results of the national official control of GMOs; carries out scientific research aimed at developing, improving, validating and harmonising detection and quantification methods, in cooperation with other scientific institutions, the Community Reference Laboratory and within the European Network of GMOs laboratories (ENGL); collaborates with the Ministry of Health in the definition of control programmes and promotes educational and training initiatives. Objectives defined for 2004-2006, activities in progress and goals already achieved are presented.

  7. The GMO-Nanotech (Dis)Analogy?

    ERIC Educational Resources Information Center

    Sandler, Ronald; Kay, W. D.

    2006-01-01

    The genetically-modified-organism (GMO) experience has been prominent in motivating science, industry, and regulatory communities to address the social and ethical dimensions of nanotechnology. However, there are some significant problems with the GMO-nanotech analogy. First, it overstates the likelihood of a GMO-like backlash against…

  8. A versatile, non genetically modified organism (GMO)-based strategy for controlling low-producer mutants in Bordetella pertussis cultures using antigenic modulation.

    PubMed

    Goffin, Philippe; Slock, Thomas; Smessaert, Vincent; De Rop, Philippe; Dehottay, Philippe

    2015-08-01

    The uncontrolled presence of non-producer mutants negatively affects bioprocesses. In Bordetella pertussis cultures, avirulent mutants emerge spontaneously and accumulate. We characterized the dynamics of accumulation using high-throughput growth assays and competition experiments between virulent and avirulent (bvg(-) ) isolates. A fitness advantage of bvg(-) cells was identified as the main driver for bvg(-) accumulation under conditions of high virulence factor production. Conversely, under conditions that reduce their expression (antigenic modulation), bvg(-) takeover could be avoided. A control strategy was derived, which consists in applying modulating conditions whenever virulence factor production is not required. It has a wide range of applications, from routine laboratory operations to vaccine manufacturing, where pertussis toxin yields were increased 1.4-fold by performing early pre-culture steps in modulating conditions. Because it only requires subtle modifications of the culture medium and does not involve genetic modifications, this strategy is applicable to any B. pertussis isolate, and should facilitate regulatory acceptance of process changes for vaccine production. Strategies based on the same concept, could be derived for other industrially relevant micro-organisms. This study illustrates how a sound scientific understanding of physiological principles can be turned into a practical application for the bioprocess industry, in alignment with Quality by Design principles.

  9. Random amplified polymorphic DNA analysis of genetically modified organisms.

    PubMed

    Yoke-Kqueen, Cheah; Radu, Son

    2006-12-15

    Randomly amplified polymorphic DNA (RAPD) was used to analyzed 78 samples comprises of certified reference materials (soya and maize powder), raw seeds (soybean and maize), processed food and animal feed. Combination assay of two arbitrary primers in the RAPD analysis enable to distinguish genetically modified organism (GMO) reference materials from the samples tested. Dendrogram analysis revealed 13 clusters at 45% similarity from the RAPD. RAPD analysis showed that the maize and soybean samples were clustered differently besides the GMO and non-GMO products.

  10. Traceability of genetically modified organisms.

    PubMed

    Aarts, Henk J M; van Rie, Jean-Paul P F; Kok, Esther J

    2002-01-01

    EU regulations stipulate the labeling of food products containing genetically modified organisms (GMOs) unless the GMO content is due to adventitious and unintended 'contamination' and not exceeding the 1% level at ingredient basis. In addition, member states have to ensure full traceability at all stages of the placing on the market of GMOs. Both requirements ensure consumers 'right to know', facilitate enforcement of regulatory requirements and are of importance for environmental monitoring and postmarket surveillance. Besides administrative procedures, such as used in quality certification systems, the significance of adequate molecular methods becomes more and more apparent. During the last decade a considerable number of molecular methods have been developed and validated that enable the detection, identification and quantification of GMO impurities. Most of them rely on the PCR technology and can only detect one specific stretch of DNA. It can, however, be anticipated that in the near future the situation will become more complex. The number of GMO varieties, including 'stacked-gene' varieties, which will enter the European Market will increase and it is likely that these varieties will harbor more variable constructs. New tools will be necessary to keep up with these developments. One of the most promising techniques is microarray analysis. This technique enables the screening for a large number of different GMOs within a single experiment.

  11. Consumer perception of genetically modified organisms and sources of information.

    PubMed

    Wunderlich, Shahla; Gatto, Kelsey A

    2015-11-01

    Genetically modified organisms (GMOs) have been available for commercial purchase since the 1990s, allowing producers to increase crop yields through bioengineering that creates herbicide-resistant and insect-resistant varieties. However, consumer knowledge about GMOs has not increased at the same rate as the adoption of GMO crops. Consumers worldwide are displaying limited understanding, misconceptions, and even unfamiliarity with GMO food products. Many consumers report that they receive information about GMO food products from the media, Internet, and other news sources. These sources may be less reliable than scientific experts whom consumers trust more to present the facts. Although many in the United States support mandatory GMO labeling (similar to current European standards), consumer awareness of current GMO labeling is low. A distinction must also be made between GMO familiarity and scientific understanding, because those who are more familiar with it tend to be more resistant to bioengineering, whereas those with higher scientific knowledge scores tend to have less negative attitudes toward GMOs. This brings to question the relation between scientific literacy, sources of information, and overall consumer knowledge and perception of GMO foods.

  12. GMOtrack: generator of cost-effective GMO testing strategies.

    PubMed

    Novak, Petra Krau; Gruden, Kristina; Morisset, Dany; Lavrac, Nada; Stebih, Dejan; Rotter, Ana; Zel, Jana

    2009-01-01

    Commercialization of numerous genetically modified organisms (GMOs) has already been approved worldwide, and several additional GMOs are in the approval process. Many countries have adopted legislation to deal with GMO-related issues such as food safety, environmental concerns, and consumers' right of choice, making GMO traceability a necessity. The growing extent of GMO testing makes it important to study optimal GMO detection and identification strategies. This paper formally defines the problem of routine laboratory-level GMO tracking as a cost optimization problem, thus proposing a shift from "the same strategy for all samples" to "sample-centered GMO testing strategies." An algorithm (GMOtrack) for finding optimal two-phase (screening-identification) testing strategies is proposed. The advantages of cost optimization with increasing GMO presence on the market are demonstrated, showing that optimization approaches to analytic GMO traceability can result in major cost reductions. The optimal testing strategies are laboratory-dependent, as the costs depend on prior probabilities of local GMO presence, which are exemplified on food and feed samples. The proposed GMOtrack approach, publicly available under the terms of the General Public License, can be extended to other domains where complex testing is involved, such as safety and quality assurance in the food supply chain.

  13. GMDD: a database of GMO detection methods

    PubMed Central

    Dong, Wei; Yang, Litao; Shen, Kailin; Kim, Banghyun; Kleter, Gijs A; Marvin, Hans JP; Guo, Rong; Liang, Wanqi; Zhang, Dabing

    2008-01-01

    Background Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. Results GMO Detection method Database (GMDD) has collected almost all the previous developed and reported GMOs detection methods, which have been grouped by different strategies (screen-, gene-, construct-, and event-specific), and also provide a user-friendly search service of the detection methods by GMO event name, exogenous gene, or protein information, etc. In this database, users can obtain the sequences of exogenous integration, which will facilitate PCR primers and probes design. Also the information on endogenous genes, certified reference materials, reference molecules, and the validation status of developed methods is included in this database. Furthermore, registered users can also submit new detection methods and sequences to this database, and the newly submitted information will be released soon after being checked. Conclusion GMDD contains comprehensive information of GMO detection methods. The database will make the GMOs analysis much easier. PMID:18522755

  14. Avoiding genetically modified foods in GMO Ground Zero: A reflective self-narrative.

    PubMed

    Edwards, Sachi

    2015-05-01

    I engage in a reflective self-narrative of my experience attempting to maintain a diet free of genetically modified organisms. Social tension over the genetically modified organism industry in Hawai'i, United States, has led to public debates over jobs and social identities. Drawing on local media sources, grassroots organizations, and blog posts, I describe the way this tension has shaped my experience with food, eating, and being with others as a genetically modified organism avoider. I utilize discursive positioning to make sense of my experiences by locating them within the ongoing public conversations that give structure to the daily lives of Hawai'i's residents.

  15. Non-GMO genetically edited crop plants.

    PubMed

    Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Velasco, Riccardo; Kim, Jin-Soo; Viola, Roberto

    2015-09-01

    Direct delivery of purified Cas9 protein with guide RNA into plant cells, as opposed to plasmid-mediated delivery, displays high efficiency and reduced off-target effects. Following regeneration from edited cells, the ensuing plant is also likely to bypass genetically modified organism (GMO) legislation as the genome editing complex is degraded in the recipient cells.

  16. GMO Reignited in Science but Not in Law: A Flawed Framework Fuels France's Stalemate.

    PubMed

    Robbins, Patricia B

    2014-01-01

    Following a statement released by a multitude of prominent scientists contesting the idea that there is a consensus on the safety of genetically modified organisms ("GMO"), this article addresses the European Union's ("EU") GMO regulatory framework, which has reluctantly permitted France to maintain an illegal ban on. MON8 10 for over a decade now. It notes that while the statement did nothing more than reignite the debate on GMO, much could and should be done to improve the framework to accommodate for the lack of true scientific understanding about the effects of GMO. This article identifies the specific areas of weakness in the EU GMO regulatory framework and recommends specific alterations. It concludes that although France's MON810 ban is illegal under existing law, the country's fears are neither unfounded nor unsupported and that the EU should work to alter its existing legal structure to parallel today's scientific uncertainty regarding GMO safety.

  17. A high-throughput multiplex method adapted for GMO detection.

    PubMed

    Chaouachi, Maher; Chupeau, Gaëlle; Berard, Aurélie; McKhann, Heather; Romaniuk, Marcel; Giancola, Sandra; Laval, Valérie; Bertheau, Yves; Brunel, Dominique

    2008-12-24

    A high-throughput multiplex assay for the detection of genetically modified organisms (GMO) was developed on the basis of the existing SNPlex method designed for SNP genotyping. This SNPlex assay allows the simultaneous detection of up to 48 short DNA sequences (approximately 70 bp; "signature sequences") from taxa endogenous reference genes, from GMO constructions, screening targets, construct-specific, and event-specific targets, and finally from donor organisms. This assay avoids certain shortcomings of multiplex PCR-based methods already in widespread use for GMO detection. The assay demonstrated high specificity and sensitivity. The results suggest that this assay is reliable, flexible, and cost- and time-effective for high-throughput GMO detection.

  18. Consumer Perception of Genetically Modified Organisms and Sources of Information123

    PubMed Central

    Wunderlich, Shahla; Gatto, Kelsey A

    2015-01-01

    Genetically modified organisms (GMOs) have been available for commercial purchase since the 1990s, allowing producers to increase crop yields through bioengineering that creates herbicide-resistant and insect-resistant varieties. However, consumer knowledge about GMOs has not increased at the same rate as the adoption of GMO crops. Consumers worldwide are displaying limited understanding, misconceptions, and even unfamiliarity with GMO food products. Many consumers report that they receive information about GMO food products from the media, Internet, and other news sources. These sources may be less reliable than scientific experts whom consumers trust more to present the facts. Although many in the United States support mandatory GMO labeling (similar to current European standards), consumer awareness of current GMO labeling is low. A distinction must also be made between GMO familiarity and scientific understanding, because those who are more familiar with it tend to be more resistant to bioengineering, whereas those with higher scientific knowledge scores tend to have less negative attitudes toward GMOs. This brings to question the relation between scientific literacy, sources of information, and overall consumer knowledge and perception of GMO foods. PMID:26567205

  19. Development of a qualitative real-time PCR method to detect 19 targets for identification of genetically modified organisms.

    PubMed

    Peng, Cheng; Wang, Pengfei; Xu, Xiaoli; Wang, Xiaofu; Wei, Wei; Chen, Xiaoyun; Xu, Junfeng

    2016-01-01

    As the amount of commercially available genetically modified organisms (GMOs) grows recent years, the diversity of target sequences for molecular detection techniques are eagerly needed. Considered as the gold standard for GMO analysis, the real-time PCR technology was optimized to produce a high-throughput GMO screening method. With this method we can detect 19 transgenic targets. The specificity of the assays was demonstrated to be 100 % by the specific amplification of DNA derived from reference material from 20 genetically modified crops and 4 non modified crops. Furthermore, most assays showed a very sensitive detection, reaching the limit of ten copies. The 19 assays are the most frequently used genetic elements present in GM crops and theoretically enable the screening of the known GMO described in Chinese markets. Easy to use, fast and cost efficient, this method approach fits the purpose of GMO testing laboratories.

  20. Current and new approaches in GMO detection: challenges and solutions.

    PubMed

    Fraiture, Marie-Alice; Herman, Philippe; Taverniers, Isabel; De Loose, Marc; Deforce, Dieter; Roosens, Nancy H

    2015-01-01

    In many countries, genetically modified organisms (GMO) legislations have been established in order to guarantee the traceability of food/feed products on the market and to protect the consumer freedom of choice. Therefore, several GMO detection strategies, mainly based on DNA, have been developed to implement these legislations. Due to its numerous advantages, the quantitative PCR (qPCR) is the method of choice for the enforcement laboratories in GMO routine analysis. However, given the increasing number and diversity of GMO developed and put on the market around the world, some technical hurdles could be encountered with the qPCR technology, mainly owing to its inherent properties. To address these challenges, alternative GMO detection methods have been developed, allowing faster detections of single GM target (e.g., loop-mediated isothermal amplification), simultaneous detections of multiple GM targets (e.g., PCR capillary gel electrophoresis, microarray, and Luminex), more accurate quantification of GM targets (e.g., digital PCR), or characterization of partially known (e.g., DNA walking and Next Generation Sequencing (NGS)) or unknown (e.g., NGS) GMO. The benefits and drawbacks of these methods are discussed in this review.

  1. See what you eat--broad GMO screening with microarrays.

    PubMed

    von Götz, Franz

    2010-03-01

    Despite the controversy of whether genetically modified organisms (GMOs) are beneficial or harmful for humans, animals, and/or ecosystems, the number of cultivated GMOs is increasing every year. Many countries and federations have implemented safety and surveillance systems for GMOs. Potent testing technologies need to be developed and implemented to monitor the increasing number of GMOs. First, these GMO tests need to be comprehensive, i.e., should detect all, or at least the most important, GMOs on the market. This type of GMO screening requires a high degree of parallel tests or multiplexing. To date, DNA microarrays have the highest number of multiplexing capabilities when nucleic acids are analyzed. This trend article focuses on the evolution of DNA microarrays for GMO testing. Over the last 7 years, combinations of multiplex PCR detection and microarray detection have been developed to qualitatively assess the presence of GMOs. One example is the commercially available DualChip GMO (Eppendorf, Germany; http://www.eppendorf-biochip.com), which is the only GMO screening system successfully validated in a multicenter study. With use of innovative amplification techniques, promising steps have recently been taken to make GMO detection with microarrays quantitative.

  2. Current and New Approaches in GMO Detection: Challenges and Solutions

    PubMed Central

    Fraiture, Marie-Alice; Herman, Philippe; Taverniers, Isabel; De Loose, Marc; Deforce, Dieter; Roosens, Nancy H.

    2015-01-01

    In many countries, genetically modified organisms (GMO) legislations have been established in order to guarantee the traceability of food/feed products on the market and to protect the consumer freedom of choice. Therefore, several GMO detection strategies, mainly based on DNA, have been developed to implement these legislations. Due to its numerous advantages, the quantitative PCR (qPCR) is the method of choice for the enforcement laboratories in GMO routine analysis. However, given the increasing number and diversity of GMO developed and put on the market around the world, some technical hurdles could be encountered with the qPCR technology, mainly owing to its inherent properties. To address these challenges, alternative GMO detection methods have been developed, allowing faster detections of single GM target (e.g., loop-mediated isothermal amplification), simultaneous detections of multiple GM targets (e.g., PCR capillary gel electrophoresis, microarray, and Luminex), more accurate quantification of GM targets (e.g., digital PCR), or characterization of partially known (e.g., DNA walking and Next Generation Sequencing (NGS)) or unknown (e.g., NGS) GMO. The benefits and drawbacks of these methods are discussed in this review. PMID:26550567

  3. Uninformed and disinformed society and the GMO market.

    PubMed

    Twardowski, Tomasz; Małyska, Aleksandra

    2015-01-01

    The EU has a complicated regulatory framework, and this is slowing down the approval process of new genetically modified (GM) crops. Currently, labeling of GM organisms (GMOs) is mandatory in all Member States. However, the USA, in which GMO labeling is not mandatory, continues to lead the production of biotech crops, biopharmaceuticals, biomaterials, and bioenergy.

  4. The structuring of GMO release and evaluation in EU law.

    PubMed

    von Kries, Caroline; Winter, Gerd

    2012-04-01

    Genetically modified organisms (GMOs) and their behavior in the environment are complex and can only be assessed if the different components are distinguished. This article examines, how by EU law the real causation processes from the GMO release to various endpoints are dissected, individually analysed and then again viewed in their entirety. In addition, the articles includes, how the intellectual process of assessment is divided into the steps of tiered generation, shared submission and structured evaluation of relevant knowledge. The framework proposed for such an examination allows to identify strengths and weaknesses of GMO risk assessment in the EU.

  5. Determining ecoregions for environmental and GMO monitoring networks.

    PubMed

    Graef, F; Schmidt, G; Schröder, W; Stachow, U

    2005-09-01

    A representative environmental monitoring network at the regional scale cannot use raster-based or random sampling designs, but requires a stratified sampling procedure integrating different information layers, and it has to occur in ecologically differing homogeneous regions (ecoregions). These we have determined using a set of spatial strata with ecological variables which we analysed with classification and regression trees (CART). We present a framework for environmental monitoring, that covers different scales, and we transfer the framework to a potential GMO (genetically modified organisms) monitoring network. We use ecoregion and other environmental strata together with existing environmental monitoring networks to determine GMO monitoring sites more precisely.

  6. Environmental risk assessment in GMO analysis.

    PubMed

    Pirondini, Andrea; Marmiroli, Nelson

    2010-01-01

    Genetically modified or engineered organisms (GMOs, GEOs) are utilised in agriculture, expressing traits of interest, such as insect or herbicide resistance. Soybean, maize, cotton and oilseed rape are the GM crops with the largest acreage in the world. The distribution of GM acreage in the different countries is related with the different positions concerning labelling of GMO products: based on the principle of substantial equivalence, or rather based on the precautionary principle. The paper provides an overview on how the risks associated with release of GMO in the environments can be analysed and predicted, in view of a possible coexistence of GM and non-GM organisms in agriculture.Risk assessment procedures, both qualitative and quantitative, are compared in the context of application to GMOs considering also legislation requirements (Directive 2001/18/EC). Criteria and measurable properties to assess harm for human health and environmental safety are listed, and the possible consequences are evaluated in terms of significance.Finally, a mapping of the possible risks deriving from GMO release is reported, focusing on gene transfer to related species, horizontal gene transfer, direct and indirect effects on non target organisms, development of resistance in target organisms, and effects on biodiversity.

  7. Environmental risk assessment in GMO analysis.

    PubMed

    Pirondini, Andrea; Marmiroli, Nelson

    2008-01-01

    Genetically modified or engineered organisms (GMOs, GEOs) are utilised in agriculture, expressing traits of interest, such as insect or herbicide resistance. Soybean, maize, cotton and oilseed rape are the GM crops with the largest acreage in the world. The distribution of GM acreage in the different countries is related with the different positions concerning labelling of GMO products: based on the principle of substantial equivalence, or rather based on the precautionary principle. The paper provides an overview on how the risks associated with release of GMO in the environments can be analysed and predicted, in view of a possible coexistence of GM and non-GM organisms in agriculture.Risk assessment procedures, both qualitative and quantitative, are compared in the context of application to GMOs considering also legislation requirements (Directive 2001/18/EC). Criteria and measurable properties to assess harm for human health and environmental safety are listed, and the possible consequences are evaluated in terms of significance.Finally, a mapping of the possible risks deriving from GMO release is reported, focusing on gene transfer to related species, horizontal gene transfer, direct and indirect effects on non target organisms, development of resistance in target organisms, and effects on biodiversity.

  8. The development and standardization of testing methods for genetically modified organisms and their derived products.

    PubMed

    Zhang, Dabing; Guo, Jinchao

    2011-07-01

    As the worldwide commercialization of genetically modified organisms (GMOs) increases and consumers concern the safety of GMOs, many countries and regions are issuing labeling regulations on GMOs and their products. Analytical methods and their standardization for GM ingredients in foods and feed are essential for the implementation of labeling regulations. To date, the GMO testing methods are mainly based on the inserted DNA sequences and newly produced proteins in GMOs. This paper presents an overview of GMO testing methods as well as their standardization.

  9. Chinese newspaper coverage of genetically modified organisms

    PubMed Central

    2012-01-01

    Background Debates persist around the world over the development and use of genetically modified organisms (GMO). News media has been shown to both reflect and influence public perceptions of health and science related debates, as well as policy development. To better understand the news coverage of GMOs in China, we analyzed the content of articles in two Chinese newspapers that relate to the development and promotion of genetically modified technologies and GMOs. Methods Searching in the Chinese National Knowledge Infrastructure Core Newspaper Database (CNKI-CND), we collected 77 articles, including news reports, comments and notes, published between January 2002 and August 2011 in two of the major Chinese newspapers: People’s Daily and Guangming Daily. We examined articles for perspectives that were discussed and/or mentioned regarding GMOs, the risks and benefits of GMOs, and the tone of news articles. Results The newspaper articles reported on 29 different kinds of GMOs. Compared with the possible risks, the benefits of GMOs were much more frequently discussed in the articles. 48.1% of articles were largely supportive of the GM technology research and development programs and the adoption of GM cottons, while 51.9% of articles were neutral on the subject of GMOs. Risks associated with GMOs were mentioned in the newspaper articles, but none of the articles expressed negative tones in regards to GMOs. Conclusion This study demonstrates that the Chinese print media is largely supportive of GMOs. It also indicates that the print media describes the Chinese government as actively pursuing national GMO research and development programs and the promotion of GM cotton usage. So far, discussion of the risks associated with GMOs is minimal in the news reports. The media, scientists, and the government should work together to ensure that science communication is accurate and balanced. PMID:22551150

  10. A novel GMO biosensor for rapid ultrasensitive and simultaneous detection of multiple DNA components in GMO products.

    PubMed

    Huang, Lin; Zheng, Lei; Chen, Yinji; Xue, Feng; Cheng, Lin; Adeloju, Samuel B; Chen, Wei

    2015-04-15

    Since the introduction of genetically modified organisms (GMOs), there has been on-going and continuous concern and debates on the commercialization of products derived from GMOs. There is an urgent need for development of highly efficient analytical methods for rapid and high throughput screening of GMOs components, as required for appropriate labeling of GMO-derived foods, as well as for on-site inspection and import/export quarantine. In this study, we describe, for the first time, a multi-labeling based electrochemical biosensor for simultaneous detection of multiple DNA components of GMO products on the same sensing interface. Two-round signal amplification was applied by using both an exonuclease enzyme catalytic reaction and gold nanoparticle-based bio-barcode related strategies, respectively. Simultaneous multiple detections of different DNA components of GMOs were successfully achieved with satisfied sensitivity using this electrochemical biosensor. Furthermore, the robustness and effectiveness of the proposed approach was successfully demonstrated by application to various GMO products, including locally obtained and confirmed commercial GMO seeds and transgenetic plants. The proposed electrochemical biosensor demonstrated unique merits that promise to gain more interest in its use for rapid and on-site simultaneous multiple screening of different components of GMO products.

  11. Off-label prescription of genetically modified organism medicines in europe: emerging conflicts of interest?

    PubMed

    Schagen, Frederik H E; Hoeben, Rob C; Hospers, Geke A P

    2014-10-01

    Recently, the first human medicine containing a genetically modified organism (GMO medicine) was authorized for use in the European market. Just as any medicinal product, the market authorization for a GMO medicine contains a precise description of the therapeutic use for which the medicinal product is intended. Within this use, the application of the GMO medicine is permitted, without the need for the institution to obtain a specific permit. In practice, however, medicinal products are also frequently prescribed for treatment outside the registered therapeutic use, a practice that is referred to as "off-label use." While off-label use of conventional medicines is permitted and has been very useful, the off-label use of GMO medicines is not covered in the European Union (EU) legislation or guidelines and falls under each member state's national environmental legislation. This implies that in the Netherlands and most other EU member states, an environmental permit will be required for any institution that uses the GMO medicine outside the registered application(s). In the Netherlands, this permit is identical to the permits required for the execution of clinical trials involving nonregistered GMOs. The application procedure for such permit is time-consuming. This process can therefore limit the therapeutic options for medical professionals. As a consequence, desired treatment regimens could be withheld for certain patient (groups). To make future off-label use of GMO medicines permissible in a way that is acceptable for all stakeholders, regulators should adopt a proactive attitude and formulate transparent legislative procedures for this. Only then the field can maintain the public acceptance of GMO medicines, while maintaining the freedom to operate of medical professionals.

  12. Molecular toolbox for the identification of unknown genetically modified organisms.

    PubMed

    Ruttink, Tom; Demeyer, Rolinde; Van Gulck, Elke; Van Droogenbroeck, Bart; Querci, Maddalena; Taverniers, Isabel; De Loose, Marc

    2010-03-01

    Competent laboratories monitor genetically modified organisms (GMOs) and products derived thereof in the food and feed chain in the framework of labeling and traceability legislation. In addition, screening is performed to detect the unauthorized presence of GMOs including asynchronously authorized GMOs or GMOs that are not officially registered for commercialization (unknown GMOs). Currently, unauthorized or unknown events are detected by screening blind samples for commonly used transgenic elements, such as p35S or t-nos. If (1) positive detection of such screening elements shows the presence of transgenic material and (2) all known GMOs are tested by event-specific methods but are not detected, then the presence of an unknown GMO is inferred. However, such evidence is indirect because it is based on negative observations and inconclusive because the procedure does not identify the causative event per se. In addition, detection of unknown events is hampered in products that also contain known authorized events. Here, we outline alternative approaches for analytical detection and GMO identification and develop new methods to complement the existing routine screening procedure. We developed a fluorescent anchor-polymerase chain reaction (PCR) method for the identification of the sequences flanking the p35S and t-nos screening elements. Thus, anchor-PCR fingerprinting allows the detection of unique discriminative signals per event. In addition, we established a collection of in silico calculated fingerprints of known events to support interpretation of experimentally generated anchor-PCR GM fingerprints of blind samples. Here, we first describe the molecular characterization of a novel GMO, which expresses recombinant human intrinsic factor in Arabidopsis thaliana. Next, we purposefully treated the novel GMO as a blind sample to simulate how the new methods lead to the molecular identification of a novel unknown event without prior knowledge of its transgene

  13. [The lack of information on genetically modified organisms in Brazil].

    PubMed

    Ribeiro, Isabelle Geoffroy; Marin, Victor Augustus

    2012-02-01

    This article presents a review about the labeling of products that have Genetically Modified Organisms (GMO), also called transgenic elements in their composition. It addresses the conventions, laws and regulations relating to such products currently governing the market, the adequacy of these existing standards and their acceptance by society. It also examines the importance of the cautionary principle when assessing the application of new technologies or technologies where little is known or where there is no relevant scientific knowledge about the potential risks to the environment, human health and society.

  14. Development and validation of a multiplex real-time PCR method to simultaneously detect 47 targets for the identification of genetically modified organisms.

    PubMed

    Cottenet, Geoffrey; Blancpain, Carine; Sonnard, Véronique; Chuah, Poh Fong

    2013-08-01

    Considering the increase of the total cultivated land area dedicated to genetically modified organisms (GMO), the consumers' perception toward GMO and the need to comply with various local GMO legislations, efficient and accurate analytical methods are needed for their detection and identification. Considered as the gold standard for GMO analysis, the real-time polymerase chain reaction (RTi-PCR) technology was optimised to produce a high-throughput GMO screening method. Based on simultaneous 24 multiplex RTi-PCR running on a ready-to-use 384-well plate, this new procedure allows the detection and identification of 47 targets on seven samples in duplicate. To comply with GMO analytical quality requirements, a negative and a positive control were analysed in parallel. In addition, an internal positive control was also included in each reaction well for the detection of potential PCR inhibition. Tested on non-GM materials, on different GM events and on proficiency test samples, the method offered high specificity and sensitivity with an absolute limit of detection between 1 and 16 copies depending on the target. Easy to use, fast and cost efficient, this multiplex approach fits the purpose of GMO testing laboratories.

  15. Production of certified reference materials for the detection of genetically modified organisms.

    PubMed

    Trapmann, Stefanie; Schimmel, Heinz; Kramer, Gerard Nico; Van den Eede, Guy; Pauwels, Jean

    2002-01-01

    Certified reference materials (CRMs) are an essenIial tool in the quality assurance of analytical measurements. They are produced, certified, and used in accordance with relevant ISO (International Organization for Standardization) and BCR (Community Bureau of Reference) guidelines. The Institute for Reference Materials and Measurements (IRMM; Geel, Belgium) has produced the first powdery genetically modified organism (GMO) CRMs in cooperation with the Institute for Health and Consumer Protection (Ispra, Italy). Until now, different weight percentages in the range of 0-5% for 4 GMOs in Europe were produced and certified: Bt (Bacillus thuringiensis)-11 and Bt-176 maize, Roundup Ready soybean, and MON810 maize. Bt-11 and Bt-176 maize and Roundup Ready soybean were produced by IRMM on behalf of Fluka Chemie AG (Buchs, Switzerland). Characterization of used base material is the first step in production and is especially important for GMO CRMs. The production of powdery GMO CRMs and methods used for production control are described. Thorough control of homogeneity and stability are essential for certification of reference materials and ensure validity of the certificate for each bottle of a batch throughout a defined shelf-life. Because production of reference materials and their maintenance are very labor- and cost-intensive tasks, the usefulness of new types of GMO CRMs must be estimated carefully.

  16. New approaches in GMO detection.

    PubMed

    Querci, Maddalena; Van den Bulcke, Marc; Zel, Jana; Van den Eede, Guy; Broll, Hermann

    2010-03-01

    The steady rate of development and diffusion of genetically modified plants and their increasing diversification of characteristics, genes and genetic control elements poses a challenge in analysis of genetically modified organisms (GMOs). It is expected that in the near future the picture will be even more complex. Traditional approaches, mostly based on the sequential detection of one target at a time, or on a limited multiplexing, allowing only a few targets to be analysed at once, no longer meet the testing requirements. Along with new analytical technologies, new approaches for the detection of GMOs authorized for commercial purposes in various countries have been developed that rely on (1) a smart and accurate strategy for target selection, (2) the use of high-throughput systems or platforms for the detection of multiple targets and (3) algorithms that allow the conversion of analytical results into an indication of the presence of individual GMOs potentially present in an unknown sample. This paper reviews the latest progress made in GMO analysis, taking examples from the most recently developed strategies and tools, and addresses some of the critical aspects related to these approaches.

  17. Public health issues related with the consumption of food obtained from genetically modified organisms.

    PubMed

    Paparini, Andrea; Romano-Spica, Vincenzo

    2004-01-01

    Genetically Modified Organisms (GMOs) are a fact of modern agriculture and a major field of discussion in biotechnology. As science incessantly achieves innovative and unexpected breakthroughs, new medical, political, ethical and religious debates arise over the production and consumption of transgenic organisms. Despite no described medical condition being directly associated with a diet including approved GM crops in large exposed populations such as 300,000,000 Americans and a billion Chinese, public opinion seems to look at this new technology with either growing concern or even disapproval. It is generally recognized that a high level of vigilance is necessary and highly desirable, but it should also be considered that GMOs are a promising new challenge for the III Millennium societies, with remarkable impact on many disciplines and fields related to biotechnology. To acquire a basic knowledge on GMO production, GM-food consumption, GMO interaction with humans and environment is of primary importance for risk assessment. It requires availability of clear data and results from rigorous experiments. This review will focus on public health risks related with a GMO-containing diet. The objective is to summarize state of the art research, provide fundamental technical information, point out problems and perspectives, and make available essential tools for further research. Are GMO based industries and GMO-derived foods safe to human health? Can we consider both social, ethical and public health issues by means of a constant and effective monitoring of the food chain and by a clear, informative labeling of the products? Which are the so far characterized or alleged hazards of GMOs? And, most importantly, are these hazards actual, potential or merely contrived? Several questions remain open; answers and solutions belong to science, to politics and to the personal opinion of each social subject.

  18. Detection of nonauthorized genetically modified organisms using differential quantitative polymerase chain reaction: application to 35S in maize.

    PubMed

    Cankar, Katarina; Chauvensy-Ancel, Valérie; Fortabat, Marie-Noelle; Gruden, Kristina; Kobilinsky, André; Zel, Jana; Bertheau, Yves

    2008-05-15

    Detection of nonauthorized genetically modified organisms (GMOs) has always presented an analytical challenge because the complete sequence data needed to detect them are generally unavailable although sequence similarity to known GMOs can be expected. A new approach, differential quantitative polymerase chain reaction (PCR), for detection of nonauthorized GMOs is presented here. This method is based on the presence of several common elements (e.g., promoter, genes of interest) in different GMOs. A statistical model was developed to study the difference between the number of molecules of such a common sequence and the number of molecules identifying the approved GMO (as determined by border-fragment-based PCR) and the donor organism of the common sequence. When this difference differs statistically from zero, the presence of a nonauthorized GMO can be inferred. The interest and scope of such an approach were tested on a case study of different proportions of genetically modified maize events, with the P35S promoter as the Cauliflower Mosaic Virus common sequence. The presence of a nonauthorized GMO was successfully detected in the mixtures analyzed and in the presence of (donor organism of P35S promoter). This method could be easily transposed to other common GMO sequences and other species and is applicable to other detection areas such as microbiology.

  19. Relative quantification in seed GMO analysis: state of art and bottlenecks.

    PubMed

    Chaouachi, Maher; Bérard, Aurélie; Saïd, Khaled

    2013-06-01

    Reliable quantitative methods are needed to comply with current EU regulations on the mandatory labeling of genetically modified organisms (GMOs) and GMO-derived food and feed products with a minimum GMO content of 0.9 %. The implementation of EU Commission Recommendation 2004/787/EC on technical guidance for sampling and detection which meant as a helpful tool for the practical implementation of EC Regulation 1830/2003, which states that "the results of quantitative analysis should be expressed as the number of target DNA sequences per target taxon specific sequences calculated in terms of haploid genomes". This has led to an intense debate on the type of calibrator best suitable for GMO quantification. The main question addressed in this review is whether reference materials and calibrators should be matrix based or whether pure DNA analytes should be used for relative quantification in GMO analysis. The state of the art, including the advantages and drawbacks, of using DNA plasmid (compared to genomic DNA reference materials) as calibrators, is widely described. In addition, the influence of the genetic structure of seeds on real-time PCR quantitative results obtained for seed lots is discussed. The specific composition of a seed kernel, the mode of inheritance, and the ploidy level ensure that there is discordance between a GMO % expressed as a haploid genome equivalent and a GMO % based on numbers of seeds. This means that a threshold fixed as a percentage of seeds cannot be used as such for RT-PCR. All critical points that affect the expression of the GMO content in seeds are discussed in this paper.

  20. GMO Detection

    NASA Astrophysics Data System (ADS)

    Ovesná, Jaroslava; Demnerová, Kateřina; Pouchová, Vladimíra

    Modern agriculture and the food industry are under constant pressure to produce healthier, tastier and cheaper food, while at the same time maintaining and improving safety standards. Consequently, these industries are all the time demanding still better, more efficient genotypes of crop species and farm animals suited to a wide range of usages. Farmers, in particular, are calling for species that are more resistant to disease, that have improved adaptation to stress, and that facilitate simpler farming systems while also increasing yield and productivity. At the same time, scientists believe that such animal and crop varieties could provide a source of food for poor countries and, thereby, help to prevent, and ultimately eliminate, third-world malnutrition (Biotechnology Industry Organization, 2008; Monastra & Rossi, 2003; Herdt, 2006).

  1. Environmental risk assessment for medicinal products containing genetically modified organisms.

    PubMed

    Anliker, B; Longhurst, S; Buchholz, C J

    2010-01-01

    Many gene therapy medicinal products and also some vaccines consist of, or contain, genetically modified organisms (GMOs), which require specific consideration in the environmental risk assessment (ERA) before marketing authorisation or clinical trial applications. The ERA is performed in order to identify the potential risks for public health and the environment, which may arise due to the clinical use of these medicinal products. If such environmental risks are identified and considered as not acceptable, the ERA should go on to propose appropriate risk management strategies capable to reduce these risks. This article will provide an overview of the legal basis and requirements for the ERA of GMO-containing medicinal products in the context of marketing authorisation in the EU and clinical trials in Germany. Furthermore, the scientific principles and methodology that generally need to be followed when preparing an ERA for GMOs are discussed.

  2. DNA enrichment approaches to identify unauthorized genetically modified organisms (GMOs).

    PubMed

    Arulandhu, Alfred J; van Dijk, Jeroen P; Dobnik, David; Holst-Jensen, Arne; Shi, Jianxin; Zel, Jana; Kok, Esther J

    2016-07-01

    With the increased global production of different genetically modified (GM) plant varieties, chances increase that unauthorized GM organisms (UGMOs) may enter the food chain. At the same time, the detection of UGMOs is a challenging task because of the limited sequence information that will generally be available. PCR-based methods are available to detect and quantify known UGMOs in specific cases. If this approach is not feasible, DNA enrichment of the unknown adjacent sequences of known GMO elements is one way to detect the presence of UGMOs in a food or feed product. These enrichment approaches are also known as chromosome walking or gene walking (GW). In recent years, enrichment approaches have been coupled with next generation sequencing (NGS) analysis and implemented in, amongst others, the medical and microbiological fields. The present review will provide an overview of these approaches and an evaluation of their applicability in the identification of UGMOs in complex food or feed samples.

  3. First application of a microsphere-based immunoassay to the detection of genetically modified organisms (GMOs): quantification of Cry1Ab protein in genetically modified maize.

    PubMed

    Fantozzi, Anna; Ermolli, Monica; Marini, Massimiliano; Scotti, Domenico; Balla, Branko; Querci, Maddalena; Langrell, Stephen R H; Van den Eede, Guy

    2007-02-21

    An innovative covalent microsphere immunoassay, based on the usage of fluorescent beads coupled to a specific antibody, was developed for the quantification of the endotoxin Cry1Ab present in MON810 and Bt11 genetically modified (GM) maize lines. In particular, a specific protocol was developed to assess the presence of Cry1Ab in a very broad range of GM maize concentrations, from 0.1 to 100% [weight of genetically modified organism (GMO)/weight]. Test linearity was achieved in the range of values from 0.1 to 3%, whereas fluorescence signal increased following a nonlinear model, reaching a plateau at 25%. The limits of detection and quantification were equal to 0.018 and 0.054%, respectively. The present study describes the first application of quantitative high-throughput immunoassays in GMO analysis.

  4. Suggestions for the assessment of the allergenic potential of genetically modified organisms.

    PubMed

    Spök, Armin; Gaugitsch, Helmut; Laffer, Sylvia; Pauli, Gabrielle; Saito, Hirohisa; Sampson, Hugh; Sibanda, Elopy; Thomas, Wayne; van Hage, Marianne; Valenta, Rudolf

    2005-06-01

    The prevalence of allergic diseases has been increasing continuously and, accordingly, there is a great desire to evaluate the allergenic potential of components in our daily environment (e.g., food). Although there is almost no scientific evidence that genetically modified organisms (GMOs) exhibit increased allergenicity compared with the corresponding wild type significant concerns have been raised regarding this matter. In principle, it is possible that the allergenic potential of GMOs may be increased due to the introduction of potential foreign allergens, to potentially upregulated expression of allergenic components caused by the modification of the wild type organism or to different means of exposure. According to the current practice, the proteins to be introduced into a GMO are evaluated for their physiochemical properties, sequence homology with known allergens and occasionally regarding their allergenic activity. We discuss why these current rules and procedures cannot predict or exclude the allergenicity of a given GMO with certainty. As an alternative we suggest to improve the current evaluation by an experimental comparison of the wild-type organism with the whole GMO regarding their potential to elicit reactions in allergic individuals and to induce de novo sensitizations. We also recommend that the suggested assessment procedures be equally applied to GMOs as well as to natural cultivars in order to establish effective measures for allergy prevention.

  5. Distortion of genetically modified organism quantification in processed foods: influence of particle size compositions and heat-induced DNA degradation.

    PubMed

    Moreano, Francisco; Busch, Ulrich; Engel, Karl-Heinz

    2005-12-28

    Milling fractions from conventional and transgenic corn were prepared at laboratory scale and used to study the influence of sample composition and heat-induced DNA degradation on the relative quantification of genetically modified organisms (GMO) in food products. Particle size distributions of the obtained fractions (coarse grits, regular grits, meal, and flour) were characterized using a laser diffraction system. The application of two DNA isolation protocols revealed a strong correlation between the degree of comminution of the milling fractions and the DNA yield in the extracts. Mixtures of milling fractions from conventional and transgenic material (1%) were prepared and analyzed via real-time polymerase chain reaction. Accurate quantification of the adjusted GMO content was only possible in mixtures containing conventional and transgenic material in the form of analogous milling fractions, whereas mixtures of fractions exhibiting different particle size distributions delivered significantly over- and underestimated GMO contents depending on their compositions. The process of heat-induced nucleic acid degradation was followed by applying two established quantitative assays showing differences between the lengths of the recombinant and reference target sequences (A, deltal(A) = -25 bp; B, deltal(B) = +16 bp; values related to the amplicon length of the reference gene). Data obtained by the application of method A resulted in underestimated recoveries of GMO contents in the samples of heat-treated products, reflecting the favored degradation of the longer target sequence used for the detection of the transgene. In contrast, data yielded by the application of method B resulted in increasingly overestimated recoveries of GMO contents. The results show how commonly used food technological processes may lead to distortions in the results of quantitative GMO analyses.

  6. NAIMA as a solution for future GMO diagnostics challenges.

    PubMed

    Dobnik, David; Morisset, Dany; Gruden, Kristina

    2010-03-01

    In the field of genetically modified organism (GMO) diagnostics, real-time PCR has been the method of choice for target detection and quantification in most laboratories. Despite its numerous advantages, however, the lack of a true multiplexing option may render real-time PCR less practical in the face of future GMO detection challenges such as the multiplicity and increasing complexity of new transgenic events, as well as the repeated occurrence of unauthorized GMOs on the market. In this context, we recently reported the development of a novel multiplex quantitative DNA-based target amplification method, named NASBA implemented microarray analysis (NAIMA), which is suitable for sensitive, specific and quantitative detection of GMOs on a microarray. In this article, the performance of NAIMA is compared with that of real-time PCR, the focus being their performances in view of the upcoming challenge to detect/quantify an increasing number of possible GMOs at a sustainable cost and affordable staff effort. Finally, we present our conclusions concerning the applicability of NAIMA for future use in GMO diagnostics.

  7. Controversy over genetically modified organisms: the governing laws and regulations.

    PubMed

    Keatley, K L

    2000-01-01

    Genetically Modified Organisms (GMOs) are increasingly becoming a topic of controversy in the U.S. and abroad. The public is questioning their safety and wanting the products labeled as genetically modified. There are other concerns from some of the scientific world and some government officials and organizations such as the Food & Agricultural Organization (FAO) that question whether adequate research has been done to qualify GMOs as safe for long-term use. Of particular concern are the allergenic properties, a GMO may impart, possible transfer effects of antibiotic resistance (given that antibiotic resistant marker genes are used for many GMOs), the expression of previously unexpressed traits, and the drift of pollen from genetically modified crops. It has also been noted that the laws and regulations governing the biotechnology world are outdated, are not comprehensive, and span too many agencies. The primary agencies currently regulating biotechnology are the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA).

  8. Microchip capillary gel electrophoresis using programmed field strength gradients for the ultra-fast analysis of genetically modified organisms in soybeans.

    PubMed

    Kim, Yun-Jeong; Chae, Joon-Seok; Chang, Jun Keun; Kang, Seong Ho

    2005-08-12

    We have developed a novel method for the ultra-fast analysis of genetically modified organisms (GMOs) in soybeans by microchip capillary gel electrophoresis (MCGE) using programmed field strength gradients (PFSG) in a conventional glass double-T microchip. Under the programmed electric field strength and 0.3% poly(ethylene oxide) sieving matrix, the GMO in soybeans was analyzed within only 11 s of the microchip. The MCGE-PFSG method was a program that changes the electric field strength during GMO analysis, and was also applied to the ultra-fast analysis of PCR products. Compared to MCGE using a conventional and constantly applied electric field, the MCGE-PFSG analysis generated faster results without the loss of resolving power and reproducibility for specific DNA fragments (100- and 250-bp DNA) of GM-soybeans. The MCGE-PFSG technique may prove to be a new tool in the GMO analysis due to its speed, simplicity, and high efficiency.

  9. A temperature-tolerant multiplex elements and genes screening system for genetically modified organisms based on dual priming oligonucleotide primers and capillary electrophoresis.

    PubMed

    Fu, Wei; Wei, Shuang; Wang, Chenguang; Du, Zhixin; Zhu, Pengyu; Wu, Xiyang; Wu, Gang; Zhu, Shuifang

    2017-08-15

    High throughput screening systems are the preferred solution to meet the urgent requirement of increasing number of genetically modified organisms (GMOs). In this study, we have successfully developed a multiplex GMO element screening system with dual priming oligonucleotide (DPO) primers. This system can detect the cauliflower mosaic virus 35S (CaMV 35S), terminator of nopaline synthase gene (NOS), figwort mosaic virus 35S (FMV 35S) promoter, neomycin phosphotransferaseII (NPTII), Bt Cry 1Ab, phosphinothricin acetyltransferase genes (bar) and Streptomyces viridochromogenes (pat) simultaneously, which covers more than 90% of all authorized GMO species worldwide. This system exhibits a high tolerance to annealing temperatures, high specificity and a limit of detection equal to conventional PCR. A total of 214 samples from markets, national entry-exit agencies, the Institute for Reference Materials and Measurement (IRMM) and the American Oil Chemists' Society (AOCS) were also tested for applicability. This screening system is therefore suitable for GMO screening.

  10. Practical experiences with an extended screening strategy for genetically modified organisms (GMOs) in real-life samples.

    PubMed

    Scholtens, Ingrid; Laurensse, Emile; Molenaar, Bonnie; Zaaijer, Stephanie; Gaballo, Heidi; Boleij, Peter; Bak, Arno; Kok, Esther

    2013-09-25

    Nowadays most animal feed products imported into Europe have a GMO (genetically modified organism) label. This means that they contain European Union (EU)-authorized GMOs. For enforcement of these labeling requirements, it is necessary, with the rising number of EU-authorized GMOs, to perform an increasing number of analyses. In addition to this, it is necessary to test products for the potential presence of EU-unauthorized GMOs. Analysis for EU-authorized and -unauthorized GMOs in animal feed has thus become laborious and expensive. Initial screening steps may reduce the number of GMO identification methods that need to be applied, but with the increasing diversity also screening with GMO elements has become more complex. For the present study, the application of an informative detailed 24-element screening and subsequent identification strategy was applied in 50 animal feed samples. Almost all feed samples were labeled as containing GMO-derived materials. The main goal of the study was therefore to investigate if a detailed screening strategy would reduce the number of subsequent identification analyses. An additional goal was to test the samples in this way for the potential presence of EU-unauthorized GMOs. Finally, to test the robustness of the approach, eight of the samples were tested in a concise interlaboratory study. No significant differences were found between the results of the two laboratories.

  11. Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR.

    PubMed

    Kodama, Takashi; Kurosawa, Yasunori; Kitta, Kazumi; Naito, Shigehiro

    2010-01-01

    The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount (%) was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount (%) are functions only of concentration similar to the Horwitz curve. We proposed S(R) = 0.1971C 0.8685 and S(r) = 0.1478C 0.8424, where C is the GMO amount (%). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.

  12. New multiplex PCR methods for rapid screening of genetically modified organisms in foods.

    PubMed

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products.

  13. New multiplex PCR methods for rapid screening of genetically modified organisms in foods

    PubMed Central

    Datukishvili, Nelly; Kutateladze, Tamara; Gabriadze, Inga; Bitskinashvili, Kakha; Vishnepolsky, Boris

    2015-01-01

    We present novel multiplex PCR methods for rapid and reliable screening of genetically modified organisms (GMOs). New designed PCR primers targeting four frequently used GMO specific sequences permitted identification of new DNA markers, in particular 141 bp fragment of cauliflower mosaic virus (CaMV) 35S promoter, 224 bp fragment of Agrobacterium tumefaciens nopaline synthase (NOS) terminator, 256 bp fragment of 5-enolppyruvylshikimate-phosphate synthase (epsps) gene and 258 bp fragment of Cry1Ab delta-endotoxin (cry1Ab) gene for GMO screening. The certified reference materials containing Roundup Ready soybean (RRS) and maize MON 810 were applied for the development and optimization of uniplex and multiplex PCR systems. Evaluation of amplification products by agarose gel electrophoresis using negative and positive controls confirmed high specificity and sensitivity at 0.1% GMO for both RRS and MON 810. The fourplex PCR was developed and optimized that allows simultaneous detection of three common transgenic elements, such as: CaMV 35S promoter, NOS terminator, epsps gene together with soybean-specific lectin gene. The triplex PCR developed enables simultaneous identification of transgenic elements, such as: 35S promoter and cry1Ab gene together with maize zein gene. The analysis of different processed foods demonstrated that multiplex PCR methods developed in this study are useful for accurate and fast screening of GM food products. PMID:26257724

  14. Optimization of digital droplet polymerase chain reaction for quantification of genetically modified organisms.

    PubMed

    Gerdes, Lars; Iwobi, Azuka; Busch, Ulrich; Pecoraro, Sven

    2016-03-01

    Digital PCR in droplets (ddPCR) is an emerging method for more and more applications in DNA (and RNA) analysis. Special requirements when establishing ddPCR for analysis of genetically modified organisms (GMO) in a laboratory include the choice between validated official qPCR methods and the optimization of these assays for a ddPCR format. Differentiation between droplets with positive reaction and negative droplets, that is setting of an appropriate threshold, can be crucial for a correct measurement. This holds true in particular when independent transgene and plant-specific reference gene copy numbers have to be combined to determine the content of GM material in a sample. Droplets which show fluorescent units ranging between those of explicit positive and negative droplets are called 'rain'. Signals of such droplets can hinder analysis and the correct setting of a threshold. In this manuscript, a computer-based algorithm has been carefully designed to evaluate assay performance and facilitate objective criteria for assay optimization. Optimized assays in return minimize the impact of rain on ddPCR analysis. We developed an Excel based 'experience matrix' that reflects the assay parameters of GMO ddPCR tests performed in our laboratory. Parameters considered include singleplex/duplex ddPCR, assay volume, thermal cycler, probe manufacturer, oligonucleotide concentration, annealing/elongation temperature, and a droplet separation evaluation. We additionally propose an objective droplet separation value which is based on both absolute fluorescence signal distance of positive and negative droplet populations and the variation within these droplet populations. The proposed performance classification in the experience matrix can be used for a rating of different assays for the same GMO target, thus enabling employment of the best suited assay parameters. Main optimization parameters include annealing/extension temperature and oligonucleotide concentrations. The

  15. Nanoparticle-based DNA biosensor for visual detection of genetically modified organisms.

    PubMed

    Kalogianni, Despina P; Koraki, Theodora; Christopoulos, Theodore K; Ioannou, Penelope C

    2006-01-15

    Although screening of raw ingredients and food products for genetically modified organisms (GMO) may be accomplished by detecting either the exogenous DNA or the novel protein, DNA is the preferred analyte because of its superior stability during food processing. The development of DNA biosensors is of increasing importance due to the growing demand for rapid and reliable methods for GMO detection. We report the first DNA biosensor in a dry-reagent dipstick configuration for visual detection and confirmation of GMO-related sequences by hybridization within minutes. The sensor is disposable and does not require special instrumentation. It detects the 35S promoter and nopaline synthase (NOS) terminator sequences that are present in the majority of transgenic plants. The target sequences are amplified by the polymerase chain reaction (PCR) and hybridized (7min) with probes bearing oligo(dA) tail. The biotinylated product is applied to the sensor followed by immersion in the appropriate buffer. Migration of the buffer rehydrates gold nanoparticles conjugated to oligo(dT), which hybridize with the oligo(dA) tails. The hybrids are captured by immobilized streptavidin at the test zone of the sensor giving a characteristic red line due to the accumulation of the nanoparticles. The excess of nanoparticle conjugates are captured at the control zone by immobilized oligo(dA) strands. Amplified 35S or NOS DNA is detectable at 0.16nM. Soybean powder certified reference material with 0.1% GMO content is clearly detectable after 35 and 40 amplification cycles for 35S and NOS sequence, respectively. The sensor was also applied to real samples from various sources.

  16. A high-throughput liquid bead array-based screening technology for Bt presence in GMO manipulation.

    PubMed

    Fu, Wei; Wang, Huiyu; Wang, Chenguang; Mei, Lin; Lin, Xiangmei; Han, Xueqing; Zhu, Shuifang

    2016-03-15

    The number of species and planting areas of genetically modified organisms (GMOs) has been rapidly developed during the past ten years. For the purpose of GMO inspection, quarantine and manipulation, we have now devised a high-throughput Bt-based GMOs screening method based on the liquid bead array. This novel method is based on the direct competitive recognition between biotinylated antibodies and beads-coupled antigens, searching for Bt presence in samples if it contains Bt Cry1 Aa, Bt Cry1 Ab, Bt Cry1 Ac, Bt Cry1 Ah, Bt Cry1 B, Bt Cry1 C, Bt Cry1 F, Bt Cry2 A, Bt Cry3 or Bt Cry9 C. Our method has a wide GMO species coverage so that more than 90% of the whole commercialized GMO species can be identified throughout the world. Under our optimization, specificity, sensitivity, repeatability and availability validation, the method shows a high specificity and 10-50 ng/mL sensitivity of quantification. We then assessed more than 1800 samples in the field and food market to prove capacity of our method in performing a high throughput screening work for GMO manipulation. Our method offers an applicant platform for further inspection and research on GMO plants.

  17. [Detection of genetically modified organisms obtained from food samples ].

    PubMed

    Monma, Kimio; Araki, Rie; Ichikawa, Hisatsugu; Sato, Masaki; Uno, Naomichi; Sato, Kazue; Tobe, Takashi; Kuribara, Hideo; Matsuoka, Takeshi; Hino, Akihiro; Saito, Kazuo

    2004-08-01

    Genetially modified organisms (GMOs) were explored in food samples obtained from November 2000 to March 2003 in the Tokyo area by using PCR and real-time PCR techniques. The existence of Roundup Ready Soybean (RRS) was surveyed in processed foods derived from soybeans, such as tofu, boiled soybean, kinako, nama-age, abura-age, natto, miso, soymilk and yuba. RRS was detected in 3 of 37 tofu, 2 of 3 nama-age, 2 of 3 yuba and 3 of 3 abura-age samples. The CBH351 in 70 processed corn foods, NewLeaf Plus and NewLeaf Y in 50 processed potato foods, and 55-1 papaya in 16 papayas were surveyed. These GMOs were not detected among the samples. Qualitative and quantitative analyses of RRS and genetically modified (GM) corn were performed in soybean, corn and semi-processed corn products such as corn meal, corn flour and corn grits. RRS was detected in 42 of 178 soybean samples, and the amount of RRS in RRS-positive samples was determined. The content was in the range of 0.1-1.4% in identity-preserved soybeans (non-GMO), and 49.8-78.8% in non-segregated soybeans. On the other hand, GM corns were detected in 8 of 26 samples. The amount of GM corn in GM corn-positive samples was in the range of 0.1-2.0%.

  18. The politics and science behind GMO acceptance.

    PubMed

    Varzakas, Theodoros H; Arvanitoyannis, Ioannis S; Baltas, Haralambos

    2007-01-01

    The question of nutritional quality has arisen in the International Community over the last few years along with other important issues such as population aging, multipopulation societies, and political conflicts. The nutritional issue is questioned both quantitatively and qualitatively. It is well known that the planet faces enormous problems with food that is available. Nowadays 20% of the population consumes approximately 80% of the produced energy and natural resources. During the last 15 years, a series of food scares and crises (BSE, dioxin, foot and mouth disease, bird flu) have seriously undermined public confidence in food producers and operators and their capacity to produce safe food. As a result, food safety has become a top priority of the European legislative authorities. Genetically Modified Organisms (GMOs) is the new food safety concern which despite the intense reactions from Non Governmental Organizations and consumer organizations have entered our lives with inadequate legislative measures to protect consumers from their consumption. The GMO issue will be the issue for discussion in the long run not only for the European Community but also for the international community as far as scientific, economical, political, ideological, ethical, and human issues are concerned. These issues are discussed in this paper along with a case of study of GM fish.

  19. Development of a qualitative, multiplex real-time PCR kit for screening of genetically modified organisms (GMOs).

    PubMed

    Dörries, Hans-Henno; Remus, Ivonne; Grönewald, Astrid; Grönewald, Cordt; Berghof-Jäger, Kornelia

    2010-03-01

    The number of commercially available genetically modified organisms (GMOs) and therefore the diversity of possible target sequences for molecular detection techniques are constantly increasing. As a result, GMO laboratories and the food production industry currently are forced to apply many different methods to reliably test raw material and complex processed food products. Screening methods have become more and more relevant to minimize the analytical effort and to make a preselection for further analysis (e.g., specific identification or quantification of the GMO). A multiplex real-time PCR kit was developed to detect the 35S promoter of the cauliflower mosaic virus, the terminator of the nopaline synthase gene of Agrobacterium tumefaciens, the 35S promoter from the figwort mosaic virus, and the bar gene of the soil bacterium Streptomyces hygroscopicus as the most widely used sequences in GMOs. The kit contains a second assay for the detection of plant-derived DNA to control the quality of the often processed and refined sample material. Additionally, the plant-specific assay comprises a homologous internal amplification control for inhibition control. The determined limits of detection for the five assays were 10 target copies/reaction. No amplification products were observed with DNAs of 26 bacterial species, 25 yeasts, 13 molds, and 41 not genetically modified plants. The specificity of the assays was further demonstrated to be 100% by the specific amplification of DNA derived from reference material from 22 genetically modified crops. The applicability of the kit in routine laboratory use was verified by testing of 50 spiked and unspiked food products. The herein described kit represents a simple and sensitive GMO screening method for the reliable detection of multiple GMO-specific target sequences in a multiplex real-time PCR reaction.

  20. Development and validation of duplex, triplex, and pentaplex real-time PCR screening assays for the detection of genetically modified organisms in food and feed.

    PubMed

    Huber, Ingrid; Block, Annette; Sebah, Daniela; Debode, Frédéric; Morisset, Dany; Grohmann, Lutz; Berben, Gilbert; Stebih, Dejan; Milavec, Mojca; Zel, Jana; Busch, Ulrich

    2013-10-30

    Worldwide, qualitative methods based on PCR are most commonly used as screening tools for genetically modified material in food and feed. However, the increasing number and diversity of genetically modified organisms (GMO) require effective methods for simultaneously detecting several genetic elements marking the presence of transgenic events. Herein we describe the development and validation of a pentaplex, as well as complementary triplex and duplex real-time PCR assays, for the detection of the most common screening elements found in commercialized GMOs: P-35S, T-nos, ctp2-cp4-epsps, bar, and pat. The use of these screening assays allows the coverage of many GMO events globally approved for commercialization. Each multiplex real-time PCR assay shows high specificity and sensitivity with an absolute limit of detection below 20 copies for the targeted sequences. We demonstrate by intra- and interlaboratory tests that the assays are robust as well as cost- and time-effective for GMO screening if applied in routine GMO analysis.

  1. PCR-free quantitative detection of genetically modified organism from raw materials. An electrochemiluminescence-based bio bar code method.

    PubMed

    Zhu, Debin; Tang, Yabing; Xing, Da; Chen, Wei R

    2008-05-15

    A bio bar code assay based on oligonucleotide-modified gold nanoparticles (Au-NPs) provides a PCR-free method for quantitative detection of nucleic acid targets. However, the current bio bar code assay requires lengthy experimental procedures including the preparation and release of bar code DNA probes from the target-nanoparticle complex and immobilization and hybridization of the probes for quantification. Herein, we report a novel PCR-free electrochemiluminescence (ECL)-based bio bar code assay for the quantitative detection of genetically modified organism (GMO) from raw materials. It consists of tris-(2,2'-bipyridyl) ruthenium (TBR)-labeled bar code DNA, nucleic acid hybridization using Au-NPs and biotin-labeled probes, and selective capture of the hybridization complex by streptavidin-coated paramagnetic beads. The detection of target DNA is realized by direct measurement of ECL emission of TBR. It can quantitatively detect target nucleic acids with high speed and sensitivity. This method can be used to quantitatively detect GMO fragments from real GMO products.

  2. Analysis of genetically modified organisms by pyrosequencing on a portable photodiode-based bioluminescence sequencer.

    PubMed

    Song, Qinxin; Wei, Guijiang; Zhou, Guohua

    2014-07-01

    A portable bioluminescence analyser for detecting the DNA sequence of genetically modified organisms (GMOs) was developed by using a photodiode (PD) array. Pyrosequencing on eight genes (zSSIIb, Bt11 and Bt176 gene of genetically modified maize; Lectin, 35S-CTP4, CP4EPSPS, CaMV35S promoter and NOS terminator of the genetically modified Roundup ready soya) was successfully detected with this instrument. The corresponding limit of detection (LOD) was 0.01% with 35 PCR cycles. The maize and soya available from three different provenances in China were detected. The results indicate that pyrosequencing using the small size of the detector is a simple, inexpensive, and reliable way in a farm/field test of GMO analysis.

  3. Detection methods and performance criteria for genetically modified organisms.

    PubMed

    Bertheau, Yves; Diolez, Annick; Kobilinsky, André; Magin, Kimberly

    2002-01-01

    Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness. Performance criteria should provide objective tools to accept or reject specific methods, to validate them, to ensure compatibility between validated methods, and be used on a routine basis to reject data outside an acceptable range of variability. When selecting a method of detection, it is also important to consider its applicability, its field of applications, and its limitations, by including factors such as its ability to detect the target analyte in a given matrix, the duration of the analyses, its cost effectiveness, and the necessary sample sizes for testing. Thus, the current GMO detection methods should be evaluated against a common set of performance criteria.

  4. Rationalizing the GMO Debate: The Ordonomic Approach to Addressing Agricultural Myths

    PubMed Central

    Hielscher, Stefan; Pies, Ingo; Valentinov, Vladislav; Chatalova, Lioudmila

    2016-01-01

    The public discourse on the acceptability of genetically modified organisms (GMOs) is not only controversial, but also infused with highly emotional and moralizing rhetoric. Although the assessment of risks and benefits of GMOs must be a scientific exercise, many debates on this issue seem to remain impervious to scientific evidence. In many cases, the moral psychology attributes of the general public create incentives for both GMO opponents and proponents to pursue misleading public campaigns, which impede the comprehensive assessment of the full spectrum of the risks and benefits of GMOs. The ordonomic approach to economic ethics introduced in this research note is helpful for disentangling the socio-economic and moral components of the GMO debate by re- and deconstructing moral claims. PMID:27171102

  5. Rationalizing the GMO Debate: The Ordonomic Approach to Addressing Agricultural Myths.

    PubMed

    Hielscher, Stefan; Pies, Ingo; Valentinov, Vladislav; Chatalova, Lioudmila

    2016-05-09

    The public discourse on the acceptability of genetically modified organisms (GMOs) is not only controversial, but also infused with highly emotional and moralizing rhetoric. Although the assessment of risks and benefits of GMOs must be a scientific exercise, many debates on this issue seem to remain impervious to scientific evidence. In many cases, the moral psychology attributes of the general public create incentives for both GMO opponents and proponents to pursue misleading public campaigns, which impede the comprehensive assessment of the full spectrum of the risks and benefits of GMOs. The ordonomic approach to economic ethics introduced in this research note is helpful for disentangling the socio-economic and moral components of the GMO debate by re- and deconstructing moral claims.

  6. Genetically modified and wild soybeans: an immunologic comparison.

    PubMed

    Yum, Hye-Yung; Lee, Soo-Young; Lee, Kyung-Eun; Sohn, Myung-Hyun; Kim, Kyu-Earn

    2005-01-01

    Most traits introduced into genetically engineered crops result from the expression of new proteins. As the first step toward assessing the allergenic potential of genetically modified organism (GMO) food, immunologic and physicochemical characterizations are needed. We prepared crude extract from GMO soybeans, wild soybeans, curd, and soy milk and then performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). After acidification with HCl, the samples were separated to globulin and whey. To evaluate changes in protein composition, either the samples were heated or pepsin was added. Polymerase chain reaction with primer encoding the 35S-promotor and the 3-enol-pyruvyl-shikimat-5-phosphat-synthase gene were performed, respectively, to detect the GMO component. SDS-PAGE results showed definite protein bands at 80 kDa in GMO soybean, 50 kDa in wild soybean, and a similar distribution of protein bands was noticed below 40 kDa. It was difficult to observe protein distribution because of modifications that occurred during processing in soybean-processed products. After heating, proteins of GMO and wild soybeans showed similar distributions and no distinct bands were detected at 50 and 80 kDa. Although SDS-PAGE analyses of raw GMO and wild soybeans differed, the same protein bands of 68, 37, and 20 kDa were observed in the globulin fraction after acidification. After adding pepsin, 20- and 68-kDa bands were found preserved in GMO and wild soybeans. The polymerase chain reaction procedures with primers specific to GMO soybeans showed that GMO soybeans and some curd samples included a GMO component. The skin test results of 49 patients showed 13 positive results to wild soybeans and 8 positive results to GMO soybeans. One patient had a positive skin test result to GMO soybeans only. Sera from nine patients with positive skin tests to the crude extract and a positive capsulated allergen product test to the soybean antigen were used for the immunoblotting

  7. Can Systematic Reviews Inform GMO Risk Assessment and Risk Management?

    PubMed Central

    Kohl, Christian; Frampton, Geoff; Sweet, Jeremy; Spök, Armin; Haddaway, Neal Robert; Wilhelm, Ralf; Unger, Stefan; Schiemann, Joachim

    2015-01-01

    Systematic reviews represent powerful tools to identify, collect, synthesize, and evaluate primary research data on specific research questions in a highly standardized and reproducible manner. They enable the defensible synthesis of outcomes by increasing precision and minimizing bias whilst ensuring transparency of the methods used. This makes them especially valuable to inform evidence-based risk analysis and decision making in various topics and research disciplines. Although seen as a “gold standard” for synthesizing primary research data, systematic reviews are not without limitations as they are often cost, labor and time intensive and the utility of synthesis outcomes depends upon the availability of sufficient and robust primary research data. In this paper, we (1) consider the added value systematic reviews could provide when synthesizing primary research data on genetically modified organisms (GMO) and (2) critically assess the adequacy and feasibility of systematic review for collating and analyzing data on potential impacts of GMOs in order to better inform specific steps within GMO risk assessment and risk management. The regulatory framework of the EU is used as an example, although the issues we discuss are likely to be more widely applicable. PMID:26322307

  8. Can Systematic Reviews Inform GMO Risk Assessment and Risk Management?

    PubMed

    Kohl, Christian; Frampton, Geoff; Sweet, Jeremy; Spök, Armin; Haddaway, Neal Robert; Wilhelm, Ralf; Unger, Stefan; Schiemann, Joachim

    2015-01-01

    Systematic reviews represent powerful tools to identify, collect, synthesize, and evaluate primary research data on specific research questions in a highly standardized and reproducible manner. They enable the defensible synthesis of outcomes by increasing precision and minimizing bias whilst ensuring transparency of the methods used. This makes them especially valuable to inform evidence-based risk analysis and decision making in various topics and research disciplines. Although seen as a "gold standard" for synthesizing primary research data, systematic reviews are not without limitations as they are often cost, labor and time intensive and the utility of synthesis outcomes depends upon the availability of sufficient and robust primary research data. In this paper, we (1) consider the added value systematic reviews could provide when synthesizing primary research data on genetically modified organisms (GMO) and (2) critically assess the adequacy and feasibility of systematic review for collating and analyzing data on potential impacts of GMOs in order to better inform specific steps within GMO risk assessment and risk management. The regulatory framework of the EU is used as an example, although the issues we discuss are likely to be more widely applicable.

  9. US regulatory system for genetically modified [genetically modified organism (GMO), rDNA or transgenic] crop cultivars.

    PubMed

    McHughen, Alan; Smyth, Stuart

    2008-01-01

    This paper reviews the history of the federal regulatory oversight of plant agricultural biotechnology in the USA, focusing on the scientific and political forces moulding the continually evolving regulatory structure in place today. Unlike most other jurisdictions, the USA decided to adapt pre-existing legislation to encompass products of biotechnology. In so doing, it established an overarching committee (Office of Science and Technology Policy) to study and distribute various regulatory responsibilities amongst relevant agencies: the Food and Drug Administration, Environmental Protection Agency and US Department of Agriculture. This paper reviews the history and procedures of each agency in the execution of its regulatory duties and investigates the advantages and disadvantages of the US regulatory strategy.

  10. Qualitative and quantitative evaluation of the genomic DNA extracted from GMO and non-GMO foodstuffs with four different extraction methods.

    PubMed

    Peano, Clelia; Samson, Maria Cristina; Palmieri, Luisa; Gulli, Mariolina; Marmiroli, Nelson

    2004-11-17

    The presence of DNA in foodstuffs derived from or containing genetically modified organisms (GMO) is the basic requirement for labeling of GMO foods in Council Directive 2001/18/CE (Off. J. Eur. Communities 2001, L1 06/2). In this work, four different methods for DNA extraction were evaluated and compared. To rank the different methods, the quality and quantity of DNA extracted from standards, containing known percentages of GMO material and from different food products, were considered. The food products analyzed derived from both soybean and maize and were chosen on the basis of the mechanical, technological, and chemical treatment they had been subjected to during processing. Degree of DNA degradation at various stages of food production was evaluated through the amplification of different DNA fragments belonging to the endogenous genes of both maize and soybean. Genomic DNA was extracted from Roundup Ready soybean and maize MON810 standard flours, according to four different methods, and quantified by real-time Polymerase Chain Reaction (PCR), with the aim of determining the influence of the extraction methods on the DNA quantification through real-time PCR.

  11. [Progress on biosafety assessment of marker genes in genetically modified foods].

    PubMed

    Yang, Lichen; Yang, Xiaoguang

    2003-05-01

    Marker genes are useful in facilitating the detection of genetically modified organisms(GMO). These genes play an important role during the early identification stage of GMO development, but they exist in the mature genetically modified crops. So the safety assessment of these genes could not be neglected. In this paper, all the study on the biosafety assessment of marker genes were reviewed, their possible hazards and risks were appraised, and the marker genes proved safe were list too. GMO Labeling the is one important regulations for the development of genetically modified foods in the market. The accurate detecting techniques for GMO are the basis for setting up labeling regulation. In addition, some methods used to remove marker genes in genetically modified foods were introduced in the paper, which can eliminate their biosafety concern thoroughly.

  12. Organically modified silicate aerogels, ``Aeromosils``

    SciTech Connect

    Kramer, S.J.; Mackenzie, J.D.; Rubio-Alonso, F.

    1996-12-31

    Aerogels derived from sol-gel oxides such as silica have become quite scientifically popular because of their extremely low densities, high surface areas, and their interesting optical, dielectric, thermal and acoustic properties. However, their commercial applicability has thus far been rather limited, due in great part to their brittleness and hydrophilicity. In prior work by the research group, modifying silicate gel structures with flexible, organic containing polymers such as polydimethylsiloxane imparted significant compliance (even rubbery behavior) and hydrophobicity. These materials have been referred to as Ormosils. This study expounds on the current effort to extend these desirable properties to aerogels, and in-so-doing, creating novel ``Aeromosils``. Reactive incorporation of hydroxy-terminal polydimethylsiloxane (PDMS) into silica sol-gels was made using both acid and two-step acid/base catalyzed processes. Aerogels were derived by employing the supercritical CO{sub 2} technique. Analyses of microstructure were made using nitrogen adsorption (BET surface area and pore size distribution), and some mechanical strengths were derived from tensile strength testing. Interesting Aeromosil properties obtained include optical transparency, surface areas of up to 1,200 m{sup 2}/g, rubberiness, and better strength than corresponding silica aerogels with elongations at break exceeding 5% in some cases.

  13. Golden rice: scientific, regulatory and public information processes of a genetically modified organism.

    PubMed

    Moghissi, A Alan; Pei, Shiqian; Liu, Yinzuo

    2016-01-01

    Historically, agricultural development evolved in three phases. During the first phase the plants were selected on the basis of the availability of a plant with desirable properties at a specific location. The second phase provided the agricultural community with crossbreeding plants to achieve improvement in agricultural production. The evolution of biological knowledge has provided the ability to genetically engineer (GE) crops, one of the key processes within genetically modified organisms (GMO). This article uses golden rice, a species of transgenic Asian rice which contains a precursor of vitamin A in the edible part of the plant as an example of GE/GMO emphasizing Chinese experience in agricultural evolution. It includes a brief review of agricultural evolution to be followed by a description of golden rice development. Golden rice was created as a humanitarian project and has received positive comments by the scientific community and negative voices from certain environmental groups. In this article, we use the Best Available Science (BAS) Concept and Metrics for Evaluation of Scientific Claims (MESC) derived from it to evaluate claims and counter claims on scientific aspects of golden rice. This article concludes that opposition to golden rice is based on belief rather than any of its scientifically derived nutritional, safety or environmental properties.

  14. Putting problem formulation at the forefront of GMO risk analysis.

    PubMed

    Tepfer, Mark; Racovita, Monica; Craig, Wendy

    2013-01-01

    When applying risk assessment and the broader process of risk analysis to decisions regarding the dissemination of genetically modified organisms (GMOs), the process has a tendency to become remarkably complex. Further, as greater numbers of countries consider authorising the large-scale dissemination of GMOs, and as GMOs with more complex traits reach late stages of development, there has been increasing concern about the burden posed by the complexity of risk analysis. We present here an improved approach for GMO risk analysis that gives a central role to problem formulation. Further, the risk analysis strategy has been clarified and simplified in order to make rigorously scientific risk assessment and risk analysis more broadly accessible to diverse stakeholder groups.

  15. Optimization of digital droplet polymerase chain reaction for quantification of genetically modified organisms

    PubMed Central

    Gerdes, Lars; Iwobi, Azuka; Busch, Ulrich; Pecoraro, Sven

    2016-01-01

    Digital PCR in droplets (ddPCR) is an emerging method for more and more applications in DNA (and RNA) analysis. Special requirements when establishing ddPCR for analysis of genetically modified organisms (GMO) in a laboratory include the choice between validated official qPCR methods and the optimization of these assays for a ddPCR format. Differentiation between droplets with positive reaction and negative droplets, that is setting of an appropriate threshold, can be crucial for a correct measurement. This holds true in particular when independent transgene and plant-specific reference gene copy numbers have to be combined to determine the content of GM material in a sample. Droplets which show fluorescent units ranging between those of explicit positive and negative droplets are called ‘rain’. Signals of such droplets can hinder analysis and the correct setting of a threshold. In this manuscript, a computer-based algorithm has been carefully designed to evaluate assay performance and facilitate objective criteria for assay optimization. Optimized assays in return minimize the impact of rain on ddPCR analysis. We developed an Excel based ‘experience matrix’ that reflects the assay parameters of GMO ddPCR tests performed in our laboratory. Parameters considered include singleplex/duplex ddPCR, assay volume, thermal cycler, probe manufacturer, oligonucleotide concentration, annealing/elongation temperature, and a droplet separation evaluation. We additionally propose an objective droplet separation value which is based on both absolute fluorescence signal distance of positive and negative droplet populations and the variation within these droplet populations. The proposed performance classification in the experience matrix can be used for a rating of different assays for the same GMO target, thus enabling employment of the best suited assay parameters. Main optimization parameters include annealing/extension temperature and oligonucleotide concentrations

  16. Identification of potentially hazardous human gene products in GMO risk assessment.

    PubMed

    Bergmans, Hans; Logie, Colin; Van Maanen, Kees; Hermsen, Harm; Meredyth, Michelle; Van Der Vlugt, Cécile

    2008-01-01

    Genetically modified organisms (GMOs), e.g. viral vectors, could threaten the environment if by their release they spread hazardous gene products. Even in contained use, to prevent adverse consequences, viral vectors carrying genes from mammals or humans should be especially scrutinized as to whether gene products that they synthesize could be hazardous in their new context. Examples of such potentially hazardous gene products (PHGPs) are: protein toxins, products of dominant alleles that have a role in hereditary diseases, gene products and sequences involved in genome rearrangements, gene products involved in immunomodulation or with an endocrine function, gene products involved in apoptosis, activated proto-oncogenes. For contained use of a GMO that carries a construct encoding a PHGP, the precautionary principle dictates that safety measures should be applied on a "worst case" basis, until the risks of the specific case have been assessed. The potential hazard of cloned genes can be estimated before empirical data on the actual GMO become available. Preliminary data may be used to focus hazard identification and risk assessment. Both predictive and empirical data may also help to identify what further information is needed to assess the risk of the GMO. A two-step approach, whereby a PHGP is evaluated for its conceptual dangers, then checked by data bank searches, is delineated here.

  17. Practicable group testing method to evaluate weight/weight GMO content in maize grains.

    PubMed

    Mano, Junichi; Yanaka, Yuka; Ikezu, Yoko; Onishi, Mari; Futo, Satoshi; Minegishi, Yasutaka; Ninomiya, Kenji; Yotsuyanagi, Yuichi; Spiegelhalter, Frank; Akiyama, Hiroshi; Teshima, Reiko; Hino, Akihiro; Naito, Shigehiro; Koiwa, Tomohiro; Takabatake, Reona; Furui, Satoshi; Kitta, Kazumi

    2011-07-13

    Because of the increasing use of maize hybrids with genetically modified (GM) stacked events, the established and commonly used bulk sample methods for PCR quantification of GM maize in non-GM maize are prone to overestimate the GM organism (GMO) content, compared to the actual weight/weight percentage of GM maize in the grain sample. As an alternative method, we designed and assessed a group testing strategy in which the GMO content is statistically evaluated based on qualitative analyses of multiple small pools, consisting of 20 maize kernels each. This approach enables the GMO content evaluation on a weight/weight basis, irrespective of the presence of stacked-event kernels. To enhance the method's user-friendliness in routine application, we devised an easy-to-use PCR-based qualitative analytical method comprising a sample preparation step in which 20 maize kernels are ground in a lysis buffer and a subsequent PCR assay in which the lysate is directly used as a DNA template. This method was validated in a multilaboratory collaborative trial.

  18. Degradation and half-life of DNA present in biomass from a genetically-modified organism during land application.

    PubMed

    Halter, Mathew C; Zahn, James A

    2017-02-01

    White biotechnology has made a positive impact on the chemical industry by providing safer, more efficient chemical manufacturing processes that have reduced the use of toxic chemicals, harsh reaction conditions, and expensive metal catalysts, which has improved alignment with the principles of Green Chemistry. The genetically-modified (GM) biocatalysts that are utilized in these processes are typically separated from high-value products and then recycled, or eliminated. Elimination routes include disposal in sanitary landfills, incineration, use as a fuel, animal feed, or reuse as an agricultural soil amendment or other value-added products. Elimination routes that have the potential to impact the food chain or environment have been more heavily scrutinized for the fate and persistence of biological products. In this study, we developed and optimized a method for monitoring the degradation of strain-specific DNA markers from a genetically-modified organism (GMO) used for the commercial production of 1,3-propanediol. Laboratory and field tests showed that a marker for heterologous DNA in the GM organism was no longer detectable by end-point polymerase chain reaction (PCR) after 14 days. The half-life of heterologous DNA was increased by 17% (from 42.4 to 49.7 h) after sterilization of the soil from a field plot, which indicated that abiotic factors were important in degradation of DNA under field conditions. There was no evidence for horizontal transfer of DNA target sequences from the GMO to viable organisms present in the soil.

  19. Allergy assessment of foods or ingredients derived from biotechnology, gene-modified organisms, or novel foods.

    PubMed

    Poulsen, Lars K

    2004-11-01

    The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein and a risk of sensitizing susceptible individuals. No single predictive test exists to perform a hazard assessment in relation to allergenic properties of newly expressed proteins in gene-modified organisms (GMOs). Instead, performance of a weighted risk analysis based on the decision tree approach has been suggested. The individual steps of this analysis comprise sequence homology to known allergens, specific or targeted serum screens for immunoglobulin E (IgE) cross-reactions to known allergens, digestability studies of the proteins in simulated gastric and/or intestinal fluids, and animal studies. These steps are discussed and five examples of risk evaluation of GMOs or novel foods are presented. These include ice-structuring protein derived from fish, microbial transglutaminase, GMO-soybeans, amylase and the Nangai nut.

  20. How does the World Trade Organization know? The mobilization and staging of scientific expertise in the GMO trade dispute.

    PubMed

    Bonneuil, Christophe; Levidow, Les

    2012-02-01

    The World Trade Organization (WTO) dispute settlement procedure is a key arena for establishing global legal norms for what counts as relevant knowledge. As a high-profile case, the WTO trade dispute on GMOs mobilized scientific expertise in somewhat novel ways. Early on, the Panel put the dispute under the Sanitary and Phytosanitary (SPS) Agreement through a new legal ontology; it classified transgenes as potential pests and limited all environmental issues to the 'plant and animal health' category. The selection of scientific experts sought a multi-party consensus through a fast adversarial process, reflecting a specific legal epistemology. For the SPS framing, focusing on the defendant's regulatory procedures, the Panel staged scientific expertise in specific ways that set up how experts were questioned, the answers they would give, their specific role in the legal arena, and the way their statements would complement the Panel's findings. In these ways, the dispute settlement procedure co-produced legal and scientific expertise within the Panel's SPS framework. Moreover, the Panel operated a procedural turn in WTO jurisprudence by representing its findings as a purely legal-administrative judgement on whether the EC's regulatory procedures violated the SPS Agreement, while keeping implicit its own judgements on substantive risk issues. As this case illustrates, the WTO settlement procedure mobilizes scientific expertise for sophisticated, multiple aims: it recruits a source of credibility from the scientific arena, thus reinforcing the standard narrative of 'science-based trade discipline', while also constructing new scientific expertise for the main task--namely, challenging trade restrictions for being unduly cautious.

  1. Farmers' valuation of incentives to produce genetically modified organism-free milk: Insights from a discrete choice experiment in Germany.

    PubMed

    Schreiner, J A; Latacz-Lohmann, U

    2015-11-01

    This paper investigates farmers' willingness to participate in a genetically modified organism (GMO)-free milk production scheme offered by some German dairy companies. The empirical analysis is based upon discrete choice experiments with 151 dairy farmers from 2 regions in Germany. A conditional logit estimation reveals a strong positive effect of the price premium on offer. Reliable feed monitoring and free technical support increase the likelihood of scheme adoption, the latter however only in farms that have been receiving technical support in other fields. By contrast, any interference with the entrepreneurial autonomy of farmers, through pre-arranged feed procurement or prescriptive advice on the part of the dairy company, lowers acceptance probabilities. Farmers' attitudes toward cultivation of genetically modified soy, their assessment of the market potential of GMO-free milk and future feed prices were found to be significant determinants of adoption, as are farmer age, educational status, and current feeding regimens. Respondents requested on average a mark-up of 0.80 eurocents per kilogram of milk to accept a contract. Comparison of the estimates for the 2 regions suggests that farmers in northern Germany are, on average, more likely to convert to genetically modified-free production; however, farmers in the south are, ceteris paribus, more responsive to an increase in the price premium offered. A latent class model reveals significant differences in the valuation of scheme attributes between 2 latent classes of adopters and nonadopters.

  2. Organically modified silicas on metal nanowires.

    PubMed

    Dean, Stacey L; Stapleton, Joshua J; Keating, Christine D

    2010-09-21

    Organically modified silica coatings were prepared on metal nanowires using a variety of silicon alkoxides with different functional groups (i.e., carboxyl groups, polyethylene oxide, cyano, dihydroimidazole, and hexyl linkers). Organically modified silicas were deposited onto the surface of 6-μm-long, ∼300-nm-wide, cylindrical metal nanowires in suspension by the hydrolysis and polycondensation of silicon alkoxides. Syntheses were performed at several ratios of tetraethoxysilane to an organically modified silicon alkoxide to incorporate desired functional groups into thin organosilica shells on the nanowires. These coatings were characterized using transmission electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy. All of the organically modified silicas prepared here were sufficiently porous to allow the removal of the metal nanowire cores by acid etching to form organically modified silica nanotubes. Additional functionality provided to the modified silicas as compared to unmodified silica prepared using only tetraethoxysilane precursors was demonstrated by chromate adsorption on imidazole-containing silicas and resistance to protein adsorption on polyethyleneoxide-containing silicas. Organically modified silica coatings on nanowires and other nano- and microparticles have potential application in fields such as biosensing or nanoscale therapeutics due to the enhanced properties of the silica coatings, for example, the prevention of biofouling.

  3. GMOMETHODS: the European Union database of reference methods for GMO analysis.

    PubMed

    Bonfini, Laura; Van den Bulcke, Marc H; Mazzara, Marco; Ben, Enrico; Patak, Alexandre

    2012-01-01

    In order to provide reliable and harmonized information on methods for GMO (genetically modified organism) analysis we have published a database called "GMOMETHODS" that supplies information on PCR assays validated according to the principles and requirements of ISO 5725 and/or the International Union of Pure and Applied Chemistry protocol. In addition, the database contains methods that have been verified by the European Union Reference Laboratory for Genetically Modified Food and Feed in the context of compliance with an European Union legislative act. The web application provides search capabilities to retrieve primers and probes sequence information on the available methods. It further supplies core data required by analytical labs to carry out GM tests and comprises information on the applied reference material and plasmid standards. The GMOMETHODS database currently contains 118 different PCR methods allowing identification of 51 single GM events and 18 taxon-specific genes in a sample. It also provides screening assays for detection of eight different genetic elements commonly used for the development of GMOs. The application is referred to by the Biosafety Clearing House, a global mechanism set up by the Cartagena Protocol on Biosafety to facilitate the exchange of information on Living Modified Organisms. The publication of the GMOMETHODS database can be considered an important step toward worldwide standardization and harmonization in GMO analysis.

  4. Detecting un-authorized genetically modified organisms (GMOs) and derived materials.

    PubMed

    Holst-Jensen, Arne; Bertheau, Yves; de Loose, Marc; Grohmann, Lutz; Hamels, Sandrine; Hougs, Lotte; Morisset, Dany; Pecoraro, Sven; Pla, Maria; Van den Bulcke, Marc; Wulff, Doerte

    2012-01-01

    Genetically modified plants, in the following referred to as genetically modified organisms or GMOs, have been commercially grown for almost two decades. In 2010 approximately 10% of the total global crop acreage was planted with GMOs (James, 2011). More than 30 countries have been growing commercial GMOs, and many more have performed field trials. Although the majority of commercial GMOs both in terms of acreage and specific events belong to the four species: soybean, maize, cotton and rapeseed, there are another 20+ species where GMOs are commercialized or in the pipeline for commercialization. The number of GMOs cultivated in field trials or for commercial production has constantly increased during this time period. So have the number of species, the number of countries involved, the diversity of novel (added) genetic elements and the global trade. All of these factors contribute to the increasing complexity of detecting and correctly identifying GMO derived material. Many jurisdictions, including the European Union (EU), legally distinguish between authorized (and therefore legal) and un-authorized (and therefore illegal) GMOs. Information about the developments, field trials, authorizations, cultivation, trade and observations made in the official GMO control laboratories in different countries around the world is often limited, despite several attempts such as the OECD BioTrack for voluntary dissemination of data. This lack of information inevitably makes it challenging to detect and identify GMOs, especially the un-authorized GMOs. The present paper reviews the state of the art technologies and approaches in light of coverage, practicability, sensitivity and limitations. Emphasis is put on exemplifying practical detection of un-authorized GMOs. Although this paper has a European (EU) bias when examples are given, the contents have global relevance.

  5. Nanoparticles modified with multiple organic acids

    NASA Technical Reports Server (NTRS)

    Cook, Ronald Lee (Inventor); Luebben, Silvia DeVito (Inventor); Myers, Andrew William (Inventor); Smith, Bryan Matthew (Inventor); Elliott, Brian John (Inventor); Kreutzer, Cory (Inventor); Wilson, Carolina (Inventor); Meiser, Manfred (Inventor)

    2007-01-01

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  6. Nanoparticles modified with multiple organic acids

    DOEpatents

    Cook, Ronald Lee; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew; Elliott, Brian John; Kreutzer, Cory; Wilson, Carolina; Meiser, Manfred

    2007-07-17

    Surface-modified nanoparticles of boehmite, and methods for preparing the same. Aluminum oxyhydroxide nanoparticles are surface modified by reaction with selected amounts of organic acids. In particular, the nanoparticle surface is modified by reactions with two or more different carboxylic acids, at least one of which is an organic carboxylic acid. The product is a surface modified boehmite nanoparticle that has an inorganic aluminum oxyhydroxide core, or part aluminum oxyhydroxide core and a surface-bonded organic shell. Organic carboxylic acids of this invention contain at least one carboxylic acid group and one carbon-hydrogen bond. One embodiment of this invention provides boehmite nanoparticles that have been surface modified with two or more acids one of which additional carries at least one reactive functional group. Another embodiment of this invention provides boehmite nanoparticles that have been surface modified with multiple acids one of which has molecular weight or average molecular weight greater than or equal to 500 Daltons. Yet, another embodiment of this invention provides boehmite nanoparticles that are surface modified with two or more acids one of which is hydrophobic in nature and has solubility in water of less than 15 by weight. The products of the methods of this invention have specific useful properties when used in mixture with liquids, as filler in solids, or as stand-alone entities.

  7. [Assessment of allergenicity of genetically modified food crops].

    PubMed

    Schauzu, M; Pöting, A; Rubin, D; Lampen, A

    2012-03-01

    The placing on the European Union's market of genetically modified crops requires authorization by the European Commission which is based on the proof that the derived foods are as safe as their conventional counterparts. The assessment of potential allergenicity is part of the necessary investigations recommended in the updated Guidance Document of the Scientific Panel on Genetically Modified Organisms (GMO) of the European Food Safety Authority (EFSA), which is based on internationally agreed recommendations. All genetically modified crops which so far have been authorized in the European Union were evaluated by the EFSA GMO Panel which considered it unlikely that their overall allergenicity has been altered.

  8. Development of melting temperature-based SYBR Green I polymerase chain reaction methods for multiplex genetically modified organism detection.

    PubMed

    Hernández, Marta; Rodríguez-Lázaro, David; Esteve, Teresa; Prat, Salomé; Pla, Maria

    2003-12-15

    Commercialization of several genetically modified crops has been approved worldwide to date. Uniplex polymerase chain reaction (PCR)-based methods to identify these different insertion events have been developed, but their use in the analysis of all commercially available genetically modified organisms (GMOs) is becoming progressively insufficient. These methods require a large number of assays to detect all possible GMOs present in the sample and thereby the development of multiplex PCR systems using combined probes and primers targeted to sequences specific to various GMOs is needed for detection of this increasing number of GMOs. Here we report on the development of a multiplex real-time PCR suitable for multiple GMO identification, based on the intercalating dye SYBR Green I and the analysis of the melting curves of the amplified products. Using this method, different amplification products specific for Maximizer 176, Bt11, MON810, and GA21 maize and for GTS 40-3-2 soybean were obtained and identified by their specific Tm. We have combined amplification of these products in a number of multiplex reactions and show the suitability of the methods for identification of GMOs with a sensitivity of 0.1% in duplex reactions. The described methods offer an economic and simple alternative to real-time PCR systems based on sequence-specific probes (i.e., TaqMan chemistry). These methods can be used as selection tests and further optimized for uniplex GMO quantification.

  9. Development and validation of a 48-target analytical method for high-throughput monitoring of genetically modified organisms.

    PubMed

    Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

    2015-01-05

    The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection.

  10. Development and Validation of A 48-Target Analytical Method for High-throughput Monitoring of Genetically Modified Organisms

    PubMed Central

    Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

    2015-01-01

    The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection. PMID:25556930

  11. Knowlege of, attitudes toward, and acceptance of genetically modified organisms among prospective teachers of biology, home economics, and grade school in Slovenia.

    PubMed

    Sorgo, Andrej; Ambrožič-Dolinšek, Jana

    2010-05-01

    The objective of this study was to investigate knowledge, opinions, and attitudes toward, as well as readiness to accept genetically modified organisms (GMOs) among prospective primary and secondary Slovene teachers. Our findings are that prospective teachers want to take an active role in rejecting or supporting individual GMOs and are aware of the importance of education about genetically modified organism (GMO) items and their potential significance for society. Through cluster analysis, we recognized four clusters of GMOs, separated by degree of genetically modified acceptability. GM plants and microorganisms which are recognized as useful are accepted. They are undecided about organisms used in research or medicine and reject organisms used for food consumption and for fun. There are only weak correlations between knowledge and attitudes and knowledge and acceptance of GMOs, and a strong correlation between attitudes and acceptance. The appropriate strategies and actions for improving university courses in biotechnology are discussed.

  12. A screening method for the detection of the 35S promoter and the nopaline synthase terminator in genetically modified organisms in a real-time multiplex polymerase chain reaction using high-resolution melting-curve analysis.

    PubMed

    Akiyama, Hiroshi; Nakamura, Fumi; Yamada, Chihiro; Nakamura, Kosuke; Nakajima, Osamu; Kawakami, Hiroshi; Harikai, Naoki; Furui, Satoshi; Kitta, Kazumi; Teshima, Reiko

    2009-11-01

    To screen for unauthorized genetically modified organisms (GMO) in the various crops, we developed a multiplex real-time polymerase chain reaction high-resolution melting-curve analysis method for the simultaneous qualitative detection of 35S promoter sequence of cauliflower mosaic virus (35SP) and the nopaline synthase terminator (NOST) in several crops. We selected suitable primer sets for the simultaneous detection of 35SP and NOST and designed the primer set for the detection of spiked ColE1 plasmid to evaluate the validity of the polymerase chain reaction (PCR) analyses. In addition, we optimized the multiplex PCR conditions using the designed primer sets and EvaGreen as an intercalating dye. The contamination of unauthorized GMO with single copy similar to NK603 maize can be detected as low as 0.1% in a maize sample. Furthermore, we showed that the present method would be applicable in identifying GMO in various crops and foods like authorized GM soybean, authorized GM potato, the biscuit which is contaminated with GM soybeans and the rice which is contaminated with unauthorized GM rice. We consider this method to be a simple and reliable assay for screening for unauthorized GMO in crops and the processing food products.

  13. A high-throughput method for GMO multi-detection using a microfluidic dynamic array.

    PubMed

    Brod, Fábio Cristiano Angonesi; van Dijk, Jeroen P; Voorhuijzen, Marleen M; Dinon, Andréia Zilio; Guimarães, Luis Henrique S; Scholtens, Ingrid M J; Arisi, Ana Carolina Maisonnave; Kok, Esther J

    2014-02-01

    The ever-increasing production of genetically modified crops generates a demand for high-throughput DNA-based methods for the enforcement of genetically modified organisms (GMO) labelling requirements. The application of standard real-time PCR will become increasingly costly with the growth of the number of GMOs that is potentially present in an individual sample. The present work presents the results of an innovative approach in genetically modified crops analysis by DNA based methods, which is the use of a microfluidic dynamic array as a high throughput multi-detection system. In order to evaluate the system, six test samples with an increasing degree of complexity were prepared, preamplified and subsequently analysed in the Fluidigm system. Twenty-eight assays targeting different DNA elements, GM events and species-specific reference genes were used in the experiment. The large majority of the assays tested presented expected results. The power of low level detection was assessed and elements present at concentrations as low as 0.06 % were successfully detected. The approach proposed in this work presents the Fluidigm system as a suitable and promising platform for GMO multi-detection.

  14. Development of a peptide nucleic acid polymerase chain reaction clamping assay for semiquantitative evaluation of genetically modified organism content in food.

    PubMed

    Peano, C; Lesignoli, F; Gulli, M; Corradini, R; Samson, M C; Marchelli, R; Marmiroli, N

    2005-09-15

    In the present study a peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping method was developed and applied to the detection of genetically modified organisms (GMO), to test PCR products for band identity and to obtain a semiquantitative evaluation of GMO content. The minimal concentration of PNA necessary to block the PCR was determined by comparing PCRs containing a constant amount of DNA in the presence of increasing concentration of target-specific PNA. The lowest PNA concentration at which specific inhibition took place, by the inhibition of primer extension and/or steric hindrance, was the most efficient condition. Optimization of PCR clamping by PNA was observed by testing five different PNAs with a minimum of 13 bp to a maximum of 15 bp, designed on the target sequence of Roundup Ready soybean. The results obtained on the DNA extracted from Roundup Ready soybean standard flour were verified also on DNA extracted from standard flours of maize GA21, Bt176, Bt11, and MON810. A correlation between the PNA concentration necessary for inducing PCR clamping and the percentage of the GMO target sequence in the sample was found.

  15. Protection against Shiga-Toxigenic Escherichia coli by Non-Genetically Modified Organism Receptor Mimic Bacterial Ghosts.

    PubMed

    Paton, Adrienne W; Chen, Austen Y; Wang, Hui; McAllister, Lauren J; Höggerl, Florian; Mayr, Ulrike Beate; Shewell, Lucy K; Jennings, Michael P; Morona, Renato; Lubitz, Werner; Paton, James C

    2015-09-01

    Shiga-toxigenic Escherichia coli (STEC) causes severe gastrointestinal infections in humans that may lead to life-threatening systemic sequelae, such as the hemolytic uremic syndrome (HUS). Rapid diagnosis of STEC infection early in the course of disease opens a window of opportunity for therapeutic intervention, for example, by administration of agents that neutralize Shiga toxin (Stx) in the gut lumen. We previously developed a recombinant bacterium that expresses a mimic of the Stx receptor globotriaosyl ceramide (Gb3) on its surface through modification of the lipopolysaccharide (A. W. Paton, R. Morona, and J. C. Paton, Nat Med 6:265-270, 2000, http://dx.doi.org/10.1038/73111). This construct was highly efficacious in vivo, protecting mice from otherwise fatal STEC disease, but the fact that it is a genetically modified organism (GMO) has been a barrier to clinical development. In the present study, we have overcome this issue by development of Gb3 receptor mimic bacterial ghosts (BGs) that are not classified as GMOs. Gb3-BGs neutralized Stx1 and Stx2 in vitro with high efficiency, whereas alternative Gb3-expressing non-GMO subbacterial particles (minicells and outer membrane blebs) were ineffective. Gb3-BGs were highly efficacious in a murine model of STEC disease. All mice (10/10) treated with Gb3-BGs survived challenge with a highly virulent O113:H21 STEC strain and showed no pathological signs of renal injury. In contrast, 6/10 mice treated with control BGs succumbed to STEC challenge, and survivors exhibited significant weight loss, neutrophilia, and histopathological evidence of renal damage. Thus, Gb3-BGs offer a non-GMO approach to treatment of STEC infection in humans, particularly in an outbreak setting.

  16. Protection against Shiga-Toxigenic Escherichia coli by Non-Genetically Modified Organism Receptor Mimic Bacterial Ghosts

    PubMed Central

    Paton, Adrienne W.; Chen, Austen Y.; Wang, Hui; McAllister, Lauren J.; Höggerl, Florian; Mayr, Ulrike Beate; Shewell, Lucy K.; Jennings, Michael P.; Morona, Renato; Lubitz, Werner

    2015-01-01

    Shiga-toxigenic Escherichia coli (STEC) causes severe gastrointestinal infections in humans that may lead to life-threatening systemic sequelae, such as the hemolytic uremic syndrome (HUS). Rapid diagnosis of STEC infection early in the course of disease opens a window of opportunity for therapeutic intervention, for example, by administration of agents that neutralize Shiga toxin (Stx) in the gut lumen. We previously developed a recombinant bacterium that expresses a mimic of the Stx receptor globotriaosyl ceramide (Gb3) on its surface through modification of the lipopolysaccharide (A. W. Paton, R. Morona, and J. C. Paton, Nat Med 6:265–270, 2000, http://dx.doi.org/10.1038/73111). This construct was highly efficacious in vivo, protecting mice from otherwise fatal STEC disease, but the fact that it is a genetically modified organism (GMO) has been a barrier to clinical development. In the present study, we have overcome this issue by development of Gb3 receptor mimic bacterial ghosts (BGs) that are not classified as GMOs. Gb3-BGs neutralized Stx1 and Stx2 in vitro with high efficiency, whereas alternative Gb3-expressing non-GMO subbacterial particles (minicells and outer membrane blebs) were ineffective. Gb3-BGs were highly efficacious in a murine model of STEC disease. All mice (10/10) treated with Gb3-BGs survived challenge with a highly virulent O113:H21 STEC strain and showed no pathological signs of renal injury. In contrast, 6/10 mice treated with control BGs succumbed to STEC challenge, and survivors exhibited significant weight loss, neutrophilia, and histopathological evidence of renal damage. Thus, Gb3-BGs offer a non-GMO approach to treatment of STEC infection in humans, particularly in an outbreak setting. PMID:26099582

  17. Evaluation of plasmid and genomic DNA calibrants used for the quantification of genetically modified organisms.

    PubMed

    Caprioara-Buda, M; Meyer, W; Jeynov, B; Corbisier, P; Trapmann, S; Emons, H

    2012-07-01

    The reliable quantification of genetically modified organisms (GMOs) by real-time PCR requires, besides thoroughly validated quantitative detection methods, sustainable calibration systems. The latter establishes the anchor points for the measured value and the measurement unit, respectively. In this paper, the suitability of two types of DNA calibrants, i.e. plasmid DNA and genomic DNA extracted from plant leaves, for the certification of the GMO content in reference materials as copy number ratio between two targeted DNA sequences was investigated. The PCR efficiencies and coefficients of determination of the calibration curves as well as the measured copy number ratios for three powder certified reference materials (CRMs), namely ERM-BF415e (NK603 maize), ERM-BF425c (356043 soya), and ERM-BF427c (98140 maize), originally certified for their mass fraction of GMO, were compared for both types of calibrants. In all three systems investigated, the PCR efficiencies of plasmid DNA were slightly closer to the PCR efficiencies observed for the genomic DNA extracted from seed powders rather than those of the genomic DNA extracted from leaves. Although the mean DNA copy number ratios for each CRM overlapped within their uncertainties, the DNA copy number ratios were significantly different using the two types of calibrants. Based on these observations, both plasmid and leaf genomic DNA calibrants would be technically suitable as anchor points for the calibration of the real-time PCR methods applied in this study. However, the most suitable approach to establish a sustainable traceability chain is to fix a reference system based on plasmid DNA.

  18. [Genetically modified food--unnecessary controversy?].

    PubMed

    Tchórz, Michał; Radoniewicz-Chagowska, Anna; Lewandowska-Stanek, Hanna; Szponar, Elzbieta; Szponar, Jarosław

    2012-01-01

    Fast development of genetic engineering and biotechnology allows use of genetically modified organisms (GMO) more and more in different branches of science and economy. Every year we can see an increase of food amount produced with the use of modification of genetic material. In our supermarkets we can find brand new types of plants, products including genetically modified ingredients or meat from animals fed with food containing GMO. This article presents general information about genetically modified organisms, it also explains the range of genetic manipulation, use of newly developed products and current field area for GMO in the world. Based on scientific data the article presents benefits from development of biotechnology in reference to modified food. It also presents the voice of skeptics who are extremely concerned about the impact of those organisms on human health and natural environment. Problems that appear or can appear as a result of an increase of GMO are very important not only from a toxicologist's or a doctor's point of view but first of all from the point of view of ordinary consumers--all of us.

  19. Detection and traceability of genetically modified organisms in the food production chain.

    PubMed

    Miraglia, M; Berdal, K G; Brera, C; Corbisier, P; Holst-Jensen, A; Kok, E J; Marvin, H J P; Schimmel, H; Rentsch, J; van Rie, J P P F; Zagon, J

    2004-07-01

    Both labelling and traceability of genetically modified organisms are current issues that are considered in trade and regulation. Currently, labelling of genetically modified foods containing detectable transgenic material is required by EU legislation. A proposed package of legislation would extend this labelling to foods without any traces of transgenics. These new legislations would also impose labelling and a traceability system based on documentation throughout the food and feed manufacture system. The regulatory issues of risk analysis and labelling are currently harmonised by Codex Alimentarius. The implementation and maintenance of the regulations necessitates sampling protocols and analytical methodologies that allow for accurate determination of the content of genetically modified organisms within a food and feed sample. Current methodologies for the analysis of genetically modified organisms are focused on either one of two targets, the transgenic DNA inserted- or the novel protein(s) expressed- in a genetically modified product. For most DNA-based detection methods, the polymerase chain reaction is employed. Items that need consideration in the use of DNA-based detection methods include the specificity, sensitivity, matrix effects, internal reference DNA, availability of external reference materials, hemizygosity versus homozygosity, extrachromosomal DNA, and international harmonisation. For most protein-based methods, enzyme-linked immunosorbent assays with antibodies binding the novel protein are employed. Consideration should be given to the selection of the antigen bound by the antibody, accuracy, validation, and matrix effects. Currently, validation of detection methods for analysis of genetically modified organisms is taking place. In addition, new methodologies are developed, including the use of microarrays, mass spectrometry, and surface plasmon resonance. Challenges for GMO detection include the detection of transgenic material in materials

  20. What Risk Assessments of Genetically Modified Organisms Can Learn from Institutional Analyses of Public Health Risks

    PubMed Central

    Rajan, S. Ravi; Letourneau, Deborah K.

    2012-01-01

    The risks of genetically modified organisms (GMOs) are evaluated traditionally by combining hazard identification and exposure estimates to provide decision support for regulatory agencies. We question the utility of the classical risk paradigm and discuss its evolution in GMO risk assessment. First, we consider the problem of uncertainty, by comparing risk assessment for environmental toxins in the public health domain with genetically modified organisms in the environment; we use the specific comparison of an insecticide to a transgenic, insecticidal food crop. Next, we examine normal accident theory (NAT) as a heuristic to consider runaway effects of GMOs, such as negative community level consequences of gene flow from transgenic, insecticidal crops. These examples illustrate how risk assessments are made more complex and contentious by both their inherent uncertainty and the inevitability of failure beyond expectation in complex systems. We emphasize the value of conducting decision-support research, embracing uncertainty, increasing transparency, and building interdisciplinary institutions that can address the complex interactions between ecosystems and society. In particular, we argue against black boxing risk analysis, and for a program to educate policy makers about uncertainty and complexity, so that eventually, decision making is not the burden that falls upon scientists but is assumed by the public at large. PMID:23193357

  1. What risk assessments of genetically modified organisms can learn from institutional analyses of public health risks.

    PubMed

    Rajan, S Ravi; Letourneau, Deborah K

    2012-01-01

    The risks of genetically modified organisms (GMOs) are evaluated traditionally by combining hazard identification and exposure estimates to provide decision support for regulatory agencies. We question the utility of the classical risk paradigm and discuss its evolution in GMO risk assessment. First, we consider the problem of uncertainty, by comparing risk assessment for environmental toxins in the public health domain with genetically modified organisms in the environment; we use the specific comparison of an insecticide to a transgenic, insecticidal food crop. Next, we examine normal accident theory (NAT) as a heuristic to consider runaway effects of GMOs, such as negative community level consequences of gene flow from transgenic, insecticidal crops. These examples illustrate how risk assessments are made more complex and contentious by both their inherent uncertainty and the inevitability of failure beyond expectation in complex systems. We emphasize the value of conducting decision-support research, embracing uncertainty, increasing transparency, and building interdisciplinary institutions that can address the complex interactions between ecosystems and society. In particular, we argue against black boxing risk analysis, and for a program to educate policy makers about uncertainty and complexity, so that eventually, decision making is not the burden that falls upon scientists but is assumed by the public at large.

  2. Assessment of DNA degradation induced by thermal and UV radiation processing: implications for quantification of genetically modified organisms.

    PubMed

    Ballari, Rajashekhar V; Martin, Asha

    2013-12-01

    DNA quality is an important parameter for the detection and quantification of genetically modified organisms (GMO's) using the polymerase chain reaction (PCR). Food processing leads to degradation of DNA, which may impair GMO detection and quantification. This study evaluated the effect of various processing treatments such as heating, baking, microwaving, autoclaving and ultraviolet (UV) irradiation on the relative transgenic content of MON 810 maize using pRSETMON-02, a dual target plasmid as a model system. Amongst all the processing treatments examined, autoclaving and UV irradiation resulted in the least recovery of the transgenic (CaMV 35S promoter) and taxon-specific (zein) target DNA sequences. Although a profound impact on DNA degradation was seen during the processing, DNA could still be reliably quantified by Real-time PCR. The measured mean DNA copy number ratios of the processed samples were in agreement with the expected values. Our study confirms the premise that the final analytical value assigned to a particular sample is independent of the degree of DNA degradation since the transgenic and the taxon-specific target sequences possessing approximately similar lengths degrade in parallel. The results of our study demonstrate that food processing does not alter the relative quantification of the transgenic content provided the quantitative assays target shorter amplicons and the difference in the amplicon size between the transgenic and taxon-specific genes is minimal.

  3. Development of sampling approaches for the determination of the presence of genetically modified organisms at the field level.

    PubMed

    Sustar-Vozlic, Jelka; Rostohar, Katja; Blejec, Andrej; Kozjak, Petra; Cergan, Zoran; Meglic, Vladimir

    2010-03-01

    In order to comply with the European Union regulatory threshold for the adventitious presence of genetically modified organisms (GMOs) in food and feed, it is important to trace GMOs from the field. Appropriate sampling methods are needed to accurately predict the presence of GMOs at the field level. A 2-year field experiment with two maize varieties differing in kernel colour was conducted in Slovenia. Based on the results of data mining analyses and modelling, it was concluded that spatial relations between the donor and receptor field were the most important factors influencing the distribution of outcrossing rate (OCR) in the field. The approach for estimation fitting function parameters in the receptor (non-GM) field at two distances from the donor (GM) field (10 and 25 m) for estimation of the OCR (GMO content) in the whole receptor field was developed. Different sampling schemes were tested; a systematic random scheme in rows was proposed to be applied for sampling at the two distances for the estimation of fitting function parameters for determination of OCR. The sampling approach had already been validated with some other OCR data and was practically applied in the 2009 harvest in Poland. The developed approach can be used for determination of the GMO presence at the field level and for making appropriate labelling decisions. The importance of this approach lies in its possibility to also address other threshold levels beside the currently prescribed labelling threshold of 0.9% for food and feed.

  4. MACRO: a combined microchip-PCR and microarray system for high-throughput monitoring of genetically modified organisms.

    PubMed

    Shao, Ning; Jiang, Shi-Meng; Zhang, Miao; Wang, Jing; Guo, Shu-Juan; Li, Yang; Jiang, He-Wei; Liu, Cheng-Xi; Zhang, Da-Bing; Yang, Li-Tao; Tao, Sheng-Ce

    2014-01-21

    The monitoring of genetically modified organisms (GMOs) is a primary step of GMO regulation. However, there is presently a lack of effective and high-throughput methodologies for specifically and sensitively monitoring most of the commercialized GMOs. Herein, we developed a multiplex amplification on a chip with readout on an oligo microarray (MACRO) system specifically for convenient GMO monitoring. This system is composed of a microchip for multiplex amplification and an oligo microarray for the readout of multiple amplicons, containing a total of 91 targets (18 universal elements, 20 exogenous genes, 45 events, and 8 endogenous reference genes) that covers 97.1% of all GM events that have been commercialized up to 2012. We demonstrate that the specificity of MACRO is ~100%, with a limit of detection (LOD) that is suitable for real-world applications. Moreover, the results obtained of simulated complex samples and blind samples with MACRO were 100% consistent with expectations and the results of independently performed real-time PCRs, respectively. Thus, we believe MACRO is the first system that can be applied for effectively monitoring the majority of the commercialized GMOs in a single test.

  5. Detection and quantification of genetically modified organisms using very short, locked nucleic acid TaqMan probes.

    PubMed

    Salvi, Sergio; D'Orso, Fabio; Morelli, Giorgio

    2008-06-25

    Many countries have introduced mandatory labeling requirements on foods derived from genetically modified organisms (GMOs). Real-time quantitative polymerase chain reaction (PCR) based upon the TaqMan probe chemistry has become the method mostly used to support these regulations; moreover, event-specific PCR is the preferred method in GMO detection because of its high specificity based on the flanking sequence of the exogenous integrant. The aim of this study was to evaluate the use of very short (eight-nucleotide long), locked nucleic acid (LNA) TaqMan probes in 5'-nuclease PCR assays for the detection and quantification of GMOs. Classic TaqMan and LNA TaqMan probes were compared for the analysis of the maize MON810 transgene. The performance of the two types of probes was tested on the maize endogenous reference gene hmga, the CaMV 35S promoter, and the hsp70/cryIA(b) construct as well as for the event-specific 5'-integration junction of MON810, using plasmids as standard reference molecules. The results of our study demonstrate that the LNA 5'-nuclease PCR assays represent a valid and reliable analytical system for the detection and quantification of transgenes. Application of very short LNA TaqMan probes to GMO quantification can simplify the design of 5'-nuclease assays.

  6. Organic intercalation of structure modified vermiculite.

    PubMed

    Wu, Nian; Wu, Limei; Liao, Libing; Lv, Guocheng

    2015-11-01

    The experiment used cationic surfactants of different chain lengths to intercalate structure modified vermiculites. The influences of structure modification, chain length and dosage of surfactants on the intercalation behavior of vermiculites were studied, and intercalation mechanism and features of interlayer chemical reactions were discussed. Results indicate that structure modified vermiculites with different layer charge have different intercalation behavior. The basal spacing of the organic intercalated modified vermiculite is the largest when acid concentration used in structure modification is 0.003 mol/L, and increases with increasing the chain length and dosage of the organics. Molecular dynamics simulation verifies that interlayer organics align almost parallel to structure layer of vermiculite, with alkyl chain stretching to the middle of interlayer space. -N(+) groups of the three surfactants locate above the leached [SiO4], which has stronger interaction with interlayer organic cations. Electrostatic force is the main interaction force between interlayer organics and structure layer of vermiculite, and then is Van der Waals force, no chemical bond formed.

  7. Multiplex polymerase chain reaction-capillary gel electrophoresis: a promising tool for GMO screening--assay for simultaneous detection of five genetically modified cotton events and species.

    PubMed

    Nadal, Anna; Esteve, Teresa; Pla, Maria

    2009-01-01

    A multiplex polymerase chain reaction assay coupled to capillary gel electrophoresis for amplicon identification by size and color (multiplex PCR-CGE-SC) was developed for simultaneous detection of cotton species and 5 events of genetically modified (GM) cotton. Validated real-time-PCR reactions targeting Bollgard, Bollgard II, Roundup Ready, 3006-210-23, and 281-24-236 junction sequences, and the cotton reference gene acp1 were adapted to detect more than half of the European Union-approved individual or stacked GM cotton events in one reaction. The assay was fully specific (<1.7% of false classification rate), with limit of detection values of 0.1% for each event, which were also achieved with simulated mixtures at different relative percentages of targets. The assay was further combined with a second multiplex PCR-CGE-SC assay to allow simultaneous detection of 6 cotton and 5 maize targets (two endogenous genes and 9 GM events) in two multiplex PCRs and a single CGE, making the approach more economic. Besides allowing simultaneous detection of many targets with adequate specificity and sensitivity, the multiplex PCR-CGE-SC approach has high throughput and automation capabilities, while keeping a very simple protocol, e.g., amplification and labeling in one step. Thus, it is an easy and inexpensive tool for initial screening, to be complemented with quantitative assays if necessary.

  8. One simple DNA extraction device and its combination with modified visual loop-mediated isothermal amplification for rapid on-field detection of genetically modified organisms.

    PubMed

    Zhang, Miao; Liu, Yinan; Chen, Lili; Quan, Sheng; Jiang, Shimeng; Zhang, Dabing; Yang, Litao

    2013-01-02

    Quickness, simplicity, and effectiveness are the three major criteria for establishing a good molecular diagnosis method in many fields. Herein we report a novel detection system for genetically modified organisms (GMOs), which can be utilized to perform both on-field quick screening and routine laboratory diagnosis. In this system, a newly designed inexpensive DNA extraction device was used in combination with a modified visual loop-mediated isothermal amplification (vLAMP) assay. The main parts of the DNA extraction device included a silica gel membrane filtration column and a modified syringe. The DNA extraction device could be easily operated without using other laboratory instruments, making it applicable to an on-field GMO test. High-quality genomic DNA (gDNA) suitable for polymerase chain reaction (PCR) and isothermal amplification could be quickly isolated from plant tissues using this device within 15 min. In the modified vLAMP assay, a microcrystalline wax encapsulated detection bead containing SYBR green fluorescent dye was introduced to avoid dye inhibition and cross-contaminations from post-LAMP operation. The system was successfully applied and validated in screening and identification of GM rice, soybean, and maize samples collected from both field testing and the Grain Inspection, Packers, and Stockyards Administration (GIPSA) proficiency test program, which demonstrated that it was well-adapted to both on-field testing and/or routine laboratory analysis of GMOs.

  9. DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products.

    PubMed

    Turkec, Aydin; Kazan, Hande; Karacanli, Burçin; Lucas, Stuart J

    2015-08-01

    In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products.

  10. Event-specific qualitative and quantitative PCR detection of the GMO carnation (Dianthus caryophyllus) variety Moonlite based upon the 5'-transgene integration sequence.

    PubMed

    Li, P; Jia, J W; Jiang, L X; Zhu, H; Bai, L; Wang, J B; Tang, X M; Pan, A H

    2012-04-27

    To ensure the implementation of genetically modified organism (GMO)-labeling regulations, an event-specific detection method was developed based on the junction sequence of an exogenous integrant in the transgenic carnation variety Moonlite. The 5'-transgene integration sequence was isolated by thermal asymmetric interlaced PCR. Based upon the 5'-transgene integration sequence, the event-specific primers and TaqMan probe were designed to amplify the fragments, which spanned the exogenous DNA and carnation genomic DNA. Qualitative and quantitative PCR assays were developed employing the designed primers and probe. The detection limit of the qualitative PCR assay was 0.05% for Moonlite in 100 ng total carnation genomic DNA, corresponding to about 79 copies of the carnation haploid genome; the limit of detection and quantification of the quantitative PCR assay were estimated to be 38 and 190 copies of haploid carnation genomic DNA, respectively. Carnation samples with different contents of genetically modified components were quantified and the bias between the observed and true values of three samples were lower than the acceptance criterion (<25%) of the GMO detection method. These results indicated that these event-specific methods would be useful for the identification and quantification of the GMO carnation Moonlite.

  11. EFSA's scientific activities and achievements on the risk assessment of genetically modified organisms (GMOs) during its first decade of existence: looking back and ahead.

    PubMed

    Devos, Yann; Aguilera, Jaime; Diveki, Zoltán; Gomes, Ana; Liu, Yi; Paoletti, Claudia; du Jardin, Patrick; Herman, Lieve; Perry, Joe N; Waigmann, Elisabeth

    2014-02-01

    Genetically modified organisms (GMOs) and derived food and feed products are subject to a risk analysis and regulatory approval before they can enter the market in the European Union (EU). In this risk analysis process, the role of the European Food Safety Authority (EFSA), which was created in 2002 in response to multiple food crises, is to independently assess and provide scientific advice to risk managers on any possible risks that the use of GMOs may pose to human and animal health and the environment. EFSA's scientific advice is elaborated by its GMO Panel with the scientific support of several working groups and EFSA's GMO Unit. This review presents EFSA's scientific activities and highlights its achievements on the risk assessment of GMOs for the first 10 years of its existence. Since 2002, EFSA has issued 69 scientific opinions on genetically modified (GM) plant market registration applications, of which 62 for import and processing for food and feed uses, six for cultivation and one for the use of pollen (as or in food), and 19 scientific opinions on applications for marketing products made with GM microorganisms. Several guidelines for the risk assessment of GM plants, GM microorganisms and GM animals, as well as on specific issues such as post-market environmental monitoring (PMEM) were elaborated. EFSA also provided scientific advice upon request of the European Commission on safeguard clause and emergency measures invoked by EU Member States, annual PMEM reports, the potential risks of new biotechnology-based plant breeding techniques, evaluations of previously assessed GMOs in the light of new scientific publications, and the use of antibiotic resistance marker genes in GM plants. Future challenges relevant to the risk assessment of GMOs are discussed. EFSA's risk assessments of GMO applications ensure that data are analysed and presented in a way that facilitates scientifically sound decisions that protect human and animal health and the environment.

  12. Genetically modified organisms (GMOs) and aquaculture.

    PubMed

    Beardmore, J A; Porter, Joanne S

    2003-01-01

    This paper reviews the nature of genetically modified organisms (GMOs), the range of aquatic species in which GMOs have been produced, the methods and target genes employed, the benefits to aquaculture, the problems attached to use of GMOs in aquatic species and the regulatory and other social frameworks surrounding them. A set of recommendations aimed at best practice is appended. This states the potential value of GMOs in aquaculture but also calls for improved knowledge particularly of sites of integration, risk analysis, progress in achieving sterility in fish for production and better dissemination of relevant information.

  13. [The EU law on genetically modified organisms: the European Commission changes the strategy in order to allow, restrict, or prohibit its culture].

    PubMed

    González Vaqué, Luis

    2010-01-01

    On July 13 2010, the European Commission adopted a series of measures which outline a new approach on Genetically Modified Organisms (GMOs) cultivation in the Member States. This proposal, which still retains the basis of the existing science-based GMO authorisation system, will be implemented through: a Communication from the Commission, explaining the new approach on the freedom for Member States to decide on the cultivation of genetically modified crops; the "Proposal for a Regulation of the European Parliament and of the Council amending Directive 2001/18/EC as regards the possibility for the Member States to restrict or prohibit the cultivation of GMOs in their territory"; and a new "European Commission Recommendation (2010/C 200/01) of 13 July 2010 on guidelines for the development of national co-existence measures to avoid the unintended presence of GMOs in conventional and organic crops".

  14. Capillary electrophoresis with electrochemiluminescent detection for highly sensitive assay of genetically modified organisms.

    PubMed

    Guo, Longhua; Yang, Huanghao; Qiu, Bin; Xiao, Xueyang; Xue, Linlin; Kim, Donghwan; Chen, Guonan

    2009-12-01

    A capillary electrophoresis coupled with electrochemiluminescent detection system (CE-ECL) was developed for the detection of polymerase chain reaction (PCR) amplicons. The ECL luminophore, tris(1,10-phenanthroline) ruthenium(II) (Ru(phen)(3)(2+)), was labeled to the PCR primers before amplification. Ru(phen)(3)(2+) was then introduced to PCR amplicons by PCR amplification. Eventually, the PCR amplicons were separated and detected by the homemade CE-ECL system. The detection of a typical genetically modified organism (GMO), Roundup Ready Soy (RRS), was shown as an example to demonstrate the reliability of the proposed approach. Four pairs of primers were amplified by multiple PCR (MPCR) simultaneously, three of which were targeted on the specific sequence of exogenous genes of RRS, and another was targeted on the endogenous reference gene of soybean. Both the conditions for PCR amplification and CE-ECL separation and detection were investigated in detail. Results showed that, under the optimal conditions, the proposed method can accurately identifying RRS. The corresponding limit of detection (LOD) was below 0.01% with 35 PCR cycles.

  15. Visual detection of multiple genetically modified organisms in a capillary array.

    PubMed

    Shao, Ning; Chen, Jianwei; Hu, Jiaying; Li, Rong; Zhang, Dabing; Guo, Shujuan; Hui, Junhou; Liu, Peng; Yang, Litao; Tao, Sheng-Ce

    2017-01-31

    There is an urgent need for rapid, low-cost multiplex methodologies for the monitoring of genetically modified organisms (GMOs). Here, we report a C[combining low line]apillary A[combining low line]rray-based L[combining low line]oop-mediated isothermal amplification for M[combining low line]ultiplex visual detection of nucleic acids (CALM) platform for the simple and rapid monitoring of GMOs. In CALM, loop-mediated isothermal amplification (LAMP) primer sets are pre-fixed to the inner surface of capillaries. The surface of the capillary array is hydrophobic while the capillaries are hydrophilic, enabling the simultaneous loading and separation of the LAMP reaction mixtures into each capillary by capillary forces. LAMP reactions in the capillaries are then performed in parallel, and the results are visually detected by illumination with a hand-held UV device. Using CALM, we successfully detected seven frequently used transgenic genes/elements and five plant endogenous reference genes with high specificity and sensitivity. Moreover, we found that measurements of real-world blind samples by CALM are consistent with results obtained by independent real-time PCRs. Thus, with an ability to detect multiple nucleic acids in a single easy-to-operate test, we believe that CALM will become a widely applied technology in GMO monitoring.

  16. Novel GMO-Based Vaccines against Tuberculosis: State of the Art and Biosafety Considerations

    PubMed Central

    Leunda, Amaya; Baldo, Aline; Goossens, Martine; Huygen, Kris; Herman, Philippe; Romano, Marta

    2014-01-01

    Novel efficient vaccines are needed to control tuberculosis (TB), a major cause of morbidity and mortality worldwide. Several TB vaccine candidates are currently in clinical and preclinical development. They fall into two categories, the one of candidates designed as a replacement of the Bacille Calmette Guérin (BCG) to be administered to infants and the one of sub-unit vaccines designed as booster vaccines. The latter are designed as vaccines that will be administered to individuals already vaccinated with BCG (or in the future with a BCG replacement vaccine). In this review we provide up to date information on novel tuberculosis (TB) vaccines in development focusing on the risk assessment of candidates composed of genetically modified organisms (GMO) which are currently evaluated in clinical trials. Indeed, these vaccines administered to volunteers raise biosafety concerns with respect to human health and the environment that need to be assessed and managed. PMID:26344627

  17. Applicability of Three Alternative Instruments for Food Authenticity Analysis: GMO Identification

    PubMed Central

    Burrell, A.; Foy, C.; Burns, M.

    2011-01-01

    Ensuring foods are correctly labelled for ingredients derived from genetically modified organisms (GMOs) is an issue facing manufacturers, retailers, and enforcement agencies. DNA approaches for the determination of food authenticitys often use the polymerase chain reaction (PCR), and PCR products can be detected using capillary or gel electrophoresis. This study examines the fitness for purpose of the application of three laboratory electrophoresis instruments (Agilent Bioanalyzer 2100, Lab901 TapeStation, and Shimadzu MCE-202 MultiNA) for the detection of GMOs using PCR based on a previously validated protocol. Whilst minor differences in the performance characteristics of bias and precision were observed, all three instruments demonstrated their applicability in using this protocol for screening of GMO ingredients. PMID:21527985

  18. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    PubMed

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-01-01

    Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by fusing them to various cell-wall binding domains, of which the Lysine motif domain (LysM) is particularly well studied. Fusion proteins have been isolated from recombinant bacteria or from their growth medium and displayed on unmodified bacteria, enabling heterologous surface display. This was demonstrated on non-viable cells devoid of protein content, termed bacteria-like particles, and on various species of genus Lactobacillus. Of the latter, Lactobacillus salivarius ATCC 11741 was recently shown to be particularly amenable for LysM-mediated display. Possible regulatory implications of heterologous surface display are discussed, particularly those relevant for the European Union.

  19. Applicability of three alternative instruments for food authenticity analysis: GMO identification.

    PubMed

    Burrell, A; Foy, C; Burns, M

    2011-03-06

    Ensuring foods are correctly labelled for ingredients derived from genetically modified organisms (GMOs) is an issue facing manufacturers, retailers, and enforcement agencies. DNA approaches for the determination of food authenticitys often use the polymerase chain reaction (PCR), and PCR products can be detected using capillary or gel electrophoresis. This study examines the fitness for purpose of the application of three laboratory electrophoresis instruments (Agilent Bioanalyzer 2100, Lab901 TapeStation, and Shimadzu MCE-202 MultiNA) for the detection of GMOs using PCR based on a previously validated protocol. Whilst minor differences in the performance characteristics of bias and precision were observed, all three instruments demonstrated their applicability in using this protocol for screening of GMO ingredients.

  20. Novel GMO-Based Vaccines against Tuberculosis: State of the Art and Biosafety Considerations.

    PubMed

    Leunda, Amaya; Baldo, Aline; Goossens, Martine; Huygen, Kris; Herman, Philippe; Romano, Marta

    2014-06-16

    Novel efficient vaccines are needed to control tuberculosis (TB), a major cause of morbidity and mortality worldwide. Several TB vaccine candidates are currently in clinical and preclinical development. They fall into two categories, the one of candidates designed as a replacement of the Bacille Calmette Guérin (BCG) to be administered to infants and the one of sub-unit vaccines designed as booster vaccines. The latter are designed as vaccines that will be administered to individuals already vaccinated with BCG (or in the future with a BCG replacement vaccine). In this review we provide up to date information on novel tuberculosis (TB) vaccines in development focusing on the risk assessment of candidates composed of genetically modified organisms (GMO) which are currently evaluated in clinical trials. Indeed, these vaccines administered to volunteers raise biosafety concerns with respect to human health and the environment that need to be assessed and managed.

  1. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    PubMed Central

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-01-01

    Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by fusing them to various cell-wall binding domains, of which the Lysine motif domain (LysM) is particularly well studied. Fusion proteins have been isolated from recombinant bacteria or from their growth medium and displayed on unmodified bacteria, enabling heterologous surface display. This was demonstrated on non-viable cells devoid of protein content, termed bacteria-like particles, and on various species of genus Lactobacillus. Of the latter, Lactobacillus salivarius ATCC 11741 was recently shown to be particularly amenable for LysM-mediated display. Possible regulatory implications of heterologous surface display are discussed, particularly those relevant for the European Union. PMID:25880164

  2. Potential of cross-priming amplification and DNA-based lateral-flow strip biosensor for rapid on-site GMO screening.

    PubMed

    Huang, Xin; Zhai, Congcong; You, Qimin; Chen, Hongjun

    2014-07-01

    The requirement to monitor the presence of genetically modified organisms (GMO) in a variety of marked products has generated an increasing demand for reliable, rapid, and time and cost-effective analytical methods. Here we report an on-site method for rapid detection of cauliflower mosaic virus promoter (CaMV 35S), a common element present in most GMO, using cross-priming amplification (CPA) technology. Detection was achieved using a DNA-based contamination-proof strip biosensor. The limit of detection was 30 copies for the pBI121 plasmid containing the CaMV 35S gene. The certified reference sample of GM maize line MON810 was detectable even at the low relative mass concentration of 0.05%. The developed CPA method had high specificity for the CaMV 35S gene, as compared with other GM lines not containing this gene and non-GM products. The method was further validated using nine real-world samples, and the results were confirmed by real-time PCR analysis. Because of its simplicity, rapidity, and high sensitivity, this method of detecting the CaMV 35S gene has great commercial prospects for rapid GMO screening of high-consumption food and agriculture products.

  3. PCR-Free Detection of Genetically Modified Organisms Using Magnetic Capture Technology and Fluorescence Cross-Correlation Spectroscopy

    PubMed Central

    Zhou, Xiaoming; Xing, Da; Tang, Yonghong; Chen, Wei R.

    2009-01-01

    The safety of genetically modified organisms (GMOs) has attracted much attention recently. Polymerase chain reaction (PCR) amplification is a common method used in the identification of GMOs. However, a major disadvantage of PCR is the potential amplification of non-target DNA, causing false-positive identification. Thus, there remains a need for a simple, reliable and ultrasensitive method to identify and quantify GMO in crops. This report is to introduce a magnetic bead-based PCR-free method for rapid detection of GMOs using dual-color fluorescence cross-correlation spectroscopy (FCCS). The cauliflower mosaic virus 35S (CaMV35S) promoter commonly used in transgenic products was targeted. CaMV35S target was captured by a biotin-labeled nucleic acid probe and then purified using streptavidin-coated magnetic beads through biotin-streptavidin linkage. The purified target DNA fragment was hybridized with two nucleic acid probes labeled respectively by Rhodamine Green and Cy5 dyes. Finally, FCCS was used to detect and quantify the target DNA fragment through simultaneously detecting the fluorescence emissions from the two dyes. In our study, GMOs in genetically engineered soybeans and tomatoes were detected, using the magnetic bead-based PCR-free FCCS method. A detection limit of 50 pM GMOs target was achieved and PCR-free detection of GMOs from 5 µg genomic DNA with magnetic capture technology was accomplished. Also, the accuracy of GMO determination by the FCCS method is verified by spectrophotometry at 260 nm using PCR amplified target DNA fragment from GM tomato. The new method is rapid and effective as demonstrated in our experiments and can be easily extended to high-throughput and automatic screening format. We believe that the new magnetic bead-assisted FCCS detection technique will be a useful tool for PCR-free GMOs identification and other specific nucleic acids. PMID:19956680

  4. PCR-free detection of genetically modified organisms using magnetic capture technology and fluorescence cross-correlation spectroscopy.

    PubMed

    Zhou, Xiaoming; Xing, Da; Tang, Yonghong; Chen, Wei R

    2009-11-26

    The safety of genetically modified organisms (GMOs) has attracted much attention recently. Polymerase chain reaction (PCR) amplification is a common method used in the identification of GMOs. However, a major disadvantage of PCR is the potential amplification of non-target DNA, causing false-positive identification. Thus, there remains a need for a simple, reliable and ultrasensitive method to identify and quantify GMO in crops. This report is to introduce a magnetic bead-based PCR-free method for rapid detection of GMOs using dual-color fluorescence cross-correlation spectroscopy (FCCS). The cauliflower mosaic virus 35S (CaMV35S) promoter commonly used in transgenic products was targeted. CaMV35S target was captured by a biotin-labeled nucleic acid probe and then purified using streptavidin-coated magnetic beads through biotin-streptavidin linkage. The purified target DNA fragment was hybridized with two nucleic acid probes labeled respectively by Rhodamine Green and Cy5 dyes. Finally, FCCS was used to detect and quantify the target DNA fragment through simultaneously detecting the fluorescence emissions from the two dyes. In our study, GMOs in genetically engineered soybeans and tomatoes were detected, using the magnetic bead-based PCR-free FCCS method. A detection limit of 50 pM GMOs target was achieved and PCR-free detection of GMOs from 5 microg genomic DNA with magnetic capture technology was accomplished. Also, the accuracy of GMO determination by the FCCS method is verified by spectrophotometry at 260 nm using PCR amplified target DNA fragment from GM tomato. The new method is rapid and effective as demonstrated in our experiments and can be easily extended to high-throughput and automatic screening format. We believe that the new magnetic bead-assisted FCCS detection technique will be a useful tool for PCR-free GMOs identification and other specific nucleic acids.

  5. Genetically modified organisms and visceral leishmaniasis.

    PubMed

    Chhajer, Rudra; Ali, Nahid

    2014-01-01

    Vaccination is the most effective method of preventing infectious diseases. Since the eradication of small pox in 1976, many other potentially life compromising if not threatening diseases have been dealt with subsequently. This event was a major leap not only in the scientific world already burdened with many diseases but also in the mindset of the common man who became more receptive to novel treatment options. Among the many protozoan diseases, the leishmaniases have emerged as one of the largest parasite killers of the world, second only to malaria. There are three types of leishmaniasis namely cutaneous (CL), mucocutaneous (ML), and visceral (VL), caused by a group of more than 20 species of Leishmania parasites. Visceral leishmaniasis, also known as kala-azar is the most severe form and almost fatal if untreated. Since the first attempts at leishmanization, we have killed parasite vaccines, subunit protein, or DNA vaccines, and now we have live recombinant carrier vaccines and live attenuated parasite vaccines under various stages of development. Although some research has shown promising results, many more potential genes need to be evaluated as live attenuated vaccine candidates. This mini-review attempts to summarize the success and failures of genetically modified organisms used in vaccination against some of major parasitic diseases for their application in leishmaniasis.

  6. Plants with stacked genetically modified events: to assess or not to assess?

    PubMed

    Kok, Esther J; Pedersen, Jan; Onori, Roberta; Sowa, Slawomir; Schauzu, Marianna; De Schrijver, Adinda; Teeri, Teemu H

    2014-02-01

    The principles for the safety assessment of genetically modified (GM) organisms (GMOs) are harmonised worldwide to a large extent. There are, however, still differences between the European GMO regulations and the GMO regulations as they have been formulated in other parts of the world. One of these differences relates to the so-called 'stacked GM events', that is, GMOs, plants so far, where new traits are combined by conventional crossing of different GM plants. This paper advocates rethinking the current food/feed safety assessment of stacked GM events in Europe based on an analysis of different aspects that currently form the rationale for the safety assessment of stacked GM events.

  7. Monitoring the presence of genetically modified food on the market of the Republic of Croatia.

    PubMed

    Cattunar, Albert; Capak, Krunoslav; Novak, Jelena Zafran; Mićović, Vladimir; Doko-Jelinić, Jagoda; Malatestinić, Dulija

    2011-12-01

    From the beginning of the human race people have been applying different methods to change the genetic material of either plants or animals in order to increase their yield as well as to improve the quality and quantity of food. Genetically modified organism (GMO) means an organism in which the genetic material has been altered in a way that does not occur naturally by mating and/or natural recombination. Analysing the presence of GMO in food is done by detecting the presence of either specific DNA sequences inserted in the genome of transgenic organism, or detecting proteins as a result of the expression of the inserted DNA. In this work food testing for the presence of genetically modified organisms was conducted during the period from 2004 to 2007 in the GMO laboratory of the Croatian National Institute of Public Health. According to the regulations, among the samples in which the presence of GMO was detected, all those which had more than 0.9% of GMO content were either rejected from the border or removed from the market, because such GM food has to be appropriately labelled. Among the food samples which were analysed in 2004: 127 (2.37%) of a total of 1226 samples contained more than 0.9% of GMOs; in 2005 there was only one in 512 (0.20%) samples in total; in 2006 there were 4 out of 404 samples (0.99%), and in 2007: 7 of a total of 655 samples (1.07%) had GMO content above the allowed threshold of 0.9%.

  8. Risk assessment for release of genetically modified organisms: a virus to reduce the fertility of introduced wild mice, Mus domesticus.

    PubMed

    Williams, C K

    2002-01-01

    Risk assessment is a key task in developing genetically modified organisms (GMOs) intended for release into the environment. A risk assessment protocol is described, focusing on genetically modified biological control agents intended to reduce fertility in mammalian pests. The protocol is being applied to development of an immunocontraceptive murine cytomegalovirus vaccine intended to reduce the frequency and extent of costly troublesome plagues of introduced house mice, Mus domesticus, in southern Australia. Success of the agent, including regulatory approval for release to target populations, will depend on demonstrated biosafety, on the biophysical consequences of releasing the agent, and on public perceptions of the consequences and ongoing risks. The proposed risk assessment protocol addresses biosafety and the biophysical and social risks. It elicits perceptions of interaction and risk from the project scientists and from representatives of interested or affected sectors of society. The perceptions are documented for examination interactively in subsequent socially inclusive formal risk assessments. Representatives of the relevant social sectors participate with the scientists, iteratively if needed, in a workshop to assess the risks of releasing the particular GMO into the environment, using a formal inductive procedure, GENHAZ, designed specifically for assessment and management of the risks of GMOs. Use of this protocol is intended to precede and complement risk assessment and risk management procedures specified by gene technology legislation and regulations.

  9. Multi-wall carbon nanotubes (MWCNTs)-doped polypyrrole DNA biosensor for label-free detection of genetically modified organisms by QCM and EIS.

    PubMed

    Truong, Thi Ngoc Lien; Tran, Dai Lam; Vu, Thi Hong An; Tran, Vinh Hoang; Duong, Tuan Quang; Dinh, Quang Khieu; Tsukahara, Toshifumi; Lee, Young Hoon; Kim, Jong Seung

    2010-01-15

    In this paper, we describe DNA electrochemical detection for genetically modified organism (GMO) based on multi-wall carbon nanotubes (MWCNTs)-doped polypyrrole (PPy). DNA hybridization is studied by quartz crystal microbalance (QCM) and electrochemical impedance spectroscopy (EIS). An increase in DNA complementary target concentration results in a decrease in the faradic charge transfer resistance (R(ct)) and signifying "signal-on" behavior of MWCNTs-PPy-DNA system. QCM and EIS data indicated that the electroanalytical MWCNTs-PPy films were highly sensitive (as low as 4pM of target can be detected with QCM technique). In principle, this system can be suitable not only for DNA but also for protein biosensor construction.

  10. [Risk assessment of genetically modified organisms].

    PubMed

    Costa, Thadeu Estevam Moreira Maramaldo; Dias, Aline Peçanha Muzy; Scheidegger, Erica Miranda Damasio; Marin, Victor Augustus

    2011-01-01

    Since the commercial approve in 1996, the global area of transgenic crops has raised more than 50 times. In the last two decades, governments have been planning strategies and protocols for safety assessment of food and feed genetically modified (GM). Evaluation of food safety should be taken on a case-by-case analysis depending on the specific traits of the modified crops and the changes introduced by the genetic modification, using for this the concept of substantial equivalence. This work presents approaches for the risk assessment of GM food, as well as some problems related with the genetic construction or even with the expression of the inserted gene.

  11. Detection limits of the strip test and PCR for genetically modified corn in Brazil.

    PubMed

    Nascimento, V E; Von Pinho, É V R; Von Pinho, R G; do Nascimento, A D

    2012-08-16

    Brazilian legislation establishes a labeling limit for products that contain more than 1% material from genetically modified organisms (GMOs). We assessed the sensitivity of the lateral flow strip test in detection of the GMO corn varieties Bt11 and MON810 and the specificity and sensitivity of PCR techniques for their detection. For the strip test, the GMO seeds were mixed with conventional seeds at levels of 0.2, 0.4 and 0.8% for Bt11, and 0.4, 0.8 and 1.6% for MON810. Three different methodologies were assessed and whole seeds, their endosperm and embryonic axis were used. For the PCR technique, the GMO seeds of each of the two varieties were mixed with conventional seeds at levels of 20, 10, 5, 2, 1, and 0.5%. The seeds were ground and the DNA extracted. For detection of the GMO material, specific primers were used for MON810 and Bt11 and maize zein as an endogenous control. The sensitivity of the strip test varied for both maize varieties and methodologies. The test was positive for Bt11 only at 0.8%, in contrast with the detection limit of 0.4% indicated by the manufacturer. In the multiplex PCR, the primers proved to be specific for the different varieties. These varieties were detected in samples with one GMO seed in 100. Thus, this technique proved to be efficient in detecting contaminations equal to or greater than 1%.

  12. [Removal of red tide organisms by organo-modified bentonite].

    PubMed

    Deng, Yuesong; Xu, Zirong; Xia, Meisheng; Ye, Ying; Hu, Caihong

    2004-01-01

    A series of organo-bentonites were synthesized by exchanging cation surfactants such as cyltrimethylammonium bromide and cetyltrimethylammonium to remove red tide organisms Skeletonema costatum. The results showed that the removal rate of Skeletonema costatum by the bentonites was in the order of cyltrimethylammonium surfactant modified iron pillared bentonite > cetyltrimethylammoium surfactant modified iron pillared bentonite > iron pillared bentonite > cyltrimethylammonium surfactant modified sodium bentonite > cetyltrimethylammoium surfactant modified > sodium bentonite. The removal rate of Skeletonema costatum was related to the length of alkyl chains and the amount of cation surfactants exchanged on bentonites.

  13. Construction of measurement uncertainty profiles for quantitative analysis of genetically modified organisms based on interlaboratory validation data.

    PubMed

    Macarthur, Roy; Feinberg, Max; Bertheau, Yves

    2010-01-01

    A method is presented for estimating the size of uncertainty associated with the measurement of products derived from genetically modified organisms (GMOs). The method is based on the uncertainty profile, which is an extension, for the estimation of uncertainty, of a recent graphical statistical tool called an accuracy profile that was developed for the validation of quantitative analytical methods. The application of uncertainty profiles as an aid to decision making and assessment of fitness for purpose is also presented. Results of the measurement of the quantity of GMOs in flour by PCR-based methods collected through a number of interlaboratory studies followed the log-normal distribution. Uncertainty profiles built using the results generally give an expected range for measurement results of 50-200% of reference concentrations for materials that contain at least 1% GMO. This range is consistent with European Network of GM Laboratories and the European Union (EU) Community Reference Laboratory validation criteria and can be used as a fitness for purpose criterion for measurement methods. The effect on the enforcement of EU labeling regulations is that, in general, an individual analytical result needs to be < 0.45% to demonstrate compliance, and > 1.8% to demonstrate noncompliance with a labeling threshold of 0.9%.

  14. A highly sensitive and specific method for the screening detection of genetically modified organisms based on digital PCR without pretreatment.

    PubMed

    Fu, Wei; Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Du, Zhixin; Tian, Wenying; Wang, Qin; Wang, Huiyu; Xu, Wentao; Zhu, Shuifang

    2015-08-04

    Digital PCR has developed rapidly since it was first reported in the 1990 s. It was recently reported that an improved method facilitated the detection of genetically modified organisms (GMOs). However, to use this improved method, the samples must be pretreated, which could introduce inaccuracy into the results. In our study, we explored a pretreatment-free digital PCR detection method for the screening for GMOs. We chose the CaMV35s promoter and the NOS terminator as the templates in our assay. To determine the specificity of our method, 9 events of GMOs were collected, including MON810, MON863, TC1507, MIR604, MIR162, GA21, T25, NK603 and Bt176. Moreover, the sensitivity, intra-laboratory and inter-laboratory reproducibility of our detection method were assessed. The results showed that the limit of detection of our method was 0.1%, which was lower than the labeling threshold level of the EU. The specificity and stability among the 9 events were consistent, respectively. The intra-laboratory and inter-laboratory reproducibility were both good. Finally, the perfect fitness for the detection of eight double-blind samples indicated the good practicability of our method. In conclusion, the method in our study would allow more sensitive, specific and stable screening detection of the GMO content of international trading products.

  15. A highly sensitive and specific method for the screening detection of genetically modified organisms based on digital PCR without pretreatment

    PubMed Central

    Fu, Wei; Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Du, Zhixin; Tian, Wenying; Wang, Qin; Wang, Huiyu; Xu, Wentao; Zhu, Shuifang

    2015-01-01

    Digital PCR has developed rapidly since it was first reported in the 1990s. It was recently reported that an improved method facilitated the detection of genetically modified organisms (GMOs). However, to use this improved method, the samples must be pretreated, which could introduce inaccuracy into the results. In our study, we explored a pretreatment-free digital PCR detection method for the screening for GMOs. We chose the CaMV35s promoter and the NOS terminator as the templates in our assay. To determine the specificity of our method, 9 events of GMOs were collected, including MON810, MON863, TC1507, MIR604, MIR162, GA21, T25, NK603 and Bt176. Moreover, the sensitivity, intra-laboratory and inter-laboratory reproducibility of our detection method were assessed. The results showed that the limit of detection of our method was 0.1%, which was lower than the labeling threshold level of the EU. The specificity and stability among the 9 events were consistent, respectively. The intra-laboratory and inter-laboratory reproducibility were both good. Finally, the perfect fitness for the detection of eight double-blind samples indicated the good practicability of our method. In conclusion, the method in our study would allow more sensitive, specific and stable screening detection of the GMO content of international trading products. PMID:26239916

  16. Are good ideas enough? The impact of socio-economic and regulatory factors on GMO commercialisation.

    PubMed

    Vàzquez-Salat, Núria

    2013-01-01

    In recent years scientific literature has seen an increase in publications describing new transgenic applications. Although technically-sound, these promising developments might not necessarily translate into products available to the consumer. This article highlights the impact of external factors on the commercial viability of Genetically Modified (GM) animals in the pharmaceutical and food sectors. Through the division of the production chain into three Policy Domains -Science, Market and Public- I present an overview of the broad range of regulatory and socio-economic components that impacts on the path towards commercialisation of GM animals. To further illustrate the unique combination of forces that influence each application, I provide an in-depth analysis of two real cases: GM rabbits producing human polyclonal antibodies (pharmaceutical case study) and GM cows producing recombinant human lactoferrin (food case study). The inability to generalise over the commercial success of a given transgenic application should encourage researchers to perform these type of exercises early in the R & D process. Furthermore, through the analysis of these case studies we can observe a change in the biopolitics of Genetically Modified Organisms (GMOs). Contrary to the GM plant biopolitical landscape, developing states such as China and Argentina are placing themselves as global leaders in GM animals. The pro-GM attitude of these states is likely to cause a shift in the political evolution of global GMO governance.

  17. Development of a real-time PCR method for the differential detection and quantification of four solanaceae in GMO analysis: potato (Solanum tuberosum), tomato (Solanum lycopersicum), eggplant (Solanum melongena), and pepper (Capsicum annuum).

    PubMed

    Chaouachi, Maher; El Malki, Redouane; Berard, Aurélie; Romaniuk, Marcel; Laval, Valérie; Brunel, Dominique; Bertheau, Yves

    2008-03-26

    The labeling of products containing genetically modified organisms (GMO) is linked to their quantification since a threshold for the presence of fortuitous GMOs in food has been established. This threshold is calculated from a combination of two absolute quantification values: one for the specific GMO target and the second for an endogenous reference gene specific to the taxon. Thus, the development of reliable methods to quantify GMOs using endogenous reference genes in complex matrixes such as food and feed is needed. Plant identification can be difficult in the case of closely related taxa, which moreover are subject to introgression events. Based on the homology of beta-fructosidase sequences obtained from public databases, two couples of consensus primers were designed for the detection, quantification, and differentiation of four Solanaceae: potato (Solanum tuberosum), tomato (Solanum lycopersicum), pepper (Capsicum annuum), and eggplant (Solanum melongena). Sequence variability was studied first using lines and cultivars (intraspecies sequence variability), then using taxa involved in gene introgressions, and finally, using taxonomically close taxa (interspecies sequence variability). This study allowed us to design four highly specific TaqMan-MGB probes. A duplex real time PCR assay was developed for simultaneous quantification of tomato and potato. For eggplant and pepper, only simplex real time PCR tests were developed. The results demonstrated the high specificity and sensitivity of the assays. We therefore conclude that beta-fructosidase can be used as an endogenous reference gene for GMO analysis.

  18. MS-based analytical methodologies to characterize genetically modified crops.

    PubMed

    García-Cañas, Virginia; Simó, Carolina; León, Carlos; Ibáñez, Elena; Cifuentes, Alejandro

    2011-01-01

    The development of genetically modified crops has had a great impact on the agriculture and food industries. However, the development of any genetically modified organism (GMO) requires the application of analytical procedures to confirm the equivalence of the GMO compared to its isogenic non-transgenic counterpart. Moreover, the use of GMOs in foods and agriculture faces numerous criticisms from consumers and ecological organizations that have led some countries to regulate their production, growth, and commercialization. These regulations have brought about the need of new and more powerful analytical methods to face the complexity of this topic. In this regard, MS-based technologies are increasingly used for GMOs analysis to provide very useful information on GMO composition (e.g., metabolites, proteins). This review focuses on the MS-based analytical methodologies used to characterize genetically modified crops (also called transgenic crops). First, an overview on genetically modified crops development is provided, together with the main difficulties of their analysis. Next, the different MS-based analytical approaches applied to characterize GM crops are critically discussed, and include "-omics" approaches and target-based approaches. These methodologies allow the study of intended and unintended effects that result from the genetic transformation. This information is considered to be essential to corroborate (or not) the equivalence of the GM crop with its isogenic non-transgenic counterpart.

  19. An animal welfare perspective on animal testing of GMO crops.

    PubMed

    Kolar, Roman; Rusche, Brigitte

    2008-01-01

    The public discussion on the introduction of agro-genetic engineering focuses mainly on economical, ecological and human health aspects. The fact is neglected that laboratory animals must suffer before either humans or the environment are affected. However, numerous animal experiments are conducted for toxicity testing and authorisation of genetically modified plants in the European Union. These are ethically questionable, because death and suffering of the animals for purely commercial purposes are accepted. Therefore, recent political initiatives to further increase animal testing for GMO crops must be regarded highly critically. Based on concrete examples this article demonstrates that animal experiments, on principle, cannot provide the expected protection of users and consumers despite all efforts to standardise, optimise or extend them.

  20. Genetic modification through oligonucleotide-mediated mutagenesis. A GMO regulatory challenge?

    PubMed

    Breyer, Didier; Herman, Philippe; Brandenburger, Annick; Gheysen, Godelieve; Remaut, Erik; Soumillion, Patrice; Van Doorsselaere, Jan; Custers, René; Pauwels, Katia; Sneyers, Myriam; Reheul, Dirk

    2009-01-01

    In the European Union, the definition of a GMO is technology-based. This means that a novel organism will be regulated under the GMO regulatory framework only if it has been developed with the use of defined techniques. This approach is now challenged with the emergence of new techniques. In this paper, we describe regulatory and safety issues associated with the use of oligonucleotide-mediated mutagenesis to develop novel organisms. We present scientific arguments for not having organisms developed through this technique fall within the scope of the EU regulation on GMOs. We conclude that any political decision on this issue should be taken on the basis of a broad reflection at EU level, while avoiding discrepancies at international level.

  1. A semi-quantitative approach to GMO risk-benefit analysis.

    PubMed

    Morris, E Jane

    2011-10-01

    In many countries there are increasing calls for the benefits of genetically modified organisms (GMOs) to be considered as well as the risks, and for a risk-benefit analysis to form an integral part of GMO regulatory frameworks. This trend represents a shift away from the strict emphasis on risks, which is encapsulated in the Precautionary Principle that forms the basis for the Cartagena Protocol on Biosafety, and which is reflected in the national legislation of many countries. The introduction of risk-benefit analysis of GMOs would be facilitated if clear methodologies were available to support the analysis. Up to now, methodologies for risk-benefit analysis that would be applicable to the introduction of GMOs have not been well defined. This paper describes a relatively simple semi-quantitative methodology that could be easily applied as a decision support tool, giving particular consideration to the needs of regulators in developing countries where there are limited resources and experience. The application of the methodology is demonstrated using the release of an insect resistant maize variety in South Africa as a case study. The applicability of the method in the South African regulatory system is also discussed, as an example of what might be involved in introducing changes into an existing regulatory process.

  2. DNA content in embryo and endosperm of maize kernel (Zea mays L.): impact on GMO quantification.

    PubMed

    Trifa, Youssef; Zhang, David

    2004-03-10

    PCR-based techniques are the most widely used methods for the quantification of genetically modified organisms (GMOs) through the determination of the ratio of transgenic DNA to total DNA. It is shown that the DNA content per mass unit is significantly different among 10 maize cultivars. The DNA contents of endosperms, embryos, and teguments of individual kernels from 10 maize cultivars were determined. According to our results, the tegument's DNA ratio reaches at maximum 3.5% of the total kernel's DNA, whereas the endosperm's and the embryo's DNA ratios are nearly equal to 50%. The embryo cells are diploid and made of one paternal and one maternal haploid genome, whereas the endosperm is constituted of triploid cells made of two maternal haploid genomes and one paternal haploid genome. Therefore, it is shown, in this study, that the accuracy of the GMO quantification depends on the reference material used as well as on the category of the transgenic kernels present in the mixture.

  3. Individual detection of genetically modified maize varieties in non-identity-preserved maize samples.

    PubMed

    Akiyama, Hiroshi; Sakata, Kozue; Kondo, Kazunari; Tanaka, Asako; Liu, Ming S; Oguchi, Taichi; Furui, Satoshi; Kitta, Kazumi; Hino, Akihiro; Teshima, Reiko

    2008-03-26

    In many countries, the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved GM varieties. The GMO content in a maize sample containing the combined-trait (stacked) GM maize as determined by the currently available methodology is likely to be overestimated. However, there has been little information in the literature on the mixing level and varieties of stacked GM maize in real sample grains. For the first time, the GMO content of non-identity-preserved (non-IP) maize samples imported from the United States has been successfully determined by using a previously developed individual kernel detection system coupled to a multiplex qualitative PCR method followed by multichannel capillary gel electrophoresis system analysis. To clarify the GMO content in the maize samples imported from the United States, determine how many stacked GM traits are contained therein, and which GM trait varieties frequently appeared in 2005, the GMO content (percent) on a kernel basis and the varieties of the GM kernels in the non-IP maize samples imported from the United States were investigated using the individual kernel analysis system. The average (+/-standard deviation) of the GMO contents on a kernel basis in five non-IP sample lots was determined to be 51.0+/-21.6%, the percentage of a single GM trait grains was 39%, and the percentage of the stacked GM trait grains was 12%. The MON810 grains and NK603 grains were the most frequent varieties in the single GM traits. The most frequent stacked GM traits were the MON810xNK603 grains. In addition, the present study would provide the answer and impact for the quantification of GM maize content in the GM maize kernels on labeling regulation.

  4. Rheological characterization of geopolymer binder modified by organic resins

    NASA Astrophysics Data System (ADS)

    Cekalová, M.; Kovárík, T.; Rieger, D.

    2017-01-01

    The purpose of this study is going to investigate properties of alkali-activated powder (calcined kaoilinitic clay and granulated blast furnace slag) prepared as a geopolymer paste and modified by various amount of organic resin. Hybrid organic-inorganic binders were prepared as a mix of organic resin and geopolymer inorganic paste under vacuum conditions. The process of solidification was investigated by measurements of storage (G’) and loss modulus ( G’) in torsion. The measurement was conducted in oscillatory mode by constant strain of 0.01 %. This strain is set in linear visco-elastic region for minimization influence of paste structure. The effect of organic resin is presented and determined by changes of viscosity (‘n*), modules in torsion and tangent of loss angle (tan 8). Results indicate that addition of organic resin significantly affects the initial viscosity and hardening kinetics.

  5. Evaluation of the reliability of maize reference assays for GMO quantification.

    PubMed

    Papazova, Nina; Zhang, David; Gruden, Kristina; Vojvoda, Jana; Yang, Litao; Buh Gasparic, Meti; Blejec, Andrej; Fouilloux, Stephane; De Loose, Marc; Taverniers, Isabel

    2010-03-01

    A reliable PCR reference assay for relative genetically modified organism (GMO) quantification must be specific for the target taxon and amplify uniformly along the commercialised varieties within the considered taxon. Different reference assays for maize (Zea mays L.) are used in official methods for GMO quantification. In this study, we evaluated the reliability of eight existing maize reference assays, four of which are used in combination with an event-specific polymerase chain reaction (PCR) assay validated and published by the Community Reference Laboratory (CRL). We analysed the nucleotide sequence variation in the target genomic regions in a broad range of transgenic and conventional varieties and lines: MON 810 varieties cultivated in Spain and conventional varieties from various geographical origins and breeding history. In addition, the reliability of the assays was evaluated based on their PCR amplification performance. A single base pair substitution, corresponding to a single nucleotide polymorphism (SNP) reported in an earlier study, was observed in the forward primer of one of the studied alcohol dehydrogenase 1 (Adh1) (70) assays in a large number of varieties. The SNP presence is consistent with a poor PCR performance observed for this assay along the tested varieties. The obtained data show that the Adh1 (70) assay used in the official CRL NK603 assay is unreliable. Based on our results from both the nucleotide stability study and the PCR performance test, we can conclude that the Adh1 (136) reference assay (T25 and Bt11 assays) as well as the tested high mobility group protein gene assay, which also form parts of CRL methods for quantification, are highly reliable. Despite the observed uniformity in the nucleotide sequence of the invertase gene assay, the PCR performance test reveals that this target sequence might occur in more than one copy. Finally, although currently not forming a part of official quantification methods, zein and SSIIb

  6. Synthesis and postmodification of functionally relevant organically modified silica particles

    NASA Astrophysics Data System (ADS)

    Brozek, Eric

    This thesis describes the synthesis and properties of organically modified silica (ORMOSIL) particles with possible applications in the field of drug delivery. Nanoparticle drug delivery methods take advantage of the unique physical properties of nanoscale architecture to deliver a large payload of drug to a targeted site. They are highly porous, contain many organic functionalities for covalent attachment, and their surfaces can be functionalized. A particle-based approach allows for the delivery of a large and localized payload in a single package. Initial study focused on the generation of submicron organically modified silica particles containing boron. This involved the synthesis of vinyl-enriched silica particles and the postmodification of the vinyl functionalities throughout the particle body. Hydroboration and bromination of the vinyl functionalities showed for the first time that the organic functionalities of ORMOSIL particles could be significantly modified. Next, new organically modified silica particle types were developed. These new particle types incorporated unique organic functionalities that may undergo additional functionalization. Organic functionalities included alkenyl-, cyano-, mercapto-, and isocyanto- throughout the particle body. The different organic functionalities were then modified to demonstrate their reactivity. Finally, a particle containing nuclei suitable for neutron capture therapy, a fluorescent tag, and targeting ligand was synthesized. Boron was the active nuclei, fluorescein was the fluorescent label, useful for in vitro studies, and folic acid is a broad field targeting ligand, useful in targeting a variety of cancer types. The particle containing the three unique motifs underwent early stages of in vitro studies against the OVCAR-3 cell line. This thesis has considerably advanced the field of ORMOSIL chemistry through the development and modification of new ORMOSIL products. While initial efforts were geared toward the

  7. Conservation biology, genetically modified organisms, and the biosafety protocol.

    PubMed

    Hill, Ryan; Sendashonga, Cyrie

    2006-12-01

    Concerns have been raised regarding the potential adverse effects on biological diversity of the use of living modified organisms (LMOs, which are commonly known by similar terms such as genetically modified organisms). At the international level these concerns are addressed in part by an agreement known as the Cartagena Protocol on Biosafety and include potential toxic effects of insect-resistant crops on nontarget organisms and potential ecological effects of gene flow from modified crops, fish, microorganisms, or insects to wild species or counterparts. We reviewed the protocol's main provisions, including those dealing with risk assessment and risk management, decision making on imports, documentation accompanying shipments, and liability resulting from damages caused by LMOs. A medium-term program of work has been adopted by the parties, which includes the potential contribution of conservation biologists to delivering capacity building, developing risk assessment guidance, evaluating mechanisms of potential ecological damages from LMOs, and other issues. Conservation biologists and other experts have opportunities to influence the negotiations and implementation of the protocol by providing inputs at meetings, offering expertise to governments and organizations, and participating in or developing relevant projects and initiatives. Involvement of conservation biologists in the implementation and further development of the protocol would contribute to its effectiveness.

  8. Quantification of the 35S promoter in DNA extracts from genetically modified organisms using real-time polymerase chain reaction and specificity assessment on various genetically modified organisms, part I: operating procedure.

    PubMed

    Fernandez, Sophie; Charles-Delobel, Chrystèle; Geldreich, Angèle; Berthier, Georges; Boyer, Francine; Collonnier, Cécile; Coué-Philippe, Géraldine; Diolez, Annick; Duplan, Marie-Noëlle; Kebdani, Naïma; Romaniuk, Marcel; Feinberg, Max; Bertheau, Yves

    2005-01-01

    A highly sensitive quantitative real-time assay targeted on the 35S promoter of a commercial genetically modified organism (GMO) was characterized (sF/sR primers) and developed for an ABI Prism 7700 Sequence Detection System and TaqMan chemistry. The specificity assessment and performance criteria of sF/sR assay were compared to other P35S-targeted published assays. sF/sR primers amplified a 79 base pair DNA sequence located in a part of P35S that is highly conserved among many caulimovirus strains, i.e., this consensus part of CaMV P35S is likely to be present in many GM events. According to the experimental conditions, the absolute limit of detection for Bt176 corn was estimated between 0.2 and 2 copies of equivalent genome (CEG). The limit of quantification was reached below 0.1% Bt176 content. A Cauliflower Mosaic Virus control (CaMV) qualitative assay targeted on the ORF III of the viral genome was also used as a control (primers 3F/3R) to assess the presence of CaMV in plant-derived products. The specificity of this test was assessed on various CaMV strains, including the Figwort Mosaic Virus (FMV) and solanaceous CaMV strains. Considering the performance of sF/sR quantification test, the highly conserved sequence, and the small size of the amplicon, this assay was tested in a collaborative study in order to be proposed as an international standard.

  9. Multiple organ histopathological changes in broiler chickens fed on genetically modified organism.

    PubMed

    Cîrnatu, Daniela; Jompan, A; Sin, Anca Ileana; Zugravu, Cornelia Aurelia

    2011-01-01

    Diet can influence the structural characteristics of internal organs. An experiment involving 130 meat broilers was conducted during 42 days (life term for a meat broiler) to study the effect of feed with protein from genetically modified soy. The 1-day-old birds were randomly allocated to five study groups, fed with soy, sunflower, wheat, fish flour, PC starter. In the diet of each group, an amount of protein from soy was replaced with genetically modified soy (I - 0%, II - 25%, III - 50%, IV - 75%, V - 100% protein from genetically modified soy). The level of protein in soy, either modified, or non-modified, was the same. Organs and carcass weights were measured at about 42 days of age of the birds and histopathology exams were performed during May-June 2009. No statistically significant differences were observed in mortality, growth performance variables or carcass and organ yields between broilers consuming diets produced with genetically modified soybean fractions and those consuming diets produced with near-isoline control soybean fractions. Inflammatory and degenerative liver lesions, muscle hypertrophy, hemorrhagic necrosis of bursa, kidney focal tubular necrosis, necrosis and superficial ulceration of bowel and pancreatic dystrophies were found in tissues from broilers fed on protein from genetically modified soy. Different types of lesions found in our study might be due to other causes (parasites, viral) superimposed but their presence exclusively in groups fed with modified soy raises some serious questions about the consequences of use of this type of feed.

  10. Analysis of the Threat of Genetically Modified Organisms for Biological Warfare

    DTIC Science & Technology

    2011-05-01

    www.thehastingscenter.org/synthetic-biology- bioethics -briefing-book/ Accessed 30 August 2010  6      ‐ Growth of commercial GMO activities. - GMO knowledge base...Garfinkel, et al., http://www.thehastingscenter.org/synthetic-biology- bioethics -briefing-book/ Accessed 30 August 2010 M.F. Brink, “Developing efficient

  11. Retraction of a study on genetically modified corn: Expert investigations should speak louder during controversies over safety.

    PubMed

    Xia, Jufeng; Song, Peipei; Xu, Lingzhong; Tang, Wei

    2015-04-01

    Over the past few years, genetically modified organisms (GMO) have gradually become more familiar after numerous reports of problems with GMO safety, such as genetically modified (GM) potatoes disrupting immunity, GM corn inducing tumors, and GM rice being fed to unwitting Chinese children. Every time, these reports cause panic among the population and lead to objections to GMO in various fora. After each incident, the scientific community has delivered its academic appraisal and refuted rumors through slow and cautious investigations and evaluations. Unfortunately, during each event media outlets quickly scare the public about food safety and ignore the ensuing comments from scientists. Although scientists have investigated each GMO crisis and reached scientific and rational conclusions, they have less ability to disseminate information than the media, so the public is not promptly informed of their rational and objective viewpoints as experts. Thus, scientists need greater ability to disseminate information from scientific investigations and evaluations in order to correct the intemperate reporting by attention-seeking media.

  12. Plant biotechnology. Italian scientists blast GMO restrictions.

    PubMed

    Frank, L

    2000-12-15

    While plant scientists around the world celebrate the complete sequence of the genome of the mustardlike plant Arabidopsis thaliana (see p. 2054), embattled colleagues in Italy are protesting new rules that bar all field trials involving genetically modified organisms (GMOs). The researchers hope to turn the prevailing tide by bringing their plight to the attention of colleagues around the world and exerting pressure on their government through a petition drive.

  13. [Genetically modified organisms: a new threat to food safety].

    PubMed

    Spendeler, Liliane

    2005-01-01

    This article analyzes all of the food safety-related aspects related to the use of genetically modified organisms into agriculture and food. A discussion is provided as to the uncertainties related to the insertion of foreign genes into organisms, providing examples of unforeseen, undesirable effects and of instabilities of the organisms thus artificially fabricated. Data is then provided from both official agencies as well as existing literature questioning the accuracy and reliability of the risk analyses as to these organisms being harmless to health and discusses the almost total lack of scientific studies analyzing the health safety/dangerousness of transgenic foods. Given all these unknowns, other factors must be taken into account, particularly genetic contamination of the non-genetically modified crops, which is now starting to become widespread in some parts of the world. Not being able of reversing the situation in the even of problems is irresponsible. Other major aspects are the impacts on the environment (such as insects building up resistances, the loss of biodiversity, the increase in chemical products employed) with indirect repercussions on health and/or future food production. Lastly, thoughts for discussion are added concerning food safety in terms of food availability and food sovereignty, given that the transgenic seed and related agrochemicals market is currently cornered by five large-scale transnational companies. The conclusion entails an analysis of biotechnological agriculture's contribution to sustainability.

  14. Novel DEA with organically modified silicone elastomer for permittivity enhancement

    NASA Astrophysics Data System (ADS)

    Böse, Holger; Uhl, Detlev; Rabindranath, Raman

    2012-04-01

    Dielectric elastomer actuators (DEA) based on an organically modified silicone elastomer are introduced. The elastomer carries fluorinated sidegroups in the polysiloxane molecular chain and is synthesized from precursors which all are fluorinated. A fluorinated silicone oil is added in consecutive concentration steps as a softening agent. The electric properties of the modified silicone elastomers in terms of the permittivity, specific conductivity and electric breakdown field strength were investigated and compared with those of the unmodified silicone elastomer as the reference material. Moreover, the mechanical characteristics like Young's modulus in tensile and compressional load as well as the storage and loss modulus in shear load were studied. The permittivity of the modified silicone is enhanced by 80 % compared to the unmodified silicone elastomer. No strong alteration of the specific conductivity occurs. The electric breakdown field strength is comparable to that of the reference material. Simultaneously, the Young's modulus is decreased by the softening agent. Actuation measurements on model actuators show, that the actuation strain of the best materials surmounts that of the unmodified reference material by a factor of up to 5. The modified silicone elastomer materials can also be used for dielectric elastomer sensors and generators.

  15. Biocontainment of genetically modified organisms by synthetic protein design

    NASA Astrophysics Data System (ADS)

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-02-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

  16. Biocontainment of genetically modified organisms by synthetic protein design.

    PubMed

    Mandell, Daniel J; Lajoie, Marc J; Mee, Michael T; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E; Gregg, Christopher J; Stoddard, Barry L; Church, George M

    2015-02-05

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

  17. Biocontainment of genetically modified organisms by synthetic protein design

    PubMed Central

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-01-01

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient either because they impose evolutionary pressure on the organism to eject the safeguard, because they can be circumvented by environmentally available compounds, or because they can be overcome by horizontal gene transfer (HGT). Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code to confer metabolic dependence on nonstandard amino acids for survival. The resulting GMOs cannot metabolically circumvent their biocontainment mechanisms using environmentally available compounds, and they exhibit unprecedented resistance to evolutionary escape via mutagenesis and HGT. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by reliance on synthetic metabolites. PMID:25607366

  18. Biocontainment of genetically modified organisms by synthetic protein design

    DOE PAGES

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; ...

    2015-01-21

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. In this paper, we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass theirmore » biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. Finally, this work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.« less

  19. Biocontainment of genetically modified organisms by synthetic protein design

    SciTech Connect

    Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

    2015-01-21

    Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. In this paper, we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. Finally, this work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

  20. Supercritical extraction of phenols from organically modified smectite

    SciTech Connect

    Park, S.J.; Yeo, S.D.

    1999-01-01

    Supercritical extraction has been performed in a fixed column to desorb phenol and 4-nitrophenol from organically modified smectite. The experiments were carried out in the sequence of adsorption of hexadecyltrimethylammonium (HDTMA) to montmorillonite, adsorption of phenols to organoclay in aqueous solutions, desorption of phenols from loaded organoclay using supercritical carbon dioxide, and adsorption of phenols to regenerated organoclay. The desorption characteristics of phenols were investigated at various pressures up to 420 bar; at temperatures of 40, 60, and 70 C, and at low concentrations of a cosolvent. The extraction percentages of phenols reached up to 90% in 3 hours of extraction. The results showed that under the experimental conditions investigated, the activity of HDTMA was intact during the supercritical extraction of phenols, and hence HDTMA-modified montmorillonite exhibited undiminished adsorption power toward phenols after several regeneration cycles.

  1. Detection of genetically modified organisms by electrochemiluminescence PCR method.

    PubMed

    Liu, Jinfeng; Xing, Da; Shen, Xingyan; Zhu, Debin

    2004-10-15

    With the development of biotechnology, more and more genetically modified organisms (GMOs) have entered commercial market. Because of the safety concerns, detection and characterization of GMOs have attracted much attention recently. In this study, electrochemiluminescence polymerase chain reaction (ECL-PCR) combined with hybridization technique was applied to detect the GMOs in genetically modified (GM) soybeans and papayas for the first time. Whether the soybeans and the papayas contain GM components was discriminated by detecting the Cauliflower mosaic virus 35S (CaMV35S) promoter. The experiment results show that the detection limit for CaMV35S promoter is 100 fmol, and the GM components can be clearly identified in GM soybeans and papayas. The technique may provide a new means in GMOs detection due to its simplicity and high efficiency.

  2. GMO foods and crops: Africa's choice.

    PubMed

    Paarlberg, Robert

    2010-11-30

    There is a scientific consensus, even in Europe, that the GMO foods and crops currently on the market have brought no documented new risks either to human health or to the environment. Europe has decided to stifle the use of this new technology, not because of the presence of risks, but because of the absence so far of direct benefits to most Europeans. Farmers in Europe are few in number, and they are highly productive even without GMOs. In Africa, by contrast, 60% of all citizens are still farmers and they are not yet highly productive. For Africa, the choice to stifle new technology with European-style regulations carries a much higher cost.

  3. Modified carbon surfaces as "organic electrodes" that exhibit conductance switching.

    PubMed

    Solak, Ali Osman; Eichorst, Laura R; Clark, William J; McCreery, Richard L

    2003-01-15

    Glassy carbon (GC) surfaces modified with monolayers of biphenyl and nitrobiphenyl molecules were examined as voltammetric electrodes for ferrocene, benzoquinone, and tetracyanoquinodimethane electrochemistry in acetonitrile. The modified electrodes exhibited slower electron transfer than unmodified GC, by factors that varied with the monolayer and redox system. However, after a negative potential excursion to approximately -2.0 V versus Ag+/Ag, the modified electrodes exhibited much faster electron-transfer kinetics, approaching those observed on unmodified GC. The effect is attributed to an apparently irreversible structural change in the biphenyl or nitrobiphenyl monolayer, which increases the rate of electron tunneling. The transition to the "ON" state is associated with electron injection into the monolayer similar to that observed in previous spectroscopic investigations and causes a significant decrease in the calculated HOMO-LUMO gap for the monolayer molecule. Once the monolayer is switched ON, it supports rapid electron exchange with outer-sphere redox systems, but not with dopamine, which requires adsorption to the GC surface. The increase in electron-transfer rate with electron injection is consistent with an increase in electron tunneling rate through the monolayer, caused by a significant decrease in tunneling barrier height. The ON electrode can reduce biphenyl- or nitrobiphenyldiazonium reagent in solution to permit formation of a second modification layer of biphenyl or nitrobiphenyl molecules. This "double derivatization" procedure was used to prepare tetraphenyl- and nitrotetraphenyl-modified electrodes, which exhibit significantly slower electron transfer than their biphenyl and nitrobiphenyl counterparts. A "switching" electrode may have useful properties for electroanalytical applications and possibly in electrocatalysis. In addition, the ON state represents an "organic electrode" in which electron transfer occurs at an interface between an

  4. Loop-mediated isothermal amplification (LAMP) method for detection of genetically modified maize T25.

    PubMed

    Xu, Junyi; Zheng, Qiuyue; Yu, Ling; Liu, Ran; Zhao, Xin; Wang, Gang; Wang, Qinghua; Cao, Jijuan

    2013-11-01

    The loop-mediated isothermal amplification (LAMP) assay indicates a potential and valuable means for genetically modified organism (GMO) detection especially for its rapidity, simplicity, and low cost. We developed and evaluated the specificity and sensitivity of the LAMP method for rapid detection of the genetically modified (GM) maize T25. A set of six specific primers was successfully designed to recognize six distinct sequences on the target gene, including a pair of inner primers, a pair of outer primers, and a pair of loop primers. The optimum reaction temperature and time were verified to be 65°C and 45 min, respectively. The detection limit of this LAMP assay was 5 g kg(-1) GMO component. Comparative experiments showed that the LAMP assay was a simple, rapid, accurate, and specific method for detecting the GM maize T25.

  5. Safety assessment and detection methods of genetically modified organisms.

    PubMed

    Xu, Rong; Zheng, Zhe; Jiao, Guanglian

    2014-01-01

    Genetically modified organisms (GMOs), are gaining importance in agriculture as well as the production of food and feed. Along with the development of GMOs, health and food safety concerns have been raised. These concerns for these new GMOs make it necessary to set up strict system on food safety assessment of GMOs. The food safety assessment of GMOs, current development status of safety and precise transgenic technologies and GMOs detection have been discussed in this review. The recent patents about GMOs and their detection methods are also reviewed. This review can provide elementary introduction on how to assess and detect GMOs.

  6. The Detection of Genetically Modified Organisms: An Overview

    NASA Astrophysics Data System (ADS)

    Ovesná, Jaroslava; Demnerová, Kateřina; Pouchová, Vladimíra

    Genetically modified organisms (GMOs) are those whose genetic material has been altered by the insertion of a new gene or by the deletion of an existing one(s). Modern biotechnology, in particular, the rise of genetic engineering, has supported the development of GMOs suitable for research purposes and practical applications (Gepts, 2002; Novoselova,Meuwissen, & Huirne, 2007; Sakakibara & Saito, 2006). For over 20 years GM bacteria and other GM organisms have been used in laboratories for the study of gene functions (Maliga & Small, 2007; Ratledge & Kristiansen, 2006). Agricultural plants were the first GMOs to be released into the environment and placed on the market. Farmers around the world use GMsoybeans, GMcorn and GM cotton that are herbicide tolerant, or insect resistant, or combine several traits that reduce the costs associated with crop production (Corinne, Fernandez-Cornejo, & Goodhue, 2004).

  7. Antimicrobial activity of organically modified nano-clays.

    PubMed

    Hong, Seek-In; Rhim, Jong-Whan

    2008-11-01

    Antimicrobial activity of three kinds of commercially available montmorillonite nano-clays including a naturally occurring one (Cloisite Na+) and two organically modified ones (Cloisite 20A and Cloisite 30B) against four representative pathogenic bacteria (two Gram-positive ones such as Staphylococcus aureus and Listeria monocytogenes, and two Gram-negative ones such as Salmonella typhimurium and E. coli O157:H7) was investigated. Antimicrobial activity was found to be dependent on the type of nano-clay and microorganisms tested. Among the nano-clays tested, Cloisite 30B showed the highest antibacterial activity followed by Cloisite 20A, however, the unmodified montmorillonite (Cloisite Na+) did not show any antibacterial activity. Especially, Cloisite 30B inactivated Gram-positive bacteria completely within an hour of incubation and inactivated Gram-negative bacteria by more than 2-3 log cycles after 8 hours incubation. SEM and TEM images of cell structure indicated that the organically modified nano-clay caused rupture of cell membrane and inactivation of the bacteria. This finding of antimicrobial activity of the organo-clay would open a new opportunity to develop polymer nanocomposites with additional functionality, i.e., antimicrobial function.

  8. Organically modified titania nanoparticles for sustained drug release applications.

    PubMed

    Sethi, Komal; Roy, Indrajit

    2015-10-15

    In this paper, we report the synthesis, characterization of drug-doped organically modified titania nanoparticles, and their applications in sustained drug release. The drug-doped nanoparticles were synthesized in the hydrophobic core of oil-in-water microemulsion medium. Structural aspects obtained through TEM and FESEM depicted that organically modified titania nanoparticles are monodispersed with spherical morphology, with an average size of around 200 nm. Their polymorphic forms and porosity were determined using powder XRD and BET, respectively, which showed that they are present in the anatase form, with a surface area of 136.5 m(2)/g and pore-diameter of 5.23 nm. After synthesis and basic structural characterizations, optical properties were studied for both fluorophore and drug encapsulated nanoparticles. The results showed that though the optical properties of the fluorophore are partially diminished upon nanoencapsulation, it became more stable against chemical quenching. The nanoparticles showed pH-dependent drug release pattern. In vitro studies showed that the nanoparticles were efficiently uptaken by cells. Cell viability assay results showed that though the placebo nanoparticles are non-cytotoxic, the drug-doped nanoparticles show drug-induced toxicity. Therefore, such porous nanoparticles can be used in non-toxic drug delivery applications.

  9. A theoretical introduction to "combinatory SYBRGreen qPCR screening", a matrix-based approach for the detection of materials derived from genetically modified plants.

    PubMed

    Van den Bulcke, Marc; Lievens, Antoon; Barbau-Piednoir, Elodie; MbongoloMbella, Guillaume; Roosens, Nancy; Sneyers, Myriam; Casi, Amaya Leunda

    2010-03-01

    The detection of genetically modified (GM) materials in food and feed products is a complex multi-step analytical process invoking screening, identification, and often quantification of the genetically modified organisms (GMO) present in a sample. "Combinatory qPCR SYBRGreen screening" (CoSYPS) is a matrix-based approach for determining the presence of GM plant materials in products. The CoSYPS decision-support system (DSS) interprets the analytical results of SYBRGREEN qPCR analysis based on four values: the C(t)- and T(m) values and the LOD and LOQ for each method. A theoretical explanation of the different concepts applied in CoSYPS analysis is given (GMO Universe, "Prime number tracing", matrix/combinatory approach) and documented using the RoundUp Ready soy GTS40-3-2 as an example. By applying a limited set of SYBRGREEN qPCR methods and through application of a newly developed "prime number"-based algorithm, the nature of subsets of corresponding GMO in a sample can be determined. Together, these analyses provide guidance for semi-quantitative estimation of GMO presence in a food and feed product.

  10. Detecting authorized and unauthorized genetically modified organisms containing vip3A by real-time PCR and next-generation sequencing.

    PubMed

    Liang, Chanjuan; van Dijk, Jeroen P; Scholtens, Ingrid M J; Staats, Martijn; Prins, Theo W; Voorhuijzen, Marleen M; da Silva, Andrea M; Arisi, Ana Carolina Maisonnave; den Dunnen, Johan T; Kok, Esther J

    2014-04-01

    The growing number of biotech crops with novel genetic elements increasingly complicates the detection of genetically modified organisms (GMOs) in food and feed samples using conventional screening methods. Unauthorized GMOs (UGMOs) in food and feed are currently identified through combining GMO element screening with sequencing the DNA flanking these elements. In this study, a specific and sensitive qPCR assay was developed for vip3A element detection based on the vip3Aa20 coding sequences of the recently marketed MIR162 maize and COT102 cotton. Furthermore, SiteFinding-PCR in combination with Sanger, Illumina or Pacific BioSciences (PacBio) sequencing was performed targeting the flanking DNA of the vip3Aa20 element in MIR162. De novo assembly and Basic Local Alignment Search Tool searches were used to mimic UGMO identification. PacBio data resulted in relatively long contigs in the upstream (1,326 nucleotides (nt); 95 % identity) and downstream (1,135 nt; 92 % identity) regions, whereas Illumina data resulted in two smaller contigs of 858 and 1,038 nt with higher sequence identity (>99 % identity). Both approaches outperformed Sanger sequencing, underlining the potential for next-generation sequencing in UGMO identification.

  11. Real-time polymerase chain reaction detection of cauliflower mosaic virus to complement the 35S screening assay for genetically modified organisms.

    PubMed

    Cankar, Katarina; Ravnikar, Maja; Zel, Jana; Gruden, Kristina; Toplak, Natasa

    2005-01-01

    Labeling of genetically modified organisms (GMOs) is now in place in many countries, including the European Union, in order to guarantee the consumer's choice between GM and non-GM products. Screening of samples is performed by polymerase chain reaction (PCR) amplification of regulatory sequences frequently introduced into genetically modified plants. Primers for the 35S promoter from Cauliflower mosaic virus (CaMV) are those most frequently used. In virus-infected plants or in samples contaminated with plant material carrying the virus, false-positive results can consequently occur. A system for real-time PCR using a TaqMan minor groove binder probe was designed that allows recognition of virus coat protein in the sample, thus allowing differentiation between transgenic and virus-infected samples. We measured the efficiency of PCR amplification, limits of detection and quantification, range of linearity, and repeatability of the assay in order to assess the applicability of the assay for routine analysis. The specificity of the detection system was tested on various virus isolates and plant species. All 8 CaMV isolates were successfully amplified using the designed system. No cross-reactivity was detected with DNA from 3 isolates of the closely related Carnation etched ring virus. Primers do not amplify plant DNA from available genetically modified maize and soybean lines or from different species of Brassicaceae or Solanaceae that are natural hosts for CaMV. We evaluated the assay for different food matrixes by spiking CaMV DNA into DNA from food samples and have successfully amplified CaMV from all samples. The assay was tested on rapeseed samples from routine GMO testing that were positive in the 35S screening assay, and the presence of the virus was confirmed.

  12. Organically Modified Nanoclay-Reinforced Rigid Polyurethane Films

    NASA Astrophysics Data System (ADS)

    Park, Yong Tae; Qian, Yuqiang; Lindsay, Chris; Stein, Andreas; Macosko, Christopher

    2012-02-01

    The nanodispersion of vermiculite in polyurethanes was investigated to produce organoclay-reinforced rigid gas barrier films. Reducing gas transport can improve the insulation performance of closed cell polyurethane foam. In a previous study, the dispersion of vermiculite in polyurethanes without organic modification was not sufficient due to the non-uniform dispersion morphology. When vermiculite was modified by cation exchange with long-chain quaternary ammonium cations, the dispersion in methylene diphenyl diisocyanate (MDI) was significantly improved. Dispersion was improved by combining high intensity dispersive mixing with efficient distributive mixing. Polymerization conditions were also optimized in order to provide a high state of nanodispersion in the polyurethane nanocomposite. The dispersions were characterized using rheological, microscopic and scattering/diffraction techniques. The final nanocomposites showed enhancement of mechanical properties and reduction in permeability to carbon dioxide at low clay concentration (around 2 wt percent).

  13. Assessment of a direct hybridization microarray strategy for comprehensive monitoring of genetically modified organisms (GMOs).

    PubMed

    Turkec, Aydin; Lucas, Stuart J; Karacanli, Burçin; Baykut, Aykut; Yuksel, Hakki

    2016-03-01

    Detection of GMO material in crop and food samples is the primary step in GMO monitoring and regulation, with the increasing number of GM events in the world market requiring detection solutions with high multiplexing capacity. In this study, we test the suitability of a high-density oligonucleotide microarray platform for direct, quantitative detection of GMOs found in the Turkish feed market. We tested 1830 different 60nt probes designed to cover the GM cassettes from 12 different GM cultivars (3 soya, 9 maize), as well as plant species-specific and contamination controls, and developed a data analysis method aiming to provide maximum throughput and sensitivity. The system was able specifically to identify each cultivar, and in 10/12 cases was sensitive enough to detect GMO DNA at concentrations of ⩽1%. These GMOs could also be quantified using the microarray, as their fluorescence signals increased linearly with GMO concentration.

  14. The GMOseek matrix: a decision support tool for optimizing the detection of genetically modified plants

    PubMed Central

    2013-01-01

    Background Since their first commercialization, the diversity of taxa and the genetic composition of transgene sequences in genetically modified plants (GMOs) are constantly increasing. To date, the detection of GMOs and derived products is commonly performed by PCR-based methods targeting specific DNA sequences introduced into the host genome. Information available regarding the GMOs’ molecular characterization is dispersed and not appropriately organized. For this reason, GMO testing is very challenging and requires more complex screening strategies and decision making schemes, demanding in return the use of efficient bioinformatics tools relying on reliable information. Description The GMOseek matrix was built as a comprehensive, online open-access tabulated database which provides a reliable, comprehensive and user-friendly overview of 328 GMO events and 247 different genetic elements (status: 18/07/2013). The GMOseek matrix is aiming to facilitate GMO detection from plant origin at different phases of the analysis. It assists in selecting the targets for a screening analysis, interpreting the screening results, checking the occurrence of a screening element in a group of selected GMOs, identifying gaps in the available pool of GMO detection methods, and designing a decision tree. The GMOseek matrix is an independent database with effective functionalities in a format facilitating transferability to other platforms. Data were collected from all available sources and experimentally tested where detection methods and certified reference materials (CRMs) were available. Conclusions The GMOseek matrix is currently a unique and very valuable tool with reliable information on GMOs from plant origin and their present genetic elements that enables further development of appropriate strategies for GMO detection. It is flexible enough to be further updated with new information and integrated in different applications and platforms. PMID:23965170

  15. Development and interlaboratory validation of quantitative polymerase chain reaction method for screening analysis of genetically modified soybeans.

    PubMed

    Takabatake, Reona; Onishi, Mari; Koiwa, Tomohiro; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

    2013-01-01

    A novel real-time polymerase chain reaction (PCR)-based quantitative screening method was developed for three genetically modified soybeans: RRS, A2704-12, and MON89788. The 35S promoter (P35S) of cauliflower mosaic virus is introduced into RRS and A2704-12 but not MON89788. We then designed a screening method comprised of the combination of the quantification of P35S and the event-specific quantification of MON89788. The conversion factor (Cf) required to convert the amount of a genetically modified organism (GMO) from a copy number ratio to a weight ratio was determined experimentally. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDR), respectively. The determined RSDR values for the method were less than 25% for both targets. We consider that the developed method would be suitable for the simple detection and approximate quantification of GMO.

  16. A Novel Pretreatment-Free Duplex Chamber Digital PCR Detection System for the Absolute Quantitation of GMO Samples

    PubMed Central

    Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Luo, Yunbo; Xu, Wentao

    2016-01-01

    Digital polymerase chain reaction (PCR) has developed rapidly since it was first reported in the 1990s. However, pretreatments are often required during preparation for digital PCR, which can increase operation error. The single-plex amplification of both the target and reference genes may cause uncertainties due to the different reaction volumes and the matrix effect. In the current study, a quantitative detection system based on the pretreatment-free duplex chamber digital PCR was developed. The dynamic range, limit of quantitation (LOQ), sensitivity and specificity were evaluated taking the GA21 event as the experimental object. Moreover, to determine the factors that may influence the stability of the duplex system, we evaluated whether the pretreatments, the primary and secondary structures of the probes and the SNP effect influence the detection. The results showed that the LOQ was 0.5% and the sensitivity was 0.1%. We also found that genome digestion and single nucleotide polymorphism (SNP) sites affect the detection results, whereas the unspecific hybridization within different probes had little side effect. This indicated that the detection system was suited for both chamber-based and droplet-based digital PCR. In conclusion, we have provided a simple and flexible way of achieving absolute quantitation for genetically modified organism (GMO) genome samples using commercial digital PCR detection systems. PMID:26999129

  17. A Novel Pretreatment-Free Duplex Chamber Digital PCR Detection System for the Absolute Quantitation of GMO Samples.

    PubMed

    Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Luo, Yunbo; Xu, Wentao

    2016-03-18

    Digital polymerase chain reaction (PCR) has developed rapidly since it was first reported in the 1990s. However, pretreatments are often required during preparation for digital PCR, which can increase operation error. The single-plex amplification of both the target and reference genes may cause uncertainties due to the different reaction volumes and the matrix effect. In the current study, a quantitative detection system based on the pretreatment-free duplex chamber digital PCR was developed. The dynamic range, limit of quantitation (LOQ), sensitivity and specificity were evaluated taking the GA21 event as the experimental object. Moreover, to determine the factors that may influence the stability of the duplex system, we evaluated whether the pretreatments, the primary and secondary structures of the probes and the SNP effect influence the detection. The results showed that the LOQ was 0.5% and the sensitivity was 0.1%. We also found that genome digestion and single nucleotide polymorphism (SNP) sites affect the detection results, whereas the unspecific hybridization within different probes had little side effect. This indicated that the detection system was suited for both chamber-based and droplet-based digital PCR. In conclusion, we have provided a simple and flexible way of achieving absolute quantitation for genetically modified organism (GMO) genome samples using commercial digital PCR detection systems.

  18. "You Say Tomato, I Say Solanum Lycopersicum Containing Beta-ionone and Phenylacetaldehyde": an Analysis of Connecticut's GMO Labeling Legislation.

    PubMed

    Nunziato, Travis

    2014-01-01

    "You Say Tomato, I Say Solanum Lycopersicum Containing Beta-ionone and Phenylacetaldehyde" discusses the importance of requiring labels on products that contain genetically modified organisms, focusing on Connecticut's GMO Labeling statutes, as it is they are the first of their kind in the nation. The article will compare Connecticut's law to the legislation found in Australia, highlighting the positive aspects of Connecticut's bill and identifying its key weaknesses, namely the "trigger clause" found in the statute. Part I will provide an overview of Genetic Modification and provide a brief history of Biotechnology. It will also provide a brief overview of the federal regulatory framework in biotechnology, as well as evaluate the United States Food and Drug Association's role of regulating genetic modification. Part I will conclude by discussing how the American public has shown that labeling GMOs is important, and something that should occur. Part II of this article will explore Connecticut's recent legislation requiring labels on products that contain GMOs. Part III will explore Australia's legislation requiring labels on products containing GMOs, comparing Australia's law to Connecticut's legislation.

  19. Influence of the organic complex concentration on adsorption of herbicide in organic modified montmorillonite

    NASA Astrophysics Data System (ADS)

    Kaludjerovic, Lazar; Tomic, Zorica; Djurovic, Rada; Milosevic, Maja

    2016-04-01

    Pesticides are recognized as an important source of potential pollution to soil and water due to their mobility and degradation in soils. Results presented in this paper show impact of the organic complex concentration on the adsorption of herbicides (acetochlor) at the surface of the organic modified montmorillonite. In this work, natural montmorillonite from Bogovina, located near Boljevac municipality, was used for organic modification. Cation-exchange capacity of this montmorillonite was determined by extraction with ammonium acetate (86 mmol/100g of clay). Montmorillonite have been modified first with NaCl and than with two organic complexes, hexadecyltrimethylammonium bromide (HDTMA) and phenyltrimethylammonium chloride (PTMA). For both organic complexes, three saturation concentrations were selected for monitoring of the herbicide adsorption (43 mmol/100g of clay (0.5 CEC), 86 mmol/100g of clay (1 CEC) and 129 mmol/100g of clay (1.5 CEC)). Changes in the properties of the inorganic and organic bentonite have been examined using the X-ray powder diffraction (XRPD) and batch equilibrium method. Increase in basal spacing (d) of montmorillonites saturated with 1.5 CEC of organic cation indicate that sorption of PTMA and HDTMA can exceed the saturation of 1 CEC. Both organic montmorillonites have shown higher uptake of the herbicide, compared to the inorganic montmorillonite. Comparing the values Freundlich coefficients in batch equilibrium method, (presented in the form of log Kf and 1/n), it can be seen that the sorption decreases in the series: 0.5CEC> 1CEC> 1.5CEC> NaM, for both organic montmorillonites.

  20. Consumer knowledge and attitudes about genetically modified food products and labelling policy.

    PubMed

    Vecchione, Melissa; Feldman, Charles; Wunderlich, Shahla

    2015-05-01

    The purpose of this study was to examine the relationship between consumer knowledge, attitudes and behaviours towards foods containing genetically modified organisms (GMOs) and the prevalence of GMO labelling in northern New Jersey supermarkets. This cross-sectional study surveyed 331 adults, New Jersey supermarket customers (mean age 26 years old, 79.8% women). The results show a strong, positive correlation between consumer attitudes towards foods not containing GMOs and purchasing behaviour (Pearson's r = 0.701, p < 0.001) with lesser correlations between knowledge and behaviour (Pearson's r = 0.593, p < 0.001) and knowledge and attitudes (Pearson's r = 0.413, p < 0.001). GMO labelling would assist consumers in making informed purchase decisions.

  1. 46 CFR 52.25-10 - Organic fluid vaporizer generators (modifies PVG-1 through PVG-12).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Organic fluid vaporizer generators (modifies PVG-1... (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-10 Organic fluid vaporizer generators (modifies PVG-1 through PVG-12). (a) Organic fluid vaporizer generators and parts thereof shall meet...

  2. 46 CFR 52.25-10 - Organic fluid vaporizer generators (modifies PVG-1 through PVG-12).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Organic fluid vaporizer generators (modifies PVG-1... (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-10 Organic fluid vaporizer generators (modifies PVG-1 through PVG-12). (a) Organic fluid vaporizer generators and parts thereof shall meet...

  3. 46 CFR 52.25-10 - Organic fluid vaporizer generators (modifies PVG-1 through PVG-12).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Organic fluid vaporizer generators (modifies PVG-1... (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-10 Organic fluid vaporizer generators (modifies PVG-1 through PVG-12). (a) Organic fluid vaporizer generators and parts thereof shall meet...

  4. Influence of reaction condition on viscosity of polyurethane modified epoxy based on glycerol monooleate

    NASA Astrophysics Data System (ADS)

    Triwulandari, Evi; Ramadhan, Mohammad Kemilau; Ghozali, Muhammad

    2017-01-01

    Polyurethane modified epoxy based on glycerol monooleate (PME-GMO) was synthesized. GMO as polyol for synthesis of PME-GMO was synthesized via Fisher Esterification between oleic acid from palm oil and glycerol by using sulfuric acid as catalyst with time variation i.e. 3, 4, 5 and 6 hours at 160°C. Characterizations of GMO were carried out by analysis of acid number, hydroxyl value and FTIR. The data show that the conversion of oleic acid to ester compound is directly proportional with the increasing of reaction time but the enhancement is not significant after 3 hours. Furthermore, GMO product was used as polyol for modification of epoxy with polyurethane. Modification of epoxy with polyurethane was performed by reacted epoxy, tolonate and GMO simultaneously in one step. In this research, the reaction condition was varied i.e. time reaction (0.5; 1; 1.5; 2; 2.5 hours), composition of polyurethane used (10%, 20% toward epoxy) and rasio of tolonate and GMO (NCO/OH ratio) as component of polyurethane (1.5 and 2.5). Characterization of polyurethane modified epoxy based on glycerol (PME-GMO) was conducted by viscosity and FTIR analysis. The viscosity of PME-GMO increased with increasing of reaction time, polyurethane composition and NCO/OH ratio.

  5. Fuzzy-logic based strategy for validation of multiplex methods: example with qualitative GMO assays.

    PubMed

    Bellocchi, Gianni; Bertholet, Vincent; Hamels, Sandrine; Moens, W; Remacle, José; Van den Eede, Guy

    2010-02-01

    This paper illustrates the advantages that a fuzzy-based aggregation method could bring into the validation of a multiplex method for GMO detection (DualChip GMO kit, Eppendorf). Guidelines for validation of chemical, bio-chemical, pharmaceutical and genetic methods have been developed and ad hoc validation statistics are available and routinely used, for in-house and inter-laboratory testing, and decision-making. Fuzzy logic allows summarising the information obtained by independent validation statistics into one synthetic indicator of overall method performance. The microarray technology, introduced for simultaneous identification of multiple GMOs, poses specific validation issues (patterns of performance for a variety of GMOs at different concentrations). A fuzzy-based indicator for overall evaluation is illustrated in this paper, and applied to validation data for different genetically modified elements. Remarks were drawn on the analytical results. The fuzzy-logic based rules were shown to be applicable to improve interpretation of results and facilitate overall evaluation of the multiplex method.

  6. Development and Validation of a P-35S, T-nos, T-35S and P-FMV Tetraplex Real-time PCR Screening Method to Detect Regulatory Genes of Genetically Modified Organisms in Food.

    PubMed

    Eugster, Albert; Murmann, Petra; Kaenzig, Andre; Breitenmoser, Alda

    2014-10-01

    In routine analysis screening methods based on real-time PCR (polymerase chain reaction) are most commonly used for the detection of genetically modified (GM) plant material in food and feed. Screening tests are based on sequences frequently used for GM development, allowing the detection of a large number of GMOs (genetically modified organisms). Here, we describe the development and validation of a tetraplex real-time PCR screening assay comprising detection systems for the regulatory genes Cauliflower Mosaic Virus 35S promoter, Agrobacterium tumefaciens nos terminator, Cauliflower Mosaic Virus 35S terminator and Figwort Mosaic Virus 34S promoter. Three of the four primer and probe combinations have already been published elsewhere, whereas primers and probe for the 35S terminator have been developed in-house. Adjustment of primer and probe concentrations revealed a high PCR sensitivity with insignificant physical cross-talk between the four detection channels. The sensitivity of each PCR-system is sufficient to detect a GMO concentration as low as 0.05% of the containing respective element. The specificity of the described tetraplex is high when tested on DNA from GM maize, soy, rapeseed and tomato. We also demonstrate the robustness of the system by inter-laboratory tests. In conclusion, this method provides a sensitive and reliable screening procedure for the detection of the most frequently used regulatory elements present in GM crops either authorised or unauthorised for food.

  7. Correction of the lack of commutability between plasmid DNA and genomic DNA for quantification of genetically modified organisms using pBSTopas as a model.

    PubMed

    Zhang, Li; Wu, Yuhua; Wu, Gang; Cao, Yinglong; Lu, Changming

    2014-10-01

    Plasmid calibrators are increasingly applied for polymerase chain reaction (PCR) analysis of genetically modified organisms (GMOs). To evaluate the commutability between plasmid DNA (pDNA) and genomic DNA (gDNA) as calibrators, a plasmid molecule, pBSTopas, was constructed, harboring a Topas 19/2 event-specific sequence and a partial sequence of the rapeseed reference gene CruA. Assays of the pDNA showed similar limits of detection (five copies for Topas 19/2 and CruA) and quantification (40 copies for Topas 19/2 and 20 for CruA) as those for the gDNA. Comparisons of plasmid and genomic standard curves indicated that the slopes, intercepts, and PCR efficiency for pBSTopas were significantly different from CRM Topas 19/2 gDNA for quantitative analysis of GMOs. Three correction methods were used to calibrate the quantitative analysis of control samples using pDNA as calibrators: model a, or coefficient value a (Cva); model b, or coefficient value b (Cvb); and the novel model c or coefficient formula (Cf). Cva and Cvb gave similar estimated values for the control samples, and the quantitative bias of the low concentration sample exceeded the acceptable range within ±25% in two of the four repeats. Using Cfs to normalize the Ct values of test samples, the estimated values were very close to the reference values (bias -13.27 to 13.05%). In the validation of control samples, model c was more appropriate than Cva or Cvb. The application of Cf allowed pBSTopas to substitute for Topas 19/2 gDNA as a calibrator to accurately quantify the GMO.

  8. Toward a workable biosafety system for regulating genetically modified organisms in Ethiopia: balancing conservation and competitiveness.

    PubMed

    Abraham, Adane

    2013-01-01

    On September 9, 2009, Ethiopia enacted a highly restrictive biosafety law firmly based on precautionary principles as a foundation for its GMO regulation system. Its drafting process, led by the country's Environmental Protection Authority, was judged as biased, focusing only on protecting the environment from perceived risks, giving little attention to potential benefits of GMOs. Many of its provisions are very stringent, exceeding those of Cartagena Protocol on Biosafety, while others cannot be fulfilled by applicants, collectively rendering the emerged biosafety system unworkable. These provisions include requirements for advance informed agreement and rigorous socioeconomic assessment in risk evaluation for all GMO transactions, including contained research use-which requires the head of the competent national authority of the exporting country to take full responsibility for GMO-related information provided-and stringent labeling, insurance and monitoring requirements for all GMO activities. Furthermore, there is no provision to establish an independent national biosafety decision-making body(ies). As a result, foreign technology owners that provide highly demanded technologies like Bt cotton declined to work with Ethiopia. There is a fear that the emerged biosafety system might also continue to suppress domestic genetic engineering research and development. Thus, to benefit from GMOs, Ethiopia has to revise its biosafety system, primarily by making changes to some provisions of the law in a way that balances its diverse interests of conserving biodiversity, protecting the environment and enhancing competition in agricultural and other economic sectors.

  9. The possibility of aromorphosis in further development of closed human life support systems using genetically modified organisms

    NASA Astrophysics Data System (ADS)

    Gitelson, Josef

    evolution of the CES, the use of the advantages offered by genetically modified organisms produced by modern biotechnology can be regarded as aromorphosis. If the genetic program of biosyntheses performed by plants in-cludes the new genes that will program the synthesis of all molecules necessary for humans, the plants, both unicellular and higher, will produce the whole range of food substances perfectly corresponding to the requirements of the human body. This is a long way, but the investment of resources and time will be justified not only by the creation of an LSS for long-distance space missions and colonization of planets that will contain as many closed loops as possible and be energy efficient. This will also be a convenient and safest instrument to study and justify the wide use of products of genetically modified plants on Earth. Today, humanity is extremely wary of this idea because of its novelty. As experimental human life support ecosystems are closed systems, they provide the most reliable and safest instrument for studying issues related to GMO and preparing scientifically based suggestions for their practical use. The report will contain data on the spectra of mismatches between vegetable foods produced in BIOS-3 and human requirements, and the objectives of correcting the biosynthesis programs in the CES.

  10. The GMO Sumrule and the πNN Coupling Constant

    NASA Astrophysics Data System (ADS)

    Ericson, T. E. O.; Loiseau, B.; Thomas, A. W.

    The isovector GMO sumrule for forward πN scattering is critically evaluated using the precise π-p and π-d scattering lengths obtained recently from pionic atom measurements. The charged πNN coupling constant is then deduced with careful analysis of systematic and statistical sources of uncertainties. This determination gives directly from data gc2(GMO)/4π = 14.17±0.09 (statistic) ±0.17 (systematic) or fc2/ 4π=0.078(11). This value is half-way between that of indirect methods (phase-shift analyses) and the direct evaluation from from backward np differential scattering cross sections (extrapolation to pion pole). From the π-p and π-d scattering lengths our analysis leads also to accurate values for (1/2)(aπ-p+aπ-n) and (1/2) (aπ-p-aπ-n).

  11. Destruction of public and governmental experiments of GMO in Europe.

    PubMed

    Kuntz, Marcel

    2012-01-01

    The purpose of this article is to compile the destruction of GMO trials from academic or governmental research institutes in Europe, in a factual manner and to highlight their main characteristics. About 80 acts of vandalism against academic or governmental research on GMOs are identified, mainly in 4 countries; namely France, Germany, the United Kingdom and Switzerland. Examples are also provided for Italy and Belgium. The general conclusions that can be drawn from these acts are also discussed.

  12. The GMO case in France: politics, lawlessness and postmodernism.

    PubMed

    Kuntz, Marcel

    2014-07-03

    The GMO debacle in France is analyzed in the light of the balance of forces around this controversy, the changes in position of governments and the opponents' strategic use of intimidation. These factors have caused insurmountable difficulties for scientific experimentations and assessment of the technology, as well as for farmers attempting to grow GM maize in this country. The change from a "modern" to a "postmodern" framing of official public debates and scientific institutions has not appeased confrontations concerning GMOs.

  13. [Emergent retention of organic liquid by modified bentonites: property and mechanism].

    PubMed

    Li, Yu; Liu, Xian-Jun; Zhang, Xing-Wang; Lei, Le-Cheng

    2012-03-01

    In this study, the property and mechanism of modified bentonites synthesized by long chain quaternary ammonium compounds which would be used in the emergent retention of typical organic liquid (benzene, chlorobenzene, nitrobenzene and diesel) were investigated and a pilot-scale simulation experiment was conducted. The unit retention capacity of modified bentonites for organic liquid (2.83-9.01 g x g(-1)) was much higher than that of conventional retention agents (0.28-1.17 g x g(-1)). The property and amount of the surfactants used and viscosity of organic liquid had a significant influence on the retention capacity of modified bentonites for the organic liquid, for example, the bentonites modified by cetyltrimethylammonium (CTMAB) with an adding quantity of 100% CEC showed the highest efficiency in the retention of organic liquid. In the simulation experiment, organic liquid could be retained effectively within 30 min by emergent retention device with modified bentonites and the retention efficiency might reach positively up to 90%. Results indicated that modifications using surfactants could enhance the hydrophobicity and interlayer space of the modified bentonites and make their retention capacities for organic liquid improved.

  14. How scary! An analysis of visual communication concerning genetically modified organisms in Italy.

    PubMed

    Ventura, Vera; Frisio, Dario G; Ferrazzi, Giovanni; Siletti, Elena

    2016-04-01

    Several studies provide evidence of the role of written communication in influencing public perception towards genetically modified organisms, whereas visual communication has been sparsely investigated. This article aims to evaluate the exposure of the Italian population to scary genetically modified organism-related images. A set of 517 images collected through Google are classified considering fearful attributes, and an index that accounts for the scary impact of these images is built. Then, through an ordinary least-squares regression, we estimate the relationship between the Scary Impact Index and a set of variables that describes the context in which the images appear. The results reveal that the first (and most viewed) Google result images contain the most frightful contents. In addition, the agri-food sector in Italy is strongly oriented towards offering a negative representation of genetically modified organisms. Exposure to scary images could be a factor that affects the negative perception of genetically modified organisms in Italy.

  15. Validation of PCR methods for quantitation of genetically modified plants in food.

    PubMed

    Hübner, P; Waiblinger, H U; Pietsch, K; Brodmann, P

    2001-01-01

    For enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients, quantitative detection methods such as quantitative competitive (QC-PCR) and real-time PCR are applied by official food control laboratories. The experiences of 3 European food control laboratories in validating such methods were compared to describe realistic performance characteristics of quantitative PCR detection methods. The limit of quantitation (LOQ) of GMO-specific, real-time PCR was experimentally determined to reach 30-50 target molecules, which is close to theoretical prediction. Starting PCR with 200 ng genomic plant DNA, the LOQ depends primarily on the genome size of the target plant and ranges from 0.02% for rice to 0.7% for wheat. The precision of quantitative PCR detection methods, expressed as relative standard deviation (RSD), varied from 10 to 30%. Using Bt176 corn containing test samples and applying Bt176 specific QC-PCR, mean values deviated from true values by -7to 18%, with an average of 2+/-10%. Ruggedness of real-time PCR detection methods was assessed in an interlaboratory study analyzing commercial, homogeneous food samples. Roundup Ready soybean DNA contents were determined in the range of 0.3 to 36%, relative to soybean DNA, with RSDs of about 25%. Taking the precision of quantitative PCR detection methods into account, suitable sample plans and sample sizes for GMO analysis are suggested. Because quantitative GMO detection methods measure GMO contents of samples in relation to reference material (calibrants), high priority must be given to international agreements and standardization on certified reference materials.

  16. Multiplex electrochemical DNA platform for femtomolar-level quantification of genetically modified soybean.

    PubMed

    Manzanares-Palenzuela, C Lorena; de-los-Santos-Álvarez, Noemí; Lobo-Castañón, María Jesús; López-Ruiz, Beatriz

    2015-06-15

    Current EU regulations on the mandatory labeling of genetically modified organisms (GMOs) with a minimum content of 0.9% would benefit from the availability of reliable and rapid methods to detect and quantify DNA sequences specific for GMOs. Different genosensors have been developed to this aim, mainly intended for GMO screening. A remaining challenge, however, is the development of genosensing platforms for GMO quantification, which should be expressed as the number of event-specific DNA sequences per taxon-specific sequences. Here we report a simple and sensitive multiplexed electrochemical approach for the quantification of Roundup-Ready Soybean (RRS). Two DNA sequences, taxon (lectin) and event-specific (RR), are targeted via hybridization onto magnetic beads. Both sequences are simultaneously detected by performing the immobilization, hybridization and labeling steps in a single tube and parallel electrochemical readout. Hybridization is performed in a sandwich format using signaling probes labeled with fluorescein isothiocyanate (FITC) or digoxigenin (Dig), followed by dual enzymatic labeling using Fab fragments of anti-Dig and anti-FITC conjugated to peroxidase or alkaline phosphatase, respectively. Electrochemical measurement of the enzyme activity is finally performed on screen-printed carbon electrodes. The assay gave a linear range of 2-250 pM for both targets, with LOD values of 650 fM (160 amol) and 190 fM (50 amol) for the event-specific and the taxon-specific targets, respectively. Results indicate that the method could be applied for GMO quantification below the European labeling threshold level (0.9%), offering a general approach for the rapid quantification of specific GMO events in foods.

  17. Thermal properties of organic and modified inorganic aerogels

    SciTech Connect

    Pekala, R.W.; Hrubesh, L.W.

    1992-08-01

    Aerogels are open-cell foams that have already been shown to be among the best thermal insulating solid materials known. Improvements in the thermal insulating properties of aerogels are possible by synthesizing new organic varieties, by using additives within existing aerogel matrix, and by optimizing their nanostructures. We discuss these approaches and give some examples of aerogels which demonstrate the improvements.

  18. Cry1A(b)16 Toxin from Bacillus thuringiensis: Theoretical Refinement of Three-Dimensional Structure and Prediction of Peptides as Molecular Markers for Detection of Genetically Modified Organisms.

    PubMed

    Plácido, Alexandra; Coelho, Andreia; Nascimento, Lucas Abreu do; Vasconcelos, Andreanne Gomes; Barroso, Maria Fátima; Ramos-Jesus, Joilson; Costa, Vladimir; Lima, Francisco das Chagas Alves; Delerue-Matos, Cristina; Ramos, Ricardo Martins; Marani, Mariela M; Leite, José Roberto de Souza de Almeida

    2017-03-18

    Transgenic maize produced by the insertion of the Cry transgene into its genome became the second most cultivated crop worldwide. Cry gene from Bacillus thuringiensis kurstaki expresses protein derivatives of crystalline endotoxins which confer insect resistance onto the maize crop. Mandatory labeling of processed food containing or made by genetically modified organisms is in force in many countries, so, it is very urgent to develop fast and practical methods for GMO identification, e.g., biosensors. In the absence of an available empirical structure of Cry1A(b)16 protein, a theoretical model was effectively generated, in this work, by homology modeling and molecular dynamics simulations based on two available homologous protein structures. Molecular dynamics simulations were carried out to refine the selected model, and an analysis of its global structure was performed. The refined models of Cry1A(b)16 showed a standard fold and structural characteristics similar to those seen in Bacillus thuringiensis Cry1A(a) insecticidal toxin and Bacillus thuringiensis serovar kurstaki Cry1A(c) toxin. After in silico analysis of Cry1A(b)16, two immunoreactive candidate peptides were selected and specific polyclonal antibodies were produced resulting in antibody-peptide interaction. Biosensing devices are expected to be developed for detection of the Cry1A(b) protein as a marker of transgenic maize in food. This article is protected by copyright. All rights reserved.

  19. Development of an event-specific hydrolysis probe quantitative real-time polymerase chain reaction assay for Embrapa 5.1 genetically modified common bean (Phaseolus vulgaris).

    PubMed

    Treml, Diana; Venturelli, Gustavo L; Brod, Fábio C A; Faria, Josias C; Arisi, Ana C M

    2014-12-10

    A genetically modified (GM) common bean event, namely Embrapa 5.1, resistant to the bean golden mosaic virus (BGMV), was approved for commercialization in Brazil. Brazilian regulation for genetically modified organism (GMO) labeling requires that any food containing more than 1% GMO be labeled. The event-specific polymerase chain reaction (PCR) method has been the primary trend for GMO identification and quantitation because of its high specificity based on the flanking sequence. This work reports the development of an event-specific assay, named FGM, for Embrapa 5.1 detection and quantitation by use of SYBR Green or hydrolysis probe. The FGM assay specificity was tested for Embrapa 2.3 event (a noncommercial GM common bean also resistant to BGMV), 46 non-GM common bean varieties, and other crop species including maize, GM maize, soybean, and GM soybean. The FGM assay showed high specificity to detect the Embrapa 5.1 event. Standard curves for the FGM assay presented a mean efficiency of 95% and a limit of detection (LOD) of 100 genome copies in the presence of background DNA. The primers and probe developed are suitable for the detection and quantitation of Embrapa 5.1.

  20. Electrochemiluminescence-PCR detection of genetically modified organisms

    NASA Astrophysics Data System (ADS)

    Liu, Jinfeng; Xing, Da; Shen, Xingyan; Zhu, Debin

    2005-01-01

    The detection methods for genetically modified (GM) components in foods have been developed recently. But many of them are complicated and time-consuming; some of them need to use the carcinogenic substance, and can"t avoid false-positive results. In this study, an electrochemiluminescence polymerase chain reaction (ECL-PCR) method for detection GM tobaccos is proposed. The Cauliflower mosaic virus 35S (CaMV35S) promoter was amplified by PCR, Then hybridized with a Ru(bpy)32+ (TBR)-labeled and a biotinylated probe. The hybridization products were captured onto streptavidin-coated paramagnetic beads, and detected by measuring the electrochemiluminescence (ECL) signal of the TBR label. Whether the tobaccos contain GM components was discriminated by detecting the ECL signal of CaMV35S promoter. The experiment results show that the detection limit for CaMV35S promoter is 100 fmol, and the GM components can be clearly identified in GM tobaccos. The ECL-PCR method provide a new means in GMOs detection due to its safety, simplicity and high efficiency.

  1. 48 CFR 215.404-72 - Modified weighted guidelines method for nonprofit organizations other than FFRDCs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... guidelines method for nonprofit organizations other than FFRDCs. 215.404-72 Section 215.404-72 Federal... METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 215.404-72 Modified weighted guidelines method for nonprofit organizations other than FFRDCs. (a) Definition. As used in this subpart,...

  2. Formamide as an organic modifier in MEKC with SDS.

    PubMed

    Téllez, Adolfo; Kenndler, Ernst

    2009-01-01

    The effect of formamide (FA) as a modifier on the retention in MEKC with SDS as the detergent was investigated. The mobility of a series of alkylphenones and of a zwitterionic fluorescent compound as a function of the FA and the SDS concentration was determined for this purpose. Buffering electrolyte was borate, pH 9.23, with total ionic strength of 50 mM. The dependence of the mobility on the FA content - up to 63% w/w - of the BGE (at 10 mM SDS) allows the conclusion that the micelles are destabilized, and the CMC is shifted to higher values. In the system containing 33% FA or more no micelles are present anymore, and the retention factors of all compounds tend to zero. In an MEKC system with 27% v/v FA the CMC of SDS is increased from 2.4 mM in the aqueous BGE with the same buffer composition to 9.7 mM, a behavior that is in contrast to electrolyte-free FA-water systems. The partition constants of free analytes and the formation constants of the adduct between analyte and detergent monomer (assuming 1:1 stoichiometry) were derived from the dependence of the mobility on the SDS concentration. In addition, the involved equilibria were extended by that from the distribution of the analyte-monomer adduct between aqueous and micellar phase, and the according partition constants were derived as well. A selective change in the extent of partitioning was observed for the zwitterionic compound. In general, all binding constants were decreased upon addition of FA, though to a different extent. Although the binding constants of the analyte-monomer associate were only slightly influenced, the most pronounced decrease is found for their partitioning into the micelles.

  3. Testing for genetically modified organisms (GMOs): Past, present and future perspectives.

    PubMed

    Holst-Jensen, Arne

    2009-01-01

    This paper presents an overview of GMO testing methodologies and how these have evolved and may evolve in the next decade. Challenges and limitations for the application of the test methods as well as to the interpretation of results produced with the methods are highlighted and discussed, bearing in mind the various interests and competences of the involved stakeholders. To better understand the suitability and limitations of detection methodologies the evolution of transformation processes for creation of GMOs is briefly reviewed.

  4. Development and validation of real-time PCR screening methods for detection of cry1A.105 and cry2Ab2 genes in genetically modified organisms.

    PubMed

    Dinon, Andréia Z; Prins, Theo W; van Dijk, Jeroen P; Arisi, Ana Carolina M; Scholtens, Ingrid M J; Kok, Esther J

    2011-05-01

    Primers and probes were developed for the element-specific detection of cry1A.105 and cry2Ab2 genes, based on their DNA sequence as present in GM maize MON89034. Cry genes are present in many genetically modified (GM) plants and they are important targets for developing GMO element-specific detection methods. Element-specific methods can be of use to screen for the presence of GMOs in food and feed supply chains. Moreover, a combination of GMO elements may indicate the potential presence of unapproved GMOs (UGMs). Primer-probe combinations were evaluated in terms of specificity, efficiency and limit of detection. Except for specificity, the complete experiment was performed in 9 PCR runs, on 9 different days and by testing 8 DNA concentrations. The results showed a high specificity and efficiency for cry1A.105 and cry2Ab2 detection. The limit of detection was between 0.05 and 0.01 ng DNA per PCR reaction for both assays. These data confirm the applicability of these new primer-probe combinations for element detection that can contribute to the screening for GM and UGM crops in food and feed samples.

  5. Micro-organism and cell viability on antimicrobially modified titanium.

    PubMed

    Omori, S; Shibata, Y; Arimoto, T; Igarashi, T; Baba, K; Miyazaki, T

    2009-10-01

    When titanium is anodized by discharge in NaCl solution, both antimicrobial activity and osteoconductivity are conferred. The viability of adherent micro-organisms and cells on antimicrobial titanium remains uncertain. We hypothesized that a thin peroxidation barrier would efficiently destroy adherent bacteria, whereas adherent osteoblastic cells would be viable, since these cells adhere to the surface indirectly though serum proteins. The efficacy of antimicrobial titanium appears to be based on peroxidation, since peroxidation products were detected in parallel with the destruction of bacterial cell-surface structures. The peroxidation effect of antimicrobial titanium was confined to the surface within narrow limits. The viability of osteoblastic cells on the surface was strongly dependent on the presence of serum protein, whereas that of adherent Streptococcus mutans was not affected by the presence of serum proteins. Therefore, differences in the adherent systems used by bacteria and osteoblastic cells are important determinants of their viability on antimicrobial titanium.

  6. The GMO case in France: Politics, lawlessness and postmodernism

    PubMed Central

    Kuntz, Marcel

    2014-01-01

    The GMO debacle in France is analyzed in the light of the balance of forces around this controversy, the changes in position of governments and the opponents’ strategic use of intimidation. These factors have caused insurmountable difficulties for scientific experimentations and assessment of the technology, as well as for farmers attempting to grow GM maize in this country. The change from a “modern” to a “postmodern” framing of official public debates and scientific institutions has not appeased confrontations concerning GMOs. PMID:25437234

  7. Development of a certified reference material for genetically modified potato with altered starch composition.

    PubMed

    Broothaerts, Wim; Corbisier, Philippe; Emons, Hendrik; Emteborg, Håkan; Linsinger, Thomas P J; Trapmann, Stefanie

    2007-06-13

    The presence of genetically modified organisms (GMOs) in food and feed products is subject to regulation in the European Union (EU) and elsewhere. As part of the EU authorization procedure for GMOs intended for food and feed use, reference materials must be produced for the quality control of measurements to quantify the GMOs. Certified reference materials (CRMs) are available for a range of herbicide- and insect-resistant genetically modified crops such as corn, soybean, and cotton. Here the development of the first CRM for a GMO that differs from its non-GMO counterpart in a major compositional constituent, that is, starch, is described. It is shown that the modification of the starch composition of potato (Solanum tuberosum L.) tubers, together with other characteristics of the delivered materials, have important consequences for the certification strategy. Moreover, the processing and characterization of the EH92-527-1 potato material required both new and modified procedures, different from those used routinely for CRMs produced from genetically modified seeds.

  8. Innovative fiber coating systems based on organic modified ceramics

    NASA Astrophysics Data System (ADS)

    Schuster, Kay; Kobelke, Jens; Rose, Klaus; Helbig, Manfred; Zoheidi, Mohammad; Heinze, Alexander

    2010-02-01

    We describe the application of inorganic organic hybrid materials (ORMOCERs) as optical fiber coatings for use in Fiber Bragg Grating sensors and high power transmission fibers. The materials are UV curable, enable a single layer thickness of about 50 μm and show high a high peak temperature stability >300 °C. Regarding the fiber protection the coatings have been investigated using tensile strength measurements before and after temperature load. Best coatings maintain the high tensile strength of 68 N (125 μm fiber) with a Weibull parameter of 182 after a temperature cycling up to 300 °C. For the first time a low refractive index ORMOCER will be presented showing a numerical aperture of 0.47 at a wavelength of 1000 nm on a pure silica fiber. This corresponds to a refractive index of 1.37. The fiber possesses a fiber loss of 18 dB/km at a wavelength of 1000 nm. The fibers have been coated using a gravity as well as pressure technology. The latter possesses extremely minimized die equipment and is therefore well applicable for small coating amounts. The so called dead volume within the coating die is about 1 ml. The overall dead volume is only influenced by the supply pipe and can be reduced down to 5 ml.

  9. Attitudes to genetically modified food over time: How trust in organizations and the media cycle predict support.

    PubMed

    Marques, Mathew D; Critchley, Christine R; Walshe, Jarrod

    2015-07-01

    This research examined public opinion toward genetically modified plants and animals for food, and how trust in organizations and media coverage explained attitudes toward these organisms. Nationally representative samples (N=8821) over 10 years showed Australians were less positive toward genetically modified animals compared to genetically modified plants for food, especially in years where media coverage was high. Structural equation modeling found that positive attitudes toward different genetically modified organisms for food were significantly associated with higher trust in scientists and regulators (e.g. governments), and with lower trust in watchdogs (e.g. environmental movement). Public trust in scientists and watchdogs was a stronger predictor of attitudes toward the use of genetically modified plants for food than animals, but only when media coverage was low. Results are discussed regarding the moral acceptability of genetically modified organisms for food, the media's role in shaping public opinion, and the role public trust in organizations has on attitudes toward genetically modified organisms.

  10. Options for Organizing the Tanker Airlift Control Center Flight Dispatch Function: An Exploratory Concept Study

    DTIC Science & Technology

    2000-06-01

    Jeffrey A. Sheppard, Major, USAF AFIT/ GMO /ENS/00E-10 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright...Force, Department of Defense, or the U. S. Government. AFIT/ GMO /ENS/00E-10 OPTIONS FOR ORGANIZING THE TANKER AIRLIFT CONTROL CENTER FLIGHT...Program Goal…….……….…61 vi AFIT/ GMO /ENS/00E-10 Abstract The Tanker Airlift Control Center (TACC) is the central execution agency for

  11. Multiplex quantification of 12 European Union authorized genetically modified maize lines with droplet digital polymerase chain reaction.

    PubMed

    Dobnik, David; Spilsberg, Bjørn; Bogožalec Košir, Alexandra; Holst-Jensen, Arne; Žel, Jana

    2015-08-18

    Presence of genetically modified organisms (GMO) in food and feed products is regulated in many countries. The European Union (EU) has implemented a threshold for labeling of products containing more than 0.9% of authorized GMOs per ingredient. As the number of GMOs has increased over time, standard-curve based simplex quantitative polymerase chain reaction (qPCR) analyses are no longer sufficiently cost-effective, despite widespread use of initial PCR based screenings. Newly developed GMO detection methods, also multiplex methods, are mostly focused on screening and detection but not quantification. On the basis of droplet digital PCR (ddPCR) technology, multiplex assays for quantification of all 12 EU authorized GM maize lines (per April first 2015) were developed. Because of high sequence similarity of some of the 12 GM targets, two separate multiplex assays were needed. In both assays (4-plex and 10-plex), the transgenes were labeled with one fluorescence reporter and the endogene with another (GMO concentration = transgene/endogene ratio). It was shown that both multiplex assays produce specific results and that performance parameters such as limit of quantification, repeatability, and trueness comply with international recommendations for GMO quantification methods. Moreover, for samples containing GMOs, the throughput and cost-effectiveness is significantly improved compared to qPCR. Thus, it was concluded that the multiplex ddPCR assays could be applied for routine quantification of 12 EU authorized GM maize lines. In case of new authorizations, the events can easily be added to the existing multiplex assays. The presented principle of quantitative multiplexing can be applied to any other domain.

  12. VAPOR PHASE MERCURY SORPTION BY ORGANIC SULFIDE MODIFIED BIMETALLIC IRON-COPPER NANOPARTICLE AGGREGATES

    EPA Science Inventory

    Novel organic sulfide modified bimetallic iron-copper nanoparticle aggregate sorbent materials have been synthesized for removing elemental mercury from vapor streams at elevated temperatures (120-140 °C). Silane based (disulfide silane and tetrasulfide silane) and alkyl sulfide ...

  13. 75 FR 5363 - Self-Regulatory Organizations; NYSE Arca, Inc.; Order Approving Proposed Rule Change Modifying...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-02

    ... Prices'' service and to add a usage-based fee alternative for that service. The proposed rule change was.... Description of the Proposal The Exchange proposes several changes to the NYSE Arca Realtime Reference Prices... COMMISSION Self-Regulatory Organizations; NYSE Arca, Inc.; Order Approving Proposed Rule Change Modifying...

  14. A comparison of protein and phenolic compounds in seed from GMO and non-GMO soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean protein is a valuable and important component in human and animal diets. Approximately 94% of the soybean planted in the US is genetically modified (GM) to enhance quality and productivity. Since value-added traits are continuously being developed by genetic modification, it is important t...

  15. Organically modified porous hydroxyapatites: A comparison between alkylphosphonate grafting and citrate chelation

    SciTech Connect

    El-Hammari, L.; Marroun, H.; Laghzizil, A.; Saoiabi, A.; Roux, C.; Livage, J.; Coradin, T.

    2008-04-15

    Two alternative methods to prepare organically modified porous hydroxyapatites following a 'one pot' approach were compared. The partial substitution of inorganic phosphates by alkylphosphonates leads to mesoporous materials with high specific surface area (>200 m{sup 2} g{sup -1}). The incorporation of the organic moieties within the hydroxyapatite structure is confirmed by Infra-red and solid-state NMR spectroscopy and depends on the nature of the alkyl chain. However, it induces a significant loss of the material crystallinity. In contrast, the introduction of citrate, a calcium-chelating agent, to the precursor solution does not improve the material specific surface area but allows a better control of the hydroxyapatite structure, both in terms of crystallinity and pore size distribution. - Graphical abstract: Evolution of pore size distribution of hydroxyapatite (HAp) after alkylphosphonate grafting (20% TPOH) or citrate addition (c-HAp) demonstrates the formation of organically modified mesoporous materials.

  16. Surfactant-modified zeolites as permeable barriers to organic and inorganic groundwater contaminants

    SciTech Connect

    Bowman, R.S.; Sullivan, E.J.

    1995-10-01

    We have shown in laboratory experiments that natural zeolites treated with hexadecyltrimethylammonium (HDTMA) are effective sorbents for nonpolar organics, inorganic cations, and inorganic anions. Due to their low cost ({approximately}$0.75/kg) and granular nature, HDTMA-zeolites appear ideal candidates for reactive, permeable subsurface barriers. The HDTMA-zeolites are stable over a wide range of pH (3-13), ionic strength (1 M Cs{sup +} or Ca{sup 2+}), and in organic solvents. Surfactant-modified zeolites sorb nonpolar organics (benzene, toluene, xylene, chlorinated aliphatics) via a partitioning mechanism, inorganic cations (Pb{sup 2+}) via ion exchange and surface complexation, and inorganic anions (CrO{sub 4}{sup 2-}, SeO{sub 4}{sup 2-}, SO{sub 4}{sup 2-}) via surface precipitation.The goal of this work is to demonstrate the use of surfactant-modified zeolite as a permeable barrier to ground water contaminants.

  17. Removal of organic pollutants by surfactant modified zeolite: comparison between ionizable phenolic compounds and non-ionizable organic compounds.

    PubMed

    Xie, Jie; Meng, Wenna; Wu, Deyi; Zhang, Zhenjia; Kong, Hainan

    2012-09-15

    The aim of this study was to examine the adsorption capability and mechanism of hexadecyltrimethylammonium modified zeolite, which was synthesized from coal fly ash, for the removal of ionizable phenolic compounds (phenol, p-chlorophenol and bisphenol A, with different pK(a)) and non-ionizable organic compounds (aniline, nitrobenzene, and naphthalene, with different hydrophobicity). The obtained zeolite was identified as type Na-P1 (Na(6)Al(6)Si(10)O(32)·12H(2)O, JCPDS code 39-0219), which is classified into the gismondine group with a pore size of 3.1 Å × 4.5 Å [100] and 2.8 Å × 4.8 Å [101]. The adsorption of the two kinds of organic compounds was due to loaded surfactant bilayer because modified zeolite showed great ability for the removal of organic chemicals while little adsorption by zeolite was observed. The isotherm data of ionizable compounds fitted well to the Langmuir model but those of non-ionizable chemicals followed a linear equation. Uptake of ionizable compounds depended greatly on pH, increasing at alkaline pH conditions. In contrary, adsorption of non-ionizable chemicals was essentially the same at all pH levels studied. The adsorption of both kinds of organic compounds correlated well to k(ow) value, suggesting that more hydrophobic organic contaminants are more easily retained by modified zeolite. Based on the different adsorption behavior, the uptake of non-ionizable pollutants was thought to be a single partitioning process into the surfactant bilayer. For ionizable compounds, however, interaction of the phenol group(s) with the positively charged "head" of surfactant additionally functions.

  18. Data in support of the detection of genetically modified organisms (GMOs) in food and feed samples.

    PubMed

    Alasaad, Noor; Alzubi, Hussein; Kader, Ahmad Abdul

    2016-06-01

    Food and feed samples were randomly collected from different sources, including local and imported materials from the Syrian local market. These included maize, barley, soybean, fresh food samples and raw material. GMO detection was conducted by PCR and nested PCR-based techniques using specific primers for the most used foreign DNA commonly used in genetic transformation procedures, i.e., 35S promoter, T-nos, epsps, cryIA(b) gene and nptII gene. The results revealed for the first time in Syria the presence of GM foods and feeds with glyphosate-resistant trait of P35S promoter and NOS terminator in the imported soybean samples with high frequency (5 out of the 6 imported soybean samples). While, tests showed negative results for the local samples. Also, tests revealed existence of GMOs in two imported maize samples detecting the presence of 35S promoter and nos terminator. Nested PCR results using two sets of primers confirmed our data. The methods applied in the brief data are based on DNA analysis by Polymerase Chain Reaction (PCR). This technique is specific, practical, reproducible and sensitive enough to detect up to 0.1% GMO in food and/or feedstuffs. Furthermore, all of the techniques mentioned are economic and can be applied in Syria and other developing countries. For all these reasons, the DNA-based analysis methods were chosen and preferred over protein-based analysis.

  19. The occurrence of antibiotic resistance genes in Taq polymerases and a decontamination method applied to the detection of genetically modified crops.

    PubMed

    Perron, André; Raymond, Philippe; Simard, Robin

    2006-03-01

    Different antibiotic resistance (AR) genes, such as Bla, Tet and NPTII, contaminate commercially available Taq polymerases. The specificity of the AR gene PCR can be increased when using a restriction enzyme-based decontamination of polymerase. The elimination of Taq polymerase contamination allows the use of PCR tests to screen seeds (corn) and processed food for the presence of genetically modified organisms (GMO) based on the detection of AR genes. Without a decontamination procedure for AR genes, PCR screening tests should be interpreted with caution.

  20. Effects of organic modifiers on the size-controlled synthesis of hydroxyapatite nanorods

    NASA Astrophysics Data System (ADS)

    Wang, Aili; Yin, Hengbo; Liu, Dong; Wu, Huixiong; Wada, Yuji; Ren, Min; Xu, Yiqing; Jiang, Tingshun; Cheng, Xiaonong

    2007-01-01

    Size-controlled synthesis of hydroxyapatite nanorods were carried out by chemical precipitation method using polyethylene glycol (MW 600), Tween 20, trisodium citrate, and D-sorbitol as organic modifiers and starting from calcium nitrate, phosphoric acid, and ammonia solution. The influence of the organic modifiers on the sizes of the resultant HAP nanorods was investigated under different synthesis temperatures. It was found that polyethylene glycol was beneficial to the formation of HAP nanorods with a larger aspect ratio (average length/average diameter) at high synthesis temperature, Tween 20 and trisodium citrate favored the formation of small-sized HAP nanorods, and D-sorbitol helped the formation of HAP nanorods with long length at low synthesis temperatures.

  1. Fatal attraction: the intuitive appeal of GMO opposition.

    PubMed

    Blancke, Stefaan; Van Breusegem, Frank; De Jaeger, Geert; Braeckman, Johan; Van Montagu, Marc

    2015-07-01

    Public opposition to genetically modified organisms (GMOs) remains strong. By contrast, studies demonstrate again and again that GM crops make a valuable contribution to the development of a sustainable type of agriculture. The discrepancy between public opinion and the scientific evidence requires an explanation. We argue that intuitive expectations about the world render the human mind vulnerable to particular misrepresentations of GMOs. We explain how the involvement of particular intuitions accounts for the popularity, persistence, and typical features of GM opposition and tackle possible objections to our approach. To conclude, we discuss the implications for science education, science communication, and the environmental movement.

  2. Carbon-dot organic surface modifier analysis by solution-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Philippidis, Aggelos; Spyros, Apostolos; Anglos, Demetrios; Bourlinos, Athanasios B.; Zbořil, Radek; Giannelis, Emmanuel P.

    2013-07-01

    Carbon dots (C-dots) represent a new class of carbon-based materials that were discovered recently and have drawn the interest of the scientific community, particularly because of their attractive optical properties and their potential as fluorescent sensors. Investigation of the chemical structure of C-dots is extremely important for correlating the surface modifier composition with C-dot optical properties and allow for structure-properties fine tuning. In this article, we report the structural analysis of the surface modifiers of three different types of C-dot nanoparticles (Cwax, Cws, and Csalt) by use of 1D- and 2D-high-resolution NMR spectroscopy in solution. We unambiguously verify that the structure of the modifier chains remains chemically unchanged during the passivation procedure, and confirm the covalent attachment of the modifiers to the nanoparticle core, which contributes no signal to the solution-state NMR spectra. To our knowledge, this is the first study confirming the full structural assignment of C-dot organic surface modifiers by use of solution NMR spectroscopy.

  3. Functionalization of organically modified silica with gold nanoparticles in the presence of lignosulfonate.

    PubMed

    Konował, Emilia; Modrzejewska-Sikorska, Anna; Motylenko, Mykhailo; Klapiszewski, Łukasz; Wysokowski, Marcin; Bazhenov, Vasilii V; Rafaja, David; Ehrlich, Hermann; Milczarek, Grzegorz; Jesionowski, Teofil

    2016-04-01

    It is shown that lignosulfonate (LS) can be used as an effective reducing agent for gold ions and simultaneously as a stabilizing agent for gold nanoparticles (AuNPs). When organically modified silica is introduced to the reaction mixture, most of the AuNPs grow on the surface of the silica due to hydrophobic interactions between LS and organic layers covering the solid particles. It was also found that the structure of the organic layer is crucial for the effective deposition of gold nanoparticles onto silica spheres in terms of particle size and gold content in the final SiO2-LS-AuNPs composites. Due to the hydrophobicity of the modified silica it was necessary to carry out the modification in mixed organic/aqueous solvent. The polarity of the organic co-solvent was found to have an effect on the size of the deposited Au-NPs and their quantity. The physical appearance of the obtained hybrids was analyzed by colorimetry, and their structure and composition were evaluated using transmission electron microscopy (TEM). Additionally dispersive and thermal properties were examined by dynamic light scattering (DLS) and thermogravimetry (TG), respectively. The obtained multifunctional hybrid materials exhibits remarkable catalytic activity for the reduction of C.I. Basic Blue 9 (Methylene Blue) by borohydride.

  4. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize.

    PubMed

    Séralini, Gilles-Eric; Clair, Emilie; Mesnage, Robin; Gress, Steeve; Defarge, Nicolas; Malatesta, Manuela; Hennequin, Didier; de Vendômois, Joël Spiroux

    2012-11-01

    The health effects of a Roundup-tolerant genetically modified maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone (from 0.1 ppb in water), were studied 2 years in rats. In females, all treated groups died 2-3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs. All results were hormone and sex dependent, and the pathological profiles were comparable. Females developed large mammary tumors almost always more often than and before controls, the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5-5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3-2.3 greater. Males presented 4 times more large palpable tumors than controls which occurred up to 600 days earlier. Biochemistry data confirmed very significant kidney chronic deficiencies; for all treatments and both sexes, 76% of the altered parameters were kidney related. These results can be explained by the non linear endocrine-disrupting effects of Roundup, but also by the overexpression of the transgene in the GMO and its metabolic consequences.

  5. Effect of algal flocculation on dissolved organic matters using cationic starch modified soils.

    PubMed

    Shi, Wenqing; Bi, Lei; Pan, Gang

    2016-07-01

    Modified soils (MSs) are being increasingly used as geo-engineering materials for the sedimentation removal of cyanobacterial blooms. Cationic starch (CS) has been tested as an effective soil modifier, but little is known about its potential impacts on the treated water. This study investigated dissolved organic matters in the bloom water after algal removal using cationic starch modified soils (CS-MSs). Results showed that the dissolved organic carbon (DOC) could be decreased by CS-MS flocculation and the use of higher charge density CS yielded a greater DOC reduction. When CS with the charge density of 0.052, 0.102 and 0.293meq/g were used, DOC was decreased from 3.4 to 3.0, 2.3 and 1.7mg/L, respectively. The excitation-emission matrix fluorescence spectroscopy and UV254 analysis indicated that CS-MS exhibits an ability to remove some soluble organics, which contributed to the DOC reduction. However, the use of low charge density CS posed a potential risk of DOC increase due to the high CS loading for effective algal removal. When CS with the charge density of 0.044meq/g was used, DOC was increased from 3.4 to 3.9mg/L. This study suggested, when CS-MS is used for cyanobacterial bloom removal, the content of dissolved organic matters in the treated water can be controlled by optimizing the charge density of CS. For the settled organic matters, other measures (e.g., capping treatments using oxygen loaded materials) should be jointly applied after algal flocculation.

  6. Enhanced sorption of organic contaminants by smectitic soils modified with a cationic surfactant

    SciTech Connect

    Sheng, G.; Wang, X.; Wu, S.; Boyd, S.A.

    1998-07-01

    Soils, subsoils, and aquifer materials can be modified with hydrophobic cationic surfactants to increase their sorptive capabilities for organic contaminants. In this study, the authors evaluated the adsorption/desorption of hexadecyltrimethylammonium (HDTMA) by smectitic soils, and the sorptive characteristics of the resultant organo-modified soils for trichloroethylene and chlorobenzene. Adsorption of HDTMA with loading levels up to 70% of the cation exchange capacity (0.70 CEC) was nearly quantitative and resulted in an equivalent release of Ca{sup 2+} from the soils, indicating ion exchange as the sole mechanism over this range. At higher loadings, HDTMA is adsorbed by both ion exchange and hydrophobic bonding. The selectivity coefficients for HDTMA replacing Ca{sup 2+} were very high (10{sup 9}-10{sup 7} between 0.1 and 0.8 CEC), indicating the high chemical stability of HDTMA-soil complexes at these loadings. Desorption is more significant for HDTMA adsorbed via hydrophobic bonding than via ion exchange. Sorption coefficients for trichloroethylene and chlorobenzene on HDTMA-modified soils (0.7 CEC) were 20 to 60 and 100 to 350 times higher, respectively, than those on the corresponding unmodified soils. The HDTMA derived phase was 10 to 30 and 80 to 160 times more effective than natural soil organic matter as a sorptive phase for trichloroethylene and chlorobenzene, respectively. A synergistic effect on sorption of trichloroethylene and chlorobenzene in binary solute systems was observed. The sorptive characteristics of HDTMA modified smectitic soils for organic contaminants are similar to those of pure HDTMA-smectites.

  7. New GMO regulations for old: Determining a new future for EU crop biotechnology.

    PubMed

    Davison, John; Ammann, Klaus

    2017-01-02

    In this review, current EU GMO regulations are subjected to a point-by point analysis to determine their suitability for agriculture in modern Europe. Our analysis concerns present GMO regulations as well as suggestions for possible new regulations for genome editing and New Breeding Techniques (for which no regulations presently exist). Firstly, the present GMO regulations stem from the early days of recombinant DNA and are not adapted to current scientific understanding on this subject. Scientific understanding of GMOs has changed and these regulations are now, not only unfit for their original purpose, but, the purpose itself is now no longer scientifically valid. Indeed, they defy scientific, economic, and even common, sense. A major EU regulatory preconception is that GM crops are basically different from their parent crops. Thus, the EU regulations are "process based" regulations that discriminate against GMOs simply because they are GMOs. However current scientific evidence shows a blending of classical crops and their GMO counterparts with no clear demarcation line between them. Canada has a "product based" approach and determines the safety of each new crop variety independently of the process used to obtain it. We advise that the EC re-writes it outdated regulations and moves toward such a product based approach.  Secondly, over the last few years new genomic editing techniques (sometimes called New Breeding Techniques) have evolved. These techniques are basically mutagenesis techniques that can generate genomic diversity and have vast potential for crop improvement. They are not GMO based techniques (any more than mutagenesis is a GMO technique), since in many cases no new DNA is introduced. Thus they cannot simply be lumped together with GMOs (as many anti-GMO NGOs would prefer). The EU currently has no regulations to cover these new techniques. In this review, we make suggestions as to how these new gene edited crops may be regulated. The EU is at a

  8. Simultaneous complexation of organic compounds and heavy metals by a modified cyclodextrin

    SciTech Connect

    Wang, X.; Brusseau, M.L.

    1995-10-01

    The cleanup of contaminated soil and groundwater at hazardous waste sites has become a major focus of research and policy debate. A major factor complicating the cleanup of many sites is the cooccurrence of organic compounds and heavy metals, the so-called mixed wastes. We investigated the ability of a modified cyclodextrin to simultaneously complex low-polarity organic compounds and heavy metals. The results of the experiments showed that carboxymethyl-{beta}-cyclodextrin could simultaneously increase the apparent aqueous solubilities of the selected organic compounds (anthracene, trichlorobenzene; biphenyl, and ODT) and complex with Cd{sup 2+}. This complexation was not significantly affected by changes in pH or by the presence of relatively high concentrations of Ca{sup 2+}. It is possible that this reagent can be used successfully to remediate hazardous waste sites contaminated by mixed wastes. 11 refs., 7 figs.

  9. A preamplification approach to GMO detection in processed foods.

    PubMed

    Del Gaudio, S; Cirillo, A; Di Bernardo, G; Galderisi, U; Cipollaro, M

    2010-03-01

    DNA is widely used as a target for GMO analysis because of its stability and high detectability. Real-time PCR is the method routinely used in most analytical laboratories due to its quantitative performance and great sensitivity. Accurate DNA detection and quantification is dependent on the specificity and sensitivity of the amplification protocol as well as on the quality and quantity of the DNA used in the PCR reaction. In order to enhance the sensitivity of real-time PCR and consequently expand the number of analyzable target genes, we applied a preamplification technique to processed foods where DNA can be present in low amounts and/or in degraded forms thereby affecting the reliability of qualitative and quantitative results. The preamplification procedure utilizes a pool of primers targeting genes of interest and is followed by real-time PCR reactions specific for each gene. An improvement of Ct values was found comparing preamplified vs. non-preamplified DNA. The strategy reported in the present study will be also applicable to other fields requiring quantitative DNA testing by real-time PCR.

  10. Rapid amplification of genetically modified organisms using a circular ferrofluid-driven PCR microchip.

    PubMed

    Sun, Yi; Kwok, Yien-Chian; Foo-Peng Lee, Peter; Nguyen, Nam-Trung

    2009-07-01

    The use of genetically modified organisms (GMOs) as food and in food products is becoming more and more widespread. Polymerase chain reaction (PCR) technology is extensively used for the detection of GMOs in food products in order to verify compliance with labeling requirements. In this paper, we present a novel close-loop ferrofluid-driven PCR microchip for rapid amplification of GMOs. The microchip was fabricated in polymethyl methacrylate by CO2 laser ablation and was integrated with three temperature zones. PCR solution was contained in a circular closed microchannel and was driven by magnetic force generated by an external magnet through a small oil-based ferrofluid plug. Successful amplification of genetically modified soya and maize were achieved in less than 13 min. This PCR microchip combines advantages of cycling flexibility and quick temperature transitions associated with two existing microchip PCR techniques, and it provides a cost saving and less time-consuming way to conduct preliminary screening of GMOs.

  11. The Use of Modified Bentonite for Removal of Aromatic Organics from Contaminated Soil.

    PubMed

    Gitipour; Bowers; Bodocsi

    1997-12-15

    This study investigates the clay-aromatic interactions with a view to the use of bentonite clay for binding benzene, toluene, ethylbenzene, and o-xylene (BTEX compounds) in contaminated soils. BTEX compounds are the most toxic aromatic constituents of gasoline present in many underground storage tanks. Modified (organophilic) and ordinary bentonites are used to remove these organics. The organophilic bentonites are prepared by replacing the exchangeable inorganic cations present in bentonite particles with a quaternary ammonium salt. Various clay-to-soil ratios were applied to determine the efficiency of the modified bentonite in enhancing the cement-based solidification/stabilization (S/S) of BTEX contaminated soils. Toxicity characteristics leaching procedure (TCLP) tests were performed on soil samples to evaluate the leaching of the organics. In addition, X-ray diffraction analyses were conducted to assess the changes in the basal spacing of the clays as a result of their interaction with BTEX compounds. The findings of this study reveal that organophilic bentonite can act as a successful adsorbent for removing the aromatic organics from contaminated soil. Thus, this material is viable for enhancing the performance of cement-based S/S processes, as an adsorbent for petroleum spills, and for landfill liners and slurry walls. Copyright 1997 Academic Press.

  12. Development and Evaluation of Event-Specific Quantitative PCR Method for Genetically Modified Soybean MON87701.

    PubMed

    Tsukahara, Keita; Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Nishimaki-Mogami, Tomoko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2016-01-01

    A real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) soybean event, MON87701. First, a standard plasmid for MON87701 quantification was constructed. The conversion factor (Cf) required to calculate the amount of genetically modified organism (GMO) was experimentally determined for a real-time PCR instrument. The determined Cf for the real-time PCR instrument was 1.24. For the evaluation of the developed method, a blind test was carried out in an inter-laboratory trial. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDr), respectively. The determined biases and the RSDr values were less than 30 and 13%, respectively, at all evaluated concentrations. The limit of quantitation of the method was 0.5%, and the developed method would thus be applicable for practical analyses for the detection and quantification of MON87701.

  13. How to deal with the upcoming challenges in GMO detection in food and feed.

    PubMed

    Broeders, Sylvia R M; De Keersmaecker, Sigrid C J; Roosens, Nancy H C

    2012-01-01

    Biotech crops are the fastest adopted crop technology in the history of modern agriculture. The commercialisation of GMO is in many countries strictly regulated laying down the need for traceability and labelling. To comply with these legislations, detection methods are needed. To date, GM events have been developed by the introduction of a transgenic insert (i.e., promoter, coding sequence, terminator) into the plant genome and real-time PCR is the detection method of choice. However, new types of genetic elements will be used to construct new GMO and new crops will be transformed. Additionally, the presence of unauthorised GMO in food and feed samples might increase in the near future. To enable enforcement laboratories to continue detecting all GM events and to obtain an idea of the possible presence of unauthorised GMO in a food and feed sample, an intensive screening will become necessary. A pragmatic, cost-effective, and time-saving approach is presented here together with an overview of the evolution of the GMO and the upcoming needs.

  14. How to Deal with the Upcoming Challenges in GMO Detection in Food and Feed

    PubMed Central

    Broeders, Sylvia R. M.; De Keersmaecker, Sigrid C. J.; Roosens, Nancy H. C.

    2012-01-01

    Biotech crops are the fastest adopted crop technology in the history of modern agriculture. The commercialisation of GMO is in many countries strictly regulated laying down the need for traceability and labelling. To comply with these legislations, detection methods are needed. To date, GM events have been developed by the introduction of a transgenic insert (i.e., promoter, coding sequence, terminator) into the plant genome and real-time PCR is the detection method of choice. However, new types of genetic elements will be used to construct new GMO and new crops will be transformed. Additionally, the presence of unauthorised GMO in food and feed samples might increase in the near future. To enable enforcement laboratories to continue detecting all GM events and to obtain an idea of the possible presence of unauthorised GMO in a food and feed sample, an intensive screening will become necessary. A pragmatic, cost-effective, and time-saving approach is presented here together with an overview of the evolution of the GMO and the upcoming needs. PMID:23193359

  15. Genetically Modified (GM) Foods and Ethical Eating.

    PubMed

    Dizon, Francis; Costa, Sarah; Rock, Cheryl; Harris, Amanda; Husk, Cierra; Mei, Jenny

    2016-02-01

    The ability to manipulate and customize the genetic code of living organisms has brought forth the production of genetically modified organisms (GMOs) and consumption of genetically modified (GM) foods. The potential for GM foods to improve the efficiency of food production, increase customer satisfaction, and provide potential health benefits has contributed to the rapid incorporation of GM foods into the American diet. However, GM foods and GMOs are also a topic of ethical debate. The use of GM foods and GM technology is surrounded by ethical concerns and situational judgment, and should ideally adhere to the ethical standards placed upon food and nutrition professionals, such as: beneficence, nonmaleficence, justice and autonomy. The future of GM foods involves many aspects and trends, including enhanced nutritional value in foods, strict labeling laws, and potential beneficial economic conditions in developing nations. This paper briefly reviews the origin and background of GM foods, while delving thoroughly into 3 areas: (1) GMO labeling, (2) ethical concerns, and (3) health and industry applications. This paper also examines the relationship between the various applications of GM foods and their corresponding ethical issues. Ethical concerns were evaluated in the context of the code of ethics developed by the Academy of Nutrition and Dietetics (AND) that govern the work of food and nutrition professionals. Overall, there is a need to stay vigilant about the many ethical implications of producing and consuming GM foods and GMOs.

  16. Poly(imide)/Organically-Modified Montmorillonite Nanocomposite as a Potential Membrane for Alkaline Fuel Cells

    PubMed Central

    Battirola, Liliane C.; Gasparotto, Luiz H. S.; Rodrigues-Filho, Ubirajara P.; Tremiliosi-Filho, Germano

    2012-01-01

    In this work we evaluated the potentiality of a poly(imide) (PI)/organically-modified montmorillonite (O-MMT) nanocomposite membrane for the use in alkaline fuel cells. Both X-ray diffraction and scanning electron microscopy revealed a good dispersion of O-MMT into the PI matrix and preservation of the O-MMT layered structure. When compared to the pure PI, the addition of O-MMT improved thermal stability and markedly increased the capability of absorbing electrolyte and ionic conductivity of the composite. The results show that the PI/O-MMT nanocomposite is a promising candidate for alkaline fuel cell applications. PMID:24958290

  17. USE OF CATIONIC SURFACTANTS TO MODIFY SOIL SURFACES TO PROMOTE SORPTION AND RETARD MIGRATION OF HYDROPHOBIC ORGANIC COMPOUNDS

    EPA Science Inventory

    Cationic surfactants can be used to modify surfaces of soils and subsurface materials to promote adsorption of hydrophobic organic compounds (HOC). Batch and column experiments were performed to investigate this phenomenon with the cationic surfactant dodecylpyridinium (DP), a se...

  18. Organic thin-film transistors based on solution-processable benzodithiophene dimers modified with hexyl groups

    NASA Astrophysics Data System (ADS)

    Hirota, Takeshi; Toake, Hitoshi; Osuga, Hideji; Uno, Kazuyuki; Tanaka, Ichiro

    2017-04-01

    Benzodithiophene dimers modified with hexyl groups (2C6-BDT-dimer) were investigated as solution-processable organic semiconductors for organic thin-film transistors (OTFTs). Since 2C6-BDT-dimer crystals have an anisotropic shape, flow coating was adopted to grow polycrystalline films. The flow-coated films were inferior to the vacuum-evaporated ones in terms of their crystallinity estimated from X-ray diffraction data. However, the hole mobility of the OTFTs with the flow-coated films, which was 1.7 cm2 V‑1 s‑1 at maximum, was higher than that of the OTFTs with vacuum-evaporated films because the one-dimensional thin crystals of the flow-coated films were aligned in the flow-coating direction.

  19. Thermally stable organically modified layered silicates based on alkyl imidazolium salts.

    PubMed

    Goswami, Shailesh K; Ghosh, Smita; Mathias, Lon J

    2012-02-15

    A series of imidazolium salts having various substituents and functional groups were synthesized and characterized by FTIR and NMR spectroscopy. Organic modification of natural and synthetic layered silicates involving montmorillonite (MMT), laponite (lap), and synthetic mica (mica) was carried out by ion-exchange reaction. The obtained organo-clays were characterized by FTIR and powder X-ray diffraction techniques. Results indicate that these organically modified clays have much higher thermal stabilities compared to their corresponding imidazolium halides. It was also observed from TGA analysis that thermal stability does not depend on the functional group present at the 3-position of the imidazolium salts. These studies strongly supports premise that the removal of halide is necessary to improve the thermal stability of the organo-clay produced.

  20. Selective degradation of organic dyes by a resin modified Fe-based metal-organic framework under visible light irradiation

    NASA Astrophysics Data System (ADS)

    Araya, Tirusew; Chen, Chun-cheng; Jia, Man-ke; Johnson, David; Li, Ruiping; Huang, Ying-ping

    2017-02-01

    Metal organic frameworks (MOFs), a new class of porous crystalline materials have attracted attention because of potential applications in environmental remediation. In this work, an Fe-based MOF, FeBTC (BTC = 1,3,5-tricarboxylic acid), was successfully modified with Amberlite IRA-200 resin to yield a novel heterogeneous photocatalyst, A@FeBTC. The modification resulted in higher photocatalytic activity than FeBTC under the same conditions. After 60 min of visible light illumination (λ ≥ 420 nm) 99% of rhodamine B was degraded. The modification lowers the zeta potential, enhancing charge-based selective adsorption and subsequent photocatalytic degradation of cationic dye pollutants. The composite also improved catalyst stability and recyclability by significantly reducing loss of iron leaching. Photoluminescence studies show that introduction of the resin reduces the recombination rate of photogenerated charge carriers thereby improving the photocatalytic activity of the composite. Finally, a plausible photocatalytic reaction mechanism is proposed.

  1. Organization of mixed dimethyldioctadecylammonium and choline modifiers on the surface of synthetic hectorite.

    PubMed

    Andriani, Yosephine; Jack, Kevin S; Gilbert, Elliot P; Edwards, Grant A; Schiller, Tara L; Strounina, Ekaterina; Osman, Azlin F; Martin, Darren J

    2013-11-01

    Understanding the nature of mixed surfactant self-assembly on the surface of organoclays is an important step toward optimizing their performance in polymer nanocomposites and for other potential applications, where selective surface interactions are crucial. In segmented thermoplastic polyurethane nanocomposite systems, dual-modified organoclays have shown significantly better performance compared to their single-modified counterparts. Until now, we had not fully characterized the physical chemistry of these dual-modified layered silicates, but had hypothesized that the enhanced composite performance arises due to some degree of nanoscale phase separation on the nanofiller surface, which enables enhanced compatibilization and more specific and inclusive interactions with the nanoscale hard and soft domains in these thermoplastic elastomers. This work examines the organization of quaternary alkyl ammonium compounds on the surface of Lucentite SWN using X-ray diffraction (XRD), thermogravimetric analysis (TGA), attenuated total reflectance Fourier-transfer infrared (ATR FT-IR), (13)C cross-polarization (CP)/magic angle spinning (MAS) nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS). When used in combination with choline, dimethyldioctadecylammonium (DMDO) was observed to self-assemble into discontinuous hydrophobic domains. The inner part of these hydrophobic domains was essentially unaffected by the choline (CC); however, surfactant intermixing was observed either at the periphery or throughout the choline-rich phase surrounding those domains.

  2. Simultaneous Detection of Genetically Modified Organisms in a Mixture by Multiplex PCR-Chip Capillary Electrophoresis.

    PubMed

    Patwardhan, Supriya; Dasari, Srikanth; Bhagavatula, Krishna; Mueller, Steffen; Deepak, Saligrama Adavigowda; Ghosh, Sudip; Basak, Sanjay

    2015-01-01

    An efficient PCR-based method to trace genetically modified food and feed products is in demand due to regulatory requirements and contaminant issues in India. However, post-PCR detection with conventional methods has limited sensitivity in amplicon separation that is crucial in multiplexing. The study aimed to develop a sensitive post-PCR detection method by using PCR-chip capillary electrophoresis (PCR-CCE) to detect and identify specific genetically modified organisms in their genomic DNA mixture by targeting event-specific nucleotide sequences. Using the PCR-CCE approach, novel multiplex methods were developed to detect MON531 cotton, EH 92-527-1 potato, Bt176 maize, GT73 canola, or GA21 maize simultaneously when their genomic DNAs in mixtures were amplified using their primer mixture. The repeatability RSD (RSDr) of the peak migration time was 0.06 and 3.88% for the MON531 and Bt176, respectively. The RSD (RSDR) of the Cry1Ac peak ranged from 0.12 to 0.40% in multiplex methods. The method was sensitive in resolving amplicon of size difference up to 4 bp. The PCR-CCE method is suitable to detect multiple genetically modified events in a composite DNA sample by tagging their event specific sequences.

  3. Modified kinetic-hydraulic UASB reactor model for treatment of wastewater containing biodegradable organic substrates.

    PubMed

    El-Seddik, Mostafa M; Galal, Mona M; Radwan, A G; Abdel-Halim, Hisham S

    2016-01-01

    This paper addresses a modified kinetic-hydraulic model for up-flow anaerobic sludge blanket (UASB) reactor aimed to treat wastewater of biodegradable organic substrates as acetic acid based on Van der Meer model incorporated with biological granules inclusion. This dynamic model illustrates the biomass kinetic reaction rate for both direct and indirect growth of microorganisms coupled with the amount of biogas produced by methanogenic bacteria in bed and blanket zones of reactor. Moreover, the pH value required for substrate degradation at the peak specific growth rate of bacteria is discussed for Andrews' kinetics. The sensitivity analyses of biomass concentration with respect to fraction of volume of reactor occupied by granules and up-flow velocity are also demonstrated. Furthermore, the modified mass balance equations of reactor are applied during steady state using Newton Raphson technique to obtain a suitable degree of freedom for the modified model matching with the measured results of UASB Sanhour wastewater treatment plant in Fayoum, Egypt.

  4. Effect of food processing on plant DNA degradation and PCR-based GMO analysis: a review.

    PubMed

    Gryson, Nicolas

    2010-03-01

    The applicability of a DNA-based method for GMO detection and quantification depends on the quality and quantity of the DNA. Important food-processing conditions, for example temperature and pH, may lead to degradation of the DNA, rendering PCR analysis impossible or GMO quantification unreliable. This review discusses the effect of several food processes on DNA degradation and subsequent GMO detection and quantification. The data show that, although many of these processes do indeed lead to the fragmentation of DNA, amplification of the DNA may still be possible. Length and composition of the amplicon may, however, affect the result, as also may the method of extraction used. Also, many techniques are used to describe the behaviour of DNA in food processing, which occasionally makes it difficult to compare research results. Further research should be aimed at defining ingredients in terms of their DNA quality and PCR amplification ability, and elaboration of matrix-specific certified reference materials.

  5. GMO quantification: valuable experience and insights for the future.

    PubMed

    Milavec, Mojca; Dobnik, David; Yang, Litao; Zhang, Dabing; Gruden, Kristina; Zel, Jana

    2014-10-01

    Cultivation and marketing of genetically modified organisms (GMOs) have been unevenly adopted worldwide. To facilitate international trade and to provide information to consumers, labelling requirements have been set up in many countries. Quantitative real-time polymerase chain reaction (qPCR) is currently the method of choice for detection, identification and quantification of GMOs. This has been critically assessed and the requirements for the method performance have been set. Nevertheless, there are challenges that should still be highlighted, such as measuring the quantity and quality of DNA, and determining the qPCR efficiency, possible sequence mismatches, characteristics of taxon-specific genes and appropriate units of measurement, as these remain potential sources of measurement uncertainty. To overcome these problems and to cope with the continuous increase in the number and variety of GMOs, new approaches are needed. Statistical strategies of quantification have already been proposed and expanded with the development of digital PCR. The first attempts have been made to use new generation sequencing also for quantitative purposes, although accurate quantification of the contents of GMOs using this technology is still a challenge for the future, and especially for mixed samples. New approaches are needed also for the quantification of stacks, and for potential quantification of organisms produced by new plant breeding techniques.

  6. Organic and genetically modified soybean diets: consequences in growth and in hematological indicators of aged rats.

    PubMed

    Daleprane, Julio Beltrame; Feijó, Tatiana Silveira; Boaventura, Gilson Teles

    2009-03-01

    The aim of this study was to evaluate the protein quality of organic and genetically modified soy by feeding specific diets to rats. Three groups of Wistar rats (n=10) were used, and each group was named according to the food that they ate. There was an organic soy group (OG), a genetically modified soy group (GG), and a control group (CG). All animals received water and diet ad libitum for 455 days. At the end of this period, the weight of the GG group was the same as that of the OG, and both were higher than CG. Protein intake was similar for the OG and GG, which were significantly lower (p<0.0005) than the CG. The growth rate (GR) of the rats, albumin levels, and total levels of serum protein were comparable for all groups. Hematocrit (p<0.04) and hemoglobin (p<0.03) for the OG and GG were less than the CG. Although the OG and GG demonstrated reduced hematocrit and hemoglobin, both types of soy were utilized in a way similar to casein. This result suggests that the protein quality of soy is parallel to the standard protein casein in terms of growth promotion but not hematological indicators.

  7. Endotoxin and gender modify lung function recovery after occupational organic dust exposure: a 30 year study

    PubMed Central

    Valeri, Linda; Zhang, Feng-ying; Zheng, Bu-Yong; Mehta, Amar J.; Shi, Jing; Su, Li; Brown, Dan; Eisen, Ellen A; Christiani, David C.

    2015-01-01

    OBJECTIVES The purpose of this study is to determine the trajectory of lung function change after exposure cessation to occupational organic dust exposure, and to identify factors that modify improvement. METHODS The Shanghai Textile Worker Study is a longitudinal study of 447 cotton workers exposed to endotoxin-containing dust and 472 silk workers exposed to non-endotoxin-containing dust. Spirometry was performed at 5 year intervals. Air sampling was performed to estimate individual cumulative exposures. The effect of work cessation on FEV1 was modeled using generalized additive mixed effects models to identify the trajectory of FEV1 recovery. Linear mixed effects models incorporating interaction terms were used to identify modifiers of FEV1 recovery. Loss to follow-up was accounted for with inverse probability of censoring weights. RESULTS 74.2% of the original cohort still alive participated in 2011. Generalized additive mixed models identified a non-linear improvement in FEV1 for all workers after exposure cessation, with no plateau noted 25 years after retirement. Linear mixed effects models incorporating interaction terms identified prior endotoxin exposure (p=0.01) and male gender (p=0.002) as risk factors for impaired FEV1 improvement after exposure cessation. After adjusting for gender, smoking delayed the onset of FEV1 gain but did not affect the overall magnitude of change. CONCLUSIONS Lung function improvement after cessation of exposure to organic dust is sustained. Endotoxin exposure and male gender are risk factors for less FEV1 improvement. PMID:25666844

  8. Novel Organically Modified Core-Shell Clay for Epoxy Composites—“SOBM Filler 1”

    PubMed Central

    Iheaturu, Nnamdi Chibuike; Madufor, Innocent Chimezie

    2014-01-01

    Preparation of a novel organically modified clay from spent oil base drilling mud (SOBM) that could serve as core-shell clay filler for polymers is herein reported. Due to the hydrophilic nature of clay, its compatibility with polymer matrix was made possible through modification of the surface of the core clay sample with 3-aminopropyltriethoxysilane (3-APTES) compound prior to its use. Fourier transform infrared (FT-IR) spectroscopy was used to characterize clay surface modification. Electron dispersive X-ray diffraction (EDX) and scanning electron microscopy (SEM) were used to expose filler chemical composition and morphology, while electrophoresis measurement was used to examine level of filler dispersion. Results show an agglomerated core clay powder after high temperature treatment, while EDX analysis shows that the organically modified clay is composed of chemical inhomogeneities, wherein elemental compositions in weight percent vary from one point to the other in a probe of two points. Micrographs of the 3-APTES coupled SOBM core-shell clay filler clearly show cloudy appearance, while FT-IR indicates 25% and 5% increases in fundamental vibrations band at 1014 cm−1 and 1435 cm−1, respectively. Furthermore, 3-APTES coupled core-shell clay was used to prepare epoxy composites and tested for mechanical properties. PMID:27355022

  9. Synergistic effect of silver seeds and organic modifiers on the morphology evolution mechanism of silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Aili; Yin, Hengbo; Ren, Min; Liu, Yuming; Jiang, Tingshun

    2008-08-01

    Triangular, truncated triangular, quadrangular, hexagonal, and net-structured silver nanoplates as well as decahedral silver nanoparticles were manipulatively prepared starting from silver nitrate and silver seeds in the presence of poly(ethylene glycol) (PEG), poly( N-vinyl pyrrolidone) (PVP), and Tween 80 at room temperature, respectively. UV-vis spectroscopy, XRD, HRTEM, SAED, and FTIR were used to illustrate the crystal growth process and to characterize the resultant silver nanoparticles. It was found that the silver seeds and organic modifiers synergistically affected the morphology evolution of the silver nanoparticles. The co-presence of silver seeds and PEG was beneficial to the formation of triangular and truncated triangular silver nanoplates; the silver seeds and PVP favored the formation of polygonal silver nanoplates; the silver seeds and Tween 80 preferred to the formation of net-structured silver plates. The morphology evolution of the resultant silver nanoparticles was correlated with the crystallinity of the silver seeds and the adsorption ability of the organic modifiers on the crystal surfaces.

  10. Not all GMOs are crop plants: non-plant GMO applications in agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the time since the tools of modern biotechnology have become available, the most commonly applied and often discussed genetically modified organisms are genetically modified crop plants, although genetic engineering is also being used successfully in organisms other than plants, including bacteri...

  11. Intercalation behavior of poly(ethylene glycol) in organically modified montmorillonite

    NASA Astrophysics Data System (ADS)

    Zhu, Shipeng; Peng, Hongmei; Chen, Jinyao; Li, Huilin; Cao, Ya; Yang, Yunhua; Feng, Zhihai

    2013-07-01

    In this paper, two kinds of organically modified montmorillonite (OMMT) were prepared using alkylammonium surfactants with different alkyl chain numbers. XRD results showed the interlayer spacing of OMMT increased with low concentration surfactants. With further increasing the surfactants concentration, the interlayer spacing of OMMT was unchanged. Meanwhile, FTIR was used to characterize the local environments of surfactants in the interlayer space of OMMT. The results suggested that the double chain surfactant D-18 preferred to adopt highly ordered conformation compared with single chain surfactant S-18 in interlayer space of OMMT. It indicated that the surface property of the OMMT is affected by the concentration and configuration of the intercalated surfactants. Moreover, the effect of the OMMT type, or more particularly the chemical nature of the organic modifier in the interlayer spacing and the poly(ethylene glycol) (PEG) concentration onintercalation behavior of PEG chains in OMMT were investigated with XRD and DSC.The results indicated that PEG chains could not intercalate into Na-MMT when the surfactants were saturated in interlayer space of Na-MMT. PEG chains could intercalate into the interlayer space of SM when the S-18 concentration was lower than 2.00CEC, implying that the low surfactant concentration modified SM provided a better environment (presumably through the balanced hydrophobic and hydrophilic surfaces) for the PEG intercalation as well. However, PEG did not intercalate into the interlayer space of DM when the D-18 concentration was higher than 1.00CEC. It could be attributed to the hydrophobic double alkyl chains of DM increased with D-18. The increased hydrophobic properties in the interlayer space of 1.50DM hybrids can prevent the intercalation of hydrophilic PEG.

  12. Genetically modified organisms in the United States: implementation, concerns, and public perception.

    PubMed

    Oeschger, Max P; Silva, Catherine E

    2007-01-01

    We examine the state of biotechnology with respect to genetically modified (GM) organisms in agriculture. Our focus is on the USA, where there has been significant progress and implementation but where, to date, the matter has drawn little attention. GM organisms are the result of lateral gene transfers, the transfer of genes from one species to another, or sometimes, from one kingdom to another. The introduction of foreign genes makes some people very uncomfortable, and a small group of activists have grave concerns about the technology. Attempts by activists to build concern in the general public have garnered little attention; however, the producers of GM organisms have responded to their concerns and established extensive testing programs to be applied to each candidate organism that is produced. In the meantime, GM varieties of corn, cotton, soybean and rapeseed have been put into agricultural production and are now extensively planted. These crops, and the other, newer GM crops, have produced no problems and have pioneered a silent agricultural revolution in the USA.

  13. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology.

    PubMed

    Johnston, Robyn; Candela, Héctor; Hake, Sarah; Foster, Toshi

    2010-07-01

    Plant lateral organs, such as leaves, have three primary axes of growth-proximal-distal, medial--lateral and adaxial-abaxial (dorsal-ventral). Although most leaves are planar, modified leaf forms, such as the bikeeled grass prophyll, can be found in nature. A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive mutations in the maize (Zea mays) KANADI (KAN) gene milkweed pod1 (mwp1), which promotes abaxial cell identity, strongly affect development of the prophyll and silks (fused carpels). The prophyll is reduced to two unfused midribs and the silks are narrow and misshapen. Our data indicate that the prophyll and other fused organs are particularly sensitive to disruptions in adaxial-abaxial polarity. In addition, lateral and proximal-distal growth of most lateral organs is reduced in the mwp1-R mutant, supporting a role for the adaxial-abaxial boundary in promoting growth along both axes. We propose that the adaxial-abaxial patterning mechanism has been co-opted during evolution to generate diverse organ morphologies.

  14. Organically Modified Silica Nanoparticles Are Biocompatible and Can Be Targeted to Neurons In Vivo

    PubMed Central

    Kumar, Rajiv; Iacobucci, Gary J.; Kuznicki, Michelle L.; Kosterman, Andrew; Bergey, Earl J.; Prasad, Paras N.; Gunawardena, Shermali

    2012-01-01

    The application of nanotechnology in biological research is beginning to have a major impact leading to the development of new types of tools for human health. One focus of nanobiotechnology is the development of nanoparticle-based formulations for use in drug or gene delivery systems. However most of the nano probes currently in use have varying levels of toxicity in cells or whole organisms and therefore are not suitable for in vivo application or long-term use. Here we test the potential of a novel silica based nanoparticle (organically modified silica, ORMOSIL) in living neurons within a whole organism. We show that feeding ORMOSIL nanoparticles to Drosophila has no effect on viability. ORMOSIL nanoparticles penetrate into living brains, neuronal cell bodies and axonal projections. In the neuronal cell body, nanoparticles are present in the cytoplasm, but not in the nucleus. Strikingly, incorporation of ORMOSIL nanoparticles into the brain did not induce aberrant neuronal death or interfered with normal neuronal processes. Our results in Drosophila indicate that these novel silica based nanoparticles are biocompatible and not toxic to whole organisms, and has potential for the development of long-term applications. PMID:22238611

  15. [Animal models for assessment of GMO allergenicity: advantages and limitations].

    PubMed

    Adel-Patient, K; Wal, J M

    2004-03-01

    Incidence of IgE-mediated allergic reactions to foods is increasing as well as the severity of associated symptoms and numerous foods are now incriminated, probably in relation with modifications of dietary habits and increased exposure to new or modified food ingredients. Therefore, the introduction on the market of food composed of or derived from genetically modified organisms (GMOs) raised the question of their potential allergenicity. Particularly with regards to the allergenicity of a newly expressed protein, it is necessary to obtain, from several steps in the risk assessment process, a cumulative body of evidence which minimises any uncertainty. This may include the use of animal model despite no fully reliable validated model is available yet. Such animal models should allow to address 3 major issues: Is the novel protein a sensitizer, i.e. does it possess intrinsic properties that allow to sensitize a predisposed individual? Is the protein an elicitor i.e. is it able to elicit an allergic reaction in a sensitised individual? And is the protein an adjuvant, i.e. can it facilitate or enhance the sensitisation to an other protein? Animal models under investigation currently include mice, rats and guinea pigs but models such as dogs and swine also appeared a few years ago. The aim is to mimic the mechanism and characteristics of the sensitisation phase and/or the elicitation phase of the allergic reaction as it occurs in atopic humans. They are necessary because sensitisation studies can obviously not be done in human and because in vitro tests cannot reproduce the complexity of the immune system. We propose a mouse model which mimics both phases of the allergic reaction. It has permitted to evidence that biochemical and clinical manifestations occuring during the active phases of the allergic reaction differ according to the structure of the allergen used for the challenge. This may allow to compare the allergenic potential of a genetically modified protein

  16. Titanium (IV) ion-modified covalent organic frameworks for specific enrichment of phosphopeptides.

    PubMed

    Wang, Heping; Jiao, Fenglong; Gao, Fangyuan; Lv, Yayao; Wu, Qiong; Zhao, Yan; Shen, Yehua; Zhang, Yangjun; Qian, Xiaohong

    2017-05-01

    To date, plenty of new alternative materials for phosphopeptides enrichment prior to mass spectrometry (MS) analysis appear, especially immobilized metal ion affinity chromatography (IMAC) materials. The variable combinations with different metal ions, chelating ligands and solid supports offer full of optionality for IMAC. However, further improvement was predicted by the tedious and complex synthetic process. In this work, a novel covalent organic framework (COF)-based IMAC material (denoted TpPa-2-Ti(4+)) was prepared simply by direct immobilizing Ti (IV) into TpPa-2 COFs without any extra chelating ligands. The structure and composition of as-prepared composites were confirmed by PXRD, FT-IR and XPS, and a new flower-shaped Ti(4+)-IMAC with regular micro-nano hierarchical structure was observed in the SEM and TEM images. The obtained titanium (IV) ion-modified covalent organic frameworks demonstrated low limit of detection (4 fmol) and largely-satisfactory selectivity (β-casein: BSA=1:100) for phosphopeptide capturing from β-casein. Similarly, 18 and 17 phosphopeptides could be easily detected in the tryptic digest of α-casein or the digest mixture of α-casein and BSA (1:50). They were also successfully applied for enrichment of phosphopeptides from non-fat milk and HeLa cells with high sensitivity and satisfactory selectivity. All above results showed that the new titanium (IV) ion-modified covalent organic framework is expected to be a potential IMAC for phosphopeptide enrichment in large-scale phosphoproteomics studies.

  17. Detection of genetically modified DNA in fresh and processed foods sold in Kuwait.

    PubMed

    Al-Salameen, Fadila; Kumar, Vinod; Al-Aqeel, Hamed; Al-Hashash, Hanadi; Hejji, Ahmed Bin

    2012-01-01

    Developments in genetic engineering technology have led to an increase in number of food products that contain genetically engineered crops in the global market. However, due to lack of scientific studies, the presence of genetically modified organisms (GMOs) in the Kuwaiti food market is currently ambiguous. Foods both for human and animal consumption are being imported from countries that are known to produce GM food. Therefore, an attempt has been made to screen foods sold in the Kuwaiti market to detect GMOs in the food. For this purpose, samples collected from various markets in Kuwait have been screened by SYBR green-based real time polymerase chain reaction (RT-PCR) method. Further confirmation and GMO quantification was performed by TaqMan-based RT-PCR. Results indicated that a significant number of food commodities sold in Kuwait were tested positive for the presence of GMO. Interestingly, certain processed foods were tested positive for more than one transgenic events showing complex nature of GMOs in food samples. Results of this study clearly indicate the need for well-defined legislations and regulations on the marketing of approved GM food and its labeling to protect consumer's rights.

  18. 9th International Symposium on the Biosafety of Genetically Modified Organisms. Session VII: Risk management and monitoring.

    PubMed

    Schiemann, Joachim

    2006-01-01

    Biosafety regulatory frameworks are intended to serve as mechanisms for ensuring the safe use of biotechnology products without imposing unacceptable risk to human health or the environment, or unintended constraints to technology transfer. In several regulatory systems GMO risk assessment has been separated from GMO risk management. As a consequence, risk assessment can be performed on a purely scientific basis, whereas risk management can take additional aspects (e.g. socio-economic or ethical) into consideration. For instance, the European Food Safety Authority (EFSA), the keystone of European Union risk assessment regarding food and feed safety, provides independent scientific advice and clear communication on existing and emerging risks in close collaboration with national authorities and in open consultation with its stakeholders. Risk management measures are not within the remit of EFSA, and remain the responsibility of the European Commission and Member States.

  19. Tuning the solubility of boron nitride nanosheets in organic solvents by using block copolymer as a "Janus" modifier.

    PubMed

    Liu, Yi-Tao; Xie, Xu-Ming; Ye, Xiong-Ying

    2013-01-14

    The solubility of boron nitride nanosheets (BNNSs) in different organic solvents is smartly tuned by using a "Janus" modifier, P(S-b-MMA), which enriches our choice of organic solvents for BNNSs, including low-boiling-point acetone, alkanes, cycloalkanes and benzene series, that are viewed as nonsolvents of BNNSs.

  20. Enzyme-modified electrolyte-gated organic field-effect transistors

    NASA Astrophysics Data System (ADS)

    Buth, Felix; Donner, Andreas; Stutzmann, Martin; Garrido, Jose A.

    2012-10-01

    Organic solution-gated field-effect transistors (SGFETs) can be operated at low voltages in aqueous environments, paving the way to the use of organic semiconductors in bio-sensing applications. However, it has been shown that these devices exhibit only a rather weak sensitivity to standard electrolyte parameters such as pH and ionic strength. In order to increase the sensitivity and to add specificity towards a given analyte, the covalent attachment of functional groups and enzymes to the device surface would be desirable. In this contribution we demonstrate that enzyme modified organic SGFETs can be used for the in-situ detection of penicillin in the low μM regime. In a first step, silane molecules with amine terminal groups are grafted to α-sexithiophene-based thin film transistors. Surface characterization techniques like X-ray photoemission confirm the modification of the surface with these functional groups, which are stable in standard aqueous electrolytes. We show that the presence of surface-bound amphoteric groups (e.g. amino or carboxylic moieties) increases the pH-sensitivity of the organic SGFETs. In addition, these groups serve as anchoring sites for the attachment of the enzyme penicillinase. The resulting enzyme-FETs are used for the detection of penicillin, enabling the study of the influence of the buffer strength and the pH of the electrolyte on the enzyme kinetics. The functionalization of the organic FETs shown here can be extended to a large variety of enzymes, allowing the specific detection of different chemical and biochemical analytes.

  1. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    NASA Astrophysics Data System (ADS)

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-03-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants.

  2. Edible safety requirements and assessment standards for agricultural genetically modified organisms.

    PubMed

    Deng, Pingjian; Zhou, Xiangyang; Zhou, Peng; Du, Zhong; Hou, Hongli; Yang, Dongyan; Tan, Jianjun; Wu, Xiaojin; Zhang, Jinzhou; Yang, Yongcun; Liu, Jin; Liu, Guihua; Li, Yonghong; Liu, Jianjun; Yu, Lei; Fang, Shisong; Yang, Xiaoke

    2008-05-01

    This paper describes the background, principles, concepts and methods of framing the technical regulation for edible safety requirement and assessment of agricultural genetically modified organisms (agri-GMOs) for Shenzhen Special Economic Zone in the People's Republic of China. It provides a set of systematic criteria for edible safety requirements and the assessment process for agri-GMOs. First, focusing on the degree of risk and impact of different agri-GMOs, we developed hazard grades for toxicity, allergenicity, anti-nutrition effects, and unintended effects and standards for the impact type of genetic manipulation. Second, for assessing edible safety, we developed indexes and standards for different hazard grades of recipient organisms, for the influence of types of genetic manipulation and hazard grades of agri-GMOs. To evaluate the applicability of these criteria and their congruency with other safety assessment systems for GMOs applied by related organizations all over the world, we selected some agri-GMOs (soybean, maize, potato, capsicum and yeast) as cases to put through our new assessment system, and compared our results with the previous assessments. It turned out that the result of each of the cases was congruent with the original assessment.

  3. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    PubMed Central

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-01-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants. PMID:27009902

  4. Characterization of the Morphology and Rapid Expansion of Swellable Organically Modified Silica

    NASA Astrophysics Data System (ADS)

    Christman, Lilianna E.; Logue, Amanda; Edmiston, Paul L.; Lehman, Susan Y.

    2011-03-01

    Swellable organically modified silica (SOMS) is a novel sol-gel derived material.~ SOMS is hydrophobic and selectively absorbs non-polar liquids and immediately swells 5 to 6 times upon absorption.~ SOMS can be used to remove organic contaminants from water; the contaminant can then be recovered and the SOMS reused.~ We have investigated the SOMS swelling behavior of neat organic liquids usng macroscopic measurements of the force exerted during expansion and through atomic force microscopy (AFM) of the surface. ~A powdered SOMS sample was placed in a cylinder with an adjustable piston.~ Solvent percolated into the cylinder and the piston gradually moved to allow expansion while measuring the force using a load cell.~ During expansion the SOMS exerted forces up to 150 N per gram of material.~ AFM shows the surface of the SOMS is textured with cauliflower-like features.~ In unswollen SOMS, these globules have length scales of a few hundred nanometers, while for SOMS swollen in a solvent the features expand to several micrometers.

  5. Using surfactant-modified clays to determine sorption mechanisms for a representative organic base, quinoline.

    PubMed

    Bonczek, J L; Nkedi-Kizza, P

    2007-01-01

    Sorption of a representative ionizable nitrogen heterocycle, quinoline (pKa = 4.92), was investigated to determine the relative contributions of the neutral and protonated species to the overall process. Batch sorption experiments were conducted on surfactant-modified clays that were synthesized from the exchange of hexadecyltrimethylammonium cations for resident sodium cations on a specimen smectite (Swy-2) at 0, 60, 80, and 100% of the clay's cation exchange capacity (CEC). Hexadecyltrimethylammonium exchange creates highly effective organic partitioning domains within the clay interlayers in proportion to their coverage on the exchange complex. The fractionally exchanged clays, therefore, provided discrete exchange and organic partitioning domains for the protonated and neutral species of quinoline. Data were described by a combined Langmuir-linear isotherm that permitted independent characterization of both sorption components. Results indicated that cationic sorption dominated but that the neutral species can contribute substantially given sufficient organic carbon content relative to the CEC and at pH above the pKa of quinoline. The data obtained in this study for quinoline demonstrated that the combined isotherm (including cation exchange and hydrophobic partitioning terms) describes sorption data and compares favorably with the purely empirical Freundlish isotherm.

  6. Modifying the thermal conductivity of small molecule organic semiconductor thin films with metal nanoparticles

    PubMed Central

    Wang, Xinyu; Parrish, Kevin D.; Malen, Jonathan A.; Chan, Paddy K. L.

    2015-01-01

    Thermal properties of organic semiconductors play a significant role in the performance and lifetime of organic electronic devices, especially for scaled-up large area applications. Here we employ silver nanoparticles (Ag NPs) to modify the thermal conductivity of the small molecule organic semiconductor, dinaphtho[2,3-b:2’,3’-f]thieno[3,2-b]thiophene (DNTT). The differential 3-ω method was used to measure the thermal conductivity of Ag-DNTT hybrid thin films. We find that the thermal conductivity of pure DNTT thin films do not vary with the deposition temperature over a range spanning 24 °C to 80 °C. The thermal conductivity of the Ag-DNTT hybrid thin film initially decreases and then increases when the Ag volume fraction increases from 0% to 32%. By applying the effective medium approximation to fit the experimental results of thermal conductivity, the extracted thermal boundary resistance of the Ag-DNTT interface is 1.14 ± 0.98 × 10−7 m2-K/W. Finite element simulations of thermal conductivity for realistic film morphologies show good agreement with experimental results and effective medium approximations. PMID:26531766

  7. Modifying the thermal conductivity of small molecule organic semiconductor thin films with metal nanoparticles.

    PubMed

    Wang, Xinyu; Parrish, Kevin D; Malen, Jonathan A; Chan, Paddy K L

    2015-11-04

    Thermal properties of organic semiconductors play a significant role in the performance and lifetime of organic electronic devices, especially for scaled-up large area applications. Here we employ silver nanoparticles (Ag NPs) to modify the thermal conductivity of the small molecule organic semiconductor, dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT). The differential 3-ω method was used to measure the thermal conductivity of Ag-DNTT hybrid thin films. We find that the thermal conductivity of pure DNTT thin films do not vary with the deposition temperature over a range spanning 24 °C to 80 °C. The thermal conductivity of the Ag-DNTT hybrid thin film initially decreases and then increases when the Ag volume fraction increases from 0% to 32%. By applying the effective medium approximation to fit the experimental results of thermal conductivity, the extracted thermal boundary resistance of the Ag-DNTT interface is 1.14 ± 0.98 × 10(-7) m(2)-K/W. Finite element simulations of thermal conductivity for realistic film morphologies show good agreement with experimental results and effective medium approximations.

  8. Polyethylene/organically-modified layered-silicate nanocomposites with antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Songtipya, P.; Jimenez-Gasco, M. M.; Manias, E.

    2009-03-01

    Despite the very intensive research on polymer nanocomposites, the opportunities for new functionalities possible by nanofillers still remain largely untapped. Here, we present polyethylene/inorganic nanocomposites that exhibit strongly enhanced mechanical performance and, at the same time, also an antimicrobial activity originating from the organo-filler nature. Specifically, PE/organically-modified layered-silicate nanocomposites were prepared via melt-processing, and antimicrobial activity was designed by proper choice of their organic modification. Their antimicrobial activity was measured against three micotoxinogen fungal strains (Penicillium roqueforti and claviforme, and Fusarium graminearum) as model soil-borne plant and food contaminants. Montmorillonite-based organofillers, which only differ in their organic modification, were used to exemplify how these surfactants can be designed to render antifungal activity to the nanocomposites. The comparative discussion of the growth of fungi on unfilled PE and nanocomposite PE films is used to demonstrate how the antimicrobial efficacy is dictated by the surfactant chemistry and, further, how the nanocomposites' inhibitory activity compares to that of the organo-fillers and the surfactants.

  9. Interactions between above- and belowground organisms modified in climate change experiments

    NASA Astrophysics Data System (ADS)

    Stevnbak, Karen; Scherber, Christoph; Gladbach, David J.; Beier, Claus; Mikkelsen, Teis N.; Christensen, Søren

    2012-11-01

    Climate change has been shown to affect ecosystem process rates and community composition, with direct and indirect effects on belowground food webs. In particular, altered rates of herbivory under future climate can be expected to influence above-belowground interactions. Here, we use a multifactor, field-scale climate change experiment and independently manipulate atmospheric CO2 concentration, air and soil temperature and drought in all combinations since 2005. We show that changes in these factors modify the interaction between above- and belowground organisms. We use an insect herbivore to experimentally increase aboveground herbivory in grass phytometers exposed to all eight combinations of climate change factors for three years. Aboveground herbivory increased the abundance of belowground protozoans, microbial growth and microbial nitrogen availability. Increased CO2 modified these links through a reduction in herbivory and cascading effects through the soil food web. Interactions between CO2, drought and warming can affect belowground protozoan abundance. Our findings imply that climate change affects aboveground-belowground interactions through changes in nutrient availability.

  10. How habitat-modifying organisms structure the food web of two coastal ecosystems

    PubMed Central

    van der Zee, Els M.; Angelini, Christine; Govers, Laura L.; Christianen, Marjolijn J. A.; Altieri, Andrew H.; van der Reijden, Karin J.; Silliman, Brian R.; van de Koppel, Johan; van der Geest, Matthijs; van Gils, Jan A.; van der Veer, Henk W.; Piersma, Theunis; de Ruiter, Peter C.; Olff, Han; van der Heide, Tjisse

    2016-01-01

    The diversity and structure of ecosystems has been found to depend both on trophic interactions in food webs and on other species interactions such as habitat modification and mutualism that form non-trophic interaction networks. However, quantification of the dependencies between these two main interaction networks has remained elusive. In this study, we assessed how habitat-modifying organisms affect basic food web properties by conducting in-depth empirical investigations of two ecosystems: North American temperate fringing marshes and West African tropical seagrass meadows. Results reveal that habitat-modifying species, through non-trophic facilitation rather than their trophic role, enhance species richness across multiple trophic levels, increase the number of interactions per species (link density), but decrease the realized fraction of all possible links within the food web (connectance). Compared to the trophic role of the most highly connected species, we found this non-trophic effects to be more important for species richness and of more or similar importance for link density and connectance. Our findings demonstrate that food webs can be fundamentally shaped by interactions outside the trophic network, yet intrinsic to the species participating in it. Better integration of non-trophic interactions in food web analyses may therefore strongly contribute to their explanatory and predictive capacity. PMID:26962135

  11. Semiconducting ferroelectric SbSI quantum dots in organically modified TiO2 matrix

    NASA Astrophysics Data System (ADS)

    Ye, Hui; Xu, Yuhuan; Mackenzie, John D.

    2000-05-01

    Semiconducting ferro electric antimony sulphoiodide (SbSI) microcrystallite doped organically modified TiO2 thin film and bulk solids are successfully fabricated by the sol- gel process. Ferro electric SbSI crystallites have some attractive properties, including high dielectric permittivity, high electro-optical coefficient and high photoconductivity. SbSI is also an intrinsic semiconductor with a relatively narrow energy gap. If the crystal size is near its Bohr radius and the microcrystallites are dispersed in a suitable matrix, a dramatic improvement of the third order non linearity will be achieved due to the quantum confinement effect. It is clear that the SbSI quantum dot composites are good candidates for electro-optical devices. Glycidoxypropyltrimetroxysilane modified TiO2 is used as the matrix and SbSI is synthesized in situ by using SbI3 SC9NH2)2 and H2S gas. The size is controlled by the heat-treatment conditions and is characterized by the XRD and HRTEM measurements. The optical absorption spectrum gives evidence of the quantum confinement effect. The third order susceptibility of the SbSI quantum dot is measured by the degenerate four wave mixing method.

  12. Rapid detection of genetically modified organisms on a continuous-flow polymerase chain reaction microfluidics.

    PubMed

    Li, Yuyuan; Xing, Da; Zhang, Chunsun

    2009-02-01

    The ability to perform DNA amplification on a microfluidic device is very appealing. In this study, a compact continuous-flow polymerase chain reaction (PCR) microfluidics was developed for rapid analysis of genetically modified organisms (GMOs) in genetically modified soybeans. The device consists of three pieces of copper and a transparent polytetrafluoroethylene capillary tube embedded in the spiral channel fabricated on the copper. On this device, the P35S and Tnos sequences were successfully amplified within 9min, and the limit of detection of the DNA sample was estimated to be 0.005 ng microl(-1). Furthermore, a duplex continuous-flow PCR was also reported for the detection of the P35S and Tnos sequences in GMOs simultaneously. This method was coupled with the intercalating dye SYBR Green I and the melting curve analysis of the amplified products. Using this method, temperature differences were identified by the specific melting temperature values of two sequences, and the limit of detection of the DNA sample was assessed to be 0.01 ng microl(-1). Therefore, our results demonstrated that the continuous-flow PCR assay could discriminate the GMOs in a cost-saving and less time-consuming way.

  13. How habitat-modifying organisms structure the food web of two coastal ecosystems.

    PubMed

    van der Zee, Els M; Angelini, Christine; Govers, Laura L; Christianen, Marjolijn J A; Altieri, Andrew H; van der Reijden, Karin J; Silliman, Brian R; van de Koppel, Johan; van der Geest, Matthijs; van Gils, Jan A; van der Veer, Henk W; Piersma, Theunis; de Ruiter, Peter C; Olff, Han; van der Heide, Tjisse

    2016-03-16

    The diversity and structure of ecosystems has been found to depend both on trophic interactions in food webs and on other species interactions such as habitat modification and mutualism that form non-trophic interaction networks. However, quantification of the dependencies between these two main interaction networks has remained elusive. In this study, we assessed how habitat-modifying organisms affect basic food web properties by conducting in-depth empirical investigations of two ecosystems: North American temperate fringing marshes and West African tropical seagrass meadows. Results reveal that habitat-modifying species, through non-trophic facilitation rather than their trophic role, enhance species richness across multiple trophic levels, increase the number of interactions per species (link density), but decrease the realized fraction of all possible links within the food web (connectance). Compared to the trophic role of the most highly connected species, we found this non-trophic effects to be more important for species richness and of more or similar importance for link density and connectance. Our findings demonstrate that food webs can be fundamentally shaped by interactions outside the trophic network, yet intrinsic to the species participating in it. Better integration of non-trophic interactions in food web analyses may therefore strongly contribute to their explanatory and predictive capacity.

  14. Favorable Influence of Hydrophobic Surfaces on Protein Structure in Porous Organically-modified Silica Glasses

    PubMed Central

    Menaa, Bouzid; Herrero, Mar; Rives, Vicente; Lavrenko, Mayya; Eggers, Daryl K.

    2008-01-01

    Organically-modified siloxanes were used as host materials to examine the influence of surface chemistry on protein conformation in a crowded environment. The sol-gel materials were prepared from tetramethoxysilane and a series of monosubstituted alkoxysilanes, RSi(OR′)3, featuring alkyl groups of increasing chain length in the R-position. Using circular dichroism spectroscopy in the far-UV region, apomyoglobin was found to transit from an unfolded state to a native-like helical state as the content of the hydrophobic precursor increased from 0–15%. At a fixed molar content of 5% RSi(OR’)3, the helical structure of apomyoglobin increased with the chain length of the R-group, i.e. methyl < ethyl < n-propyl < n-butyl < n-hexyl. This trend also was observed for the tertiary structure of ribonuclease A, suggesting that protein folding and biological activity are sensitive to the hydrophilic/hydrophobic balance of neighboring surfaces. The observed changes in protein structure did not correlate with total surface area or the average pore size of the modified glasses, but scanning electron microscopy images revealed an interesting relationship between surface morphology and alkyl chain length. The unexpected benefit of incorporating a low content of hydrophobic groups into a hydrophilic surface may lead to materials with improved biocompatibility for use in biosensors and implanted devices. PMID:18359512

  15. Study of malachite green adsorption by organically modified clay using a batch method

    NASA Astrophysics Data System (ADS)

    Arellano-Cárdenas, Sofía; López-Cortez, Socorro; Cornejo-Mazón, Maribel; Mares-Gutiérrez, Juan Carlos

    2013-09-01

    The adsorption of toxic dye malachite green from aqueous effluents by organically modified clay was studied in a batch system. The organoclay (OC) used was prepared by the intercalation of cationic surfactant hexadecyltrimethylammonium bromide in a Mexican montmorillonite. The effects of initial dye concentration, temperature, pH, and contact time were investigated. The OC showed a high dye removal (99.6%) from an initial dye concentration of 60 mg L-1 at pH 6 and 25 °C. The adsorption capacity was independent of pH and increased with the temperature. Equilibrium data were well fitted by Langmuir adsorption model. The rate of sorption was adjusted to a pseudo second-order kinetic model.

  16. An electrochemiluminescence non-PCR method for the detection of genetically modified organisms

    NASA Astrophysics Data System (ADS)

    Liu, Jinfeng; Xing, Da; Zhu, Debin

    2006-09-01

    An electrochemiluminescence non-PCR method has been developed for the detection of genetically modified organisms (GMOs) in crops. Genomic DNA of GMOs was digested with two restriction endonucleases (FOK I and BsrD I), and hybridized with three Ru(bpy) 3 2+ (TBR)-labeled and one biotinylated probes. The hybridization products were captured onto streptavidin-coated paramagnetic beads, and detected by measuring the electrochemiluminescence (ECL) signal of the TBR label. Whether the tobaccos contain GM components was discriminated by detecting the ECL signal of CaMV35S promoter. The experiment results show that the detection limit for CaMV35S promoter is 100 fmol, and the GM components can be clearly identified in GM tobaccos. The ECL non-PCR method will provide a new means in GMOs detection due to its safety, simplicity and high efficiency.

  17. Modified Fenton oxidation of diesel fuel in arctic soils rich in organic matter and iron.

    PubMed

    Sherwood, Mary K; Cassidy, Daniel P

    2014-10-01

    Modified Fenton (MF) chemistry was tested in the laboratory to treat three diesel fuel-contaminated soils from the Canadian arctic rich in soil organic matter (SOM) and Fe oxides. Reactors were dosed with hydrogen peroxide (HP), and treatment was compared in reactors with SOM as the only chelate vs. reactors to which ethylenediaminetetraacetate (EDTA) was added. Concentrations of diesel fuel and HP were measured over time, and the oxidation of both diesel fuel and SOM were quantified in each soil. A distinct selectivity for oxidation of diesel fuel over SOM was observed. Reactors with EDTA showed significantly less diesel fuel oxidation and lower oxidant efficiency (diesel fuel oxidized/HP consumed) than reactors with SOM as the only chelate. The results from these studies demonstrate that MF chemistry can be an effective remedial tool for contaminated arctic soils, and challenge the traditional conceptual model that SOM reduces the efficiency of MF treatment through excessive scavenging of oxidant.

  18. Energy transfer studies in binary laser dye mixtures in organically modified silicates

    NASA Astrophysics Data System (ADS)

    Al-Maliki, Firas J.

    2014-08-01

    Energy transfer of binary dye mixture (Rhodamine110, as donor, and Oxizine1and/or Nile blue as acceptors) doped in organically modified silicates (ORMOSILs) matrix has been studied. The energy transfer process from donor molecules to acceptor molecules in the final bulk samples has been observed spectrally. Some of energy transfer parameters have been determined as a function of acceptor concentration. Stern-Volmer relation of energy transfer has been proved and the dominant mechanism of the energy transfer of dye mixture doped in such matrices has been determined. The results show that the emission properties of acceptor molecules (Ox1 and Nb) can be enhanced using the dye mixing recipe in sol-gel matrices.

  19. Development of real-time PCR method for the detection and the quantification of a new endogenous reference gene in sugar beet "Beta vulgaris L.": GMO application.

    PubMed

    Chaouachi, Maher; Alaya, Akram; Ali, Imen Ben Haj; Hafsa, Ahmed Ben; Nabi, Nesrine; Bérard, Aurélie; Romaniuk, Marcel; Skhiri, Fethia; Saïd, Khaled

    2013-01-01

    KEY MESSAGE : Here, we describe a new developed quantitative real-time PCR method for the detection and quantification of a new specific endogenous reference gene used in GMO analysis. The key requirement of this study was the identification of a new reference gene used for the differentiation of the four genomic sections of the sugar beet (Beta vulgaris L.) (Beta, Corrollinae, Nanae and Procumbentes) suitable for quantification of genetically modified sugar beet. A specific qualitative polymerase chain reaction (PCR) assay was designed to detect the sugar beet amplifying a region of the adenylate transporter (ant) gene only from the species of the genomic section I of the genus Beta (cultivated and wild relatives) and showing negative PCR results for 7 species of the 3 other sections, 8 related species and 20 non-sugar beet plants. The sensitivity of the assay was 15 haploid genome copies (HGC). A quantitative real-time polymerase chain reaction (QRT-PCR) assay was also performed, having high linearity (R (2) > 0.994) over sugar beet standard concentrations ranging from 20,000 to 10 HGC of the sugar beet DNA per PCR. The QRT-PCR assay described in this study was specific and more sensitive for sugar beet quantification compared to the validated test previously reported in the European Reference Laboratory. This assay is suitable for GMO quantification in routine analysis from a wide variety of matrices.

  20. Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

    PubMed

    Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

    2002-01-01

    Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system.

  1. Modeling sorption and diffusion of organic sorbate in hexadecyltrimethylammonium-modified clay nanopores - a molecular dynamics simulation study.

    PubMed

    Zhao, Qian; Burns, Susan E

    2013-03-19

    Organoclays are highly sorptive engineered materials that can be used as amendments in barrier systems or geosynthetic liners. The performance of confining and isolating the nonpolar organic contaminants by those barrier/lining systems is essentially controlled by the process of organic contaminant mass transport in nanopores of organoclays. In this article, we use molecular dynamics (MD) simulations to study the sorption and diffusion of organic sorbates in interlayers of sodium montmorillonite and hexadecyltrimethylammonium (HDTMA(+))-modified montmorillonite clays. Simulated system consisted of the clay framework, interlayer organic cation, water, and organic sorbate. Their interactions were addressed by the combined force field of ClayFF, constant-valence force field, and SPC water model. Simulation results indicated that in HDTMA coated clay nanopores, diffusion of nonpolar species benzene was slowed because they were subjected to influence of both the pore wall and the HDTMA surfactant. This suggested the nonpolar organic compound diffusion in organophilic clays can be affected by molecular size of diffusive species, clay pore size, and organic surfactant loading. Additionally, a model that connected the diffusion rate of organic compounds in the bulk organoclay matrix with macropores and nanopores was established. The impact of intercalated organic cations on the diffusion dominated mass transport of organic compounds yielded insight into the prediction of the apparent diffusion behavior of organic compounds in organic-modified clays.

  2. Cell-surface modification of non-GMO without chemical treatment by novel GMO-coupled and -separated cocultivation method.

    PubMed

    Miura, Natsuko; Aoki, Wataru; Tokumoto, Naoki; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2009-02-01

    We developed a novel method to coat living non-genetically modified (GM) cells with functional recombinant proteins. First, we prepared GM yeast to secrete constructed proteins that have two domains: a functional domain and a binding domain that recognizes other cells. Second, we cocultivated GM and non-GM yeasts that share and coutilize the medium containing recombinant proteins produced by GM yeasts using a filter-membrane-separated cultivation reactor. We confirmed that GM yeast secreted enhanced green fluorescent protein (EGFP) fusion proteins to culture medium. After cocultivation, EGFP fusion proteins produced by GM yeast were targeted to non-GM yeast (Saccharomyces cerevisiae BY4741DeltaCYC8 strain) cell surface. Yeast cell-surface engineering is a useful method that enables the coating of GM yeast cell surface with recombinant proteins to produce highly stable and accumulated protein particles. The results of this study suggest that development of cell-surface engineering from GM organisms (GMOs) to living non-GMOs by our novel cocultivation method is possible.

  3. Interface modified thermally stable hole transporting layer for efficient organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Grover, Rakhi; Srivastava, Ritu; Dagar, Janardan; Kamalasanan, M. N.; Mehta, D. S.

    2014-08-01

    Electrical transport in thermally stable 2, 7-bis [N, N-bis (4-methoxy-phenyl) amino]-9, 9-spirobifluorene (MeO-Spiro-TPD) thin films has been investigated as a function of temperature and organic layer thickness. ITO/MeO-Spiro-TPD interface was found to be injection limited and has been studied in detail to find barrier height for hole injection. The thickness of tetra-fluoro-tetracyano-quinodimethane thin films were optimized to be used as hole injection buffer layer which resulted in switching of charge transport mechanism from injection limited to space charge limited conduction above a critical thickness of 3 nm. Hole mobility has been measured using transient space charge limited conduction (SCLC), field dependent SCLC, and top contact transistor characteristics. The charge carrier transport in interface modified hole only devices was analysed using Gaussian disorder model. The thermal stability of MeO-Spiro-TPD has been investigated by atomic force microscopy and X-ray diffraction studies. The study indicates a thermally stable and highly efficient hole transport material for application in organic semiconductor based devices.

  4. Colloidal crystallization of colloidal silica modified with ferrocenyl group-contained polymers in organic solvents.

    PubMed

    Yoshinaga, Kohji; Shigeta, Maki; Komune, Seishu; Mouri, Emiko; Nakai, Akemi

    2007-01-15

    Surface modification of colloidal silica with ferrocenyl-grafted polymer and colloidal crystallization of the particles in organic solvent were studied. Poly(methyl methacrylate-co-vinylferrocene)-grafted silica never formed colloidal crystals in polar solvent, such as acetone, acetonitrile, ethanol and N,N-dimethylformamide (DMF), while poly(methyl methacrylate-co-ferrocenyl acrylate)-grafted silica gave colloidal crystallization in DMF. The particles prepared by grafting of poly(N,N-dimethylacrylamide-co-vinylferrocene), with vinylferrocene (Vfc) mole fraction of 1/13 and 1/23, were observed to give the crystallization in ethanol and DMF over particle volume fraction of 0.058. Further, silica modified with copolymer of Vfc and N-vinyl-2-pyrrolidone, N-vinylcarbazole or N-isopropylacrylamide formed colloidal crystals in ethanol and DMF. Especially, poly(N-isopropylacrylamide-co-Vfc)-grafted silica, which was composed of the highest mole fraction of vinylferrocene, 1/3, afforded colloidal crystallization in ethanol over particle volume fraction of 0.053. Relatively high polar vinylferrocene copolymer grafting of silica resulted in colloidal polymerization in organic solvents.

  5. Interactions between organic amendments and phosphate fertilizers modify phosphate sorption processes in an acid soil

    SciTech Connect

    Sckefe, C.R.; Patti, A.F.; Clune, T.S.; Jackson, W.R.

    2008-07-15

    To determine how organic amendments and phosphate fertilizers interact to modify P sorption processes, three phosphate fertilizers were applied to lignite- and compost-amended acid soil and incubated for either 3 or 26 days. The fertilizers applied were potassium dihydrogen phosphate, triple superphosphate, and diammonium phosphate (DAP). After 3 days of incubation, sorption of all three P sources was decreased in the lignite-amended treatments, whereas P sorption was increased in the compost-amended treatments. Increased incubation time (26 days) resulted in significantly decreased P sorption when DAP was added to lignite-amended treatments. Addition of triple superphosphate increased P sorption in lignite- and compost-amended treatments and decreased solution pH compared with DAP application. In addition to the effect of P source, differences in P sorption between the lignite- and compost-amended treatments were driven by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment and fertilizer addition also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. It is proposed that the combination of lignite and DAP may contribute to decreased P sorption in acid soils, with the positive effects likely caused by both chemical and biological processes, including the formation of soluble organic-metal complexes.

  6. Increased efficacy for in-house validation of real-time PCR GMO detection methods.

    PubMed

    Scholtens, I M J; Kok, E J; Hougs, L; Molenaar, B; Thissen, J T N M; van der Voet, H

    2010-03-01

    To improve the efficacy of the in-house validation of GMO detection methods (DNA isolation and real-time PCR, polymerase chain reaction), a study was performed to gain insight in the contribution of the different steps of the GMO detection method to the repeatability and in-house reproducibility. In the present study, 19 methods for (GM) soy, maize canola and potato were validated in-house of which 14 on the basis of an 8-day validation scheme using eight different samples and five on the basis of a more concise validation protocol. In this way, data was obtained with respect to the detection limit, accuracy and precision. Also, decision limits were calculated for declaring non-conformance (>0.9%) with 95% reliability. In order to estimate the contribution of the different steps in the GMO analysis to the total variation variance components were estimated using REML (residual maximum likelihood method). From these components, relative standard deviations for repeatability and reproducibility (RSD(r) and RSD(R)) were calculated. The results showed that not only the PCR reaction but also the factors 'DNA isolation' and 'PCR day' are important factors for the total variance and should therefore be included in the in-house validation. It is proposed to use a statistical model to estimate these factors from a large dataset of initial validations so that for similar GMO methods in the future, only the PCR step needs to be validated. The resulting data are discussed in the light of agreed European criteria for qualified GMO detection methods.

  7. Not all GMOs are crop plants: non-plant GMO applications in agriculture.

    PubMed

    Hokanson, K E; Dawson, W O; Handler, A M; Schetelig, M F; St Leger, R J

    2014-12-01

    Since tools of modern biotechnology have become available, the most commonly applied and often discussed genetically modified organisms are genetically modified crop plants, although genetic engineering is also being used successfully in organisms other than plants, including bacteria, fungi, insects, and viruses. Many of these organisms, as with crop plants, are being engineered for applications in agriculture, to control plant insect pests or diseases. This paper reviews the genetically modified non-plant organisms that have been the subject of permit approvals for environmental release by the United States Department of Agriculture/Animal and Plant Health Inspection Service since the US began regulating genetically modified organisms. This is an indication of the breadth and progress of research in the area of non-plant genetically modified organisms. This review includes three examples of promising research on non-plant genetically modified organisms for application in agriculture: (1) insects for insect pest control using improved vector systems; (2) fungal pathogens of insects to control insect pests; and (3) virus for use as transient-expression vectors for disease control in plants.

  8. A specific endogenous reference for genetically modified common bean (Phaseolus vulgaris L.) DNA quantification by real-time PCR targeting lectin gene.

    PubMed

    Venturelli, Gustavo L; Brod, Fábio C A; Rossi, Gabriela B; Zimmermann, Naíra F; Oliveira, Jaison P; Faria, Josias C; Arisi, Ana C M

    2014-11-01

    The Embrapa 5.1 genetically modified (GM) common bean was approved for commercialization in Brazil. Methods for the quantification of this new genetically modified organism (GMO) are necessary. The development of a suitable endogenous reference is essential for GMO quantification by real-time PCR. Based on this, a new taxon-specific endogenous reference quantification assay was developed for Phaseolus vulgaris L. Three genes encoding common bean proteins (phaseolin, arcelin, and lectin) were selected as candidates for endogenous reference. Primers targeting these candidate genes were designed and the detection was evaluated using the SYBR Green chemistry. The assay targeting lectin gene showed higher specificity than the remaining assays, and a hydrolysis probe was then designed. This assay showed high specificity for 50 common bean samples from two gene pools, Andean and Mesoamerican. For GM common bean varieties, the results were similar to those obtained for non-GM isogenic varieties with PCR efficiency values ranging from 92 to 101 %. Moreover, this assay presented a limit of detection of ten haploid genome copies. The primers and probe developed in this work are suitable to detect and quantify either GM or non-GM common bean.

  9. Quantification of genetically modified soybeans using a combination of a capillary-type real-time PCR system and a plasmid reference standard.

    PubMed

    Toyota, Akie; Akiyama, Hiroshi; Sugimura, Mitsunori; Watanabe, Takahiro; Kikuchi, Hiroyuki; Kanamori, Hisayuki; Hino, Akihiro; Esaka, Muneharu; Maitani, Tamio

    2006-04-01

    Because the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved genetically modified varieties in many countries, there is a need for a rapid and useful method of GMO quantification in food samples. In this study, a rapid detection system was developed for Roundup Ready Soybean (RRS) quantification using a combination of a capillary-type real-time PCR system, a LightCycler real-time PCR system, and plasmid DNA as the reference standard. In addition, we showed for the first time that the plasmid and genomic DNA should be similar in the established detection system because the PCR efficiencies of using plasmid DNA and using genomic DNA were not significantly different. The conversion factor (Cf) to calculate RRS content (%) was further determined from the average value analyzed in three laboratories. The accuracy and reproducibility of this system for RRS quantification at a level of 5.0% were within a range from 4.46 to 5.07% for RRS content and within a range from 2.0% to 7.0% for the relative standard deviation (RSD) value, respectively. This system rapidly monitored the labeling system and had allowable levels of accuracy and precision.

  10. On-site detection of stacked genetically modified soybean based on event-specific TM-LAMP and a DNAzyme-lateral flow biosensor.

    PubMed

    Cheng, Nan; Shang, Ying; Xu, Yuancong; Zhang, Li; Luo, Yunbo; Huang, Kunlun; Xu, Wentao

    2017-05-15

    Stacked genetically modified organisms (GMO) are becoming popular for their enhanced production efficiency and improved functional properties, and on-site detection of stacked GMO is an urgent challenge to be solved. In this study, we developed a cascade system combining event-specific tag-labeled multiplex LAMP with a DNAzyme-lateral flow biosensor for reliable detection of stacked events (DP305423× GTS 40-3-2). Three primer sets, both event-specific and soybean species-specific, were newly designed for the tag-labeled multiplex LAMP system. A trident-like lateral flow biosensor displayed amplified products simultaneously without cross contamination, and DNAzyme enhancement improved the sensitivity effectively. After optimization, the limit of detection was approximately 0.1% (w/w) for stacked GM soybean, which is sensitive enough to detect genetically modified content up to a threshold value established by several countries for regulatory compliance. The entire detection process could be shortened to 120min without any large-scale instrumentation. This method may be useful for the in-field detection of DP305423× GTS 40-3-2 soybean on a single kernel basis and on-site screening tests of stacked GM soybean lines and individual parent GM soybean lines in highly processed foods.

  11. Detection and identification of multiple genetically modified events using DNA insert fingerprinting.

    PubMed

    Raymond, Philippe; Gendron, Louis; Khalf, Moustafa; Paul, Sylvianne; Dibley, Kim L; Bhat, Somanath; Xie, Vicki R D; Partis, Lina; Moreau, Marie-Eve; Dollard, Cheryl; Coté, Marie-José; Laberge, Serge; Emslie, Kerry R

    2010-03-01

    Current screening and event-specific polymerase chain reaction (PCR) assays for the detection and identification of genetically modified organisms (GMOs) in samples of unknown composition or for the detection of non-regulated GMOs have limitations, and alternative approaches are required. A transgenic DNA fingerprinting methodology using restriction enzyme digestion, adaptor ligation, and nested PCR was developed where individual GMOs are distinguished by the characteristic fingerprint pattern of the fragments generated. The inter-laboratory reproducibility of the amplified fragment sizes using different capillary electrophoresis platforms was compared, and reproducible patterns were obtained with an average difference in fragment size of 2.4 bp. DNA insert fingerprints for 12 different maize events, including two maize hybrids and one soy event, were generated that reflected the composition of the transgenic DNA constructs. Once produced, the fingerprint profiles were added to a database which can be readily exchanged and shared between laboratories. This approach should facilitate the process of GMO identification and characterization.

  12. Interlaboratory validation of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    PubMed

    Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

    2011-01-01

    To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize.

  13. Development and application of a multi-targeting reference plasmid as calibrator for analysis of five genetically modified soybean events.

    PubMed

    Pi, Liqun; Li, Xiang; Cao, Yiwei; Wang, Canhua; Pan, Liangwen; Yang, Litao

    2015-04-01

    Reference materials are important in accurate analysis of genetically modified organism (GMO) contents in food/feeds, and development of novel reference plasmid is a new trend in the research of GMO reference materials. Herein, we constructed a novel multi-targeting plasmid, pSOY, which contained seven event-specific sequences of five GM soybeans (MON89788-5', A2704-12-3', A5547-127-3', DP356043-5', DP305423-3', A2704-12-5', and A5547-127-5') and sequence of soybean endogenous reference gene Lectin. We evaluated the specificity, limit of detection and quantification, and applicability of pSOY in both qualitative and quantitative PCR analyses. The limit of detection (LOD) was as low as 20 copies in qualitative PCR, and the limit of quantification (LOQ) in quantitative PCR was 10 copies. In quantitative real-time PCR analysis, the PCR efficiencies of all event-specific and Lectin assays were higher than 90%, and the squared regression coefficients (R(2)) were more than 0.999. The quantification bias varied from 0.21% to 19.29%, and the relative standard deviations were from 1.08% to 9.84% in simulated samples analysis. All the results demonstrated that the developed multi-targeting plasmid, pSOY, was a credible substitute of matrix reference materials, and could be used as a reliable reference calibrator in the identification and quantification of multiple GM soybean events.

  14. Multifunctional organically modified silica nanoparticles for chemotherapy, adjuvant hyperthermia and near infrared imaging.

    PubMed

    Nagesetti, Abhignyan; McGoron, Anthony J

    2016-11-01

    We report a novel system of organically modified silica nanoparticles (Ormosil) capable of near infrared fluorescence and chemotherapy with adjuvant hyperthermia for image guided cancer therapy. Ormosil nanoparticles were loaded with a chemotherapeutic, Doxorubicin (DOX) and cyanine dye, IR820. Ormosil particles had a mean diameter of 51.2±2.4 nanometers and surface charge of -40.5±0.8mV. DOX was loaded onto Ormosil particles via physical adsorption (FDSIR820) or covalent linkage (CDSIR820) to the silanol groups on the Ormosil surface. Both formulations retained DOX and IR820 over a period of 2 days in aqueous buffer, though CDSIR820 retained more DOX (93.2%) compared to FDSIR820 (77.0%) nanoparticles. Exposure to near infrared laser triggered DOX release from CDSIR820. Uptake of nanoparticles was determined by deconvolution microscopy in ovarian carcinoma cells (Skov-3). CDSIR820 localized in the cell lysosomes whereas cells incubated with FDSIR820 showed DOX fluorescence from the nucleus indicating leakage of DOX from the nanoparticle matrix. FDSIR820 nanoparticles showed severe toxicity in Skov-3 cells whereas CDSIR820 particles had the same cytotoxicity profile as bare (No DOX and IR820) Ormosil particles. Furthermore, exposure of CDSIR820 nanoparticles to Near Infrared laser at 808 nanometers resulted in generation of heat (to 43°C from 37°C) and resulted in enhanced cell killing compared to Free DOX treatment. Bio-distribution studies showed that CDSIR820 nanoparticles were primarily present in the organs of Reticuloendothelial (RES) system.

  15. Development of Health Equity Indicators in Primary Health Care Organizations Using a Modified Delphi

    PubMed Central

    Wong, Sabrina T.; Browne, Annette J.; Varcoe, Colleen; Lavoie, Josée; Fridkin, Alycia; Smye, Victoria; Godwin, Olive; Tu, David

    2014-01-01

    Objective The purpose of this study was to develop a core set of indicators that could be used for measuring and monitoring the performance of primary health care organizations' capacity and strategies for enhancing equity-oriented care. Methods Indicators were constructed based on a review of the literature and a thematic analysis of interview data with patients and staff (n = 114) using procedures for qualitatively derived data. We used a modified Delphi process where the indicators were circulated to staff at the Health Centers who served as participants (n = 63) over two rounds. Indicators were considered part of a priority set of health equity indicators if they received an overall importance rating of>8.0, on a scale of 1–9, where a higher score meant more importance. Results Seventeen indicators make up the priority set. Items were eliminated because they were rated as low importance (<8.0) in both rounds and were either redundant or more than one participant commented that taking action on the indicator was highly unlikely. In order to achieve health care equity, performance at the organizational level is as important as assessing the performance of staff. Two of the highest rated “treatment” or processes of care indicators reflects the need for culturally safe and trauma and violence-informed care. There are four indicators that can be used to measure outcomes which can be directly attributable to equity responsive primary health care. Discussion These indicators and subsequent development of items can be used to measure equity in the domains of treatment and outcomes. These areas represent targets for higher performance in relation to equity for organizations (e.g., funding allocations to ongoing training in equity-oriented care provision) and providers (e.g., reflexive practice, skill in working with the health effects of trauma). PMID:25478914

  16. [Genetically modified plants and food safety. State of the art and discussion in the European Union].

    PubMed

    Schauzu, M

    2004-09-01

    Placing genetically modified (GM) plants and derived products on the European Union's (EU) market has been regulated by a Community Directive since 1990. This directive was complemented by a regulation specific for genetically modified and other novel foods in 1997. Specific labelling requirements have been applicable for GM foods since 1998. The law requires a pre-market safety assessment for which criteria have been elaborated and continuously adapted in accordance with the state of the art by national and international bodies and organisations. Consequently, only genetically modified products that have been demonstrated to be as safe as their conventional counterparts can be commercialized. However, the poor acceptance of genetically modified foods has led to a de facto moratorium since 1998. It is based on the lack of a qualified majority of EU member states necessary for authorization to place genetically modified plants and derived foods on the market. New Community Regulations are intended to end this moratorium by providing a harmonized and transparent safety assessment, a centralised authorization procedure, extended labelling provisions and a traceability system for genetically modified organisms (GMO) and derived food and feed.

  17. Encapsulation of cobalt porphyrins in organically modified silica gel glasses and their nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Zheng, Chan; Huang, Li; Li, Wei; Chen, Wenzhe

    2017-01-01

    2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin Cobalt(II) (CoPor) was introduced into nanostructured organically modified silica (ORMOSIL) using a sol-gel technique. Scanning electron microscopy, Fourier transform infrared (FT-IR), thermogravimetric analysis, and UV-Vis spectroscopy were performed to investigate the morphology, structure, thermal stability, and linear optical properties of the resulting gel glasses. The FT-IR spectrum and UV-Vis spectra strongly indicated the formation of a silica gel glass network and the successful encapsulation of CoPor in ORMOSIL silica gel glasses, respectively. The introduction of guest CoPor molecules induces silica to form more condensed surface characteristics, owing to the fact that CoPor can promote the hydrolysis and polycondensation procedure, and hence have better thermal stability as compared to blank silica gel glasses. Meanwhile, the dimerization phenomenon in a liquid matrix can be effectively suppressed in a silica solid-state matrix and is attributed to the `cage protection effect.' The nonlinear optical (NLO) properties of CoPor gel glasses were investigated using the open-aperture Z-scan technique at 532 nm. The NLO performance of CoPor-incorporated solid-state silica gel glasses has been improved in comparison with those dispersed in dimethylformamide solution. More significantly, the NLO properties of CoPor-doped ORMOSIL gel glasses can be controlled by adjusting the concentration of the CoPor molecules.

  18. Influence of dissolved organic carbon on the efficiency of P sequestration by a lanthanum modified clay.

    PubMed

    Dithmer, Line; Nielsen, Ulla Gro; Lundberg, Daniel; Reitzel, Kasper

    2016-06-15

    A laboratory scale experiment was set up to test the effect of dissolved organic carbon (DOC) as well as ageing of the La-P complex formed during phosphorus (P) sequestration by a La modified clay (Phoslock(®)). Short term (7 days) P adsorption studies revealed a significant negative effect of added DOC on the P sequestration of Phoslock(®), whereas a long-term P adsorption experiment revealed that the negative effect of added DOC was reduced with time. The reduced P binding efficiency is kinetic, as evident from solid-state (31)P magic-angle spinning (MAS) NMR spectroscopy, who showed that the P binding did not change in the presence of DOC. (31)P MAS NMR also reveals that up to 26% of the sequestered phosphate is as loosely bound redox-sensitive P species on the surface of rhabdophane (LaPO4 · nH2O, n ≤ 3). The ratio between the loosely bound P and lanthanum phosphate did not change with time, however both NMR and La LIII-extended x-ray absorption fine structure (EXAFS) spectroscopy shows a transformation of lanthanum phosphate from the initially formed rhabdophane towards the more stable monazite (LaPO4). Furthermore, the effect of natural DOC on the P binding capacity was tested using water and pore water from 16 Danish lakes. Whilst DOC has an immediate negative impact on P binding in the lake water, with time this effect is reduced.

  19. Absolute quantitation of isoforms of post-translationally modified proteins in transgenic organism.

    PubMed

    Li, Yaojun; Shu, Yiwei; Peng, Changchao; Zhu, Lin; Guo, Guangyu; Li, Ning

    2012-08-01

    Post-translational modification isoforms of a protein are known to play versatile biological functions in diverse cellular processes. To measure the molar amount of each post-translational modification isoform (P(isf)) of a target protein present in the total protein extract using mass spectrometry, a quantitative proteomic protocol, absolute quantitation of isoforms of post-translationally modified proteins (AQUIP), was developed. A recombinant ERF110 gene overexpression transgenic Arabidopsis plant was used as the model organism for demonstration of the proof of concept. Both Ser-62-independent (14)N-coded synthetic peptide standards and (15)N-coded ERF110 protein standard isolated from the heavy nitrogen-labeled transgenic plants were employed simultaneously to determine the concentration of all isoforms (T(isf)) of ERF110 in the whole plant cell lysate, whereas a pair of Ser-62-dependent synthetic peptide standards were used to quantitate the Ser-62 phosphosite occupancy (R(aqu)). The P(isf) was finally determined by integrating the two empirically measured variables using the following equation: P(isf) = T(isf) · R(aqu). The absolute amount of Ser-62-phosphorylated isoform of ERF110 determined using AQUIP was substantiated with a stable isotope labeling in Arabidopsis-based relative and accurate quantitative proteomic approach. The biological role of the Ser-62-phosphorylated isoform was demonstrated in transgenic plants.

  20. Self-assembled hybrid metal oxide base catalysts prepared by simply mixing with organic modifiers

    PubMed Central

    Tamura, Masazumi; Kishi, Ryota; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-01-01

    Multidentate materials formed by simply mixing heterogeneous and homogeneous components are promising for construction of versatile active sites on the surface of heterogeneous compounds, however, to the best of our knowledge, there are no reports on such materials. Self-assembly of hetero-hybrid catalytic materials occurs when heterogeneous catalysts having adjacent Lewis acid-Lewis base sites are mixed with an organic modifier that contains at least two Lewis base functional groups. Here we demonstrate the strategy by combining cerium oxide and 2-cyanopyridine that self-assembles to form a charge-transfer complex in methanol that exhibits a 2,000-fold increase in reaction rate for hydromethoxylation of acrylonitrile with high selectivity compared with cerium oxide or 2-cyanopyridine alone. The catalytic system is applied to the transesterification and Knoevenagel condensation affording 14-fold and 11-fold higher activity, respectively, than cerium oxide alone. These results demonstrate the potential versatility of the catalytic system and the generality of the catalyst preparation strategy. PMID:26436638

  1. An event-specific DNA microarray to identify genetically modified organisms in processed foods.

    PubMed

    Kim, Jae-Hwan; Kim, Su-Youn; Lee, Hyungjae; Kim, Young-Rok; Kim, Hae-Yeong

    2010-05-26

    We developed an event-specific DNA microarray system to identify 19 genetically modified organisms (GMOs), including two GM soybeans (GTS-40-3-2 and A2704-12), thirteen GM maizes (Bt176, Bt11, MON810, MON863, NK603, GA21, T25, TC1507, Bt10, DAS59122-7, TC6275, MIR604, and LY038), three GM canolas (GT73, MS8xRF3, and T45), and one GM cotton (LLcotton25). The microarray included 27 oligonucleotide probes optimized to identify endogenous reference targets, event-specific targets, screening targets (35S promoter and nos terminator), and an internal target (18S rRNA gene). Thirty-seven maize-containing food products purchased from South Korean and US markets were tested for the presence of GM maize using this microarray system. Thirteen GM maize events were simultaneously detected using multiplex PCR coupled with microarray on a single chip, at a limit of detection of approximately 0.5%. Using the system described here, we detected GM maize in 11 of the 37 food samples tested. These results suggest that an event-specific DNA microarray system can reliably detect GMOs in processed foods.

  2. Self-assembled hybrid metal oxide base catalysts prepared by simply mixing with organic modifiers

    NASA Astrophysics Data System (ADS)

    Tamura, Masazumi; Kishi, Ryota; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-10-01

    Multidentate materials formed by simply mixing heterogeneous and homogeneous components are promising for construction of versatile active sites on the surface of heterogeneous compounds, however, to the best of our knowledge, there are no reports on such materials. Self-assembly of hetero-hybrid catalytic materials occurs when heterogeneous catalysts having adjacent Lewis acid-Lewis base sites are mixed with an organic modifier that contains at least two Lewis base functional groups. Here we demonstrate the strategy by combining cerium oxide and 2-cyanopyridine that self-assembles to form a charge-transfer complex in methanol that exhibits a 2,000-fold increase in reaction rate for hydromethoxylation of acrylonitrile with high selectivity compared with cerium oxide or 2-cyanopyridine alone. The catalytic system is applied to the transesterification and Knoevenagel condensation affording 14-fold and 11-fold higher activity, respectively, than cerium oxide alone. These results demonstrate the potential versatility of the catalytic system and the generality of the catalyst preparation strategy.

  3. Designing multilayered nanoplatforms for SERS-based detection of genetically modified organisms

    NASA Astrophysics Data System (ADS)

    Uluok, Saadet; Guven, Burcu; Eksi, Haslet; Ustundag, Zafer; Tamer, Ugur; Boyaci, Ismail Hakki

    2015-01-01

    In this study, the multilayered surface-enhanced Raman spectroscopy (SERS) platforms were developed for the analysis of genetically modified organisms (GMOs). For this purpose, two molecules [11-mercaptoundecanoic acid (11-MUA) and 2-mercaptoethylamine (2-MEA)] were attached with Aurod and Auspherical nanoparticles to form multilayered constructions on the gold (Au)slide surface. The best multilayered platform structure was chosen depending on SERS enhancement, and this surface was characterised with atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared spectroscopy. After the optimum multilayered SERS platform and nanoparticle interaction was identified, the oligonucleotides on the Aurod nanoparticles and Auslide were combined to determine target concentrations from the 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) signals using SERS. The correlation between the SERS intensities for DTNB and target concentrations was found to be linear within a range of 10 pM to 1 µM, and with a detection limit of 34 fM. The selectivity and specificity of the developed sandwich assay were tested using negative and positive controls, and nonsense and real sample studies. The obtained results showed that the multilayered SERS sandwich method allows for sensitive, selective, and specific detection of oligonucleotide sequences.

  4. Sorption of aromatic ionizable organic compounds to montmorillonites modified by hexadecyltrimethyl ammonium and polydiallyldimethyl ammonium.

    PubMed

    Xu, Huaizhou; Wan, Yuqiu; Li, Hui; Zheng, Shourong; Zhu, Dongqiang

    2011-01-01

    Environmental residues of aromatic ionizable organic compounds (AIOCs) have received considerable attention due to their potential human health and ecological risks. The main objective of this study was to investigate the key factors and mechanisms controlling sorption of a series of anionic and zwitterionic AIOCs (two aromatic sulfonates, 4-methyl-2,6-dinitrophenol, tetracycline, sulfamethoxazole, and tannic acid) to montmorillonites modified with hexadecyltrimethyl ammonium (HDTMA) and polydiallyldimethyl ammonium (PDADMA). Compared with naphthalene (a nonpolar and nonionic solute), all AIOCs showed stronger sorption (the sorbent-to-solution distribution coefficient was in the order of 10-10 L kg) to the two organoclays in spite of the much lower hydrophobicity, indicating the predominance of electrostatic interaction in sorption. The proposed electrostatic mechanism of the tested AIOCs was supported by the pH dependency of sorption to the two organoclays. The two organoclays manifested weaker sorption affinity but faster sorption kinetics for bulky AIOCs than commercial activated carbon, resulting from the high accessibility of sorption sites in the open, ordered clay interlayer. The findings of this study highlight the potential of using HDTMA- and PDADMA-exchanged montmorillonites as effective sorbents for AIOCs in water and wastewater treatments.

  5. Reducing breast biopsies by ultrasonographic analysis and a modified self-organizing map

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Greenleaf, James F.; Gisvold, John J.

    1997-05-01

    Recent studies suggest that visual evaluation of ultrasound images could decrease negative biopsies of breast cancer diagnosis. However, visual evaluation requires highly experienced breast sonographers. The objective of this study is to develop computerized radiologist assistant to reduce breast biopsies needed for evaluating suspected breast cancer. The approach of this study utilizes a neural network and tissue features extracted from digital sonographic breast images. The features include texture parameters of breast images: characteristics of echoes within and around breast lesions, and geometrical information of breast tumors. Clusters containing only benign lesions in the feature space are then identified by a modified self- organizing map. This newly developed neural network objectively segments population distributions of lesions and accurately establishes benign and equivocal regions.t eh method was applied to high quality breast sonograms of a large number of patients collected with a controlled procedure at Mayo Clinic. The study showed that the number of biopsies in this group of women could be decreased by 40 percent to 59 percent with high confidence and that no malignancies would have been included in the nonbiopsied group. The advantages of this approach are that it is robust, simple, and effective and does not require highly experienced sonographers.

  6. Characterizing Corrosion Effects of Weak Organic Acids Using a Modified Bono Test

    NASA Astrophysics Data System (ADS)

    Zhou, Yuqin; Turbini, Laura J.; Ramjattan, Deepchand; Christian, Bev; Pritzker, Mark

    2013-12-01

    To meet environmental requirements and achieve benefits of cost-effective manufacturing, no-clean fluxes (NCFs) or low-solids fluxes have become popular in present electronic manufacturing processes. Weak organic acids (WOAs) as the activation ingredients in NCFs play an important role, especially in the current lead-free and halogen-free soldering technology era. However, no standard or uniform method exists to characterize the corrosion effects of WOAs on actual metallic circuits of printed wiring boards (PWBs). Hence, the development of an effective quantitative test method for evaluating the corrosion effects of WOAs on the PWB's metallic circuits is imperative. In this paper, the modified Bono test, which was developed to quantitatively examine the corrosion properties of flux residues, is used to characterize the corrosion effects of five WOAs (i.e., abietic acid, succinic acid, glutaric acid, adipic acid, and malic acid) on PWB metallic circuits. Experiments were performed under three temperature/humidity conditions (85°C/85% RH, 60°C/93% RH, and 40°C/93% RH) using two WOA solution concentrations. The different corrosion effects among the various WOAs were best reflected in the testing results at 40°C and 60°C. Optical microscopy was used to observe the morphology of the corroded copper tracks, and scanning electron microscopy (SEM) energy-dispersive x-ray (EDX) characterization was performed to determine the dendrite composition.

  7. Adsorption of o-, m- and p-nitrophenols onto organically modified bentonites.

    PubMed

    Koyuncu, Hülya; Yıldız, Nuray; Salgın, Uğur; Köroğlu, Fatmanur; Calımlı, Ayla

    2011-01-30

    Experiments were conducted on the adsorption characteristics of o-, m- and p-nitrophenols by organically modified bentonites at different temperatures. Two organobentonites (HDTMA-B and PEG-B) were synthesized using hexadecyltrimethylammonium bromide (HDTMABr) and poly(ethylene glycol) butyl ether (PEG). Synthesized HDTMA-B and PEG-B were characterized by XRD, FTIR and DTA-TG analyses and their specific surface area, particle size and pore size distributions were determined. BET surface areas and basal spacings (d(001)) of the HDTMA-B and PEG-B were found to be 38.71 m(2)g(-1), 69.04 m(2)g(-1) and 21.96 Å, 15.17 Å, respectively. Increased adsorption with temperature indicates that the process is endothermic for o-nitrophenol. On the other hand m- and p-nitrophenols exhibited lower rates of adsorption at higher temperatures suggesting a regular exothermic process taking place. Results were analyzed according to the Langmuir, Freundlich and Dubinin-Redushkevich (D-R) isotherm equations using linearized correlation coefficient at different temperatures. R(L) separation factors for Langmuir and the n values for Freundlich isotherms showed that m- and p-nitrophenols are favorably adsorbed by HDTMA-B and, p-nitrophenol is favored by PEG-B. Adsorption of o-, m- and p-nitrophenols as single components or from their binary mixtures on HDTMA-B and, p-nitrophenol on PEG-B are all defined to be physical in nature.

  8. Superior Charge Storage and Power Density of a Conducting Polymer-Modified Covalent Organic Framework

    PubMed Central

    2016-01-01

    The low conductivity of two-dimensional covalent organic frameworks (2D COFs), and most related coordination polymers, limits their applicability in optoelectronic and electrical energy storage (EES) devices. Although some networks exhibit promising conductivity, these examples generally lack structural versatility, one of the most attractive features of framework materials design. Here we enhance the electrical conductivity of a redox-active 2D COF film by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) within its pores. The resulting poly(3,4-ethylenedioxythiophene) (PEDOT)-infiltrated COF films exhibit dramatically improved electrochemical responses, including quantitative access to their redox-active groups, even for 1 μm-thick COF films that otherwise provide poor electrochemical performance. PEDOT-modified COF films can accommodate high charging rates (10–1600 C) without compromising performance and exhibit both a 10-fold higher current response relative to unmodified films and stable capacitances for at least 10 000 cycles. This work represents the first time that electroactive COFs or crystalline framework materials have shown volumetric energy and power densities comparable with other porous carbon-based electrodes, thereby demonstrating the promise of redox-active COFs for EES devices. PMID:27725966

  9. Quartz crystal microbalance (QCM) affinity biosensor for genetically modified organisms (GMOs) detection.

    PubMed

    Mannelli, Ilaria; Minunni, Maria; Tombelli, Sara; Mascini, Marco

    2003-03-01

    A DNA piezoelectric sensor has been developed for the detection of genetically modified organisms (GMOs). Single stranded DNA (ssDNA) probes were immobilised on the sensor surface of a quartz crystal microbalance (QCM) device and the hybridisation between the immobilised probe and the target complementary sequence in solution was monitored. The probe sequences were internal to the sequence of the 35S promoter (P) and Nos terminator (T), which are inserted sequences in the genome of GMOs regulating the transgene expression. Two different probe immobilisation procedures were applied: (a) a thiol-dextran procedure and (b) a thiol-derivatised probe and blocking thiol procedure. The system has been optimised using synthetic oligonucleotides, which were then applied to samples of plasmidic and genomic DNA isolated from the pBI121 plasmid, certified reference materials (CRM), and real samples amplified by the polymerase chain reaction (PCR). The analytical parameters of the sensor have been investigated (sensitivity, reproducibility, lifetime etc.). The results obtained showed that both immobilisation procedures enabled sensitive and specific detection of GMOs, providing a useful tool for screening analysis in food samples.

  10. Superior Charge Storage and Power Density of a Conducting Polymer-Modified Covalent Organic Framework.

    PubMed

    Mulzer, Catherine R; Shen, Luxi; Bisbey, Ryan P; McKone, James R; Zhang, Na; Abruña, Héctor D; Dichtel, William R

    2016-09-28

    The low conductivity of two-dimensional covalent organic frameworks (2D COFs), and most related coordination polymers, limits their applicability in optoelectronic and electrical energy storage (EES) devices. Although some networks exhibit promising conductivity, these examples generally lack structural versatility, one of the most attractive features of framework materials design. Here we enhance the electrical conductivity of a redox-active 2D COF film by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) within its pores. The resulting poly(3,4-ethylenedioxythiophene) (PEDOT)-infiltrated COF films exhibit dramatically improved electrochemical responses, including quantitative access to their redox-active groups, even for 1 μm-thick COF films that otherwise provide poor electrochemical performance. PEDOT-modified COF films can accommodate high charging rates (10-1600 C) without compromising performance and exhibit both a 10-fold higher current response relative to unmodified films and stable capacitances for at least 10 000 cycles. This work represents the first time that electroactive COFs or crystalline framework materials have shown volumetric energy and power densities comparable with other porous carbon-based electrodes, thereby demonstrating the promise of redox-active COFs for EES devices.

  11. Chemically modified polymeric resins for separation of cations, organic acids, and small polar moleculea by high performance liquid chromatography

    SciTech Connect

    Morris, John B.

    1993-07-01

    This thesis is divided into 4 parts: a review, ion chromatography of metal cations on carboxylic resins, separation of hydrophilic organic acids and small polar compounds on macroporous resin columns, and use of eluent modifiers for liquid chromatographic separation of carboxylic acids using conductivity detection.

  12. ASSESSING POSSIBLE ECOLOGICAL RISKS OF GENETICALLY MODIFIED CROPS: GENE EXPRESSION ASSAYS AND GENETIC MONITORING OF NON-TARGET ORGANISMS

    EPA Science Inventory

    Widespread planting of genetically modified crops with the Bt transgene pesticide has led to concern over non-target effects of Bt compounds in agroecosystems. While some research suggests that non-target organisms exposed to Bt toxin exhibit reduced fecundity and increased morta...

  13. ENVIRONMENTAL RESEARCH BRIEF: USE OF CATIONIC SURFACTANTS TO MODIFY AQUIFER MATERIALS TO REDUCE THE MOBILITY OF HYDROPHOBIC ORGANIC COMPOUNDS

    EPA Science Inventory

    Cationic surfactants can be used to modify surfaces of soils and subsurface materials to promote sorption of hydrophobic organic compounds (HOC) and retard their migration. For example, cationic surfactants could be injected into an aquifer downgradient from a source of HOC conta...

  14. REUSABLE ADSORBENTS FOR DILUTE SOLUTIONS SEPARATION. 5: PHOTODEGRADATION OF ORGANIC COMPOUNDS ON SURFACTANT-MODIFIED TITANIA. (R828598C753)

    EPA Science Inventory

    A semiconductor titania (TiO2) surface was modified by surfactant adsorption to make it more hydrophobic and to increase the adsorption of hydrophobic organic compounds (HOCs) and their photodegradation rates under UV irradiation. Photocatalytic experiments using Ti...

  15. Multiplex quantification of four DNA targets in one reaction with Bio-Rad droplet digital PCR system for GMO detection

    PubMed Central

    Dobnik, David; Štebih, Dejan; Blejec, Andrej; Morisset, Dany; Žel, Jana

    2016-01-01

    The advantages of the digital PCR technology are already well documented until now. One way to achieve better cost efficiency of the technique is to use it in a multiplexing strategy. Droplet digital PCR platforms, which include two fluorescence filters, support at least duplex reactions and with some developments and optimization higher multiplexing is possible. The present study not only shows a development of multiplex assays in droplet digital PCR, but also presents a first thorough evaluation of several parameters in such multiplex digital PCR. Two 4-plex assays were developed for quantification of 8 different DNA targets (7 genetically modified maize events and maize endogene). Per assay, two of the targets were labelled with one fluorophore and two with another. As current analysis software does not support analysis of more than duplex, a new R- and Shiny-based web application analysis tool (http://bit.ly/ddPCRmulti) was developed that automates the analysis of 4-plex results. In conclusion, the two developed multiplex assays are suitable for quantification of GMO maize events and the same approach can be used in any other field with a need for accurate and reliable quantification of multiple DNA targets. PMID:27739510

  16. Multiplex quantification of four DNA targets in one reaction with Bio-Rad droplet digital PCR system for GMO detection

    NASA Astrophysics Data System (ADS)

    Dobnik, David; Štebih, Dejan; Blejec, Andrej; Morisset, Dany; Žel, Jana

    2016-10-01

    The advantages of the digital PCR technology are already well documented until now. One way to achieve better cost efficiency of the technique is to use it in a multiplexing strategy. Droplet digital PCR platforms, which include two fluorescence filters, support at least duplex reactions and with some developments and optimization higher multiplexing is possible. The present study not only shows a development of multiplex assays in droplet digital PCR, but also presents a first thorough evaluation of several parameters in such multiplex digital PCR. Two 4-plex assays were developed for quantification of 8 different DNA targets (7 genetically modified maize events and maize endogene). Per assay, two of the targets were labelled with one fluorophore and two with another. As current analysis software does not support analysis of more than duplex, a new R- and Shiny-based web application analysis tool (http://bit.ly/ddPCRmulti) was developed that automates the analysis of 4-plex results. In conclusion, the two developed multiplex assays are suitable for quantification of GMO maize events and the same approach can be used in any other field with a need for accurate and reliable quantification of multiple DNA targets.

  17. Multiplex quantification of four DNA targets in one reaction with Bio-Rad droplet digital PCR system for GMO detection.

    PubMed

    Dobnik, David; Štebih, Dejan; Blejec, Andrej; Morisset, Dany; Žel, Jana

    2016-10-14

    The advantages of the digital PCR technology are already well documented until now. One way to achieve better cost efficiency of the technique is to use it in a multiplexing strategy. Droplet digital PCR platforms, which include two fluorescence filters, support at least duplex reactions and with some developments and optimization higher multiplexing is possible. The present study not only shows a development of multiplex assays in droplet digital PCR, but also presents a first thorough evaluation of several parameters in such multiplex digital PCR. Two 4-plex assays were developed for quantification of 8 different DNA targets (7 genetically modified maize events and maize endogene). Per assay, two of the targets were labelled with one fluorophore and two with another. As current analysis software does not support analysis of more than duplex, a new R- and Shiny-based web application analysis tool (http://bit.ly/ddPCRmulti) was developed that automates the analysis of 4-plex results. In conclusion, the two developed multiplex assays are suitable for quantification of GMO maize events and the same approach can be used in any other field with a need for accurate and reliable quantification of multiple DNA targets.

  18. Multigeneration reproductive and developmental toxicity study of bar gene inserted into genetically modified potato on rats.

    PubMed

    Rhee, Gyu Seek; Cho, Dae Hyun; Won, Yong Hyuck; Seok, Ji Hyun; Kim, Soon Sun; Kwack, Seung Jun; Lee, Rhee Da; Chae, Soo Yeong; Kim, Jae Woo; Lee, Byung Mu; Park, Kui Lea; Choi, Kwang Sik

    2005-12-10

    Each specific protein has an individual gene encoding it, and a foreign gene introduced to a plant can be used to synthesize a new protein. The identification of potential reproductive and developmental toxicity from novel proteins produced by genetically modified (GM) crops is a difficult task. A science-based risk assessment is needed in order to use GM crops as a conventional foodstuff. In this study, the specific characteristics of GM food and low-level chronic exposure were examined using a five-generation animal study. In each generation, rats were fed a solid pellet containing 5% GM potato and non-GM potato for 10 wk prior to mating in order to assess the potential reproductive and developmental toxic effects. In the multigeneration animal study, there were no GM potato-related changes in body weight, food consumption, reproductive performance, and organ weight. Polymerase chain reaction (PCR) was carried out using extracted genomic DNA to examine the possibility of gene persistence in the organ tissues after a long-term exposure to low levels of GM feed. In each generation, the gene responsible for bar was not found in any of the reproductive organs of the GM potato-treated male and female rats, and the litter-related indexes did not show any genetically modified organism (GMO)-related changes. The results suggest that genetically modified crops have no adverse effects on the multigeneration reproductive-developmental ability.

  19. Thermodynamic studies on the solvent effects in chromatography on molecularly imprinted polymers. 1. Nature of the organic modifier.

    PubMed

    Kim, Hyunjung; Guiochon, Georges

    2005-03-15

    Molecularly imprinted polymers (MIPs) are used as highly enantioselective stationary phases in liquid chromatography. To optimize the binding performance of MIPs, different types of polar modifiers are frequently used. Previous studies have shown that the hydrogen-bonding donor parameter (HBD) of the modifier has a large influence on the binding performance of MIPs in chiral separations. This possibility is addressed in a detailed thermodynamic study of a Fmoc-L-tryptophan (Fmoc-L-Trp) imprinted polymer, eluted with four different polar modifiers, i.e., THF, propan-2-ol, methanol, and acetic acid, which have different HBDs (0.00, 0.33, 0.43, and 0.61, respectively). Adsorption isotherm data for each enantiomer in each of these organic modifiers were acquired by frontal analysis over a 20 000 dynamic concentration range. Nonlinear regression of the isotherm data, along with independent calculation of the affinity energy distributions, identified four different types of binding sites coexisting for the enantiomers on the MIP. The exception was acetic acid, which has the highest HBD. In this case, three types of binding sites only coexist on the MIP. The isotherm parameters obtained from these data show the following: (1) The association energies of the two enantiomers with a given type of sites have a similar magnitude; however, the density of the sites is higher for the template than for its antipode. (2) The nature of the organic modifier has a larger influence on the density of high-energy sites than on the association constant of these sites. (3) The molecular size of the organic modifier has a larger influence on the site density (especially for Fmoc-D-Trp) than does HBD. (4) Using an organic modifier with a higher HBD reduces the enantioselectivity on each site. (5) High-energy sites are more enantioselective than low-energy ones. (6) Using an organic modifier with a high HBD causes a larger reduction in the density of high-energy sites approached by the

  20. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    SciTech Connect

    Xiao, Teng

    2012-01-01

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  1. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    NASA Astrophysics Data System (ADS)

    Xiao, Teng

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxy-thiophene):polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3-hexylthiophene) (P3HT):phenyl-C 61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  2. The current state of GMO governance: are we ready for GM animals?

    PubMed

    Vàzquez-Salat, Núria; Salter, Brian; Smets, Greet; Houdebine, Louis-Marie

    2012-01-01

    Given the history of GMO conflict and debate, the GM animal future is dependent on the response of the regulatory landscape and its associated range of interest groups at national, regional and international levels. Focusing on the EU and the USA, this article examines the likely form of that multi-level response, the increased role of cultural values, the contribution of new and existing interest groups and the consequent implications for the commercialization of both green and red GM animal biotechnology.

  3. Fabrication of novel GMO/Eudragit E100 nanostructures for enhancing oral bioavailability of carvedilol.

    PubMed

    Patil, Sharvil S; Roy, Krishtey; Choudhary, Bhavana; Mahadik, Kakasaheb R

    2016-08-01

    In the present work, novel nanostructures comprising of glyceryl monooleate (GMO) and Eudragit E100 were prepared using high intensity ultrasonic homogenization. 3(2) Factorial design approach was used for optimization of nanostructures. Results of regression analysis revealed that the amount of GMO and Eudragit E100 had a drastic effect on particle size and percent entrapment efficiency. Optimized carvedilol-loaded nanostructures (Car-NS) were characterized by FTIR, TEM, DSC, in vitro drug release study. Pharmacokinetic parameters such as Cmax, Tmax, Ke, Ka, Vd and AUC were estimated for Car-NS upon its oral administration in Sprague-Dawley rats. Particle size of Car-NS was found to be 183 ± 2.43 nm with an entrapment efficiency of 81.4 ± 0.512%. FTIR studies revealed loading and chemical compatibility of carvedilol with the components of nanostructures. DSC thermograms did not show endothermic peak for melting of carvedilol which could be attributed to solubilization of carvedilol in molten GMO during DSC run. The prepared Car-NS released carvedilol in sustained manner over a period of 10 h as suggested by in vitro drug release study. The pharmacokinetic study of Car-NS showed significant improvement in Cmax (two fold, p < 0.001) and AUC (four folds, p < 0.001) of carvedilol when compared to carvedilol suspension. Car-NS were found to be stable for a period of 3 months. Thus, a stable, floating, multiparticulate GMO/Eudragit E100 nanostructures having ability to release the drug in sustained manner with enhanced oral bioavailability can prove to be a promising carrier system for poorly water soluble drugs.

  4. Use of cysteine-modified TiO{sub 2} photocatalyst for treatment of combined organic/inorganic wastewaters

    SciTech Connect

    Peters, R.W.; Wu, J.M.; Meshkov, N.; Thurnauer, M.C.; Ostafin, A.G.

    1995-03-01

    The utilization of semiconductor-based photocatalysts, such as titanium dioxide (TiO{sub 2}), for carrying out photochemical reactions to treat water contaminated with organic and inorganic compounds has received considerable attention in recent years. The authors strategy for optimizing the process of photocatalytic reduction of heavy metals on TiO{sub 2} colloids involves modifying the colloid surface. Specific project objectives included: (1) identification and development of potential biomimetic photocatalysts for simultaneous heavy metal recovery and organic destruction; (2) identification of treatment conditions that minimize the residual metal concentration(s) contained in the effluent, even in the presence of complexants and interferences, and development of appropriate scale-up criteria; and (3) determination of system performance, including an economic analysis for comparison with conventional technologies (such as pump-and-treat using metal hydroxide precipitation of ion exchange). The experimental results indicate that simultaneous removal of organic compounds (such as naphthalene) and inorganic compounds (such as lead ions) in aqueous solution can be achieved using a TiO{sub 2} photocatalyst system with UV light. The removal rates of organic and inorganic compounds can be enhanced through surface modification of the TiO{sub 2} photocatalyst using an organic substance such as cysteine. The cysteine-modified TiO{sub 2} photocatalyst enhanced the oxidation rates of organics as well as the reduction rates of heavy metals in the irradiated solution, resulting in improved treatment efficiencies for combined organic/inorganic wastestreams.

  5. Postsynthetically Modified Covalent Organic Frameworks for Efficient and Effective Mercury Removal.

    PubMed

    Sun, Qi; Aguila, Briana; Perman, Jason; Earl, Lyndsey D; Abney, Carter W; Cheng, Yuchuan; Wei, Hao; Nguyen, Nicholas; Wojtas, Lukasz; Ma, Shengqian

    2017-02-22

    A key challenge in environmental remediation is the design of adsorbents bearing an abundance of accessible chelating sites with high affinity, to achieve both rapid uptake and high capacity for the contaminants. Herein, we demonstrate how two-dimensional covalent organic frameworks (COFs) with well-defined mesopore structures display the right combination of properties to serve as a scaffold for decorating coordination sites to create ideal adsorbents. The proof-of-concept design is illustrated by modifying sulfur derivatives on a newly designed vinyl-functionalized mesoporous COF (COF-V) via thiol-ene "click" reaction. Representatively, the material (COF-S-SH) synthesized by treating COF-V with 1,2-ethanedithiol exhibits high efficiency in removing mercury from aqueous solutions and the air, affording Hg(2+) and Hg(0) capacities of 1350 and 863 mg g(-1), respectively, surpassing all those of thiol and thioether functionalized materials reported thus far. More significantly, COF-S-SH demonstrates an ultrahigh distribution coefficient value (Kd) of 2.3 × 10(9) mL g(-1), which allows it to rapidly reduce the Hg(2+) concentration from 5 ppm to less than 0.1 ppb, well below the acceptable limit in drinking water (2 ppb). We attribute the impressive performance to the synergistic effects arising from densely populated chelating groups with a strong binding ability within ordered mesopores that allow rapid diffusion of mercury species throughout the material. X-ray absorption fine structure (XAFS) spectroscopic studies revealed that each Hg is bound exclusively by two S via intramolecular cooperativity in COF-S-SH, further interpreting its excellent affinity. The results presented here thus reveal the exceptional potential of COFs for high-performance environmental remediation.

  6. Development of nanostructured and surface modified semiconductors for hybrid organic-inorganic solar cells.

    SciTech Connect

    Hsu, Julia, W. P.

    2008-09-01

    Solar energy conversion is increasingly being recognized as one of the principal ways to meet future energy needs without causing detrimental environmental impact. Hybrid organic-inorganic solar cells (SCs) are attracting particular interest due to the potential for low cost manufacturing and for use in new applications, such as consumer electronics, architectural integration and light-weight sensors. Key materials advantages of these next generation SCs over conventional semiconductor SCs are in design opportunities--since the different functions of the SCs are carried out by different materials, there are greater materials choices for producing optimized structures. In this project, we explore the hybrid organic-inorganic solar cell system that consists of oxide, primarily ZnO, nanostructures as the electron transporter and poly-(3-hexylthiophene) (P3HT) as the light-absorber and hole transporter. It builds on our capabilities in the solution synthesis of nanostructured semiconducting oxide arrays to this photovoltaic (PV) technology. The three challenges in this hybrid material system for solar applications are (1) achieving inorganic nanostructures with critical spacing that matches the exciton diffusion in the polymer, {approx} 10 nm, (2) infiltrating the polymer completely into the dense nanostructure arrays, and (3) optimizing the interfacial properties to facilitate efficient charge transfer. We have gained an understanding and control over growing oriented ZnO nanorods with sub-50 nm diameters and the required rod-to-rod spacing on various substrates. We have developed novel approaches to infiltrate commercially available P3HT in the narrow spacing between ZnO nanorods. Also, we have begun to explore ways to modify the interfacial properties. In addition, we have established device fabrication and testing capabilities at Sandia for prototype devices. Moreover, the control synthesis of ZnO nanorod arrays lead to the development of an efficient anti

  7. Development and application of a general plasmid reference material for GMO screening.

    PubMed

    Wu, Yuhua; Li, Jun; Wang, Yulei; Li, Xiaofei; Li, Yunjing; Zhu, Li; Li, Jun; Wu, Gang

    The use of analytical controls is essential when performing GMO detection through screening tests. Additionally, the presence of taxon-specific sequences is analyzed mostly for quality control during GMO detection. In this study, 11 commonly used genetic elements involving three promoters (P-35S, P-FMV35S and P-NOS), four marker genes (Bar, NPTII, HPT and Pmi), and four terminators (T-NOS, T-35S, T-g7 and T-e9), together with the reference gene fragments from six major crops of maize, soybean, rapeseed, rice, cotton and wheat, were co-integrated into the same single plasmid to construct a general reference plasmid pBI121-Screening. The suitability test of pBI121-Screening plasmid as reference material indicated that the non-target sequence on the pBI121-Screening plasmid did not affect the PCR amplification efficiencies of screening methods and taxon-specific methods. The sensitivity of screening and taxon-specific assays ranged from 5 to 10 copies of pBI121-Screening plasmid, meeting the sensitivity requirement of GMO detection. The construction of pBI121-Screening solves the lack of a general positive control for screening tests, thereby reducing the workload and cost of preparing a plurality of the positive control.

  8. Organically modified low-grade kaolin as a secondary containment material for underground storage tanks.

    PubMed

    Moon, Chul-Hwan; Lee, Jai-Young; Oh, Byung-Taek; Choi, Sang-Il

    2007-08-01

    Batch scale reactions were conducted to evaluate the efficacy of modified low-grade kaolin for the treatment of petroleum contaminants. Low-grade kaolin, which has been unvalued as material in the mining process because of its low quality for commercial products, was modified with HDTMA (hexadecyl-trimethylammonium), and its efficiency was compared with that of HDTMA-modified bentonite, which is used as a secondary containment barrier for underground storage tanks. The sorption capacity and hydraulic conductivity of both the HDTMA-modified bentonite and low-grade kaolin were investigated and showed distribution coefficients in the sorption of benzene, toluene, ethylbenzene and xylene ranging between 45.7 and 583.7 and 57.0 and 525.1, respectively. The hydraulic conductivities were 2.53 x 10(-8) and 5.62 x 10(-8) cm/s for the HDTMA-modified bentonite and low-grade kaolin, respectively. These results suggest that HDTMA-modified low-grade kaolin could be used as a hydraulic barrier against advection migration of petroleum contaminants. Simulation of the one-dimensional transport of benzene through a liner made of either one of the compounds was also performed. These results also showed that HDTMA-modified kaolin more effectively retards the transport of benzene.

  9. Comparative study of electroless nickel film on different organic acids modified cuprammonium fabric (CF)

    NASA Astrophysics Data System (ADS)

    Zhao, Hang; Lu, Yinxiang

    2016-01-01

    Nickel films were grown on citric acid (CA), malic acid (MA) and oxalic acid (OA) modified cuprammonium fabric (CF) substrates via electroless nickel deposition. The nickel films were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their individual deposition rate and electromagnetic interference (EMI) shielding effectiveness (SE) were also investigated to compare the properties of electroless nickel films. SEM images illustrated that the nickel film on MA modified CF substrate was smooth and uniform, and the density of nickel nuclei was much higher. Compared with that of CA modified CF, the coverage of nickel nuclei on OA and MA modified CF substrate was very limited and the nickel particles size was too big. XRD analysis showed that the nickel films deposited on the different modified CF substrates had a structure with Ni (1 1 1) preferred orientation. All the nickel coatings via different acid modification were firmly adhered to the CF substrates, as demonstrated by an ultrasonic washing test. The result of tensile test indicated that the electroless nickel plating on CF has ability to strengthen the CF substrate while causes limited effect on tensile elongation. Moreover, the nickel film deposited on MA modified CF substrate showed more predominant in EMI SE than that deposited on CA or OA modified CF.

  10. Application of whole genome shotgun sequencing for detection and characterization of genetically modified organisms and derived products.

    PubMed

    Holst-Jensen, Arne; Spilsberg, Bjørn; Arulandhu, Alfred J; Kok, Esther; Shi, Jianxin; Zel, Jana

    2016-07-01

    The emergence of high-throughput, massive or next-generation sequencing technologies has created a completely new foundation for molecular analyses. Various selective enrichment processes are commonly applied to facilitate detection of predefined (known) targets. Such approaches, however, inevitably introduce a bias and are prone to miss unknown targets. Here we review the application of high-throughput sequencing technologies and the preparation of fit-for-purpose whole genome shotgun sequencing libraries for the detection and characterization of genetically modified and derived products. The potential impact of these new sequencing technologies for the characterization, breeding selection, risk assessment, and traceability of genetically modified organisms and genetically modified products is yet to be fully acknowledged. The published literature is reviewed, and the prospects for future developments and use of the new sequencing technologies for these purposes are discussed.

  11. Synthesis and characterization of a sphere-like modified chitosan and acrylate resin composite for organics absorbency

    NASA Astrophysics Data System (ADS)

    Xin, S. S.; Wang, Y. H.; Li, Q. R.; Zhang, Q.; Wang, X. P.

    2015-07-01

    In this study, the chitosan (deacetylation degree >95%) was modified with vinyltriethoxysilane (A151) and became hydrophobic. The modified chitosan and acrylate resin composite can be synthesized by butyl methacrylate (BMA), butyl acrylate (BA), poly vinyl alcoho(PVA), N,N’-methylene bisacrylamide (MBA), benzoyl peroxide (BPO), and ethyl acetate under microwave irradiation. The optimal synthetic condition was as follows: the molar ratio of BA and BMA was 1.5:1, the dosage of ethyl acetate, PVA, MBA, BPO and modified chitosan were 50 wt.%, 10 wt.%, 1.5 wt.%, 2.0 wt.% and 1.0 wt.% of monomers, respectively. The adsorption capacity of the composite for CHCl3 and CCl4 were approximate to 53 g/g and 44 g/g, respectively. The organics absorbency and regeneration of the samples were also tested, and the samples were characterized by analysis of the scanning electron microscope and simultaneous thermo gravimetric/differential thermal.

  12. Aquaculture: Incorporating risk assessment and risk management into public policies on genetically modified finfish and shellfish

    SciTech Connect

    Hallerman, E.M.; Kapuscinski, A.R.

    1995-12-31

    Genetically modified finfish and shellfish pose economic benefits to aquaculture, but also pose ecological and genetic risks to ecosystems receiving such organisms. Realization of benefits with minimization of risks posed by a new technology can be addressed through the processes of risk assessment and risk management. Public policies adopted by individual countries will reflect differences in the outocme of risk assessment and risk management processes resulting from differences among the receiving ecosystems and sets of human values at issue. A number of countries and international institutions have begun development of policies for oversight of genetically modified aquatic organisms. In the United States, a working group commissioned by the U.S. Department of Agriculture incorporated risk assessment and risk management principles into draft performance standards for safely conducting research with genetically modified finfish and shellfish. The performance standards address research with a broad range of aquatic GMO`s and compliance is intended to be voluntary. In contrast, the Canadian policy mandates adherence to specified guidelines for experiments with transgenic aquatic organisms; establishment as national policy is expended soon.

  13. Adsorption mechanism in RPLC. Effect of the nature of the organic modifier

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2005-07-01

    The adsorption isotherms of phenol and caffeine were acquired by frontal analysis on two different adsorbents, Kromasil-C{sub 18} and Discovery-C{sub 18}, with two different mobile phases, aqueous solutions of methanol (MeOH/H{sub 2}O = 40/60 and 30/70, v/v) and aqueous solutions of acetonitrile (MeCN/H{sub 2}O = 30/70 and 20/80, v/v). The adsorption isotherms are always strictly convex upward in methanol/water solutions. The calculations of the adsorption energy distribution confirm that the adsorption data for phenol are best modeled with the bi-Langmuir and the tri-Langmuir isotherm models for Kromasil-C{sub 18} and Discovery-C{sub 18}, respectively. Because its molecule is larger and excluded from the deepest sites buried in the bonded layer, the adsorption data of caffeine follow bi-Langmuir isotherm model behavior on both adsorbents. In contrast, with acetonitrile/water solutions, the adsorption data of both phenol and caffeine deviate far less from linear behavior. They were best modeled by the sum of a Langmuir and a BET isotherm models. The Langmuir term represents the adsorption of the analyte on the high-energy sites located within the C{sub 18} layers and the BET term its adsorption on the low-energy sites and its accumulation in an adsorbed multilayer system of acetonitrile on the bonded alkyl chains. The formation of a complex adsorbed phase containing up to four layers of acetonitrile (with a thickness of 3.4 {angstrom} each) was confirmed by the excess adsorption isotherm data measured for acetonitrile on Discovery-C{sub 18}. A simple interpretation of this change in the isotherm curvature at high concentrations when methanol is replaced with acetonitrile as the organic modifier is proposed, based on the structure of the interface between the C{sub 18} chains and the bulk mobile phase. This new model accounts for all the experimental observations.

  14. An organic surface modifier to produce a high work function transparent electrode for high performance polymer solar cells.

    PubMed

    Choi, Hyosung; Kim, Hak-Beom; Ko, Seo-Jin; Kim, Jin Young; Heeger, Alan J

    2015-02-04

    Modification of an ITO electrode with small-molecule organic surface modifier, 4-chloro-benzoic acid (CBA), via a simple spin-coating method produces a high-work-function electrode with high transparency and a hydrophobic surface. As an alternative to PEDOT:PSS, CBA modification achieves efficiency enhancement up to 8.5%, which is attributed to enhanced light absorption within the active layer and smooth hole transport from the active layer to the anode.

  15. Effect of organically modified clay on mechanical properties, cytotoxicity and bactericidal properties of poly(ɛ-caprolactone) nanocomposites

    NASA Astrophysics Data System (ADS)

    Kumar, Sachin; Mishra, Anupam; Chatterjee, Kaushik

    2014-12-01

    The objective of this study was to evaluate the use of organically-modified clay nanoparticles in poly(ɛ-caprolactone) (PCL) for developing biodegradable composites. PCL nanocomposites reinforced with two different types of organically-modified clay (Cloisite 30B, C30B and Cloisite 93A, C93A) were prepared by melt-mixing. Morphology of PCL/clay nanocomposites characterized by scanning electron microscopy indicated good dispersion of nanoclay in the PCL matrix. Reinforcement of nanoclay in PCL enhanced mechanical properties without affecting thermal and degradation properties of PCL. Cytocompatibility of PCL/clay nanocomposites was studied using both osteoblasts and endothelial cells in vitro. Both composites (PCL/C30B and PCL/C93A) were cytotoxic with high toxicity observed for C30B even at low content of 1 wt %. The cytotoxicity was found to arise due to leachables from PCL/clay composites. Electrical conductivity measurements of aqueous media confirmed leaching of cationic surfactant from the PCL/clay composites PCL matrix. Both composites were found to be bactericidal but C30B was more effective than C93A. Taken together, it was observed that organically-modified nanoclay as fillers in PCL improves mechanical properties and imparts bactericidal properties but with increased risk of toxicity. These PCL/clay composites may be useful as stronger packaging material with antibacterial properties but are not suited as biomedical implants or for food packaging applications.

  16. DNA degradation in genetically modified rice with Cry1Ab by food processing methods: implications for the quantification of genetically modified organisms.

    PubMed

    Xing, Fuguo; Zhang, Wei; Selvaraj, Jonathan Nimal; Liu, Yang

    2015-05-01

    Food processing methods contribute to DNA degradation, thereby affecting genetically modified organism detection and quantification. This study evaluated the effect of food processing methods on the relative transgenic content of genetically modified rice with Cry1Ab. In steamed rice and rice noodles, the levels of Cry1Ab were ⩾ 100% and <83%, respectively. Frying and baking in rice crackers contributed to a reduction in Pubi and Cry1Ab, while microwaving caused a decrease in Pubi and an increase in Cry1Ab. The processing methods of sweet rice wine had the most severe degradation effects on Pubi and Cry1Ab. In steamed rice and rice noodles, Cry1Ab was the most stable, followed by SPS and Pubi. However, in rice crackers and sweet rice wine, SPS was the most stable, followed by Cry1Ab and Pubi. Therefore, Cry1Ab is a better representative of transgenic components than is Pubi because the levels of Cry1Ab were less affected compared to Pubi.

  17. Genetically modified crops: detection strategies and biosafety issues.

    PubMed

    Kamle, Suchitra; Ali, Sher

    2013-06-15

    Genetically modified (GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis (Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism (GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities, detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted.

  18. Hypothetical link between infertility and genetically modified food.

    PubMed

    Gao, Mingxia; Li, Bin; Yuan, Wenzhen; Zhao, Lihui; Zhang, Xuehong

    2014-01-01

    It is speculated that genetically modified food (GMF)/genetically modified organism (GMO) is responsible for infertility development. The risk linked with a wide use of GMFs/GMOs offers the basic elements for social criticism. However, to date, it has not been justified whether the bad effects are directly resulted from products of genetic modifications or trans-genesis process. Extensive experience with the risk assessment of whole foods has been applied recently on the safety and nutritional testing of GMFs/GMOs. Investigations have tested the safety of GMFs including sub-acute, chronic, reproductive, multi-generation and carcinogenicity studies. We extrapolated the potential risks associated with GMFs/GMOs on reproduction, and analyzed the multi-aspect linked between infertility and GMFs/GMOs. It could be conjectured that GMFs/GMOs could be potential hazard on reproduction, linking to the development of infertility through influencing the endocrine metabolism, endometriosis. However, little evidence shows the impaction on embryo or reproductive related tumor due to the limited literatures, and needs further research. The article presents some related patents on GMFs/GMOs, and some methods for tracking GMOs.

  19. Introducing a decomposition rate modifier in the Rothamsted Carbon Model to predict soil organic carbon stocks in saline soils.

    PubMed

    Setia, Raj; Smith, Pete; Marschner, Petra; Baldock, Jeff; Chittleborough, David; Smith, Jo

    2011-08-01

    Soil organic carbon (SOC) models such as the Rothamsted Carbon Model (RothC) have been used to estimate SOC dynamics in soils over different time scales but, until recently, their ability to accurately predict SOC stocks/carbon dioxide (CO(2)) emissions from salt-affected soils has not been assessed. Given the large extent of salt-affected soils (19% of the 20.8 billion ha of arable land on Earth), this may lead to miss-estimation of CO(2) release. Using soils from two salt-affected regions (one in Punjab, India and one in South Australia), an incubation study was carried out measuring CO(2) release over 120 days. The soils varied both in salinity (measured as electrical conductivity (EC) and calculated as osmotic potential using EC and water content) and sodicity (measured as sodium adsorption ratio, SAR). For soils from both regions, the osmotic potential had a significant positive relationship with CO(2)-C release, but no significant relationship was found between SAR and CO(2)-C release. The monthly cumulative CO(2)-C was simulated using RothC. RothC was modified to take into account reductions in plant inputs due to salinity. A subset of non-salt-affected soils was used to derive an equation for a "lab-effect" modifier to account for changes in decomposition under lab conditions and this modifier was significantly related with pH. Using a subset of salt-affected soils, a decomposition rate modifier (as a function of osmotic potential) was developed to match measured and modelled CO(2)-C release after correcting for the lab effect. Using this decomposition rate modifier, we found an agreement (R(2) = 0.92) between modelled and independently measured data for a set of soils from the incubation experiment. RothC, modified by including reduced plant inputs due to salinity and the salinity decomposition rate modifier, was used to predict SOC stocks of soils in a field in South Australia. The predictions clearly showed that SOC stocks are reduced in saline soils

  20. How well is Environmental Biosafety Research supporting the scientific debate on the biosafety of genetically modified organisms (GMOs)?

    PubMed

    Craig, Wendy; Lewandowski, Remigiusz; Degrassi, Giuliano; Ripandelli, Decio

    2007-01-01

    One of the most direct routes to informing scientific debates is through the timely publication of relevant research results. By making a comparison of the number and type of articles published by Environmental Biosafety Research (EBR) with those from other journals active in the arena of GMO biosafety, it is possible to shed light on the answer to the question posed in the title. To do this, we have used a unique open access online tool, the Biosafety Bibliographic Database (BBD) that has been provided by ICGEB since 1990. As of June 2007, the BBD contained 6694 records pertaining to scientific publications (full references and abstracts), and appearing in international and national scientific periodicals and books. Based on the records in the BBD, biosafety research activity over the past 16-17 years can be summarized by analyzing basic statistics. The BBD should prove to be a useful starting point for diverse bibliometric studies of publications in this area.

  1. Gone with the Wind: Conceiving of Moral Responsibility in the Case of GMO Contamination.

    PubMed

    Robaey, Zoë

    2016-06-01

    Genetically modified organisms are a technology now used with increasing frequency in agriculture. Genetically modified seeds have the special characteristic of being living artefacts that can reproduce and spread; thus it is difficult to control where they end up. In addition, genetically modified seeds may also bring about uncertainties for environmental and human health. Where they will go and what effect they will have is therefore very hard to predict: this creates a puzzle for regulators. In this paper, I use the problem of contamination to complicate my ascription of forward-looking moral responsibility to owners of genetically modified organisms. Indeed, how can owners act responsibly if they cannot know that contamination has occurred? Also, because contamination creates new and unintended ownership, it challenges the ascription of forward-looking moral responsibility based on ownership. From a broader perspective, the question this paper aims to answer is as follows: how can we ascribe forward-looking moral responsibility when the effects of the technologies in question are difficult to know or unknown? To solve this problem, I look at the epistemic conditions for moral responsibility and connect them to the normative notion of the social experiment. Indeed, examining conditions for morally responsible experimentation helps to define a range of actions and to establish the related epistemic virtues that owners should develop in order to act responsibly where genetically modified organisms are concerned.

  2. Deactivation of photocatalytically active ZnO nanoparticle and enhancement of its compatibility with organic compounds by surface-capping with organically modified silica

    NASA Astrophysics Data System (ADS)

    Cao, Zhi; Zhang, Zhijun

    2011-02-01

    Tetraethyl orthosilicate (TEOS) and dimethyldiethoxysilane (DEDMS) were used as co-precursors to prepare organically modified silica (ormosil) via sol-gel process. The resultant ormosil was adopted for surface-capping of ZnO nanoparticle, where methyl (organic functional group) and silica (inorganic component) were simultaneously introduced onto the surface of the nanoparticles for realizing dual surface-modification. The ormosil-capped ZnO nanoparticle showed strong hydrophobicity and good compatibility with organic phases, as well as effectively decreased photocatalytic activity and almost unchanged ultraviolet (UV)-shielding ability. More importantly, the comprehensive properties of ormosil-capped ZnO nanoparticle could be manipulated by adjusting the molar ratio of TEOS to DEDMS during sol-gel process. This should help to open a wider window to better utilizing the unique and highly attractive properties such as high UV-shielding ability and high-visible light transparency of ZnO nanoparticle in sunscreen cosmetics.

  3. Training Organizations in Use of a Modified Stream Visual Assessment Protocol

    ERIC Educational Resources Information Center

    Obropta, Christopher C.; Yergeau, Steven E.

    2011-01-01

    The Stream Visual Assessment Protocol (SVAP) was evaluated as a means to increase watershed surveys in New Jersey. Groups were trained in an SVAP modified for New Jersey streams. Participants in three training workshops were surveyed to determine the usefulness of SVAP as a cost-effective method to evaluate watershed health. Many respondents found…

  4. Influence of modified soils on the removal of diesel fuel oil from water and the growth of oil degradation micro-organism.

    PubMed

    Gao, B; Yang, L; Wang, X; Zhao, J; Sheng, G

    2000-08-01

    Three soils were modified with two kinds of cationic surfactants in order to increase their sorptive capabilities for organic contaminants. Sorption of diesel fuel oil in water by these modified soils had been investigated. Modified soils can effectively sorb diesel fuel oil from water. The sorption capability of modified soils is: HDTMA-black soil > HDTMA-yellow brown soil > HDTMA-red soil > TMA-black soil > TMA-yellow brown soil > TMA-red soil. Sorption of diesel fuel oil by natural soils and HDTMA modified soils is via partition, the sorption isotherms can be expressed by Henry equation, and logK(SOM) is 2.42-2.80, logK(HDTMA) is 3.37-3.60. Sorption isotherms of TMA modified soils can be expressed by Langmuir equation, the saturation sorption capacities are 1150 (TMA-black soil), 750 (TMA-yellow-brown soil), 171 mg/kg (TMA-red soil), respectively. A diesel fuel oil degradation micro-organism (Pseudomonas sp.) was isolated in the lab. To test the influence of the modified soils on the micro-organism, various growth curves of Pseudomonas in different conditions were drawn. Pseudomonas can grow very well with natural soils and TMA modified soils. The acclimation period of Pseudomonas is reduced. As to HDTMA modified soils, HDTMA loading amount is very important. When HDTMA loading amount is no higher than 0.5 CEC, the micro-organism can grow very well after a long acclimation period.

  5. [Supervision of foods containing components of genetically modified organisms and the problems of labeling this type of products].

    PubMed

    Onishchenko, G G

    2010-01-01

    Commercial production of genetically modified (GM) crops as food or feed is regarded as a promising social area in the development of modern biotechnology. The Russian Federation has set up a governmental system to regulate the use of biotechnology products, which is based on Russian and foreign experience and the most up-to-date scientific approaches. The system for evaluating the quality and safety of GM foodstuffs envisages the postregistration monitoring of their circulation as an obligatory stage. For these purposes, the world community applies two methods: enzyme immunoassay and polymerase chain reaction. It should be noted that there are various approaches to GM food labeling in the world; this raises the question of whether the labeling of foods that are prepared from genetically modified organisms, but contain no protein or DNA is to be introduced in Russia, as in the European Union.

  6. Process for depositing thin film layers onto surfaces modified with organic functional groups and products formed thereby

    DOEpatents

    Tarasevich, B.J.; Rieke, P.C.

    1998-06-02

    A method is provided for producing a thin film product, comprising a first step in which an underlying substrate of a first material is provided. The underlying substrate includes a plurality of unmodified sites. The underlying substrate is then chemically modified wherein a plurality of organic functional groups are attached to a plurality of the unmodified sites. The arrangement and type of the functional group used can be selected for the purpose of controlling particular properties of the second material deposited. A thin film layer of at least one second material is then deposited onto the chemically modified underlying substrate. This can be accomplished by connecting the thin film to the underlying substrate by binding the thin film to the functional groups. 5 figs.

  7. Process for depositing thin film layers onto surfaces modified with organic functional groups and products formed thereby

    DOEpatents

    Tarasevich, Barbara J.; Rieke, Peter C.

    1998-01-01

    A method is provided for producing a thin film product, comprising a first step in which an underlying substrate of a first material is provided. The underlying substrate includes a plurality of unmodified sites. The underlying substrate is then chemically modified wherein a plurality of organic functional groups are attached to a plurality of the unmodified sites. The arrangement and type of the functional group used can be selected for the purpose of controlling particular properties of the second material deposited. A thin film layer of at least one second material is then deposited onto the chemically modified underlying substrate. This can be accomplished by connecting the thin film to the underlying substrate by binding the thin film to the functional groups.

  8. Using Riverine Natural Organic Matter to Test the Hypothesis that Soil Organic Matter is Modified by Contact with Sodium Hydroxide

    NASA Astrophysics Data System (ADS)

    Perdue, E. Michael; Driver, Shamus; Hertkorn, Norbert; Harir, Mourad; Schmitt-Kopplin, Philippe

    2016-04-01

    It has been postulated by some scientists that soil humic acids and fulvic acids are an artifact of alkaline extractions of soil. Riverine natural organic matter (NOM) is obtained in part by dissolution and transport of organic matter from soils by meteoric waters at acidic to circumneutral pH. The NOM may be fractionated into humic acid (HA), fulvic acid (FA), and hydrophilic NOM by adsorption of HA and FA onto XAD-8 resin at pH < 2, followed by their desorption with NaOH at pH 13. Alternatively, riverine NOM may be concentrated using reverse osmosis (RO) and desalted by cation exchange. Several properties of Suwannee River NOM prior to its isolation, after concentration by RO, and after the XAD-8 process are compared to detect modifications that might have resulted from exposure of the sample to low and high pH.

  9. [Labeling of food containing genetically modified organisms: international policies and Brazilian legislation].

    PubMed

    Costa, Thadeu Estevam Moreira Maramaldo; Marin, Victor Augustus

    2011-08-01

    The increase in surface area planted with genetically modified crops, with the subsequent transfer of such crops into the general environment for commercial trade, has raised questions about the safety of these products. The introduction of the Cartagena Protocol on Biosafety has led to the need to produce information and ensure training in this area for the implementation of policies on biosafety and for decision-making on the part of governments at the national, regional and international level. This article presents two main standpoints regarding the labeling of GM products (one adopted by the United States and the other by the European Union), as well as the position adopted by Brazil and its current legislation on labeling and commercial release of genetically modified (GM) products.

  10. Detection of Cry1Ab protein in gastrointestinal contents but not visceral organs of genetically modified Bt11-fed calves.

    PubMed

    Chowdhury, E H; Shimada, N; Murata, H; Mikami, O; Sultana, P; Miyazaki, S; Yoshioka, M; Yamanaka, N; Hirai, N; Nakajima, Y

    2003-03-01

    The fate of insecticidal Cry1Ab protein was examined in the gastrointestinal (GI) contents and visceral organs of calves fed insect-resistant genetically modified maize Bt11. Twelve cross-breed (Japanese black x Holstein) calves were fed either Bt11 or non-genetically modified isoline maize for 90 d. Peripheral blood, rumen juice and feces were collected fortnightly, and GI contents and visceral organs were collected at slaughter at the end of the experiment. Samples were checked for Cry1Ab protein by immunological methods, and visceral organs were examined pathologically. Trace amounts of Cry1Ab protein were detected in the GI contents but not in the liver, spleen, kidney, muscle or mesenteric lymph nodes. No lesions were observed pathologically. Cry1Ab protein in the feces was degraded quickly at atmospheric temperature. These results suggested that only a trace amount of Cry1Ab protein survived passage through the GI tract but was not transferred to liver, spleen, kidney, lymph nodes or muscles.

  11. Event-specific quantitative detection of nine genetically modified maizes using one novel standard reference molecule.

    PubMed

    Yang, Litao; Guo, Jinchao; Pan, Aihu; Zhang, Haibo; Zhang, Kewei; Wang, Zhengming; Zhang, Dabing

    2007-01-10

    With the development of genetically modified organism (GMO) detection techniques, the Polymerase Chain Reaction (PCR) technique has been the mainstay for GMO detection, and real-time PCR is the most effective and important method for GMO quantification. An event-specific detection strategy based on the unique and specific integration junction sequences between the host plant genome DNA and the integrated gene is being developed for its high specificity. This study establishes the event-specific detection methods for TC1507 and CBH351 maizes. In addition, the event-specific TaqMan real-time PCR detection methods for another seven GM maize events (Bt11, Bt176, GA21, MON810, MON863, NK603, and T25) were systematically optimized and developed. In these PCR assays, the fluorescent quencher, TAMRA, was dyed on the T-base of the probe at the internal position to improve the intensity of the fluorescent signal. To overcome the difficulties in obtaining the certified reference materials of these GM maizes, one novel standard reference molecule containing all nine specific integration junction sequences of these GM maizes and the maize endogenous reference gene, zSSIIb, was constructed and used for quantitative analysis. The limits of detection of these methods were 20 copies for these different GM maizes, the limits of quantitation were about 20 copies, and the dynamic ranges for quantification were from 0.05 to 100% in 100 ng of DNA template. Furthermore, nine groups of the mixed maize samples of these nine GM maize events were quantitatively analyzed to evaluate the accuracy and precision. The accuracy expressed as bias varied from 0.67 to 28.00% for the nine tested groups of GM maize samples, and the precision expressed as relative standard deviations was from 0.83 to 26.20%. All of these indicated that the established event-specific real-time PCR detection systems and the reference molecule in this study are suitable for the identification and quantification of these GM

  12. 46 CFR 52.25-10 - Organic fluid vaporizer generators (modifies PVG-1 through PVG-12).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-10 Organic fluid vaporizer generators... requirements of PVG-1 through PVG-12 of section I of the ASME Boiler and Pressure Vessel Code (incorporated...

  13. 46 CFR 52.25-10 - Organic fluid vaporizer generators (modifies PVG-1 through PVG-12).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-10 Organic fluid vaporizer generators... requirements of PVG-1 through PVG-12 of section I of the ASME Boiler and Pressure Vessel Code (incorporated...

  14. The fabrication of YBa2Cu3O7-x film by metal organic deposition using terpineol-modified trifluoroacetates

    NASA Astrophysics Data System (ADS)

    Ding, Fazhu; Gu, Hongwei; Li, Tao

    2008-09-01

    Dense and homogeneous superconductive YBa2Cu3O7-x (YBCO) thin films were grown epitaxially on single-crystal LaAlO3 (LAO) substrates by a new MOD method with terpineol-modified trifluoroacetic solution. The YBCO precursor solution incorporated with terpineol enabled a remarkable decrease in the organic pyrolysis process. The YBCO films have an onset critical temperature of 90 K and Jc (77 K, 0 T) of 3.8 MA cm-2. The addition of terpineol was suggested to be responsible for the smoother and low-stressed YBCO films.

  15. A new PCR-CGE (size and color) method for simultaneous detection of genetically modified maize events.

    PubMed

    Nadal, Anna; Coll, Anna; La Paz, Jose-Luis; Esteve, Teresa; Pla, Maria

    2006-10-01

    We present a novel multiplex PCR assay for simultaneous detection of multiple transgenic events in maize. Initially, five PCR primers pairs specific to events Bt11, GA21, MON810, and NK603, and Zea mays L. (alcohol dehydrogenase) were included. The event specificity was based on amplification of transgene/plant genome flanking regions, i.e., the same targets as for validated real-time PCR assays. These short and similarly sized amplicons were selected to achieve high and similar amplification efficiency for all targets; however, its unambiguous identification was a technical challenge. We achieved a clear distinction by a novel CGE approach that combined the identification by size and color (CGE-SC). In one single step, all five targets were amplified and specifically labeled with three different fluorescent dyes. The assay was specific and displayed an LOD of 0.1% of each genetically modified organism (GMO). Therefore, it was adequate to fulfill legal thresholds established, e.g., in the European Union. Our CGE-SC based strategy in combination with an adequate labeling design has the potential to simultaneously detect higher numbers of targets. As an example, we present the detection of up to eight targets in a single run. Multiplex PCR-CGE-SC only requires a conventional sequencer device and enables automation and high throughput. In addition, it proved to be transferable to a different laboratory. The number of authorized GMO events is rapidly growing; and the acreage of genetically modified (GM) varieties cultivated and commercialized worldwide is rapidly increasing. In this context, our multiplex PCR-CGE-SC can be suitable for screening GM contents in food.

  16. Published GMO studies find no evidence of harm when corrected for multiple comparisons.

    PubMed

    Panchin, Alexander Y; Tuzhikov, Alexander I

    2017-03-01

    A number of widely debated research articles claiming possible technology-related health concerns have influenced the public opinion on genetically modified food safety. We performed a statistical reanalysis and review of experimental data presented in some of these studies and found that quite often in contradiction with the authors' conclusions the data actually provides weak evidence of harm that cannot be differentiated from chance. In our opinion the problem of statistically unaccounted multiple comparisons has led to some of the most cited anti-genetically modified organism health claims in history. We hope this analysis puts the original results of these studies into proper context.

  17. Development and applicability of a ready-to-use PCR system for GMO screening.

    PubMed

    Rosa, Sabrina F; Gatto, Francesco; Angers-Loustau, Alexandre; Petrillo, Mauro; Kreysa, Joachim; Querci, Maddalena

    2016-06-15

    With the growing number of GMOs introduced to the market, testing laboratories have seen their workload increase significantly. Ready-to-use multi-target PCR-based detection systems, such as pre-spotted plates (PSP), reduce analysis time while increasing capacity. This paper describes the development and applicability to GMO testing of a screening strategy involving a PSP and its associated web-based Decision Support System. The screening PSP was developed to detect all GMOs authorized in the EU in one single PCR experiment, through the combination of 16 validated assays. The screening strategy was successfully challenged in a wide inter-laboratory study on real-life food/feed samples. The positive outcome of this study could result in the adoption of a PSP screening strategy across the EU; a step that would increase harmonization and quality of GMO testing in the EU. Furthermore, this system could represent a model for other official control areas where high-throughput DNA-based detection systems are needed.

  18. Organic Matter Loading Modifies the Microbial Community Responsible for Nitrogen Loss in Estuarine Sediments.

    PubMed

    Babbin, Andrew R; Jayakumar, Amal; Ward, Bess B

    2016-04-01

    Coastal marine sediments, as locations of substantial fixed nitrogen loss, are very important to the nitrogen budget and to the primary productivity of the oceans. Coastal sediment systems are also highly dynamic and subject to periodic natural and anthropogenic organic substrate additions. The response to organic matter by the microbial community involved in nitrogen loss processes was evaluated using mesocosms of Chesapeake Bay sediments. Over the course of a 50-day incubation, rates of anammox and denitrification were measured weekly using (15)N tracer incubations, and samples were collected for genetic analysis. Rates of both nitrogen loss processes and gene abundances associated with them corresponded loosely, probably because heterogeneities in sediments obscured a clear relationship. The rates of denitrification were stimulated more, and the fraction of nitrogen loss attributed to anammox slightly reduced, by the higher organic matter addition. Furthermore, the large organic matter pulse drove a significant and rapid shift in the denitrifier community composition as determined using a nirS microarray, indicating that the diversity of these organisms plays an essential role in responding to anthropogenic inputs. We also suggest that the proportion of nitrogen loss due to anammox in these coastal estuarine sediments may be underestimated due to temporal dynamics as well as from methodological artifacts related to conventional sediment slurry incubation approaches.

  19. Modified Anaerobic Digestion Model No.1 for dry and semi-dry anaerobic digestion of solid organic waste.

    PubMed

    Liotta, Flavia; Chatellier, Patrice; Esposito, Giovanni; Fabbricino, Massimiliano; Frunzo, Luigi; van Hullebusch, Eric D; Lens, Piet N L; Pirozzi, Francesco

    2015-01-01

    The role of total solids (TS) content in anaerobic digestion of selected complex organic matter, e.g. rice straw and food waste, was investigated. A range of TS from wet (4.5%) to dry (23%) was evaluated. A modified version of the Anaerobic Digestion Model No.1 for a complex organic substrate is proposed to take into account the effect of the TS content on anaerobic digestion. A linear function that correlates the kinetic constants of three specific processes (i.e. disintegration, acetate and propionate up-take) was included in the model. Results of biomethanation and volatile fatty acids production tests were used to calibrate the proposed model. Model simulations showed a good agreement between numerical and observed data.

  20. Removal of methyl orange on modified ostrich bone waste--a novel organic-inorganic biocomposite.

    PubMed

    Arshadi, M; Faraji, A R; Amiri, M J; Mehravar, M; Gil, A

    2015-05-15

    The synthesis and growth behavior of the chemically modified ostrich bone wastes as bioadsorbents for the removal of methyl orange from aqueous solutions have been investigated. The ostrich bone wastes were treated with cetyltrimethylammonium bromide (CTABr) and sodium dodecyl benzene sulfonate (SDBS). The synthesized biomaterials were characterized by several physicochemical techniques. The modified ostrich bone with CTABr was found to be effective as adsorbent for the removal of methyl orange (MO) from aqueous solutions. The effect of the experimental conditions on the adsorption behavior was studied by varying the contact time, initial MO concentration, temperature, initial pH, chemical modification process, and amount of adsorbent. The contact time to attain equilibrium for maximum adsorption (90%) was found to be 50 min. The adsorption kinetics of MO has been studied in terms of pseudo-first- and -second-order kinetics, and the Freundlich, Langmuir and Langmuir-Freundlich isotherm models have also been applied to the equilibrium adsorption data. The adsorption process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model.

  1. Growth of Fe-Pt Magnetic Nanoparticles on Silica Particles Modified with Organic Molecules

    NASA Astrophysics Data System (ADS)

    Kitamoto, Yoshitaka; Fuchigami, Teruaki; Namiki, Yoshihisa

    2013-11-01

    In the present paper, we describe the formation of an assembly composed of Fe-Pt magnetic nanoparticles on a template particle. The assembly is composed of a magnetic nanoshell for core/shell particles or hollow particles for application in nanomedicine devices. For this purpose, magnetic nanoparticles should be densely accumulated or deposited on template particles, Fe-Pt nanoparticles completely cover silica template particles by modifying them with a polymer such as poly(diallyldimethylammonium chloride) (PDDA), polyethyleneimine (PEI), or poly(N-vinyl-2-pyrrolidone) (PVP) followed by the polyol reduction of Fe and Pt compounds. Studies of their morphological, crystallographic, and magnetic properties reveal that Fe-Pt nanoparticles are selectively grown on the polymer-modified silica template particles; the polymer probably supplies nucleation sites for the formation of such nanoparticles. The species of polymer used strongly affects crystallographic and magnetic properties of the nanoparticles, particularly, the atomic ordering of Fe-Pt nanoparticles formed on silica template particles.

  2. Molecular dynamics simulations to aid the rational design of organic friction modifiers.

    PubMed

    Davidson, J E; Hinchley, S L; Harris, S G; Parkin, A; Parsons, S; Tasker, P A

    2006-12-01

    Molecular dynamics simulations were performed under conditions of constant volume and temperature and of constant pressure and temperature to elucidate the structure activity relationships of a series of non-ionic surfactant molecules derived from vegetable fat and employed as friction modifiers in commercial engine oils. The simulations show the extent to which intermolecular hydrogen bonding is important in determining the stability of the monolayer formed by the surfactant molecules and show that mono-alkanoyl glyceride molecules are able to pack more efficiently, forming significantly more intermolecular hydrogen bonds and occupying approximately half the volume needed by di-alkanoyl glyceride molecules. Density profiles are presented which show significant mixing of the hydrophobic tail groups and a non-polar solvent. The distribution of torsion angles in the tail groups shows that the conformation is consistent with a liquid at finite temperature rather than a crystal structure. The measured friction coefficients of equimolar solutions of the glycerides show that the efficacy as friction modifiers varies in the order mono-, di- and the tri-oleyl glyceride, which is consistent with the efficacy of film formation predicted by the molecular dynamics calculations.

  3. Development and in-house validation of the event-specific polymerase chain reaction detection methods for genetically modified soybean MON89788 based on the cloned integration flanking sequence.

    PubMed

    Liu, Jia; Guo, Jinchao; Zhang, Haibo; Li, Ning; Yang, Litao; Zhang, Dabing

    2009-11-25

    Various polymerase chain reaction (PCR) methods were developed for the execution of genetically modified organism (GMO) labeling policies, of which an event-specific PCR detection method based on the flanking sequence of exogenous integration is the primary trend in GMO detection due to its high specificity. In this study, the 5' and 3' flanking sequences of the exogenous integration of MON89788 soybean were revealed by thermal asymmetric interlaced PCR. The event-specific PCR primers and TaqMan probe were designed based upon the revealed 5' flanking sequence, and the qualitative and quantitative PCR assays were established employing these designed primers and probes. In qualitative PCR, the limit of detection (LOD) was about 0.01 ng of genomic DNA corresponding to 10 copies of haploid soybean genomic DNA. In the quantitative PCR assay, the LOD was as low as two haploid genome copies, and the limit of quantification was five haploid genome copies. Furthermore, the developed PCR methods were in-house validated by five researchers, and the validated results indicated that the developed event-specific PCR methods can be used for identification and quantification of MON89788 soybean and its derivates.

  4. Minimizing use of fish meal in sunshine bass diets using standard and new varieties of non-genetically modified soybeans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved plant ingredients are needed to support sustainable culture of carnivorous fish, such as hybrid striped bass (HSB). We are evaluating meals made from new strains of non-genetically-modified soybeans (non-GMO) with high protein and reduced anti-nutritional factors (ANFs) on HSB nutrient dige...

  5. Hyperdynamic sepsis modifies a PEEP-mediated redistribution in organ blood flows

    SciTech Connect

    Bersten, A.D.; Gnidec, A.A.; Rutledge, F.S.; Sibbald, W.J. )

    1990-05-01

    Changes in organ blood flow (Q) produced by 20 cm H2O positive end-expiratory pressure (PEEP) were measured before and after the induction of hyperdynamic sepsis in nine unanesthetized sheep. During the baseline nonseptic study, PEEP was associated with a 9% fall in thermodilution-measured systemic Q, although arterial perfusing pressures were unaffected. Concurrently, microsphere-derived Q was maintained to the brain and heart, but fell to liver, spleen, pancreas, kidney, large intestine, and gastrocnemius. Twenty-four to 36 h after cecal ligation and perforation, a pre-PEEP septic study demonstrated an increase in all of the cardiac index (CI) and systemic O2 delivery when compared with the nonseptic study, whereas whole-body O2 extraction was depressed. Although PEEP depressed systemic Q during the septic study to a greater extent than during the nonseptic study (p less than 0.02), absolute organ Q fell only to pancreas, liver, and spleen. Relative to the simultaneous fall in the CI, Q to some splanchnic organs was not depressed by PEEP to the same magnitude in the septic as in the nonseptic study. When an infusion of Ringer's lactate subsequently restored systemic Q to pre-PEEP septic levels, individual flows that had been depressed by PEEP were not restored. Furthermore, Q-kidney continued to fall, such that the postfluid Q-kidney (-19%) was significantly less than was demonstrated in the pre-PEEP septic study. We postulate that differences noted in the distribution of organ Q between the nonseptic and hyperdynamic septic studies after the application of PEEP were secondary to the vasculopathy of sepsis and/or an alteration in the function of specific organ microcirculations. However, these data do not address whether the changes in organ Q distribution after a PEEP-mediated depression in systemic Q during sepsis significantly restricted tissue DO2.

  6. In vitro apatite formation on organic polymers modified with a silane coupling reagent.

    PubMed

    Shirosaki, Yuki; Kubo, Masaaki; Takashima, Seisuke; Tsuru, Kanji; Hayakawa, Satoshi; Osaka, Akiyoshi

    2005-09-22

    Gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) was grafted to high-density polyethylene, polyamide and silicone rubber substrates by the emulsion polymerization procedure in order to provide these organic polymers with in vitro apatite-forming ability. The contact angles towards distilled water of the gamma-MPS-grafted specimens were lower than those of the original organic polymer specimens, indicating that the grafted substrates were more hydrophilic. The in vitro apatite formation in a simulated body fluid (Kokubo solution) was confirmed for several of the gamma-MPS-grafted specimens.

  7. In vitro apatite formation on organic polymers modified with a silane coupling reagent

    PubMed Central

    Shirosaki, Yuki; Kubo, Masaaki; Takashima, Seisuke; Tsuru, Kanji; Hayakawa, Satoshi; Osaka, Akiyoshi

    2005-01-01

    γ-Methacryloxypropyltrimethoxysilane (γ-MPS) was grafted to high-density polyethylene, polyamide and silicone rubber substrates by the emulsion polymerization procedure in order to provide these organic polymers with in vitro apatite-forming ability. The contact angles towards distilled water of the γ-MPS-grafted specimens were lower than those of the original organic polymer specimens, indicating that the grafted substrates were more hydrophilic. The in vitro apatite formation in a simulated body fluid (Kokubo solution) was confirmed for several of the γ-MPS-grafted specimens. PMID:16849191

  8. Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics.

    PubMed

    Kanibolotsky, Alexander L; Findlay, Neil J; Skabara, Peter J

    2015-01-01

    The aim of this review is to give an update on current progress in the synthesis, properties and applications of thiophene-based conjugated systems bearing tetrathiafulvalene (TTF) units. We focus mostly on the synthesis of poly- and oligothiophenes with TTF moieties fused to the thiophene units of the conjugated backbone either directly or via a dithiin ring. The electrochemical behaviour of these materials and structure-property relationships are discussed. The study is directed towards the development of a new type of organic semiconductors based on these hybrid materials for application in organic field effect transistors and solar cells.

  9. Optical tracking of organically modified silica nanoparticles as DNA carriers: a nonviral, nanomedicine approach for gene delivery.

    PubMed

    Roy, Indrajit; Ohulchanskyy, Tymish Y; Bharali, Dhruba J; Pudavar, Haridas E; Mistretta, Ruth A; Kaur, Navjot; Prasad, Paras N

    2005-01-11

    This article reports a multidisciplinary approach to produce fluorescently labeled organically modified silica nanoparticles as a nonviral vector for gene delivery and biophotonics methods to optically monitor intracellular trafficking and gene transfection. Highly monodispersed, stable aqueous suspensions of organically modified silica nanoparticles, encapsulating fluorescent dyes and surface functionalized by cationic-amino groups, are produced by micellar nanochemistry. Gel-electrophoresis studies reveal that the particles efficiently complex with DNA and protect it from enzymatic digestion of DNase 1. The electrostatic binding of DNA onto the surface of the nanoparticles, due to positively charged amino groups, is also shown by intercalating an appropriate dye into the DNA and observing the Forster (fluorescence) resonance energy transfer between the dye (energy donor) intercalated in DNA on the surface of nanoparticles and a second dye (energy acceptor) inside the nanoparticles. Imaging by fluorescence confocal microscopy shows that cells efficiently take up the nanoparticles in vitro in the cytoplasm, and the nanoparticles deliver DNA to the nucleus. The use of plasmid encoding enhanced GFP allowed us to demonstrate the process of gene transfection in cultured cells. Our work shows that the nanomedicine approach, with nanoparticles acting as a drug-delivery platform combining multiple optical and other types of probes, provides a promising direction for targeted therapy with enhanced efficacy as well as for real-time monitoring of drug action.

  10. Copper Contamination of Self-Assembled Organic Monolayer Modified Silicon Surfaces Following a "Click" Reaction Characterized with LAPS and SPIM.

    PubMed

    Wu, Fan; Zhang, De-Wen; Wang, Jian; Watkinson, Michael; Krause, Steffi

    2017-04-04

    A copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) reaction combined with microcontact printing was used successfully to pattern alkyne-terminated self-assembled organic monolayer-modified silicon surfaces. Despite the absence of a copper peak in X-ray photoelectron spectra, copper contamination was found and visualized using light-addressable potentiometric sensors (LAPS) and scanning photo-induced impedance microscopy (SPIM) after the "click"-modified silicon surfaces were rinsed with hydrochloric acid (HCl) solution, which was frequently used to remove copper residues in the past. Even cleaning with an ethylenediaminetetraacetic acid (EDTA) solution did not remove the copper residue completely. Different strategies for avoiding copper contamination, including the use of bulky chelators for the copper(I) catalyst and rinsing with different reagents, were tested. Only cleaning of the silicon surfaces with an EDTA solution containing trifluoroacetic acid (TFA) after the click modification proved to be an effective method as confirmed by LAPS and SPIM results, which showed the expected potential shift due to the surface charge introduced by functional groups in the monolayer and allowed, for the first time, imaging the impedance of an organic monolayer.

  11. Optical tracking of organically modified silica nanoparticles as DNA carriers: A nonviral, nanomedicine approach for gene delivery

    NASA Astrophysics Data System (ADS)

    Roy, Indrajit; Ohulchanskyy, Tymish Y.; Bharali, Dhruba J.; Pudavar, Haridas E.; Mistretta, Ruth A.; Kaur, Navjot; Prasad, Paras N.

    2005-01-01

    This article reports a multidisciplinary approach to produce fluorescently labeled organically modified silica nanoparticles as a nonviral vector for gene delivery and biophotonics methods to optically monitor intracellular trafficking and gene transfection. Highly monodispersed, stable aqueous suspensions of organically modified silica nanoparticles, encapsulating fluorescent dyes and surface functionalized by cationic-amino groups, are produced by micellar nanochemistry. Gel-electrophoresis studies reveal that the particles efficiently complex with DNA and protect it from enzymatic digestion of DNase 1. The electrostatic binding of DNA onto the surface of the nanoparticles, due to positively charged amino groups, is also shown by intercalating an appropriate dye into the DNA and observing the Förster (fluorescence) resonance energy transfer between the dye (energy donor) intercalated in DNA on the surface of nanoparticles and a second dye (energy acceptor) inside the nanoparticles. Imaging by fluorescence confocal microscopy shows that cells efficiently take up the nanoparticles in vitro in the cytoplasm, and the nanoparticles deliver DNA to the nucleus. The use of plasmid encoding enhanced GFP allowed us to demonstrate the process of gene transfection in cultured cells. Our work shows that the nanomedicine approach, with nanoparticles acting as a drug-delivery platform combining multiple optical and other types of probes, provides a promising direction for targeted therapy with enhanced efficacy as well as for real-time monitoring of drug action. nonviral vector | ORMOSIL nanoparticles | confocal microscopy

  12. History of safe use as applied to the safety assessment of novel foods and foods derived from genetically modified organisms.

    PubMed

    Constable, A; Jonas, D; Cockburn, A; Davi, A; Edwards, G; Hepburn, P; Herouet-Guicheney, C; Knowles, M; Moseley, B; Oberdörfer, R; Samuels, F

    2007-12-01

    Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and absence of evidence of harm, they are generally regarded as safe to eat. This 'history of safe use' of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria. The term should be regarded as a working concept used to assist the safety assessment of a food product. Important factors in establishing a history of safe use include: the period over which the traditional food has been consumed; the way in which it has been prepared and used and at what intake levels; its composition and the results of animal studies and observations from human exposure. This paper is aimed to assist food safety professionals in the safety evaluation and regulation of novel foods and foods derived from genetically modified organisms, by describing the practical application and use of the concept of 'history of safe use'.

  13. Genetically modified and organic crops in developing countries: a review of options for food security.

    PubMed

    Azadi, Hossein; Ho, Peter

    2010-01-01

    Since two decades ago, when the first GM crops were introduced, there have increasingly been hot debates on the applications of gene manipulation. Currently, the development of GM crop varieties has raised a wide range of new legal, ethical and economic questions in agriculture. There is a growing body of literature reflecting the socio-economic and environmental impacts of GM crops which aims to criticize their value for farming systems. While organic crops are promoted as environmentally-friendly products in developed countries, they have provoked great controversy in developing countries facing food security and a low agricultural productivity. Discussion has been especially vigorous when organic farming was introduced as an alternative method. There are in fact, a few tradeoffs in developing countries. On the one hand, farmers are encouraged to accept and implement GM crops because of their higher productivity, while on the other hand, organic farming is encouraged because of socio-economic and environmental considerations. A crucial question facing such countries is therefore, whether GM crops can co-exist with organic farming. This paper aims to review the main considerations and tradeoffs.

  14. Demonstration of Pelvic Anatomy by Modified Midline Transection that Maintains Intact Internal Pelvic Organs

    ERIC Educational Resources Information Center

    Steinke, Hanno; Saito, Toshiyuki; Herrmann, Gudrun; Miyaki, Takayoshi; Hammer, Niels; Sandrock, Mara; Itoh, Masahiro; Spanel-Borowski, Katharina

    2010-01-01

    Gross dissection for demonstrating anatomy of the human pelvis has traditionally involved one of two approaches, each with advantages and disadvantages. Classic hemisection in the median plane through the pelvic ring transects the visceral organs but maintains two symmetric pelvic halves. An alternative paramedial transection compromises one side…

  15. Statistical framework for detection of genetically modified organisms based on Next Generation Sequencing.

    PubMed

    Willems, Sander; Fraiture, Marie-Alice; Deforce, Dieter; De Keersmaecker, Sigrid C J; De Loose, Marc; Ruttink, Tom; Herman, Philippe; Van Nieuwerburgh, Filip; Roosens, Nancy

    2016-02-01

    Because the number and diversity of genetically modified (GM) crops has significantly increased, their analysis based on real-time PCR (qPCR) methods is becoming increasingly complex and laborious. While several pioneers already investigated Next Generation Sequencing (NGS) as an alternative to qPCR, its practical use has not been assessed for routine analysis. In this study a statistical framework was developed to predict the number of NGS reads needed to detect transgene sequences, to prove their integration into the host genome and to identify the specific transgene event in a sample with known composition. This framework was validated by applying it to experimental data from food matrices composed of pure GM rice, processed GM rice (noodles) or a 10% GM/non-GM rice mixture, revealing some influential factors. Finally, feasibility of NGS for routine analysis of GM crops was investigated by applying the framework to samples commonly encountered in routine analysis of GM crops.

  16. 20 Years of hypertension research using genetically modified animals: no clinically promising approaches in sight.

    PubMed

    Stingl, Lavinia; Völkel, Manfred; Lindl, Toni

    2009-01-01

    The incidence of essential or primary hypertension is increasing, especially in the northern hemisphere, but although the disease displays clear symptoms, its aetiology appears very complex, and thus no causal treatment is available yet. In the 1990's, genetically modified animals (GMO) were considered to be the key to solving this problem of high complexity. However, until now, although a few approaches have shown that old, well-known drugs have a positive effect (decrease of blood pressure) on such animal models of hypertension, no approach has appeared in the literature of this area of research which might indicate a direct connection between GMO and a therapeutic strategy to treat or prevent this type of hypertension in humans. Instead, criticism of the GMO approach has accumulated in the last years, arguing that it is misleading as this disease does not have a monogenic cause and so complementary regulatory mechanisms could prevent the true identification of the function of the modified genes. Furthermore, the technology is best developed in mice, whose physiology of blood pressure is different from that of humans. Because of species specificity, it is not easy to extrapolate the results from animal models of hypertension to human hypertension. Also, in the years 2000 to 2004 a reorientation of the technology and the aims of this kind of research took place. Therefore, although these approaches are without exception deemed "very promising" in the literature, it cannot be expected that research on GMO will make any contribution to a new therapeutic strategy in the near future.

  17. No need for conspiracy: self-organized cartel formation in a modified trust game.

    PubMed

    Peixoto, Tiago P; Bornholdt, Stefan

    2012-05-25

    We investigate the dynamics of a trust game on a mixed population, where individuals with the role of buyers are forced to play against a predetermined number of sellers whom they choose dynamically. Agents with the role of sellers are also allowed to adapt the level of value for money of their products, based on payoff. The dynamics undergoes a transition at a specific value of the strategy update rate, above which an emergent cartel organization is observed, where sellers have similar values of below-optimal value for money. This cartel organization is not due to an explicit collusion among agents; instead, it arises spontaneously from the maximization of the individual payoffs. This dynamics is marked by large fluctuations and a high degree of unpredictability for most of the parameter space and serves as a plausible qualitative explanation for observed elevated levels and fluctuations of certain commodity prices.

  18. No Need for Conspiracy: Self-Organized Cartel Formation in a Modified Trust Game

    NASA Astrophysics Data System (ADS)

    Peixoto, Tiago P.; Bornholdt, Stefan

    2012-05-01

    We investigate the dynamics of a trust game on a mixed population, where individuals with the role of buyers are forced to play against a predetermined number of sellers whom they choose dynamically. Agents with the role of sellers are also allowed to adapt the level of value for money of their products, based on payoff. The dynamics undergoes a transition at a specific value of the strategy update rate, above which an emergent cartel organization is observed, where sellers have similar values of below-optimal value for money. This cartel organization is not due to an explicit collusion among agents; instead, it arises spontaneously from the maximization of the individual payoffs. This dynamics is marked by large fluctuations and a high degree of unpredictability for most of the parameter space and serves as a plausible qualitative explanation for observed elevated levels and fluctuations of certain commodity prices.

  19. The use of GMOs (genetically modified organisms): agricultural biotechnology or agricultural biopolitics?

    PubMed

    Nuti, Marco; Felici, Cristiana; Agnolucci, Monica

    2007-01-01

    Agricultural biotechnologies embrace a large array of conventional and modern technologies, spanning from composting organic by-products of agriculture to innovative improvement of quality traits of about twenty out of the mostly cultivated plants. In EU a rather restrictive legislative framework has been installed for GMOs, requiring a risk assessment disproportionate with respect to conventional agriculture and organic farming products. The latter are far from being proved safe for human and animal health, and for the environment. Biotechnology of GMOs has been overtaken by biopolitics. On one side there are biotechnological challenges to be tackled, on another side there is plenty of ground for biopolitical decisions about GMOs. Perhaps the era of harsh confrontation could be fruitfully replaced by sensible cooperation, in order to get a sustainable agricultural development.

  20. Poly(sulfobetaine methacrylate)s as electrode modifiers for inverted organic electronics.

    PubMed

    Lee, Hyunbok; Puodziukynaite, Egle; Zhang, Yue; Stephenson, John C; Richter, Lee J; Fischer, Daniel A; DeLongchamp, Dean M; Emrick, Todd; Briseno, Alejandro L

    2015-01-14

    We demonstrate the use of poly(sulfobetaine methacrylate) (PSBMA), and its pyrene-containing copolymer, as solution-processable work function reducers for inverted organic electronic devices. A notable feature of PSBMA is its orthogonal solubility relative to solvents typically employed in the processing of organic semiconductors. A strong permanent dipole moment on the sulfobetaine moiety was calculated by density functional theory. PSBMA interlayers reduced the work function of metals, graphene, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by over 1 eV, and an ultrathin interlayer of PSBMA reduced the electron injection barrier between indium tin oxide (ITO) and C70 by 0.67 eV. As a result, the performance of organic photovoltaic devices with PSBMA interlayers is significantly improved, and enhanced electron injection is demonstrated in electron-only devices with ITO, PEDOT:PSS, and graphene electrodes. This work makes available a new class of dipole-rich, counterion-free, pH insensitive polymer interlayers with demonstrated effectiveness in inverted devices.

  1. Model studies on the detectability of genetically modified feeds in milk.

    PubMed

    Poms, R E; Hochsteiner, W; Luger, K; Glössl, J; Foissy, H

    2003-02-01

    Detecting the use of genetically modified feeds in milk has become important, because the voluntary labeling of milk and dairy products as "GMO free" or as "organically grown" prohibits the employment of genetically modified organisms (GMOs). The aim of this work was to investigate whether a DNA transfer from foodstuffs like soya and maize was analytically detectable in cow's milk after digestion and transportation via the bloodstream of dairy cows and, thus, whether milk could report for the employment of transgene feeds. Blood, milk, urine, and feces of dairy cows were examined, and foreign DNA was detected by polymerase chain reaction by specifically amplifying a 226-bp fragment of the maize invertase gene and a 118-bp fragment of the soya lectin gene. An intravenous application of purified plant DNA showed a fast elimination of marker DNA in blood or its reduction below the detection limit. With feeding experiments, it could be demonstrated that a specific DNA transfer from feeds into milk was not detectable. Therefore, foreign DNA in milk cannot serve as an indicator for the employment of transgene feeds unless milk is directly contaminated with feed components or airborne feed particles.

  2. Microbead-assisted PDA sensor for the detection of genetically modified organisms.

    PubMed

    Lim, Min-Cheol; Shin, Yeo-Jae; Jeon, Tae-Joon; Kim, Hae-Yeong; Kim, Young-Rok

    2011-05-01

    A simple and sensitive approach for the detection of marker protein, phosphinothricin acetyltransferase, from genetically modified crops was developed based on the colorimetric transition of polydiacetylene (PDA) vesicles in combination with silica microbeads. PDAs have attracted a great deal of interests as a transducing material due to their special features that allow colorimetric response to sensory signals, as well as their inherent simplicity. However, most PDA-based biosensors require additional analytical equipment such as a fluorescence microscope or UV-Vis spectrometer. In this study, we report a new approach to increase the degree of color transition by coupling antibody-conjugated PDA vesicles with silica microbeads in an effort to monitor the results with the unaided eye or simple RGB analysis. By immobilizing PDA vesicles on silica microbeads, we were able to overcome the disadvantages of colloidal PDA-based sensors and increase the degree of colorimetric changes in response to target molecules to a concentration as low as 20 nM. The additional stresses were given to PDA vesicles by antigen-antibody bridging of PDA vesicles coupled with microbeads, resulting in enhanced blue-red color transition. All the results showed that PDA vesicles in conjunction with silica microbeads will be a promising transducing material for the detection of target proteins in diagnostic and biosensing applications.

  3. Key elements in a strategic approach to capacity building in the biosafety of genetically modified organisms.

    PubMed

    Araya-Quesada, Marianela; Degrassi, Giuliano; Ripandelli, Decio; Craig, Wendy

    2010-01-01

    In recent times, it has become imperative for countries to define and implement policy in biosafety due to the widespread adoption of genetically modified crops. As such, countries wishing to utilise transgenic technologies in the development of advanced agricultural products must have regulations in place coupled with trained personnel in national competent authorities able to contribute effectively to the decision-making process. Capacity building initiatives play an important role in supporting such individuals, institutions and governmental authorities by providing training and/or physical structures/equipment and technical assistance. There are many types of capacity building activities; however not all have the same relevance in different regions of the world. For capacity building to be effective, a strategic approach incorporating a variety of forms and disciplines is desired. This commentary discusses the importance of factors such as: the targeting of support to relevant beneficiary(ies); the identification of specific needs and the incorporation of socio-economic conditions when elaborating effective strategies designed to help building capacity. Moreover, the importance of interaction and collaboration amongst the various capacity builders is also discussed such that unnecessary duplication of efforts and best use of available human and economic resources results.

  4. Effect of organic matter strength on anammox for modified greenhouse turtle breeding wastewater treatment.

    PubMed

    Chen, Chongjun; Huang, Xiaoxiao; Lei, Chenxiao; Zhang, Tian C; Wu, Weixiang

    2013-11-01

    Anaerobic ammonium-N removal from modified greenhouse turtle breeding wastewater with different chemical oxygen demand (COD) strengths (194.0-577.8 mg L(-1)) at relatively fixed C/N ratios (≈ 2) was investigated using a lab-scale up-flow anaerobic sludge blanket (UASB) anammox reactor. During the entire experiment, the total nitrogen (TN) removal efficiency was about 85% or higher, while the average COD removal efficiency was around 56.5 ± 7.9%. Based on the nitrogen and carbon balance, the nitrogen removal contribution was 79.6 ± 4.2% for anammox, 12.7 ± 3.0% for denitrification+denitritation and 7.7 ± 4.9% for other mechanisms. Denaturing gradient gel electrophoresis (DGGE) analyses revealed that Planctomycete, Proteobacteria and Chloroflexi bacteria were coexisted in the reactor. Anammox was always dominant when the reactor was fed with different COD concentrations, which indicated the stability of the anammox process with the coexistence of the denitrification process in treating greenhouse turtle breeding wastewater.

  5. [Transport of large organic ions through syringomycin channels in the membranes containing dipole modifiers].

    PubMed

    Efimova, S S; Ostroumova, O S; Malev, V V; Shchagina, L V

    2011-01-01

    The effect of the membrane dipole potential (Phid) on a conductance and a steady-state number of functioning channels formed by cyclic lipodepsipeptide syringomycin E (SRE) in bilayer lipid membranes made from phosphocholine and bathed in 0.4 M solution of sodium salts of aspartate, gluconate and chloride was shown. The magnitude of Phid was varied with the introduction to membrane bathing solutions of phloretin, which reduces the Phid, and RH 421, increasing the Phid. It was established that in all studied systems the increase in the membrane dipole potential cause a decrease in the steady-state number of open channels. In the systems containing sodium salts of aspartate (Asp) or gluconate (Glc), changes in the number of functioning channels are in an order of magnitude smaller than in systems containing sodium chloride. At the same time, the conductance (g) of single SRE-channels on the membranes bathed in NaCI solution increases with the increase in Phid, and in the systems containing NaAsp or NaGlc the conductance of single channels does not depend on the Phid. The latter is due to the lack of cation/anion selectivity of the SRE-channels in these systems. The different channel-forming activity of SRE in the experimental systems is defined by the gating charge of the channel and the partition coefficient of the dipole modifiers between the lipid and aqueous phases.

  6. Detection of genetically modified organisms in foreign-made processed foods containing corn and potato.

    PubMed

    Monma, Kimio; Araki, Rie; Sagi, Naoki; Satoh, Masaki; Ichikawa, Hisatsugu; Satoh, Kazue; Tobe, Takashi; Kamata, Kunihiro; Hino, Akihiro; Saito, Kazuo

    2005-06-01

    Investigations of the validity of labeling regarding genetically modified (GM) products were conducted using polymerase chain reaction (PCR) methods for foreign-made processed foods made from corn and potato purchased in the Tokyo area and in the USA. Several kinds of GM crops were detected in 12 of 32 samples of processed corn samples. More than two GM events for which safety reviews have been completed in Japan were simultaneously detected in 10 samples. GM events MON810 and Bt11 were most frequently detected in the samples by qualitative PCR methods. MON810 was detected in 11 of the 12 samples, and Bt11 was detected in 6 of the 12 samples. In addition, Roundup Ready soy was detected in one of the 12 samples. On the other hand, CBH351, for which the safety assessment was withdrawn in Japan, was not detected in any of the 12 samples. A trial quantitative analysis was performed on six of the GM maize qualitatively positive samples. The estimated amounts of GM maize in these samples ranged from 0.2 to 2.8%, except for one sample, which contained 24.1%. For this sample, the total amount found by event-specific quantitative analysis was 23.8%. Additionally, Roundup Ready soy was detected in one sample of 21 potato-processed foods, although GM potatoes were not detected in any sample.

  7. The ZNF217 oncogene is a candidate organizer of repressive histone modifiers

    PubMed Central

    Banck, Michaela S.; Li, Side; Nishio, Hitomi; Wang, Cheng; Beutler, Andreas S.; Walsh, Martin J.

    2010-01-01

    The zinc finger protein 217 (ZNF217) is an important oncogene based on the high frequency of amplification and overexpression in many cancer types, but its molecular mode of gene regulation is poorly understood. We purified a complex of nuclear ZNF217-binding proteins by affinity chromatography and identified its components by mass spectrometry as Jarid1b/Plu-1, G9a, LSD1, CoREST and CtBP1. Individual binding of these with ZNF217 was confirmed by co-immunoprecipiation (IP). Known activities of these proteins suggested a role of the ZNF217 complex in histone modification. Using in vitro assays the following activities were demonstrated: Histone H3 lysine 4 trimethyl (H3K4me3) demethylase activity, which co-fractionated with Jarid1b/Plu-1 in anion-exchange chromatography; H3K9 methylation, the known principal activity of G9a; and H3K27 methylation. The latter suggested EZH2 as another ZNF217 binding candidate, which could be confirmed by co-IP. Taken together, these findings suggest that ZNF217 assembles a distinct set of histone modifying proteins at target DNA sites that act synergistically in transcriptional repression. PMID:19242095

  8. Modified spontaneous emission of organic molecules in-filled in inverse opals.

    PubMed

    Deng, Lier; Wang, Yongsheng; He, Dawei

    2011-11-01

    Inverse opals were prepared by replication of colloidal crystal templates made from silica spheres 298 nm in diameter. The air between the silica spheres was filled with the mixture of the monomer poly(methyl methacrylate) (PMMA) and the organic molecule Alq3 that can be subsequently polymerized. After removing the silica sphere templates, the photonic bandgap effect on the spontaneous emission of Alq3 were investigated. The dip in the fluorescence spectrum was interpreted in terms of redistribution of the photon density of states in the photonic crystal.

  9. Organic photovoltaic solar cells with cathode modified by ZnO.

    PubMed

    Kim, Hyeong Pil; Yusoff, Abd Rashid Bin Mohd; Jang, Jin

    2013-07-01

    Solution processed cathode organic photovoltaic cells (OPVs) utilizing thin layer of ZnO with 27% increase in power conversion efficiency (PCE) to control devices have been demonstrated. Devices without the presence of ZnO layer have much lower PCE than the ones with ZnO layer. Cathode modification layer can be used to reduce photogenerated excitions and finally improve the performance of the OPVs. The successful demonstrations of OPVs with an introduction of ZnO cathode layer give promise of further device progresses.

  10. High-performance tandem organic light-emitting diodes based on a buffer-modified p/n-type planar organic heterojunction as charge generation layer

    NASA Astrophysics Data System (ADS)

    Wu, Yukun; Sun, Ying; Qin, Houyun; Hu, Shoucheng; Wu, Qingyang; Zhao, Yi

    2017-04-01

    High-performance tandem organic light-emitting diodes (TOLEDs) were realized using a buffer-modified p/n-type planar organic heterojunction (OHJ) as charge generation layer (CGL) consisting of common organic materials, and the configuration of this p/n-type CGL was "LiF/N,N'-diphenyl-N,N'-bis(1-napthyl)-1,1'-biphenyl-4,4'-diamine (NPB)/4,7-diphenyl-1,10-phenanthroline (Bphen)/molybdenum oxide (MoOx)". The optimized TOLED exhibited a maximum current efficiency of 77.6 cd/A without any out-coupling techniques, and the efficiency roll-off was greatly improved compared to the single-unit OLED. The working mechanism of the p/n-type CGL was discussed in detail. It is found that the NPB/Bphen heterojunction generated enough charges under a forward applied voltage and the carrier extraction was a tunneling process. These results could provide a new method to fabricate high-performance TOLEDs.

  11. Biological activity of insulin in GMO gels and the effect of agitation.

    PubMed

    Sadhale, Y; Shah, J C

    1999-11-25

    Glyceryl monooleate (GMO)-water cubic phase gel was previously shown to protect insulin from agitation induced aggregation. However, it is not known if insulin is biologically active in the gel and what effect agitation has on insulin in the gel. Therefore, the objective was to determine the stability of insulin in cubic phase gel in terms of its biological activity in a suitable animal model such as Sprague-Dawley rats. Effect of agitation on biological activity of insulin in cubic phase GMO gel was determined by subcutaneous injections of the agitated and non-agitated gels to two groups of previously fasted rats and measuring the effect on their blood glucose levels. Two groups of rats administered with agitated insulin solution and normal saline were used as controls. The biological activity of insulin was evaluated by comparing AAC (area above the blood glucose level-time curve, in %-h), C(max) (maximum % decrease in blood glucose levels) and t(max) (time required to attain C(max), in h) values for the four groups of rats. Since cubic phase gel is highly viscous, therapeutic equivalency of insulin in the lamellar phase gel, which converts in situ into cubic phase gel, was compared to insulin solution with normal saline as the control, using AAC, C(max) and t(max) of the blood glucose profile. Insulin was biologically active in both agitated and non-agitated gels; however, upon agitation, insulin in solution totally lost its hypoglycemic activity. Agitation of insulin in the cubic phase gel was seen to have very little deleterious effect on its biological activity. Insulin in the lamellar phase gel was not only biologically active but also therapeutically equivalent to insulin solution based on AAC (327.9+/-100.8 and 431.7+/-113.3), C(max) (57. 1+/-7.0 and 70.2+/-6.5) and t(max) (2.8+/-0.7 and 4.0+/-1.7) for the lamellar phase gel and insulin solution, respectively (no significant difference, P0.05). In summary, GMO cubic phase gel protected insulin from

  12. Organic photovoltaic cells with stable top metal electrodes modified with polyethylenimine.

    PubMed

    Khan, Talha M; Zhou, Yinhua; Dindar, Amir; Shim, Jae Won; Fuentes-Hernandez, Canek; Kippelen, Bernard

    2014-05-14

    Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin layer of the amine-containing nonconjugated polymer, polyethylenimine (PEIE), between the photoactive organic semiconductor layer and stable metal electrodes such as aluminum, silver, or gold. Devices with structure ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene):indene-C60-bis-adduct (P3HT:ICBA)/PEIE/Al demonstrated overall photovoltaic device performance comparable to devices containing calcium electron-collecting electrodes, ITO/PEDOT:PSS/P3HT:ICBA/Ca/Al, with open-circuit voltage of 775±6 mV, short-circuit current density of 9.1±0.5 mA cm(-2), fill factor of 0.65±0.01, and power conversion efficiency of 4.6±0.3%, averaged over 5 devices at 1 sun.

  13. Empirical Calculations of {sup 29}Si NMR Chemical Shielding Tensors: A Partial Charge Model Investigation of Hydrolysis in Organically Modified Alkoxy Silanes

    SciTech Connect

    Alam, Todd M.; Henry, Marc

    1999-08-05

    Organically modified alkoxy silanes play an important role in tailoring different properties of silica produced by the sol-gel method. Changes in the size and functionality of the organic group allows control of both physical and chemical properties of the resulting gel, with the kinetics of the polymerization process playing an important role in the design of new siloxane materials. High resolution {sup 29}Si NMR has proven to be valuable tool for monitoring the polymerization reaction, and has been used to investigate a variety of organically modified alkoxy silane systems.

  14. Modified natural clinoptilolite detoxifies small mammal's organism loaded with lead II: genetic, cell, and physiological effects.

    PubMed

    Topashka-Ancheva, Margarita; Beltcheva, Michaela; Metcheva, Roumiana; Rojas, J Antonio Heredia; Rodriguez-De la Fuente, Abraham O; Gerasimova, Tsvetelina; Rodríguez-Flores, Laura E; Teodorova, Svetla E

    2012-06-01

    The detoxification capacity of the clinoptilolite modification KLS-10-MA used as food additive in small mammals, chronically lead-exposed, was proven for the first time. The modified clinoptilolite was prepared based on natural Bulgarian clinoptilolite deposits. As a powder, it was mechanically mixed at 12.5% concentration with the conventional forage for small rodents. Lead in the form of aqueous solution of Pb(NO(3))(2) was diluted in the drinking water. In the ecotoxicological experiment covering 90 days, imprinting control region laboratory mice were used. They were allocated into four groups: group 1, (control): animals fed with conventional food for small rodents and water; group 2: animals fed with conventional food + clinosorbent KLS-10-MA and water; group 3: animals fed with conventional food and water + Pb(NO(3))(2); and group 4: animals fed with conventional food + KLS-10-MA and water + Pb(NO(3))(2). A group of non-exposed healthy animals was fed with conventional forage mixed with KLS-10-MA to prove eventual toxicity of the sorbent and influence on growth performance. The changes in the chromosome structure, mitotic index, erythrocyte form, erythropoiesis, and body weight gain were recorded. On day 90, the following relations were established: Pb-exposed and clinoptilolite-supplemented mice exhibited 2.3-fold lower chromosome aberrations frequency, 2.5-fold higher mitotic index, and 1.5-fold higher percentage normal erythrocytes 1.3-fold higher body weight compared to Pb-exposed and unsupplemented animals. The obtained data showed that the sorbent is practically non-toxic. The results of the present study encourage a further elaboration of a reliable drug based on the tested substance in the cases of chronic lead intoxication.

  15. Uptake and toxic effects of surface modified nanomaterials in freshwater aquatic organisms

    NASA Astrophysics Data System (ADS)

    Seda, Brandon Casey

    Nanomaterials are a class of materials with unique properties due to their size, and the association of these properties with the toxicity of nanomaterials is poorly understood. The present study assessed the toxic effects of stable aqueous colloidal suspensions of three distinctly different classes of nanomaterials in aquatic organisms. The fullerene, C70, was stabilized through non-covalent surface modification with gallic acid. Toxicity of C70-gallic acid was confirmed to exhibit similar toxic effects as C60-fullerene, including changes in antioxidative processes in Daphnia magna. Daphnia magna fecundity was significantly reduced in 21d bioassays at C70-gallic concentrations below quantifiable limits (0.03 mg/L C70). Antioxidant enzyme activities of glutathione peroxidase and superoxide dismutase as well as lipid peroxidation suggested that exposed organisms experienced oxidative stress. Carbon dots are a class of nanomaterials proposed for use as nontoxic alternatives to semiconductor quantum dots for photoluminescent applications, because of the difference in toxicity of their core components: carbon as opposed to heavy metals. In vivo analysis of treated organisms by confocal fluorescence microscopy revealed carbon dots were absorbed and systemically distributed regardless of particle size. The present study did not find any evidence of acute toxicity at concentrations up to 10mg/L carbon dots. These concentrations also failed to produce negative effects in Ceriodaphnia dubia bioassays to predict chronic toxicity. Carbon dots also failed to elicit developmental toxic effects in zebrafish. The toxic effects of semiconductor quantum dots have been partially attributed to the release of heavy metals with their degradation, particularly cadmium. Laser ablation inductively coupled mass spectrometry was used to compare the uptake of cadmium, selenium and zinc in Daphnia magna treated to CdSe/ZnS quantum dots or CdCl2. These quantum dots were observed to accumulate

  16. Photophysical properties of luminescent silicon nanoparticles surface-modified with organic molecules via hydrosilylation.

    PubMed

    Miyano, Mari; Kitagawa, Yuichi; Wada, Satoshi; Kawashima, Akira; Nakajima, Ayako; Nakanishi, Takayuki; Ishioka, Junya; Shibayama, Tamaki; Watanabe, Seiichi; Hasegawa, Yasuchika

    2016-01-01

    Luminescent silicon nanoparticles have attracted considerable attention for their potential uses in various applications. Many approaches have been reported to protect the surface of silicon nanoparticles and prevent their easy oxidation. Various air-stable luminescent silicon nanoparticles have been successfully prepared. However, the effect of interactions of the π-electron system with the silicon surface on the excited state properties of silicon nanoparticles is unclear. In this study, we have successfully prepared silicon nanoparticles protected with three organic compounds (styrene, 1-decene, and 1-vinyl naphthalene) and have examined their photophysical properties. The ligand π-electron systems on the silicon surface promoted the light harvesting ability for the luminescence through a charge transfer transition between the protective molecules and silicon nanoparticles and also enhanced the radiative rate of the silicon nanoparticles.

  17. The assessment of DNA from marine organisms via a modified salting-out protocol.

    PubMed

    Ferrara, Giovanni Battista; Murgia, Barbara; Parodi, Anna Maria; Valisano, Laura; Cerrano, Carlo; Palmisano, Giulio; Bavestrello, Giorgio; Sara, Michele

    2006-01-01

    We developed a rapid, practical and non-toxic salting-out method for the extraction of DNA from marine organisms, and tested it on two representative species of Porifera and Cnidaria, both living in association with symbiotic zooxanthellae. We tested the efficiency of the protocol by comparing the output of the method for fresh tissue, frozen tissue and tissue stored in ethanol. It proved to be effective for extracting DNA in the case of the methods of preservation considered here, and for obtaining quantities of DNA comparable to those obtained via the traditional approach. The DNA from both species was of good quality. The DNA obtained was amplified by PCR using specific primers for the large ribosomal subunit, allowing the identification of the presence of both the host and symbiont genomes.

  18. Removing organic contaminants with bifunctional iron modified rectorite as efficient adsorbent and visible light photo-Fenton catalyst.

    PubMed

    Zhao, Xiaorong; Zhu, Lihua; Zhang, Yingying; Yan, Jingchun; Lu, Xiaohua; Huang, Yingping; Tang, Heqing

    2012-05-15

    Iron-modified rectorite (FeR) was prepared as both adsorbent and catalyst. The iron modification increased layer-to-layer spacing and surface area of rectorite, leading to much increased adsorption of Rhodamine B (RhB) on rectorite. The maximum adsorption capacity of RhB on FeR reached 101mgg(-1) at pH 4.5, being 11 folds of that on the unmodified one. The iron modification also enabled rectorite to have efficient visible light photocatalytic ability. The apparent rate constant for the degradation of RhB (80μM) at 298K and pH 4.5 in the presence of H(2)O(2) (6.0mM) and FeR (0.4gL(-1)) was evaluated to be 0.0413min(-1) under visible light and 0.122min(-1) under sunlight, respectively. The analysis with electron spin resonance spin-trapping technique supported that the iron modified rectorite effectively catalyzed the decomposition of H(2)O(2) into hydroxyl radicals. On the basis of the characterization and analysis, the new bifunctional material was well clarified as both adsorbent and photocatalyst in the removing of organic pollutants.

  19. Collaborative ring trial of the papaya endogenous reference gene and its polymerase chain reaction assays for genetically modified organism analysis.

    PubMed

    Wei, Jiaojun; Li, Feiwu; Guo, Jinchao; Li, Xiang; Xu, Junfeng; Wu, Gang; Zhang, Dabing; Yang, Litao

    2013-11-27

    The papaya (Carica papaya L.) Chymopapain (CHY) gene has been reported as a suitable endogenous reference gene for genetically modified (GM) papaya detection in previous studies. Herein, we further validated the use of the CHY gene and its qualitative and quantitative polymerase chain reaction (PCR) assays through an interlaboratory collaborative ring trial. A total of 12 laboratories working on detection of genetically modified organisms participated in the ring trial and returned test results. Statistical analysis of the returned results confirmed the species specificity, low heterogeneity, and single-copy number of the CHY gene among different papaya varieties. The limit of detection of the CHY qualitative PCR assay was 0.1%, while the limit of quantification of the quantitative PCR assay was ∼25 copies of haploid papaya genome with acceptable PCR efficiency and linearity. The differences between the tested and true values of papaya content in 10 blind samples ranged from 0.84 to 6.58%. These results indicated that the CHY gene was suitable as an endogenous reference gene for the identification and quantification of GM papaya.

  20. Effects of tobacco genetically modified to express protease inhibitor bovine spleen trypsin inhibitor on non-target soil organisms.

    PubMed

    O'Callaghan, Maureen; Brownbridge, Michael; Stilwell, Wendy B; Gerard, Emily M; Burgess, Elisabeth P J; Barraclough, Emma I; Christeller, John T

    2007-01-01

    Effects of tobacco genetically modified to express the protease inhibitor bovine spleen trypsin inhibitor (BSTI) were examined in laboratory assays against three earthworm and one collembolan species. BSTI is a serine protease inhibitor that can bind to the digestive trypsins of insects feeding on modified plants, resulting in reduced growth and survival. Protease inhibitors are active against a broad range of insects, so may have a large impact on non-target organisms. Survival and fecundity of the collembolan Folsomia candida were unaffected by consumption of artificial diet containing BSTI-expressing tobacco leaf or powdered freeze-dried BSTI-expressing tobacco leaf that was added to soil. Similarly, mortality and growth of earthworms Aporrectodea caliginosa and Lumbricus rubellus did not differ significantly between soil augmented with BSTI-expressing tobacco leaves or unmodified control leaves. The redworm Eisenia fetida gained less weight when provided with BSTI-expressing leaves in one assay, but when the experiment was repeated, there was no significant difference between treatments. BSTI-expressing tobacco and unmodified control leaves decomposed at the same rate, indicating that the inhibitor had no effect on the overall function of the decomposer community of micro-flora and fauna in soil.

  1. Electrochemically assisted fabrication of size-exclusion films of organically modified silica and application to the voltammetry of phospholipids

    PubMed Central

    Mehdi, B. Layla; Rutkowska, Iwona A.; Kulesza, Pawel J.

    2013-01-01

    Modification of electrodes with nm-scale organically modified silica films with pores diameters controlled at 10- and 50-nm is described. An oxidation catalyst, mixed-valence ruthenium oxide with cyano crosslinks or gold nanoparticles protected by dirhodium-substituted phosophomolybdate (AuNP-Rh2PMo11), was immobilized in the pores. These systems comprise size-exclusion films at which the biological compounds, phosphatidylcholine and cardiolipin, were electrocatalytically oxidized without interference from surface-active concomitants such as bovine serum albumin. 10-nm pores were obtained by adding generation-4 poly(amidoamine) dendrimer, G4-PAMAM, to a (CH3)3SiOCH3 sol. 50-nm pores were obtained by modifying a glassy carbon electrode (GC) with a sub-monolayer film of aminopropyltriethoxylsilane, attaching 50-nm diameter poly(styrene sulfonate), PSS, spheres to the protonated amine, transferring this electrode to a (CH3)3SiOCH3 sol, and electrochemically generating hydronium at uncoated GC sites, which catalyzed ormosil growth around the PSS. Voltammetry of Fe(CN)63− and Ru(NH3)63+ demonstrated the absence of residual charge after removal of the templating agents. With the 50-nm system, the pore structure was sufficiently defined to use layer-by-layer electrostatic assembly of AuNP-Rh2PMo11 therein. Flow injection amperometry of phosphatidylcholine and cardiolipin demonstrated analytical utility of these electrodes. PMID:23935394

  2. Air-processable silane-coupled polymers to modify a dielectric for solution-processed organic semiconductors.

    PubMed

    Jang, Mi; Yu, Young Chang; Jeon, Hyeonyeol; Youk, Ji Ho; Yang, Hoichang

    2015-03-11

    Poly(styrene-r-3-methacryloxypropyltrimethoxysilane) (PSMPTS) copolymers were synthesized by the free radical polymerization of styrene and 3-methacryloxypropyltrimethoxysilane (MPTS) for use as surface modifiers. PSMPTS copolymers were spun-cast onto a hydrophilic SiO2 layer and were then annealed at 150 °C in ambient air. The polystyrene (PS)-based copolymer, with a molecular weight of 32 700 g mol(-1) and approximately 30 MPTS coupling sites, was easily grafted onto the SiO2 surface after annealing periods longer than 1 min, yielding a physicochemically stable layer. On the untreated and polymer-treated dielectrics, spin-casting of an ultrasonicated poly(3-hexyl thiophene) (P3HT) solution yielded highly interconnected crystal nanofibrils of P3HT. The resulting organic field-effect transistors (OFETs) showed similar mobility values of 0.01-0.012 cm(2) V(-1) s(-1) for all surfaces. However, the threshold voltage (Vth) drastically decreased from +13 (for bare SiO2) to 0 V by grafting the PSMPTS copolymers to the SiO2 surface. In particular, the interfacial charge traps that affect Vth were minimized by grafting the 11 mol % MPTS-loaded copolymer to the polar dielectric surface. We believe that this ambient-air-processable silane-coupled copolymer can be used as a solution-based surface modifier for continuous, large-scale OFET fabrication.

  3. A modified method for the determination of chemical oxygen demand (COD) for samples with high salinity and low organics.

    PubMed

    Vyrides, I; Stuckey, D C

    2009-01-01

    This study proposes a modification to the standard method for the determination of the chemical oxygen demand of samples with a salinity up to 40 g NaCl/L and low organic concentrations (20-230 mg COD/L). The masking of chloride by the use of a HgSO(4):Cl ratio of 20:1 prior to digestion, and the use of 3g K(2)Cr(2)O(7)/L in the digestion solution resulted in an error of less than 10% and 12% for samples containing 40 g NaCl/L at 20-190 mg COD/L and 230 mg COD/L, respectively. Comparison of the standard method with the new proposed method using a synthetic sewage highlights the large errors (50-85%) of the standard method in contrast to an error of less than 10% for the proposed modified method.

  4. Synthesis and application of novel composites of associative polymers with organically modified montmorillonites in water/oil emulsions

    NASA Astrophysics Data System (ADS)

    Han, Zixuan; Jiang, Guancheng; Li, Qingyang

    2015-12-01

    This paper is focused on the study of the rheology performance of water in oil (W/O) emulsions with novel composites of associative polymer/organically modified montmorillonite (AP/OMMT), further the mechanism of AP/OMMT is explored and then applied into deepwater drilling industry. In this study, both the yield point and gel strengths of W/O emulsions showed stability in a wide temperature range. Based on a combined use of FT-IR, particle-size distribution, XRD and TEM analysis, the probable mechanism was determined due to the identification of the structure of AP/OMMT. The results indicate that the formation of interlayered AP/OMMT between dispersed water droplets and the OMMT layers is primarily responsible for the excellent ability of improving rheology. In addition to this, the slippage and separation of OMMT colloidal particles due to the "weak multi-points adsorption" also contributed considerably to the rheology.

  5. Pasture degradation modifies soil organic matter properties and biochemical functioning in Tibetan grasslands

    NASA Astrophysics Data System (ADS)

    Spielvogel, Sandra; Steingräber, Laura; Schleuß, Per; Kuzyakov, Yakov; Guggenberger, Georg

    2015-04-01

    Kobresia pastures of the Tibetan Plateau represent the world's largest alpine ecosystem. Moderate husbandry on Kobresia pastures is beneficial for the storage of soil organic carbon (OC), nitrogen (N) and other nutrients and prevents erosion by establishment of sedge-turf root mats with high OC allocation rates below ground. However, undisturbed root mats are affected by freezing and thawing processes, which cause initial ice cracks. As a consequence decomposition of root mat layers will be accelerated and current sedentarization programs with concomitant increased grazing intensity may additionally enhance root mat degradation. Finally, cracks are enlarged by water and wind erosion as well as pika activities until bare soil surface areas without root mat horizons occur. The aim of this study was to understand the impact of the root mat layer on soil organic carbon stabilization and microbial functioning depending on soil depths and to predict future changes (OC, N and nutrient losses, soil microbial functioning in SOM transformation) by overgrazing and climate change. We investigated the mineral soil below Kobresia root mats along a false time degradation sequence ranging from stage 1 (intact root mat) to stage 4 (mats with large cracks and bare soil patches). Vertical gradients of δ13C values, neutral sugar, cutin and suberin contents as well as microbial biomass estimated by total phospholipid fatty acid (PLFA), microbial community composition (PLFA profiles) and activities of six extracellular enzymes involved in the C, N, and P cycle were assessed. Soil OC and N contents as well as C/N ratios indicate an increasing illuviation of topsoil material into the subsoil with advancing root mat degradation. This was confirmed by more negative δ13C values as well as significantly (p ≤ 0.05) increasing contributions of cutin derived hydroxy fatty acids to OC in the subsoils from degradation stages 1 to 4. PLFA profiles were surprisingly similar in the subsoils of

  6. Evaporation-induced self-organization of inkjet-printed organic semiconductors on surface-modified dielectrics for high-performance organic transistors.

    PubMed

    Lim, Jungah; Lee, Wihyoung; Kwak, Donghoon; Cho, Kilwon

    2009-05-05

    We demonstrate the influence of the surface wettability of a dielectric substrate on the crystalline microstructure and film morphology of an inkjet-printed organic semiconductor, namely 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS_PEN), using various self-assembled monolayers (SAMs). Self-aligned crystals with highly ordered crystalline structure are developed by printing on hydrophilic surfaces with high surface energy. It is found that the pinning of the contact line induces an outward convective flow as the evaporation proceeds, which results in the nucleation of crystals and the self-assembly of TIPS_PEN molecules from the periphery to the central region of the droplet. However, for hydrophobic surfaces with low surface energy, small agglomerates with random orientation of molecules are formed, which is induced by depinning of the contact line. The field-effect transistors fabricated with self-organized crystals printed on hydrophilic surfaces exhibit a high field-effect mobility of 0.15 cm(2) V(-1 )s(-1). These results indicate that the control of both the evaporation behavior and the contact line dynamics in a drying droplet plays an important role in the printing of organic semiconductor films with uniform morphology and desired molecular orientation for the direct-write fabrication of high-performance organic transistors.

  7. Osteogenic activity and antibacterial effect of porous titanium modified with metal-organic framework films.

    PubMed

    Chen, Junyu; Zhang, Xin; Huang, Chao; Cai, He; Hu, Shanshan; Wan, Qianbing; Pei, Xibo; Wang, Jian

    2017-03-01

    As a new class of crystalline nanoporous materials, metal-organic frameworks (MOFs) have recently been used for biomedical applications due to their large surface area, high porosity, and theoretically infinite structures. To improve the biological performance of titanium, MOF films were applied to surface modification of titanium. Zn-based MOF films composed of zeolitic imidazolate framework-8 (ZIF-8) crystals with nanoscale and microscale sizes (nanoZIF-8 and microZIF-8) were prepared on porous titanium surfaces by hydrothermal and solvothermal methods, respectively. The ZIF-8 films were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The nanoZIF-8 film exhibited good biocompatibility, whereas the microZIF-8 film showed obvious cytotoxicity to MG63 cells. Compared to pure titanium and alkali- and heat-treated porous titanium, the nanoZIF-8 film not only enhanced alkaline phosphatase (ALP) activity, extracellular matrix mineralization, and expression of osteogenic genes (ALP, Runx2) in MG63 cells but also inhibited the growth of Streptococcus mutans. These results indicate that MOF films or coatings may be promising candidates for bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 834-846, 2017.

  8. Highly Sensitive Glucose Sensor Based on Organic Electrochemical Transistor with Modified Gate Electrode.

    PubMed

    Ji, Xudong; Chan, Paddy K L

    2017-01-01

    An organic electrochemical transistor (OECT) with a glucose oxidase (GOx) and poly(n-vinyl-2-pyrrolidone)-capped platinum nanoparticles (Pt NPs) gate electrode was successfully integrated with a microfluidic channel to act as a highly sensitive chip-based glucose sensor. The sensing mechanism relies on the enzymatic reaction between glucose and GOx followed by electrochemical oxidation of hydrogen peroxide (H2O2) produced in the enzymatic reaction. This process largely increases the electrolyte potential that applies on PEDOT:PSS channel and causes more cations penetrate into PEDOT:PSS film to reduce it to semi-conducting state resulting in lower electric current between the source and the drain. The extremely high sensitivity and low detection limit (0.1 μM) of the sensor was achievable due to highly efficient Pt NPs catalysis in oxidation of H2O2. Pt NPs were deposited by a bias-free two-step dip coating method followed by a UV-Ozone post-treatment to enhance catalytic ability. A polydimethylsiloxane (PDMS) microfluidic channel was directly attached to the OECT active layer, providing a short detection time (~1 min) and extremely low analyte consumption (30 μL). Our sensor has great potential for real-time, noninvasive, and portable glucose sensing applications due to its compact size and high sensitivity.

  9. Retention of organophosphorous insecticides on a calcareous soil modified by organic amendments and a surfactant.

    PubMed

    Hernández-Soriano, M Carmen; Peña, Aránzazu; Mingorance, M Dolores

    2007-05-25

    Pesticides may affect soil quality since they are applied either directly to the soil or transported from the treated crops. Although the soil is able to partially retain environmental contaminants, the use of organic amendments, such as sewage sludge, peat or surfactants, may increase the retention in the upper soil layers, where the contaminants can be degraded and thus diminish their environmental fate. The effect of adding sewage sludge, peat and humic acids, together with a cationic surfactant to the soil, on the adsorption and desorption of organophosphorous insecticides has been studied. The results indicate that humic acids induce an adsorption increment of the pesticides, while peat and sewage sludge do not significantly affect pesticide adsorption at the dosage applied. The use of a cationic surfactant considerably enhances the insecticide retention. The increase was highest for the combined application of the surfactant and the humic acids. Desorption isotherms are inversely related to the adsorption behaviour, being higher for only soil, lower for soil added with carbon-rich amendments, and drastically reduced when the cationic surfactant is present. Concerning the insecticides, adsorption and desorption are related to their physicochemical properties.

  10. Assessment of phytoavailability of heavy metals in tropical soils by modified Neubauer method (organic extractor).

    NASA Astrophysics Data System (ADS)

    Mellis, E. V.; Rodella, A. A.; Levy, C. C. B.

    2012-04-01

    quantities of Cu, Ni and Zn extracted by plants. As a possible term of comparison with the contents of heavy metals in leaf tissue of rice, it might be considered to phytotoxic levels in mg kg-1: 30 to 20 for Cu, 50 to 100 for Ni and 500 to 1500 for Zn. The concentration of Cu extracted by rice plants had significant influence only for the amount of sludge factor regardless of its source. The elements Ni and Zn showed significant response to both doses of sludge used in the field, and for the type of sludge used, with the greatest accumulation of these metals in the samples treated with domestic and industrial sewage (Sludge Barueri - SB). Based on these results it can be concluded that the modified Neubauer method can be an efficient method for the determination of phytoavailable metals in soils, requiring further studies to confirm such efficiency.

  11. 2003 Agribusiness Group Paper

    DTIC Science & Technology

    2003-01-01

    contested political issue as the production and consumption of genetically modified organisms ( GMO ) dominates discussion in this critical...available documentation regarding scientific research, production methods, and GMO achievements demonstrate that there are no scientifically valid...concerns about GMO food safety. The US readily accepts and uses GMOs while nations of the European Union remain uncomfortable. In the near term

  12. Nitrogen removal from high organic loading wastewater in modified Ludzack-Ettinger configuration MBBR system.

    PubMed

    Torkaman, Mojtaba; Borghei, Seyed Mehdi; Tahmasebian, Sepehr; Andalibi, Mohammad Reza

    2015-01-01

    A moving bed biofilm reactor with pre-denitrification configuration was fed with a synthetic wastewater containing high chemical oxygen demand (COD) and ammonia. By changing different variables including ammonium and COD loading, nitrification rate in the aerobic reactor and denitrification rate in the anoxic reactor were monitored. Changing the influent loading was achieved via adjusting the inlet COD (956-2,096 mg/L), inlet ammonium (183-438 mg/L), and hydraulic retention time of the aerobic reactor (8, 12, and 18 hours). The overall organic loading rate was in the range of 3.60-17.37 gCOD/m2·day, of which 18.5-91% was removed in the anoxic reactor depending on the operational conditions. Considering the complementary role of the aerobic reactor, the overall COD removal was in the range 87.3-98.8%. In addition, nitrification rate increased with influent ammonium loading, the maximum rate reaching 3.05 gNH4/m2·day. One of the most important factors affecting nitrification rate was influent C:N entering the aerobic reactor, by increasing which nitrification rate decreased asymptotically. Nitrate removal efficiency in the anoxic reactor was also controlled by the inlet nitrate level entering the anoxic reactor. Furthermore, by increasing the nitrate loading rate from 0.91 to 3.49 gNO/m3·day, denitrification rate increased from 0.496 to 2.47 gNO/m3·day.

  13. Application of a modified sequential organ failure assessment score to critically ill patients.

    PubMed

    Namendys-Silva, S A; Silva-Medina, M A; Vásquez-Barahona, G M; Baltazar-Torres, J A; Rivero-Sigarroa, E; Fonseca-Lazcano, J A; Domínguez-Cherit, G

    2013-02-01

    The purpose of the present study was to explore the usefulness of the Mexican sequential organ failure assessment (MEXSOFA) score for assessing the risk of mortality for critically ill patients in the ICU. A total of 232 consecutive patients admitted to an ICU were included in the study. The MEXSOFA was calculated using the original SOFA scoring system with two modifications: the PaO2/FiO2 ratio was replaced with the SpO2/FiO2 ratio, and the evaluation of neurologic dysfunction was excluded. The ICU mortality rate was 20.2%. Patients with an initial MEXSOFA score of 9 points or less calculated during the first 24 h after admission to the ICU had a mortality rate of 14.8%, while those with an initial MEXSOFA score of 10 points or more had a mortality rate of 40%. The MEXSOFA score at 48 h was also associated with mortality: patients with a score of 9 points or less had a mortality rate of 14.1%, while those with a score of 10 points or more had a mortality rate of 50%. In a multivariate analysis, only the MEXSOFA score at 48 h was an independent predictor for in-ICU death with an OR = 1.35 (95%CI = 1.14-1.59, P < 0.001). The SOFA and MEXSOFA scores calculated 24 h after admission to the ICU demonstrated a good level of discrimination for predicting the in-ICU mortality risk in critically ill patients. The MEXSOFA score at 48 h was an independent predictor of death; with each 1-point increase, the odds of death increased by 35%.

  14. g-C3N4 Modified biochar as an adsorptive and photocatalytic material for decontamination of aqueous organic pollutants

    NASA Astrophysics Data System (ADS)

    Pi, Liu; Jiang, Rui; Zhou, Wangchi; Zhu, Hua; Xiao, Wei; Wang, Dihua; Mao, Xuhui

    2015-12-01

    Converting the waste biomasses with high-carbon content into value-added materials is an environmental-friendly way for their utilization. In this study, a leaf-derived biochar is modified with graphitic C3N4 to fulfill an affordable composite material capable of removing organic pollutants via adsorptive and photocatalytic processes simultaneously. The preparation process includes a carbonization process of chestnut leaf biomass and a followed condensation reaction of melamine at 520 °C. The characterization shows that biochar and C3N4 existed in the composites in their pristine status, and the effective connection of C3N4 and biochar was established. The adsorptive performance of the composites is governed by the biochar content in the composite, thus showing favorable performance for the removal of cationic dye methylene blue (MB). The condensation reaction of the melamine precursor has a coalescing effect on the dispersed biochar, resulting in the growth of particle size of composite. The composites prepared at different biochar/melamine ratios all show a photocatalytic activity on decolorization of MB. In terms of the specific photocatalytic activity of C3N4 in the composite, biochar/melamine ratio of 0.5:1 is the best. Unlike the conventional adsorptive carbon materials which have saturated adsorption capacity, the composite in this study retain a sustaining decontamination capability due to the photocatalytic degradation of adsorbed organic pollutants under irradiation.

  15. Epitaxial Growth of MOF Thin Film for Modifying the Dielectric Layer in Organic Field-Effect Transistors.

    PubMed

    Gu, Zhi-Gang; Chen, Shan-Ci; Fu, Wen-Qiang; Zheng, Qingdong; Zhang, Jian

    2017-03-01

    Metal-organic framework (MOF) thin films are important in the application of sensors and devices. However, the application of MOF thin films in organic field effect transistors (OFETs) is still a challenge to date. Here, we first use the MOF thin film prepared by a liquid-phase epitaxial (LPE) approach (also called SURMOFs) to modify the SiO2 dielectric layer in the OFETs. After the semiconductive polymer of PTB7-Th (poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b:4,5-b']dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate]) was coated on MOF/SiO2 and two electrodes on the semiconducting film were deposited sequentially, MOF-based OFETs were fabricated successfully. By controlling the LPE cycles of SURMOF HKUST-1 (also named Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate), the performance of the HKUST-1/SiO2-based OFETs showed high charge mobility and low threshold voltage. This first report on the application of MOF thin film in OFETs will offer an effective approach for designing a new kind of materials for the OFET application.

  16. Design of multiplex calibrant plasmids, their use in GMO detection and the limit of their applicability for quantitative purposes owing to competition effects.

    PubMed

    Debode, Frédéric; Marien, Aline; Janssen, Eric; Berben, Gilbert

    2010-03-01

    Five double-target multiplex plasmids to be used as calibrants for GMO quantification were constructed. They were composed of two modified targets associated in tandem in the same plasmid: (1) a part of the soybean lectin gene and (2) a part of the transgenic construction of the GTS40-3-2 event. Modifications were performed in such a way that each target could be amplified with the same primers as those for the original target from which they were derived but such that each was specifically detected with an appropriate probe. Sequence modifications were done to keep the parameters of the new target as similar as possible to those of its original sequence. The plasmids were designed to be used either in separate reactions or in multiplex reactions. Evidence is given that with each of the five different plasmids used in separate wells as a calibrant for a different copy number, a calibration curve can be built. When the targets were amplified together (in multiplex) and at different concentrations inside the same well, the calibration curves showed that there was a competition effect between the targets and this limits the range of copy numbers for calibration over a maximum of 2 orders of magnitude. Another possible application of multiplex plasmids is discussed.

  17. A statistical simulation model for field testing of non-target organisms in environmental risk assessment of genetically modified plants

    PubMed Central

    Goedhart, Paul W; van der Voet, Hilko; Baldacchino, Ferdinando; Arpaia, Salvatore

    2014-01-01

    Genetic modification of plants may result in unintended effects causing potentially adverse effects on the environment. A comparative safety assessment is therefore required by authorities, such as the European Food Safety Authority, in which the genetically modified plant is compared with its conventional counterpart. Part of the environmental risk assessment is a comparative field experiment in which the effect on non-target organisms is compared. Statistical analysis of such trials come in two flavors: difference testing and equivalence testing. It is important to know the statistical properties of these, for example, the power to detect environmental change of a given magnitude, before the start of an experiment. Such prospective power analysis can best be studied by means of a statistical simulation model. This paper describes a general framework for simulating data typically encountered in environmental risk assessment of genetically modified plants. The simulation model, available as Supplementary Material, can be used to generate count data having different statistical distributions possibly with excess-zeros. In addition the model employs completely randomized or randomized block experiments, can be used to simulate single or multiple trials across environments, enables genotype by environment interaction by adding random variety effects, and finally includes repeated measures in time following a constant, linear or quadratic pattern in time possibly with some form of autocorrelation. The model also allows to add a set of reference varieties to the GM plants and its comparator to assess the natural variation which can then be used to set limits of concern for equivalence testing. The different count distributions are described in some detail and some examples of how to use the simulation model to study various aspects, including a prospective power analysis, are provided. PMID:24834325

  18. A statistical simulation model for field testing of non-target organisms in environmental risk assessment of genetically modified plants.

    PubMed

    Goedhart, Paul W; van der Voet, Hilko; Baldacchino, Ferdinando; Arpaia, Salvatore

    2014-04-01

    Genetic modification of plants may result in unintended effects causing potentially adverse effects on the environment. A comparative safety assessment is therefore required by authorities, such as the European Food Safety Authority, in which the genetically modified plant is compared with its conventional counterpart. Part of the environmental risk assessment is a comparative field experiment in which the effect on non-target organisms is compared. Statistical analysis of such trials come in two flavors: difference testing and equivalence testing. It is important to know the statistical properties of these, for example, the power to detect environmental change of a given magnitude, before the start of an experiment. Such prospective power analysis can best be studied by means of a statistical simulation model. This paper describes a general framework for simulating data typically encountered in environmental risk assessment of genetically modified plants. The simulation model, available as Supplementary Material, can be used to generate count data having different statistical distributions possibly with excess-zeros. In addition the model employs completely randomized or randomized block experiments, can be used to simulate single or multiple trials across environments, enables genotype by environment interaction by adding random variety effects, and finally includes repeated measures in time following a constant, linear or quadratic pattern in time possibly with some form of autocorrelation. The model also allows to add a set of reference varieties to the GM plants and its comparator to assess the natural variation which can then be used to set limits of concern for equivalence testing. The different count distributions are described in some detail and some examples of how to use the simulation model to study various aspects, including a prospective power analysis, are provided.

  19. Electrochemical sensor for multiplex screening of genetically modified DNA: identification of biotech crops by logic-based biomolecular analysis.

    PubMed

    Liao, Wei-Ching; Chuang, Min-Chieh; Ho, Ja-An Annie

    2013-12-15

    Genetically modified (GM) technique, one of the modern biomolecular engineering technologies, has been deemed as profitable strategy to fight against global starvation. Yet rapid and reliable analytical method is deficient to evaluate the quality and potential risk of such resulting GM products. We herein present a biomolecular analytical system constructed with distinct biochemical activities to expedite the computational detection of genetically modified organisms (GMOs). The computational mechanism provides an alternative to the complex procedures commonly involved in the screening of GMOs. Given that the bioanalytical system is capable of processing promoter, coding and species genes, affirmative interpretations succeed to identify specified GM event in terms of both electrochemical and optical fashions. The biomolecular computational assay exhibits detection capability of genetically modified DNA below sub-nanomolar level and is found interference-free by abundant coexistence of non-GM DNA. This bioanalytical system, furthermore, sophisticates in array fashion operating multiplex screening against variable GM events. Such a biomolecular computational assay and biosensor holds great promise for rapid, cost-effective, and high-fidelity screening of GMO.

  20. Comprehensive GMO detection using real-time PCR array: single-laboratory validation.

    PubMed

    Mano, Junichi; Harada, Mioko; Takabatake, Reona; Furui, Satoshi; Kitta, Kazumi; Nakamura, Kosuke; Akiyama, Hiroshi; Teshima, Reiko; Noritake, Hiromichi; Hatano, Shuko; Futo, Satoshi; Minegishi, Yasutaka; Iizuka, Tayoshi

    2012-01-01

    We have developed a real-time PCR array method to comprehensively detect genetically modified (GM) organisms. In the method, genomic DNA extracted from an agricultural product is analyzed using various qualitative real-time PCR assays on a 96-well PCR plate, targeting for individual GM events, recombinant DNA (r-DNA) segments, taxon-specific DNAs, and donor organisms of the respective r-DNAs. In this article, we report the single-laboratory validation of both DNA extraction methods and component PCR assays constituting the real-time PCR array. We selected some DNA extraction methods for specified plant matrixes, i.e., maize flour, soybean flour, and ground canola seeds, then evaluated the DNA quantity, DNA fragmentation, and PCR inhibition of the resultant DNA extracts. For the component PCR assays, we evaluated the specificity and LOD. All DNA extraction methods and component PCR assays satisfied the criteria set on the basis of previous reports.

  1. 76 FR 43698 - Lake Champlain Sea Lamprey Control Alternatives Workgroup

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... technically feasible, cost effective, and environmentally safe. The primary objective of the meeting will be... Wildlife Resources Office, on potential for using Genetically Modified Organism (GMO) technology to...

  2. Genetically modified crops and aquatic ecosystems: considerations for environmental risk assessment and non-target organism testing.

    PubMed

    Carstens, Keri; Anderson, Jennifer; Bachman, Pamela; De Schrijver, Adinda; Dively, Galen; Federici, Brian; Hamer, Mick; Gielkens, Marco; Jensen, Peter; Lamp, William; Rauschen, Stefan; Ridley, Geoff; Romeis, Jörg; Waggoner, Annabel

    2012-08-01

    Environmental risk assessments (ERA) support regulatory decisions for the commercial cultivation of genetically modified (GM) crops. The ERA for terrestrial agroecosystems is well-developed, whereas guidance for ERA of GM crops in aquatic ecosystems is not as well-defined. The purpose of this document is to demonstrate how comprehensive problem formulation can be used to develop a conceptual model and to identify potential exposure pathways, using Bacillus thuringiensis (Bt) maize as a case study. Within problem formulation, the insecticidal trait, the crop, the receiving environment, and protection goals were characterized, and a conceptual model was developed to identify routes through which aquatic organisms may be exposed to insecticidal proteins in maize tissue. Following a tiered approach for exposure assessment, worst-case exposures were estimated using standardized models, and factors mitigating exposure were described. Based on exposure estimates, shredders were identified as the functional group most likely to be exposed to insecticidal proteins. However, even using worst-case assumptions, the exposure of shredders to Bt maize was low and studies supporting the current risk assessments were deemed adequate. Determining if early tier toxicity studies are necessary to inform the risk assessment for a specific GM crop should be done on a case by case basis, and should be guided by thorough problem formulation and exposure assessment. The processes used to develop the Bt maize case study are intended to serve as a model for performing risk assessments on future traits and crops.

  3. Using multiple PCR and CE with chemiluminescence detection for simultaneous qualitative and quantitative analysis of genetically modified organism.

    PubMed

    Guo, Longhua; Qiu, Bin; Chi, Yuwu; Chen, Guonan

    2008-09-01

    In this paper, an ultrasensitive CE-CL detection system coupled with a novel double-on-column coaxial flow detection interface was developed for the detection of PCR products. A reliable procedure based on this system had been demonstrated for qualitative and quantitative analysis of genetically modified organism-the detection of Roundup Ready Soy (RRS) samples was presented as an example. The promoter, terminator, function and two reference genes of RRS were amplified with multiplex PCR simultaneously. After that, the multiplex PCR products were labeled with acridinium ester at the 5'-terminal through an amino modification and then analyzed by the proposed CE-CL system. Reproducibility of analysis times and peak heights for the CE-CL analysis were determined to be better than 0.91 and 3.07% (RSD, n=15), respectively, for three consecutive days. It was shown that this method could accurately and qualitatively detect RRS standards and the simulative samples. The evaluation in terms of quantitative analysis of RRS provided by this new method was confirmed by comparing our assay results with those of the standard real-time quantitative PCR (RT-QPCR) using SYBR Green I dyes. The results showed a good coherence between the two methods. This approach demonstrated the possibility for accurate qualitative and quantitative detection of GM plants in a single run.

  4. Assessing environmental impacts of genetically modified plants on non-target organisms: The relevance of in planta studies.

    PubMed

    Arpaia, Salvatore; Birch, A Nicholas E; Kiss, Jozsef; van Loon, Joop J A; Messéan, Antoine; Nuti, Marco; Perry, Joe N; Sweet, Jeremy B; Tebbe, Christoph C

    2017-04-01

    In legal frameworks worldwide, genetically modified plants (GMPs) are subjected to pre-market environmental risk assessment (ERA) with the aim of identifying potential effects on the environment. In the European Union, the EFSA Guidance Document introduces the rationale that GMPs, as well as their newly produced metabolites, represent the potential stressor to be evaluated during ERA. As a consequence, during several phases of ERA for cultivation purposes, it is considered necessary to use whole plants or plant parts in experimental protocols. The importance of in planta studies as a strategy to address impacts of GMPs on non-target organisms is demonstrated, to evaluate both effects due to the intended modification in plant phenotype (e.g. expression of Cry proteins) and effects due to unintended modifications in plant phenotype resulting from the transformation process (e.g. due to somaclonal variations or pleiotropic effects). In planta tests are also necessary for GMPs in which newly expressed metabolites cannot easily be studied in vitro. This paper reviews the scientific literature supporting the choice of in planta studies as a fundamental tool in ERA of GMPs in cultivation dossiers; the evidence indicates they can realistically mimic the ecological relationships occurring in their receiving environments and provide important insights into the biology and sustainable management of GMPs.

  5. Sorption of organic molecules on surfaces of a microporous polymer adsorbent modified with different quantities of uracil

    NASA Astrophysics Data System (ADS)

    Gus'kov, V. Yu.; Ganieva, A. G.; Kudasheva, F. Kh.

    2016-11-01

    The sorption of organic molecules on the surfaces of a number of adsorbents based on a microporous copolymer of styrene and divinylbenzene modified with different quantities of uracil is studied by means of inverse gas chromatography at infinite dilution. Samples containing 10-6, 10-5, 10-4, 10-3, 10-2, and 0.5 × 10‒1 weight parts of uracil (the pC of uracil ranges from 1.3 to 6) are studied. The contributions from different intermolecular interactions to the Helmholtz energy of sorption are calculated via the linear free energy relationship. It is found that as the concentration of uracil on the surface of the polymer adsorbent grows, the contributions from different intermolecular interactions and the conventional polarity of the surface have a bend at pC = 3, due probably to the formation of a supramolecular structure of uracil. Based on the obtained results, it is concluded that the formation of the supramolecular structure of uracil on the surface of the polymer adsorbent starts when pC < 3.

  6. In silico peptide prediction for antibody generation to recognize 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in genetically modified organisms.

    PubMed

    Marani, Mariela M; Costa, Joana; Mafra, Isabel; Oliveira, Maria Beatriz P P; Camperi, Silvia A; Leite, José Roberto de Souza Almeida

    2015-03-01

    For the prospective immunorecognition of 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) as a biomarker protein expressed by transgenic soybean, an extensive in silico evaluation of the referred protein was performed. The main objective of this study was the selection of a set of peptides that could function as potential immunogens for the production of novel antibodies against CP4-EPSPS protein. For this purpose, the protein was in silico cleaved with trypsin/chymotrypsin and the resultant peptides were extensively analyzed for further selection of the best candidates for antibody production. The analysis enabled the successful proposal of four peptides with potential immunogenicity for their future use as screening biomarkers of genetically modified organisms. To our knowledge, this is the first attempt to select and define potential linear epitopes for the immunization of animals and, subsequently, to generate adequate antibodies for CP4-EPSPS recognition. The present work will be followed by the synthesis of the candidate peptides to be incubated in animals for antibody generation and potential applicability for the development of an immunosensor for CP4-EPSPS detection.

  7. A rapid method for detection of genetically modified organisms based on magnetic separation and surface-enhanced Raman scattering.

    PubMed

    Guven, Burcu; Boyacı, İsmail Hakkı; Tamer, Ugur; Çalık, Pınar

    2012-01-07

    In this study, a new method combining magnetic separation (MS) and surface-enhanced Raman scattering (SERS) was developed to detect genetically modified organisms (GMOs). An oligonucleotide probe which is specific for 35 S DNA target was immobilized onto gold coated magnetic nanospheres to form oligonucleotide-coated nanoparticles. A self assembled monolayer was formed on gold nanorods using 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) and the second probe of the 35 S DNA target was immobilized on the activated nanorod surfaces. Probes on the nanoparticles were hybridized with the target oligonucleotide. Optimization parameters for hybridization were investigated by high performance liquid chromatography. Optimum hybridization parameters were determined as: 4 μM probe concentration, 20 min immobilization time, 30 min hybridization time, 55 °C hybridization temperature, 750 mM buffer salt concentration and pH: 7.4. Quantification of the target concentration was performed via SERS spectra of DTNB on the nanorods. The correlation between the target concentration and the SERS signal was found to be linear within the range of 25-100 nM. The analyses were performed with only one hybridization step in 40 min. Real sample analysis was conducted using Bt-176 maize sample. The results showed that the developed MS-SERS assay is capable of detecting GMOs in a rapid and selective manner.

  8. Functional dual hydrophilic dendrimer-modified metal-organic framework for the selective enrichment of N-glycopeptides.

    PubMed

    Wang, Yanan; Wang, Jiaxi; Gao, Mingxia; Zhang, Xiangmin

    2017-04-08

    Analysis of protein glycosylation remains a significant challenge due to the low abundance of glycoproteins or N-glycopeptides. Here we have synthesized an amino-functionalized metal-organic framework (MOF) MIL-101(Cr)-NH2 whose surface is grafted with a hydrophilic dendrimer poly(amidoamine) (PAMAM) for N-glycopeptide enrichment based on the hydrophilic interactions. The selected substrate MOF MIL-101(Cr) owns high surface area which provides nice support for peptide adsorption. In addition, the MOF displayed a good hydrophilic property after being modified with amino groups. Most importantly, the grafted hydrophilic dendrimer PAMAM was firstly applied in the post-synthetic modification (PSM) of MOFs. And this functionalization route using macromolecular dendrimer opens a new perspective in MOFs design. Owing to its long dendritic chains and abundant amino groups, our material displayed dual hydrophilic property. In the enrichment of standard glycoprotein horseradish peroxidase (HRP) digestion, the functional MOF material was shown to have low detection limit (1 fmol/μL) and good selectivity when the concentration of nonglycopeptides was 100 fold higher than the target N-glycopeptides. All the results proved that MIL-101(Cr)-NH2 @PAMAM has great potential in the glycoproteome analysis. This article is protected by copyright. All rights reserved.

  9. Gondola-shaped tetra-rhenium metallacycles modified evanescent wave infrared chemical sensors for selective determination of volatile organic compounds.

    PubMed

    Huang, Genin Gary; Lee, Chung-Jay; Tsai, Bo-Chan; Yang, Jyisy; Sathiyendiran, Malaichamy; Lu, Kuang-Lieh

    2011-07-15

    Water-stable and cavity-contained rhenium metallacycles were synthesized, and their ability to selectively interact with volatile organic compounds (VOCs) systematically studied using attenuated total reflection infrared (ATR-IR) spectroscopy. Integrating the unique properties of rhenium metallacycles into optical sensing technologies significantly improves selectivity in detecting aromatic compounds. To explore the interaction of rhenium metallacycles with VOCs, the surface of ATR sensing elements was modified with the synthesized rhenium metallacycles and used to detect VOCs. The results indicate that rhenium metallacycles have crown ether-like recognition sites, which can selectively interact with aromatic compounds, especially those bearing polar functional groups. The IR absorption bands of rhenium metallacycles shift significantly upon adsorption of aromatic VOCs, revealing a strong interaction between the tetra-rhenium metallacycles and guest aromatic compounds. Optimizing the thickness of the metallacycles coated on the surface of the sensing element led to rapid response in detection. The dynamic range of response was generally up to 30 mg/L with detection limits ca. 30 μg/L. Further studies of the effect of interferences indicate that recovery can be higher than 95% for most of the compounds tested. The results on the flow-cell device indicated that the performances were similar to a static detection system but the detection of VOCs can be largely simplified.

  10. A tris(8-hydroxyquinoline) aluminum-based organic bistable device using ITO surfaces modified by Ag nanoparticles

    NASA Astrophysics Data System (ADS)

    Jiao, Bo; Wu, Zhaoxin; Dong, Hua; Ning, Shuya; Hou, Xun

    2013-11-01

    A tris (8-hydroxyquinoline) aluminum (Alq3)-based organic bistable device (OBD) using Al electrode and ITO electrode modified by Ag nanoparticles (NPs) was reported. The OBD exhibits high ON/OFF switching ratios in the range of 102-103 and long retention time over 104 s. The influence of the Ag NPs densities, as well as the Alq3 film thickness on the switch performance current-voltage (I-V) of the OBDs was studied. Correlation between filament formation mechanism and charge storage mechanism was observed by analysing the I-V characteristics of OBDs with different Alq3 film thickness. As for the Alq3 film with thickness of 300 nm, the trapping effect of Ag NPs leads to both ON and OFF states for OBD; for 100 nm thick Alq3 film, the effect of filamentation dominates in the ON and OFF states of OBD. For the case of 200 nm thick Alq3 film, however, the ON state results from the filamentation effect, while trapping effect is responsible for the OFF state. In addition, the diffusion effect of Al atoms in Alq3 film in the devices was discussed and was expected to explain this thickness-dependence relationship.

  11. Synthesis of different sized and porous hydroxyapatite nanorods without organic modifiers and their 5-fluorouracil release performance.

    PubMed

    Ji, Yuqin; Wang, Aili; Wu, Gang; Yin, Hengbo; Liu, Shuxin; Chen, Bujun; Liu, Fanggang; Li, Xiaoyun

    2015-12-01

    Porous biocompatible hydroxyapatite (HAP) nanorods of various sizes were synthesized by the combination of chemical precipitation and hydrothermal method without the use of organic modifiers. The HAP nanorod samples were characterized by powder X-ray diffraction, transmission electron microscopy, and N2 adsorption/desorption techniques. HAP nanorods with average diameters and average lengths ranging from 8.5 to 26.6 nm and from 23.1 to 49.7 nm, respectively, could be controllably synthesized via these methods. Low autoclaving temperature and high pH value favored the formation of relatively small HAP nanorods. The TEM images showed that the nanorods possessed porous structures with average pore diameters ranging from 1.6 to 2.7 nm. These HAP nanoparticles effectively prolonged the release time of 5-fluorouracil up to 24h. The as-synthesized HAP nanorods displayed no cytotoxicity to bone marrow stem cells at low HAP concentration, indicating that these nanorod materials could serve as potential carriers for novel drug release systems.

  12. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method.

  13. Detection of genetically modified organisms in foods by protein- and DNA-based techniques: bridging the methods.

    PubMed

    van Duijn, Gert J; van Biert, Ria; Bleeker-Marcelis, Henriette; Van Boeijen, Ineke; Adan, Abdi Jama; Jhakrie, Soeniei; Hessing, Martin

    2002-01-01

    According to European Commission (EC) Regulation 1139/98, foods and food ingredients that are to be delivered to the final consumer in which either protein or DNA resulting from genetic modification is present, shall be subject to additional specific labeling requirements. Since 1994, genetically altered tomatoes, squash, potatoes, canola, cotton, and soy have been on the market. Recently, insect-resistant and herbicide-tolerant maize varieties have been introduced. Soy and maize are 2 of the most important vegetable crops in the world. During the past 4 years, both protein- and DNA-based methods have been developed and applied for detection of transgenic soy and maize, and their derivatives. For protein-based detection, specific monoclonal and polyclonal antibodies have been developed; for immunochemical detection, Western blot analysis and enzyme-linked immunosorbent assays are the most prominent examples. For detection of genetically modified organisms (GMOs) at the level of DNA, polymerase chain reaction-based methods are mainly used. For these reactions, highly specific primer sets are needed. This study compares the principally different methods. Specificity of methods and the possible risks of false-positive or false-negative results are considered in relation to sampling, matrix effects, and food processing procedures. In addition, quantitative aspects of protein- and DNA-based GM detection methods are presented and discussed. This is especially relevant as EC regulation 49/2000, which defines a threshold for an unintentional comingling of 1%, came into force on April 10, 2000.

  14. Spectrophotometric determination of organic nitrogen by a modified Lassaigne method and its application to meat products and baby food.

    PubMed

    Demirata, Birsen; Apak, Resat; Afsar, Hüseyin; Tor, Izzet

    2002-01-01

    A modified Lassaigne method was developed for N determination based on fusion of the organic substance with metallic Na, conversion of the cyanide in the aqueous leachate to thiocyanate by ammonium polysulfide treatment, and colorimetric measurement of the thiocyanate formed by the addition of excessive ferric ions in acidic medium. The mean molar absorptivity of the Fe(NCS)2+ complex at 480 nm is 2.96 x 10(3) L/mol x cm, enabling quantitation of 0.25-7.72 ppm N (linear range) in the final solution. The relative amounts of Na, (NH4)2S2, and Fe(III) with respect to nitrogen in the analyte were optimized. The developed method was successfully applied to the determination of N in various brands of baby food, and it was compared statistically with the conventional Kjeldahl and elemental analysis methods. Protein nitrogen in a number of meat products was also precisely determined by the developed method. Thus, the total digestion time of the conventional Kjeldahl method was reduced considerably (e.g., to approximately 15 min for a dried sample) with a relatively simple spectrophotometric method requiring no sophisticated instrumentation.

  15. Knowledge of, Attitudes toward, and Acceptance of Genetically Modified Organisms among Prospective Teachers of Biology, Home Economics, and Grade School in Slovenia

    ERIC Educational Resources Information Center

    Sorgo, Andrej; Ambrozic-Dolinsek, Jana

    2010-01-01

    The objective of this study was to investigate knowledge, opinions, and attitudes toward, as well as readiness to accept genetically modified organisms (GMOs) among prospective primary and secondary Slovene teachers. Our findings are that prospective teachers want to take an active role in rejecting or supporting individual GMOs and are aware of…

  16. Modified atmosphere packaging (MAP) impacts on organic Chinese red raspberry (Rubus idaeus L.) fruit on quality and active components over postharvest storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate modified atmosphere packaging (MAP) impacts on market quality and actives preservation of organic Chinese red raspberry (Rubus idaeus L.) fruit over postharvest storage. Fruit were harvested, cooled, and sorted for uniform maturity and quality. Fruit were ...

  17. Multiplex enrichment quantitative PCR (ME-qPCR): a high-throughput, highly sensitive detection method for GMO identification.

    PubMed

    Fu, Wei; Zhu, Pengyu; Wei, Shuang; Zhixin, Du; Wang, Chenguang; Wu, Xiyang; Li, Feiwu; Zhu, Shuifang

    2017-04-01

    Among all of the high-throughput detection methods, PCR-based methodologies are regarded as the most cost-efficient and feasible methodologies compared with the next-generation sequencing or ChIP-based methods. However, the PCR-based methods can only achieve multiplex detection up to 15-plex due to limitations imposed by the multiplex primer interactions. The detection throughput cannot meet the demands of high-throughput detection, such as SNP or gene expression analysis. Therefore, in our study, we have developed a new high-throughput PCR-based detection method, multiplex enrichment quantitative PCR (ME-qPCR), which is a combination of qPCR and nested PCR. The GMO content detection results in our study showed that ME-qPCR could achieve high-throughput detection up to 26-plex. Compared to the original qPCR, the Ct values of ME-qPCR were lower for the same group, which showed that ME-qPCR sensitivity is higher than the original qPCR. The absolute limit of detection for ME-qPCR could achieve levels as low as a single copy of the plant genome. Moreover, the specificity results showed that no cross-amplification occurred for irrelevant GMO events. After evaluation of all of the parameters, a practical evaluation was performed with different foods. The more stable amplification results, compared to qPCR, showed that ME-qPCR was suitable for GMO detection in foods. In conclusion, ME-qPCR achieved sensitive, high-throughput GMO detection in complex substrates, such as crops or food samples. In the future, ME-qPCR-based GMO content identification may positively impact SNP analysis or multiplex gene expression of food or agricultural samples. Graphical abstract For the first-step amplification, four primers (A, B, C, and D) have been added into the reaction volume. In this manner, four kinds of amplicons have been generated. All of these four amplicons could be regarded as the target of second-step PCR. For the second-step amplification, three parallels have been taken for

  18. Selection of focal earthworm species as non-target soil organisms for environmental risk assessment of genetically modified plants.

    PubMed

    van Capelle, Christine; Schrader, Stefan; Arpaia, Salvatore

    2016-04-01

    By means of a literature survey, earthworm species of significant relevance for soil functions in different biogeographical regions of Europe (Atlantic, Boreal, Mediterranean) were identified. These focal earthworm species, defined here according to the EFSA Guidance Document on the environmental risk assessment (ERA) of genetically modified plants, are typical for arable soils under crop rotations with maize and/or potatoes within the three regions represented by Ireland, Sweden and Spain, respectively. Focal earthworm species were selected following a matrix of four steps: Identification of functional groups, categorization of non-target species, ranking species on ecological criteria, and final selection of focal species. They are recommended as appropriate non-target organisms to assess environmental risks of genetically modified (GM) crops; in this case maize and potatoes. In total, 44 literature sources on earthworms in arable cropping systems including maize or potato from Ireland, Sweden and Spain were collected, which present information on species diversity, individual density and specific relevance for soil functions. By means of condensed literature data, those species were identified which (i) play an important functional role in respective soil systems, (ii) are well adapted to the biogeographical regions, (iii) are expected to occur in high abundances under cultivation of maize or potato and (iv) fulfill the requirements for an ERA test system based on life-history traits. First, primary and secondary decomposers were identified as functional groups being exposed to the GM crops. In a second step, anecic and endogeic species were categorized as potential species. In step three, eight anecic and endogeic earthworm species belonging to the family Lumbricidae were ranked as relevant species: Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea longa, Allolobophora chlorotica, Lumbricus terrestris, Lumbricus friendi, Octodrilus complanatus and

  19. Antibiotic resistance marker genes as environmental pollutants in GMO-pristine agricultural soils in Austria.

    PubMed

    Woegerbauer, Markus; Zeinzinger, Josef; Gottsberger, Richard Alexander; Pascher, Kathrin; Hufnagl, Peter; Indra, Alexander; Fuchs, Reinhard; Hofrichter, Johannes; Kopacka, Ian; Korschineck, Irina; Schleicher, Corina; Schwarz, Michael; Steinwider, Johann; Springer, Burkhard; Allerberger, Franz; Nielsen, Kaare M; Fuchs, Klemens

    2015-11-01

    Antibiotic resistance genes may be considered as environmental pollutants if anthropogenic emission and manipulations increase their prevalence above usually occurring background levels. The prevalence of aph(3')-IIa/nptII and aph(3')-IIIa/nptIII - frequent marker genes in plant biotechnology conferring resistance to certain aminoglycosides - was determined in Austrian soils from 100 maize and potato fields not yet exposed to but eligible for GMO crop cultivation. Total soil DNA extracts were analysed by nptII/nptIII-specific TaqMan real time PCR. Of all fields 6% were positive for nptII (median: 150 copies/g soil; range: 31-856) and 85% for nptIII (1190 copies/g soil; 13-61600). The copy-number deduced prevalence of nptIII carriers was 14-fold higher compared to nptII. Of the cultivable kanamycin-resistant soil bacteria 1.8% (95% confidence interval: 0-3.3%) were positive for nptIII, none for nptII (0-0.8%). The nptII-load of the studied soils was low rendering nptII a typical candidate as environmental pollutant upon anthropogenic release into these ecosystems.

  20. Characterization and optimization of GMO-based gels with long term release for intraarticular administration.

    PubMed

    Réeff, J; Gaignaux, A; Goole, J; Siepmann, J; Siepmann, F; Jerome, C; Thomassin, J M; De Vriese, C; Amighi, K

    2013-07-15

    Osteoarthritis is characterized by slow degenerative processes in the articular cartilage within synovial joints. It could be interesting to develop a sustained-release formulation that could be effective on both pain/inflammation and restoration of mechanical integrity of the joint. Recently, an injectable system based on glycerol monooleate (GMO), containing clonidine as a model hydrophilic analgesic/anti-inflammatory drug and hyaluronic acid as a viscoelastic scaffold, showed promising potential as a biodegradable and biocompatible preparation to sustain the drug activity. However, drug release from the system is relatively fast (complete within 1 week) and the underlying drug release mechanisms not fully understood. The aims of this study were: (i) to significantly improve this type of local controlled drug delivery system by further sustaining clonidine release, and (ii) to elucidate the underlying mass transport mechanisms. The addition of FDA-approved inactive ingredients such as sodium oleate or purified soybean oil was found to be highly effective. The release rate could be substantially reduced (e.g., 50% release after 10 days), due to the increased hydrophobicity of the systems, resulting in slower and reduced water uptake and reduced drug mobility. Interestingly, Fick's second law of diffusion could be used to quantitatively describe drug release.

  1. Effects of organic modifier and temperature on the enantiomeric separation of several azole drugs using supercritical fluid chromatography and the Chiralpak AD column.

    PubMed

    Toribio, L; Bernal, J L; Martín, M T; Bernal, J; Del Nozal, M J

    2014-01-01

    The effects of organic modifier and temperature on the enantioseparation of 10 triazoles and eight imidazoles, using supercritical fluid chromatography with the Chiralpak AD column, have been investigated in this work. For this purpose four different organic modifiers (methanol, ethanol, 2-propanol and acetonitrile) were evaluated. Only in the case of two compounds could the enantiomeric separation not be achieved with any of the modifiers tested; the rest of compounds were baseline or partially resolved with at least one of the modifiers. The alcohol-type modifiers provided the best results in terms of retention time and resolution. In general, retention increased in the order methanol < ethanol < 2-propanol; moreover it was possible to establish a relationship between the retention and the number of aromatic rings and dioxolane groups in the molecule, that is, the higher the number is, the higher the retention time. From the study of the temperature effect, the enthalpy-entropy compensation was demonstrated for all the compounds, except for bifonazole using methanol and miconazole using acetonitrile. This suggested that both analytes are enantiomerically resolved through different mechanisms.

  2. Enhanced transport of 2,2',5,5'-polychlorinated biphenyl by natural organic matter (NOM) and surfactant-modified fullerene nanoparticles (nC60).

    PubMed

    Wang, Lilin; Huang, Yi; Kan, Amy T; Tomson, Mason B; Chen, Wei

    2012-05-15

    Stable colloidal suspensions of buckminsterfullerene (nC(60)) in aqueous environments can significantly affect the fate and transport of hydrophobic organic contaminants by serving as a contaminant carrier. In this study, we examined enhanced transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in saturated sandy soil columns by a variety of nC(60) samples, including an nC(60) sample prepared by the typical solvent exchange method, as well as eight natural organic matter (NOM) or surfactant-modified nC(60) samples, prepared by phase-transferring C(60) from toluene to an NOM or a surfactant solution. Whereas the NOM- and surfactant-modified nC(60) samples have mobility similar to the unmodified nC(60), their contaminant-mobilizing capabilities are significantly greater: breakthrough of PCB increases by 47.2 to 227% with the surfactant-modified nC(60) samples and by 233 to 370% with the NOM-modified nC(60) samples. The significantly enhanced contaminant-mobilizing capability of the modified nC(60) is likely due to a combined effect of increased adsorption affinities and increased tendency of desorption nonequilibrium, likely caused by the changes of nC(60) aggregation properties induced by the presence of NOM or surfactant. Findings in this study indicate that nC(60) formed in different processes might have vastly different effects on contaminant fate and transport.

  3. The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms.

    PubMed

    Semenov, Alexander V; Elsas, Jan Dirk; Glandorf, Debora C M; Schilthuizen, Menno; Boer, Willem F

    2013-08-01

    To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on varied experimental designs. The recent EFSA guidance document for environmental risk assessment (2010) does not provide clear and structured suggestions that address the statistics of field trials on effects on NTO's. This review examines existing practices in GM plant field testing such as the way of randomization, replication, and pseudoreplication. Emphasis is placed on the importance of design features used for the field trials in which effects on NTO's are assessed. The importance of statistical power and the positive and negative aspects of various statistical models are discussed. Equivalence and difference testing are compared, and the importance of checking the distribution of experimental data is stressed to decide on the selection of the proper statistical model. While for continuous data (e.g., pH and temperature) classical statistical approaches - for example, analysis of variance (ANOVA) - are appropriate, for discontinuous data (counts) only generalized linear models (GLM) are shown to be efficient. There is no golden rule as to which statistical test is the most appropriate for any experimental situation. In particular, in experiments in which block designs are used and covariates play a role GLMs should be used. Generic advice is offered that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in this testing. The combination of decision trees and a checklist for field trials, which are provided, will help in the interpretation of the statistical analyses of field trials and to assess whether such analyses were correctly applied. We offer generic advice to risk assessors and applicants that will

  4. Targeting helicase-dependent amplification products with an electrochemical genosensor for reliable and sensitive screening of genetically modified organisms.

    PubMed

    Moura-Melo, Suely; Miranda-Castro, Rebeca; de-Los-Santos-Álvarez, Noemí; Miranda-Ordieres, Arturo J; Dos Santos Junior, J Ribeiro; da Silva Fonseca, Rosana A; Lobo-Castañón, Maria Jesús

    2015-08-18

    Cultivation of genetically modified organisms (GMOs) and their use in food and feed is constantly expanding; thus, the question of informing consumers about their presence in food has proven of significant interest. The development of sensitive, rapid, robust, and reliable methods for the detection of GMOs is crucial for proper food labeling. In response, we have experimentally characterized the helicase-dependent isothermal amplification (HDA) and sequence-specific detection of a transgene from the Cauliflower Mosaic Virus 35S Promoter (CaMV35S), inserted into most transgenic plants. HDA is one of the simplest approaches for DNA amplification, emulating the bacterial replication machinery, and resembling PCR but under isothermal conditions. However, it usually suffers from a lack of selectivity, which is due to the accumulation of spurious amplification products. To improve the selectivity of HDA, which makes the detection of amplification products more reliable, we have developed an electrochemical platform targeting the central sequence of HDA copies of the transgene. A binary monolayer architecture is built onto a thin gold film where, upon the formation of perfect nucleic acid duplexes with the amplification products, these are enzyme-labeled and electrochemically transduced. The resulting combined system increases genosensor detectability up to 10(6)-fold, allowing Yes/No detection of GMOs with a limit of detection of ∼30 copies of the CaMV35S genomic DNA. A set of general utility rules in the design of genosensors for detection of HDA amplicons, which may assist in the development of point-of-care tests, is also included. The method provides a versatile tool for detecting nucleic acids with extremely low abundance not only for food safety control but also in the diagnostics and environmental control areas.

  5. The cellular uptake of meta-tetra(hydroxyphenyl)chlorin entrapped in organically modified silica nanoparticles is mediated by serum proteins

    NASA Astrophysics Data System (ADS)

    Compagnin, Chiara; Baù, Luca; Mognato, Maddalena; Celotti, Lucia; Miotto, Giovanni; Arduini, Maria; Moret, Francesca; Fede, Caterina; Selvestrel, Francesco; Rio Echevarria, Iria M.; Mancin, Fabrizio; Reddi, Elena

    2009-08-01

    Nanosized objects made of various materials are gaining increasing attention as promising vehicles for the delivery of therapeutic and diagnostic agents for cancer. Photodynamic therapy (PDT) appears to offer a very attractive opportunity to implement drug delivery systems since no release of the sensitizer is needed to obtain the therapeutic effect and the design of the nanovehicle should be much easier. The aim of our study was to investigate the use of organic-modified silica nanoparticles (NPs) for the delivery of the second-generation photosensitizer meta-tetra(hydroxyphenyl)chlorin (mTHPC) to cancer cells in vitro. mTHPC was entrapped in NPs (~33 nm diameter) in a monomeric form which produced singlet oxygen with a high efficiency. In aqueous media with high salt concentrations, the NPs underwent aggregation and precipitation but their stability could be preserved in the presence of foetal bovine serum. The cellular uptake, localization and phototoxic activity of mTHPC was determined comparatively in human oesophageal cancer cells after its delivery by the NPs and the standard solvent ethanol/poly(ethylene glycol) 400/water (20:30:50, by vol). The NP formulation reduced the cellular uptake of mTHPC by about 50% in comparison to standard solvent while it did not affect the concentration-dependent photokilling activity of mTHPC and its intracellular localization. Fluorescence resonance energy transfer measurements, using NPs with mTHPC physically entrapped and a cyanine covalently linked, and ultracentrifugation experiments indicated that mTHPC is transferred from NPs to serum proteins when present in the medium. However, the coating of the NP surface with poly(ethylene glycol) largely prevented the transfer to proteins. In conclusion, mTHPC is rapidly transferred from the uncoated nanoparticles to the serum proteins and then internalized by the cells as a protein complex, irrespective of its modality of delivery.

  6. Assessment of the nutritional values of genetically modified wheat, corn, and tomato crops.

    PubMed

    Venneria, Eugenia; Fanasca, Simone; Monastra, Giovanni; Finotti, Enrico; Ambra, Roberto; Azzini, Elena; Durazzo, Alessandra; Foddai, Maria Stella; Maiani, Giuseppe

    2008-10-08

    The genetic modification in fruit and vegetables could lead to changes in metabolic pathways and, therefore, to the variation of the molecular pattern, with particular attention to antioxidant compounds not well-described in the literature. The aim of the present study was to compare the quality composition of transgenic wheat ( Triticum durum L.), corn ( Zea mays L.), and tomato ( Lycopersicum esculentum Mill.) to the nontransgenic control with a similar genetic background. In the first experiment, Ofanto wheat cultivar containing the tobacco rab1 gene and nontransgenic Ofanto were used. The second experiment compared two transgenic lines of corn containing Bacillus thuringiensis "Cry toxin" gene (PR33P67 and Pegaso Bt) to their nontransgenic forms. The third experiment was conducted on transgenic tomato ( Lycopersicum esculentum Mill.) containing the Agrobacterium rhizogenes rolD gene and its nontransgenic control (cv. Tondino). Conventional and genetically modified crops were compared in terms of fatty acids content, unsaponifiable fraction of antioxidants, total phenols, polyphenols, carotenoids, vitamin C, total antioxidant activity, and mineral composition. No significant differences were observed for qualitative traits analyzed in wheat and corn samples. In tomato samples, the total antioxidant activity (TAA), measured by FRAP assay, and the naringenin content showed a lower value in genetically modified organism (GMO) samples (0.35 mmol of Fe (2+) 100 g (-1) and 2.82 mg 100 g (-1), respectively), in comparison to its nontransgenic control (0.41 mmol of Fe (2+) 100 g (-1) and 4.17 mg 100 g (-1), respectively). On the basis of the principle of substantial equivalence, as articulated by the World Health Organization, the Organization for Economic Cooperation and Development, and the United Nations Food and Agriculture Organization, these data support the conclusion that GM events are nutritionally similar to conventional varieties of wheat, corn, and tomato on

  7. Real-time PCR array as a universal platform for the detection of genetically modified crops and its application in identifying unapproved genetically modified crops in Japan.

    PubMed

    Mano, Junichi; Shigemitsu, Natsuki; Futo, Satoshi; Akiyama, Hiroshi; Teshima, Reiko; Hino, Akihiro; Furui, Satoshi; Kitta, Kazumi

    2009-01-14

    We developed a novel type of real-time polymerase chain reaction (PCR) array with TaqMan chemistry as a platform for the comprehensive and semiquantitative detection of genetically modified (GM) crops. Thirty primer-probe sets for the specific detection of GM lines, recombinant DNA (r-DNA) segments, endogenous reference genes, and donor organisms were synthesized, and a 96-well PCR plate was prepared with a different primer-probe in each well as the real-time PCR array. The specificity and sensitivity of the array were evaluated. A comparative analysis with the data and publicly available information on GM crops approved in Japan allowed us to assume the possibility of unapproved GM crop contamination. Furthermore, we designed a Microsoft Excel spreadsheet application, Unapproved GMO Checker version 2.01, which helps process all the data of real-time PCR arrays for the easy assumption of unapproved GM crop contamination. The spreadsheet is available free of charge at http://cse.naro.affrc.go.jp/jmano/index.html .

  8. A Study of Stakeholder Views to Shape a Communication Strategy for GMO in Brazil

    PubMed Central

    Capalbo, Deise Maria Fontana; Arantes, Olivia Márcia Nagy; Maia, Alexandre Gori; Borges, Izaias Carvalho; da Silveira, José Maria Ferreira Jardim

    2015-01-01

    This paper analyzes the view of stakeholders on genetically modified organisms (GMOs) and the implications of these views on communication strategies for agricultural biotechnology in Brazil. It identifies and describes common groups of attitudes toward GMOs using multivariate statistical analyses. The study then looks for patterns of association between the common attitude groups and the following variables: socioeconomic characteristics trust in institutions as information sources and familiarity with the Brazilian biosafety authority. The article contributes to the understanding of public awareness by highlighting how information sources, trust in institutions, and socioeconomic characteristics, such as age and occupational qualification, play important roles in defining patterns of attitudes toward GMOs. The paper also discusses the implications of this knowledge for the development of a communication strategy plan that would promote public awareness and stimulate a well-informed Brazilian public debate on biosafety. PMID:26618152

  9. Worldviews and discursive construction of GMO-related risk perceptions in Turkey.

    PubMed

    Veltri, Giuseppe A; Suerdem, Ahmet K

    2013-02-01

    This paper analyses the discursive construction of the genetically modified organisms (GMOs) issue in the Turkish political arena following the public debate on the pending legislation on biosecurity. The study proposes an operational approach to semiotic/actor network theory (Latour) applied to public representations of a new technology within the theoretical frameworks of social representation theory and cultural theory of risks. It aims to highlight how different worldviews produce different risk discourses of GMOs in Turkey. Using cluster analysis to inductively extract evaluative categories, we use these to identify themes by human coding. Lastly, we apply formal concept analysis to link themes to actors and their worldviews, establishing their semantic networks. Formal concept analysis revealed four discourse networks reflecting nationalist, Islamist, progressive (left) and neo-liberal worldviews. Finally, these structures will be grounded back in the articles for a richer interpretive analysis.

  10. A Study of Stakeholder Views to Shape a Communication Strategy for GMO in Brazil.

    PubMed

    Capalbo, Deise Maria Fontana; Arantes, Olivia Márcia Nagy; Maia, Alexandre Gori; Borges, Izaias Carvalho; da Silveira, José Maria Ferreira Jardim

    2015-01-01

    This paper analyzes the view of stakeholders on genetically modified organisms (GMOs) and the implications of these views on communication strategies for agricultural biotechnology in Brazil. It identifies and describes common groups of attitudes toward GMOs using multivariate statistical analyses. The study then looks for patterns of association between the common attitude groups and the following variables: socioeconomic characteristics trust in institutions as information sources and familiarity with the Brazilian biosafety authority. The article contributes to the understanding of public awareness by highlighting how information sources, trust in institutions, and socioeconomic characteristics, such as age and occupational qualification, play important roles in defining patterns of attitudes toward GMOs. The paper also discusses the implications of this knowledge for the development of a communication strategy plan that would promote public awareness and stimulate a well-informed Brazilian public debate on biosafety.

  11. Evaluation of organ doses and effective dose according to the ICRP Publication 110 reference male/female phantom and the modified ImPACT CT patient dosimetry.

    PubMed

    Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Matsunaga, Yuta; Kawaguchi, Ai; Katada, Kazuhiro; Toyama, Hiroshi; Koshida, Kichiro; Suzuki, Shouichi

    2014-09-07

    We modified the Imaging Performance Assessment of CT scanners (ImPACT) to evaluate the organ doses and the effective dose based on the International Commission on Radiological Protection (ICRP) Publication 110 reference male/female phantom with the Aquilion ONE ViSION Edition scanner. To select the new CT scanner, the measurement results of the CTDI100,c and CTDI100,p for the 160 (head) and the 320 (body) mm polymethylmethacrylate phantoms, respectively, were entered on the Excel worksheet. To compute the organ doses and effective dose of the ICRP reference male/female phantom, the conversion factors obtained by comparison between the organ doses of different types of phantom were applied. The organ doses and the effective dose were almost identical for the ICRP reference male/female and modified ImPACT. The results of this study showed that, with the dose assessment of the ImPACT, the difference in sex influences only testes and ovaries. Because the MIRD-5 phantom represents a partially hermaphrodite adult, the phantom has the dimensions of the male reference man including testes, ovaries, and uterus but no female breasts, whereas the ICRP male/female phantom includes whole-body male and female anatomies based on high-resolution anatomical datasets. The conversion factors can be used to estimate the doses of a male and a female accurately, and efficient dose assessment can be performed with the modified ImPACT.

  12. Expression of PAT and NPT II proteins during the developmental stages of a genetically modified pepper developed in Korea.

    PubMed

    Kim, Hyo Jin; Lee, Si Myung; Kim, Jae Kwang; Ryu, Tae Hun; Suh, Seok Cheol; Cho, Hyun Suk

    2010-10-27

    Estimation of the protein levels introduced in a biotechnology-derived product is conducted as part of an overall safety assessment. An enzyme-linked immunosorbent assay (ELISA) was used to analyze phosphinothricin acetyltransferase (PAT) and neomycin phosphotransferase II (NPT II) protein expression in a genetically modified (GM) pepper plant developed in Korea. PAT and NPT II expression levels, based on both dry weight and fresh weight, were variable among different plant generations and plant sections from isolated genetically modified organism (GMO) fields at four developmental stages. PAT expression was highest in leaves at anthesis (11.44 μg/gdw and 2.17 μg/gfw) and lowest in roots (0.12 μg/gdw and 0.01 μg/gfw). NPT II expression was also highest in leaves at anthesis (17.31 μg/gdw and 3.41 μg/gfw) and lowest in red pepper (0.65 μg/gdw and 0.12 μg/gfw). In pollen, PAT expression was 0.59-0.62 μg/gdw, while NPT II was not detected. Both PAT and NPT II showed a general pattern of decreased expression with progression of the growing season. As expected, PAT and NPT II protein expression was not detectable in control pepper plants.

  13. Development and validation of an event-specific quantitative PCR method for genetically modified maize MIR162.

    PubMed

    Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2014-01-01

    A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize event, MIR162. We first prepared a standard plasmid for MIR162 quantification. The conversion factor (Cf) required to calculate the genetically modified organism (GMO) amount was empirically determined for two real-time PCR instruments, the Applied Biosystems 7900HT (ABI7900) and the Applied Biosystems 7500 (ABI7500) for which the determined Cf values were 0.697 and 0.635, respectively. To validate the developed method, a blind test was carried out in an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDr). The determined biases were less than 25% and the RSDr values were less than 20% at all evaluated concentrations. These results suggested that the limit of quantitation of the method was 0.5%, and that the developed method would thus be suitable for practical analyses for the detection and quantification of MIR162.

  14. Loop-mediated isothermal amplification: rapid visual and real-time methods for detection of genetically modified crops.

    PubMed

    Randhawa, Gurinder Jit; Singh, Monika; Morisset, Dany; Sood, Payal; Zel, Jana

    2013-11-27

    A rapid, reliable, and sensitive loop-mediated isothermal amplification (LAMP) system was developed for screening of genetically modified organisms (GMOs). The optimized LAMP assays using designed primers target commonly employed promoters, i.e., Cauliflower Mosaic Virus 35S (P-35S) and Figwort Mosaic Virus promoter (P-FMV), and marker genes, i.e., aminoglycoside 3'-adenyltransferase (aadA), neomycin phosphotransferase II (nptII), and β-glucuronidase (uidA). The specificity and performance of the end-point and real-time LAMP assays were confirmed using eight genetically modified (GM) cotton events on four detection systems, employing two chemistries. LAMP assays on the isothermal real-time system were found to be most sensitive, detecting up to four target copies, within 35 min. The LAMP assays herein presented using alternate detection systems can be effectively utilized for rapid and cost-effective screening of the GM status of a sample, irrespective of the crop species or GM trait. These assays coupled with a fast and simple DNA extraction method may further facilitate on-site GMO screening.

  15. The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms

    PubMed Central

    Semenov, Alexander V; Elsas, Jan Dirk; Glandorf, Debora C M; Schilthuizen, Menno; Boer, Willem F

    2013-01-01

    Abstract To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on varied experimental designs. The recent EFSA guidance document for environmental risk assessment (2010) does not provide clear and structured suggestions that address the statistics of field trials on effects on NTO's. This review examines existing practices in GM plant field testing such as the way of randomization, replication, and pseudoreplication. Emphasis is placed on the importance of design features used for the field trials in which effects on NTO's are assessed. The importance of statistical power and the positive and negative aspects of various statistical models are discussed. Equivalence and difference testing are compared, and the importance of checking the distribution of experimental data is stressed to decide on the selection of the proper statistical model. While for continuous data (e.g., pH and temperature) classical statistical approaches – for example, analysis of variance (ANOVA) – are appropriate, for discontinuous data (counts) only generalized linear models (GLM) are shown to be efficient. There is no golden rule as to which statistical test is the most appropriate for any experimental situation. In particular, in experiments in which block designs are used and covariates play a role GLMs should be used. Generic advice is offered that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in this testing. The combination of decision trees and a checklist for field trials, which are provided, will help in the interpretation of the statistical analyses of field trials and to assess whether such analyses were correctly applied. We offer generic advice to risk assessors and

  16. The strains recommended for use in the bacterial reverse mutation test (OECD guideline 471) can be certified as non-genetically modified organisms.

    PubMed

    Sugiyama, Kei-Ichi; Yamada, Masami; Awogi, Takumi; Hakura, Atsushi

    2016-01-01

    The bacterial reverse mutation test, commonly called Ames test, is used worldwide. In Japan, the genetically modified organisms (GMOs) are regulated under the Cartagena Domestic Law, and organisms obtained by self-cloning and/or natural occurrence would be exempted from the law case by case. The strains of Salmonella typhimurium and Escherichia coli recommended for use in the bacterial reverse mutation test (OECD guideline 471), have been considered as non-GMOs because they can be constructed by self-cloning or naturally occurring bacterial strains, or do not disturb the biological diversity. The present article explains the reasons why these tester strains should be classified as non-GMOs.

  17. Simultaneous removal of multiple pesticides from water: effect of organically modified clays as coagulant aid and adsorbent in coagulation-flocculation process.

    PubMed

    Shabeer, T P Ahammed; Saha, Ajoy; Gajbhiye, V T; Gupta, Suman; Manjaiah, K M; Varghese, Eldho

    2014-01-01

    Contamination of drinking water sources with agrochemical residues became a major concern in the twenty-first century. Coagulation-flocculation is the most widely used water-treatment process, but the efficiency to remove pesticides and other organic pollutants are limited compared to adsorption process. Thus, simultaneous action of adsorption on normal bentonite or organo-modified montmorillonite clays [modified with octadecylamine (ODA-M) and octadecylamine + amino-propyltriethoxysilane (ODAAPS-M)] followed by coagulation-flocculation by alum and poly aluminium chloride has been evaluated for removal of 10 different pesticides, namely atrazine, lindane, metribuzin, aldrin, chlorpyriphos, pendimethalin, alpha-endosulphan, beta-endosulphan, p,p'-DDT, cypermethrin and two of its metabolites, endosulphan sulphate and p,p'-DDE, from water. The coagulation without integration of adsorption was less effective (removal % varies from 12 to 49) than the adsorption-coagulation integrated system (removal % varies from 71 to 100). Further, coagulation integrated with adsorption was more effective when organically modified montmorillonite was used as adsorbent compared to normal bentonite. The removal efficiency of organic clay depends upon the concentration of pesticides, doses of clay minerals, and efficiency was more for ODAAPS-M as compared to ODA-M. The combination of ODAAPS-M-clay with coagulants was also used efficiently for the removal of pesticides from natural and fortified natural water collected and the results exhibit the usefulness of this remediation technique for application in water decontamination and in treatment of industrial and agricultural waste waters.

  18. At the end of the day everything boils down to politics: the evolving of German policy toward GMO crops and the existing stagnation.

    PubMed

    Katzek, Jens

    2014-07-03

    Today it is "en vogue" to oppose the use of GMO plants not only in the environmental- and consumer-protection movement, the Green and the Social Democratic Party in Germany, but also in the conservative parties of the political spectrum. This article describes how such an atmosphere was able to develop over the last twenty years. An atmosphere in which almost everyone in favor of GMO plants within these parties is now quiet-because the political price of supporting the technology would be simply too high.

  19. At the end of the day everything boils down to politics: The evolving of German policy toward GMO crops and the existing stagnation

    PubMed Central

    Katzek, Jens

    2014-01-01

    Today it is “en vogue” to oppose the use of GMO plants not only in the environmental- and consumer-protection movement, the Green and the Social Democratic Party in Germany, but also in the conservative parties of the political spectrum. This article describes how such an atmosphere was able to develop over the last twenty years. An atmosphere in which almost everyone in favor of GMO plants within these parties is now quiet—because the political price of supporting the technology would be simply too high. PMID:25437236

  20. Solid-phase extraction using bis(indolyl)methane-modified silica reinforced with multiwalled carbon nanotubes for the simultaneous determination of flavonoids and aromatic organic acid preservatives.

    PubMed

    Wang, Na; Liao, Yuan; Wang, Jiamin; Tang, Sheng; Shao, Shijun

    2015-12-01

    A novel bis(indolyl)methane-modified silica reinforced with multiwalled carbon nanotubes sorbent for solid-phase extraction was designed and synthesized by chemical immobilization of nitro-substituted 3,3'-bis(indolyl)methane on silica modified with multiwalled carbon nanotubes. Coupled with high-performance liquid chromatography analysis, the extraction properties of the sorbent were evaluated for flavonoids and aromatic organic acid compounds. Under optimum conditions, the sorbent can simultaneously extract five flavonoids and two aromatic organic acid preservatives in aqueous solutions in a single-step solid-phase extraction procedure. Wide linear ranges were obtained with correlation coefficients (R(2) ) ranging from 0.9843 to 0.9976, and the limits of detection were in the range of 0.5-5 μg/L for the compounds tested. Compared with the silica modified with multiwalled carbon nanotubes sorbent and the nitro-substituted 3,3'-bis(indolyl)methane-modified silica sorbent, the developed sorbent exhibited higher extraction efficiency toward the selected analytes. The synergistic effect of nitro-substituted 3,3'-bis(indolyl)methane and multiwalled carbon nanotubes not only improved the surface-to-volume ratio but also enhanced multiple intermolecular interactions, such as hydrogen bonds, π-π, and hydrophobic interactions, between the new sorbent and the selected analytes. The as-established solid-phase extraction with high-performance liquid chromatography and diode array detection method was successfully applied to the simultaneous determination of flavonoids and aromatic organic acid preservatives in grape juices with recoveries ranging from 83.9 to 112% for all the selected analytes.

  1. [Revocation of authorizations on GMO under the precautionary principle (with special attention to the Justice Tribunal of the European Communities].

    PubMed

    Escajedo San Epifanio, Leire

    2003-01-01

    During the last decade, the european institutions have done a great effort in order to introduce the precautionary principle, applicable to the management of serious and uncertain risks. Under the protection of the precautionary principle, european authorities and authorities of the member states have partially modified, suspended or revoked authorizations relative to genetically modified organisms. Is it rightful this use of the precautionary principle? This is the matter that the European Communities Justice Court has faced when the affected companies have lodge their appeals against this decisions.

  2. A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

    PubMed

    Amaru, Stephanie

    2014-01-01

    In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

  3. Postharvest color and texture retention in organic Chinese red raspberry and sea-buckthorn fruit during modified atmosphere storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Color and texture are among the key quality attributes for small fruit. Postharvest approaches such as modified atmosphere packaging (MAP) along with cold chain management have been shown to support retention of fruit quality during handling and distribution. The objective of this study was to inves...

  4. Transgenic mosquitoes and the fight against malaria: managing technology push in a turbulent GMO world.

    PubMed

    Knols, Bart G J; Bossin, Hervé C; Mukabana, Wolfgang R; Robinson, Alan S

    2007-12-01

    Genetic modification (GM) of mosquitoes (which renders them genetically modified organisms, GMOs) offers opportunities for controlling malaria. Transgenic strains of mosquitoes have been developed and evaluation of these to 1) replace or suppress wild vector populations and 2) reduce transmission and deliver public health gains are an imminent prospect. The transition of this approach from confined laboratory settings to open field trials in disease-endemic countries (DECs) is a staged process that aims to maximize the likelihood of epidemiologic benefits while minimizing potential pitfalls during implementation. Unlike conventional approaches to vector control, application of GM mosquitoes will face contrasting expectations of multiple stakeholders, the management of which will prove critical to safeguard support and avoid antagonism, so that potential public health benefits can be fully evaluated. Inclusion of key stakeholders in decision-making processes, transfer of problem-ownership to DECs, and increased support from the wider malaria research community are important prerequisites for this. It is argued that the many developments in this field require coordination by an international entity to serve as a guiding coalition to stimulate collaborative research and facilitate stakeholder involvement. Contemporary developments in the field of modern biotechnology, and in particular GM, requires competencies beyond the field of biology, and the future of transgenic mosquitoes will hinge on the ability to govern the process of their introduction in societies in which perceived risks may outweigh rational and responsible involvement.

  5. Approaches in the risk assessment of genetically modified foods by the Hellenic Food Safety Authority.

    PubMed

    Varzakas, Theodoros H; Chryssochoidis, G; Argyropoulos, D

    2007-04-01

    Risk analysis has become important to assess conditions and take decisions on control procedures. In this context it is considered a prerequisite in the evaluation of GM food. Many consumers worldwide worry that food derived from genetically modified organisms (GMOs) may be unhealthy and hence regulations on GMO authorisations and labelling have become more stringent. Nowadays there is a higher demand for non-GM products and these products could be differentiated from GM products using the identity preservation system (IP) that could apply throughout the grain processing system. IP is the creation of a transparent communication system that encompasses HACCP, traceability and related systems in the supply chain. This process guarantees that certain characteristics of the lots of food (non-GM origin) are maintained "from farm to fork". This article examines the steps taken by the Hellenic Food Safety Authority to examine the presence of GMOs in foods. The whole integrated European legislation framework currently in place still needs to be implemented in Greece. Penalties should be enforced to those who import, process GMOs without special licence and do not label those products. Similar penalties should be enforced to those companies that issue false certificates beyond the liabilities taken by the food enterprises for farmers' compensation. We argue that Greece has no serious reasons to choose the use of GMOs due to the fact that the structural and pedologic characteristics of the Greek agriculture favour the biological and integrated cultivation more. Greece is not in favour of the politics behind coexistence of conventional and GM plants and objects to the use of GMOs in the food and the environment because the processor has a big burden in terms of money, time and will suffer a great deal in order to prove that their products are GMO free or that any contamination is adventitious or technically unavoidable. Moreover, Greece owns a large variety of genetic

  6. Ultraviolet-radiation-curing of an organically modified silicate-based material system with epoxy functionality, and the role of titanium

    NASA Astrophysics Data System (ADS)

    Çopuroğlu, Mehmet; Şen, Murat

    2012-09-01

    An organically modified silicate-based material system with epoxy functionality was synthesised by the sol-gel method using some certain Si- and Ti-alkoxide precursors. The resultant system was processed with ultraviolet (UV)-radiation. Influences of certain synthesis and process parameters, including Ti content, sol ageing time, and UV-irradiation time, on various properties of the system were detailed. Overall results demonstrated that Ti-based precursors and UV-radiation could be employed to modify the microstructure, and that the final properties of the system might be tuned by an optimal combination of these two parameters. This preliminary study therefore revealed that this technique described herein might be used to develop a new process regime to obtain materials of this type with desired properties.

  7. Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

    SciTech Connect

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter; Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan

    2015-03-16

    An approach is presented to modify the work function of solution-processed sol-gel derived zinc oxide (ZnO) over an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester as the active layer. These devices compete with or even surpass the performance of the reference on indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Our findings highlight the potential of properly modified ZnO as electron or hole extracting electrodes in hybrid optoelectronic devices.

  8. Alkylaminopyridine-Modified Aluminum Aminoterephthalate Metal-Organic Frameworks as Components of Reactive Self-Detoxifying Materials

    DTIC Science & Technology

    2012-08-07

    strategy in which the MOF particles were deposited on a reactive adhesive composed of polyisobutylene/toluene diisocyanate ( PIB /TDI) blends...strategy in which the MOF particles were deposited on a reactive adhesive composed of polyisobutylene/toluene diisocyanate ( PIB /TDI) blends. Following...suberate-activated conjugation. The resulting MOF-4-MAP modified PIB /TDI elastomeric films were mechanically flexible and capable of degrading

  9. Docosahexaenoic acid modifies the clustering and size of lipid rafts and the lateral organization and surface expression of MHC class I of EL4 cells.

    PubMed

    Shaikh, Saame Raza; Rockett, Benjamin Drew; Salameh, Muhammad; Carraway, Kristen

    2009-09-01

    An emerging molecular mechanism by which docosahexaenoic acid (DHA) exerts its effects is modification of lipid raft organization. The biophysical model, based on studies with liposomes, shows that DHA avoids lipid rafts because of steric incompatibility between DHA and cholesterol. The model predicts that DHA does not directly modify rafts; rather, it incorporates into nonrafts to modify the lateral organization and/or conformation of membrane proteins, such as the major histocompatibility complex (MHC) class I. Here, we tested predictions of the model at a cellular level by incorporating oleic acid, eicosapentaenoic acid (EPA), and DHA, compared with a bovine serum albumin (BSA) control, into the membranes of EL4 cells. Quantitative microscopy showed that DHA, but not EPA, treatment, relative to the BSA control diminished lipid raft clustering and increased their size. Approximately 30% of DHA was incorporated directly into rafts without changing the distribution of cholesterol between rafts and nonrafts. Quantification of fluorescence colocalization images showed that DHA selectively altered MHC class I lateral organization by increasing the fraction of the nonraft protein into rafts compared with BSA. Both DHA and EPA treatments increased antibody binding to MHC class I compared with BSA. Antibody titration showed that DHA and EPA did not change MHC I conformation but increased total surface levels relative to BSA. Taken together, our findings are not in agreement with the biophysical model. Therefore, we propose a model that reconciles contradictory viewpoints from biophysical and cellular studies to explain how DHA modifies lipid rafts on several length scales. Our study supports the notion that rafts are an important target of DHA's mode of action.

  10. Selection of Suitable DNA Extraction Methods for Genetically Modified Maize 3272, and Development and Evaluation of an Event-Specific Quantitative PCR Method for 3272.

    PubMed

    Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2016-01-01

    A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize, 3272. We first attempted to obtain genome DNA from this maize using a DNeasy Plant Maxi kit and a DNeasy Plant Mini kit, which have been widely utilized in our previous studies, but DNA extraction yields from 3272 were markedly lower than those from non-GM maize seeds. However, lowering of DNA extraction yields was not observed with GM quicker or Genomic-tip 20/G. We chose GM quicker for evaluation of the quantitative method. We prepared a standard plasmid for 3272 quantification. The conversion factor (Cf), which is required to calculate the amount of a genetically modified organism (GMO), was experimentally determined for two real-time PCR instruments, the Applied Biosystems 7900HT (the ABI 7900) and the Applied Biosystems 7500 (the ABI7500). The determined Cf values were 0.60 and 0.59 for the ABI 7900 and the ABI 7500, respectively. To evaluate the developed method, a blind test was conducted as part of an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSDr). The determined values were similar to those in our previous validation studies. The limit of quantitation for the method was estimated to be 0.5% or less, and we concluded that the developed method would be suitable and practical for detection and quantification of 3272.

  11. International collaborative study of the endogenous reference gene, sucrose phosphate synthase (SPS), used for qualitative and quantitative analysis of genetically modified rice.

    PubMed

    Jiang, Lingxi; Yang, Litao; Zhang, Haibo; Guo, Jinchao; Mazzara, Marco; Van den Eede, Guy; Zhang, Dabing

    2009-05-13

    One rice ( Oryza sativa ) gene, sucrose phosphate synthase (SPS), has been proven to be a suitable endogenous reference gene for genetically modified (GM) rice detection in a previous study. Herein are the reported results of an international collaborative ring trial for validation of the SPS gene as an endogenous reference gene and its optimized qualitative and quantitative polymerase chain reaction (PCR) systems. A total of 12 genetically modified organism (GMO) detection laboratories from seven countries participated in the ring trial and returned their results. The validated results confirmed the species specificity of the method through testing 10 plant genomic DNAs, low heterogeneity, and a stable single-copy number of the rice SPS gene among 7 indica varieties and 5 japonica varieties. The SPS qualitative PCR assay was validated with a limit of detection (LOD) of 0.1%, which corresponded to about 230 copies of haploid rice genomic DNA, while the limit of quantification (LOQ) for the quantitative PCR system was about 23 copies of haploid rice genomic DNA, with acceptable PCR efficiency and linearity. Furthermore, the bias between the test and true values of eight blind samples ranged from 5.22 to 26.53%. Thus, we believe that the SPS gene is suitable for use as an endogenous reference gene for the identification and quantification of GM rice and its derivates.

  12. Interlaboratory transfer of a PCR multiplex method for simultaneous detection of four genetically modified maize lines: Bt11, MON810, T25, and GA21.

    PubMed

    Hernández, Marta; Rodríguez-Lázaro, David; Zhang, David; Esteve, Teresa; Pla, Maria; Prat, Salomé

    2005-05-04

    The number of cultured hectares and commercialized genetically modified organisms (GMOs) has increased exponentially in the past 9 years. Governments in many countries have established a policy of labeling all food and feed containing or produced by GMOs. Consequently, versatile, laboratory-transferable GMO detection methods are in increasing demand. Here, we describe a qualitative PCR-based multiplex method for simultaneous detection and identification of four genetically modified maize lines: Bt11, MON810, T25, and GA21. The described system is based on the use of five primers directed to specific sequences in these insertion events. Primers were used in a single optimized multiplex PCR reaction, and sequences of the amplified fragments are reported. The assay allows amplification of the MON810 event from the 35S promoter to the hsp intron yielding a 468 bp amplicon. Amplification of the Bt11 and T25 events from the 35S promoter to the PAT gene yielded two different amplicons of 280 and 177 bp, respectively, whereas amplification of the 5' flanking region of the GA21 gave rise to an amplicon of 72 bp. These fragments are clearly distinguishable in agarose gels and have been reproduced successfully in a different laboratory. Hence, the proposed method comprises a rapid, simple, reliable, and sensitive (down to 0.05%) PCR-based assay, suitable for detection of these four GM maize lines in a single reaction.

  13. A novel quadruplex real-time PCR method for simultaneous detection of Cry2Ae and two genetically modified cotton events (GHB119 and T304-40)

    PubMed Central

    2014-01-01

    Background To date, over 150 genetically modified (GM) crops are widely cultivated. To comply with regulations developed for genetically modified organisms (GMOs), including labeling policies, many detection methods for GMO identification and quantification have been developed. Results To detect the entrance and exit of unauthorized GM crop events in China, we developed a novel quadruplex real-time PCR method for simultaneous detection and quantification of GM cotton events GHB119 and T304-40 in cotton-derived products (based on the 5′-flanking sequence) and the insect-resistance gene Cry2Ae. The limit of detection was 10 copies for GHB119 and Cry2Ae and 25 copies for T304-40. The limit of quantification was 25 copies for GHB119 and Cry2Ae and 50 copies for T304-40. Moreover, low bias and acceptable standard deviation and relative standard deviation values were obtained in quantification analysis of six blind samples containing different GHB119 and T304-40 ingredients. Conclusions The developed quadruplex quantitative method could be used for quantitative detection of two GM cotton events (GHB119 and T304-40) and Cry2Ae gene ingredient in cotton derived products. PMID:24884946

  14. An emerging class of volatile organic compound sorbents: Friedel-Crafts modified polystyrenes. 2: Performance comparison with commercially-available sorbents and isotherm analysis

    SciTech Connect

    Simpson, E.J.; Koros, W.J.; Schechter, R.S.

    1996-12-01

    The performance of Friedel-Crafts modified polystyrene (FCMPS) as a volatile organic compound (VOC) sorbent is compared with commercially available polymers and activated carbon. Detailed analyses of the equilibrium isotherms are presented, including vapor phase isotherm temperature dependence and isosteric heats of sorption. Although significant absorption contributions are observed for the polymeric sorbents of this study, the data are mathematically well represented by Polanyi potential analysis. FCMPS can be synthesized with desirable performance qualities such as ultimate VOC sorption capacity of {approximately}2 mL/g, competitively high capacity in dilute streams versus activated carbon, insensitivity to humidity in vapor phase applications, and comparative ease of regeneration.

  15. Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations

    PubMed Central

    PIÑEYRO-NELSON, A; VAN HEERWAARDEN, J; PERALES, H R; SERRATOS-HERNÁNDEZ, J A; RANGEL, A; HUFFORD, M B; GEPTS, P; GARAY-ARROYO, A; RIVERA-BUSTAMANTE, R; ÁLVAREZ-BUYLLA, E R

    2009-01-01

    A possible consequence of planting genetically modified organisms (GMOs) in centres of crop origin is unintended gene flow into traditional landraces. In 2001, a study reported the presence of the transgenic 35S promoter in maize landraces sampled in 2000 from the Sierra Juarez of Oaxaca, Mexico. Analysis of a large sample taken from the same region in 2003 and 2004 could not confirm the existence of transgenes, thereby casting doubt on the earlier results. These two studies were based on different sampling and analytical procedures and are thus hard to compare. Here, we present new molecular data for this region that confirm the presence of transgenes in three of 23 localities sampled in 2001. Transgene sequences were not detected in samples taken in 2002 from nine localities, while directed samples taken in 2004 from two of the positive 2001 localities were again found to contain transgenic sequences. These findings suggest the persistence or re-introduction of transgenes up until 2004 in this area. We address variability in recombinant sequence detection by analyzing the consistency of current molecular assays. We also present theoretical results on the limitations of estimating the probability of transgene detection in samples taken from landraces. The inclusion of a limited number of female gametes and, more importantly, aggregated transgene distributions may significantly lower detection probabilities. Our analytical and sampling considerations help explain discrepancies among different detection efforts, including the one presented here, and provide considerations for the establishment of monitoring protocols to detect the presence of transgenes among structured populations of landraces. PMID:19143938

  16. Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations.

    PubMed

    Piñeyro-Nelson, A; Van Heerwaarden, J; Perales, H R; Serratos-Hernández, J A; Rangel, A; Hufford, M B; Gepts, P; Garay-Arroyo, A; Rivera-Bustamante, R; Alvarez-Buylla, E R

    2009-02-01

    A possible consequence of planting genetically modified organisms (GMOs) in centres of crop origin is unintended gene flow into traditional landraces. In 2001, a study reported the presence of the transgenic 35S promoter in maize landraces sampled in 2000 from the Sierra Juarez of Oaxaca, Mexico. Analysis of a large sample taken from the same region in 2003 and 2004 could not confirm the existence of transgenes, thereby casting doubt on the earlier results. These two studies were based on different sampling and analytical procedures and are thus hard to compare. Here, we present new molecular data for this region that confirm the presence of transgenes in three of 23 localities sampled in 2001. Transgene sequences were not detected in samples taken in 2002 from nine localities, while directed samples taken in 2004 from two of the positive 2001 localities were again found to contain transgenic sequences. These findings suggest the persistence or re-introduction of transgenes up until 2004 in this area. We address variability in recombinant sequence detection by analyzing the consistency of current molecular assays. We also present theoretical results on the limitations of estimating the probability of transgene detection in samples taken from landraces. The inclusion of a limited number of female gametes and, more importantly, aggregated transgene distributions may significantly lower detection probabilities. Our analytical and sampling considerations help explain discrepancies among different detection efforts, including the one presented here, and provide considerations for the establishment of monitoring protocols to detect the presence of transgenes among structured populations of landraces.

  17. Governing GMOs in the USA: science, law and public health.

    PubMed

    Yang, Y Tony; Chen, Brian

    2016-04-01

    Controversy surrounds the production and consumption of genetically modified organisms (GMOs). Proponents argue that GMO food sources represent the only viable solution to food shortages in an ever-growing global population. Science reports no harm from GMO use and consumption so far. Opponents fear the potentially negative impact that GMO development and use could have on the environment and consumers, and are concerned about the lack of data on the long-term effects of GMO use. We discuss the development of GMO food sources, the history of legislation and policy for the labeling requirements of GMO food products, and the health, environmental, and legal rationale for and against GMO food labeling. The Food and Drug Administration regulates food with GMOs within a coordinated framework of federal agencies. Despite mounting scientific evidence that GMO foods are substantially equivalent to traditionally bred food sources, debate remains over the appropriateness of GMO food labeling. In fact, food manufacturers have mounted a First Amendment challenge against Vermont's passage of a law that requires GMO labeling. Mandatory GMO labeling is not supported by science. Compulsory GMO labels may not only hinder the development of agricultural biotechnology, but may also exacerbate the misconception that GMOs endanger people's health.

  18. Modified natural clinoptilolite detoxifies small mammal's organism loaded with lead I. Lead disposition and kinetic model for lead bioaccumulation.

    PubMed

    Beltcheva, Michaela; Metcheva, Roumiana; Popov, Nikolay; Teodorova, Svetla E; Heredia-Rojas, J Antonio; Rodríguez-de la Fuente, Abraham O; Rodríguez-Flores, Laura E; Topashka-Ancheva, Margarita

    2012-06-01

    Zeolites, especially clinoptilolites, have wide application in removing heavy metals from different solutions and wastewater. The detoxification capacity of the clinoptilolite sorbent KLS-10-MA, a modified natural Bulgarian zeolite, applied as a food supplement in conditions of an ecotoxicological experiment with conventional food and lead was demonstrated for the first time. Laboratory mice, inbred imprinting control region strain, were used in a 90-day ecotoxicological experiment. Animals were divided into four experimental groups. Lead bioaccumulations in exposed and non-supplemented/supplemented with KLS-10-MA animals were compared. As additional control, healthy animals non-exposed to Pb were fed with conventional forage mixed with 12.5% KLS-10-MA. The dietary inclusion of the sorbent reduced Pb concentrations in exposed and supplemented mice by 84%, 89%, 91%, 77%, and 88% in carcass, liver, kidneys, bones, and feces, respectively. A mathematical model was proposed to outline the common trends of bone Pb bioaccumulation in exposed and non-supplemented/supplemented animals. Characteristic parameters of the kinetics of Pb concentrations were determined. Based on the model, the coefficient of absorption of Pb by gastrointestinal mucosa in the supplemented mice was found-η = 3.53% (versus η = 15% in non-supplemented ones). The present study clearly indicates that there is a realistic perspective to create a new drug based on modified natural clinoptilolites in cases of chronic heavy metal intoxication, without negatively affecting the environment.

  19. Indium tin oxide modified transparent nanotube thin films as effective anodes for flexible organic light-emitting diodes

    SciTech Connect

    Li Jianfeng; Liu Jun; Wang, Lian; Marks, Tobin J.; Hu Liangbing; Gruener, George

    2008-08-25

    Sn-doped In{sub 2}O{sub 3} (ITO) modified single-walled carbon nanotube (SW-CNT) transparent electrodes are fabricated on flexible polyethyleneterephthalate (PET) substrates by stamp printing SW-CNT films, followed by room temperature ion-assisted deposition of ITO. Polymer light-emitting diodes (PLEDs) using such film as anodes exhibit superior performance versus CNT-only controls. Flexible PLEDs with the following structure: PET/CNT(30 nm)-ITO(45 nm)/poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate)/[poly(9,9-dioctyl-fluorene-co-N- (4-butylphenyl)diphenylamine)]+(4,4{sup '}-bis[(p-trichlorosilyl propylphenyl)-phenylamino]biphenyl)/[poly (9,9-dioctylfluorene-co-benzothiadiazole)]/CsF/Al, achieve a maximum light output of 8900 cd/m{sup 2} with a current efficiency of 4.5 cd/A. Bending test comparisons with ITO/PET show the ITO modified CNT/PET electrodes to be far more mechanically flexible.

  20. Solid-phase microfibers based on polyethylene glycol modified single-walled carbon nanotubes for the determination of chlorinated organic carriers in textiles.

    PubMed

    Zhang, Wei-Ya; Sun, Yin; Wang, Cheng-Ming; Wu, Cai-Ying

    2011-09-01

    Based on polyethylene glycol modified single-walled carbon nanotubes, a novel sol-gel fiber coating was prepared and applied to the headspace microextraction of chlorinated organic carriers (COCs) in textiles by gas chromatography-electron capture detection. The preparation of polyethylene glycol modified single-walled carbon nanotubes and the sol-gel fiber coating process was stated and confirmed by infrared spectra, Raman spectroscopy, and scanning electron microscopy. Several parameters affecting headspace microextraction, including extraction temperature, extraction time, salting-out effect, and desorption time, were optimized by detecting 11 COCs in simulative sweat samples. Compared with the commercial solid-phase microextraction fibers, the sol-gel polyethylene glycol modified single-walled carbon nanotubes fiber showed higher extraction efficiency, better thermal stability, and longer life span. The method detection limits for COCs were in the range from 0.02 to 7.5 ng L(-1) (S/N = 3). The linearity of the developed method varied from 0.001 to 50 μg L(-1) for all analytes, with coefficients of correlation greater than 0.974. The developed method was successfully applied to the analysis of trace COCs in textiles, the recoveries of the analytes indicated that the developed method was considerably useful for the determination of COCs in ecological textile samples.

  1. In-house validation and quality control of real-time PCR methods for GMO detection: a practical approach.

    PubMed

    Ciabatti, I; Froiio, A; Gatto, F; Amaddeo, D; Marchesi, U

    2006-01-01

    GMO detection and quantification methods in the EU are mainly based on real-time PCR. The analytical methods in use must be validated, first on an intra-laboratory scale and through a collaborative trial thereafter. Since a consensual protocol for intra-laboratory validation of real-time PCR methods is lacking, we provide a practical approach for the in-house validation of quantitative real-time PCR methods, establishing acceptability criteria and quality controls for PCR runs. Parameters such as limit of detection, limit of quantification, precision, trueness, linear dynamic range, PCR efficiency, robustness and specificity are considered. The protocol is sufficiently detailed to be directly applicable, increases the reliability of results and their harmonization among different laboratories, and represents a necessary preliminary step before proceeding to a time-consuming and costly full validation study.

  2. Simultaneous detection of genetically modified organisms by multiplex ligation-dependent genome amplification and capillary gel electrophoresis with laser-induced fluorescence.

    PubMed

    García-Cañas, Virginia; Mondello, Monica; Cifuentes, Alejandro

    2010-07-01

    In this work, an innovative method useful to simultaneously analyze multiple genetically modified organisms is described. The developed method consists in the combination of multiplex ligation-dependent genome dependent amplification (MLGA) with CGE and LIF detection using bare-fused silica capillaries. The MLGA process is based on oligonucleotide constructs, formed by a universal sequence (vector) and long specific oligonucleotides (selectors) that facilitate the circularization of specific DNA target regions. Subsequently, the circularized target sequences are simultaneously amplified with the same couple of primers and analyzed by CGE-LIF using a bare-fused silica capillary and a run electrolyte containing 2-hydroxyethyl cellulose acting as both sieving matrix and dynamic capillary coating. CGE-LIF is shown to be very useful and informative for optimizing MLGA parameters such as annealing temperature, number of ligation cycles, and selector probes concentration. We demonstrate the specificity of the method in detecting the presence of transgenic DNA in certified reference and raw commercial samples. The method developed is sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 1% of GA21, 1% of MON863, and 1% of MON810 in maize samples with signal-to-noise ratios for the corresponding DNA peaks of 15, 12, and 26, respectively. These results demonstrate, to our knowledge for the first time, the great possibilities of MLGA techniques for genetically modified organisms analysis.

  3. Photoluminescent properties of novel rare earth organic-inorganic nanocomposite with TiO2 modified silica via double crosslinking units.

    PubMed

    Zhao, Yan; Yan, Bing

    2012-01-01

    A series of novel organic/inorganic rare earth (europium, terbium) hybrid materials through the coordination bond and covalent bond are synthesized and form an inorganic Si-O-Si by the sol-gel process. Mercapto-functionalized 4-mercaptobenzoic acid (MBA-Si) is obtained by using MBA and 3-(triethoxysilyl)-propyl isocyanate (TESPIC) as an organic bridge molecule, and then the carboxyl group of the precursor MBA-Si is used to modify the titanium dioxide, so as to sensitize the luminescence of rare earth ions. CdS-TiO(2) is added to observe the influence of photoluminescence. 3-mercaptopropyltrimethoxysilane (MPS) is also used to modify the CdS quantum dot and obtain MPS functionalized MPS-CdS nanocomposite. These multicomponent hybrids with double cross-linking siloxane (MBA-Si) covalently bonding MPS-CdS are characterized. Subsequently, 1,10-phenanthroline (Phen) and 2,2,-bipyridyl (Bipy) as the assistant ligands together with water molecules are introduced into the rare earth hybrid system. The FT-IR, X-ray diffraction, UV-Vis, thermogravimetry and especially the photoluminescence properties of them are studied in detail.

  4. Greening pharmaceutical applications of liquid chromatography through using propylene carbonate-ethanol mixtures instead of acetonitrile as organic modifier in the mobile phases.

    PubMed

    Tache, Florentin; Udrescu, Stefan; Albu, Florin; Micăle, Florina; Medvedovici, Andrei

    2013-03-05

    Substitution of acetonitrile (ACN) as organic modifier in mobile phases for liquid chromatography by mixtures of propylene carbonate (PC) and ethanol (EtOH) may be considered a greener approach for pharmaceutical applications. Such a replacement is achievable without any major compromise in terms of elution order, chromatographic retention, efficiency and peak symmetry. This has been equally demonstrated for reverse phase (RP), ion pair formation (IP) and hydrophilic interaction liquid chromatography (HILIC) separation modes. The impact on the sensitivity induced by the replacement between these organic solvents is discussed for UV-vis and mass spectrometric detection. A comparison between Van Deemter plots obtained under elution conditions based on ACN and PC/EtOH is presented. The alternative elution modes were also compared in terms of thermodynamic parameters, such as standard enthalpy (ΔH⁰) and entropic contributions to the partition between the mobile and the stationary phases, for some model compounds. Van't Hoff plots demonstrated that differences between the thermodynamic parameters are minor when shifting from ACN/water to PC/EtOH/water elution on an octadecyl chemically modified silicagel stationary phase. As long as large volume injection (LVI) of diluents non-miscible with the mobile phase is a recently developed topic having a high potential of greening the sample preparation procedures through elimination of the solvent evaporation stage, this feature was also assessed in the case of ACN replacement by PC/EtOH.

  5. Coherence between legal requirements and approaches for detection of genetically modified organisms (GMOs) and their derived products.

    PubMed

    Holst-Jensen, Arne; De Loose, Marc; Van den Eede, Guy

    2006-04-19

    Analytical methods for the qualitative and quantitative detection of genetically modified (GM) products may serve multiple purposes. Legal requirements differ among jurisdictions, ranging from no requirements to mandatory use of event-specific quantitation and implementation of production chain traceability. Although efforts have been taken to harmonize the analytical methodology at national, regional, and international levels, no normative international standards have yet been established. Lack of coherence between analytical methodologies and their applicabilities, on the one hand, and legislation, on the other hand, is a major problem. Here, key points where coherence is lacking are discussed. These include the definition of units of measurements, expression of GM material quantities, terminology, and inconsistent legal status of products derived from related but slightly different transformation routes. Finally, recommendations to improve the coherence are brought forward, including guidance to stakeholders for prediction of product-specific GM material quantities from gene ratios in the originating seed.

  6. Organically modified silica with pyrazole-3-carbaldehyde as a new sorbent for solid-liquid extraction of heavy metals.

    PubMed

    Radi, Smaail; Tighadouini, Said; Bacquet, Maryse; Degoutin, Stéphanie; Cazier, Francine; Zaghrioui, Mustapha; Mabkhot, Yahia N

    2013-12-24

    A new chelating matrix, SiNP, has been prepared by immobilizing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel modified with 3-aminopropyl-trimethoxysilane. This new chelating material was well characterized by elemental analysis, FT-IR spectroscopy, cross polarization magic angle spinning solid state 13C-NMR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore size, and scanning electron microscopy (SEM). The new product exhibits good chemical and thermal stability as determined by thermogravimetry curves (TGA). The new prepared material was used as an adsorbent for the solid-phase extraction (SPE) of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions using a batch method, prior to their determination by flame atomic adsorption spectrometry. The adsorption capacity was investigated using kinetics and pH effects. Common coexisting ions did not interfere with separation and determination.

  7. Tolerance and Long-Term MRI Imaging of Gadolinium-Modified Meshes Used in Soft Organ Repair

    PubMed Central

    Letouzey, Vincent; Huberlant, Stéphanie; Cornille, Arnaud; Blanquer, Sébastien; Guillaume, Olivier; Lemaire, Laurent; Garric, Xavier; de Tayrac, Renaud

    2015-01-01

    Background Synthetic meshes are frequently used to reinforce soft tissues. The aim of this translational study is to evaluate tolerance and long-term MRI visibility of two recently developed Gadolinium-modified meshes in a rat animal model. Materials and Methods Gadolinium-poly-ε-caprolactone (Gd-PCL) and Gadolinium-polymethylacrylate (Gd-PMA) modified meshes were implanted in Wistar rats and their tolerance was assessed daily. Inflammation and biocompatibility of the implants were assessed by histology and immunohistochemistry after 30 days post implantation. Implants were visualised by 7T and 3T MRI at day 30 and at day 90. Diffusion of Gadolinium in the tissues of the implanted animals was assessed by Inductively Coupled Plasma Mass Spectrometry. Results Overall Gd-PMA coated implants were better tolerated as compared to those coated with Gd-PCL. In fact, Gd-PMA implants were characterised by a high ratio collagen I/III and good vascularisation of the integration tissues. High resolution images of the coated mesh were obtained in vivo with experimental 7T as well as 3T clinical MRI. Mass spectrometry analyses showed that levels of Gadolinium in animals implanted with coated mesh were similar to those of the control group. Conclusions Meshes coated with Gd-PMA are better tolerated as compared to those coated with Gd-PCL as no signs of erosion or significant inflammation were detected at 30 days post implantation. Also, Gd-PMA coated meshes were clearly visualised with both 7T and 3T MRI devices. This new technique of mesh optimisation may represent a valuable tool in soft tissue repair and management. PMID:25811855

  8. Genetically Modified Organisms and the Future Global Nutrient Supply: Part of the Solution or a New Problem?

    PubMed

    Phillips, Peter W B

    2016-01-01

    For almost a generation now, scientists and policy makers have enthusiastically advanced genetically modified (GM) crops as a solution to both global food security and, specifically, the micronutrient needs of the hidden hungry. While genetic modification offers the prospect of overcoming technological barriers to food security, the gap between the vision and reality remains large. This chapter examines the impact of GM crops at three levels. Undoubtedly, at the micro level, bio-fortification offers a real opportunity to enhance the availability of micronutrients. However, the inexorable 'research sieve' ruthlessly culls most technical candidates in the agri-food system. GM bio-fortified foods, such as Golden RiceTM, remain only a promise. At the meso level, GM crops have generated benefits for both producers and consumers who have adopted GM crops, but given that the technology has been differentially applied to maize, the average diet for the food insecure has become somewhat less balanced. Finally, while GM crops have increased yields and the global food supply, these have come at the cost of more complex and costly trade and market systems, which impair access and availability. In essence, while biotechnology offers some tantalizing technological prospects, the difficulties of getting the corresponding benefits to the most needy have dampened some of the enthusiasm.

  9. Modified dislocation filter method: toward growth of GaAs on Si by metal organic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Hu, Haiyang; Wang, Jun; He, Yunrui; Liu, Kai; Liu, Yuanyuan; Wang, Qi; Duan, Xiaofeng; Huang, Yongqing; Ren, Xiaomin

    2016-06-01

    In this paper, metamorphic growth of GaAs on (001) oriented Si substrate, with a combination method of applying dislocation filter layer (DFL) and three-step growth process, was conducted by metal organic chemical vapor deposition. The effectiveness of the multiple InAs/GaAs self-organized quantum dot (QD) layers acting as a dislocation filter was researched in detail. And the growth conditions of the InAs QDs were optimized by theoretical calculations and experiments. A 2-μm-thick buffer layer was grown on the Si substrate with the three-step growth method according to the optimized growth conditions. Then, a 114-nm-thick DFL and a 1-μm-thick GaAs epilayer were grown. The results we obtained demonstrated that the DFL can effectively bend dislocation direction via the strain field around the QDs. The optimal structure of the DFL is composed of three-layer InAs QDs with a growth time of 55 s. The method could reduce the etch pit density from about 3 × 106 cm-2 to 9 × 105 cm-2 and improve the crystalline quality of the GaAs epilayers on Si.

  10. Microbial response to modified precipitation patterns in tallgrass prairie soil: molecular mechanisms, activity rates and organic matter dynamics

    NASA Astrophysics Data System (ADS)

    Zeglin, L. H.; David, M.; Bottomley, P.; Hettich, R. L.; Jansson, J.; Jumpponen, A.; Rice, C. W.; Tringe, S.; VerBerkmoes, N. C.; Myrold, D.

    2011-12-01

    A significant amount of carbon (C) is processed and stored in prairie soils: grasslands cover 6.1-7.4% of the earth's land surface and hold 7.3-11.4% of global soil C. Global change models predict that the future precipitation regime across the North American Great Plains will entail less frequent but larger rainfall events. The response of prairie soil microbial C processing and allocation to this scenario of higher hydrologic variability is not known, but will be a key determiner of the future capacity for prairie soil C sequestration. We are approaching this problem by assessing soil microbial function (respiration, C utilization efficiency, extracellular enzyme activity) and molecular indicators of dominant C allocation pathways (soil transcriptome, proteome and metabolome) under ambient and experimentally modified precipitation regimes. The rainfall manipulation plots (RaMPs) at the Konza Prairie Long-Term Ecological Research (LTER) site in eastern Kansas, USA is a replicated field manipulation of the magnitude and frequency of natural precipitation that was established in 1998. We collected soil before, during and after a rainfall event in both ambient and modified precipitation treatments and measured the microbial response. Microbial respiration doubled in both treatments during the water addition, and cellobiohydrolase enzyme potential activity (a catalyst of cellulose hydrolysis) increased slightly, but no significant effect of altered precipitation treatment has emerged. The fungal and bacterial ribosomal gene composition was also similar between precipitation treatments. Although pools of genes and extracellular enzymes may be relatively static during short-term dynamic conditions, transcript and intracellular protein abundances may be more indicative of the active microbial metabolic response to rapid shifts in soil moisture. Thus, analysis of transcript and protein composition is underway. In addition, we have implemented a series of lab experiments

  11. [Analysis the properties of Cr2O7(2-) adsorption onto functional organic reagent modified nano-SiO2 by flame atomic absorption spectroscopy].

    PubMed

    Zhang, Zu-Lei; Li, Lei

    2011-02-01

    A new type of functional organic reagent modified nano-SiO2 sorbent (Si/ (CH2)3-NH-CO-Ph-CH2-P(C6H5)3 Br) was synthesized by several reasonable organic combination reactions using nano-SiO2, gamma-Aminopropyl triethoxysilane (KH-550) and functional organic reagent (COOH-Ph-CH2-P(C6 H5)3 Br) as raw materials. The prepared new sorbent was characterized by using FTIR, particle diameter and TG. A batch of adsorption experiments was performed to evaluate its adsorption behavior of Cr2O7(2-) by flame atomic absorption spectroscopy (FAAS). The effects of solution pH, shaken time and sorbent amount on the extraction of Cr2O7(2-) from aqueous solutions were studied. Results showed that when under the optimum conditions the solution pH 1, sorbent amount = 0.1 g, and shaken time = 30 min, the adsorption efficiency can be more than 95%. It indicated that this novel sorbent (Si/ (CH2)3-NH-CO-Ph-CH2-P (C6 H5)3 Br) was a solid sorbent being efficient and low-cost, with convenient separation, and can remove trace Cr2 O7(2-) in environmental waste water.

  12. Thermodynamics of the adsorption of organic molecules on graphitized carbon black modified with a monolayer of 5-hydroxy-6-methyluracil

    NASA Astrophysics Data System (ADS)

    Gus'kov, V. Yu.; Ivanov, S. P.; Shaikhitdinova, Yu. F.; Kudasheva, F. Kh.

    2016-10-01

    Thermodynamic characteristics of the adsorption of alkanes, alcohols, arenes, and esters on graphitized carbon black with a deposited monolayer (0.17%) of 5-hydroxy-6-methyluracil are studied by means of inverse gas chromatography at infinite dilution. It is established that size effects (violation of the additivity of molar changes in internal energy and the entropy of adsorption for pairs of molecules of one homologous series that differ by one methyl group) are observed when organic molecules are adsorbed on the surface of the resulting adsorbent. The size effects are similar to those observed when 1% 5-hydroxy-6-methyluracil is deposited on graphitized carbon black. It is concluded that the observed violation of additivity is associated with cavities in the supramolecular structure.

  13. Influence of chromophore dipole moments in parameters of organic light emitting devices based on phenyl and methyl modified pyrazoloquinoline.

    PubMed

    Gondek, E; Nizioł, J; Danel, A; Szlachcic, P; Pluciński, K; Sanetra, J; Kityk, I V

    2010-05-01

    Absorption, photo- and electroluminescence spectra of some trityl substituted 1H-pyrazolo[3,4-b]quinolines derivatives (methyl- and phenyl substituted) and fabrication of the single layered organic light emitting diodes are reported. The bulky trityl substituent was introduced to prevent aggregation and crystallization of the dopant in polymer matrix. Role of ground state dipole moments in the observed red Stokes shift, electroluminescent features and photocarrier transport is explored. The maximally achieved brightness about 50Cd/m(2) is observed in the spectral range extending from 443nm up to 462nm. The voltage threshold was varied from 7.8V up to 10V. The brightness-current dependences show an existence of at least two types of carrier injections.

  14. Hydrophilic solid-phase extraction of melamine with ampholine-modified hybrid organic-inorganic silica material.

    PubMed

    Wang, Tingting; Zhu, Yiming; Ma, Junfeng; Xuan, Rongrong; Gao, Haoqi; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2015-01-01

    In this work, an ampholine-functionalized hybrid organic-inorganic silica sorbent was successfully used to extract melamine from a milk formula sample by a hydrophilic interaction solid-phase extraction protocol. Primary factors affecting the extraction efficiency of the material such as extraction solvent, elution solvent, sample loading volume, and elution volume have been thoroughly optimized. Under the optimized hydrophilic solid-phase extraction conditions, the recoveries of melamine spiked in milk formula samples ranged from 86.2 to 101.8% with relative standard deviations of 4.1-9.4% (n = 3). The limit of detection (S/N = 3) was 0.32 μg/g. The adsorption capacity toward melamine was 30 μg of melamine per grams of sorbent. Due to its simplicity, rapidity and cost effectiveness, the newl